Many electric utilities have a heavily debt-laden capital structure. A number of factors have contributed to this situation, but chief among them is the theory that increased debt improves a corporation's earnings per share. This theory is derived from a relatively simple financial model which relates earnings per share, capital structure, interest costs, and income. Using a more comprehensive model, this paper shows that reducing debt as a percentage of capital structure can improve the interest coverage, earnings per share, and market price per share of electric utilities.
A method is described and illustrated for explicit incorporation of and computation with ranges of initial conditions, functions, and parameter values in dynamic models using interval analysis. This approach is neither a statistical nor fuzzy set analysis but instead utilizes interval arithmetic which is particularly well suited for computerization. When a dynamic model is couched in interval analytic terms, ranges of all possible solutions are generated allowing not only an analysis of ranges of behavior modes but for sensitivity and stability analysis to be performed as a natural part of the model. Moreover, uncertainties such as specification, numerical method (e.g., numerical integration), and roundoff errors can also be analyzed in conjunction with or separate from the interval dynamic model.
Burnout is a problem associated with work in social service organizations. It is characterized by loss of energy, negative attitudes, and decreased performance. This system dynamics model encompasses the literature on burnout and belongs to a general class of stress and motivational models which describe problems of alcoholism and sexual harassment in the work place, etc. The gap between performance and professional expectations generates physical and psychological fatigue, which decreases involvement and performance. Supervisors frequently ignore the workers' problems, but will initiate structure when quality is perceived to decrease. The gap between expectations and performance may account for burnout initially, but cannot account for maintaining burnout after expectations decrease. Learned helpless may be the mechanisms that sustains burnout.
With a new information system, the "order-production-distribution" system can be managed as a whole in terms of corporate performance. But there is a possibility that such a system can be damaged easily from degraded information conveyed through an information network. This paper is concerned with an approach to dealing with degraded information in light of risk management with the system dynamics philosophy.
This microcomputer workshop is being developed to encourage exploration, testing, and discussion of the impact of alternative arms-building policies. The model allows participants to adjust parameters that reflect a number of psychological, technical, and political factors. For example, participants can represent one country's tendency to overestimate the strength of the other and underestimate its own strength. Before releasing the model to the public, we are reviewing its conceptual soundness and its educational effectiveness to be sure that it reflects empirically supported technical, psychological, and political realities. The presentation of this paper and the early versions of the workshop are part of this preliminary review process.
A simulation model of the passenger transportation system is presented. The model has been built in order to carry out a series of simulation experiments. The purpose of these experiments is to compare the effects of sore transportation policies on road congestion, modal-split, air pollution and transportation fuel consumption. System dynamics principles have been used for simulating the model. The statistics of Delhi urban area have been used to calibrate the model.
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.
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)
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.
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.