수치해석을 이용한 전동차용 IGBT 모듈의 피로 수명 예측

권오영,장영문,이영호,좌성훈,Kwon, Oh Young,Jang, Young Moon,Lee, Young-ho,Choa, Sung-Hoon 한국마이크로전자및패키징학회 2017 마이크로전자 및 패키징학회지 Vol.24 No.1

본 연구에서는 전동차의 전력 변환 장치로 많이 사용되고 있는 고전압 대전류용(3,300 V/1200 A급) insulated gate bipolar transistor(IGBT) 모듈에 대하여 열 사이클 조건하에서의 열-기계적 응력해석 및 피로수명해석을 수행하였다. 특히 최근 고전압 IGBT용으로 개발되고 있는 구리(copper) 와이어, 리본(ribbon) 와이어를 사용하였을 경우의 응력 및 피로수명을 기존의 알루미늄 와이어와 비교하여 분석하였다. 알루미늄 와이어 보다는 구리 와이어에 응력이 3배 이상 많이 발생하였다. 리본 와이어의 경우 원형 와이어 보다 응력이 더 크게 발생하며, 구리 리본 와이어의 응력이 제일 높았다. 칩과 direct bond copper(DBC)를 접합하고 있는 칩 솔더부의 피로해석을 수행한 결과, 솔더의 크랙은 주로 솔더의 모서리에서 발생하였다. 원형 와이어를 사용할 경우 솔더의 크랙은 약 35,000 사이클에서 발생하기 시작하였으며, 알루미늄 와이어 보다는 구리 와이어에서의 크랙의 발생 면적이 더 컸다. 반면 리본 와이어를 사용하였을 경우 크랙의 면적은 원형 와이어를 사용하였을 경우보다 적음을 알 수 있다. DBC와 베이스 플레이트 사이에 존재하는 솔더의 경우 크랙의 성장 속도는 와이어의 재질이나 형태에 관계없이 비슷하였다. 그러나 칩 솔더에 비하여 크랙의 발생이 일찍 시작하며, 40,000 사이클이 되면 전체 솔더의 반 이상이 파괴됨을 알 수 있었다. 따라서 칩 솔더 보다는 DBC와 베이스 플레이트 사이에 존재하는 솔더의 신뢰성이 더 큰 문제가 될 것으로 판단된다. In this study, the thermomechanical stress and fatigue analysis of a high voltage and high current (3,300 V/1200 A) insulated gate bipolar transistor (IGBT) module used for electric locomotive applications were performed under thermal cycling condition. Especially, the reliability of the copper wire and the ribbon wire were compared with that of the conventional aluminum wire. The copper wire showed three times higher stress than the aluminum wire. The ribbon type wire showed a higher stress than the circular type wire, and the copper ribbon wire showed the highest stress. The fatigue analysis results of the chip solder connecting the chip and the direct bond copper (DBC) indicated that the crack of the solder mainly occurred at the outer edge of the solder. In case of the circular wire, cracking of the solder occurred at 35,000 thermal cycles, and the crack area in the copper wire was larger than that of the aluminum wire. On the other hand, when the ribbon wire was used, the crack area was smaller than that of the circular wire. In case of the solder existing between DBC and base plate, the crack growth rate was similar regardless of the material and shape of the wire. However, cracking occurred earlier than chip solder, and more than half of the solder was failed at 40,000 cycles. Therefore, it is expected that the reliability of the solder between DBC and base plate would be worse than the chip solder.

단일 카메라를 이용한 3차원 공간 정보 생성

권오영,서경택,Kwon, Oh-Young,Seo, Kyoung-Taek 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.12

