HVPE 법을 통한 GaN 성장 시 기판 종류 및 V/III 비에 따른 잔류 stress 특성 연구

이주형,이승훈,이희애,강효상,오누리,이성철,이성국,박재화,Lee, Joo Hyung,Lee, Seung Hoon,Lee, Hee Ae,Kang, Hyo Sang,Oh, Nuri,Yi, Sung Chul,Lee, Seong Kuk,Park, Jae Hwa 한국결정성장학회 2020 한국결정성장학회지 Vol.30 No.2

The characteristics of the residual stress on the types of the substrate was investigated with adjusting the V/III ratio during GaN growth via the HVPE method. GaN single crystal layers were grown on a sapphire substrate and a GaN template under the conditions of V/III ratio 5, 10, and 15, respectively. During GaN growth, multiple hexagonal pits in GaN single crystal were differently revealed in accordance with growth condition and substrate type, and their distribution and depth were measured via optical microscopy(OM) and white light interferometry(WLI). As a result, it was confirmed that the distribution area and depth of hexagonal pit tended to increase as the V/III ratio increased. Moreover, it was found that the residual stress in GaN single crystal decreased as the distribution area and depth of the pit increased through measuring micro Raman spectrophotometer. In the case of GaN growth according to substrate type, the GaN on GaN template showed lower residual stress than the GaN grown on sapphire substrate.

모델링과 검증에 의한 파이프 라인 시스템의 유출 탐지

이주형,여영구,송형근,이광순 ( Joo Hyeong Lee,Yeong Koo Yeo,Hyung Keun Song,Kwang Soo Lee ) 한국화학공학회 1992 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.30 No.5

A leakage detection method based on a physical model of a pipeline system is proposed. Based on fundamental balance equations for liquid transporation in a pipeline, the method was constructed to diagnose the leak point as well as to detect the leakage. The proposed method was evaluated in a water transporting pipeline system of which the length is 97.6 m and inner diameter is 3/8, respectively. As a result, the method could discriminate the leakage whenever the leaking rate is more than 3% of the total flowrate and localize the leaking point within 3% of accuracy depend on the leaking rate.

노후 콘크리트 구조물의 실용적 유지관리를 위한 콘크리트 구조물 안전진단 지침 분석

이주형,조재열,Lee, Joo-Hyung,Cho, Jae-Yeol 한국토지주택공사 토지주택연구원 2020 토지주택연구 Vol.11 No.3

In South Korea, problems caused by material deterioration of time-worn concrete structures have been increased recently. Because severe material deterioration could damage the structure's safety, it's important to evaluate the old structure's condition and structural capacity regularly to keep its proper performance. The safety evaluation of concrete structures has been initiated and performed periodically since 1995 according to a guideline in accordance with a law in Korea. The guideline prescribes the evaluation types, intervals and methods of the target structure. A lot of cost and labor have been invested every year to carry out the regular safety evaluation. However, it's not clear that the current manual could inspect the old structure's condition and assess the structural capacity precisely. Thus, the verification study initiated to figure out the Korean safety evaluation manual's practicalness. First, the Korean manual was analyzed and then compared with that of other countries for concrete bridges which are representative concrete structure. After that, the previously written evaluation reports were collected and analyzed to find out how the safety evaluation has been carried out. Based on the study results, the parts requiring verification of the manual were drawn. A research program is in progress in order to verify the parts by performing tests with actual structural members from decommissioned concrete bridges.

전방십자인대 손상으로 인한 슬관절 불안정성에 따른 경골 골단 해면골 미세구조 변화 : 내방과 외방에서의 해면골 미세구조 패턴 변화

이주형,전경진,김한성,임도형,Lee, Joo-Hyung,Chun, Keyoung-Jin,Kim, Han-Sung,Lim, Do-Hyung 대한의용생체공학회 2012 의공학회지 Vol.33 No.2

