Advances in computer software allow modelers to design, with relative ease, sophisticated, realistic educational tools. With these advances, new issues arise about how to make this educational software productive and stimulating, without limiting the freedom of the user or creating simply a computerized workbook.Such simulation games have great educational potential for people who play video and home computer games, and sometimes for students in classrooms. The games must address three information levels: (1) real-world details, (2) simulation of model, and (3) conceptual understanding of structure and dynamics. The systems viewpoint on the particular model must be clearly explained; otherwise users will have much fun but learn little. Feedback during the game teaches this system understanding without requiring textbook readings. Such feedback requires new modes of “expert” computer analysis which need to be developed. Other tools need to be developed to help in creation of simulation games and to give the games abilities that they do not yet have, such as access to database of models, pictures, and text, and connections between simulation games.
Japanese old age population is gradually increasing and this tendency weakens economic conditions of Japanese welfare annuity system. Therefore it is important for us to study future conditions of this system.This model contains 4 sectors: Demography, total premium income, total pension expenditure and reserve of the welfare annuity system.The demographic sector covers populations of 5 three-year age groups under 14 years of age and 13 five-year age groups above 15 years of age. This sector was first formulated for a simulation model of dental diseases and is now applied to this model. Total premium income for the welfare annuity system is the sum of premiums of workers, employer contribution and government contribution, for which populations of five-year age groups are used. Total pension expenditure is the sum of base pensions and earning related pensions. Here is used population of 60-64 age group. Total premiums plus interest income of the reserves of the welfare annuity system minus total pension expenditures flow into the reserves of the welfare annuity system.The length of the simulation is 63 years from 1963 to 2025.This study is a research project of the Japan Productivity Center.
The paper suggests a novel approach to policy design in system dynamics models. The approach is based on optimal control theory to evolve synthetic policy structures and then design realistic policies for the famous production - distribution model of Forrester. New policy sets have been presented for purchase decision rate at retail and distributor sectors and manufacturing decision rate at factory. It is shown that the suggested policy sets show a marked improvement of model behavior over that obtained by Forrester. The approach suggested here will enhance the art of policy design.
Eroding competitiveness, declining productivity growth, explosive technological, political and environmental change, and dissolution of market and national boundaries form the familiar litany of problems which threaten traditional organizational structures and management practices. In the turbulence at the close of the century it is widely argued that organizations must change more rapidly than ever before.
The automobile fuel market in Italy is appreciably different from that in other European countries and even more unlike the American context.As a matter of fact, the alternative and available automobile fuels in this country are the following: -gasoline (petrol),-gas oil (diesel oil),-liquefied gas (LPG), plus a very small amount of natural gas, each with its own price. In addition, price differences are considerably greater than in other countries.In view of the fact that gasoline is the most expensive fuel and gas oil the least expensive, the Italian Government has adopted a peculiar tax called “Superbollo” meant to penalize car owners with diesel powered engines and those with both gasoline and LPG powered engines, but to a different degree.The alternatives access by drivers (car-users) to different fuel resources has influenced and countries to influence the automobile industry’s approach to the Italian market.On the other hand, the different fuel prices, plus the varying annual amount of the ‘Superbollo” tax, influences the motorist’s decision in buying and using differently powered cars.The decision is obviously affected by the consumption rate for each type of fuel and the driver’s expected mileage per year.This paper aims to underline and analyze the hypothesis on the mix of the three main fuels used in Italy, trying to give results principally on the basis of: -price-changing of each fuel, -tax-value of “Supperbollo”, -different driver-mileage taking into account the pollution-cost of each of the three fuel solutions. The system, which is the subject of the study, will be analyzed using System Dynamics methodology, with a dynamic model.
The close similarity between the Indian census, Government of India and U.N. population estimates and those from the Constrained Coalition and Logistic Model (CCLM) has been demonstrated which enhances the usage of differential equation modeling for studies on population growth processes. The CCLM incorporates the legitimate requirement of an upper bound for the aggregate population thereby implying the rate of natural increase to reach the zero level. The numerical value assumed for the upper bound is based on food supply - arable land availability, and accounts for advances in agriculture productivity. However, other factors such as quality of life, environmental degradation, per capita income, etc. can also be used to arrive at an upper bound. The model holds good promise for usage for other developing countries.
The use of computer tools to aid in decision-making and problem-solving activities suggests a view of negotiation in which parties collaborate to improve the quality of the information and knowledge on which they base their joint decisions. In this view, negotiation is characterized as a process of discovery and design. The effectiveness of negotiation is defined in three dimensions: legitimacy, feasibility, and efficiency. Computer tools are discussed in the context of information strategies, or ways in which negotiators use information in their efforts to ‘discover and design’ solutions.
This paper presents results of extended experimentation with selected models of social phenomena widely used by the system dynamicists in their studies on deterministic chaos. The models selected include various versions of a simple model of migratory dynamics and a model of resource allocation in a firm, and a simple model of long-term economic fluctuations. Chaotic modes seem to appear in each of the experimented model, either due to non-robust or unrealistic rate formulation, or from unrealistic parameter or input specifications or both. Minor changes on the models experimented with, which improve their correspondence to reality, eliminate chaotic modes. The paper raises the issue of the relevance of the chaotic models to real-world phenomena and policy design for system improvement.
This paper suggests that the possibility to experiment with relationships using system dynamics should lend the method easily to introducing practicum in the theory-based disciplines. This would however, require modifying teaching formats and creating new text materials and user-friendly computer programs suitable for use by students with little computer or mathematical expertise. A simulation laboratory consisting of a text and a user-friendly simulation program developed recently by the author on issues of economic development is presented as an example of material needed for integrating practicum with teaching.
The paper considers how students learn commodity production and circulation via gaming experiments. We review two of them.In the first, players run into reproduction on a decreasing scale aggravated if not caused by their non-cooperative behavior. In this economy social and private benefits and costs diverge. Undertaking an investment a capitalist firm chooses typically that technique which maximizes profitability, while the society is interested in that which requires the minimum input of labor.In the second, players bring up extended reproduction receiving incompatible norms and setting new priorities with associated strategies of cooperative behavior. Social and individual interests draw together consequently.