• 한국기계가공학회지
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• 제11권4호
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• pp.25-30
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• 2012

The transportation is almost dependent on a single fuel petroleum with transportation energy dilemma. Hybrid Electric Vehicle(HEV) technology holds more advantages on efficiency improvements for petroleum consumption at the transportation. And bearing is recognized as the important component of gearbox. Gearboxes for HEV transmission have been ensured the highest reliability over some years in withstanding high dynamic loads. At the same time, the demands of lightweight design and cost minimization are required by thought-out design, high-quality material, superior production quality and maintenance. In order to design a reliable and lightweight gearbox, it is necessary to analyze bearing rating life methods between standard and different bearing companies with calculation methods for modification factors. In this paper, the influence of life time of bearings will be pointed out. Bearing contact stress and load stress distribution of HEV gearbox are obtained and compared with Romaxdesigner and BearinX. And the unequal wear of the left bearing for the gearbox intermediate shaft is investigated between simulation and test.

• 유공압시스템학회논문집
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• 제5권4호
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• pp.1-9
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• 2008

In this paper, an energy regeneration algorithm is proposed to make the maximum use of the regenerative braking energy for a parallel hybrid electric vehicle(HEV) equipped with a continuous variable transmission(CVT). The regenerative algorithm is developed by considering the battery state of charge(SOC), vehicle velocity and motor capacity. The hydraulic module consists of a reducing valve and a power unit to supply the front wheel brake pressure according to the control algorithm. In order to evaluate the performance of the regenerative braking algorithm and the hydraulic module, a hardware-in-the-loop simulation (HILS) is performed. In the HILS system, the brake system consists of four wheel brakes and the hydraulic module. Dynamic characteristics of the HEV are simulated using an HEV simulator. In the HEV simulator, each element of the HEV powertrain such as internal combustion engine, motor, battery and CVT is modelled using MATLAB/$Simulink^{(R)}$. In the HILS, a driver operates the brake pedal with his or her foot while the vehicle speed is displayed on the monitor in real time. It is found from the HILS that the regenerative braking algorithm and the hydraulic module suggested in this paper provide a satisfactory braking performance in tracking the driving schedule and maintaining the battery state of charge.

• 한국자동차공학회논문집
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• 제13권6호
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• pp.38-47
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• 2005

In this paper, a regenerative braking algorithm is proposed to make the maximum use of the regenerative braking energy for an independent front and rear motor drive parallel HEV. In the regenerative braking algorithm, the regenerative torque is determined by considering the motor capacity, motor efficiency, battery SOC, gear ratio, clutch state, engine speed and vehicle velocity. To implement the regenerative braking algorithm, HEV powertrain models including the internal combustion engine, electric motor, battery, manual transmission and the regenerative braking system are developed using MATLAB, and the regenerative braking performance is investigated by the simulator. Simulation results show that the proposed regenerative braking algorithm contributes to increasing the battery SOC, which recuperates 60 percent of the total braking energy while satisfying the design specification of the control logic. In addition, a control algorithm which limits the regenerative braking is suggested by considering the battery power capacity and dynamic response characteristics of the hydraulic control module.

• Agribusiness and Information Management
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• 제6권2호
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• pp.40-48
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• 2014

As basic research to develop HEV and EV agricultural field machinery, the present study analyzes the technical trend of electric agricultural field machinery through product analysis, paper analysis, and patent analysis concerning HEV and EV in the automobile, construction machinery, and agricultural machinery sectors. For product analysis, the homepages of companies in these sectors were consulted to analyze the number of products of each company. For paper analysis, key words related to HEV and EV were selected, a search formula was drawn up, and articles search sites were consulted. And for patent analysis too, key words were selected and then a search formula was drawn up to examine published patent applications or registered patent applications, and trends were analyzed by structure, country, and year. The number of HEV and EV products were 17 in the automobile area, 8 in construction machinery, and 4 in agricultural machinery. Notably, in the agricultural machinery area, all HEV and EV products were from advanced companies overseas. In terms of papers, papers published in the past 5 years were searched and 33,195 papers were from the automobile area, 3,806 were from construction machinery, and 2,687, the fewest papers, were from the agricultural machinery area. A search of patents in the electric drive technology area in Korea, USA, and Japan, and Europe showed 1,927 valid patents, with 1,120 in Japan, 497 in USA, 193 in Korea, and 117 in Europe. Analysis of the trend of research on electric agricultural field machinery by product, paper, and patent shows the development of HEV and EV technology in Korea is insufficient compared to USA, Japan, and Europe, which means rapid technological development is needed.

• 전력전자학회논문지
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• 제17권4호
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• pp.359-367
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• 2012

In this paper, the input split type series-parallel hybrid electric vehicle (SPHEV) is established and the interpretation of the dynamic characteristics in four kinds of HEV modes, such as electric vehicle mode, engine mode, hybrid mode, and regeneration mode, is described. For this research, the forward-facing approach simulation method is chosen, which is useful for vehicle dynamic analysis. The rating of each powertrain component is designed based on energy-based concept and electrical peaking hybrid (ELPH) method. Finally, the designed powertrain is evaluated with the developed PSiM simulator and simulation results are shown.

