• Title/Summary/Keyword: Client-server system

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The Synchronization of WWW Browsers between Server and Client on Web-based Real-time Remote Lecture (웹 기반의 실시간 원격강의를 위한 서버와 클라이언트간의 웹브라우저 동기화)

  • Lee, Jeom-Suk;Lee, Bu-Gwon;Seo, Yeong-Geon
    • The KIPS Transactions:PartA
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    • v.8A no.1
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    • pp.70-74
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    • 2001
  • A general web-based remote lecture system uses video data and audio data to provide synchronize between teacher and students. This system requires high bandwidth, high speed networking, television, compression and computing technologies between server and client for remote lecture over Internet. As a result, this system can decrease an efficiency for lecturing over current Internet. So, this paper proposes a new mechanism calling as ‘Synchronization of WWW browsers between server and client’to cope with above problems and finally pursues low cost needed for real-time remote lecture over Internet. The mechanism means that every browser of teacher and students displays the same page and the action of teacher is transferred to the browser of student. And, this can be implemented by Windows hooking APIs, Memory Mapping, and DLL (Dynamic Link Library) programming technology. This paper points to the design and implementation of LAS (Lecture Assistant Server) and LAC (Lecture Assistant Client) to perform the synchronization between server and client.

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PDA-based Text Localization System Using Client/Server Architecture (Client/Server 구조를 이용한 PDA기반의 문자 추출 시스템)

  • 박안진;정기철
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04b
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    • pp.751-753
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    • 2004
  • PDA에서 사용하는 대부분의 CPU는 실수 연산 구성요소(float computation component)가 없는 정수(integer) CPU를 사용한다. 인공 신경망(neural network)과 같은 실수 연산이 많은 알고리즘은 PDA에서 많은 수행시간을 가진다. 본 논문에서는 이런 단점을 해결하기 위해 무선 랜(LAN)으로 연결된 Client(PDA)/Server(PC) 구조를 이용한 효과적인 문자 추출 시스템을 제안한다. Client(PDA)는 대략적인 문자 추출 결과를 JPEG으로 압축하여 전송속도를 최소화한다. Server(PC)는 Client(PDA)의 결과를 바탕으로 정밀한 문자 영역 추출을 위해, 텍스춰 분류 방법과 연결 성분 분석 방법을 이용한다. 실험에서 제안한 방법은 속도뿐만 아니라 문자 추출에서도 효과적이었다.

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Oil Spill Response System using Server-client GIS

  • Kim, Hye-Jin;Lee, Moon-Jin;Oh, Se-Woong
    • Journal of Navigation and Port Research
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    • v.35 no.9
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    • pp.735-740
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    • 2011
  • It is necessary to develop the one stop system in order to protect our marine environment rapidly from oil spill accident. The purpose of this study is to develop real time database for oil spill prediction modeling and implement real time prediction modelling with ESI and server-client GIS based user interface. The existing oil spill prediction model cannot provide one stop information system for public and government who should protect sea from oil spill accident. The development of multi user based information system permits integrated handling of real time meteorological data from external ftp. A server-client GIS based model is integrated on the basis of real time database and ESI map to provide the result of the oil spill prediction model. End users can access through the client interface and request analysis such as oil spill prediction and GIS functions on the network as their own purpose.

A Mechanism of CAS Client Personalization through separating CAS Service of Protocol A.1 on TTA.KO-07.0079 XCAS (TTA.KO-07.0079 XCAS 프로토콜 A.1의 CAS 서비스 분리를 통한 CAS Client 개인화 메커니즘)

  • Kim, Young-Mo;Jang, Eun-Gyeom;Choi, Yong-Rak
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.11
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    • pp.57-66
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    • 2010
  • CAS Client personalization means to issue CAS ID or Key for CAS service, which is Core Technology for CAS operation. Protocol A.1 on TTA.KR-07.0079 XCAS, stores CAS Client personalization data from CAS server in XCAS server, and transmits the personalization data by request of XCAS HOST for CAS Client personalization. However, this may increase Network Traffic and CAS Client image management in XCAS server. In this thesis, to complement this, CAS Client personalization is executed on CAS Server by separating CAS service field. Therefore this can distribute Image management and Network Traffic of XCAS server.

Development of Automatic Dependent Surveillance System with Java on Web Environment (자바를 이용한 인터넷 웹 방식의 항공기 자동감시시스템의 개발)

  • Yoon, Chong-Ho
    • Journal of Advanced Navigation Technology
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    • v.3 no.2
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    • pp.132-138
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    • 1999
  • This paper describes the development of an automatic dependent surveillance system(ADS) with Java on Web environment. The ADS consists of a server module and a client one. The server module performs a database server for gathering GPS data from airplanes. It also dose an Web server function for sending Java applet to clients. The applet enables each client to obtain the current flight information from the server via the Internet without a special client software. This client-server based ADS with Java environment has several advantages over other systems. One is not to need for installing special client software on each client system. The other is its simplicity on system maintenance. The reason why it has simplicity is to require only server program modification including the applet without updating client software. After testing the ADS system with the flight information of a Mooney, we can show that the prototype system can be a candidate for developing commercial products.

