A Survey of Agent-Based Modeling Practices (January 1998 to July 2008)

In the 1990s, Agent-Based Modeling (ABM) began gaining popularity and represents a departure from the more classical simulation approaches. This departure, its recent development and its increasing application by non-traditional simulation disciplines indicates the need to continuously assess the current state of ABM and identify opportunities for improvement. To begin to satisfy this need, we surveyed and collected data from 279 articles from 92 unique publication outlets in which the authors had constructed and analyzed an agent-based model. From this large data set we establish the current practice of ABM in terms of year of publication, field of study, simulation software used, purpose of the simulation, acceptable validation criteria, validation techniques and complete description of the simulation. Based on the current practice we discuss six improvements needed to advance ABM as an analysis tool. These improvements include the development of ABM specific tools that are independent of software, the development of ABM as an independent discipline with a common language that extends across domains, the establishment of expectations for ABM that match their intended purposes, the requirement of complete descriptions of the simulation so others can independently replicate the results, the requirement that all models be completely validated and the development and application of statistical and non-statistical validation techniques specifically for ABM.Agent-Based Modeling, Survey, Current Practices, Simulation Validation, Simulation Purpose

Assessing the socio-economic benefits from green and blue space rehabilitation: a case study for the Confluence area in Lyon

This paper aims to demonstrate the added socio-economic value of green/blue spaces inurban areas. The Sustainable Urban Landscape Development (SULD) hedonic pricingsimulation model is applied to the case-study of Confluence in Lyon, France. Scenariosimulations are performed for the establishment of urban parks, along with the requalificationof riverfronts and development of road infrastructure. Results show that the first twointerventions (parks and parks plus requalification) attract high-income households and,hence, lead to increases in real estate values up to +28%. The latter intervention (parks plusnew road infrastructure) also attracts low-income households, which leads to a smallerincrease in real estate values. SULD aids in improving urban planning strategies, in terms ofdrafting plans, public discussion and monitoring

Illustrating a new 'conceptual design pattern' for agent-based models of land use via five case studies—the MR POTATOHEAD framework

This chapter presents a "conceptual design pattern" (CDP) that represents key elements of standard ABM/LUCC models in a comprehensive logical framework and includes basic functionality and data often present in ABM/LUCC models. The CDP illustrates the key building blocks for ABM/LUCC models, creating a template to assist scholars new to the field to understand existing models and design their own models. Second, the framework facilitates direct comparison of the structure and function of existing models. We present five separately developed models within this framework (SLUDGE, SOME, FEARLUS, LUCITA, and SYPRIA), demonstrating how multiple models can be represented and compared within the same meta-structure. The exercise highlights elements common to all models, demonstrates the unique contributions of each model, reveals commonalities between models, and highlights processes associated with land-use change that are not covered by our models. The CDP as presented here is very much a work in progress, and we welcome feedback from other ABM/LUCC developers, in the hopes of ultimately developing a shared model representation that will accelerate the development of not only ABM/LUCC, but also the theory of land-use change

The Guadaira Greenbelt (Seville): analysis and evaluation of a peri-urban rehabilitation proposal

El Guadaíra es un río que en su curso bajo ha experimentado diversas transformaciones, desde las intervenciones históricas en el río para la instalación de molinos de agua hasta las realizadas en el cauce desde principios del siglo xx para mitigar las inundaciones en la ciudad de Sevilla. Se realiza un análisis crítico y valoración de la Propuesta de Actuación denominada Anillo Verde del Guadaíra para la recuperación del espacio periurbano marginal vinculado a la última transformación encauzamiento del río en 1977. Se analiza y valora el alcance ecológico y social de esta propuesta a través de un análisis DAFO, con un objetivo claramente socio-ambiental que busca la sostenibilidad del área de intervención, que es analizada y discutida con otras experiencias nacionales e internacionales. En las conclusiones se destacan los errores relativos a las especies relacionadas con las formaciones vegetales de ribera mediterráneas, que es una de las debilidades más importantes de la propuesta. Se concluye que se adapta a los objetivos de la ENRR, pero no se adapta a los patrones académicos en base a la investigación en restauración de ríos y riberasThe river Guadaira in its lower course has undergone various transformations, from historical interventions for the installation of water mills, to those made in the riverbed since the beginning of the 20th century to mitigate floods in the city of Seville. A critical analysis and assessment is made of proposed ‘Guadaira Greenbelt’ for the recovery of the marginal peri-urban space linked to the most recent transformation of the river in 1977. The ecological and social scope of this proposal is analysed and evaluated in a SWOT analysis, with a clearly socio-environmental objective that seeks the sustainability of the area, which is discussed in comparison other national and international experiences. The conclusions highlight the errors related to the Mediterranean riparian plant formations, which is one of the most important weaknesses of the proposal. The research concludes that the proposal meets the objectives of the ENRR, but does not adapt to the academic patterns on research on river and river restoratio

A new tool for Epidemiology? The usefulness of dynamic agent models in understanding place effects on health

major focus of recent work on the spatial patterning of health has been the study of how features of residential environments or neighborhoods may affect health. Place effects on health emerge from complex interdependent processes in which individuals interact with each other and their environment and in which both individuals and environments adapt and change over time. Traditional epidemiologic study designs and statistical regression approaches are unable to examine these dynamic processes. These limitations have constrained the types of questions asked, the answers received, and the hypotheses and theoretical explanations that are developed. Agent-based models and other systems-dynamics models may help to address some of these challenges. Agent-based models are computer representations of systems consisting of heterogeneous microentities that can interact and change/adapt over time in response to other agents and features of the environment. Using these models, one can observe how macroscale dynamics emerge from microscale interactions and adaptations. A number of challenges and limitations exist for agent-based modeling. Nevertheless, use of these dynamic models may complement traditional epidemiologic analyses and yield additional insights into the processes involved and the interventions that may be most useful.http://deepblue.lib.umich.edu/bitstream/2027.42/60335/1/A new tool for Epdiemiology The usefulness of dynamic agent models in understanding place effects on health.pd