Knee joint instability by anterior cruciate ligament(ACL) rupture is allowing the abnormal loading condition at the tibial epiphysis locally, resulting in producing locally different bone bruise. The study examined difference between local alteration patterns of trabecular bone microarchitecture at medial and lateral parts of the tibial epiphysis by ACL rupture. Fourteen SD rats were divided into Control(CON; n = 7) and Anterior Cruciate Ligament Transection(ACLT; n = 7) groups. The tibial joints were then scanned by in vivo ${\mu}$-CT at 0, 4, and 8 weeks post-surgery. The results showed that alteration pattern on trabecular bone microarchitecture at medial part was significantly higher than that at lateral part of the tibial epiphysis in ACLT group from 0 to 8 weeks(P < 0.05). Tb.Th and Tb.Sp distributions were well corresponded with differences between aforementioned trabecular bone microarchitectural alteration pattens at medial and lateral parts of the tibial epiphysis in ACLT group from 0 to 8 weeks(P < 0.05). These findings suggest that the alteration patterns of trabecular bone microarchitecture should be locally and periodically considered, particularly with respect to the prediction of bone fracture risk by ACL rupture. Improved understanding of the alteration patterns at medial and lateral trabecular bone microarchitectures at the tibial epiphysis may assist in developing more targeted treatment interventions for knee joint instability secondary to ACL rupture.

주택규모 선택에 영향을 미치는 가구원수별 특성에 관한 연구

이주형,임종현,강남훈,Lee, Joo-Hyung,Lim, Jong-Hyun,Kang, Nam-Hoon 한국주거학회 2010 한국주거학회 논문집 Vol.21 No.2

The housing market requires customized housing to be supplied according to the various characteristics of households. Multinominal Logistic Regression was used to analyze the effects of variables of household characteristics according to the number of family members on the choice of housing size in the scope of the whole country's housing market. Analysis showed that the number of family members has its own characteristics. When a household has a smaller number of family members, there are more variables affecting choice of housing size. Living and housing expenses variables served as significant variables that affect all household types. Results showed that households with more living and housing expenses are more likely to choose a large sized house and where households have a greater number of family members, there is more influence on that choice. The age of the householder was only found to be a meaningful variable in 1-2 person households and 3-4 person households, particularly in the choice of a small or large sized house. This shows that the age of the householder does not play an important role in choosing medium sized houses for households of under 4 people, but affects the choice of small and large sized houses. The academic ability of household members also served as a significant variable. While 1-2 person households with high academic ability tend to select a large sized house, 3-4 person households with high academic ability tend to select a small sized house. It is observed that members of both 1-2 person households and 3-4 person households tend to select their house between a large sized house and a small sized house in order to own their own houses. The result of this research suggests that there are various and detailed variables on the choice of housing size. Especially, a notable result is that household characteristics more significantly affect the housing size choice of 1-2 person households, while the trend of an aging society will more significantly affect a 3-4 person households' choice of a large sized house. Therefore, a study on the choice of housing size according to characteristics of elderly households and 1-2 person households should be continually analyzed.

체조선수의 성숙도에 따른 신체적 자기효능감과 경기력의 관계

이주형 ( Joo Hyung Lee ) 한국스포츠리서치 2007 한국 스포츠 리서치 Vol.18 No.4

The purpose of this study was to identify the causal relationships among maturity, physical self-efficacy and performance of gymnastics athletes. The instrument for data collection was a questionnaire in which maturity as identified by Kim(1995) and physical self-efficacy by Lee(1997). 200 subjected were selected from gymnastics teams in Korea by the cluster sampling method. Among these selected subject, 193 responded, and data analyses consisted of employing factor analysis, correlation and covariance structure analysis using SPSS/PC+ 14.0 and AMOS 5.0. The following results were obtained: The relationships among maturity, physical self-efficacy and performance were the causal relation. First, maturity statistically and significantly influences physical self-efficacy. Second, physical self-efficacy statistically and significantly influences performance of gymnastics athletes.

