In this paper, we study a manufacturing system of serial stages with general service times, in which the production of each stage and the coordination of stages are controlled by Kanban discipline. This Kanban discipline is modeled as a Discrete Event Dynamic System and a system of recursive equations is applied to study the dynamics of the system. The recursive relationship enables us to compare this Kanban discipline with the other blocking disciplines such as transfer blocking, service blocking, block-and-hold b, and block-and-hold K, and the Kanban is shown to be superior to the other disciplines in terms of makespan and throughput. As a special case, two stages Kanban system is modeled as $C_2/C_2/1/N$ queueing system, and a recursive algorithm is developed to calculate the system performance. In optimizing the system performance, the stochastic optimization approach of Robbins-Monro is employed via perturbation analysis, the way to estimate the stochastic partial derivative based on only one sample trajectory of the system, and the required commuting condition is verified. Then the stochastic convexity result is established to provide second-order optimality condition for this parametric optimization problem.

This paper is organized as follows. Section 2 illustrates several applications of neural networks. Section 3 presents the theoretical aspects of the major neural network paradigms as well as the structure of the back -propagation network used in the study. Section 4 describes the experiment including data analysis, modeling, and the performance criteria followed by the detailed discussion of the experimental results. Future research avenues including advantages and limitations of neural network are presented in the last section.

The size of software collection at any organization is increasing rapidly with the use of computer becomes popular for various applications. This trend points out the importance of proper 'catalog'or 'directory' for software collections, however, only 'title list' is found in practice. The problem of no proper directory with software collection would be more serious than the problem with book collection since browsing is not possible with softwares. Many of the expensive softwares will be a waste of money to purchase and to hold if no catalog about them is provided. In this paper the difficulties in applying AACR2 to software cataloging and the most important characteristic of computer software are discussed as well as presenting the necessity of localized information due to the requirement of a machine to be used, the difficulty using subject-based-call-number scheme, an expected way of searching software to design a location indicator, software qualifications to be cataloged, and so on. In addition, an analysis of randomly selected softwares after a cataloging practice is followed.

The QOS(Quality of Service) recognized by the customer will become the most important thing under the competitive telecommunications market. Korea Telecom is going to develop many system to manage the telecommunication network, to improve the level of QOS, and to increase the revenue. Operation and Maintenance Adiministration System is one of the systems developed to meet those purposes efficiently. This system gathers qualities data from telephone offices or operation centers and analyze the results of QOS improvement activities and evaluate overall QOS. And also system makes it possible to improve the cost/effectiveness of operation and maintenance of telecommunication network. Operation and Maintenance Administration System has four functional modules, i.e., the user interface module, the database management module, the QOS management module, and the database conversion module. The purpose of this study is to develop the QOS management program, one of the four functional modules of the system,using FOCUS 4GL/DBMS. Since Operation and Maintenance Administration System is developed using FOCUS 4GL, every user can handle and maintain the system very easily and reduce system backlogs.

Decision Support System(DSS) is an advanced information system concept prevailing since 1980s. It supports managers' decision making activities by providing not only information but decision alternatives. It essentially consists of the components of database, modelbase and dialogue systems. With the development of its databases, POSCO needs a number of modelbases in establishing DSSs in various areas such as production planning and investment. This research particularly focuses on establishment of a mid-and long-range investment DSS and investigates the necessity and the problems of an investment DSS and the decision criteria for investment priority. We (1) propose a modelbase which uses the concepts of Analytic Hierarchy Process(AHP) and Zero-Base Budgeting(ZBB), along with an appropriate scoring method, database and dialogue system to support the investment manager in evaluating investment proposals ; (2) implement the system using relational database management system ; and (3) discuss the results of implementing the investment DSS.

The purpose of this paper is to study the sensitivity analysis in the matrix game. The third type sensitivity analysis is defined as finding the characteristic region of an element of the payoff matrix in which the set of current active strategies is preserved. First by using the relationship between matrix game and linear programming, we induce the conditions which must be satisfied for preserving the set of current active strategies. Second we show the characteristic regions of active and inactive strategy. It is found that the characteristic regions we suggests in this paper are same with that of the type one sensitivity analysis suggested by Sung[3] except only one case.

This paper addresses the problem of locating a telephone switching center at new establishing city or town. There have been several studies on the location of telephone switching center at an existing telephone network to cope with the expanding subsciber's demand, in most of which only the economic factors were considered and was determined where the switching center is established in order to minimize the total cost. This paper, However, deals with the social factors as well as the economic ones. We develop a location model considered these two factors simultaneously by using a fuzzy approach. Finally, we apply the model to locate a new telephone switching center at the Haeundae where the Pusan City intends to construct a new town.

A two phase heuristic algorithm has been developed for the resolution of resource conflicts in a single project scheduling problem. Phase 1 of the algorithm generates a feasible schedule by repairing resource conflicts. Phase 2 finds local improvements in the schedule found in phase 1. Then, the algorithm has been applied to multi project and job shop scheduling. Computational results are compared with those of dispatching procedures. Index Terms-disjunctive constraints, heuristic algorithm, project scheduling, job-shop scheduling.