비동기 전송모드 다중화기의 효과적인 통신정보량 제어에 관한 연구

조석팔 聖潔大學校 情報産業技術硏究所 1998 情報産業技術論叢 Vol.3 No.-

The transmission services satisfying characteristics of each traffic should be supported in the data communication networks. Existing packet multiplexing technique was difficult to serve real-time service due to delay. But Asynchronous Transfer Mode using cell can provide high-speed cell transmission and flexible bandwidth allocations. This paper propose the scheme and the management algorithm of the cell-based multiplexer The proposed multiplexer model is composed of two buffers which can store cells with two characteristics that is, delay sensitivity and loss sensitivity. Also threshold is set to protect high priority cell in each buffer and when the input traffics are unbalanced, variable service time period is operated to satisfy the characteristics of each input traffics. We analyze the performance of the proposed multiplexer model using queueing theory and present transmission parameters which satisfy high quality of services.

잠재적 의미 분석을 이용한 정보 검색

김창민 聖潔大學校 情報産業技術硏究所 1997 情報産業技術論叢 Vol.2 No.-

Most systems that manage distributed information have difficulties in retrieving relevant information for they are not able to include the exact semantics of retrieval queries that users request. In this paper, we proposed automatic query expansion based on term distribution which reflect semantic of retrival term to enhance the performance of information retrival and we evaluated the performance. We use LSI(Latent Semantic Indexing)'s SVD(Singular Value Dacomposition) technique to measure the term distribution which appear similar to query. And we measure the similarity to compared numerical value with query terms. Also we researched the method for setting the threshold according to area distribution in other to choose additional terms automatically. Finally, we applied the proposed method in this paper to two experimental DB's to evaluate the performance.

전자상거래 경쟁력 강화와 정보보호기술 개발 전략에 관한 연구

안익수,주해종 聖潔大學校 情報産業技術硏究所 1999 情報産業技術論叢 Vol.4 No.-

Electronic Commerce is emerging as one method for the commercial activities in domestic and abroad. In view of the growing trend of the Electronic Commercial market, there is no doubt that the Electronic Commerce shall take the main position of the information society in the 21st century. As the least developed country in this field and with the inferior competition, our country has to analyze the mutual relationship between the Electronic Commerce and national interest and prepare the proper and immediate response. If not, out country will be a straggler in this new global market environment. In this paper, we will access the development of Electronic Commerce in the market concept and look over the way to strengthen the competition. In this paper, our situation and problems is analyzed by dividing the Electronic Commercial market into the products sale market and environment construction market, and the statistics for enhancing the market share and competition is proposed through the development of the information protection technology.

전파모델 연구를 위한 데이터 분석 모듈 개발

김용규 聖潔大學校 情報産業技術硏究所 1999 情報産業技術論叢 Vol.4 No.-

In order to provide various communication service, it is required to measure and analysis of field data so that propagation characteristics can be properly applied. This paper proposes a software tools that is used for analysis of measuring data that come from various device and format. By the proposed tools, analysis process can be standardization. In this tool, all process modules are merged into single application environment, so that efficiency and robustness are improved. The proposed modules are easily linked to previous analysis module.

XML 저작도구의 설계

김길준,정용득 聖潔大學校 情報産業技術硏究所 1998 情報産業技術論叢 Vol.3 No.-

XML is a language which simplified standard to be adapted to WWW environment by W3C. In addition to the various advantage of SGML functions such as extendibility, structure, verification of documentation, it included URL link embedding and style-sheet function required by WWW environment. This paper proposed the WWW authoring tool based on XML. This authoring tool is designed to UNIX operating system workstation connected with network as a WWW server and was tested by using Windows 95/NT operating PC as a client system. The Proposed system based on XML, is will be serviceable on highly speed communication network of future.

코바 응용 프로그램 구현과 성능 분석

금영욱 聖潔大學校 情報産業技術硏究所 1999 情報産業技術論叢 Vol.4 No.-

In this paper, we develop CORBA-based distributed applications using two different languages, Java and C++. We use four combinations of two languages for server/client such as Java/Java, Java/C++, C++/Java, C++/C++. This is to exploit one of the CORBA advantages that CORBA enables any object developed in different languages to communicate with each other. For this purpose, we install and implement ORB products from two popular commercial ORB vendors, In prise and IONA. We also evaluate the performance of each combination of languages using two vendor products. The results show that C++ usually outperforms Java as expected, but Java/C++ combination performs better than C++/C++ in the remote case. It is also observed that In prise products are better than IONA's in terms of performance.

문서 영상 전송에 있어서의 효과적인 오류 정정방법에 관한 연구

조석팔 聖潔大學校 情報産業技術硏究所 1997 情報産業技術論叢 Vol.2 No.-

The document image quality depends on transmission characteristics. The Error Correction Mode to be used to normal error correction, in the improvement of document image quality which was damaged by electrically poor line characteristics and noise, is powerful to the single error pattern but weak to burst error pattern. Here Forward Error Correction, that is very strong to random error pattern, is applied to burst error with converting it into random pattern to improve the document image quality. This suggest the possibility of error correction to the burst error pattern and the confirmation of the error fixing process thru experiment.

객체 지향 개발을 위한 OMT 동적 모델 개선에 관한 연구

안익수,노환주,김길준 聖潔大學校 情報産業技術硏究所 1997 情報産業技術論叢 Vol.2 No.-

Statecharts is usually used as the specification model for dynamic model and reactive system, Statecharts is a superior computation model, but aspect of data is expressed by global variables and side effects to them, so the readability is lower when we describe larger systems in Statecharts. Moreover state structure in Statecharts is less relevancy to structure of object model. In this paper we propose the specification model OMT++. In OMT++, dynamic model is described with the structure of object model, which have more relevancy to structure of object model and more locality caused by making each object have state transition diagram and data. We show the prosperity of OMT++ through examples, and compare with Statecharts, and give operational semantics of OMT++.

특정 전파환경에서의 수신신호 감도에 관한 연구

김인겸 聖潔大學校 情報産業技術硏究所 1999 情報産業技術論叢 Vol.4 No.-

In this paper, it is presented the characteristics of the signal fading in three propagation environment. At first, the fading of a propagation signal is experimented in LOS(Line of Sight) regions without any obstacle. In the second, the signal fading is experimented in residential regions which have various houses and apartments. Finally signal fading is measured in the center of the city that have various markets, offices, and buildings. The fading of measured signals is very compatible in the existent propagation models. Especially the doppler effect is verified in the LOS region. The large scale fading and small scale fading are verified in the experimented data in the high frequency propagation environment for IMT-2000.

광역 코드분할다중접속 셀룰러 망에 관한 연구

조석팔 聖潔大學校 情報産業技術硏究所 1999 情報産業技術論叢 Vol.4 No.-

This paper reviews the spreading techniques of use in direct sequence Code Division Multiple Access cellular networks, and the theoretical background for sequences used in Code Division Multiple Access and wideband Code Division Multiple Access, and the main characteristics of the Maximal length, Gold sequences, as well as variable-and fixed-length orthogonal codes. This paper suggests a resonable method of multiple spreading for channelization and scrambling in Code Division Multiple Access and W-Code Division Multiple Access realizations.