Distal Femoral Medial Opening Wedge Osteotomy for Post-Traumatic, Distal Femoral Varus Deformity

Myoung­Soo Cha,송시영,Koo-Hyun Jung,Young-­Jin Seo 대한슬관절학회 2019 대한슬관절학회지 Vol.31 No.1

Restoration of neutral mechanical alignment of the lower limb is an important factor in the treatment of unicompartmental arthrosis. Traditionally, medial opening wedge high tibial osteotomy has been widely performed to correct varus malalignment with unicompartmental arthrosis. However, an ideal indication for the high tibial osteotomy is the knee with metaphyseal tibial varus malalignment. The basic principle of corrective osteotomy is performing an osteotomy at the center of the deformity to prevent abnormal joint line obliquity. If pathologic distal femoral varus deformity is the cause of genu varum, the osteotomy should be performed in the distal femur. Reports of medial opening wedge distal femoral osteotomy (DFO) to correct varus malalignment are rare. We present a case of this very rare and challenging condition in a 47­year­old male, which was successfully treated by medial opening wedge DFO.

벤처캐피탈의 투자의사결정 연구: 판단분석의 활용

차명수 ( Myoung Soo Cha ) 한국중소기업학회 2009 기업가정신과 벤처연구 Vol.12 No.4

Sevoflurane이 상처 치유 과정에 미치는 영향

차명수 ( Myoung Soo Cha ),이현정 ( Hyeon Jeong Lee ),배재호 ( Jae Ho Bae ),양우성 ( Woo Seong Yang ),백승완 ( Seong Wan Baik ) 대한마취과학회 2009 Korean Journal of Anesthesiology Vol.57 No.1

Background: Wound healing process is a tissue response to trauma which leads to tissue repair through complex biological stages. Sevoflurane is a widely used inhalation anesthetic for surgery, but there has been no study about its effect on wound healing process. This study was undertaken to evaluate the effect of sevoflurane on wound healing process. Methods: Male Sprague-Dawley rats (200-300 g) were used. Two circular full-thickness skin defects of 8 mm in diameter were made on dorsum of rats. After wound formation, the animals were divided into 4 groups: 1, 2, 4, 8 hr exposure to sevoflurane, respectively. Wound sizes and regional blood flow around the wounds were measured. The expression of basic fibroblast growth factor (bFGF), transforming growth factor β1 (TGFβ1), collagen 1, and collagen 3 mRNA were detected 7 days after wound formation by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Wound size was significantly increased in 8 hr group at 3 and 7 days after wound formation. Regional blood flow was significantly decreased in 4 hr and 8 hr groups at 3 days after wound formation. The bFGF, collagen 1 and 3 mRNA expressions were significantly decreased in 8 hr exposure group. Conclusions: These results suggest that sevoflurane exposure influences the regional blood flow, wound size, expression of bFGF, and production of collagen 1 and 3 during the wound healing process. (Korean J Anesthesiol 2009; 57: 78~83)

