용접 열영향부 미세조직 및 재질 예측 모델링: V. 저합금강의 초기 오스테나이트 결정립크기 및 냉각 속도의 영향을 고려한 용접 열영향부 상변태 모델

김상훈,문준오,이윤기,정홍철,이창희,Kim, Sang-Hoon,Moon, Joon-Oh,Lee, Yoon-Ki,Jeong, Hong-Chul,Lee, Chang-Hee 대한용접접합학회 2010 대한용접·접합학회지 Vol.28 No.3

In this study, to predict the microstructure in weld HAZ of low alloyed steel, prediction model for the phase transformation considering the influence of prior austenite grain size and cooling rate was developed. For this study, six low alloyed steels were designed and the effect of alloying elements was also investigated. In order to develop the prediction model for ferrite transformation, isothermal ferrite transformation behaviors were analyzed by dilatometer system and 'Avrami equation' which was modified to consider the effect of prior austenite grain size. After that, model for ferrite phase transformation during continuous cooling was proposed based on the isothermal ferrite transformation model through applying the 'Additivity rule'. Also, start temperatures of ferrite transformation were predicted by $A_{r3}$ considering the cooling rate. CCT diagram was calculated through this model, these results were in good agreement with the experimental results. After ferrite transformation, bainite transformation was predicted using Esaka model which corresponded most closely to the experimental results among various models. The start temperatures of bainite transformation were determined using K. J. Lee model. Phase fraction of martensite was obtained according to phase fractions of ferrite and bainite.

2급 치근이개부 치료 시 흡수성 차폐막, 동종골 이식 및 혈소판 농축 혈장의 골 재생 효과에 대한 디지털 공제술의 정량적 분석

김상훈,임성빈,정진형,Kim, Sang-Hoon,Lim, Sung-Bin,Chung, Chin-Hyung 대한치주과학회 2002 Journal of Periodontal & Implant Science Vol.32 No.1

The purpose of this study was to evaluate effect of platelet rich plasma on the treatment of Grade II furcation involvement, with Demineralized Freeze-Dried Bone(Dembone(R)) and bioabsorable membrane(BioMesh(R)) in humans by digital subtraction radiography. 12 teeth(control group) were treated with Demineralized Freeze-Dried Bone(Dembone(R)) and bioabsorable membrane(BioMesh(R)), and 12 teeth(test group) were treated with Demineralized Freeze-Dried Bone(Dembone(R)), bioabsorable membrane(BioMesh(R)) and Platelet Rich Plasma. The change of bone density was assessed by digital subtraction radiography in this study. The change of mineral content by as much as 5%(vol) could be perceived in the subtracted images. The change of mineral content was assessed in the method that two radiographs are put into computer program to be overlapped and the previous image is subtracted by the later one. Both groups were statistically analyzed by Wilcoxon signed Ranks Test and Mann-whitney Test using SPSS program (5% significance level). The results were as follows: 1. In test group, the radiopacity in 3 months after surgery were significantly increased than 1 month after surgery(p<0.05). However. there were no significant difference between 1 month after surgery and 3 months after surgery in control group(p>0.05). 2. In test and control group, the radiopacity in 6 months after surgery were significantly increased than 1 month after surgery(p<0.05) 3. In test and control group, the radiopacity in 6 months after surgery were significantly increased than 3 months after surgery(p<0.05). 4. There were no significant difference between test group and control group at 1 month, 3 months after surgery, but radiopacity in test group were significantly increased than control group at 6 months after surgery(p<0.05). In conclusion, Platelet Rich Plasma can enhance bone density.

직류시보전동기의 속도제어를 위한 뉴로-퍼지 제어기 설계

김상훈,강영호,고봉운,김낙교,Kim, Sang-Hoon,Kang, Young-Ho,Ko, Bong-Woon,Kim, Lark-Kyo 대한전기학회 2002 전기학회논문지 D Vol.51 No.2

In this study, a neuro-fuzzy controller which has the characteristic of fuzzy control and artificial neural network is designed. A fuzzy rule to be applied is automatically selected by the allocated neurons. The neurons correspond to fuzzy rules are created by an expert. To adapt the more precise model is implemented by error back-propagation learning algorithm to adjust the link-weight of fuzzy membership function in the neuro-fuzzy controller. The more classified fuzzy rule is used to include the property of dual mode method. In order to verify the effectiveness of the proposed algorithm designed above, an operating characteristic of a DC servo motor with variable load is investigated.

