• Journal of Internet Computing and Services
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• v.5 no.6
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• pp.1-10
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• 2004

A web robot is a software that has abilities of tracking and collecting web documents on the Internet(l), The performance scalability of recent web robots reached the limit CIS the number of web documents on the internet has increased sharply as the rapid growth of the Internet continues, Accordingly, it is strongly demanded to study on the performance scalability in searching and collecting documents on the web. 'Design of web robot based on Multi-Agent to speed up documents collection ' rather than 'Sequentially executing Web Robot based on the existing Fork-Join method' and the results of analysis on its performance scalability is presented in the thesis, For collection speedup, a Multi-Agent based web robot performs the independent process for inactive URL ('Dead-links' URL), which is caused by overloaded web documents, temporary network or web-server disturbance, after dividing them into each agent. The agents consist of four component; Loader, Extractor, Active URL Scanner and inactive URL Scanner. The thesis models a Multi-Agent based web robot based on 'Amdahl's Law' to speed up documents collection, introduces a numerical formula for collection speedup, and verifies its performance improvement by comparing data from the formula with data from experiments based on the formula. Moreover, 'Dynamic URL Partition algorithm' is introduced and realized to minimize the workload of the web server by maximizing a interval of the web server which can be a collection target.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.510-512
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• 2007

이기종의 다양한 컴퓨터 시스템과 네트워크 장비 그리고 소프트웨어가 서로 혼재되어 있는 오늘날의 IT 환경을 효과적으로 관리하기 어려워짐에 따라 기업은 막대한 총 소유비용을 지출하고 있다. 이러한 상황을 효과적으로 대처하기 위하여, 분산 이기종 환경에서 플랫폼 독립적인 동시에 기술 중립적인 방법으로 시스템 자원을 감시, 통제, 조정하기 위한 표준 기술이 DMTF 를 중심으로 활발하게 개발되고 있다. 본 논문에서는 소형 단말기를 포함한 수많은 정보기기가 모두 네트워크로 연결되는 유비쿼터스 환경에서의 표준화된 시스템 관리를 가능케 하는 경량 CIM 서버가 가져야 할 요구사항을 도출하기 위해 현재 가장 대표적인 CIM 서버 솔루션을 중심으로 그 특징을 분석한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.523-528
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• 2001

In this paper, we describe the internet-based remote home automation system that con control and manage home appliances or digital devices bi-directionally through Internet. The platform-independency of VRML and Java applet enables users to access their home appliances and to check current state of them in t he virtual reality environment. The main focus is on three aspects. One is on the virtual reality technology to support the user interface efficiently by using 3D GUI in web-browser. Another is on the system architecture that consists of Home server and its manager server called Gate server in this paper. These servers have been implemented by Java RMI which is the basic single programming interface for distribution of objects and services using Java technology. The third, remote PLC controller and each digital devices are composed of home networking by PLC using CEBus protocol.

• Journal of Multimedia Information System
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• v.2 no.4
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• pp.327-332
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• 2015

Recently, as microcomputers and sensors have been miniaturized due to dropdown of their market rates, this lead to a favorable environment for implementing the Internet of Things. Smart clothing refers to a system which can be wearable or portable, and allows people to communicate or conduct sensing. Applying the Internet of things, the role of the server computer is to receive and process data obtained from the sensor. An ordinary PC can act as a server but during the implementation of IoT, a PC has limited application due to a large size and the inconvenient portability. This study proposes a model that allows a variety of functions while implementation with the server from the sensing using the Arduino and Raspberry Pi. If we apply this proposed model, everyone can easily and inexpensively experience mobile IoT system.

