TY - JOUR A1 - Myachykov, Andriy A1 - Chapman, Ashley J. A1 - Fischer, Martin H. T1 - Cross-representational interactions BT - Interface and overlap mechanisms JF - Frontiers in psychology N2 - A crucial question facing cognitive science concerns the nature of conceptual representations as well as the constraints on the interactions between them. One specific question we address in this paper is what makes cross-representational interplay possible? We offer two distinct theoretical scenarios: according to the first scenario, co-activated knowledge representations interact with the help of an interface established between them via congruent activation in a mediating third-party general cognitive mechanism, e.g., attention. According to the second scenario, co-activated knowledge representations interact due to an overlap between their features, for example when they share a magnitude component. First, we make a case for cross representational interplay based on grounded and situated theories of cognition. Second, we discuss interface-based interactions between distinct (i.e., non-overlapping) knowledge representations. Third, we discuss how co-activated representations may share their architecture via partial overlap. Finally, we outline constraints regarding the flexibility of these proposed mechanisms. KW - representation KW - cross-representational interaction KW - simulation KW - embodiment KW - grounded cognition Y1 - 2017 SN - 1664-1078 VL - 7 PB - Frontiers Research Foundation CY - Lausanne ER - TY - THES A1 - Panzer, Marcel T1 - Design of a hyper-heuristics based control framework for modular production systems T1 - Design eines auf Hyperheuristiken basierenden Steuerungsframeworks für modulare Produktionssysteme N2 - Volatile supply and sales markets, coupled with increasing product individualization and complex production processes, present significant challenges for manufacturing companies. These must navigate and adapt to ever-shifting external and internal factors while ensuring robustness against process variabilities and unforeseen events. This has a pronounced impact on production control, which serves as the operational intersection between production planning and the shop- floor resources, and necessitates the capability to manage intricate process interdependencies effectively. Considering the increasing dynamics and product diversification, alongside the need to maintain constant production performances, the implementation of innovative control strategies becomes crucial. In recent years, the integration of Industry 4.0 technologies and machine learning methods has gained prominence in addressing emerging challenges in production applications. Within this context, this cumulative thesis analyzes deep learning based production systems based on five publications. Particular attention is paid to the applications of deep reinforcement learning, aiming to explore its potential in dynamic control contexts. Analysis reveal that deep reinforcement learning excels in various applications, especially in dynamic production control tasks. Its efficacy can be attributed to its interactive learning and real-time operational model. However, despite its evident utility, there are notable structural, organizational, and algorithmic gaps in the prevailing research. A predominant portion of deep reinforcement learning based approaches is limited to specific job shop scenarios and often overlooks the potential synergies in combined resources. Furthermore, it highlights the rare implementation of multi-agent systems and semi-heterarchical systems in practical settings. A notable gap remains in the integration of deep reinforcement learning into a hyper-heuristic. To bridge these research gaps, this thesis introduces a deep reinforcement learning based hyper- heuristic for the control of modular production systems, developed in accordance with the design science research methodology. Implemented within a semi-heterarchical multi-agent framework, this approach achieves a threefold reduction in control and optimisation complexity while ensuring high scalability, adaptability, and robustness of the system. In comparative benchmarks, this control methodology outperforms rule-based heuristics, reducing throughput times and tardiness, and effectively incorporates customer and order-centric metrics. The control artifact facilitates a rapid scenario generation, motivating for further research efforts and bridging the gap to real-world applications. The overarching goal is to foster a synergy between theoretical insights and practical solutions, thereby enriching scientific discourse and addressing current industrial challenges. N2 - Volatile Beschaffungs- und Absatzmärkte sowie eine zunehmende Produktindividualisierung konfrontieren Fertigungsunternehmen mit beträchtlichen Herausforderungen. Diese erfordern eine Anpassung der Produktion an sich ständig wechselnde