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-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- This paper demonstrates the use of System Dynamics as a device to simulate a system of infantry and artillery cooperating in joint combat operation.The system under study does not represent a real or actual battle-field. The model represents a scenario describes hypothetical system of accepted theoretical structure of how infantry and artillery may co-operate in order to achieve a desired advance on a real battle-field.The paper will give attention to the planning and controlling of any need to such co-operation, and will give better insights to decision makers before and during such joint operations.We make no claim for revealing analysis of any army strategy, and seek only to show how a System Dynamics model could do if it were constructed by people who fully understood the problems and had access to information at which we can only make guesses.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- In this paper we will assume that the qualitative information about a given concrete system comprises no numerical information beyond the signs of the influences, the relative value of these influences and the classification of the variables in a system as levels, rates and auxiliaries. With this information we try to get as much knowledge as possible on the behavior modes of the system, in the concrete meaning given to behavior mode in the qualitative theory of nonlinear dynamical systems.Our aim is to explore how the formal qualitative analysis techniques, based on the second of the above senses of qualitative, can be used to solve the kind of questions suggested by the first of the uses. In this way a synthesis of both senses can be reached.The results here reported are still in a work progress stage. For instance, a computer implementation of them is being developed. However we think that they are interesting enough to deserve publication.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- In a dynamic simulation game portraying a multiplier-accelerator problem, there are major differences between high and low performers; high performers voice specific concerns for future states of the system, while low performers are less likely to think about the future. Planning, especially incorporating the deceptive nature of feedback, is necessary in systems that exhibit diverging long and short term behaviors. A comparison of game results with written reports show that there is a positive relationship between performance and understanding of the game. These results are contrary to previous research where performance and understanding have been unrelated (Broadbent et al. 1978, 1986), but can be explained by the added complexity of non-linear feedback tasks with shifts in loop dominance. Such tasks are, in contrast to simple regression models, non-routine and therefore verbal and behavior aspects of decision makers' mental models correspond.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- In this paper, using simulation experiments, we demonstrate that the “structurally-oriented” behavior tests and other standard behavior tests are different in a fundamental sense. We also show how the structurally-oriented behavior tests can help diagnose/remove structural flaws. Thus, we suggest that such tests be identified and analyzed by System Dynamics in more detail. It is hoped that the tests will be improved, standardized and implemented as part of all major SD simulation software.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- This paper intends to explore the potential of the System Dynamics approach as a new auxiliary science for the historical analysis. To this end a portable DYNAMO-like package, called STEC, has been developed.The paper, first, describes the peculiarities of the System Dynamics method as a tool for historical research, and gives an outline of the project; second, it argues that the scanty diffusion of System Dynamics might be due, among other factors, to the lack of public domain software; third, it asserts that the “old style” data processing (command line interface and batch mode) can prove itself still usable and fruitful; and last, it shows the STEC main features.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- We have developed a dynamic model of DNA replication control in bacterial cells and of the subsequent cell division. The main hypothesis is that a certain protein, which has a negative feedback regulation on its own production, is an essential factor in initiation of the replication. The model is stochastic in the sense that the kinetic association and dissociation processes are assumed to take place in accordance with a Poisson probability distribution with mean values that match experimentally determined constants. An important feature of our model is that it shows correlation between the magnitude of the kinetic rate constants and the size, stability and the dynamics of the cell. The model thus allows us to analyze the distribution of cell volumes at the time of initiation for different growth rate, different association and dissociation constants, and different promoter strengths.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- The results from studies on more complex tasks, such as concept learning and problem solving, are confusing: some results indicate negative effects of feedback delays, other results no effects of delays and even some positive effects (see Brehmer & Allard, 1988a). Thus, the problem of the effects of feedback delays is in need of study. This paper will review some of the results from a research program designed to investigate the problem of delays in a relatively complex computer simulated micro world which subjects must learn to control.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- Criteria for evaluating success of management schools in terms of contribution to society are presented. The network of interactions that make a management school successful is described. It contains links with the dominant power groups: business community, government, unions and public institutions in general. It includes students, alumni, and staff. Business needs, research results, schools' prestige and attractiveness to faculty are also part of it. The nature of the interrelations and their relative importance are examined during the four phases of a management training institution: feasibility analysis, planning, launching and sustained operations. Some causes peculiar to mature management schools' frequent stagnation and decay are examined and preventative actions suggested.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- Operational Research (OR) had its origins in the need to make decisions about the use of resources in support of national defence. The specific case was the invention of radar in the late 1930's and the military problem was to decide how this new technology could best be employed, in conjunction with the existing assets, such as fighter aircraft, for the air defence of the United Kingdom. It was, in short, necessary to conduct research into how military operations could be carried out, and hence the discipline was born. In fact, for the last 50 years, the military have been the major users of mathematical modelling. System Dynamics is, however, a relatively new tool in military analysis. This paper surveys a few published applications and suggests reasons why SD is particularly appropriate for certain classes of military problems. The paper then goes on to discuss the potential role of SD in the analysis of strategic problems. Finally, some problems of military theory are discussed.
-
- Type:
- Document
- Date Created:
- 1989
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 229aea09844305a482784be9fca550ff, 23d738ba88f8333bc39725f9cb5bd0b8, and a656a490ae4bb95659d385b98804153f
- Description:
- Results of an ongoing study investigating the effect of different task feedback characteristics on human performance are reported. In a computer-assisted experiment, subjects were asked to perform a dynamic stock-adjustment control. A subject's control action enters the system in two ways: it effects the stock to be adjusted and it feeds back on the disturbance that impinges on the system. The latter effect is varied with respect to its strength and its delay. The major finding that emerges from the experiment is that increasing strength in the feedback link (in either a positive or negative direction) worsens performance. An effect of delay length on performance could not be shown.