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-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- The Dutch public authorities are confronted with large backlogs in processing the archives of their services. In view of this, the Ministry of the Interior, which is responsible for coordination of these processing activities, wanted to have a planning model for simulation, in a quantitative sense, of the archives movements within the public administration. The underlying thought was that such a model would enable problems in the fields of depot space, cost structure, allocation expertise and processing speed to be approached in a more adequate manner. A first exploration of the problem area (October 1984 - April 1985) showed that the quantitative problem of the processing backlogs is to a great extent affected by qualitative processes within the records management system and between said system and the client system. It was concluded that a planning model focused on quantitative factors cannot make an effective contribution towards solving the problems as the effects of measures aimed solely at efficiency will in the long run be affected adversely by qualitative processes. When the study was continued (September 1985 – April 1986), it was therefore decided to further investigate the processes of a more qualitative nature and to analyse their coherence. The results obtained provide a first step towards development of a simulation model for the records management system which, while supporting the relevant policies in this field, forms a tool for determining the, effects of policy changes in the system both in the short and in the long run.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- System Dynamics Research and Consult has been asked bythe Ministry of Justice in The Netherlands to develop a simulation model of the criminal justice system. In this system a number of feedback mechanism are present that have negative side effects on the society. The first steps in the development of the model were taken. A number of small models of parts of the system were made to gain insight in the behaviour of some variables that are hard to quantify. A larger semi-dynamic model was developed to study the behaviour of the variables that are better to quantify. All models have to be integrated in the next part of the project in order to refine the forecasts.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- System Dynamics has proven to be a useful paradigm for the construction of a policy analysis model in support of energy conservation decisions in the United States Pacific Northwest. This paper outlines the most important complexities faced by the Bonneville Power Administration planners, how system dynamics has provided a framework for analysis and how the integrated model currently used by staff members (the Conservation Policy Analysis Model) has been applied successfully to a wide range of problems.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- In this paper, the dominant approach to the modelling of physical systems is described: it uses local laws and powerful numerical tools. For linear problems, it leads to eigenvalues and eigenvectors, in a suitable functional space, from which it is possible to construct the response to any excitation using the Green's resolvant. This approach has led to important progress in engineering physics. Nevertheless, a systemic approach is useful in physics and irreplaceable for living systems. This second way uses global laws of the phenomenon in addition with a dynamical identification of the system using some adequate experiments. We illustrate this method on the modelling of a solar plant, which is correctly represented by a simple ordinary differential equation.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- This study uses a system dynamics model to understand the process of economic growth in the oil dependent economy of Indonesia. Many long-run growth patterns resulting from the various intuitively appealing development policies are analysed and an attempt is made to identify the best policy set for attaining a sustainable growth pattern. The study shows that influencing factor prices in a way to facilitate adoption of capital intensive technologies increases acceleration of growth and is a key policy to sustain growth in the long run.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- A new approach to Environmental Impact Assessment (EIA), based on system dynamics concepts is presented in this paper. System dynamics models will however be useful in EIA only if people are able to develop"good" models. The conceptual basis for building an expert system designed to guide people in developing system dynamics models is introduced in this work. Such an expert system will have two main modules: a system dynamics component, which will include basic system dynamics concepts and heuristics; and a specific application component, which will consist of the main relations and rules governing a givenenvironmental area. The system will also include an interface with a dynamic simulation language and with a decision aiding formulation.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- The analysis of the evolution of non linear dynamical systems is a complex task. The cases where: i) the model equations can be regarded as a careful and reliable representation of the real system and, therefore, need no revision or modification; ii) the parameter values are precisely known; iii) the initial conditions are precisely known, are rather rare. At least one of the previous conditions is not fulfilled in most of the systems of interest for System Dynamicists. Therefore qualitative analysis of dynamical systems, i.e. the study and classification of their asymptotic behaviours, is of extreme importance, at least in long term models.The methodologies of knowledge representation recently developed in the field of expert systems can be applied to this problem. We therefore developed MAPS, an expert advisor for the qualitative analysis of dynamical systems. MAPS takes the system equations as input, classifies them according to their features and performs the necessary calculations at each stage, sending appropriate messages to the modelist. At present MAPS deals with autonomous second order systems of ordinary differential equations. Further developments are foreseen concerning the study of higher order sytems and the design of an "equations database" for comparison with previously analyzed equations.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- The United States Occupational Safety and Health Administration (OSHA) regulates the level of occupational safety and health within firms and inspects firms for violations of its regulations. Regression-based evaluations of occupational health and safety conditions in the United States generally conclude that OSHA's regulation fails to increase either the level of safety or safety-related investment. However, case studies and other forms of qualitative research suggest that regulation does increase both. Resolving this discrepancy requires a research strategy that combines elements of qualitative research and quantitative research. Simulation modelling can be used to bridge these two methods. Generally, the research project constructs a simulation model of accident generation within firms, generates synthetic data from variations of the model, and evaluates the sensitivity of regression methods to variations in the model. This paper presents the structure and base run behavior of the model used in this research project.
-
- Type:
- Document
- Date Created:
- 1986
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 8be0def879466bb233ec7ae0e7a56898, a6ba3d432669bb4e7e5d1d631a535030, and 23d738ba88f8333bc39725f9cb5bd0b8
- Description:
- A field study carried out during the last seven years on a wintering population of Common Cranes (Grus grus) in Spain allowed us to gather accurate field data on-certain relevant demographic parameters: (a) the size of the Western Palearctic population of this species is estimated to be around 40000 birds, and (b) the age composition in autumn is estimated for 1979-85 to be around 13.5% young. These data enabled us to develop and test a population dynamics model which combines the density- and age-dependent effects on productivity and survival rates. The parameters of the productivity and survival functions were varied within biologically reasonable limits. From the series of possible combinations we selected those that fitted our field data on population size and age structure best. Each variable was then varied to study their influence on the model.