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Sample records for generalization comparing agent-based

  1. Agent-based transportation planning compared with scheduling heuristics

    NARCIS (Netherlands)

    Mes, Martijn; Heijden, van der Matthieu; Harten, van Aart

    2004-01-01

    Here we consider the problem of dynamically assigning vehicles to transportation orders that have di¤erent time windows and should be handled in real time. We introduce a new agent-based system for the planning and scheduling of these transportation networks. Intelligent vehicle agents schedule thei

  2. Agent-based transportation planning compared with scheduling heuristics

    NARCIS (Netherlands)

    Mes, Martijn R.K.; van der Heijden, Matthijs C.; van Harten, Aart

    2004-01-01

    Here we consider the problem of dynamically assigning vehicles to transportation orders that have di¤erent time windows and should be handled in real time. We introduce a new agent-based system for the planning and scheduling of these transportation networks. Intelligent vehicle agents schedule

  3. Comparing stochastic differential equations and agent-based modelling and simulation for early-stage cancer.

    Science.gov (United States)

    Figueredo, Grazziela P; Siebers, Peer-Olaf; Owen, Markus R; Reps, Jenna; Aickelin, Uwe

    2014-01-01

    There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1) Does this new stochastic formulation produce similar results to the agent-based version? (2) Can these methods be used interchangeably? (3) Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.

  4. Comparing stochastic differential equations and agent-based modelling and simulation for early-stage cancer.

    Directory of Open Access Journals (Sweden)

    Grazziela P Figueredo

    Full Text Available There is great potential to be explored regarding the use of agent-based modelling and simulation as an alternative paradigm to investigate early-stage cancer interactions with the immune system. It does not suffer from some limitations of ordinary differential equation models, such as the lack of stochasticity, representation of individual behaviours rather than aggregates and individual memory. In this paper we investigate the potential contribution of agent-based modelling and simulation when contrasted with stochastic versions of ODE models using early-stage cancer examples. We seek answers to the following questions: (1 Does this new stochastic formulation produce similar results to the agent-based version? (2 Can these methods be used interchangeably? (3 Do agent-based models outcomes reveal any benefit when compared to the Gillespie results? To answer these research questions we investigate three well-established mathematical models describing interactions between tumour cells and immune elements. These case studies were re-conceptualised under an agent-based perspective and also converted to the Gillespie algorithm formulation. Our interest in this work, therefore, is to establish a methodological discussion regarding the usability of different simulation approaches, rather than provide further biological insights into the investigated case studies. Our results show that it is possible to obtain equivalent models that implement the same mechanisms; however, the incapacity of the Gillespie algorithm to retain individual memory of past events affects the similarity of some results. Furthermore, the emergent behaviour of ABMS produces extra patters of behaviour in the system, which was not obtained by the Gillespie algorithm.

  5. Mobile Agent-Based Software Systems Modeling Approaches: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Aissam Belghiat

    2016-06-01

    Full Text Available Mobile agent-based applications are special type of software systems which take the advantages of mobile agents in order to provide a new beneficial paradigm to solve multiple complex problems in several fields and areas such as network management, e-commerce, e-learning, etc. Likewise, we notice lack of real applications based on this paradigm and lack of serious evaluations of their modeling approaches. Hence, this paper provides a comparative study of modeling approaches of mobile agent-based software systems. The objective is to give the reader an overview and a thorough understanding of the work that has been done and where the gaps in the research are.

  6. GENERALIZED LANDSCAPE THEORY: AGENT-BASED APPROACH TO ALLIANCE FORMATIONS IN CIVIL AVIATION INDUSTRY

    Institute of Scientific and Technical Information of China (English)

    Kyoichi Kijima

    2001-01-01

    The purpose of this paper is to generalize Landscape theory proposed by R.Axelrod and, then, to apply it to the civil aviation industry for simulating alliance formations in it. Landscape theory provides a well-known agent-based simulation model for analyzing alliance (or coalition) formation process. When a set N of agents or autonomous decision makers is given, the theory assumes that each agent tries to make a coalition in such a way that the resulting alliance minimizes its frustration. The theory is essentially based on two premises. One is that a propensity is symmetric,i.e., the propensity of agent i toward j is exactly the same as that of j toward i for anyagents i and j in N. The other is that the number of alliances is restricted to two, i.e., at any moment N is partitioned into two parties. Though the two basic premises underpin the theory and make the model simple and operational, they do not always reflect alliance formation processes in a realistic way. A generalized Landscape theory that this paper proposes removes them and allows asymmetric propensity and existence of alliances of any number. Since the premises are essential for the model, the generalization requires a drastic reconstruction of the whole idea of the theory. Finally, we analyze a real alliance formation process in the civil aviation industry.This analysis provides interesting insights about the industry as well as some validation of our generalized Landscape theory.

  7. Comparing Simulation Output Accuracy of Discrete Event and Agent Based Models: A Quantitive Approach

    CERN Document Server

    Majid, Mazlina Abdul; Siebers, Peer-Olaf

    2010-01-01

    In our research we investigate the output accuracy of discrete event simulation models and agent based simulation models when studying human centric complex systems. In this paper we focus on human reactive behaviour as it is possible in both modelling approaches to implement human reactive behaviour in the model by using standard methods. As a case study we have chosen the retail sector, and here in particular the operations of the fitting room in the women wear department of a large UK department store. In our case study we looked at ways of determining the efficiency of implementing new management policies for the fitting room operation through modelling the reactive behaviour of staff and customers of the department. First, we have carried out a validation experiment in which we compared the results from our models to the performance of the real system. This experiment also allowed us to establish differences in output accuracy between the two modelling methids. In a second step a multi-scenario experimen...

  8. Building v/s Exploring Models: Comparing Learning of Evolutionary Processes through Agent-based Modeling

    Science.gov (United States)

    Wagh, Aditi

    Two strands of work motivate the three studies in this dissertation. Evolutionary change can be viewed as a computational complex system in which a small set of rules operating at the individual level result in different population level outcomes under different conditions. Extensive research has documented students' difficulties with learning about evolutionary change (Rosengren et al., 2012), particularly in terms of levels slippage (Wilensky & Resnick, 1999). Second, though building and using computational models is becoming increasingly common in K-12 science education, we know little about how these two modalities compare. This dissertation adopts agent-based modeling as a representational system to compare these modalities in the conceptual context of micro-evolutionary processes. Drawing on interviews, Study 1 examines middle-school students' productive ways of reasoning about micro-evolutionary processes to find that the specific framing of traits plays a key role in whether slippage explanations are cued. Study 2, which was conducted in 2 schools with about 150 students, forms the crux of the dissertation. It compares learning processes and outcomes when students build their own models or explore a pre-built model. Analysis of Camtasia videos of student pairs reveals that builders' and explorers' ways of accessing rules, and sense-making of observed trends are of a different character. Builders notice rules through available blocks-based primitives, often bypassing their enactment while explorers attend to rules primarily through the enactment. Moreover, builders' sense-making of observed trends is more rule-driven while explorers' is more enactment-driven. Pre and posttests reveal that builders manifest a greater facility with accessing rules, providing explanations manifesting targeted assembly. Explorers use rules to construct explanations manifesting non-targeted assembly. Interviews reveal varying degrees of shifts away from slippage in both

  9. Comparing large-scale computational approaches to epidemic modeling: Agent-based versus structured metapopulation models

    Directory of Open Access Journals (Sweden)

    Merler Stefano

    2010-06-01

    Full Text Available Abstract Background In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. Methods We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. Results The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age

  10. An integrated ant colony optimization approach to compare strategies of clearing market in electricity markets. Agent-based simulation

    Energy Technology Data Exchange (ETDEWEB)

    Azadeh, A.; Maleki-Shoja, B. [Department of Industrial Engineering and Center of Excellence for Intelligent Experimental Mechanics, College of Engineering, University of Tehran (Iran); Skandari, M.R. [Department of Industrial Engineering, University of Florida, Gainesville (United States)

    2010-10-15

    In this paper, an innovative model of agent based simulation, based on Ant Colony Optimization (ACO) algorithm is proposed in order to compare three available strategies of clearing wholesale electricity markets, i.e. uniform, pay-as-bid, and generalized Vickrey rules. The supply side actors of the power market are modeled as adaptive agents who learn how to bid strategically to optimize their profit through indirect interaction with other actors of the market. The proposed model is proper for bidding functions with high number of dimensions and enables modelers to avoid curse of dimensionality as dimension grows. Test systems are then used to study the behavior of each pricing rule under different degrees of competition and heterogeneity. Finally, the pricing rules are comprehensively compared using different economic criteria such as average cleared price, efficiency of allocation, and price volatility. Also, principle component analysis (PCA) is used to rank and select the best price rule. To the knowledge of the authors, this is the first study that uses ACO for assessing strategies of wholesale electricity market. (author)

  11. An integrated ant colony optimization approach to compare strategies of clearing market in electricity markets: Agent-based simulation

    Energy Technology Data Exchange (ETDEWEB)

    Azadeh, A., E-mail: aazadeh@ut.ac.i [Department of Industrial Engineering and Center of Excellence for Intelligent Experimental Mechanics, College of Engineering, University of Tehran (Iran, Islamic Republic of); Skandari, M.R. [Department of Industrial Engineering, University of Florida, Gainesville (United States); Maleki-Shoja, B. [Department of Industrial Engineering and Center of Excellence for Intelligent Experimental Mechanics, College of Engineering, University of Tehran (Iran, Islamic Republic of)

    2010-10-15

    In this paper, an innovative model of agent based simulation, based on Ant Colony Optimization (ACO) algorithm is proposed in order to compare three available strategies of clearing wholesale electricity markets, i.e. uniform, pay-as-bid, and generalized Vickrey rules. The supply side actors of the power market are modeled as adaptive agents who learn how to bid strategically to optimize their profit through indirect interaction with other actors of the market. The proposed model is proper for bidding functions with high number of dimensions and enables modelers to avoid curse of dimensionality as dimension grows. Test systems are then used to study the behavior of each pricing rule under different degrees of competition and heterogeneity. Finally, the pricing rules are comprehensively compared using different economic criteria such as average cleared price, efficiency of allocation, and price volatility. Also, principle component analysis (PCA) is used to rank and select the best price rule. To the knowledge of the authors, this is the first study that uses ACO for assessing strategies of wholesale electricity market.

  12. Comparing administered and market-based water allocation systems through a consistent agent-based modeling framework.

    Science.gov (United States)

    Zhao, Jianshi; Cai, Ximing; Wang, Zhongjing

    2013-07-15

    Water allocation can be undertaken through administered systems (AS), market-based systems (MS), or a combination of the two. The debate on the performance of the two systems has lasted for decades but still calls for attention in both research and practice. This paper compares water users' behavior under AS and MS through a consistent agent-based modeling framework for water allocation analysis that incorporates variables particular to both MS (e.g., water trade and trading prices) and AS (water use violations and penalties/subsidies). Analogous to the economic theory of water markets under MS, the theory of rational violation justifies the exchange of entitled water under AS through the use of cross-subsidies. Under water stress conditions, a unique water allocation equilibrium can be achieved by following a simple bargaining rule that does not depend upon initial market prices under MS, or initial economic incentives under AS. The modeling analysis shows that the behavior of water users (agents) depends on transaction, or administrative, costs, as well as their autonomy. Reducing transaction costs under MS or administrative costs under AS will mitigate the effect that equity constraints (originating with primary water allocation) have on the system's total net economic benefits. Moreover, hydrologic uncertainty is shown to increase market prices under MS and penalties/subsidies under AS and, in most cases, also increases transaction, or administrative, costs.

  13. Comparing System Dynamics and Agent-Based Simulation for Tumour Growth and its Interactions with Effector Cells

    CERN Document Server

    Figueredo, Grazziela P

    2011-01-01

    There is little research concerning comparisons and combination of System Dynamics Simulation (SDS) and Agent Based Simulation (ABS). ABS is a paradigm used in many levels of abstraction, including those levels covered by SDS. We believe that the establishment of frameworks for the choice between these two simulation approaches would contribute to the simulation research. Hence, our work aims for the establishment of directions for the choice between SDS and ABS approaches for immune system-related problems. Previously, we compared the use of ABS and SDS for modelling agents' behaviour in an environment with nomovement or interactions between these agents. We concluded that for these types of agents it is preferable to use SDS, as it takes up less computational resources and produces the same results as those obtained by the ABS model. In order to move this research forward, our next research question is: if we introduce interactions between these agents will SDS still be the most appropriate paradigm to be u...

  14. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  15. Modeling and simulation of complex systems a framework for efficient agent-based modeling and simulation

    CERN Document Server

    Siegfried, Robert

    2014-01-01

    Robert Siegfried presents a framework for efficient agent-based modeling and simulation of complex systems. He compares different approaches for describing structure and dynamics of agent-based models in detail. Based on this evaluation the author introduces the "General Reference Model for Agent-based Modeling and Simulation" (GRAMS). Furthermore he presents parallel and distributed simulation approaches for execution of agent-based models -from small scale to very large scale. The author shows how agent-based models may be executed by different simulation engines that utilize underlying hard

  16. Cross-site comparison of land-use decision-making and its consequences across land systems with a generalized agent-based model.

    Science.gov (United States)

    Magliocca, Nicholas R; Brown, Daniel G; Ellis, Erle C

    2014-01-01

    Local changes in land use result from the decisions and actions of land-users within land systems, which are structured by local and global environmental, economic, political, and cultural contexts. Such cross-scale causation presents a major challenge for developing a general understanding of how local decision-making shapes land-use changes at the global scale. This paper implements a generalized agent-based model (ABM) as a virtual laboratory to explore how global and local processes influence the land-use and livelihood decisions of local land-users, operationalized as settlement-level agents, across the landscapes of six real-world test sites. Test sites were chosen in USA, Laos, and China to capture globally-significant variation in population density, market influence, and environmental conditions, with land systems ranging from swidden to commercial agriculture. Publicly available global data were integrated into the ABM to model cross-scale effects of economic globalization on local land-use decisions. A suite of statistics was developed to assess the accuracy of model-predicted land-use outcomes relative to observed and random (i.e. null model) landscapes. At four of six sites, where environmental and demographic forces were important constraints on land-use choices, modeled land-use outcomes were more similar to those observed across sites than the null model. At the two sites in which market forces significantly influenced land-use and livelihood decisions, the model was a poorer predictor of land-use outcomes than the null model. Model successes and failures in simulating real-world land-use patterns enabled the testing of hypotheses on land-use decision-making and yielded insights on the importance of missing mechanisms. The virtual laboratory approach provides a practical framework for systematic improvement of both theory and predictive skill in land change science based on a continual process of experimentation and model enhancement.

  17. Cross-site comparison of land-use decision-making and its consequences across land systems with a generalized agent-based model.

    Directory of Open Access Journals (Sweden)

    Nicholas R Magliocca

    Full Text Available Local changes in land use result from the decisions and actions of land-users within land systems, which are structured by local and global environmental, economic, political, and cultural contexts. Such cross-scale causation presents a major challenge for developing a general understanding of how local decision-making shapes land-use changes at the global scale. This paper implements a generalized agent-based model (ABM as a virtual laboratory to explore how global and local processes influence the land-use and livelihood decisions of local land-users, operationalized as settlement-level agents, across the landscapes of six real-world test sites. Test sites were chosen in USA, Laos, and China to capture globally-significant variation in population density, market influence, and environmental conditions, with land systems ranging from swidden to commercial agriculture. Publicly available global data were integrated into the ABM to model cross-scale effects of economic globalization on local land-use decisions. A suite of statistics was developed to assess the accuracy of model-predicted land-use outcomes relative to observed and random (i.e. null model landscapes. At four of six sites, where environmental and demographic forces were important constraints on land-use choices, modeled land-use outcomes were more similar to those observed across sites than the null model. At the two sites in which market forces significantly influenced land-use and livelihood decisions, the model was a poorer predictor of land-use outcomes than the null model. Model successes and failures in simulating real-world land-use patterns enabled the testing of hypotheses on land-use decision-making and yielded insights on the importance of missing mechanisms. The virtual laboratory approach provides a practical framework for systematic improvement of both theory and predictive skill in land change science based on a continual process of experimentation and model

  18. Agent-Based Cloud Computing

    OpenAIRE

    Sim, Kwang Mong

    2012-01-01

    Agent-based cloud computing is concerned with the design and development of software agents for bolstering cloud service\\ud discovery, service negotiation, and service composition. The significance of this work is introducing an agent-based paradigm for\\ud constructing software tools and testbeds for cloud resource management. The novel contributions of this work include: 1) developing\\ud Cloudle: an agent-based search engine for cloud service discovery, 2) showing that agent-based negotiatio...

  19. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...

  20. Intelligent Complex Evolutionary Agent-Based Systems

    Science.gov (United States)

    Iantovics, Barna; Enǎchescu, Cǎlin

    2009-04-01

    In this paper, we investigate the possibility to develop intelligent agent-based complex systems that use evolutionary learning techniques in order to adapt for the efficient solving of the problems by reorganizing their structure. For this investigation is proposed a complex multiagent system called EAMS (Evolutionary Adaptive Multiagent System), which using an evolutionary learning technique can learn different patterns of reorganization. The realized study proves that evolutionary techniques successfully can be used to create complex multiagent systems capable to intelligently reorganize their structure during their life cycle. The practical establishment of the intelligence of a computational system in generally, an agent-based system in particularly consists in how efficiently and flexibly the system can solve difficult problems.

  1. An Agent Based Classification Model

    CERN Document Server

    Gu, Feng; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, principles and models which are applied to prob- lem solving. The Dendritic Cell Algorithm (DCA)[2] is an AIS algorithm that is developed specifi cally for anomaly detection. It has been successfully applied to intrusion detection in computer security. It is believed that agent-based mod- elling is an ideal approach for implementing AIS, as intelligent agents could be the perfect representations of immune entities in AIS. This model evaluates the feasibility of re-implementing the DCA in an agent-based simulation environ- ...

  2. Agent Based Reasoning in Multilevel Flow Modeling

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2012-01-01

    to launch the MFM Workbench into an agent based environment, which can complement disadvantages of the original software. The agent-based MFM Workbench is centered on a concept called “Blackboard System” and use an event based mechanism to arrange the reasoning tasks. This design will support the new...

  3. Agent-based Modelling, a new kind of research

    DEFF Research Database (Denmark)

    Held, Fabian P.; Wilkinson, Ian F.; Marks, Robert E.

    2014-01-01

    We discuss the use of Agent-based Modelling for the development and testing of theories about emergent social phenomena in marketing and the social sciences in general. We address both theoretical aspects about the types of phenomena that are suitably addressed with this approach and practical...

  4. Agent-Based Design for E-learning Environment

    Directory of Open Access Journals (Sweden)

    Khadidja Harbouche

    2007-01-01

    Full Text Available We presented an agent-based e-learning environment. Our aim was to allow many users to interact collectively and intelligently with the environment. In this cooperation model, human users and artificial agents carry out tasks in the learners’ service. We define the internal structure of our kernel supposed to work within Internet/Intranet settings. Design was structured in three parts: individual learning space, collaborative space, and cooperative space. We advocate the employment of an agent-based approach, a suitable for two main reasons: agents were a natural metaphor of human acts, and the learning systems are generally complex. Prometheus methodology used for the design and emphasis placed on the agent-based features.

  5. Russian and Foreign Experience of Integration of Agent-Based Models and Geographic Information Systems

    Directory of Open Access Journals (Sweden)

    Konstantin Anatol’evich Gulin

    2016-11-01

    Full Text Available The article provides an overview of the mechanisms of integration of agent-based models and GIS technology developed by Russian and foreign researchers. The basic framework of the article is based on critical analysis of domestic and foreign literature (monographs, scientific articles. The study is based on the application of universal scientific research methods: system approach, analysis and synthesis, classification, systematization and grouping, generalization and comparison. The article presents theoretical and methodological bases of integration of agent-based models and geographic information systems. The concept and essence of agent-based models are explained; their main advantages (compared to other modeling methods are identified. The paper characterizes the operating environment of agents as a key concept in the theory of agent-based modeling. It is shown that geographic information systems have a wide range of information resources for calculations, searching, modeling of the real world in various aspects, acting as an effective tool for displaying the agents’ operating environment and allowing to bring the model as close as possible to the real conditions. The authors also focus on a wide range of possibilities for various researches in different spatial and temporal contexts. Comparative analysis of platforms supporting the integration of agent-based models and geographic information systems has been carried out. The authors give examples of complex socio-economic models: the model of a creative city, humanitarian assistance model. In the absence of standards for research results description, the authors focus on the models’ elements such as the characteristics of the agents and their operation environment, agents’ behavior, rules of interaction between the agents and the external environment. The paper describes the possibilities and prospects of implementing these models

  6. General practitioners and energy healers compared

    DEFF Research Database (Denmark)

    Ostenfeld-Rosenthal, Ann

    Purpose The purpose of the research project was to compare MUS patients’ experience of respectively GP consultation rituals and spiritual healing rituals. Background Medically unexplained symptoms (MUS) are defined as: physical symptoms for which no adequate physiological basis can be found...... paradigm constitutes an obstacle for the GP to offer the MUS patients the best treatment and support. The paper concludes with some reflections on what constitutes ‘the good healer’....

  7. Agent-based modeling of sustainable behaviors

    CERN Document Server

    Sánchez-Maroño, Noelia; Fontenla-Romero, Oscar; Polhill, J; Craig, Tony; Bajo, Javier; Corchado, Juan

    2017-01-01

    Using the O.D.D. (Overview, Design concepts, Detail) protocol, this title explores the role of agent-based modeling in predicting the feasibility of various approaches to sustainability. The chapters incorporated in this volume consist of real case studies to illustrate the utility of agent-based modeling and complexity theory in discovering a path to more efficient and sustainable lifestyles. The topics covered within include: households' attitudes toward recycling, designing decision trees for representing sustainable behaviors, negotiation-based parking allocation, auction-based traffic signal control, and others. This selection of papers will be of interest to social scientists who wish to learn more about agent-based modeling as well as experts in the field of agent-based modeling.

  8. Modeling of Agile Manufacturing Execution Systems with an Agent-based Approach

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Agile manufacturing execution systems (AMES) are used to help manufacturers optimize shop floor production in an agile way. And the modeling of AMES is the key issue of realizing AMES. This paper presents an agent-based approach to AMES modeling. Firstly, the characteristics of AMES and its requirements on modeling are discussed. Secondly, a comparative analysis of modeling methods is carried out, and AMES modeling using an agent-based approach is put forward. Agent-based modeling method not only inherit ...

  9. Agent-based modeling and network dynamics

    CERN Document Server

    Namatame, Akira

    2016-01-01

    The book integrates agent-based modeling and network science. It is divided into three parts, namely, foundations, primary dynamics on and of social networks, and applications. The book begins with the network origin of agent-based models, known as cellular automata, and introduce a number of classic models, such as Schelling’s segregation model and Axelrod’s spatial game. The essence of the foundation part is the network-based agent-based models in which agents follow network-based decision rules. Under the influence of the substantial progress in network science in late 1990s, these models have been extended from using lattices into using small-world networks, scale-free networks, etc. The book also shows that the modern network science mainly driven by game-theorists and sociophysicists has inspired agent-based social scientists to develop alternative formation algorithms, known as agent-based social networks. The book reviews a number of pioneering and representative models in this family. Upon the gi...

  10. Agent-based Modelling, a new kind of research

    DEFF Research Database (Denmark)

    Held, Fabian P.; Wilkinson, Ian F.; Marks, Robert E.;

    2014-01-01

    We discuss the use of Agent-based Modelling for the development and testing of theories about emergent social phenomena in marketing and the social sciences in general. We address both theoretical aspects about the types of phenomena that are suitably addressed with this approach and practical gu...... development. The main goal of this paper was to make research on complex social systems more accessible and help anticipate and structure the research process. © 2014 Australian and New Zealand Marketing Academy.......We discuss the use of Agent-based Modelling for the development and testing of theories about emergent social phenomena in marketing and the social sciences in general. We address both theoretical aspects about the types of phenomena that are suitably addressed with this approach and practical...

  11. Agent Based Model of Young Researchers in Higher Education Institutions

    Directory of Open Access Journals (Sweden)

    Josip Stepanic

    2013-04-01

    Full Text Available Group of young researchers in higher education institutions in general perform demandable tasks with relatively high contribution to institutions’ and societies’ innovation production. In order to analyse in more details interaction among young researchers and diverse institutions in society, we aim toward developing the numerical simulation, agent-based model.This article presents foundations of the model, preliminary results of its simulation along with perspectives of its further development and improvements.

  12. Essays in Agent-Based Macro and Monetary Economics

    OpenAIRE

    Lengnick, Matthias

    2015-01-01

    This dissertation consists of three major parts. The first part (chapter 2 and 3) presents different models which integrate macroeconomics with agent-based financial markets. These models feature bounded rational expectations. They are applied to analyse the impact of financial market speculation on the macro economy in general and the performance of several kinds of financial transaction taxes as well as conventional and unconventional monetary policy in particular. The second part (chapter ...

  13. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V. cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  14. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn, Ellen-Wien; Doldersum, Tom; Useya, Juliana; Augustijn, Denie

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse d

  15. Agent based computational model of trust

    NARCIS (Netherlands)

    A. Gorobets (Alexander); B. Nooteboom (Bart)

    2004-01-01

    textabstractThis paper employs the methodology of Agent-Based Computational Economics (ACE) to investigate under what conditions trust can be viable in markets. The emergence and breakdown of trust is modeled in a context of multiple buyers and suppliers. Agents adapt their trust in a partner, the w

  16. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn-Beckers, Petronella; Doldersum, Tom; Useya, Juliana; Augustijn, Dionysius C.M.

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  17. Agent-based simulation of animal behaviour

    NARCIS (Netherlands)

    C.M. Jonker (Catholijn); J. Treur

    1998-01-01

    textabstract In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for

  18. Agent Based Modeling Applications for Geosciences

    Science.gov (United States)

    Stein, J. S.

    2004-12-01

    Agent-based modeling techniques have successfully been applied to systems in which complex behaviors or outcomes arise from varied interactions between individuals in the system. Each individual interacts with its environment, as well as with other individuals, by following a set of relatively simple rules. Traditionally this "bottom-up" modeling approach has been applied to problems in the fields of economics and sociology, but more recently has been introduced to various disciplines in the geosciences. This technique can help explain the origin of complex processes from a relatively simple set of rules, incorporate large and detailed datasets when they exist, and simulate the effects of extreme events on system-wide behavior. Some of the challenges associated with this modeling method include: significant computational requirements in order to keep track of thousands to millions of agents, methods and strategies of model validation are lacking, as is a formal methodology for evaluating model uncertainty. Challenges specific to the geosciences, include how to define agents that control water, contaminant fluxes, climate forcing and other physical processes and how to link these "geo-agents" into larger agent-based simulations that include social systems such as demographics economics and regulations. Effective management of limited natural resources (such as water, hydrocarbons, or land) requires an understanding of what factors influence the demand for these resources on a regional and temporal scale. Agent-based models can be used to simulate this demand across a variety of sectors under a range of conditions and determine effective and robust management policies and monitoring strategies. The recent focus on the role of biological processes in the geosciences is another example of an area that could benefit from agent-based applications. A typical approach to modeling the effect of biological processes in geologic media has been to represent these processes in

  19. Empirically Based, Agent-based models

    Directory of Open Access Journals (Sweden)

    Elinor Ostrom

    2006-12-01

    Full Text Available There is an increasing drive to combine agent-based models with empirical methods. An overview is provided of the various empirical methods that are used for different kinds of questions. Four categories of empirical approaches are identified in which agent-based models have been empirically tested: case studies, stylized facts, role-playing games, and laboratory experiments. We discuss how these different types of empirical studies can be combined. The various ways empirical techniques are used illustrate the main challenges of contemporary social sciences: (1 how to develop models that are generalizable and still applicable in specific cases, and (2 how to scale up the processes of interactions of a few agents to interactions among many agents.

  20. Improving Agent Based Modeling of Critical Incidents

    Directory of Open Access Journals (Sweden)

    Robert Till

    2010-04-01

    Full Text Available Agent Based Modeling (ABM is a powerful method that has been used to simulate potential critical incidents in the infrastructure and built environments. This paper will discuss the modeling of some critical incidents currently simulated using ABM and how they may be expanded and improved by using better physiological modeling, psychological modeling, modeling the actions of interveners, introducing Geographic Information Systems (GIS and open source models.

  1. Agent-based simulation of animal behaviour

    OpenAIRE

    Jonker, C.M.; Treur, J.

    1998-01-01

    In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for multi-agent systems DESIRE and its software environment supports the conceptual and detailed design, and execution of these models. Experiments reported in the literature on animal behaviour have been simulated for a num...

  2. Assurance in Agent-Based Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gilliom, Laura R.; Goldsmith, Steven Y.

    1999-05-10

    Our vision of the future of information systems is one that includes engineered collectives of software agents which are situated in an environment over years and which increasingly improve the performance of the overall system of which they are a part. At a minimum, the movement of agent and multi-agent technology into National Security applications, including their use in information assurance, is apparent today. The use of deliberative, autonomous agents in high-consequence/high-security applications will require a commensurate level of protection and confidence in the predictability of system-level behavior. At Sandia National Laboratories, we have defined and are addressing a research agenda that integrates the surety (safety, security, and reliability) into agent-based systems at a deep level. Surety is addressed at multiple levels: The integrity of individual agents must be protected by addressing potential failure modes and vulnerabilities to malevolent threats. Providing for the surety of the collective requires attention to communications surety issues and mechanisms for identifying and working with trusted collaborators. At the highest level, using agent-based collectives within a large-scale distributed system requires the development of principled design methods to deliver the desired emergent performance or surety characteristics. This position paper will outline the research directions underway at Sandia, will discuss relevant work being performed elsewhere, and will report progress to date toward assurance in agent-based systems.

  3. Evolutionary game theory using agent-based methods.

    Science.gov (United States)

    Adami, Christoph; Schossau, Jory; Hintze, Arend

    2016-12-01

    Evolutionary game theory is a successful mathematical framework geared towards understanding the selective pressures that affect the evolution of the strategies of agents engaged in interactions with potential conflicts. While a mathematical treatment of the costs and benefits of decisions can predict the optimal strategy in simple settings, more realistic settings such as finite populations, non-vanishing mutations rates, stochastic decisions, communication between agents, and spatial interactions, require agent-based methods where each agent is modeled as an individual, carries its own genes that determine its decisions, and where the evolutionary outcome can only be ascertained by evolving the population of agents forward in time. While highlighting standard mathematical results, we compare those to agent-based methods that can go beyond the limitations of equations and simulate the complexity of heterogeneous populations and an ever-changing set of interactors. We conclude that agent-based methods can predict evolutionary outcomes where purely mathematical treatments cannot tread (for example in the weak selection-strong mutation limit), but that mathematics is crucial to validate the computational simulations.

  4. Comparative Study of Algorithms for Automated Generalization of Linear Objects

    Science.gov (United States)

    Azimjon, S.; Gupta, P. K.; Sukhmani, R. S. G. S.

    2014-11-01

    Automated generalization, rooted from conventional cartography, has become an increasing concern in both geographic information system (GIS) and mapping fields. All geographic phenomenon and the processes are bound to the scale, as it is impossible for human being to observe the Earth and the processes in it without decreasing its scale. To get optimal results, cartographers and map-making agencies develop set of rules and constraints, however these rules are under consideration and topic for many researches up until recent days. Reducing map generating time and giving objectivity is possible by developing automated map generalization algorithms (McMaster and Shea, 1988). Modification of the scale traditionally is a manual process, which requires knowledge of the expert cartographer, and it depends on the experience of the user, which makes the process very subjective as every user may generate different map with same requirements. However, automating generalization based on the cartographic rules and constrains can give consistent result. Also, developing automated system for map generation is the demand of this rapid changing world. The research that we have conveyed considers only generalization of the roads, as it is one of the indispensable parts of a map. Dehradun city, Uttarakhand state of India was selected as a study area. The study carried out comparative study of the generalization software sets, operations and algorithms available currently, also considers advantages and drawbacks of the existing software used worldwide. Research concludes with the development of road network generalization tool and with the final generalized road map of the study area, which explores the use of open source python programming language and attempts to compare different road network generalization algorithms. Thus, the paper discusses the alternative solutions for automated generalization of linear objects using GIS-technologies. Research made on automated of road network

  5. Agent-based Algorithm for Spatial Distribution of Objects

    KAUST Repository

    Collier, Nathan

    2012-06-02

    In this paper we present an agent-based algorithm for the spatial distribution of objects. The algorithm is a generalization of the bubble mesh algorithm, initially created for the point insertion stage of the meshing process of the finite element method. The bubble mesh algorithm treats objects in space as bubbles, which repel and attract each other. The dynamics of each bubble are approximated by solving a series of ordinary differential equations. We present numerical results for a meshing application as well as a graph visualization application.

  6. Many-body methods in agent-based epidemic models

    CERN Document Server

    Nakamura, Gilberto M

    2016-01-01

    The susceptible-infected-susceptible (SIS) agent-based model is usually employed in the investigation of epidemics. The model describes a Markov process for a single communicable disease among susceptible (S) and infected (I) agents. However, the disease spreading forecasting is often restricted to numerical simulations, while analytic formulations lack both general results and perturbative approaches since they are subjected to asymmetric time generators. Here, we discuss perturbation theory, approximations and application of many-body techniques in epidemic models in the framework for squared norm of probability vector $|P(t)| ^2$, in which asymmetric time generators are replaced by their symmetric counterparts.

  7. Multiscale agent-based consumer market modeling.

    Energy Technology Data Exchange (ETDEWEB)

    North, M. J.; Macal, C. M.; St. Aubin, J.; Thimmapuram, P.; Bragen, M.; Hahn, J.; Karr, J.; Brigham, N.; Lacy, M. E.; Hampton, D.; Decision and Information Sciences; Procter & Gamble Co.

    2010-05-01

    Consumer markets have been studied in great depth, and many techniques have been used to represent them. These have included regression-based models, logit models, and theoretical market-level models, such as the NBD-Dirichlet approach. Although many important contributions and insights have resulted from studies that relied on these models, there is still a need for a model that could more holistically represent the interdependencies of the decisions made by consumers, retailers, and manufacturers. When the need is for a model that could be used repeatedly over time to support decisions in an industrial setting, it is particularly critical. Although some existing methods can, in principle, represent such complex interdependencies, their capabilities might be outstripped if they had to be used for industrial applications, because of the details this type of modeling requires. However, a complementary method - agent-based modeling - shows promise for addressing these issues. Agent-based models use business-driven rules for individuals (e.g., individual consumer rules for buying items, individual retailer rules for stocking items, or individual firm rules for advertizing items) to determine holistic, system-level outcomes (e.g., to determine if brand X's market share is increasing). We applied agent-based modeling to develop a multi-scale consumer market model. We then conducted calibration, verification, and validation tests of this model. The model was successfully applied by Procter & Gamble to several challenging business problems. In these situations, it directly influenced managerial decision making and produced substantial cost savings.

  8. Agent-based modeling and simulation

    CERN Document Server

    Taylor, Simon

    2014-01-01

    Operational Research (OR) deals with the use of advanced analytical methods to support better decision-making. It is multidisciplinary with strong links to management science, decision science, computer science and many application areas such as engineering, manufacturing, commerce and healthcare. In the study of emergent behaviour in complex adaptive systems, Agent-based Modelling & Simulation (ABMS) is being used in many different domains such as healthcare, energy, evacuation, commerce, manufacturing and defense. This collection of articles presents a convenient introduction to ABMS with pa

  9. An Agent-Based Distributed Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    J.Li; J.Y.H.Fuh; Y.F.Zhang; A.Y.C.Nee

    2006-01-01

    Agent theories have shown their promising capability in solving distributed complex system ever since its development. In this paper, one multi-agent based distributed product design and manufacturing planning system is presented. The objective of the research is to develop a distributed collaborative design environment for supporting cooperation among the existing engineering functions. In the system, the functional agents for design, manufacturability evaluation,process planning and scheduling are efficiently integrated with a facilitator agent. This paper firstly gives an introduction to the system structure, and the definitions for each executive agent are then described and a prototype of the proposed is also included at the end part.

  10. Agent-based Cloud service composition

    OpenAIRE

    Sim, Kwang Mong; Gutierrez-Garcia, J. Octavio

    2013-01-01

    Service composition in multi-Cloud environments\\ud must coordinate self-interested participants, automate\\ud service selection, (re)configure distributed services, and deal\\ud with incomplete information about Cloud providers and\\ud their services. This work proposes an agent-based approach\\ud to compose services in multi-Cloud environments for different\\ud types of Cloud services: one-time virtualized services,\\ud e.g., processing a rendering job, persistent virtualized services,\\ud e.g., in...

  11. Agent-based transport simulation versus equilibrium assignment for private vehicle traffic in Gauteng

    CSIR Research Space (South Africa)

    Fourie, PJ

    2010-08-01

    Full Text Available This paper compares the performance of an agent-based microsimulation technology (MATSim) with that of an established equilibrium assignment model (EMME/2) for the private vehicle traffic demands description from the Gauteng Transportation Study...

  12. Comparing Adherence in Cardiac Clinic Versus General Outpatient ...

    African Journals Online (AJOL)

    Scale-8 (MMAS-8) is not an interval scale, the mean score cannot be compared by t-test as ... In general, facility-based studies pose a threat of “social desirability bias” in assessing adherence as patients tend to hide poor adherence from ...

  13. Agent-based modelling in synthetic biology.

    Science.gov (United States)

    Gorochowski, Thomas E

    2016-11-30

    Biological systems exhibit complex behaviours that emerge at many different levels of organization. These span the regulation of gene expression within single cells to the use of quorum sensing to co-ordinate the action of entire bacterial colonies. Synthetic biology aims to make the engineering of biology easier, offering an opportunity to control natural systems and develop new synthetic systems with useful prescribed behaviours. However, in many cases, it is not understood how individual cells should be programmed to ensure the emergence of a required collective behaviour. Agent-based modelling aims to tackle this problem, offering a framework in which to simulate such systems and explore cellular design rules. In this article, I review the use of agent-based models in synthetic biology, outline the available computational tools, and provide details on recently engineered biological systems that are amenable to this approach. I further highlight the challenges facing this methodology and some of the potential future directions. © 2016 The Author(s).

  14. An Agent-Based Monetary Production Simulation Model

    DEFF Research Database (Denmark)

    Bruun, Charlotte

    2006-01-01

    An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable......An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable...

  15. An Agent-Based Monetary Production Simulation Model

    DEFF Research Database (Denmark)

    Bruun, Charlotte

    2006-01-01

    An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable......An Agent-Based Simulation Model Programmed in Objective Borland Pascal. Program and source code is downloadable...

  16. Spatial interactions in agent-based modeling

    CERN Document Server

    Ausloos, Marcel; Merlone, Ugo

    2014-01-01

    Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution o...

  17. Agent based modeling in tactical wargaming

    Science.gov (United States)

    James, Alex; Hanratty, Timothy P.; Tuttle, Daniel C.; Coles, John B.

    2016-05-01

    Army staffs at division, brigade, and battalion levels often plan for contingency operations. As such, analysts consider the impact and potential consequences of actions taken. The Army Military Decision-Making Process (MDMP) dictates identification and evaluation of possible enemy courses of action; however, non-state actors often do not exhibit the same level and consistency of planned actions that the MDMP was originally designed to anticipate. The fourth MDMP step is a particular challenge, wargaming courses of action within the context of complex social-cultural behaviors. Agent-based Modeling (ABM) and its resulting emergent behavior is a potential solution to model terrain in terms of the human domain and improve the results and rigor of the traditional wargaming process.

  18. Econophysics of agent-based models

    CERN Document Server

    Aoyama, Hideaki; Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2014-01-01

    The primary goal of this book is to present the research findings and conclusions of physicists, economists, mathematicians and financial engineers working in the field of "Econophysics" who have undertaken agent-based modelling, comparison with empirical studies and related investigations. Most standard economic models assume the existence of the representative agent, who is “perfectly rational” and applies the utility maximization principle when taking action. One reason for this is the desire to keep models mathematically tractable: no tools are available to economists for solving non-linear models of heterogeneous adaptive agents without explicit optimization. In contrast, multi-agent models, which originated from statistical physics considerations, allow us to go beyond the prototype theories of traditional economics involving the representative agent. This book is based on the Econophys-Kolkata VII Workshop, at which many such modelling efforts were presented. In the book, leading researchers in the...

  19. Agent based reasoning for the non-linear stochastic models of long-range memory

    Science.gov (United States)

    Kononovicius, A.; Gontis, V.

    2012-02-01

    We extend Kirman's model by introducing variable event time scale. The proposed flexible time scale is equivalent to the variable trading activity observed in financial markets. Stochastic version of the extended Kirman's agent based model is compared to the non-linear stochastic models of long-range memory in financial markets. The agent based model providing matching macroscopic description serves as a microscopic reasoning of the earlier proposed stochastic model exhibiting power law statistics.

  20. Markov chain aggregation for agent-based models

    CERN Document Server

    Banisch, Sven

    2016-01-01

    This self-contained text develops a Markov chain approach that makes the rigorous analysis of a class of microscopic models that specify the dynamics of complex systems at the individual level possible. It presents a general framework of aggregation in agent-based and related computational models, one which makes use of lumpability and information theory in order to link the micro and macro levels of observation. The starting point is a microscopic Markov chain description of the dynamical process in complete correspondence with the dynamical behavior of the agent-based model (ABM), which is obtained by considering the set of all possible agent configurations as the state space of a huge Markov chain. An explicit formal representation of a resulting “micro-chain” including microscopic transition rates is derived for a class of models by using the random mapping representation of a Markov process. The type of probability distribution used to implement the stochastic part of the model, which defines the upd...

  1. Validating agent based models through virtual worlds.

    Energy Technology Data Exchange (ETDEWEB)

    Lakkaraju, Kiran; Whetzel, Jonathan H.; Lee, Jina; Bier, Asmeret Brooke; Cardona-Rivera, Rogelio E.; Bernstein, Jeremy Ray Rhythm

    2014-01-01

    As the US continues its vigilance against distributed, embedded threats, understanding the political and social structure of these groups becomes paramount for predicting and dis- rupting their attacks. Agent-based models (ABMs) serve as a powerful tool to study these groups. While the popularity of social network tools (e.g., Facebook, Twitter) has provided extensive communication data, there is a lack of ne-grained behavioral data with which to inform and validate existing ABMs. Virtual worlds, in particular massively multiplayer online games (MMOG), where large numbers of people interact within a complex environ- ment for long periods of time provide an alternative source of data. These environments provide a rich social environment where players engage in a variety of activities observed between real-world groups: collaborating and/or competing with other groups, conducting battles for scarce resources, and trading in a market economy. Strategies employed by player groups surprisingly re ect those seen in present-day con icts, where players use diplomacy or espionage as their means for accomplishing their goals. In this project, we propose to address the need for ne-grained behavioral data by acquiring and analyzing game data a commercial MMOG, referred to within this report as Game X. The goals of this research were: (1) devising toolsets for analyzing virtual world data to better inform the rules that govern a social ABM and (2) exploring how virtual worlds could serve as a source of data to validate ABMs established for analogous real-world phenomena. During this research, we studied certain patterns of group behavior to compliment social modeling e orts where a signi cant lack of detailed examples of observed phenomena exists. This report outlines our work examining group behaviors that underly what we have termed the Expression-To-Action (E2A) problem: determining the changes in social contact that lead individuals/groups to engage in a particular behavior

  2. Pattern-oriented modeling of agent-based complex systems: Lessons from ecology

    Science.gov (United States)

    Grimm, Volker; Revilla, Eloy; Berger, Uta; Jeltsch, Florian; Mooij, Wolf M.; Railsback, Steven F.; Thulke, Hans-Hermann; Weiner, Jacob; Wiegand, Thorsten; DeAngelis, Donald L.

    2005-01-01

    Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and agent-based models. No general framework for designing, testing, and analyzing bottom-up models has yet been established, but recent advances in ecological modeling have come together in a general strategy we call pattern-oriented modeling. This strategy provides a unifying framework for decoding the internal organization of agent-based complex systems and may lead toward unifying algorithmic theories of the relation between adaptive behavior and system complexity.

  3. Pattern-oriented modeling of agent-based complex systems: lessons from ecology.

    Science.gov (United States)

    Grimm, Volker; Revilla, Eloy; Berger, Uta; Jeltsch, Florian; Mooij, Wolf M; Railsback, Steven F; Thulke, Hans-Hermann; Weiner, Jacob; Wiegand, Thorsten; DeAngelis, Donald L

    2005-11-11

    Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and agent-based models. No general framework for designing, testing, and analyzing bottom-up models has yet been established, but recent advances in ecological modeling have come together in a general strategy we call pattern-oriented modeling. This strategy provides a unifying framework for decoding the internal organization of agent-based complex systems and may lead toward unifying algorithmic theories of the relation between adaptive behavior and system complexity.

  4. Agent Based Model of Livestock Movements

    Science.gov (United States)

    Miron, D. J.; Emelyanova, I. V.; Donald, G. E.; Garner, G. M.

    The modelling of livestock movements within Australia is of national importance for the purposes of the management and control of exotic disease spread, infrastructure development and the economic forecasting of livestock markets. In this paper an agent based model for the forecasting of livestock movements is presented. This models livestock movements from farm to farm through a saleyard. The decision of farmers to sell or buy cattle is often complex and involves many factors such as climate forecast, commodity prices, the type of farm enterprise, the number of animals available and associated off-shore effects. In this model the farm agent's intelligence is implemented using a fuzzy decision tree that utilises two of these factors. These two factors are the livestock price fetched at the last sale and the number of stock on the farm. On each iteration of the model farms choose either to buy, sell or abstain from the market thus creating an artificial supply and demand. The buyers and sellers then congregate at the saleyard where livestock are auctioned using a second price sealed bid. The price time series output by the model exhibits properties similar to those found in real livestock markets.

  5. Agent-based modeling in ecological economics.

    Science.gov (United States)

    Heckbert, Scott; Baynes, Tim; Reeson, Andrew

    2010-01-01

    Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.

  6. An agent-based approach to financial stylized facts

    Science.gov (United States)

    Shimokawa, Tetsuya; Suzuki, Kyoko; Misawa, Tadanobu

    2007-06-01

    An important challenge of the financial theory in recent years is to construct more sophisticated models which have consistencies with as many financial stylized facts that cannot be explained by traditional models. Recently, psychological studies on decision making under uncertainty which originate in Kahneman and Tversky's research attract a lot of interest as key factors which figure out the financial stylized facts. These psychological results have been applied to the theory of investor's decision making and financial equilibrium modeling. This paper, following these behavioral financial studies, would like to propose an agent-based equilibrium model with prospect theoretical features of investors. Our goal is to point out a possibility that loss-averse feature of investors explains vast number of financial stylized facts and plays a crucial role in price formations of financial markets. Price process which is endogenously generated through our model has consistencies with, not only the equity premium puzzle and the volatility puzzle, but great kurtosis, asymmetry of return distribution, auto-correlation of return volatility, cross-correlation between return volatility and trading volume. Moreover, by using agent-based simulations, the paper also provides a rigorous explanation from the viewpoint of a lack of market liquidity to the size effect, which means that small-sized stocks enjoy excess returns compared to large-sized stocks.

  7. Statistical Agent Based Modelization of the Phenomenon of Drug Abuse

    Science.gov (United States)

    di Clemente, Riccardo; Pietronero, Luciano

    2012-07-01

    We introduce a statistical agent based model to describe the phenomenon of drug abuse and its dynamical evolution at the individual and global level. The agents are heterogeneous with respect to their intrinsic inclination to drugs, to their budget attitude and social environment. The various levels of drug use were inspired by the professional description of the phenomenon and this permits a direct comparison with all available data. We show that certain elements have a great importance to start the use of drugs, for example the rare events in the personal experiences which permit to overcame the barrier of drug use occasionally. The analysis of how the system reacts to perturbations is very important to understand its key elements and it provides strategies for effective policy making. The present model represents the first step of a realistic description of this phenomenon and can be easily generalized in various directions.

  8. Statistical Agent Based Modelization of the Phenomenon of Drug Abuse

    CERN Document Server

    Di Clemente, Riccardo; 10.1038/srep00532

    2012-01-01

    We introduce a statistical agent based model to describe the phenomenon of drug abuse and its dynamical evolution at the individual and global level. The agents are heterogeneous with respect to their intrinsic inclination to drugs, to their budget attitude and social environment. The various levels of drug use were inspired by the professional description of the phenomenon and this permits a direct comparison with all available data. We show that certain elements have a great importance to start the use of drugs, for example the rare events in the personal experiences which permit to overcame the barrier of drug use occasionally. The analysis of how the system reacts to perturbations is very important to understand its key elements and it provides strategies for effective policy making. The present model represents the first step of a realistic description of this phenomenon and can be easily generalized in various directions.

  9. Agent-based multi-optional model of innovations diffusion

    CERN Document Server

    Laciana, Carlos E

    2013-01-01

    We propose a formalism that allows the study of the process of diffusion of several products competing in a common market. It is based on the generalization of the statistics Ising model (Potts model). For the implementation, agent based modeling is used, applied to a problem of three options; to adopt a product A, a product B, or non-adoption. A launching strategy is analyzed for one of the two products, which delays its launching with the objective of competing with improvements. The proportion reached by one and another product is calculated at market saturation. The simulations are produced varying the social network topology, the uncertainty in the decision, and the population's homogeneity.

  10. New family of generalized metrics for comparative imaging system evaluation

    Science.gov (United States)

    Russ, M.; Singh, V.; Loughran, B.; Bednarek, D. R.; Rudin, S.

    2015-03-01

    A family of imaging task-specific metrics designated Relative Object Detectability (ROD) metrics was developed to enable objective, quantitative comparisons of different x-ray systems. Previously, ROD was defined as the integral over spatial frequencies of the Fourier Transform of the object function, weighted by the detector DQE for one detector, divided by the comparable integral for another detector. When effects of scatter and focal spot unsharpness are included, the generalized metric, GDQE, is substituted for the DQE, resulting in the G-ROD metric. The G-ROD was calculated for two different detectors with two focal spot sizes using various-sized simulated objects to quantify the improved performance of new high-resolution CMOS detector systems. When a measured image is used as the object, a Generalized Measured Relative Object Detectability (GM-ROD) value can be generated. A neuro-vascular stent (Wingspan) was imaged with the high-resolution Micro-Angiographic Fluoroscope (MAF) and a standard flat panel detector (FPD) for comparison using the GM-ROD calculation. As the lower integration bound increased from 0 toward the detector Nyquist frequency, increasingly superior performance of the MAF was evidenced. Another new metric, the R-ROD, enables comparing detectors to a reference detector of given imaging ability. R-RODs for the MAF, a new CMOS detector and an FPD will be presented. The ROD family of metrics can provide quantitative more understandable comparisons for different systems where the detector, focal spot, scatter, object, techniques or dose are varied and can be used to optimize system selection for given imaging tasks.

  11. Return Migration After Brain Drain: An Agent Based Simulation Approach

    CERN Document Server

    Biondo, A E; Rapisarda, A

    2012-01-01

    The Brain Drain phenomenon is particularly heterogeneous and is characterized by peculiar specifications. It influences the economic fundamentals of both the country of origin and the host one in terms of human capital accumulation. Here, the brain drain is considered from a microeconomic perspective: more precisely we focus on the individual rational decision to return, referring it to the social capital owned by the worker. The presented model, restricted to the case of academic personnel, compares utility levels to justify agent's migration conduct and to simulate several scenarios with a NetLogo agent based model. In particular, we developed a simulation framework based on two fundamental individual features, i.e. risk aversion and initial expectation, which characterize the dynamics of different agents according to the random evolution of their personal social networks. Our main result is that, according to the value of risk aversion and initial expectation, the probability of return migration depends on...

  12. Mobile Agent Based Framework for Integrating Digital Library System

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Few of the current approaches to achieve the integration of digital library system have considered the influence of network factors on quality of service for the integration system of digital libraries. For this reason, a mobile agent based framework for integrating digital library system is proposed. Based on this framework, a prototype system is implemented and the key technique for it are described. Compared with the current approaches, using mobile agent technique to achieve the integration of digital library system can not only avoid transmitting a lot of data on the network, lower the dependence on network bandwidth for the system, but also improve the quality of service for the integration system of digital libraries in intermitted or unreliable network connection settings.

  13. Decentralized Autonomous-Agent-Based Infrastructure for Agile Multiparallel Manufacturing

    NARCIS (Netherlands)

    Ing. Erik Puik; Leo van Moergestel; John-Jules Meyer; Daniël Telgen

    2011-01-01

    This paper describes an agent-based software infrastructure for agile industrial production. This production is done on special devices called equiplets. A grid of these equiplets connected by a fast network is capable of producing a variety of different products in parallel. The multi-agent-based

  14. An Active Learning Exercise for Introducing Agent-Based Modeling

    Science.gov (United States)

    Pinder, Jonathan P.

    2013-01-01

    Recent developments in agent-based modeling as a method of systems analysis and optimization indicate that students in business analytics need an introduction to the terminology, concepts, and framework of agent-based modeling. This article presents an active learning exercise for MBA students in business analytics that demonstrates agent-based…

  15. Agent-based Modeling Methodology for Analyzing Weapons Systems

    Science.gov (United States)

    2015-03-26

    43 Figure 14: Simulation Study Methodology for the Weapon System Analysis Metrics Definition and Data Collection The analysis plan calls for...AGENT-BASED MODELING METHODOLOGY FOR ANALYZING WEAPONS SYSTEMS THESIS Casey D. Connors, Major, USA...AGENT-BASED MODELING METHODOLOGY FOR ANALYZING WEAPONS SYSTEMS THESIS Presented to the Faculty Department of Operational Sciences

  16. Pattern-oriented modeling of agent-based complex systems: lessons from ecology

    NARCIS (Netherlands)

    Grimm, V.; Revilla, E.; Berger, U.; Jeltsch, F.; Mooij, W.M.; Railsback, S.F.; Thulke, H-H.; Weiner, J.; Wiegand, T.; DeAngelis, D.L.

    2005-01-01

    Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and agent-b

  17. Land-use change arising from rural land exchange : an agent-based simulation model

    NARCIS (Netherlands)

    Bakker, Martha M.; Alam, Shah Jamal; van Dijk, Jerry; Rounsevell, Mark D. A.

    2015-01-01

    Land exchange can be a major factor driving land-use change in regions with high pressure on land, but is generally not incorporated in land-use change models. Here we present an agent-based model to simulate land-use change arising from land exchange between multiple agent types representing farmer

  18. Pattern-oriented modeling of agent-based complex systems: lessons from ecology

    NARCIS (Netherlands)

    Grimm, V.; Revilla, E.; Berger, U.; Jeltsch, F.; Mooij, W.M.; Railsback, S.F.; Thulke, H-H.; Weiner, J.; Wiegand, T.; DeAngelis, D.L.

    2005-01-01

    Agent-based complex systems are dynamic networks of many interacting agents; examples include ecosystems, financial markets, and cities. The search for general principles underlying the internal organization of such systems often uses bottom-up simulation models such as cellular automata and

  19. Agent-Based Models as “Interested Amateurs”

    Directory of Open Access Journals (Sweden)

    Peter George Johnson

    2015-04-01

    Full Text Available This paper proposes the use of agent-based models (ABMs as “interested amateurs” in policy making, and uses the example of the SWAP model of soil and water conservation adoption to demonstrate the potential of this approach. Daniel Dennett suggests experts often talk past or misunderstand each other, seek to avoid offending each other or appearing ill-informed and generally err on the side of under-explaining a topic. Dennett suggests that these issues can be overcome by including “interested amateurs” in discussions between experts. In the context of land use policy debates, and policy making more generally, this paper suggests that ABMs have particular characteristics that make them excellent potential “interested amateurs” in discussions between our experts: policy stakeholders. This is demonstrated using the SWAP (Soil and Water Conservation Adoption model, which was used with policy stakeholders in Ethiopia. The model was successful in focussing discussion, inviting criticism, dealing with sensitive topics and drawing out understanding between stakeholders. However, policy stakeholders were still hesitant about using such a tool. This paper reflects on these findings and attempts to plot a way forward for the use of ABMs as “interested amateurs” and, in the process, make clear the differences in approach to other participatory modelling efforts.

