2022
Clemen, Thomas; Ahmady-Moghaddam, Nima; Glake, Daniel; Lenfers, Ulfia; Ocker, Florian; Osterholz, Daniel; Stroebele, Jonathan
Toward a Movement Paradigm for Artificial Human Agents Inproceedings
In: pp. 176-187, Annual Modeling and Simulation Conference (ANNSIM) Annual Modeling and Simulation Conference (ANNSIM), San Diego State University, San Diego, CA, USA, 2022.
@inproceedings{Clemen2022a,
title = {Toward a Movement Paradigm for Artificial Human Agents},
author = {Clemen, Thomas and Ahmady-Moghaddam, Nima and Glake, Daniel and Lenfers, Ulfia and Ocker, Florian and Osterholz, Daniel and Stroebele, Jonathan},
doi = {10.23919/ANNSIM55834.2022.9859271},
year = {2022},
date = {2022-07-20},
urldate = {2022-07-20},
journal = {Proceedings of the 2022 Annual Modeling and Simulation Conference (ANNSIM)},
pages = {176-187},
publisher = {Annual Modeling and Simulation Conference (ANNSIM)},
address = {San Diego State University, San Diego, CA, USA},
organization = {Annual Modeling and Simulation Conference (ANNSIM)},
abstract = {The behavioral logic of agents in agent-based simulation models is becoming increasingly complex. This intrinsic development calls for new approaches to understanding and analyzing agent behavior. For example, when applying an agent-based model (ABM) without knowing the full model specifications, its agents – particularly their decision-making processes – are a black box to the user. Similarly, when designing an ABM, the individual steps of an agent’s decision-making trajectories might cease to be fully traceable when the model becomes sufficiently complex. Under such circumstances, ABM users and designers are forced to infer underlying reasons for behaviors from observation. This process is comparable to ecologists observing the behavior of organisms. In this contribution, we focus on the movement behavior of spatially explicit human agents. We reflect on the Movement Ecology Paradigm (MEP) and transfer some of its conceptual results to the world of human agents. Notably, we outline the MEP’s Why-Where-How complex and assess whether these three questions are sufficient for describing human agents’ underlying motivations for movement behaviors. A first, basic version of the Human Agent Movement Paradigm (HAMP) is proposed. Like the ODD protocol in ecology, the HAMP can be seen as an initial step toward a standard protocol to describe the movement of spatially explicit agents.},
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The behavioral logic of agents in agent-based simulation models is becoming increasingly complex. This intrinsic development calls for new approaches to understanding and analyzing agent behavior. For example, when applying an agent-based model (ABM) without knowing the full model specifications, its agents – particularly their decision-making processes – are a black box to the user. Similarly, when designing an ABM, the individual steps of an agent’s decision-making trajectories might cease to be fully traceable when the model becomes sufficiently complex. Under such circumstances, ABM users and designers are forced to infer underlying reasons for behaviors from observation. This process is comparable to ecologists observing the behavior of organisms. In this contribution, we focus on the movement behavior of spatially explicit human agents. We reflect on the Movement Ecology Paradigm (MEP) and transfer some of its conceptual results to the world of human agents. Notably, we outline the MEP’s Why-Where-How complex and assess whether these three questions are sufficient for describing human agents’ underlying motivations for movement behaviors. A first, basic version of the Human Agent Movement Paradigm (HAMP) is proposed. Like the ODD protocol in ecology, the HAMP can be seen as an initial step toward a standard protocol to describe the movement of spatially explicit agents.
Tolk, Andreas; Clemen, Thomas; Gilbert, Nigel; Macal, Charles M.
How Can We Provide Better Simulation-Based Policy Support? Inproceedings
In: pp. 188-198, Annual Modeling and Simulation Conference (ANNSIM) Annual Modeling and Simulation Conference (ANNSIM), San Diego State University, San Diego, CA, USA, 2022.
@inproceedings{Clemen2022b,
title = {How Can We Provide Better Simulation-Based Policy Support?},
author = {Tolk, Andreas and Clemen, Thomas and Gilbert, Nigel and Macal, Charles M.},
doi = {10.23919/ANNSIM55834.2022.9859512},
year = {2022},
date = {2022-07-20},
journal = {Proceedings of the 2022 Annual Modeling and Simulation Conference (ANNSIM)},
pages = {188-198},
publisher = {Annual Modeling and Simulation Conference (ANNSIM)},
address = {San Diego State University, San Diego, CA, USA},
organization = {Annual Modeling and Simulation Conference (ANNSIM)},
abstract = {This paper collects the positions of four experts who participated in a panel on simulation-based policy support. The experts are well known for their contributions in this domain, predominantly for their use of agent-based approaches. The first section addresses the increasing requirements to integrate social modeling to support the evaluation of the socio-economic impact of policies, including questions of equity. Artificial societies are presented as enablers. The second section observes that the purpose of a simulation model is very much linked to its usefulness for supporting policy decisions. This implies requirements for learning agents and better representation of time and space. The third section focuses on the need to give agents more active behavior, to let them drive the action. While digital twin technology promises to help, the current state of the art seems insufficient. The section closes by looking at trust in simulation models, which will be needed for policy support.},
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This paper collects the positions of four experts who participated in a panel on simulation-based policy support. The experts are well known for their contributions in this domain, predominantly for their use of agent-based approaches. The first section addresses the increasing requirements to integrate social modeling to support the evaluation of the socio-economic impact of policies, including questions of equity. Artificial societies are presented as enablers. The second section observes that the purpose of a simulation model is very much linked to its usefulness for supporting policy decisions. This implies requirements for learning agents and better representation of time and space. The third section focuses on the need to give agents more active behavior, to let them drive the action. While digital twin technology promises to help, the current state of the art seems insufficient. The section closes by looking at trust in simulation models, which will be needed for policy support.
Lenfers, Ulfia; Ahmady-Moghaddam, Nima; Clemen, Thomas
In: Fehr, Rainer; Augustin, Jobst (Ed.): Nachhaltige StadtGesundheit Hamburg II: Neue Ziele, Wege, Initiativen, vol. 5, Chapter 3.6, pp. 480, oekom, Waltherstraße 29, 80337 Munich, 1, 2022, ISBN: 978-3-96238-390-9.
@inbook{Lenfers2022b,
title = {Ein digitaler Zwilling des Hamburger Verkehrsgeschehens als Analysetool für epidemiologische Fragestellungen am Beispiel der Verbreitung von Viren über den öffentlichen Nahverkehr},
author = {Lenfers, Ulfia and Ahmady-Moghaddam, Nima and Clemen, Thomas},
editor = {Fehr, Rainer and Augustin, Jobst},
doi = {10.14512/9783962389512},
isbn = {978-3-96238-390-9},
year = {2022},
date = {2022-07-07},
booktitle = {Nachhaltige StadtGesundheit Hamburg II: Neue Ziele, Wege, Initiativen},
volume = {5},
pages = {480},
publisher = {oekom},
address = {Waltherstraße 29, 80337 Munich},
edition = {1},
chapter = {3.6},
abstract = {Gesundheit und Nachhaltigkeit sind essenziell für das Wohlergehen jeder Stadtgesellschaft. Dieser Band führt die exemplarische Analyse Hamburger StadtGesundheit fort und fokussiert auch das Thema Nachhaltigkeit. Facetten der historischen Entwicklung, der Hamburger Stadtepidemiologie und der Steuerung von StadtGesundheit - samt Blick auf lokale Einrichtungen und Projekte - ergänzen sich mit neuen Wegen der Versorgung sowie der Prävention und Gesundheitsförderung. Gezeigt werden außerdem weitere Stadtsektoren, deren enge Verbindung zum Thema Gesundheit die Coronapandemie überdeutlich belegt. Die Fallstudie vertieft die Situationsbeschreibung einer Großstadt und den bestehenden Entwicklungsbedarf.
Die »Edition Nachhaltige Gesundheit in Stadt und Region« wird unterstützt von der Fritz und Hildegard Berg-Stiftung im Stifterverband. },
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Gesundheit und Nachhaltigkeit sind essenziell für das Wohlergehen jeder Stadtgesellschaft. Dieser Band führt die exemplarische Analyse Hamburger StadtGesundheit fort und fokussiert auch das Thema Nachhaltigkeit. Facetten der historischen Entwicklung, der Hamburger Stadtepidemiologie und der Steuerung von StadtGesundheit - samt Blick auf lokale Einrichtungen und Projekte - ergänzen sich mit neuen Wegen der Versorgung sowie der Prävention und Gesundheitsförderung. Gezeigt werden außerdem weitere Stadtsektoren, deren enge Verbindung zum Thema Gesundheit die Coronapandemie überdeutlich belegt. Die Fallstudie vertieft die Situationsbeschreibung einer Großstadt und den bestehenden Entwicklungsbedarf.
Die »Edition Nachhaltige Gesundheit in Stadt und Region« wird unterstützt von der Fritz und Hildegard Berg-Stiftung im Stifterverband.
Die »Edition Nachhaltige Gesundheit in Stadt und Region« wird unterstützt von der Fritz und Hildegard Berg-Stiftung im Stifterverband.
Ahmady-Moghaddam, Nima; Osterholz, Daniel; Clemen, Thomas
Implementation and Application of a Base Model for Agent-Based Modelling Situated in Hamburg, Germany Inproceedings
In: Simulation in den Umwelt- und Geowissenschaften (Workshop Müncheberg 2021), pp. 99–110, GI (Gesellschaft für Informatik) Shaker Verlag, 2022, ISBN: 978-3-8440-8551-8.
@inproceedings{Ahm2022a,
title = {Implementation and Application of a Base Model for Agent-Based Modelling Situated in Hamburg, Germany},
author = {Ahmady-Moghaddam, Nima and Osterholz, Daniel and Clemen, Thomas},
isbn = {978-3-8440-8551-8},
year = {2022},
date = {2022-04-29},
urldate = {2022-04-29},
booktitle = {Simulation in den Umwelt- und Geowissenschaften (Workshop Müncheberg 2021)},
volume = {1},
issue = {1},
pages = {99--110},
publisher = {Shaker Verlag},
organization = {GI (Gesellschaft für Informatik)},
abstract = {Agent-based models (ABMs) that are set in a specific geographic region tend to be rooted in similar geodata to define the setting and, by extension, tend to have a similar representation in their
environments. At the core, their agent types also tend to be similar. For example, ABMs that model a city’s traffic flow are likely populated by representations of vehicles and people as agents, just as ABMs that model the spread of infectious diseases might be populated by people and pathogens as agents. If these data and components that are common to ABMs with similar settings are gathered and implemented in a generalized fashion, the resulting model can potentially be used to develop a wide range of more domain-specific scenarios in the given setting. We refer to such a model as a base model. In this article, we describe the conception and implementation of a base model for the city of Hamburg, Germany. The process of data collection and preparation is outlined, and the portability of the approach to other geographic settings is highlighted. The base model's applicability is demonstrated by using it to create two simulation scenarios, each focused on a different domain and research question. Simulation data are analysed to address the research questions and showcase the base model’s potential. While data availability is one of the main limiting factors of a base model's efficacy, we find that a well-maintained and up-to-date base model can be a valuable tool for modellers and stakeholders, especially when required to make informed decisions under time constraints.},
keywords = {},
pubstate = {published},
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Agent-based models (ABMs) that are set in a specific geographic region tend to be rooted in similar geodata to define the setting and, by extension, tend to have a similar representation in their
environments. At the core, their agent types also tend to be similar. For example, ABMs that model a city’s traffic flow are likely populated by representations of vehicles and people as agents, just as ABMs that model the spread of infectious diseases might be populated by people and pathogens as agents. If these data and components that are common to ABMs with similar settings are gathered and implemented in a generalized fashion, the resulting model can potentially be used to develop a wide range of more domain-specific scenarios in the given setting. We refer to such a model as a base model. In this article, we describe the conception and implementation of a base model for the city of Hamburg, Germany. The process of data collection and preparation is outlined, and the portability of the approach to other geographic settings is highlighted. The base model's applicability is demonstrated by using it to create two simulation scenarios, each focused on a different domain and research question. Simulation data are analysed to address the research questions and showcase the base model’s potential. While data availability is one of the main limiting factors of a base model's efficacy, we find that a well-maintained and up-to-date base model can be a valuable tool for modellers and stakeholders, especially when required to make informed decisions under time constraints.
environments. At the core, their agent types also tend to be similar. For example, ABMs that model a city’s traffic flow are likely populated by representations of vehicles and people as agents, just as ABMs that model the spread of infectious diseases might be populated by people and pathogens as agents. If these data and components that are common to ABMs with similar settings are gathered and implemented in a generalized fashion, the resulting model can potentially be used to develop a wide range of more domain-specific scenarios in the given setting. We refer to such a model as a base model. In this article, we describe the conception and implementation of a base model for the city of Hamburg, Germany. The process of data collection and preparation is outlined, and the portability of the approach to other geographic settings is highlighted. The base model's applicability is demonstrated by using it to create two simulation scenarios, each focused on a different domain and research question. Simulation data are analysed to address the research questions and showcase the base model’s potential. While data availability is one of the main limiting factors of a base model's efficacy, we find that a well-maintained and up-to-date base model can be a valuable tool for modellers and stakeholders, especially when required to make informed decisions under time constraints.
Lenfers, U. A.; Ahmady-Moghaddam, N.; Glake, D.; Ocker, F.; Weyl, J.; Clemen, T.
Modeling the Future Tree Distribution in a South African Savanna Ecosystem: An Agent-Based Model Approach Journal Article
In: Land, vol. 11, iss. 5, no. 619, 2022, ISSN: 2073-445X.
