도가니 구조 변경을 통한 6H-SiC 단결정의 직경 확장에 관한 연구

김정규,견명옥,서정두,안준호,김정곤,구갑렬,이원재,김일수,신병철,Kim, Jung-Gyu,Kyun, Myung-Ok,Seo, Jung-Doo,An, Joon-Ho,Kim, Jung-Gon,Ku, Kap-Ryeol,Lee, Won-Jae,Kim, Il-Soo,Shin, Byoung-Chul 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.7

A sublimation method using the SiC seed crystal and SiC powder as the source material is commonly adopted to grow SiC bulk single crystal. However, it has proved to be difficult to achieve the high quality crystal and the process reliability because SiC single crystal should be grown at very high temperature in closed system. In this study, SiC crystal boules were prepared with different angles in trapezoid-shaped graphite seed holders using sublimation physical vapor transport technique (PVT) and then their crystal quality was systematically investigated. The temperature distribution in the growth system and the crystal shape were varied with angles in trapezoid-shaped graphite seed holders, which was successfully simulated using 'Virtual Reactor'. The SiC polytype proved to be the n-type 6H-SiC from the typical absorption spectrum of SiC crystal. The micropipe densities of SiC wafers in this study were measured to be < $100/cm^2$. Consequently, SiC single crystal with large diameter was successfully achieved with changing angle in trapezoid-shaped graphite seed holders.

학업성취(學業成就)와 관련(關聯)된 지능변인(知能變因), 인지양식변인(認知洋式變因), 창의성(創意性) 변인(變因)에 대한 통합분석(統合分析)

김정규 ( Jung Kyu Kim ),구병두 ( Byung Doo Ku ) 건국대학교 교육연구소 1993 교사와 교육(구 교육논집) Vol.17 No.-

This study was designed to synthesize quantitatively the master`s theses and doctoral dissertations focusing on the effects of academic achievements in intellectual function variable group. This task was accomplished by utilizing the meta-analysis technique of research integration as defined by Glass(1982). Basically, meta-analysis is a statistical analysis of summary findings of many empirical studies. Its purpose is to draw reliable and general conclusions from a large and complex body of literature on a common topic. Thus, the primary purpose of this study was to conduct a quantitative synthesis of 42 master`s theses and doctoral dissertations focusing on the effects of academic achievements in intellectural function variable group. The intellectual function variable group categorized three independent variables in this study. These three independent variables are intelligence, creativity, and cogntive style. This study also assessed the relation between moderator variables and effect size. The morderator variables investigated included grade, curriculum area, experimental period, number of subject, source of studies, sex, geographic area, and school type. This study set the following questions to be answered. Problem 1 : How large are the effect sizes of the three independent variables selected in this study? Problem 2 : How large are the effect sizes of the interaction effect between three independent variables and eight moderator variables? The standard procedures analogous to those performed during primary research was used in this meta-analysis: locating studies (data collection), coding the characteristics and outcomes of the studies(evaluation of data points) and using statistical procedures of meta-analysis in order to describe the overall and subsample effects(date analysis and interpretation) . The result of this study may be summarized as follows : 1. The grand average degree of effects of the academic achievement variables proposed in this study turned out to be. 939. This mean that is the average effect size of the academic achievement variables of the controlled group is 50 percentile in the normal distribution, that of the experimental group becomes 82.64 percentile. As it were, the latter surpasses the former by 32.64 percentile. 2. Among the three independent variables of academic achievement proposed in this study, intelligence variables showed the highest effect size, its effect size being 1.223. The second highest one is creativity variable whose effect size is .890. On the other hand, cognitive style variable was proved to have the lowest effect size in this study. 3. The intelligence variable had the most effect on the academic achievements regardless of male or female, grades(ages), and subjects.

유도레일 및 고압살수를 이용한 열화교각의 절삭 및 숏크리트 보수재료 개발

윤경구,이계근,김정규,하태호,Yun, Kyong-Ku,Lee, Kye-Guen,Kim, Jung-Gyu,Ha, Taeho 한국건설순환자원학회 2022 한국건설순환자원학회지 Vol.17 No.3

유도레일 및 고압살수를 이용한 열화교각의 절삭 및 숏크리트 보수재료 개발

윤경구,이계근,김정규,하태호,Yun, Kyong-Ku,Lee, Kye-Guen,Kim, Jung-Gyu,Ha, Taeho 한국건설순환자원학회 2022 한국건설순환자원학회지 Vol.17 No.3

