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        • 메탄올-가솔린 혼합연료의 기관성능에 관한 연구

          沈炳珉 三陟大學校 2001 論文集 Vol.34 No.1

          The results of this study about engine performance and organization due to the change of engine operating components for methanol-gasoline blend fuel, are as follows 1) The engine power output was increased according to the in crease of engine rpm, The change of engine of air-fuel ratio was maximum near the stoichiometry in each blend rate, and the engine power output due to the change of spart advance was maximum near the MBT in each blend rate 2) The optimum conditions of methanol-gasoline blend fuel were N=1400rpm, SA=35˚ btc in this experimental engine. The conditions were little changed due to the in crease of methanol blend rate and the optimum air-fuel ratio was reveled near the soichiometry in each blend rate. 3) BSFC was increased according to the soichiometry in each blend rate, and that of M-100fuel(methanol 100%) was increased 2 times compared with that of M-30 fuel. 4) The change in maximum rate of heat release was increased according to the increase of methanol blend rate, and this coincided with the tendency in the change of maximum pressure(Pmax)of cycle.

        • 메탄올 연료도입에 따른 배기성능의 개선에 관한 연구

          沈炳珉,李正閏 三陟大學校 1998 論文集 Vol.31 No.1

          The result of this study on engine characteristic and exhaust characteristic in according to the variation of methanol-fuel introduction amounts with the two-systemic injection fuel supply method for exhanst performance improvement without the change of the conventional spark ignition engine are as follows. 1. The mass burned was to the fast combustion in according to increased methanol-fuel introduction amount, finally cycle miximum pressure on the increased. 2. Torque was being increased in according to increased mathanal fuel introduction amount, and this reason was that increase of volumetric efficiency in according to be increased in take air amount. A increasing rate of Torque of high percentage methanol(M-85) fuel is 8 Percent at equivalence ratio Φ=0.9 to Compared with M-O fuel. 3. Brake specific fuel consumption (B SFC) was increased in according to the increase of methanol-fuel intraduction amount, and the reason is that low heating value of methanol-fuel. 4. Nox generation was being decreased at methanol-fuel introduction amount was on the increased. The rate of Nox improvement of M-85 was 16 percent at Φ=0.9, compared with M-O fuel. 5. The generation of C0 was being very decreased in according to increased methanol-fuel introduction amount, and that of HC was being very increased.

        • 배기성능 개선을 위한 메타놀기관의 EGR 및 흡기가열의 효과

          沈炳珉 三陟大學校 1997 論文集 Vol.30 No.1

          The purpose of this paper is to investigate the relationship between the exhaust gas characteristic and engine performance through changing of engine operation factors when EGR apparatus and the inlet mixture heating system are employed for this experiment. The results are as follows 1. When EGR was operated, MBT have to be decided. for the engine were made optimal driveness in according to increasement of EGR percent. In this paper, could appear the relationship of MBT for EGR precent. In this paper, could appear the relationship of MBT for EGR percent and the variable of engine driving, also could made spacial Coordinate for the variable of engine driving, also could made spacial Coordinate for the variable of engine driving. 2. In according to the increasement of EGR change, NOx Concentrations were apparently decreased due to the increasement of EGR ratio. Though NOx concentrations were hardly diminished due to the effect of heating the inlet mixture, it is expect to diminished NOx Concentration from the extension of air-fuel ratio for every EGR change. 3. In according to the effect of EGR ratio, HC, CO concentrations were increased owing to the increasement of EGR ratio. HC, CO concentrations were decreased about 10.7% and 7.6% air-fuel ratio 6.5. 4. In according to EGR and heating of inlet, engine output is decreased. In case of heating of inlet, the decreasement of output showed 7.3% at air-fuel ratio 6.5 were compared of in case of non-heating. In case of 0% and 5% of EGR diminished the engine output of 7.3%, 3.9% and 10% of EGR diminished the engine output of 1%.

        • 분산형 임무관리 시스템에 대한 동적시험환경 개발

          심주현(Ju hyen Sim),황성민(Sung min Hwang),민상기(Sang ki Min),정성진(Sun jin Jung),김병국(Byoung kug Kim),김재형(Byoung kug Kim),배준성(Jun sung Bae),최기한(Jun sung Bae) 항공우주시스템공학회 2017 항공우주시스템공학회 학술대회 발표집 Vol.2017 No.1

          '스콜라' 이용 시 소속기관이 구독 중이 아닌 경우, 오후 4시부터 익일 오전 7시까지 원문보기가 가능합니다.

          이중화 네트워크 기반의 분산형 임무관리 시스템 소프트웨어에 대한 신뢰성 검증 및 기능/성능 검증의 효율성과 다형성을 고려하여 동적시험환경을 개발하였다. 시나리오 및 Plug-In 기반의 시험환경 설계를 통해 다양한 실행 환경을 발생할 수 있는 분산형 임무관리 시스템을 효율적으로 검증할 수 있었으며, 대상 무기체계의 추가된 Subsystem에도 유연하게 대응할 수 있도록 확장성을 고려한 설계를 적용 하였다. 개발된 동적시험환경은 대상 시험체계의 SIL 통합 이전에 적용하여 전체 소프트웨어 개발 프로세스의 단축을 꾀할 수 있었으며, 자동 반복 및 부하 시험들을 통해 전체 분산형 임무관리 시스템의 안정성을 통합적인 관점에서 확인 및 검증할 수 있었다.

