• Title/Summary/Keyword: 전우회

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Fault-tolerance Analysis of Link Line of Beta-network in the Multicomputer System (다중 컴퓨터 시스템에서의 Beta-network의 링크선에 관한 Fault-tolerance 분석)

  • 전우천;김성천
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.4
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    • pp.610-617
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    • 1987
  • This thesis is concerned with fault-tolerance of a B-net (Beta-network) which is a kind of interconnection network in the multicomputer system. In this paper, a method for obtaining Maximal Tolerable Fault Set(MTFS) of link line connecting switching elements in the arbitrary B-net is presented. Using this method, it is seen that testing of DFA capability is possible when s-a-faults of link line occur, and criterion for determining degree of fault- tolerance of a B-net in terms of link line is introduced.

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A Study on Design, Fabrication Techniques and Test Results of 1.2kV 180A Inductive Superconducting Fault Current Limiter by Conduction-Cooled System (전도냉각에 의한 1.2 KV/80 A급 유도형 고온초전도 한류기의 설계, 제작 및 테스트에 관한 연구)

  • 강형구;전우용;이승제;안민철;배덕권;윤용수;고태국
    • Progress in Superconductivity and Cryogenics
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    • v.5 no.2
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    • pp.30-35
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    • 2003
  • The inductive superconducting fault current limiter (SFCLJ limits the fault current with its dc reactor. To fabricate the optimal dc reactor for inductive SFCL, several design and manufacturing technologies are necessary. In this paper, the manufacturing technology for dc reactor and cryogenic cooling method are described in detail. GM-cryocooler was used enlarge the critical current of dc reactor by cooling down the temperature of dc reactor about 20 K. Moreover, the results of short circuit test were described. Finally, the thermal characteristics of conduction-cooled system were discussed and then, sub-cooled nitrogen system was proposed to enhance the thermal stability of dc reactor.

OpenMP Implementation using POSIX thread library on ARM11MPCore (ARM11MPCore에서 POSIX 쓰레드를 이용한 OpenMP 구현)

  • Lee, Jae-Won;Jeun, Woo-Chul;Ha, Soon-Hoi
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.10b
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    • pp.414-418
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    • 2007
  • 멀티프로세서 환경에서 OpenMP는 MPI 에 비해 병렬 프로그래밍을 쉽게 할 수 있다는 장점을 가지고 있고, OpenMP는 표준이 없는 병렬 프로그래밍 세계에서 실질적인 표준으로써 인정받고 있다. OPenMP는 대상 플랫폼에 따라 OpenMP 구현을 다르게 해야 하기 때문에 새로운 프로세서가 등장하면 그에 맞는 OpenMP구현을 만들어야 한다. 이 논문에선 다중 프로세서 시스템-온-칩 시스템인 ARM11MPCore 시스템 위에 POSIX 쓰레드에 기반하여 OpenMP 환경을 구축하고 그 성능을 측정한다.

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Implementation and Translation of Major OpenMP Directives for Chip Multiprocessor without using OS (단일 칩 다중 프로세서상에서 운영체제를 사용하지 않은 OpenMP 구현 및 주요 디렉티브 변환)

  • Jeun, Woo-Chul;Ha, Soon-Hoi
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.4
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    • pp.145-157
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    • 2007
  • OpenMP is an attractive parallel programming model for a chip multiprocessor because there is no standard parallel programming method for a chip multiprocessor and it is easy to write a parallel program in OpenMP. Then, chip multiprocessor systems can have various architectures according to target application programs. So, we need to implement OpenMP in different way for each system. In this paper, we propose the implementation and the effective translation of major OpenMP directives for a chip multiprocessor without using OS to improve the performance without using special hardware and without extending the OpenMP directives. We present the experimental results on our target platform CT3400.

Voltammetric Determination of Cobalt(Ⅱ) Using Carbon Paste Electrodes Modified with 1-(2-Pyridylazo)-2-naphthol

