• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.30-31
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• 2012

본 논문에서는 Android System 핵심 부분을 기존의 System Server 에 Application Server 를 더하여 2개의 서버로 재구성하는 방안을 논의한다. Application Server 는 DalvikVM 과 Application 저장/스케줄링 프로세스로 구성한다. Application Server 가 모든 사용자의 Application 을 저장하고 스케줄링하고 DalvikVM에 할당하여 실행시키도록 한다. 이 방법은 사용자 입장에서는 단순화된 Android System 구조로 인하여 응용의 개발이 용이해지고 응용의 반응도 빠르게 된다. 시스템 입장에서도 구조가 단순해져서 실행 효율이 좋아지고 메모리 사용 효율도 좋아진다.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.229-233
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• 2003

최근, 인터넷 사용자가 급증하면서 빠른 서비스에 대한 문제가 큰 관심이 되고있다. 특히 데이터베이스 시스템에서 저장 삭세 수정 등은 사용자에게 긴 대기시간을 요구할 수도 있기 때문에 사용자의 불평을 야기할 수 있다. 이 논문에서는 3-티어 방식에서 요즘 많이 사용되는 application server의 cache에 대해서 말하고자 한다. 기존 application server는 데이터를 application server cache에 저장하여 같은 데이터를 서비스할 경우 server의 cache를 사용하지만 이 논문에서 제안하는 것은 접속된 client를 관리하여 각각의 client에 cache를 만들고 application server나 또는 데이터베이스 server가 서비스를 하지 못할 경우는 가장 최근의 데이터를 가지고 있는 client를 찾아 client cache에 있는 데이터를 서비스 하자는 것이다.

• Journal of Korea Multimedia Society
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• v.7 no.10
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• pp.1400-1411
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• 2004

Recently, explosion of internet user requires fundamental changes on the architecture of Web service system, from single server system to clustered server system, in parallel with the effort for improving the scalability of the single internet server system. But current cluster-based server systems are dedicated to the single application, for example, One-IP server system. One-IP server system has a clustered computing node with the same function and tries to distribute each request based on the If to the clustered node evenly. In this paper, we implemented the more useful application service platform. It works on shared clustered server(back-end server) with an application server(front-end server) for a particular service. An application server provides a particular service at a low load by itself, but as the load increases, it reconfigures itself with one or more available server from the shared cluster and distributes the load on selected server evenly We used PVM for an effective management of the clustered server. We found the implemented application service platform provides more stable and scalable operation characteristics and has remarkable performance improvement on the dynamic load changes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.296-301
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• 2000

This paper provides the solution for supporting H.323 services through firewalls with proxy server. The paper Provides a survey of H.323 Protocol, and framework for firewalls. The Paper also discusses the issues of H.323 and proxy server - why H.323 is hard for firewalls, and service scenarios with H.323 terminals and proxy server. Finally, the paper propose an application proxy service architecture for supporting H.323 protocol.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1361-1373
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• 2001

In the firewall systems of 3-tier client/server systems, in general, data transmission speed is declined rapidly according to the duplicated proxy services in application server and fire wall server. In this paper, an application server configuration containing the proxy functions of firewall system is proposed so that the high speed data transmission can be achieved. The proposed application server can form the dual-homed gateway by means of the additional network interface card. The screened router of application server forms the screened subnet gateway that can separate the internal network. The proposed server configuration is more effective in traffic control than the traditional firewall systems and provides high speed data transmission with the functions of firewall. It can be also cost-effective alternative to the firewall system.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.361-364
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• 2002

EJB(Enterprise JavaBeans)는 서버 상의 Java 컴포넌트와 그 컴포넌트를 위한 동작 환경을 제공하는 전체 프레임웍(Framework)이다. EJB 에서 동작하는 컴포넌트를 엔터프라이즈 빈(Enterprise Bean)이라고 하고, 그 컴포넌트가 동작하기 위한 환경을 컨테이너(Container)라 한다 EJB 에서는 기존에 개발자가 직접 컴포넌트로 제공해 주어야 하는 트랜잭션, 영속성, 보안문제, 데이터베이스 연결 풀링, 쓰레딩 관리 같은 기능을 컨테이너에서 처리해 줌으로 일반 개발자는 복잡한 하부 로직에 신경쓰지 않으면서 더 쉽고 빠르게 동일한 기능을 구현할 수 있게 된다. 본 논문에서는 이러한 EJB 컨테이너를 설계함에 있어서 하나의 중요한 요소인 트랜잭션 관리에 관한 설계를 논한다.

• 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.

• The Transactions of the Korea Information Processing Society
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• v.2 no.5
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• pp.797-806
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• 1995

The Client-Server model is a computing technique that efficiently uses distributed resources via networks. But, generating an application using Client- Server model requires many different expertises to developers in comparison to that of using the centralized computing method. That is, and application developer must be familiar with network programming and GUI(Graphical User Interface) techniques in addition to conventional programming skills. Accordingly, the time and man power have been issued for building a Client-Server system. To alleviate these problem, the Client-Server applications development tools are needed To meet such a need, we developed a GUI based tool, called Hanuri/C, for generating Client-Server application programs. In comparison to existing Client-Server tools, Hanuri/C is reinforced Multimedia facilities, Hanuri/C is reinforced Multimedia facilities. Hanuri/C is considered as a front-end part of distributed system software. That is, Hanuri/C is a Client-Server tool similar to Forth Generation Language(4GL) supporting multimedia application on top of the Distributed Computing environment(DCE). In this paper, we present the design and implementation method of the middleware part of Hanuri/c.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.358-368
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• 2018

The mobile characteristics of the smart phone are well suited to on-the-site oriented services and are being utilized in a variety of ways. However, since most applications operate on a central server basis, Internet access is inevitable, and there are various problems such as an increase in server maintenance cost and security deterioration. Although researches have been proposed to utilize the smart phone itself as a server to improve it, these methods are based on downsizing the PC-based web server or modifying the smart phone kernel. These methods have the problems that a end user has to use the rooting, and they are not able to effectively utilize various communication means of a smart phone. In this paper, we propose a design and implementation of an application level smart phone web server. The server receives the document request from the remote via the Internet and in the local area using the WPAN. At this time, the web document is stored as an internal file structure of the smart phone application. We proposed the phttp protocol which uses server's phone number as ID for document request. Through the implementation, we analyzed the capacity and latency of stored data and its effectiveness is evaluated.