• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.665-668
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• 2003

In this paper, we have designed and implemented the RAID controller board which connects to the host computer with serial ATA interface and connects to the disks with parallel ATA interface. Serial ATA interface is proposed to overcome the design limitation of parallel ATA while enabling the storage interface to scale with the slowing media rate demands for PC platforms. Serial ATA is to replace parallel ATA with the compatibility with existing operating systems and drivers, adding performance headroom for years to come. It Moreover, serial ATA provides even faster transfer rate of 150 Mbytes/s which is larger than that of current parallel ATA. The RAID controller board designed in this paper combines up to 4 disks with parallel ATA interface, and connects to PC host computer with serial ATA interface. We have implemented RAID controller using Verilog HDL language with FPGA chip. The RAID controller supports RAID level 0 and 1 functionality. Experimently, the average read/write performance of parallel ATA interface is about 30 Mbytes/s. Therefore, when 4 parallel disks is connected to the RAID controller board, we can get almost full throughput of serial ATA protocol using the RAID level 0 configuration with 4 disks.

• 한국멀티미디어학회논문지
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• 제4권6호
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• pp.579-587
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• 2001

본 논문은 그래픽 사용자 인터페이스를 이용하여 병렬 프로그래밍 환경을 설계하고 구현하였다. 병렬 프로그램은 다양한 하드웨어의 특성에 따라 또는 프로그램의 특성에 따라 사용자가 병렬 프로그램을 작성하여야 하기 때문에 사용자가 병렬 프로그램을 작성하는 것은 매우 어렵다. 본 논문에서는 이런 문제를 도와주기 위하여 기존의 병렬 컴파일러에서 제공되고 있는 텍스트 위주의 병렬화 정보 대신에 그래픽 사용자 인터페이스를 이용하여 편안하고 쉽게 병렬화 정보를 제공하는 병렬 프로그래밍 환경을 제안하고, 구현하였다. 본 논문의 병렬 프로그래밍 환경은 종속성 분석, CFG, HTG, 루프 병렬화 등의 기능을 제공한다.

• Structural Engineering and Mechanics
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• 제26권1호
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• pp.99-109
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• 2007

A cracked composite specimen, comprised of an epoxy and an aluminium plate, was fractured under a tensile load. In this paper, two crack configurations were investigated. The first was an artificial center crack positioned in the epoxy plate parallel to the material interface. The other was for two edge cracks in the epoxy plate, again, parallel to the interface. A tensile test was carried out by gradually increasing the applied load and it was verified that the cracks always moved suddenly in an outward direction from the interface. The d/a ratio was gradually reduced to zero, and it was confirmed that the maximum stress intensity factor value for the artificial center crack, $K_{{\theta}{\theta}}^{max}$, approached that of an artificial interface crack,$K_{{\theta}{\theta}}^{ifc\;max}$ (where: 2a is the crack length and d is the offset between the crack and interface). The same phenomenon was also verified for the edge cracks. Specifically, when the offset, d, was reduced to zero, the maximum stress intensity factor value, $K_{{\theta}{\theta}}^{max}$, approached that of an artificial interface edge crack.

• 산업기술연구
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• 제21권A호
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• pp.97-103
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• 2001

This paper presents the development of the I/O Interface for the real time parallel data communication between controller of a six-axis industrial robot(CRS-A460) and an external computer. The proposed I/O Interface consists of the hardware I/O interface and the software that is downloaded to the robot controller and executed by the controller operating system. The constitution of the digital I/O Port for CRS-A460 robot controller and the digital I/O board for IBM-PC are presented as well as the Process Control Program of the robot controller. The developed protocol for the parallel data communication is described. The data communication is tested, and the performance is analysed. In particular, it is shown that the real-time constraint of the robot controller process is satisfied.

