The ring routing and wavelength assignment problem arose in the planning of optical communication networks which use WDM rings. Traffic demands are given for each pair of nodes in an ring : each demand must be routed one of the two possible connections round the ring and the wavelength assignments must be made so that there are no conflicts : that is. no two connections whose routes share a link can be assigned the same wavelength along that link. The objective is to minimize the number of used wavelengths. We propose the local optimal routing for the problem and show that there always exists an optimal solution satisfying it. Furthermore we suggest a new lower bound for the problem and show that it is very efficient for the worst case example.

This paper is aimed at surveying the method that supports logical and theoretical back grounds of electricity service pricing, to investigate whether the ESPM can reflect comprehensively the various interests of parties and persons concerned with electricity supply and demand, and analyzing the practical applicability of the model in short-term perspectives. The major findings of this study can be summarized as fellows. First, the ESPM explains what process the equilibrium price is attained through, which is the essential concept and object in evaluating the value of public enterprises or utilities and the price of electricity Second, the ESPM provides the logics and methods that can objectify the discrete price by each electricity user. Third, the ESPM presents theoretical logics and practical methods that can calculate the basic price and the variable price per electricity unit which are key concepts in the two-part tariff. Fourth, the ESPM has powerful practical applicabilities in the reasonable electricity pricing and in the explanation for the balance between parties and persons interested with electricity supply and demand.

The transaction tables of the existing association algorithms have two column attributes : It is composed of transaction identifier (Transaction_id) and an item identifier (item). In this kind of structure, as the volume of data becomes larger, the performance for the SQL query statements came applicable decreases. Therefore, we propose advanced association rules algorithm of n-items which can transact multiple items (Transaction_id, Item 1, Item 2…, Item n). In this structure, performance hours can be contracted more than the single item structures, because count can be computed by query of the input transaction tables. Our experimental results indicate that performance of the n items structure is up to 2 times better than the single item. As a result of this paper, the proposed algorithm can be applied to internet shopping, searching engine and etc.

We study a multi-component production/inventory system in which individual components are made to meet various demand types. We assume that the demands arrive according to a Poisson process, but there is a fixed probability that a demand requests a particular kit of different components. Each component is produced by a flow line with several stations in which the processing times of each station follow a two-stage Coxian distribution. The production of each component is operated by an independent base-stock policy with blocking. We assume that the time needed to assemble final products follows a general distribution and the capacity of an assembling facility is sufficiently large. The objective of this study is to obtain key performance measures such as the distribution of the number of each orders for each final product and the mean time of fulfilling a customer order. The basic principle of the proposed approximation method is to decompose the original system into a set of subsystems, each subsystem being associated with a flow line. Each subsystem is analyzed in isolation using a Marie's method. An iterative procedure is then used to determine the unknown parameters of each subsystem. Numerical results show that the accuracy of the approximation method is acceptable.

This paper considers subway crew scheduling problem. Crew scheduling is concerned with finding a minimum number of assignments of crews to a given timetable satisfying various restrictions. Traditionally, crew scheduling problem has been formulated as a set covering or set partitioning problem possessing exponentially many variables, but even the LP relaxation of the problem is hard to solve due to the exponential number of variables. In this paper. we propose two basic techniques that solve the subway crew scheduling problem in a reasonable time, though the optimality of the solution is not guaranteed. We develop an algorithm that solves the column-generation problem in polynomial time. In addition, the integrality of the solution is accomplished by variable-fixing technique. Computational result for a real instance is reported.

A satisfiability problem in propositional logic is the problem of checking for the existence of a set of truth values of atomic prepositions that renders an input propositional formula true. This paper describes an empirical investigation of a particular integer programming approach, using the set covering model, to solve satisfiability problems. Our satisfiability engine, SETSAT, is a fully integrated, linear programming based, branch and bound method using various symbolic routines for the reduction of the logic formulas. SETSAT has been implemented in the integer programming shell MINTO which, in turn, uses the CPLEX linear programming system. The logic processing routines were written in C and integrated into the MINTO functions. The experiments were conducted on a benchmark set of satisfiability problems that were compiled at the University of Ulm in Germany. The computational results indicate that our approach is competitive with the state of the art.