  20. Using the Agent-Based Modeling in Economic Field

    Directory of Open Access Journals (Sweden)

    Nora Mihail

    2006-12-01

    Full Text Available The last ten years of the XX century has been the witnesses of the apparition of a new scientific field, which is usually defined as the study of “Complex adaptive systems”. This field, generic named Complexity Sciences, shares its subject, the general proprieties of complex systems across traditional disciplinary boundaries, with cybernetics and general systems theory. But the development of Complexity Sciences approaches is determined by the extensive use of Agent-Based-Models (ABM as a research tool and an emphasis on systems, such as markets, populations or ecologies, which are less integrated or “organized” than the ones, such as companies and economies, intensively studied by the traditional disciplines. For ABM, a complex system is a system of individual agents who have the freedom to act in ways that are not always totally predictable, and whose actions are interconnected such that one agent’s actions changes the context (environment for other agents. These are many examples of such complex systems: the stock market, the human body immune system, a business organization, an institution, a work-team, a family etc.

  1. Agent-Based Decision Control—How to Appreciate Multivariate Optimisation in Architecture

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer; Perkov, Thomas Holmer; Kolarik, Jakub

    2015-01-01

    in the early design stage. The main focus is to demonstrate the optimisation method, which is done in two ways. Firstly, the newly developed agent-based optimisation algorithm named Moth is tested on three different single objective search spaces. Here Moth is compared to two evolutionary algorithms. Secondly......, the method is applied to a multivariate optimisation problem. The aim is specifically to demonstrate optimisation for entire building energy consumption, daylight distribution and capital cost. Based on the demonstrations Moth’s ability to find local minima is discussed. It is concluded that agent-based...... optimisation algorithms like Moth open up for new uses of optimisation in the early design stage. With Moth the final outcome is less dependent on pre- and post-processing, and Moth allows user intervention during optimisation. Therefore, agent-based models for optimisation such as Moth can be a powerful...

  2. A comparison of Nash equilibria analysis and agent-based modelling for power markets

    Energy Technology Data Exchange (ETDEWEB)

    Krause, T.; Andersson, G. [EEH Power Systems Laboratory, ETH Zuerich, (Switzerland); Beck, E.V.; Cherkaoui, R.; Germond, A. [LRE Laboratoire de Reseaux Electriques, EPFL-STI-LRE, Lausanne (Switzerland); Ernst, D. [Universitede Liege, Institut Montefiore Batiment B28, Liege (Belgium)

    2006-11-15

    In this paper we compare Nash equilibria analysis and agent-based modelling for assessing the market dynamics of network-constrained pool markets. Power suppliers submit their bids to the market place in order to maximize their payoffs, where we apply reinforcement learning as a behavioral agent model. The market clearing mechanism is based on the locational marginal pricing scheme. Simulations are carried out on a benchmark power system. We show how the evolution of the agent-based approach relates to the existence of a unique Nash equilibrium or multiple equilibria in the system. Additionally, the parameter sensitivity of the results is discussed. (author)

  3. Apnea after Awake Regional and General Anesthesia in Infants: The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

    National Research Council Canada - National Science Library

    Davidson, Anew J; Morton, Neil S; Arnup, Sarah J; de Graaff, Jurgen C; Disma, Nicola; Withington, Davinia E; Frawley, Geoff; Hunt, Rodney W; Hardy, Pollyanna; Khotcholava, Magda; von Ungern Sternberg, Britta S; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen; Absalom, Anthony

    2015-01-01

    ...) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (GA...

  4. Agent-Based Collaborative Traffic Flow Management Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose agent-based game-theoretic approaches for simulation of strategies involved in multi-objective collaborative traffic flow management (CTFM). Intelligent...

  5. Use of agent based simulation for traffic safety assessment

    CSIR Research Space (South Africa)

    Conradie, Dirk CU

    2008-07-01

    Full Text Available This paper describes the development of an agent based Computational Building Simulation (CBS) tool, termed KRONOS that is being used to work on advanced research questions such as traffic safety assessment and user behaviour in buildings...

  6. Agent Based Processing of Global Evaluation Function

    CERN Document Server

    Hossain, M Shahriar; Joarder, Md Mahbubul Alam

    2011-01-01

    Load balancing across a networked environment is a monotonous job. Moreover, if the job to be distributed is a constraint satisfying one, the distribution of load demands core intelligence. This paper proposes parallel processing through Global Evaluation Function by means of randomly initialized agents for solving Constraint Satisfaction Problems. A potential issue about the number of agents in a machine under the invocation of distribution is discussed here for securing the maximum benefit from Global Evaluation and parallel processing. The proposed system is compared with typical solution that shows an exclusive outcome supporting the nobility of parallel implementation of Global Evaluation Function with certain number of agents in each invoked machine.

  7. ACO Agent Based Routing in AOMDV Environment

    Directory of Open Access Journals (Sweden)

    Kaur Amanpreet

    2016-01-01

    Full Text Available Mobile Ad-hoc Network (MANET is a group of moving nodes which can communicate with each other without the help of any central stationary node. All the nodes in the MANET act as router for forwarding data packets. The nodes in the network also move randomly and there exists no fixed infrastructure. So, path breaks are the frequent problem in MANET. The routing protocol faces a lot of problem due these path breaks. Therefore, the routing protocol which is multipath in nature is more reliable than a unipath routing protocol. Ant colony optimization is a relatively new technique which is suitable for the optimization problems. AOMDV is a multipath routing protocol. Thus, if there happens to be path break, the packets can start following the new path which has already been selected. In this paper, we are trying to add ant’s agents into AOMDV behavior. In this way, the new protocol will be benefited by the dual properties i.e. of ant’s nature and multipath nature of AOMDV. The modified concept is simulated and the outcomes are compared with AOMDV, AODV and DSR routing protocols for few performance parameters. Results obtained are encouraging; the new algorithm performs better than traditional unipath and multipath routing protocols.

  8. Synchronisation of fertility with carrying capacity; an investigation using classical and agent based modeling

    Directory of Open Access Journals (Sweden)

    Hugh Crozier Murrell

    2013-05-01

    Full Text Available A generalized Verhulst model subject to seasonal change in both fertility rate and carrying capacity is outlined. Numerical solutions to the Verhulst equations are employed to obtain optimal fertility rate phase shift with respect to carrying capacity. Possible natural selection for a preferred season of conception is investigated using agent based simulations. Both experiments indicate that synchronization of fertility rate to environment carrying capacity is beneficial to species survival.

  9. Engineering interrelated electricity markets. An agent-based computational approach

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, Anke [Mannheim Univ. (Germany). Dieter Schwarz Chair of Business Administration and Information Systems

    2008-07-01

    Due to the characteristics of electricity, power markets rank among the most complex markets operated at present. The requirements of an environmentally sustainable, economically efficient, and secure energy supply have resulted in the emergence of several interrelated markets that have to be carefully engineered in order to ensure efficient market outcomes. This book presents an agent-based simulation model that facilitates electricity market research. Simulation outcomes from this model are validated against price data from German power markets. The results significantly contribute to existing research in agent-based simulation and electricity market modeling, and provide insights into the impact of the market structure and market design on electricity prices. The book addresses researchers, lecturers and students who are interested in applying agent-based simulation to power markets. It provides a thorough discussion of the methodology and helpful details for model implementation. (orig.)

  10. Apnea after Awake Regional and General Anesthesia in Infants : The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

    NARCIS (Netherlands)

    Davidson, Andrew J.; Morton, Neil S.; Arnup, Sarah J.; De Graaff, Jurgen C.|info:eu-repo/dai/nl/249966271; Disma, Nicola; Withington, Davinia E.; Frawley, Geoff; Hunt, Rodney W.; Hardy, Pollyanna; Khotcholava, Magda; Von Ungern Sternberg, Britta S.; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen; Lee, Katherine; Sheppard, Suzette; Hartmann, Penelope; Ragg, Philip; Backstrom, Marie; Costi, David; Von Ungern-Sternberg, Britta S.; Knottenbelt, Graham; Montobbio, Giovanni; Mameli, Leila; Giribaldi, Gaia; Prato, Alessio Pini; Mattioli, Girolamo; Wolfler, Andrea; Izzo, Francesca; Sonzogni, Valter; Van Gool, Jose T D G; Numan, Sandra C.; Kalkman, Cor J.; Hagenaars, J. H M; Absalom, Anthony R.; Hoekstra, Frouckje M.; Volkers, Martin J.; Furue, Koto; Gaudreault, Josee; Berde, Charles; Soriano, Sulpicio; Young, Vanessa; Sethna, Navil; Kovatsis, Pete; Cravero, Joseph P.; Bellinger, David; Marmor, Jacki; Lynn, Anne; Ivanova, Iskra; Hunyady, Agnes; Verma, Shilpa; Polaner, David; Thomas, Joss; Meuller, Martin; Haret, Denisa; Szmuk, Peter; Steiner, Jeffery; Kravitz, Brian; Suresh, Santhanam; Hays, Stephen R.; Taenzer, Andreas H.; Maxwell, Lynne G.; Williams, Robert K.; Bell, Graham T.; Dorris, Liam; Adey, Claire; Bagshaw, Oliver; Chisakuta, Anthony; Eissa, Ayman; Stoddart, Peter; Davis, Annette; Myles, Paul; Wolf, Andy; McIntosh, Neil; Carlin, John; Leslie, Kate; De Lima, Jonathan; Hammer, Greg; Field, David; Gebski, Val; Tibboel, Dick

    2015-01-01

    Background: Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (

  11. Apnea after Awake Regional and General Anesthesia in Infants : The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

    NARCIS (Netherlands)

    Davidson, Andrew J; Morton, Neil S; Arnup, Sarah J; de Graaff, Jurgen C; Disma, Nicola; Withington, Davinia E; Frawley, Geoff; Hunt, Rodney W; Hardy, Pollyanna; Khotcholava, Magda; von Ungern Sternberg, Britta S; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen; Absalom, Anthony

    2015-01-01

    BACKGROUND: Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (

  12. Apnea after Awake Regional and General Anesthesia in Infants : The General Anesthesia Compared to Spinal Anesthesia Study-Comparing Apnea and Neurodevelopmental Outcomes, a Randomized Controlled Trial

    NARCIS (Netherlands)

    Davidson, Andrew J.; Morton, Neil S.; Arnup, Sarah J.; De Graaff, Jurgen C.; Disma, Nicola; Withington, Davinia E.; Frawley, Geoff; Hunt, Rodney W.; Hardy, Pollyanna; Khotcholava, Magda; Von Ungern Sternberg, Britta S.; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen; Lee, Katherine; Sheppard, Suzette; Hartmann, Penelope; Ragg, Philip; Backstrom, Marie; Costi, David; Von Ungern-Sternberg, Britta S.; Knottenbelt, Graham; Montobbio, Giovanni; Mameli, Leila; Giribaldi, Gaia; Prato, Alessio Pini; Mattioli, Girolamo; Wolfler, Andrea; Izzo, Francesca; Sonzogni, Valter; Van Gool, Jose T D G; Numan, Sandra C.; Kalkman, Cor J.; Hagenaars, J. H M; Absalom, Anthony R.; Hoekstra, Frouckje M.; Volkers, Martin J.; Furue, Koto; Gaudreault, Josee; Berde, Charles; Soriano, Sulpicio; Young, Vanessa; Sethna, Navil; Kovatsis, Pete; Cravero, Joseph P.; Bellinger, David; Marmor, Jacki; Lynn, Anne; Ivanova, Iskra; Hunyady, Agnes; Verma, Shilpa; Polaner, David; Thomas, Joss; Meuller, Martin; Haret, Denisa; Szmuk, Peter; Steiner, Jeffery; Kravitz, Brian; Suresh, Santhanam; Hays, Stephen R.; Taenzer, Andreas H.; Maxwell, Lynne G.; Williams, Robert K.; Bell, Graham T.; Dorris, Liam; Adey, Claire; Bagshaw, Oliver; Chisakuta, Anthony; Eissa, Ayman; Stoddart, Peter; Davis, Annette; Myles, Paul; Wolf, Andy; McIntosh, Neil; Carlin, John; Leslie, Kate; De Lima, Jonathan; Hammer, Greg; Field, David; Gebski, Val; Tibboel, Dick

    2015-01-01

    Background: Postoperative apnea is a complication in young infants. Awake regional anesthesia (RA) may reduce the risk; however, the evidence is weak. The General Anesthesia compared to Spinal anesthesia study is a randomized, controlled trial designed to assess the influence of general anesthesia (

  13. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models.

    Science.gov (United States)

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics--from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the 'Emerging Intelligence Market Hypothesis' to reconcile the pervasive presence of 'noise traders' with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

  14. Physics and financial economics (1776-2014): puzzles, Ising and agent-based models

    Science.gov (United States)

    Sornette, Didier

    2014-06-01

    This short review presents a selected history of the mutual fertilization between physics and economics—from Isaac Newton and Adam Smith to the present. The fundamentally different perspectives embraced in theories developed in financial economics compared with physics are dissected with the examples of the volatility smile and of the excess volatility puzzle. The role of the Ising model of phase transitions to model social and financial systems is reviewed, with the concepts of random utilities and the logit model as the analog of the Boltzmann factor in statistical physics. Recent extensions in terms of quantum decision theory are also covered. A wealth of models are discussed briefly that build on the Ising model and generalize it to account for the many stylized facts of financial markets. A summary of the relevance of the Ising model and its extensions is provided to account for financial bubbles and crashes. The review would be incomplete if it did not cover the dynamical field of agent-based models (ABMs), also known as computational economic models, of which the Ising-type models are just special ABM implementations. We formulate the ‘Emerging Intelligence Market Hypothesis’ to reconcile the pervasive presence of ‘noise traders’ with the near efficiency of financial markets. Finally, we note that evolutionary biology, more than physics, is now playing a growing role to inspire models of financial markets.

  15. On infrastructure network design with agent-based modelling

    NARCIS (Netherlands)

    Chappin, E.J.L.; Heijnen, P.W.

    2014-01-01

    We have developed an agent-based model to optimize green-field network design in an industrial area. We aim to capture some of the deep uncertainties surrounding infrastructure design by modelling it developing specific ant colony optimizations. Hence, we propose a variety of extensions to our

  16. Agent-based services for B2B electronic commerce

    Science.gov (United States)

    Fong, Elizabeth; Ivezic, Nenad; Rhodes, Tom; Peng, Yun

    2000-12-01

    The potential of agent-based systems has not been realized yet, in part, because of the lack of understanding of how the agent technology supports industrial needs and emerging standards. The area of business-to-business electronic commerce (b2b e-commerce) is one of the most rapidly developing sectors of industry with huge impact on manufacturing practices. In this paper, we investigate the current state of agent technology and the feasibility of applying agent-based computing to b2b e-commerce in the circuit board manufacturing sector. We identify critical tasks and opportunities in the b2b e-commerce area where agent-based services can best be deployed. We describe an implemented agent-based prototype system to facilitate the bidding process for printed circuit board manufacturing and assembly. These activities are taking place within the Internet Commerce for Manufacturing (ICM) project, the NIST- sponsored project working with industry to create an environment where small manufacturers of mechanical and electronic components may participate competitively in virtual enterprises that manufacture printed circuit assemblies.

  17. Agent-based Multimodal Interface for Dynamically Autonomous Mobile Robots

    Science.gov (United States)

    2003-01-01

    Agent-based Multimodal Interface for Dynamically Autonomous Mobile Robots Donald Sofge, Magdalena Bugajska, William Adams, Dennis...computing paradigm for integrated distributed artificial intelligence systems on autonomous mobile robots (Figure 1). Figure 1 – CoABS Grid...Architecture for Dynamically Autonomous Mobile Robots The remainder of the paper is organized as follows. Section 2 describes our integrated AI

  18. Agent-based modelling of socio-technical systems

    CERN Document Server

    van Dam, Koen H; Lukszo, Zofia

    2012-01-01

    Here is a practical introduction to agent-based modelling of socio-technical systems, based on methodology developed at TU Delft, which has been deployed in a number of case studies. Offers theory, methods and practical steps for creating real-world models.

  19. A Large Scale, High Resolution Agent-Based Insurgency Model

    Science.gov (United States)

    2013-09-30

    2007). HSCB Models can be employed for simulating mission scenarios, determining optimal strategies for disrupting terrorist networks, or training and...High Resolution Agent-Based Insurgency Model ∑ = ⎜ ⎜ ⎝ ⎛ − −− = desired 1 move,desired, desired,,desired, desired,, N j ij jmoveij moveiD rp prp

  20. Simulating cancer growth with multiscale agent-based modeling.

    Science.gov (United States)

    Wang, Zhihui; Butner, Joseph D; Kerketta, Romica; Cristini, Vittorio; Deisboeck, Thomas S

    2015-02-01

    There have been many techniques developed in recent years to in silico model a variety of cancer behaviors. Agent-based modeling is a specific discrete-based hybrid modeling approach that allows simulating the role of diversity in cell populations as well as within each individual cell; it has therefore become a powerful modeling method widely used by computational cancer researchers. Many aspects of tumor morphology including phenotype-changing mutations, the adaptation to microenvironment, the process of angiogenesis, the influence of extracellular matrix, reactions to chemotherapy or surgical intervention, the effects of oxygen and nutrient availability, and metastasis and invasion of healthy tissues have been incorporated and investigated in agent-based models. In this review, we introduce some of the most recent agent-based models that have provided insight into the understanding of cancer growth and invasion, spanning multiple biological scales in time and space, and we further describe several experimentally testable hypotheses generated by those models. We also discuss some of the current challenges of multiscale agent-based cancer models.

  1. MAIA: a framework for developing agent-based social simulations

    NARCIS (Netherlands)

    Ghorbani, Amineh; Dignum, Virginia; Bots, Pieter; Dijkema, Gerhard

    2013-01-01

    In this paper we introduce and motivate a conceptualization framework for agent-based social simulation, MAIA: Modelling Agent systems based on Institutional Analysis. The MAIA framework is based on Ostrom's Institutional Analysis and Development framework, and provides an extensive set of modelling

  2. An agent-based architecture for multimodal interaction

    NARCIS (Netherlands)

    Jonker, C.M.; Treur, J.; Wijngaards, W.C.A.

    2001-01-01

    In this paper, an executable generic process model is proposed for combined verbal and non-verbal communication processes and their interaction. The agent-based architecture can be used to create multimodal interaction. The generic process model has been designed, implemented and used to simulate

  3. Agent-Based Decentralized Control Method for Islanded Microgrids

    DEFF Research Database (Denmark)

    Li, Qiang; Chen, Feixiong; Chen, Minyou;

    2016-01-01

    In this paper, an agent-based decentralized control model for islanded microgrids is proposed, which consists of a two-layer control structure. The bottom layer is the electrical distribution microgrid, while the top layer is the communication network composed of agents. An agent is regarded as a...

  4. On infrastructure network design with agent-based modelling

    NARCIS (Netherlands)

    Chappin, E.J.L.; Heijnen, P.W.

    2014-01-01

    We have developed an agent-based model to optimize green-field network design in an industrial area. We aim to capture some of the deep uncertainties surrounding infrastructure design by modelling it developing specific ant colony optimizations. Hence, we propose a variety of extensions to our exist

  5. An Intelligent Agent Based on Virtual Geographic Environment System

    Institute of Scientific and Technical Information of China (English)

    SHEN Dayong; LIN Hui; GONG Jianhua; ZHAO Yibin; FANG Zhaobao; GUO Zhongyang

    2004-01-01

    On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi-user, multi-thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.

  6. Agent-based analysis of organizations : formalization and simulation

    NARCIS (Netherlands)

    Dignum, M.V.; Tick, C.

    2008-01-01

    Organizational effectiveness depends on many factors, including individual excellence, efficient structures, effective planning and capability to understand and match context requirements. We propose a way to model organizational performance based on a combination of formal models and agent-based si

  7. An agent-based architecture for multimodal interaction

    NARCIS (Netherlands)

    Jonker, C.M.; Treur, J.; Wijngaards, W.C.A.

    2001-01-01

    In this paper, an executable generic process model is proposed for combined verbal and non-verbal communication processes and their interaction. The agent-based architecture can be used to create multimodal interaction. The generic process model has been designed, implemented and used to simulate di

  8. Self-reported psychopathic traits in sexually offending juveniles compared with generally offending juveniles and general population youth.

    Science.gov (United States)

    Boonmann, Cyril; Jansen, Lucres M C; 't Hart-Kerkhoffs, Lisette A; Vahl, Pauline; Hillege, Sanne L; Doreleijers, Theo A H; Vermeiren, Robert R J M

    2015-01-01

    The aim of the current study is to gain a better insight into the relationship between sexually aggressive behaviour and psychopathy in youths; juveniles who sexually offended (JSOs) were compared with generally offending youths and a general population group. Seventy-one JSOs, 416 detained general offenders, and 331 males from the general population were assessed by means of the Youth Psychopathic traits Inventory (YPI), a self-report instrument. Sexually and generally offending juveniles had significantly lower levels of self-reported psychopathic traits than youths from the general population. Juvenile sexual offenders and generally offending juveniles did not differ in self-reported psychopathic traits. Furthermore, no differences in self-reported psychopathic traits were found between subgroups of JSOs (i.e., child molesters, solo offenders, and group offenders). The finding that self-reported psychopathic traits are less prevalent in offending juveniles than in general population youths raises questions about the usefulness of the YPI when comparing psychopathic traits between clinical samples and general-population samples.

  9. Simulating GenCo bidding strategies in electricity markets with an agent-based model

    Energy Technology Data Exchange (ETDEWEB)

    Botterud, Audun; Thimmapuram, Prakash R.; Yamakado, Malo

    2005-12-15

    In this paper we use an agent-based simulation model, EMCAS, to analyze market power in electricity markets. We focus on the effect of congestion management on the ability of generating companies (GenCos) to raise prices beyond competitive levels. An 11-node test power system is used to compare a market design based on locational marginal pricing with a market design that uses system marginal pricing and congestion management by counter trading. Bidding strategies based on both physical and economic withholding are compared to a base case with production cost bidding. The results show that unilateral market power is exercised under both pricing mechanisms. However, the largest changes in consumer costs and GenCo profits due to strategic bidding occur under the locational marginal pricing scheme. The analysis also illustrates that agent-based modeling can contribute important insights into the complex interactions between the participants in transmission-constrained electricity markets. (Author)

  10. Artificial Immune Systems Metaphor for Agent Based Modeling of Crisis Response Operations

    OpenAIRE

    Khalil, Khaled M.; Abdel-Aziz, M.; Nazmy, Taymour T.; Salem, Abdel-Badeeh M.

    2010-01-01

    Crisis response requires information intensive efforts utilized for reducing uncertainty, calculating and comparing costs and benefits, and managing resources in a fashion beyond those regularly available to handle routine problems. This paper presents an Artificial Immune Systems (AIS) metaphor for agent based modeling of crisis response operations. The presented model proposes integration of hybrid set of aspects (multi-agent systems, built-in defensive model of AIS, situation management, a...

  11. Analyzing the Validity of Relationship Banking through Agent-based Modeling

    Science.gov (United States)

    Nishikido, Yukihito; Takahashi, Hiroshi

    This article analyzes the validity of relationship banking through agent-based modeling. In the analysis, we especially focus on the relationship between economic conditions and both lenders' and borrowers' behaviors. As a result of intensive experiments, we made the following interesting findings: (1) Relationship banking contributes to reducing bad loan; (2) relationship banking is more effective in enhancing the market growth compared to transaction banking, when borrowers' sales scale is large; (3) keener competition among lenders may bring inefficiency to the market.

  12. Investigating mathematical models of immuno-interactions with early-stage cancer under an agent-based modelling perspective

    Science.gov (United States)

    2013-01-01

    Many advances in research regarding immuno-interactions with cancer were developed with the help of ordinary differential equation (ODE) models. These models, however, are not effectively capable of representing problems involving individual localisation, memory and emerging properties, which are common characteristics of cells and molecules of the immune system. Agent-based modelling and simulation is an alternative paradigm to ODE models that overcomes these limitations. In this paper we investigate the potential contribution of agent-based modelling and simulation when compared to ODE modelling and simulation. We seek answers to the following questions: Is it possible to obtain an equivalent agent-based model from the ODE formulation? Do the outcomes differ? Are there any benefits of using one method compared to the other? To answer these questions, we have considered three case studies using established mathematical models of immune interactions with early-stage cancer. These case studies were re-conceptualised under an agent-based perspective and the simulation results were then compared with those from the ODE models. Our results show that it is possible to obtain equivalent agent-based models (i.e. implementing the same mechanisms); the simulation output of both types of models however might differ depending on the attributes of the system to be modelled. In some cases, additional insight from using agent-based modelling was obtained. Overall, we can confirm that agent-based modelling is a useful addition to the tool set of immunologists, as it has extra features that allow for simulations with characteristics that are closer to the biological phenomena. PMID:23734575

  13. Nonlinear multi-analysis of agent-based financial market dynamics by epidemic system

    Science.gov (United States)

    Lu, Yunfan; Wang, Jun; Niu, Hongli

    2015-10-01

    Based on the epidemic dynamical system, we construct a new agent-based financial time series model. In order to check and testify its rationality, we compare the statistical properties of the time series model with the real stock market indices, Shanghai Stock Exchange Composite Index and Shenzhen Stock Exchange Component Index. For analyzing the statistical properties, we combine the multi-parameter analysis with the tail distribution analysis, the modified rescaled range analysis, and the multifractal detrended fluctuation analysis. For a better perspective, the three-dimensional diagrams are used to present the analysis results. The empirical research in this paper indicates that the long-range dependence property and the multifractal phenomenon exist in the real returns and the proposed model. Therefore, the new agent-based financial model can recurrence some important features of real stock markets.

  14. Agent-Based vs. Equation-based Epidemiological Models:A Model Selection Case Study

    Energy Technology Data Exchange (ETDEWEB)

    Sukumar, Sreenivas R [ORNL; Nutaro, James J [ORNL

    2012-01-01

    This paper is motivated by the need to design model validation strategies for epidemiological disease-spread models. We consider both agent-based and equation-based models of pandemic disease spread and study the nuances and complexities one has to consider from the perspective of model validation. For this purpose, we instantiate an equation based model and an agent based model of the 1918 Spanish flu and we leverage data published in the literature for our case- study. We present our observations from the perspective of each implementation and discuss the application of model-selection criteria to compare the risk in choosing one modeling paradigm to another. We conclude with a discussion of our experience and document future ideas for a model validation framework.

  15. Friendship Dynamics: Modelling Social Relationships through a Fuzzy Agent-Based Simulation

    Directory of Open Access Journals (Sweden)

    Samer Hassan

    2011-01-01

    This study shows how to simulate these friendship dynamics in an agent-based model that applies fuzzy sets theory to implement agent attributes, rules, and social relationships, explaining the process in detail. Although in principle it may be thought that the use of fuzzy sets theory makes agent-based modelling more elaborated, in practice it saves the modeller from taking some arbitrary decisions on how to use crisp values for representing properties that are inherently fuzzy. The consequences of applying fuzzy sets and operations to define a fuzzy friendship relationship are compared with a simpler implementation, with crisp values. By integrating agent computational models and fuzzy set theory, this paper provides useful insights into scholars and practitioners to tackle the uncertainty inherent to social relationships in a systematic way.

  16. Nonlinear multi-analysis of agent-based financial market dynamics by epidemic system.

    Science.gov (United States)

    Lu, Yunfan; Wang, Jun; Niu, Hongli

    2015-10-01

    Based on the epidemic dynamical system, we construct a new agent-based financial time series model. In order to check and testify its rationality, we compare the statistical properties of the time series model with the real stock market indices, Shanghai Stock Exchange Composite Index and Shenzhen Stock Exchange Component Index. For analyzing the statistical properties, we combine the multi-parameter analysis with the tail distribution analysis, the modified rescaled range analysis, and the multifractal detrended fluctuation analysis. For a better perspective, the three-dimensional diagrams are used to present the analysis results. The empirical research in this paper indicates that the long-range dependence property and the multifractal phenomenon exist in the real returns and the proposed model. Therefore, the new agent-based financial model can recurrence some important features of real stock markets.

  17. Novel insights in agent-based complex automated negotiation

    CERN Document Server

    Lopez-Carmona, Miguel; Ito, Takayuki; Zhang, Minjie; Bai, Quan; Fujita, Katsuhide

    2014-01-01

    This book focuses on all aspects of complex automated negotiations, which are studied in the field of autonomous agents and multi-agent systems. This book consists of two parts. I: Agent-Based Complex Automated Negotiations, and II: Automated Negotiation Agents Competition. The chapters in Part I are extended versions of papers presented at the 2012 international workshop on Agent-Based Complex Automated Negotiation (ACAN), after peer reviews by three Program Committee members. Part II examines in detail ANAC 2012 (The Third Automated Negotiating Agents Competition), in which automated agents that have different negotiation strategies and are implemented by different developers are automatically negotiated in the several negotiation domains. ANAC is an international competition in which automated negotiation strategies, submitted by a number of universities and research institutes across the world, are evaluated in tournament style. The purpose of the competition is to steer the research in the area of bilate...

  18. Recent advances in agent-based complex automated negotiation

    CERN Document Server

    Ito, Takayuki; Zhang, Minjie; Fujita, Katsuhide; Robu, Valentin

    2016-01-01

    This book covers recent advances in Complex Automated Negotiations as a widely studied emerging area in the field of Autonomous Agents and Multi-Agent Systems. The book includes selected revised and extended papers from the 7th International Workshop on Agent-Based Complex Automated Negotiation (ACAN2014), which was held in Paris, France, in May 2014. The book also includes brief introductions about Agent-based Complex Automated Negotiation which are based on tutorials provided in the workshop, and brief summaries and descriptions about the ANAC'14 (Automated Negotiating Agents Competition) competition, where authors of selected finalist agents explain the strategies and the ideas used by them. The book is targeted to academic and industrial researchers in various communities of autonomous agents and multi-agent systems, such as agreement technology, mechanism design, electronic commerce, related areas, as well as graduate, undergraduate, and PhD students working in those areas or having interest in them.

  19. A Framework for Agent-based Human Interaction Support

    Directory of Open Access Journals (Sweden)

    Axel Bürkle

    2008-10-01

    Full Text Available In this paper we describe an agent-based infrastructure for multimodal perceptual systems which aims at developing and realizing computer services that are delivered to humans in an implicit and unobtrusive way. The framework presented here supports the implementation of human-centric context-aware applications providing non-obtrusive assistance to participants in events such as meetings, lectures, conferences and presentations taking place in indoor "smart spaces". We emphasize on the design and implementation of an agent-based framework that supports "pluggable" service logic in the sense that the service developer can concentrate on coding the service logic independently of the underlying middleware. Furthermore, we give an example of the architecture's ability to support the cooperation of multiple services in a meeting scenario using an intelligent connector service and a semantic web oriented travel service.

  20. Tutorial on agent-based modeling and simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Macal, C. M.; North, M. J.; Decision and Information Sciences

    2005-01-01

    Agent-based modeling and simulation (ABMS) is a new approach to modeling systems comprised of autonomous, interacting agents. ABMS promises to have far-reaching effects on the way that businesses use computers to support decision-making and researchers use electronic laboratories to support their research. Some have gone so far as to contend that ABMS is a third way of doing science besides deductive and inductive reasoning. Computational advances have made possible a growing number of agent-based applications in a variety of fields. Applications range from modeling agent behavior in the stock market and supply chains, to predicting the spread of epidemics and the threat of bio-warfare, from modeling consumer behavior to understanding the fall of ancient civilizations, to name a few. This tutorial describes the theoretical and practical foundations of ABMS, identifies toolkits and methods for developing ABMS models, and provides some thoughts on the relationship between ABMS and traditional modeling techniques.

  1. Agent-Based Service Composition in Cloud Computing

    Science.gov (United States)

    Gutierrez-Garcia, J. Octavio; Sim, Kwang-Mong

    In a Cloud-computing environment, consumers, brokers, and service providers interact to achieve their individual purposes. In this regard, service providers offer a pool of resources wrapped as web services, which should be composed by broker agents to provide a single virtualized service to Cloud consumers. In this study, an agent-based test bed for simulating Cloud-computing environments is developed. Each Cloud participant is represented by an agent, whose behavior is defined by means of colored Petri nets. The relationship between web services and service providers is modeled using object Petri nets. Both Petri net formalisms are combined to support a design methodology for defining concurrent and parallel service choreographies. This results in the creation of a dynamic agent-based service composition algorithm. The simulation results indicate that service composition is achieved with a linear time complexity despite dealing with interleaving choreographies and synchronization of heterogeneous services.

  2. Pain expressiveness and altruistic behavior: an exploration using agent-based modeling.

    Science.gov (United States)

    de C Williams, Amanda C; Gallagher, Elizabeth; Fidalgo, Antonio R; Bentley, Peter J

    2016-03-01

    Predictions which invoke evolutionary mechanisms are hard to test. Agent-based modeling in artificial life offers a way to simulate behaviors and interactions in specific physical or social environments over many generations. The outcomes have implications for understanding adaptive value of behaviors in context. Pain-related behavior in animals is communicated to other animals that might protect or help, or might exploit or predate. An agent-based model simulated the effects of displaying or not displaying pain (expresser/nonexpresser strategies) when injured and of helping, ignoring, or exploiting another in pain (altruistic/nonaltruistic/selfish strategies). Agents modeled in MATLAB interacted at random while foraging (gaining energy); random injury interrupted foraging for a fixed time unless help from an altruistic agent, who paid an energy cost, speeded recovery. Environmental and social conditions also varied, and each model ran for 10,000 iterations. Findings were meaningful in that, in general, contingencies that evident from experimental work with a variety of mammals, over a few interactions, were replicated in the agent-based model after selection pressure over many generations. More energy-demanding expression of pain reduced its frequency in successive generations, and increasing injury frequency resulted in fewer expressers and altruists. Allowing exploitation of injured agents decreased expression of pain to near zero, but altruists remained. Decreasing costs or increasing benefits of helping hardly changed its frequency, whereas increasing interaction rate between injured agents and helpers diminished the benefits to both. Agent-based modeling allows simulation of complex behaviors and environmental pressures over evolutionary time.

  3. Tutorial on Agent-based Modeling and Simulation

    Science.gov (United States)

    2007-06-01

    World of Science. New York: Wiley Crichton , Michael , 2002, Prey, HarperCollins. Epstein JM, Axtell R. 1996. Growing Artificial Societies...other author(s): Michael J. North and Charles M. Macal Principal Author’s Organization and address: Argonne National Laboratory 9700 S. Cass Avenue...on Agent-based Modeling and Simulation Michael J. North and Charles M. Macal Center for Complex Adaptive Agent Systems Simulation (CAS2) Decision

  4. Agent-based Modeling with MATSim for Hazards Evacuation Planning

    Science.gov (United States)

    Jones, J. M.; Ng, P.; Henry, K.; Peters, J.; Wood, N. J.

    2015-12-01

    Hazard evacuation planning requires robust modeling tools and techniques, such as least cost distance or agent-based modeling, to gain an understanding of a community's potential to reach safety before event (e.g. tsunami) arrival. Least cost distance modeling provides a static view of the evacuation landscape with an estimate of travel times to safety from each location in the hazard space. With this information, practitioners can assess a community's overall ability for timely evacuation. More information may be needed if evacuee congestion creates bottlenecks in the flow patterns. Dynamic movement patterns are best explored with agent-based models that simulate movement of and interaction between individual agents as evacuees through the hazard space, reacting to potential congestion areas along the evacuation route. The multi-agent transport simulation model MATSim is an agent-based modeling framework that can be applied to hazard evacuation planning. Developed jointly by universities in Switzerland and Germany, MATSim is open-source software written in Java and freely available for modification or enhancement. We successfully used MATSim to illustrate tsunami evacuation challenges in two island communities in California, USA, that are impacted by limited escape routes. However, working with MATSim's data preparation, simulation, and visualization modules in an integrated development environment requires a significant investment of time to develop the software expertise to link the modules and run a simulation. To facilitate our evacuation research, we packaged the MATSim modules into a single application tailored to the needs of the hazards community. By exposing the modeling parameters of interest to researchers in an intuitive user interface and hiding the software complexities, we bring agent-based modeling closer to practitioners and provide access to the powerful visual and analytic information that this modeling can provide.

  5. Agent based decision support in the supply chain context

    OpenAIRE

    Hilletofth, Per; Lättilä, Lauri

    2012-01-01

    Purpose – The purpose of this paper is to investigate the benefits and the barriers of agent based decision support (ABDS) systems in the supply chain context. Design/methodology/approach – Two ABDS systems have been developed and evaluated. The first system concerns a manufacturing supply chain while the second concerns a service supply chain. The systems are based on actual case companies. Findings – This research shows that the benefits of ABDS systems in the supply chain context include t...

  6. Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

    Science.gov (United States)

    Hu, Xiaolin; Puddy, Richard

    This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

  7. An agent-based multi-scale wind generation model

    Energy Technology Data Exchange (ETDEWEB)

    Kremers, E.; Lewald, N. [Karlsruhe Univ., Karlsruhe (Germany). European Inst. for Energy Research; Barambones, O.; Gonzalez de Durana, J.M. [Univ. of the Basque Country, Vitoria (Spain). Dept. of Engineering

    2009-07-01

    The introduction of renewable energies, the liberalization of energy markets and the emergence of new, distributed producers that feed into the grid at almost every level of the system have all contributed to a paradigm shift in energy systems. This paper presented an agent-based model for simulating wind power systems on multiple time scales. The purpose of the study was to generate a flexible model that would permit simulating the output of a wind farm. The model was developed using multiparadigm modelling. It also combined a variety of approaches such as agent-based modelling, discrete events and dynamic systems. The paper explained the theoretical background concerning the basic models for wind speed generation and power turbines, as well as the fundamentals of agent-based modelling. The implementation of these models was illustrated. The paper also discussed several sample simulations and discussed the application of the model. It was concluded that the paradigm change encompassed new tools and methods that could deal with decentralized decision-making, planning and self-organisation. The large amount of new technologies in the energy production chain requires a shift from a top-down to a more bottom-up approach. 12 refs., 1 tab., 7 figs.

  8. Agent-based modeling and simulation Part 3 : desktop ABMS.

    Energy Technology Data Exchange (ETDEWEB)

    Macal, C. M.; North, M. J.; Decision and Information Sciences

    2007-01-01

    Agent-based modeling and simulation (ABMS) is a new approach to modeling systems comprised of autonomous, interacting agents. ABMS promises to have far-reaching effects on the way that businesses use computers to support decision-making and researchers use electronic laboratories to support their research. Some have gone so far as to contend that ABMS 'is a third way of doing science,' in addition to traditional deductive and inductive reasoning (Axelrod 1997b). Computational advances have made possible a growing number of agent-based models across a variety of application domains. Applications range from modeling agent behavior in the stock market, supply chains, and consumer markets, to predicting the spread of epidemics, the threat of bio-warfare, and the factors responsible for the fall of ancient civilizations. This tutorial describes the theoretical and practical foundations of ABMS, identifies toolkits and methods for developing agent models, and illustrates the development of a simple agent-based model of shopper behavior using spreadsheets.

  9. Deterministic Agent-Based Path Optimization by Mimicking the Spreading of Ripples.

    Science.gov (United States)

    Hu, Xiao-Bing; Wang, Ming; Leeson, Mark S; Di Paolo, Ezequiel A; Liu, Hao

    2016-01-01

    Inspirations from nature have contributed fundamentally to the development of evolutionary computation. Learning from the natural ripple-spreading phenomenon, this article proposes a novel ripple-spreading algorithm (RSA) for the path optimization problem (POP). In nature, a ripple spreads at a constant speed in all directions, and the node closest to the source is the first to be reached. This very simple principle forms the foundation of the proposed RSA. In contrast to most deterministic top-down centralized path optimization methods, such as Dijkstra's algorithm, the RSA is a bottom-up decentralized agent-based simulation model. Moreover, it is distinguished from other agent-based algorithms, such as genetic algorithms and ant colony optimization, by being a deterministic method that can always guarantee the global optimal solution with very good scalability. Here, the RSA is specifically applied to four different POPs. The comparative simulation results illustrate the advantages of the RSA in terms of effectiveness and efficiency. Thanks to the agent-based and deterministic features, the RSA opens new opportunities to attack some problems, such as calculating the exact complete Pareto front in multiobjective optimization and determining the kth shortest project time in project management, which are very difficult, if not impossible, for existing methods to resolve. The ripple-spreading optimization principle and the new distinguishing features and capacities of the RSA enrich the theoretical foundations of evolutionary computation.

  10. AN INTELLIGENT MOBILE-AGENT BASED SCALABLE NETWORK MANAGEMENT ARCHITECTURE FOR LARGE-SCALE ENTERPRISE SYSTEM

    Directory of Open Access Journals (Sweden)

    A.K. Sharma

    2012-02-01

    Full Text Available Several Mobile Agent based distributed network management models have been proposed in recent times toaddress the scalability and flexibility problems of centralized (SNMP or CMIP management modelsmodels. Though the use of Mobile Agents to distribute and delegate management tasks comes handy indealing with the previously stated issues, many of the agent-based management frameworks like initial flatbed models and static mid-level managers employing mobile agents models cannot efficiently meet thedemands of current networks which are growing in size and complexity. Moreover, varied technologies,such as SONET, ATM, Ethernet, DWDM etc., present at different layers of the Access, Metro and Core(long haul sections of the network, have contributed to the complexity in terms of their own framing andprotocol structures. Thus, controlling and managing the traffic in these networks is a challenging task. Thispaper presents an intelligent scalable hierarchical agent based model for the management of large-scalecomplex networks to address aforesaid issues. The cost estimation, carried out with a view to compute theoverall management cost in terms of management data overhead, is being presented. The results obtainedthereafter establish the usefulness of the presented architecture as compare to centralized and flat bedagent based models.

  11. Simulating Transport and Land Use Interdependencies for Strategic Urban Planning—An Agent Based Modelling Approach

    Directory of Open Access Journals (Sweden)

    Nam Huynh

    2015-10-01

    Full Text Available Agent based modelling has been widely accepted as a promising tool for urban planning purposes thanks to its capability to provide sophisticated insights into the social behaviours and the interdependencies that characterise urban systems. In this paper, we report on an agent based model, called TransMob, which explicitly simulates the mutual dynamics between demographic evolution, transport demands, housing needs and the eventual change in the average satisfaction of the residents of an urban area. The ability to reproduce such dynamics is a unique feature that has not been found in many of the like agent based models in the literature. TransMob, is constituted by six major modules: synthetic population, perceived liveability, travel diary assignment, traffic micro-simulator, residential location choice, and travel mode choice. TransMob is used to simulate the dynamics of a metropolitan area in South East of Sydney, Australia, in 2006 and 2011, with demographic evolution. The results are favourably compared against survey data for the area in 2011, therefore validating the capability of TransMob to reproduce the observed complexity of an urban area. We also report on the application of TransMob to simulate various hypothetical scenarios of urban planning policies. We conclude with discussions on current limitations of TransMob, which serve as suggestions for future developments.

  12. The agent-based spatial information semantic grid

    Science.gov (United States)

    Cui, Wei; Zhu, YaQiong; Zhou, Yong; Li, Deren

    2006-10-01

    Analyzing the characteristic of multi-Agent and geographic Ontology, The concept of the Agent-based Spatial Information Semantic Grid (ASISG) is defined and the architecture of the ASISG is advanced. ASISG is composed with Multi-Agents and geographic Ontology. The Multi-Agent Systems are composed with User Agents, General Ontology Agent, Geo-Agents, Broker Agents, Resource Agents, Spatial Data Analysis Agents, Spatial Data Access Agents, Task Execution Agent and Monitor Agent. The architecture of ASISG have three layers, they are the fabric layer, the grid management layer and the application layer. The fabric layer what is composed with Data Access Agent, Resource Agent and Geo-Agent encapsulates the data of spatial information system so that exhibits a conceptual interface for the Grid management layer. The Grid management layer, which is composed with General Ontology Agent, Task Execution Agent and Monitor Agent and Data Analysis Agent, used a hybrid method to manage all resources that were registered in a General Ontology Agent that is described by a General Ontology System. The hybrid method is assembled by resource dissemination and resource discovery. The resource dissemination push resource from Local Ontology Agent to General Ontology Agent and the resource discovery pull resource from the General Ontology Agent to Local Ontology Agents. The Local Ontology Agent is derived from special domain and describes the semantic information of local GIS. The nature of the Local Ontology Agents can be filtrated to construct a virtual organization what could provides a global scheme. The virtual organization lightens the burdens of guests because they need not search information site by site manually. The application layer what is composed with User Agent, Geo-Agent and Task Execution Agent can apply a corresponding interface to a domain user. The functions that ASISG should provide are: 1) It integrates different spatial information systems on the semantic The Grid

  13. Evaluating the effect of human activity patterns on air pollution exposure using an integrated field-based and agent-based modelling framework

    Science.gov (United States)

    Schmitz, Oliver; Beelen, Rob M. J.; de Bakker, Merijn P.; Karssenberg, Derek

    2015-04-01

    Constructing spatio-temporal numerical models to support risk assessment, such as assessing the exposure of humans to air pollution, often requires the integration of field-based and agent-based modelling approaches. Continuous environmental variables such as air pollution are best represented using the field-based approach which considers phenomena as continuous fields having attribute values at all locations. When calculating human exposure to such pollutants it is, however, preferable to consider the population as a set of individuals each with a particular activity pattern. This would allow to account for the spatio-temporal variation in a pollutant along the space-time paths travelled by individuals, determined, for example, by home and work locations, road network, and travel times. Modelling this activity pattern requires an agent-based or individual based modelling approach. In general, field- and agent-based models are constructed with the help of separate software tools, while both approaches should play together in an interacting way and preferably should be combined into one modelling framework, which would allow for efficient and effective implementation of models by domain specialists. To overcome this lack in integrated modelling frameworks, we aim at the development of concepts and software for an integrated field-based and agent-based modelling framework. Concepts merging field- and agent-based modelling were implemented by extending PCRaster (http://www.pcraster.eu), a field-based modelling library implemented in C++, with components for 1) representation of discrete, mobile, agents, 2) spatial networks and algorithms by integrating the NetworkX library (http://networkx.github.io), allowing therefore to calculate e.g. shortest routes or total transport costs between locations, and 3) functions for field-network interactions, allowing to assign field-based attribute values to networks (i.e. as edge weights), such as aggregated or averaged

  14. A Harris-Todaro Agent-Based Model to Rural-Urban Migration

    Science.gov (United States)

    Espíndola, Aquino L.; Silveira, Jaylson J.; Penna, T. J. P.

    2006-09-01

    The Harris-Todaro model of the rural-urban migration process is revisited under an agent-based approach. The migration of the workers is interpreted as a process of social learning by imitation, formalized by a computational model. By simulating this model, we observe a transitional dynamics with continuous growth of the urban fraction of overall population toward an equilibrium. Such an equilibrium is characterized by stabilization of rural-urban expected wages differential (generalized Harris-Todaro equilibrium condition), urban concentration and urban unemployment. These classic results obtained originally by Harris and Todaro are emergent properties of our model.

  15. An artificial intelligence approach for modeling molecular self-assembly: agent-based simulations of rigid molecules.

    Science.gov (United States)

    Fortuna, Sara; Troisi, Alessandro

    2009-07-23

    Agent-based simulations are rule-based models traditionally used for the simulations of complex systems. In this paper, an algorithm based on the concept of agent-based simulations is developed to predict the lowest energy packing of a set of identical rigid molecules. The agents are identified with rigid portions of the system under investigation, and they evolve following a set of rules designed to drive the system toward the lowest energy minimum. The algorithm is compared with a conventional Metropolis Monte Carlo algorithm, and it is applied on a large set of representative models of molecules. For all the systems studied, the agent-based method consistently finds a significantly lower energy minima than the Monte Carlo algorithm because the system evolution includes elements of adaptation (new configurations induce new types of moves) and learning (past successful choices are repeated).

  16. Complexity and agent-based modelling in urban research

    DEFF Research Database (Denmark)

    Fertner, Christian

    Urbanisation processes are results of a broad variety of actors or actor groups and their behaviour and decisions based on different experiences, knowledge, resources, values etc. The decisions done are often on a micro/individual level but resulting in macro/collective behaviour. In urban research...... influence on the bigger system. Traditional scientific methods or theories often tried to simplify, not accounting complex relations of actors and decision-making. The introduction of computers in simulation made new approaches in modelling, as for example agent-based modelling (ABM), possible, dealing...

  17. Agent-based simulation of electricity markets. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Sensfuss, F.; Ragwitz, M. [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany); Genoese, M.; Moest, D. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Industriebetriebslehre und Industrielle Produktion

    2007-07-01

    Liberalisation, climate policy and promotion of renewable energy are challenges to players of the electricity sector in many countries. Policy makers have to con-sider issues like market power, bounded rationality of players and the appear-ance of fluctuating energy sources in order to provide adequate legislation. Fur-thermore the interactions between markets and environmental policy instru-ments become an issue of increasing importance. A promising approach for the scientific analysis of these developments is the field of agent-based simulation. The goal of this article is to provide an overview of the current work applying this methodology to the analysis of electricity markets. (orig.)

  18. An Agent-Based Modeling for Pandemic Influenza in Egypt

    OpenAIRE

    Khalil, Khaled M.; Abdel-Aziz, M.; Nazmy, Taymour T.; Salem, Abdel-Badeeh M.

    2010-01-01

    Pandemic influenza has great potential to cause large and rapid increases in deaths and serious illness. The objective of this paper is to develop an agent-based model to simulate the spread of pandemic influenza (novel H1N1) in Egypt. The proposed multi-agent model is based on the modeling of individuals' interactions in a space time context. The proposed model involves different types of parameters such as: social agent attributes, distribution of Egypt population, and patterns of agents' i...

  19. Agent-based computational economics using NetLogo

    CERN Document Server

    Damaceanu, Romulus-Catalin

    2013-01-01

    Agent-based Computational Economics using NetLogo explores how researchers can create, use and implement multi-agent computational models in Economics by using NetLogo software platform. Problems of economic science can be solved using multi-agent modelling (MAM). This technique uses a computer model to simulate the actions and interactions of autonomous entities in a network, in order to analyze the effects on the entire economic system. MAM combines elements of game theory, complex systems, emergence and evolutionary programming. The Monte Carlo method is also used in this e-book to introduc

  20. Emergent Macroeconomics An Agent-Based Approach to Business Fluctuations

    CERN Document Server

    Delli Gatti, Domenico; Gallegati, Mauro; Giulioni, Gianfranco; Palestrini, Antonio

    2008-01-01

    This book contributes substantively to the current state-of-the-art of macroeconomics by providing a method for building models in which business cycles and economic growth emerge from the interactions of a large number of heterogeneous agents. Drawing from recent advances in agent-based computational modeling, the authors show how insights from dispersed fields like the microeconomics of capital market imperfections, industrial dynamics and the theory of stochastic processes can be fruitfully combined to improve our understanding of macroeconomic dynamics. This book should be a valuable resource for all researchers interested in analyzing macroeconomic issues without recurring to a fictitious representative agent.

  1. SPY AGENT BASED SECURE DATA AGGREGATION IN WSN

    Directory of Open Access Journals (Sweden)

    T. Lathies Bhasker

    2014-12-01

    Full Text Available Wireless sensor network consist lot of sensor devices which are activated by using the battery power. These sensor devices are mostly used in hostile environment, military applications etc. So in this type of environment it is highly difficult to collect and transmit the data to the Sink without any data lost. In this paper we proposed SPY Agent based secure data aggregation scheme. Here one SPY Agent moves around the network and monitors the aggregator nodes i.e, the Cluster Heads for secure data collection. In the Simulation section we have analyzed our proposed architecture for both proactive and reactive protocols.

  2. An Agent-based Model of a Capitalist Economy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li-jun; CHENG Dai-zhan

    2002-01-01

    In this paper we investigate the stabilizing role of taxation in an agent based model of a capitalist economy. The model may be considered as a control system with taxation as the control. But it differs from conventional model of control systems. It has some significant characters of complex systems.The system is described and studied by combining the mathematical formulas with computer simulations.Several related concepts as "output" and "control" etc. are reconsidered from new view-points. Via this problem we explore some phenomenon in controlled complex systems.

  3. System-Awareness for Agent-based Power System Control

    DEFF Research Database (Denmark)

    Heussen, Kai; Saleem, Arshad; Lind, Morten

    2010-01-01

    Operational intelligence in electric power systems is focused in a small number of control rooms that coordinate their actions. A clear division of responsibility and a command hierarchy organize system operation. With multi-agent based control systems, this control paradigm may be shifted...... to a more decentralized openaccess collaboration control paradigm. This shift cannot happen at once, but must fit also with current operation principles. In order to establish a scalable and transparent system control architecture, organizing principles have to be identified that allow for a smooth...

  4. An Agent Based Model for Social Class Emergence

    Science.gov (United States)

    Yang, Xiaoxiang; Rodriguez Segura, Daniel; Lin, Fei; Mazilu, Irina

    We present an open system agent-based model to analyze the effects of education and the society-specific wealth transactions on the emergence of social classes. Building on previous studies, we use realistic functions to model how years of education affect the income level. Numerical simulations show that the fraction of an individual's total transactions that is invested rather than consumed can cause wealth gaps between different income brackets in the long run. In an attempt to incorporate the network effects, we also explore how the probability of interactions among agents depending on the spread of their income brackets affects wealth distribution.

  5. An agent-based simulation of extirpation of Ceratitis capitata applied to invasions in California.

    Science.gov (United States)

    Manoukis, Nicholas C; Hoffman, Kevin

    2014-01-01

    We present an agent-based simulation (ABS) of Ceratitis capitata ("Medfly") developed for estimating the time to extirpation of this pest in areas where quarantines and eradication treatments were immediately imposed. We use the ABS, implemented in the program MED-FOES, to study seven different outbreaks that occurred in Southern California from 2008 to 2010. Results are compared with the length of intervention and quarantine imposed by the State, based on a linear developmental model (thermal unit accumulation, or "degree-day"). MED-FOES is a useful tool for invasive species managers as it incorporates more information from the known biology of the Medfly, and includes the important feature of being demographically explicit, providing significant improvements over simple degree-day calculations. While there was general agreement between the length of quarantine by degree-day and the time to extirpation indicated by MED-FOES, the ABS suggests that the margin of safety varies among cases and that in two cases the quarantine may have been excessively long. We also examined changes in the number of individuals over time in MED-FOES and conducted a sensitivity analysis for one of the outbreaks to explore the role of various input parameters on simulation outcomes. While our implementation of the ABS in this work is motivated by C. capitata and takes extirpation as a postulate, the simulation is very flexible and can be used to study a variety of questions on the invasion biology of pest insects and methods proposed to manage or eradicate such species.

  6. AGENT-BASED SIMULATION FOR KANSEI ENGINEERING: TESTING A FUZZY LINEAR QUANTIFICATION METHOD IN AN ARTIFICIAL WORLD

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper argues that agent-based simulation can be used as a way for testing Kansei Engineering methods which deal with the human reaction from sensory to mental state, that is, sensitivity, sense,sensibility, feeling, esthetics, emotion affection and intuition. A new fuzzy linear quantification method is tested in an artificial world by agent-based modeling and simulations, and the performance of the fuzzy linear method is compared with that of a genetic algorithm. The simulations can expand people's imagination and enhance people's intuition that the new fuzzy linear quantification method is effective.

