• Korean Journal of Remote Sensing
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• v.31 no.1
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• pp.1-9
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• 2015

Mobility and cloud platform have become the dominant paradigm to develop web services dealing with huge and diverse digital contents for scientific solution or engineering application. These two trends are technically combined into mobile cloud computing environment taking beneficial points from each. The intention of this study is to design and implement a mobile cloud application for remotely sensed image fusion for the further practical geo-based mobile services. In this implementation, the system architecture consists of two parts: mobile web client and cloud application server. Mobile web client is for user interface regarding image fusion application processing and image visualization and for mobile web service of data listing and browsing. Cloud application server works on OpenStack, open source cloud platform. In this part, three server instances are generated as web server instance, tiling server instance, and fusion server instance. With metadata browsing of the processing data, image fusion by Bayesian approach is performed using functions within Orfeo Toolbox (OTB), open source remote sensing library. In addition, similarity of fused images with respect to input image set is estimated by histogram distance metrics. This result can be used as the reference criterion for user parameter choice on Bayesian image fusion. It is thought that the implementation strategy for mobile cloud application based on full open sources provides good points for a mobile service supporting specific remote sensing functions, besides image fusion schemes, by user demands to expand remote sensing application fields.

• The Journal of Society for e-Business Studies
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• v.6 no.3
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• pp.209-225
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• 2001

This paper Proposes the individual roles for developing small web application systems based on the Client/Server architecture with the activities and artifacts of each role and cooperation. The roles of Web Server part (i.e. User Interface Designer, Web Designer, HTML Writer), the roles of Application Server part (i.e. Domain Expert, Application Developer, Tester) and the roles of DB Server part (i.e. Database Administrator, Data Designer) are described. Furthermore, the role of the Development Leader that participates in development and manages all works in project and finds the solutions of problems in project, is also discussed. The Domain Expert analyzes the domain of the application in order to send the artifacts to the Application Developer. Then the Application Developer analyzes, designs and implements the application based on the artifacts of the Domain Expert and integrates the implemented program modules. Roles are related each other in this way, and cooperate until the application development is completed. Finally, we analyzed and compared these roles with the roles of RUP(Rational Unified process) and web wave. Suggested roles in this paper turned out to be efficient compared to the roles of the existing large-scale methodology.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.305-307
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• 2012

World Wide Web (WWW)의 지속적인 성장으로 인해 Web Service의 Response Time을 수집하는 방식에 관한 연구가 진행되고 있다. 현재 Client Response Time을 수집하는 방식은 sniffer[1] 를 이용한 Agent 방식을 사용하고 있다. 하지만, 기존의 방식은 클라이언트 PC에 설치되어 수집하게 되므로 Agent의 설치가 쉽지 않고, 관리 또한 어려운 문제점을 갖고 있다. 이러한 문제점을 개선하기 위하여, 본 논문에서는 Web Application Server (WAS)[2] 에서의 Dynamic HTML 변경을 통해 Client에 추가적인 Application을 설치하지 않고도 Client의 Response Time을 Collection하는 방식에 대하여 제안하였다. 이를 통해, 사용자 (End-User)에게 추가적인 응용 프로그램을 설치하지 않고도 Dynamic HTML 을 이용하여 Client Response Time을 수집함과 동시에 Server에 Feedback할 수 있다.

• The KIPS Transactions:PartD
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• v.15D no.1
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• pp.147-154
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• 2008

Along with the trend of internet use, various web application developments have been performed to provide information that was managed in the internal database on the web by making a web server page. However, in most cases, a direct program was made without a systematic developmental methodology or with the application of a huge developmental methodology that is inappropriate and decreased the efficiency of the development. A web application that fails to follow a systematic developmental methodology and uses a script language can decrease the productivity of the program development, maintenance, and reuse. In this thesis, the auto writing tool for a dynamic web server page was designed and established by using a database for web application development based on a fast and effective script. It suggests a regularized script model and makes a standardized script for the data bound control tag creator by analyzing a dynamic web server page pattern with the database in order to contribute to productivity by being used in the web application development and maintenance.