국내 주거환경개선사업의 정비구역 지정기준에 관한 연구

이주형(Lee, Joo Hyung),변준석(Byun, Jun Seok),김민창(Kim, Min Chang) 한국부동산학회 2012 不動産學報 Vol.51 No.-

1. CONTENTS (1) RESEARCH OBJECTIVES This study starts with the notice that there is problem with the assignment standards of residental environment improvement project. (2) RESEARCH METHOD This research suggesting the major solution through status analysis examine suitability of variables on worker and expert and AHP(Analytic Hierarchy Process) helped the process of this study. (3) RESEARCH FINDINGS The tool of this research, to tighten the criteria, gather physical, social, economic improvement indicator from the case study and set 23 indicator system with 5 parent items, physical standard, social, standard, resident characteristic, urban service, and policy. 2. RESULTS As the result from AHP method evaluating status of 23 indicator, the rate of subsidy recipient in improvement project scheduled region is a matter of the highest priority for selection standard. For the second rank; income level, the third rank; the ratio of disaster risk, the forth rank; access of public transportation, the fifth rank; the ratio of decrepit housing, the sixth rank; number of negligent accident in recent 10 years, the seventh rank; poor urban landscape according to resident’s view, the eighth rank; level of education facilities, the ninth rank; flood risk of the region and the tenth rank; the ratio of squatter settlement were determined as major indicator to decide the assignment standard.

입지별 주상복합 개발 특성에 관한 연구

이주형(Lee, Joo Hyung),채두병(Chae, Du Byeong),박희수(Park, Hee Soo) 韓國不動産學會 2010 不動産學報 Vol.41 No.-

1. CONTENTS (1) RESEARCH OBJECTIVES The purpose of this study is to analyze the spatial characteristics of mixed residential? commercial developments in Seoul (2) RESEARCH METHOD The characteristics of development according to locations are deducted by principle analysis and the results are verified through the ANOV A analysis (3) RESEARCH FINDINGS housing←commercial development is very important by the aspect of urban planning as a result of functioning to each simple architectural development as well as deciding the direction of urban development and urban spatial structure m existing cities 2. RESULTS the result from this research which analyses the characteristics of location based housing-commercial development demonstrates that the housing-commercial development in Seooul presents refleιting the characteristics of each architectural plan rather than realizing the direction of housing commercia development. Therefore, the legislation is urgently required because there is a possibility to expand housing-cαnmercial development later in the case of Seoul whose existing cities have been deterioration. In addition to this, it is necessary to nnprove accαnmodating the complex of three dimensional land use as conceming an exclusive zoning system.

ICAO 「글로벌 항공보안계획」 실행에 관한 연구 - 국내 실행 방안 검토 및 실행방안 제시 -

이주형 ( Joo-hyung Lee ),황호원 ( Ho-won Hwang ) 한국항공경영학회 2018 한국항공경영학회지 Vol.16 No.3

ICAO recently prepared new aviation security policies and resolutions for future aviation security paradigm. Recently, ICAO adopted Global Aviation Security Plan(GASeP) regulated comprehensive and detailed aviation improvement plans for world wide. Reviewing ICAO Global Aviation Security Plan, this study suggests the several improvements plan of Republic of Korea aviation security to improve aviation ad airport security measures in the field of aviation in 5 main areas. First, to enhance security risk awareness and response, proper security analysis methodology should be developed and information sharing systems should be established. Especially airport landside security mitigation measure and insider threat mitigation procedures are necessary. Second, to develop security culture and human capability related portions of regulations should be made and more detailed requirements should be established to make effective security culture. Third, to improve technological resources and foster innovation, minimum security detection criteria should be determined at national level and it is essential to set up innovative security equipment management methodology. Fourth, to improve aviation security oversight and quality assurance, Republic of Korea should establish more efficient oversight systems. In order to achieve this goal, Republic of Korea should introduce proper analysis system on security oversight systems. Also it is necessary to set the mutual cooperation structure with foreign countries. Fifth, to increase cooperation and support stipulated in ICAO GASeP, Republic of Korea should set up supporting system and appropriate system for providing related information to airports, airlines and stockholders. In conclusion, it is necessary to form task force team urgently for developing implementing plans of ICAO GASeP in order to maintain world best security system in the world. Also We also pay attention to check, review and supplement the implementation of 5 key tasks regarding the ICAO GASeP.

간헐진동과 연속진동이 라텍스개질 콘크리트에 미치는 영향

이주형(Lee Joo-Hyung),홍창우(Hong Chang-Woo),정원경(Jeong Won-Kyong),윤경구(Yun Kyong-Ku) 대한토목학회 2004 대한토목학회논문집 D Vol.24 No.2D