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- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- In this paper we review the algorithm to identify the type of variables (levels, rates, auxiliaries) which appear in the influence diagram. This algorithm has been implemented on a personal computer at the Cagliari University.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- There has been a great deal of work done in the simplification of linear dynamic models. Given that most models that are in use are nonlinear this has restricted the applicability of the available techniques. By concentrating on a particular nonlinear phenomenon, in this case shifting loop dominance, it is possible to use the techniques of linear analysis for the simplification of nonlinear models. The theory for this is developed and it is shown how this can be applied to the model. For purposes of exposition the market growth model is used and the results are encouraging. Though there is still a good deal of work to be done it seems feasible to develop simplification techniques for nonlinear models that address directly the nature of the nonlinearities.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- Much of the work done in system dynamics has been criticized for making insufficient use of statistical estimation techniques. There have been various responses to this criticism concentrating on the other sources of information available to the model builder. One of the major hurdles to the use of statistical estimation techniques is an understanding of when they are likely to be useful in system dynamics modeling. In this paper we consider different estimation techniques and how useful they can be in system dynamics modeling. The work is meant to be a practical guide that will allow the modeler interested in statistical estimation to gain some understanding of the different approaches available. We concentrate or attention to the special problems that the system dynamics modeler is likely to encounter in estimation.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- Studies of deterministic systems which apparently exhibit chaotic behavior are attracting much interest in disciplines ranging from physics to economics. A particularly interesting case of a simple electrical network has been studied recently in the physics literature with the objective of isolating minimal characteristics essential to chaotic behavior. A system dynamics formulation has been given to the numerical simulation of this system. Instructional laboratory exercises comprising both observations on the electrical circuit and computer simulation of the circuit are being implemented for the upper level undergraduate and graduate students.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- The Jutland Technological Institute (JTI), Aarhus, Denmark, has embarked a project to promote the utilization of System Dynamics models in Danish Industries. The vehicle of this projekct is a new type of hybrid computer, the MOSES (Modular Symbolic Electronic Simulator) system, developed at the Technical University of Denmark. In ongoing projects the MOSES system has demonstrated itself as an invaluable “discussion” partner. We have performed a series of seminars with managers from medium and large sized Danish companies. At these seminars some of the generic structures of growth companies have been discussed and related to Danish conditions. This report contains a brief description of the MOSES system and a description of the ongoing project.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- This is a report of several applications of System Dynamic Methodology to banks, with particular emphasis given to their structure and their Decision Making in terms of System Dynamic concepts. Aplications range from policy design and long term planning to the design of Decision Support systems. The first part presents relationships between money flows and accounting information. Next, some policy design results are presented. Later on, the estimation of the parameters of the SD model is transformed into the heart of a Decision Support System.
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Fritz, Richard G., "Economic Development and Financial Deepening: A Study of Causation and Dynamics"
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- The direction of causality between financial deepening and economic development is tested. Using factor analysis, two indexes are developed to represent the two economic phenomena for the Philippines. Time series causality tests are used to evaluate the direction of causality. The results indicate the causal pattern reverses over the history of the sample. Reversal is viewed as the result of financial repression. The structural dynamics implied by the empirical time series test is evaluated using a system dynamics model. The growth promoting and growth inhibiting roles of the financial sector are simulated in the dynamic structure of a dynamic economic development model.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- A representation of socio-economic systems using reduced models allows a “qualitative” type of analysis to be carried out. It is often the case, especially in the long term process, that the main interest is directed towards the asymptotic behavior of the solutions as a function of the initial state and to evaluating the properties of stability of stationary states. In this article, after a short outline of the procedure and methodology adopted, we describe the application of these techniques in the construction and use of a dynamic model for the design of a tourist village. The model, which mainly deals with the impact of man on the environment, serves to evaluate the social and economic effects of the construction of a tourist centre in a national environment which must be conserved.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- Power demand forecasting methodologies which are currently being used by electricity authorities are end use method, trend method and Scheer's formula. These methodologies being static in nature, do not take into account the future power supply position, while becoming an important instrument of economic change the growth of power generation activity itself is totally dependent upon the overall economic development thus forming an important feedback loop in the economic system. Present paper discusses a power economy system dynamic model for estimation of future demand and supply position of Power.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- The paper is an attempt at a theory of relations connecting feasible observations/ or measurements/ and feasible decisions/ or controls/ in general cybernetic systems. The theory gives a formal framework and a tool for quantitative analysis of the following facts: 1. An increase in observation possibilities, e.g. an increase of the precision of measurement, enlarging the scope of observation etc., results in an increase in decision possibilities by making more effective decisions possible. This works also in the other direction: if there are more feasible decision, new observations or measurements become available. 2. In the framework of a cybernetic model no decisions and/or observations which generate antinomies can be simultaneously feasible. This creates interesting and important constraints on measurements and decisions in systems which include man or where a human or automatic decision maker is an object of observation, and where the results of observation may be known to this decision maker. 