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-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- For many years, system dynamicists have speculated that most corporate troubles could be explained by a small number (perhaps ten to twenty) of generic models, behavior modes, and syndromes (sets of symptoms) they create. Recent advances have renewed interest in creating management education materials, using such generic models to provide a consistent and known environment for active learning, using actual case studies for realism and detail, and using the computer-supported hypertext format of user-directed inquiry. A project at MIT integrated these advances in computer-based studies. This paper precedes systematic development of computer-based cases; it identifies 17 problematic syndromes and behavior modes. They are generic in the sense that they occur commonly in a variety of companies, as a result of common structures and policies. The 17 were identified from published modeling studies, interviews with executives, and unpublished consulting studies. The list of common corporate syndromes will be used in selecting the cases upon which to base the computer-based case studies. The list should also facilitate the problem-identification phase of consulting for individual corporations.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- Synthetic data methods are used to test the robustness of estimators of the parameters within a simple linear oscillator. Econometric methods are used to estimate the known parameters in the model.The major result is that the deviations from the estimates to the true values of the parameters increase with the sample interval. The influence from stochastic inputs is marginal.This is due to, that for great sample interval, the lag in the causal dependency is relatively small compared to the interval between the observations involved.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- The purpose of this research is to evaluate the relation between the development of financial markets and their institutions and the process of economic growth and development. Throughout the world less developed countries are facing various stages of an international financial crisis. Major banks in the industrialized world, as well as the IMF and World Bank have extended credit to these countries expecting the resulting economic growth to yield the necessary dividends for repayment. However the most expeditious road to growth and development has never been a certain one. One controversy deals with the timing and maturity of the financial institutions and financial markets. This overall process is called “financial deepening.” Previous published research polarizes the role of financial institutions in the process of economic development between supply-leading position and the demand-following hypothesis.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- The purpose of this research is to describe the impact that linguistic structure has had on the method of modeling in system dynamics. In the structuralist framework, language is viewed as a system of signs which structure our patterns of thought and influence our behavior. Learned languages are incorporated into the structure of the unconscious which then contains and constrains the capacity for communication and discourse. Linguistic systems are not isomorphic. Thus, when the language used in communicating social, political, and economic ideas changes, (i.e., from verbal to static linear mathematics; or from verbal to dynamic nonlinear mathematics), this affects the theoretical structure of the discipline. The symbolic linguistic structure employed in system dynamic models offers a powerful alternative methodology for scientists to investigate social reality.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- Well structured system dynamic models are often quite useful in the analysis of the policy impacts in the face of multiple sources of uncertainty. Simulation searches for a “robust” policy that performs well under widely varying conditions are often the most rewarding portion of a system dynamics study. This paper reports the results of two studies where the analysis of uncertainty is carried a step further. Here, we are interested not only in policy impacts under widely varying conditions but whether a policy can reduce the uncertainty of the system.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- Bank institutions occupy a special position in the economy as they have to guarantee a frictionless money movement. Compared with industrial companies, banks do not produce concrete products but provide abstract services with money as their output object. These services- when they are included in balance sheet- are reflected in the accounts as sales relations. Therefore a balance sheet model is applied in order to reflect general decisions in banking and to show how these decisions affect banking business in terms of volume and profit.The analysed bank is the London branch of a Continental bank. The branch acts on the markets as a commercial bank. These kind of representations are the most common ones in the financial center of London.The branch offers four different kind of products: Traditional, specialized, contingent and treasury products. These products determine the statement of asset and liabilities and in addition are also the income earners of the branch.The behaviour of the branch is determined by decision rules, market developments, the juristical position and internal restrictions. This behaviour is tested by adopting different scenarios.The System Dynamics bank model is adaptable to individual circumstances of other banks and therefore it offers practical support for the management of financial institutions.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- A participatory simulation based on the market growth model is developed. The performance of eight subjects is evaluated and compared against the results of simulation analysis of the model. Compared to the benchmark derived from the simulation analysis, the subjects' performance is surprisingly low. It is argued that participatory simulations can be valuable teaching instruments but that they need to be combined with additional learning support tools.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- Figure 1 illustrates the structure of the model.People flow from a Susceptible Population after invasion by HIV and become members of the HIV population capable of infecting other susceptibles.Then, infected people either move into a state of(i) clinical AIDS ( governed by the Symptom Emergence Ratio, SER) or into one of several other states(ii) die from other unrelated causes(iii) retire altogether from sexual activity on account of their age(iv) retire altogether from sexual intercourse as a reaction to knowledge of their condition(v) acquire a medically non-infectious stateAll these states render the host non-infectious since we assume that patients with clinical AIDS will no longer be sexually active.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- This paper discusses the general structure and implementation of a System Dynamics model of the New Zealand economy. The model, called SDMACRO, has been developed at the New Zealand Planning Council to provide likely trend movements, some 10-15 years into the future, in the key macro-economic aggregates including gross domestic product, capital formation, population, employment, exports, imports, and the current account balance. The base case run of the model is presented together with scenarios which show optimistic and pessimistic future outlooks for the New Zealand economy. In addition, the paper briefly describes how SDMACRO is used with a 22 sector general equilibrium model, Julianne, as part of another Planning Council study which examines national and sectoral development paths of the New Zealand economy up to 1995. Finally, some recent extensions to SDMACRO are outlined.
-
- Type:
- Document
- Date Created:
- 1988
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, 74bc8d76f7112f877dcc1bed073089e6, and ff3ca29802c9b5ed0bd77a0a9e76375a
- Description:
- The following is meant to be an example of the combination of an Expert System (XPS) and a System Dynamics (SD) model in which the farreaching effects of cash management decisions in a complex of feedback relationships in a company are illustrated.The great advantage in proceeding this way is to use the results of an Expert System as constants and initials in a System Dynamics model. That means, that the user is enabled to study the results of a static Expert System in a dynamic model.The mentioned System Dynamics model is created on the background of an ancillary supplier for the car industry. Rather to simulate the real system in a very detailed way the model reduces this real system to the main areas of the company. As in this paper the point of main emphasis is to demonstrate a possible way of linkage of the two systems a short problem definition is followed by the description of the most important feedback-loops in causal-loop diagrams of the System Dynamic model. Subsequently the outcome of a model simulation with it's graphic and tabular results is to be analysed under the aspect of influence of constants and initials originating from the Expert System concerning cash management decisions.