  7. Novel Agent Based-approach for Industrial Diagnosis: A Combined use Between Case-based Reasoning and Similarity Measure

    Directory of Open Access Journals (Sweden)

    Fatima Zohra Benkaddour

    2016-12-01

    Full Text Available In spunlace nonwovens industry, the maintenance task is very complex, it requires experts and operators collaboration. In this paper, we propose a new approach integrating an agent- based modelling with case-based reasoning that utilizes similarity measures and preferences module. The main purpose of our study is to compare and evaluate the most suitable similarity measure for our case. Furthermore, operators that are usually geographically dispersed, have to collaborate and negotiate to achieve mutual agreements, especially when their proposals (diagnosis lead to a conflicting situation. The experimentation shows that the suggested agent-based approach is very interesting and efficient for operators and experts who collaborate in INOTIS enterprise.

  8. Comparing General and Special Education Preservice Teachers' Test Performance Using Traditional and Anchored Instruction

    Science.gov (United States)

    Malone, D. Michael; Langone, John

    2005-01-01

    Data comparing the effects of traditional lectures and instruction paired with video anchors on test scores of general education and special education preservice teachers are presented. The sample in both the experimental and control groups included a mixture of preservice teachers including those beginning a general education early childhood…

  9. An agent-based microsimulation of critical infrastructure systems

    Energy Technology Data Exchange (ETDEWEB)

    BARTON,DIANNE C.; STAMBER,KEVIN L.

    2000-03-29

    US infrastructures provide essential services that support the economic prosperity and quality of life. Today, the latest threat to these infrastructures is the increasing complexity and interconnectedness of the system. On balance, added connectivity will improve economic efficiency; however, increased coupling could also result in situations where a disturbance in an isolated infrastructure unexpectedly cascades across diverse infrastructures. An understanding of the behavior of complex systems can be critical to understanding and predicting infrastructure responses to unexpected perturbation. Sandia National Laboratories has developed an agent-based model of critical US infrastructures using time-dependent Monte Carlo methods and a genetic algorithm learning classifier system to control decision making. The model is currently under development and contains agents that represent the several areas within the interconnected infrastructures, including electric power and fuel supply. Previous work shows that agent-based simulations models have the potential to improve the accuracy of complex system forecasting and to provide new insights into the factors that are the primary drivers of emergent behaviors in interdependent systems. Simulation results can be examined both computationally and analytically, offering new ways of theorizing about the impact of perturbations to an infrastructure network.

  10. A Multi Agent Based Model for Airport Service Planning

    Directory of Open Access Journals (Sweden)

    W.H. Ip

    2010-09-01

    Full Text Available Aviation industry is highly dynamic and demanding in nature that time and safety are the two most important factors while one of the major sources of delay is aircraft on ground because of it complexity, a lot of machinery like vehicles are involved and lots of communication are involved. As one of the aircraft ground services providers in Hong Kong International Airport, China Aircraft Services Limited (CASL aims to increase competitiveness by better its service provided while minimizing cost is also needed. One of the ways is to optimize the number of maintenance vehicles allocated in order to minimize chance of delay and also operating costs. In the paper, an agent-based model is proposed for support decision making in vehicle allocation. The overview of the aircrafts ground services procedures is firstly mentioned with different optimization methods suggested by researchers. Then, the agent-based approach is introduced and in the latter part of report and a multi-agent system is built and proposed which is decision supportive for CASL in optimizing the maintenance vehicles' allocation. The application provides flexibility for inputting number of different kinds of vehicles, simulation duration and aircraft arrival rate in order to simulation different scenarios which occurs in HKIA.

  11. LEARNING REPOSITORY ADAPTABILITY IN AN AGENT-BASED UNIVERSITY ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Vanco Cabukovski

    2016-06-01

    Full Text Available Automated e-Learning Systems (AeLS are fundamental to contemporary educational concepts worldwide.It has become a standard not only in support to the formal curriculum, but containing social platform capabilities, gamification elements and functionalities fostering communities of experts, also for faster knowledge dissemination. Additionally, AeLSs support internal communications and customizable analytics and methodologies to quickly identify learning performance, which in turn can be used as feedback to implement adaptability in tailoring the content management to meet specific individual needs. The volume of fast growing AeLS content of supplement material and exchanged communication combined with the already huge material archived in the university libraries is enormous and needs sophisticated managing through electronic repositories. Such integration of content management systems (CMS present challenges which can be solved optimally with the use of distributed management implemented through agent-based systems. This paper depicts a successful implementation of an Integrated Intelligent Agent Based UniversityInformation System (IABUIS.

  12. Empirical agent-based modelling challenges and solutions

    CERN Document Server

    Barreteau, Olivier

    2014-01-01

    This instructional book showcases techniques to parameterise human agents in empirical agent-based models (ABM). In doing so, it provides a timely overview of key ABM methodologies and the most innovative approaches through a variety of empirical applications.  It features cutting-edge research from leading academics and practitioners, and will provide a guide for characterising and parameterising human agents in empirical ABM.  In order to facilitate learning, this text shares the valuable experiences of other modellers in particular modelling situations. Very little has been published in the area of empirical ABM, and this contributed volume will appeal to graduate-level students and researchers studying simulation modeling in economics, sociology, ecology, and trans-disciplinary studies, such as topics related to sustainability. In a similar vein to the instruction found in a cookbook, this text provides the empirical modeller with a set of 'recipes'  ready to be implemented. Agent-based modeling (AB...

  13. Evaluation of development prospects of renewable energy: agent based modelling

    Science.gov (United States)

    Klevakina, E. A.; Zabelina, I. A.; Murtazina, M. Sh

    2017-01-01

    The paper describes the agent-based model usage to evaluate the dynamics and the perspectives of alternative energy adopting in the Eastern regions of Russia. It includes a brief review of the agent-based models that can be used for estimation of alternatives in the process of transition to “green” economics. The authors show that active usage of solar energy in Russia is possible at the rural household level, when the climate conditions are appropriate. Adoption of solar energy sources decreases the energy production based on the conventional sources and improves the quality of environment in the regions. A complex regional multi-agent model is considered in this paper. The model consists of several private models and uses GIS technologies. These private models are a demographic and migration model of the region and a diffusion of the innovations model. In these models, agents are humans who live within the boundaries of the agents-municipalities, and agents as well are large-scale producers of electricity that pollutes the environment. Such a structure allows us to determine the changes in the demand for electricity generated by traditional sources. A simulation software will assist to identify the opportunities for implementation of alternative energy sources in the Eastern regions of Russia.

  14. Strengthening Theoretical Testing in Criminology Using Agent-based Modeling.

    Science.gov (United States)

    Johnson, Shane D; Groff, Elizabeth R

    2014-07-01

    The Journal of Research in Crime and Delinquency (JRCD) has published important contributions to both criminological theory and associated empirical tests. In this article, we consider some of the challenges associated with traditional approaches to social science research, and discuss a complementary approach that is gaining popularity-agent-based computational modeling-that may offer new opportunities to strengthen theories of crime and develop insights into phenomena of interest. Two literature reviews are completed. The aim of the first is to identify those articles published in JRCD that have been the most influential and to classify the theoretical perspectives taken. The second is intended to identify those studies that have used an agent-based model (ABM) to examine criminological theories and to identify which theories have been explored. Ecological theories of crime pattern formation have received the most attention from researchers using ABMs, but many other criminological theories are amenable to testing using such methods. Traditional methods of theory development and testing suffer from a number of potential issues that a more systematic use of ABMs-not without its own issues-may help to overcome. ABMs should become another method in the criminologists toolbox to aid theory testing and falsification.

  15. Modelling of robotic work cells using agent based-approach

    Science.gov (United States)

    Sękala, A.; Banaś, W.; Gwiazda, A.; Monica, Z.; Kost, G.; Hryniewicz, P.

    2016-08-01

    In the case of modern manufacturing systems the requirements, both according the scope and according characteristics of technical procedures are dynamically changing. This results in production system organization inability to keep up with changes in a market demand. Accordingly, there is a need for new design methods, characterized, on the one hand with a high efficiency and on the other with the adequate level of the generated organizational solutions. One of the tools that could be used for this purpose is the concept of agent systems. These systems are the tools of artificial intelligence. They allow assigning to agents the proper domains of procedures and knowledge so that they represent in a self-organizing system of an agent environment, components of a real system. The agent-based system for modelling robotic work cell should be designed taking into consideration many limitations considered with the characteristic of this production unit. It is possible to distinguish some grouped of structural components that constitute such a system. This confirms the structural complexity of a work cell as a specific production system. So it is necessary to develop agents depicting various aspects of the work cell structure. The main groups of agents that are used to model a robotic work cell should at least include next pattern representatives: machine tool agents, auxiliary equipment agents, robots agents, transport equipment agents, organizational agents as well as data and knowledge bases agents. In this way it is possible to create the holarchy of the agent-based system.

  16. INSPECTING COMPLIANCE TO MANY RULES: AN AGENT-BASED MODEL

    Directory of Open Access Journals (Sweden)

    Slaven Smojver

    2016-12-01

    Full Text Available Ever increasing scope and complexity of regulations and other rules that govern human society emphasise importance of the inspection of compliance to those rules. Often-used approaches to the inspection of compliance suffer from drawbacks such as overly idealistic assumptions and narrowness of application. Specifically, inspection models are frequently limited to situations where inspected entity has to comply with only one rule. Furthermore, inspection strategies regularly overlook some useful and available information such as varying costs of compliance to different rules. This article presents an agent-based model for inspection of compliance to many rules, which addresses abovementioned drawbacks. In the article, crime economic, game-theoretic and agent-based modelling approaches to inspection are briefly described, as well as their impact on the model. The model is described and simulation of a simplified version of the model is presented. The obtained results demonstrate that inspection strategies which take into account rules’ compliance costs perform significantly better than random strategies and better than cycle-based strategies. Additionally, the results encourage further, wider testing and validation of the model.

  17. Comparing Image-Based Methods for Assessing Visual Clutter in Generalized Maps

    Science.gov (United States)

    Touya, G.; Decherf, B.; Lalanne, M.; Dumont, M.

    2015-08-01

    Map generalization abstracts and simplifies geographic information to derive maps at smaller scales. The automation of map generalization requires techniques to evaluate the global quality of a generalized map. The quality and legibility of a generalized map is related to the complexity of the map, or the amount of clutter in the map, i.e. the excessive amount of information and its disorganization. Computer vision research is highly interested in measuring clutter in images, and this paper proposes to compare some of the existing techniques from computer vision, applied to generalized maps evaluation. Four techniques from the literature are described and tested on a large set of maps, generalized at different scales: edge density, subband entropy, quad tree complexity, and segmentation clutter. The results are analyzed against several criteria related to generalized maps, the identification of cluttered areas, the preservation of the global amount of information, the handling of occlusions and overlaps, foreground vs background, and blank space reduction.

  18. COMPARING IMAGE-BASED METHODS FOR ASSESSING VISUAL CLUTTER IN GENERALIZED MAPS

    Directory of Open Access Journals (Sweden)

    G. Touya

    2015-08-01

    Full Text Available Map generalization abstracts and simplifies geographic information to derive maps at smaller scales. The automation of map generalization requires techniques to evaluate the global quality of a generalized map. The quality and legibility of a generalized map is related to the complexity of the map, or the amount of clutter in the map, i.e. the excessive amount of information and its disorganization. Computer vision research is highly interested in measuring clutter in images, and this paper proposes to compare some of the existing techniques from computer vision, applied to generalized maps evaluation. Four techniques from the literature are described and tested on a large set of maps, generalized at different scales: edge density, subband entropy, quad tree complexity, and segmentation clutter. The results are analyzed against several criteria related to generalized maps, the identification of cluttered areas, the preservation of the global amount of information, the handling of occlusions and overlaps, foreground vs background, and blank space reduction.

  19. Developmental aspects of fear: Comparing the acquisition and generalization of conditioned fear in children and adults.

    Science.gov (United States)

    Schiele, Miriam A; Reinhard, Julia; Reif, Andreas; Domschke, Katharina; Romanos, Marcel; Deckert, Jürgen; Pauli, Paul

    2016-05-01

    Most research on human fear conditioning and its generalization has focused on adults whereas only little is known about these processes in children. Direct comparisons between child and adult populations are needed to determine developmental risk markers of fear and anxiety. We compared 267 children and 285 adults in a differential fear conditioning paradigm and generalization test. Skin conductance responses (SCR) and ratings of valence and arousal were obtained to indicate fear learning. Both groups displayed robust and similar differential conditioning on subjective and physiological levels. However, children showed heightened fear generalization compared to adults as indexed by higher arousal ratings and SCR to the generalization stimuli. Results indicate overgeneralization of conditioned fear as a developmental correlate of fear learning. The developmental change from a shallow to a steeper generalization gradient is likely related to the maturation of brain structures that modulate efficient discrimination between danger and (ambiguous) safety cues.

  20. Empirical agent-based land market: Integrating adaptive economic behavior in urban land-use models

    NARCIS (Netherlands)

    Filatova, Tatiana

    2015-01-01

    This paper introduces an economic agent-based model of an urban housing market. The RHEA (Risks and Hedonics in Empirical Agent-based land market) model captures natural hazard risks and environmental amenities through hedonic analysis, facilitating empirical agent-based land market modeling. RHEA i

  1. ModelforAnalyzing Human Communication Network Based onAgent-Based Simulation

    Science.gov (United States)

    Matsuyama, Shinako; Terano, Takao

    This paper discusses dynamic properties of human communications networks, which appears as a result of informationexchanges among people. We propose agent-based simulation (ABS) to examine implicit mechanisms behind the dynamics. The ABS enables us to reveal the characteristics and the differences of the networks regarding the specific communicationgroups. We perform experiments on the ABS with activity data from questionnaires survey and with virtual data which isdifferent from the activity data. We compare the difference between them and show the effectiveness of the ABS through theexperiments.

  2. Artificial Immune Systems Metaphor for Agent Based Modeling of Crisis Response Operations

    CERN Document Server

    Khalil, Khaled M; Nazmy, Taymour T; Salem, Abdel-Badeeh M

    2010-01-01

    Crisis response requires information intensive efforts utilized for reducing uncertainty, calculating and comparing costs and benefits, and managing resources in a fashion beyond those regularly available to handle routine problems. This paper presents an Artificial Immune Systems (AIS) metaphor for agent based modeling of crisis response operations. The presented model proposes integration of hybrid set of aspects (multi-agent systems, built-in defensive model of AIS, situation management, and intensity-based learning) for crisis response operations. In addition, the proposed response model is applied on the spread of pandemic influenza in Egypt as a case study.

  3. Agent-Based Approach for Modelling the Labour Migration from China to Russia

    Directory of Open Access Journals (Sweden)

    Valeriy Leonidovich Makarov

    2017-06-01

    Full Text Available The article describes the process of labour migration from China to Russia and shows its modelling using the agent-based approach. This approach allows us to simulate an artificial society in a computer program taking into account the diversity of individuals under consideration, as well as to model a set of laws and rules of conduct that make up the institutional environment in which the members of this society live. A brief review and analysis of agent-based migration models presented in the foreign literature are given. The agent-based model of labour migration from China to Russia developed by the Central Economic Mathematical Institute of the Russian Academy of Sciences simulates human behaviour close to reality, which is based on their internal purposes, determining the agents choice of territory as a place of residence. Therefore, at the development of the agents of the model and their behaviour algorithms, as well as the organization of the environment in which they exist and interact, the main characteristics of the population of two neighbouring countries and their demographic processes have been considered. Using the model, two experiments have been conducted. The purpose of the first of them was to assess the effect of depreciation of the rubble against the yuan on the overall indexes of labour migration, as well as its structure. In the second experiment, the procedure of the search of the information by agents for the migratory decision-making was changing. Namely, all generalizing information on the average salary by types of activity and skill level of employees, both in China and Russia, became available to all agents irrespective of their qualification level.

  4. On Changing the Framework of Psychology: Comparative Psychology Is What General Psychology Should Be.

    Science.gov (United States)

    Demarest, Jack

    1987-01-01

    Discusses the on-going debate between comparative and behaviorist frameworks in psychology. Advocates a comparative framework and suggests methods to avoid misconceptions about the field. A framework for reorganizing the focus of general psychology and integrating it into a neofunctionalist perspective is included. (DH)

  5. Comparing the Perceptions of Inclusion between General Education and Special Education Teachers

    Science.gov (United States)

    Bruster, Debra Dungan

    2014-01-01

    This causal-comparative, quantitative study compared the perceptions of inclusion of students with disabilities in the mainstream classroom that are held by high school general education teachers and high school special education teachers that teach in inclusive settings. The study determined there is a difference between the perceptions of…

  6. Agent-based cognitive model for human resources competence management.

    Science.gov (United States)

    Oliveira, Stefan; Gluz, João Carlos

    2010-01-01

    This chapter presents an agent-based cognitive model aimed to represent human competency concepts and competence management processes of psychological nature. This model is implemented by a multiagent system application intended to help managers of software development projects to select, based on the competence management model, the right professionals to integrate a development team. There are several software engineering methodologies that can be used to design and develop multiagent systems. However, due to the necessity to handle human competency concepts of cognitive nature, like aptitudes, interests, abilities and knowledge, we were driven to choose methodologies that can handle these concepts since the inception of the system. To do so, we integrated the TROPOS methodology, and a set of software engineering methods derived from intelligent tutoring systems research to successfully analyze and design the proposed system. At the end of the paper we present a study case, showing how the proposed system should be applied to the domain of website development.

  7. Capacity Analysis for Parallel Runway through Agent-Based Simulation

    Directory of Open Access Journals (Sweden)

    Yang Peng

    2013-01-01

    Full Text Available Parallel runway is the mainstream structure of China hub airport, runway is often the bottleneck of an airport, and the evaluation of its capacity is of great importance to airport management. This study outlines a model, multiagent architecture, implementation approach, and software prototype of a simulation system for evaluating runway capacity. Agent Unified Modeling Language (AUML is applied to illustrate the inbound and departing procedure of planes and design the agent-based model. The model is evaluated experimentally, and the quality is studied in comparison with models, created by SIMMOD and Arena. The results seem to be highly efficient, so the method can be applied to parallel runway capacity evaluation and the model propose favorable flexibility and extensibility.

  8. Building Distributed Web GIS: A Mobile-Agent Based Approach

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The diversity of GISs and the wide-spread availability of WWWhave l e d to an increasing amount of research on integrating a variety of heterogeneous and autonomous GISs in a cooperative environment to construct a new generation o f GIS characterizing in open architecture, distributed computation, interoperabi lity, and extensibility. Our on-going research project MADGI S (Mobile Agent based Distributed Geographic Information System) is reported, in which we pro pose the architecture of MADGIS to meet the requirements of integrating distribu ted GIS applications under Internet environment. We first describe the architect ure of MADGIS, and detailed discussions focusing on the structure of client site , server site and mobile agent in MADGIS. Then we explore key techniques for MAD GIS implementation.

  9. Next frontier in agent-based complex automated negotiation

    CERN Document Server

    Ito, Takayuki; Zhang, Minjie; Robu, Valentin

    2015-01-01

    This book focuses on automated negotiations based on multi-agent systems. It is intended for researchers and students in various fields involving autonomous agents and multi-agent systems, such as e-commerce tools, decision-making and negotiation support systems, and collaboration tools. The contents will help them to understand the concept of automated negotiations, negotiation protocols, negotiating agents’ strategies, and the applications of those strategies. In this book, some negotiation protocols focusing on the multiple interdependent issues in negotiations are presented, making it possible to find high-quality solutions for the complex agents’ utility functions. This book is a compilation of the extended versions of the very best papers selected from the many that were presented at the International Workshop on Agent-Based Complex Automated Negotiations.

  10. An Agent-Based Modeling for Pandemic Influenza in Egypt

    CERN Document Server

    Khalil, Khaled M; Nazmy, Taymour T; Salem, Abdel-Badeeh M

    2010-01-01

    Pandemic influenza has great potential to cause large and rapid increases in deaths and serious illness. The objective of this paper is to develop an agent-based model to simulate the spread of pandemic influenza (novel H1N1) in Egypt. The proposed multi-agent model is based on the modeling of individuals' interactions in a space time context. The proposed model involves different types of parameters such as: social agent attributes, distribution of Egypt population, and patterns of agents' interactions. Analysis of modeling results leads to understanding the characteristics of the modeled pandemic, transmission patterns, and the conditions under which an outbreak might occur. In addition, the proposed model is used to measure the effectiveness of different control strategies to intervene the pandemic spread.

  11. Complexity and agent-based modelling in urban research

    DEFF Research Database (Denmark)

    Fertner, Christian

    Urbanisation processes are results of a broad variety of actors or actor groups and their behaviour and decisions based on different experiences, knowledge, resources, values etc. The decisions done are often on a micro/individual level but resulting in macro/collective behaviour. In urban research...... influence on the bigger system. Traditional scientific methods or theories often tried to simplify, not accounting complex relations of actors and decision-making. The introduction of computers in simulation made new approaches in modelling, as for example agent-based modelling (ABM), possible, dealing...... of complexity for a majority of science, there exists a huge number of scientific articles, books, tutorials etc. to these topics which doesn’t make it easy for a novice in the field to find the right literature. The literature used gives an optimistic outlook for the future of this methodology, although ABM...

  12. Autonomous Traffic Control System Using Agent Based Technology

    CERN Document Server

    M, Venkatesh; V, Srinivas

    2011-01-01

    The way of analyzing, designing and building of real-time projects has been changed due to the rapid growth of internet, mobile technologies and intelligent applications. Most of these applications are intelligent, tiny and distributed components called as agent. Agent works like it takes the input from numerous real-time sources and gives back the real-time response. In this paper how these agents can be implemented in vehicle traffic management especially in large cities and identifying various challenges when there is a rapid growth of population and vehicles. In this paper our proposal gives a solution for using autonomous or agent based technology. These autonomous or intelligent agents have the capability to observe, act and learn from their past experience. This system uses the knowledge flow of precedent signal or data to identify the incoming flow of forthcoming signal. Our architecture involves the video analysis and exploration using some Intelligence learning algorithm to estimate and identify the...

  13. Agent-based distributed hierarchical control of dc microgrid systems

    DEFF Research Database (Denmark)

    Meng, Lexuan; Vasquez, Juan Carlos; Guerrero, Josep M.

    2014-01-01

    In order to enable distributed control and management for microgrids, this paper explores the application of information consensus and local decisionmaking methods formulating an agent based distributed hierarchical control system. A droop controlled paralleled DC/DC converter system is taken...... as a case study. The objective is to enhance the system efficiency by finding the optimal sharing ratio of load current. Virtual resistances in local control systems are taken as decision variables. Consensus algorithms are applied for global information discovery and local control systems coordination....... Standard genetic algorithm is applied in each local control system in order to search for a global optimum. Hardware-in-Loop simulation results are shown to demonstrate the effectiveness of the method....

  14. Agent-based Simulation of the Maritime Domain

    Directory of Open Access Journals (Sweden)

    O. Vaněk

    2010-01-01

    Full Text Available In this paper, a multi-agent based simulation platform is introduced that focuses on legitimate and illegitimate aspects of maritime traffic, mainly on intercontinental transport through piracy afflicted areas. The extensible architecture presented here comprises several modules controlling the simulation and the life-cycle of the agents, analyzing the simulation output and visualizing the entire simulated domain. The simulation control module is initialized by various configuration scenarios to simulate various real-world situations, such as a pirate ambush, coordinated transit through a transport corridor, or coastal fishing and local traffic. The environmental model provides a rich set of inputs for agents that use the geo-spatial data and the vessel operational characteristics for their reasoning. The agent behavior model based on finite state machines together with planning algorithms allows complex expression of agent behavior, so the resulting simulation output can serve as a substitution for real world data from the maritime domain.

  15. An Agent Based approach to design Serious Game

    Directory of Open Access Journals (Sweden)

    Manuel Gentile

    2014-06-01

    Full Text Available Serious games are designed to train and educate learners, opening up new learning approaches like exploratory learning and situated cognition.  Despite growing interest in these games, their design is still an artisan process.On the basis of experiences in designing computer simulation, this paper proposes an agent-based approach to guide the design process of a serious game. The proposed methodology allows the designer to strike the right equilibrium between educational effectiveness and entertainment, realism and complexity.The design of the PNPVillage game is used as a case study. The PNPVillage game aims to introduce and foster an entrepreneurial mindset among young students. It was implemented within the framework of the European project “I  can… I cannot… I go!” Rev.2

  16. Agent Based Modeling on Organizational Dynamics of Terrorist Network

    Directory of Open Access Journals (Sweden)

    Bo Li

    2015-01-01

    Full Text Available Modeling organizational dynamics of terrorist network is a critical issue in computational analysis of terrorism research. The first step for effective counterterrorism and strategic intervention is to investigate how the terrorists operate with the relational network and what affects the performance. In this paper, we investigate the organizational dynamics by employing a computational experimentation methodology. The hierarchical cellular network model and the organizational dynamics model are developed for modeling the hybrid relational structure and complex operational processes, respectively. To intuitively elucidate this method, the agent based modeling is used to simulate the terrorist network and test the performance in diverse scenarios. Based on the experimental results, we show how the changes of operational environments affect the development of terrorist organization in terms of its recovery and capacity to perform future tasks. The potential strategies are also discussed, which can be used to restrain the activities of terrorists.

  17. AGENT based structural static and dynamic collaborative optimization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A static and dynamic collaborative optimization mode for complex machine system and itsontology project relationship are put forward, on which an agent-based structural static and dynamiccollaborative optimization system is constructed as two agent colonies: optimization agent colony andfinite element analysis colony. And a two-level solving strategy as well as the necessity and possibilityfor handing with finite element analysis model in multi-level mode is discussed. Furthermore, the coop-eration of all FEA agents for optimal design of complicated structural is studied in detail. Structural stat-ic and dynamic collaborative optimization of hydraulic excavator working equimpent is taken as an ex-ample to show that the system is reliable.

  18. A Formal Approach for Agent Based Large Concurrent Intelligent Systems

    CERN Document Server

    Chaudhary, Ankit

    2011-01-01

    Large Intelligent Systems are so complex these days that an urgent need for designing such systems in best available way is evolving. Modeling is the useful technique to show a complex real world system into the form of abstraction, so that analysis and implementation of the intelligent system become easy and is useful in gathering the prior knowledge of system that is not possible to experiment with the real world complex systems. This paper discusses a formal approach of agent-based large systems modeling for intelligent systems, which describes design level precautions, challenges and techniques using autonomous agents, as its fundamental modeling abstraction. We are discussing Ad-Hoc Network System as a case study in which we are using mobile agents where nodes are free to relocate, as they form an Intelligent Systems. The designing is very critical in this scenario and it can reduce the whole cost, time duration and risk involved in the project.

  19. Agent-based simulation of a financial market

    Science.gov (United States)

    Raberto, Marco; Cincotti, Silvano; Focardi, Sergio M.; Marchesi, Michele

    2001-10-01

    This paper introduces an agent-based artificial financial market in which heterogeneous agents trade one single asset through a realistic trading mechanism for price formation. Agents are initially endowed with a finite amount of cash and a given finite portfolio of assets. There is no money-creation process; the total available cash is conserved in time. In each period, agents make random buy and sell decisions that are constrained by available resources, subject to clustering, and dependent on the volatility of previous periods. The model proposed herein is able to reproduce the leptokurtic shape of the probability density of log price returns and the clustering of volatility. Implemented using extreme programming and object-oriented technology, the simulator is a flexible computational experimental facility that can find applications in both academic and industrial research projects.

  20. A spatial web/agent-based model to support stakeholders' negotiation regarding land development.

    Science.gov (United States)

    Pooyandeh, Majeed; Marceau, Danielle J

    2013-11-15

    Decision making in land management can be greatly enhanced if the perspectives of concerned stakeholders are taken into consideration. This often implies negotiation in order to reach an agreement based on the examination of multiple alternatives. This paper describes a spatial web/agent-based modeling system that was developed to support the negotiation process of stakeholders regarding land development in southern Alberta, Canada. This system integrates a fuzzy analytic hierarchy procedure within an agent-based model in an interactive visualization environment provided through a web interface to facilitate the learning and negotiation of the stakeholders. In the pre-negotiation phase, the stakeholders compare their evaluation criteria using linguistic expressions. Due to the uncertainty and fuzzy nature of such comparisons, a fuzzy Analytic Hierarchy Process is then used to prioritize the criteria. The negotiation starts by a development plan being submitted by a user (stakeholder) through the web interface. An agent called the proposer, which represents the proposer of the plan, receives this plan and starts negotiating with all other agents. The negotiation is conducted in a step-wise manner where the agents change their attitudes by assigning a new set of weights to their criteria. If an agreement is not achieved, a new location for development is proposed by the proposer agent. This process is repeated until a location is found that satisfies all agents to a certain predefined degree. To evaluate the performance of the model, the negotiation was simulated with four agents, one of which being the proposer agent, using two hypothetical development plans. The first plan was selected randomly; the other one was chosen in an area that is of high importance to one of the agents. While the agents managed to achieve an agreement about the location of the land development after three rounds of negotiation in the first scenario, seven rounds were required in the second

  1. An Adaptive Agent-Based Model of Homing Pigeons: A Genetic Algorithm Approach

    Directory of Open Access Journals (Sweden)

    Francis Oloo

    2017-01-01

    Full Text Available Conventionally, agent-based modelling approaches start from a conceptual model capturing the theoretical understanding of the systems of interest. Simulation outcomes are then used “at the end” to validate the conceptual understanding. In today’s data rich era, there are suggestions that models should be data-driven. Data-driven workflows are common in mathematical models. However, their application to agent-based models is still in its infancy. Integration of real-time sensor data into modelling workflows opens up the possibility of comparing simulations against real data during the model run. Calibration and validation procedures thus become automated processes that are iteratively executed during the simulation. We hypothesize that incorporation of real-time sensor data into agent-based models improves the predictive ability of such models. In particular, that such integration results in increasingly well calibrated model parameters and rule sets. In this contribution, we explore this question by implementing a flocking model that evolves in real-time. Specifically, we use genetic algorithms approach to simulate representative parameters to describe flight routes of homing pigeons. The navigation parameters of pigeons are simulated and dynamically evaluated against emulated GPS sensor data streams and optimised based on the fitness of candidate parameters. As a result, the model was able to accurately simulate the relative-turn angles and step-distance of homing pigeons. Further, the optimised parameters could replicate loops, which are common patterns in flight tracks of homing pigeons. Finally, the use of genetic algorithms in this study allowed for a simultaneous data-driven optimization and sensitivity analysis.

  2. Linking agent-based models and stochastic models of financial markets.

    Science.gov (United States)

    Feng, Ling; Li, Baowen; Podobnik, Boris; Preis, Tobias; Stanley, H Eugene

    2012-05-29

    It is well-known that financial asset returns exhibit fat-tailed distributions and long-term memory. These empirical features are the main objectives of modeling efforts using (i) stochastic processes to quantitatively reproduce these features and (ii) agent-based simulations to understand the underlying microscopic interactions. After reviewing selected empirical and theoretical evidence documenting the behavior of traders, we construct an agent-based model to quantitatively demonstrate that "fat" tails in return distributions arise when traders share similar technical trading strategies and decisions. Extending our behavioral model to a stochastic model, we derive and explain a set of quantitative scaling relations of long-term memory from the empirical behavior of individual market participants. Our analysis provides a behavioral interpretation of the long-term memory of absolute and squared price returns: They are directly linked to the way investors evaluate their investments by applying technical strategies at different investment horizons, and this quantitative relationship is in agreement with empirical findings. Our approach provides a possible behavioral explanation for stochastic models for financial systems in general and provides a method to parameterize such models from market data rather than from statistical fitting.

  3. The more information, the more negative stigma towards schizophrenia: Brazilian general population and psychiatrists compared.

    Science.gov (United States)

    Loch, Alexandre Andrade; Hengartner, Michael Pascal; Guarniero, Francisco Bevilacqua; Lawson, Fabio Lorea; Wang, Yuan-Pang; Gattaz, Wagner Farid; Rössler, Wulf

    2013-02-28

    Findings on stigmatizing attitudes toward individuals with schizophrenia have been inconsistent in comparisons between mental health professionals and members of the general public. In this regard, it is important to obtain data from understudied sociocultural settings, and to examine how attitudes toward mental illness vary in such settings. Nationwide samples of 1015 general population individuals and 1414 psychiatrists from Brazil were recruited between 2009 and 2010. Respondents from the general population were asked to identify an unlabeled schizophrenia case vignette. Psychiatrists were instructed to consider "someone with stabilized schizophrenia". Stereotypes, perceived prejudice and social distance were assessed. For the general population, stigma determinants replicated findings from the literature. The level of the vignette's identification constituted an important correlate. For psychiatrists, determinants correlated in the opposite direction. When both samples were compared, psychiatrists showed the highest scores in stereotypes and perceived prejudice; for the general population, the better they recognized the vignette, the higher they scored in those dimensions. Psychiatrists reported the lowest social distance scores compared with members of the general population. Knowledge about schizophrenia thus constituted an important determinant of stigma; consequently, factors influencing stigma should be further investigated in the general population and in psychiatrists as well. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Rural-urban migration including formal and informal workers in the urban sector: an agent-based numerical simulation study

    Science.gov (United States)

    Branco, Nilton; Oliveira, Tharnier; Silveira, Jaylson

    2012-02-01

    The goal of this work is to study rural-urban migration in the early stages of industrialization. We use an agent-based model and take into account the existence of informal and formal workers on the urban sector and possible migration movements, dependent on the agents' social and private utilities. Our agents are place on vertices of a square lattice, such that each vertex has only one agent. Rural, urban informal and urban formal workers are represented by different states of a three-state Ising model. At every step, a fraction a of the agents may change sectors or migrate. The total utility of a given agent is then calculated and compared to a random utility, in order to check if this agent turns into an actual migrant or changes sector. The dynamics is carried out until an equilibrium state is reached and equilibrium variables are then calculated and compared to available data. We find that a generalized Harris-Todaro condition is satisfied [1] on these equilibrium regimes, i.e, the ratio between expected wages between any pair of sectors reach a constant value. [4pt] [1] J. J. Silveira, A. L. Esp'indola and T. J. Penna, Physica A, 364, 445 (2006).

  5. Evaluating Water Demand Using Agent-Based Modeling

    Science.gov (United States)

    Lowry, T. S.

    2004-12-01

    The supply and demand of water resources are functions of complex, inter-related systems including hydrology, climate, demographics, economics, and policy. To assess the safety and sustainability of water resources, planners often rely on complex numerical models that relate some or all of these systems using mathematical abstractions. The accuracy of these models relies on how well the abstractions capture the true nature of the systems interactions. Typically, these abstractions are based on analyses of observations and/or experiments that account only for the statistical mean behavior of each system. This limits the approach in two important ways: 1) It cannot capture cross-system disruptive events, such as major drought, significant policy change, or terrorist attack, and 2) it cannot resolve sub-system level responses. To overcome these limitations, we are developing an agent-based water resources model that includes the systems of hydrology, climate, demographics, economics, and policy, to examine water demand during normal and extraordinary conditions. Agent-based modeling (ABM) develops functional relationships between systems by modeling the interaction between individuals (agents), who behave according to a probabilistic set of rules. ABM is a "bottom-up" modeling approach in that it defines macro-system behavior by modeling the micro-behavior of individual agents. While each agent's behavior is often simple and predictable, the aggregate behavior of all agents in each system can be complex, unpredictable, and different than behaviors observed in mean-behavior models. Furthermore, the ABM approach creates a virtual laboratory where the effects of policy changes and/or extraordinary events can be simulated. Our model, which is based on the demographics and hydrology of the Middle Rio Grande Basin in the state of New Mexico, includes agent groups of residential, agricultural, and industrial users. Each agent within each group determines its water usage

  6. Serious games experiment toward agent-based simulation

    Science.gov (United States)

    Wein, Anne; Labiosa, William

    2013-01-01

    We evaluate the potential for serious games to be used as a scientifically based decision-support product that supports the United States Geological Survey’s (USGS) mission--to provide integrated, unbiased scientific information that can make a substantial contribution to societal well-being for a wide variety of complex environmental challenges. Serious or pedagogical games are an engaging way to educate decisionmakers and stakeholders about environmental challenges that are usefully informed by natural and social scientific information and knowledge and can be designed to promote interactive learning and exploration in the face of large uncertainties, divergent values, and complex situations. We developed two serious games that use challenging environmental-planning issues to demonstrate and investigate the potential contributions of serious games to inform regional-planning decisions. Delta Skelta is a game emulating long-term integrated environmental planning in the Sacramento-San Joaquin Delta, California, that incorporates natural hazards (flooding and earthquakes) and consequences for California water supplies amidst conflicting water interests. Age of Ecology is a game that simulates interactions between economic and ecologic processes, as well as natural hazards while implementing agent-based modeling. The content of these games spans the USGS science mission areas related to water, ecosystems, natural hazards, land use, and climate change. We describe the games, reflect on design and informational aspects, and comment on their potential usefulness. During the process of developing these games, we identified various design trade-offs involving factual information, strategic thinking, game-winning criteria, elements of fun, number and type of players, time horizon, and uncertainty. We evaluate the two games in terms of accomplishments and limitations. Overall, we demonstrated the potential for these games to usefully represent scientific information

  7. Apnea after awake-regional and general anesthesia in infants: The General Anesthesia compared to Spinal anesthesia (GAS) study: comparing apnea and neurodevelopmental outcomes, a randomized controlled trial

    Science.gov (United States)

    Davidson, Andrew J.; Morton, Neil S.; Arnup, Sarah J.; de Graaff, Jurgen C.; Disma, Nicola; Withington, Davinia E.; Frawley, Geoff; Hunt, Rodney W.; Hardy, Pollyanna; Khotcholava, Magda; von Ungern Sternberg, Britta S.; Wilton, Niall; Tuo, Pietro; Salvo, Ida; Ormond, Gillian; Stargatt, Robyn; Locatelli, Bruno Guido; McCann, Mary Ellen

    2015-01-01

    Background Post-operative apnea is a complication in young infants. Awake-regional anesthesia (RA) may reduce the risk; however the evidence is weak. The General Anesthesia compared to Spinal anesthesia (GAS) study is a randomized, controlled, trial designed to assess the influence of general anesthesia (GA) on neurodevelopment. A secondary aim is to compare rates of apnea after anesthesia. Methods Infants ≤ 60 weeks postmenstrual age scheduled for inguinal herniorraphy were randomized to RA or GA. Exclusion criteria included risk factors for adverse neurodevelopmental outcome and infants born < 26 weeks’ gestation. The primary outcome of this analysis was any observed apnea up to 12 hours post-operatively. Apnea assessment was unblinded. Results 363 patients were assigned to RA and 359 to GA. Overall the incidence of apnea (0 to 12 hours) was similar between arms (3% in RA and 4% in GA arms, Odds Ratio (OR) 0.63, 95% Confidence Intervals (CI): 0.31 to 1.30, P=0.2133), however the incidence of early apnea (0 to 30 minutes) was lower in the RA arm (1% versus 3%, OR 0.20, 95%CI: 0.05 to 0.91, P=0.0367). The incidence of late apnea (30 minutes to 12 hours) was 2% in both RA and GA arms (OR 1.17, 95%CI: 0.41 to 3.33, P=0.7688). The strongest predictor of apnea was prematurity (OR 21.87, 95% CI 4.38 to 109.24) and 96% of infants with apnea were premature. Conclusions RA in infants undergoing inguinal herniorraphy reduces apnea in the early post-operative period. Cardio-respiratory monitoring should be used for all ex-premature infants. PMID:26001033

  8. Is the efficacy of psychopharmacological drugs comparable to the efficacy of general medicine medication?

    Directory of Open Access Journals (Sweden)

    Seemüller Florian

    2012-02-01

    Full Text Available Abstract There is an ongoing debate concerning the risk benefit ratio of psychopharmacologic compounds. With respect to the benefit, recent reports and meta-analyses note only small effect sizes with comparably high placebo response rates in the psychiatric field. These reports together with others lead to a wider, general critique on psychotropic drugs in the scientific community and in the lay press. In a recently published article, Leucht and his colleagues compare the efficacy of psychotropic drugs with the efficacy of common general medicine drugs in different indications according to results from reviewed meta-analyses. The authors conclude that, overall, the psychiatric drugs were generally not less effective than most other medical drugs. This article will highlight some of the results of this systematic review and discuss the limitations and the impact of this important approach on the above mentioned debate.

  9. Psychological acculturation and juvenile delinquency: comparing Moroccan immigrant families from a general and pretrial detention population.

    Science.gov (United States)

    Stevens, Gonneke W J M; Veen, Violaine C; Vollebergh, Wilma A M

    2014-04-01

    Although several theoretical notions have been proposed predicting a relationship between acculturation orientation and juvenile delinquency, the available empirical research is scarce and limited. To extend former research, in this study, we used latent class analyses to compare bidimensional psychological acculturation orientation of Moroccan immigrant boys in pretrial detention with those of Moroccan boys in the general population. We also examined their parents' acculturation orientation. We found that boys in pretrial detention were clearly overrepresented in the integrated psychological acculturation class and underrepresented in the separated psychological acculturation class when we compared them with the boys in the general population. Highly similar results were found for their parents. In contrast, boys in pretrial detention were as likely to be faced with an intergenerational acculturation gap as boys from the general population.

  10. Brief Cognitive Behavioural Therapy Compared to Optimised General Practitioners? Care for Depression: A Randomised Trial

    NARCIS (Netherlands)

    Schene, A. H.; Baas, K. D.; Koeter, M.; Lucassen, P.; Bockting, C. L. H.; Wittkampf, K. F.; van Weert, H. C.; Huyser, J.

    2014-01-01

    Background: How to treat Major Depressive Disorder (MDD) in primary care? Studies that compared (brief) Cognitive Behavioural Therapy (CBT) with care as usual by the General Practitioner (GP) found the first to be more effective. However, to make a fair comparison GP care should be optimised and pro

  11. Brief Cognitive Behavioural Therapy compared to optimised general practitioners’ care for depression : A randomised trial

    NARCIS (Netherlands)

    Schene, A.H.; Baas, K.D.; Koeter, M.W.J.; Lucassen, P.; Bockting, C.L.H.; Wittkampf, K.A.; Huyser, J.; van Weert, H.C.

    2014-01-01

    Background: How to treat Major Depressive Disorder (MDD) in primary care? Studies that compared (brief) Cognitive Behavioural Therapy (CBT) with care as usual by the General Practitioner (GP) found the first to be more effective. However, to make a fair comparison GP care should be optimised and pro

  12. Comparative Study of Bullying Victimization among Students in General and Special Education

    Science.gov (United States)

    Hartley, Michael T.; Bauman, Sheri; Nixon, Charisse L.; Davis, Stan

    2015-01-01

    Research on bullying is an important avenue for understanding the social integration of students in special education. Focused on 3,305 students who self-reported victimization of two to three times per month or more, this study compared the pattern of verbal, relational, and physical bullying among students in general education and special…

  13. Comparing Multicultural with General Counseling Knowledge and Skill Competency for Students Who Completed Counselor Training

    Science.gov (United States)

    Cates, Jennifer T.; Schaefle, Scott E.; Smaby, Marlowe H.; Maddux, Cleborne D.; LeBeauf, Ireon

    2007-01-01

    This study evaluates the effectiveness of a counselor education program in teaching multicultural counseling knowledge and skills. Standardized examination scores and rater evaluations compare multicultural with general counseling knowledge and skill competency for students who completed a counseling master's program. The relationship between…

  14. Mortality among patients with cleared hepatitis C virus infection compared to the general population

    DEFF Research Database (Denmark)

    Omland, Lars Haukali; Christensen, Peer Brehm; Krarup, Henrik Bygum;

    2011-01-01

    The increased mortality in HCV-infected individuals partly stems from viral damage to the liver and partly from risk-taking behaviours. We examined mortality in patients who cleared their HCV-infection, comparing it to that of the general population. We also addressed the question whether prognos...... differed according to age, substance abuse (alcohol abuse and injection drug use) and comorbidity....

  15. Sleep Difficulties and Insomnia Symptoms in Norwegian Musicians Compared to the General Population and Workforce.

    Science.gov (United States)

    Vaag, Jonas; Saksvik-Lehouillier, Ingvild; Bjørngaard, Johan Håkon; Bjerkeset, Ottar

    2016-01-01

    Sleep problems are reported as common among performing artists and musicians. However, epidemiological research comparing musicians to different groups of the general population is lacking. For this study, 4,168 members of the Norwegian Musician's Union were invited to an online survey regarding work and health. Of the 2,121 (51%) respondents, 1,607 were active performing musicians. We measured prevalence of insomnia symptoms using the Bergen Insomnia Scale (BIS), and compared this sample to a representative sample of the general Norwegian population (n = 2,645). Overall, musicians had higher prevalence of insomnia symptoms compared to the general population (Prevalence Difference 6.9, 95% Confidence Interval 3.9-10.0). Item response analysis showed that this difference was mainly explained by nonrestorative sleep and dissatisfaction with sleep among musicians. An additional analysis, comparing musicians to the general Norwegian workforce (n = 8,518) on sleep difficulties, confirmed this tendency (Prevalence Difference 6.2, 95% Confidence Interval 4.3-8.1). Musicians performing classical, contemporary, rock, and country music reported the highest prevalence of insomnia, and these genres might be of special interest when developing preventative measures, treatment strategies, and further research on sleep difficulties among musicians.

  16. Multi-agent Based Charges subsystem for Supply Chain Logistics

    Directory of Open Access Journals (Sweden)

    Pankaj Rani

    2012-05-01

    Full Text Available The main objective of this paper is to design charges subsystem using multi agent technology which deals with calculation, accrual and collection of various charges levied at the goods in a supply chain Logistics. Accrual of various charges such as freight, demurrage, and wharfage take place implicitly in the SC system at the various events of different subsystems which is collected and calculated by software agents. An Agent-based modeling is an approach based on the idea that a system is composed of decentralized individual ‘agents’ and that each agent interacts with other agents according to its localized knowledge. Our aim is to design a flexible architecture that can deal with next generation supply chain problems based on a multi-agent architecture. In this article, a multi agent system has been developed to calculate charges levied at various stages on good sheds.. Each entity is modeled as one agent and their coordination lead to control inventories and minimize the total cost of SC by sharing information and forecasting knowledge and using negotiation mechanism.

  17. Agent-based modeling to simulate the dengue spread

    Science.gov (United States)

    Deng, Chengbin; Tao, Haiyan; Ye, Zhiwei

    2008-10-01

    In this paper, we introduce a novel method ABM in simulating the unique process for the dengue spread. Dengue is an acute infectious disease with a long history of over 200 years. Unlike the diseases that can be transmitted directly from person to person, dengue spreads through a must vector of mosquitoes. There is still no any special effective medicine and vaccine for dengue up till now. The best way to prevent dengue spread is to take precautions beforehand. Thus, it is crucial to detect and study the dynamic process of dengue spread that closely relates to human-environment interactions where Agent-Based Modeling (ABM) effectively works. The model attempts to simulate the dengue spread in a more realistic way in the bottom-up way, and to overcome the limitation of ABM, namely overlooking the influence of geographic and environmental factors. Considering the influence of environment, Aedes aegypti ecology and other epidemiological characteristics of dengue spread, ABM can be regarded as a useful way to simulate the whole process so as to disclose the essence of the evolution of dengue spread.

  18. Agent-based mapping of credit risk for sustainable microfinance.

    Science.gov (United States)

    Lee, Joung-Hun; Jusup, Marko; Podobnik, Boris; Iwasa, Yoh

    2015-01-01

    By drawing analogies with independent research areas, we propose an unorthodox framework for mapping microfinance credit risk--a major obstacle to the sustainability of lenders outreaching to the poor. Specifically, using the elements of network theory, we constructed an agent-based model that obeys the stylized rules of microfinance industry. We found that in a deteriorating economic environment confounded with adverse selection, a form of latent moral hazard may cause a regime shift from a high to a low loan payment probability. An after-the-fact recovery, when possible, required the economic environment to improve beyond that which led to the shift in the first place. These findings suggest a small set of measurable quantities for mapping microfinance credit risk and, consequently, for balancing the requirements to reasonably price loans and to operate on a fully self-financed basis. We illustrate how the proposed mapping works using a 10-year monthly data set from one of the best-known microfinance representatives, Grameen Bank in Bangladesh. Finally, we discuss an entirely new perspective for managing microfinance credit risk based on enticing spontaneous cooperation by building social capital.

  19. A SIMULATION OF CONTRACT FARMING USING AGENT BASED MODELING

    Directory of Open Access Journals (Sweden)

    Yuanita Handayati

    2016-12-01

    Full Text Available This study aims to simulate the effects of contract farming and farmer commitment to contract farming on supply chain performance by using agent based modeling as a methodology. Supply chain performance is represented by profits and service levels. The simulation results indicate that farmers should pay attention to customer requirements and plan their agricultural activities in order to fulfill these requirements. Contract farming helps farmers deal with demand and price uncertainties. We also find that farmer commitment is crucial to fulfilling contract requirements. This study contributes to this field from a conceptual as well as a practical point of view. From the conceptual point of view, our simulation results show that different levels of farmer commitment have an impact on farmer performance when implementing contract farming. From a practical point of view, the uncertainty faced by farmers and the market can be managed by implementing cultivation and harvesting scheduling, information sharing, and collective learning as ways of committing to contract farming.

  20. Smart Agent Based Mobile Tutoring and Querying System

    Directory of Open Access Journals (Sweden)

    Suresh Sankaranarayanan

    2012-08-01

    Full Text Available With our busy schedules today and the rising cost of education there is a need to find a convenient and cost effective means of maximizing our educational/training experiences. New trends in the delivery/access of information are becoming more technology based in all areas of society with education being no exception. The ubiquitous use of mobile devices has led to a boom in m-commerce. Mobile devices provide many services in commercial environments such as mobile banking, mobile purchasing, mobile learning, etc. It is therefore fitting that we seek to use mobile devices as a platform in delivering our convenient and cost effective solution. The proposed agent based Mobile tutoring system seeks to provide a student with a rich learning experience that will provide them with the relevant reading material based on their stage of development which allows them to move at their own pace. The system will allow the user to be able to ask certain questions and get explanations as if they were interacting with a human tutor but with the added benefit of being able to do this anytime in any location via their mobile phone.

  1. Complete agent based simulation of mini-grids

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez de Durana, J.M.; Barambones, O. [Univ. of the Basque Country, Vitoria (Spain). Dept. Ingeniera de Sistemas y Automatica; Kremers, E.; Viejo, P. [Karlsruhe Univ., Karlsruhe (Germany). European Inst. for Energy Research

    2009-07-01

    Most people without access to electricity live in remote and rural areas of developing countries where micro-grids have a high potential to actively participate in the electrification of such areas. Micro-grids may be fed by electricity from different renewable and conventional decentralized sources. There are several interesting hybrid renewable energy system (HRES) micro-grid applications, such as mobile equipment; autonomous equipment; small village electricity power supply; water pumping and irrigation systems; communications power supply; and mobile health emergency clinics. This paper presented a review of some of the main types of HRESs. The paper described an agent based model of a simple example of one such system, a micro-grid, oriented to designing a decentralized supervisor control. The model was implemented using AnyLogic and was primarily intended as a tool for design, development and demonstration of micro-grid control strategies. According to simulation results, the model could be used to analyze micro-grid design, operation strategies and economic benefits. 6 refs., 6 figs.

  2. Agent-based modelling of heating system adoption in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Sopha, Bertha Maya; Kloeckner, Christian A.; Hertwich, Edgar G.

    2010-07-01

    Full text: This paper introduces agent-based modelling as a methodological approach to understand the effect of decision making mechanism on the adoption of heating systems in Norway. The model is used as an experimental/learning tool to design possible interventions, not for prediction. The intended users of the model are therefore policy designers. Primary heating system adoptions of electric heating, heat pump and wood pellet heating were selected. Random topology was chosen to represent social network among households. Agents were households with certain location, number of peers, current adopted heating system, employed decision strategy, and degree of social influence in decision making. The overall framework of decision-making integrated theories from different disciplines; customer behavior theory, behavioral economics, theory of planned behavior, and diffusion of innovation, in order to capture possible decision making processes in households. A mail survey of 270 Norwegian households conducted in 2008 was designed specifically for acquiring data for the simulation. The model represents real geographic area of households and simulates the overall fraction of adopted heating system under study. The model was calibrated with historical data from Statistics Norway (SSB). Interventions with respects to total cost, norms, indoor air quality, reliability, supply security, required work, could be explored using the model. For instance, the model demonstrates that a considerable total cost (investment and operating cost) increase of electric heating and heat pump, rather than a reduction of wood pellet heating's total cost, are required to initiate and speed up wood pellet adoption. (Author)

  3. MAST – A Mobile Agent-based Security Tool

    Directory of Open Access Journals (Sweden)

    Marco Carvalho

    2004-08-01

    Full Text Available One of the chief computer security problems is not the long list of viruses and other potential vulnerabilities, but the vast number of systems that continue to be easy prey, as their system administrators or owners simply are not able to keep up with all of the available patches, updates, or needed configuration changes in order to protect them from those known vulnerabilities. Even up-to-date systems could become vulnerable to attacks, due to inappropriate configuration or combined used of applications and services. Our mobile agent-based security tool (MAST is designed to bridge this gap, and provide automated methods to make sure that all of the systems in a specific domain or network are secured and up-to-date with all patches and updates. The tool is also designed to check systems for misconfigurations that make them vulnerable. Additionally, this user interface is presented in a domain knowledge model known as a Concept Map that provides a continuous learning experience for the system administrator.

  4. Using Crowdsourced Geodata for Agent-Based Indoor Evacuation Simulations

    Directory of Open Access Journals (Sweden)

    Alexander Zipf

    2012-08-01

    Full Text Available Crowdsourced geodata has been proven to be a rich and major data source for environmental simulations and analysis, as well as the visualization of spatial phenomena. With the increasing size and complexity of public buildings, such as universities or hotels, there is also an increasing demand for information about indoor spaces. Trying to stimulate this growing demand, both researchers and Volunteered Geographic Information (VGI communities envision to extend established communities towards indoors. It has already been showcased that VGI from OpenStreetMap (OSM can be utilized for different applications in Spatial Data Infrastructures (SDIs as well as for simple shortest path computations inside buildings. The here presented research now tries to utilize crowdsourced indoor geodata for more complex indoor routing scenarios of multiple users. Essentially, it will be investigated if, and to what extent, the available data can be utilized for performing indoor evacuation simulations with the simulation framework MATSim. That is, this paper investigates the suitability of crowdsourced indoor information from OSM (IndoorOSM for evacuation simulations. Additionally, the applicability of MATSim for agent-based indoor evacuation simulations is conducted. The paper discusses the automatic generation simulation-related data, and provides experimental results for two different evacuation scenarios. Furthermore, limitations of the IndoorOSM data and the MATSim framework for indoor evacuation simulations are elaborated and discussed.

  5. Dynamic calibration of agent-based models using data assimilation.

    Science.gov (United States)

    Ward, Jonathan A; Evans, Andrew J; Malleson, Nicolas S

    2016-04-01

    A widespread approach to investigating the dynamical behaviour of complex social systems is via agent-based models (ABMs). In this paper, we describe how such models can be dynamically calibrated using the ensemble Kalman filter (EnKF), a standard method of data assimilation. Our goal is twofold. First, we want to present the EnKF in a simple setting for the benefit of ABM practitioners who are unfamiliar with it. Second, we want to illustrate to data assimilation experts the value of using such methods in the context of ABMs of complex social systems and the new challenges these types of model present. We work towards these goals within the context of a simple question of practical value: how many people are there in Leeds (or any other major city) right now? We build a hierarchy of exemplar models that we use to demonstrate how to apply the EnKF and calibrate these using open data of footfall counts in Leeds.

