Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

청소년층에서 형성되는 요추 후방골각의 발생기전

김영수,오성훈,박형천,정태섭 대한신경외과학회 1988 Journal of Korean neurosurgical society Vol.17 No.5

The bony spur formation without degenerative change in the lumbar spines in the young age group is quite interesting and is not uncommon. This bony spur is different from the degenerative spur in the old age group in shape and mechanism of formation. The authors analyzed 25 patients below 29 years old with such posterior lumbar bony spur. We concluded that posterioly lacated Schmorl's node is main cause of the bony pour in young age group at lumbar region.

정신분열병 환자들의 自己灣入에 관한 예비 연구

박성봉,김영미,전성일,이기철,김영훈,정영조,이영렬,이정호,최영민 大韓神經精神醫學會 1997 신경정신의학 Vol.36 No.6

목 적 : 정 신분열병 환자의 자기만입 정도에 영향을 미치는 인구학적 변인들 및 질병연관 변인들을 규명해 보고자 하였다. 또한. 환자들의 자기만입과 병식 사이의 연관성. 자기만입과 자존심 사이의 연관성을 알아보고자 하였다. 방 법 : 정신과 의사가 병록지와 면담을 통하여 대상 정신분열병 환자들의 인구학적 변인들 및 질병연관 변인들에 관한 자료를 얻고 환자들의 병식 정도를 평가한 후, 환자들로 하여금 자기보고형의 자기만입 척도와 자존심 척도를 시행하게 하였다. 총 111명의 환자가 연구대상으로 선택되었다. 결과: . 1) 여자가 남자보다 유의하게 높은 자기만입 척도 점수를 나타내었다 2) 질병연관 변인들 중 하위집단 사이에 자기만입 척도 점수의 유의한 차이를 보이는 변은 없었다. 3) 자기만입 척도 점수와 병식 점수 사이에 유의한 상관관계가 없었다. 4) 자기만입 척도 점수와 자존심 척도 점수 사이에 유의한 역상관 관계를 보였다. 결 론 : 본 예비 연구의 결과로 보아 정신분열 병 환자의 병식이 부족한 상태에서도 자기만입이 진행될 수 있으며. 자기만입이 심할수록 환자의 자존심이 저하되는 것으로 생각된다. 또한 여자 환자들이 남자 환자들보다 자기만입에 더 취약한 것으로 생각된다. 따라서 정신분열 병 환자의 이해와 치료를 위하여 자기만입에 관한 지속적인 연구가 필요할 것으로 생각된다. objective : This study was conducted to identify demographic variables and illness related variables which may affect the severity of self-engulfment in the patients with schizophrenia. We also studied the relationship between self-engulfment and insight, and the relationship between self-engulfment and self-esteem. Methods : Data on demographic variables and illness related variables for the subjects were gathered from hospital records and clinical interviews by the psychiatrists. Degree of insight for the subjects was assessed through clinical interviews by the psychiatrists. Degree of self-engulfment and self-esteem for the subjects was assessed from the self-engulfment scale and the self-esteem scale respectively. A total of 111 patients with schizophrenia were selected for statistical analysis. Results 1) The females exhibited significantly higher scores than the males on the self-engulfment scale. 2) There was no illness related variable, which exhibited a significant difference among subgroups on the self-engulfment scale. 3) There was no significant correlation between the self-engulfment scores and the insight 4) There was a significantly inverse correlation between the self-engulfment scores and the self-esteem scores. Conclusion : The results of this preliminary study suggest that self-engulfment may develop despite lack of insight and that there was inverse relationship between self-engulfment and self-esteem in the patients with schizophrenia. It also suggests that females are more subject to self-engulfment than males. So, authors suggest that it is valuable to do further studies of self-engulfment in the patients with schizophrenia.