@article{Lenfers2022a,
title = {Modeling the Future Tree Distribution in a South African Savanna Ecosystem: An Agent-Based Model Approach},
author = {Lenfers, U.A. and Ahmady-Moghaddam, N. and Glake, D. and Ocker, F. and Weyl, J. and Clemen, T.},
url = {https://www.mdpi.com/2073-445X/11/5/619},
doi = {10.3390/land11050619},
issn = {2073-445X},
year = {2022},
date = {2022-04-22},
urldate = {2022-04-22},
journal = {Land},
volume = {11},
number = {619},
issue = {5},
abstract = {Understanding the dynamics of tree species and their demography is necessary for predicting future developments in savanna ecosystems. In this contribution, elephant-tree and firewood collector-tree interactions are compared using a multiagent model. To investigate these dynamics, we compared three different tree species in two plots. The first plot is located in the protected space of Kruger National Park (KNP), South Africa, and the second plot in the rural areas of the Bushbuckridge Municipality, South Africa. The agent-based modeling approach enabled the modeling of individual trees with characteristics such as species, age class, size, damage class, and life history. A similar level of detail was applied to agents that represent elephants and firewood collectors. Particular attention was paid to modeling purposeful behavior of humans in contrast to more instinct-driven actions of elephants. The authors were able to predict future developments by simulating the time period between 2010 and 2050 with more than 500,000 individual trees. Modeling individual trees for a time span of 40 years might yield more detailed information than a simple woody mass aggregation. The results indicate a significant trend toward more and thinner trees together with a notable reduction in mature trees, while the total aboveground biomass appears to stay more or less constant. Furthermore, the KNP scenarios show an increase in young Combretum apiculatum, which may correspond to bush encroachment.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Understanding the dynamics of tree species and their demography is necessary for predicting future developments in savanna ecosystems. In this contribution, elephant-tree and firewood collector-tree interactions are compared using a multiagent model. To investigate these dynamics, we compared three different tree species in two plots. The first plot is located in the protected space of Kruger National Park (KNP), South Africa, and the second plot in the rural areas of the Bushbuckridge Municipality, South Africa. The agent-based modeling approach enabled the modeling of individual trees with characteristics such as species, age class, size, damage class, and life history. A similar level of detail was applied to agents that represent elephants and firewood collectors. Particular attention was paid to modeling purposeful behavior of humans in contrast to more instinct-driven actions of elephants. The authors were able to predict future developments by simulating the time period between 2010 and 2050 with more than 500,000 individual trees. Modeling individual trees for a time span of 40 years might yield more detailed information than a simple woody mass aggregation. The results indicate a significant trend toward more and thinner trees together with a notable reduction in mature trees, while the total aboveground biomass appears to stay more or less constant. Furthermore, the KNP scenarios show an increase in young Combretum apiculatum, which may correspond to bush encroachment.
2021
Günther, Gerrit; Clemen, Thomas; Duttmann, Rainer; Schuett, Brigitta; Knitter, Daniel
Of Animal Husbandry and Food Production—A First Step towards a Modular Agent-Based Modelling Platform for Socio-Ecological Dynamics Bachelor Thesis
2021, ISSN: 2073-445X.
@bachelorthesis{Guenther2021a,
title = {Of Animal Husbandry and Food Production—A First Step towards a Modular Agent-Based Modelling Platform for Socio-Ecological Dynamics},
author = {Günther, Gerrit and Clemen, Thomas and Duttmann, Rainer and Schuett, Brigitta and Knitter, Daniel},
url = {https://www.mdpi.com/2073-445X/10/12/1366},
doi = {10.3390/land10121366},
issn = {2073-445X},
year = {2021},
date = {2021-12-10},
journal = {Land 2021},
volume = {10},
number = {12},
abstract = {Agent-based models provide detailed, bottom-up approaches to investigate complex socio-ecological systems. This study presents a first step towards a modular agent-based simulation that is based upon empirical data, as well as environmental suitability maps and an assessment of livestock units. To illustrate the capabilities of our simulation, we use a geographically explicit approach to simulate a component of the production of animal products of a rural settlement in the lower Bakırçay catchment, western Turkey. The model structurally couples various agent types representing several elements and processes of the animal husbandry and food production value chain, such as sedentary herders—practising daily, short-distance pastoralism—and their flocks of goats and sheep, as well as milking and slaughtering. The modelling tool captures the fundamental socio-ecological dynamics of animal husbandry and food production in rural settlements. Therefore, the tool is valuable as a basis to discuss hypotheses regarding the number of animals that are needed to cover the requirements of different growing populations. },
keywords = {},
pubstate = {published},
tppubtype = {bachelorthesis}
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Agent-based models provide detailed, bottom-up approaches to investigate complex socio-ecological systems. This study presents a first step towards a modular agent-based simulation that is based upon empirical data, as well as environmental suitability maps and an assessment of livestock units. To illustrate the capabilities of our simulation, we use a geographically explicit approach to simulate a component of the production of animal products of a rural settlement in the lower Bakırçay catchment, western Turkey. The model structurally couples various agent types representing several elements and processes of the animal husbandry and food production value chain, such as sedentary herders—practising daily, short-distance pastoralism—and their flocks of goats and sheep, as well as milking and slaughtering. The modelling tool captures the fundamental socio-ecological dynamics of animal husbandry and food production in rural settlements. Therefore, the tool is valuable as a basis to discuss hypotheses regarding the number of animals that are needed to cover the requirements of different growing populations.
Lenfers, Ulfia Annette; Ahmady-Moghaddam, Nima; Glake, Daniel; Ocker, Florian; Ströbele, Jonathan; Clemen, Thomas
Incorporating Multi-Modal Travel Planning into an Agent-Based Model: A Case Study at the Train Station Kellinghusenstraße in Hamburg Journal Article
In: Land 2021, vol. 10, no. 11, 2021, ISSN: 2073-445X.
@article{Lenfers2021b,
title = {Incorporating Multi-Modal Travel Planning into an Agent-Based Model: A Case Study at the Train Station Kellinghusenstraße in Hamburg},
author = {Ulfia Annette Lenfers and Nima Ahmady-Moghaddam and Daniel Glake and Florian Ocker and Jonathan Ströbele and Thomas Clemen},
editor = {Simon Elias Bibri},
url = {https://www.mdpi.com/2073-445X/10/11/1179/htm},
doi = {10.3390/land10111179},
issn = {2073-445X},
year = {2021},
date = {2021-11-03},
journal = {Land 2021},
volume = {10},
number = {11},
abstract = {Models can provide valuable decision support in the ongoing effort to create a sustainable and effective modality mix in urban settings. Modern transportation infrastructures must meaningfully combine public transport with other mobility initiatives such as shared and on-demand systems. The increase of options and possibilities in multi-modal travel implies an increase in complexity when planning and implementing such an infrastructure. Multi-agent systems are well-suited for addressing questions that require an understanding of movement patterns and decision processes at the individual level. Such models should feature intelligent software agents with flexible internal logic and accurately represent the core functionalities of new modalities. We present a model in which agents can choose between owned modalities, station-based bike sharing modalities, and free-floating car sharing modalities as they exit the public transportation system and seek to finish their personal multi-modal trip. Agents move on a multi-modal road network where dynamic constraints in route planning are evaluated based on an agent’s query. Modality switch points (MSPs) along the route indicate the locations at which an agent can switch from one modality to the next (e.g., a bike rental station to return a used rental bike and continue on foot). The technical implementation of MSPs within the road network was a central focus in this work. To test their efficacy in a controlled experimental setting, agents optimized only the travel time of their multi-modal routes. However, the functionalities of the model enable the implementation of different optimization criteria (e.g., financial considerations or climate neutrality) and unique agent preferences as well. Our findings show that the implemented MSPs enable agents to switch between modalities at any time, allowing for the kind of versatile, individual, and spontaneous travel that is common in modern multi-modal settings. },
keywords = {},
pubstate = {published},
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Models can provide valuable decision support in the ongoing effort to create a sustainable and effective modality mix in urban settings. Modern transportation infrastructures must meaningfully combine public transport with other mobility initiatives such as shared and on-demand systems. The increase of options and possibilities in multi-modal travel implies an increase in complexity when planning and implementing such an infrastructure. Multi-agent systems are well-suited for addressing questions that require an understanding of movement patterns and decision processes at the individual level. Such models should feature intelligent software agents with flexible internal logic and accurately represent the core functionalities of new modalities. We present a model in which agents can choose between owned modalities, station-based bike sharing modalities, and free-floating car sharing modalities as they exit the public transportation system and seek to finish their personal multi-modal trip. Agents move on a multi-modal road network where dynamic constraints in route planning are evaluated based on an agent’s query. Modality switch points (MSPs) along the route indicate the locations at which an agent can switch from one modality to the next (e.g., a bike rental station to return a used rental bike and continue on foot). The technical implementation of MSPs within the road network was a central focus in this work. To test their efficacy in a controlled experimental setting, agents optimized only the travel time of their multi-modal routes. However, the functionalities of the model enable the implementation of different optimization criteria (e.g., financial considerations or climate neutrality) and unique agent preferences as well. Our findings show that the implemented MSPs enable agents to switch between modalities at any time, allowing for the kind of versatile, individual, and spontaneous travel that is common in modern multi-modal settings.
Glake, Daniel; Ritter, Norbert; Ocker, Florian; Ahmady-Moghaddam, Nima; Osterholz, Daniel; Lenfers, Ulfia; Clemen, Thomas
Hierarchical Semantics Matching For Heterogeneous Spatio-Temporal Sources Conference
Proceedings of the 30th ACM International Conference on Information & Knowledge Management, Association for Computing Machinery Association for Computing Machinery, New York, NY, USA, 2021, ISBN: 978-1-4503-8446-9.
@conference{Glake2021a,
title = {Hierarchical Semantics Matching For Heterogeneous Spatio-Temporal Sources},
author = {Glake, Daniel and Ritter, Norbert and Ocker, Florian and Ahmady-Moghaddam, Nima and Osterholz, Daniel and Lenfers, Ulfia and Clemen, Thomas},
url = {https://doi.org/10.1145/3459637.3482350},
doi = {10.1145/3459637.3482350},
isbn = {978-1-4503-8446-9},
year = {2021},
date = {2021-10-26},
booktitle = {Proceedings of the 30th ACM International Conference on Information & Knowledge Management},
pages = {565–575},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
organization = {Association for Computing Machinery},
abstract = {Spatio-temporal data are semantically valuable information used for various analytical tasks to identify spatially relevant and temporally limited correlations within a domain. The increasing availability and data acquisition from multiple sources with their typically high heterogeneity are getting more and more attention. However, these sources often lack interconnecting shared keys, making their integration a challenging problem. For example, publicly available parking data that consist of point data on parking facilities with fluctuating occupancy and static location data on parking spaces cannot be directly correlated. Both data sets describe two different aspects from distinct sources in which parking spaces and fluctuating occupancy are part of the same semantic model object. Especially for ad hoc analytical tasks on integrated models, these missing relationships cannot be handled using join operations as usual in relational databases. The reason lies in the lack of equijoin relationships, comparing for equality of strings and additional overhead in loading data up before processing. This paper addresses the optimization problem of finding suitable partners in the absence of equijoin relations for heterogeneous spatio-temporal data, applicable to ad hoc analytics. We propose a graph-based approach that achieves good recall and performance scaling via hierarchically separating the semantics along spatial, temporal, and domain-specific dimensions. We evaluate our approach using public data, showing that it is suitable for many standard join scenarios and highlighting its limitations.},
keywords = {},
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}
Spatio-temporal data are semantically valuable information used for various analytical tasks to identify spatially relevant and temporally limited correlations within a domain. The increasing availability and data acquisition from multiple sources with their typically high heterogeneity are getting more and more attention. However, these sources often lack interconnecting shared keys, making their integration a challenging problem. For example, publicly available parking data that consist of point data on parking facilities with fluctuating occupancy and static location data on parking spaces cannot be directly correlated. Both data sets describe two different aspects from distinct sources in which parking spaces and fluctuating occupancy are part of the same semantic model object. Especially for ad hoc analytical tasks on integrated models, these missing relationships cannot be handled using join operations as usual in relational databases. The reason lies in the lack of equijoin relationships, comparing for equality of strings and additional overhead in loading data up before processing. This paper addresses the optimization problem of finding suitable partners in the absence of equijoin relations for heterogeneous spatio-temporal data, applicable to ad hoc analytics. We propose a graph-based approach that achieves good recall and performance scaling via hierarchically separating the semantics along spatial, temporal, and domain-specific dimensions. We evaluate our approach using public data, showing that it is suitable for many standard join scenarios and highlighting its limitations.
Lufyagila, Beston; Machuve, Dina; Clemen, Thomas
IoT-powered system for environmental conditions monitoring in poultry house: A case of Tanzania Journal Article
In: African Journal of Science Technology Innovation and Development, vol. 14, no. 4, pp. 1020-1031, 2021.
@article{Lufyagila2021a,
title = {IoT-powered system for environmental conditions monitoring in poultry house: A case of Tanzania},
author = {Lufyagila, Beston and Machuve, Dina and Clemen, Thomas},
url = {https://www.tandfonline.com/doi/full/10.1080/20421338.2021.1924348},
doi = {10.1080/20421338.2021.1924348},
year = {2021},
date = {2021-07-15},
urldate = {2021-07-15},
journal = {African Journal of Science Technology Innovation and Development},
volume = {14},
number = {4},
pages = {1020-1031},
abstract = {Poultry health is imperative for the continued growth of poultry and increased production. Environmental conditions such as temperature, humidity, and ammonia gas have an impact on poultry health. They affect the respiratory system and eventually cause death. In Tanzania, most smallholder farmers use charcoal and kerosene stoves to control the environmental parameters since they have limited access to low-cost, secure, and user-friendly poultry house monitoring systems. However, these traditional methods are unreliable, difficult to manage, not environmentally friendly, and inaccurate. Data were collected from 120 poultry farmers in Arusha and Kilimanjaro regions using convenience and snowball sampling techniques. Of the respondents, 43% revealed that smallholder farmers do not adopt automated systems despite being available because they are expensive. In this study, a system based on the Internet of Things (IoT) was developed for environmental conditions monitoring in poultry houses for low-resourced smallholder farmers in Tanzania. The system saves time (84%) and labour costs (66.7%) compared to the traditional system, as the farmer can monitor and control the conditions securely, reliably, and remotely. The study also proposes an algorithm for the system to work online and offline (i.e.,, synchronizing with the cloud server when internet access is available).},
keywords = {},
pubstate = {published},
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}
Poultry health is imperative for the continued growth of poultry and increased production. Environmental conditions such as temperature, humidity, and ammonia gas have an impact on poultry health. They affect the respiratory system and eventually cause death. In Tanzania, most smallholder farmers use charcoal and kerosene stoves to control the environmental parameters since they have limited access to low-cost, secure, and user-friendly poultry house monitoring systems. However, these traditional methods are unreliable, difficult to manage, not environmentally friendly, and inaccurate. Data were collected from 120 poultry farmers in Arusha and Kilimanjaro regions using convenience and snowball sampling techniques. Of the respondents, 43% revealed that smallholder farmers do not adopt automated systems despite being available because they are expensive. In this study, a system based on the Internet of Things (IoT) was developed for environmental conditions monitoring in poultry houses for low-resourced smallholder farmers in Tanzania. The system saves time (84%) and labour costs (66.7%) compared to the traditional system, as the farmer can monitor and control the conditions securely, reliably, and remotely. The study also proposes an algorithm for the system to work online and offline (i.e.,, synchronizing with the cloud server when internet access is available).
