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OpenMP를 이용한 철도신호에서의 LDPC 적용에 관한 연구
박주열(Park Joo-Yul),김효상(Kim Hyo-Sang),박태기(Park Tae-ki),김봉택(Kim Bong-Taek),정기석(Chung Ki-Seok) 한국철도학회 2009 한국철도학회 학술발표대회논문집 Vol.2009 No.11월
There have been lots of researches for High Performance Digital Signal Processing performance enhancement on a multi-core processor. These kinds of parallelizing can enable massive signal processing, so we can have advantage's of processing various of signal processing standards without additional DSP's or other accelerating hardwares. In this paper we introduce Low Density Parity Check(LDPC) which is one of the Foward Error Correction(FEC). And we have achieved computational time reduce by using OpenMP as a parallelizing scheme.
박주열(Park Joo-Yul),김효상(Kim Hyo-Sang),박태기(Park Tae-ki),김봉택(Kim Bong-Taek),정기석(Chung Ki-Seok) 한국철도학회 2009 한국철도학회 학술발표대회논문집 Vol.2009 No.5월
As the railway transportation is getting faster and its operation speed has increased rapidly, its signal control has been complicated. For real time signal processing it is very important to prohibit any critical error from causing the system to malfunction. Today, most of the railroad's controling communications between wayside and train are made in one way. Therefore, by using a forward error correction technique, which receiver can actively correct the signal error, we can increase the performance and the stability of the railroad signaling system. In this paper, we introduce low density parity check(LDPC) that is used by next generation wireless communications and DMB technique. We verified that we can achieve low bit error rate(BER) in high signal to noise ratio(SNR) by using LDPC.
박태기,박건용,이병권 한국화학공학회 1985 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.23 No.6
Ammonia와 ethylene oxide로부터 이루어지는 ethanolamines 合成反應에서 反應速度常數 및 活性化에너지의 결정 등 反應速度式을 중심으로 한 ethanolamines제조과정을 回分式 실험에 의한 反應機構分析을 통해 고찰해 보았다. 반응을 2차의 非可逆 competitive consecutive reaction 이라고 가정하고, 28wt%의 ammonia 수용액을 사용하는 경우 反應速度 k₁은 20℃에서 1.235×10^(-3)ℓ/min·㏖, 35℃에서 3.243×10^(-3)ℓ/min·㏖, 50℃에서 7.784×10^(-3)ℓ/min·㏖, 活性化에너지는 약 11,500㎈/㏖로 구해졌다. 또 反應速度常數比가 K₂(=k₂/k₁)=8.51-0.051 C_W, K₃(=k₃/k₁)=14.81-0.196C_W로 구해져 물 濃度에 대한 1차 減少函數의 관계가 확인되었다. 反應速度 k₁과 速度常數比 k₂, k₃로부터 數値解析的으로 계산된 결과들은 實驗値와 매우 잘 一致하였다. A study on the reaction mechanism for the manufacture of ethanolamines from aqueous ammonia and ethylene oxide was carried out in a bench scale batch reactor. Rate constants and activation energy were determined by assuming that the reaction occurred in the manner of irreversible competitive consecutive second order reaction. In the case of 28% aqueous ammonia as a reactant, the reaction rate constants in the first step (k₁) were calculated to be 1.235×10^(-3)ℓ /min·㏖, 3.243×10^(-3)ℓ/min·㏖, and 7.784×10^(-3)ℓ/min·㏖ at 20 ℃, 35℃ and 50℃ respectively. The calculated activation energy was about 11,500 ㎈/㏖. Process simulation using these calculated results was found satisfactory in good accordance with the actual experimental results.
박건유,박태기,정문조 한국화학공학회 1983 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.21 No.5
상용공장에서 사용되는 관형반응기를 사용하여 CHClF₂의 열분해 반응에 대한 반응속도론적 연구를 하였다. CHClF₂는 열분해 반응에 의하여 C₂F₄와 HCl을 생성하며 C₂F₄는 polytetrafluoroethylene의 단량체로서 사용되고 있다. 반응이 층류구간에서 진행되므로 반응기 내부에 온도 및 속도의 구배가 존재하며 반경방향의 온도구배를 측정한 결과 2차 곡선과 잘 일치함을 알 수 있었다. 각 반응조건하에서 얻어진 전환율과 온도 및 속도구배를 사용하고 확산 및 가역반응을 고려하여 활성화 에너지와 Arrhenius상수를 계산하였으며 계산과정에서 computer 를 사용하였다. 계산 결과 γ_A = k₁[CHClF₂] - k₂[CF₂:] [HCl] (k₁= A_(1e)^(-E₁/RT), k₂= A_(2e)^(-E₂/RT) 로 표시되는 반응속도식에서 E₁= 48,951 ㎈/mole A₁= 0.3358 × 10^(15)/sec E₂= 5,117 ㎈/mole A₂= 0.1452 × 10^(14)㎤/mole·sec 의 값을 얻을 수 있었다. Kinetic study has been made on the pyrolysis of CHClF₂ using a tubular reactor of a commercial plant scale under the commercial plant conditions. CHClF₂ is decoposed to HCl and C₂F₄, which is used as a monomer of polytetrafluoroethylene. The pyrolysis proceeds in the laminar flow range, so temperature and velocity gradient exist in the reactor. The activation energies and Arrhenius constants were calculated by computer. Temperature gradient, velocity gradient, diffusion and reversibility of the reactions were considered in the calculation. The parameters were found to be E₁= 48,951 ㎈/mole, A₁= 0.3358 × 10^(15)/sec E₂= 5,117 ㎈/mole, A₂= 0.1452 × 10^(14)㎤/mole·sec in the following overall rate equation, where k₁= A₁Exp(-E₁/RT), k₂= A₂Exp(-E₂/RT)· γ_A = k₁[CHClF₂] - k₂[CF₂:] [HCl]