externe Einflüsse und eine hohe Prozessrobustheit gegenüber unvorhersehbaren Schwankungen. Ein Schlüsselelement in diesem Kontext ist die Produktionssteuerung, die als operative Schnittstelle zwischen der Produktions- planung und den Fertigungsressourcen fungiert und eine effiziente Handhabung zahlreicher Prozessinterdependenzen sicherstellen muss. Angesichts dieser gesteigerten Produktionsdynamik und Produktvielfalt rücken innovative Steuerungsansätze in den Vordergrund. In jüngerer Zeit wurden daher verstärkt Industrie-4.0-Ansätze und Methoden des maschinellen Lernens betrachtet. Im Kontext der aktuellen Forschung analysiert die vorliegende kumulative Arbeit Deep-Learning basierte Produktionssysteme anhand von fünf Publikationen. Hierbei wird ein besonderes Augenmerk auf die Anwendungen des Deep Reinforcement Learning gelegt, um dessen Potenzial zu ergründen. Die Untersuchungen zeigen, dass das Deep Reinforcement Learning in vielen Produktionsanwendungen sowohl herkömmlichen Ansätzen als auch an- deren Deep-Learning Werkzeugen überlegen ist. Diese Überlegenheit ergibt sich vor allem aus dem interaktiven Lernprinzip und der direkten Interaktion mit der Umwelt, was es für die dynamische Produktionssteuerung besonders geeignet macht. Dennoch werden strukturelle, organisatorische und algorithmische Forschungslücken identifiziert. Die überwiegende Mehrheit der untersuchten Ansätze fokussiert sich auf Werkstattfertigungen und vernachlässigt dabei potenzielle Prozesssynergien modularer Produktionssysteme. Ferner zeigt sich, dass Multi- Agenten- und Mehr-Ebenen-Systeme sowie die Kombination verschiedener algorithmischer Ansätze nur selten zur Anwendung kommen. Um diese Forschungslücken zu adressieren, wird eine auf Deep Reinforcement Learning basierende Hyper-Heuristik für die Steuerung modularer Produktionssysteme vorgestellt, die nach der Design Science Research Methodology entwickelt wird. Ein semi-heterarchisches Multi-Agenten-System ermöglicht eine dreifache Reduktion der Steuerungs- und Optimierungs- komplexität und gewährleistet gleichzeitig eine hohe Systemadaptabilität und -robustheit. In Benchmarks übertrifft das Steuerungskonzept regelbasierte Ansätze, minimiert Durchlaufzeiten und Verspätungen und berücksichtigt kunden- sowie auftragsorientierte Kennzahlen. Die ent- wickelte Steuerungsmethodik ermöglicht einen schnellen Szenarienentwurf, um dadurch weitere Forschungsbemühungen zu stimulieren und die bestehende Transferlücke zur Realität weiter zu überbrücken. Das Ziel dieser Forschungsarbeit ist es, eine Synergie zwischen theoretischen Erkenntnissen und Praxis-relevanten Lösungen zu schaffen, um sowohl den wissenschaftlichen Diskurs zu bereichern als auch Antworten auf aktuelle industrielle Herausforderungen zu bieten. KW - modular production KW - deep learning KW - modulare Produktion KW - Produktionssteuerung KW - Deep Learning KW - Reinforcement Learning KW - Simulation KW - production control KW - reinforcement learning KW - simulation Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-633006 ER - TY - GEN A1 - Bender, Benedict A1 - Grum, Marcus A1 - Gronau, Norbert A1 - Alfa, Attahiru A1 - Maharaj, B. T. T1 - Design of a worldwide simulation system for distributed cyber-physical production networks T2 - 2019 IEEE International Conference on Engineering, Technology and Innovation (ICE/ITMC) N2 - Modern production infrastructures of globally operating companies usually consist of multiple distributed production sites. While the organization of individual sites consisting of Industry 4.0 components itself is demanding, new questions regarding the organization and allocation of resources emerge considering the total production network. In an attempt to face the challenge of efficient distribution and processing both within and across sites, we aim to provide a hybrid simulation approach as a first step towards optimization. Using hybrid simulation allows us to include real and simulated concepts and thereby benchmark different approaches with reasonable effort. A simulation concept is conceptualized and demonstrated qualitatively using a global multi-site example. KW - production networks KW - geographical distribution KW - task realization strategies KW - Industry 4.0 KW - simulation KW - evaluation Y1 - 2019 SN - 978-1-7281-3401-7 SN - 978-1-7281-3402-4 U6 - https://doi.org/10.1109/ICE.2019.8792609 SN - 2334-315X PB - IEEE CY - New York ER - TY - JOUR A1 - Wetzel, Maria A1 - Kempka, Thomas A1 - Kühn, Michael T1 - Diagenetic trends of synthetic reservoir sandstone properties assessed by digital rock physics JF - Minerals N2 - Quantifying interactions and dependencies among geometric, hydraulic and mechanical properties of reservoir sandstones is of particular importance for the exploration and utilisation of the geological subsurface and can be assessed by synthetic sandstones comprising the microstructural complexity of natural rocks. In the present