• Convergence Security Journal
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• v.4 no.2
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• pp.17-25
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• 2004

As Internet and Internet users are rapidly increasing and getting popularized in the world the existing firewall has limitations to detect attacks which exploit vulnerability of web server. And these attacks are increasing. Most of all, intrusions using web application's programming error are occupying for the most part. In this paper, we introduced real-time web-server agent which analyze web-server based log and detect web-based attacks after the analysis of the web-application's vulnerability. We propose the method using real-time agent which remove Process ID(pid) and block out attacker's If if it detects the intrusion through the decision stage after judging attack types and patterns.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.405-415
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• 1999

웹의 성장은 점차 복잡한 응용에 대한 요구를 가중시켰으며, 데이타베이스와 웹과의 효율적인 연동 역시 중요한 문제가 되었다. 본 논문에서는 이와 같은 환경을 효율적으로 지원하기 위한 웹 응용 서버 WATS를 설계하고 구현하였다. WATS에서 응용 프로그램은 컴포넌트 단위로 작성된 후 동적으로 링크되고 요청을 처리할 응용 서버가 대기 상태로 존재하는 확장 API 응용 서버 방식으로 구현되었으며, 이러한 웹 서버와 응용 서버의 분리 구조는 대량의 요청을 처리하기에 적합하다. 또한 컴포넌트를 특성에 따라 분류한 후 각 특성에 적합한 특성 기반 스케줄링 알고리즘을 적용하여 프로세스 부하 균형을 이루었으며, 이 기법이 일반적인 라운드 로빈 스케줄링 알고리즘보다 좋은 성능을 나타냄을 성능 측정을 통해서 보인다.Abstract The increasing popularity of the World-Wide-Web (WWW) has resulted in demand for more complex applications, and web gateways to database became core component in such applications. In this paper, we have designed and implemented WATS in order to support these environments. In WATS, application components are dynamically linked with application server processes. And it is implemented as extensible API application server architecture and is able to process a large amount of requests through separating web server from application server. Also we classify the components into various categories according to its own properties and devise process load balancing algorithm by using property-based scheduling. We show WATS using this algorithm performs better than those using general round-robin algorithm.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.113-118
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• 2008

The present research addresses the system design for building a geospatially-based web services application for mobile users. In recent years, geospatial information(GI) and Geographic Information Systems(GIS) are significant resources in decision-making analyses at various levels of society and activities. Recently, the integration of GIS and web services, called GIS web services, provides the wider implementation of GIS. At the present time, accessing, presenting, and manipulating updatedgeospatial information to locate geo-related facility services are real challenges related to application developers to implement for foot-travelers properly. The present paper investigates how the web services work in a GIS for discovering geo-related facility services such as a restaurant and post office in the user's vicinity. Thus, a prototype, with an architecture consisting of a windows application on the client side as well as facility services and geo-engineon the server side, were designed and implemented with the proposed GIS web services platform. On both the client and server sides, visual studio .Net technology was used. A geo-engine on the server side was also built with ESRI's MapObjects. Following successful implementation of the prototype presented in this study, the mobile user is able to invoke remote web services to assess the location of various facilities such as restaurants. Moreover, the present research demonstratesthat web services are not restricted only to web-based use, but can also be utilized by any web-connected application.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.1
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• pp.23-32
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• 2009

Although the web is becoming a widely accepted medium, it provides relatively poor performance and low availability. A cluster consists of a collection of interconnected stand-alone computers working together and provides a high-availability solution in application area such as web services or information systems. Web server clusters require a high-availability service with a proactive and practical fault management. However, as the system complexity grows, it is not easy to meet the requirement. Therefore, web server clusters must have self-fault management capability for meeting high-availability requirement. In this paper, we propose high availability web server clusters using self-healing technique with a minimal human intervention. Our experimental results show that a proposed method can be used to improve the availability of web server clusters.

• 한국디지털정책학회:학술대회논문집
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• 2004.11a
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• pp.211-219
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• 2004

Due to rapid increases in Internet users, it becomes essential to provide well-established web services and monitor web server's load for the sake of reliable web server management. The existing web server load monitoring has been based on such cable methods as RPC, RMI, CORBA and etc. But it has the limitation in bringing information both anywhere and anytime over the Internet. This thesis is aimed to realize real-time wireless web server monitoring system based on Wireless Application Protocol (WAP). As any user can log on wirelessly to the Internet at any time through wireless terminals like PDA, the realization will make possible instant and real-time web server monitoring.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.4
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• pp.216-223
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• 2013

As the fast growth of using Internet, the requests of clients having different types and pressing loads on the server have been increased in World Wide Web. Thus the interesting issue is how to measure the real capacity of a Web Server. There have been much recent studies about measuring the capacity of web server. But the cause of Server response time delay is not just server itself but also network packet loss. To measure the practical capacity of web server, we generate scalable clients using Posix Thread, transport packets which were generated by scalable clients to the server using UDP and receive the packets which were the remain packet from network packet loss using TCP. In this paper, we propose a method to measure the practical capacity of a web server using the Scalable Clients based on Posix Thread and the transport on Application level.