• ETRI Journal
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• v.32 no.2
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• pp.292-301
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• 2010

Increasing convergence among heterogeneous radio networks is expected to be a key feature of future ubiquitous services. The convergence of radio networks in combination with dynamic spectrum allocation (DSA) could be a beneficial means to solve the growing demand for radio spectrum. DSA might enhance the spectrum utilization of involved radio networks to comply with user requirements for high-quality multimedia services. This paper proposes a simple spectrum allocation algorithm and presents an analytical model of dynamic spectrum resource allocation between two networks using a 4-D Markov chain. We argue that there may exist a break-even point for choosing whether or not to adopt DSA in a system. We point out certain circumstances where DSA is not a viable alternative. We also discuss the performance of DSA against the degree of resource sharing using the proposed analytical model and simulations. The presented analytical model is not restricted to DSA, and can be applied to a general resource sharing study.

• Journal of Digital Convergence
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• v.6 no.4
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• pp.45-52
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• 2008

The purpose of this study was to verify and analyze the factors that influence the intention using the travel-blog. This study sought to find out the motivation factors of a Blog. Also, This paper tests the updated model of information systems success proposed by Delone and McLean using a field study of a travel-blog. The three dimensions of the blog Quality were information, design and system. And The three dimensions of the motivation factors were pride, enjoyment and ease of use. Questionaries are collected from 196 peoples who are using the travel-blog. The results of study show, first, that information quality, pride and enjoyment are significant predictors of user satisfaction, second, that pride, enjoyment, and satisfaction are significant of reuse intention with the travel-blog. Third, ease of use did not have positive effects on reuse intention to travel-blog.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.113-116
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• 2001

XML (extensible Markup Language) is a flexible way to create common information formats and share both the format and the data on the World Wide Web, intranets, and elsewhere. A document type definition (DTD) is a specific definition of the rules of the Standard Generalized Markup Language. A relational database management system (RDBMS) is a program that lets you create, update, and administer a relational database. An RDBMS takes Structured Query Language (SQL) statements entered by a user or contained in an application program and creates, updates, or provides access to the database. This paper has been studied a method of mappings from XML DTD to RDB schemas based on object model.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.979-982
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• 2006

암호 API 및 PKI 클래스를 토대로 하는 PKI 시스템의 개발은 암호 알고리즘을 활용한 보안 서비스의 중요한 위치를 차지하고 있으며, 현재 네트워크 기반의 각종 서비스에서 강력한 보안 기능을 제공하는 부분으로, 각종 보안 서비스의 제공을 위해서 가장 먼저 구축되어야 할 부분이다. 본 논문에서는 자바 암호 API 및 PKI 관련 클래스를 바탕으로 사용자 인증(User Authentication), 인가(Authorization), 부인-방지(Non-Requdation), 전자서명(Electronic Signature) 등의 보안 서비스를 제공할 수 있는 X.509 전자인증서를 발행하는 PKI 시스템을 연구하였으며, 향후 각종 보안 서비스의 제공에 있어서 중요한 위치를 차지할 수 있을 것이다. 또한, 자바 기반의 PKI 시스템은 이식성이 매우 높으며, 개별 서비스에 대한 모듈 형식으로 구성되어 있어, 그 활용의 범위가 고정되지 않고 다양한 시스템 및 서비스에 적용할 수 있는 장점을 가지고 있다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.135-145
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• 1997

The statistical approach to quality control aims at alerting its user to any variations in the properties of a manufactured product. Motorola developed and pursued a quality management program called six sigma. The goal of six sigma programs is to improve customer satisfaction through reducing and eliminating defects. six sigma uses several statistical measure to characterize defect levels and process capabilities. The upper and lower specification limits are $\pm6\sigma$(sigma) from nominal, and the process mean is centered at nominal. only 0.002PPM are outside specification limits. Cp=2. this is the design target in a six sigma program. This article presents an important tool available for quality control of a production process at the occurrence of defects in manufactured products at view low levels to improve the efficiency of the manufacturing productivity and to satisfy customer through the reduction of defect rates. To understand the consequences of the level of quality on competitive position, a more technical perspective is needed.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.337-344
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• 1999

A database program, named Geoscope, was developed to effectively manage the enormous boreholes log data produced during the geotechnical investigation works in construction and mining Industry This program was designed to give a maximum conveniences to the end users when dealing with the geotechnical data obtained. Most of the values related to geotechnlcal attributes can be selected by a simple click of the mouse in list boxes or small windows provided by the program. Logging chart is automatically created at the same time as the input of the data in the form designated by the user. The made file format and the relational database system adopted in this program, furthermore, can allow the data to be associated with other GIS programs.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.485-488
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• 1998

Elementary school pupils frequently have difficult acquiring creative writing skills, i.e. how to develop the idea to be expressed, how to compose the materials of the outcome or contents. In this paper, we focus on the problems of how to support creative writing work to arrange materials in order to formulate ideas as the stories develop. the stories develop. The basic ideas behind the method are that(1) a basic story is automatically generated by GA-based operations and shown to a user as sequences of pictures, (2) IGA(Interactive Genetic Algorithm) is used to evaluate and select a preferred story, (3) the results are combined with previously stored stories using case-based techniques. Based on these ideas, we have developed a computer supported environment for this purpose and conducted related experiments.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.194-197
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• 1999

In AVL, GIS analyze the information from the vehicles to provide commercial or other value far user. As spatial analysis functions in GIS make a new valuable information using the vehicle's position and geographic object's location, they perform an important roles to improve the management efficiency of vehicles. Most GIS however are used static data for the spatial analysis, so the research area on AVL used dynamic vehicle location has generated unsuitable result. In this study, we use GPS real time tracking data to perform spatial analysis between moving vehicle and static geographic object. The method proposed in this paper considers the driving direction of vehicle and creates the result which is located in forward of vehicle. In this paper, two spatial analysis functions, near and connectivity, are developed.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.873-882
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• 2004

Multimedia database system can be improve data transferring efficiency by consulting catalogue database which is storing the object and serving multimedia meta-database and perform the pre-scheduling for data transferring and by delaying of transferring to reduce the responding timeand reordering the data by various method of transferring. By Introducing these techniques we can enhance the server resources utilizing, minimizing the users responding time and can decrease failure at the scheduling itself and easily search and transfer the information that the user wanted. Like this, the importance of multimedia information treating skill and efficient management are widely recognized and expected lots of research and development to form a butter efficient multimedia database syst

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.106-109
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• 2011

본 논문에서는 자동차 내부에 무선 센서 네트워크를 구축하여 데이터를 획득하고 처리하는 시스템을 개발하였다. 자동차 관리 시스템은 자동차 외부의 주행상황에 대한 정보를 받으며, 동시에 자동차 내부의 상태를 점검하고 사용자에게 내부 정보를 보여줌으로서 전문적인 지식 없이도 자신의 차를 유지 및 관리할 수 있도록 한다. 특히 사용자에게 접근이 용이하게 구현되어 승차자가 느끼는 시스템 접근의 어려움을 감소시키고 실질적인 편의를 도모한다. 시스템 구성은 차체 내부 데이터를 수집하는 단말 노드, 시리얼 통신용 수신 게이트웨이, 차체 정보를 처리하는 인터페이스 응용으로 분류된다. 자동차 관리 시스템의 성능을 확인하기 위해, 관련 하드웨어와 프로그램을 간략히 설명한다. 이를 위해 무선 센서 네트워크와 센싱 하드웨어의 특징을 기술하고, 이를 이용한 차량의 각종 전기신호와 센서들을 통합 제어하는 시스템을 제시한다.