study, three highly resolved samples of the Fontainebleau, Berea and Bentheim sandstones are generated by means of a process-based approach, which combines the gravity-driven deposition of irregularly shaped grains and their diagenetic cementation by three different schemes. The resulting evolution in porosity, permeability and rock stiffness is examined and compared to the respective micro-computer tomographic (micro-CT) scans. The grain contact-preferential scheme implies a progressive clogging of small throats and consequently produces considerably less connected and stiffer samples than the two other schemes. By contrast, uniform quartz overgrowth continuously alters the pore space and leads to the lowest elastic properties. The proposed stress-dependent cementation scheme combines both approaches of contact-cement and quartz overgrowth, resulting in granulometric, hydraulic and elastic properties equivalent to those of the respective micro-CT scans, where bulk moduli slightly deviate by 0.8%, 4.9% and 2.5% for the Fontainebleau, Berea and Bentheim sandstone, respectively. The synthetic samples can be further altered to examine the impact of mineral dissolution or precipitation as well as fracturing on various petrophysical correlations, which is of particular relevance for numerous aspects of a sustainable subsurface utilisation. KW - digital core reconstruction KW - micro-CT scan KW - pore-scale KW - cementation KW - permeability-porosity relationship KW - elastic rock properties KW - numerical KW - simulation Y1 - 2021 U6 - https://doi.org/10.3390/min11020151 SN - 2075-163X VL - 11 IS - 2 PB - MDPI CY - Basel ER - TY - THES A1 - Konon, Alexander T1 - Essays on career choice under risk and ambiguity T1 - Essays über Karrierewahl unter Risiko und Unsicherheit N2 - This dissertation consists of five self-contained essays, addressing different aspects of career choices, especially the choice of entrepreneurship, under risk and ambiguity. In Chapter 2, the first essay develops an occupational choice model with boundedly rational agents, who lack information, receive noisy feedback, and are restricted in their decisions by their personality, to analyze and explain puzzling empirical evidence on entrepreneurial decision processes. In the second essay, in Chapter 3, I contribute to the literature on entrepreneurial choice by constructing a general career choice model on the basis of the assumption that outcomes are partially ambiguous. The third essay, in Chapter 4, theoretically and empirically analyzes the impact of media on career choices, where information on entrepreneurship provided by the media is treated as an informational shock affecting prior beliefs. The fourth essay, presented in Chapter 5, contains an empirical analysis of the effects of cyclical macro variables (GDP and unemployment) on innovative start-ups in Germany. In the fifth, and last, essay in Chapter 6, we examine whether information on personality is useful for advice, using the example of career advice. N2 - Diese Dissertation besteht aus fünf eigenständigen Aufsätzen, die sich mit verschiedenen Aspekten von Berufswahl, insbesondere der Wahl von Entrepreneurship, unter Risiko und Unsicherheit befassen. In Kapitel 2 entwickelt der erste Aufsatz ein Berufswahlmodell mit begrenzt-rationalen Agenten, die eingeschränkte Information haben, Feedback mit Rauschkomponenten erhalten und in ihren Entscheidungen durch ihre Persönlichkeit eingeschränkt sind, um einige bisher unerklärte Charakteristika von unternehmerischen Entscheidungsprozessen zu analysieren und zu erklären. Im zweiten Aufsatz in Kapitel 3 wird die Literatur zur Karrierewahl durch eine neue Perspektive ergänzt. Der Aufsatz konstruiert ein allgemeines Modell auf der Grundlage der Annahme, dass Entscheidungsergebnisse (teilweise) unsicher sind. Der dritte Aufsatz in Kapitel 4 analysiert theoretisch und empirisch die Auswirkung von Medien auf Berufsentscheidungen. Informationen über Entrepreneurship, die von den Medien zur Verfügung gestellt werden, werden als Informationsschocks behandelt, die vorherige Überzeugungen beeinflussen. Der vierte Aufsatz, der in Kapitel 5 vorgestellt wird, enthält eine empirische Analyse der Auswirkungen von zyklischen, regionalen Makrovariablen (Bruttoinlandsprodukt und Arbeitslosigkeit) auf innovative Start-Ups in Deutschland. Im fünften und letzten Aufsatz in Kapitel 6 untersuchen wir am Beispiel der Berufsberatung, ob Informationen über die Persönlichkeit für Vorhersagen und Empfehlungen nützlich sind. KW - ambiguity KW - entrepreneurship KW - Bayesian learning KW - simulation KW - Unsicherheit KW - Entrepreneurship KW - Bayes'sches Lernen KW - Simulationsmodelle Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-416466 ER - TY - JOUR A1 - Ghahremani, Sona A1 - Giese, Holger T1 - Evaluation of self-healing systems BT - An analysis of the state-of-the-art and required improvements JF - Computers