Suchergebnisse

"Agent-Based Modelling ist der zurzeit gängige Ansatz zur computergestützten Theoriebildung in den Sozialwissenschaften. Seine Wurzeln liegen in verschiedenen sozialwissenschaftlichen Simulationsverfahren der letzten fünf oder sechs Jahrzehnte und in der Forschung zur Künstlichen Intelligenz. Unter agentenbasierter Simulation versteht man die Benutzung eines aus vielen autonomen Software-Objekten (Agenten) bestehenden formalen Modells zum Verständnis, zur Vorhersage oder zur Veranschaulichung von Prozessen, die in der realen Welt zwischen menschlichen Individuen auf Mikro-, Meso- oder Makroebene ablaufen. Das Modell bildet wesentliche Züge des modellierten Weltausschnitts ab, unterschiedliche Anfangsbedingungen und Parameter bringen im Allgemeinen qualitativ oder mindestens quantitativ verschiedene Prozessverläufe hervor. In den Sozialwissenschaften, die sich mit besonders komplexen Systemen beschäftigen, in denen große Zahlen von Komponenten einander in höchst vielfältiger Weise beeinflussen, wird die Methode vielfältig genutzt, um aus Annahmen über Verhalten und Handlungsbedingungen von Individuen Schlussfolgerungen über strukturbildende Prozesse auf der Ebene von Gruppen oder gar Gesellschaften zu ziehen. Als computergestützte Variante des Plan- oder Rollenspiels, bei der Teile des modellierten Realitätsausschnitts durch Menschen, andere durch Computerprogramme abgebildet werden, setzt sich in letzter Zeit die partizipative agentenbasierte Simulation durch." (Autorenreferat)

In a logistics system the number of possible applications of qualitative and quantitative modelling efforts is practically infinite. The situations or problems which can be analysed range from micro operations (e.g., analysing alternative order picking systems) to macro planning issues (e.g., determining the number and location of warehouses to be employed in a future distribution system). This range of potential applications not only reflects the scope of the models (micro to macro) but it also incorporates another relevant dimension: planning. The planning axis is anchored at one end by operations models which are constructed to analyse daily operating practices. The other end of the continuum is represented by long range planning models. These models are used to aid logistics managers in their attempts to design systems to cope with the future. In many situations exact classification of individual models along these two dimensions is difficult. However, this categorisation is a useful framework within which to view the scope of the modelling discussed in this paper. This presentation will focus on the macro planning models that are being employed both in military and industrial logistics to aid the systems planner in his attempts to structure logistics systems for the future.

Modelling as Research Methodology is written for the scientist and student researching the (expected) functioning of systems under specified conditions. As such, it represents an introduction to the use of modelling in natural, human and economical sciences. The book is divided into two sections. The first section illustrates the universal nature of modelling as aid to the researcher. In the second section, several typical examples of modelling are described.

1 The labour market: theory and experience -- 1.1 The concept of the labour market -- 1.2 The supply and demand for labour -- 1.3 Models of unemployment -- 1.4 Macroeconomics and the labour market -- 1.5 The Phillips curve and the NAIRU -- 1.6 Some features of the data -- References -- 2 Some formal models of the aggregate labour market -- 2.1 Introduction -- 2.2 Labour demand -- 2.3 Some formal models -- Appendix A -- References -- 3 The disequilibrium approach to modelling the labour market -- 3.1 Introduction -- 3.2 The multimarket non-clearing model -- 3.3 The labour market in disequilibrium -- 3.4 Empirical results -- 3.5 Policy implications -- 3.6 Conclusions -- References -- 4 A neoclassical model of the UK labour market -- 4.1 Introduction -- 4.2 Theory -- 4.3 Econometric results -- 4.4 Simulations -- Appendix A -- References -- 5 A new classical model of the labour marketg -- 5.1 The model in outline -- 5.2 The labour market in detail -- 5.3 The demand for labour -- 5.4 Responses to critics -- 5.5 Conclusions -- Acknowledgement -- References -- 6 Imperfect competition and the labour market -- 6.1 Introduction -- 6.2 Price and employment behaviour -- 6.3 Wage determination -- 6.4 The labour market in a macromodel -- 6.5 Empirical analysis of the British labour market -- 6.6 Summary and conclusions -- References -- 7 An international perspective -- 7.1 Introduction -- 7.2 Multi-country studies: some comments -- 7.3 Selected applications of labour market models -- 7.4 Multi-country studies: some examples -- 7.5 Institutional characteristics -- 7.6 Concluding comments -- Acknowledgements -- References.

The on-going globalisation and the increasing demand for flexibility in modern businesses have made transport, together with business logistics, a major functional domain. Transport growth is essentially for economic growth but is not without negative impacts. External effects such as pollution, congestion, accidents and damage to infrastructure generate considerable social costs that impose a heavy burden on society. This title addresses the need to develop new freight transport models and scientific tools to provide sound solutions that consider the wide range of internal and external impacts. The international contributions push forward frontiers in freight transport modelling and analysis.