2024-T_4 Al Alloy의 破壞擧動에 關한 硏究

車龍勳,尹聖雲,金永碩 조선대학교 기초과학연구소 1986 自然科學硏究 Vol.9 No.1

Stress-Corrosion Cracking deals with the fracture of Stressed metals having an environmental cause. It is to be distinguished from localized reactions such as intergranular Corrosion which operate independent of a tensional stress. Stress-Corresion cracking should also be distinguished from failures resulting from corrossion fatigue. The latter is a term applied to cracking of a metal subject to cycles of repeated or alternate stress in a corrosive environment. This paper is based on an experiment analysing the Stress Corrosion cracking behavior of 2024-T_4 Aluminum in 3.5% NaCl SoIution was investigated using precracked compact tension specimens by constant exposure method. Precracked Specimens were loaded externally in tension by constant deflection techniques. The results obtained in this study were as follows; 1. Crack was observed to propagate from Crack-tip perendicular to the direction of tensile Stress. 2. Threshold Stress of 2024-T_4 specimen was 12-13 Ksi √in at 4 X 10^-3 in/hr 3. Al alloys showing that intergranular crack-sensitive paths.

순천향대학교 사회과학대 학생의 진로인식 및 진로지도개선에 관한 연구

심영수,차석빈,김용하,최한준 순천향대학교사회과학연구소 2003 순천향 사회과학연구 Vol.9 No.1

This study conducted an empirical research to find ways to guide the career of college students in the social science at Soonchunhyang university. Research findings are as follows. 1) About 42% respondents answered that they did job-seeking efforts. 2) With regard to job preparing efforts, students spent their time on improving their English ability, major classes, computer ability, and license obtaining. 3) Job-related information sources in the school were not fully utilized by the students. 4) In the future, students hope that our school strengthen its PR efforts, open more English-related classes, improve its school image as a local university, and provide more job-related information The study concludes with implications of the study results and suggestions for career guidance of students.

제4경추의 형태와 초경을 통한 성숙지표에 관한 연구

이규홍,황용인,김윤지,박양호,백승학,차경석 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.1

본 연구는 측모 두부 규격 방사선사진을 이용하여 성장 중인 아동의 제4경추 형태를 경추 몸체부 하연의 만곡 정도에 따라 분류하고 초경의 시기와 수완부 골 성숙 단계를 평가하여, 성장 중인 아동의 골격적 부정교합의 진단 및 악정형 치료를 위한 성장 시기 평가에 제4경추의 형태 변화가 진단의 참고자료로 활용될 수 있는지를 연구하였다. 11-14세 여자 환자 중, 같은 날짜에 촬영된 측모 두부 규격 방사선사진과 수완부 방사선사진이 모두 있는 81명을 대상으로 환자의 측모 두부 규격 방사선사진상 제4경추 몸체부 하연의 만곡 정도에 따라 세 그룹으로 분류하였다. (Group A - 제4경추 몸체부 하연의 만곡 정도가 1.05 mm 이하, Group B -제4경추 몸체부 하연의 만곡 정도가 1.05- 2.07 mm 사이, Group C -제4경추 몸체부 하연의 만곡 정도가 2.07 mm 이상)세 그룹에서 각각 제4경추 몸체부의 수직 길이, 수평 길이, 수직/수평 비율, 초경의 시기, 수완부 골 성숙 단계를 측정한 결과 다음과 같은 결론을 얻었다. 평균 수완부 골 성숙 단계는 Group A가 SMI 5.67 ± 2.57단계, Group B는 SMI 8,73 ± 2.41 단계, Group C는 SMI 10.00 ± 1.47단계로 나타났다. GroupA에서 Group B, Group C로 갈수록 제4경추의 수직 길이, 수평 길이, 수직/수평 비율, 수완부 골 성숙 단계에 있어서 각각 유의하게 더 큰 값을 보였다. 본 연구대상 아동의 평균 초경 시기는 11.64 ± 0.92세를 보였다. 제4경추 몸체부 하연의 만곡 정도, 수직 길이, 수평 길이, 수직/수평 비율은 수완부 골 성숙 단계와 각각 서로 유의한 양의 상관관계를 나타냈다. 초경을 경험한 그룹이 초경을 경험하지 않은 그룹에 비해 제4경추의 수직 길이, 수평 길이, 수직/수평 비율, 수완부 골 성숙 단계에 있어서 유의하게 큰 값을 보였다. 연구 결과 측모 두부 규격 방사선사진상 제4경추 하연의 만곡 깊이가 2.07 mm 이상인 경우 성장의 완료 단계에 가까운 시기로 나타나 이 시기의 악정형적 치료는 큰 효과를 얻을 수 없을 것으로 사료된다. Objective: This study analyzed the morphologic changes of the fourth cervical vertebra body to determine the skeletal age of orthodontic patients during growth. Methods: Eighty-one female patients aged from 11 to 14 who had cephalograms taken on the same day were examined. The subjects were divided into three groups depending on the depth of the concavity of the lower border of the fourth cervical vertebra (Group A: less than 1.05 mm, Group B: 1.05 - 2.07 mm, Group C: greater than 2.07 mm). Menarcheal timing, SMI stage, length, width and ratio of length and width of the fourth cervical vertebra body were analyzed and the following results were obtained. Results: The average SMI stage of group A,B and C were 5.67 ± 2.57, 8.73 ± 2.41, and 10.00 ± 1.47, respectively. Length, width, ratio of length and width, and SMI stage were greater in group B than group A and in group C than group B. Mean menarcheal timing was 11.64 ± 0.92 years. Concavity depth, length, width, ratio of length and width showed a significant positive correlation with SMI stage, especially with the concavity depth. Conclusion: The results of this study propose a simple method for determining the timing of orthopedic treatment by measuring the concavity depth of the fourth cervical vertebra on the cephalogram.