N2 - Evaluating the performance of self-adaptive systems is challenging due to their interactions with often highly dynamic environments. In the specific case of self-healing systems, the performance evaluations of self-healing approaches and their parameter tuning rely on the considered characteristics of failure occurrences and the resulting interactions with the self-healing actions. In this paper, we first study the state-of-the-art for evaluating the performances of self-healing systems by means of a systematic literature review. We provide a classification of different input types for such systems and analyse the limitations of each input type. A main finding is that the employed inputs are often not sophisticated regarding the considered characteristics for failure occurrences. To further study the impact of the identified limitations, we present experiments demonstrating that wrong assumptions regarding the characteristics of the failure occurrences can result in large performance prediction errors, disadvantageous design-time decisions concerning the selection of alternative self-healing approaches, and disadvantageous deployment-time decisions concerning parameter tuning. Furthermore, the experiments indicate that employing multiple alternative input characteristics can help with reducing the risk of premature disadvantageous design-time decisions. KW - self-healing KW - failure model KW - performance KW - simulation KW - evaluation Y1 - 2020 U6 - https://doi.org/10.3390/computers9010016 SN - 2073-431X VL - 9 IS - 1 PB - MDPI CY - Basel ER - TY - GEN A1 - Al-Halbouni, Djamil A1 - Holohan, Eoghan P. A1 - Taheri, Abbas A1 - Schöpfer, Martin P. J. A1 - Emam, Sacha A1 - Dahm, Torsten T1 - Geomechanical modelling of sinkhole development using distinct elements BT - model verification for a single void space and application to the Dead Sea area T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Mechanical and/or chemical removal of material from the subsurface may generate large subsurface cavities, the destabilisation of which can lead to ground collapse and the formation of sinkholes. Numerical simulation of the interaction of cavity growth, host material deformation and overburden collapse is desirable to better understand the sinkhole hazard but is a challenging task due to the involved high strains and material discontinuities. Here, we present 2-D distinct element method numerical simulations of cavity growth and sinkhole development. Firstly, we simulate cavity formation by quasi-static, stepwise removal of material in a single growing zone of an arbitrary geometry and depth. We benchmark this approach against analytical and boundary element method models of a deep void space in a linear elastic material. Secondly, we explore the effects of properties of different uniform materials on cavity stability and sinkhole development. We perform simulated biaxial tests to calibrate macroscopic geotechnical parameters of three model materials representative of those in which sinkholes develop at the Dead Sea shoreline: mud, alluvium and salt. We show that weak materials do not support large cavities, leading to gradual sagging or suffusion-style subsidence. Strong materials support quasi-stable to stable cavities, the overburdens of which may fail suddenly in a caprock or bedrock collapse style. Thirdly, we examine the consequences of layered arrangements of weak and strong materials. We find that these are more susceptible to sinkhole collapse than uniform materials not only due to a lower integrated strength of the overburden but also due to an inhibition of stabilising stress arching. Finally, we compare our model sinkhole geometries to observations at the Ghor Al-Haditha sinkhole site in Jordan. Sinkhole depth ∕ diameter ratios of 0.15 in mud, 0.37 in alluvium and 0.33 in salt are reproduced successfully in the calibrated model materials. The model results suggest that the observed distribution of sinkhole depth ∕ diameter values in each material type may partly reflect sinkhole growth trends. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1061 KW - rock mass KW - karst KW - dissolution KW - reflection KW - subsidence KW - subrosion KW - collapse KW - simulation KW - scale KW - fault Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-468435 SN - 1866-8372 IS - 1061 ER - TY - JOUR A1 - Fritz, Amelie A1 - Makeyeva, Angelina A1 - Staub, Kaspar A1 - Groth, Detlef T1 - Influence of network properties on a migration induced secular height trend by Monte Carlo simulation JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: Recent research reported height biased migration of taller individuals and a Monte Carlo simulation showed that such preferential migration of taller individuals into network hubs can induce a secular trend of height. In the simulation model taller agents in the hubs raise the overall height of all individuals in the