• Title/Summary/Keyword: client-server systems

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Design and Implementation of the EEIS Considering the Load of DB Server

  • Kim, Chang-Geun;Park, Byeong-Jin;Tack, Han-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.37-43
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    • 2003
  • Current Internet system of the entrance exam information to the university that is depending on searching key to solve the overloaded problem in the network and DB server or other tools to support HTML edit, haven't satisfied user's wants by supplying uniformed searching system. So this thesis will establish EEIS(Entrance Examination Information System) to prevent database overload phenomena when many users request a great amount of data at the same time and improve the decrease of speed and overload problem in DB server. EEIS playa role of bridge between outside client and DB server by placing VVS(Virtual View Server) between web server and DB server. By that method this system give users several usefulness in convenience and variety by supplying realtime data searching function to user. EEIS also give inner system manager more efficiency and speed in control the management system by solving those problem. This system is design and implementation to satisfy user's desire and give them more convenience and bring up the confidence of university that adopt this system at the end.

A Comparison Study for Optimal Implementation of the EDI Systems of Port Logistics (항만물류 EDI 시스템의 최적 구현을 위한 비교 분석)

  • 김현수;박남규;한계섭;최형림;조재형
    • The Journal of Information Systems
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    • v.10 no.2
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    • pp.103-128
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    • 2001
  • At present, the EDI systems are indispensable software in port logistics industry. Currently, a monopolistic VAN/EDI service provider operates the EDI services. The current EDI client software has the 2-tier fat client/server architecture. However, the current EDI software is lack of Web interface and causes lots of cost for maintenance. Therefore, a variety of implementation architecture has been being tried by using script, XML and distributed object-oriented technology. Web/EDI and XML/EDI are the new EDI systems, However, the EDI systems have some limitations such as speed. This study intends to compare the variety implementation architecture for the EDI systems in the users' perspective and explore the strong and weak points of each architecture. We compared the EDI systems based on our experience of more than 2-years of implementation project for the EDI systems of port logistics. We categorized the EDI systems as client application EDI, Web EDI using script, XML/EDI, and 3-tier distributed object-oriented EDI system. We compared them with criteria such as speed, program maintenance, easiness of implementation and usage, security, and load balancing and fail-over. Finally we discuss the direction of optimal EDI system architecture for the future.

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Low Overhead System Monitoring Based on SNMP for Embedded Systems (임베디드 시스템들을 위한 SNMP 기반의 저부하 시스템 모니터링)

  • Kim Tae-Su;Kim Dong-Uk;Kim Yong-Seok
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.43 no.3 s.309
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    • pp.1-9
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    • 2006
  • SNMP is a standard protocol for management of networking devices. Nowadays, most computer systems have capability to act as SNMP agents. In this paper, we developed a low overhead version of SNMP library for embedded systems, and implemented a monitoring software based on the library for a large number of target systems. The monitoring system consists of a monitoring server, SNMP agents, and client programs. The monitoring server collects status information from SNMP agents running on the monitoring targets, and sends summary information to client programs. We implemented two versions of clients, Java based standalone program and Web based program.

Spatio-temporal Query Processing Systems for Ubiquitous Environments

  • Kim, Jeong Joon;Kang, Jeong Jin;Rothwell, Edward J.;Lee, Ki Young
    • International Journal of Internet, Broadcasting and Communication
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    • v.5 no.2
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    • pp.1-4
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    • 2013
  • With the recent development of the ubiquitous computing technology, there are increasing interest and research in technologies such as sensors and RFID related to information recognition and location positioning in various ubiquitous fields. Especially, RTLS (Real-Time Locating Services) dealing with spatio-temporal data is emerging as a promising technology. For these reasons, the ISO/IEC published RTLS standard specification for compatibility and interoperability in RTLS. Therefore, in this paper, we designed and implemented Spatio-temporal Query Processing Systems for efficiently managing and searching the incoming Spatio-temporal data stream of moving objects. Spatio-temporal Query Processing Systems's spatio-temporal middleware maintains interoperability among heterogeneous devices and guarantees data integrity in query processing through real time processing of unceasing spatio-temporal data streams and two way synchronization of spatio-temporal DBMSs. Web Server uses the SOAP(Simple Object Access Protocol) message between client and server for interoperability and translates client's SOAP message into CQL(Continuous Query Language) of the spatio-temporal middleware.

Design and Implementation of a Digital Evidence Management Model Based on Hyperledger Fabric

  • Jeong, Junho;Kim, Donghyo;Lee, Byungdo;Son, Yunsik
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.760-773
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    • 2020
  • When a crime occurs, the information necessary for solving the case, and various pieces of the evidence needed to prove the crime are collected from the crime scene. The tangible residues collected through scientific methods at the crime scene become evidence at trial and a clue to prove the facts directly against the offense of the suspect. Therefore, the scientific investigation and forensic handling for securing objective forensic in crime investigation is increasingly important. Today, digital systems, such as smartphones, CCTVs, black boxes, etc. are increasingly used as criminal information investigation clues, and digital forensic is becoming a decisive factor in investigation and trial. However, the systems have the risk that digital forensic may be damaged or manipulated by malicious insiders in the existing centralized management systems based on client/server structure. In this paper, we design and implement a blockchain based digital forensic management model using Hyperledger Fabric and Docker to guarantee the reliability and integrity of digital forensic. The proposed digital evidence management model allows only authorized participants in a distributed environment without a central management agency access the network to share and manage potential crime data. Therefore, it could be relatively safe from malicious internal attackers compared to the existing client/server model.