DBD 반응기에서 플라즈마 방전형태에 따른 PFC_(s) 가스의 분해 특성

김관태,김용호,차민석,송영훈,김석준,류정인 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.5

Perfluorocompounds(PFC_(s)), such as tetrafluoromethane (CF₄) and hexafluoroethane (C₂F_(6)), have been widely used as plasma etching and chemical vapor deposition (CVD) gases for semiconductor manufacturing processes. Since these PFC_(s) are known to cause a greenhouse effect intensively, there has been a growing interest in reducing PFC_(s) emissions. Among various CF₄ decomposing techniques, a dielectric barrier discharge (DBD) is considered as one of a promising candidate because it has been successfully used for generating ozone (O₃) and decomposing nitrogen oxide (NO). Firstly, optimal concentration of oxygen for CF₄ decomposition was found to figure out how many primary and secondary reactions are associated with DBD process. Secondary, to find effective discharge method for CF₄ decomposition, a streamer and a glow mode in DBD are experimentally compared, which includes (ⅰ) coaxialcylinder DBD, (ⅱ) DBD reactor packed with glass beads. and (ⅲ) a glow mode operation with a helium gas. The test results showed that optimal concentration of oxygen was ranged 500 ppm~1% for treating 500 ppm of CF₄ and helium glow discharge was the most efficient one to decompose CF₄.

갈치속젓의 휘발성성분에 관한 연구

김훈,장성민,윤성숙,박승영,김소정,차용준 Institute of Genetic Engineering Changwon National 1999 Gene and Protein Vol.3 No.1

Volatile components in salt-fermented hair tail viscera were anlayzed by simultaneous steam distillation-solvent extraction method and gas chromatography/mass spectrometry method. Seventy four compounds were detected and composed mainly of aldehydes(15 compounds), ketones(7), alcohols(13), nitrogen containing compounds(5), esters(6), sulfur containing compounds(4), aromatic compounds(10) and miscellaneous compounds(14). Among these, some compound groups which were known to have generally the low flavor thresholds, such as aldehydes, ketones, nitrogen containing compounds, esters having low molecular weight and sulfur containing compounds, were supposed to be having major effects on the overall flavor of salt-fermented hair tail viscera.

The Effect of Crisis Responsibility for Unfair Ticket Sales on Attitude Toward KBO-league

( Yong Suk Cha ),( Doe Kyune Yoo ),( Hee Yoon Nam ),( Kyung Ro Chang ) 한국체육학회 2015 국제스포츠과학 학술대회 Vol.2015 No.1

Purpose: Since 2015, the Korea Baseball Organization (KBO) combined their identity as ``KBO League`` to maximize the value of professional baseball while opening a new era consisting 10 professional baseball teams with a new team, kt wiz. The KBO league, which is truly positioned as a national sport, have rapidly developed with great mark in international competitions, marketing activities by each clubs, and professional channel for baseball league. Although it has been thirty-four years that the Korean Professional Baseball league was founded, ticket issues are still on the question. It`s especially harder to get ticket for rival matches, post seasons, and Korean series. Therefore, doubt and distrust of fans have never disappeared, and these problems could be a decisive variable for popularity of professional baseball league affecting fan`s attitude toward the KBO league. Method: The purpose of this study was to investigate fan`s recognition about unfair ticket sales in professional baseball and what effect it has on fan`s attitude towards the KBO. More specifically, the analysis focused on the differences in changes of league trust, league image, and league reputation depending on crisis responsibility about ticket sales. In order to fulfill this purpose, a questionnaire survey was conducted on 350 baseball fans and 323 samples were used for the analysis. Frequency analysis, reliability analysis, correlation analysis and two-way RG-RM ANOVA were carried out using PASW 18.0 program. Result: In terms of league trust, the interaction effect between crisis responsibility on unfair ticket sales and pre-post measurements appeared to be significant. A degree of decline in league trust was significantly higher in a group which perceived the crisis responsibility of the KBO at higher level compared to those who perceived the crisis responsibility at lower level. Furthermore, for league image, the interaction effect between crisis responsibility on unfair ticket sales and pre-post measurements appeared to be significant. A degree of decline in league image was significantly higher in a group which perceived the crisis responsibility of the KBO at higher level compared to those who perceived the crisis responsibility at lower level. However, no significant interaction effect was evident between crisis responsibility and pre-post measurements for league reputation. Conclusion: This study proved that league trust and image of the KBO have been changed after fans perceived unfair ticket sales. Thus, there should be a constant effort into improving systems for fair and clear ticket sales.

