• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.5
• /
• pp.1035-1041
• /
• 2004

Currently users are tend to use multimedia data types in their applications. Main features of multimedia data types are large amount of data compared to conventional data types. In this reason, it's hard to load data into main memory and to search. That is the cause of occur disk input and output frequently, and decrease the system performance. In this paper, we describe to have fast and efficient access to multimedia data using index technique. Index method presented by paper consists of two parts : one is index file part for keywords and the other is posting file part for the list of file names. Of course, we use keyword. But user is not charge of memory for the keywords. Users just use natural language to insert, delete and search data what he or she wants. Internally, System makes keywords from natural language to get access to multimedia data. It provides convenience to users. Using this study to develop one's application for multimedia, one may have a chance for advanced performance of a system and getting a result speedily.

• Communications of the Korean Institute of Information Scientists and Engineers
• /
• v.5 no.1
• /
• pp.04-10
• /
• 1987

We consider a time sharing computer system with a single processor where tasks ofK different types arrive at the system according to independent time homogeneous Poisson processes from outside. A task, after given a quantum for processing, leaves the system, or changes the type and rejoins the system according to specified probabilitycs. While many existing priority time sharing models determine the priorities of tasks strictly by their service time requirements, this paper develops a new scheduling rule wherein the importances or urgencies in addition to the service time requirements of tasks are counted, by inposing an appropriate reward structure on the system. Also presented is the algorithm through which to determine the rankings of K types according to this new scheduling rule.

• The Journal of Information Systems
• /
• v.10 no.2
• /
• pp.129-150
• /
• 2001

In this study, we model a decentralized supply chain system which is managed by four types of centers, sequentially located: Retailer, Wholesaler, Distributor, and Factory Each center contributes to enhancing the performance of the supply chain system individually with its own local inventory information. Through experiments which are performed with a programmed simulation (like the MIT beer game), we investigate how the information lead time improvement in each center affects the whole system. And we show that the impact of the lead time improvement in the downstream, like retailers, affects more to the system than the one in the upstream, like factories, in a cost-effective way. Moreover, by using information lead time for each center, we analyze how much the extent of the improvement affects the whole system, especially for the total cost and the order level.

• Journal of Korea Society of Industrial Information Systems
• /
• v.4 no.1
• /
• pp.97-101
• /
• 1999

The most important technical problem in EC is about secure electronic payment systems. Electronic payment systems come three different types distinguished by the payment method: electronic cash, electronic check, and creditcard. In these types, electronic cash payment system is popular and practical as in real commerce. But electronic cash can be copied easily, then it is infeasible to prevent user from double-spending a coin. In this paper, we overview several requirements for secure electronic payment system and present other proposed additions to the results. At last we present a model system which considers requirements above examined.

• International Journal of Computer Science & Network Security
• /
• v.21 no.11
• /
• pp.287-293
• /
• 2021

The purpose of this article is to consider the distance education system, its principles, features and means. One of its existing and promising tools is video conferencing. The article discusses the types of video conferencing, hardware and software, features and requirements for communication channels, types of information transmitted through these channels.

• Journal of the Korean Society of Systems Engineering
• /
• v.6 no.2
• /
• pp.29-35
• /
• 2010

In general, an Architecture of a system is embodied as applied results of a requirement analysis of a system in early development phase. These efforts play a important role in analyzing and understanding a system considering operational, functional, and physical view and deriving a correct solution before developing the system. In this paper, the architecture of the Tube Transportation System(TTS) known as the new transportation system in Railway Domain is depicted by performance parameter has already developed. The existing performance parameters are shown by a variety of types with many meanings rather than types of general requirements refined. As these early performance parameters have analyzed and complemented to a level of requirement by requirement managers and other domain specialists, the architecture of the Tube Transportation System was developed systematically and then system requirements will be drawn up definitely. The presented architecture will provide a framework of developing a TTS and also offer an information in performance analysis of TTS.

• Journal of Environmental Science International
• /
• v.21 no.8
• /
• pp.939-951
• /
• 2012

This study is conducted to estimate the air temperature decreasing effects by restoring urban streams using WRF/CALMET coupled system. The types of land use on covered streams are constructed with the land cover map from Korea ministry of environment. Restoring covered streams changes the types of land use on covered areas to water. Two different types of land use(CASE 1 and CASE 2) are inputted to the WRF/CALMET coupled system in order to calculate the temperature difference. The results of the WRF/CALMET coupled system are similar to the observed values at automatic weather stations(AWS) in Busan area. Restoring covered streams causes temperature to be decreased by about $0.34{\sim}2^{\circ}C$ according to the locations of streams and the regions that temperature is reduced are widely distributed over the restored area. Reduction of temperature is increased rapidly from morning and maximus at 13LST. Natural restoration of streams will reduce the built-up area within urban. With this, temperature reductions which are the cause to weaken the urban heat island appear. Relief of urban heat island will help to improve the air quality such as accumulation of air pollutants in within urban area.

• International Commerce and Information Review
• /
• v.10 no.1
• /
• pp.193-214
• /
• 2008

This study aims to examine similarities and differences of each e-B/L types as well as identify problems of e-B/L utilization and directions for improvement. Especially, it suggests strategies for the realization of e-B/L through reviewing and analyzing commercial types of e-B/L, which have been developed so far. Although e-B/L succeeded in realizing the function as a certificate of title and its distribution value, it has not been fully implemented due to operational problems. Subsequently, e-B/L was realized in the Bolero project as an attempt of system to make up for shortcomings in the failure of previous e-B/L types, but it has still a number of problems. To solve this problem and make use of e-B/L more efficiently, this study focuses on the specific ways to introduce e-B/L and suggest directions for the development of e-Nego system. Preparation of electronic documents is a prerequisite for the development of the e-Nego system, taking distribution of electronic documents into consideration. Next, compatibility of electronic documentation and paper-based documents should be realized, with the guarantee of authenticity of electronic documents.

• Industrial Engineering and Management Systems
• /
• v.15 no.3
• /
• pp.278-288
• /
• 2016

Automation ensures accurate and well-organized container transportation in container terminals. This paper addresses operational issues such as equipment scheduling and the coordination between various pieces of equipment in a rail-based automated container terminal. Containers are relayed using multiple types of equipment from road trucks to a vessel and vice versa. Therefore, handshaking is required during a container transfer between different pieces of equipment. Synchronization between the schedules of all the equipment is important to reduce equipment waiting times and the time required for transporting containers, which results in a short turnaround time for a vessel. This paper proposes an integrated control system with the objective of synchronizing the operations of different types of equipment, provides a list of decisions to be made by the control module of each type of equipment, and shows all the required information transfers between control modules. A scheme for the integrated scheduling of multiple types of equipment is proposed. The decisions made by each control module in a real-time fashion are listed with detailed explanations, and the information transfer between managers in a real-time situation at the proposed terminal is described.

• The Journal of Society for e-Business Studies
• /
• v.2 no.1
• /
• pp.53-77
• /
• 1997

This paper presents an efficient methodology for information system development by adopting the concept of extended components which can achieve the improvement of development productivity, reductrion of development time periods, quality improvement of information systems, etc. when information development projects are carried out. First of all, for efficient development of information systems, development steps of current methodologies for information system analysis are subdivided into components in detail and outputs required at each step are defined. The components are extended by types and various application methods are proposed in each step of information system development. In addition, a method which uses advantages of current methods such as SDLC, prototyping, and RAD, is also proposed. In this research, a CASE tool named S-Designer is used for the development of extended components and their interface, and a system development method called DSDM for the deviation of detailed steps and corresponding outputs.