  6. Agent-based modelling of consumer energy choices

    Science.gov (United States)

    Rai, Varun; Henry, Adam Douglas

    2016-06-01

    Strategies to mitigate global climate change should be grounded in a rigorous understanding of energy systems, particularly the factors that drive energy demand. Agent-based modelling (ABM) is a powerful tool for representing the complexities of energy demand, such as social interactions and spatial constraints. Unlike other approaches for modelling energy demand, ABM is not limited to studying perfectly rational agents or to abstracting micro details into system-level equations. Instead, ABM provides the ability to represent behaviours of energy consumers -- such as individual households -- using a range of theories, and to examine how the interaction of heterogeneous agents at the micro-level produces macro outcomes of importance to the global climate, such as the adoption of low-carbon behaviours and technologies over space and time. We provide an overview of ABM work in the area of consumer energy choices, with a focus on identifying specific ways in which ABM can improve understanding of both fundamental scientific and applied aspects of the demand side of energy to aid the design of better policies and programmes. Future research needs for improving the practice of ABM to better understand energy demand are also discussed.

  7. Agent-based mapping of credit risk for sustainable microfinance.

    Directory of Open Access Journals (Sweden)

    Joung-Hun Lee

    Full Text Available By drawing analogies with independent research areas, we propose an unorthodox framework for mapping microfinance credit risk--a major obstacle to the sustainability of lenders outreaching to the poor. Specifically, using the elements of network theory, we constructed an agent-based model that obeys the stylized rules of microfinance industry. We found that in a deteriorating economic environment confounded with adverse selection, a form of latent moral hazard may cause a regime shift from a high to a low loan payment probability. An after-the-fact recovery, when possible, required the economic environment to improve beyond that which led to the shift in the first place. These findings suggest a small set of measurable quantities for mapping microfinance credit risk and, consequently, for balancing the requirements to reasonably price loans and to operate on a fully self-financed basis. We illustrate how the proposed mapping works using a 10-year monthly data set from one of the best-known microfinance representatives, Grameen Bank in Bangladesh. Finally, we discuss an entirely new perspective for managing microfinance credit risk based on enticing spontaneous cooperation by building social capital.

  8. Measure of Landscape Heterogeneity by Agent-Based Methodology

    Science.gov (United States)

    Wirth, E.; Szabó, Gy.; Czinkóczky, A.

    2016-06-01

    With the rapid increase of the world's population, the efficient food production is one of the key factors of the human survival. Since biodiversity and heterogeneity is the basis of the sustainable agriculture, the authors tried to measure the heterogeneity of a chosen landscape. The EU farming and subsidizing policies (EEA, 2014) support landscape heterogeneity and diversity, nevertheless exact measurements and calculations apart from statistical parameters (standard deviation, mean), do not really exist. In the present paper the authors' goal is to find an objective, dynamic method that measures landscape heterogeneity. It is achieved with the so called agent-based modelling, where randomly dispatched dynamic scouts record the observed land cover parameters and sum up the features of a new type of land. During the simulation the agents collect a Monte Carlo integral as a diversity landscape potential which can be considered as the unit of the `greening' measure. As a final product of the ABM method, a landscape potential map is obtained that can serve as a tool for objective decision making to support agricultural diversity.

  9. Mobile Agent-Based Directed Diffusion in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Victor C. M. Leung

    2007-01-01

    Full Text Available In the environments where the source nodes are close to one another and generate a lot of sensory data traffic with redundancy, transmitting all sensory data by individual nodes not only wastes the scarce wireless bandwidth, but also consumes a lot of battery energy. Instead of each source node sending sensory data to its sink for aggregation (the so-called client/server computing, Qi et al. in 2003 proposed a mobile agent (MA-based distributed sensor network (MADSN for collaborative signal and information processing, which considerably reduces the sensory data traffic and query latency as well. However, MADSN is based on the assumption that the operation of mobile agent is only carried out within one hop in a clustering-based architecture. This paper considers MA in multihop environments and adopts directed diffusion (DD to dispatch MA. The gradient in DD gives a hint to efficiently forward the MA among target sensors. The mobile agent paradigm in combination with the DD framework is dubbed mobile agent-based directed diffusion (MADD. With appropriate parameters set, extensive simulation shows that MADD exhibits better performance than original DD (in the client/server paradigm in terms of packet delivery ratio, energy consumption, and end-to-end delivery latency.

  10. Agent-based Market Research Learning Environment for New Entrepreneurs

    Directory of Open Access Journals (Sweden)

    Alejandro Valencia

    2012-01-01

    Full Text Available Due to the importance of creating alternative mechanisms to generate know-how on potential markets for new entrepreneurs this paper proposes an agent-based learning environment to help them learning market research strategies within new businesses. An instructor agent, serving as a learning assistant within the MAS environment guides new entrepreneurs to identify their most adequate market niche. The integration of MAS-CommonKADS and GAIA methodologies is used along with AUML diagrams in order to design and develop this agentbased learning environment, called MaREMAS. The paper thus describes all the stages concerning MaREMAS construction focusing on the conceptualization, analysis, design, prototype development, and validation. The tests developed in the MaREMAS learning environment were satisfactory, however, it is proposed as future work to provide the system a more robust statistical module that allows a better analysis of the research variables and hence be able to generate more useful suggestions to the entrepreneur.

  11. Agent-based reasoning for distributed multi-INT analysis

    Science.gov (United States)

    Inchiosa, Mario E.; Parker, Miles T.; Perline, Richard

    2006-05-01

    Fully exploiting the intelligence community's exponentially growing data resources will require computational approaches differing radically from those currently available. Intelligence data is massive, distributed, and heterogeneous. Conventional approaches requiring highly structured and centralized data will not meet this challenge. We report on a new approach, Agent-Based Reasoning (ABR). In NIST evaluations, the use of ABR software tripled analysts' solution speed, doubled accuracy, and halved perceived difficulty. ABR makes use of populations of fine-grained, locally interacting agents that collectively reason about intelligence scenarios in a self-organizing, "bottom-up" process akin to those found in biological and other complex systems. Reproduction rules allow agents to make inferences from multi-INT data, while movement rules organize information and optimize reasoning. Complementary deterministic and stochastic agent behaviors enhance reasoning power and flexibility. Agent interaction via small-world networks - such as are found in nervous systems, social networks, and power distribution grids - dramatically increases the rate of discovering intelligence fragments that usefully connect to yield new inferences. Small-world networks also support the distributed processing necessary to address intelligence community data challenges. In addition, we have found that ABR pre-processing can boost the performance of commercial text clustering software. Finally, we have demonstrated interoperability with Knowledge Engineering systems and seen that reasoning across diverse data sources can be a rich source of inferences.

  12. E-laboratories : agent-based modeling of electricity markets.

    Energy Technology Data Exchange (ETDEWEB)

    North, M.; Conzelmann, G.; Koritarov, V.; Macal, C.; Thimmapuram, P.; Veselka, T.

    2002-05-03

    Electricity markets are complex adaptive systems that operate under a wide range of rules that span a variety of time scales. These rules are imposed both from above by society and below by physics. Many electricity markets are undergoing or are about to undergo a transition from centrally regulated systems to decentralized markets. Furthermore, several electricity markets have recently undergone this transition with extremely unsatisfactory results, most notably in California. These high stakes transitions require the introduction of largely untested regulatory structures. Suitable laboratories that can be used to test regulatory structures before they are applied to real systems are needed. Agent-based models can provide such electronic laboratories or ''e-laboratories.'' To better understand the requirements of an electricity market e-laboratory, a live electricity market simulation was created. This experience helped to shape the development of the Electricity Market Complex Adaptive Systems (EMCAS) model. To explore EMCAS' potential as an e-laboratory, several variations of the live simulation were created. These variations probed the possible effects of changing power plant outages and price setting rules on electricity market prices.

  13. An Agent-Based Model of Institutional Life-Cycles

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    Manuel Wäckerle

    2014-08-01

    Full Text Available We use an agent-based model to investigate the interdependent dynamics between individual agency and emergent socioeconomic structure, leading to institutional change in a generic way. Our model simulates the emergence and exit of institutional units, understood as generic governed social structures. We show how endogenized trust and exogenously given leader authority influences institutional change, i.e., diversity in institutional life-cycles. It turns out that these governed institutions (destructure in cyclical patterns dependent on the overall evolution of trust in the artificial society, while at the same time, influencing this evolution by supporting social learning. Simulation results indicate three scenarios of institutional life-cycles. Institutions may, (1 build up very fast and freeze the artificial society in a stable but fearful pattern (ordered system; (2 exist only for a short time, leading to a very trusty society (highly fluctuating system; and (3 structure in cyclical patterns over time and support social learning due to cumulative causation of societal trust (complex system.

  14. Nonlinear scaling analysis approach of agent-based Potts financial dynamical model.

    Science.gov (United States)

    Hong, Weijia; Wang, Jun

    2014-12-01

    A financial agent-based price model is developed and investigated by one of statistical physics dynamic systems-the Potts model. Potts model, a generalization of the Ising model to more than two components, is a model of interacting spins on a crystalline lattice which describes the interaction strength among the agents. In this work, we investigate and analyze the correlation behavior of normalized returns of the proposed financial model by the power law classification scheme analysis and the empirical mode decomposition analysis. Moreover, the daily returns of Shanghai Composite Index and Shenzhen Component Index are considered, and the comparison nonlinear analysis of statistical behaviors of returns between the actual data and the simulation data is exhibited.

  15. On the specificity of face cognition compared with general cognitive functioning across adult age.

    Science.gov (United States)

    Hildebrandt, Andrea; Wilhelm, Oliver; Schmiedek, Florian; Herzmann, Grit; Sommer, Werner

    2011-09-01

    Face cognition is considered a specific human ability, clearly differentiable from general cognitive functioning. Its specificity is primarily supported by cognitive-experimental and neuroimaging research, but recently also from an individual differences perspective. However, no comprehensive behavioral data are available, which would allow estimating lifespan changes of the covariance structure of face-cognition abilities and general cognitive functioning as well as age-differences in face cognition after accounting for interindividual variability in general cognition. The present study aimed to fill this gap. In an age-heterogeneous (18-82 years) sample of 448 adults, we found no factorial dedifferentiation between face cognition and general cognition. Age-related differences in face memory were still salient after taking into account changes in general cognitive functioning. Face cognition thus remains a specific human ability compared with general cognition, even until old age. We discuss implications for models of cognitive aging and suggest that it is necessary to include more explicitly special social abilities in those models.

  16. Thread Group Multithreading: Accelerating the Computation of an Agent-Based Power System Modeling and Simulation Tool -- C GridLAB-D

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shuangshuang; Chassin, David P.

    2014-01-06

    GridLAB-DTM is an open source next generation agent-based smart-grid simulator that provides unprecedented capability to model the performance of smart grid technologies. Over the past few years, GridLAB-D has been used to conduct important analyses of smart grid concepts, but it is still quite limited by its computational performance. In order to break through the performance bottleneck to meet the need for large scale power grid simulations, we develop a thread group mechanism to implement highly granular multithreaded computation in GridLAB-D. We achieve close to linear speedups on multithreading version compared against the single-thread version of the same code running on general purpose multi-core commodity for a benchmark simple house model. The performance of the multithreading code shows favorable scalability properties and resource utilization, and much shorter execution time for large-scale power grid simulations.

  17. COMPARATIVE STUDY OF MODIFIED RADICAL MASTECTOMY PERFORMED UNDER LOCAL ANAESTHESIA WITH DEXMEDETOMIDINE INFUSION VS. GENERAL ANAESTHESIA

    Directory of Open Access Journals (Sweden)

    Ramesan Chayampurath

    2016-11-01

    Full Text Available BACKGROUND The incidence of breast cancer is on the rise in developing countries. Though, there have been significant advances in general anaesthesia, surgery in elderly and those with comorbid illness still have an attendant morbidity and mortality. After the introduction of local anaesthesia by Kolher in 1884 and in spite of steady refinement, local anaesthesia is still not being widely used in major general surgical procedures. MATERIALS AND METHODS The study was conducted in Government Medical College, Calicut, a tertiary care centre in Kerala. The outcome of Modified Radical Mastectomy performed under Local Anaesthesia (LA and dexmedetomidine infusion was compared to similar cases done under General Anaesthesia (GA. RESULTS Rapid recovery from sedation leading to early restoration of normal physical activity was observed in the LA group when compared to GA group. Early initiation of oral feeds was possible in the former group as Postoperative Nausea and Vomiting (PONV was significantly less. Effective postoperative pain relief and significant reduction in respiratory complications was observed in the LA group compared to GA group. CONCLUSION Modified Radical Mastectomy under LA and procedural sedation with dexmedetomidine was significantly better in selected cases when compared to similar cases done under GA with respect to early recovery pain relief and decreased incidence of respiratory complications.

  18. Agent-based modeling of host-pathogen systems: The successes and challenges.

    Science.gov (United States)

    Bauer, Amy L; Beauchemin, Catherine A A; Perelson, Alan S

    2009-04-29

    Agent-based models have been employed to describe numerous processes in immunology. Simulations based on these types of models have been used to enhance our understanding of immunology and disease pathology. We review various agent-based models relevant to host-pathogen systems and discuss their contributions to our understanding of biological processes. We then point out some limitations and challenges of agent-based models and encourage efforts towards reproducibility and model validation.

  19. Agent-based modelling of nest site selection by bees and ants

    OpenAIRE

    Bolis, Reem

    2016-01-01

    In this study we develop an agent-based time discrete model to show how honeybees and ants are able to choose the best site available under different circumstances. We focus on the agent-based model introduced by Christian List, Christian Elsholtz and Thomas Seeley in their paper: Independence and interdependence in collective decision making: an agent-based model of nest-site choice by honeybee swarms. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 364(1518...

  20. Comparative study of general, local and topical anesthesia for cataract surgery

    Directory of Open Access Journals (Sweden)

    Tarighat Monfared MH

    2001-07-01

    Full Text Available Recently, small incision cataract extraction by phaco and implantation of a foldable intraocular lense with topical anesthesia has used in an attempt to decrease the complication of general anesthesia and peribulbar injection. To compare effects and complications of topical, local and general anesthesia, 92 patients admitted to Imam Hosein hospital for cataract surgery, were randomly assigned to three groups and surgery was done under different methods of anesthesia. During routine ECCE, lid and globe movements, miosis and viterous bulg were observed more in topical anesthesia than the other techniques, but serious complications such as posterior capsular rupture and viterous loss were not seen. Because of less systemic and local complications and rapid return of vision and possibility of outpatient surgery, topical anesthesia should be considered as an alternative to local and general methods.

  1. Agent Based Modeling of Human Gut Microbiome Interactions and Perturbations.

    Directory of Open Access Journals (Sweden)

    Tatiana Shashkova

    Full Text Available Intestinal microbiota plays an important role in the human health. It is involved in the digestion and protects the host against external pathogens. Examination of the intestinal microbiome interactions is required for understanding of the community influence on host health. Studies of the microbiome can provide insight on methods of improving health, including specific clinical procedures for individual microbial community composition modification and microbiota correction by colonizing with new bacterial species or dietary changes.In this work we report an agent-based model of interactions between two bacterial species and between species and the gut. The model is based on reactions describing bacterial fermentation of polysaccharides to acetate and propionate and fermentation of acetate to butyrate. Antibiotic treatment was chosen as disturbance factor and used to investigate stability of the system. System recovery after antibiotic treatment was analyzed as dependence on quantity of feedback interactions inside the community, therapy duration and amount of antibiotics. Bacterial species are known to mutate and acquire resistance to the antibiotics. The ability to mutate was considered to be a stochastic process, under this suggestion ratio of sensitive to resistant bacteria was calculated during antibiotic therapy and recovery.The model confirms a hypothesis of feedbacks mechanisms necessity for providing functionality and stability of the system after disturbance. High fraction of bacterial community was shown to mutate during antibiotic treatment, though sensitive strains could become dominating after recovery. The recovery of sensitive strains is explained by fitness cost of the resistance. The model demonstrates not only quantitative dynamics of bacterial species, but also gives an ability to observe the emergent spatial structure and its alteration, depending on various feedback mechanisms. Visual version of the model shows that spatial

  2. Intelligent Agent based Flight Search and Booking System

    Directory of Open Access Journals (Sweden)

    Floyd Garvey

    2012-07-01

    Full Text Available The world globalization is widely used, and there are several definitions that may fit this one word. However the reality remains that globalization has impacted and is impacting each individual on this planet. It is defined to be greater movement of people, goods, capital and ideas due to increased economic integration, which in turn is propelled, by increased trade and investment. It is like moving towards living in a borderless world. With the reality of globalization, the travel industry has benefited significantly. It could be said that globalization is benefiting from the flight industry. Regardless of the way one looks at it, more persons are traveling each day and are exploring several places that were distant places on a map. Equally, technology has been growing at an increasingly rapid pace and is being utilized by several persons all over the world. With the combination of globalization and the increase in technology and the frequency in travel there is a need to provide an intelligent application that is capable to meeting the needs of travelers that utilize mobile phones all over. It is a solution that fits in perfectly to a user’s busy lifestyle, offers ease of use and enough intelligence that makes a user’s experience worthwhile. Having recognized this need, the Agent based Mobile Airline Search and Booking System is been developed that is built to work on the Android to perform Airline Search and booking using Biometric. The system also possess agent learning capability to perform the search of Airlines based on some previous search pattern .The development been carried out using JADE-LEAP Agent development kit on Android.

  3. Validation techniques of agent based modelling for geospatial simulations

    Science.gov (United States)

    Darvishi, M.; Ahmadi, G.

    2014-10-01

    One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS) is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS), biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI's ArcGIS, OpenMap, GeoTools, etc) for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

  4. Validation techniques of agent based modelling for geospatial simulations

    Directory of Open Access Journals (Sweden)

    M. Darvishi

    2014-10-01

    Full Text Available One of the most interesting aspects of modelling and simulation study is to describe the real world phenomena that have specific properties; especially those that are in large scales and have dynamic and complex behaviours. Studying these phenomena in the laboratory is costly and in most cases it is impossible. Therefore, Miniaturization of world phenomena in the framework of a model in order to simulate the real phenomena is a reasonable and scientific approach to understand the world. Agent-based modelling and simulation (ABMS is a new modelling method comprising of multiple interacting agent. They have been used in the different areas; for instance, geographic information system (GIS, biology, economics, social science and computer science. The emergence of ABM toolkits in GIS software libraries (e.g. ESRI’s ArcGIS, OpenMap, GeoTools, etc for geospatial modelling is an indication of the growing interest of users to use of special capabilities of ABMS. Since ABMS is inherently similar to human cognition, therefore it could be built easily and applicable to wide range applications than a traditional simulation. But a key challenge about ABMS is difficulty in their validation and verification. Because of frequent emergence patterns, strong dynamics in the system and the complex nature of ABMS, it is hard to validate and verify ABMS by conventional validation methods. Therefore, attempt to find appropriate validation techniques for ABM seems to be necessary. In this paper, after reviewing on Principles and Concepts of ABM for and its applications, the validation techniques and challenges of ABM validation are discussed.

  5. Integrated methodological frameworks for modelling agent-based advanced supply chain planning systems: A systematic literature review

    Directory of Open Access Journals (Sweden)

    Luis Antonio Santa-Eulalia

    2011-12-01

    Full Text Available Purpose: The objective of this paper is to provide a systematic literature review of recent developments in methodological frameworks for the modelling and simulation of agent-based advanced supply chain planning systems.Design/methodology/approach: A systematic literature review is provided to identify, select and make an analysis and a critical summary of all suitable studies in the area. It is organized into two blocks: the first one covers agent-based supply chain planning systems in general terms, while the second one specializes the previous search to identify those works explicitly containing methodological aspects.Findings: Among sixty suitable manuscripts identified in the primary literature search, only seven explicitly considered the methodological aspects. In addition, we noted that, in general, the notion of advanced supply chain planning is not considered unambiguously, that the social and individual aspects of the agent society are not taken into account in a clear manner in several studies and that a significant part of the works are of a theoretical nature, with few real-scale industrial applications. An integrated framework covering all phases of the modelling and simulation process is still lacking in the literature visited.Research limitations/implications: The main research limitations are related to the period covered (last four years, the selected scientific databases, the selected language (i.e. English and the use of only one assessment framework for the descriptive evaluation part.Practical implications: The identification of recent works in the domain and discussion concerning their limitations can help pave the way for new and innovative researches towards a complete methodological framework for agent-based advanced supply chain planning systems.Originality/value: As there are no recent state-of-the-art reviews in the domain of methodological frameworks for agent-based supply chain planning, this paper contributes to

  6. A comparative study of pain following endodontic treatment under general anesthesia

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    Feizi Ghader

    2015-01-01

    Full Text Available   Background and Aims: Postoperativee endodontic pain is an outstanding problem for dental patients. Therefore, a successful management of endodontic pain has become as one of the main dental objectives. The aim of the present study was to compare the postoperative endodontic pain in patients under general anesthesia versus local anesthesia.   Materials and Methods: For conducting this clinical trial study, 50 patients having mandibular molars candidate for root canal therapy were selected. Twenty-five patients treated under general anesthesia because of their fear, anxiety or gag reflex. Other 25 patients treated under local anesthesia. All teeth were prepared using engine-driven rotary system in a crown-down technique and filled using lateral condensation technique. Heft- parker visual analog scale was used to measure the degree of pain at 6, 12, 24, and 48 hours after the treatment. Mann-Whitney, Chi-square, and T-tests were used to compare the intensity of postoperative pain between the groups.   Results: The mean intensity of postoperative pain in local and general anesthesia groups at 6, 12 and 24 hours had statistically significant difference (P<0.05.   Conclusion: Postoperative pain in patients who treated under general anesthesia was significantly less than the patients who treated under local anesthesia.

  7. Brief Cognitive Behavioural Therapy Compared to Optimised General Practitioners? Care for Depression: A Randomised Trial

    OpenAIRE

    Schene, A.H.; Baas, K.D.; Koeter, M; Lucassen, P.; Bockting, C.L.H.; Wittkampf, K. F.; van Weert, H.C.; Huyser, J.

    2014-01-01

    Background: How to treat Major Depressive Disorder (MDD) in primary care? Studies that compared (brief) Cognitive Behavioural Therapy (CBT) with care as usual by the General Practitioner (GP) found the first to be more effective. However, to make a fair comparison GP care should be optimised and protocolised according to current evidence based guidelines for depression. So far this has not been the case. We studied whether a protocolised 8 session CBT is more effective than optimised and prot...

  8. Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurements

    OpenAIRE

    Zhang, M.; Lin, W.; Klein, S.; J. Bacmeister; Bony, S.; Cederwall, R.; Del Genio, A; Hack, J.; Loeb, N.; Lohmann, U.; P. Minnis; Musat, I.; Pincus, R; Stier, P.; Suarez, M.

    2005-01-01

    To assess the current status of climate models in simulating clouds, basic cloud climatologies from ten atmospheric general circulation models are compared with satellite measurements from the International Satellite Cloud Climatology Project (ISCCP) and the Clouds and Earth's Radiant Energy System (CERES) program. An ISCCP simulator is employed in all models to facilitate the comparison. Models simulated a four-fold difference in high-top clouds. There are also, however, large uncertainties ...

  9. COMPARATIVE STUDY OF SPINAL ANESTHESIA AND GENERAL ANESTHESIA IN CHILDREN UNDERGOING SURGERIES BELOW UMBILICUS

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    Ashish

    2014-09-01

    Full Text Available AIM: Aim of our study to compare the spinal anaesthesia and general anaesthesia in children undergoing surgeries below umbilicus. OBJECTIVE: to assess the patient comfort in pt. with GA and pt. with spinal anaesthesia, the adequate surgical condition, assess the hemodynamic change, assess the post op analgesia and to assess the post op complication. MATERIAL AND METHOD: 60 ASA grade I & II children of either sex, aged 5-12 yrs undergoing elective surgeries for the lower abdominal, perineal and lower limb surgeries were taken. After taking a detailed history, thorough general physical examination, all pertinent investigation were carried out to exclude any systemic disease. Patients were classified randomly into 2 groups (30 patients in each group. Group A: General anesthesia was given. Group P: subarachnoid block was given. Intraoperative monitoring consisted of SPO2, PR, NIBP, RR and assessment of duration of post-operative analgesia. P-value <0.05 consider significant. RESULT: Analysis revealed that there were no significant differences between the patients with respect to age, sex, duration and type of surgery In SAB since less general anaesthetic drug including parental opioid are used the risk and postoperative respiratory depression is minimal. The stress response to surgery is also limited and recovery is fast. Postoperatively complications like sore throat, laryngeal irritation, cough etc. was also less associated with it. CONCLUSION pediatric spinal anesthesia is not only a safe alternative to general anesthesia but often the anesthesia technique of choice in many lower abdominal and lower limb surgeries in children. The misconception regarding its safety and flexibility is broken and is now found to be even more cost effective. It is much preferred technique special for common day case surgeries generally performed in the pediatric age group.

  10. A multi-agent based intelligent configuration method for aircraft fleet maintenance personnel

    Directory of Open Access Journals (Sweden)

    Feng Qiang

    2014-04-01

    Full Text Available A multi-agent based fleet maintenance personnel configuration method is proposed to solve the mission oriented aircraft fleet maintenance personnel configuration problem. The maintenance process of an aircraft fleet is analyzed first. In the process each aircraft contains multiple parts, and different parts are repaired by personnel with different majors and levels. The factors and their relationship involved in the process of maintenance are analyzed and discussed. Then the whole maintenance process is described as a 3-layer multi-agent system (MAS model. A communication and reasoning strategy among the agents is put forward. A fleet maintenance personnel configuration algorithm is proposed based on contract net protocol (CNP. Finally, a fleet of 10 aircraft is studied for verification purposes. A mission type with 3 waves of continuous dispatch is imaged. Compared with the traditional methods that can just provide configuration results, the proposed method can provide optimal maintenance strategies as well.

  11. An agent-based interaction model for Chinese personal income distribution

    Science.gov (United States)

    Zou, Yijiang; Deng, Weibing; Li, Wei; Cai, Xu

    2015-10-01

    The personal income distribution in China was studied by employing the data from China Household Income Projects (CHIP) between 1990 and 2002. It was observed that the low and middle income regions could be described by the log-normal law, while the large income region could be well fitted by the power law. To characterize these empirical findings, a stochastic interactive model with mean-field approach was discussed, and the analytic result shows that the wealth distribution is of the Pareto type. Then we explored the agent-based model on networks, in which the exchange of wealth among agents depends on their connectivity. Numerical results suggest that the wealth of agents would largely rely on their connectivity, and the Pareto index of the simulated wealth distributions is comparable to those of the empirical data. The Pareto behavior of the tails of the empirical wealth distributions is consistent with that of the 'mean-field' model, as well as numerical simulations.

  12. Investigating Output Accuracy for a Discrete Event Simulation Model and an Agent Based Simulation Model

    CERN Document Server

    Majid, Mazlina Abdul; Siebers, Peer-Olaf

    2010-01-01

    In this paper, we investigate output accuracy for a Discrete Event Simulation (DES) model and Agent Based Simulation (ABS) model. The purpose of this investigation is to find out which of these simulation techniques is the best one for modelling human reactive behaviour in the retail sector. In order to study the output accuracy in both models, we have carried out a validation experiment in which we compared the results from our simulation models to the performance of a real system. Our experiment was carried out using a large UK department store as a case study. We had to determine an efficient implementation of management policy in the store's fitting room using DES and ABS. Overall, we have found that both simulation models were a good representation of the real system when modelling human reactive behaviour.

  13. An agent based model for simulating the spread of sexually transmitted infections.

    Science.gov (United States)

    Rutherford, Grant; Friesen, Marcia R; McLeod, Robert D

    2012-01-01

    This work uses agent-based modelling (ABM) to simulate sexually transmitted infection (STIs) spread within a population of 1000 agents over a 10-year period, as a preliminary investigation of the suitability of ABM methodology to simulate STI spread. The work contrasts compartmentalized mathematical models that fail to account for individual agents, and ABMs commonly applied to simulate the spread of respiratory infections. The model was developed in C++ using the Boost 1.47.0 libraries for the normal distribution and OpenGL for visualization. Sixteen agent parameters interact individually and in combination to govern agent profiles and behaviours relative to infection probabilities. The simulation results provide qualitative comparisons of STI mitigation strategies, including the impact of condom use, promiscuity, the form of the friend network, and mandatory STI testing. Individual and population-wide impacts were explored, with individual risk being impacted much more dramatically by population-level behaviour changes as compared to individual behaviour changes.

  14. Agent-based model for the h-index - Exact solution

    CERN Document Server

    Żogała-Siudem, Barbara; Cena, Anna; Gagolewski, Marek

    2015-01-01

    The Hirsch's $h$-index is perhaps the most popular citation-based measure of the scientific excellence. In 2013 G. Ionescu and B. Chopard proposed an agent-based model for this index to describe a publications and citations generation process in an abstract scientific community. With such an approach one can simulate a single scientist's activity, and by extension investigate the whole community of researchers. Even though this approach predicts quite well the $h$-index from bibliometric data, only a solution based on simulations was given. In this paper, we complete their results with exact, analytic formulas. What is more, due to our exact solution we are able to simplify the Ionescu-Chopard model which allows us to obtain a compact formula for $h$-index. Moreover, a simulation study designed to compare both, approximated and exact, solutions is included. The last part of this paper presents evaluation of the obtained results on a real-word data set.

  15. Complexity and Multifractal of Volatility Duration for Agent-Based Financial Dynamics and Real Markets

    Science.gov (United States)

    Yang, Ge; Wang, Jun

    2016-11-01

    A random agent-based financial model is developed and investigated by the finite-range multitype contact dynamic system, in an attempt to reproduce and study the dynamics of financial markets. And an analysis method of detecting duration and intensity relationship in volatility series is introduced, called the volatility duration analysis. Then the auto-correlation analysis suggests that there exists evident volatility clustering feature in absolute volatility durations for the simulation data and the real data. Besides, the Lempel-Ziv complexity analysis is applied to study the complexity of the returns, the corresponding absolute returns and the volatility duration returns, which can reflect the fluctuation behaviors, the volatility behaviors and the volatility duration behaviors. At last, the multifractal phenomena of volatility durations of returns are comparatively studied for Shanghai Composite Index and the proposed model by multifractal detrended fluctuation analysis.

  16. Prediction Markets and Beliefs about Climate: Results from Agent-Based Simulations

    Science.gov (United States)

    Gilligan, J. M.; John, N. J.; van der Linden, M.

    2015-12-01

    Climate scientists have long been frustrated by persistent doubts a large portion of the public expresses toward the scientific consensus about anthropogenic global warming. The political and ideological polarization of this doubt led Vandenbergh, Raimi, and Gilligan [1] to propose that prediction markets for climate change might influence the opinions of those who mistrust the scientific community but do trust the power of markets.We have developed an agent-based simulation of a climate prediction market in which traders buy and sell future contracts that will pay off at some future year with a value that depends on the global average temperature at that time. The traders form a heterogeneous population with different ideological positions, different beliefs about anthropogenic global warming, and different degrees of risk aversion. We also vary characteristics of the market, including the topology of social networks among the traders, the number of traders, and the completeness of the market. Traders adjust their beliefs about climate according to the gains and losses they and other traders in their social network experience. This model predicts that if global temperature is predominantly driven by greenhouse gas concentrations, prediction markets will cause traders' beliefs to converge toward correctly accepting anthropogenic warming as real. This convergence is largely independent of the structure of the market and the characteristics of the population of traders. However, it may take considerable time for beliefs to converge. Conversely, if temperature does not depend on greenhouse gases, the model predicts that traders' beliefs will not converge. We will discuss the policy-relevance of these results and more generally, the use of agent-based market simulations for policy analysis regarding climate change, seasonal agricultural weather forecasts, and other applications.[1] MP Vandenbergh, KT Raimi, & JM Gilligan. UCLA Law Rev. 61, 1962 (2014).

  17. A Systematic Review of Agent-Based Modelling and Simulation Applications in the Higher Education Domain

    Science.gov (United States)

    Gu, X.; Blackmore, K. L.

    2015-01-01

    This paper presents the results of a systematic review of agent-based modelling and simulation (ABMS) applications in the higher education (HE) domain. Agent-based modelling is a "bottom-up" modelling paradigm in which system-level behaviour (macro) is modelled through the behaviour of individual local-level agent interactions (micro).…

  18. [Immunization educational game in general practice waiting rooms. A comparative study].

    Science.gov (United States)

    Rolland, Marie-Aude; Gignon, Maxime

    2015-01-01

    The general practitioner’s (GP) waiting room is an ideal place to conduct health education actions. The use of tools in GP waiting rooms would appear to be a useful approach, but the available tools are not very efficient. The objective of this study was to study the efficacy of a game compared with two other health education strategies. A comparative study was conducted in two general practices. 212 patients were divided into three groups using a paper-game or a booklet or nothing in the waiting room, before a discussion about immunization with the practitioner. The capacity of the tool to encourage questions about immunization was estimated by the GP at the end of the consultation by a questionnaire. The use of a tool in the waiting room facilitated the discussion between patients and practitioners (34% vs 12%, pgame induced longer discussions than the booklet (1 minute 32 seconds vs 1 minute 14 seconds, pgame and the booklet had a comparable acceptability. Using a multistep education strategy facilitated discussion between the patient and the practitioner. However, the GP is required to trigger the conversation.

  19. Comparing stream-specific to generalized temperature models to guide salmonid management in a changing climate

    Science.gov (United States)

    Andrew K. Carlson,; William W. Taylor,; Hartikainen, Kelsey M.; Dana M. Infante,; Beard, Douglas; Lynch, Abigail

    2017-01-01

    Global climate change is predicted to increase air and stream temperatures and alter thermal habitat suitability for growth and survival of coldwater fishes, including brook charr (Salvelinus fontinalis), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus mykiss). In a changing climate, accurate stream temperature modeling is increasingly important for sustainable salmonid management throughout the world. However, finite resource availability (e.g. funding, personnel) drives a tradeoff between thermal model accuracy and efficiency (i.e. cost-effective applicability at management-relevant spatial extents). Using different projected climate change scenarios, we compared the accuracy and efficiency of stream-specific and generalized (i.e. region-specific) temperature models for coldwater salmonids within and outside the State of Michigan, USA, a region with long-term stream temperature data and productive coldwater fisheries. Projected stream temperature warming between 2016 and 2056 ranged from 0.1 to 3.8 °C in groundwater-dominated streams and 0.2–6.8 °C in surface-runoff dominated systems in the State of Michigan. Despite their generally lower accuracy in predicting exact stream temperatures, generalized models accurately projected salmonid thermal habitat suitability in 82% of groundwater-dominated streams, including those with brook charr (80% accuracy), brown trout (89% accuracy), and rainbow trout (75% accuracy). In contrast, generalized models predicted thermal habitat suitability in runoff-dominated streams with much lower accuracy (54%). These results suggest that, amidst climate change and constraints in resource availability, generalized models are appropriate to forecast thermal conditions in groundwater-dominated streams within and outside Michigan and inform regional-level salmonid management strategies that are practical for coldwater fisheries managers, policy makers, and the public. We recommend fisheries professionals reserve resource

  20. The Generality of Adult Development Stages and Transformations: Comparing Meaning-making and Logical Reasoning

    Directory of Open Access Journals (Sweden)

    Tom Hagström

    2015-09-01

    Full Text Available Human development theories differ in “context sensitivity,” covering those stressing development stages and those stressing continuously progressing changes. The former theories differ in whether, how and why the stages are regarded as being generalized across domains, i.e. their generality claims. Piaget’s developmental stage theory of logical complexity of children and adolescents fulfill “strong” such claims, including fixed stage sequentiality of increasing complexity levels and higher stage structures integrating earlier ones. His theory has inspired a number of adult development stage theories with varying generality claims. These provide suggestions of stages and stage transitions reaching beyond “pure” cognition, integrating more of e.g. emotional, value and moral dimensions. From a neo-Piagetian perspective, core generality aspects seem to concern on the one hand logical reasoning and on the other hand meaning-making. This raises questions of how these aspects are related to each other in terms of stage structures and transformations. The aim of the article is to discern general features in adult development stage structures and transitions, in terms of logical reasoning and meaning making. This is carried out by a “thought experiment” interrelating two theories that differ in these respects but that are both based on Piaget’s theory, namely Robert Kegan’s constructive developmental Subject-Object Theory (SOT and Michael Common´s behaviouristic Model of Hierarchical Complexity (MHC. This comparing approach concerns the 3rd, 4th and 5th order of consciousness as well as transitions between these according to SOT, and order 9 to 12 and corresponding transitions according to MHC. The thought experiment indicates that the generality claims of both models can be argued for without one of them necessarily being subordinated to the other one. Both theories are interpreted as differing but partly overlapping structures of

  1. Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

    Science.gov (United States)

    Augustijn, Ellen-Wien; Doldersum, Tom; Augustijn, Denie

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

  2. A Comparative Analysis of a Community and General Sample of Lesbian, Gay, and Bisexual Individuals.

    Science.gov (United States)

    Kuyper, Lisette; Fernee, Henk; Keuzenkamp, Saskia

    2016-04-01

    Samples recruited at lesbian, gay, and bisexual (LGB) venues have certain benefits, but a major drawback is that these samples are prone to bias as they only contain LGB participants who visit such venues. Empirical data with regard to the potential differences between LGB community samples and LGB general samples may shed some light on the generalizability of research findings from convenience samples recruited through LGB venues. The current study attempted to contribute to existing knowledge by examining differences in social demographics, sexual orientation, minority stress, and mental health between a convenience sample recruited at LGB venues ("community sample," N = 3,403) and an LGB sample recruited from a general research panel in the Netherlands ("panel sample," N = 1,000). Various differences were found. In general, community participants were younger, reported a more exclusive same-sex sexual orientation, were more open about their sexual orientation, had lower levels of internalized homonegativity, and encountered more negative social reactions on their LGB status. They also reported higher levels of psychological distress and suicidality. The Nagelkerke R (2) of the analyses (which were adjusted for sociodemographic differences) ranged from .08 (suicide plans among men) to .27 (sexual attraction among women). However, while the estimates of sociodemographics, sexual orientation, minority stress, and mental well-being differed, the relationships between these constructs were comparable in both samples. Implications and suggestions for future studies are discussed.

  3. Premature age-related comorbidities among HIV-infected persons compared with the general population.

    Science.gov (United States)

    Guaraldi, Giovanni; Orlando, Gabriella; Zona, Stefano; Menozzi, Marianna; Carli, Federica; Garlassi, Elisa; Berti, Alessandra; Rossi, Elisa; Roverato, Alberto; Palella, Frank

    2011-12-01

    Human immunodeficiency virus (HIV)-infected patients may have a greater risk of noninfectious comorbidities (NICMs) compared with the general population. We assessed the prevalence and risk factors for NICMs in a large cohort of HIV-infected adults and compared these findings with data from matched control subjects. We performed a case-control study involving antiretroviral therapy (ART)-experienced HIV-infected patients treated at Modena University, Italy, from 2002 through 2009. These patients were compared with age-, sex-, and race-matched adults (control subjects) from the general population included in the CINECA ARNO database. NICMs included cardiovascular disease, hypertension, diabetes mellitus, bone fractures, and renal failure. Polypathology (Pp) was defined as the concurrent presence of ≥2 NICMs. Logistic regression models were constructed to evaluate associated predictors of NICMs and Pp. There were 2854 patients and 8562 control subjects. The mean age was 46 years, and 37% were women. Individual NICM and Pp prevalences in each age stratum were higher among patients than among controls (all P <.001). Pp prevalence among patients aged 41-50 years was similar to that among controls aged 51-60 years (P value was not statistically significant); diabetes mellitus, cardiovascular disease, bone fractures, and renal failure were statistically independent after adjustment for sex, age, and hypertension. Logistic regression models showed that independent predictors of Pp in the overall cohort were (all P < .001) age (odds ratio [OR], 1.11), male sex (OR, 1.77), nadir CD4 cell count <200 cells/μL (OR, 4.46), and ART exposure (OR, 1.01). Specific age-related NICMs and Pp were more common among HIV-infected patients than in the general population. The prevalence of Pp in HIV-infected persons anticipated Pp prevalence observed in the general population among persons who were 10 years older, and HIV-specific cofactors (lower nadir CD4 cell count and more prolonged

  4. Exposure of Prague's homeless population to lead and cadmium, compared to Prague's general population.

    Science.gov (United States)

    Hrncírová, Dana; Batáriová, Andrea; Cerná, Milena; Procházka, Bohumír; Dlouhý, Pavel; Andel, Michal

    2008-10-01

    Homelessness is a growing problem in the Czech Republic where homeless people represent a specific minority group beset by many problems linked to their divergent lifestyle. It was therefore expected that the homeless population would be at greater risk of exposure to environmental pollutants than the general population. The aim of our study was to compare blood lead (B-Pb) and blood cadmium (B-Cd) levels in the homeless population (HP) with those obtained from the Human Biomonitoring Project (CZ-HBM), which used blood donors considered representative of the general population (GP). We present data obtained between 2004 and 2006 for B-Pb and B-Cd in 257 Prague homeless adults and compare them to B-Pb and B-Cd levels in 104 Prague adult blood donors from the CZ-HBM project in 2005. The mean (geometric) B-Pb levels in men were 36.5 (HP) and 35.4microg/l (GP), which is not significantly different. However, statistically significant differences were observed between men and women in the GP (Phomeless nonsmokers (geometric means 1.06 and 1.18microg/l in men and women, respectively) were more than 2.5 times higher than in the nonsmoking GP (0.36 and 0.38microg/l for men and women, respectively). B-Cd levels were significantly (Phomeless population under study might be exposed to lead and cadmium more extensively than the general population of Prague and that homeless women represent a particularly vulnerable population group.

  5. Developing an Agent-Based Model to Simulate Urban Land-Use Expansion (Case Study: Qazvin

    Directory of Open Access Journals (Sweden)

    F. Nourian

    2012-01-01

    and Logistic Regression, M.S. Thesis. Supervisors: Hossein, S.M., and Salman Mahini, A. Advisors: Ghasempouri, M. and Gholamali Fard, M., Faculty of Natural Resource and Marine Science,Tarbiat Modarres University.Lambin, E. F., (1994 Modelling Deforestation Processes: A Review. Luxembourg: European Commission, Directorate-General XIII. Report no. EUR-15744-EN.Ligmann-Zielinska, A., & Jankowski, P. (2010. Exploring normative scenarios of land use development decisions with an agent-based simulation laboratory. Computers, Environment and Urban Systems, 34, 409–423.Ligmann-Zielinska, A., and Jankowski, P., (2007 Agent-Based Models as Laboratories for Spatially Explicit Planning Policies, Environment and Planning B: Planning and Design, Vol.34. pp: 316-335.Loibl, W., & Toetzer, T., (2003 Modeling growth and densification in suburban regions-simulation of landscape transition with spatial agents. Environmental Modelling & Software, 18,553-563.Macal C.M. and North M.J., (2007 Agent-Based Modeling and Simulation: Desktop ABMS, In: S. G. Henderson, B. Biller, M.-H. Hsieh, J. Shortle, J. D. Tew, and R. R. Barton, (eds. Proceedings of the 2007 Winter Simulation Conference, Argonne National Laboratory, pp: 743-760.Maes, P., (1994 Modeling adaptive autonomous agents. Artificial Life, 1, 135-162.Malleson, N., Heppenstall A., & See, L. (2010. Crime reduction through simulation: An agent-based model of burglary. Computers, Environment and Urban Systems, 34, 236–250.Masuda J.R. and Garvin, T., (2008 Whose Heartland?: The politics of place in a rural–urban interface, Journal of Rural Studies, Volume 24, Issue 1, Pages 112-123.Matthews R., Gilbert N., Roach A., Polhill J.G. and Gotts N.M., 2007, Agent-based land-use models: a review of applications, Landscape Ecology, Vol.22, pp:1447-1459.Miller E., Hunt J.D., Abraham J.E. and Salvini P.A., 2004, Microsimulating urban systems, Computers Environment and Urban Systems, Vol.28, pp: 9-44.Mousavi, M.N., Saeidabadi, R., and Fahar, R

  6. The self-reported health of U.S. flight attendants compared to the general population.

    Science.gov (United States)

    McNeely, Eileen; Gale, Sara; Tager, Ira; Kincl, Laurel; Bradley, Julie; Coull, Brent; Hecker, Steve

    2014-03-10

    Few studies have examined the broad health effects of occupational exposures in flight attendants apart from disease-specific morbidity and mortality studies. We describe the health status of flight attendants and compare it to the U.S. population. In addition, we explore whether the prevalence of major health conditions in flight attendants is associated with length of exposure to the aircraft environment using job tenure as a proxy. We surveyed flight attendants from two domestic U.S. airlines in 2007 and compared the prevalence of their health conditions to contemporaneous cohorts in the National Health and Nutrition Survey (NHANES), 2005-2006 and 2007-2008. We weighted the prevalence of flight attendant conditions to match the age distribution in the NHANES and compared the two populations stratified by gender using the Standardized Prevalence Ratio (SPR). For leading health conditions in flight attendants, we analyzed the association between job tenure and health outcomes in logistic regression models. Compared to the NHANES population (n =5,713), flight attendants (n = 4,011) had about a 3-fold increase in the age-adjusted prevalence of chronic bronchitis despite considerably lower levels of smoking. In addition, the prevalence of cardiac disease in female flight attendants was 3.5 times greater than the general population while their prevalence of hypertension and being overweight was significantly lower. Flight attendants reported 2 to 5.7 times more sleep disorders, depression, and fatigue, than the general population. Female flight attendants reported 34% more reproductive cancers. Health conditions that increased with longer job tenure as a flight attendant were chronic bronchitis, heart disease in females, skin cancer, hearing loss, depression and anxiety, even after adjusting for age, gender, body mass index (BMI), education, and smoking. This study found higher rates of specific diseases in flight attendants than the general population. Longer

  7. Laparoscopic cholecystectomy under neuraxial anesthesia compared with general anesthesia: Systematic review and meta-analyses.

    Science.gov (United States)

    Longo, Marcelo A; Cavalheiro, Bárbara T; de Oliveira Filho, Getúlio R

    2017-09-01

    Pneumoperitoneum during laparoscopic cholecystectomy (LC) can cause hypercapnia, hypoxemia, hemodynamic changes and shoulder pain. General anesthesia (GA) enables the control of intraoperative pain and ventilation. The need for GA has been questioned by studies suggesting that neuraxial anesthesia (NA) is adequate for LC. To quantify the prevalence of intraoperative pain and to verify whether evidence on the maintenance of ventilation, circulation and surgical anesthesia during NA compared with GA is consistent. Systematic review with meta-analyses. Anesthesia for laparoscopic cholecystectomy. We searched Medline, Cochrane and EBSCO databases up to 2016 for randomized controlled trials that compared LC in the two groups under study, neuraxial (subarachnoid or epidural) and general anesthesia. The primary outcome was the prevalence of intraoperative pain referred to the shoulder in the NA group. Hemodynamic and respiratory outcomes and adverse effects in both groups were also collected. Eleven comparative studies were considered eligible. The pooled prevalence of shoulder pain was 25%. Intraoperative hypotension and bradycardia occurred more frequently in patients who received NA, with a risk ratio of 4.61 (95% confidence interval [CI] 1.70-12.48, p=0.003) and 6.67 (95% CI 2.02-21.96, p=0.002), respectively. Postoperative nausea and vomiting was more prevalent in patients who submitted to GA. The prevalence of postoperative urinary retention did not differ between the techniques. Postoperative headache was more prevalent in patients who received NA, while the postoperative pain intensity was lower in this group. Performing meta-analyses on hypertension, hypercapnia and hypoxemia was not possible. NA as sole anesthetic technique, although feasible for LC, was associated with intraoperative pain referred to the shoulder, required anesthetic conversion in 3.4% of the cases and did not demonstrate evidence of respiratory benefits for patients with normal pulmonary

  8. Comparable Measures of Accessibility to Public Transport Using the General Transit Feed Specification

    Directory of Open Access Journals (Sweden)

    Jinjoo Bok

    2016-03-01

    Full Text Available Public transport plays a critical role in the sustainability of urban settings. The mass mobility and quality of urban lives can be improved by establishing public transport networks that are accessible to pedestrians within a reasonable walking distance. Accessibility to public transport is characterized by the ease with which inhabitants can reach means of transportation such as buses or metros. By measuring the degree of accessibility to public transport networks using a common data format, a comparative study can be conducted between different cities or metropolitan areas with different public transit systems. The General Transit Feed Specification (GTFS by Google Developers allows this by offering a common format based on text files and sharing the data set voluntarily produced and contributed by the public transit agencies of many participating cities around the world. This paper suggests a method to assess and compare public transit accessibility in different urban areas using the GTFS feed and demographic data. To demonstrate the value of the new method, six examples of metropolitan areas and their public transit accessibility are presented and compared.

  9. A comparative analysis of exposure doses between the radiation workers in dental and general hospital

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Nam Hee; Chung, Woon Kwan; Dong, Kyung Rae; Ju, Yong Jin; Song, Ha Jin [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of); Choi, Eun Jin [Dept. of Public Health and Medicine, Dongshin University, Naju (Korea, Republic of)

    2015-02-15

    Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higher in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workers. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum 50 mSv y{sup -1}). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the future. Should try to minimize the radiation individual dose of

  10. Comparative analysis of general characteristics of ischemic stroke of BAD and non-BAD CISS subtypes.

    Science.gov (United States)

    Mei, Bin; Liu, Guang-zhi; Yang, Yang; Liu, Yu-min; Cao, Jiang-hui; Zhang, Jun-jian

    2015-12-01

    Based on the recently proposed Chinese ischemic stroke subclassification (CISS) system, intracranial branch atheromatous disease (BAD) is divided into large artery atherosclerosis (LAA) and penetrating artery disease (PAD). In the current retrospective analysis, we compared the general characteristics of BAD-LAA with BAD-PAD, BAD-LAA with non-BAD-LAA and BAD-PAD with non-BAD-PAD. The study included a total of 80 cases, including 45 cases of BAD and 35 cases of non-BAD. Subjects were classified using CISS system: BAD-LAA, BAD-PAD, non-BAD-LAA and non-BAD-PAD. In addition to analysis of general characteristics, the correlation between the factors and the two subtypes of BAD was evaluated. The number of cases included in the analysis was: 32 cases of BAD-LAA, 13 cases of BAD-PAD, 21 cases of non-BAD-LAA, and 14 cases of non-BAD-PAD. Diabetes mellitus affected more non-BAD-LAA patients than BAD-LAA patients (P=0.035). In comparison with non-BAD-PAD, patients with BAD-PAD were younger (P=0.040), had higher initial NIHSS score (PBAD, the PAD subtype was associated with smoking (OR=0.043; P=0.011), higher low-density lipoprotein (OR=5.339; P=0.029), ischemic heart disease (OR=9.383; P=0.047) and diabetes mellitus (OR=12.59; P=0.020). It was concluded that large artery atherosclerosis was the primary mechanism of BAD. The general characteristics showed no significant differences between the CISS subtypes of LAA and PAD within BAD, as well as between the BAD and non-BAD within LAA subtype. Several differences between PAD subtypes of BAD and non-BAD were revealed.

  11. General Equilibrium Analysis of Electricity Market Liberalization in Singapore: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Fenglong XIAO

    2011-12-01

    Full Text Available The liberalization in electricity market in Singapore has being undertaken for more than 15 years. This paper evaluates the influence of competition policies by computable general equilibrium (CGE model. Instead of the direct measurement of the impact of competition policy, the benefit of liberalization is reflected by the simulation of a hypothetical regulatory condition. Comparing to the regulatory scenario, simulation result implies the current liberalization raises GDP and exchange rate significantly, but also leaves the tradeoff between higher national income and lower consumer welfare to government. If such choice of economic policy is necessary for political demand, a formal legal framework is required to enforce the restoration of the economy from regulatory restrictions.

  12. Comparative model accuracy of a data-fitted generalized Aw-Rascle-Zhang model

    CERN Document Server

    Fan, Shimao; Seibold, Benjamin

    2013-01-01

    The Aw-Rascle-Zhang (ARZ) model can be interpreted as a generalization of the Lighthill-Whitham-Richards (LWR) model, possessing a family of fundamental diagram curves, each of which represents a class of drivers with a different empty road velocity. A weakness of this approach is that different drivers possess vastly different densities at which traffic flow stagnates. This drawback can be overcome by modifying the pressure relation in the ARZ model, leading to the generalized Aw-Rascle-Zhang (GARZ) model. We present an approach to determine the parameter functions of the GARZ model from fundamental diagram measurement data. The predictive accuracy of the resulting data-fitted GARZ model is compared to other traffic models by means of a three-detector test setup, employing two types of data: vehicle trajectory data, and sensor data. This work also considers the extension of the ARZ and the GARZ models to models with a relaxation term, and conducts an investigation of the optimal relaxation time.

  13. Comparing Locus of Control, Assertiveness and General Health among Young Drug Addicts in Iran

    Directory of Open Access Journals (Sweden)

    Shahriar Shahidi

    2009-04-01

    Full Text Available "n "nObjective:The aim of this research was to compare the characteristics of assertiveness, locus of control and general health among young drug dependent patients in Iran. "n "nMethods: Three groups of Iranians: were choosed. The first group included drug dependent patients who had volunteered for treatment and had registered in the local Welfare Organization; the second group included dependent patients who were in the prison; and the third group held nondependent patients. All the participants were male and were matched for age and educational level . The following instruments were used in the present study: locus of control  uestionnaire , Assertiveness Scale and the General Health Questionnaire, GHQ. "n "nResults: The results of the present research showed that there were significant differences among the three groups in ssertiveness, locus of control and GHQ scores. It was found that participants in the non addictive group were more assertive and more internal in their locus of control and had higher GHQ scores than the other two groups. The participants in the prison group reported less assertiveness and lower GHQ scores than the non addictive group ; and their locus of control was more external. Conclusion: "n The results this study may be useful in terms of possible strategies for changing an attributive style in young adults in the framework of psychotherapy

  14. The Internet and Generalized Functions of the Public Sphere: Transformative Potentials From a Comparative Perspective

    Directory of Open Access Journals (Sweden)

    Adrian Rauchfleisch

    2016-04-01

    Full Text Available Almost since the advent of the Internet, there has been great interest in analyzing and understanding online communication from the perspective of public sphere theory. The question of whether the properties of the Internet and, specifically, social media actually contribute to the public sphere is the matter of ongoing and somewhat heated scientific debate. The aim of the article is twofold. First, we propose a hierarchical model of generalized functions of public sphere. On a theoretical level, we interweave different strands of thought on the public sphere, and the resulting model is more inclusive and less rigid than each of those strands on their own. We identify four generalized functions: identity building, agenda-setting, control and criticism, and deliberation. The Internet does not contribute equally to these functions and we evaluate the impact of the Internet on each of these functions as a diminishing marginal utility. Second, we empirically explore the plausibility of our model in a global comparative analysis with focus on the Internet. With the help of macro-level variables which indicate the structural preconditions for a public sphere, we identify the highest possible function of the public sphere for each country to which the Internet can potentially contribute. Based on this approach, future research can be contextualized: case-study-based research can plausibly articulate expectations regarding the impact of the Internet on the public sphere.