The Need, Objectives and Measures for Citizen Involvement in Preventing Crime and Administration of Criminal Justice System

Cha, Yong Suk 한국형사정책학회 1992 刑事政策 Vol.6 No.-

Effect Modification on Death by Age and Sex in Elderly Hip Fracture

Suk-Yong Jang,Yong Han Cha,Na-Kyum Park,Kap-Jung Kim,Won-Sik Choy 대한골대사학회 2022 대한골대사학회지 Vol.29 No.4

Background: This study compared the effects of hip fractures on mortality according to sex and age in a nationwide cohort of elderly patients with hip fractures and controls. Methods: Patients with hip fractures and matched controls were selected from the National Health Insurance Service-Senior cohort. Time-dependent propensity score matching was estimated from a Cox proportional hazards model with January 1, 2005, as the baseline and hip fracture as an event. Patients were matched by age and sex to participants at risk of developing a hip fracture at time zero. The effect size is presented as hazard ratio (HR) using a Cox proportional hazards model with a robust variance estimator that accounts for clustering within the matched pairs. Results: Altogether, 14,283 patients with incident hip fractures and 28,566 matched controls were identified. The HR of male sex in hip fractures was 1.31 (95% confidence interval [CI], 1.22−1.40; Pinteraction<0.01). Moreover, the HR of age group in hip fractures was 0.73 (95% CI, 0.66−0.80; Pinteraction< 0.01) between the 65 to 74 and 75 to 84 years groups, 0.76 (95% CI, 0.71−0.81; Pinteraction< 0.01) between the 75 to 84 and ≥85 years groups, and 0.55 (95% CI, 0.50−0.61; Pinteraction< 0.01) between the 65 to 74 and ≥85 years groups. Conclusions: Male sex increases the risk of death in elderly patients with hip fractures versus matched controls, but the increased risk of death with age in hip fractures was decreased compared to that in matched controls

독수(毒樹)의 과실이론(果實理論)

차용석 ( Yong Suk Cha ) 한양대학교 법학연구소 1991 법학논총 Vol.8 No.-

양형론(量刑論)을 생각해 본다

차용석 ( Yong Suk Cha ) 법조협회 2006 法曹 Vol.55 No.4

본고는 형사재판에 있어서의 양형의 중요성을 강조하고 이제는 이 문제가 형법학의 서자나 방자의 지위에 있지않고 중심적 위치를 점하여야 함을 논하고 있다. 따라서 단편적인 연구나 실천의 과제가 아니고 마치 범죄성립요소의 체계론에 못지않게 양형체계론을 구축하여 관련항목을 이론적이고 체계적으로 연구하는 양형학으로의 발전을 지향하여야 함을 논하고 있다. 우리의 현재상황도 이 문제를 재판상의 중요과제로 연구하고 있고 또한 실무에 있어서 양형기준표를 성안하여 시행하려는 단계에 이르고 있다. 이에 즈음하여 양형학에는 어떤 과제가 포함되어야 하고 각국의 연구 및 실천의 상황은 어떠한가를 논평하고 있다. 양형학에서 다루어야 할 세부분야는 대개 다음과 같다. 1) 양형과정에 관련하는 각 기관의 역할 분담(여기 기관에는 심지어는 증인,피해자, 민간인 등도 포함된다), 2) 그 동안의 양형의 불균등, 불평등 현상에 대한 과학적 연구, 3) 양형기준표의 작성 및 여기에의 법관의 구속 문제, 4) 판결전 조사절차 및 그 보고의 문제, 5)선고 위원회의 구성, 6)양형의 지도원리, 특히 형벌이념과의 이론적인 관련성의 문제 7) 각종의 양형인자의 설정 및 그 정밀화 작업 등이 중요연구 및 실천 과제로 될 것이다. 양형의 과학성, 합리성, 타당성을 고양하기 위한 기타 문제도 심도있게 연구되어야 할 것이다.