Various problems on logistics systems have been dealt with recently as research issues since they were regarded critical for taking up a better position in the increasingly competitive global market. In particular, the freight transportation is considered as a key factor which affects the economic competitiveness of a whole nation as well as the production cost of individual companies. The objective of this study is to identify main issues and review recent foreign and domestic studies related to the freight transportation. The studies are classified into two categories according to the hierarchical level in the decision making process: infra structure design and transportation strategies, service design and operation. Main issues are introduced with a brief review on the related literature and methodologies applied.

This paper describes how studies at the Institute of Asian Pacific Studies for Multi-Clients, started in 1996, have gone beyond the boundary of 'production', to their present status. In addition, the issues on 'logistics' are suggested and new concepts of 'neo-logistics' are shown to be used as a solution for them. The essential meaning of logistics is explained and the importance of the systems concept is emphasized which can be used as an objective for the logistics engineering.

This paper presents a model for assessing the efficiency of logistics activities in distribution centers. The DEA approach is adopted to compare the relative efficiency of distribution centers, where considered as input and output factors are warehouse floor area, field storage area, average inventory level, overhead costs, number of workers, number of orders, and total value of goods handled. The artificial neural network approach is also adopted to overcome the limitation of DEA. The 12 distribution centers of Korea Telecom are studied for the validation of the model, which results in 84.9% of learning accuracy. This model can be used to identify the inefficient factors in a distribution center and to reveal changes in the degree of efficiency over time.

The objective of this paper is to help organizations select a suitable telecommunications media and dynamic route guidance system (DRGS) for an intelligent transport system (ITS) taking into account both cost and functionality. The media selection criteria and wireless communications for an ITS are discussed along with various DRGS. We describe which kind of telecommunication media and DRGS are suitable. The strategy of an ITS in Korea is described in regards to telecommunication media and DRGS.

The Korean government has made efforts to establish ITS (Intelligent Transport System) strategic plans and to implement ITS. Commercial Vehicle Operation (CVO) has been developed in Korea as one of five subsystems in ITS and also in the context of Integrated Logistics Information Systems (ILIS). A low-level strategic plan of CVO is fixed on October, 1997, which has two subsystems and six major services. In this paper, services, requirements and information technologies for CVO are introduced as well as operational tests, deployment cases and cost-effectiveness.

Fleet sizing and distribution of empty equipments are two of the most critical problems in managing transportation system. This paper develops a cost model for sizing a fleet and establishing decentralized redistribution polices of empty equipments by building from inventory theory of multi-echelon system in hub-and-spoke network. An analytical approach to determine control variables of redistribution policies in each terminal and fleet size of the transportation system is proposed and its results are validated by simulation model. Numerical experiments are conducted with respect to parameters of the model and test results for assumptions of the model are discussed.

This study is to develop a vehicle scheduling system for the efficient delivery of goods to places of business. For gathering data and testing the system developed, we have chosen a company which is located in Taegu city and has more than 700 delivery points over Taegu city and Kyungbuk province. We consider multiple vehicle types, travel time restrictions on vehicles, vehicle acceptance restrictions at delivery points, and other operational restrictions. We divide the whole delivery points into 44 regions and generate a region-based shortest path tree. Based on the shortest path tree, we perform vehicle assignment sequentially for each vehicle used. Then vehicle routings are determined. We have implemented the whole procedure on computer system. The system developed is flexible enough to be applicable to other companies by just changing the standard data.

The important issue for intra-city vehicle scheduling is to measure and store actual vehicle travel speeds between customer locations. Travel speeds(and times) in nearly all metropolitan areas change drastically during the day because of congestion in certain parts of the city road network. We propose three models for estimating departure time-dependent travel speeds between locations that relieve much burden for the data collection and computer storage requirements. Two of the three models use a least squares method and the rest one employs a neural network trained with the back-propagation rule. On a real-world study using the travel speed data collected in Seoul, we found out that the neural network model is more accurate than the other two models.

This study is focussed on an optimal vehicle routing model for multi-supply centers in two-echelon logistic system. The aim of this study is to deliver goods for demand sites with optimal decision. This study investigated an integrated model using step-by-step approach based on relationship that exists between the inventory allocation and vehicle routing with restricted amount of inventory and transportations such as the capability of supply centers, vehicle capacity and transportation parameters. Three sub-models are developed: 1) sector-clustering model, 2) a vehicle-routing model based on clustering and a heuristic algorithm, and 3) a vehicle route scheduling model using TSP-solver based on genetic and branch-and-bound algorithm. Also, we have developed computer programs for each sub-models and user interface with visualization for major inputs and outputs. The application and superior performance of the proposed model are demonstrated by several sample runs for the inventory-allocation and vehicle routing problems.

In these days many people have studied on the berthing problem. The operation rules differ from port so port and the problem is highly dependent on the environment of port. The purpose of this study is to develop a decision support system decision makers of the berthing problem for Inchon Port. The system is developed with graphic user interface(GUI) using user-interactive approach and some general and specific rules for Inchon Prot are considered. The system is composed of the following four parts ; the input/output part, the automatic berthing part by the system using rules, the manual berthing part by user, and the part for modifying results or handling exceptional events. The system is designed to assign ship to berths by matching the characteristics with environmental and operational constraints of Inchon Port. We expect that this system can provide decision makers with an efficient and fast way to berthing and can reduce wastes of time, space, and manpower in port operations.