The Development of the Automatic Demand Response Systems Based on SEP 2.0 for the Appliances's Energy Reduction on Smart Grid Environments (스마트 그리드 환경에서 가전기기의 에너지 저감을 위한 SEP 2.0 기반의 자동수요반응 시스템 개발)

  • Jung, Jin-uk;Kim, Su-hong;Jin, Kyo-hong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.9
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    • pp.1799-1807
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    • 2016
  • In this paper, we propose the automatic demand response systems which reduce the electric power consumption for the period automatically distinct from the existing passive demand response that a subscriber directly controls the energy consumption. The proposed systems are based on SEP 2.0 and consist of the demand response management program, the demand response server, and the demand response client. The demand response program shows the current status of the electric power use to a subscriber and supports the function which the administrator enables to creates or cancels a demand response event. The demand response server transmits the demand response event received from the demand response management program to the demand response client through SEP 2.0 protocol, and it stores the metering data from the demand response client in a database. After extracting the data, such as the demand response the start time, the duration, the reduction level, the demand response client reduces the electric power consumption for the period.

Design and Implementation of IMAP Server Supporting E-mail Address Internationalization(EAI) in a Mobile Environment (모바일 환경에서 다국어 전자 우편 주소 지원을 위한 IMAP 서버 설계 및 구현)

  • Lee, Jin-Kyu;Kim, Kyongsok
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.10
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    • pp.343-348
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    • 2015
  • Due to the need for multilingual e-mail address, EAI Working Group of the IETF has created a wide range of standards associated with e-mail address internationalization(EAI) since 2006. One of the authors and colleagues designed and implemented the mail server, SMTPUTF8, that supports EAI RFC protocols. SMTPUTF8 mail server is composed of new SMTP and POP3 servers supporting EAI RFC protocols. However, SMTPUTF8 did not include a new IMAP server supporting EAI RFC protocol. Recently many people are using smart phones to read and send e-mail messages in a mobile environment. IMAP server is more useful than POP3 server in a mobile environment. Therefore, in this paper, the authors have designed and implemented IMAP server and client app that complies with the IMAP standard (RFC) published by EAI WG of IETF to support multilingual e-mail address. This IMAP server is added to the SMTPUTF8 mail server so that users can access e-mail messages via IMAP client app in a mobile environment.

An Effective Protection Mechanism for SSL Man-in-the-Middle Proxy Attacks (SSL MITM 프록시 공격에 대한 효과적 방어방법)

  • Lim, Cha-Sung;Lee, Woo-Key;Jo, Tae-Chang
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.6
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    • pp.693-697
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    • 2010
  • In current e-commerce system, it happens that client's confidential information such as credit card numbers, pin numbers, or digital certificate may pass through a web proxy server or an altered proxy server without client's awareness. Even though the confidential information is encrypted and sent through SSL(Secure Sockets Layer) or TLS(Transport Layer Security) protocol, it can be exposed to the risk of sniffing by the digital certificate forgery at the proxy server, which is called the SSL MITM(Man-In-The-Middle) Proxy attack. In this paper, current credit card web-payment systems, which is weak at proxy information alternation attack, are analyzed. A resolution with certificate proxy server is also proposed to prevent the MITM attack.

Implementing Embedded systems with ORB for Distributed Control Systems

  • Kim, Kangsoo;Myungsun Ryou;Wookhyun Kwon
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.94.3-94
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    • 2002
  • Modern distributed control systems focus on system openness, network system architecture and PC based controller. This paper discusses the embedded systems with ORB for distributed control systems. Embedded systems have merits such as small size, low cost and user convenience. ORB allows users to program easily by using IDL and provides client/server network for heterogeneous platforms. By using embedded systems and ORB, we implement the system and validate it by using VME system. The developed system has benefits when it is applied to distributed control systems.

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The T-tree index recovery for distributed main-memory database systems in ATM switching systems (ATM 교환기용 분산 주기억장치 상주 데이터베이스 시스템에서의 T-tree 색인 구조의 회복 기법)

  • 이승선;조완섭;윤용익
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.9
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    • pp.1867-1879
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    • 1997
  • DREAM-S is a distributed main-memory database system for the real-time processing of shared operational datra in ATM switching systems. DREAM-S has a client-server architecture in which only the server has the diskstorage, and provides the T-Tree index structure for efficient accesses to the data. We propose a recovery technique for the T-Tree index structre in DREAM-S. Although main-memory database system offer efficient access performance, the database int he main-memory may be broken when system failure such as database transaction failure or power failure occurs. Therfore, a recovery technique that recovers the database (including index structures) is essential for fault tolerant ATM switching systems. Proposed recovery technique relieves the bottleneck of the server processors disk operations by maintaining the T-Tree index structure only in the main-memory. In addition, fast recovery is guaranteed even in large number of client systems since the T-Tree index structure(s) in each system can be recovered cncurrently.

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