경제성을 얻기 위해 단일 카메라를 이용하여 3차원 복원을 수행한 뒤 그 정보를 토대로 운전자에게 전방에 존재하는 장애물의 통과 여부를 알려줄 수 있는 운전 보조 장치에 관한 연구를 진행한다. 그 결과 depth 정보는 떨어지나 직진상의 장애물을 통과 할 수 있는 정보를 제공할 수 있다. 3차원 복원을 위해서는 내부파라미터를 측정하고, 특징점을 찾아 매칭하여 기본행렬을 계산하고 이를 토대로 삼각측량을 수행하여 얻는다. 실험을 통해 결과를 확인해 보면 depth 정보는 불완전하나, 장애물 통과 여부를 판단 할 수 있는 X, Y 축의 정보는 신뢰성을 가진다. Run 3D reconstruction using a single camera, based on the information, we are advancing research on driving assistance apparatus or can be informed how to pass the obstacle existing ahead the driver. As a result depth information falls but it is possible to provide information that can pass through an obstacle on the straight. For 3D reconstruction by measuring the internal parameters, it calculates the Fundamental matrix and matching to find the feature points obtained by executing the triangulation on the basis of this. When the through experiments try to confirm the results, the depth information is present error information in the X and Y axes which can determine whether or not to pass through an obstacle has reliability.

스트레스 인식변화기법의 공군 조종사 적용 효과

권오영,Kwon, Oh-young 한국항공운항학회 2018 한국항공운항학회지 Vol.26 No.3

Stress is the main source of a human error or can potentially contribute to it. Recently, the rate of accidents which is associated with human factors among the total aircraft accidents is showing a tendency of gradual increase. In order to prevent the accidents related to human factors, stress mitigation of the mission personnel is highly required. In this study, a 'stress cognitive alteration' technique, which is one of the stress relief methods, is applied to the Air Force pilots to verify if the technique is effective in reducing stress. The 'stress cognitive alteration' technique is comprised of two parts: a positive function of stress and a process to positively alter the physical, psychological response to stress. As a result of the application, it is found that this technique has an effect of reducing stress of the pilots under a relatively high level of stress.

공군 조종사의 공정문화 수준에 영향을 주는 요인 연구

권오영,Kwon, Oh-young 한국항공운항학회 2021 한국항공운항학회지 Vol.29 No.1

Just culture is an important factors in safety culture, and is related to the degree to which potential risk information is shared. Since the importance of the level of just culture has been highlighted in the aspect that it is related to the prevention of various safety accidents, research on just culture was required. In previous studies, there are attempts to develop a scale to measure the level of just culture and to reveal the degree of predicting the experience of accidents or errors and the actual reporting experience. However, It was not possible to clarify the factors that facilitate and inhibit the level of just culture for the formation of just culture. This study was conducted to help improve the level of the organization's just culture by specifically identifying factors that facilitate and inhibit the impact on the level of the just culture. As a result, it was possible to find the facilitating and inhibiting factors affecting the 6 factors of just culture.

확률분포 생성을 통한 근사 행렬 곱셈 간소화 방법

권오영,서경택,Kwon, Oh-Young,Seo, Kyoung-Taek 한국정보통신학회 2022 한국정보통신학회논문지 Vol.26 No.11

Matrix multiplication is a fundamental operation widely used in science and engineering. There is an approximate matrix multiplication method as a way to reduce the amount of computation of matrix multiplication. Approximate matrix multiplication determines an appropriate probability distribution for selecting columns and rows of matrices, and performs approximate matrix multiplication by selecting columns and rows of matrices according to this distribution. Probability distributions are generated by considering both matrices A and B participating in matrix multiplication. In this paper, we propose a method to generate a probability distribution that selects columns and rows of matrices to be used for approximate matrix multiplication, targeting only matrix A. Approximate matrix multiplication was performed on 1000×1000 ~ 5000×5000 matrices using existing and proposed methods. The approximate matrix multiplication applying the proposed method compared to the conventional method has been shown to be closer to the original matrix multiplication result, averaging 0.02% to 2.34%.

논문 : 남한산성과 조선 후기의 대명의리론

권오영 ( Oh Young Kwon ) 한국실학학회 2004 한국실학연구 Vol.8 No.-

최한기의 학문관과 (學問觀) 기학의 (氣學) 성격

권오영 ( Oh Young Kwon ) 일지사 1994 韓國學報 Vol.20 No.4

자체 제작한 호흡 동기화 장치를 통한 흉부 일반촬영 검사의 호흡 재현성 평가

권오영(Oh-Young Kwon),이창훈(Chang-Hun Lee),용금주(Keum-Ju Yong),진선희(Seon-Hui Jin),정다빈(Da-Bin Jung),허영철(Yeong-Cheol Heo) 한국방사선학회 2021 한국방사선학회 논문지 Vol.15 No.7