A decision support system is introduced for the efficient operation of port container terminals. It consists of ship planning subsystem, yard planning subsystem, resource management subsystem, real-time control subsystem, and simulation subsystem. The system is intended to support the planning process of the planners and the operation process of the administrators in the container terminals. It is assumed that the transfer cranes and the yard tractor/trailers are used to handle containers in the marshaling yard. The system is explained in terms of the functions of each subsystem and the data flows among various subsystems.

The relative importance of Logistics in steelworks industry is rather higher among other business activities. The objective of the paper is to propose the methodology for real-time vehicle scheduling for scrap disposal in the steelworks industry. Currently, the rule necessary to assign vehicles to a specific job is strictly fixed. The paper adopts the multi-pass rule selector (MPRS) that suggests a promising rule used for vehicle dispatching for a period of time. The MPRS is regularly invoked if necessary and then evaluates a set of rule candidates to select the best rule with respect to the system performance criteria. The experiment shows that the proposed approach outperforms the current single-pass strategy.

Automated Storage/Retrieval Systems(AS/RS) are widely utilized to increase the efficiency of logistics system. In this paper, to offer the basic data required for the standardization and automation of AS/RS, we look into the conditions of several domestic AS/RS manufacturing companies and examine the national and international market conditions and the technical levels of domestic companies. And also, for the domestic companies, government departments and logistics related organizations, we survey and analyze the present state for the installation, implementation and operation of AS/RS and the related equipment systems, and the degree of recognition for the relational aspects.

In this paper, two parts of neural networks were proposed for determination of optimal EDM parameters. One is pattern recognition neural network that can be selecting expert neural network suitable to the EDM mode. The other is expert neural network that can be determining optimal EDM parameters such as pulse on time and pulse off time. Prior to determination of EDM parameters, Peak current, which is related to the EDM area closely, determined base on EDM area that is calculated from CAD data, firstly. Then, the other EDM parameters determined by the expert neural network that is selected to the EDM mode.

In multiparty multimedia communication, each participant not only receives information from other participants but also generates real-time data streams to distribute to others and therefore the difference between source and destination is not clear in terms of data transmission. During a teleconference session, many sub-multicast trees may be generated to exchange information to specific members within the multicast group and if those sub-multicast trees use the same fixed multicast tree, the blocking probability will be high and it is hard to provide QoS for each sub-multicast group. Also, even though there exits some shortcuts between each sub-multicast group, fixed multicast tree does not allow to use those shortcuts. Thus to overcome these problems. We propose a network resource reservation protocol and show that its effectiveness in terms of blocking probability and network resources usage.

This study has empirically analyzed the competitive strategies of the Korean component manufacturers. To differentiate the competitive strategies, the study employed two indexes: degree of support from customer firms and degree of internal innovation process. The performance measures include cost, quality, delivery and flexibility. 115 questionnaires were finally collected from the Korean part manufacturers and used for the final analyses. ANOVA, Chi-squared tests and t-tests were employed for statistical analyses. There are two major findings in this study. First, both internal innovation and external support from customers are equally important to improve manufacturing competitiveness of Korean component manufacturers. Second, strategic path to improve competitiveness of Korean component manufacturers is as follows: focusing on internal innovation ${\rightarrow}$ seeking for formal relationship with customers ${\rightarrow}$ pursuing external support from customers.

The maintainability prediction of an underwater military system is considered. A general and parctical prediction method for maintainability using MIL-HDBK-472 is presented. We develop a computer program to predict MTTR of an underwater military system. A case study is made to explain the proposed maintainability prediction method.

This paper is concerned with the bicriteria vehicle routing problems with time window constraints(BVRPTW). The BVRPTW is to determine the most favorable vehicle routes that minimize the total vehicle travel time and the total customer wait time which are, more often than not, conflicting. We construct a linear goal programming (GP) model for the BVRPTW and propose a heuristic algorithm to relieve a computational burden inherent to the application of the GP model. The heuristic algorithm consists of a parallel insertion method for clustering and a sequential linear goal programming procedure for routing. The results of computational experiments showed that the proposed algorithm finds successfully more favorable solutions than the Potvin an Rousseau's method that is known as a very good heuristic for the VRPs with time window constraints, through the change of target values and the decision maker's goal priority structure.

This paper describes a machine vision algorithm for inspecting a crimpled terminal. The crimpled terminal is one of wire harness assemblies which transmit current or signals between a pair of electrical or electronic assemblies. The major defect considered is wire exposure on wire barrels. To detect the wire exposure, we develope a multi-layer perceptron in which three features extracted from the image of the crimpled terminal are used as input data. The three features are edginess, variance, and total number of valley points(TVP). The multi-layer neural network has been successfully tested on a number of real specimens collected from a wire-harness factory.

This paper describes the development of on-the-machine measuring(OMM) system which can directly measure the two and three dimensional machined accuracy using a scanning probe in milling machine. Two algorithms, NC program based continuous path(CP) measurement and CAD data assisted point to point(PTP) measurement, are developed for three dimensional measurements, with consideration of the characteristics of the scanning probe. The algorithms are used to develop an auto measuring system. The delveloped system is compared with the CMM (Coordinate Measuring Machine) in terms of accuracy and repeatability. The OMM system is expected to realize measurement time reduction and hence result in high productivity.

Since the natural gas air-conditioning not only increases the base load of the gas company but also decreases the summer peak load of the electricity company, it is considerded as an efficient demand-side management program. This paper suggests the economic evaluation method of the gas air-conditioning program from the perspectives of the participants, the pipeline gas company, the local distribution company, the electricity company, and the total resources. The absorption type gas air-conditioning/space-heating is selected as a case study to illustrate the economic analysis of the natural gas air-conditioning.