남성화를 보이는 여성에서 발견된 난소의 Steroid Cell Tumor 1예

조인호,정대훈,박영미,서영진,손영실,정철회,강영미,정수전,김영남,이경복,성문수,김기태 인제대학교 2006 仁濟醫學 Vol.27 No.-

Steroid cell tumor is a rare ovarian sex cord-stromal tumor which accounts for 0.1% of all ovarian tumors. Until now, only 4 cases have been reported in domestic literatures. Steroid cell tumor often secrets testosterone and presents virilization in adult women or precocious puberty in children. Treatment is often performed by surgical removal, adjuvant chemotherapy and radiation, but completely accepted treatment was not existed. We experienced a case of steroid cell tumor, which was manifested by typical virilization in a 43-year old patient, who was previously performed hysterectomy and unilateral oophorectomy. So, we present with a brief review of the literatures.

격투스포츠 선수의 스포츠맨십 분석

박태훈(Park Tae-Hoon),유기성(Yoo Ki-Seong),유원용(Ryu Won-Yong),김영욱(Kim Young-Wook),이양구(Lee Yang-Gu),공창빈(Kong Chang-Bin),이상호(Lee Sang-Ho),김태영(Kim Tae-Young) 한국체육과학회 2010 한국체육과학회지 Vol.19 No.3

This research examines whether difference that is some in inclination of combat sports player's sportsmanship is, and accordingly is purposeful to clear relation. combat sports (fencing, Taekwondo, boxing, induction, wrestling, wrestling) player who research target is having player life in middle·high·an university 399 people be . Used Korean-made measure (KMSOS) that Seong-changhun (2003) verifies changing based on Vallerand MSOS by a tool to measure sportsmanship of players. Data processing used SPSS 12.0 programs. Did reliability analysis that use Cronbach'a coefficient to verify believability of an irradiation tool, Difference of sportsmanship used t-test, one-way ANOVA. In this research, drew following conclusion. First, man appeared higher level than woman in wave and human desire, decision respect, and woman appeared higher level than man in victory or defeat excessive fondness. Second, exercise immersion, decision respect, victory or defeat excessive fondness appeared level that minority is taller than majority. Third, in exercise immersion high school player decision respect appear, and tendency of level that middle school playing the first stone is high in victory or defeat excessive fondness appeared. Fourth, striking radical type of player appeared higher level than Geuraepeulring type of player in companion respect factor. Fifth, player less than exercise career 4 years appeared higher level than player less than 7 years and player more than 7 years for victory or defeat excessive fondness factor. Sixth, Taekwondo for best and companion respect factor, high level appeared to boxing item players.

하악골 골절에 대한 임상통계학적 연구

이성훈,김기영,조규승,소광섭,박홍주,조요기,오희균,유선열 大韓顎顔面成形再建外科學會 1998 Maxillofacial Plastic Reconstructive Surgery Vol.20 No.1

디지털 콘텐츠 산업의 공간분포 특성에 관한 연구

김성훈,임용민,이시형,홍일영 남서울대학교 2010 남서울대학교 논문집 Vol.16 No.1-1

Digital contents industry is a developing industry which is being recognized for its growth possibility. This study is intended to understand the spacial distribution of digital contents industry. To do so, spatial range of this study is set in metropolitan regions to grasp the clustered regions. To understand the clustered regions of digital contents industry, spatial cluster analysis was enforced. As a result, total of 7 clusters were formed. 7 clusters are all located in Seoul, and 4 out of 7 are concentrated in Kangnam Gu. This study grasped the characteristics of these clusters. Locational factors of each company categories, which are the cause of such characteristic, are scheduled to be researched more specifically in the future. Key Words : digital contents industry, Spatial distribution, cluster, Locational factor, Spatial clustering

Pade 近似化 方法에 依한 필터의 設計

郭勳星,金英百 全北大學校 1981 論文集 Vol.23 No.-

A rational approximation procedure for digital filter design is presented in this paper. More specially, an explicit expression for the designed filter transfer function can be obtained once a rational approximation for the analytic part of the Fourier series expansion of the desired filter characteristic is determined. To demonstrate the efficiency of this technique, we derive a two-sided Pade´ approximation from the one-sided Pade´ approximant. Two examples are given to illustrate this design procedure.