기업 초기 최고경영진 및 최고경영자의 특성이 ICT 벤처기업의 장기생존에 미치는 영향

차명수(Myoung Soo Cha),임성준(Seong-Joon Limb) 한국인사조직학회 2017 인사조직연구 Vol.25 No.3

This study empirically investigated the imprinting effect of initial conditions regarding the top management team of venture firms on their long-term survival. Previous research on upper echelons theory suggest that TMT/CEO demo-graphic characteristics (age, education level), TMT heterogeneity (age, past industry experience, functional background) and the moderating effects of TMT characteristics on CEO characteristics would influence firm performance. Based on the concept of organizational imprinting this study attempted to extend the upper echelon theory by examining whether aforementioned charac-teristics of a firm’s top management at the time of its IPO indeed affect its long-term survival. The sample of this study consisted of 151 information and communication technology (ICT) venture firms that were newly registered in KOSDAQ from 1999 to 2002. A venture firm was considered to be survived if it was still listed in KOSDAQ at the end of 2012. Employing a survival analysis method, this study empirically examined which characteristics of a firm’s top management at the time of its IPO indeed affect its long-term survival. In addition, in order to verify likely stronger imprinting effects of top management characteristics in the event of environmental jolt, separate analyses were conducted before and after 2008, when the global financial crisis occurred. Survival analysis results suggest that (1) a TMT’s average age at the time of IPO had U-shaped relationships with a firm’s long-term failure, (2) the TMT’s average education level and the CEO’s age at the time of the IPO had positive imprinting effect on a firm’s long-term survival, and (3) top management characteristics at the time of IPO indeed had greater imprinting effects on a firm’s long-term survival when it faced an environmental jolt. 본 연구는 신생 벤처기업의 최고경영진과 관련된 초기 조건들이 기업의 장기생존에 영향을 미치는 각인효과(imprinting effect)를 최고경영층이론을 중심으로 분석한 것이다. 이를 위해 1999년부터 2002년까지 KOSDAQ에 신규 등록한 ICT분야 151개 벤처기업 들을 표본으로 2012년 말까지 KOSDAQ 법인목록에서의 존속 혹은 삭제 여부를 살펴보고, 생존분석 기법을 통해 이에 영향을 미친 요인들에 대해 실증 분석해 보았다. 최고경영층 이론의 선행연구에 기초하여 TMT/CEO의 인구통계학적 특성(연령, 교육수준), TMT의 다양성(연령, 과거 산업 경험, 기능적 배경) 및 CEO 특성에 대한 TMT 특성의 조절효과를 기업 생존에 영향을 미칠 수 있는 요인으로 설정하였다. 또한 급격한 환경적 충격이 있을 때 신생벤처기업 초기 최고경영진 구성의 각인효과가 기업의 생존에 미치는 영향이 어떻게 달라지는지 살펴보기 위해 생존분석의 시점을 글로벌 금융위기가 발생한 2008년 이전과 이후로 나누어 추가 분석해보았다. 실증분석 결과 첫째, 초기 TMT의 인구통계학적 특성 중 TMT의 평균 연령은 기업실패와 U자 관계를 가지며, TMT의 교육수준이 높을수록, CEO의 나이가 많을수록 기업생존에 유리한 것으로 나타났다. 둘째, 글로벌 금융위기 이전과 이후의 생존분석을 통해 환경의 급격한 충격이 있을 때에 초기 CEO 및 TMT의 특성이 기업생존에 미치는 영향력이 더 클 수 있다는 것을 발견했다. 본 연구는 신생 벤처기업의 초기 TMT 및 CEO의 인구통계학적 특성으로 대리(proxy) 측정되는 초기 경영의사결정의 구조 및 조건이 장기적인 기업생존에 영향을 미치는 각인효과(imprinting effect)를 검증하였고 또한 그 효과가 급격한 환경적 충격이 있을 때 더 크게 나타난다는 점을 제시하였다는 점에서 의의를 찾을 수 있다.

Inhibition of Sialidase Activity for Enhanced Sialylation of Albumin-erythropoietin in Biphasic CHO Cell Cultures

Soo-Ah SHIN,Joon-Serk SEO,Hyun-Myoung CHA,Jin-Hyuk LIM,Yeon-Kyeong SHIN,Hye-Eun SHIM,Dong-Il KIM 한국생물공학회 2015 한국생물공학회 학술대회 Vol.2015 No.4

Associations of Elderly Onset Headache With Occurrence of Poor Functional Outcome, Cardiovascular Disease, and Cognitive Dysfunction During Long-term Follow-up

Soo-Jin Cho,Byung-Kun Kim,Byung-Su Kim,김재문,김수경,문희수,Myoung-Jin Cha,Kwang-Yeol Park,손종희,Min Kyung Chu,송태진 대한노인병학회 2018 Annals of geriatric medicine and research Vol.22 No.4

Background: Although the frequency and intensity of headaches decrease in older adults, headaches in this population are still an important neurological disorder. The purpose of this study was to investigate the associations of headache characteristics in older adults with the development of cardiovascular disease and cognitive dysfunction. Methods: We prospectively enrolled 125 older (≥ 65 years old) patients with headache who were mak-ing their first visit to outpatient clinics and who had no prior history of cognitive dysfunc-tion from 11 hospitals in Korea between August 2014 and February 2015. We investigated the occurrence of newly developed/or recurrent headache, cardiovascular disease, cog-nitive dysfunction, and poor functional outcomes. Results: The mean age of all included patients was 72.6 years, 68.8% were women, and 43 (34.4%) had newly developed/or recurrent headache during follow-up. During a median follow-up of 31 months (interquartile range, 28–34 months), 21 participants (16.8%) experienced cardiovascular disease, and 26 (20.8%) developed cognitive dysfunction. Upon multivariate analysis and after adjust-ing for sex, age, and other factors, presence of newly developed/or recurrent headache was found to be associated with cardiovascular disease (hazard ratio [HR], 4.03; 95% confidence interval [CI], 1.28–12.61; p=0.017) and frequency of headache for the recent 3 months was related with cognitive dysfunction (HR, 1.05; 95% CI, 1.00–1.09; p=0.017) and poor functional outcomes (HR, 1.06; 95% CI, 1.01–1.11; p=0.011). Conclusion: Our study demonstrated that there is an increased risk of cardiovascular disease, cognitive dysfunction, and poor functional outcomes in older patients with frequent, newly devel-oped, or recurrent headache.