  15. Comparative assessment of scoring functions on an updated benchmark: 2. Evaluation methods and general results.

    Science.gov (United States)

    Li, Yan; Han, Li; Liu, Zhihai; Wang, Renxiao

    2014-06-23

    Our comparative assessment of scoring functions (CASF) benchmark is created to provide an objective evaluation of current scoring functions. The key idea of CASF is to compare the general performance of scoring functions on a diverse set of protein-ligand complexes. In order to avoid testing scoring functions in the context of molecular docking, the scoring process is separated from the docking (or sampling) process by using ensembles of ligand binding poses that are generated in prior. Here, we describe the technical methods and evaluation results of the latest CASF-2013 study. The PDBbind core set (version 2013) was employed as the primary test set in this study, which consists of 195 protein-ligand complexes with high-quality three-dimensional structures and reliable binding constants. A panel of 20 scoring functions, most of which are implemented in main-stream commercial software, were evaluated in terms of "scoring power" (binding affinity prediction), "ranking power" (relative ranking prediction), "docking power" (binding pose prediction), and "screening power" (discrimination of true binders from random molecules). Our results reveal that the performance of these scoring functions is generally more promising in the docking/screening power tests than in the scoring/ranking power tests. Top-ranked scoring functions in the scoring power test, such as X-Score(HM), ChemScore@SYBYL, ChemPLP@GOLD, and PLP@DS, are also top-ranked in the ranking power test. Top-ranked scoring functions in the docking power test, such as ChemPLP@GOLD, Chemscore@GOLD, GlidScore-SP, LigScore@DS, and PLP@DS, are also top-ranked in the screening power test. Our results obtained on the entire test set and its subsets suggest that the real challenge in protein-ligand binding affinity prediction lies in polar interactions and associated desolvation effect. Nonadditive features observed among high-affinity protein-ligand complexes also need attention.

  16. Comparing neighborhoods of adults with serious mental illness and of the general population: research implications.

    Science.gov (United States)

    Byrne, Thomas; Prvu Bettger, Janet; Brusilovskiy, Eugene; Wong, Yin-Ling Irene; Metraux, Stephen; Salzer, Mark S

    2013-08-01

    The International Classification of Functioning, Disability and Health emphasizes the importance of assessing the impact of environmental factors on functioning and disability. Drawing on this emphasis, this study used a set of objective measures to compare the characteristics of neighborhoods of adults with serious mental illness and of the general population. It also examined the relationship between neighborhood characteristics and neighborhood concentration of persons with serious mental illness. The sample comprised 15,246 adults who were treated for serious mental illness in Philadelphia between 1997 and 2000. Principal-components analysis of 22 neighborhood characteristics resulted in an ideal-factor solution of six components. The mean values of each component in neighborhoods of persons with serious mental illness were compared with values in an equally sized group of neighborhoods created by randomly generated addresses representative of the city's general population. Ordinary least-squares regression was used to assess the association between neighborhood characteristics and neighborhood concentration of persons with serious mental illness. Neighborhoods in which adults with serious mental illness resided had higher levels of physical and structural inadequacy, drug-related activity, and crime than comparison neighborhoods. Higher levels of physical and structural inadequacy, crime, drug-related activity, social instability, and social isolation were associated with higher concentration of persons with serious mental illness in the neighborhood's adult population. The differences in neighborhood characteristics identified in this study point to factors that merit closer attention as potential barriers or facilitators in the functioning, participation, and community integration of persons with serious mental illness.

  17. 34 CFR 222.75 - How does the Secretary compute the average per pupil expenditure of generally comparable local...

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false How does the Secretary compute the average per pupil expenditure of generally comparable local educational agencies under this subpart? 222.75 Section 222.75... pupil expenditure of generally comparable local educational agencies under this subpart? The...

  18. Regional disaster impact analysis: comparing input-output and computable general equilibrium models

    Science.gov (United States)

    Koks, Elco E.; Carrera, Lorenzo; Jonkeren, Olaf; Aerts, Jeroen C. J. H.; Husby, Trond G.; Thissen, Mark; Standardi, Gabriele; Mysiak, Jaroslav

    2016-08-01

    A variety of models have been applied to assess the economic losses of disasters, of which the most common ones are input-output (IO) and computable general equilibrium (CGE) models. In addition, an increasing number of scholars have developed hybrid approaches: one that combines both or either of them in combination with noneconomic methods. While both IO and CGE models are widely used, they are mainly compared on theoretical grounds. Few studies have compared disaster impacts of different model types in a systematic way and for the same geographical area, using similar input data. Such a comparison is valuable from both a scientific and policy perspective as the magnitude and the spatial distribution of the estimated losses are born likely to vary with the chosen modelling approach (IO, CGE, or hybrid). Hence, regional disaster impact loss estimates resulting from a range of models facilitate better decisions and policy making. Therefore, this study analyses the economic consequences for a specific case study, using three regional disaster impact models: two hybrid IO models and a CGE model. The case study concerns two flood scenarios in the Po River basin in Italy. Modelling results indicate that the difference in estimated total (national) economic losses and the regional distribution of those losses may vary by up to a factor of 7 between the three models, depending on the type of recovery path. Total economic impact, comprising all Italian regions, is negative in all models though.

  19. Breast augmentation under general anesthesia versus monitored anesthesia care: a retrospective comparative study.

    Science.gov (United States)

    Eldor, Liron; Weissman, Avi; Fodor, Lucian; Carmi, Nurit; Ullmann, Yehuda

    2008-09-01

    Breast augmentation is one of the leading esthetic surgeries, enjoying high satisfaction rates. Pain, nausea, and vomiting are frequent shortcomings of the immediate postoperative period. The aim of this study was to compare breast augmentation from the anesthetic point of view: general anesthesia (GA) versus monitored anesthesia care (MAC). The charts of 115 patients were reviewed in this retrospective study performed over a period of 2 years. Sixty-nine women chose to have the surgery done under MAC, and 46 under GA. Statistically significant differences were noted in both postoperative hospital stay (16.1 +/- 6.78 hours vs. 11.7 +/- 6.10 hours) and frequency of vomiting (mean, 0.5 vs. 0.22 times per patient) after GA and MAC, respectively (Mann-Whitney, P < 0.01). Postoperative pain, assessed using the visual analog scale, was significantly higher (mean visual analog scale, 5 vs. 3.27) when the prosthesis was placed in the submuscular plane compared with the subglandular plane (Mann-Whitney, P = 0.043). When offered a choice, more women preferred MAC over GA for their breast augmentation procedure. Less vomiting and shorter postoperative hospitalization were prominent in the MAC group.

  20. Multi-Agent Based Agile (XP) Software Development Process Scheduling Model

    National Research Council Canada - National Science Library

    Y M Malgwi; N V Blamah

    2015-01-01

    .... In such changing environment agile development methodology is suited. In this paper, a multi-agent based approach to process scheduling was adopted, where each activity is viewed as an autonomous and flexible agent process...

  1. Why technical trading may be successful? A lesson from the agent-based modeling

    Science.gov (United States)

    Schmidt, Anatoly B.

    2002-01-01

    It is shown using a simple agent-based market dynamics model that if the technical traders are able to affect the market liquidity, their concerted actions can move the market price in the direction favorable to their strategy.

  2. Agent-Based Simulation and Assessment of NAS Security and Safety Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The key innovation proposed here is the use of agent-based modeling and simulation to evaluate the safety of the National Airspace under crisis operations and...

  3. Agent-based Social Simulation tools: Brahms and NetLogo

    NARCIS (Netherlands)

    Sie, Rory

    2010-01-01

    Sie, R. L. L. (2010, 21 September). Agent-based Social Simulation tools: Brahms and NetLogo. Presentation at the Learning Networks Plenary, Heerlen, The Netherlands: Open University of the Netherlands.

  4. Practicality of Agent-Based Modeling of Civil Violence: an Assessment

    CERN Document Server

    Thron, Christopher

    2015-01-01

    Joshua Epstein (2002) proposed a simple agent-based model to describe the formation and evolution of spontaneous civil violence (such as riots or violent demonstrations). In this paper we study the practical applicability of Epstein's model.

  5. A Comparative Study between Intramuscular Midazolam and Oral Clonidine As A Premedication For General Anesthesia

    Directory of Open Access Journals (Sweden)

    Jignasa J Patel

    2015-12-01

    Full Text Available Background: Most anesthesiologists agree on the need for efficient pre-medication. The pattern of desired effects of a pre-medication is however, complex and includes relief of anxiety, sedation and relaxation of the patient. The present study was undertaken to compare the effects of Midazolam and clonidine as premedication. Methodology: A comparative study between midazolam and clonidine as a premedication for general anesthesia was conducted. Patients were divided in two groups: Group I: Inj. Midazolam 0.07 mg/kg i.m. before surgery; Group II Tab.Clonidine 4 and micro;g/kg oral, 2 hours before surgery. Pulse rate, blood pressure, state of excitement, apprehension and sedation were noted at the time of giving premedication. Results: Majority of cases in both the groups were in the age group of 16-30 years (56%. Gender wise distribution shows 40% cases were males and 60% were females. The sedation score, apprehension score and excitement score in both the groups before and after induction was statistically significant. There is no significant difference in dose requirement of pentothal for induction between midazolam and clonidine group. The amnesia score shows that midazolam produces more potent and perfect amnesia as compared to clonidine. Amnesia score in both the groups was statistically significant Conclusion: It was concluded from the present study that midazolam was superior to clonidine in its sedative and anxiolytic effects, had a potent amnesia and does not attenuate hemodynamic response to laryngoscopy and intubation and does not prolong recovery time. [Natl J Med Res 2015; 5(4.000: 312-315

  6. Predictability of Shanghai Stock Market by Agent-based Mix-game Model

    CERN Document Server

    Gou, C

    2005-01-01

    This paper reports the effort of using agent-based mix-game model to predict financial time series. It introduces the prediction methodology by means of mix-game model and gives an example of its application to forecasting Shanghai Index. The results show that this prediction methodology is effective and agent-based mix-game model is a potential good model to predict time series of financial markets.

  7. Mobile Agent Based Hierarchical Intrusion Detection System in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Surraya Khanum

    2012-01-01

    Full Text Available Security mechanism is a fundamental requirement of wireless networks in general and Wireless Sensor Networks (WSN in particular. Therefore, it is necessary that this security concern must be articulate right from the beginning of the network design and deployment. WSN needs strong security mechanism as it is usually deployed in a critical, hostile and sensitive environment where human labour is usually not involved. However, due to inbuilt resource and computing restriction, security in WSN needs a special consideration. Traditional security techniques such as encryption, VPN, authentication and firewalls cannot be directly applied to WSN as it provides defence only against external threats. The existing literature shows that there seems an inverse relationship between strong security mechanism and efficient network resource utilization. In this research article, we have proposed a Mobile Agent Based Hierarchical Intrusion Detection System (MABHIDS for WSN. The Proposed scheme performs two levels of intrusion detection by utilizing minimum possible network resources. Our proposed idea enhance network lifetime by reducing the work load on Cluster Head (CH and it also provide enhanced level of security in WSN.

  8. Study of the attractor structure of an agent-based sociological model

    Science.gov (United States)

    Timpanaro, André M.; Prado, Carmen P. C.

    2011-03-01

    The Sznajd model is a sociophysics model that is based in the Potts model, and used for describing opinion propagation in a society. It employs an agent-based approach and interaction rules favouring pairs of agreeing agents. It has been successfully employed in modeling some properties and scale features of both proportional and majority elections (see for instance the works of A. T. Bernardes and R. N. Costa Filho), but its stationary states are always consensus states. In order to explain more complicated behaviours, we have modified the bounded confidence idea (introduced before in other opinion models, like the Deffuant model), with the introduction of prejudices and biases (we called this modification confidence rules), and have adapted it to the discrete Sznajd model. This generalized Sznajd model is able to reproduce almost all of the previous versions of the Sznajd model, by using appropriate choices of parameters. We solved the attractor structure of the resulting model in a mean-field approach and made Monte Carlo simulations in a Barabási-Albert network. These simulations show great similarities with the mean-field, for the tested cases of 3 and 4 opinions. The dynamical systems approach that we devised allows for a deeper understanding of the potential of the Sznajd model as an opinion propagation model and can be easily extended to other models, like the voter model. Our modification of the bounded confidence rule can also be readily applied to other opinion propagation models.

  9. Partner choice promotes cooperation: the two faces of testing with agent-based models.

    Science.gov (United States)

    Campennì, Marco; Schino, Gabriele

    2014-03-07

    Reciprocity is one of the most debated among the mechanisms that have been proposed to explain the evolution of cooperation. While a distinction can be made between two general processes that can underlie reciprocation (within-pair temporal relations between cooperative events, and partner choice based on benefits received), theoretical modelling has concentrated on the former, while the latter has been often neglected. We developed a set of agent-based models in which agents adopted a strategy of obligate cooperation and partner choice based on benefits received. Our models tested the ability of partner choice both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Populations formed by agents adopting a strategy of obligate cooperation and partner choice based on benefits received showed differentiated "social relationships" and a positive correlation between cooperation given and received, two common phenomena in animal cooperation. When selection across multiple generations was added to the model, agents adopting a strategy of partner choice based on benefits received outperformed selfish agents that did not cooperate. Our results suggest partner choice is a significant aspect of cooperation and provides a possible mechanism for its evolution.

  10. Overall and cause-specific mortality in HIV-positive subjects compared to the general population

    Directory of Open Access Journals (Sweden)

    Belen Alejos

    2014-11-01

    Full Text Available Introduction: Emerging non-AIDS related causes of death have been observed in HIV-positive subjects in industrialized countries. We aimed to analyze overall and cause-specific excess of mortality of HIV-positive patients compared to the general population and to assess the effect of prognostic factors. Material and Methods: We used generalized linear models with Poisson error structure to estimate overall and cause-specific excess of mortality in HIV-positive patients from 2004 to 2012 in the cohort of the Spanish Network of HIV Research (CoRIS, compared to Spanish general population and to assess the impact of multiple risk factors. We investigated differences between short-term and long-term risk factors effects on excess of mortality. Multiple Imputation by Chained Equations was used to deal with missing data. Results: In 9162 patients there were 363 deaths, 16.0% were non-AIDS malignancies, 10.5% liver and 0.3% cardiovascular related. Excess mortality was 1.20 deaths per 100 person years (py for all-cause mortality, 0.16 for liver, 0.10 for non-AIDS malignancies and 0.03 for cardiovascular. Short-term (first-year follow-up excess Hazard Ratio (eHR for global mortality for baseline AIDS was 4.27 (95% CI 3.06–6.01 and 1.47 (95% CI 0.95–2.27 for HCV coinfection; long-term (subsequent follow-up eHR for baseline AIDS was 0.88 (95% CI 0.58–1.35 and 4.48 (95% CI 2.71–7.42 for HCV coinfection. Lower CD4 count and higher viral load at entry, lower education, being male and over 50 years were predictors for overall excess mortality. Excess of liver mortality was higher in patients with CD4 counts at entry below 200 cells compared to those above 350 (eHR: 6.49, 95% CI 1.21–34.84 and in HCV-coinfected patients (eHR: 3.85, 95% CI 0.85– 17.37, although it was borderline significant. Patients over 50 years old (eHR: 5.55, 95%CI 2.4–12.85 and HCV coinfected (eHR: 5.81, 95% CI 2.6–13 showed a higher risk of non-AIDS malignancies mortality

  11. Comparative outcomes of peripheral nerve blocks versus general anesthesia for hip fractures in geriatric Chinese patients

    Directory of Open Access Journals (Sweden)

    Liu JL

    2014-05-01

    Full Text Available Jun Le Liu,1,* Xiao Lin Wang,1,* Mao Wei Gong,1,* Hai Xing Mai,2 Shu Jun Pei,1 Wei Xiu Yuan,1 Hong Zhang11Anesthesia and Operation Center, Chinese People’s Liberation Army General Hospital and Medical School of Chinese People’s Liberation Army, Beijing, People’s Republic of China; 2Department of Urology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, People’s Republic of China*These authors contributed equally to this workBackground: Geriatric patients undergoing hemiarthroplasty for hip fractures have unacceptably high rates of postoperative complications and mortality. Whether anesthesia type can affect the outcomes has still been inconclusive.Objectives: We compared general anesthesia (GA and peripheral nerve blocks (PNBs on postoperative complications and mortality in elderly patients with femoral neck fractures (FNF undergoing hemiarthroplasty.Materials and methods: This retrospective study involved data collection from an electronic database. Two hundred and seventeen patients underwent hemiarthroplasty for FNF between January 2008 and December 2012 at the Chinese People’s Liberation Army General Hospital. Data on mortality within in-hospital, 30-day, and 1-year, complications, comorbidities, blood loss and transfusion, operative time, postoperative hospital length of stay, intensive care unit admission, and hospital charge were collected and analyzed. Univariate and multivariate Cox regression analyses of all variables were used for 30-day and 1-year mortality.Results: Seventy-two patients receiving GA and 145 receiving PNBs were eventually submitted and analyzed. Mortality was 6.9%, 14.7%, and 23.5% at in-hospital, 30-day, and 1-year, respectively postoperatively, while mortality and cardiovascular complications did not differ between the two anesthetic techniques. Preoperative comorbidities and intraoperative parameters were not statistically different except that patients receiving GA were more likely

  12. Evaluation of wholesale electric power market rules and financial risk management by agent-based simulations

    Science.gov (United States)

    Yu, Nanpeng

    dissertation, basic financial risk management concepts relevant for wholesale electric power markets are carefully explained and illustrated. In addition, the financial risk management problem in wholesale electric power markets is generalized as a four-stage process. Within the proposed financial risk management framework, the critical problem of financial bilateral contract negotiation is addressed. This dissertation analyzes a financial bilateral contract negotiation process between a generating company and a load-serving entity in a wholesale electric power market with congestion managed by locational marginal pricing. Nash bargaining theory is used to model a Pareto-efficient settlement point. The model predicts negotiation results under varied conditions and identifies circumstances in which the two parties might fail to reach an agreement. Both analysis and agent-based simulation are used to gain insight regarding how relative risk aversion and biased price estimates influence negotiated outcomes. These results should provide useful guidance to market participants in their bilateral contract negotiation processes.

  13. Agent-based modelling of shifting cultivation field patterns, Vietnam

    DEFF Research Database (Denmark)

    Jepsen, Martin Rudbeck; Leisz, S.; Rasmussen, K.;

    2006-01-01

    costs associated with fencing of fields, and are faced with physical constraints. The simulation results are compared with land-cover data obtained from remote sensing. Comparisons are made on patterns as detected visually and using the mean nearest-neighbour ratio. Baseline simulation outputs show high...

  14. An Agent-based Model of Food Safety Practices Adoption

    NARCIS (Netherlands)

    Verwaart, T.; Valeeva, N.I.

    2011-01-01

    Food processors and governments have an interest to motivate suppliers of animal products to implement food safety measures. This paper proposes an agentbased simulation model to compare possible consequences of alternative communication programs and incentive systems. The agent model combines econo

  15. An agent-based model for Leishmania major infection

    Science.gov (United States)

    Dancik, Garrett M.; Jones, Douglas E.; Dorman, Karin S.

    Leishmania are protozoan parasites transmitted by bites of infected sandflies. Over 20 species of Leishmania, endemic in 88 countries, are capable of causing human disease. Disease is either cutaneous, where skin ulcers occur on exposed surfaces of the body, or visceral, with near certain mortality if untreated. C3HeB/FeJ mice are resistant to L. major, but develop chronic cutaneous lesions when infected with another species L. amazonensis. The well-characterized mechanism of resistance to L. major depends on a CD4+ Thl immune response, macrophage activation, and elimination of the parasite [Sacks 2002]. The factors that account for host susceptibility to L. Amazonensis, however, are not completely understood, despite being generally attributed to a weakened Th1 response [Vanloubbeck 2004].

  16. On the generality of crowding: visual crowding in size, saturation, and hue compared to orientation.

    Science.gov (United States)

    van den Berg, Ronald; Roerdink, Jos B T M; Cornelissen, Frans W

    2007-07-17

    Perception of peripherally viewed shapes is impaired when surrounded by similar shapes. This phenomenon is commonly referred to as "crowding". Although studied extensively for perception of characters (mainly letters) and, to a lesser extent, for orientation, little is known about whether and how crowding affects perception of other features. Nevertheless, current crowding models suggest that the effect should be rather general and thus not restricted to letters and orientation. Here, we report on a series of experiments investigating crowding in the following elementary feature dimensions: size, hue, and saturation. Crowding effects in these dimensions were benchmarked against those in the orientation domain. Our primary finding is that all features studied show clear signs of crowding. First, identification thresholds increase with decreasing mask spacing. Second, for all tested features, critical spacing appears to be roughly half the viewing eccentricity and independent of stimulus size, a property previously proposed as the hallmark of crowding. Interestingly, although critical spacings are highly comparable, crowding magnitude differs across features: Size crowding is almost as strong as orientation crowding, whereas the effect is much weaker for saturation and hue. We suggest that future theories and models of crowding should be able to accommodate these differences in crowding effects.

  17. General Astrophysics and Comparative Planetology with the Terrestrial Planet Finder Missions

    CERN Document Server

    Kuchner, M J

    2005-01-01

    The two Terrestrial Planet Finder (TPF) missions aim to perform spectroscopy on extrasolar Earths; TPF-C will operate in visible light, and TPF-I will operate in the mid-infrared. Extrasolar Earths are assumed to be roughly 26 magnitude in V band, roughly 0.3 microJy in the mid-IR, and located as close as roughly 30 milliarcseconds from a reasonable set of target stars, demanding high sensitivity, angular resolution and dynamic range to study. With capabilities matched to this task, the TPF missions could easily undertake a broad range of further scientific investigations. This document discusses the potential of TPF for general astrophysics and comparative planetology beyond its base mission, focusing on science obtainable with no or minimal modifications to the mission design, but also exploring possible modifications to TPF with high scientific merit and no impact on the basic search for extrasolar Earth analogs. It addresses both TPF-C and TPF-I, but emphasizes TPF-C, because its launch is planned for 201...

  18. A Conceptual Framework for Representing Human Behavior Characteristics in a System of Systems Agent-Based Survivability Simulation

    Science.gov (United States)

    2010-11-22

    distribution is unlimited. A CONCEPTUAL FRAMEWORK FOR REPRESENTING HUMAN BEHAVIOR CHARACTERISTICS IN A SYSTEM OF SYSTEMS AGENT-BASED SURVIVABILITY...27411 -0001 ABSTRACT A CONCEPTUAL FRAMEWORK FOR REPRESENTING HUMAN BEHAVIOR CHARACTERISTICS IN A SYSTEM OF SYSTEMS AGENT-BASED SURVIVABILITY SIMULATION...TITLE AND SUBTITLE A CONCEPTUAL FRAMEWORK FOR REPRESENTING HUMAN BEHAVIOR CHARACTERISTICS IN A SYSTEM OF SYSTEMS AGENT-BASED SURVIVABILITY

  19. Opening the black box—Development, testing and documentation of a mechanistically rich agent-based model

    DEFF Research Database (Denmark)

    Topping, Chris J.; Høye, Toke; Olesen, Carsten Riis

    2010-01-01

    Although increasingly widely used in biology, complex adaptive simulation models such as agent-based models have been criticised for being difficult to communicate and test. This study demonstrates the application of pattern-oriented model testing, and a novel documentation procedure to present a...... be compared to real-world data allows the formulation and testing of varied hypotheses in ways not tractable to experimentation. In the case of the brown hare the results provide a new insight into population regulation and the causes of the declines...

  20. Comparative heart failure profile over a 3-year period in a Romanian general hospital

    Directory of Open Access Journals (Sweden)

    Pop D

    2013-07-01

    Full Text Available Dana Pop,1 Oana Maria Penciu,1 Adela Viviana Sitar-Taut,2 Dumitru Tudor Zdrenghea11Department of Cardiology, Clinical Rehabilitation Hospital, "Iuliu Hatieganu" University of Medicine and Pharmacy, Cluj-Napoca, Romania; 2"Babes-Bolyai" University, Cluj-Napoca, RomaniaBackground: Heart failure (HF has become an increasingly significant public health problem, associated with repeated hospitalizations, high costs, low quality of life, and decreased survival rate. The progress of the disease may be slowed if treatment is administered in accordance with current guidelines.Objectives: To compare the clinical profile of HF patients in a Romanian general hospital over a 3-year period.Methods and results: We studied two cohorts of patients admitted in the cardiology department of a rehabilitation hospital with a diagnosis of chronic HF New York Heart Association class II–IV. The first, in 2006, included 415 patients, 67.08 ± 10.59 years; the second, in 2009, included 500 patients, 67.31 ± 11.27 years. Considering all patients, the left ventricle ejection fraction (LVEF was not statistically different in the two cohorts. Compared to the 2006 cohort, the 2009 female cohort had higher LVEF (60.49% ± 13.41% vs 64.42% ± 13.79%, P < 0.05, while males over 65 years of age had lower LVEF (52.75% ± 15.02% vs 54.37% ± 15.23%, P = NS. For females, the probability of having LVEF ,45% was higher in 2006 (odds ratio = 1.573. HF with preserved LVEF was more common in females, both in 2006 (78.2% vs 54.2% and 2009 (87.2% vs 57.3%. In the 2009 cohort, LVEF was higher both in young patients (59.08% ± 14.22% vs 55.35% ± 14.92% and patients ≥ than 75 years of age (62.28% ± 13.81% vs 56.79% ± 14.81% compared to the 2006 cohort. Ischemic heart disease was the main underlying cause for HF in both cohorts.Conclusion: HF appeared to have the same clinical profile over a 3-year period. Females diagnosed with HF showed higher rates of preserved LVEF.Keywords: heart

  1. Dynamics of bloggers’ communities: Bipartite networks from empirical data and agent-based modeling

    Science.gov (United States)

    Mitrović, Marija; Tadić, Bosiljka

    2012-11-01

    We present an analysis of the empirical data and the agent-based modeling of the emotional behavior of users on the Web portals where the user interaction is mediated by posted comments, like Blogs and Diggs. We consider the dataset of discussion-driven popular Diggs, in which all comments are screened by machine-learning emotion detection in the text, to determine positive and negative valence (attractiveness and aversiveness) of each comment. By mapping the data onto a suitable bipartite network, we perform an analysis of the network topology and the related time-series of the emotional comments. The agent-based model is then introduced to simulate the dynamics and to capture the emergence of the emotional behaviors and communities. The agents are linked to posts on a bipartite network, whose structure evolves through their actions on the posts. The emotional states (arousal and valence) of each agent fluctuate in time, subject to the current contents of the posts to which the agent is exposed. By an agent’s action on a post its current emotions are transferred to the post. The model rules and the key parameters are inferred from the considered empirical data to ensure their realistic values and mutual consistency. The model assumes that the emotional arousal over posts drives the agent’s action. The simulations are preformed for the case of constant flux of agents and the results are analyzed in full analogy with the empirical data. The main conclusions are that the emotion-driven dynamics leads to long-range temporal correlations and emergent networks with community structure, that are comparable with the ones in the empirical system of popular posts. In view of pure emotion-driven agents actions, this type of comparisons provide a quantitative measure for the role of emotions in the dynamics on real blogs. Furthermore, the model reveals the underlying mechanisms which relate the post popularity with the emotion dynamics and the prevalence of negative

  2. AN AGENT BASED TRANSACTION PROCESSING SCHEME FOR DISCONNECTED MOBILE NODES

    Directory of Open Access Journals (Sweden)

    J.L. Walter Jeyakumar

    2010-12-01

    Full Text Available We present a mobile transaction framework in which mobile users can share data which is stored in the cache of a mobile agent. This mobile agent is a special mobile node which coordinates the sharing process. The proposed framework allows mobile affiliation work groups to be formed dynamically with a mobile agent and mobile hosts. Using short range wireless communication technology, mobile users can simultaneously access the data from the cache of the mobile agent. The data Access Manager module at the mobile agent enforces concurrency control using cache invalidation technique. This model supports disconnected mobile computing allowing mobile agent to move along with the Mobile Hosts. The proposed Transaction frame work has been simulated in Java 2 and performance of this scheme is compared with existing frame works.

  3. Agent-based modelling of mosquito foraging behaviour for malaria control

    Science.gov (United States)

    Gu, Weidong; Novak, Robert J.

    2009-01-01

    Summary Traditional environmental management programmes require extensive coverage of larval habitats to reduce drastically the emergence of adult mosquitoes. Recent studies have highlighted the impact of reduced availability of aquatic habitats on mosquito foraging for hosts and oviposition sites. In this study, we developed an agent-based model to track the status and movement of mosquitoes individually. Mosquito foraging was represented as a two-stage process: random flight when the resource was not within the mosquito’s perception range and directional flight to the resource when it was detected. Three scenarios of targeted source reduction were devised to eliminate all aquatic habitats within certain distances of human habitations. For comparison, three conventional source reductions randomly eliminated the same numbers of aquatic habitats as their corresponding targeted scenarios. Our results show that the elimination of habitats within 100 m, 200 m and 300 m of surrounding houses resulted in 13%, 91% and 94% reductions in malaria incidence, respectively; compared with −3%, 19% and 44%, respectively, for the corresponding conventional interventions. These findings indicate that source reduction might not require coverage of extensive areas, as previously thought, and that the distance to human habitations can be used for habitat targeting. PMID:19200566

  4. Quantitative Agent Based Model of Opinion Dynamics: Polish Elections of 2015.

    Directory of Open Access Journals (Sweden)

    Pawel Sobkowicz

    Full Text Available We present results of an abstract, agent based model of opinion dynamics simulations based on the emotion/information/opinion (E/I/O approach, applied to a strongly polarized society, corresponding to the Polish political scene between 2005 and 2015. Under certain conditions the model leads to metastable coexistence of two subcommunities of comparable size (supporting the corresponding opinions-which corresponds to the bipartisan split found in Poland. Spurred by the recent breakdown of this political duopoly, which occurred in 2015, we present a model extension that describes both the long term coexistence of the two opposing opinions and a rapid, transitory change due to the appearance of a third party alternative. We provide quantitative comparison of the model with the results of polls and elections in Poland, testing the assumptions related to the modeled processes and the parameters used in the simulations. It is shown, that when the propaganda messages of the two incumbent parties differ in emotional tone, the political status quo may be unstable. The asymmetry of the emotions within the support bases of the two parties allows one of them to be 'invaded' by a newcomer third party very quickly, while the second remains immune to such invasion.

  5. Agent-Based Crowd Simulation Considering Emotion Contagion for Emergency Evacuation Problem

    Science.gov (United States)

    Faroqi, H.; Mesgari, M.-S.

    2015-12-01

    During emergencies, emotions greatly affect human behaviour. For more realistic multi-agent systems in simulations of emergency evacuations, it is important to incorporate emotions and their effects on the agents. In few words, emotional contagion is a process in which a person or group influences the emotions or behavior of another person or group through the conscious or unconscious induction of emotion states and behavioral attitudes. In this study, we simulate an emergency situation in an open square area with three exits considering Adults and Children agents with different behavior. Also, Security agents are considered in order to guide Adults and Children for finding the exits and be calm. Six levels of emotion levels are considered for each agent in different scenarios and situations. The agent-based simulated model initialize with the random scattering of agent populations and then when an alarm occurs, each agent react to the situation based on its and neighbors current circumstances. The main goal of each agent is firstly to find the exit, and then help other agents to find their ways. Numbers of exited agents along with their emotion levels and damaged agents are compared in different scenarios with different initialization in order to evaluate the achieved results of the simulated model. NetLogo 5.2 is used as the multi-agent simulation framework with R language as the developing language.

  6. AGENT-BASED CROWD SIMULATION CONSIDERING EMOTION CONTAGION FOR EMERGENCY EVACUATION PROBLEM

    Directory of Open Access Journals (Sweden)

    H. Faroqi

    2015-12-01

    Full Text Available During emergencies, emotions greatly affect human behaviour. For more realistic multi-agent systems in simulations of emergency evacuations, it is important to incorporate emotions and their effects on the agents. In few words, emotional contagion is a process in which a person or group influences the emotions or behavior of another person or group through the conscious or unconscious induction of emotion states and behavioral attitudes. In this study, we simulate an emergency situation in an open square area with three exits considering Adults and Children agents with different behavior. Also, Security agents are considered in order to guide Adults and Children for finding the exits and be calm. Six levels of emotion levels are considered for each agent in different scenarios and situations. The agent-based simulated model initialize with the random scattering of agent populations and then when an alarm occurs, each agent react to the situation based on its and neighbors current circumstances. The main goal of each agent is firstly to find the exit, and then help other agents to find their ways. Numbers of exited agents along with their emotion levels and damaged agents are compared in different scenarios with different initialization in order to evaluate the achieved results of the simulated model. NetLogo 5.2 is used as the multi-agent simulation framework with R language as the developing language.

  7. An Exploratory Study of the Butterfly Effect Using Agent-Based Modeling

    Science.gov (United States)

    Khasawneh, Mahmoud T.; Zhang, Jun; Shearer, Nevan E. N.; Rodriquez-Velasquez, Elkin; Bowling, Shannon R.

    2010-01-01

    This paper provides insights about the behavior of chaotic complex systems, and the sensitive dependence of the system on the initial starting conditions. How much does a small change in the initial conditions of a complex system affect it in the long term? Do complex systems exhibit what is called the "Butterfly Effect"? This paper uses an agent-based modeling approach to address these questions. An existing model from NetLogo library was extended in order to compare chaotic complex systems with near-identical initial conditions. Results show that small changes in initial starting conditions can have a huge impact on the behavior of chaotic complex systems. The term the "butterfly effect" is attributed to the work of Edward Lorenz [1]. It is used to describe the sensitive dependence of the behavior of chaotic complex systems on the initial conditions of these systems. The metaphor refers to the notion that a butterfly flapping its wings somewhere may cause extreme changes in the ecological system's behavior in the future, such as a hurricane.

  8. General practitioners' psychosocial resources, distress, and sickness absence: a study comparing the UK and Finland.

    Science.gov (United States)

    Heponiemi, Tarja; Elovainio, Marko; Presseau, Justin; Eccles, Martin P

    2014-06-01

    Many countries, including the UK and Finland, face difficulties in recruiting GPs and one reason for these difficulties may be due to negative psychosocial work environments. To compare psychosocial resources (job control and participative safety), distress and sickness absences between GPs from the UK and those from Finland. We also examined differences in how psychosocial resources are associated with distress and sickness absence and how distress is associated with sickness absence for both countries. Two independent cross-sectional surveys conducted in general practice in the UK and Finland. Analyses of covariance were used for continuous outcome variables and logistic regression for dichotomized variable (sickness absence) adjusted for gender, qualification year and response format. UK GPs reported more opportunities to control their work and had higher levels of participative safety but were more distressed than Finnish GPs. Finnish GPs were 2.3 (95% confidence interval = 1.8-3.1) times more likely to report sickness absence spells than UK GPs. Among Finnish GPs, job control opportunities and high participative safety were associated with lower levels of distress, but not among UK GPs. Among UK GPs, higher distress was associated with 2.1 (95% confidence interval = 1.3-3.6) times higher likelihood of sickness absence spells, but among Finnish GPs there were no such association. In Finland, primary health care organizations should try to improve participative safety and increase control opportunities of physicians to decrease GP distress, whereas in the UK, other work or private life factors may be more important. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Antibiotics dispensing for URTIs by community pharmacists and general medical practitioners in Penang, Malaysia: A comparative study using simulated patients

    OpenAIRE

    Alabid, Alamin Hassan M. A.; Ibrahim, Mohamed Izham Mohamed; Hassali,Mohamed Azmi

    2014-01-01

    Background: In Malaysia, doctors in private clinics (often called dispensing doctors) are permitted to dispense medicines. This potentially may compromise rational dispensing of medicines in general and antibiotics in particular. Aim: This study explored, assessed and compared dispensing of antibiotics between Community Pharmacist (CP) and General Practitioners (GPs) regarding symptomatic diagnosis, antibiotic categories, adherence to therapeutic doses and promotion of generic antibiotics...

  10. Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry

    Science.gov (United States)

    Holme, Thomas

    2014-01-01

    Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…

  11. Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry

    Science.gov (United States)

    Holme, Thomas

    2014-01-01

    Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…

  12. Incidence of Postoperative Deep Venous Thrombosis Is Higher among Cardiac and Vascular Surgery Patients as Compared with General Surgery Patients.

    Science.gov (United States)

    Aziz, Faisal; Patel, Mayank; Ortenzi, Gail; Reed, Amy B

    2015-01-01

    Unlike general surgery patients, most of vascular and cardiac surgery patients receive therapeutic anticoagulation during operations. The purpose of this study was to report the incidence of deep venous thrombosis (DVT) among cardiac and vascular surgery patients, compared with general surgery. The American College of Surgeons National Surgical Quality Improvement Program database was queried for all patients who underwent surgical procedures from 2005 to 2010. Patients who developed DVT within 30 days of an operation were identified. The incidence of DVT was compared among vascular, general, and cardiac surgery patients. Risk factors for developing postoperative DVT were identified and compared among these patients. Of total 2,669,772 patients underwent surgical operations in the period between 2005 and 2010. Of all the patients, 18,670 patients (0.69%) developed DVT. The incidence of DVT among different surgical specialties was cardiac surgery (2%), vascular surgery (0.99%), and general surgery (0.66%). The odds ratio for developing DVT was 1.5 for vascular surgery patients and 3 for cardiac surgery patients, when compared with general surgery patients (P cardiac surgery was 2, when compared with vascular surgery (P cardiac surgery patients as compared with that of general surgery patients. Intraoperative anticoagulation does not prevent the occurrence of DVT in the postoperative period. These patients should receive DVT prophylaxis in the perioperative period, similar to other surgical patients according to evidence-based guidelines. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Going beyond the unitary curve: incorporating richer cognition into agent-based water resources models

    Science.gov (United States)

    Kock, B. E.

    2008-12-01

    The increased availability and understanding of agent-based modeling technology and techniques provides a unique opportunity for water resources modelers, allowing them to go beyond traditional behavioral approaches from neoclassical economics, and add rich cognition to social-hydrological models. Agent-based models provide for an individual focus, and the easier and more realistic incorporation of learning, memory and other mechanisms for increased cognitive sophistication. We are in an age of global change impacting complex water resources systems, and social responses are increasingly recognized as fundamentally adaptive and emergent. In consideration of this, water resources models and modelers need to better address social dynamics in a manner beyond the capabilities of neoclassical economics theory and practice. However, going beyond the unitary curve requires unique levels of engagement with stakeholders, both to elicit the richer knowledge necessary for structuring and parameterizing agent-based models, but also to make sure such models are appropriately used. With the aim of encouraging epistemological and methodological convergence in the agent-based modeling of water resources, we have developed a water resources-specific cognitive model and an associated collaborative modeling process. Our cognitive model emphasizes efficiency in architecture and operation, and capacity to adapt to different application contexts. We describe a current application of this cognitive model and modeling process in the Arkansas Basin of Colorado. In particular, we highlight the potential benefits of, and challenges to, using more sophisticated cognitive models in agent-based water resources models.

  14. Implementing an Agent Based Artificial Stock Market Model in JADE – An Illustration

    Directory of Open Access Journals (Sweden)

    PN Kumar

    2013-06-01

    Full Text Available Agent-based approach to economic and financial analysis is a suitable research methodolgy for developing and understanding the complex patterns and phenomena that are observed in economic systems. In agent-based financial market models, prices can be endogenously formed by the system itself as the result of interaction of market participants. By using agents for the study, heterogeneous, boundedly rational, and adaptive behaviour of market participants can be analysed and its impact assessed. The collective behaviour of such groups is determined by the interaction of individual behaviours distributed across the group. This being the scenario prevailing in stock markets, agent based models are suitable for the study. Through this paper, we have attempted to illustrate a detailed implementation of multi agents in an artificial stock market invoking the agent-based methodology on Java Agent Development (JADE environment, a platform to develop multi-agent systems. The Extended Glosten and Milgrom Model, an agent based artificial stock market model, has been chosen to depict the multi-agent environment model in JADE.

  15. Agent-based modeling of deforestation in southern Yucatan, Mexico, and reforestation in the Midwest United States.

    Science.gov (United States)

    Manson, Steven M; Evans, Tom

    2007-12-26

    We combine mixed-methods research with integrated agent-based modeling to understand land change and economic decision making in the United States and Mexico. This work demonstrates how sustainability science benefits from combining integrated agent-based modeling (which blends methods from the social, ecological, and information sciences) and mixed-methods research (which interleaves multiple approaches ranging from qualitative field research to quantitative laboratory experiments and interpretation of remotely sensed imagery). We test assumptions of utility-maximizing behavior in household-level landscape management in south-central Indiana, linking parcel data, land cover derived from aerial photography, and findings from laboratory experiments. We examine the role of uncertainty and limited information, preferences, differential demographic attributes, and past experience and future time horizons. We also use evolutionary programming to represent bounded rationality in agriculturalist households in the southern Yucatán of Mexico. This approach captures realistic rule of thumb strategies while identifying social and environmental factors in a manner similar to econometric models. These case studies highlight the role of computational models of decision making in land-change contexts and advance our understanding of decision making in general.

  16. Applying GIS and high performance agent-based simulation for managing an Old World Screwworm fly invasion of Australia.

    Science.gov (United States)

    Welch, M C; Kwan, P W; Sajeev, A S M

    2014-10-01

    Agent-based modelling has proven to be a promising approach for developing rich simulations for complex phenomena that provide decision support functions across a broad range of areas including biological, social and agricultural sciences. This paper demonstrates how high performance computing technologies, namely General-Purpose Computing on Graphics Processing Units (GPGPU), and commercial Geographic Information Systems (GIS) can be applied to develop a national scale, agent-based simulation of an incursion of Old World Screwworm fly (OWS fly) into the Australian mainland. The development of this simulation model leverages the combination of massively data-parallel processing capabilities supported by NVidia's Compute Unified Device Architecture (CUDA) and the advanced spatial visualisation capabilities of GIS. These technologies have enabled the implementation of an individual-based, stochastic lifecycle and dispersal algorithm for the OWS fly invasion. The simulation model draws upon a wide range of biological data as input to stochastically determine the reproduction and survival of the OWS fly through the different stages of its lifecycle and dispersal of gravid females. Through this model, a highly efficient computational platform has been developed for studying the effectiveness of control and mitigation strategies and their associated economic impact on livestock industries can be materialised.

  17. Comparing salivary cotinine concentration in non-smokers from the general population and hospitality workers in Spain.

    Science.gov (United States)

    Martínez-Sánchez, Jose M; Fu, Marcela; Pérez-Ríos, Mónica; López, María J; Moncada, Albert; Fernández, Esteve

    2009-12-01

    The objective was to compare the pattern of exposure to second-hand smoke (SHS) among non-smokers in the general population and in hospitality workers. We used the adult (16-64 years) non-smokers of two independent studies (general population and hospitality workers) in Spain. We assessed the exposure to SHS by means of questionnaire and salivary cotinine concentration. The salivary cotinine concentration by sex, age, educational level, day of week of saliva collection, and exposure to SHS were always higher in hospitality workers than in the general population. Our results indicated that non-smoker hospitality workers have higher levels of exposure to SHS than general population.

  18. The Generality of Adult Development Stages and Transformations: Comparing Meaning-making and Logical Reasoning

    OpenAIRE

    Tom Hagström; Kristian Stålne

    2015-01-01

    Human development theories differ in “context sensitivity,” covering those stressing development stages and those stressing continuously progressing changes. The former theories differ in whether, how and why the stages are regarded as being generalized across domains, i.e. their generality claims. Piaget’s developmental stage theory of logical complexity of children and adolescents fulfill “strong” such claims, including fixed stage sequentiality of increasing complexity levels and higher st...

  19. General Theory versus ENA Theory: Comparing Their Predictive Accuracy and Scope.

    Science.gov (United States)

    Ellis, Lee; Hoskin, Anthony; Hartley, Richard; Walsh, Anthony; Widmayer, Alan; Ratnasingam, Malini

    2015-12-01

    General theory attributes criminal behavior primarily to low self-control, whereas evolutionary neuroandrogenic (ENA) theory envisions criminality as being a crude form of status-striving promoted by high brain exposure to androgens. General theory predicts that self-control will be negatively correlated with risk-taking, while ENA theory implies that these two variables should actually be positively correlated. According to ENA theory, traits such as pain tolerance and muscularity will be positively associated with risk-taking and criminality while general theory makes no predictions concerning these relationships. Data from Malaysia and the United States are used to test 10 hypotheses derived from one or both of these theories. As predicted by both theories, risk-taking was positively correlated with criminality in both countries. However, contrary to general theory and consistent with ENA theory, the correlation between self-control and risk-taking was positive in both countries. General theory's prediction of an inverse correlation between low self-control and criminality was largely supported by the U.S. data but only weakly supported by the Malaysian data. ENA theory's predictions of positive correlations between pain tolerance, muscularity, and offending were largely confirmed. For the 10 hypotheses tested, ENA theory surpassed general theory in predictive scope and accuracy.

  20. A COMPARATIVE STUDY OF EPIDURAL VS. GENERAL ANAESTHESIA FOR LAPAROSCOPIC CHOLECYSTECTOMY

    Directory of Open Access Journals (Sweden)

    Jayadheer D

    2016-07-01

    Full Text Available BACKGROUND Laparoscopic cholecystectomy has many benefits for patients including reduced postoperative pain, postoperative stay, and fewer wound-related complications. Specifically, obese patients and patients with severe respiratory diseases are benefited with laparoscopic procedures. The procedure is normally performed under general anaesthesia. But off late, this procedure was tried under regional successfully especially under epidural anaesthesia. Various reports in the literature suggest the safety of the use of spinal, epidural, and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of regional anaesthesia include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective postoperative analgesia, and early ambulation and recovery. However, regional anaesthesia maybe associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies maybe required to establish the advantage of regional anaesthesia over general anaesthesia for its eventual global use in different patient populations. METHODS 40 patients with the ASA (American Society of Anaesthesiologists class I and II were enrolled after taking prior written consent for laparoscopic cholecystectomy at King George Hospital, Visakhapatnam. These 40 patients were divided into two groups of equal size and randomised using random numbers. One group was given general anaesthesia and in the other group procedures were performed under epidural anaesthesia. Two patients in the epidural group required general anaesthesia. RESULTS 40 patients were divided and studied of which the results proved that general anaesthesia was better over epidural anaesthesia except for the disadvantages namely cost factor, PONV, and high risk of

  1. An Intelligent Mobile-Agent Based Scalable Network Management Architecture for Large-Scale Enterprise System

    CERN Document Server

    Sharma, A K; Singh, Vijay

    2012-01-01

    Several Mobile Agent based distributed network management models have been proposed in recent times to address the scalability and flexibility problems of centralized (SNMP or CMIP management models) models. Though the use of Mobile Agents to distribute and delegate management tasks comes handy in dealing with the previously stated issues, many of the agent-based management frameworks like initial flat bed models and static mid-level managers employing mobile agents models cannot efficiently meet the demands of current networks which are growing in size and complexity. Moreover, varied technologies, such as SONET, ATM, Ethernet, DWDM etc., present at different layers of the Access, Metro and Core (long haul) sections of the network, have contributed to the complexity in terms of their own framing and protocol structures. Thus, controlling and managing the traffic in these networks is a challenging task. This paper presents an intelligent scalable hierarchical agent based model for the management of large-scal...

  2. Demeter, persephone, and the search for emergence in agent-based models.

    Energy Technology Data Exchange (ETDEWEB)

    North, M. J.; Howe, T. R.; Collier, N. T.; Vos, J. R.; Decision and Information Sciences; Univ. of Chicago; PantaRei Corp.; Univ. of Illinois

    2006-01-01

    In Greek mythology, the earth goddess Demeter was unable to find her daughter Persephone after Persephone was abducted by Hades, the god of the underworld. Demeter is said to have embarked on a long and frustrating, but ultimately successful, search to find her daughter. Unfortunately, long and frustrating searches are not confined to Greek mythology. In modern times, agent-based modelers often face similar troubles when searching for agents that are to be to be connected to one another and when seeking appropriate target agents while defining agent behaviors. The result is a 'search for emergence' in that many emergent or potentially emergent behaviors in agent-based models of complex adaptive systems either implicitly or explicitly require search functions. This paper considers a new nested querying approach to simplifying such agent-based modeling and multi-agent simulation search problems.

  3. A Multi-Agent Based Energy Management Solution for Integrated Buildings and Microgrid System

    DEFF Research Database (Denmark)

    Anvari-Moghaddam, Amjad; Rahimi-Kian, Ashkan; Mirian, Maryam S.

    2017-01-01

    In this paper, an ontology-driven multi-agent based energy management system (EMS) is proposed for monitoring and optimal control of an integrated homes/buildings and microgrid system with various renewable energy resources (RESs) and controllable loads. Different agents ranging from simple......-reflex to complex learning agents are designed and implemented to cooperate with each other to reach an optimal operating strategy for the mentioned integrated energy system (IES) while meeting the system’s objectives and related constraints. The optimization process for the EMS is defined as a coordinated...... distributed generation (DG) and demand response (DR) management problem within the studied environment and is solved by the proposed agent-based approach utilizing cooperation and communication among decision agents. To verify the effectiveness and applicability of the proposed multi-agent based EMS, several...

  4. Agent Based Modeling and Simulation of Pedestrian Crowds In Panic Situations

    KAUST Repository

    Alrashed, Mohammed

    2016-11-01

    The increasing occurrence of panic stampedes during mass events has motivated studying the impact of panic on crowd dynamics and the simulation of pedestrian flows in panic situations. The lack of understanding of panic stampedes still causes hundreds of fatalities each year, not to mention the scarce methodical studies of panic behavior capable of envisaging such crowd dynamics. Under those circumstances, there are thousands of fatalities and twice that many of injuries every year caused be crowd stampede worldwide, despite the tremendous efforts of crowd control and massive numbers of safekeeping forces. Pedestrian crowd dynamics are generally predictable in high-density crowds where pedestrians cannot move freely and thus gives rise to self-propelling interactions between pedestrians. Although every pedestrian has personal preferences, the motion dynamics can be modeled as a social force in such crowds. These forces are representations of internal preferences and objectives to perform certain actions or movements. The corresponding forces can be controlled for each individual to represent a different variety of behaviors that can be associated with panic situations such as escaping danger, clustering, and pushing. In this thesis, we use an agent-based model of pedestrian behavior in panic situations to predict the collective human behavior in such crowd dynamics. The proposed simulations suggests a practical way to alleviate fatalities and minimize the evacuation time in panic situations. Moreover, we introduce contagious panic and pushing behavior, resulting in a more realistic crowd dynamics model. The proposed methodology describes the intensity and spread of panic for each individual as a function of distances between pedestrians.

  5. Consentaneous agent-based and stochastic model of the financial markets.

    Directory of Open Access Journals (Sweden)

    Vygintas Gontis

    Full Text Available We are looking for the agent-based treatment of the financial markets considering necessity to build bridges between microscopic, agent based, and macroscopic, phenomenological modeling. The acknowledgment that agent-based modeling framework, which may provide qualitative and quantitative understanding of the financial markets, is very ambiguous emphasizes the exceptional value of well defined analytically tractable agent systems. Herding as one of the behavior peculiarities considered in the behavioral finance is the main property of the agent interactions we deal with in this contribution. Looking for the consentaneous agent-based and macroscopic approach we combine two origins of the noise: exogenous one, related to the information flow, and endogenous one, arising form the complex stochastic dynamics of agents. As a result we propose a three state agent-based herding model of the financial markets. From this agent-based model we derive a set of stochastic differential equations, which describes underlying macroscopic dynamics of agent population and log price in the financial markets. The obtained solution is then subjected to the exogenous noise, which shapes instantaneous return fluctuations. We test both Gaussian and q-Gaussian noise as a source of the short term fluctuations. The resulting model of the return in the financial markets with the same set of parameters reproduces empirical probability and spectral densities of absolute return observed in New York, Warsaw and NASDAQ OMX Vilnius Stock Exchanges. Our result confirms the prevalent idea in behavioral finance that herding interactions may be dominant over agent rationality and contribute towards bubble formation.

  6. Consentaneous agent-based and stochastic model of the financial markets.

    Science.gov (United States)

    Gontis, Vygintas; Kononovicius, Aleksejus

    2014-01-01

    We are looking for the agent-based treatment of the financial markets considering necessity to build bridges between microscopic, agent based, and macroscopic, phenomenological modeling. The acknowledgment that agent-based modeling framework, which may provide qualitative and quantitative understanding of the financial markets, is very ambiguous emphasizes the exceptional value of well defined analytically tractable agent systems. Herding as one of the behavior peculiarities considered in the behavioral finance is the main property of the agent interactions we deal with in this contribution. Looking for the consentaneous agent-based and macroscopic approach we combine two origins of the noise: exogenous one, related to the information flow, and endogenous one, arising form the complex stochastic dynamics of agents. As a result we propose a three state agent-based herding model of the financial markets. From this agent-based model we derive a set of stochastic differential equations, which describes underlying macroscopic dynamics of agent population and log price in the financial markets. The obtained solution is then subjected to the exogenous noise, which shapes instantaneous return fluctuations. We test both Gaussian and q-Gaussian noise as a source of the short term fluctuations. The resulting model of the return in the financial markets with the same set of parameters reproduces empirical probability and spectral densities of absolute return observed in New York, Warsaw and NASDAQ OMX Vilnius Stock Exchanges. Our result confirms the prevalent idea in behavioral finance that herding interactions may be dominant over agent rationality and contribute towards bubble formation.

  7. Stimulating household flood risk mitigation investments through insurance and subsidies: an Agent-Based Modelling approach

    Science.gov (United States)

    Haer, Toon; Botzen, Wouter; de Moel, Hans; Aerts, Jeroen

    2015-04-01

    In the period 1998-2009, floods triggered roughly 52 billion euro in insured economic losses making floods the most costly natural hazard in Europe. Climate change and socio/economic trends are expected to further aggrevate floods losses in many regions. Research shows that flood risk can be significantly reduced if households install protective measures, and that the implementation of such measures can be stimulated through flood insurance schemes and subsidies. However, the effectiveness of such incentives to stimulate implementation of loss-reducing measures greatly depends on the decision process of individuals and is hardly studied. In our study, we developed an Agent-Based Model that integrates flood damage models, insurance mechanisms, subsidies, and household behaviour models to assess the effectiveness of different economic tools on stimulating households to invest in loss-reducing measures. Since the effectiveness depends on the decision making process of individuals, the study compares different household decision models ranging from standard economic models, to economic models for decision making under risk, to more complex decision models integrating economic models and risk perceptions, opinion dynamics, and the influence of flood experience. The results show the effectiveness of incentives to stimulate investment in loss-reducing measures for different household behavior types, while assuming climate change scenarios. It shows how complex decision models can better reproduce observed real-world behaviour compared to traditional economic models. Furthermore, since flood events are included in the simulations, the results provide an analysis of the dynamics in insured and uninsured losses for households, the costs of reducing risk by implementing loss-reducing measures, the capacity of the insurance market, and the cost of government subsidies under different scenarios. The model has been applied to the City of Rotterdam in The Netherlands.

  8. A Multi-Agent Based Equipment Bidding System on the Web

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper puts forward a new framework of multi-agent based equipment bidding system on the Web(MAEBSW). The purpose of the paper is to make the process of enterprise equipment bidding, especially the decisionprocess of enterprise equipment bidding, more intelligent. The system discussed in this paper is an efficient method forthe enterprises doing business electronically. We also present our opinion of the approaches to defining agents. We em-phasize the importance of agent being able to provide explanation about its behavior for the user or other agents. Based onthis opinion we design a new common architecture of most agents in MAEBSW.