Modelling Urban Growth: Towards an Agent Based Microeconomic Approach to Urban Dynamics and Spatial Policy Simulation

Urban growth, urban sprawl if uncoordinated and dispersed, can be considered one of the most important policy agendas in modern urban regions. While no single policy option or remedy exists, understanding the urban growth system is the first step towards sustainable urban growth futures. Spatially explicit and dynamic urban growth models provide valuable simulations that encapsulate essential knowledge in planning and policy making such as how and where urban growth can occur and what the driving forces of such changes are. Over the past two decades, cellular automata (CA) models have proven to be an effective modelling approach to the study of complex urban growth systems. More recently Agent Based Modelling (ABM) has developed to yield a useful framework for understanding complex urban systems and this provides an arena for exploring the possible outcome states of various policy actions. Yet most research efforts of this sort adopt physical and heuristic approaches which tend to neglect socio-economic dynamics which is critical in shaping urban form and its transformation. This thesis aims to develop an agent based urban simulation model which has a more rigid theoretical explanation of agent behaviour than most such models hitherto. However, before developing such an agent based model, this study first conducted a series of experimental simulations with two well-known generic CA based urban models, SLEUTH and Metronamica, in order to better understand the complexity of designing and applying this class of urban models. Although CA and ABM are two distinctive modelling approaches, they share certain fundamentals concerning the complexity of systems and thus the empirical simulations with widely used CA models provide useful insights for the development of a new dedicated agent based urban growth model. For this purpose, each CA model is calibrated to the study area of the Seoul Metropolitan Area, Korea. The research then moves towards developing an agent based model based on microeconomic foundations. Utility maximising residential location choices made by households are modelled as the main impetus for urban growth through agglomeration and sprawl. Furthermore, based on such urban dynamics, alternative planning policy options such as greenbelts and public transportation are simulated so that their impacts can be clarified and assessed. In this way, the model is also able to examine how planning policies alter the economic utility of households and redirect market-led urban development. These results confirm the unique value of such modelling approaches. Yet, new research challenges such as the estimation of model parameters and the use of such models in planning support continue to dominate this field and in conclusion, we identify future research directions which build on these challenge

Agent-based modelling – a new method for investigating environmental problems

The agent-based modelling (ABM) represents a newly emerged domain with multiple applications. They started to develop in late 1940’s and they reached maturity in 2000’s – 2010’s. Nowadays, more and more studies are being made using ABM, proving that they are a powerful tool in exploring patterns, interactions and behaviours. As their name suggest, they rely on agents. There is still no formal definition for agents, but they are considered to be autonomous entities, capable of having a certain behaviour and to interact with other agents and/or with the environment they belong to. The environment, the agents and the interactions established form the ABM. Even though this type of models has evolved from mathematics, thanks to computer development, and especially computer graphics, they now offer the possibility to visually explore certain behaviours and to identify a pattern. Also, of great importance and contributing directly to the ABMs application expansion, is the development of a variety of toolkits used for designing agent-based models. Many of the toolkits are open source and continuously implement more simplified programming language. These are the main reasons for which ABMs are used nowadays in a very wide range of domains – from ecology to healthcare and medicine, from archaeology to stock markets, from combats and air traffic control to emergency situations, from social and natural sciences to robotics

Lean Six Sigma in Action : Problems and prospects of expansive learning in an international aircraft

Objectives. This research addressed the problems and prospects of Lean Six Sigma (LSS), one of the world's most popular organizational development methods at present. The study enriched this method by suggesting a more sustainable way of organizational development. The previous research on LSS mainly focused on the technical tools in utilizing the production process. Drawing on the theory of Expansive Learning, this research evaluated the learning process of LSS by focusing on the practitioners. The purpose of the research was twofold. First, it analyzed the contradictions of LSS project activity in the research site. It was expected to uncover the problems that jeopardized the learning process of the practitioners. Second, it discussed the zone of proximal development (ZPD) of LSS project activity for the research site, with the purpose of shedding light on the possibilities of future development and learning. Methods. The research site was an international aircraft manufacturer in China. Eleven LSS practitioners were interviewed, including eight Green Belts, one Black Belt, one Master Black Belt and one Green Belt team member. The data were analyzed by adopting three methods: the analysis of conceptions, the Analysis of discursive manifestations of contradictions, and the analysis of action-activity transformation in expansive learning. The ZPD was sketched from two dimensions: the first one by analyzing the action-activity transformation of the practitioners; the second one by evaluating the conception of "what have expanded" in the practitioners due to the project experiences. Results and conclusions. The analysis uncovered eight contradictions in LSS project activity system. Five were scattered in the project activity itself between or within varied elements of activity. Three were between the project activity, the department-based work activity and the LSS training activity. One case in which the GB's trials in breaking the constraints in his own project resulted in collective expansive learning efforts cross projects was analyzed as the representation of action-activity transformation. In addition, some practitioners had re-conceptualized their work motivation through the project experience, seeing Lean Six Sigma as a conceptual tool for understanding strategic work planning and gaining long-term work motivation. In conclusion, two dimensions of the ZPD were suggested: first, an integrated top-down and bottom-up approaches for organizational transformation; second, transcending from LSS as the "concrete tool in individual skill appropriation" to the "conceptual tool in collective work reconceptualization". The organizations adopting the LSS method can reflect on this thesis to improve their LSS practices by paying attention to the "critical transition agent" for cross-functional processes' interaction, the employees' learning initiatives and work motivation