network by a community effect. However, it could be seen that the actual network structure influences the strength of this effect. In this paper the background and the influence of the network structure on the strength of the secular trend by migration is investigated. Material and methods: Three principal network types are analyzed: networks derived from street connections in Switzerland, more regular fishing net like networks and randomly generated ones. Our networks have between 10 and 152 nodes and between 20 and 307 edges connecting the nodes. Depending on the network size between 5.000 and 90.000 agents with an average height of 170 cm (SD 6.5 cm) are initially released into the network. In each iteration new agents are regenerated based on the actual average body height of the previous iteration and, to a certain proportion, corrected by body heights in the neighboring nodes. After generating new agents, a certain number of them migrated into neighbor nodes, the model let preferentially taller agents migrate into network hubs. Migration is balanced by back migration of the same number of agents from nodes with high centrality measures to less connected nodes. The latter is random as well, but not biased by the agents height. Furthermore the distribution of agents per node and their correlation to the centrality of the nodes is varied in a systematic manner. After 100 iterations, the secular trend, i.e. the gain in body height for the different networks, is investigated in relation to the network properties. Results: We observe an increase of average agent body height after 100 iterations if height biased migration is enabled. The increase rate depends on the height of the neighboring factor, the population distribution, the relationship between population in the nodes and their centrality as well as on the network topology. Networks with uniform like distributions of the agents in the nodes, uncorrelated associations between node centrality and agent number per node, as well as very heterogeneous networks with very different node centralities lead to biggest gains in average body height. Conclusion: Our simulations show, that height biased migration into network hubs can possibly contribute to the secular trend of height increase in the human population. The strength of this "tall by migration" event depends on the actual properties of the underlying network. There is a possible significance of this mechanism for social networks, when hubs are represented by individuals and edges as their personal relationships. However, the required high number of iterations to achieve significant effects in more natural network structures in our models requires further studies to test the relevance and real effect sizes in real world scenarios. KW - secular trend KW - body height KW - simulation KW - community effect KW - Monte Carlo method KW - network KW - centrality measures Y1 - 2019 U6 - https://doi.org/10.1127/anthranz/2019/1032 SN - 0003-5548 VL - 76 IS - 5 SP - 433 EP - 443 PB - Schweizerbart CY - Stuttgart ER - TY - THES A1 - Wagner, Anja T1 - Konzeption und Aufbau eines Geoinformationssystems zur Modellierung und Simulation von Offenlandschaften N2 - Zwischen 1990 und 1994 wurden rund 1000 Liegenschaften, die in der ehemaligen DDR von der Sowjetarmee und der NVA für militärische Übungen genutzt wurden, an Bund und Länder übergeben. Die größten Truppenübungsplätze liegen in Brandenburg und sind heute teilweise in Großschutzgebiete integriert, andere Plätze werden von der Bundeswehr weiterhin aktiv genutzt. Aufgrund des militärischen Betriebs sind die Böden dieser Truppenübungsplätze oft durch Blindgänger, Munitionsreste, Treibstoff- und Schmierölreste bis hin zu chemischen Kampfstoffen belastet. Allerdings existieren auf fast allen Liegenschaften neben diesen durch Munition und militärische Übungen belasteten Bereichen auch naturschutzfachlich wertvolle Flächen; gerade in den Offenlandbereichen kann dies durchaus mit einer Belastung durch Kampfmittel einhergehen. Charakteristisch für diese offenen Flächen, zu denen u.a. Zwergstrauchheiden, Trockenrasen, wüstenähnliche Sandflächen und andere nährstoffarme baumlose Lebensräume gehören, sind Großflächigkeit, Abgeschiedenheit sowie ihre besondere Nutzung und Bewirtschaftung, d.h. die Abwesenheit von land- und forstwirtschaftlichem Betrieb sowie von Siedlungsflächen. Diese Charakteristik war die Grundlage für die Entwicklung einer speziell angepassten Flora und Fauna. Nach Beendigung des Militärbetriebs setzte dann in weiten Teilen eine großflächige Sukzession – die allmähliche Veränderung der Zusammensetzung von Pflanzen- und Tiergesellschaften – ein, die diese offenen Bereiche teilweise bereits in Wald verwandelte und somit verschwinden ließ. Dies wiederum führte zum Verlust der an diese Offenlandflächen gebundenen Tier- und Pflanzenarten. Zur Erhaltung, Gestaltung und Entwicklung dieser offenen Flächen wurden