• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.577-579
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• 2001

컴포넌트 소프트웨어의 주된 목적은 소프트웨어 개발에 있어서 재사용을 증가시키고 개발자간의 협동과 협조를 증가시키기 위한 것이다. 이러한 컴포넌트 기습이 가져야 할 가장 중요한 특징으로는 상호운용성이 있다. 이러한 상 운용성을 위해 분산 컴포넌트의 다양한 서비스들을 뵐 환경의 사용자들이 사용할 수 있게 하기 위해서, 웹 기반에서의 XML을 이용하였고, 현재 웹 기반의 환경에서 여러 가지 웹 기술들이 사용되고 있으므로, 이들 기술들을 사용하여 비교할 만한 가치가 있다. 따라서 본 논문에서는 분산 객체 패러다임중 하나인 CORBA의 컴포넌트들과 웹 환경의 사용자들의 상호운용성을 위해 CORBA와 XML의 연동을 위한 응용 웹 서버의 구조를 제안하고, 옹용 웹 서버 구조의 성능 분석을 한다.

• Publications of The Korean Astronomical Society
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• v.24 no.1
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• pp.83-91
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• 2009

We have designed data processing server system to include data archiving, photometric processing and light curve analysis for KMTNet (Korea Microlensing Telescope Network). Outputs of each process are reported to the main photometric database, which manages the whole processing steps and archives the photometric results. The database is developed using ORACLE 11g Release 2 engine. It allows to select objects applying any set of criteria such as RA/DEC coordinate and Star ID, etc. We tested the performance of the database using the OGLE photometric data. The searching time for querying 70,000,000 records was under 1 second. The database is fully accessed using query forms via web page.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2531-2533
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• 2002

In this paper, we evaluate feasibility of an object-oriented method in a distributed real-time control environment through the prediction of delay expected. We adopt CAN as the distributed network and the application layer of the CAN is composed of client/server communication model of COM and surroundings for the support of real-time capability of the COM. Mathematical models formalizing delays which are predicted to invoke in the COM architecture are proposed. Sensors and actuators which are widely used in distributed network-based systems are represented by COM objects in this paper. It is expected that the mathematical models can be used to protect distributed network-based systems from violation of real-time features by the COM.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2840-2842
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• 2002

인터넷 전자상거래의 발달로 데스크탑 컴퓨터만이 아니라 냉장고, 달리는 차안, PDA, 핸드폰 등 생활 영역 곳곳에서도 전자상거래를 할 수 있다. 이런 다양한 서비스를 보장하기 위해서 서비스 제공자는 같은 상품이라도 상황에 따라 다양한 화질의 이미지를 제공한다. 현재 전자상거래에서 쓰이는 이미지들은 같은 상품임에도 구하고, 쇼핑몰마다 각각 따로 저장하고 있고, 하나의 이미지도 쓰임새에 따라 다른 해상도로 각각 저장되어 있다. 인터넷의 자원은 한정되어 있기 때문에 이미지가 분산되어 저장되면 자원을 낭비하게 된다. 또한, 이미지를 효율적으로 관리하기 어렵다. 따라서, 다양한 이미지들을 효율적으로 사용하는 방법의 필요성이 대두되고 있다. 본 논문에서는 인터넷에서 이미지 파일을 사용하고 저장하는데 효율적인 웹 이미지 서버를 구현하고 성능을 평가하였다.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.79-83
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• 2015

This paper suggested a cyber collaboration platform based on web for food safety service. We implemented the cyber collaboration platform for food safety service so that the users participated in collaborative work may refer shared media objects as the same view to others. In this paper, we discussed a model for increasing reliability of food safety data through N screen server and client model. This paper explained a performance analysis of a system with function comparison running on multimedia collaboration work based on web and N screen techniques.

• International Journal of Reliability and Applications
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• v.8 no.1
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• pp.67-82
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• 2007

This paper deals with the effectiveness analysis of an engineering system, which has two units of different strengths in parallel and one unit as a cold standby unit. Failure times for all the units have negative exponential distribution whereas their repair times have general distribution. Single server caters the need for the system. The effectiveness analysis of the system is done by using regenerative point technique. The different measures of effectiveness such as mean sojourn time, mean time to system failure, availability, busy period, etc, are derived. Cost factors also taken into consideration.

• The Journal of the Acoustical Society of Korea
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• v.22 no.4E
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• pp.176-182
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• 2003

As the needs for wireless Internet service is increasing, the needs for secure m-commerce is also increasing. Conventional security techniques are reinforced by biometric security technique. This paper utilized the voice as biometric security techniques. We developed speaker verification system for m-commerce (mobile commerce) via wireless internet and wireless application protocol (WAP). We named this system the mVprotek. We implemented the system as client-server architecture. The clients are mobile phone simulator and personal digital assistant (PDA). The verification results are obtained by integrating the mVprotek system with SK Telecom's code dimension multiple access (CDMA) system. Utilizing f-ratio weighting and virtual cohort model normalization showed much better performance than conventional background model normalization technique.

• Korean Journal of Computational Design and Engineering
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• v.8 no.3
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• pp.175-183
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• 2003

This paper introduces a Web-based vibration analysis system for rotary-type refrigerator compressors. Concern for vibration reduction in compressors has been growing for many years. What is important in vibration reduction is to easily predict the vibration without using a physical compressor. The dynamic model of the compressor is represented as a multi-body dynamic system. Solving the dynamic model is run on a high-performance server. The interfaces of the system are accessible via Web browsers, such as Netscape or Explorer. Anyone who wants to analyze the vibration of the rotary compressor or share the results data can access the system over the Internet regardless of their OS, platform, or location.

• Journal of the Korea Society for Simulation
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• v.9 no.2
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• pp.51-61
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• 2000

In recent years, significant advances in computers and communication technologies have made multimedia services feasible. As a result, various queueing models and cost models on architecture and data placement for multimedia server have been proposed. However, most of these models do not evaluate dependability of systems. In the design phase of a system, simulation is an important experimental means for performance and dependability analysis. Fault injection simulation has been used in evaluation of dependability metric. In this paper, we develop fault injection simulation model to analyze dependability of parallel video servers. In addition, we evaluate reliability and MTTF(Mean Time To Failure) of systems by using the simulator.

• ETRI Journal
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• v.35 no.2
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• pp.234-244
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• 2013

Internet protocol television (IPTV) service depends on the network quality of service (QoS) and bandwidth of the broadband service provider. IEEE 802.16j mobile multihop relay Worldwide Interoperability for Microwave Access networks have the opportunity to offer high bandwidth capacity by introducing relay stations. However, to actually satisfy QoS requirements for offering IPTV services (HDTV, SDTV, Web TV, and mobile TV) for heterogeneous users' requests, providers must use a video server for each IPTV service type, which increases the network load, especially bandwidth consumption and forwarding time. In this paper, we present a solution for forwarding IPTV video streaming to diverse subscribers via an 802.16j broadband wireless access network. In particular, we propose a new multicast tree construction and aggregation mechanism based on the unique property of prime numbers. Performance evaluation results show that the proposed scheme reduces both bandwidth consumption and forwarding time.