3. The observation/measurement/ takes tome and changes its object and thus the result of observation always refers to past rather than to the present. This normally is due to physical effects through other phenomena, like psychological, may also be important depending on the nature of the object. The facts of group 1 are in a sense opposite to those of groups 2 and 3. This leads to the existence of optimum decision-measurement possibilities. Conditions for this optimum to exist together with its significance for biological and technological system will be discussed. The subject of this paper is of interdisciplinary interest and has been studied, partially and from particular angles, within the framework of control theory/facts of group 1/, mathematical logic/theory of antimonies, principles of mathematics-mainly facts of group 2/, physics/theory of measurement, principles of quantum machanics-mainly facts of group 3/ and philosophy/the classic problems of free will and consciousness/. The relevance of the presented theory to these fields will also be discussed.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- This paper presents the findings of my research in artificial intelligence applications for system dynamics. The sudden appearance of microcomputers in homes, schools, and businesses has opened an opportunity for dissemination of system dynamics to a wider audience than we could have ever hope to reach with the earlier computer technologies. This opportunity should not be lost by clinging to obsolete, or soon to be obsolete, technologies. User-friendly micro-based software should be immediately available to those individuals, schools, and corporations who are interested in systems thinking. The demand for such systems far surpasses the current supply. Artificial Intelligence software is now available for microcomputers. This new software development can significantly improve current and future systems for the novice and the experienced system dynamicist.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- “Generic models,” as the term is emerging, denotes a model representing the underlying causes of commonly occuring sets of problems, whose purpose is for education, rather than for policy analysis per se. Preliminary uses of generic models have been an exciting and efficient means of transmitting insights. This paper is a status report on the modeling of a company's conversion to a new production or product technology. Based on information sources including in-depth interviews within such companies, the authors' previous experiences, and published surveys and cases, the planned model focuses on management goals, staffing, and acquisitions of the skills necessary to deal with the new technology or product. Although the model does not explain every (complete or partial) implementation failure, it seems relevant to a significant fraction of such failures. The authors intend to develop the model and curriculum materials for management education and portions of university courses on technology management.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- Although there are more than 3000 end uses of aluminium in the world and more than 300 in India, yet there are five sectors viz. power, consumer durables, transport, building consturction canning and packaging which account for more than 90% of aluminium consumption. To study the dynamics of demand of aluminium in these sectors, system dynamics model having various sectors viz. Population, economy, power, consumer durables, construction, packaging and canning, transport and aluminium consumption model has been simulated from 1970 to 2000 A.D. using dynamo.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- Within the MIT System Dynamics National Model, the risk-free interest rate is determined jointly by the normal interest rate and by liquidity. The normal rate is the rate which agents believe would obtain under normal circumstances, in the absence of transitory pressures. The normal rate continually adjusts to new interest rate conditions. During times of deficient liquidity, agents will increase the risk-free rate above the normal rate. The converse also holds. The risk-free rate will continue to adjust until pressures in the system are relaxed. Estimation results support the national model theory of interest rate formation.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- This paper presents a computerized system dynamics game in which the player makes "annual" decisions controlling the availability and evaluation of a new medical product with uncertain potential and possible (though initially undetected) side effects. The game has been implemented using the popular spreadsheet program Lotus 1-2-3. This program has on-screen display capabilities allowing for the construction of a user-friendly game that requires no knowledge of system dynamics. A detailed discussion of game mechanics is followed by a description of a classroom experience which led to further development of the original version of the game and some general insights about game-building.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- In the past, the most popular computer models for the construction management of major buildings were large models based on the graph theory and their consequent discrete event simulation on the mainframe computer to have a view of the operational level. We think that in the future if we want to remain competitive on the world market the trend will be the use of small system dynamics generic models in relation to micro-computers at the strategic management level that can generate the reference modes i.e. the project control baselines.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- The long term success of System Dynamics is largely dependent upon the dissemination of systems thinking to a considerable segment of the general public. A strategy for exposing a non-academic, adult audience to the basic characteristics of systems is developed, using the ADAPT Learning Cycle, System Dynamics, and the Social Fabric Matrix.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- China has the greatest population in the world. The impact of the population on Chinese economic development is great. Based on Chinese National Economic Model NATN3, the relationship between the population control policy in China and Chinese economic development are obtained by simulation of the policy analysis.
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- The System Dynamics Generalized Substitution Modeling is presented. This modeling considered the influence factors of circumstance by introducting action function. The methodelogy is based on the System Dynamics with econometrics, combining three postulates in product substitution and decomposing multi-product into several two-product substitution. Parameter estimation, which existed in all System Dynamics Modelings, is one important but still unsolved problem. Now this problem has been solved in our paper by orthogonal simulation, it is based on the orthogonal theory and generalized least squares (GLS)
-
- Type:
- Document
- Date Created:
- 1985
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 8cc5e98280358f60c3a33cc99e75a20e, and 11576afb39e5cd4a779a3912c119ca81
- Description:
- A multi-sector, input-output version of Sterman's simple Long Wave Model is developed to investigate the validity of the capital self-ordering theory for a more realistic system with diverse capital types. Simulation experiments with varying capital lifetimes and input-output coefficients tend to reproduce the characteristic fluctuations in capital production, caused by self-ordering, with a period in the 30 to 70 year range. However, complex patterns of oscillation with wide variance in period can emerge, explained by varying dominance of self-ordering loops. The analysis thus confirms the destabilizing effect of self-ordering and its significance for long term fluctuations while raising issues and generating new insights about the-long wave.