daher von einer interdisziplinären Gruppe von Naturwissenschaftlern verschiedene Methoden und Konzepte auf ihre jeweilige Wirksamkeit untersucht. So konnten schließlich die für die jeweiligen Standortbedingungen geeigneten Maßnahmen eingeleitet werden. Voraussetzung für die Einleitung der Maßnahmen sind zum einen Kenntnisse zu diesen jeweiligen Standortbedingungen, d.h. zum Ist-Zustand, sowie zur Entwicklung der Flächen, d.h. zur Dynamik. So kann eine Abschätzung über die zukünftige Flächenentwicklung getroffen werden, damit ein effizienter Maßnahmeneinsatz stattfinden kann. Geoinformationssysteme (GIS) spielen dabei eine entscheidende Rolle zur digitalen Dokumentation der Biotop- und Nutzungstypen, da sie die Möglichkeit bieten, raum- und zeitbezogene Geometrie- und Sachdaten in großen Mengen zu verarbeiten. Daher wurde ein fachspezifisches GIS für Truppenübungsplätze entwickelt und implementiert. Die Aufgaben umfassten die Konzeption der Datenbank und des Objektmodells sowie fachspezifischer Modellierungs-, Analyse- und Präsentationsfunktionen. Für die Integration von Fachdaten in die GIS-Datenbank wurde zudem ein Metadatenkatalog entwickelt, der in Form eines zusätzlichen GIS-Tools verfügbar ist. Die Basisdaten für das GIS wurden aus Fernerkundungsdaten, topographischen Karten sowie Geländekartierungen gewonnen. Als Instrument für die Abschätzung der zukünftigen Entwicklung wurde das Simulationstool AST4D entwickelt, in dem sowohl die Nutzung der (Raster-)Daten des GIS als Ausgangsdaten für die Simulationen als auch die Nutzung der Simulationsergebnisse im GIS möglich ist. Zudem können die Daten in AST4D raumbezogen visualisiert werden. Das mathematische Konstrukt für das Tool war ein so genannter Zellulärer Automat, mit dem die Flächenentwicklung unter verschiedenen Voraussetzungen simuliert werden kann. So war die Bildung verschiedener Szenarien möglich, d.h. die Simulation der Flächenentwicklung mit verschiedenen (bekannten) Eingangsparametern und den daraus resultierenden unterschiedlichen (unbekannten) Endzuständen. Vor der Durchführung einer der drei in AST4D möglichen Simulationsstufen können angepasst an das jeweilige Untersuchungsgebiet benutzerspezifische Festlegungen getroffen werden. N2 - Between 1990 and 1994 more than a thousand military properties in East Germany used for military exercise by the Soviet army and the East German forces were handed over to government institutions of the national state and federal states (Laender), respectively. The largest military training areas are located in the federal state of Brandenburg. Some of these are, by now, part of environmentally protected areas, others are still being used by the German forces. As a result of long-lasting military operations the soils of these areas are heavily polluted by ammunition, duds, fuel and lubricants as well as a range of chemicals. Due to these special environmental conditions specifically adapted vegetation and fauna developed in these environments which make these areas valuable from an environmental protection perspective. Unlike other environments in North West Germany these former military training areas are characterised by wideness, separateness as well as the absence of agricultural, forest and settlement land use. This allowed for the development of a characteristic vegetation cover composed of dwarf bush heaths, drying lawns, desert-like sand surfaces and other nutrient-poor treeless habitats. Following the end of military use the process of succession – a gradual change of flora and fauna over space and time – set in. More a than a decade later the former open plains have, in part, developed into forests. The loss of open range land effected the disappearance of adapted animal and plant populations. To retain, preserve and develop these environmentally valuable areas different methods and concepts were examined for the respective effectiveness by multi-disciplinary group of scientists. Prerequisites of the application of methods to preserve the open plains are up-to-date knowledge of local conditions as well as in-depth understanding of the land surface developments and their dynamics, in particular. Based on this expertise the future surface development of these areas can be estimated which, in term, is a prerequisite for selecting the appropriate methods. Geo information systems (GIS) play an important role for the digital documentation and monitoring of biotopes, land use etc as they provide for acquisition, processing and storage of mass geo data including their locational and feature attributes. To make this GIS functionality available for the management and development of former military training areas a dedicated GIS has been developed and implemented. Tasks tackled included a database concept and object model as well as application-specific modelling, analysis and map presentation functions. Integration of relevant spatial and attribute data into