Nima Ahmady-Moghaddam Ulfia A. Lenfers, Daniel Glake; Clemen, Thomas
Improving Model Predictions—Integration of Real-Time Sensor Data into a Running Simulation of an Agent-Based Model Journal Article
In: Sustainability, vol. 13, no. 13, 2021.
@article{Lenfers2021,
title = {Improving Model Predictions—Integration of Real-Time Sensor Data into a Running Simulation of an Agent-Based Model},
author = {Ulfia A. Lenfers, Nima Ahmady-Moghaddam, Daniel Glake, Florian Ocker, Daniel Osterholz, Jonathan Ströbele and Thomas Clemen},
editor = {Philippe J. Giabbanelli and Arika Ligmann-Zielinska},
url = {https://doi.org/10.3390/su13137000},
doi = {10.3390/su13137000},
year = {2021},
date = {2021-06-22},
journal = {Sustainability},
volume = {13},
number = {13},
abstract = {The current trend towards living in big cities contributes to an increased demand for efficient and sustainable space and resource allocation in urban environments. This leads to enormous pressure for resource minimization in city planning. One pillar of efficient city management is a smart intermodal traffic system. Planning and organizing the various kinds of modes of transport in a complex and dynamically adaptive system such as a city is inherently challenging. By deliberately simplifying reality, models can help decision-makers shape the traffic systems of tomorrow. Meanwhile, Smart City initiatives are investing in sensors to observe and manage many kinds of urban resources, making up a part of the Internet of Things (IoT) that produces massive amounts of data relevant for urban planning and monitoring. We use these new data sources of smart cities by integrating real-time data of IoT sensors in an ongoing simulation. In this sense, the model is a digital twin of its real-world counterpart, being augmented with real-world data. To our knowledge, this is a novel instance of real-time correction during simulation of an agent-based model. The process of creating a valid mapping between model components and real-world objects posed several challenges and offered valuable insights, particularly when studying the interaction between humans and their environment. As a proof-of-concept for our implementation, we designed a showcase with bike rental stations in Hamburg-Harburg, a southern district of Hamburg, Germany. Our objective was to investigate the concept of real-time data correction in agent-based modeling, which we consider to hold great potential for improving the predictive capabilities of models. In particular, we hope that the chosen proof-of-concept informs the ongoing politically supported trends in mobility—away from individual and private transport and towards—in Hamburg.},
keywords = {},
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The current trend towards living in big cities contributes to an increased demand for efficient and sustainable space and resource allocation in urban environments. This leads to enormous pressure for resource minimization in city planning. One pillar of efficient city management is a smart intermodal traffic system. Planning and organizing the various kinds of modes of transport in a complex and dynamically adaptive system such as a city is inherently challenging. By deliberately simplifying reality, models can help decision-makers shape the traffic systems of tomorrow. Meanwhile, Smart City initiatives are investing in sensors to observe and manage many kinds of urban resources, making up a part of the Internet of Things (IoT) that produces massive amounts of data relevant for urban planning and monitoring. We use these new data sources of smart cities by integrating real-time data of IoT sensors in an ongoing simulation. In this sense, the model is a digital twin of its real-world counterpart, being augmented with real-world data. To our knowledge, this is a novel instance of real-time correction during simulation of an agent-based model. The process of creating a valid mapping between model components and real-world objects posed several challenges and offered valuable insights, particularly when studying the interaction between humans and their environment. As a proof-of-concept for our implementation, we designed a showcase with bike rental stations in Hamburg-Harburg, a southern district of Hamburg, Germany. Our objective was to investigate the concept of real-time data correction in agent-based modeling, which we consider to hold great potential for improving the predictive capabilities of models. In particular, we hope that the chosen proof-of-concept informs the ongoing politically supported trends in mobility—away from individual and private transport and towards—in Hamburg.
Glake, Daniel; Panse, Fabian; Ritter, Norbert; Clemen, Thomas; Lenfers, Ulfia
Data Management in Multi-Agent Simulation Systems Inproceedings
In: Sattler, Kai-Uwe; Herschel, Melanie; Lehner, Wolfgang (Ed.): Proceedings of the 2021 GI Workshop Datenbanksysteme für Business, Technologie und Web (BTW), pp. 423-436, Gesellschaft für Informatik (GI) Gesellschaft für Informatik (GI), Bonn, Germany, 2021, ISBN: 978-3-88579-705-0.
@inproceedings{Glake2021ab,
title = {Data Management in Multi-Agent Simulation Systems},
author = {Glake, Daniel and Panse, Fabian and Ritter, Norbert and Clemen, Thomas and Lenfers, Ulfia},
editor = {Sattler, Kai-Uwe and Herschel, Melanie and Lehner, Wolfgang},
doi = {10.18420/btw2021-22},
isbn = {978-3-88579-705-0},
year = {2021},
date = {2021-06-15},
booktitle = {Proceedings of the 2021 GI Workshop Datenbanksysteme für Business, Technologie und Web (BTW)},
journal = {Proceedings of the 2021 GI Workshop Datenbanksysteme für Business, Technologie und Web (BTW)},
volume = {1},
pages = {423-436},
publisher = {Gesellschaft für Informatik (GI)},
address = {Bonn, Germany},
organization = {Gesellschaft für Informatik (GI)},
abstract = {Multi-agent simulations are an upcoming trend to deal with the urgent need to predict complex situations as they arise in many real-life areas, such as disaster or traffic management. Such simulations require large amounts of heterogeneous data ranging from spatio-temporal to standard object properties. This and the increasing demand for large scale and real-time simulations pose many challenges for data management. In this paper, we present the architecture of a typical agent-based simulation system, describe several data management challenges that arise in such a data ecosystem, and discuss their current solutions within our multi-agent simulation system MARS.},
keywords = {},
pubstate = {published},
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Multi-agent simulations are an upcoming trend to deal with the urgent need to predict complex situations as they arise in many real-life areas, such as disaster or traffic management. Such simulations require large amounts of heterogeneous data ranging from spatio-temporal to standard object properties. This and the increasing demand for large scale and real-time simulations pose many challenges for data management. In this paper, we present the architecture of a typical agent-based simulation system, describe several data management challenges that arise in such a data ecosystem, and discuss their current solutions within our multi-agent simulation system MARS.
Günther, Gerrit; Knitter, Daniel; Clemen, Thomas
Agropastoralism in Ancient Pergamon - An Agent-based Modelling Approach Inproceedings
In: Proceedings of the LAC2020+1, 2021, (Poster).
@inproceedings{Guenther2021b,
title = {Agropastoralism in Ancient Pergamon - An Agent-based Modelling Approach},
author = {Günther, Gerrit and Knitter, Daniel and Clemen, Thomas},
year = {2021},
date = {2021-06-15},
booktitle = {Proceedings of the LAC2020+1},
abstract = {With the domestication of animals since the Neolithic period, animal husbandry has developed into one of the main subsistence strategies for many cultures around the world (Vretemark et al., 2010; Garvin et al., 2018) and altered the way of life of human societies (Vigne, 2011) — with strong demographic transformations characterising this shift towards a food production based on animal husbandry and the cultivation of plants (Hershkovitz, 2008).
Land use practices and human-spatial organisation are integral to understand the rural and urban economy of an area. Agent-based modelling provides a bottom-up approach for studying complex systems. This study focuses on a rural settlement in the vicinity of Pergamon (modern Bergama, Turkey) during the transition from the Hellenistic to the Roman Imperial Period. The aim of the study is to provide a theory-based, modular simulation tool that allows to investigate various aspects and possibilities of socio-ecological dynamics.},
note = {Poster},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
With the domestication of animals since the Neolithic period, animal husbandry has developed into one of the main subsistence strategies for many cultures around the world (Vretemark et al., 2010; Garvin et al., 2018) and altered the way of life of human societies (Vigne, 2011) — with strong demographic transformations characterising this shift towards a food production based on animal husbandry and the cultivation of plants (Hershkovitz, 2008).
Land use practices and human-spatial organisation are integral to understand the rural and urban economy of an area. Agent-based modelling provides a bottom-up approach for studying complex systems. This study focuses on a rural settlement in the vicinity of Pergamon (modern Bergama, Turkey) during the transition from the Hellenistic to the Roman Imperial Period. The aim of the study is to provide a theory-based, modular simulation tool that allows to investigate various aspects and possibilities of socio-ecological dynamics.
Land use practices and human-spatial organisation are integral to understand the rural and urban economy of an area. Agent-based modelling provides a bottom-up approach for studying complex systems. This study focuses on a rural settlement in the vicinity of Pergamon (modern Bergama, Turkey) during the transition from the Hellenistic to the Roman Imperial Period. The aim of the study is to provide a theory-based, modular simulation tool that allows to investigate various aspects and possibilities of socio-ecological dynamics.
Clemen, Thomas; Lenfers, Ulfia A.; Dybulla, Janus; Ferreira, Sam M.; Kiker, Greg A.; Martens, Carola; Scheiter, Simon
A cross-scale modeling framework for decision support on elephant management in Kruger National Park, South Africa Journal Article
In: Ecological Informatics, vol. 62, pp. 101266, 2021, ISSN: 15749541.
@article{Clemenk,
title = {A cross-scale modeling framework for decision support on elephant management in Kruger National Park, South Africa},
author = {Clemen, Thomas and Lenfers, Ulfia A. and Dybulla, Janus and Ferreira, Sam M. and Kiker, Greg A. and Martens, Carola and Scheiter, Simon},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1574954121000571},
doi = {10.1016/j.ecoinf.2021.101266},
issn = {15749541},
year = {2021},
date = {2021-05-31},
journal = {Ecological Informatics},
volume = {62},
pages = {101266},
abstract = {Conservation areas, like national parks, are hotspots of social-ecological and social-economic activities. The resulting interactions contribute to an inherent complexity of these systems, making simulation models a vital form of support for their management activities. These models are often unimodal, i.e., limited by design to only one particular question or a specific temporal and spatial scale. We implemented the cross-scale and multi-modal base model MARS KNP for the Kruger National Park, South Africa that combines the agent-based paradigm with a dynamic vegetation model.
As a proof-of-concept, we developed an elephant movement model within MARS KNP to evaluate the base model's decision-support capabilities. The study was mainly focused on the underlying software mechanisms that allow easy integration of multi-scale spatio-temporal data objects. MARS agents can probe, interact with, and modify these objects. We found that this feature is essential for a cross-scale integration of different modeling approaches.
Additionally, we propose a definition of the term ‘base model’ to shorten the provisioning time of decision-support tools.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Conservation areas, like national parks, are hotspots of social-ecological and social-economic activities. The resulting interactions contribute to an inherent complexity of these systems, making simulation models a vital form of support for their management activities. These models are often unimodal, i.e., limited by design to only one particular question or a specific temporal and spatial scale. We implemented the cross-scale and multi-modal base model MARS KNP for the Kruger National Park, South Africa that combines the agent-based paradigm with a dynamic vegetation model.
As a proof-of-concept, we developed an elephant movement model within MARS KNP to evaluate the base model's decision-support capabilities. The study was mainly focused on the underlying software mechanisms that allow easy integration of multi-scale spatio-temporal data objects. MARS agents can probe, interact with, and modify these objects. We found that this feature is essential for a cross-scale integration of different modeling approaches.
Additionally, we propose a definition of the term ‘base model’ to shorten the provisioning time of decision-support tools.
As a proof-of-concept, we developed an elephant movement model within MARS KNP to evaluate the base model's decision-support capabilities. The study was mainly focused on the underlying software mechanisms that allow easy integration of multi-scale spatio-temporal data objects. MARS agents can probe, interact with, and modify these objects. We found that this feature is essential for a cross-scale integration of different modeling approaches.
Additionally, we propose a definition of the term ‘base model’ to shorten the provisioning time of decision-support tools.
Clemen, Thomas; Ahmady-Moghaddam, Nima; Lenfers, Ulfia A.; Ocker, Florian; Osterholz, Daniel; Ströbele, Jonathan; Glake, Daniel
Multi-Agent Systems and Digital Twins for Smarter Cities Inproceedings
In: Proceedings of the 2021 ACM SIGSIM Conference on Principles of Advanced Discrete Simulation, pp. 45–55, ACM, 2021, ISBN: 9781450382960.