  • 배준웅;박유철;이상학;전우성;장혜영
    • Bulletin of the Korean Chemical Society
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    • v.17 no.11
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    • pp.995-999
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    • 1996
  • A method for the determination of cobalt(Ⅱ) by differential pulse voltammetry using a carbon paste electrode constructed by incorporating 1-(2-pyridylazo)-2-naphthol(PAN) into a conventional carbon paste mixture composed of graphite powder and Nujol oil has been developed. Several influencing factors for the determination of cobalt(Ⅱ) were studied in detail and the optimum analytical conditions were found to be as follows: pH, 4.6; composition of electrode, 20%; temperature of deposition, 43 ℃; time of preconcentration, 15 min. Regeneration of the electrode surface for the continuous uses of the electrode was achieved by exposing the carbon paste electrode to an acidic solution. Response of the electrode was reproducible for the uses of five times and the relative standard deviations were 6.7 and 4.6% for 2.0×10-5 M and 4.0×10-6 M cobalt(Ⅱ), respectively. The calibration curve for cobalt(Ⅱ) obtained by differential pulse voltammetry was divided into two linear ranges of 1.7× 10-6-1.3×10-4 M and 2.0×10-7-8.0×10-7 M. The detection limit was estimated to be 1.3×10-7 M. The effects of coexisting ions were also investigated to test the applicability of the proposed method to the determination of cobalt(Ⅱ) in real samples.

Design and Implementation of Ethernet Bandwidth Manager for Supporting Controlled-Load Service (부하제어형 서비스 지원을 위한 이더넷 대역폭 관리기의 설계 및 구현)

  • Kim, Byeong-Sik;Lee, Jae-Kuk;Chun, Woo-Jik
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.4
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    • pp.430-440
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    • 2000
  • To support Integrated Services in the Internet, the Internet Engineering Task Force(IETF) has developed new mechanisms. These new mechanisms include Resource Reservation Protocol(RSVP) and Integrated Services model. RSVP and Integrated Services are independent of the underlying link layer technologies and it is necessary to define the mapping of RSVP and Integrated Services specifications onto specific link layer technologies. IETF proposed a Subnet Bandwidth Manager(SBM) providing a method for mapping RSVP onto IEEE802 style networks. However, the SBM has several constraints and problems. For solving these constraints and problems, we design and implement a new Ethernet Bandwidth Manager(EBM). This paper discusses (1) new bandwidth management mechanism independent of RSVP, (2) simulation of Ethernet bandwidth to analyze the characteristics of Ethernet and accomplish Ethernet bandwidth management, (3) design and implemetation of EBM that allows Controlled-Load Service, and (4) results of our experiments on EBM.

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A VPN controlled by CE Routers on MPLS Networks (CE 라우터 기반의 MPLS VPN)

  • Lee, Young-Seok;Han, Min-Ho;Chun, Woo-Jik;Choi, Hoon
    • Journal of KIISE:Information Networking
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    • v.29 no.1
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    • pp.31-39
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    • 2002
  • The VPN(Virtual Private Network) is a private network constructed logically on a public network infrastructure. There have been numerous studies to support the VPN services by using different technologies such as IP in IP, GRE, L2TP, MPLS and so on. Among these technologies, MPLS has shown many merits in aspects of QoS, security, and management, compared with other technologies. As an enhancement of the VPN that is controlled by MPLS PE(Provider Edge) routers, this paper presents the VPN controlled by MPLS CE(Customer Edge) routers. The functional architecture of the CE based VPN and operations of the CE routers are described along with the performance comparison of CE based MPLS VPN. It has been shown that the CE based VPN has more advantages than PE based VPN with respect to independency, scalability, security, and complexity.

Analysis of Exposure Dose According to Chest and Abdomen Combine CT Exam Method (CT 흉·복부 통합검사 시 선량분석)

  • Mo, KyeongHwan;Han, DongKyoon;Lim, HyunSoo;Jeon, WooJin
    • Journal of the Korean Society of Radiology
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    • v.8 no.7
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    • pp.401-408
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    • 2014
  • The purpose of this study is confirmed to usefulness between division exam and combine exam of chest and abdomen according to comparing chest and abdomen radiation dose of division exam and combine exam in CT exam method. This study was conducted on patients who were admitted to the E hospital from July 2013 to March 2014 underwent CT studies for the diagnosis of chest and abdomen disease. In study result, male dose were more higher than female dose according to gender analysis of exposure dose that combine exam effective dose were male $33.10{\pm}2.75mSv$, female $31.66{\pm}3.12mSv$ and chest exam effective dose were male $9.07{\pm}2.62mSv$, female $8.30{\pm}2.18mSv$(p<0.05). And, division exam dose and combine exam dose were similar in gender comparison (p>0.05). And, combine exam effective dose, only chest exam effective dose, only abdomen exam effective dose were more higher than DRL(Diagnostic Reference Level) in comparison of patient exposure dose with DRL (p<0.05). In conclusion, chest-abdomen combine exam dose and division exam dose were similar. The chest-abdomen combine study can be used as follow-up and emergency trauma patients. That study will be reduce exam time and the occurrence risk of side effect of the contrast medium.