• 한국환경보건학회지
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• 제32권2호
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• pp.164-170
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• 2006

Ethylene oxide is a genotoxic carcinogen with widespread uses as industrial chemical intermediate and gaseous sterilant. 2-hydroxyethylated N-terminal valine in Hb is a good biomarker for biological monitoring of ethylene oxide exposure, because of its stability. For measuring the hemoglobin adduct formed by exposure of ethylene oxide, we studied the determination of (N-2-hydroxy-ethyl)valine(HEV) in hemoglobin adduct by using GC/MS. Firstly we synthesized HEV with 2-amino-ethanol and bromoisovaleric acid(BIVA) and confirmed it with GC/MS-FID. Its fragmentations were m/z 116(base ion, M+-45) and m/z 130(M+-31). For measuring HEV with higher sensitivity, we use derivatives which were PFPITH(pentafluorophenylisothiocianate) and TBDMS (tributyldimethylsilylation) by using Edman procedure. Its fragmentation were m/z 425(M+-57), m/z 383(M+-99) and m/z 172(M+-310) by using GC/MS. We did biological monitoring for mice inhalation exposure with 400 ppm ethylene oxide. The concentrations of hemoglobin adduct were $168{\pm}3.8\;and\;512{\pm}04$(nmol g-1 globin) at 0.5 hr/day 400 ppm ethylene oxide inhalation exposure group, and $631{\pm}17\;and\;2265{\pm}9.4$(nmol g-1 globin) at 1.0 hr/day 400 ppm ethylene oxide inhalation exposure for 1 and 4 weeks, respectively. We confirmed that (N-2-hydroxy-ethyl)valine(HEV) of hemoglobin was a good biomarker for biomonitoring of ethylene oxide exposure, and can measured with derivatives such as PFPITH(pentafluorophenylisothiocianate) and TBDMS(tributyldimethylsilylation) by using GC/MS.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1575-1580
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• 2011

Toyota사의 PRIUS THS 시스템을 이용하여 HEV 알고리즘 분석을 통한 THS의 주행 모드 변환에 따른 실시간 모니터링 시스템을 개발하고자 한다. 병렬형 하이브리드 시스템의 경우에 엔진과 전동기를 주행 상태 최적인 상태로 운행하기 위해서는 다양한 제어전략이 필요하다. 본 연구를 통하여 주행 가능한 THS 차량의 주행에 필요한 입 출력 정보를 실시간적으로 모니터링할 수 있는 시스템을 개발한 결과, 하이브리드 자동차의 동력 분할 및 에너지 활용을 극대화시키기 위한 수단의 하나로 차량의 주행모드 변화에 따른 각 구성요소의 동작 상태를 모니터링 가능하게 되었다. 개발된 시스템은 제어전략의 체계적인 수립과 실시간 데이터 분석이 가능하기 때문에 HEV자동차의 알고리즘 분석해석을 통해 HEV자동차의 개발 기반에 유용하게 활용될 것이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.125-128
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• 2007

In these recent years, low cost and stable battery electrode materials have been studied for HV/HEV application. Spinel cathode material $LiMn_2O_4$ is widely studied as a promising cathode material of lithium ion secondary batteries because of it is low cost, easily to be prepared and capable to be operated in high voltage range. In this study, $LiMn_2O_4$ was undergoing surface modification with spinel lithium titanium oxide by sol-gel method in order to enhance its capacity retention. Properties of both unmodified and surface-modified $LiMn_2O_4$ were characterized by XRD, SEM, particle size analyzer while their cycling performance was tested with charge and discharge tester.

• 한국미생물·생명공학회지
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• 제46권4호
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• pp.320-325
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• 2018

E형 간염바이러스는 전세계적으로 매년 2천만건의 감염을 일으키는 것으로 알려져 있다. 흥미로운 것은 임산부에서 특히 높은 치사율을 보이는데, 무려 20-30%의 사망률을 보인다는 점이다. 면역능이 있는 감염환자에서는 E형 간염바이러스 감염은 별다른 증상 없이 자연 치유되지만, 면역능이 낮은 에이즈환자나 고령환자에서는 만성감염을 일으킬 수도 있으며 사망에 이르게 할 수도 있다. 따라서, E형 간염바이러스의 증식억제에 면역반응의 중요성이 높으며, 특히 인터페론 반응이 중요한 역할을 할 것으로 사료된다. 본 연구팀은 E형 간염바이러스의 프로티아제가 RIG-I 의존적 제 1형 인터페론 반응을 유의미하게 억제하는 것을 관찰하였다. 또한 바이러스 프로티아제가 RIG-I의 하위 신혼전달 분자의 하나인 MAVS의 활성도 농도 의존적으로 억제하는 것으로 분석하였다. E형 간염바이러스에 의한 제 1형 인터페론 반응 억제의 구체적인 작용 기작을 밝힌다면 효과적인 항바이러스제제의 개발의 초석을 놓을 수 있을 것으로 기대된다.

• 대한수의학회지
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• 제47권4호
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• pp.425-428
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• 2007

From January to June 2006, 54 suckling pigs had been submitted in virology lab., College of Veterinary Medicine, Seoul National University. All pigs had suffered from various symptoms such as respiratory sign, enteric signs, neurologic signs, etc. Among 54 pigs, 24 pigs (44.4%) were positive for porcine hemagglutinating encephalomyelitis virus (HEV) through reverse transcription-nested polymerase chain reaction. According to this result, HEV infections seemed to be prevalent and widespread in Korean swine farms, and the infection is associated with respiratory signs and neurologic signs more than enteric signs. The HEV positive pigs showing respiratory signs were co-infected with viruses such as PRRSV, and PCV2, or bacteria such as Pasteurella spp. The single infection may subclinically have an influence on outbreak of other respiratory pathogens in suckling pigs.