@inproceedings{Clemen2021,
title = {Multi-Agent Systems and Digital Twins for Smarter Cities},
author = {Clemen, Thomas and Ahmady-Moghaddam, Nima and Lenfers, Ulfia A. and Ocker, Florian and Osterholz, Daniel and Ströbele, Jonathan and Glake, Daniel},
url = {https://dl.acm.org/doi/10.1145/3437959.3459254},
doi = {10.1145/3437959.3459254},
isbn = {9781450382960},
year = {2021},
date = {2021-05-01},
booktitle = {Proceedings of the 2021 ACM SIGSIM Conference on Principles of Advanced Discrete Simulation},
volume = {1},
number = {1},
pages = {45–55},
publisher = {ACM},
abstract = {An intelligent combination of the Internet of Things (IoT) and approaches to modeling and simulation is one of the most challenging endeavors for future cities, manufacturing industries, and predictive maintenance. Digital Twins take on a unique role here. However, the question of what a Digital Twin is and what differentiates it from a regular model is still open. We present an experimental setup for integrating an existing simulation model of Hamburg's traffic system with the city's real-time sensor network. The Digital Twin is implemented using the large-scale multi-agent framework MARS. The entire process from the model description to retrieving real-time data from the IoT sensors and incorporating it in the simulation is presented. As a first prototypical example, a multi-modal mobility model was connected to real-world bike-sharing locations in Hamburg. We find that the combination of multi-agent systems and IoT sensors as a Digital Twin shows enormous potential for city planners, policy stakeholders, and other decision-makers. By correcting the course of a simulation via real-time data, the corridor-of-uncertainty that is intrinsic to some simulation models' use can be reduced significantly. Furthermore, any divergence of simulated and sampled data can lead to a deeper understanding of complex adaptive systems like big cities.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
An intelligent combination of the Internet of Things (IoT) and approaches to modeling and simulation is one of the most challenging endeavors for future cities, manufacturing industries, and predictive maintenance. Digital Twins take on a unique role here. However, the question of what a Digital Twin is and what differentiates it from a regular model is still open. We present an experimental setup for integrating an existing simulation model of Hamburg's traffic system with the city's real-time sensor network. The Digital Twin is implemented using the large-scale multi-agent framework MARS. The entire process from the model description to retrieving real-time data from the IoT sensors and incorporating it in the simulation is presented. As a first prototypical example, a multi-modal mobility model was connected to real-world bike-sharing locations in Hamburg. We find that the combination of multi-agent systems and IoT sensors as a Digital Twin shows enormous potential for city planners, policy stakeholders, and other decision-makers. By correcting the course of a simulation via real-time data, the corridor-of-uncertainty that is intrinsic to some simulation models' use can be reduced significantly. Furthermore, any divergence of simulated and sampled data can lead to a deeper understanding of complex adaptive systems like big cities.
2020
Zhou, Yanling; Ma, Linshan; Clemen, Thomas
Single-Stack Deep-Query Quad-Tree RFID Tag Anti-collision Algorithm Journal Article
In: International Journal of Computer Theory and Engineering, vol. 12, no. 6, pp. 140–144, 2020, ISSN: 17938201.
@article{Zhou2020,
title = {Single-Stack Deep-Query Quad-Tree RFID Tag Anti-collision Algorithm},
author = {Zhou, Yanling and Ma, Linshan and Clemen, Thomas},
url = {http://www.ijcte.org/index.php?m=content&c=index&a=show&catid=114&id=1562},
doi = {10.7763/ijcte.2020.v12.1279},
issn = {17938201},
year = {2020},
date = {2020-12-31},
journal = {International Journal of Computer Theory and Engineering},
volume = {12},
number = {6},
pages = {140--144},
abstract = {The problem of tag collision is the main problem affecting the performance of RFID systems. Probabilistic tag anti-collision algorithms have tag starvation and cannot recognize some tags. This paper proposes a deterministic query-tree algorithm, that is, a single-stack deep query-tree RFID tag anti-collision algorithm, which successfully implements tag anti-collision by generating new query code and tag recognition. The algorithm uses the highest two collision bits of the collision code to form four new query codes. The query tree formed by the query code is a depth-first traversal quad-tree. The algorithm introduces a single-stack storage mechanism, and the query code uses a depth-first traversal algorithm. In the entire tag recognition process, the structure of the query code spanning tree was improved, and the degree of the branch node was 4. This combination of depth-first traversal and single-stack mechanism effectively shortened the recognition time, saved memory space, and reduced the number of tag collisions. And the algorithm is simple and easy to implement. When the number of tags increases, the efficiency of the algorithm will be more clearly reflected.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The problem of tag collision is the main problem affecting the performance of RFID systems. Probabilistic tag anti-collision algorithms have tag starvation and cannot recognize some tags. This paper proposes a deterministic query-tree algorithm, that is, a single-stack deep query-tree RFID tag anti-collision algorithm, which successfully implements tag anti-collision by generating new query code and tag recognition. The algorithm uses the highest two collision bits of the collision code to form four new query codes. The query tree formed by the query code is a depth-first traversal quad-tree. The algorithm introduces a single-stack storage mechanism, and the query code uses a depth-first traversal algorithm. In the entire tag recognition process, the structure of the query code spanning tree was improved, and the degree of the branch node was 4. This combination of depth-first traversal and single-stack mechanism effectively shortened the recognition time, saved memory space, and reduced the number of tag collisions. And the algorithm is simple and easy to implement. When the number of tags increases, the efficiency of the algorithm will be more clearly reflected.
Glake, Daniel; Ritter, Norbert; Clemen, Thomas
Utilizing Spatio-Temporal Data in Multi-Agent Simulation Inproceedings
In: B. Feng K.-H. Bae, S. Kim; Thiesing, R. (Ed.): 2020 Winter Simulation Conference (WSC), pp. 242–253, IEEE, 2020, ISBN: 978-1-7281-9499-8.
@inproceedings{Glake2020,
title = {Utilizing Spatio-Temporal Data in Multi-Agent Simulation},
author = {Glake, Daniel and Ritter, Norbert and Clemen, Thomas},
editor = {K.-H. Bae, B. Feng, S. Kim, S. Lazarova-Molnar, Z. Zheng, T. Roeder}, and R. Thiesing},
url = {https://ieeexplore.ieee.org/document/9384124/},
doi = {10.1109/WSC48552.2020.9384124},
isbn = {978-1-7281-9499-8},
year = {2020},
date = {2020-12-18},
booktitle = {2020 Winter Simulation Conference (WSC)},
volume = {2020-Decem},
pages = {242--253},
publisher = {IEEE},
abstract = {Spatio-temporal properties strongly influence a large proportion of multi-agent simulations (MAS) in their application domains. Time-dependent simulations benefit from correct and time-sensitive input data that match the current simulated time or offer the possibility to take into account previous simulation states in their modelling perspective. In this paper, we present the concepts and semantics of data-driven simulations with vector and raster data and extend them by a time dimension that applies at run-time within the simulation execution or in conjunction with the definition of MAS models. We show that the semantics consider the evolution of spatio-temporal objects with their temporal relationships between spatial entities.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Spatio-temporal properties strongly influence a large proportion of multi-agent simulations (MAS) in their application domains. Time-dependent simulations benefit from correct and time-sensitive input data that match the current simulated time or offer the possibility to take into account previous simulation states in their modelling perspective. In this paper, we present the concepts and semantics of data-driven simulations with vector and raster data and extend them by a time dimension that applies at run-time within the simulation execution or in conjunction with the definition of MAS models. We show that the semantics consider the evolution of spatio-temporal objects with their temporal relationships between spatial entities.
Nyambo, Devotha G; Luhanga, Edith T; Yonah, Zaipuna O; Mujibi, Fidalis D N; Clemen, Thomas
Leveraging peer-to-peer farmer learning to facilitate better strategies in smallholder dairy husbandry Journal Article
In: Adaptive Behavior, 2020.
@article{Nyambo2020,
title = {Leveraging peer-to-peer farmer learning to facilitate better strategies in smallholder dairy husbandry},
author = {Devotha G Nyambo and Edith T Luhanga and Zaipuna O Yonah and Fidalis D N Mujibi and Thomas Clemen},
doi = {10.1177/1059712320971369},
year = {2020},
date = {2020-12-01},
journal = {Adaptive Behavior},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lenfers, Ulfia; Glake, Daniel; Ocker, Florian; Clemen, Thomas
2020.
@conference{Lenfers2020b,
title = {Überbewirtschaftung, Verbuschung und Klimawandel - Was geschieht mit den Bäumen in der Savanne Südafrikas? Ergebnisse einer Agenten-basierten Modellierung des Savannen-Ökosystems in zwei verschiedenen Nutzungsformen},
author = {Ulfia Lenfers and Daniel Glake and Florian Ocker and Thomas Clemen},
url = {https://www.researchgate.net/publication/344458142_Uberbewirtschaftung_Verbuschung_und_Klimawandel_-_Was_geschieht_mit_den_Baumen_in_der_Savanne_Sudafrikas_Ergebnisse_einer_Agenten-basierten_Modellierung_des_Savannen-Okosystems_in_zwei_verschiedenen_N},
year = {2020},
date = {2020-10-01},
abstract = {berbewirtschaftung, Verbuschung und Klimawandel-Was geschieht mit den Bäumen in der Savanne Südafrikas? Ergebnisse einer Agenten-basierten Modellierung des Savannen-Ökosystems in zwei verschiedenen Nutzungsformen Lenfers, U. A.; Glake, D.; Ocker, F.; Clemen, T. Zusammenfassung: Bäume in der Savanne werden in hohem Maße von Tieren und Menschen genutzt. In dieser Studie werden unterschiedliche Baumarten in einem Simulationszeitraum von 2010 bis 2050 unter zwei verschiedenen Klimaszenarien mittel Agenten-basierter Modellierung verglichen. Besondere Betrachtung gilt dem Vergleich zwischen natur-naher Nutzung im Krüger Nationalpark (Elefanten) und einer Nutzung im ländlichen Raum (Feuerholzsammler). Agenten-basierte Modellierung ermöglicht es sowohl aggregierte Biomassewerte aller Bäume über den Zeitverlauf zu beobachten, als auch die verschiedenen Baumarten und Altersgruppen miteinander zu vergleichen. Es zeigt sich, dass bereits innerhalb der Arten und der Altersklassen Veränderungen zu beobachten sind, die in den aggregierten Werten so nicht zu erkennen sind. Auch wenn Bäume sehr langsam auf Veränderungen reagieren, lassen sich aus Altersgruppenverschiebungen und den Veränderungen in der Artenzusammensetzung Tendenzen ableiten, die es erlauben einen Blick in zukünftige Verteilungen unterschiedlicher Baumarten unter verschiedenen Nutzungen zu wagen. Damit können die Ergebnisse dieser Arbeit auch als ein Frühwarnsystem für die Entscheider vor Ort dienen.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
berbewirtschaftung, Verbuschung und Klimawandel-Was geschieht mit den Bäumen in der Savanne Südafrikas? Ergebnisse einer Agenten-basierten Modellierung des Savannen-Ökosystems in zwei verschiedenen Nutzungsformen Lenfers, U. A.; Glake, D.; Ocker, F.; Clemen, T. Zusammenfassung: Bäume in der Savanne werden in hohem Maße von Tieren und Menschen genutzt. In dieser Studie werden unterschiedliche Baumarten in einem Simulationszeitraum von 2010 bis 2050 unter zwei verschiedenen Klimaszenarien mittel Agenten-basierter Modellierung verglichen. Besondere Betrachtung gilt dem Vergleich zwischen natur-naher Nutzung im Krüger Nationalpark (Elefanten) und einer Nutzung im ländlichen Raum (Feuerholzsammler). Agenten-basierte Modellierung ermöglicht es sowohl aggregierte Biomassewerte aller Bäume über den Zeitverlauf zu beobachten, als auch die verschiedenen Baumarten und Altersgruppen miteinander zu vergleichen. Es zeigt sich, dass bereits innerhalb der Arten und der Altersklassen Veränderungen zu beobachten sind, die in den aggregierten Werten so nicht zu erkennen sind. Auch wenn Bäume sehr langsam auf Veränderungen reagieren, lassen sich aus Altersgruppenverschiebungen und den Veränderungen in der Artenzusammensetzung Tendenzen ableiten, die es erlauben einen Blick in zukünftige Verteilungen unterschiedlicher Baumarten unter verschiedenen Nutzungen zu wagen. Damit können die Ergebnisse dieser Arbeit auch als ein Frühwarnsystem für die Entscheider vor Ort dienen.
Lenfers, Ulfia
2020.
@phdthesis{Lenfers2020,
title = {Current and potential distribution of selected savanna tree species in the South African Lowveld by applying agent-based modeling},
author = {Ulfia Lenfers},
url = {https://www.researchgate.net/publication/343554859_Current_and_potential_distribution_of_selected_savanna_tree_species_in_the_South_African_Lowveld_by_applying_agent-based_modeling},
year = {2020},
date = {2020-08-01},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
Tropmann-Frick, Marina; Clemen, Thomas
Towards Enhancing of Situational Awareness for Cognitive Software Agents Conference
2020.
@conference{Tropmann-Frick2020,
title = {Towards Enhancing of Situational Awareness for Cognitive Software Agents},
author = {Marina Tropmann-Frick and Thomas Clemen},
url = {https://www.researchgate.net/publication/340600619_Towards_Enhancing_of_Situational_Awareness_for_Cognitive_Software_Agents},
year = {2020},
date = {2020-04-01},
abstract = {Software agents have gained increasing attention in the field of creating digital twins of physical, biological, and human entities. The processing of sensory inputs, individual perception, and the selection of suitable actions are essential processes in here, and agent-based frameworks can be utilized for supporting the design, the implementation, and the test. This paper reflects a work-in-progress project at an early stage. However, a conceptual model is presented for an analytical situation awareness component combining agent-based approach and data science algorithms.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Software agents have gained increasing attention in the field of creating digital twins of physical, biological, and human entities. The processing of sensory inputs, individual perception, and the selection of suitable actions are essential processes in here, and agent-based frameworks can be utilized for supporting the design, the implementation, and the test. This paper reflects a work-in-progress project at an early stage. However, a conceptual model is presented for an analytical situation awareness component combining agent-based approach and data science algorithms.
Weyl, Julius; Lenfers, Ulfia; Clemen, Thomas; Glake, Daniel; Panse, Fabian; Ritter, Norbert
LARGE-SCALE TRAFFIC SIMULATION FOR SMART CITY PLANNING WITH MARS Conference
2020.