고온 내산화성 고 Si , Mo 구상흑연주철의 특성에 관한 연구

김석원,우기도,한상원,김정규,김대영 ( Sug Won Kim,Kee Do Woo,Sang Won Han,Jung Ku Kim,Dae Yong Kim ) 한국주조공학회 1998 한국주조공학회지 Vol.18 No.2

N/A The physical and chemical characteristics of Ductile Cast Iron(DCI) have been well known because of many studies about DCI. So it has a wide application in the field of heavy and automobile industry because DCI has a good combination of excellent castability and good mechanical properties. But its usage has been often restricted to use in parts such as exhaust manifold required high heat resistance in automobile industry. So, in this study, in order to achieve high heat resistance in DCI, DCI with addition of high Si and Mo alloy elements have been researched on mechanical properties, including heat resistances systematically. With the increase of Mo and Si content, the size and number of graphite in matrix of DCI increased and the pearlite in DCI matrix is transferred to ferrite because of Si strong former of ferrite, otherwhile carbide in matrix increased because of Mo carbide former. In the test of oxidation property, Si and Mo played an important role to retard oxidation of DCI. By the: addition of Si and Mo, the Charpy impact energy was decreased, whereas the total hardness was increased. (Received February 20, 1998)

반탄화 공정 변화에 따른 바이오매스 연료의 특성 연구

엄태인(Tae-In Ohm),채종성(Jong-Seong Chae),김정규(Jung-Ku Kim),최수아(Soo-A Choi),오세천(Sea-Cheon Oh) 한국연소학회 2014 KOSCOSYMPOSIUM논문집 Vol.2014 No.11

In this study, we carried out torrefaction experiment using PKS(Palm Kernel Shell), and Bagasse as a raw material of oversee of herbaceous biomass and using waste wood and logging residue as a raw material of domestic of woody biomass. And then, by analyzing the physical & chemical properties, we investigated the characteristics as a fuel. By using the result of thermo gravimetric analysis, the biomass residue was torrefied for 30 minutes at a temperature range of 250-350℃ in anaerobic condition. As a result, torrefied materials of moisture content are lower than raw , but of fixed carbon, calorific value and ash are higher than raw.

學業成就와 關聯된 知能變因, 認知樣式變因, 創意性 變因에 대한 統合分析

김정규,구병두 建國大學校 敎育硏究所 1993 論文集 Vol.17 No.-

This study was designed to synthesize quantitatively the master's theses and doctoral dissertations focusing on the effects of academic achievements in intellectual function variable group. This task was accomplished by utilizing the meta-analysis technique of research integration as defined by Glass(1982). Basically, meta-analysis is a statistical analysis of summary findings of many empirical studies. Its purpose is to draw reliable and general conclusions from a large and complex body of literature on a common topic. Thus, the primary purpose of this study was to conduct a quantitative synthesis of 42 master's theses and doctoral dissertations focusing on the effects of academic achievements in intellectural function variable group. The intellectual function variable group categorized three independent variables in this study. These three independent variables are intelligence, creativity, and cogntive style. This study also assessed the relation between moderator variables and effect size. The moderator variables investigated included grade, curriculum area, experimental period, number of subject, source of studies, sex, geographic area, and school type. This study set the following questions to be answered. Problem 1 : How large are the effect sizes of the three independent variables selected in this study? Problem 2 : How large are the effect sizes of the interaction effect between three independent variables and eight moderator variables? The standard procedures analogous to those performed during primary research was used in this meta-analysis : locating studies(data collection), coding the characteristics and outcomes of the studies(evaluation of data points) and using statistical procedures of meta-analysis in order to describe the overall and subsample effects(data analysis and interpretation). The result of this study may be summarized as follows : 1. The grand average degree of effects of the academic achievement variables proposed in this study turned out to be.939. This mean that is the average effect size of the academic achievement variables of the controlled group is 50 percentile in the normal distribution, that of the experimental group becomes 82.64 percentile. As it were, the latter surpasses the former by 32.64 percentile. 2. Among the three independent variables of academic achievement proposed in this study, intelligence variables showed the highest effect size, its effect size being 1.223. the second highest one is creativity variable whose effect size is .890. On the other hand, cognitive style variable was proved to have the lowest effect size in this study. 3. The intelligence variable had the most effect on the academic achievements regardless of male of female, grades(ages), and subjects.