거대자기이방성 스핀벨브 구조에서 자화 곤란축 방향에서의 자기 센서 감도 향상

정구훈,김시년,임상호 한국자기학회 2017 한국자기학회 학술연구발표회 논문개요집 Vol.2017 No.5

고감도 지자기센서 개발을 위한 미앤더 패턴의 거대자기저항 박막

김시년,정구훈,안지훈,이기승,유천열,신광호,임상호 한국자기학회 2017 한국자기학회 학술연구발표회 논문개요집 Vol.2017 No.5

6.25 동란 초기 충북 영동지구의 민간인 살상사건에 관한 연구(1) : 노근리의 미군 대양군 집단살상사건을 중심으로 Focused the Nokeun Ri cilvilian massacre incident by the U.S Army

최병수,정구훈 충북대학교 인문과학연구소 1999 人文學誌 Vol.17 No.1

Ⅰ. Around noon of July 23, 1950, American soldiers arrived at Jukog Ri, Yongdong Eup, Yongdong Gun, North Chungchong Province. They ordered the villagers to evacuate the village to Imkae Ri(mountain village) which is located about 2kms away from their hometown toward south. On the evening of July 25th, 1950, a group of American soldiers rushed into Imkae Ri and ordered the villagers, 500-600, to gather together. They promised to take the villagers to a safe place, toward Taegu(city). When 500-600 refugees, led by the American soldiers following the Seoul-Pusan national road, arrived at Haka Ri, Yongdong Eup, which is about 8kms away from Nokeun Ri, it was lated in the night. The American soldiers then led all of the refugees into a nearby stream, and ordered them to stay there during that night. At dawn, July 26th, the refugees had found that the U.S. soldiers had disappeared. Therefore, the refugees marched to south on their own toward Taegu, where no one else was there except the villagers themselves. Around noon of July 26th, 1950, when the refugee group arrived at Nokeun Ri, Hwanggan Myun, Yongdong Gun, suddenly four or five American soldiers appeared and commanded the refugees to stand on the railroad tracks and inspected the refugees' bodies and the personal belongings of the refugees. The American soldiers could not find any weapon. The American soldiers proceeded to send a radio message to somewhere. Shortly afterwards, two planes flew over from the south. The American soldiers fled and the planes flew over and dropped bombs on the refugees and fired machine guns at the refugees. Many refugees were killed. Those who survived, escaped into small water caves and two large tunnels, located below the railroad. The U.S. soldiers then ordered the refugees residing in the small cave to come out. They pushed the remaining refugees into the tunnels. Next, the U.S. soldiers fired their guns at both entrances of the two tunnels, continued day and night, from noon of 26th to dawn of 29th, for four days resulted in lots of deaths. Ⅱ. U.S Army Force Compensation Office in Korea tells that there is no evidence that the U.S. soldiers were there and if so, U.S Army is not responsible for Nokeun Ri massacre incident because it occured during the battle. However, 1. Referring to 5th Cavalry Regimental History of the U.S 1st Cavalry Division, there is a report that the 5th Cavalry Regimental CP was in KaRi(which is a nearby of the refugees stayed at night of 25th), located about 7-8kms away from the Nokeun Ri toward Seoul, at 01:35-07:25 in July, 26th. And there is another report that backward CP of the 5th Cavalry Regiment was in Hwanggan Myun, located about 2kms from the incident spot to the Taegu direction at 17:00 in July, 26th. And it is certain that the Nokeun Ri area was an operational zone of the 1st Cavalry Division at that time because the headquarters of the 1st Cavalry Division was in Hwanggan Myun, referring to the $quot;The korean War$quot;, published by Japan War Research institute. 