• 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.

• 한국정보처리학회논문지
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• 제2권3호
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• pp.417-424
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• 1995

본 논문에서는 정량화(Quantification) 문제를 MFT(Mean Field Theroy)를 통해서 해결하는 기법을 제안한다. 통계학에서 중요한 문제의 하나인 정량화 문제는 주어진 공간에서 대상들간의 유사성에 따라서 최적의 상태를 갖도록 하는 문제이다. 평균장 접근 방법에 기초한 한개의 변수로 표현되는 확률적 시뮬레이티드 아닐링을 제안하고 정량화 문제를 패널티(penalty) 파라메타 항을 첨가한 비한정된 최적화 문제로 변형하 여 MFT를 적용하였다. 또한 연속변수를 갖는 신경회로망에서 실제 값을 계산하는 것 보다 평균장 접근방법으로 계산하는것이 더 빠르게 계산될 수 있음을 확인하였다. 본 논문에서 제안한 방법이 실험결과 해석적인 방법보다 좋은 정량적 결과를 보였다.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1995-2003
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• 2014

Power semiconductor devices have been the major backbone for high-power electronic devices. One of important parameters in view of power semiconductor devices often characterize with a high breakdown voltage. Therefore, many efforts have been made, since the development of the Insulated Gate Bipolar Transistor (IGBT), toward having higher level of breakdown voltage, whereby the typical design thereof is focused on the structure using the field ring. In this study, in an attempt to make up more optimized field-ring structure, the characteristics of the field ring were investigated with the use of theoretical arithmetic model and methodologically the design of experiments (DOE). In addition, the IGBT having the field-ring structure was designed via simulation based on the finding from the above, the result of which was also analyzed. Lastly, the current study described the trench field-ring structure taking advantages of trench-etching process having the improved field-ring structure, not as simple as the conventional one. As a result of the simulation, it was found that the improved trench field-ring structure leads to more desirable voltage divider than relying on the conventional field-ring structure.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 춘계학술대회 논문집
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• pp.517-518
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• 2006

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2009년도 발표 논문집 제18권
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• pp.236-239
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• 2009

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(I)
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• pp.575-578
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• 1987

• 건축역사연구
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• 제8권3호
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• pp.9-22
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• 1999

The purpose of this study is to analyse the architectural character of JE-DAMG at farm village in Ulsan. JE-DANG means the building for DONG-JE (the sacrificial rite of a village). The regions of this study are KANG-DONG MYEN, and UNG-CHON MYEN in Ulsan. The method of this study is the analysis of them after the actual field surveys of 47 JE-DANGs in these regions The survey contains the area, the height, the period of the erection, the architectural structure, the roof shape, the material, the landowner, SHIN-CHE (means a god's name and shape), DANG-SU tree and so on. Methods of the survey are the field survey, the interview of villager, the analysis of reference data and so on. Results of the study are below. JE-DANGs(buildings) of these regions had been built first in the period of Japanese occupancy and erections of them had continued until 1970's. Since then, they have been rebuilt. The primary JE-DANG is characterized by a tiled roof, a wooden post lintel, a mud-plastered wall, and a wooden door. After rebuilding, characters are a flat slab, a tiled roof, a structure of using red bricks, and the area is getting larger than the primary JE-DANG, but 1 KAN persists without variety. Most of houses in the inland area like UNG-CHON MYEN face the south, and ones in the coastal area like KANG-BONG MYEN face the east. Generally there is DANG-SU tree behind JE-DANG. That proves DANG-SU tree to be the object of the rite. The species of DANG-SU is a pine in general ,but various in UNG-CHON MYEN. In general names of the god are DONG-SHIN , DANG-SAN SHIN and SUNG-HWANG SHIN. I think that the landownership of JE-DANG should change the private ownership into the village ownership to preserve JE-DANG though most of lands of JE-DANG are private ones.

• 한국도로학회논문집
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• 제16권2호
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• pp.43-52
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• 2014

PURPOSES : To solve problems in current compaction control DCPT(Dynamic Cone Penetrometer Test), highly correlated with various testing methods, simple, and economic is being applied. However, it、s hard to utilize DCPT results due to the few numerical analyses for DCPT have been performed and the lack of data accumulation. Therefore, this study tried to verify the validation of numerical modeling for DCPT by comparing and analyzing the results of numerical analyses with field tests. METHODS: The ground elastic modulus and PR(Penetration Rate) value were estimated by using PFC(Particle Flow Code) 3D program based on the discrete element method. Those values were compared and analyzed with the result of field tests. Also, back analysis was conducted to describe ground elastic modulus of field tests. RESULTS : Relative errors of PR value between the numerical analyses and field tests were calculated to be comparatively low. Also, the relationship between elastic modulus and PR value turned out to be similar. CONCLUSIONS : Numerical modeling of DCPT is considered to be suitable for describing field tests by carrying out numerical analysis using PFC 3D program.

• 전기학회논문지
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• 제64권6호
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• pp.872-877
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• 2015

The Permanent Magnet (PM) machine used at speed control using field-weakening control method. But the field-weakening current, which reduces the field flux for high speeds, causes significant copper and core losses. Therefore, this paper deals with the PM performance evaluations in a pole changing memory motor (PCMM). The PCMM can change the number of magnetic poles and produce two types of torque. When the motor operates with eight poles, it produces a magnetic torque at low rotational speeds. When the motor changes to four poles, it produces both magnetic torque and reluctance torque at high speeds. The paper explain the principle and basic characteristics of the motor by using a finite element method magnetic-field analysis, which consists of a PM magnetized by a pulse d-axis current of the armature winding. The results of our experiment show that the proposed motor reduces core loss by 10% and 55% under no-load and load conditions, and doubles the speed range of the motor.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.187-189
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• 2006

Transient finite element method for analysis of moving coil needs many number of elements and much time to make calculation. Therefore, induction heating process for moving coil was simulated by traveling the position of the heating planes in this paper. In the magnetic and thermal analyses, temperature-dependent magnetic and thermal material properties were considered. Finite element program was developed and finite element results were compared with the experimental results.