        • SCIESCOPUSKCI등재

          Compressed Channel Feedback for Correlated Massive MIMO Systems

          Sim, Min Soo,Park, Jeonghun,Chae, Chan-Byoung,Heath, Robert W. Jr. The Korean Institute of Communications and Informa 2016 Journal of communications and networks Vol.18 No.1

          Massive multiple-input multiple-output (MIMO) is a promising approach for cellular communication due to its energy efficiency and high achievable data rate. These advantages, however, can be realized only when channel state information (CSI) is available at the transmitter. Since there are many antennas, CSI is too large to feed back without compression. To compress CSI, prior work has applied compressive sensing (CS) techniques and the fact that CSI can be sparsified. The adopted sparsifying bases fail, however, to reflect the spatial correlation and channel conditions or to be feasible in practice. In this paper, we propose a new sparsifying basis that reflects the long-term characteristics of the channel, and needs no change as long as the spatial correlation model does not change. We propose a new reconstruction algorithm for CS, and also suggest dimensionality reduction as a compression method. To feed back compressed CSI in practice, we propose a new codebook for the compressed channel quantization assuming no other-cell interference. Numerical results confirm that the proposed channel feedback mechanisms show better performance in point-to-point (single-user) and point-to-multi-point (multi-user) scenarios.

        • SCISCIESCOPUS

          Underwater acoustic source localization using closely spaced hydrophone pairs

          Sim, Min Seop,Choi, Bok-Kyoung,Kim, Byoung-Nam,Lee, Kyun Kyung Institute of Pure and Applied Physics 2016 Japanese Journal of Applied Physics Vol.55 No.7

          <P>Underwater sound source position is determined using a line array. However, performance degradation occurs owing to a multipath environment, which generates incoherent signals. In this paper, a hydrophone array is proposed for underwater source position estimation robust to a multipath environment. The array is composed of three pairs of sensors placed on the same line. The source position is estimated by performing generalized cross-correlation (GCC). The proposed system is not affected by a multipath time delay because of the close distance between closely spaced sensors. The validity of the array is confirmed by simulation using acoustic signals synthesized by eigenrays. (C) 2016 The Japan Society of Applied Physics</P>

        • A pneumatic micro cell chip for the differentiation of human mesenchymal stem cells under mechanical stimulation

          Sim, Woo Young,Park, Sin Wook,Park, Sang Hyug,Min, Byoung Hyun,Park, So Ra,Yang, Sang Sik Royal Society of Chemistry 2007 Lab on a chip Vol.7 No.12

          <P>A new micro cell chip which can induce stem cells to differentiate into specific body cell types has been designed and fabricated for tissue engineering. This paper presents the test results of a micro cell stimulator which can provide a new miniaturized tool in cell stimulation, culture and analysis for stem cell research. The micro cell stimulator is designed to apply compressive pressure to the hMSCs (human mesenchymal stem cells) for inducing osteogenesis. The micro cell stimulator is based on the pneumatic actuator with a flexible diaphragm which consists of an air chamber and cell chambers. The hMSCs under cyclic compressive stimulation for one week were observed and assessed by monitoring CD90 (Thy-1), actin, alkaline phosphatase (ALP) and alizarin red expression. The results suggest that cyclic mechanical stimulation is attributed to the different phenomenon of cultured hMSCs in cell proliferation and differentiation. These results are important for the feasibility of the micro cell stimulator to provide the reduction of the necessary quantity of cells, process cost and the increase of the throughput.</P> <P>Graphic Abstract</P><P>A new micro cell chip which can induce stem cells to differentiate into specific body cell types has been designed and fabricated for tissue engineering. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b712361m'> </P>

        • 메타놀 燃料의 機關性能과 排氣가스 組成에 關한 硏究

          沈炳珉 三陟大學校 1996 論文集 Vol.29 No.1

          The results of this study which is a primitive experiment to use Methanol as alternative fuel and aims for the decrease of exhaust gas emissions, are as follows. The engine power output of methanol fuel is higher than it of M-30(Methanol 30+Gasoline 70) fuel and maximum power is appeared near N=1,400rpm, A/F=6.5 and SA=35°btc. Also, BSFC is more increased than the case of M-30 fuel. The maximum rate of heat release is decreased according to the increasing of engine speed, is appeared near A/F=6.5 and is not changed with Variation of the spark time. The NOx concentrations of methanol fuel is more decreased than it of M-30 fuel and is not affected with engine Speed. HC concentrations of methanol fuel is higher than it of M-30 fuel according to Variation of Spark time and CO concentrations is Lower than the case of M-30 fuel. The max. NOx concentrations of methanol fuel is appeared near air~fuel ratio A/F=7.3 and H.C concentrations is minimum value near A/F=8.5.

        • 불꽃 點火機關의 最適 運轉條件 決定에 關한 硏究

          沈炳珉 三陟大學校 1996 論文集 Vol.29 No.1

          This study is concerned with the fuel-economy and performance problem, and the purpose of this study control of the operating factors to obtain optimum performance in spark Ignition Engine. This paper discusses the determination of the optium driving conditions. Two objectives, torque condition and brake specific fuel consumption, are considered for optimization. The effects of the three variables(air-fuel ratio, engine speed and spark advance) on the objective function are analyzed by experiments and computer calculation. experimental model and several constraints of actual engine operation are required to obtion the optimum conditions. Gradient projection method is used to find the maximum of multivariable, nonlinear function subject to linear constraints.

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