  9. Agent-Based Modeling of Cancer Stem Cell Driven Solid Tumor Growth.

    Science.gov (United States)

    Poleszczuk, Jan; Macklin, Paul; Enderling, Heiko

    2016-01-01

    Computational modeling of tumor growth has become an invaluable tool to simulate complex cell-cell interactions and emerging population-level dynamics. Agent-based models are commonly used to describe the behavior and interaction of individual cells in different environments. Behavioral rules can be informed and calibrated by in vitro assays, and emerging population-level dynamics may be validated with both in vitro and in vivo experiments. Here, we describe the design and implementation of a lattice-based agent-based model of cancer stem cell driven tumor growth.

  10. Using Agent Base Models to Optimize Large Scale Network for Large System Inventories

    Science.gov (United States)

    Shameldin, Ramez Ahmed; Bowling, Shannon R.

    2010-01-01

    The aim of this paper is to use Agent Base Models (ABM) to optimize large scale network handling capabilities for large system inventories and to implement strategies for the purpose of reducing capital expenses. The models used in this paper either use computational algorithms or procedure implementations developed by Matlab to simulate agent based models in a principal programming language and mathematical theory using clusters, these clusters work as a high performance computational performance to run the program in parallel computational. In both cases, a model is defined as compilation of a set of structures and processes assumed to underlie the behavior of a network system.

  11. An Agent-Based Model for Studying Child Maltreatment and Child Maltreatment Prevention

    Science.gov (United States)

    Hu, Xiaolin; Puddy, Richard W.

    This paper presents an agent-based model that simulates the dynamics of child maltreatment and child maltreatment prevention. The developed model follows the principles of complex systems science and explicitly models a community and its families with multi-level factors and interconnections across the social ecology. This makes it possible to experiment how different factors and prevention strategies can affect the rate of child maltreatment. We present the background of this work and give an overview of the agent-based model and show some simulation results.

  12. Aluminium in an ocean general circulation model compared with the West Atlantic Geotraces cruises

    NARCIS (Netherlands)

    van Hulten, M. M. P.; Sterl, A.; Tagliabue, A.; Dutay, J. -C.; Gehlen, M.; de Baar, H. J. W.; Middag, R.

    2013-01-01

    A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated

  13. Aluminium in an ocean general circulation model compared with the West Atlantic Geotraces cruises

    CSIR Research Space (South Africa)

    Van Hulten, M

    2013-10-01

    Full Text Available A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing...

  14. Influence of public alcohol and tobacco use on general practitioners' advice: an international comparative study.

    NARCIS (Netherlands)

    Pas, L.; Boerma, W.; Spreeuwenberg, P.; Saunders, J.B.; Zee, J. van der

    2002-01-01

    Background: Efficacy of advice for substance use is proven in general practice. Studies show high variability of perfomance. Especially intercountry variability has rarely been taken into account. Aim: To study the influence of public tobacco and alcohol use and health service characteristics on the

  15. Critical Thinking Skills among Elementary School Students: Comparing Identified Gifted and General Education Student Performance

    Science.gov (United States)

    Kettler, Todd

    2014-01-01

    Education reform efforts, including the current adoption of Common Core State Standards, have increased attention to teaching critical thinking skills to all students. This study investigated the critical thinking skills of fourth-grade students from a school district in Texas, including 45 identified gifted students and 163 general education…

  16. Myths and Misconceptions in Popular Psychology: Comparing Psychology Students and the General Public

    Science.gov (United States)

    Furnham, Adrian; Hughes, David J.

    2014-01-01

    This study examined the prevalence of psychological myths and misconceptions among psychology students and within the general population. In total, 829 participants completed a 249-item questionnaire designed to measure a broad range of psychological myths. Results revealed that psychological myths and misconceptions are numerous and widely held.…

  17. Critical Thinking Skills among Elementary School Students: Comparing Identified Gifted and General Education Student Performance

    Science.gov (United States)

    Kettler, Todd

    2014-01-01

    Education reform efforts, including the current adoption of Common Core State Standards, have increased attention to teaching critical thinking skills to all students. This study investigated the critical thinking skills of fourth-grade students from a school district in Texas, including 45 identified gifted students and 163 general education…

  18. Myths and Misconceptions in Popular Psychology: Comparing Psychology Students and the General Public

    Science.gov (United States)

    Furnham, Adrian; Hughes, David J.

    2014-01-01

    This study examined the prevalence of psychological myths and misconceptions among psychology students and within the general population. In total, 829 participants completed a 249-item questionnaire designed to measure a broad range of psychological myths. Results revealed that psychological myths and misconceptions are numerous and widely held.…

  19. Aluminium in an ocean general circulation model compared with the West Atlantic Geotraces cruises

    NARCIS (Netherlands)

    van Hulten, M. M. P.; Sterl, A.; Tagliabue, A.; Dutay, J. -C.; Gehlen, M.; de Baar, H. J. W.; Middag, R.

    2013-01-01

    A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated

  20. A COMPARATIVE ANALYSIS HH Rajak* 1 Introduction It is a generally

    African Journals Online (AJOL)

    Dr Tanya du Plessis

    was no room for inferring such an intention and thus, they helped propel Britain into a new age. 3 ..... In the matter of debt avoidance, while the courts were ... substance of business decision-making, have generally avoided this troubling area.

  1. A General and Intuitive Approach to Understand and Compare the Torque Production Capability of AC Machines

    DEFF Research Database (Denmark)

    Wang, Dong; Lu, Kaiyuan; Rasmussen, Peter Omand

    2014-01-01

    -frame, through complicated mathematical manipulations. This is a more mathematical approach rather than explaining the physics behind torque production, which even brings a lot of difficulties to specialist. This paper introduces a general and intuitive approach to obtain the dq-frame torque equation of various...

  2. Excess of health care use in general practice and of comorbid chronic conditions in cancer patients compared to controls

    Directory of Open Access Journals (Sweden)

    Jabaaij Lea

    2012-06-01

    Full Text Available Abstract Background The number of cancer patients and the number of patients surviving initial treatments is expected to rise. Traditionally, follow-up monitoring takes place in secondary care. The contribution of general practice is less visible and not clearly defined. This study aimed to compare healthcare use in general practice of patients with cancer during the follow-up phase compared with patients without cancer. We also examined the influence of comorbid conditions on healthcare utilisation by these patients in general practice. Methods We compared health care use of N=8,703 cancer patients with an age and gender-matched control group of patients without cancer from the same practice. Data originate from the Netherlands Information Network of General Practice (LINH, a representative network consisting of 92 general practices with 350,000 enlisted patients. Health care utilisation was assessed using data on contacts with general practice, prescription and referral rates recorded between 1/1/2001 and 31/12/2007. The existence of additional comorbid chronic conditions (ICPC coded was taken into account. Results Compared to matched controls, cancer patients had more contacts with their GP-practice (19.5 vs. 11.9, p Conclusion We found that cancer patients in the follow-up phase consulted general practice more often and suffered more often from comorbid chronic conditions, compared to patients without cancer. It is expected that the number of cancer patients will rise in the years to come and that primary health care professionals will be more involved in follow-up care. Care for comorbid chronic conditions, communication between specialists and GPs, and coordination of tasks then need special attention.

  3. Local Anesthesia Combined With Sedation Compared With General Anesthesia for Ambulatory Operative Hysteroscopy

    DEFF Research Database (Denmark)

    Brix, Lone Dragnes; Thillemann, Theis Muncholm; Nikolajsen, Lone

    2016-01-01

    anesthesia combined with sedation (group LA + S; n = 76) or general anesthesia (group GA; n = 77). Primary outcome was the worst pain intensity score in the postanesthesia care unit (PACU) rated by the patients on a numerical rating scale. FINDING: Data from 144 patients were available for analysis (LA + S...... was shorter (P anesthesia with sedation can be recommended as a first choice anesthetic technique for operative ambulatory hysteroscopy....

  4. A Randomized Prospective Trial Comparing Paravertebral Block and General Anesthesia for Operative Treatment of Breast Cancer

    Science.gov (United States)

    2001-10-01

    anesthesia; 1. The risks and complications of general anesthesia may include, but are not limited to: temporary sore throat , hoarseness, injury to...Marrow 26 = Lymphoma 27 = Mesothelioma 28 = Lymph Nodes 29 = Cervical 30 = Testicular 31 = Eye 32 = Throat 33 = Bowel 34 = Mouth 35...The patient was farther sedated with ketamine , no further discomfort was noted, and the patient tolerated the remaining portion of the procedure

  5. [Multidimensional diagnosis in general medicine. Comparative study of the use of various instruments].

    Science.gov (United States)

    Becchi, M A; Franzelli, A; Moscardelli, S; De Pieri, P; Zeni, L; Paccagnella, B

    1994-10-01

    This study was performed to test three instruments for functional status assessment in General Practice: the Dartmouth Coop Charts (COOP Charts), the Functional Status Questionnaire (FSQ) and the Duke University Health Profile (DUHP). All the instruments covered a score of functional aspects in physical, mental and social areas, providing a multidimensional measure of health status. We used these three instruments, validated by international studies, to acquire information concerning their feasibility and acceptability among patients from rural communities needing primary care and to test their validity in differentiating between patient subgroups. The COOP Charts, the FSQ and the DUHP were administered by physicians respectively to 98, 100 and 97 patients, waiting for a visit in the ambulatories of their General Practitioner. Answers relating to each instrument were analyzed according to sex, age and education of patients. All the instruments seemed to be feasible and acceptable, but only the COOP Charts and the FSQ were able to discriminate between different sex, age and scolarity groups. Taking into account the need to elaborate answers according to a formula when using the FSQ, we concluded that the best instrument for General Practice to provide a multidimensional measure of health status seems to be the COOP Charts.

  6. Age and sex dependencies of anxiety and depression in cardiologic patients compared with the general population

    Science.gov (United States)

    Hinz, Andreas; Kittel, Jörg; Karoff, Marthin; Schwarz, Reinhold

    2004-01-01

    Objective: The aim of this study was to test age and sex effects on anxiety and depression using the Hospital Anxiety and Depression Scale HADS. Method: Sample 1 consisted of 2037 subjects of the German general population, and sample 2 comprised 2696 cardiologic patients. Results: In the group of the general population we observed a linear increase of depression and (to a lower extent) of anxiety with age. In contrast to that, the patients reached their anxiety and depression maxima in the range of 50 to 60 years, with decreasing mean values for older patients. This effect was observed in both sexes and was proved by an ANOVA interaction between age category and population (P<0.001). In the age range over 70 years the mean depression scores of the patients were even lower than those of the general population. Especially high anxiety and depression scores were found for retired males under 60 years of age. Conclusion: Premature retirement is associated with anxiety and depression in cardiologic patients which partly accounts for the different age effects of the samples. Longitudinal studies are needed to explain the underlying mechanisms of the age effects in more detail. PMID:19742054

  7. The Hunt Opinion Model-An Agent Based Approach to Recurring Fashion Cycles.

    Science.gov (United States)

    Apriasz, Rafał; Krueger, Tyll; Marcjasz, Grzegorz; Sznajd-Weron, Katarzyna

    2016-01-01

    We study a simple agent-based model of the recurring fashion cycles in the society that consists of two interacting communities: "snobs" and "followers" (or "opinion hunters", hence the name of the model). Followers conform to all other individuals, whereas snobs conform only to their own group and anticonform to the other. The model allows to examine the role of the social structure, i.e. the influence of the number of inter-links between the two communities, as well as the role of the stability of links. The latter is accomplished by considering two versions of the same model-quenched (parameterized by fraction L of fixed inter-links) and annealed (parameterized by probability p that a given inter-link exists). Using Monte Carlo simulations and analytical treatment (the latter only for the annealed model), we show that there is a critical fraction of inter-links, above which recurring cycles occur. For p ≤ 0.5 we derive a relation between parameters L and p that allows to compare both models and show that the critical value of inter-connections, p*, is the same for both versions of the model (annealed and quenched) but the period of a fashion cycle is shorter for the quenched model. Near the critical point, the cycles are irregular and a change of fashion is difficult to predict. For the annealed model we also provide a deeper theoretical analysis. We conjecture on topological grounds that the so-called saddle node heteroclinic bifurcation appears at p*. For p ≥ 0.5 we show analytically the existence of the second critical value of p, for which the system undergoes Hopf's bifurcation.

  8. The Hunt Opinion Model—An Agent Based Approach to Recurring Fashion Cycles

    Science.gov (United States)

    Apriasz, Rafał; Krueger, Tyll; Marcjasz, Grzegorz; Sznajd-Weron, Katarzyna

    2016-01-01

    We study a simple agent-based model of the recurring fashion cycles in the society that consists of two interacting communities: “snobs” and “followers” (or “opinion hunters”, hence the name of the model). Followers conform to all other individuals, whereas snobs conform only to their own group and anticonform to the other. The model allows to examine the role of the social structure, i.e. the influence of the number of inter-links between the two communities, as well as the role of the stability of links. The latter is accomplished by considering two versions of the same model—quenched (parameterized by fraction L of fixed inter-links) and annealed (parameterized by probability p that a given inter-link exists). Using Monte Carlo simulations and analytical treatment (the latter only for the annealed model), we show that there is a critical fraction of inter-links, above which recurring cycles occur. For p ≤ 0.5 we derive a relation between parameters L and p that allows to compare both models and show that the critical value of inter-connections, p*, is the same for both versions of the model (annealed and quenched) but the period of a fashion cycle is shorter for the quenched model. Near the critical point, the cycles are irregular and a change of fashion is difficult to predict. For the annealed model we also provide a deeper theoretical analysis. We conjecture on topological grounds that the so-called saddle node heteroclinic bifurcation appears at p*. For p ≥ 0.5 we show analytically the existence of the second critical value of p, for which the system undergoes Hopf’s bifurcation. PMID:27835679

  9. Evolutionary perspectives on collective decision making: Studying the implications of diversity and social network structure with agent-based simulations

    CERN Document Server

    Sayama, Hiroki; Yammarino, Francis J

    2013-01-01

    Collective, especially group-based, managerial decision making is crucial in organizations. Using an evolutionary theory approach to collective decision making, agent-based simulations were conducted to investigate how collective decision making would be affected by the agents' diversity in problem understanding and/or behavior in discussion, as well as by their social network structure. Simulation results indicated that groups with consistent problem understanding tended to produce higher utility values of ideas and displayed better decision convergence, but only if there was no group-level bias in collective problem understanding. Simulation results also indicated the importance of balance between selection-oriented (i.e., exploitative) and variation-oriented (i.e., explorative) behaviors in discussion to achieve quality final decisions. Expanding the group size and introducing non-trivial social network structure generally improved the quality of ideas at the cost of decision convergence. Simulations with ...

  10. MODELING OF INVESTMENT STRATEGIES IN STOCKS MARKETS: AN APPROACH FROM MULTI AGENT BASED SIMULATION AND FUZZY LOGIC

    Directory of Open Access Journals (Sweden)

    ALEJANDRO ESCOBAR

    2010-01-01

    Full Text Available This paper presents a simulation model of a complex system, in this case a financial market, using a MultiAgent Based Simulation approach. Such model takes into account microlevel aspects like the Continuous Double Auction mechanism, which is widely used within stock markets, as well as investor agents reasoning who participate looking for profits. To model such reasoning several variables were considered including general stocks information like profitability and volatility, but also some agent's aspects like their risk tendency. All these variables are incorporated throughout a fuzzy logic approach trying to represent in a faithful manner the kind of reasoning that nonexpert investors have, including a stochastic component in order to model human factors.

  11. Polypharmacy in older adults with human immunodeficiency virus infection compared with the general population

    National Research Council Canada - National Science Library

    Gimeno-Gracia, Mercedes; Crusells-Canales, María José; Armesto-Gómez, Francisco Javier; Compaired-Turlán, Vicente; Rabanaque-Hernández, María José

    2016-01-01

    .... To quantify polypharmacy and profile types of non-antiretroviral drugs collected at community pharmacies in 2014 by HIV-positive individuals on antiretroviral therapy and to compare these findings...

  12. A general view of politic system classifications in comparative political science of Ancient Greek era

    OpenAIRE

    Yılmaz, Nihat

    2014-01-01

    The popularity of Comparative Political Science, as a sub-discipline of the Political Science, is on a continuous increase today. This discipline receives many attentions as it provides detailed knowledge on politic systems of various countries. The historical background of such an area, which is drawing more and more interest in our day, is traced back to very old eras. The first political system classification made in the Comparative Political Science appeared in the Ancient Greek era. For ...

  13. Evaluating Urban Parking Policies with Agent-Based Model of Driver Parking Behavior

    NARCIS (Netherlands)

    Martens, C.J.C.M.; Benenson, I.

    2008-01-01

    This paper presents an explicit agent-based model of parking search in a city. In the model, “drivers” drive toward their destination, search for parking, park, remain at the parking place, and leave. The city’s infrastructure is represented by a high-resolution geographic information system (GIS) o

  14. PARKAGENT: An agent-based model of parking in the city

    NARCIS (Netherlands)

    Benenson, I.; Martens, C.J.C.M.; Birfir, S.

    2008-01-01

    In this paper, we present PARKAGENT, an agent-based, spatially explicit model for parking in the city. Unlike traditional parking models, PARKAGENT simulates the behavior of each driver in a spatially explicit environment and is able to capture the complex self-organizing dynamics of a large collect

  15. An agent-based information management model of the Chinese pig sector

    NARCIS (Netherlands)

    Osinga, S.A.; Kramer, M.R.; Hofstede, G.J.; Roozmand, O.; Beulens, A.J.M.

    2010-01-01

    This paper investigates the effect of a selected top-down measure (what-if scenario) on actual agent behaviour and total system behaviour by means of an agent-based simulation model, when agents’ behaviour cannot fully be managed because the agents are autonomous. The Chinese pork sector serves as c

  16. Adaptive build-up and breakdown of trust : An agent based computational approach

    NARCIS (Netherlands)

    Gorobets, A.; Nooteboom, B.

    2005-01-01

    This article employs Agent-Based Computational Economics (ACE) to investigate whether, and under what conditions, trust is viable in markets. The emergence and breakdown of trust is modeled in a context of multiple buyers and suppliers. Agents develop trust in a partner as a function of observed loy

  17. An Agent-based Extensible Climate Control System for Sustainable Greenhouse Production

    DEFF Research Database (Denmark)

    Sørensen, Jan Corfixen; Jørgensen, Bo Nørregaard; Klein, Mark

    2011-01-01

    The slow adoption pace of new control strategies for sustainable greenhouse climate control by industrial growers is mainly due to the complexity of identifying and resolving potentially conflicting climate control requirements. In this paper, we present a multi-agent-based climate control system...

  18. Agent-Based Learning Environments as a Research Tool for Investigating Teaching and Learning.

    Science.gov (United States)

    Baylor, Amy L.

    2002-01-01

    Discusses intelligent learning environments for computer-based learning, such as agent-based learning environments, and their advantages over human-based instruction. Considers the effects of multiple agents; agents and research design; the use of Multiple Intelligent Mentors Instructing Collaboratively (MIMIC) for instructional design for…

  19. Exploring the Structure and Task Dynamics of Terrorist Organizations Using Agent Based Modeling

    Science.gov (United States)

    2008-12-01

    policy or position of the Department of Defense or the U.S. Government. 12a. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release...Terrorist Networks, Agent Based Modeling, 2004 Madrid Attacks, Backcasting , Computational Organization Simulation 16. PRICE CODE 17. SECURITY...be understood in order to apply effective policies and practices to safeguard citizens, assets, and interests. For decades, terrorist cells have

  20. Agent-Based Modeling of Consumer Decision making Process Based on Power Distance and Personality

    NARCIS (Netherlands)

    Roozmand, O.; Ghasem-Aghaee, N.; Hofstede, G.J.; Nematbakhsh, M.A.; Baraani, A.; Verwaart, T.

    2011-01-01

    Simulating consumer decision making processes involves different disciplines such as: sociology, social psychology, marketing, and computer science. In this paper, we propose an agent-based conceptual and computational model of consumer decision-making based on culture, personality and human needs.

  1. High performance computing for three-dimensional agent-based molecular models.

    Science.gov (United States)

    Pérez-Rodríguez, G; Pérez-Pérez, M; Fdez-Riverola, F; Lourenço, A

    2016-07-01

    Agent-based simulations are increasingly popular in exploring and understanding cellular systems, but the natural complexity of these systems and the desire to grasp different modelling levels demand cost-effective simulation strategies and tools. In this context, the present paper introduces novel sequential and distributed approaches for the three-dimensional agent-based simulation of individual molecules in cellular events. These approaches are able to describe the dimensions and position of the molecules with high accuracy and thus, study the critical effect of spatial distribution on cellular events. Moreover, two of the approaches allow multi-thread high performance simulations, distributing the three-dimensional model in a platform independent and computationally efficient way. Evaluation addressed the reproduction of molecular scenarios and different scalability aspects of agent creation and agent interaction. The three approaches simulate common biophysical and biochemical laws faithfully. The distributed approaches show improved performance when dealing with large agent populations while the sequential approach is better suited for small to medium size agent populations. Overall, the main new contribution of the approaches is the ability to simulate three-dimensional agent-based models at the molecular level with reduced implementation effort and moderate-level computational capacity. Since these approaches have a generic design, they have the major potential of being used in any event-driven agent-based tool. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Numerical Problems and Agent-Based Models for a Mass Transfer Course

    Science.gov (United States)

    Murthi, Manohar; Shea, Lonnie D.; Snurr, Randall Q.

    2009-01-01

    Problems requiring numerical solutions of differential equations or the use of agent-based modeling are presented for use in a course on mass transfer. These problems were solved using the popular technical computing language MATLABTM. Students were introduced to MATLAB via a problem with an analytical solution. A more complex problem to which no…

  3. The Impact of a Peer-Learning Agent Based on Pair Programming in a Programming Course

    Science.gov (United States)

    Han, Keun-Woo; Lee, EunKyoung; Lee, YoungJun

    2010-01-01

    This paper analyzes the educational effects of a peer-learning agent based on pair programming in programming courses. A peer-learning agent system was developed to facilitate the learning of a programming language through the use of pair programming strategies. This system is based on the role of a peer-learning agent from pedagogical and…

  4. Numerical Problems and Agent-Based Models for a Mass Transfer Course

    Science.gov (United States)

    Murthi, Manohar; Shea, Lonnie D.; Snurr, Randall Q.

    2009-01-01

    Problems requiring numerical solutions of differential equations or the use of agent-based modeling are presented for use in a course on mass transfer. These problems were solved using the popular technical computing language MATLABTM. Students were introduced to MATLAB via a problem with an analytical solution. A more complex problem to which no…

  5. Easing the adoption of agent-based modelling (ABM) in tourism research

    NARCIS (Netherlands)

    Johnson, Peter; Nicholls, Sarah; Student, Jillian; Amelung, Bas; Baggio, Rodolfo; Balbi, Stefano; Boavida-Portugal, Ines; Jong, de Eline; Hofstede, G.J.; Lamers, M.A.J.; Pons, Marc; Steiger, Robert

    2016-01-01

    Agent-based modelling (ABM) is an emerging approach in tourism research. Despite the natural fit between theories of tourism as a complex, interconnected system, and the generative approach supported in ABM, there has been only limited integration within mainstream tourism research. This research le

  6. Research on monocentric model of urbanization by agent-based simulation

    Science.gov (United States)

    Xue, Ling; Yang, Kaizhong

    2008-10-01

    Over the past years, GIS have been widely used for modeling urbanization from a variety of perspectives such as digital terrain representation and overlay analysis using cell-based data platform. Similarly, simulation of urban dynamics has been achieved with the use of Cellular Automata. In contrast to these approaches, agent-based simulation provides a much more powerful set of tools. This allows researchers to set up a counterpart for real environmental and urban systems in computer for experimentation and scenario analysis. This Paper basically reviews the research on the economic mechanism of urbanization and an agent-based monocentric model is setup for further understanding the urbanization process and mechanism in China. We build an endogenous growth model with dynamic interactions between spatial agglomeration and urban development by using agent-based simulation. It simulates the migration decisions of two main types of agents, namely rural and urban households between rural and urban area. The model contains multiple economic interactions that are crucial in understanding urbanization and industrial process in China. These adaptive agents can adjust their supply and demand according to the market situation by a learning algorithm. The simulation result shows this agent-based urban model is able to perform the regeneration and to produce likely-to-occur projections of reality.

  7. Easing the adoption of agent-based modelling (ABM) in tourism research

    NARCIS (Netherlands)

    Johnson, Peter; Nicholls, Sarah; Student, Jillian; Amelung, Bas; Baggio, Rodolfo; Balbi, Stefano; Boavida-Portugal, Ines; Jong, de Eline; Hofstede, G.J.; Lamers, M.A.J.; Pons, Marc; Steiger, Robert

    2017-01-01

    Agent-based modelling (ABM) is an emerging approach in tourism research. Despite the natural fit between theories of tourism as a complex, interconnected system, and the generative approach supported in ABM, there has been only limited integration within mainstream tourism research. This research

  8. Lapse of time effects on tax evasion in an agent-based econophysics model

    Science.gov (United States)

    Seibold, Götz; Pickhardt, Michael

    2013-05-01

    We investigate an inhomogeneous Ising model in the context of tax evasion dynamics where different types of agents are parameterized via local temperatures and magnetic fields. In particular, we analyze the impact of lapse of time effects (i.e. backauditing) and endogenously determined penalty rates on tax compliance. Both features contribute to a microfoundation of agent-based econophysics models of tax evasion.

  9. Agent-based models for higher-order theory of mind

    NARCIS (Netherlands)

    de Weerd, Harmen; Verbrugge, Rineke; Verheij, Bart; Kamiński, Bogumił; Koloch, Grzegorz

    2014-01-01

    Agent-based models are a powerful tool for explaining the emergence of social phenomena in a society. In such models, individual agents typically have little cognitive ability. In this paper, we model agents with the cognitive ability to make use of theory of mind. People use this ability to reason

  10. Demand Response Integration Through Agent-Based Coordination of Consumers in Virtual Power Plants

    DEFF Research Database (Denmark)

    Clausen, Anders; Umair, Aisha; Ma, Zheng;

    2016-01-01

    The transition towards an electricity grid based on renewable energy production induces fluctuation in electricity generation. This challenges the existing electricity grid design, where generation is expected to follow demand for electricity. In this paper, we propose a multi-agent based Virtual...

  11. The Agent-based Model on Real-time Data Warehousing

    Institute of Scientific and Technical Information of China (English)

    YouzhiXu; JieShen

    2004-01-01

    The conventional data warehouse can only analyze historical data. This paper proposes a concept of agent-based real-time data warehouse in BI system, With this model we can improve the real-time performance of data warehouse. On the other hand, the BI system flexibility is enhanced in this model, which makes it much more efficient to manage the distributed environment.

  12. Evaluating Urban Parking Policies with Agent-Based Model of Driver Parking Behavior

    NARCIS (Netherlands)

    Martens, C.J.C.M.; Benenson, I.

    2008-01-01

    This paper presents an explicit agent-based model of parking search in a city. In the model, “drivers” drive toward their destination, search for parking, park, remain at the parking place, and leave. The city’s infrastructure is represented by a high-resolution geographic information system (GIS) o

  13. Targeting and timing promotional activities : An agent-based model for the takeoff of new products

    NARCIS (Netherlands)

    Delre, S. A.; Jager, W.; Bijmolt, T. H. A.; Janssen, M. A.

    2007-01-01

    Many marketing efforts focus on promotional activities that support the launch of new products. Promotional strategies may play a crucial role in the early stages of the product life cycle, and determine to a large extent the diffusion of a new product. This paper proposes an agent-based model to si

  14. A study of the diffusion of alternative fuel vehicles : An agent-based modeling approach

    NARCIS (Netherlands)

    Zhang, Ting; Gensler, Sonja; Garcia, Rosanna

    This paper demonstrates the use of an agent-based model (ABM) to investigate factors that can speed the diffusion of eco-innovations, namely alternative fuel vehicles (AFVs). The ABM provides the opportunity to consider the interdependencies inherent between key participants in the automotive

  15. Targeting and timing promotional activities : An agent-based model for the takeoff of new products

    NARCIS (Netherlands)

    Delre, S. A.; Jager, W.; Bijmolt, T. H. A.; Janssen, M. A.

    Many marketing efforts focus on promotional activities that support the launch of new products. Promotional strategies may play a crucial role in the early stages of the product life cycle, and determine to a large extent the diffusion of a new product. This paper proposes an agent-based model to

  16. Agent-based analysis and simulation of meta-reasoning processes in strategic naval planning

    NARCIS (Netherlands)

    Hoogendoorn, M.; Jonker, C.M.; Maanen, P.P. van; Treur, J.

    2009-01-01

    This paper presents analysis and simulation of meta-reasoning processes based on an agent-based meta-level architecture for strategic reasoning in naval planning. The architecture was designed as a generic agent model and instantiated with decision knowledge acquired from naval domain experts and wa

  17. Using Agent-Based Technologies to Enhance Learning in Educational Games

    Science.gov (United States)

    Tumenayu, Ogar Ofut; Shabalina, Olga; Kamaev, Valeriy; Davtyan, Alexander

    2014-01-01

    Recent research has shown that educational games positively motivate learning. However, there is a little evidence that they can trigger learning to a large extent if the game-play is supported by additional activities. We aim to support educational games development with an Agent-Based Technology (ABT) by using intelligent pedagogical agents that…

  18. Agent-Based Modeling of Consumer Decision making Process Based on Power Distance and Personality

    NARCIS (Netherlands)

    Roozmand, O.; Ghasem-Aghaee, N.; Hofstede, G.J.; Nematbakhsh, M.A.; Baraani, A.; Verwaart, T.

    2011-01-01

    Simulating consumer decision making processes involves different disciplines such as: sociology, social psychology, marketing, and computer science. In this paper, we propose an agent-based conceptual and computational model of consumer decision-making based on culture, personality and human needs.

  19. Multi-dimensional information diffusion and balancing market supply: an agent-based approach

    NARCIS (Netherlands)

    Osinga, S.A.; Kramer, M.R.; Hofstede, G.J.; Beulens, A.J.M.

    2013-01-01

    This agent-based information management model is designed to explore how multi-dimensional information, spreading through a population of agents (for example farmers) affects market supply. Farmers make quality decisions that must be aligned with available markets. Markets distinguish themselves by

  20. An Agent-Based Dynamic Model of Politics, Fertility and Economic Development

    Directory of Open Access Journals (Sweden)

    Zining Yang

    2016-08-01

    Full Text Available In the political economy of development, government policy choices at a single point in time can dramatically affect a country's development path by impacting fertility, economic and political decisions across generations. Combining system dynamics and agent-based modeling approaches in a complex adaptive system, a simulation framework of the Politics of Fertility and Economic Development (POFED is formalized to understand the relationship between politics, economic, and demography change at both macro and micro levels. First, a new political capacity measurement is used; and the system dynamics model is validated with the latest data. Second, the endogenous attributes are fused with non-cooperative game theory in an agent-based framework to simulate the interactive political economic dynamics of individual intra-societal transactions. Finally, macro and micro levels are connected with policy levers of political capacity and political instability by merging system dynamics and agent-based components. This paper also explores the agent-based model's behavioral dynamics via simulation methods to identify paths towards economic development and political stability. This model demonstrates micro level human agency can act, react and interact, thus driving macro level dynamics, while macro structures provide political, social and economic environments that constrain or incentivize micro level human behavior.

  1. PARKAGENT: An agent-based model of parking in the city

    NARCIS (Netherlands)

    Benenson, I.; Martens, C.J.C.M.; Birfir, S.

    2008-01-01

    In this paper, we present PARKAGENT, an agent-based, spatially explicit model for parking in the city. Unlike traditional parking models, PARKAGENT simulates the behavior of each driver in a spatially explicit environment and is able to capture the complex self-organizing dynamics of a large collect

  2. An agent-based approach to model land-use change at a regional scale

    NARCIS (Netherlands)

    Valbuena, D.; Verburg, P.H.; Bregt, A.; Ligtenberg, A.

    2010-01-01

    Land-use/cover change (LUCC) is a complex process that includes actors and factors at different social and spatial levels. A common approach to analyse and simulate LUCC as the result of individual decisions is agent-based modelling (ABM). However, ABM is often applied to simulate processes at local

  3. On the role of backauditing for tax evasion in an agent-based Econophysics model

    CERN Document Server

    Seibold, G

    2012-01-01

    We investigate an inhomogeneous Ising model in the context of tax evasion dynamics where different types of agents are parametrized via local temperatures and magnetic fields. In particular, we analyse the impact of backauditing and endogenously determined penalty rates on tax compliance. Both features contribute to a microfoundation of agent-based econophysics models of tax evasion.

  4. Questioning the quantity equation using an agent-based computational model

    DEFF Research Database (Denmark)

    Bruun, Charlotte

    2000-01-01

    by Stutzel (1954), argues that the functional relationship may as well be negative. Even focusing the money needed to carry out transactions, there is no immediate answer to the question of the functional relationship between trade turnover and money demand. An agent-based computational model is used...

  5. A review of urban residential choice models using agent-based modeling

    NARCIS (Netherlands)

    Huang, Qingxu; Parker, Dawn C.; Filatova, Tatiana; Sun, Shipeng

    2014-01-01

    Urban land-use modeling methods have experienced substantial improvements in the last several decades. With the advancement of urban land-use change theories and modeling techniques, a considerable number of models have been developed. The relatively young approach, agent-based modeling, provides ur

  6. On Religion and Language Evolutions Seen Through Mathematical and Agent Based Models

    Science.gov (United States)

    Ausloos, M.

    Religions and languages are social variables, like age, sex, wealth or political opinions, to be studied like any other organizational parameter. In fact, religiosity is one of the most important sociological aspects of populations. Languages are also obvious characteristics of the human species. Religions, languages appear though also disappear. All religions and languages evolve and survive when they adapt to the society developments. On the other hand, the number of adherents of a given religion, or the number of persons speaking a language is not fixed in time, - nor space. Several questions can be raised. E.g. from a oscopic point of view : How many religions/languages exist at a given time? What is their distribution? What is their life time? How do they evolve? From a "microscopic" view point: can one invent agent based models to describe oscopic aspects? Do simple evolution equations exist? How complicated must be a model? These aspects are considered in the present note. Basic evolution equations are outlined and critically, though briefly, discussed. Similarities and differences between religions and languages are summarized. Cases can be illustrated with historical facts and data. It is stressed that characteristic time scales are different. It is emphasized that "external fields" are historically very relevant in the case of religions, rending the study more " interesting" within a mechanistic approach based on parity and symmetry of clusters concepts. Yet the modern description of human societies through networks in reported simulations is still lacking some mandatory ingredients, i.e. the non scalar nature of the nodes, and the non binary aspects of nodes and links, though for the latter this is already often taken into account, including directions. From an analytical point of view one can consider a population independently of the others. It is intuitively accepted, but also found from the statistical analysis of the frequency distribution that an

  7. Multi-agent based control of large-scale complex systems employing distributed dynamic inference engine

    Science.gov (United States)

    Zhang, Daili

    Increasing societal demand for automation has led to considerable efforts to control large-scale complex systems, especially in the area of autonomous intelligent control methods. The control system of a large-scale complex system needs to satisfy four system level requirements: robustness, flexibility, reusability, and scalability. Corresponding to the four system level requirements, there arise four major challenges. First, it is difficult to get accurate and complete information. Second, the system may be physically highly distributed. Third, the system evolves very quickly. Fourth, emergent global behaviors of the system can be caused by small disturbances at the component level. The Multi-Agent Based Control (MABC) method as an implementation of distributed intelligent control has been the focus of research since the 1970s, in an effort to solve the above-mentioned problems in controlling large-scale complex systems. However, to the author's best knowledge, all MABC systems for large-scale complex systems with significant uncertainties are problem-specific and thus difficult to extend to other domains or larger systems. This situation is partly due to the control architecture of multiple agents being determined by agent to agent coupling and interaction mechanisms. Therefore, the research objective of this dissertation is to develop a comprehensive, generalized framework for the control system design of general large-scale complex systems with significant uncertainties, with the focus on distributed control architecture design and distributed inference engine design. A Hybrid Multi-Agent Based Control (HyMABC) architecture is proposed by combining hierarchical control architecture and module control architecture with logical replication rings. First, it decomposes a complex system hierarchically; second, it combines the components in the same level as a module, and then designs common interfaces for all of the components in the same module; third, replications

  8. A comparative analysis of area navigation systems in general aviation. M.S. Thesis

    Science.gov (United States)

    Dodge, S. M.

    1973-01-01

    Radio navigation systems which offer the capabilities of area navigation to general aviation operators are discussed. The systems considered are: (1) the VORTAC system, (2) the Loran-C system, and (3) the Differential Omega system. The inital analyses are directed toward a comparison of the systems with respect to their compliance to specified performance parameters and to the cost effectiveness of each system in relation to those specifications. Further analyses lead to the development of system cost sensitivity charts, and the employment of these charts allows conclusions to be drawn relative to the cost-effectiveness of the candidate navigation system.

  9. Ten-year mortality is increased after hospitalization for atopic dermatitis compared with the general population, but reduced compared with psoriasis.

    Science.gov (United States)

    Egeberg, Alexander; Skov, Lone; Andersen, Yuki M F; Mallbris, Lotus; Gislason, Gunnar H; Silverberg, Jonathan I; Wu, Jashin J; Thyssen, Jacob P

    2017-01-01

    Psoriasis and atopic dermatitis (AD) are chronic inflammatory skin disorders. Mortality is increased in psoriasis, yet no studies on mortality in AD are currently available. We investigated 10-year mortality after hospitalization for AD compared with psoriasis and the general population. Between 1996 and 2002 all Danes aged 18 years or older with a first-time hospitalization as a result of AD or psoriasis and AD-matched healthy control subjects were examined in nationwide registers. Multivariable (adjusted for age, sex, socioeconomic status, Charlson Comorbidity Index score, smoking, and medication) hazard ratios were estimated by Cox regression. The study comprised 576 and 951 hospitalized patients with AD and psoriasis, respectively, with a maximum follow-up time of 10 years. During the study period, there were 65 and 286 deaths among patients with AD and psoriasis. Risk of death was decreased in patients with AD versus psoriasis (hazard ratio 0.75; 95% confidence interval 0.57-1.00), but higher than in general population control subjects (n = 5760) (hazard ratio 1.71; 95% confidence interval 1.20-2.44). Patients hospitalized with AD died on average 8.3 years younger than control subjects. Lifestyle may have affected the risk. The 10-year mortality was significantly lower after hospitalization for AD compared with psoriasis, but increased when compared with the general population. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  10. Aluminium in an ocean general circulation model compared with the West Atlantic Geotraces cruises

    CERN Document Server

    van Hulten, Marco; Tagliabue, Alessandro; Dutay, Jean-Claude; Gehlen, Marion; de Baar, Hein J W; Middag, Rob

    2012-01-01

    A model of aluminium has been developed and implemented in an Ocean General Circulation Model (NEMO-PISCES). In the model, aluminium enters the ocean by means of dust deposition. The internal oceanic processes are described by advection, mixing and reversible scavenging. The model has been evaluated against a number of selected high-quality datasets covering much of the world ocean, especially those from the West Atlantic Geotraces cruises of 2010 and 2011. Generally, the model results are in fair agreement with the observations. However, the model does not describe well the vertical distribution of dissolved Al in the North Atlantic Ocean. The model may require changes in the physical forcing and the vertical dependency of the sinking velocity of biogenic silica to account for other discrepancies. To explore the model behaviour, sensitivity experiments have been performed, in which we changed the key parameters of the scavenging process as well as the input of aluminium into the ocean. This resulted in a bet...

  11. A comparative study of six decades of general science textbooks: Evaluating the evolution of science content

    Science.gov (United States)

    Lewis, Anna

    This study examined science textbooks over time to better understand the science content expectations that the U.S. educational system deems appropriate for 8th and 9th grade science students. The study attempted to answer the questions: (1) What specific science content has been presented via the textbook from 1952 to 2008? (2) Within which areas and in what way does the science content change? (3) Are new scientific findings reflected in 8th and 9th grade U.S. general science textbooks? Twenty-six themes were identified which reflect five areas in science: Chemistry, Physics, Earth Science, Biology, and Process of Science. Trends in science content in U.S. 8th and 9th grade general science textbooks, as revealed by this data sample, indicated no statistically significant change in depth of coverage in Physics and Process of Science over the past 60 years, no significant change in depth of coverage in Earth Science and Biology in the last 40 years, and no significant change in coverage in Chemistry over the last 30 years. Additionally, a total of sixteen new discoveries were found in the textbook sample. For classroom teachers this information may alert them to the necessity of going beyond the textbook in preparing students for life in a global society. In educational practice, this research supports and reinforces the need for inquiry learning and socioscientific curricula. It may also influence educators to challenge assumptions regarding the value and selection of the traditional classic science content.

  12. A general lock-free algorithm using compare-and-swap

    NARCIS (Netherlands)

    Gao, H.; Hesselink, W.H.

    2007-01-01

    The compare-and-swap register (CAS) is a synchronization primitive for lock-free algorithms. Most uses of it, however, Stiffer from the so-called ABA problem. The simplest and most efficient solution to the ABA problem is to include a tag with the memory location Such that the tag is incremented wit

  13. General context of economic and legal reforms international comparative studies (example of innovation development

    Directory of Open Access Journals (Sweden)

    Omelyanenko Vitaliy Analiyovych

    2016-09-01

    Full Text Available The article deals with the basics of comparative analysis of economic and legal reforms in international dimension. On the example of innovative development the features of foreign experience adaptation in economic and legal reforms were considered. The features of foreign experience perception as the “other” image as part of reform`s socio-cultural component.

  14. The effectiveness of isometric exercises as compared to general exercises in the management of chronic non-specific neck pain.

    Science.gov (United States)

    Khan, Muhammad; Soomro, Rabail Rani; Ali, Syed Shahzad

    2014-09-01

    To evaluate the effectiveness of isometric exercises as compared to general exercises in chronic non-specific neck pain. For this randomised controlled trial total 68 patients (34 each group) with chronic non-specific neck pain were recruited from Alain Poly Clinic and Institute of Physical Medicine & Rehabilitation Dow University of Health Sciences, Karachi between May, 2012 and August, 2012. Simple randomisation method was used to assign participants into isometric exercise group and general exercise groups. The isometric exercise group performed exercises for neck muscle groups with a rubber band and general exercises group performed active range of movement exercises for all neck movements. Patients in both groups received 3 supervised treatment sessions per week for 12 weeks. Visual Analogue Scale (VAS), North wick Park Neck Pain Questionnaire and goniometer were used to assess pain, disability and neck range of movements at baseline and after 12 weeks. Both interventions showed statistically significant improvements in pain, function and range of movement p = 0.001f or isometric exercise group, p = 0.04 for general exercises group and p = 0.001 for range of movement. However, mean improvements in post intervention VAS score and North wick Park Neck Pain Questionnaire score was better in isometric exercises group as compared to general exercise group. In conclusion, both interventions are effective in the treatment of chronic non-specific neck pain however; isometric exercises are clinically more effective than general exercises.

  15. Comparing the Impact of Specific Strength Training vs General Fitness Training on Professional Symphony Orchestra Musicians

    DEFF Research Database (Denmark)

    Nygaard Andersen, Lotte; Mann, Stephanie; Juul-Kristensen, Birgit

    2017-01-01

    Musculoskeletal symptoms, especially in the upper body, are frequent among professional symphony orchestra musicians. Physical exercise may relieve pain but might also interfere with playing performance. OBJECTIVE: To evaluate the feasibility and effect of "specific strength training" (SST) versus...... "general fitness training" (GFT). METHODS: A feasibility study using randomized controlled methods. Primarily, evaluations involved self-reported impact on instrument playing and satisfaction with the interventions. Secondary evaluations included pain intensity, hand-grip strength, aerobic capacity, body...... mass index, and self-assessed physical fitness. A total of 23 professional symphony orchestra musicians were randomly allocated to either the SST (n=12) or GFT (n=11) groups. Participants conducted three 20-minutes exercise periods/wk at the workplace for 9 weeks. RESULTS: Evaluations of both...

  16. Testing general relativity with compact coalescing binaries: comparing exact and predictive methods to compute the Bayes factor

    CERN Document Server

    Del Pozzo, Walter; Mandel, Ilya; Vecchio, Alberto

    2014-01-01

    The second generation of gravitational-wave detectors is scheduled to start operations in 2015. Gravitational-wave signatures of compact binary coalescences could be used to accurately test the strong-field dynamical predictions of general relativity. Computationally expensive data analysis pipelines, including TIGER, have been developed to carry out such tests. As a means to cheaply assess whether a particular deviation from general relativity can be detected, Cornish et al. and Vallisneri recently proposed an approximate scheme to compute the Bayes factor between a general-relativity gravitational-wave model and a model representing a class of alternative theories of gravity parametrised by one additional parameter. This approximate scheme is based on only two easy-to-compute quantities: the signal-to-noise ratio of the signal and the fitting factor between the signal and the manifold of possible waveforms within general relativity. In this work, we compare the prediction from the approximate formula agains...

  17. Mortality Rates in the General Irish Population Compared to Those with an Intellectual Disability from 2003 to 2012

    Science.gov (United States)

    McCarron, Mary; Carroll, Rachael; Kelly, Caraiosa; McCallion, Philip

    2015-01-01

    Background:Historically, there has been higher and earlier mortality among people with intellectual disability as compared to the general population, but there have also been methodological problems and differences in the available studies. Method: Data were drawn from the 2012 National Intellectual Disability Database and the Census in Ireland. A…

  18. Musical Practices and Methods in Music Lessons: A Comparative Study of Estonian and Finnish General Music Education

    Science.gov (United States)

    Sepp, Anu; Ruokonen, Inkeri; Ruismäki, Heikki

    2015-01-01

    This article reveals the results of a comparative study of Estonian and Finnish general music education. The aim was to find out what music teaching practices and approaches/methods were mostly used, what music education perspectives supported those practices. The data were collected using questionnaires and the results of 107 Estonian and 50…

  19. Musical Practices and Methods in Music Lessons: A Comparative Study of Estonian and Finnish General Music Education

    Science.gov (United States)

    Sepp, Anu; Ruokonen, Inkeri; Ruismäki, Heikki

    2015-01-01

    This article reveals the results of a comparative study of Estonian and Finnish general music education. The aim was to find out what music teaching practices and approaches/methods were mostly used, what music education perspectives supported those practices. The data were collected using questionnaires and the results of 107 Estonian and 50…

  20. Mortality among patients with cleared hepatitis C virus infection compared to the general population: a Danish nationwide cohort study

    DEFF Research Database (Denmark)

    Omland, Lars Haukali; Christensen, Peer Brehm; Krarup, Henrik Bygum;

    2011-01-01

    The increased mortality in HCV-infected individuals partly stems from viral damage to the liver and partly from risk-taking behaviours. We examined mortality in patients who cleared their HCV-infection, comparing it to that of the general population. We also addressed the question whether prognos...... differed according to age, substance abuse (alcohol abuse and injection drug use) and comorbidity....

  1. A Comparative Study of Campus Experiences of College Students with Mental Illnesses versus a General College Sample

    Science.gov (United States)

    Salzer, Mark S.

    2012-01-01

    Objective: Examine campus experiences and relationships of college students with mental illnesses compared to general student norms using the College Student Experiences Questionnaire to understand potential sources of distress and retention issues. Participants: Responses were obtained from 449 former and current students with mental illnesses…

  2. Epidural Steroids for Lumbosacral Radicular Syndrome Compared to Usual Care : Quality of Life and Cost Utility in General Practice

    NARCIS (Netherlands)

    Spijker-Huiges, Antje; Vermeulen, Karin; Winters, Jan C.; van Wijhe, Marten; van der Meer, Klaas

    Objective: To investigate the effect of adding segmental epidural steroid injections (SESIs) to usual care compared with usual care alone on quality of life and cost utility in lumbosacral radicular syndrome (LRS) in general practice. Design: A pragmatic randomized controlled trial. Results were

  3. Comparing generalized ensemble methods for sampling of systems with many degrees of freedom

    Science.gov (United States)

    Lincoff, James; Sasmal, Sukanya; Head-Gordon, Teresa

    2016-11-01

    We compare two standard replica exchange methods using temperature and dielectric constant as the scaling variables for independent replicas against two new corresponding enhanced sampling methods based on non-equilibrium statistical cooling (temperature) or descreening (dielectric). We test the four methods on a rough 1D potential as well as for alanine dipeptide in water, for which their relatively small phase space allows for the ability to define quantitative convergence metrics. We show that both dielectric methods are inferior to the temperature enhanced sampling methods, and in turn show that temperature cool walking (TCW) systematically outperforms the standard temperature replica exchange (TREx) method. We extend our comparisons of the TCW and TREx methods to the 5 residue met-enkephalin peptide, in which we evaluate the Kullback-Leibler divergence metric to show that the rate of convergence between two independent trajectories is faster for TCW compared to TREx. Finally we apply the temperature methods to the 42 residue amyloid-β peptide in which we find non-negligible differences in the disordered ensemble using TCW compared to the standard TREx. All four methods have been made available as software through the OpenMM Omnia software consortium (http://www.omnia.md/).

  4. A comparative study of worker and general public risks from nuclear facility operation using MACCS2

    Energy Technology Data Exchange (ETDEWEB)

    East, J.M.; O`Kula, K.R.

    1994-10-01

    Over the last five years, the US Department of Energy (DOE) has attempted to establish quantitative risk indices as minimum acceptance criteria for assurance of safe operation of its nuclear facilities. The risk indices serve as aiming points or targets to include consideration of all aspects of operation including normal conditions as well as abnormal, design basis events, and beyond-design basis events. Although initial focus of the application of these safety targets had been on DOE`s reactors, more recent assessments have also considered non-reactor facilities including those encompassing storage and nuclear processing activities. Regardless of the facility`s primary function, accident progression, event tree/fault tree logic models, and probabilistic (dose) consequence assessment model must be implemented to yield a fully integrated analysis of facility operation. The primary tool for probabilistic consequence assessment in the US is the MELCOR Accident Consequence Code System (MACCS). In this study, two version of MACCS are applied to representative source terms developed in the safety analysis associated with a waste processing facility at the Westinghouse Savannah River Company`s (WSRC`s) Savannah River Site (SRS). The MACCS versions are used to estimate population dose and subsequent health effects to workers and the general public from the SRS referenced facility operation. When combined with the frequency of occurrence evaluation, the margin of compliance with the safety targets may be quantified.

  5. Hypertensive patients in a general practice setting: comparative analysis between controlled and uncontrolled hypertension.

    Science.gov (United States)

    Santiago, Luiz Miguel; Pereira, Carolina; Botas, Philippe; Simões, Ana Rita; Carvalho, Rosa; Pimenta, Gonçalo; Neto, Glória

    2014-01-01

    To study the differences between controlled and uncontrolled hypertensive patients. This was a cross-sectional observational study of the hypertensive population on the lists of three general practitioners in the district of Coimbra in central Portugal in 2013, with a margin of error of 6% and 95% confidence interval in each sample, organized in ascending order of health care user numbers. Data were gathered electronically by the investigators after approval by the Regional Health Authority's ethics committee. A sample of 201 individuals was studied, of whom 104 (51.7%) were male and 86 (42.8%) were aged under 65 (p=0.127 for gender and age-group). Hypertension was controlled in 130 (64.7%). We found significant differences in target organ damage, more frequent in those with controlled hypertension (33.1% vs. 19.7%, p=0.031), in hypertension control, better in those taking at least one anti-hypertensive drug at night (56.9% vs. 29.6%, p<0.001), and in prescription of non-steroidal anti-inflammatory drugs, more frequent in those with uncontrolled hypertension (11.3% vs. 3.8%, p=0.043). Hypertension control is significantly associated with target organ damage, taking at least one anti-hypertensive drug at night and not taking non-steroidal anti-inflammatory drugs simultaneously. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  6. General Medical Burden in Bipolar Disorder: Findings from the LiTMUS Comparative Effectiveness Trial

    Science.gov (United States)

    Kemp, David E.; Sylvia, Louisa G.; Calabrese, Joseph R.; Nierenberg, Andrew A.; Thase, Michael E.; Reilly-Harrington, Noreen A.; Ostacher, Michael J.; Leon, Andrew C.; Ketter, Terence A.; Friedman, Edward S.; Bowden, Charles L.; Pencina, Michael; Iosifescu, Dan V.

    2013-01-01

    Objective This study examined general medical illnesses and their association with clinical features of bipolar disorder. Methods Data were cross-sectional and derived from the Lithium Treatment – Moderate Dose Use Study (LiTMUS), which randomized symptomatic adults (n=264 with available medical comorbidity scores) with bipolar disorder to moderate doses of lithium plus optimized treatment (OPT) or to OPT alone. Clinically significant high and low medical comorbidity burden were defined as a Cumulative Illness Rating Scale (CIRS) score ≥ 4 and < 4, respectively. Results The baseline prevalence of significant medical comorbidity was 53% (n=139). Patients with high medical burden were more likely to present in a major depressive episode (P=.04), meet criteria for obsessive-compulsive disorder (P=.02), and experience a greater number of lifetime mood episodes (P=0.02). They were also more likely to be prescribed a greater number of psychotropic medications (P=.002). Sixty-nine percent of the sample was overweight or obese as defined by body mass index (BMI), with African-Americans representing the racial group with the highest proportion of stage II obesity (BMI ≥ 35; 31%, n=14). Conclusions The burden of comorbid medical illnesses was high in this generalizable sample of treatment-seeking patients and appears associated with worsened course of illness and psychotropic medication patterns. (Funded by NIMH Contract N01MH80001; ClinicalTrials.gov number NCT00667745). PMID:23465084

  7. Polychlorinated biphenyl serum levels in subjects with hepatocellular carcinoma as compared with the general population

    Directory of Open Access Journals (Sweden)

    Claudia Zani

    2014-11-01

    Full Text Available Background. Polychlorinated biphenyls (PCBs have been recognized as human carcinogens and cause liver cancer in animal experimental studies. However, no study investigated their association with hepatocellular carcinoma (HCC so far.  This study aimed to evaluate the serum PCB concentration in HCC patients and in healthy subjects of the general population living in Brescia, North Italy, a highly industrialized area with heavy PCB environmental pollution due to the presence of a PCB producing factory. Methods. Lipid-adjusted PCB concentrations, computed as the sum of 24 congeners, were measured in the serum of 101 HCC patients and in 101 healthy subjects of the same age and gender.Results. Hepatitis B and C virus infection and history of heavy alcohol intake were found, alone and combined, in 87% of HCC patients. No difference was found in PCB serum concentration of HCC patients with and without, and according to, the major risk factors for liver disease. No significant difference was observed in serum total PCB concentration between HCC patients (median: 1081; range: 287.0-3182.0 ng/g lipid and healthy subjects (median: 1199.3; range: 225.7-22825 ng/g lipid. PCB congeners 118, 138, 153, 156, 180 and 194 were the only ones found over the detection limit in at least 30% of HCC patients. The serum level of PCB 118, but not that of other congeners, was higher in HCC patients than in healthy subjects.Conclusion. These findings  do not support the hypothesis that PCBs play an important role in HCC development, although a contribution by some specific congeners cannot be ruled out. 