@conference{Weyl2020,
title = {LARGE-SCALE TRAFFIC SIMULATION FOR SMART CITY PLANNING WITH MARS},
author = {Julius Weyl and Ulfia Lenfers and Thomas Clemen and Daniel Glake and Fabian Panse and Norbert Ritter},
url = {https://www.researchgate.net/publication/338886618_LARGE-SCALE_TRAFFIC_SIMULATION_FOR_SMART_CITY_PLANNING_WITH_MARS},
year = {2020},
date = {2020-01-01},
abstract = {Understanding individual mobility in larger cities is an important success factor for future smart cities. Related simulation scenarios incorporate enormous numbers of agents, with the disadvantage of long run times. In order to provide large-scale and multimodal traffic simulations, we developed MARS V3. Adapting the Modeling and Simulation as a Service (MSaaS) paradigm, a seamless workflow can be provided to the modeling community. An integrated domain-specific language allows model descriptions without a technical overhead. For this study, selected parts of an individual-based traffic model of the City of Hamburg, Germany, were taken as an example. The entire workflow from model development, open data integration, simulation, and result analysis will be described and evaluated. Performance was measured for local and cloud-based simulation execution for up to one million agents. First results show that this concept can be utilized for building decision support systems for smart cities in the near future.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Understanding individual mobility in larger cities is an important success factor for future smart cities. Related simulation scenarios incorporate enormous numbers of agents, with the disadvantage of long run times. In order to provide large-scale and multimodal traffic simulations, we developed MARS V3. Adapting the Modeling and Simulation as a Service (MSaaS) paradigm, a seamless workflow can be provided to the modeling community. An integrated domain-specific language allows model descriptions without a technical overhead. For this study, selected parts of an individual-based traffic model of the City of Hamburg, Germany, were taken as an example. The entire workflow from model development, open data integration, simulation, and result analysis will be described and evaluated. Performance was measured for local and cloud-based simulation execution for up to one million agents. First results show that this concept can be utilized for building decision support systems for smart cities in the near future.
2019
Zhou, Yanling; Clemen, Thomas
Deterministic Dual-stack Query Tree RFID tag anti-collision algorithm Journal Article
In: Journal of Physics: Conference Series, vol. 1423, pp. 012001, 2019.
@article{Zhou2019,
title = {Deterministic Dual-stack Query Tree RFID tag anti-collision algorithm},
author = {Yanling Zhou and Thomas Clemen},
doi = {10.1088/1742-6596/1423/1/012001},
year = {2019},
date = {2019-12-01},
journal = {Journal of Physics: Conference Series},
volume = {1423},
pages = {012001},
abstract = {Tag collision problems are a major issue affecting the performance of RFID systems. The probabilistic tag anti-collision algorithm has tag starvation and cannot identify some tags. This paper proposes a deterministic dual-stack query tree algorithm (DDQT). It successfully implements the anti-collision algorithm of tags by generating new query codes and tag identification functions. At the same time, the DDQT algorithm greatly saves memory space by adding a prefix code stack and a suffix code stack. The DDQT algorithm is simple, and there is no limit on the length of the electronic tag to be queried. Compared with the previous query-tree algorithms, the DDQT algorithm has obvious improvements in query comparison times, empty query times, and occupied memory space. It can effectively remove idle nodes, shorten recognition time and save memory resources, thus improving the speed and accuracy of label recognition to some extent.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tag collision problems are a major issue affecting the performance of RFID systems. The probabilistic tag anti-collision algorithm has tag starvation and cannot identify some tags. This paper proposes a deterministic dual-stack query tree algorithm (DDQT). It successfully implements the anti-collision algorithm of tags by generating new query codes and tag identification functions. At the same time, the DDQT algorithm greatly saves memory space by adding a prefix code stack and a suffix code stack. The DDQT algorithm is simple, and there is no limit on the length of the electronic tag to be queried. Compared with the previous query-tree algorithms, the DDQT algorithm has obvious improvements in query comparison times, empty query times, and occupied memory space. It can effectively remove idle nodes, shorten recognition time and save memory resources, thus improving the speed and accuracy of label recognition to some extent.
Berger, Christian; Bieri, Mari; Bradshaw, Karen; Bruemmer, Christian; Clemen, Thomas; Hickler, Thomas; Kutsch, Werner; Lenfers, Ulfia; Martens, Carola; Midgley, Guy; Mukwashi, Kanisios; Odipo, Victor; Scheiter, Simon; Schmullius, Christiane; Baade, Jussi; Toit, Justin Du; Scholes, Robert; Smit, Izak; Stevens, Nicola; Twine, Wayne
Linking scales and disciplines: an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management Journal Article
In: Climatic Change, vol. 156, 2019.
@article{Berger2019,
title = {Linking scales and disciplines: an interdisciplinary cross-scale approach to supporting climate-relevant ecosystem management},
author = {Christian Berger and Mari Bieri and Karen Bradshaw and Christian Bruemmer and Thomas Clemen and Thomas Hickler and Werner Kutsch and Ulfia Lenfers and Carola Martens and Guy Midgley and Kanisios Mukwashi and Victor Odipo and Simon Scheiter and Christiane Schmullius and Jussi Baade and Justin Du Toit and Robert Scholes and Izak Smit and Nicola Stevens and Wayne Twine},
url = {https://www.researchgate.net/publication/335670261_Linking_scales_and_disciplines_an_interdisciplinary_cross-scale_approach_to_supporting_climate-relevant_ecosystem_management},
doi = {10.1007/s10584-019-02544-0},
year = {2019},
date = {2019-09-01},
journal = {Climatic Change},
volume = {156},
abstract = {Southern Africa is particularly sensitive to climate change, due to both ecological and socio-economic factors, with rural land users among the most vulnerable groups. The provision of information to support climate-relevant decision-making requires an understanding of the projected impacts of change and complex feedbacks within the local ecosystems, as well as local demands on ecosystem services. In this paper, we address the limitation of current approaches for developing management relevant socio-ecological information on the projected impacts of climate change and human activities. We emphasise the need for linking disciplines and approaches by expounding the methodology followed in our two consecutive projects. These projects combine disciplines and levels of measurements from the leaf level (ecophysiology) to the local landscape level (flux measurements) and from the local household level (socio-economic surveys) to the regional level (remote sensing), feeding into a variety of models at multiple scales. Interdisciplinary, multi-scaled, and integrated socio-ecological approaches, as proposed here, are needed to compliment reductionist and linear, scale-specific approaches. Decision support systems are used to integrate and communicate the data and models to the local decision-makers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Southern Africa is particularly sensitive to climate change, due to both ecological and socio-economic factors, with rural land users among the most vulnerable groups. The provision of information to support climate-relevant decision-making requires an understanding of the projected impacts of change and complex feedbacks within the local ecosystems, as well as local demands on ecosystem services. In this paper, we address the limitation of current approaches for developing management relevant socio-ecological information on the projected impacts of climate change and human activities. We emphasise the need for linking disciplines and approaches by expounding the methodology followed in our two consecutive projects. These projects combine disciplines and levels of measurements from the leaf level (ecophysiology) to the local landscape level (flux measurements) and from the local household level (socio-economic surveys) to the regional level (remote sensing), feeding into a variety of models at multiple scales. Interdisciplinary, multi-scaled, and integrated socio-ecological approaches, as proposed here, are needed to compliment reductionist and linear, scale-specific approaches. Decision support systems are used to integrate and communicate the data and models to the local decision-makers.
Glake, Daniel; Weyl, Julius; Lenfers, Ulfia; Clemen, Thomas
SmartOpenHamburg Verkehrssimulation: Automatisierte OpenData Integration für Multi-Agenten Simulationen mit MARS Conference
2019.
@conference{Glake2019,
title = {SmartOpenHamburg Verkehrssimulation: Automatisierte OpenData Integration für Multi-Agenten Simulationen mit MARS},
author = {Daniel Glake and Julius Weyl and Ulfia Lenfers and Thomas Clemen},
year = {2019},
date = {2019-08-01},
abstract = {Die Analyse von geographischen Daten, insbesondere von Straßennetzwerken ist für Stadtplaner und Entscheider von großer Bedeutung. Um Veränderungen in der Stadtentwicklung zu planen, werden häufig Verkehrssimulationen eingesetzt, die zunehmend durch Multi-Agenten Modelle realisiert werden. Die daraus resultierenden Analysemöglichkeiten auf Graphen, Vektordaten und Simulationsergebnisse, sowohl mit zeitlichem Verlauf oder bezogen auf einen festgelegten Zeitpunkt, sind vielfältig. Diese Möglichkeiten werden jedoch häufig durch begrenzte Datenverfügbarkeit- und konsistenz als Simulationsgrundlage eingeschränkt. Um diesen Herausforderungen zu begegnen, wird in dieser Arbeit die MARS OpenData Import Pipeline (https://mars-group.org/smartopenhamburg5/) und ein Ausschnitt des OpenData Werkzeugs vorgestellt, mit dem sich verschiedene OpenData Quellen für spatiale und temporale Daten sammeln und automatisiert in ein gemeinsames Datenmodell integrieren lassen. Der Import ermöglicht die unmittelbare Nutzung der Daten innerhalb einer MARS Simulation zur Bereit-stellung von Agentenumgebungen. Darüber hinaus sind die Daten durch die Verwendung standardisierter GIS Formate auch abseits dessen nutzbar. Wir demonstrieren eine mikroskopische Verkehrssimulation der Stadt Hamburg und erläutern wie diese von der Pipeline aktiv Gebrauch macht.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Die Analyse von geographischen Daten, insbesondere von Straßennetzwerken ist für Stadtplaner und Entscheider von großer Bedeutung. Um Veränderungen in der Stadtentwicklung zu planen, werden häufig Verkehrssimulationen eingesetzt, die zunehmend durch Multi-Agenten Modelle realisiert werden. Die daraus resultierenden Analysemöglichkeiten auf Graphen, Vektordaten und Simulationsergebnisse, sowohl mit zeitlichem Verlauf oder bezogen auf einen festgelegten Zeitpunkt, sind vielfältig. Diese Möglichkeiten werden jedoch häufig durch begrenzte Datenverfügbarkeit- und konsistenz als Simulationsgrundlage eingeschränkt. Um diesen Herausforderungen zu begegnen, wird in dieser Arbeit die MARS OpenData Import Pipeline (https://mars-group.org/smartopenhamburg5/) und ein Ausschnitt des OpenData Werkzeugs vorgestellt, mit dem sich verschiedene OpenData Quellen für spatiale und temporale Daten sammeln und automatisiert in ein gemeinsames Datenmodell integrieren lassen. Der Import ermöglicht die unmittelbare Nutzung der Daten innerhalb einer MARS Simulation zur Bereit-stellung von Agentenumgebungen. Darüber hinaus sind die Daten durch die Verwendung standardisierter GIS Formate auch abseits dessen nutzbar. Wir demonstrieren eine mikroskopische Verkehrssimulation der Stadt Hamburg und erläutern wie diese von der Pipeline aktiv Gebrauch macht.
Michael Köhler-Bußmeier, Alena Störmer
Meta-Analysis of Social Models - Revisiting Cederman’s Emergent Polarity Model Proceeding
University of Hamburg, Department for Informatics and HAW Hamburg, Department for Informatics 2019.
@proceedings{koehler-stoermer19,
title = {Meta-Analysis of Social Models - Revisiting Cederman’s Emergent Polarity Model},
author = {Michael Köhler-Bußmeier, Alena Störmer},
url = {http://edoc.sub.uni-hamburg.de/informatik/volltexte/2019/247/pdf/koehler_stoermer_meta_analysis.pdf},
year = {2019},
date = {2019-05-23},
organization = {University of Hamburg, Department for Informatics and HAW Hamburg, Department for Informatics},
abstract = {In this contribution we analyse the prominent Emergent Polarity Model (EPM) by Eric Cederman from a meta perspective. We vary the model’s “magic” numbers over a wide range of plausible values to obtain concrete model instances of the EPM. Then we studied the sensitivity of the simulation dynamics with respect to variation of these configuration settings. We can cautiously summarise these results as follows: The model’s tendency to decrease the number of states in the long run is quite robust against variation of configurations. But on the other hand one can see that a majority of configurations tends to produce no nation development process at all: The number of states does not decrease significantly. Therefore, we obtain clear evidence that not all configurations lead to nation building while others do. The subsequent research questions that now arises is whether we can characterise those configurations that lead to nation building. And, assuming that we can identify coditions that separate these “effective” configurations from “ineffective” one, we ask wehether these conditions can be interpreted with respect to empirics.},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
In this contribution we analyse the prominent Emergent Polarity Model (EPM) by Eric Cederman from a meta perspective. We vary the model’s “magic” numbers over a wide range of plausible values to obtain concrete model instances of the EPM. Then we studied the sensitivity of the simulation dynamics with respect to variation of these configuration settings. We can cautiously summarise these results as follows: The model’s tendency to decrease the number of states in the long run is quite robust against variation of configurations. But on the other hand one can see that a majority of configurations tends to produce no nation development process at all: The number of states does not decrease significantly. Therefore, we obtain clear evidence that not all configurations lead to nation building while others do. The subsequent research questions that now arises is whether we can characterise those configurations that lead to nation building. And, assuming that we can identify coditions that separate these “effective” configurations from “ineffective” one, we ask wehether these conditions can be interpreted with respect to empirics.
Lenfers, Ulfia; Twine, Wayne; Clemen, Thomas
18.03.2019.