This paper presents an interactive decision procedure to aggregate each group member's preferences when each group member articulates his or her preference information incompletely. An index, an indicative for the preference strength between alternatives, is derived to aid each decision maker to articulate preference information about alternatives. We develop a mathematical programming model that can establish dominance relations when the preference information about values of alternatives, attribute weights, and group member's importance weights are provided incompletely. Also, the preference relation between alternatives is to be considered in the model. Based on the preference strength measure and mathematical model, we develop an interactive group decision support procedure.

This study aims at developing and empirically testing a comprehensive model of organizational justice derived from the prior empirical studies on organizational justice. The study seeks to understand the antecedents to and the consequences are addressed. The first question is what characteristics of the HRM systems determine the levels of perceived distributive and procedural justice. Hypotheses are derived from the two prominent theoretical models, i.e., the self-interests model (SIM) and the group value model (GVM). Those factors include neutrality, consistency, accuracy. ethicality. credibility. and reciprocity in the processes of making HRM decisions. All nine factors suggested by the two models aye adopted for this study as major determinants of both distributive and procedural justice. The second question of this study is related to the moderating effects of individual differences on the relationship between the SIM and GVM variables and perceived distributive and procedural justice in organizational contexts. The final research question deals with the consequences of perceived organizational justice. specifically job - related altitudes and organizational commitment. Job-related attitudes in this study refer to job satisfaction, job motivation, and job involvement, i.e., the willingness to make contributions. identification with organization, and intent to stay. In examining the consequences of perceived organizational justice, the study focuses on the interaction effects of procedural and distributive justice on the above nine outcome variables. The results show that both SIM and GVM variables significantly influence distributive and procedural justice. However, hierarchical regression analyses reveal that the GVM variables except more influence has been focused on the consequences of perceived distributive justice with regard to outcomes provided by the organization.

In this paper, a mathematical model was introduced to analyze pricing and quality strategies for the web sites of electronic intermediaries. Especially, I focused on the intermediary sites that initiate their businesses by providing free services such as free e-mail, search, and directory services. intermediaries may gather third party providers looking for new markets for their services, based on customers who want to use the free services. And intermediaries provide charged intermediary services to both of customers and providers. By analyzing the mathematical model, I can find optimal quality and prices to maximize the profit of intermediaries. And I can found also that intermediaries should make efforts to improve their productivity of developing their services to make profits.

This study establishes key factors on ISM (Internet Shopping Mall) performance in Korea. The four factors are derived from the relevant literature and clarified the concept of ISM characteristics, customer characteristics, ISM evaluation level. and perceived risks by distinguishing between its components and determinants. ISM performance indicators were derived from the previous studios classifying by ISM attitude and ISM usage. We examine on the impact of ISM characteristics and customer characteristics on the ISM evaluation level, then its level and perceived risks on the ISM performance. Hypotheses on four factors of ISM performance were tested for 172 respondents. Results indicate that four factors may partially serve as key predictors on ISM performance. ISM characteristics and customer characteristics was found to be positively influenced on ISM evaluation level, and its level also positively affected on ISM performance while perceived risks negatively affected on ISM performance.

The importance of competitive intelligence (CI), which collects/uses information about competitors, industries, etc., has been increased due to the rapidly changing business environment of today. However, there exist few domestic researches on CI. With this background, a study of domestic companies was performed that examines how the enterprise characteristics, the interest on CI, and the informatization level affect the way/level and outcome of CI. Results showed that bigger enterprises have the higher interest on CI than smaller ones and enterprises having high interest perform CI activities systematically and variously including using the internet. Further, the results uncovered the enterprises performing CI actively use the information acquired from the activity effectively in their business. The results also revealed that there are no difference between the IT companies and the others and that the jnformatization level is irrelevant to the internet CI activity level.

In this study, we consider infinite supply of raw materials and backlogged demands as given two boundary conditions. And we need not make any specific assumptions about the inter-arrival of external demand and service time distributions. Under these situations, the ultimate objective of this study is to prove the variability propagation principle in a pull serial line and is to measure it in terms of the first two moments of the inter-departure process subject to number of cards in each cell. Two preparations are required to achieve this objective : The one is to derive a true lower bound of variance of the inter-departure process. The other is to establish a constrained discrete minimax problem for the no backorder (backlogging) probabilities in each cell. We may get some fundamental results necessary to a completion for the proof through the necessary and sufficient conditions for existence of optimal solution of a constrained discrete minimax problem and the implicit function theorem. finally, we propose a numeric model to measure the variability propagation principle. Numeric examples show the validity and applicability of our study.