• Title/Summary/Keyword: H&S performance

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Design and Performance Study of Propulsion System for Korean High Speed Train (한국형 고속전철의 추진시스템 설계 및 성능 연구)

  • 박광복;김현철
    • Proceedings of the KSR Conference
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    • 1998.05a
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    • pp.349-358
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    • 1998

  • This study was carried out about the design and the performance study of propulsion system for Korean High Speed Train of maximum operating speed of 350km/h. The propulsion system was studied to two parts the formation of power transmission and the performance of traction system base on Korean-TGV. For maximum operating speed of 350km/h at Seoul-Pusan high speed line, the power of train should be have the remaining acceleration of 0.058m/s/s and the slopeability of 6%o. This performance study of propulsion system would be continued for defining of adhesion factor, friction factor and aerodynamic factor assumed to analysis and simulation.

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Performance Analysis of a Torque Converter with Three Dimensional Flow Simulation (3차원 유동해석을 통한 토크 컨버터의 성능분석)

  • Shin, S.S.;Ahn, H.H.;Lee, T.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.6
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    • pp.15-23
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    • 1998

  • A three dimensional simulation of the fluid flow in an automotive torque converter was conducted adopting the mixing plane model implemented in the computational fluid dynamics program CFD-ACE. The present numerical results for performance characteristics showed a good agreement with the experimental results. In the flow of the torque converter, recirculating flow regimes were found mostly at the suction side of each element, which caused the performance decrease. The recirculating flow can be minimized by the optimization of the blade geometries.

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Effect of Total Mixed Ration with Fermented Feed on Ruminal In vitro Fermentation, Growth Performance and Blood Characteristics of Hanwoo Steers

  • Kim, S.H.;Alam, M.J.;Gu, M.J.;Park, K.W.;Jeon, C.O.;Ha, Jong-K.;Cho, K.K.;Lee, S.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.2
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    • pp.213-223
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    • 2012

  • In this study, two experiments were conducted to evaluate the total mixed ration with fermented feed (TMRF) and total mixed ration (TMR) by rumen in vitro fermentation and their effects on the growth performance and blood characteristics of Hanwoo steers. In experiment 1, three Hanwoo steers ($600{\pm}47$ kg), each permanently fitted with a ruminal cannula were used. In this experiment, three diets designated as T1, TMRF (18.4% fermented feed, tall fescue, mammoth wild rye forage and whole crop barley); T2, TMRF (17.7% fermented feed, rice straw and whole crop barley); and T3, TMR (rice straw, whole crop barley and probiotics, but no fermented feed), which were subjected to rumen in vitro fermentation for 48 h. The results demonstrated that DM disappearance rate gradually increased with advancing fermentation time, but T1 and T2 were higher than the T3 (p<0.05) from 3 h to 12 h, but insignificant (p>0.05) at 24 and 48 h. None of the specific VFAs were affected except for acetic and non volatile lactic acids, which were produced more in T2 than in T1 and T3 at 24 h and 48 h of incubation. A/P was lower in T1 and T2 than inT3 at 24 h (p<0.05) and 48 h (p>0.05) of incubation. These results confirmed that TMRF-related treatment shows a superior performance to that of TMR during the ruminal fermentation period. In experiment 2, the three diets in experiment 1 plus 1 more control diet (concentrates, probiotics and 2% rice straw of body weight) were fed to the 48 Hanwoo steers ($160{\pm}10$ kg) for a period of 168 d. The results demonstrated that the daily and total live weight gain and feed efficiency were higher (p<0.05) in the TMRF and TMR groups than in the control group. SGOT, SGPT and BUN (p<0.05) were reduced in TMRF relative to the control and TMR groups by 168 d which confirmed that TMRF shows better blood profiles than the TMR and control groups. Overall, these results appear to show that TMRF has better in vitro ruminal characteristics than those of TMR; growth performance and blood profiles were also found to be superior in TMRF than in the TMR and control groups. Thus, our findings suggest that TMRF-based feed supplies are favorable for Hanwoo cattle.

  • https://doi.org/10.5713/ajas.2011.11186 인용 PDF KSCI

Architecture of an LDPC Decoder for DVB-S2 using reuse Technique of processing units and Memory Relocation (연산기와 메모리 재사용을 이용한 효율적인 DVB-S2 규격의 LDPC 복호기 구조)

  • Park Jae-Geun;Lee Chan-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.9 s.351
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    • pp.31-37
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    • 2006

  • Low-density parity-check (LDPC) codes are recently emerged due to its excellent performance. The standard for European high definition satellite digital video broadcast, DVB-S2 has adopted LDPC codes as a channel coding scheme. This paper proposes a DVB-S2 LDPC decoder architecture using a hybrid parity check matrix which is efficient in hardware implementation for both decoders and encoders. The hybrid H-matrices are constructed so that both the semi-random technique and the partly parallel structure can be applied to design encoders and decoders. Using the hybrid H-matrix scheme, the architecture of LDPC decoder for DVB-S2 can be very practical and efficient. In addition, we show a new Variable Node processor Unit (VNU) architecture to reuse the VNU for various code rates and optimized block memory placement to reuse. We design a DVB-S2 LDPC decoder of code rate 1/2 usng the proposed architecture. We estimate the performance of the DVB-S2 LDPC decoder and compare it with other decoders.

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