@misc{Lenfers2019,
title = {Bush encroachment, tree pushing, and coppicing in the Greater Kruger – Will there be enough mature trees to sustain the future savanna tree population?},
author = {Ulfia Lenfers and Wayne Twine and Thomas Clemen},
url = {https://www.researchgate.net/publication/331703974_Bush_encroachment_tree_pushing_and_coppicing_in_the_Greater_Kruger_-_Will_there_be_enough_mature_trees_to_sustain_the_future_savanna_tree_population},
year = {2019},
date = {2019-03-18},
abstract = {Trees in savanna ecosystems are highly used by animals and humans. In this study, we compare the different effects of elephant utilization and firewood collector preferences for Sclerocarya birrea (Marula), Senegalia nigrescens (Acacia nigrescens), and Combretum apiculatum. The potential distribution and, therefore, the structure of the savanna ecosystem under different scenarios is determined by the establishment, growth, and mortality of individual trees. A critical step to understand the future distribution of tree species is the understanding of the number of mature trees and especially their dispersal capabilities. Different strategies of the tree species have different effects on usability for elephants and firewood collectors. For example, the high content of carbon in leaves such as in Combretum apiculatum is accompanied by less palatability for the elephants but induces higher firewood quality at the same time. On the other hand, marula trees which are highly impacted by elephants are prized for their edible fruit in rural communities adjacent to the Kruger National Park, and are protected by customary law. It is a criminal offence to cut down living adult marula trees without consent of the local chief. Thus, we find a higher number of large marula trees here. Two different scenarios with elephants and trees on the one side and firewood collectors and trees on the other side where modelled to simulated tree distribution until 2100. We will present our conceptual model and first results of the comparison between the future distribution of mature trees inside and outside the KNP under different elephant management, land use, and IPCC scenarios.},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Trees in savanna ecosystems are highly used by animals and humans. In this study, we compare the different effects of elephant utilization and firewood collector preferences for Sclerocarya birrea (Marula), Senegalia nigrescens (Acacia nigrescens), and Combretum apiculatum. The potential distribution and, therefore, the structure of the savanna ecosystem under different scenarios is determined by the establishment, growth, and mortality of individual trees. A critical step to understand the future distribution of tree species is the understanding of the number of mature trees and especially their dispersal capabilities. Different strategies of the tree species have different effects on usability for elephants and firewood collectors. For example, the high content of carbon in leaves such as in Combretum apiculatum is accompanied by less palatability for the elephants but induces higher firewood quality at the same time. On the other hand, marula trees which are highly impacted by elephants are prized for their edible fruit in rural communities adjacent to the Kruger National Park, and are protected by customary law. It is a criminal offence to cut down living adult marula trees without consent of the local chief. Thus, we find a higher number of large marula trees here. Two different scenarios with elephants and trees on the one side and firewood collectors and trees on the other side where modelled to simulated tree distribution until 2100. We will present our conceptual model and first results of the comparison between the future distribution of mature trees inside and outside the KNP under different elephant management, land use, and IPCC scenarios.
2018
Berger, Christian; Bieri, Mari; Bradshaw, Karen; Bruemmer, Christian; Clemen, Thomas; Hickler, Thomas; Higgins, Steven; Lenfers, Ulfia; Martens, Carola; Midgley, Guy; Scheiter, Simon; Schmullius, Christiane; Stevens, Nicola; Twine, Wayne
EMSAfrica – Ecosystem Management Support for Climate Change in Southern Africa Presentation
01.12.2018.
@misc{Berger2018,
title = {EMSAfrica – Ecosystem Management Support for Climate Change in Southern Africa},
author = {Christian Berger and Mari Bieri and Karen Bradshaw and Christian Bruemmer and Thomas Clemen and Thomas Hickler and Steven Higgins and Ulfia Lenfers and Carola Martens and Guy Midgley and Simon Scheiter and Christiane Schmullius and Nicola Stevens and Wayne Twine},
url = {https://www.researchgate.net/publication/329450645_EMSAfrica_-_Ecosystem_Management_Support_for_Climate_Change_in_Southern_Africa},
doi = {10.13140/RG.2.2.10218.36807},
year = {2018},
date = {2018-12-01},
abstract = {Our poster presented at the 4th South African National Conference on Global Change 2018 presents the main themes of the EMSAfrica project. Southern Africa is particularly sensitive to climate change due to both ecological and socioeconomic factors. Rapidly growing population and threats to the sustainability of ecosystem service delivery at local, regional and national levels pose increasing challenges to policy and land-use decision makers. The German-South African collaborative research project “Ecosystem Management Support for Climate Change in Southern Africa” (EMSAfrica) provides an interdisciplinary, multi-scale approach to inferring management-relevant information on the impacts of climate change and human activities in rural Southern Africa. It is a follow-up of our previous project called “Adaptive Resilience in the South African Ecosystems” (ARS AfricaE, 2014-2018). During ARS AfricaE, we established six observation sites along an aridity gradient in South Africa representing different land use intensities. Our approach combines several disciplines and measurements made at a range of spatial scales, including: measurements of ecosystem-scale carbon fluxes through Eddy Covariance flux tower infrastructures; experiments and observations of plant ecophysiological traits; characterisation of vegetation structure using remote sensing; and socioeconomic surveys of human use of fuelwood. These data are used for creating, calibrating and testing dynamic vegetation and species distribution models, and further, for scaling up the information to the level of biomes. Our final objective is to produce information adapted to the needs of land-use decision makers. To this end, we have set up a cloud-based information system to integrate and operationalise the spatio-temporal data and models of ecosystems and human agents. We will use this system to provide combined and upscalable methods able to generate information that are relevant to land-use management in the local ecosystems of rural Southern Africa.},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
Our poster presented at the 4th South African National Conference on Global Change 2018 presents the main themes of the EMSAfrica project. Southern Africa is particularly sensitive to climate change due to both ecological and socioeconomic factors. Rapidly growing population and threats to the sustainability of ecosystem service delivery at local, regional and national levels pose increasing challenges to policy and land-use decision makers. The German-South African collaborative research project “Ecosystem Management Support for Climate Change in Southern Africa” (EMSAfrica) provides an interdisciplinary, multi-scale approach to inferring management-relevant information on the impacts of climate change and human activities in rural Southern Africa. It is a follow-up of our previous project called “Adaptive Resilience in the South African Ecosystems” (ARS AfricaE, 2014-2018). During ARS AfricaE, we established six observation sites along an aridity gradient in South Africa representing different land use intensities. Our approach combines several disciplines and measurements made at a range of spatial scales, including: measurements of ecosystem-scale carbon fluxes through Eddy Covariance flux tower infrastructures; experiments and observations of plant ecophysiological traits; characterisation of vegetation structure using remote sensing; and socioeconomic surveys of human use of fuelwood. These data are used for creating, calibrating and testing dynamic vegetation and species distribution models, and further, for scaling up the information to the level of biomes. Our final objective is to produce information adapted to the needs of land-use decision makers. To this end, we have set up a cloud-based information system to integrate and operationalise the spatio-temporal data and models of ecosystems and human agents. We will use this system to provide combined and upscalable methods able to generate information that are relevant to land-use management in the local ecosystems of rural Southern Africa.
Lenfers, Ulfia; Clemen, Thomas
01.10.2018.
@misc{Lenfers2018b,
title = {Can ecosystem services be agents? Multi-agent simulation, Goal oriented action planning (GOAP), Ecosystem services, firewood collection},
author = {Ulfia Lenfers and Thomas Clemen},
url = {https://www.researchgate.net/publication/331703865_Can_ecosystem_services_be_agents_Multi-agent_simulation_Goal_oriented_action_planning_GOAP_Ecosystem_services_firewood_collection},
year = {2018},
date = {2018-10-01},
abstract = {How do different human groups act and interact in the same social-ecological system? Multi-agent modelling and simulation (MAMS) can help to find out. A key element of human modelling is how agents plan their behaviour. Goal-oriented action planning (GOAP) allows agents to adapt their behaviour in relation to their own setup, personal traits and the different goals they try to fulfil. GOAP was originally developed by game developers years ago. Additionally, simulating large numbers of agents with complex behaviour demands specialized algorithms and frameworks. The massive multi-agent modelling and simulation framework MARS is under development at Hamburg University of Applied Sciences, Germany. It provides a mechanism to bridge spatial scales from the individual level up to landscapes or even entire countries. To overcome the problem of the static and sometimes non-authentic behaviour of agents we integrated GOAP into MARS. As a proof-of-concept, a firewood collection scenario was developed. In here, competing demands for land use around villages were analysed by simulation runs. Beside human agents, e.g. firewood collectors, we modelled ecosystem services in the landscape by agents also. By that, temporal changes of service provisioning could be easily described. First results show that GOAP is a suitable paradigm for modelling complex and adaptive behaviour in MAMS scenarios. Describing ecosystem services by agents obviously raises the need for large-scale multi-agent modelling and simulation frameworks. MARS can be seen as a proper step in this direction. Our results will form the foundation for a web-based decision-support information system for environmental management in regions with high social-ecological influences like, for example, the Kruger to Canyon (K2C) Biosphere in South Africa.},
keywords = {},
pubstate = {published},
tppubtype = {presentation}
}
How do different human groups act and interact in the same social-ecological system? Multi-agent modelling and simulation (MAMS) can help to find out. A key element of human modelling is how agents plan their behaviour. Goal-oriented action planning (GOAP) allows agents to adapt their behaviour in relation to their own setup, personal traits and the different goals they try to fulfil. GOAP was originally developed by game developers years ago. Additionally, simulating large numbers of agents with complex behaviour demands specialized algorithms and frameworks. The massive multi-agent modelling and simulation framework MARS is under development at Hamburg University of Applied Sciences, Germany. It provides a mechanism to bridge spatial scales from the individual level up to landscapes or even entire countries. To overcome the problem of the static and sometimes non-authentic behaviour of agents we integrated GOAP into MARS. As a proof-of-concept, a firewood collection scenario was developed. In here, competing demands for land use around villages were analysed by simulation runs. Beside human agents, e.g. firewood collectors, we modelled ecosystem services in the landscape by agents also. By that, temporal changes of service provisioning could be easily described. First results show that GOAP is a suitable paradigm for modelling complex and adaptive behaviour in MAMS scenarios. Describing ecosystem services by agents obviously raises the need for large-scale multi-agent modelling and simulation frameworks. MARS can be seen as a proper step in this direction. Our results will form the foundation for a web-based decision-support information system for environmental management in regions with high social-ecological influences like, for example, the Kruger to Canyon (K2C) Biosphere in South Africa.
Lenfers, Ulfia A; Weyl, Julius; Clemen, Thomas
Firewood Collection in South Africa: Adaptive Behavior in Social-Ecological Models Journal Article
In: Land, vol. 7, no. 3, pp. 97, 2018, ISSN: 2073-445X.
@article{Lenfers2018,
title = {Firewood Collection in South Africa: Adaptive Behavior in Social-Ecological Models},
author = {Ulfia A Lenfers and Julius Weyl and Thomas Clemen},
url = {http://www.mdpi.com/2073-445X/7/3/97},
doi = {10.3390/land7030097},
issn = {2073-445X},
year = {2018},
date = {2018-08-01},
journal = {Land},
volume = {7},
number = {3},
pages = {97},
publisher = {Multidisciplinary Digital Publishing Institute},
abstract = {Due to the fact that the South Africa's savanna landscapes are under changing conditions, the previously sustainable firewood collection system in rural areas has become a social-ecological factor in questions about landscape management. While the resilience of savannas in national parks such as Kruger National Park (KNP) in South Africa has been widely acknowledged in ecosystem management, the resilience of woody vegetation outside protected areas has been underappreciated. Collecting wood is the dominant source of energy for rural households, and there is an urgent need for land management to find sustainable solutions for this complex social-ecological system. However, the firewood collection scenario is only one example, and stands for all “human-ecosystem service” interactions under the topic of over-utilization, e.g., fishery, grazing, harvesting. Agent-based modeling combined with goal-oriented action planning (GOAP) can provide fresh insights into the relationship between individual needs of humans and changes in land use. At the same time, this modeling approach includes adaptive behavior under changing conditions. A firewood collection scenario was selected for a proof-of-concept comprising households, collectors, ecosystem services and firewood sites. Our results have shown that, even when it is predictable what a single human agent will do, massive up-scaling is needed in order to understand the whole complexity of social-ecological systems. Under changing conditions, such as climate and an increasing population, fair distribution of natural goods become an important issue.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to the fact that the South Africa's savanna landscapes are under changing conditions, the previously sustainable firewood collection system in rural areas has become a social-ecological factor in questions about landscape management. While the resilience of savannas in national parks such as Kruger National Park (KNP) in South Africa has been widely acknowledged in ecosystem management, the resilience of woody vegetation outside protected areas has been underappreciated. Collecting wood is the dominant source of energy for rural households, and there is an urgent need for land management to find sustainable solutions for this complex social-ecological system. However, the firewood collection scenario is only one example, and stands for all “human-ecosystem service” interactions under the topic of over-utilization, e.g., fishery, grazing, harvesting. Agent-based modeling combined with goal-oriented action planning (GOAP) can provide fresh insights into the relationship between individual needs of humans and changes in land use. At the same time, this modeling approach includes adaptive behavior under changing conditions. A firewood collection scenario was selected for a proof-of-concept comprising households, collectors, ecosystem services and firewood sites. Our results have shown that, even when it is predictable what a single human agent will do, massive up-scaling is needed in order to understand the whole complexity of social-ecological systems. Under changing conditions, such as climate and an increasing population, fair distribution of natural goods become an important issue.
2017
Glake, Daniel; Weyl, Julius; Dohmen, Carolin; Hüning, Christian; Clemen, Thomas
Modeling through Model Transformation with MARS 2.0 Inproceedings
In: Proceedings of the 2017 Spring Simulation Multiconference, Society for Computer Simulation International, Virginia Beach, Virginia, USA, 2017.
@inproceedings{Glake:2017,
title = {Modeling through Model Transformation with MARS 2.0},
author = {Daniel Glake and Julius Weyl and Carolin Dohmen and Christian Hüning and Thomas Clemen},
url = {http://dl.acm.org/citation.cfm?id=3106078.3106080},
year = {2017},
date = {2017-07-01},
booktitle = {Proceedings of the 2017 Spring Simulation Multiconference},
publisher = {Society for Computer Simulation International},
address = {Virginia Beach, Virginia, USA},
series = {ADS '17},
abstract = {The development of simulation models confronts scientists with the necessity of transforming concepts from theoretical models to executable code. Albeit modern simulation platforms provide APIs to abstract away technology, this task remains complex. Therefore a model-to-code transformation is essential, allowing domain experts to focus on their model instead of implementation details. This paper presents a multi-level transformation concept to facilitate building multi-agent simulations for domain experts. With domain- specific tool support, model ideas can be developed without managing technical requirements. This insures that the modeler is exclusively concerned with the conceptual model by utilizing a MARS (Multi-Agent Research and Simulation) Meta-Model (MMM) and Agent Meta-Model (AMM). We outline the MMM as underlying structure, discuss the foundations of model-driven development and the in-place transformation of the MMM as executed by the MARS modeling workflow. In addition, we present a model-to-code generator that creates the final simulation model.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The development of simulation models confronts scientists with the necessity of transforming concepts from theoretical models to executable code. Albeit modern simulation platforms provide APIs to abstract away technology, this task remains complex. Therefore a model-to-code transformation is essential, allowing domain experts to focus on their model instead of implementation details. This paper presents a multi-level transformation concept to facilitate building multi-agent simulations for domain experts. With domain- specific tool support, model ideas can be developed without managing technical requirements. This insures that the modeler is exclusively concerned with the conceptual model by utilizing a MARS (Multi-Agent Research and Simulation) Meta-Model (MMM) and Agent Meta-Model (AMM). We outline the MMM as underlying structure, discuss the foundations of model-driven development and the in-place transformation of the MMM as executed by the MARS modeling workflow. In addition, we present a model-to-code generator that creates the final simulation model.
