이성우 교수

In this paper, 3 generations of OLEV (On-Line Electrical Vehicle) are introduced. The 1st generation of OLEV is conventional E-type structure. The air gap of the 1st generation is 1cm and the input to output power efficiency is 80% with 3 kW output power. The ultra slim U-type mono rail structure is applied to the 2nd generation of OLEV. This structure is applied to the OLEV bus which achieves 52 kW output power with 72% efficiency at 17 cm air gap. SUV (Sports Utility Vehicle) equipped with the

A large-signal dynamic model of the inductive power transfer system (IPTS) for the online electric vehicle (OLEV) is developed using the recently proposed Laplace phasor transform. With the help of this dynamic model, the effect of the output capacitor and load resistance variation on the transient response of the IPTS is analyzed. The maximum pickup current and output voltage for an abrupt in-rush of the OLEV are examined by both the proposed analysis and simulations, and verified by experiment

There has been growing concern as to whether the growing investment in rural South Korea is achieving the desired ends. Empirical evidence is required to assess the current policies. Based on the logic of those policies, this study conducts an ex-post evaluation of outcomes following the termination of the Rural Traditional Theme Village program previously operated by the Rural Development Administration, a central government agency in South Korea. The research adopts farm households' non-farm i

The aim of this study was to identify the characteristics of an α-FeOOH based composite for the removal of hydrogen sulfide in room temperature gas streams. α-FeOOH was supported on commercial-activated carbon powder to avoid the agglomeration problem of composite fabrication. α-FeOOH was prepared by using FeCl3 solution (as an Fe precursor) and NH4HCO3 (as a pH control). The formation of α-FeOOH was confirmed by observing α-Fe2O3 under the hydrothermal condition. The results of the experiment i

본 연구의 목적은 서울시 범죄유발의 결정요인을 특히 공간적 특성을 중심으로 분석하여 범죄예방에 관한 도시계획적 함의를 제시하는 데 있다. 본 연구에서는 범죄가 공간적 특성과 밀접한 관련성을 가지고 있다는 가정을 설정하고 이러한 공간적 특성을 감안하여 분석할 수 있는 3가지 유형의 공간계량경제기법(SAR, SEM, SAC)을 적용하였다. 본 연구에서 분석된 주요 결과를 요약하면 다음과 같다. 첫째, 서울시 범죄 자료의 경우 공간적 종속성과 공간적 이질성이 존재하고 있는 것으로 나타났다. 둘째, 범죄와 가장 밀접한 관련성을 가지고 있는 변인은 특히 유동인구수와 유흥업소수인 것으로 드러났다. 셋째, 도시계획변인이 가지는 범죄와의 관련성은 매우 높은 것으로 드러났다. 범죄예방이라는 측면에서의 도시계획과 범죄에 대한 학문적 연구는 시민의 안전을 도모할 수 있다는 시민복리 증진의 측면에서 보다 세밀한 연구의 수행 및 정책의 집행이 이루어질 필요가 있는 것으로 판단된다.

Port competition at both the regional and global scales results in port concentration and deconcentration, respectively. Whereas a number of recent studies interpret such phenomena as the effects of global forces such as containerization, few researchers have investigated local forces, such as the evolving relationships between urban policy and port growth. This study compares how two global hub port cities in the Asia-Pacific region, Hong Kong and Singapore, have sustained their port functions

In the Inductive Power Transfer System (IPTS) for the On-Line Electric Vehicle (OLEV), the Electro Magnetic Field (EMF) should be lower than 62.5 mG at 20 kHz for the safety of pedestrians. To meet the EMF requirement a new active EMF cancel method for the recently developed I-type IPTS is proposed in this paper. The I-type IPTS has a narrow rail width structure with alternating magnetic polarity along with a roadway. The EMF canceling is applied to only pick-up where large EMF is generated due

Abstract: This study examines the determinants and employment consequences of white and black family interstate migration within the United States during the period 1985–90. We pay particular attention to selecting intact family migrants from the 1990 PUMS data to eliminate couples who migrated from different origins. Migration status is treated as a selection process and is incorporated into the employment opportunity models. We show that various socioenvironmental and fiscal factors are signif

In switching power converters, the turn on/off process of switches is crucial for the reliability and efficiency of the converter. In general, optimum switching is challenging, and it is particularly difficult for hard switching. The MOSFET synchronous buck converter having wide applications due to high switching speed and low loss, however, operates in hard switching and needs a good timing control for its switching. On/off commutation dead-times should be adjusted care fully in accordance with

Dead-time controls for synchronous buck converter are challenging due to the difficulties in accurate sensing and processing the on/off dead-time errors. For the control of dead-times, an integral feedback control using switched capacitors and a fast timing sensing circuit composed of MOSFET differential amplifiers and switched current sources are proposed. Experiments for a 3.3 V input, 1.5 V-0.3 A output converter demonstrated 1.3 ~ 4.6% efficiency improvement over a wide load current range.