본 연구의 목적은 일반촬영용 호흡 동기화 장치를 개발하여 호흡 협조가 어려운 환자의 가슴 검사를 할 때 들숨의 재현성을 높이는 것이다. 공기압 센서를 이용하여 호흡 동기화 장치를 자체 제작(X-RSD)하였고, 심폐소생술용 마네킹에 벤틸레이터를 연결하여 공기를 주입하였다. 이때 주입한 공기의 양은 SkillReporting 장치를 이용하여 정량화하였다. 마네킹의 가슴에 X-RSD를 위치한 후 공기의 양을 200-700 cc까지 100 cc 씩 총 6 단계를 나눠서 검사하였다. 오차 평가는 총 80회씩 반복 측정하여 X-RSD의 민감도를 측정하였고 민감도는 100%로 매우 정교한 결과 값을 얻을 수 있었다. 이후 가슴 측면검사를 X-RSD를 보면서 검사한 영상과, 암맹 검사한 영상을 비교평가 하였고, X-RSD의 폐 용적이 암맹 검사보다 용적도 크게 측정되고, 편차도 적게 측정되었다. 종합적으로 X-RSD를 이용하면 협조가 어려운 환자의 가슴검사에 도움을 줄 수 있으며, 일반촬영의 재촬영률을 줄여 전체적인 피폭선량 감소에 기여가 가능할 것이라 사료된다. The purpose of this study was to develop a respiratory synchronization device for X-ray (X-RSD) to increase the reproducibility of inspiration when examining the Chest X-ray of a patient who difficulty in breathing coordination. The X-RSD was self-made using an air pressure sensor and air was injected by connecting a ventilator to the mannequin for CPR. At this time, the amount of injected air was quantified using the SkillReporting device. After placing the X-RSD on the chest of the mannequin, the amount of air was tested in 6 steps from 200 to 700 cc by 100 cc increased. For the accuracy evaluation, the sensitivity of X-RSD was measured by repeating a total of 80 measurements, and the sensitivity was 100%, and very precise results were obtained. After that, the images examined while viewing the X-RSD of the chest lateral examination and the images obtained by the blind examination were compared and evaluated. The lung volume of X-RSD was larger than that of the blind test, and the deviation was smaller. Overall, the use of X-RSD can help with chest X-ray examination of patients who have difficulty in cooperating, and it is thought that it will be possible to contribute to the reduction of exposure dose by reducing the repeat rate of general X-ray examinations.