고등학교(高等學校) 재학생(在學生)들의 비합리적(非合理的) 신념(信念)과 정신병리(精神病理)

김상훈,최훈동,김학렬,Kim, Sang-Hoon,Choi, Hoon-Dong,Kim, Hack-Ryul 한국정신신체의학회 1995 정신신체의학 Vol.3 No.1

The purpose of this study is to investigate the relationship between irrational belief and psychopathology. The Korean version of Symptom Check List-90-R and Irrational Belief Test were administered to 621 high school students in group. The author used Pearson correlation coefficiency and multiple regression analysis to seek the regression patterns of the irrational belief. The results were as follows. 1) Most of the subscales of the SCL-90-R and Irrational Belief Test were correlated significantly. 2) In multiple regression analysis, the irrational belief associated with anxious overconcern was the most predictable variable for psychopathology.

정상 반월상 연골의 혈관 분포

김상훈,조홍식,이한영,이기범,민병현,Kim Sang Hoon,Cho Hong Sik,Lee Han Young,Lee Ki-Bum,Min Byung-Hyun 대한관절경학회 2003 대한관절경학회지 Vol.7 No.1

목적 : 정상 반월상 연골을 형태학적으로 계측하고 혈관 분포를 조사하여 연령과 해부학적 위치에 따른 차이를 비교하였다. 대상 및 방법 : 21구의 사체에서 반월상 연골을 채취하여 이를 연령별로 3군으로 나누고 각각을 10개의 절편으로 나누어 반월상 연골의 폭(width)과 혈관의 분포를 측정하였다. 결과 : 반월상 연골의 평균 폭은 내측이 $10.4{\pm}2.92mm$, 외측이 $10.55{\pm}2.05mm$로 측정 되었다. 혈관 분포 범위는 내측이 $20.29{\pm}8.44\%$, 외측이 $18.99{\pm}7.03\%$이었다. 해부학적 위치에 따른 혈관 분포는 내측의 경우 전각의 혈관 분포가 가장 풍부하였고(p<0.05), 외측의 경우 후각의 혈관 분포가 가장 풍부하였으며(p<.0.05) 슬와근부에서도 혈관 주행을 관찰할 수 있었다. 연령이 증가할수록 내측은 전각, 체부, 후각 모두 혈관 분포가 감소하며 외측은 체부와 후각에서 혈관 분포가 감소하는 것으로 나타났다(p<.0.05). 결론 : 내측 및 외측 반월상 연골의 혈관 분포는 해부학적 위치에 따라 달랐으며 연령이 증가함에 따라 내측과 외측에서 모두 전체적인 혈관 분포가 감소함을 알 수 있었다. Purpose : To evaluate the morphologic measurement and microvasculature of the normal human meniscus in Korean and to compare the difference of microvasculature according to the age and anatomical location. Materials and methods : Menisci of 21 cadavers divided into 3 groups according to the age. Each meniscus was divided into 10 parts of which the width and area of microvasculature were measured. Results : The average width of the medial and lateral menisci were $10.49{\pm}02.92mm$ and $10.55{\pm}2.05mm$, respectively. The average area of the microvasculature measured $20.29{\pm}8.44\%$ in the medial meniscus and $18.99{\pm}7.03\%$ in the lateral meniscus. The microvasculature of the medial meniscus was most abundant in the anterior horn and least abundant in the posterior horn (p<0.05). The lateral meniscus showed the most vessels in the posterior horn (p<0.05). The microvasculature of popliteal hiatus was not avascular but hypovascular. The area of microvasculature decreased with increasing age in all parts of the medial meniscus and body and posterior horn of the lateral meniscus (p<0.05). Conclusion : Differences in the anatomical distribution of the vessels were noted of both the medial and lateral menisci. The area of microvasculature generally decreased proportionally with increasing age in both medial and lateral meniscus.