• The Journal of Society for e-Business Studies
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• v.3 no.2
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• pp.95-112
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• 1998

With the advent and proliferation of the Internet, Electronic Commerce(EC) on the Internet has become one of the most rapidly growing area and has been the subject of much research lately. EC is commercial transactions using computers in virtual environment through computer networks. The computer system deals with various ranges of things such as products, services, and information on EC. In this paper we describe the construction methods of web site based on the personalization, Also, we present the personalization technology and architecture of the P-Commerce proposed in this paper. Finally, we describe the methods constructing EC site using P-Commerce solution.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1785-1788
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• 2005

고성능의 확장성 있는 대규모 네트워크 서버 구현시 입출력 기능 향상을 위한 방법 중 하나는 비동기 입출력 기능을 이용하는 것이다. 비동기 입출력은 기존의 poll() / select()와 같은 입출력 멀티플렉싱 기법의 불필요한 CPU 부하를 방지하고, 입출력 완료를 기다리면서 블록되지 않으므로 시스템 부하를 감소할 수 있다. 본 논문에서는 리눅스 운영체제를 위한 POSIX 표준 네트워크 비동기 입출력 기능을 설계 및 구현하였고, 실험을 통해 기존 메커니즘과의 성능 차이를 비교하였다.

• Journal of the Korea Society for Simulation
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• v.9 no.2
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• pp.1-14
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• 2000

Recently, as construction of information infra including high-speed communication networks remarkably expands, more various information services have been provided. Thus the number of internet users rapidly increases, and it results in heavy load on Web server and higher traffics on networks. The phenomena cause longer response time that means worse quality of service. To solve such problems, much effort has been attempted to loosen bottleneck on Web server, reduce traffic on networks and shorten response times by caching informations being accessed more frequently at the proxy server that is located near to clients. And it is also possible to improve internet performance further by allowing clients to share informations stored in proxy caches. In this paper, we perform simulations of hierarchical proxy caches with the 3-level 4-ary tree structure by using real web traces, and analyze cache hit ratio for various cache replacement policies and cache sizes when the delayed-store scheme is applied. According to simulation results, the delayed-store scheme increases the remote cache hit ratio, that improves quality of service by shortening the service response time.

• Proceedings of the IEEK Conference
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• summer
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• pp.285-288
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• 2004

In this paper, we present a design and experiment of PCI Express core verification model. The model targeting Endpoint core based on Verilog HDL is designed by newly-emerging SystemC, which is a new C++ class library based system design approach. In the verification model, we designed and implemented a SystemC host system model which acted as Root Complex and device driver dedicated to the PCI Express Endpoint RTL core. The verification process is scheduled by scenarios which are implemented in host model. We show that the model is useful especially for verifying the RTL model which has dependencies on system software.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.121-124
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• 2004

유비쿼터스 환경에서 스마트 객체에 부착되는 RFID 태그에는 스마트 객체를 유일하게 식별하기 위한 식별자 만이 저장되고 객체의 상세 정보는 별도의 정보 서버에 분산 저장 및 관리가 된다. 이와 같이 분산되어 있는 정보를 사용하기 위해서는 사용자가 일일이 정보 서버의 위치를 알아 내고, 각 정보 서버로부터 필요한 정보를 얻어 와야 하는 문제가 발생한다. 본 논문에서는 여러 정보 서버에 분산 저장되어 있는 다양한 종류의 객체 정보를 실시간으로 통합하여 사용자에게 제공하고, 또한 객체 정보의 유형 및 특성에 따라 카탈로그 검색, 소유권 변화, 포함 관계 변화, 추적 등의 스마트 객체에 특화된 질의 기능을 제공하기 위한 스마트 객체 정보 통합을 위한 미들웨어의 설계 내용을 소개한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.886-888
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• 2005

고품질의 확장성 있는 서비스를 제공함으로써 다수의 사용자의 요청을 처리하고 시스템을 견고하게 유지할 수 있는 인터넷 서버를 구현하기 위한 한 가지 방법은 비동기 입출력 기능(AIO)을 이용하는 것이다. 기존의 고전적인 입출력 방식인 poll()/select()에 비해 AIO는 CPU 부하를 비롯한 시스템 자원의 낭비를 줄일 수 있으며, 입출력 완료를 기다리면서 블록되지 않으므로 시스템 부하를 감소할 수 있다. 본 논문에서는 리눅스 커널에 구현되어 있는 파일 기반 AIO기능을 네트워크 소켓 상에서 동작할 수 있도록 확장 구현하였으며, 그 구조에 대하여 자세히 설명하였다. 또한 클라이언트-서버 구조를 모델링한 실험을 통해 기존 메커니즘과의 성능 차이를 비교하였다.