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A Design of Framework for Thin-Client by using X Protocol based Application (X 프로토콜 기반의 애플리케이션을 통한 씬-클라이언트 프레임워크 설계)

  • Song, Min-Gyu
    • Journal of Digital Contents Society
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    • v.10 no.4
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    • pp.509-520
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    • 2009
  • The advancement of network & application technology causes a major change for the use of IT(Information Technology) equipment, including computer and mobile system. In the process from beginning with main frame in the 1960s and 70's, through the server-client paradigm in the 1980s and toward the development of network computer since 90's, computer systems are now evolutioning from isolated physical system to complementary network based virtual system[1][2]. In network based computer system, application and data required for operation are stored at not client as local system, but at server[1]. User can use application & data on a server as if those are on a local client, and a client is now toward a developing thin and network friendly system. In this paper, we discuss possible ways for the efficient implementation of thin-client. For the use of remote application & data as if in local environment, we make use of X protocol. Unlike formal simple Client - Server paradigm, we design a Proxy for middle-tier server for the improvement of QoS and session persistence. X server, Xvfb(X virtual frame buffer) are implemented on thin client and Server, respectively and we applied XSMP(X Session Management Protocol) to our framework for session management. In the end, beyond simple transfer of server display, we suggest thin client framework for the transfter of remote server application over internet.

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Design of Thin-Client Framework for Application Sharing & Optimization of Data Access (애플리케이션 공유 및 데이터 접근 최적화를 위한 씬-클라이언트 프레임워크 설계)

  • Song, Min-Gyu
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.5
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    • pp.19-32
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    • 2009
  • In this paper, we design thin-client framework capable of application sharing & data access on the Internet, and apply related skills, such as X windows system, pseudo server, CODA file system, MPI(Message Passing Interface). We suggest a framework for the thin client to access data produced by working on a server optimally as well as to run server side application, even in the case of network down. Additionally, it needed to reflect all local computing changes to remote server when network is restored. To design thin client framework with these characteristics, in this paper, we apply distributed pseudo server and CODA file system to our framework, also utilize MPI for the purpose of more efficient computing & management. It allows for implementation of network independent computing environment of thin client, also provide scalable application service to numerous user through the elimination of bottleneck on caused by server overload. In this paper, we discuss the implementing method of thin client framework in detail.

The Implementation Methodology of Client-Server Architecture for Distributed Measurement System (분산 계측 시스템을 위한 클라이언-서버 아키텍쳐 구현 방안)

  • Song, Min-Gyu;Byun, Do-Young;Je, Do-Heung;Kim, Kwang-Dong;Roh, Duk-Gyoo;Oh, Se-Jin;Lee, Bo-Ahn
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.441-443
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    • 2004
  • With the rapid development of the Internet over the recent years, in conjunction with the transmission protocol TCP/IP and the latest version of hypertext(HTML) facilities, new opportunities have come into existence for the use of the network for the remote control of experiments and the other practical systems in engineering education. Using graphical software environments in client-server systems, remote control and monitoring system can be easily designed. Client-server systems have some general advantages when compared with simple Remote-Access Systems. In this paper we present a client-server architecture for the distributed measurement system of instrumentation over the Internet. The proposed solution allows multi-user, multi-instruments sessions to be obtained by means of a queuing process and provides instrument lock capability. Client applications can be easily developed by using conventional high-level programming languages or well-assessed virtual instrumentation frameworks.

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Control of mobile robot system with wireless transmission of image information.

  • Jeong, Sang-Hoon;Kwak, Jae-Hyuk;Lim, Joon-Hong
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.908-911
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    • 2004
  • There are various researches on mobile robot systems. Connection method between server and client of mobile robot system is one of them. In the case of mobile robot system, when connection method between server and client is wireless than wire, applications may be expanded. Also in remote monitoring environment using mobile robot system, we are interested in an effective transmission of the image information between server and client. In this paper, Bluetooth is used for connection method between server and client. One of the major applications of Bluetooth is the cable replacement for mobile and peripheral devices. Using Bluetooth, we propose the control method of mobile robot system. Bluetooth offers fast and reliable transmissions of both voice and data over the globally available 2.4GHz ISM (Industrial, Scientific and Medical) band. It has the advantage of small size, low power and low cost. It has the disadvantage of limited range and limited bandwidth. Also in order to transfer effectively image information between remote site(server) and mobile robot system(client) using Bluetooth, we applied to MPEG-2 and MPEG-4 image compression techniques and the results are compared with each other.

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Remote Dynamic Control of AM1 Robot Using Network (네트워크를 이용한 AM1 로봇의 원격 동적 제어)

  • Kim, Seong-Il;Yoon, Sin-Il;Bae, Gil-Ho;Lee, Jin;Han, Seong-Hyeon
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.556-560
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    • 2002
  • In this paper, we propose a remote controller for robot manipulator using local area network(LAN) and internet. To do this, we develope a server-client system as used in the network field. The client system is in any computer in remote place for the user to log-in the server and manage the remote factory. the server system is a computer which controls the manipulator and waits for a access from client. The server system consists of several control algorithms which is needed to drive the manipulator and networking system to transfer images that shows states of the work place, and to receive a Tmp data to run the manipulator The client system consists of 3D(dimension) graphic user interface for teaching and off-line task like simulation, external hardware interface which makes it easier for the user to teach. Using this server-client system, the user who is on remote place can edit the work schedule of manipulator, then run the machine after it is transferred and monitor the results of the task.

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