대학생의 흡연 유형 및 흡연과 심리사회적 요인의 관계에 관한 연구

김상훈,조용래,표경식,Kim, Sang-Hoon,Cho, Yong-Rae,Pyo, Kyung-Sik 한국정신신체의학회 1996 정신신체의학 Vol.4 No.2

For the purpose of examining the relationship between smoking, perceived stress and vulnerability factors, and furthermore suggesting interventions to reduce excessive smoking and prevent nicotine dependency effectively, the questionnaires of perceived stress(stressful experiences), ways of stress coping(passive and active copings), smoking motives, social influence, age, amounts of smoking, and nicotine dependency were administered to smokers among medical students in Chosun university(n=186). 1) As a result of classifying smokers by the types of smoking, the most was a type of smokers to reduce negative emotions and the next in order were addictive smokers, smoker for stimulation, smoker for pleasure, etc. 2) The effects of motive, age, and active coping style were significant, but the effects of perceived stress, passive coping style, and social influence were not significant in average amount of daily smoking. 3) The effects of motive, social influence, and age were significant, but the effects of perceived stress, passive and active coping styles were not significant in the degree of nicotine dependency. To summarize, it is concluded that there were a lot of people who smoke to solve negative emotions, but the direct effects of perceived stress and passive coping style on both average amounts of daily smoking and the degree of nicotine dependency were not significant. On the other hand, motive, age, active coping style, and social influence were proved to be more important variables than the others in explaining college students' smoking.

수중 3D 콘텐츠 제작에 관한 연구

김상훈,김태은,Kim, Sang-Hoon,Kim, Tae-Eun 한국전자통신학회 2012 한국전자통신학회 논문지 Vol.7 No.3

최근에 3D 콘텐츠에 대한 관심은 점차 늘어나고 있으며 시청자들은 다양한 3D 콘텐츠를 요구하고 있다. 이와 같은 상황에서 수중 3D는 시청자 요구에 부응할 수 있는 하나의 대안이다. 수중은 공기 중과 달리 밀도가 큰 물을 통과하기 때문에 실제 물체 보다 크고 가깝게 보이는 특성이 있다. 이에 맞게 수중 3D 콘텐츠 제작을 위해서는 카메라 사이의 간격과 물체사이의 거리 및 컨버전스 값을 새로이 수정할 필요가 있다. 본 논문에서는 수중이라는 공간이 가지는 특수성에 맞게 최적 입체값 설정 방법을 제시하였다. 또한 수중 3D 콘텐츠 제작 사례를 통해 수중 3D 콘텐츠 개발 방법을 제시하였다. 이를 통해 수중에서만 볼 수 있는 화려한 색감, 다양한 해양생물, 심해의 미개척지 등 헤아릴 수 없는 많은 촬영 소재들이 3D 콘텐츠화 될 수 있기를 기대한다. Recently, the interest of 3D contents are increased and viewers demand a variety of 3D contents. In such circumstances, underwater 3D contents are an alternative to meet the demands of viewers. Cause that underwater mass density is 1.33 times that in air the objects in underwater is bigger and closer in real. Therefore it needs to modify the distance between cameras, the distance to objects and the convergence value. In this paper, we present the method to set optimal depth values with the particularities of underwater space. In addition, through the case of underwater 3D production we present the method of underwater 3D contents development. We expect that a lot of material with colorful, variety marine organism in underwater will be made of 3D contents.

징병제하에서 왜 군 입대를 늦추는가? : 심리적, 인구통계학적 특성 검토

김상훈,김진교,정용균,Kim, Sang-Hoon,Kim, Jin-Gyo,Jeong, Yong-Gyun 한국국방경영분석학회 2006 한국국방경영분석학회지 Vol.32 No.2

