• Journal of Digital Convergence
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• v.10 no.4
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• pp.207-215
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• 2012

This paper proposes a proxy-based caching optimization scheme for improving the streaming media services in wireless mobile ad hoc networks. The proposed scheme utilizes the proxy for data packet transmission between media server and nodes in WLANs, and the proxy locates near the wireless access pointer. For caching optimization, this paper proposes NFCO (non-full cache optimization) and CFO (cache full optimization) scheme. When performs the streaming in the proxy, the NFCO and CFO is to optimize the caching performance. This paper compared the performance for optimization between the proposed scheme and the server-based scheme and rate-distortion scheme. Simulation results show that the proposed scheme has better performance than the existing server-only scheme and rate distortion scheme.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.575-578
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• 2004

현재 휴대폰은 다양한 기능을 통합하고 있고 무선 인터넷의 발달로 인해 언제 어디서나 지속적으로 네트워크가 가능한 환경이 구축됨으로써 다양한 분야에 활용되고 있다. 본 논문은 휴대폰을 사용해서 원격 PC의 데스크탑을 제어할 수 있는 시스템을 설계 및 구현하였다. 본 논문에서 제안하는 시스템은 다수의 원격 PC상에서 실행되는 VNC Server, 실행중인 다수의 VNC Server를 모니터링하는 Monitor, 원격 PC들을 제어하는 휴대폰 상의 Mobile Viewer로 구성되고, VNC Server와 Mobile Viewer와의 통신을 위해 기존의 RFB(Remote Frame Buffer) 프로토콜을 모바일 환경에 맞게 수정한 MRFB(Mobile RFB) 프로토콜을 사용하였다.

• Journal of Internet Computing and Services
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• v.5 no.3
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• pp.25-33
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• 2004

Mobile IP Low Latency Handoffs(l) allow greater support for real-time services on a Mobile IP network by minimizing the period of time when a mobile node is unable to send or receive IP packets due to the delay in the Mobile IP Registration process. However, on Mobile IP network with AAA servers that are capable of performing Authentication, Authorization, and Accounting(AAA) services, every Registration has to be traversed to the home network to achieve new session keys, that are distributed by home AAA server, for a new Mobile IP session. This communication delay is the time taken to re-authentication the mobile node and to traverse between foreign and home network even if the mobile node has been previously authorized to old foreign agent. In order to reduce these extra time overheads, we present a method that performs Low Latency Handoffs without requiring further involvement by home AAA server. The method re-uses the previously assigned session keys. To provide confidentiality and integrity of session keys in the phase of key exchange between agents, it uses a key sharing method by gateway foreign agent that performs a trusted thirty party. The proposed method allows the mobile node to perform Low Latency Handoffs with fast as well as secure operation.

• Journal of Digital Convergence
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• v.13 no.3
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• pp.193-199
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• 2015

PUSH technology is a technology that can transfer server information without user's request and it is very useful in various areas along with mobile applications. This paper suggest a suitable application model that can utilizes the PUSH technology and mobile devices by finding a useful area. For this, AdMan, a mobile application which can utilize the PUSH technology and mobile devices has been developed. AdMan is a mobile application that developed once and can be able to run on both Android and iOS based mobile devices, since it was developed by using a tool called m-Bizmaker. AdMan is a customer management and advertisement system that can bring big efficiency by utilizing the PUSH technology and mobile application under the today's mobile environment, and it is a good model of ICT technology application of modern society. As an application that can maximize the utilization of the PUSH technology and mobile devices, AdMan can realize better effectiveness if it run on a PUSH server.

• Journal of the military operations research society of Korea
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• v.23 no.2
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• pp.25-44
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• 1997

Internet users been rapidly increased due to the convenient GUI environment. Current Web-based HTTP/CGI client/server architecture has several problems such as the CGI bottleneck, no maintaince of state, and no load balancing. However, with Java and CORBA technologies called“Object Web technology”, we can solve them because Java is not only a mobile code but also a platform-independent code, and CORBA has ability to build distributed object and language-independent object model. The goal of “Object Web technology”is to create multivendor, multiOS, multilanguage“legoware”using objects. This paper implement“Book Search System”which is Web-based client/server architecture using distributed objects. Environments of this implementation are Hangul Windows NT(included IIS) server, Hangul Windows 95 client, Visigenic's VisiBroker for Java 1.2 which is a product of CORBA 2.0, HTTP protocol on TCP-IP-based, Sybase SQL Anywhere 5.0 database server, and the interface between application server and database is JDBC-ODBC bridge middleware.

• Journal of Korea Multimedia Society
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• v.12 no.6
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• pp.876-881
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• 2009

Online game servers usually has been using the static thread pool system. But this system is not fit for huge online game server because the overhead is always up-and-down. Therefore, in this paper, we suggest the new algorithm for huge online game server. This algorithm is based on the prediction-based dynamic thread pool system. But it was developed for web servers and every 0.1 seconds the system prediction the needed numbers of threads and determine the thread pool size. Some experimental results show that the check time of 0.4 seconds is the best one for online game server and if the number of worker threads do not excess or lack to the given threshold then we do not predict and keep the current state. Otherwise we apply the prediction algorithm and change the number of threads. Some experimental results shows that this proposed algorithm reduce the overhead massively and make the performance of huge online game server improved in comparison to the static thread pool system.

• Convergence Security Journal
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• v.4 no.2
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• pp.53-60
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• 2004

We describe CHAP authentication for roaming service method of visited ISP subscriber on GPRS network. We also illustrate how visited mobile ISP subscriber can access ISP server and authenticate RADIUS in home network via Gateway GPRS Support Node (GGSN) on GPRS/UMTS network for wireless internet service and roaming. For this we propose the modified CHAP message format, PCO Message format at MT, and interworking message and format between GGSN and RADIUS in home ISP network for wireless internet service of mobile ISP subscriber at GPRS network in this paper. We also show authentication results when visited mobile ISP subscriber via CHAP at GPRS network accesses the RADIUS server in home ISP network.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.264-268
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• 2007

This article presents the performance evaluation case study of circuit-switched WCDMA R5MSC(Mobile Switching Center) Server and CS-MGW(Circuit Switched Media Gateway) in 3'rd generation mobile telecommunication (UMTS : Universal Mobile Telecommunication System). The presented work adopted circuit switching scenarios recommended by 3GPP(Third Generation Partnership Project) and terrestrial spectrum calculation parameters and its values defined in ITU-R M.2023 and M.1390 to do the case study on performance evaluation of circuit switched system (R5 MSC Server and CS-MGW) in WCDMA core network. This paper describes test results by using simulator which substitutes for wireless section (MS, Node-B, RNC).

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.233-237
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• 2008

This paper presents proposal for an application (only for Windows-based Mobile) that can synchronize the Third Generation Windows-based mobile with the prescribed server. This application can be used by mobile users to send information directly to the WAS server wirelessly. In this paper a comparison between Third Generation technology and WLAN ( both are parallel technologies first one embodied by IMT-2000 standards and the second one by ITU Standards) has been made and also a comparison between Wi-Fi and Bluetooth has been made.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.132.2-132
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• 2001

In this paper, we propose an efficient configuration of a system for the remote control of a mobile robot. The interface has a video feedback and runs in standard web environments. For control servers of mobile robot and CCD camera, we use the environment with embedded web server Specific program has been developed in order to grab the images using Microsoft Visual C++ The external camera sends the video signal to a framegrabber in the PC, then this program grabs the images and puts them in shared memory in BMP format. For a video feedback, we use image feedback based on the client pull technique supported by Netscape and Internet Explorer.