Biphasic Cultivation for Inhibition of Sialidase from CHO Cells Producing Albuminerythropoietin

Soo-Ah SHIN,Joon-Serk SEO,Hyun-Myoung CHA,Jin-Hyuk LIM,Seul-Gee HWANG,Yeon-Kyeong SHIN,Dong-Il KIM 한국생물공학회 2014 한국생물공학회 학술대회 Vol.2014 No.10

DBD(Dielectric Barrier Discharges)에서 진공 플라즈마 발생에 대한 해석적 연구

신명수(Myoung-Soo Shin),차성훈(Sung-Hoon Cha),김종봉(Jong-Bong Kim),김종호(Jong-Ho Kim),김성영(Seong-Young Kim),이혜진(Hye-Jin Lee) Korean Society for Precision Engineering 2009 한국정밀공학회지 Vol.26 No.3

DBD(Dielectric Barrier Discharges) plasma is often used to clean the surface of semiconductor. The cleaning performance is affected mainly by plasma density and duration time. In this study, the plasma density is predicted by coupled simulation of flow, chemistry mixing and reaction, plasma, and electric field. 13.56 ㎒ of RF source is used to generate plasma. The effect of dielectric thickness, gap distance, and flow velocity on plasma density is investigated. It is shown that the plasma density increases as the dielectric thickness decreases and the gap distance increases.

Lead Screw 공정 설계를 위한 전조 해석

신명수 ( Myoung Soo Shin ),차성훈 ( Sung Hoon Cha ),김종봉 ( Jong Bong Kim ),김종호 ( Jong Ho Kim ),나승우 ( Seung Woo Ra ) 한국고무학회 2009 엘라스토머 및 콤포지트 Vol.44 No.4

본 연구에서는 전조공정의 수치해석을 수행하였다. 해석을 이용한 공정 인자 설계에 앞서서, 효율적이고 신뢰성 있는 해석을 위한 해석 조건에 대하여 연구를 수행하였다. 치형의 개수와 요소의 수에 대한 해석 결과를 바탕으로 해석의 정도를 보장하고 효율적으로 해석을 수행할 수 있는 조건을 설정하였다. 그리고, 프랭크 각도와 치형의 끝단부 라운드 등의 금형의 형상과 성형 온도가 유효 응력, 유효 변형율, 전조력, 그리고 크랙 발생에 미치는 영향을 알아보았다. 해석은 DEFORM-3D를 이용하여 수행하였다. 프랭크 각도와 치형의 끝단 부 라운드는 전조력에 영향을 미치는 것을 확인할 수 있었으며, 성형 온도 조건에 따라서 유효 변형률과 전조력, 그리고 크랙을 예상 할 수 있었다. This paper presents the numerical analysis of thread rolling. Firstly, the analysis is focused on the effective analysis conditions that guarantee the reliability of the analysis results. The investigated parameters are the number of teeth and the number of elements. Using the analysis results, the number of elements and the number of teeth that guarantee the results are found. And then, the effects of the process parameters such as tool shape and temperature on the thread rolling are investigated. The analysis is carried out using DEFORM-3D. The results show that the flank angle and crest round have an effect on the thread rolling load. It is also shown that temperature have significant effects on the effective strain distribution, rolling load, and crack initiation. The crack initiation is predicted using the Cockcroft-Latham criterion.

The Importance of Research Ethics and the Countermeasures for Journals: Case Study of KJFHC

Seong Soo CHA,Myoung Kil YOUN 한국연구윤리학회 2022 연구윤리 Vol.3 No.1

Purpose: The purpose of this study was to remind the importance of research ethics in research and publication, and to suggest the direction of research ethics by taking examples of research ethics recently implemented by KJFHC. Research design, data and methodology: With reference to the research of existing researchers, why research ethics is important, what are the violations of research ethics, and the efforts of the editorial committee of KJFHC to strengthen research ethics are presented as an example. Results: It is a reality that the concept of research ethics is becoming more complex and important with the introduction of various new academic fields. At this point in time, researchers need to pay more attention to the easily overlooked concept of research ethics. In research ethics, the most important thing is not punishment through monitoring and supervision, but prevention activities of research ethics that can prevent research misconduct before it occurs. As a preventive activity for research ethics, it can be said that the most important is the establishment of a systematic education system and active educational activities of universities and related institutions. Conclusions: This study avoids the general status and solutions for research ethics, and explains the case of the actual academic journal KJFHC and suggests alternatives.