Dalski, Jan; Hüning, Christian; Clemen, Thomas
An Output and 3D Visualization Concept for the MSAAS System MARS Inproceedings
In: Proceedings of the 2017 Spring Simulation Multiconference, Society for Computer Simulation International, Virginia Beach, Virginia, USA, 2017.
@inproceedings{Dalski:2017,
title = {An Output and 3D Visualization Concept for the MSAAS System MARS},
author = {Jan Dalski and Christian Hüning and Thomas Clemen},
url = {http://dl.acm.org/citation.cfm?id=3106078.3106079},
year = {2017},
date = {2017-07-01},
booktitle = {Proceedings of the 2017 Spring Simulation Multiconference},
publisher = {Society for Computer Simulation International},
address = {Virginia Beach, Virginia, USA},
series = {ADS '17},
abstract = {When running complex and large-scale multi agent simulations, the result preparation and presentation is of high importance to make efficient use of the generated data. In addition to conventional visual analytics dashboards, many use-cases could also benefit from 3D visualization approaches -- especially when dealing with spatial-related simulation scenarios. This paper presents a result output and visualization concept for the MARS (Multi-Agent Research and Simulation) simulation platform. The entire process from output selection and generation up to aggregation and 3D presentation is outlined. In order to facilitate a uniform user experience, the visualization is integrated into the existing MARS web suite and runs directly in the web browser. Because of MARS' suitability for large-scale scenarios with high agent counts and terrains with vast extents, many big data challenges have to be faced in this context. As a proof-of-concept, details from the implementation are showcased at the end of this paper.},
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When running complex and large-scale multi agent simulations, the result preparation and presentation is of high importance to make efficient use of the generated data. In addition to conventional visual analytics dashboards, many use-cases could also benefit from 3D visualization approaches -- especially when dealing with spatial-related simulation scenarios. This paper presents a result output and visualization concept for the MARS (Multi-Agent Research and Simulation) simulation platform. The entire process from output selection and generation up to aggregation and 3D presentation is outlined. In order to facilitate a uniform user experience, the visualization is integrated into the existing MARS web suite and runs directly in the web browser. Because of MARS' suitability for large-scale scenarios with high agent counts and terrains with vast extents, many big data challenges have to be faced in this context. As a proof-of-concept, details from the implementation are showcased at the end of this paper.
Lenfers, Ulfia; Wigley, Benjamin; Ndlovu,; Bruggemann,; Clemen, Thomas
Studies to detect the potential distribution of Sclerocarya birrea in the southern part of the Kruger National Park Presentation
01.03.2017.
@misc{Lenfers2017b,
title = {Studies to detect the potential distribution of Sclerocarya birrea in the southern part of the Kruger National Park},
author = {Ulfia Lenfers and Benjamin Wigley and Ndlovu and Bruggemann and Thomas Clemen},
url = {https://www.researchgate.net/publication/319755338_Studies_to_detect_the_potential_distribution_of_Sclerocarya_birrea_in_the_southern_part_of_the_Kruger_National_Park},
year = {2017},
date = {2017-03-01},
abstract = {A comparison of the current and potential distributions of selected tree species, e.g. Sclerocarya birrea (Marula) could potentially be used to detect shifting species distributions, which will become increasingly important in the light of global climate change. A thorough understanding of the main factors affecting the potential distributions of indicator tree species is therefore necessary. The mathematical concept of partial orders, in combination with Hasse diagrams may help to improve our understanding of the potential distribution of Marula in the southern part of the Kruger National Park (KNP). Correlations between soil properties and the functional traits of Marula will be presented. Two locations within the KNP were sampled in March 2016 to validate these results. For all Marulas within these sections the GPS-coordinates, stem circumference, height, damage class, age class, and stem–stem-distance between Marula trees were measured and analysed. We found differences in age class distributions between the two sites. Surprisingly, despite the fact that young Marulas are generally rare in the KNP almost 50% of the population at one site are not in an adult state.},
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A comparison of the current and potential distributions of selected tree species, e.g. Sclerocarya birrea (Marula) could potentially be used to detect shifting species distributions, which will become increasingly important in the light of global climate change. A thorough understanding of the main factors affecting the potential distributions of indicator tree species is therefore necessary. The mathematical concept of partial orders, in combination with Hasse diagrams may help to improve our understanding of the potential distribution of Marula in the southern part of the Kruger National Park (KNP). Correlations between soil properties and the functional traits of Marula will be presented. Two locations within the KNP were sampled in March 2016 to validate these results. For all Marulas within these sections the GPS-coordinates, stem circumference, height, damage class, age class, and stem–stem-distance between Marula trees were measured and analysed. We found differences in age class distributions between the two sites. Surprisingly, despite the fact that young Marulas are generally rare in the KNP almost 50% of the population at one site are not in an adult state.
Lenfers, Ulfia A; Bruggemann, Rainer; Clemen, Thomas
Exploring survival strategies of African Savanna trees by partial ordering techniques Journal Article
In: Ecological Informatics, vol. 42, pp. 14–23, 2017, ISSN: 15749541.
@article{Lenfers2017,
title = {Exploring survival strategies of African Savanna trees by partial ordering techniques},
author = {Ulfia A Lenfers and Rainer Bruggemann and Thomas Clemen},
url = {http://www.sciencedirect.com/science/article/pii/S1574954117301887},
doi = {10.1016/j.ecoinf.2017.08.008},
issn = {15749541},
year = {2017},
date = {2017-01-01},
journal = {Ecological Informatics},
volume = {42},
pages = {14--23},
abstract = {The resilience of savanna ecosystems to climate and land-use changes is an important ecological and management question. The term ‘resilience’ is used to refer to the ability of a tree species to survive in a specific location, even under changing environmental conditions. In this study, vectors of functional traits of selected savanna tree species are studied by applying partial order algorithms to them. Some ecological interpretations are obtained and are compared to published research. One finding is the high rates of nitrogen fixation for the leaves of Acacia nigrescens. In opposition to this well-known fact, we discovered that Sclerocarya birrea has a bigger average leaf area than the other four tree species. Additionally, we found high carbonate values within the leaf from Colophospermum mopane, Combretum apiculatum, and Terminalis sericea. These results correspond to different ecological strategies for the tree species in question. It became obvious that geometric structures gained from partial ordering show a very good correspondence to ecological strategies of these tree species. Concepts of partial order theory may therefore be helpful in ecosystem research.},
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The resilience of savanna ecosystems to climate and land-use changes is an important ecological and management question. The term ‘resilience’ is used to refer to the ability of a tree species to survive in a specific location, even under changing environmental conditions. In this study, vectors of functional traits of selected savanna tree species are studied by applying partial order algorithms to them. Some ecological interpretations are obtained and are compared to published research. One finding is the high rates of nitrogen fixation for the leaves of Acacia nigrescens. In opposition to this well-known fact, we discovered that Sclerocarya birrea has a bigger average leaf area than the other four tree species. Additionally, we found high carbonate values within the leaf from Colophospermum mopane, Combretum apiculatum, and Terminalis sericea. These results correspond to different ecological strategies for the tree species in question. It became obvious that geometric structures gained from partial ordering show a very good correspondence to ecological strategies of these tree species. Concepts of partial order theory may therefore be helpful in ecosystem research.
2016
Hüning, Christian; Adebahr, Mitja; Thiel-Clemen, Thomas; Dalski, Jan; Lenfers, Ulfia A; Grundmann, Lukas; Dybulla, Janus; Kiker, Gregory A
Modeling & Simulation as a Service with the Massive Multi-Agent System MARS Inproceedings
In: Proceedings of the Agent-Directed Simulation Symposium, pp. 8, Proceedings of the 2016 Spring Simulation Multiconference, San Diego, CA, USA, 2016, ISBN: 978-1-5108-2315-0.
@inproceedings{Hüning2016,
title = {Modeling & Simulation as a Service with the Massive Multi-Agent System MARS},
author = {Christian Hüning and Mitja Adebahr and Thomas Thiel-Clemen and Jan Dalski and Ulfia A Lenfers and Lukas Grundmann and Janus Dybulla and Gregory A Kiker},
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abstract = {There is an increasing demand for very large-scale agent-based models. High numbers of individual entities and complex interactions between them require new ways of modeling and simulation. The creation of a distributed simulation model imposes a major challenge in the fields of network communication and coordination to the developer. Integrating multi-scale GIS and time-series data into such a model is another challenge altogether.
We introduce the massive Multi-Agent Research and Simulation system (MARS). It is designed to provide a Modeling and Simulation as a Service (MSaaS) solution to end users. MARS allows domain experts to integrate their data and models through a user-friendly web interface. The complexity of distributed and scalable simulation is handled in the background by a mechanism we call Agent Shadowing. Finally a layer-based segmentation of the model is proposed. It allows domain specialists to focus on one aspect at a time while developing their simulation model.
A large-scale model from the ecological modeling domain is showcased. The model integrates various GIS data formats with collected time-series datasets and simulates a scalable amount of agents. Results from this simulation demonstrate the capabilities of MARS to support the workflow as required by the development of large-scale agent-based simulation models.},
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There is an increasing demand for very large-scale agent-based models. High numbers of individual entities and complex interactions between them require new ways of modeling and simulation. The creation of a distributed simulation model imposes a major challenge in the fields of network communication and coordination to the developer. Integrating multi-scale GIS and time-series data into such a model is another challenge altogether.
We introduce the massive Multi-Agent Research and Simulation system (MARS). It is designed to provide a Modeling and Simulation as a Service (MSaaS) solution to end users. MARS allows domain experts to integrate their data and models through a user-friendly web interface. The complexity of distributed and scalable simulation is handled in the background by a mechanism we call Agent Shadowing. Finally a layer-based segmentation of the model is proposed. It allows domain specialists to focus on one aspect at a time while developing their simulation model.
A large-scale model from the ecological modeling domain is showcased. The model integrates various GIS data formats with collected time-series datasets and simulates a scalable amount of agents. Results from this simulation demonstrate the capabilities of MARS to support the workflow as required by the development of large-scale agent-based simulation models.
We introduce the massive Multi-Agent Research and Simulation system (MARS). It is designed to provide a Modeling and Simulation as a Service (MSaaS) solution to end users. MARS allows domain experts to integrate their data and models through a user-friendly web interface. The complexity of distributed and scalable simulation is handled in the background by a mechanism we call Agent Shadowing. Finally a layer-based segmentation of the model is proposed. It allows domain specialists to focus on one aspect at a time while developing their simulation model.
A large-scale model from the ecological modeling domain is showcased. The model integrates various GIS data formats with collected time-series datasets and simulates a scalable amount of agents. Results from this simulation demonstrate the capabilities of MARS to support the workflow as required by the development of large-scale agent-based simulation models.
Lenfers, Ulfia A; Brüggemann, R; Thiel-Clemen, Thomas
2016.
@conference{Lenfers2016b,
title = {Von der Komplexität der Wirklichkeit hin zum Modell: Einsatz partieller Ordnungen bei der Modellentwicklung},
author = {Ulfia A Lenfers and R Brüggemann and Thomas Thiel-Clemen},
editor = {Jochen Wittmann and Thomas Thiel-Clemen and Ulfia A Lenfers},
url = {https://www.researchgate.net/publication/304242843_Von_der_Komplexitat_der_Wirklichkeit_hin_zum_Modell_Einsatz_partieller_Ordnungen_bei_der_Modellentwicklung},
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Wagner, Thomas; Moldt, Daniel; Köhler-Bußmeier, Michael
From Hornets to Hybrid Agent and Workflow Systems Conference
International Workshop on Petri Nets and Software Engineering 2016, no. 1591, 2016.
@conference{Wagner2016b,
title = {From Hornets to Hybrid Agent and Workflow Systems},
author = {Thomas Wagner and Daniel Moldt and Michael Köhler-Bußmeier},
editor = {Lawrence Cabac and Lars Kristensen and Heiko Rölke},
url = {http://ceur-ws.org/Vol-1591/paper20.pdf},
year = {2016},
date = {2016-04-01},
booktitle = {International Workshop on Petri Nets and Software Engineering 2016},
number = {1591},
pages = {301-321},
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2015
Thiel-Clemen, Thomas Lenfers Ulfia;
Arbeiten in großen Forschungsteams – Helfen Multi-Agenten Modelle Inproceedings
In: Wittmann, Jochen; Wieland, Ralf (Ed.): Wittmann, Jochen; Wieland, Ralf (Ed.): Simulation in Umwelt- und Geowissenschaften, Workshop Müncheberg, pp. 205-212, 2015.
@inproceedings{Lenfers2015,
title = {Arbeiten in großen Forschungsteams – Helfen Multi-Agenten Modelle},
author = {Thomas Lenfers Ulfia; Thiel-Clemen},
editor = {Jochen Wittmann and Ralf Wieland},
year = {2015},
date = {2015-01-01},
booktitle = {Wittmann, Jochen; Wieland, Ralf (Ed.): Simulation in Umwelt- und Geowissenschaften, Workshop Müncheberg},
pages = {205-212},
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Lenfers, Ulfia; Hüning Christian; Schnoor Alexander; Kiker Greg Thiel-Clemen Thomas;
A Benefit for KNP-Ecologists – Massive Multi-Agent Simulation with MARS Journal Article
In: Poster at Savanna Science Network Meeting, Kruger NP, South Africa, 2015.
