• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.859-861
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• 2001

VIA는 클러스터 또는 시스템 영역 네트워크를 위한 표준화된 사용자수준 통신 아키텍쳐이고, GFS는 LINUX 클러스터에서 사용할 수 있는 공유 락일 시스템이다. 클러스터 환경에서 GFS를 사용할 때 특별한 스토리지 네트워크가 설치되어 있지 않으면 GNBD를 사용한다. GNBD는 TCP/TP 상의 소켓을 기반으로 구현되어 있기 때문에, VIA를 사용하는 클러스터이더라도 VIA 하드웨어 상에서 TCP/IP 소켓을 통하여 GNBD를 작동시킨다. VIA와 같이 물리적 연결이 신뢰성이 높고 높은 수준의 기능을 제공하는 경우는 같은 클러스터 안에서 TCP/IP 프로토콜 스택을 사용할 필요가 없다. 본 논문은 VIA상에서 GNBD를 위한 고속 통신 계층(VCONN)을 제안하여, 동일한 VIA 하드웨어에서 지원되는 TCP/IP 모듈을 사용했을 때보다 읽기, 쓰기 성능을 각각 약 22%, 30% 향상시키는 방법을 소개한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.275-281
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• 2004

Socket weldment used to change the flow direction of fluid nay have flaws such as lack of fusion and cracks. Liquid penetrant testing or Radiography testing have been applied as NDT methods for flaw detection of the socket weldment. But it is difficult to detect the flaw inside of the socket weldment with these methods. In order to inspect the flaws inside the socket weldment, a ultrasonic testing method is established and a ultrasonic transducer and automated ultrasonic testing system are developed for the inspection. The automated ultrasonic testing system is based on the portable personal computer and operated by the program based Windows 98 or 2000. The system has a pulser/receiver, 100MHz high speed A/D board, and basic functions of ultrasonic flaw detector using the program. For the automated testing, motion controller board of ISA interface type is developed to control the 4-axis scanner and a real time iC-scan image of the automated testing is displayed on the monitor. A flaws with the size of less than 1mm in depth are evaluated smaller than its actual site in the testing, but the flaws larger than 1mm appear larger than its actual size on the contrary. This tendency is shown to be increasing as the flaw size increases. h reliable and objective testing results are obtained with the developed system, so that it is expected that it can contribute to safety management and detection of repair position of pipe lines of nuclear power plants and chemical plants.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.142-145
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• 2015

Presentation is the form of communication to draw out audience's behaviors in a limited time. The importance of presentation is emphasized over time. So speaker uses various remote toola. Therefor, in this paper, the remote control system for presentation using mobile network was proposed. The existing remote control applications has error on network connection, and are difficult to use without description for use. This system was designed and implemented to compensate the defect of the existing system. The system we have will connect PC and smartphones through socket to communication with TCP, which is connection-oriented transport service. It is made for users to select the files from the list of sent files and operate the process of presentation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.332-334
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• 2014

PC와 모바일 디바이스 간에 데이터를 전송하는 방법은 여러 수단이 있으나, 직접 연결 또는 동일한 IP의 소켓통신을 위한 방법만이 존재한다. 이러한 방법들은 PC 와 모바일 디바이스가 직접적으로 연결되어야 가능하며, 동일한 OS가 아닌 경우 자료형의 범위 차이로 인한 데이터 훼손이 발생한다. 이를 개선하기 위해 데이터베이스 영역을 공유하며 데이터의 입 출력 시에 Base64 코드로 변환하여 데이터의 형태를 통일 시키는 방법을 사용한다. 본 논문에서는 서로 다른 이기종 플랫폼 PC와 모바일 디바이스 간의 이미지 데이터 비교를 위하여 원본 바이트코드를 Base64로 변환 하는 과정을 거친다. 이 때 데이터양의 증가로 발생되는 전송속도 저하를 개선하기 위하여 모바일 디바이스와 데이터베이스를 직접 연결하는 JTDS 기법을 적용하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.874-876
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• 2001

클러스터링(clustering)은 병렬 처리를 위한 기술로 비교적 값이 싼 컴퓨터들을 네트웍으로 연결하여 전체가 하나의 고성능 수퍼 컴퓨터처럼 동작하게 하는 기술이다. 이 클러스터 시스템의 성능을 최대한 활용하기 위해서는 디스크 입출력에 생기는 병목현상을 해결하여야 하는데, 그 해결책의 하나로 병렬파일시스템을 들 수 있다. 기존의 병렬파일시스템은 TCP/IP기반의 소켓으로 메시지를 주고받았다 그러나 TCP/IP는 프로토콜 오버헤드가 크고 처리 속도가 느리다. 본 논문에서는 이런 오버헤드를 줄이기 위해 도입된 Lightweight 메시징 기법인 VIA(Virtual Interface Architecture)를 이용하여 병렬파일시스템을 구현하기 위한 구체적인 방안을 제시하고 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.285-286
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• 2023