  8. A comparative study of worker and general public risks from nuclear facility operation using MACCS2

    Energy Technology Data Exchange (ETDEWEB)

    East, J.M.; O`Kula, K.R. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1995-12-31

    Over the last five years, the US Department of Energy (DOE) has attempted to establish quantitative risk indices as minimum acceptance criteria for assurance of safe operation of its nuclear facilities. The risk indices serve as aiming points or targets to include consideration of all aspects of operation including normal conditions as well as abnormal, design basis events, and beyond-design basis events. Although initial focus of the application of these safety targets had been on DOE`s reactors, more recent assessments have also considered non-reactor facilities including those encompassing storage and nuclear processing activities. Regardless of the facility`s primary function, accident progression, event tree/fault tree logic models, and probabilistic (dose) consequence assessment model must be implemented to yield a fully integrated analysis of facility operation. The primary tool for probabilistic consequence assessment in the U.S. is the MELCOR Accident Consequence Code System (MACCS). In this study, two version of MACCS are applied to representative source terms developed in the safety analysis associated with a waste processing facility at the Westinghouse Savannah River Company`s (WSRC`s) Savannah River Site (SRS). The MACCS versions are used to estimate population dose and subsequent health effects to workers and the general public from the SRS referenced facility operation. When combined with the frequency of occurrence evaluation, the margin of compliance with the safety targets may be quantified. Additionally, numerical evaluation of the safety targets with the two code versions will serve as an indicator of the impact of the enhancements made to MACCS relative to earlier baseline software.

  9. Designing across ages: Multi-agent-based models and learning electricity

    Science.gov (United States)

    Sengupta, Pratim

    Electricity is regarded as one of the most challenging topics for students at all levels -- middle school -- college (Cohen, Eylon, & Ganiel, 1983; Belcher & Olbert, 2003; Eylon & Ganiel, 1990; Steinberg et al., 1985). Several researchers have suggested that naive misconceptions about electricity stem from a deep incommensurability (Slotta & Chi, 2006; Chi, 2005) or incompatibility (Chi, Slotta & Leauw, 1994; Reiner, Slotta, Chi, & Resnick, 2000) between naive and expert knowledge structures. I first present an alternative theoretical framework that adopts an emergent levels-based perspective as proposed by Wilensky & Resnick (1999). From this perspective, macro-level phenomena such as electric current and resistance, as well as behavior of linear electric circuits, can be conceived of as emergent from simple, body-syntonic interactions between electrons and ions in a circuit. I argue that adopting such a perspective enables us to reconceive commonly noted misconceptions in electricity as behavioral evidences of "slippage between levels" -- i.e., these misconceptions appear when otherwise productive knowledge elements are sometimes inappropriately activated due to certain macro-level phenomenological cues only -- and, that the same knowledge elements when activated due to phenomenological cues at both micro- and macro-levels, can engender a deeper, expert-like understanding. I will then introduce NIELS (NetLogo Investigations In Electromagnetism, Sengupta & Wilensky, 2006, 2008, 2009), a low-threshold high-ceiling (LTHC) learning environment of multi-agent-based computational models that represent phenomena such as electric current and resistance, as well as the behavior of linear electric circuits, as emergent. I also present results from implementations of NIELS in 5th, 7th and 12th grade classrooms that show the following: (a) how leveraging certain "design elements" over others in NIELS models can create new phenomenological cues, which in turn can be

  10. [Hospital day-surgery: comparative evaluation of 3 general anesthesia techniques].

    Science.gov (United States)

    Rossi, A E; Lo Sapio, D; Oliva, O; Vitale, O; Ebano, A

    1995-06-01

    For the voluntary interruption of pregnancy, three anaesthetic techniques have been compared being a random assigned to three groups of 40 patients. Induction of anaesthesia was based on fentanyl 0.005 mg/kg+midazolam 0.2 mg/kg or fentanyl 0.005 mg/kg = propofol 2.5 mg/kg or ketamina 0.5 mg/kg+propofol 2.0 mg/kg. Anaesthesia was maintained delivering in spontaneous-assisted ventilation N2O 70% in O2. In addition to the intraoperative conditions, quality and rapidity of some neurofunctional aspects of the recovery have been evaluated using the Steward Score and the Coin Counting Test respectively. Our data suggest fentanyl-propofol association as the safest one as regards the needs of one-day surgery.

  11. A general pipeline for the development of anchor markers for comparative genomics in plants

    Directory of Open Access Journals (Sweden)

    Stougaard Jens

    2006-08-01

    Full Text Available Abstract Background Complete or near-complete genomic sequence information is presently only available for a few plant species representing a large phylogenetic diversity among plants. In order to effectively transfer this information to species lacking sequence information, comparative genomic tools need to be developed. Molecular markers permitting cross-species mapping along co-linear genomic regions are central to comparative genomics. These "anchor" markers, defining unique loci in genetic linkage maps of multiple species, are gene-based and possess a number of features that make them relatively sparse. To identify potential anchor marker sequences more efficiently, we have established an automated bioinformatic pipeline that combines multi-species Expressed Sequence Tags (EST and genome sequence data. Results Taking advantage of sequence data from related species, the pipeline identifies evolutionarily conserved sequences that are likely to define unique orthologous loci in most species of the same phylogenetic clade. The key features are the identification of evolutionarily conserved sequences followed by automated design of intron-flanking Polymerase Chain Reaction (PCR primer pairs. Polymorphisms can subsequently be identified by size- or sequence variation of PCR products, amplified from mapping parents or populations. We illustrate our procedure in legumes and grasses and exemplify its application in legumes, where model plant studies and the genome- and EST-sequence data available have a potential impact on the breeding of crop species and on our understanding of the evolution of this large and diverse family. Conclusion We provide a database of 459 candidate anchor loci which have the potential to serve as map anchors in more than 18,000 legume species, a number of which are of agricultural importance. For grasses, the database contains 1335 candidate anchor loci. Based on this database, we have evaluated 76 candidate anchor loci

  12. A Comparative Analysis of General Culture Courses within the Scope of Knowledge Categories in Undergraduate Teacher Education Programs "Turkey and the USA"

    Science.gov (United States)

    Hayirsever, Fahriye; Kalayci, Nurdan

    2017-01-01

    In this study, general culture and general education courses within the scope of knowledge categories in undergraduate teacher education programs in Turkey and the USA are comparatively analyzed. The study is a comparative education study and uses a descriptive model. In the study, the general culture - general education courses taught in the…

  13. Toward an agent-based patient-physician model for the adoption of continuous glucose monitoring technology.

    Science.gov (United States)

    Verella, J Tipan; Patek, Stephen D

    2009-03-01

    Health care is a major component of the U.S. economy, and tremendous research and development efforts are directed toward new technologies in this arena. Unfortunately few tools exist for predicting outcomes associated with new medical products, including whether new technologies will find widespread use within the target population. Questions of technology adoption are rife within the diabetes technology community, and we particularly consider the long-term prognosis for continuous glucose monitoring (CGM) technology. We present an approach to the design and analysis of an agent model that describes the process of CGM adoption among patients with type 1 diabetes mellitus (T1DM), their physicians, and related stakeholders. We particularly focus on patient-physician interactions, with patients discovering CGM technology through word-of-mouth communication and through advertising, applying pressure to their physicians in the context of CGM device adoption, and physicians, concerned about liability, looking to peers for a general level of acceptance of the technology before recommending CGM to their patients. Repeated simulation trials of the agent-based model show that the adoption process reflects the heterogeneity of the adopting community. We also find that the effect of the interaction between patients and physicians is agents. Each physician, say colored by the nature of the environment as defined by the model parameters. We find that, by being able to represent the diverse perspectives of different types of stakeholders, agent-based models can offer useful insights into the adoption process. Models of this sort may eventually prove to be useful in helping physicians, other health care providers, patient advocacy groups, third party payers, and device manufacturers understand the impact of their decisions about new technologies.

  14. Health-risk behaviour among residents in deprived neighbourhoods compared with those of the general population in Denmark

    DEFF Research Database (Denmark)

    Algren, Maria Holst; Ekholm, Ola; van Lenthe, Frank

    2017-01-01

    This study compares health-risk behaviours (including the co-occurrence of health-risk behaviours) of residents in the deprived neighbourhoods with those of the general population of Denmark. It also examines associations between sociodemographic and socioeconomic characteristics and health-risk...... behaviours in deprived neighbourhoods in Denmark. Even after adjustment for socioeconomic characteristics there were large differences in health-risk behaviours between residents in deprived neighbourhoods and the general population. In the deprived neighbourhoods large sociodemographic and socioeconomic...... differences in health-risk behaviours were found among the residents. Our findings highlight the need for health promotion programmes targeting residents in deprived neighbourhoods....

  15. [A comparative study of N400 in generalized anxiety disorder versus obsessive compulsive disorder patients].

    Science.gov (United States)

    Zhang, Chen; Chen, Xing-shi; Ren, Qing-sheng; Yi, Zheng-hui; Chen, Chong; Fang, Yi-ru

    2012-09-18

    To explore the features of events-related potentials (ERP) component N400 in generalized anxiety disorder (GAD) versus obsessive compulsive disorder (OCD) patients and understand the cognitive pattern and processing characteristic for Chinese characters. ERP component N400 was recorded by Guangzhou Runjie WJ-1 ERP apparatus. And 41 GAD patients, 69 OCD patients and 58 normal controls (NC) were tested by the Chinese idioms ending with matching (congruent) or mismatching (incongruent) words. (1) Latencies: Significant differences were found of N400 latencies in ending words with the same pronunciation but different forms and meanings (NC: (377 ± 40) ms, OCD: (395 ± 43) ms, GAD: (396 ± 43) ms, congruent; NC: (415 ± 32) ms, OCD: (429 ± 35) ms, GAD: (430 ± 36) ms, incongruent), ending words with the same meaning but different pronunciations and forms (NC: (411 ± 32) ms, OCD: (424 ± 40) ms, GAD: (433 ± 39) ms, incongruent), ending words with different pronunciations, forms and meanings (NC: (399 ± 47) ms, OCD: (427 ± 53) ms, GAD: (434 ± 42) ms, congruent; NC: (442 ± 36) ms, OCD: (465 ± 35) ms, GAD: (474 ± 35) ms, incongruent) (P pronunciations, forms and meanings (incongruent situation). (2) Significant differences were found of N400 amplitudes in ending words with the same pronunciation but different forms and meanings (NC: (9 ± 5) µV, OCD: (6 ± 5) µV, GAD: (6 ± 5) µV, congruent; NC: (11 ± 6) µV, OCD: (5 ± 4) µV, GAD: (6 ± 4) µV, incongruent), ending words with similar forms but different pronunciations and meanings (NC: (9 ± 5) µV, OCD: (5 ± 4) µV, GAD: (7 ± 5) µV, congruent; NC: (14 ± 6) µV, OCD: (6 ± 5) µV, GAD: (9 ± 7) µV, incongruent), ending words with different pronunciations, forms and meanings (NC: (9 ± 5) µV, OCD: (5 ± 4) µV, GAD: (5 ± 3) µV, congruent; NC: (14 ± 6) µV, OCD: (9 ± 7) µV, GAD: (9 ± 7) µV, incongruent) (P pronunciations and meanings (congruent). The cognitive and emotional problems in GAD and OCD

  16. Comparative evaluation of propofol in nanoemulsion with solutol and soy lecithin for general anesthesia

    Directory of Open Access Journals (Sweden)

    José Carlos Rittes

    2016-06-01

    Full Text Available ABSTRACT INTRODUCTION: The vehicle for propofol in 1 and 2% solutions is soybean oil emulsion 10%, which may cause pain on injection, instability of the solution and bacterial contamination. Formulations have been proposed aiming to change the vehicle and reduce these adverse reactions. OBJECTIVES: To compare the incidence of pain caused by the injection of propofol, with a hypothesis of reduction associated with nanoemulsion and the occurrence of local and systemic adverse effects with both formulations. METHOD: After approval by the CEP, patients undergoing gynecological procedures were included in this prospective study: control (n = 25 and nanoemulsion (n = 25 groups. Heart rate, noninvasive blood pressure and peripheral oxygen saturation were monitored. Demographics and physical condition were analyzed; surgical time and total volume used of propofol; local or systemic adverse effects; changes in variables monitored. A value of p < 0.05 was considered significant. RESULTS: There was no difference between groups regarding demographic data, surgical times, total volume of propofol used, arm withdrawal, pain during injection and variables monitored. There was a statistically significant difference in pain intensity at the time of induction of anesthesia, with less pain intensity in the nanoemulsion group. CONCLUSIONS: Both lipid and nanoemulsion formulations of propofol elicited pain on intravenous injection; however, the nanoemulsion solution elicited a less intense pain. Lipid and nanoemulsion propofol formulations showed neither hemodynamic changes nor adverse effects of clinical relevance.

  17. Comparative evaluation of propofol in nanoemulsion with solutol and soy lecithin for general anesthesia.

    Science.gov (United States)

    Rittes, José Carlos; Cagno, Guilherme; Perez, Marcelo Vaz; Mathias, Ligia Andrade da Silva Telles

    2016-01-01

    The vehicle for propofol in 1 and 2% solutions is soybean oil emulsion 10%, which may cause pain on injection, instability of the solution and bacterial contamination. Formulations have been proposed aiming to change the vehicle and reduce these adverse reactions. To compare the incidence of pain caused by the injection of propofol, with a hypothesis of reduction associated with nanoemulsion and the occurrence of local and systemic adverse effects with both formulations. After approval by the CEP, patients undergoing gynecological procedures were included in this prospective study: control (n=25) and nanoemulsion (n=25) groups. Heart rate, noninvasive blood pressure and peripheral oxygen saturation were monitored. Demographics and physical condition were analyzed; surgical time and total volume used of propofol; local or systemic adverse effects; changes in variables monitored. A value of p<0.05 was considered significant. There was no difference between groups regarding demographic data, surgical times, total volume of propofol used, arm withdrawal, pain during injection and variables monitored. There was a statistically significant difference in pain intensity at the time of induction of anesthesia, with less pain intensity in the nanoemulsion group. Both lipid and nanoemulsion formulations of propofol elicited pain on intravenous injection; however, the nanoemulsion solution elicited a less intense pain. Lipid and nanoemulsion propofol formulations showed neither hemodynamic changes nor adverse effects of clinical relevance. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  18. Is it All About the Money? Not All Surgical Subspecialization Leads to Higher Lifetime Revenue when Compared to General Surgery.

    Science.gov (United States)

    Baimas-George, Maria; Fleischer, Brian; Slakey, Douglas; Kandil, Emad; Korndorffer, James R; DuCoin, Christopher

    2017-07-10

    It is believed that spending additional years gaining expertise in surgical subspecialization leads to higher lifetime revenue. Literature shows that more surgeons are pursuing fellowship training and dedicated research years; however, there are no data looking at the aggregate economic impact when training time is accounted for. It is hypothesized that there will be a discrepancy in lifetime income when delay to practice is considered. Data were collected from the Medical Group Management Association's 2015 report of average annual salaries. Fixed time of practice was set at 30 years, and total adjusted revenue was calculated based on variable years spent in research and fellowship. All total revenue outcomes were compared to general surgery and calculated in US dollars. The financial data on general surgeons and 9 surgical specialties (vascular, pediatric, plastic, breast, surgical oncology, cardiothoracic, thoracic primary, transplant, and trauma) were examined. With fellowship and no research, breast and surgical oncology made significantly less than general surgery (-$1,561,441, -$1,704,958), with a difference in opportunity cost equivalent to approximately 4 years of work. Pediatric and cardiothoracic surgeons made significantly more than general surgeons, with an increase of opportunity cost equivalent to $5,301,985 and $3,718,632, respectively. With 1 research year, trauma surgeons ended up netting less than a general surgeon by $325,665. With 2 research years, plastic and transplant surgeons had total lifetime revenues approximately equivalent to that of a general surgeon. Significant disparities exist in lifetime total revenue between surgical subspecialties and in comparison, to general surgery. Although most specialists do gross more than general surgeons, breast and surgical oncologists end up netting significantly less over their lifetime as well as trauma surgeons if they do 1 year of research. Thus, the economic advantage of completing additional

  19. Bounded Rational Managers Struggle with Talent Management - An Agent-based Modelling Approach

    DEFF Research Database (Denmark)

    Adamsen, Billy; Thomsen, Svend Erik

    of past success will provide failure rather than success in the future (Capelli.2008). Finally, we model the talent selection process either as a collective decision making process made by a group of managers or a decision process made by a single manager.It is argued that agent-based modeling is a useful....... The considered variables were: (a) decision makers’ attributes (capabilities and degree of bounded rationality), (b) characteristics of the sample where individuals are selected from (the level of capabilities and the dispersion thereof), (c) path-dependency of the organization’s success, and (d) the decision......This study applies an agent-based modeling approach to explore some aspects of an important managerial task: finding and cultivating talented individuals capable of creating value for their organization at some future state. Given that the term talent in talent management is an empty signifier...

  20. A critical survey of agent-based wholesale electricity market models

    Energy Technology Data Exchange (ETDEWEB)

    Weidlich, Anke; Veit, Daniel [University of Mannheim, Chair of Business Administration and Information Systems, Schloss, 68131 Mannheim (Germany)

    2008-07-15

    The complexity of electricity markets calls for rich and flexible modeling techniques that help to understand market dynamics and to derive advice for the design of appropriate regulatory frameworks. Agent-Based Computational Economics (ACE) is a fairly young research paradigm that offers methods for realistic electricity market modeling. A growing number of researchers have developed agent-based models for simulating electricity markets. The diversity of approaches makes it difficult to overview the field of ACE electricity research; this literature survey should guide the way through and describe the state-of-the-art of this research area. In a conclusive summary, shortcomings of existing approaches and open issues that should be addressed by ACE electricity researchers are critically discussed. (author)

  1. An Agent-Based Simulation of In-Store Customer Experiences

    CERN Document Server

    Siebers, Peer-Olaf; Celia, Helen; Clegg, Christopher

    2008-01-01

    Agent-based modelling and simulation offers a new and exciting way of understanding the world of work. In this paper we describe the development of an agent-based simulation model, designed to help to understand the relationship between human resource management practices and retail productivity. We report on the current development of our simulation model which includes new features concerning the evolution of customers over time. To test some of these features we have conducted a series of experiments dealing with customer pool sizes, standard and noise reduction modes, and the spread of the word of mouth. Our multi-disciplinary research team draws upon expertise from work psychologists and computer scientists. Despite the fact we are working within a relatively novel and complex domain, it is clear that intelligent agents offer potential for fostering sustainable organisational capabilities in the future.

  2. Integrated Agent-Based and Production Cost Modeling Framework for Renewable Energy Studies: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Giulia

    2015-10-07

    The agent-based framework for renewable energy studies (ARES) is an integrated approach that adds an agent-based model of industry actors to PLEXOS and combines the strengths of the two to overcome their individual shortcomings. It can examine existing and novel wholesale electricity markets under high penetrations of renewables. ARES is demonstrated by studying how increasing levels of wind will impact the operations and the exercise of market power of generation companies that exploit an economic withholding strategy. The analysis is carried out on a test system that represents the Electric Reliability Council of Texas energy-only market in the year 2020. The results more realistically reproduce the operations of an energy market under different and increasing penetrations of wind, and ARES can be extended to address pressing issues in current and future wholesale electricity markets.

  3. An Agent-Based Model of New Venture Creation: Conceptual Design for Simulating Entrepreneurship

    Science.gov (United States)

    Provance, Mike; Collins, Andrew; Carayannis, Elias

    2012-01-01

    There is a growing debate over the means by which regions can foster the growth of entrepreneurial activity in order to stimulate recovery and growth of their economies. On one side, agglomeration theory suggests the regions grow because of strong clusters that foster knowledge spillover locally; on the other side, the entrepreneurial action camp argues that innovative business models are generated by entrepreneurs with unique market perspectives who draw on knowledge from more distant domains. We will show you the design for a novel agent-based model of new venture creation that will demonstrate the relationship between agglomeration and action. The primary focus of this model is information exchange as the medium for these agent interactions. Our modeling and simulation study proposes to reveal interesting relationships in these perspectives, offer a foundation on which these disparate theories from economics and sociology can find common ground, and expand the use of agent-based modeling into entrepreneurship research.

  4. Agent-based and macroscopic modeling of the complex socio-economic systems

    CERN Document Server

    Kononovicius, Aleksejus

    2013-01-01

    The current economic crisis has provoked an active response from the interdisciplinary scientific community. As a result many papers suggesting what can be improved in understanding of the complex socio-economics systems were published. Some of the most prominent papers on the topic include (Bouchaud, 2009; Farmer and Foley, 2009; Farmer et al, 2012; Helbing, 2010; Pietronero, 2008). These papers share the idea that agent-based modeling is essential for the better understanding of the complex socio-economic systems and consequently better policy making. Yet in order for an agent-based model to be useful it should also be analytically tractable, possess a macroscopic treatment (Cristelli et al, 2012). In this work we shed a new light on our research group's contributions towards understanding of the correspondence between the inter-individual interactions and collective behavior. We also provide some new insights into the implications of the global and local interactions, the leadership and the predator-prey i...

  5. Preclinical animal acute toxicity studies of new developed MRI contrast agent based on gadolinium

    Science.gov (United States)

    Nam, I. F.; Zhuk, V. V.

    2015-04-01

    Acute toxicity test of new developed MRI contrast agent based on disodium salt of gadopentetic acid complex were carried out on Mus musculus and Sprague Dawley rats according to guidelines of preclinical studies [1]. Groups of six animals each were selected for experiment. Death and clinical symptoms of animals were recorded during 14 days. As a result the maximum tolerated dose (MTD) for female mice is 2.8 mM/kg of body weight, male mice - 1.4 mM/kg, female rats - 2.8 mM/kg, male rats - 5.6 mM/kg of body weight. No Observed Adverse Effect Dose (NOAEL) for female mice is 1.4 mM/kg, male mice - 0.7 mM/kg, male and female rats - 0.7 mM/kg. According to experimental data new developed MRI contrast agent based on Gd-DTPA complex is low-toxic.

  6. Fluctuation complexity of agent-based financial time series model by stochastic Potts system

    Science.gov (United States)

    Hong, Weijia; Wang, Jun

    2015-03-01

    Financial market is a complex evolved dynamic system with high volatilities and noises, and the modeling and analyzing of financial time series are regarded as the rather challenging tasks in financial research. In this work, by applying the Potts dynamic system, a random agent-based financial time series model is developed in an attempt to uncover the empirical laws in finance, where the Potts model is introduced to imitate the trading interactions among the investing agents. Based on the computer simulation in conjunction with the statistical analysis and the nonlinear analysis, we present numerical research to investigate the fluctuation behaviors of the proposed time series model. Furthermore, in order to get a robust conclusion, we consider the daily returns of Shanghai Composite Index and Shenzhen Component Index, and the comparison analysis of return behaviors between the simulation data and the actual data is exhibited.

  7. Quantitative agent based model of user behavior in an Internet discussion forum.

    Directory of Open Access Journals (Sweden)

    Pawel Sobkowicz

    Full Text Available The paper presents an agent based simulation of opinion evolution, based on a nonlinear emotion/information/opinion (E/I/O individual dynamics, to an actual Internet discussion forum. The goal is to reproduce the results of two-year long observations and analyses of the user communication behavior and of the expressed opinions and emotions, via simulations using an agent based model. The model allowed to derive various characteristics of the forum, including the distribution of user activity and popularity (outdegree and indegree, the distribution of length of dialogs between the participants, their political sympathies and the emotional content and purpose of the comments. The parameters used in the model have intuitive meanings, and can be translated into psychological observables.

  8. Quantitative agent based model of user behavior in an Internet discussion forum.

    Science.gov (United States)

    Sobkowicz, Pawel

    2013-01-01

    The paper presents an agent based simulation of opinion evolution, based on a nonlinear emotion/information/opinion (E/I/O) individual dynamics, to an actual Internet discussion forum. The goal is to reproduce the results of two-year long observations and analyses of the user communication behavior and of the expressed opinions and emotions, via simulations using an agent based model. The model allowed to derive various characteristics of the forum, including the distribution of user activity and popularity (outdegree and indegree), the distribution of length of dialogs between the participants, their political sympathies and the emotional content and purpose of the comments. The parameters used in the model have intuitive meanings, and can be translated into psychological observables.

  9. Architectural considerations for agent-based national scale policy models : LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.; Strip, David R.

    2007-09-01

    The need to anticipate the consequences of policy decisions becomes ever more important as the magnitude of the potential consequences grows. The multiplicity of connections between the components of society and the economy makes intuitive assessments extremely unreliable. Agent-based modeling has the potential to be a powerful tool in modeling policy impacts. The direct mapping between agents and elements of society and the economy simplify the mapping of real world functions into the world of computation assessment. Our modeling initiative is motivated by the desire to facilitate informed public debate on alternative policies for how we, as a nation, provide healthcare to our population. We explore the implications of this motivation on the design and implementation of a model. We discuss the choice of an agent-based modeling approach and contrast it to micro-simulation and systems dynamics approaches.

  10. Integrated Agent-Based and Production Cost Modeling Framework for Renewable Energy Studies

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Giulia

    2016-01-08

    The agent-based framework for renewable energy studies (ARES) is an integrated approach that adds an agent-based model of industry actors to PLEXOS and combines the strengths of the two to overcome their individual shortcomings. It can examine existing and novel wholesale electricity markets under high penetrations of renewables. ARES is demonstrated by studying how increasing levels of wind will impact the operations and the exercise of market power of generation companies that exploit an economic withholding strategy. The analysis is carried out on a test system that represents the Electric Reliability Council of Texas energy-only market in the year 2020. The results more realistically reproduce the operations of an energy market under different and increasing penetrations of wind, and ARES can be extended to address pressing issues in current and future wholesale electricity markets.

  11. Using Model Replication to Improve the Reliability of Agent-Based Models

    Science.gov (United States)

    Zhong, Wei; Kim, Yushim

    The basic presupposition of model replication activities for a computational model such as an agent-based model (ABM) is that, as a robust and reliable tool, it must be replicable in other computing settings. This assumption has recently gained attention in the community of artificial society and simulation due to the challenges of model verification and validation. Illustrating the replication of an ABM representing fraudulent behavior in a public service delivery system originally developed in the Java-based MASON toolkit for NetLogo by a different author, this paper exemplifies how model replication exercises provide unique opportunities for model verification and validation process. At the same time, it helps accumulate best practices and patterns of model replication and contributes to the agenda of developing a standard methodological protocol for agent-based social simulation.

  12. Empirically Grounded Agent-Based Models of Innovation Diffusion: A Critical Review

    CERN Document Server

    Zhang, Haifeng

    2016-01-01

    Innovation diffusion has been studied extensively in a variety of disciplines, including sociology, economics, marketing, ecology, and computer science. Traditional literature on innovation diffusion has been dominated by models of aggregate behavior and trends. However, the agent-based modeling (ABM) paradigm is gaining popularity as it captures agent heterogeneity and enables fine-grained modeling of interactions mediated by social and geographic networks. While most ABM work on innovation diffusion is theoretical, empirically grounded models are increasingly important, particularly in guiding policy decisions. We present a critical review of empirically grounded agent-based models of innovation diffusion, developing a categorization of this research based on types of agent models as well as applications. By connecting the modeling methodologies in the fields of information and innovation diffusion, we suggest that the maximum likelihood estimation framework widely used in the former is a promising paradigm...

  13. Numeric promoter description - A comparative view on concepts and general application.

    Science.gov (United States)

    Beier, Rico; Labudde, Dirk

    2016-01-01

    Nucleic acid molecules play a key role in a variety of biological processes. Starting from storage and transfer tasks, this also comprises the triggering of biological processes, regulatory effects and the active influence gained by target binding. Based on the experimental output (in this case promoter sequences), further in silico analyses aid in gaining new insights into these processes and interactions. The numerical description of nucleic acids thereby constitutes a bridge between the concrete biological issues and the analytical methods. Hence, this study compares 26 descriptor sets obtained by applying well-known numerical description concepts to an established dataset of 38 DNA promoter sequences. The suitability of the description sets was evaluated by computing partial least squares regression models and assessing the model accuracy. We conclude that the major importance regarding the descriptive power is attached to positional information rather than to explicitly incorporated physico-chemical information, since a sufficient amount of implicit physico-chemical information is already encoded in the nucleobase classification. The regression models especially benefited from employing the information that is encoded in the sequential and structural neighborhood of the nucleobases. Thus, the analyses of n-grams (short fragments of length n) suggested that they are valuable descriptors for DNA target interactions. A mixed n-gram descriptor set thereby yielded the best description of the promoter sequences. The corresponding regression model was checked and found to be plausible as it was able to reproduce the characteristic binding motifs of promoter sequences in a reasonable degree. As most functional nucleic acids are based on the principle of molecular recognition, the findings are not restricted to promoter sequences, but can rather be transferred to other kinds of functional nucleic acids. Thus, the concepts presented in this study could provide

  14. Proceedings 3rd NASA/IEEE Workshop on Formal Approaches to Agent-Based Systems (FAABS-III)

    Science.gov (United States)

    Hinchey, Michael (Editor); Rash, James (Editor); Truszkowski, Walt (Editor); Rouff, Christopher (Editor)

    2004-01-01

    These preceedings contain 18 papers and 4 poster presentation, covering topics such as: multi-agent systems, agent-based control, formalism, norms, as well as physical and biological models of agent-based systems. Some applications presented in the proceedings include systems analysis, software engineering, computer networks and robot control.

  15. Electricity Market Games: How Agent-Based Modeling Can Help under High Penetrations of Variable Generation

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Giulia

    2016-03-01

    Integrating increasingly high levels of variable generation in U.S. electricity markets requires addressing not only power system and grid modeling challenges but also an understanding of how market participants react and adapt to them. Key elements of current and future wholesale power markets can be modeled using an agent-based approach, which may prove to be a useful paradigm for researchers studying and planning for power systems of the future.

  16. PAMS - A New Collaborative Framework for Agent-Based Simulation of Complex Sysems

    OpenAIRE

    Nguyen Trong, Khanh; Marilleau, Nicolas; Vinh Ho, Tuong

    2008-01-01

    International audience; Major researches in the domain of complex systems are interdisciplinary, collaborative and geographically distributed. The purpose of our work is to explore a new collaborative approach that facilitates scientist's interactions during the modelling and simulating process. The originality of the presented approach is to consider models and simulators as a board of the collaboration: a shared object manipulated by a group of scientists. Agent-based simulations are powerf...

  17. Integrating adaptive behaviour in large-scale flood risk assessments: an Agent-Based Modelling approach

    Science.gov (United States)

    Haer, Toon; Aerts, Jeroen

    2015-04-01

    Between 1998 and 2009, Europe suffered over 213 major damaging floods, causing 1126 deaths, displacing around half a million people. In this period, floods caused at least 52 billion euro in insured economic losses making floods the most costly natural hazard faced in Europe. In many low-lying areas, the main strategy to cope with floods is to reduce the risk of the hazard through flood defence structures, like dikes and levees. However, it is suggested that part of the responsibility for flood protection needs to shift to households and businesses in areas at risk, and that governments and insurers can effectively stimulate the implementation of individual protective measures. However, adaptive behaviour towards flood risk reduction and the interaction between the government, insurers, and individuals has hardly been studied in large-scale flood risk assessments. In this study, an European Agent-Based Model is developed including agent representatives for the administrative stakeholders of European Member states, insurers and reinsurers markets, and individuals following complex behaviour models. The Agent-Based Modelling approach allows for an in-depth analysis of the interaction between heterogeneous autonomous agents and the resulting (non-)adaptive behaviour. Existing flood damage models are part of the European Agent-Based Model to allow for a dynamic response of both the agents and the environment to changing flood risk and protective efforts. By following an Agent-Based Modelling approach this study is a first contribution to overcome the limitations of traditional large-scale flood risk models in which the influence of individual adaptive behaviour towards flood risk reduction is often lacking.

  18. Analysis of Demand Control Policies using an Agent-based Multi-layer Power System Model

    OpenAIRE

    Kühnlenz, Florian; Nardelli, Pedro H. J.; Alves, Hirley

    2016-01-01

    This paper studies how the communication network affects the power utilization and fairness in a simplified power system model, composed by three coupled layers: physical, communication and regulatory. Using an agent-based approach, we build a scenario where individuals may cooperate (by removing a load) or not (by keeping their loads or adding one more). The agent decision reflects its desire of maximizing the delivered power based on its internal state, its global state perception, a random...

  19. Agent-based model for rural-urban migration: A dynamic consideration

    Science.gov (United States)

    Cai, Ning; Ma, Hai-Ying; Khan, M. Junaid

    2015-10-01

    This paper develops a dynamic agent-based model for rural-urban migration, based on the previous relevant works. The model conforms to the typical dynamic linear multi-agent systems model concerned extensively in systems science, in which the communication network is formulated as a digraph. Simulations reveal that consensus of certain variable could be harmful to the overall stability and should be avoided.

  20. An Agent-Based Model of Mortality Shocks, Intergenerational Effects, and Urban Crime

    OpenAIRE

    Michael Makowsky

    2006-01-01

    Rational criminals choose crime over lawfulness because it pays better; hence poverty correlates to criminal behavior. This correlation is an insufficient historical explanation. An agent-based model of urban crime, mortality, and exogenous population shocks supplements the standard economic story, closing the gap with an empirical reality that often breaks from trend. Agent decision making within the model is built around a career maximization function, with life expectancy as the key indepe...

  1. Graceful Failure and Societal Resilience Analysis Via Agent-Based Modeling and Simulation

    Science.gov (United States)

    Schopf, P. S.; Cioffi-Revilla, C.; Rogers, J. D.; Bassett, J.; Hailegiorgis, A. B.

    2014-12-01

    Agent-based social modeling is opening up new methodologies for the study of societal response to weather and climate hazards, and providing measures of resiliency that can be studied in many contexts, particularly in coupled human and natural-technological systems (CHANTS). Since CHANTS are complex adaptive systems, societal resiliency may or may not occur, depending on dynamics that lack closed form solutions. Agent-based modeling has been shown to provide a viable theoretical and methodological approach for analyzing and understanding disasters and societal resiliency in CHANTS. Our approach advances the science of societal resilience through computational modeling and simulation methods that complement earlier statistical and mathematical approaches. We present three case studies of social dynamics modeling that demonstrate the use of these agent based models. In Central Asia, we exmaine mutltiple ensemble simulations with varying climate statistics to see how droughts and zuds affect populations, transmission of wealth across generations, and the overall structure of the social system. In Eastern Africa, we explore how successive episodes of drought events affect the adaptive capacity of rural households. Human displacement, mainly, rural to urban migration, and livelihood transition particularly from pastoral to farming are observed as rural households interacting dynamically with the biophysical environment and continually adjust their behavior to accommodate changes in climate. In the far north case we demonstrate one of the first successful attempts to model the complete climate-permafrost-infrastructure-societal interaction network as a complex adaptive system/CHANTS implemented as a ``federated'' agent-based model using evolutionary computation. Analysis of population changes resulting from extreme weather across these and other cases provides evidence for the emergence of new steady states and shifting patterns of resilience.

  2. Distributed Agent-Based Networks in Support of Advanced Marine Corps Command and Control Concept

    Science.gov (United States)

    2012-09-01

    capabilities that Mobile Ad Hoc Networking ( MANET ) technologies can provide to the Marine Corps are just fully coming into view. These new...Management System, NMS, Tactical Mobile Ad hoc Networks, MANET , Agent-based, Policy-Based, Distributed Networks, Autonomic Networks 15. NUMBER OF...ABSTRACT The capabilities that Mobile Ad Hoc Networking ( MANET ) technologies can provide to the Marine Corps are just fully coming into view. These

  3. An Agent-Based Modeling Template for a Cohort of Veterans with Diabetic Retinopathy.

    Directory of Open Access Journals (Sweden)

    Theodore Eugene Day

    Full Text Available Agent-based models are valuable for examining systems where large numbers of discrete individuals interact with each other, or with some environment. Diabetic Veterans seeking eye care at a Veterans Administration hospital represent one such cohort.The objective of this study was to develop an agent-based template to be used as a model for a patient with diabetic retinopathy (DR. This template may be replicated arbitrarily many times in order to generate a large cohort which is representative of a real-world population, upon which in-silico experimentation may be conducted.Agent-based template development was performed in java-based computer simulation suite AnyLogic Professional 6.6. The model was informed by medical data abstracted from 535 patient records representing a retrospective cohort of current patients of the VA St. Louis Healthcare System Eye clinic. Logistic regression was performed to determine the predictors associated with advancing stages of DR. Predicted probabilities obtained from logistic regression were used to generate the stage of DR in the simulated cohort.The simulated cohort of DR patients exhibited no significant deviation from the test population of real-world patients in proportion of stage of DR, duration of diabetes mellitus (DM, or the other abstracted predictors. Simulated patients after 10 years were significantly more likely to exhibit proliferative DR (P<0.001.Agent-based modeling is an emerging platform, capable of simulating large cohorts of individuals based on manageable data abstraction efforts. The modeling method described may be useful in simulating many different conditions where course of disease is described in categorical stages.

  4. GAMA: multi-level and complex environment for agent-based models and simulations (demonstration)

    OpenAIRE

    Drogoul, Alexis; Amouroux, Edouard; Caillou, Philippe; Gaudou, Benoit; Grignard, Arnaud; Marilleau, Nicolas; Taillandier, Patrick; Vavaseur, Maroussia; Vo, Duc-An; Zucker, Jean-Daniel

    2013-01-01

    International audience; Agent-based models are now used in numerous application domains (ecology, social sciences, etc.) but their use is still impeded by the lack of generic yet ready-to-use tools sup- porting the design and the simulation of complex models in- tegrating multiple level of agency and realistic environments. The GAMA modeling and simulation platform is proposed to address such issues. It allows modelers to build com- plex models thanks to high-level modeling language, various ...

  5. A middleware for building contract-aware agent-based services

    OpenAIRE

    Confalonieri, Roberto; Álvarez Napagao, Sergio; Panagiotidi, Sofia; Vázquez Salceda, Javier; Willmott, Steven Nicolás

    2008-01-01

    This paper presents a middleware to help designers in the implementation of contract-aware agent-based services. The middleware provides several components, including a contract manager, a communication manager and a workflow manager, which combine to allow agents to manage contracts and the actions associated with them. The middleware is built as part of a Web service implementation of the ISTCONTRACT framework. An electronic commerce example is used to illustrate how the components of...

  6. Robust Parameter Design for Agent-Based Simulation Models With Application in a Cultural Geography Model

    Science.gov (United States)

    2010-06-01

    Ajzen , I. (2006). Theory of planned behavior . Retrieved May 24, 2010, from http://people.umass.edu/aizen/tpb.html Alt, J. K., Jackson, L. A., Hudak...Cultural Geography, Agent-Based Model (ABM), Irregular Warfare (IW), Theory of planned Behavior (TpB), Baysian Belief Nets (BBN), Counterinsurgency...Strategic Multi-layered Assessment SSTR Security, Stability, Transition and Reconstruction Operations TPB Theory of Planned Behavior TRAC-MTRY

  7. An Agent-Based Focused Crawling Framework for Topic- and Genre-Related Web Document Discovery

    OpenAIRE

    Pappas, Nikolaos; Katsimpras, Georgios; Stamatatos, Efstathios

    2012-01-01

    The discovery of web documents about certain topics is an important task for web-based applications including web document retrieval, opinion mining and knowledge extraction. In this paper, we propose an agent-based focused crawling framework able to retrieve topic- and genre-related web documents. Starting from a simple topic query, a set of focused crawler agents explore in parallel topic-specific web paths using dynamic seed URLs that belong to certain web genres and are collected from web...

  8. Regeneration of leaching agent based on Fe2(SO43 with utilization of thionic bacteria

    Directory of Open Access Journals (Sweden)

    Kušnierová Mária

    1997-09-01

    Full Text Available The creation of bacterial film using Thiobacillus ferrooxidans and possibility of its utilization for regeneration of leaching agent based on Fe2(SO43 in the process of chalcopyrite leaching has been studied. Jarosites, the products of hydrolysis of Fe2(SO43 have been used as carriers of fixed biomass. On the basis of experimental results the above-mentioned way of bioregeneration of leaching agent seems to be very effective from technical, economic and environmental point of view.

  9. Financial price dynamics and agent-based models as inspired by Benoit Mandelbrot

    Science.gov (United States)

    LeBaron, Blake

    2016-12-01

    This short note draws some connections between Mandelbrot‗s empirical legacy, and the interdisciplinary work that followed in finance. Much of this work is now labeled econophysics, but some has always been more in the realm of economics than physics. In a few areas the overlap is even becoming quite complete as in market microstructure. I will also give some ideas about the various successes and failures in this area, and some directions for the future of agent- based modeling in particular.

  10. One-week postoperative patency of lower extremity in situ bypass graft comparing epidural and general anesthesia

    DEFF Research Database (Denmark)

    Wiis, Julie Therese; Jensen-Gadegaard, Peter; Altintas, Ümit

    2014-01-01

    BACKGROUND: The purpose of this study was to determine whether anesthesia affects graft patency after lower extremity arterial in situ bypass surgery. METHODS: This investigation was a retrospective study using a national database on vascular surgical patients at a single medical institution. We...... under epidural (n = 386) or general (n = 499) anesthesia. Thirty-day mortality (3.4% for epidural anesthesia versus 4.4% general anesthesia; P = 0.414) and comorbidity were comparable in the 2 groups. Graft occlusion within 7 days after surgery was reported in 93 patients, with a similar incidence...... in the epidural (10.1%) and general (10.8%) anesthesia groups (P = 0.730). When examining a subgroup of patients (n = 242) exposed to surgery on smaller vessels (femorodistal in situ bypass procedures, n = 253), the incidence of graft occlusion was also similar in the 2 groups at 14.0% and 9.4%, respectively (P...

  11. Agent-based simulation of building evacuation using a grid graph-based model

    Science.gov (United States)

    Tan, L.; Lin, H.; Hu, M.; Che, W.

    2014-02-01

    Shifting from macroscope models to microscope models, the agent-based approach has been widely used to model crowd evacuation as more attentions are paid on individualized behaviour. Since indoor evacuation behaviour is closely related to spatial features of the building, effective representation of indoor space is essential for the simulation of building evacuation. The traditional cell-based representation has limitations in reflecting spatial structure and is not suitable for topology analysis. Aiming at incorporating powerful topology analysis functions of GIS to facilitate agent-based simulation of building evacuation, we used a grid graph-based model in this study to represent the indoor space. Such model allows us to establish an evacuation network at a micro level. Potential escape routes from each node thus could be analysed through GIS functions of network analysis considering both the spatial structure and route capacity. This would better support agent-based modelling of evacuees' behaviour including route choice and local movements. As a case study, we conducted a simulation of emergency evacuation from the second floor of an official building using Agent Analyst as the simulation platform. The results demonstrate the feasibility of the proposed method, as well as the potential of GIS in visualizing and analysing simulation results.

  12. Agent Based Simulation of Group Emotions Evolution and Strategy Intervention in Extreme Events

    Directory of Open Access Journals (Sweden)

    Bo Li

    2014-01-01

    Full Text Available Agent based simulation method has become a prominent approach in computational modeling and analysis of public emergency management in social science research. The group emotions evolution, information diffusion, and collective behavior selection make extreme incidents studies a complex system problem, which requires new methods for incidents management and strategy evaluation. This paper studies the group emotion evolution and intervention strategy effectiveness using agent based simulation method. By employing a computational experimentation methodology, we construct the group emotion evolution as a complex system and test the effects of three strategies. In addition, the events-chain model is proposed to model the accumulation influence of the temporal successive events. Each strategy is examined through three simulation experiments, including two make-up scenarios and a real case study. We show how various strategies could impact the group emotion evolution in terms of the complex emergence and emotion accumulation influence in extreme events. This paper also provides an effective method of how to use agent-based simulation for the study of complex collective behavior evolution problem in extreme incidents, emergency, and security study domains.

  13. Agent-based power sharing scheme for active hybrid power sources

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhenhua [Department of Electrical and Computer Engineering, University of Miami, Coral Gables, FL 33146 (United States)

    2008-02-15

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles. (author)

  14. Model reduction for agent-based social simulation: coarse-graining a civil violence model.

    Science.gov (United States)

    Zou, Yu; Fonoberov, Vladimir A; Fonoberova, Maria; Mezic, Igor; Kevrekidis, Ioannis G

    2012-06-01

    Agent-based modeling (ABM) constitutes a powerful computational tool for the exploration of phenomena involving emergent dynamic behavior in the social sciences. This paper demonstrates a computer-assisted approach that bridges the significant gap between the single-agent microscopic level and the macroscopic (coarse-grained population) level, where fundamental questions must be rationally answered and policies guiding the emergent dynamics devised. Our approach will be illustrated through an agent-based model of civil violence. This spatiotemporally varying ABM incorporates interactions between a heterogeneous population of citizens [active (insurgent), inactive, or jailed] and a population of police officers. Detailed simulations exhibit an equilibrium punctuated by periods of social upheavals. We show how to effectively reduce the agent-based dynamics to a stochastic model with only two coarse-grained degrees of freedom: the number of jailed citizens and the number of active ones. The coarse-grained model captures the ABM dynamics while drastically reducing the computation time (by a factor of approximately 20).

  15. Agent-based power sharing scheme for active hybrid power sources

    Science.gov (United States)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  16. Assessing the Effectiveness of Payments for Ecosystem Services: an Agent-Based Modeling Approach

    Directory of Open Access Journals (Sweden)

    Xiaodong Chen

    2014-03-01

    Full Text Available Payments for ecosystem services (PES have increasingly been implemented to protect and restore ecosystems worldwide. The effectiveness of conservation investments in PES may differ under alternative policy scenarios and may not be sustainable because of uncertainties in human responses to policies and dynamic human-nature interactions. To assess the impacts of these interactions on the effectiveness of PES programs, we developed a spatially explicit agent-based model: human and natural interactions under policies (HANIP. We used HANIP to study the effectiveness of China's Natural Forest Conservation Program (NFCP and alternative policy scenarios in a coupled human-nature system, China's Wolong Nature Reserve, where indigenous people's use of fuelwood affects forests. We estimated the effects of the current NFCP, which provides a cash payment, and an alternative payment scenario that provides an electricity payment by comparing forest dynamics under these policies to forest dynamics under a scenario in which no payment is provided. In 2007, there were 337 km² of forests in the study area of 515 km². Under the baseline projection in which no payment is provided, the forest area is expected to be 234 km² in 2030. Under the current NFCP, there are likely to be 379 km² of forests in 2030, or an increase of 145 km² of forests to the baseline projection. If the cash payment is replaced with an electricity payment, there are likely to be 435 km² of forests in 2030, or an increase of 201 km² of forests to the baseline projection. However, the effectiveness of the NFCP may be threatened by the behavior of newly formed households if they are not included in the payment scheme. In addition, the effects of socio-demographic factors on forests will also differ under different policy scenarios. Human and natural interactions under policies (HANIP and its modeling framework may also be used to assess the effectiveness of many other PES programs around

  17. Comparative analysis of methods of training and dietary habits of skilled bodybuilders in the run-general preparatory stage

    Directory of Open Access Journals (Sweden)

    Dzhym V.Y.

    2015-02-01

    Full Text Available Purpose : comparative analysis of the characteristics of methods of training and nutrition bodybuilders in the run-general of the preparatory phase (duration 4 - 5 months or 20 microcycles. Analyzed the characteristics of different methods of training bodybuilders to increase muscle mass. Material : the study involved 8 skilled bodybuilders, are included in the team of the Kharkiv region. Results : a comparative characteristic of the most commonly used methods of exercise and nutrition in bodybuilding. Discovered and proved the optimal technique for athletes depending on the original form at the beginning of general-preparatory phase of training. Driven changes in body weight, depending on the amount used Athlete of carbohydrates, proteins and fats. Conclusions : throughout the training period was characterized by severe protein diet orientation. The proportion of the nutrient was 40% in the first quarter, 50% - in the second, 60% in the third. Only in the last two microcycle decreased to 50%.

  18. Prevalence of hepatitis B virus in patients with diabetes mellitus: a comparative cross sectional study at Woldiya General Hospital, Ethiopia

    OpenAIRE

    Mekonnen, Daniel; Gebre-Selassie, Solomon; Fantaw, Surafel; Hunegnaw, Andualem; Mihret, Adane

    2014-01-01

    Introduction The overall prevalence of HBV in Ethiopia varies from 4.7-16.8% for Hepatitis B surface antigen (HBsAg) and 70-76.38% for at least one marker positive. Patients suffering from type I Diabetes Mellitus (DM) incur high risk of infection with hepatotropic viruses because of frequent hospitalization and blood tests. Methods A comparative cross sectional study was conducted at Woldiya General Hospital using 108 consented study populations from Diabetes and 108 non diabetes control gro...

  19. Agent-based modeling and simulation of clean heating system adoption in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Sopha, Bertha Maya

    2011-03-15

    A sound climate policy encouraging clean energy investment is important to mitigate global warming. Previous research has demonstrated that consumer choice indeed plays an important role in adoption of sustainable technologies. This thesis strives to gain a better understanding of consumers' decision-making on heating systems and to explore the potential application of agent-based modeling (ABM) in exploring mechanism underlying adoption in which heating system adoption by Norwegian households is taken up as a case study. An interdisciplinary approach, applying various established theories including those of psychology, is applied to create a model for consumer behavior and implement this behavior in an Agent-Based Model (ABM) to simulate heating technology diffusion. A mail-survey, carried out in autumn 2008, is a means to collect information for parameterizing the agent-based model, for gaining empirical facts, and for validating the developed model at micro-level. Survey sample consisted of 1500 Norwegian households drawn from population register and 1500 wood pellet users in Norway. The response rates were 10.3% and 34.6% for population sample and wood pellet sample respectively. This study is divided into two parts; empirical analysis and agent-based simulation. The empirical analysis aims at fully understanding the important aspects of adoption decision and their implications, in order to assist simulation. The analysis particularly contributes to the identification of differences/similarities between adopters and non adopters of wood pellet heating with respects to some key points of adoption derived from different theories, psychological factors underlying the adoption-decision of wood pellet heating, and the rationales underlying Norwegian households' decisions regarding their future heating system. The simulation study aims at exploring the mechanism of heterogeneous household decision-making giving rise to the diffusion of heating systems, and

  20. Predictors of failure of awake regional anesthesia for neonatal hernia repair: data from the General Anesthesia compared to Spinal anesthesia (GAS) study: comparing apnoea and neurodevelopmental outcomes

    Science.gov (United States)

    Frawley, Geoff; Bell, Graham; Disma, Nicola; Withington, Davinia E.; de Graaff, Jurgen C.; Morton, Neil S.; McCann, Mary Ellen; Arnup, Sarah J.; Bagshaw, Oliver; Wolfler, Andrea; Bellinger, David; Davidson, Andrew J.

    2015-01-01

    Background Awake regional anesthesia (RA) is a viable alternative to general anesthesia (GA) for infants undergoing lower abdominal surgery. Benefits include lower incidence of postoperative apnea and avoidance of anesthetic agents that may increase neuroapoptosis and worsen neurocognitive outcomes. The General Anesthesia compared to Spinal anesthesia (GAS) study compares neurodevelopmental outcomes following awake RA or GA in otherwise healthy infants. Our aim was to describe success and failure rates of RA in this study and report factors associated with failure. Methods This was a nested cohort study within a prospective randomized, controlled, observer blind, equivalence trial. Seven hundred twenty two infants ≤ 60 weeks postmenstrual age, scheduled for herniorrhaphy under anesthesia were randomly assigned to receive RA (spinal, caudal epidural or combined spinal caudal anesthetic) or GA with sevoflurane. The data of 339 infants, where spinal or combined spinal caudal anesthetic was attempted, was analyzed. Possible predictors of failure were assessed including: patient factors, technique, experience of site and anesthetist and type of local anesthetic. Results RA was sufficient for the completion of surgery in 83.2% of patients. Spinal anesthesia was successful in 86.9% of cases and combined spinal caudal anesthetic in 76.1%. Thirty four patients required conversion to GA and an additional 23 (6.8%) required brief sedation. Bloody tap on the first attempt at lumbar puncture was the only risk factor significantly associated with block failure (OR = 2.46). Conclusions The failure rate of spinal anesthesia was low. Variability in application of combined spinal caudal anesthetic limited attempts to compare the success of this technique to spinal alone. PMID:26001028

  1. Predictors of Failure of Awake Regional Anesthesia for Neonatal Hernia Repair: Data from the General Anesthesia Compared to Spinal Anesthesia Study--Comparing Apnea and Neurodevelopmental Outcomes.

    Science.gov (United States)

    Frawley, Geoff; Bell, Graham; Disma, Nicola; Withington, Davinia E; de Graaff, Jurgen C; Morton, Neil S; McCann, Mary Ellen; Arnup, Sarah J; Bagshaw, Oliver; Wolfler, Andrea; Bellinger, David; Davidson, Andrew J

    2015-07-01

    Awake regional anesthesia (RA) is a viable alternative to general anesthesia (GA) for infants undergoing lower abdominal surgery. Benefits include lower incidence of postoperative apnea and avoidance of anesthetic agents that may increase neuroapoptosis and worsen neurocognitive outcomes. The General Anesthesia compared to Spinal anesthesia study compares neurodevelopmental outcomes after awake RA or GA in otherwise healthy infants. The aim of the study is to describe success and failure rates of RA and report factors associated with failure. This was a nested cohort study within a prospective, randomized, controlled, observer-blind, equivalence trial. Seven hundred twenty-two infants 60 weeks or less postmenstrual age scheduled for herniorrhaphy under anesthesia were randomly assigned to receive RA (spinal, caudal epidural, or combined spinal caudal anesthetic) or GA with sevoflurane. The data of 339 infants, where spinal or combined spinal caudal anesthetic was attempted, were analyzed. Possible predictors of failure were assessed including patient factors, technique, experience of site and anesthetist, and type of local anesthetic. RA was sufficient for the completion of surgery in 83.2% of patients. Spinal anesthesia was successful in 86.9% of cases and combined spinal caudal anesthetic in 76.1%. Thirty-four patients required conversion to GA, and an additional 23 patients (6.8%) required brief sedation. Bloody tap on the first attempt at lumbar puncture was the only risk factor significantly associated with block failure (odds ratio = 2.46). The failure rate of spinal anesthesia was low. Variability in application of combined spinal caudal anesthetic limited attempts to compare the success of this technique to spinal alone.

  2. Routinely-collected general practice data from the electronic patient record and general practitioner active electronic questioning method: a comparative study.

    Science.gov (United States)

    De Clercq, Etienne; Moreels, Sarah; Bossuyt, Nathalie; Vanthomme, Katrien; Goderis, Geert; Van Casteren, Viviane

    2013-01-01

    The numerous existing primary care-based research networks currently use various data collection methods. In this paper, we compared routine data extracted from general practitioners' (GPs') electronic patient records (EPRs) and GPs' answers to an electronic questionnaire. We investigated for 10,307 Belgian patients 10 healthcare conditions using clinical and biological parameters (cholesterol, blood pressure, and body mass index), diagnoses (hypertension, diabetes, and personal past cardiovascular event(s)), and drug prescriptions (antidiabetic drugs, aspirin, statins, and antihypertensive drugs). We found a relatively fair agreement (Kappa≥0.40) between the two data collection methods for 7 healthcare conditions, but no agreement for the biological parameters. When EPR data was used and compared with the questioning method, the prevalence of diagnoses and drug prescriptions was relatively lower and the prevalence of clinical and biological parameters was relatively higher (all missing data excluded) in the EPR data than in the data collected using the questioning method. Using EPR data, we calculated an acceptable proxy for the prevalence as observed using the questioning method. The comparison of the two data collection methods was a worthwhile approach, in that it could highlight potential ways to improve both care quality and information systems.

