• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.63-68
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• 2003

Recently, a fuel cell is remarkable for new generation system. The fuel cell generation system converts the chemical energy of a fuel directly into electrical energy. The fuel cell generation is characterized by low voltage and high current. For connecting to general load, it needs both a step up converter and an inverter. The step up converter makes DC to DC and the inverter changes DC to AC. In this paper, full bridge converter and the single phase inverter are designed and installed for fuel cell. Simulation and experimental results are displayed under several load conditions.

• Tribology and Lubricants
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• 제24권5호
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• pp.221-227
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• 2008

This paper presents a step-by-step design of noncircular gears. From the diagram of angular velocity ratio of a noncircular gear pair, the pitch curves of the two mating gears are determined, and the perimeter of the pitch curve has been divided into equal-length segments by the number of teeth. A master tooth profile, which is a composite curve of circular arcs that represents involute, has been introduced. A noncircular gear pair has been designed by imposing the master tooth on the divided points of the pitch curve, and a full fillet has been achieved between neighbour teeth. Thus, the whole profile of the noncircular gear is a composite curve of arcs only, and consequently NC codes for wire EDM can be easily generated.

• ETRI Journal
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• 제44권4호
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• pp.695-707
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• 2022

As for the insufficient nature of the fossil fuel resources, the renewable energies as alternative fuels are imperative and highly heeded. To deliver the required electric power to the industrial and domestic consumers from DC renewable energy sources like fuel cell (FC), the power converter operates as an adjustable interface device. This paper suggests a new boost structure to provide the required voltage with wide range gain for FC power source. The proposed structure based on the boost converter and the quazi network, the so-called SBQN, can effectively enhance the FC functionality against its high operational sensitivity to experience low current ripple and also propagate voltage and current with low stress across its semiconductors. Furthermore, the switching power losses have been decreased to make this structure more durable. A full operational analysis of the proposed SBQN and its advantages over the conventional and famous structures has been compared and explained. Furthermore, a prototype of the single-phase converter has been constructed and tested in the laboratory.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.87-94
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• 2015

Recently, renewable energy sources are under the spotlight. due to the depletion of fossil fuels and environmental problem for the carbon dioxide. Among them, research on the Photovoltaic System using solar energy systems has been actively conducted. In this paper, we propose boosting the insulated DC/DC converter topologies Applied to soft-switching methods used in photovoltaic PCS. The proposed topology is of a type that combines a series of full-bridge converter and a boost converter, a full bridge converter and applying the insulation and soft switching system, the output voltage boost stage is carried out for the boost control. The proposed circuit validity was verified through the PSIM simulation and 5kW PV PCS Prototype and experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.241-243
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• 2008

In this paper, dynamic overmodulation strategies are proposed for two phase full bridge inverter. The four step operation to use maximum voltage in limited DC link is described and minimum distance, same angle and minimum switching state overmodulation techniques are presented. The simple scalar arithmetic based algorithms are proposed to implement the overmodulation techniques. Simulation results demonstrate the effectiveness of the proposed algorithms.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.53-56
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• 2008

In this paper, we propose the battery charging device for electric bicycle using photovoltaic power. DC voltage from the solar cells is low, it needs to be step-up by the power conversion device. The power conversion device applied to this paper is phase-shift full-bridge converter. This converter steps-up from 12${\sim}$22[Vdc] to 36[Vdc] for charging the battery of electric bicycle. Phase-shift full-bridge converter(PSFB) can obtain twice as much DC voltage compared with half-bridge converter, thus it has lower current stress less than half-bridge converter. It is simulated and tested the battery charging device using photovoltaic power.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (A)
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• pp.153-157
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• 2006

기존의 탐색 알고리즘은 탐색 창 내의 원점에서 탐색을 시작한다. 하지만 영상은 일정한 방향으로 규칙적으로 움직이는 것이 많기 때문에 Frame$_t$ 의 움직임 벡터(MV)가 Frame$_{t-1}$의 움직임 벡터와 같을 가능성이 크다. 이를 참고하여 본 논문에서는 시작점을 원점뿐만 아니라 Frame$_{t-1}$의 MV까지도 예측 시작점으로 선택하여 탐색의 시작점을 다양화 하였다. 실험 결과 탐색 시작점을 다양화 함으로써 full search를 제외한 diamond search, hexagonal search, 4 step search등 기존의 탐색 알고리즘보다 30$\sim$80% 더 작은 SAD값을 구할 수 있었다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2016년도 추계학술대회 논문집
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• pp.13-14
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• 2016

This paper has introduces a novel Integrated On-board Charger (IOBC) to reduce the size, weight and cost of power conversion stages in Electric Vehicles (EVs). The IOBC is composed of an OBC and a low voltage dc-dc converter (LDC). The IOBC includes a bidirectional ac-dc converter and a bidirectional full-bridge converter with an active clamp circuit. The LDC converter is a hybrid topology combining an active clamped full-bridge converter and a forward converter derived from the Weinburg converter topology. Unlike conventional OBC, the proposed IOBC is compact and the LDC converter of it can achieve a higher efficiency. In addition, the LDC converter of the proposed IOBC can achieve high step-down voltage conversion ratio, no circulating current, no reverse recovery current of the rectifier diodes and small ripple current of output inductor on the auxiliary battery. A 1kW hardware of the LDC converter is implemented to verify the performances of the proposed IOBC.

• 한국자동차공학회논문집
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• 제18권6호
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• pp.14-22
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• 2010

In this study, a large bus is tested for measuring the steering response based on the slarom test and step steer test. A full car model by using ADAMS/Car is established for computer simulation. For bus modeling, user defined templates are made and used in the simulation. Simulation results according to the slarom and step steer test are compared to the physical experiments, in which several sensors are installed to measure vehicle responses. The results obtained from the comparison show a good agreement with regard to the vehicle velocity and steering angle.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.535-540
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• 2009

Recently, autonomous robots which can achieve the complex tasks have been required with the advance of robotics. Advanced robot vision for recognition is necessary for the realization of such robots. In this paper, we propose a method to recognize an object in the actual environment. We assume that a 3D-object model used in our proposal method is the voxel data. Its inside is full up and its surface has color information. We also define the word "recognition" as the estimation of a target object's condition. This condition means the posture and the position of a target object in the actual environment. The proposal method consists of three steps. In Step 1, we extract features from the 3D-object model. In Step 2, we estimate the position of the target object. At last, we estimate the posture of the target object in Step 3. And we experiment in the actual environment. We also confirm the performance of our proposal method from results.