• 대한기계학회논문집
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• 제19권1호
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• pp.170-180
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• 1995

A parallel crack in bonded dissimilar orthotropic planes under out-of-plane loading is analyzed. The problem is formulated by Fourier integral transforms, and reduced to a pair of dual integral equations. By solving the integral equations, the asymptotic stress and displacement fields near the crack tip are determined in closed form, from which the stress intensity factor and energy release rate are obtained. Discontinuity in the stress intensity factor as the distance ratio h/a of the parallel crack approaches zero is found, while the energy releas rate is shown to be continuous at h/a = 0. This information can immediately be used to generate the stress intensity factor for the parallel crack near the interface. By employing "the maximum energy release rate criterion", it could be shown in the case of no existing crack initially that the parallel crack is formed far from the interface for the more compliant material, while it is formed close to the interface for the stiffer material. material.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.94.1-94
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• 2002

This paper is concerned with parallel FFT and Quick-Merge Sort. They are implemented on computers interconnected by VMIC 5579 reflective memory and a cluster of workstations (PCs) interconnected via Fast Ethernet. Message passing interface (MPI) parallel library is used for communication in a cluster of workstations. An improved parallel FFT is also presented to decrease an execution time in the case of a small number of hosts. Distributed shared memory (DSM), VMIC 5579 reflective memory (RM), a cluster of workstations (COW) and message passing interface (MPI) parallel library are described.

• 대한기계학회논문집
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• 제7권2호
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• pp.175-185
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• 1983

When a circular cylinder near the plane fluid-interface of different viscosities is in parallel and normal motion, solutions of the Oseen equation are obtained. Classical image method with Faxen's integral form is used to satisfy the boundary conditions on the plane interface. Coefficients of drag and lift increase as a cylinder approaches to the interface. But drag-coefficients of parallel motions with viscosity-ratio less than unity are decreased slightly. They show monotonic increase with Reynolds number in case of parallel motion, but minimum values of drag coefficients in normal motion are appeared. On the other hand Stokes' solution are obtained by taking limits of low Reynolds number except the case of parallel motion with viscosity-ratio not equal to infinity.

• 한국정보과학회논문지:시스템및이론
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• 제31권7호
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• pp.379-386
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• 2004

본 연구에서는 병렬프로그램을 효율적으로 개발할 수 있고 병렬처리 프로그램의 성능을 향상시키는 이식성을 갖는 고성능 병렬 라이브러리인 HPCL(High Performance Computing Library)을 구현하였다. HPCL은 C 언어와 Fortran 언어로 구현되었으며, Fortran 프로그램에서 메시지 전송 인터페이스인 MPI(Message Passing Interface)를 효율적으로 사용할 수 있도록 하였다. 성능 분석은 PC 클러스터와 상업용 슈퍼컴퓨터인 IBM SP4를 이용하여 병렬프로그램의 성능 향상 및 통신 오버헤드 등에 대하여 다양하게 이루어졌다.

• 인터넷정보학회논문지
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• 제9권5호
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• pp.185-193
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• 2008

대규모 병렬 시스템의 MTBF(moon time between failures)는 아주 짧아 겨우 수 시간 단위에 불과하여 장시간의 연산 도중 연산 실패로 끝나 소중한 계산 시간이 낭비되는 경우가 많다. 그러나 현재의 MPI(Message Passing Interface) 표준은 이에 대한 대안을 제시하지 않고 있다. 본 논문에서는, 비표준의 결함 내성 MPI 라이브러리가 아닌 MPI 표준 함수들만을 사용하여, 일반적인 동기 병렬 연산에 적용할 수 있는 응용 수준의 결함 내성 연산 시스템을 제안한다.

• 한국정보처리학회논문지
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• 제7권8호
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• pp.2388-2399
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• 2000

본 논문에서는 사용자의 병렬 프로그램 작성을 도와주는 병렬 프로그래밍 환경에 대해 기술한다. 병렬 프로그래밍 환경은 일반적인 컴파일러의 기능의 전위 부분에 해당하는 어휘분석과 구문분석 기능 수행하고 있으며, 프로그램에서 이용하는 변수들의 데이터 흐름 분석과 데이터 종속성 분석, 그리고, 여러 가지 병렬 프로그램 변환 기법들을 수행한다. 특히 프로그래머가 병렬 프로그램을 용이하게 작성할 수 있도록 그래픽 사용자 인터페이스를 제공한다.