This study aims to empirically investigate the effects of the individual-level characteristics on their timing decisions for their enlistments even though military services are their duties under a draft system. The individual characteristics considered include five psychological factors, such as attitude, uncertainty, information search level, future expectation, and perceived risk towards army, and other several demographic variables. Measurement scales for these psychological variables are developed and a duration model for individuals' enrollment timing decisions is also proposed. The proposed model is fitted to a survey data set collected from both those who have completed military service and those who have not. The estimation results show that two of five psychological variables, negative attitude and perceived risk, and several demographic variables, including education level, income level, residence area, and the number of family members serving the army, have meaningful impacts on the timing decisions for military service. Specifically, the enlistment timings are found to be more delayed as negative attitude towards army is stronger, perceived risk on army is higher, education level is higher, academic performance is better, income level is either low or high, residence area is either Seoul or big cities, and the proportion of family members enlisted is smaller. Several important managerial implications for alleviating problems resulting from enrollment postponements are also discussed. 본 연구에서는 징병제 하에서 군 입대 연기를 가져오는 입대대상자의 개인적 특성변수를 실증적으로 검토한다. 개인적 특성 변수는 군에 대한 태도, 군 생활의 불확실성, 군 생활에 대한 정보탐색, 군 근무환경 개선에 대한 기대, 군 생활에 대한 지각된 위험이라는 5개의 심리차원 변수와 여러 인구통계학적 변수를 사용한다. 개인적 심리차원 변수의 척도를 개발한 후, 군 입대 지연기간의 분석을 위한 기간분석 모형 또한 제안하였다. 군복무 의무를 마친 사람과 군복무를 아직 마치지 않은 사람을 포괄하여 설문조사를 한 후, 제안된 모형을 추정하였다. 추정결과 다섯 개의 심리차원 변수 중 군에 대한 부정적 태도와 군 생활에 대한 지각된 위험이 입대지연에 영향을 주며, 인구통계학적 변수의 경우에는 학력, 소득, 학점, 거주지, 가족 중 군 입대자의 비율이 입대지연에 영향을 미친다는 것이 밝혀졌다. 구체적으로 군에 대한 부정적 태도가 증가할수록, 군 생활에 대한 지각된 위험이 증가할수록, 고학력일수록, 학교성적이 높을수록, 소득수준이 낮거나 높을수록 서울특별시와 광역시에 거주할수록, 가족 중 군 입대자의 비율이 낮을수록, 입대시점이 지연되었다. 이와 같은 추정결과를 바탕으로 대한민국의 병력수급관리를 위한 여러 시사점 또한 제시하였다.

새로운 이온빔장치를 사용한 Twisted Nematic-LCD의 전기광학특성

김상훈,황정연,장미혜,김귀열,서대식,Kim Sang-Hoon,Hwang Jeoung-Yeon,Jang Mi-Hye,Kim Gwi-Yeol,Seo Dae-Shik 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.6

We studied liquid crystal (LC) alignment with ion beam (IB) on polyimide and electro-optical characteristics of twisted nematic (TN)-liquid crystal display (LCD) on the polyimide surface using obliquely ion beam (IB) exposure with new IB type equipment. A good uniform alignment of the nematic liquid crystal (NLC) alignment with the ion beam exposure on the polyimide surface was observed. In addition, it can be achieved the good EO properties of the ion-beam-aligned TN-LCD on polyimide surface. Also, the EO characteristics of the ion-beam-aligned TN-LCD on a polyimide (PI) surface with ion beam exposure using new type IB equipment is same or more superior than ion-beam-aligned TN-LCD on a polyimide (PI) surface with ion beam exposure using Kaufman-type Ar ion gun.

비정상강우를 적용한 자연사면에서의 포화깊이 산정 및 사면안정성 평가

김상훈,김성필,손영환,허준,장병욱,Kim, Sang-Hoon,Kim, Seong-Pil,Son, Young-Hwan,Heo, Joon,Chang, Pyoung-Wuck 한국농공학회 2007 한국농공학회논문집 Vol.49 No.1

In Korea, most landslides occurr during the rainy season and have shallow failure planes parallel to the slope. For these types of rainfall-induced failures, the most important factor triggering slope unstability is decrease in the matric suction of unsaturated soils with increasing saturation depth by rainfall infiltration. For this reason, estimation of cumulative infiltration has a significance. In this study, infiltration rate and cumulative infiltration are estimated by using both Mein & Larson model based on Green-Ampt infiltration model and using modified Mein & Larson model to which unsteady rainfall is applied. According to the results, the modified model is more reasonable than Mein & Larson method itself in estimation of infiltration rate and saturation depth because of considering real pending condition.