2. (a) Referring to $quot;The history of The Korean War$quot;, published by the Korea Military Academy and $quot;The Korean War$quot;, published by Japan War Research Institute and $quot;The History of the United Nations Forces in The Korean War$quot;, published by the Korean Ministry of National Defense, the North Korean Army couldn't break through the front of the U.S. Army base because of the loss of war potential. So, the 9th Regiment of the North Korean 3rd Division was stationed in Yongdong against the U.S 1st Cavalry Division, and the 7th Regiment of the North Korean 3rd division went southwest from Yongdong on the Muju road in a sweeping flank movement through Chirye against Kimchun. Therefore, it is noted that the North Korean Army was still Yongdong city, which is located 14kms away from the massacre field. There is no record that the North Korean Army and the U.S. Army had battle between Yongdong and Hwanggan in the operation note of the U.S 5th Cavalry Regimental history. On the contrary, the operations plan(No.10-50) of the U.S 1st Cavalry Division shows the command, $quot;disengage from contact with the enemy and move to new(rear) position$quot;. (b) Referring to the U.S 5th cavalry regimental history, there was a message from 2nd battalion commander to the CO of 5th cavalry regiment at 01:35-02:00 in July, 26th(here, villagers of the Jukog Ri and ImKae Ri were walked following the Seoul-Pusan national road by the command of the U.S. soldiers at that time). The message tells that an est 50 natives w/oxcarts rptd earlier to have been near this unit in hills coming out and headed toward rear. None appear armed; We have not opened fired; req an immed answer. Here, it is assumed the number of 50 that it is intended to minimize the number on purpose or it is a miss-typing of 500. The U.S 5th regimental commander commanded to the 2nd battalion commander that $quot;re natives w/oxcarts-round them repeat round them immediately$quot; as a first message. But, there is no the 2nd message for answering the message which reported by the 2nd battalion and the first report to the regimental commander. Why? There is no message about reporting the result of the first message, And he civilian massacre was happened by the U.S. Army at Nokeun Ri which is 7-8 kms away from the U.S 5th Cavalry Regimental CP at Kari to the Taegu direction after several times later. It is assumed that the above described $quot;50(0) civilians and oxcarts are the victims of the Nokeun Ri according to the incident timing and the feature of the refugee group$quot;. (c) Additionally, we can see records that the national road was cut off already by the road block three times at 08:00-08:40(NO. b) in July, 25th and at 07:50-09:00(NO. f) in July, 25th etc. in the 5th Cavalry Regimental History. Therefore, another civilians except refugees of the Jukog Ri and Imkae Ri walked through the road led by the U.S. soldiers could not walk through the same road during the above situation at all. This is the other undoubted reason that the 50(0) civilians and oxcarts are the victims of the Nokeun Ri incident. (d) According to the research by the Nokeun Ri civilian massacre incident measures committee untill the end of Feb. 1998, it figured out that the death was 130 and the severly wounded was 19. We assume that total death was about 400 including unidentified victims, if investigated in a positive light, referring to testimony of the survived victims, reports of the Cho Sun In Min Bo and recent news in Korea. Ⅲ. Actually, it has been nothing to solve the above problem between the U.S Army and the Korean Government as well. We suggest that both Korean and U.S. Governments should investigate the incident to solve the problem. And the investigation should be leaded by the Korean Government. Ⅳ. Because of short of the records, it was difficult to study the incident in detail. However, we will be going to show more detailed paper in the next time after inquiring into the truth of the matters.