실험적 척수손상후 Naloxone의 치료 효과

김영수,오성훈 대한신경외과학회 1988 Journal of Korean neurosurgical society Vol.17 No.5

The effect of naloxone on blood flow was studied in cats subjected to 400 gm-㎝ contusion injuries of the thoracic spinal cord. Ten cats were treated with 10㎎/㎏ naloxone 45 to 60 minutes after injury. Ten cats were given 10㎖ of saline instead of naloxone, and 10 cats were neither injured nor treated. Hydrogen clearance was used to measure blood flow in the lateral white column at the contusion site. Naloxone, given intravenously, significantly improved the blood flow rates in the lateral column white matter. At 2 hours after injury, the mean blood flow in the saline-treated cats fell to 6.01±0.90㎖/100gm/min, whereas it increased 8.47±1.14㎖/100gm/min in naloxone-treated cats(p<0.05). The authors conclude that naloxone may be useful for spinal cord injury.

압력 저속 냉동 방법의 쥐 치아 치주인대세포 보존 효율 평가

이영은,김의성,김진,한승훈,이승종 大韓齒科保存學會 2009 Restorative Dentistry & Endodontics Vol.34 No.4

본 연구의 목적은 흰 쥐의 상악 대구치를 발거한 후 치주인대세포를 압력을 이용한 저속 냉동 보관법으로 냉동 보관시 치주인대세포의 활성도를 저속 냉동법, 냉장 보관법과 비교하여 평가하고자 하였다. 생후 4주된 암컷 Sprague-Dawley계 흰쥐의 상악 좌우제 1, 2 대구치를 발거하여 각 군 당 18개의 쥐 치아를 MTT, WST-1 검색에 이용하였다. 실험군은 4개군으로 대조군은 즉시 발치군이며, 4℃ 냉장고에 일주일간 보관한 냉장군, 발치 후 동해방지제 처리과정을 거쳐 4℃에서 -35℃까지 -0.5℃/min 속도로 서서히 냉동시킨 뒤 -196℃에 냉동한 저속냉동군 3MPa의 압력을 가하고 -0.5℃/min 속도로 4℃에서 -35℃까지 서서히 냉동시킨 뒤 -196℃에 냉동한 압력 저속 냉동군으로 나누었다. 보존액은 F medium을 사용했으며 동해방지제로 10% dimethylsulfoxide(DMSO)를 사용하였다. 일주일 후 해동하여 MTT, WST-1 검색을 시행한 뒤 치근면을 단위면적으로 표준화하기 위해 MTT, WST-1 측정값을 Eosin 염색 후 530nm에서 측정한 흡광도 값으로 나누었다. 통계 분석을 위해 one way ANOVA를 시행하였으며 사후 검정으로는 Tukey 방법을 사용하였고 결과는 다음과 같다. 1. MTT 검색에 의한 흡광도를 Eosin 염색 후 측정한 흡광도로 나눈 값에서는 압력 저속 냉동군은 즉시 발치군보다 유의성 있게 세포 활성도가 낮았으나(p<0.05), 저속 냉동군이나 냉장군과 비교할 때는 높은 세포 활성도를 보이며 통계적 유의성이 있었다(p<0,05). 2. WST-1검색에 의한 흡광도를 Eosin 염색 후 측정한 흡광도로 나눈 값에서도 MTT 검색과 마찬가지로 압력 저속냉동군에서는 즉시 발치군보다 유의성 있게 세포 활성도가 낮았으나(p<0.05), 저속 냉동군이나 냉장군과 비교할 때는 높은 세포 활성도를 보이며 통계적 유의성이 있었다(p<0.05). 위의 결과를 통해, 3MPa(30기압) 압력을 이용한 저속 냉동 보관법은 4℃ 냉장법이나 압력을 사용하지 않은 다른 냉동 보관법에 비해 우수한 쥐 치아의 치주인대세포의 활성도를 보여 차후 치아의 재식/이식을 위한 중-장기 치아보관을 위한 방법으로의 가능성을 제시하였다. The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at 4℃ for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in 37℃ water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group. By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.