고계(古溪) 이휘령(李彙寜)의 학문과 퇴계학맥에서의 위상

권오영 ( Kwon Oh-young ) 연민학회 2019 연민학지 Vol.32 No.-

이 글은 우선 고계(古溪) 이휘령(李彙寜)의 생애를 알아보고, 이어 학문과 사상의 내용을 검토하고, 마지막으로 그의 퇴계학맥(退溪學脈)에서의 위상과 현손(玄孫) 연민(淵民) 이가원(李家源)에게까지 이어지는 가학의 전승을 탐구하였다. 이휘령은 이황의 10세(世) 종손(宗孫)이다. 그는 일찍이 경세치용(經世致用)의 학문에 치중하여 치적(治績)이 당세에 이름이 높았고, 또 가학인 이학(理學)을 깊이 탐구하였다. 그는 이황 이후의 심학(心學)의 전통을 잇는다는 의식이 강하였다. 그는 시(詩)에서 그런 의식을 강하게 드러내었는데, 주희가 「재거감흥(齋居感興)」시(詩)에서 사용했던 ‘추월(秋月)’과 ‘요금(瑤琴)’이란 시어(詩語)를 자주 인용하여 썼다. 그는 다시 주희와 이황의 심학(心學)의 거문고[瑤琴]를 안고 이황의 심학의 옛 곡조[古調]의 메아리를 찾고자 했던 것이다. 한편 19세기 이휘령이 살았던 영남 학계에서는 이황의 적전(嫡傳)이 누구에게 있느냐를 놓고 병호시비(屛虎是非)가 일어나 그 갈등이 심각하였다. 이휘령은 병론(屛論)에 속했지만, 병론과 호론(虎論)이 분열된 뒤에 영남의 연원(淵源)이 있는 고가(古家)가 서로 갈등하여 투쟁을 하자, 양론(兩論) 사이에서 중도(中道)를 지키면서 양론의 보합(保合)을 주장하였다. 이황 이후 진성이씨의 가학은 조선 후기에 그 후손들에 의해 몇 갈래로 전해졌다. 이휘령은 이황 이후 면면히 이어져온 가학을 이었다. 그의 가학은 다시 아들 이만희(李晩憙), 손자인 이중인(李中寅), 증손자인 이상호(李祥鎬) 등에게 전해졌다. 이가원은 어릴 때부터 종숙부(從叔父) 이상호의 문하에 나아가 가르침을 받았다. 이같이 연민학(淵民學)의 출현은 일조일석에 나타난 것이 아니라 이황 이후 이휘령을 거쳐 면면히 이어져온 이학과 가학의 전통에 기초하고 있다고 할 수 있다. This study is designed to research on the history and life of Lee Hui Ryeong (pen name Gogye)'s gahak (家學, family study). Then, the study focused on the his position in the School of Toegye and the transfer of gahak from him to his descendent Lee Ga Won (pen name Yeonmin). Lee Hui Ryeong was a descendant of the 10th generation of Lew Hwang. He was famous at the period as he put priority on the study which was empirical and practical and deeply researched the lihak(理學, Learning of Principle), which was the family study transferred from his ancestors. Most of all, he was very conscious that he had transferred the tradition of the shimhak (心學, Learning of Mind) since the period of Lee Hwang. He expressed this consciousness in his poem by often quoting the poem words such as 'chuwol(秋月, autumn moon)' and 'yoguem(瑤琴, music instrument)' which were used by Zhu Xi in his poem "jaegeogamheung(齋居感興)". He tried to find out the ancient melody of Lee Hang's shimhak by cherishing the geomungo(琴) of Zhu Xi and Lee Hwang's shimhak. On the other hand, the Yeongnam academic circle to which Lee Hui Ryeong belonged during 19th century, there was a severe conflict between the academic schools (Byeongron and Horon) on which school could keep the ancestral tablet of Lee Hwang. When the dispute between two schools was developed into the struggle between old families rooted in Yeongnam, he kept the middle way between two schools and argued for the reconciliation even though he belonged to the school of Byeongron, After the passing of Lee Hwang, the family study belonging to Jinseong Lee family was divided into several studies by his descendents in late Joseong period. He took over the family study which Lee Hwang started and passed it over to his descendent. His study was passed over to his son Lee Man Hee, his niece Lee Man suk, his grandson Lee Jung In, and his grand-grandsons Lee Sang Ho and Lee Young Ho and etc. Lee Ga Won got educated under his uncle Lee Sang Ho. As such, the study of Yeonmin was not made in a day but has been based on the tradition of lihak and gahak which have been passed down from Lee Hwang through Lee Hui Ryeong up to now.

카스피해 서안-코카서스 남록에서 동서 문화의 접변

권오영(Kwon, Oh-Young) 역사학회 2015 역사학보 Vol.0 No.226

Today the southern part of the Caucasus mountains and western part of Caspian Sea belong to Azerbaijan and Iran. From a historical view, this area is a point of acculturation between the East and the West. Since the 1<SUP>st</SUP> millennium B.C., many nomadic tribes(Scythians, Sarmatians, Allans) of the Steppe migrated and reached here. At the same time the strong influences from the south(Manna, Media, Achaemenid Persia, Partia, Sassanid Persia) reached this area too. Since the Middle Ages, Arabs, Turks and Mongols attacked and settled down this area. As a result there happened a complex acculturation in the blood, religion, and culture. In the modern times, Russia, Ottoman Turk, and Iran clashed mutually and Azerbaijan people was doomed to divide into two parts. So the diplomatic relations among Azerbaijan, Russia, Armenia, Turkey and Iran are getting more and more complicated. The representative ancient states in this area are Atropatena and Caucasian Albania. Recently archaeologists excavated several sites in Gabala the capital of Caucasian Albania and could accumulate abundant data about the exchange of cultural features among many states for example Partia, Sassanid Persia, Greece, Rome, Sarmatia, and Alan. So from now we are able to study the acculturation phenomenon by not only old documents but also the archaeological material.