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title = {A Benefit for KNP-Ecologists – Massive Multi-Agent Simulation with MARS},
author = {Ulfia; Hüning Christian; Schnoor Alexander; Kiker Greg Thiel-Clemen Thomas; Lenfers},
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Lenfers, Ulfia; Clemen, Thomas
Arbeiten in großen Forschungsteams - Helfen Multi-Agenten Modelle? Inproceedings
In: 2015.
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title = {Arbeiten in großen Forschungsteams - Helfen Multi-Agenten Modelle?},
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2014
Steiman, Daniel
Context-Awareness in Multiagentensimulationen auf Basis von Complex Event Processing Incollection
In: Big Data - Komplexität meistern, vol. 1. Aufl, 2014.
@incollection{Steiman:2014,
title = {Context-Awareness in Multiagentensimulationen auf Basis von Complex Event Processing},
author = {Daniel Steiman},
url = {/wp-content/uploads/papers/Context-Awareness in Multiagentensimulationen auf Basis von Complex Event Processing.pdf},
year = {2014},
date = {2014-09-25},
booktitle = {Big Data - Komplexität meistern},
volume = {1. Aufl},
abstract = {Kontextbewusste Systeme bieten die Möglichkeit, dass Anwendungen ihr Verhalten ohne die aktive Einflussnahme von Anwendern selbstständig an vorherrschende Situationen anpassen. Dazu erfassen sie Kontextdaten, die verarbeitet und zur Steuerung der Anwendung verwendet werden. Aus diesem Grund wurden bereits Toolkits, Frameworks und Ansätze entwickelt, die eine einfache Entwicklung von kontextbewussten Anwendungen ermöglichen sollen. Die bisher auf dem Gebiet der Context-Awareness vorgestellten Arbeiten weisen jedoch Nachteile auf, die einen Einsatz in bestimmten Anwendungsbereichen stark einschränken oder sogar völlig ausschließen. Dazu zählen vor allem Anwendungsbereiche, die den Anspruch haben riesige Mengen von Ereignissen und damit riesige Volumen an Kontextdaten in Echtzeit verarbeiten zu können. Dieses Paper zeigt die Nachteile bestehender Ansätze auf und befasst sich mit der Entwicklung eines Konzepts, mit dem ein breites Spektrum von Anwendungen möglichst einfach kontextbewusst gemacht werden kann. Um die Einsatzfähigkeit und die Performance des entwickelten Konzepts zu untersuchen, wird es in einem prototypischen Fallbeispiel einer Multiagentensimulation verwendet.},
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Kontextbewusste Systeme bieten die Möglichkeit, dass Anwendungen ihr Verhalten ohne die aktive Einflussnahme von Anwendern selbstständig an vorherrschende Situationen anpassen. Dazu erfassen sie Kontextdaten, die verarbeitet und zur Steuerung der Anwendung verwendet werden. Aus diesem Grund wurden bereits Toolkits, Frameworks und Ansätze entwickelt, die eine einfache Entwicklung von kontextbewussten Anwendungen ermöglichen sollen. Die bisher auf dem Gebiet der Context-Awareness vorgestellten Arbeiten weisen jedoch Nachteile auf, die einen Einsatz in bestimmten Anwendungsbereichen stark einschränken oder sogar völlig ausschließen. Dazu zählen vor allem Anwendungsbereiche, die den Anspruch haben riesige Mengen von Ereignissen und damit riesige Volumen an Kontextdaten in Echtzeit verarbeiten zu können. Dieses Paper zeigt die Nachteile bestehender Ansätze auf und befasst sich mit der Entwicklung eines Konzepts, mit dem ein breites Spektrum von Anwendungen möglichst einfach kontextbewusst gemacht werden kann. Um die Einsatzfähigkeit und die Performance des entwickelten Konzepts zu untersuchen, wird es in einem prototypischen Fallbeispiel einer Multiagentensimulation verwendet.
Baldowski, Mariusz; Busch, Jan; Pereki, Hodabalo; Thiel-Clemen, Thomas
Ermittlung der Waldbiomasse mit Hilfe eines spatial gemischten Indikators für den Abdoulaye Forest, Togo Inproceedings
In: Maretis, Dimitris K Wittmann Jochen; (Ed.): Simulation in Umwelt- und Geowissenschaften, pp. 37-49, GI Shaker, 2014, ISBN: 9783844030327.
@inproceedings{Baldowski2014,
title = {Ermittlung der Waldbiomasse mit Hilfe eines spatial gemischten Indikators für den Abdoulaye Forest, Togo},
author = {Mariusz Baldowski and Jan Busch and Hodabalo Pereki and Thomas Thiel-Clemen},
editor = {Dimitris K Wittmann Jochen; Maretis},
url = {/wp-content/uploads/papers/Ermittlung der Waldbiomasse mit Hilfe eines spatial gemischten Indikators für den Abdoulaye Forest.pdf},
isbn = {9783844030327},
year = {2014},
date = {2014-04-27},
booktitle = {Simulation in Umwelt- und Geowissenschaften},
volume = {1. Aufl.},
pages = {37-49},
publisher = {Shaker},
organization = {GI},
series = {Berichte aus der Umweltinformatik},
abstract = {Entwicklungsländer sind die anfälligsten Gebiete für den Klimawandel und klimabedingte Extremereignisse. Um klimatische Veränderungen wie Temperatur, Niederschlag und der damit verbundenen Wasserarmut sowie verstärkten Hochwasserereignissen zu identifizieren, können spatial gemischte Indikatoren zur Erstellung von sogenannten Hotspots herangezogen werden. Diese Gefahrenquellen liefern aktuelle Informationen für gezielte Maßnahmen gegen den Klimawandel. Dabei werden anhand von Segmentierung und Klassifizierung Subindikatoren ermittelt, welche zur Berechnung der Indikatoren benötigt werden, um eine Aussage über ein bestimmtes Gebiet zu treffen. Heterogen skalierte Geodaten erschweren jedoch die Erstellung von spatial gemischten Indikatoren, welche eine homogene Georeferenzierung erfordern. Insbesondere die Verschneidung von punktuell / temporal und spatial heterogenen Daten bleibt unberücksichtigt. Geoinformationssysteme bieten Funktionalitäten zur Segmentierung und Klassifizierung an. Seit kurzem treten Datawarehouses im Bereich der Ökologie als Lösung für die Probleme der entstandenen, heterogen skalierten Daten in den Vordergrund. Anhand eines Use Case in einem Krisengebiet werden Anforderungen gesammelt, um ein System zu erstellen, welches die Integration und Verschneidung der spatio-temporalen Daten über ein Wechselspiel zwischen einem Geoinformationssystem und einem Datawarehouse zur Berechnung von spatial gemischten Indikatoren ermöglicht. Wir stellen dieses System vor und beschreiben den aktuellen Stand der Forschung.},
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Entwicklungsländer sind die anfälligsten Gebiete für den Klimawandel und klimabedingte Extremereignisse. Um klimatische Veränderungen wie Temperatur, Niederschlag und der damit verbundenen Wasserarmut sowie verstärkten Hochwasserereignissen zu identifizieren, können spatial gemischte Indikatoren zur Erstellung von sogenannten Hotspots herangezogen werden. Diese Gefahrenquellen liefern aktuelle Informationen für gezielte Maßnahmen gegen den Klimawandel. Dabei werden anhand von Segmentierung und Klassifizierung Subindikatoren ermittelt, welche zur Berechnung der Indikatoren benötigt werden, um eine Aussage über ein bestimmtes Gebiet zu treffen. Heterogen skalierte Geodaten erschweren jedoch die Erstellung von spatial gemischten Indikatoren, welche eine homogene Georeferenzierung erfordern. Insbesondere die Verschneidung von punktuell / temporal und spatial heterogenen Daten bleibt unberücksichtigt. Geoinformationssysteme bieten Funktionalitäten zur Segmentierung und Klassifizierung an. Seit kurzem treten Datawarehouses im Bereich der Ökologie als Lösung für die Probleme der entstandenen, heterogen skalierten Daten in den Vordergrund. Anhand eines Use Case in einem Krisengebiet werden Anforderungen gesammelt, um ein System zu erstellen, welches die Integration und Verschneidung der spatio-temporalen Daten über ein Wechselspiel zwischen einem Geoinformationssystem und einem Datawarehouse zur Berechnung von spatial gemischten Indikatoren ermöglicht. Wir stellen dieses System vor und beschreiben den aktuellen Stand der Forschung.
Linkov, Igor; Bridges, Todd; Creutzig, Felix; Decker, Jennifer; Fox-Lent, Cate; Kröger, Wolfgang; Lambert, James H; Levermann, Anders; Montreuil, Benoit; Nathwani, Jatin; Nyer, Raymond; Renn, Ortwin; Scharte, Benjamin; Scheffler, Alexander; Schreurs, Miranda; Thiel-Clemen, Thomas
Changing the resilience paradigm Journal Article
In: Nature Climate Change, vol. 4, pp. 407–409, 2014.
@article{Linkov:2014,
title = {Changing the resilience paradigm},
author = {Igor Linkov and Todd Bridges and Felix Creutzig and Jennifer Decker and Cate Fox-Lent and Wolfgang Kröger and James H Lambert and Anders Levermann and Benoit Montreuil and Jatin Nathwani and Raymond Nyer and Ortwin Renn and Benjamin Scharte and Alexander Scheffler and Miranda Schreurs and Thomas Thiel-Clemen},
url = {http://www.nature.com/nclimate/journal/v4/n6/full/nclimate2227.html},
year = {2014},
date = {2014-01-01},
journal = {Nature Climate Change},
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Hüning, Christian; Wilmans, Jason; Feyerabend, Nils; Thiel-Clemen, Thomas
MARS - A next-gen multi-agent simulation framework Inproceedings
In: Wittmann, J; Maretis, D (Ed.): Simulation in Umwelt- und Geowissenschaften, Workshop Osnabrück, GI Shaker, 2014, ISBN: 9783844030327.
@inproceedings{Hüning:2014,
title = {MARS - A next-gen multi-agent simulation framework},
author = {Christian Hüning and Jason Wilmans and Nils Feyerabend and Thomas Thiel-Clemen},
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Thiel-Clemen, Thomas
Vernetzte Sicherheit am Beispiel Kritischer Infrastrukturen Inproceedings
In: Tagungsband Kriminalistik 2014, pp. 81–85, School of Governance, Risk & Compliance, School of Criminal Investigation & Forensic Science 2014.
@inproceedings{ThielClemen:2014,
title = {Vernetzte Sicherheit am Beispiel Kritischer Infrastrukturen},
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Köhler-Bußmeier, Michael
A Survey on Decidability Results for Elementary Object Systems Journal Article
In: Fundamenta Informaticae, vol. 130, no. 1, pp. 99-123, 2014.
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title = {A Survey on Decidability Results for Elementary Object Systems},
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2013
Noetzel, Carsten; Reintjes, Ralf; Thiel-Clemen, Thomas
Die Rolle öffentlicher Verkehrsmittel bei der Übertragung und Verbreitung von Krankheitserregern Inproceedings
In: Handels, H; Ingenerf, J (Ed.): 58. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e.V. (GMDS), 2013.
@inproceedings{Noetzel:2013,
title = {Die Rolle öffentlicher Verkehrsmittel bei der Übertragung und Verbreitung von Krankheitserregern},
author = {Carsten Noetzel and Ralf Reintjes and Thomas Thiel-Clemen},
editor = {H Handels and J Ingenerf},
year = {2013},
date = {2013-01-01},
booktitle = {58. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e.V. (GMDS)},
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Pereki, Hodabalo; Wala, Kperkouma; Thiel-Clemen, Thomas; Bessike, Michael Balinga P; Zida, M; Dourma, Marra; Batawila, Komlan; Akpagana, Koffi
Woody species diversity and important value indices in dense dry forests in Abdoulaye Wildlife Reserve ( Togo , West Africa ) Journal Article
In: International Journal of Biodiversity and Conservation, vol. 5, no. June, pp. 358–366, 2013.
@article{Pereki:2013,
title = {Woody species diversity and important value indices in dense dry forests in Abdoulaye Wildlife Reserve ( Togo , West Africa )},
author = {Hodabalo Pereki and Kperkouma Wala and Thomas Thiel-Clemen and Michael Balinga P Bessike and M Zida and Marra Dourma and Komlan Batawila and Koffi Akpagana},
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year = {2013},
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Thiel-Clemen, Thomas
Designing Good Individual-based Models in Ecology Inproceedings
In: Wittmann, J; Müller, M (Ed.): Simulation in Umwelt- und Geowissenschaften, Workshop Leipzig, pp. 97–106, GI Shaker, 2013.
@inproceedings{ThielClemen:2013b,
title = {Designing Good Individual-based Models in Ecology},
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date = {2013-01-01},
booktitle = {Simulation in Umwelt- und Geowissenschaften, Workshop Leipzig},
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publisher = {Shaker},
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Thiel-Clemen, Thomas
Information Integration in Ecological Informatics and Modelling Inproceedings
In: Wittmann, J; Müller, M (Ed.): Simulation in Umwelt- und Geowissenschaften, Workshop Leipzig, pp. 89–96, GI Shaker, 2013.
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title = {Information Integration in Ecological Informatics and Modelling},
author = {Thomas Thiel-Clemen},
editor = {J Wittmann and M Müller},
year = {2013},
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Pahl, Svend-Anjes; Thiel-Clemen, Thomas
KIS - A Crisis Team Information System Inproceedings
In: Comes, T; Fiedrich, F; Fortier, S; Geldermann, J; Yang, L (Ed.): Proceedings of the 10th International ISCRAM Conference -- Baden-Baden, Germany, May 2013, pp. 632–637, 2013.
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title = {KIS - A Crisis Team Information System},
author = {Svend-Anjes Pahl and Thomas Thiel-Clemen},
editor = {T Comes and F Fiedrich and S Fortier and J Geldermann and L Yang},
year = {2013},
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