this system required a meta data catalogue made available as an add-on GIS tool. Topographic base data for GIS input were taken from remote sensing imagery, topographic maps and additional field surveys. To simulate the development of the former military areas over space and time a specific simulation tool had to be developed as conventional GIS lack dynamic functionalities. The AST4D tool enables the user to utilise existing GIS data. Processed results, in term, can then be used within the GIS application. Additionally AST4D data may be visualised in map form. The AST4D GIS tool is based on the mathematical model of cellular automata. This model allows for the user-defined setting of status quo and simulation of future developments under different input parameters and target conditions. KW - Truppenübungsplatz KW - Offenland KW - Modellierung KW - Analyse KW - Landscape Metrics KW - Simulation KW - Szenarienbildung KW - Zellulärer Automat KW - military plains KW - open range KW - modelling KW - analysis KW - landscape metrics KW - simulation KW - scenarios KW - cellular automata Y1 - 2004 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-0001411 ER - TY - JOUR A1 - Groth, Detlef T1 - Modeling a secular trend by Monte Carlo simulation of height biased migration in a spatial network JF - Anthropologischer Anzeiger : journal of biological and clinical anthropology ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: In a recent Monte Carlo simulation, the clustering of body height of Swiss military conscripts within a spatial network with characteristic features of the natural Swiss geography was investigated. In this study I examined the effect of migration of tall individuals into network hubs on the dynamics of body height within the whole spatial network. The aim of this study was to simulate height trends. Material and methods: Three networks were used for modeling, a regular rectangular fishing net like network, a real world example based on the geographic map of Switzerland, and a random network. All networks contained between 144 and 148 districts and between 265-307 road connections. Around 100,000 agents were initially released with average height of 170 cm, and height standard deviation of 6.5 cm. The simulation was started with the a priori assumption that height variation within a district is limited and also depends on height of neighboring districts (community effect on height). In addition to a neighborhood influence factor, which simulates a community effect, body height dependent migration of conscripts between adjacent districts in each Monte Carlo simulation was used to re-calculate next generation body heights. In order to determine the direction of migration for taller individuals, various centrality measures for the evaluation of district importance within the spatial network were applied. Taller individuals were favored to migrate more into network hubs, backward migration using the same number of individuals was random, not biased towards body height. Network hubs were defined by the importance of a district within the spatial network. The importance of a district was evaluated by various centrality measures. In the null model there were no road connections, height information could not be delivered between the districts. Results: Due to the favored migration of tall individuals into network hubs, average body height of the hubs, and later, of the whole network increased by up to 0.1 cm per iteration depending on the network model. The general increase in height within the network depended on connectedness and on the amount of height information that was exchanged between neighboring districts. If higher amounts of neighborhood height information were exchanged, the general increase in height within the network was large (strong secular trend). The trend in the homogeneous fishnet like network was lowest, the trend in the random network was highest. Yet, some network properties, such as the heteroscedasticity and autocorrelations of the migration simulation models differed greatly from the natural features observed in Swiss military conscript networks. Autocorrelations of district heights for instance, were much higher in the migration models. Conclusion: This study confirmed that secular height trends can be modeled by preferred migration of tall individuals into network hubs. However, basic network properties of the migration simulation models differed greatly from the natural features observed in Swiss military conscripts. Similar network-based data from other countries should be explored to better investigate height trends with Monte Carlo migration approach. KW - secular trend KW - body height KW - simulation KW - community effect KW - Monte Carlo method KW - network Y1 - 2017 U6 - https://doi.org/10.1127/anthranz/2017/0703 SN - 0003-5548 SN - 2363-7099 VL - 74 IS - 1 SP - 81 EP - 88 PB - Schweizerbart CY - Stuttgart ER -