본 논문에서는 개인용 클라우드 서버를 구현하였다. 서로 다른 컴퓨터간의 파일 공유를 쉽게 해 주고 접속한 클라이언트간의 상태를 동기화하여 사용자 경험과 접근성을 높였다. 서버는 NodeJS환경으로 실행되며 solidjs로 만들어진 웹 페이지를 vite를 통하여 빌드하고 클라이언트에 전송하여 렌더링하고 클라이언트와 서버는 웹 소켓으로 연결되어 서버의 변경사항을 실시간으로 반영한다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.11
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• pp.1-5
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• 2010

We developed a novel micro-electro mechanical systems (MEMS) test socket using silicon on insulator (SOI) substrate with the cantilever array structure. We designed the round shaped cantilevers with the maximum length of $350{\mu}m$, the maximum width of $200{\mu}m$ and the thickness of $10{\mu}m$ for $650{\mu}m$ pitch for 8 mm x 8 mm area and 121 balls square ball grid array (BGA) packages. The MEMS test socket was fabricated by MEMS technology using metal lift off process and deep reactive ion etching (DRIE) silicon etcher and so on. The MEMS test socket has a simple structure, low production cost, fine pitch, high pin count and rapid prototyping. We verified the performances of the MEMS test sockets such as deflection as a function of the applied force, path resistance between the cantilever and the metal pad and the contact resistance. Fabricated cantilever has 1.3 gf (gram force) at $90{\mu}m$ deflection. Total path resistance was less than $17{\Omega}$. The contact resistance was approximately from 0.7 to $0.75{\Omega}$ for all cantilevers. Therefore the test socket is suitable for BGA integrated circuit (IC) packages tests.

• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.15-20
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• 2017

In this paper, Esp8266, Node.js, and TCP / IP socket communication are used to design a compact data integration device. This device is designed to configure server and client using Esp8266 module that supports Wifi connection and to support bidirectional data transmission using TCP / IP socket communication. The server is configured using the Node.js operating system, and the database is integrated using Mysql. The network is designed to have a separate IP address by assigning a private IP address to the router, such as a home network. This device can transmit data bidirectionally, store individual client data on the server side, and can check the flow of data transmitted bidirectionally through wire-shark, so that it can be used as a compact real-time data integration and convergence device.

• Fire Science and Engineering
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• v.29 no.3
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• pp.21-30
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• 2015

In this study, we try to suggest measures to reduce leakage at a joint between CPVC piping for a sprinkler system and a pipe expansion through reviews of domestic and foreign standards and related tests. The quality of the waterproof rubber packing material between a valve socket and pipe expansion nut was examined. In the leak test, the valve socket material over the expansion part of the metal pipe nut was found to use a metal part or a schlorinated polyvinyl chloride pipe nut part. In addition, the KS B 0221 standard for parallel pipe threads with threaded and thread inspection criteria and inspection standards in order to ensure an acceptable quality of valve socket, there is a need to amend the regulations to comply with the KS B 5223 (screw thread limit gauges parallel pipe threads). We do not have detailed standards for expansion piping nuts for waterproof rubber ring material, so we need to amend the relevant criteria for EPDM material to be used with excellent waterproofing, for which both NBR and EPDM are currently used.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.491-498
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• 2005

The Denial of Service(DoS) attacks, which are done by consuming all of the computing or communication resources necessary for the services, are known very difficult to be protected from. TCP has drawbacks in its connection establishment for possible DoS attacks. TCP maintains the state of each partly established connection in the connection queue until it is established completely and accepted by the application. The attackers can make the queue full by sending connection requests repeatedly and not completing the connection establishment steps for those requests. In this paper, we have designed and implemented the extended TCP for preventing from SYN Flood DoS attacks. In the extended TCP, the state of each partly established connection is not maintained in the queue until the connection is established completely. For the extended TCP, we have modified the 3-way handshake procedure of TCP and implemented the extended TCP in the Linux operating system. The test result shows $0.05\%$ delay more than original TCP, but it shows that the extended TCP is strong for SYN Flood attacks.