In light of the recent developments of transitory nature, it is likely that national defense decision-making will be more difficult to make for years to come. In other words, sudden changes in security environment would call into question the basic assumptions on which we have built our national defense planning and increase the number of the uncertain factors in the decision-making process; the subdivision and ramification of national defense management would increase the factors for decision-making and complicate even further the mutual interactions among these factors; the accelerated pace of sophistication and diversification of weapon systems and military technology would increase the risk of failure and system costs geometrically; and the reduced level of acceptance among the people on the sanctification of national defense in proportion to the rapid progress toward a more democratic and industrial society would engender an increased criticism or checking role by the National Assembly or by the mass media. As the changes in national defense environment and conditions create an innumerable number of new tasks, this paper intends to suggest a few core policy measures to improve the quality of national defense decision-making. More specifically, it proposes to 1) eradicate entirely the bureaucratic behavior and tendencies; 2) utilize actively the brain staff for quality assurance of decision-making; 3) and introduce and apply as a whole set, a total system, or an incorporated pack age the PPBEES(Planning-Programming-Budgeting-Executing-Evaluating-System)/LCMM (Life-Cycle Management Model for System Acquision), the OR/SA(Operations Research/Systems Analysis), and DMIS (Defense Management Information System).

This research paper examines the Navy of the Republic of Korea (ROK) and the Japanese Maritime Self-Defense Force (JMSDF) to determine if the two navies can cooperate to enhance the security of Northeast Asia. This paper reviews the advantages and limitations of naval cooperation between the ROK and Japan, describes the threats to both, and evaluates domestic, regional and international factors to answer the questions : Is naval cooperation possible? How would might it take? what secunity burdens might the ROK Nayy and the JMSDF be reasonably expected to assume from the United States? Paper conclusions are based on the studies within the framework of today's realities. Consequently, the conclusions may seem undramatic. However, they are based on not what could happen if all parties agreed to accept radical change, but rather upon the assumption that all parties will want to change the least for the greatest benefit.

Expert systems are in an early evolutionary phase, but it already has significant impacts on business operations. More and more organizations are becoming interested in applying expert systems as solutions to their business problems. This paper describes how systems started, what is their current situation, and what are their application areas. It outlines what is expert system and how to develop an expert system. And it analyzes expert system shells and shows some current available expert system shells. Lastly, it concludes and predicts the main attributes of the future expert systems.

The Lanchester equations are widely used for modelling the direct-fire land battle. However, it is recognized that the Lanchester based models are less applicable to direct-fire land combat when the battle size is small, the forces are near parity or the inter-firing times of the combatants do not follw a negative exponential distribution. A comprehensive investigation has been conducted to establish the circumstances under which the Lanchester based models are applicable.

The basic mathematical tools are developed to determine the optimum emplacement of limited numbers of scatterable mines on the infantry battlefield. A deterministic model is developed for heterogeneous infantry battalion level battle using APL version 7.0. The Helmbold-type combat equation is applied to claculate comparative casulties, and range dependency is also considered to establish the correlation between attrition rate coefficients and the distance of opposing forces, Based on this deterministic model the effective range for employment of scatterable mines is determined. Because mines are primarily effective when employed in conjunction with direct fire weapons, it is inferred that minefield are best employed when used within the maximum effective range of infantry weapons systems such as the M16Al rifle. The model developed verifies this fact.

This paper presents the simulation model to decide the mean size of cannibalization aircraft (MSCA) under steady state when an airbase makes use of cannibalization to support the spare parts of an airfleet. In this model, the essential factors such as mission requirements, mission time, failure time, repair time, repair capability, inventory policy, cannivalization rule are considered. The model is constructed with above factors and actual airbase operating rules for a basis. Because of the tangled interdependencies among the each factors, it is inevitable to construct the model by the simulation technique. The mission and support system of the airbase is considered as a closed queueing network with a finite number of unit The troubled aircrafts are repaired in accordance with the priorities that are determined by their repair times. The illustrative example of the model, using the actual data of xx-airbase, is presented. The model would be a useful tool not only to determine the MSCA and the size of scheduled maintenance aircraft but to evaluate the NORS (not operationally ready supply) rate and the availability of an airfleet.

This paper presents an allocation model of test times of software modules. An evaluation measure of modules which is based on the data flow path between modules is used at test phase. An evaluation measure is expressed by the possible path number of data flow for each module, which can be interpreted as an importance of individual module. Three criteria : module test time, module reliability, and system reliability is considered in this model. Multi-objective programming, hence, is used to solve this model.

This paper combines research in the areas of replacement and machine interference. Although over the past three decades there has been a great deal of research in the area of optimal replacement for stochastically deteriorating equipment and research dealing with machine interference problems : there has been a lack of research when these two areas are combined. However, the melding of these two well-known areas yields a very practical problem which demands theoretical investigation. In this paper we derive the steady state probabilities with a control limit policy for a two-machine one repairman problem. The control policy is a simple age dependent control described by the control limit, $t^{*}$. Once $t^{*}$ is fixed, the steady state probabilites that one, two, and no machines are working will be obtained.