압입시험을 통하여 초탄성 재료 물성치를 평가하는 단순한 방법

송재욱,김민석,정구훈,김현규 한국전산구조공학회 2019 한국전산구조공학회논문집 Vol.32 No.5

In this study, a new simple method for the estimation of hyperelastic material properties by indentation tests is proposed. Among hyperelastic material models, the Yeoh model with three material properties (C10, C20,C30) is adopted to describe the strain energy density in terms of strain invariants. Finite element simulations of the spherical indentation of hyperelastic materials of the Yeoh model with different material properties are performed to establish a database of indentation force-displacement curves. The indentation force-displacement curves are fitted by cubic polynomials, which are approximated as a product of third-order polynomials of (C10, C20,C30). A regression analysis is conducted to determine the coefficients of the equations for the indentation force-displacement curve approximations. A regression equation is used to estimate the hyperelastic material properties. The present method is verified by comparing the estimated material properties with true values. 본 논문에서는 압입시험을 통해서 초탄성 재료 물성치를 평가하는 간단한 방법을 제시하였다. 초탄성 재료 모델 중, 3개의 물성치(C10, C20,C30)를 가지는 Yeoh 모델을 선택하여 주연신률로 표현되는 변형률 에너지 밀도를 적용하였다. Yeoh 물성치를 변화시키며, 구형 압입시험 유한요소해석을 수행하여 압입자 반력-변위 곡선을 획득하였다. 압입자 반력-변위 곡선을 3차 다항식으로 근사하였고, 이 다항식을 물성치(C10, C20,C30)의 3차 곱으로 근사된 3차 다항식으로 표현하였다. 압입자 반력-변위 곡선 근사를 위해 회귀분석을 진행하여 수식들의 계수를 결정하였으며, 이 회귀식을 이용하여 초탄성 재료의 물성치를 평가하였다. 초탄성 재료 물성치 평가를 수행하고 오차를 비교하여 유효성을 보여 주었다.

제 2 발표장 : 2 - D 탄소 / 탄소복합재의 층간전단강도 개선에 관한 연구

손종석(J . S . Son),정구훈(K . H . Chung),김정일(J . I . Kim),주혁종(H . J . Joo),김광수(K . S . Kim) 한국복합재료학회 1999 한국복합재료학회 학술발표대회 논문집 Vol.- No.2

첨가제에 의한 저밀도 2-D 탄소 / 탄소 복합재의 층간전단강도 개선

손종석(Jong Seok Son),정구훈(Ku Hun Chung),주혁종(Hyeok Jong Joo) 한국고분자학회 2000 폴리머 Vol.24 No.6

옥시불화이트륨 분말의 고상합성 및 플라즈마 스프레이 코팅 적용

이정일,김영주,채희라,김윤정,박성주,신경선,하태빈,김지현,정구훈,류정호,Lee, Jung-Il,Kim, Young-Ju,Chae, Hui Ra,Kim, Yun Jeong,Park, Seong Ju,Sin, Gyoung Seon,Ha, Tae Bin,Kim, Ji Hyeon,Jeong, Gu Hun,Ryu, Jeong Ho 한국결정성장학회 2021 한국결정성장학회지 Vol.31 No.6

반도체 회로를 제조하기 위해서 에칭, 세척, 증착 등의 공정들이 반복적으로 진행된다. 따라서 이러한 공정이 진행되면 진공장비 내부는 부식성이 높은 가혹한 플라즈마 환경에 노출되게 된다. 따라서 반도체 공정 장비의 내부를 플라즈마 노출에 강한 재료를 사용하여 코팅층의 에칭과 오염 입자의 생성을 최소화하여야 한다. 본 연구에서는 고상합성법에 의해 Y₂O₃와 YF₃ 분말을 원료물질로 옥시불화이트륨(YOF)를 성공적으로 합성하였다. Y₂O₃와 YF₃ 분말의 혼합비율은 1.0:1.0에서 1.0:1.6까지 조절하였으며, 혼합비율이 합성된 YOF 분말의 결정구조와 미세구조에 미치는 영향을 XRD와 FE-SEM으로 조사하였다. 합성된 YOF 분말을 이용하여 알루미늄 기판에 플라즈마 스프레이법으로 성공적으로 코팅하였다. In order to manufacture a semiconductor circuit, etching, cleaning, and deposition processes are repeated. During these processes, the inside of the processing chamber is exposed to corrosive plasma. Therefore, the coating of the inner wall of the semiconductor equipment with a plasma-resistant material has been attempted to minimize the etching of the coating and particle contaminant generation. In this study, we synthesized yttrium oxyfluoride (YOF) powder by a solid-state reaction using Y₂O₃ and YF₃ as raw materials. Mixing ratio of the Y₂O₃ and YF₃ was varied from 1.0:1.0 to 1.0:1.6. Effects of the mixing ratio on crystal structure and microstructure of the synthesized YOF powder were investigated using XRD and FE-SEM. The synthesized YOF powder was successfully applied to plasma spray coating process on Al substrate.