  3. A comparative study on lecture based versus case based education on teaching general surgery to medical students

    Directory of Open Access Journals (Sweden)

    M. Moazeni Bistegani

    2013-06-01

    Full Text Available Introduction : various methods of teaching have different learning outcomes. Using a combination of teaching and training methods of training may boost education. This study compared lecture based and case based teaching as a combined approach in learning general surgery by medical students. Methods: This study was a quasi-experimental performed on two consecutive groups of 33 and 36 students who were studying general surgery course. The two styles of teaching were lecture-based and real case teaching methods. The final exam included twenty multiple choice questions. The mean scores of each group of students were collected and analyzed accordingly with descriptive tests, Fisher’s test and T-test. Results: The mean final mark of students' who received real case based education was 16.8/20 ± 1.8 and for the lecture group was 12.7± 1.7. There was a significant difference between the two groups (P <0.0001. In both groups, there were significant differences in the mean scores of questions with taxonomy two and three, but not in the questions with taxonomy one. Students' evaluation score of the teacher of the real case group increased by 1.7/20 (8.7% in the case based group compared to the lecture group. Conclusions: Case based teaching of general surgery led to a better outcome and students were more satisfied. It is recommended that case based education of surgery be encouraged.

  4. Comparing attentional control and intrusive thoughts in obsessive-compulsive disorder, generalized anxiety disorder and non clinical population.

    Directory of Open Access Journals (Sweden)

    Mehri Moradi

    2014-06-01

    Full Text Available Attention is an important factor in information processing; obsessive- compulsive disorder (OCD and generalized anxiety disorder (GAD are two main emotional disorders with a chronic course. This research examined the relationship among attentional control and intrusive thoughts (worry, rumination and obsession in these disorders. It was hypothesized that attentional control is a common factor in OCD and GAD. In addition, we compared worry, rumination and obsession among OCD, GAD and non- clinical participants.The research sample included three groups: OCD (n = 25, GAD (n = 30 and non- clinical samples (n = 56. Data were collected using the Attentional Control Scale (ACS, Rumination Response Scale (RRS, Pennsylvania State Worry Questionnaire (PSWQ, Beck Depression Inventory (BDI, Beck Anxiety Inventory (BAI, Obsessive-Compulsive Inventory-Revised (OCI-R and General Health Questionnaire (GHQ-28. Data were analyzed using MANOVA and MANCOVA by SPSS-17.Multivariate Analysis of Variance revealed that the OCD and GAD groups reported greater deficits in attentional control, higher obsessive-compulsive symptoms, rumination, worry, anxiety and depression compared to the control group.This research indicated a great attentional deficit in obsessive- compulsive disorder and generalized anxiety disorder. However, no significant difference was found between these two disorders.

  5. Comparing anger, anger expression, life stress and social support between Korean female nursing and general university students.

    Science.gov (United States)

    Jun, Won Hee; Lee, Gyungjoo

    2017-05-30

    To compare anger, anger expression, life stress and social support among female students at a nursing university and a general university and to examine factors affecting anger in each group. University students typically experience constant stress resulting from factors like academic requirements, personal relationships and career decisions; this tends to promote anger. Particularly, nursing students' anger can negatively affect the quality of care that they provide, and also their mental health. Therefore, anger management of nursing students is very important in the training and development of future nurses. Nursing education needs to confirm factors associated with anger of nursing students compared with general university students to develop specific intervention programs for decreasing their anger levels. A descriptive, cross-sectional design was used. Participants were 286 female students (146 from a nursing university and 140 from a general university); they completed self-report surveys examining anger, anger expression, life stress and social support. A stepwise multiple regression analysis was done to identify factors affecting anger. Data were collected from 15 May-10 June 2016. In the stepwise multiple regression analysis, we entered three anger expression factors, eight life stress factors and social support as explanatory variables; factors affecting anger among nursing students were anger-out and same-sex peer relationship stress. In general university students, anger-out, anger-control and anger-in were identified as factors affecting anger. Becoming proficient in beneficial anger expression techniques and reducing stress from same-sex peer relationships will reduce anger among female nursing students. © 2017 John Wiley & Sons Ltd.

  6. A Novel Application of Agent-based Modeling: Projecting Water Access and Availability Using a Coupled Hydrologic Agent-based Model in the Nzoia Basin, Kenya

    Science.gov (United States)

    Le, A.; Pricope, N. G.

    2015-12-01

    Projections indicate that increasing population density, food production, and urbanization in conjunction with changing climate conditions will place stress on water resource availability. As a result, a holistic understanding of current and future water resource distribution is necessary for creating strategies to identify the most sustainable means of accessing this resource. Currently, most water resource management strategies rely on the application of global climate predictions to physically based hydrologic models to understand potential changes in water availability. However, the need to focus on understanding community-level social behaviors that determine individual water usage is becoming increasingly evident, as predictions derived only from hydrologic models cannot accurately represent the coevolution of basin hydrology and human water and land usage. Models that are better equipped to represent the complexity and heterogeneity of human systems and satellite-derived products in place of or in conjunction with historic data significantly improve preexisting hydrologic model accuracy and application outcomes. We used a novel agent-based sociotechnical model that combines the Soil and Water Assessment Tool (SWAT) and Agent Analyst and applied it in the Nzoia Basin, an area in western Kenya that is becoming rapidly urbanized and industrialized. Informed by a combination of satellite-derived products and over 150 household surveys, the combined sociotechnical model provided unique insight into how populations self-organize and make decisions based on water availability. In addition, the model depicted how population organization and current management alter water availability currently and in the future.

  7. An agent -based Intelligent System to enhance E-Learning through Mining Techniques

    Directory of Open Access Journals (Sweden)

    S.Prakasam

    2010-05-01

    Full Text Available The growth of Internet has created new ways for education systems. Learners and teachers realize their pedagogic activities with less effort, time and money. Agent Based Intelligent System (ABIS have proved their worth in multiple ways and in multiple domains in Education. In this paper the application of an agent-based IntelligentSystem for enhancing E-learning is introduced. An ABIS is a system that provides direct customized instruction or feedback to studentswithout the intervention of human beings. With the explosion of content on the World Wide Web (WWW, the scope of application of Data and Web Mining to E- Learning applications has increased tremendously. In this work, we identify a set of applications which go one step ahead from ABIS and use the WWW to aid the learning process of the “learning object content”. Each application hasa high level of coupling with the knowledge representation model, which models the resources stored in the Digital Library.This research presents the architecture for simplifying and automating the process of creating the domain model for an intelligent e-learningsystem. In this work we present an Knowledge representation of educational resources, using the World Wide Web. The effective and accurate intelligent systems based on the mining technologies have become the most important research issue. An agent-based recommendation system helps communities of learners in searchingthe web for information. This paper reports on the conceptualstructure that has evolved to define the development process for the pedagogical agents. It also proposes getting rich source of Information,such as the hyperlinks among pages or the Web usage information using web data mining technology Based on intelligent search systems and here we propose an architecture model of e- mLearning process using the agent paradigm.

  8. Dosage and Dose Schedule Screening of Drug Combinations in Agent-Based Models Reveals Hidden Synergies.

    Science.gov (United States)

    Barros de Andrade E Sousa, Lisa C; Kühn, Clemens; Tyc, Katarzyna M; Klipp, Edda

    2015-01-01

    The fungus Candida albicans is the most common causative agent of human fungal infections and better drugs or drug combination strategies are urgently needed. Here, we present an agent-based model of the interplay of C. albicans with the host immune system and with the microflora of the host. We took into account the morphological change of C. albicans from the yeast to hyphae form and its dynamics during infection. The model allowed us to follow the dynamics of fungal growth and morphology, of the immune cells and of microflora in different perturbing situations. We specifically focused on the consequences of microflora reduction following antibiotic treatment. Using the agent-based model, different drug types have been tested for their effectiveness, namely drugs that inhibit cell division and drugs that constrain the yeast-to-hyphae transition. Applied individually, the division drug turned out to successfully decrease hyphae while the transition drug leads to a burst in hyphae after the end of the treatment. To evaluate the effect of different drug combinations, doses, and schedules, we introduced a measure for the return to a healthy state, the infection score. Using this measure, we found that the addition of a transition drug to a division drug treatment can improve the treatment reliability while minimizing treatment duration and drug dosage. In this work we present a theoretical study. Although our model has not been calibrated to quantitative experimental data, the technique of computationally identifying synergistic treatment combinations in an agent based model exemplifies the importance of computational techniques in translational research.

  9. Dosage and dose schedule screening of drug combinations in agent-based models reveals hidden synergies

    Directory of Open Access Journals (Sweden)

    Lisa Corina Barros de Andrade e Sousa1

    2016-01-01

    Full Text Available The fungus Candida albicans is the most common causative agent of human fungal infections and better drugs or drug combination strategies are urgently needed. Here, we present an agent-based model of the interplay of C. albicans with the host immune system and with the microflora of the host. We took into account the morphological change of C. albicans from the yeast to hyphae form and its dynamics during infection. The model allowed us to follow the dynamics of fungal growth and morphology, of the immune cells and of microflora in different perturbing situations. We specifically focused on the consequences of microflora reduction following antibiotic treatment. Using the agent-based model, different drug types have been tested for their effectiveness, namely drugs that inhibit cell division and drugs that constrain the yeast-to-hyphae transition. Applied individually, the division drug turned out to successfully decrease hyphae while the transition drug leads to a burst in hyphae after the end of the treatment. To evaluate the effect of different drug combinations, doses, and schedules, we introduced a measure for the return to a healthy state, the infection score. Using this measure, we found that the addition of a transition drug to a division drug treatment can improve the treatment reliability while minimizing treatment duration and drug dosage. In this work we present a theoretical study. Although our model has not been calibrated to quantitative experimental data, the technique of computationally identifying synergistic treatment combinations in an agent based model exemplifies the importance of computational techniques in translational research.

  10. Rediscovering the Economics of Keynes in an Agent-Based Computational Setting

    DEFF Research Database (Denmark)

    Bruun, Charlotte

    The aim of this paper is to use agent-based computational economics to explore the economic thinking of Keynes. Taking his starting point at the macroeconomic level, Keynes argued that economic systems are characterized by fundamental uncertainty - an uncertainty that makes rule-based behaviour...... and reliance on monetary magnitudes more optimal to the economic agent than profit- and utility optimazation in the traditional sense. Unfortunately more systematic studies of the properties of such a system was not possible at the time of Keynes. The system envisioned by Keynes holds a lot of properties...

  11. The "Wedding-Ring": An agent-based marriage model based on social interaction

    Directory of Open Access Journals (Sweden)

    Alexia Prskawetz

    2007-08-01

    Full Text Available In this paper we develop an agent-based marriage model based on social interaction. We build an population of interacting agents whose chances of marrying depend on the availability of partners, and whose willingness to marry depends on the share of relevant others in their social network who are already married. We then let the typical aggregate age pattern of marriage emerge from the bottom-up. The results of our simulation show that micro-level hypotheses founded on existing theory and evidence on social interaction can reproduce age-at-marriage patterns with both realistic shape and realistic micro-level dynamics.

  12. An Interactive Tool for Creating Multi-Agent Systems and Interactive Agent-based Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Pagliarini, Luigi

    2011-01-01

    Utilizing principles from parallel and distributed processing combined with inspiration from modular robotics, we developed the modular interactive tiles. As an educational tool, the modular interactive tiles facilitate the learning of multi-agent systems and interactive agent-based games....... The modular and physical property of the tiles provides students with hands-on experience in exploring the theoretical aspects underlying multi-agent systems which often appear as challenging to students. By changing the representation of the cognitive challenging aspects of multi-agent systems education...

  13. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob;

    2014-01-01

    A new agent-based modelling tool has been developed to allow the modelling of populations of individuals whose interactions are characterised by tightly timed dynamics. The tool was developed to model male frog calling dynamics, to facilitate research into what local rules may be employed...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

  14. Genetic Algorithms for Agent-Based Infrastructure Interdependency Modeling and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    May Permann

    2007-03-01

    Today’s society relies greatly upon an array of complex national and international infrastructure networks such as transportation, electric power, telecommunication, and financial networks. This paper describes initial research combining agent-based infrastructure modeling software and genetic algorithms (GAs) to help optimize infrastructure protection and restoration decisions. This research proposes to apply GAs to the problem of infrastructure modeling and analysis in order to determine the optimum assets to restore or protect from attack or other disaster. This research is just commencing and therefore the focus of this paper is the integration of a GA optimization method with a simulation through the simulation’s agents.

  15. STUDIES ON HORIZONTAL COMPETITION AMONG HOMOGENOUS RETAILERS THROUGH AGENT-BASED SIMULATION

    Institute of Scientific and Technical Information of China (English)

    Ming XIE; Jian CHEN

    2004-01-01

    This paper adopts agent-based simulation to study the horizontal competition among homogenous price-setting retailers in a one-to-many supply chain (a supply chain consists of one supplier and multiple retailers). We model the supplier and retailers as agents, and design their behavioral rulesrespectively. The results show that although the agents learn individually based on their own experiences, the system converges asymptotically to near Nash equilibrium steady states.When analyzing the results, we first discuss the properties of these steady states. Then based on these properties, we analyze the effects of the retailers' horizontal competition on the retail prices, retailers'profits and supplier's revenue.

  16. Agent-based Ecological Model Calibration - on the Edge of a New Approach

    CERN Document Server

    Pereira, Antonio; Reis, Luis Paulo

    2008-01-01

    The purpose of this paper is to present a new approach to ecological model calibration -- an agent-based software. This agent works on three stages: 1- It builds a matrix that synthesizes the inter-variable relationships; 2- It analyses the steady-state sensitivity of different variables to different parameters; 3- It runs the model iteratively and measures model lack of fit, adequacy and reliability. Stage 3 continues until some convergence criteria are attained. At each iteration, the agent knows from stages 1 and 2, which parameters are most likely to produce the desired shift on predicted results.

  17. Agent Based Modeling and Simulation Framework for Supply Chain Risk Management

    Science.gov (United States)

    2012-03-01

    Karimi . 2009. “Supply Chain Risk Identification Using a HAZOP-Based Approach,” AIChE Journal 55(6), 1447-1463. AFGLSC (Air Force Global...Srinivasan and I. Karimi . 2002. “Agent-based supply chain management – 1: framework,” Computers and Chemical Engineering 26(12), 1755-1769. Juttner, U...Springer: Berlin Heidelberg, 1-27. Naraharisetti, P.K., A. Adhitya, I.A. Karimi and R. Srinivasan. 2009. “From PSE to PSE2 – Decision support

  18. Multi-agent-based Approach for Determination of Time-quota in Integrated Environment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Time-quota is one of important factors in producti on system. It is affected by various factors. time-quota is studied in CAPP and p roduction schedule integration environment in this paper. An agent-based time- quota method is put forward and the structure model is established by means of i ntelligent agent in integrated environment. The method can map the influencing t ime-quota factors into part agent related to process state and machine method a gent, resorting to the function of agent rule-based reaso...

  19. AN AGENT-BASED SIMULATION ON MARKET CONSIDERING KNOWLEDGE TRANSITION AND SOCIAL IMPACT

    Institute of Scientific and Technical Information of China (English)

    Tieju Ma; Mina Ryoke; Yoshiteru Nakamori

    2002-01-01

    In this paper, an agent-based simulation about knowledge transition associated with social impact in market is introduced. In the simulation, the genetic algorithm is used to generate the next generation products and a dynamic social impact model is used to simulate how customers are influenced by other customers. The simulation and its results not only show some features and patterns of knowledge transition, but also explore and display some phenomena of business cultures. On the basis of the innovation model of knowledge-based economy, the transition between technical knowledge and products knowledge is discussed, and a fuzzy linear quantification model which can be used to simulate the transition is introduced.

  20. A Participatory Agent-Based Simulation for Indoor Evacuation Supported by Google Glass

    Directory of Open Access Journals (Sweden)

    Jesús M. Sánchez

    2016-08-01

    Full Text Available Indoor evacuation systems are needed for rescue and safety management. One of the challenges is to provide users with personalized evacuation routes in real time. To this end, this project aims at exploring the possibilities of Google Glass technology for participatory multiagent indoor evacuation simulations. Participatory multiagent simulation combines scenario-guided agents and humans equipped with Google Glass that coexist in a shared virtual space and jointly perform simulations. The paper proposes an architecture for participatory multiagent simulation in order to combine devices (Google Glass and/or smartphones with an agent-based social simulator and indoor tracking services.

  1. Interbank network and regulation policies: an analysis through agent-based simulations with adaptive learning

    OpenAIRE

    Barroso, Ricardo Vieira; Lima, Joaquim Ignacio Alves Vasconcellos; Lucchetti, Alexandre Henrique; Cajueiro, Daniel Oliveira

    2016-01-01

    We develop an agent-based model to study the impacts of a broad range of regulation policies over the banking system. It builds on an iterated version of the \\citet{DiamondDybvig1983} framework and resorts to the experience-weighted attraction learning scheme of \\citet{CamererHo1999} to model agents' adaptive learning. Thereby, we can capture not only the direct impacts of regulation policies, but also the ones that take part through shifting agents' adaptive strategies. Our results show that...

  2. Using agent-based simulation to explore sugarcane supply chain transport complexities at a mill scale

    CSIR Research Space (South Africa)

    Price

    2014-09-01

    Full Text Available stream_source_info Price_2014.pdf.txt stream_content_type text/plain stream_size 30129 Content-Encoding UTF-8 stream_name Price_2014.pdf.txt Content-Type text/plain; charset=UTF-8 Proceedings of the 2014 ORSSA Annual... Conference pp. 88–96 www.orssa.org.za/wiki/uploads/Conf/2014ORSSAConferenceProceedings.pdf ORSSA Proceedings ISBN 978-1-86822-656-6 c©2014 Using agent-based simulation to explore sugarcane supply chain transport complexities at a mill scale CS Price∗ D...

  3. An agent based approach for simulating complex systems with spatial dynamicsapplication in the land use planning

    Directory of Open Access Journals (Sweden)

    Fatimazahra BARRAMOU

    2012-12-01

    Full Text Available In this research a new agent based approach for simulating complex systems with spatial dynamics is presented. We propose architecture based on coupling between two systems: multi-agent systems and geographic information systems. We also propose a generic model of agent-oriented simulation that we will apply to the field of land use planning. In fact, simulating the evolution of the urban system is a key to help decision makers to anticipate the needs of the city in terms of installing new equipment and opening new urbanization’ areas to install the new population.

  4. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob

    2014-01-01

    by individuals to generate their observed population behaviour. A number of existing agent-modelling frameworks are considered, but none have the ability to handle large numbers of time-dependent event-generating agents; hence the construction of a new tool, RANA. The calling behaviour of the Puerto Rican Tree......A new agent-based modelling tool has been developed to allow the modelling of populations of individuals whose interactions are characterised by tightly timed dynamics. The tool was developed to model male frog calling dynamics, to facilitate research into what local rules may be employed...

  5. A Participatory Agent-Based Simulation for Indoor Evacuation Supported by Google Glass.

    Science.gov (United States)

    Sánchez, Jesús M; Carrera, Álvaro; Iglesias, Carlos Á; Serrano, Emilio

    2016-08-24

    Indoor evacuation systems are needed for rescue and safety management. One of the challenges is to provide users with personalized evacuation routes in real time. To this end, this project aims at exploring the possibilities of Google Glass technology for participatory multiagent indoor evacuation simulations. Participatory multiagent simulation combines scenario-guided agents and humans equipped with Google Glass that coexist in a shared virtual space and jointly perform simulations. The paper proposes an architecture for participatory multiagent simulation in order to combine devices (Google Glass and/or smartphones) with an agent-based social simulator and indoor tracking services.

  6. Applications of agent-based simulation for human socio-cultural behavior modeling.

    Science.gov (United States)

    Jiang, Hong; Karwowski, Waldemar; Ahram, Tareq Z

    2012-01-01

    Agent-based modeling and simulation (ABMS) has gained wide attention over the past few years. ABMS is a powerful simulation modeling technique that has a number of applications, including applications to real-world business problems [1]. This modeling technique has been used by scientists to analyze complex system-level behavior by simulating the system from the bottom up. The major application of ABMS includes social, political, biology, and economic sciences. This paper provides an overview of ABMS applications with the emphasis on modeling human socio-cultural behavior (HSCB).

  7. Finding shared decisions in stakeholder networks: An agent-based approach

    Science.gov (United States)

    Le Pira, Michela; Inturri, Giuseppe; Ignaccolo, Matteo; Pluchino, Alessandro; Rapisarda, Andrea

    2017-01-01

    We address the problem of a participatory decision-making process where a shared priority list of alternatives has to be obtained while avoiding inconsistent decisions. An agent-based model (ABM) is proposed to mimic this process in different social networks of stakeholders who interact according to an opinion dynamics model. Simulations' results show the efficacy of interaction in finding a transitive and, above all, shared decision. These findings are in agreement with real participation experiences regarding transport planning decisions and can give useful suggestions on how to plan an effective participation process for sustainable policy-making based on opinion consensus.

  8. Using an Agent-Based Modeling Simulation and Game to Teach Socio-Scientific Topics

    Directory of Open Access Journals (Sweden)

    Lori L. Scarlatos

    2014-02-01

    Full Text Available In our modern world, where science, technology and society are tightly interwoven, it is essential that all students be able to evaluate scientific evidence and make informed decisions. Energy Choices, an agent-based simulation with a multiplayer game interface, was developed as a learning tool that models the interdependencies between the energy choices that are made, growth in local economies, and climate change on a global scale. This paper presents the results of pilot testing Energy Choices in two different settings, using two different modes of delivery.

  9. Diagnosing Learning Disabilities in a Special Education By an Intelligent Agent Based System

    Directory of Open Access Journals (Sweden)

    Khaled Nasser elSayed

    2013-04-01

    Full Text Available The presented paper provides an intelligent agent based classification system for diagnosing and evaluation of learning disabilities with special education students. It provides pedagogy psychology profiles for those students and offer solution strategies with the best educational activities. It provides tools that allow class teachers to discuss psycho functions and basic skills for learning skills, then, performs psycho pedagogy evaluation by comprising a series of strategies in a semantic network knowledge base. The system’s agent performs its classification of student’s disabilities based on its past experience that it got from the exemplars that were classified by expert and acquired in its knowledge base

  10. Agent-Based Framework for Personalized Service Provisioning in Converged IP Networks

    Science.gov (United States)

    Podobnik, Vedran; Matijasevic, Maja; Lovrek, Ignac; Skorin-Kapov, Lea; Desic, Sasa

    In a global multi-service and multi-provider market, the Internet Service Providers will increasingly need to differentiate in the service quality they offer and base their operation on new, consumer-centric business models. In this paper, we propose an agent-based framework for the Business-to-Consumer (B2C) electronic market, comprising the Consumer Agents, Broker Agents and Content Agents, which enable Internet consumers to select a content provider in an automated manner. We also discuss how to dynamically allocate network resources to provide end-to-end Quality of Service (QoS) for a given consumer and content provider.

  11. Integrating Agent-based Programming with Elementary Science: The Role of Sociomathematical Norms

    CERN Document Server

    Dickes, Amanda; Sengupta, Pratim

    2016-01-01

    How can elementary grade teachers integrate programming and computational thinking with the science curriculum? To answer this question, we present results from a long-term, design-based, microgenetic study where 1) agent-based programming using ViMAP was integrated with existing elementary science curricula and 2) lessons were taught by the classroom teacher. We present an investigation of the co-development of children's computational thinking and scientific modeling and show that the integration of programming with scientific modeling can be supported by the development of sociomathematical norms for designing "mathematically good" computational models.

  12. Are psychology university student gamblers representative of non-university students and general gamblers? A comparative analysis.

    Science.gov (United States)

    Gainsbury, Sally M; Russell, Alex; Blaszczynski, Alex

    2014-03-01

    Students recruited from psychology undergraduate university populations are commonly used in psychology research, including gambling studies. However, the extent to which the use of this subpopulation produces findings that can be extrapolated to other groups is questionable. The present study was designed to compare results from university-recruited psychology student gamblers to those obtained from a sample of gamblers recruited from the general population that also included students. An online survey measuring gambling behavior and Internet gambling, attitudes and knowledge about gambling and problem gambling severity was posted on websites accessed by gamblers. Participants were recruited from two sources, a psychology undergraduate university population (n = 461) and online websites (n = 4,801). Results showed university-recruited students differed significantly from both adults and students recruited from the general population in respect to demographic variables and gambling behavior. Psychology undergraduate students were younger, more likely to be female, and had lower incomes. When relevant demographic variables were controlled, psychology undergraduate students were found to gamble less frequently, at different times, and to be at lower-risk for gambling-related problems, but had more irrational beliefs and more negative attitudes towards gambling than gamblers recruited from the general population. Results suggest that caution should be used in extrapolating findings from research using university-recruited psychology student gamblers to wide community populations due to differences related to gambling thoughts, attitudes and behaviors.

  13. Effort-Reward Imbalance and Mental Health Problems in 1074 German Teachers, Compared with Those in the General Population.

    Science.gov (United States)

    Hinz, Andreas; Zenger, Markus; Brähler, Elmar; Spitzer, Silvia; Scheuch, Klaus; Seibt, Reingard

    2016-08-01

    High degrees of premature retirement among teachers warrant investigating the occupational burden and the mental health status of this profession. A sample of 1074 German teachers participated in this study. Two samples of the general population (N = 824 and N = 792) were used as comparison groups. Work distress was assessed with the Effort-Reward-Imbalance questionnaire, and mental health problems were measured with the General Health Questionnaire (GHQ-12). Teachers reported more effort-reward imbalance (M = 0.64) compared with the general population (M = 0.57), and they perceived more mental health problems (GHQ: M = 12.1) than the comparison group (M = 9.5). School type was not associated with work stress and mental health. Teachers with leading functions perceived high degrees of effort and reward, resulting in a moderate effort-reward ratio and no heightened mental health problems. Teachers working full time reported more effort than teachers working part time, but the reward mean values of both groups were similar. This results in a somewhat unfavourable effort-reward ratio of teachers working full time. Moreover, teachers working full time reported more mental health problems. The results support the appropriateness of the effort-reward conception, applied to the profession of teachers. The higher degree of effort-reward imbalance and the level of mental health problems warrant preventive measures. Copyright © 2014 John Wiley & Sons, Ltd.

  14. The demanding attention of tuberculosis in allogeneic hematopoietic stem cell transplantation recipients: High incidence compared with general population

    Science.gov (United States)

    Lee, Hyo-Jin; Lee, Dong-Gun; Choi, Su-Mi; Park, Sun Hee; Cho, Sung-Yeon; Choi, Jae-Ki; Kim, Si-Hyun; Choi, Jung-Hyun; Yoo, Jin-Hong; Cho, Byung-Sik; Eom, Ki-Seong; Lee, Seok; Kim, Yoo-Jin; Kim, Hee-Je; Min, Chang-Ki; Kim, Dong-Wook; Lee, Jong-Wook; Min, Woo-Sung; Jung, Jung Im

    2017-01-01

    Background The risk of developing tuberculosis (TB) in allogeneic hematopoietic stem cell transplantation (HSCT) recipients is expected to be relatively high in an intermediate TB burden country. This single-center retrospective study was conducted to investigate risk factors and the incidence of TB after allogeneic HSCT. Methods From January 2004 to March 2011, 845 adult patients were enrolled. Starting April 2009, patients were given isoniazid (INH) prophylaxis based on interferon-γ release assay results. The incidence of TB was analyzed before and after April 2009, and compared it with that of the general population in Korea. Results TB was diagnosed in 21 (2.49%) of the 845 allogeneic HSCT patients. The median time to the development of TB was 386 days after transplantation (range, 49–886). Compared with the general population, the standardized incidence ratio of TB was 9.10 (95% CI; 5.59–14.79). Extensive chronic graft-versus-host disease (GVHD) was associated with the development of TB (P = 0.003). Acute GVHD, conditioning regimen with total body irradiation and conditioning intensity were not significantly related. INH prophylaxis did not reduce the incidence of TB (P = 0.548). Among 21 TB patients, one patient had INH prophylaxis. Conclusion Allogeneic HSCT recipients especially those who suffer from extensive chronic GVHD are at a high risk of developing TB. INH prophylaxis did not statistically change the incidence of TB, however, further well-designed prospective studies are needed. PMID:28278166

  15. General psychopathology, anxiety, depression and self-esteem in couples undergoing infertility treatment: a comparative study between men and women.

    Science.gov (United States)

    El Kissi, Yousri; Romdhane, Asma Ben; Hidar, Samir; Bannour, Souhail; Ayoubi Idrissi, Khadija; Khairi, Hedi; Ben Hadj Ali, Bechir

    2013-04-01

    To compare measures of psychological distress between men and women undergoing ART in the Unit of Reproductive Medicine "UMR" in the Department of Obstetrics and Gynecology at "Farhat Hached" Hospital in Sousse, Tunisia. We conducted a gender comparative study of psychological profile in infertile couples. Recruitment was done during period from January to May 2009. 100 infertile couples with primary infertility were recruited. Scores of general psychopathology, depression, anxiety and self-esteem were evaluated. We administrated questionnaires on psychological factors among infertile couples before starting a new infertility treatment cycle. Psychological factors included the symptom check-list (SCL-90-R), the hospital anxiety and depression scale (HAD-S) and the Rosenberg self-esteem scale (RSE). Infertile women had higher scores than their spouses in the three global scores of the SCL-90-R and in several items such as somatisation, obsessive symptoms, interpersonal sensitivity and phobias. Scores of HADS were higher among women for both depression and anxiety. Scores of self-esteem were lower among women. Women endorsed higher psychological distress than men across multiple symptoms domains: general psychopathology, anxiety, depression and self esteem. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  16. Modeling the Demand for Family and General Takaful in Malaysia (A Comparative Study: ARDL Approach to Cointegration

    Directory of Open Access Journals (Sweden)

    Weni Hawariyuni

    2012-01-01

    Full Text Available Objective- Nowadays, numerous studies focus on the determinant of the demand for takaful, either family or general takaful in Malaysia. In this respect, these studies employ economic and socio-demographic variables to examine the determinants of takaful. They found that income, interest rates, financial development, pensions, stocks, price of insurance, life expectancy, dependency ratio, education, and age have positive on determinants of takaful. However, previous tudies have found that inflation, savings, and unemployment rate have negative relationship with the determinant of takaful in Malaysia. This study attempts to examine the determinants of the demand for family takaful and general takaful for comparative study in Malaysia for the period of 1988 to 2010. It employs economic and socio-demographic variables to measure these determinants.Methods-Using time series data, this study applies the Autoregressive Distributive Lag (ARDL approach to cointegration to examine the determinants of the demand for family takaful and general takaful in the short and long run.Result-The findings indicate that the economic and socio-demographic variables such as income, and education have positive relationship with the demand for family takaful in the short run, but not in the long run.Conclusion-Meanwhile, it also indicates that income and education have no relationship with demand for general takaful in Malaysia in the short run and long run. It indicates that if there is an increase in income, people tend to buy more family takaful of STMB. At the same time, the educated people already aware of the takaful products, they may necessarily purchase family takaful than life insurance.

  17. The Canadian Systemic Sclerosis Oral Health Study IV: oral radiographic manifestations in systemic sclerosis compared with the general population

    Science.gov (United States)

    Dagenais, Marie; MacDonald, David; Baron, Murray; Hudson, Marie; Tatibouet, Solène; Steele, Russell; Gravel, Sabrina; Mohit, Shrisha; Sayegh, Tarek El; Pope, Janet; Fontaine, Audrey; Masseto, Ariel; Matthews, Debora; Sutton, Evelyn; Thie, Norman; Jones, Niall; Copete, Maria; Kolbinson, Dean; Markland, Janet; Nogueira-Filho, Getulio; Robinson, David; Gornitsky, Mervyn

    2015-01-01

    Objective The aim of this study was to compare oral radiologic abnormalities associated with systemic sclerosis (SSc) against abnormalities in the general population. Study Design Patients with SSc and healthy controls were enrolled in a multi-site cross-sectional study. Included in the radiology examination were a panoramic radiograph, four bitewings, and an anterior mandibular periapical radiograph. Radiographs were evaluated by two oral and maxillofacial radiologists tested for interobserver and intraobserver reliability. Chi-squared tests, Fisher exact tests, and Mann Whitney U tests were used to summarize the radiologic manifestations of patients and controls. Results We assessed 163 SSc patients and 231 controls. Widening of the periodontal ligament space (PLS) (P < .001), with higher percentage of teeth with PLS widening (P < .001), was significantly more frequent in patients with SSc than in controls. The most significant differences between the two groups were found in the molars and premolars (P < .001). Moreover, 26% of the patients with SSc had a periapical PLS greater than 0.19 mm compared with 13% of the controls (P = .003). Patients with SSc had significantly more erosions compared with controls (14.5% vs. 3.6%; P < .001), mostly in the condyles (P = .022), coronoid processes (P = .005) and other locations (P = .012). Conclusion Patients with SSc had more teeth with PLS widening and erosions of the mandible compared with controls. PMID:25959972

  18. Assortative Mating and the Reversal of Gender Inequality in Education in Europe: An Agent-Based Model: e0127806

    National Research Council Canada - National Science Library

    André Grow; Jan Van Bavel

    2015-01-01

    .... We develop an agent-based computational model that explicates the mechanisms that may have linked the reversal of gender inequality in education with observed changes in educational assortative mating...

  19. Assortative mating and the reversal of gender inequality in education in europe: an agent-based model

    National Research Council Canada - National Science Library

    Grow, André; Van Bavel, Jan

    2015-01-01

    .... We develop an agent-based computational model that explicates the mechanisms that may have linked the reversal of gender inequality in education with observed changes in educational assortative mating...

  20. Analysis of Interactions of Key Stakeholders on B2C e-Markets - Agent Based Modelling and Simulation Approach

    National Research Council Canada - National Science Library

    Aleksandar Marković; Sava Čavoški; Andrej Novović

    2016-01-01

    Background/purpose: This paper discusses the application of ABMS - agent-based modelling and simulation in the analysis of customer behaviour on B2C e-commerce websites as well as in the analysis of various business...

  1. Encouraging Sustainable Transport Choices in American Households: Results from an Empirically Grounded Agent-Based Model

    Directory of Open Access Journals (Sweden)

    Davide Natalini

    2013-12-01

    Full Text Available The transport sector needs to go through an extended process of decarbonisation to counter the threat of climate change. Unfortunately, the International Energy Agency forecasts an enormous growth in the number of cars and greenhouse gas emissions by 2050. Two issues can thus be identified: (1 the need for a new methodology that could evaluate the policy performances ex-ante and (2 the need for more effective policies. To help address these issues, we developed an Agent-Based Model called Mobility USA aimed at: (1 testing whether this could be an effective approach in analysing ex-ante policy implementation in the transport sector; and (2 evaluating the effects of alternative policy scenarios on commuting behaviours in the USA. Particularly, we tested the effects of two sets of policies, namely market-based and preference-change ones. The model results suggest that this type of agent-based approach will provide a useful tool for testing policy interventions and their effectiveness.

  2. Hierarchical Agent-Based Integrated Modelling Approach for Microgrids with Adoption of EVs and HRES

    Directory of Open Access Journals (Sweden)

    Peng Han

    2014-01-01

    Full Text Available The large adoption of electric vehicles (EVs, hybrid renewable energy systems (HRESs, and the increasing of the loads shall bring significant challenges to the microgrid. The methodology to model microgrid with high EVs and HRESs penetrations is the key to EVs adoption assessment and optimized HRESs deployment. However, considering the complex interactions of the microgrid containing massive EVs and HRESs, any previous single modelling approaches are insufficient. Therefore in this paper, the methodology named Hierarchical Agent-based Integrated Modelling Approach (HAIMA is proposed. With the effective integration of the agent-based modelling with other advanced modelling approaches, the proposed approach theoretically contributes to a new microgrid model hierarchically constituted by microgrid management layer, component layer, and event layer. Then the HAIMA further links the key parameters and interconnects them to achieve the interactions of the whole model. Furthermore, HAIMA practically contributes to a comprehensive microgrid operation system, through which the assessment of the proposed model and the impact of the EVs adoption are achieved. Simulations show that the proposed HAIMA methodology will be beneficial for the microgrid study and EV’s operation assessment and shall be further utilized for the energy management, electricity consumption prediction, the EV scheduling control, and HRES deployment optimization.

  3. Simulating the elimination of sleeping sickness with an agent-based model

    Directory of Open Access Journals (Sweden)

    Grébaut Pascal

    2016-01-01

    Full Text Available Although Human African Trypanosomiasis is largely considered to be in the process of extinction today, the persistence of human and animal reservoirs, as well as the vector, necessitates a laborious elimination process. In this context, modeling could be an effective tool to evaluate the ability of different public health interventions to control the disease. Using the Cormas® system, we developed HATSim, an agent-based model capable of simulating the possible endemic evolutions of sleeping sickness and the ability of National Control Programs to eliminate the disease. This model takes into account the analysis of epidemiological, entomological, and ecological data from field studies conducted during the last decade, making it possible to predict the evolution of the disease within this area over a 5-year span. In this article, we first present HATSim according to the Overview, Design concepts, and Details (ODD protocol that is classically used to describe agent-based models, then, in a second part, we present predictive results concerning the evolution of Human African Trypanosomiasis in the village of Lambi (Cameroon, in order to illustrate the interest of such a tool. Our results are consistent with what was observed in the field by the Cameroonian National Control Program (CNCP. Our simulations also revealed that regular screening can be sufficient, although vector control applied to all areas with human activities could be significantly more efficient. Our results indicate that the current model can already help decision-makers in planning the elimination of the disease in foci.

  4. Introducing spatial information into predictive NF-kappaB modelling--an agent-based approach.

    Directory of Open Access Journals (Sweden)

    Mark Pogson

    Full Text Available Nature is governed by local interactions among lower-level sub-units, whether at the cell, organ, organism, or colony level. Adaptive system behaviour emerges via these interactions, which integrate the activity of the sub-units. To understand the system level it is necessary to understand the underlying local interactions. Successful models of local interactions at different levels of biological organisation, including epithelial tissue and ant colonies, have demonstrated the benefits of such 'agent-based' modelling. Here we present an agent-based approach to modelling a crucial biological system--the intracellular NF-kappaB signalling pathway. The pathway is vital to immune response regulation, and is fundamental to basic survival in a range of species. Alterations in pathway regulation underlie a variety of diseases, including atherosclerosis and arthritis. Our modelling of individual molecules, receptors and genes provides a more comprehensive outline of regulatory network mechanisms than previously possible with equation-based approaches. The method also permits consideration of structural parameters in pathway regulation; here we predict that inhibition of NF-kappaB is directly affected by actin filaments of the cytoskeleton sequestering excess inhibitors, therefore regulating steady-state and feedback behaviour.

  5. Agent-based financial dynamics model from stochastic interacting epidemic system and complexity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yunfan, E-mail: yunfanlu@yeah.net; Wang, Jun; Niu, Hongli

    2015-06-12

    An agent-based financial stock price model is developed and investigated by a stochastic interacting epidemic system, which is one of the statistical physics systems and has been used to model the spread of an epidemic or a forest fire. Numerical and statistical analysis are performed on the simulated returns of the proposed financial model. Complexity properties of the financial time series are explored by calculating the correlation dimension and using the modified multiscale entropy method. In order to verify the rationality of the financial model, the real stock market indexes, Shanghai Composite Index and Shenzhen Component Index, are studied in comparison with the simulation data of the proposed model for the different infectiousness parameters. The empirical research reveals that this financial model can reproduce some important features of the real stock markets. - Highlights: • A new agent-based financial price model is developed by stochastic interacting epidemic system. • The structure of the proposed model allows to simulate the financial dynamics. • Correlation dimension and MMSE are applied to complexity analysis of financial time series. • Empirical results show the rationality of the proposed financial model.

  6. Reaching unanimous agreements within agent-based negotiation teams with linear and monotonic utility functions.

    Science.gov (United States)

    Sanchez-Anguix, Victor; Julian, Vicente; Botti, Vicente; García-Fornes, Ana

    2012-06-01

    In this article, an agent-based negotiation model for negotiation teams that negotiate a deal with an opponent is presented. Agent-based negotiation teams are groups of agents that join together as a single negotiation party because they share an interest that is related to the negotiation process. The model relies on a trusted mediator that coordinates and helps team members in the decisions that they have to take during the negotiation process: which offer is sent to the opponent, and whether the offers received from the opponent are accepted. The main strength of the proposed negotiation model is the fact that it guarantees unanimity within team decisions since decisions report a utility to team members that is greater than or equal to their aspiration levels at each negotiation round. This work analyzes how unanimous decisions are taken within the team and the robustness of the model against different types of manipulations. An empirical evaluation is also performed to study the impact of the different parameters of the model.

  7. Group-wise herding behavior in financial markets: an agent-based modeling approach.

    Science.gov (United States)

    Kim, Minsung; Kim, Minki

    2014-01-01

    In this paper, we shed light on the dynamic characteristics of rational group behaviors and the relationship between monetary policy and economic units in the financial market by using an agent-based model (ABM), the Hurst exponent, and the Shannon entropy. First, an agent-based model is used to analyze the characteristics of the group behaviors at different levels of irrationality. Second, the Hurst exponent is applied to analyze the characteristics of the trend-following irrationality group. Third, the Shannon entropy is used to analyze the randomness and unpredictability of group behavior. We show that in a system that focuses on macro-monetary policy, steep fluctuations occur, meaning that the medium-level irrationality group has the highest Hurst exponent and Shannon entropy among all of the groups. However, in a system that focuses on micro-monetary policy, all group behaviors follow a stable trend, and the medium irrationality group thus remains stable, too. Likewise, in a system that focuses on both micro- and macro-monetary policies, all groups tend to be stable. Consequently, we find that group behavior varies across economic units at each irrationality level for micro- and macro-monetary policy in the financial market. Together, these findings offer key insights into monetary policy.

  8. Mapping Cyclists’ Experiences and Agent-Based Modelling of Their Wayfinding Behaviour

    DEFF Research Database (Denmark)

    Snizek, Bernhard

    This dissertation is about modelling cycling transport behaviour. It is partly about urban experiences seen by the cyclist and about modelling, more specifically the agent-based modelling of cyclists' wayfinding behaviour. The dissertation consists of three papers. The first deals with the develo......This dissertation is about modelling cycling transport behaviour. It is partly about urban experiences seen by the cyclist and about modelling, more specifically the agent-based modelling of cyclists' wayfinding behaviour. The dissertation consists of three papers. The first deals......-based model of cycling transport behaviour using geodata, data from the Danish travel survey as well as behavioural data extracted from trajectories recorded utilising GPS units. Mapping Bicyclists’ Experiences in Copenhagen This paper presents an approach to the collection, mapping and analysing of cyclists......’ experiences. By relating spatial experiences to urban indicators such as land-use, street characteristics, cycle infrastructure, centrality and other aspects of the urban environment, their influence on cyclists’ experiences were analysed. 398 cyclists responded and plotted their most recent cycle route...

  9. An Agent-Based Model of Farmer Decision Making in Jordan

    Science.gov (United States)

    Selby, Philip; Medellin-Azuara, Josue; Harou, Julien; Klassert, Christian; Yoon, Jim

    2016-04-01

    We describe an agent based hydro-economic model of groundwater irrigated agriculture in the Jordan Highlands. The model employs a Multi-Agent-Simulation (MAS) framework and is designed to evaluate direct and indirect outcomes of climate change scenarios and policy interventions on farmer decision making, including annual land use, groundwater use for irrigation, and water sales to a water tanker market. Land use and water use decisions are simulated for groups of farms grouped by location and their behavioural and economic similarities. Decreasing groundwater levels, and the associated increase in pumping costs, are important drivers for change within Jordan'S agricultural sector. We describe how this is considered by coupling of agricultural and groundwater models. The agricultural production model employs Positive Mathematical Programming (PMP), a method for calibrating agricultural production functions to observed planted areas. PMP has successfully been used with disaggregate models for policy analysis. We adapt the PMP approach to allow explicit evaluation of the impact of pumping costs, groundwater purchase fees and a water tanker market. The work demonstrates the applicability of agent-based agricultural decision making assessment in the Jordan Highlands and its integration with agricultural model calibration methods. The proposed approach is designed and implemented with software such that it could be used to evaluate a variety of physical and human influences on decision making in agricultural water management.

  10. Walk This Way: Improving Pedestrian Agent-Based Models through Scene Activity Analysis

    Directory of Open Access Journals (Sweden)

    Andrew Crooks

    2015-09-01

    Full Text Available Pedestrian movement is woven into the fabric of urban regions. With more people living in cities than ever before, there is an increased need to understand and model how pedestrians utilize and move through space for a variety of applications, ranging from urban planning and architecture to security. Pedestrian modeling has been traditionally faced with the challenge of collecting data to calibrate and validate such models of pedestrian movement. With the increased availability of mobility datasets from video surveillance and enhanced geolocation capabilities in consumer mobile devices we are now presented with the opportunity to change the way we build pedestrian models. Within this paper we explore the potential that such information offers for the improvement of agent-based pedestrian models. We introduce a Scene- and Activity-Aware Agent-Based Model (SA2-ABM, a method for harvesting scene activity information in the form of spatiotemporal trajectories, and incorporate this information into our models. In order to assess and evaluate the improvement offered by such information, we carry out a range of experiments using real-world datasets. We demonstrate that the use of real scene information allows us to better inform our model and enhance its predictive capabilities.

  11. Agent Based Fuzzy T-S Multi-Model System and Its Applications

    Directory of Open Access Journals (Sweden)

    Xiaopeng Zhao

    2015-11-01

    Full Text Available Based on the basic concepts of agent and fuzzy T-S model, an agent based fuzzy T-S multi-model (ABFT-SMM system is proposed in this paper. Different from the traditional method, the parameters and the membership value of the agent can be adjusted along with the process. In this system, each agent can be described as a dynamic equation, which can be seen as the local part of the multi-model, and it can execute the task alone or collaborate with other agents to accomplish a fixed goal. It is proved in this paper that the agent based fuzzy T-S multi-model system can approximate any linear or nonlinear system at arbitrary accuracy. The applications to the benchmark problem of chaotic time series prediction, water heater system and waste heat utilizing process illustrate the viability and the efficiency of the mentioned approach. At the same time, the method can be easily used to a number of engineering fields, including identification, nonlinear control, fault diagnostics and performance analysis.

  12. iCrowd: agent-based behavior modeling and crowd simulator

    Science.gov (United States)

    Kountouriotis, Vassilios I.; Paterakis, Manolis; Thomopoulos, Stelios C. A.

    2016-05-01

    Initially designed in the context of the TASS (Total Airport Security System) FP-7 project, the Crowd Simulation platform developed by the Integrated Systems Lab of the Institute of Informatics and Telecommunications at N.C.S.R. Demokritos, has evolved into a complete domain-independent agent-based behavior simulator with an emphasis on crowd behavior and building evacuation simulation. Under continuous development, it reflects an effort to implement a modern, multithreaded, data-oriented simulation engine employing latest state-of-the-art programming technologies and paradigms. It is based on an extensible architecture that separates core services from the individual layers of agent behavior, offering a concrete simulation kernel designed for high-performance and stability. Its primary goal is to deliver an abstract platform to facilitate implementation of several Agent-Based Simulation solutions with applicability in several domains of knowledge, such as: (i) Crowd behavior simulation during [in/out] door evacuation. (ii) Non-Player Character AI for Game-oriented applications and Gamification activities. (iii) Vessel traffic modeling and simulation for Maritime Security and Surveillance applications. (iv) Urban and Highway Traffic and Transportation Simulations. (v) Social Behavior Simulation and Modeling.

  13. Multiple Servers - Queue Model for Agent Based Technology in Cache Consistence Maintenance of Mobile Environment

    Directory of Open Access Journals (Sweden)

    G.Shanmugarathinam

    2013-01-01

    Full Text Available Caching is one of the important techniques in mobile computing. In caching, frequently accessed data is stored in mobile clients to avoid network traffic and improve the performance in mobile computing. In a mobile computing environment, the number of mobile users increases and requests the server for any updation, but most of the time the server is busy and the client has to wait for a long time. The cache consistency maintenance is difficult for both client and the server. This paper is proposes a technique using a queuing system consisting of one or more servers that provide services of some sort to arrive mobile hosts using agent based technology. This services mechanism of a queuing system is specified by the number of servers each server having its own queue, Agent based technology will maintain the cache consistency between the client and the server .This model saves wireless bandwidth, reduces network traffic and reduces the workload on the server. The simulation result was analyzed with previous technique and the proposed model shows significantly better performance than the earlier approach.

  14. An agent-based analysis of the German electricity market with transmission capacity constraints

    Energy Technology Data Exchange (ETDEWEB)

    Veit, Daniel J.; Weidlich, Anke; Krafft, Jacob A. [University of Mannheim, Dieter Schwarz Chair of Business Administration, E-Business and E-Government, 68131 Mannheim (Germany)

    2009-10-15

    While some agent-based models have been developed for analyzing the German electricity market, there has been little research done on the emerging issue of intra-German congestion and its effects on the bidding behavior of generator agents. Yet, studies of other markets have shown that transmission grid constraints considerably affect strategic behavior in electricity markets. In this paper, the implications of transmission constraints on power markets are analyzed for the case of Germany. Market splitting is applied in the case of congestion in the grid. For this purpose, the agent-based modeling of electricity systems (AMES) market package developed by Sun and Tesfatsion is modified to fit the German context, including a detailed representation of the German high-voltage grid and its interconnections. Implications of transmission constraints on prices and social welfare are analyzed for scenarios that include strategic behavior of market participants and high wind power generation. It can be shown that strategic behavior and transmission constraints are inter-related and may pose severe problems in the future German electricity market. (author)

  15. Interbank Lending Decisions in An Economic Downturn: An Agent-Based Approach

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    Deddy P. Koesrindartoto

    2012-01-01

    Full Text Available Interbank lending is one mechanism that can make shock, which is accepted by one bank spread to other banks (contagion. There are several researchers that focused their research on analyzing the effect of interbank lending to systemic risk. However, there is a few research that analyzed the effect of banks’ decision maker’s behavior, especially on the bank interbank lending to the systemic risk. In this research, the author creates an agent-based  simulation of the banking system to analyze the effect of banks’ decision maker’s behavior to systemic risk in economic downturn condition. The preliminary result from this research is for an economic downturn in a long time period, the banking system with a low net worth to the asset's ratio threshold will produce more default bank than the banking system with a high net worth to the asset's ratio threshold. However, for an economic downturn in small time period, banking system which all bank in their system has the higher net worth to assets ratio threshold will have the default bank first than the banking system which has the lower net worth to the asset's ratio threshold. Keywords: agent-based simulation, banker behavior, interbank lending, economic downturn

  16. Uses of Agent-Based Modeling for Health Communication: the TELL ME Case Study.

    Science.gov (United States)

    Barbrook-Johnson, Peter; Badham, Jennifer; Gilbert, Nigel

    2017-08-01

    Government communication is an important management tool during a public health crisis, but understanding its impact is difficult. Strategies may be adjusted in reaction to developments on the ground and it is challenging to evaluate the impact of communication separately from other crisis management activities. Agent-based modeling is a well-established research tool in social science to respond to similar challenges. However, there have been few such models in public health. We use the example of the TELL ME agent-based model to consider ways in which a non-predictive policy model can assist policy makers. This model concerns individuals' protective behaviors in response to an epidemic, and the communication that influences such behavior. Drawing on findings from stakeholder workshops and the results of the model itself, we suggest such a model can be useful: (i) as a teaching tool, (ii) to test theory, and (iii) to inform data collection. We also plot a path for development of similar models that could assist with communication planning for epidemics.

  17. An agent-based epidemic simulation of social behaviors affecting HIV transmission among Taiwanese homosexuals.

    Science.gov (United States)

    Huang, Chung-Yuan

    2015-01-01

    Computational simulations are currently used to identify epidemic dynamics, to test potential prevention and intervention strategies, and to study the effects of social behaviors on HIV transmission. The author describes an agent-based epidemic simulation model of a network of individuals who participate in high-risk sexual practices, using number of partners, condom usage, and relationship length to distinguish between high- and low-risk populations. Two new concepts-free links and fixed links-are used to indicate tendencies among individuals who either have large numbers of short-term partners or stay in long-term monogamous relationships. An attempt was made to reproduce epidemic curves of reported HIV cases among male homosexuals in Taiwan prior to using the agent-based model to determine the effects of various policies on epidemic dynamics. Results suggest that when suitable adjustments are made based on available social survey statistics, the model accurately simulates real-world behaviors on a large scale.

  18. Simulating the elimination of sleeping sickness with an agent-based model

    Science.gov (United States)

    Grébaut, Pascal; Girardin, Killian; Fédérico, Valentine; Bousquet, François

    2016-01-01

    Although Human African Trypanosomiasis is largely considered to be in the process of extinction today, the persistence of human and animal reservoirs, as well as the vector, necessitates a laborious elimination process. In this context, modeling could be an effective tool to evaluate the ability of different public health interventions to control the disease. Using the Cormas® system, we developed HATSim, an agent-based model capable of simulating the possible endemic evolutions of sleeping sickness and the ability of National Control Programs to eliminate the disease. This model takes into account the analysis of epidemiological, entomological, and ecological data from field studies conducted during the last decade, making it possible to predict the evolution of the disease within this area over a 5-year span. In this article, we first present HATSim according to the Overview, Design concepts, and Details (ODD) protocol that is classically used to describe agent-based models, then, in a second part, we present predictive results concerning the evolution of Human African Trypanosomiasis in the village of Lambi (Cameroon), in order to illustrate the interest of such a tool. Our results are consistent with what was observed in the field by the Cameroonian National Control Program (CNCP). Our simulations also revealed that regular screening can be sufficient, although vector control applied to all areas with human activities could be significantly more efficient. Our results indicate that the current model can already help decision-makers in planning the elimination of the disease in foci. PMID:28008825

  19. Application of Biometric Security in Agent based Hotel Booking System - Android Environment

    Directory of Open Access Journals (Sweden)

    Wayne Lawrence

    2012-07-01

    Full Text Available Abstract — The process of finding the finest hotel in central location is time consuming, information overload and overwhelming and in some cases poses a security risk to the client. Some of the more advanced web sites allow for a search of the destination via a map for example hotelguidge.com and jamaica.hotels.hu. Booking of hotels is secured by the standard Secure Sockets Layer (SSL to confirm the identity of a website or server, encrypt data during transmission, and ensure the integrity of transmitted data. Even with this in place, hackers have broken the Secure Sockets Layer (SSL by targeting weaknesses in the MD5 algorithm.Recently good amount of work been carried in the use of Intelligent agents towards hotel search on J2ME based mobile handset which still has some weakness. So taking the weakness in the current agent based system, smart software agents been developed that overcomes the weakness in the previous system In addition to smart agent based system been developed and published elsewhere, we here propose to extend the system with the booking capability that allows the user to book a hotel of choice where the authenticity of the client may be determined securely using biometric security and information transmitted using Secure Sockets Layer (SSL (Server-Gated Cryptography (SGC on the internet which is novel and unique. This will be facilitated on Android 2.2-enabled mobile phone using JADE-LEAP Agent development kit.

  20. An Agent Based Intrusion Detection Model for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    B. M. Reshmi

    2006-01-01

    Full Text Available Intrusion detection has over the last few years, assumed paramount importance within the broad realm of network security, more so in case of wireless mobile ad hoc networks. The inherently vulnerable characteristics of wireless mobile ad hoc networks make them susceptible to attacks in-spite of some security measures, and it may be too late before any counter action can take effect. As such, there is a need to complement traditional security mechanisms with efficient intrusion detection and response systems. This paper proposes an agent-based model to address the aspect of intrusion detection in cluster based mobile wireless ad hoc network environment. The model comprises of a set of static and mobile agents, which are used to detect intrusions, respond to intrusions, and distribute selected and aggregated intrusion information to all other nodes in the network in an intelligent manner. The model is simulated to test its operation effectiveness by considering the performance parameters such as, detection rate, false positives, agent overheads, and intrusion information distribution time. Agent based approach facilitates flexible and adaptable security services. Also, it supports component based software engineering components such as maintainability, reachability, reusability, adaptability, flexibility, and customization.