• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.1
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• pp.67-72
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• 2001

Convolutional code and turbo code are used in the forward and backward link of IMT-2000. In this research, we will be in consideration of Viterbi algorithm In this paper, we design Viterbi decoder with 3-bits soft decision and SMT for the convolutional code in the forward link and backward link of IMT-2000 system. The major parameters of 3-bits Viterbi decoder is determined by simulation to have identical performance with the 4-bit soft decision Viterbi decoder.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.3
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• pp.137-145
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• 2014

We present a design sensitivity analysis(DSA) method for multiscale problems based on bridging scale decomposition. In this paper, we utilize a bridging scale method for the coupled system analysis. Since the analysis of full MD systems requires huge amount of computational costs, a coupled system of MD-level and continuum-level simulation is usually preferred. The information exchange between the MD and continuum levels is taken place at the MD-continuum boundary. In the bridging scale method, a generalized Langevin equation(GLE) is introduced for the reduced MD system and the GLE force using a time history kernel is applied at the boundary atoms in the MD system. Therefore, we can separately analyze the MD and continuum level simulations, which can accelerate the computing process. Once the simulation of coupled problems is successful, the need for the DSA is naturally arising for the optimization of macro-scale design, where the macro scale performance of the system is maximized considering the micro scale effects. The finite difference sensitivity is impractical for the gradient based optimization of large scale problems due to the restriction of computing costs but the analytical sensitivity for the coupled system is always accurate. In this study, we derive the analytical design sensitivity to verify the accuracy and applicability to the design optimization of the coupled system.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.715-717
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• 2001

기존의 강성 실시간 시스템은 실시간 수행만 고려되어 있어. 실시간 시스템의 성능과 효율적인 시스템 활용과는 거리가 멀다. 따라서 효율적인 시스템 활용을 통하여 보다 많은 일을 수행할 수 있게 하는 연성 실시간 시스템을 사용하게 된다. 여기서는 보상값이라는 것을 사용하여 그것의 총합을 성능평가의 기준으로 사용하며, 보상값의 합을 최대로 할 수 있는 수행시간을 찾아 스케줄링에 사용하게끔 한다. 모의 실험을 통하여 알아낸 수행시간에 따른 보상값의 변화에 대한 경향을 이용하여 최대 보상값을 얻을 수 있는 수행시간을 찾고, 실험을 통하여 얻은 결과와 비교하였다.

• Transactions of the KSME C: Technology and Education
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• v.4 no.1
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• pp.3-10
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• 2016

Heat pump unit performance is represented by the COP(Coefficient of Performance) and expressed by the one point design condition according to KS C 9306. However, when heat pump operated to the real buildings, the simulations are changed continuously according to the actual weather conditions, the building load and heat pump source conditions. The purpose of this paper is to evaluate the APF(Annual performance factor) for a climate dependent building integrated air-to-air heat pump system in major cities in Korea. TRNSYS simulation tool with an international MV standard based IPMVP 4.4.2 was utilized to perform the annual performance analysis. The APF with the multi-performance data based method was calculated as 2.29 for Daejeon residential building case while Busan residential building case appeared as the highest with 2.36.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.349-352
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• 2000

본 연구에서는 연성 실시간 태스크 즉 비디오, 오디오와 같은 태스크의 실시간 적인 특성을 만족시키기 위하여 현재 각광 받고 있는 리눅스 커널을 사용하여 연성 실시간 커널을 개발하고자 한다. 리눅스 파일시스템의 디스크 스케줄링 은 오디오와 비디오와같은 연성 실시간 태스크의 실시간 요건을 고려하지 않았다. 본 연구에서는 우선 주기 당 일정 대역폭을 요구하는 멀티미디어 서비스를 지원하기 위해 디스크 대역폭 예약이 가능한 디스크 스케줄링 기법을 제시하여 태스크간 공정한 디스크 서비스를 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1651-1654
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• 2002

대부분의 멀티미디어 응용은 제한된 시간내에 작업이 수행되어야 하는 연성 실시간 특성을 가지고 있으며, 일반직으로 윈도우즈 또는 유닉스와 같은 범용 운영체제 상에서 수행되고 있다. 하지만, 범용 운영체제는 요구 페이징에 기반한 가상 메모리 시스템을 근간으로 하고 있으므로, 연성 실시간 태스크가 요구하는 제약조건을 처리하는데 문제점을 가지고 있다. 본 논문에서는 범용 운영체제가 연성 실시간 태스크를 원활히 지원할 수 있도록 가상 메모리 시스템을 개선시키는 방법을 제시하고 있다. 주요 아이디어는 실시간 태스크가 사용하는 메모리에 대해서 태스크의 우선순위에 기반한 고립화(isolation)를 제공하는 것이며, 이를 통해서 메모리 제약 조건하에서 연성 실시간 태스크가 제한 시간을 만족시키며 수행됨을 보이고 있다.

• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.117-122
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• 2006

A novel method to find interaction dynamics between focusing direction and tracking direction in an optical pick-up is proposed. and the decoupling control to reduce the interaction effect is discussed. First, the basic principle to detect dynamic interaction analysis using back electromotive force is introduced. Second, the interaction analysis between focusing and tracking direction of is analyzed for a commercial slim type optical pick-up. Finally. decoupling control process and its simulation results are shown.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.2
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• pp.29-40
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• 1999

This study presents a simplifled calculation method for required ductility of coupling beams in precast coupled shear walls at preliminary seismic design stages. Deflection of precast coupled shear walls based on a continuum approach is combined with inelastic gap opening of horizontal connection of panels to provide a relationship between the system-level ductility and the element-level ductility in a precast coupled shear wall. The equation proposed herein for ductility requirement for coupling beams shows that higher stiffness and lower strength of coupling beams result in high ductility reuqirement. The equation also shows that the ductility requirement is proportional to the degree of gap opening of the story in question. However, the coupling beam ductility in higher stories are not affected by gap openings of horizontal connections of panel.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.149-154
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• 2019

The structural system of domestic high-rise apartments can be divided into two parts; the core wall system, which is composed of walls concentrated in the center and the shear wall system, which comprises a great number of walls distributed in the plan. In order to analyze the lateral behavior of each system, buildings with typical domestic high-rise apartment plans were selected and nonlinear static analysis was performed to investigate the their collapse mechanism. From the force-displacement relation derived from nonlinear static analysis, response modification factor was evaluated by calculating the overstrengh and ductility factor, which are important in the seismic response. The ductility of core wall system is small, but as it is governed by wind load, its overstrength is greatly estimated, and its response modification factor is calculated by the overstrengh factor. Due to a large number of walls, shear wall system has a large ductility, making the response modification factor considerably large.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.2 s.54
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• pp.206-214
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• 2009

Due to its outstanding feature, FRP is used widely for the material of strengthening in USA and Japan recently, and there have been active researches in korea as well. This study evaluates the behavior and ductility of each structure experiment using EBR and NSMR strengthening method with different AFRP types and strengthening area. There was the biggest increase in the load when the strengthening area is expanded showing a brittle aspect, and eventually the immature failure occurred. With regard to the methods, it is found that the NSMR method is more effective to strengthen the structure, and the uneven surface causes ductile failure.