• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2007년도 추계종합학술대회
• /
• pp.200-203
• /
• 2007

넓은 에너지 갭의 물질인 탄화규소(4H)기판을 사용하여, 초고내압을 위한 접합장벽 쇼트키 구조의 소자를 설계하여 제작하였다. 측정결과로써 소자의 역방향 I-V 특성은 1000V 이상의 항복전압을 보였고 p-grid의 설계 최적 길이는 $3{\mu}m$ 간격이였다. 이 연구에서는 제작한 소자의 공정 조건 파라미터들을 사용하여 I-V 특성을 모델링 하였고 I-V 특성 파라미터들을 추출하여 실제 소자 파라미터와 비교, 분석하였다.

• Tribology and Lubricants
• /
• 제31권1호
• /
• pp.1-5
• /
• 2015

In this study, we apply an ultrasonic nanocrystal surface modification (UNSM) technique to radial journal bearings (JBs) and disks made of SUJ2 and SCM440, respectively. We investigate frictional properties of untreated and UNSM-treated specimens using a ball-on-disk tester. We construct the Stribeck curve at the boundary, under mixed and full hydrodynamic lubrication conditions for the specimens using friction data obtained from JB tests. The friction at the boundary lubrication condition and the transition period to mixed lubrication condition on the UNSM-treated specimens is reduced, which improves the service life of JBs. The major effects of this reduction in the three lubrication regimes can be explained in the terms of improved mechanical properties and the presence of micro dimples. Moreover, we estimate the friction and fatigue properties of SCM440 specimens using a ball-on-disk specimen under dry and oil-lubricated conditions. Friction test results reveal that the UNSM-treated specimens show lower friction coefficient than the untreated specimens under both dry and oil-lubricated conditions. We evaluate the fatigue properties of SCM440 specimens by calculating the Hertzian stress with respect to the failure cycles. Fatigue tests results also reveal that the UNSM-treated specimens possess a longer fatigue life than the untreated specimens. The improved properties are effective in increasing the energy efficiency of bearings.

• 한국벤처창업학회:학술대회논문집
• /
• 한국벤처창업학회 2017년도 춘계학술대회
• /
• pp.54-54
• /
• 2017

이 연구의 목적은 온라인 방송으로 신규 창업점포를 광고 또는 임의 노출했을 때, 시청자들에게 미치는 영향을 측정하고 효율적인 광고를 하면서도 창업점포주들의 만족도를 높이기 위한 영향력을 미치는 변인과 효과적인 매체를 분석하고 조사하는데 있다. 이 목적을 달성하기 위하여 온라인 방송의 여러 매체들간 독립변인들과 대조군을 노출시켜, 이로 나타나는 결과 값들을 비교 분석하는 실험연구를 통해, 효과적인 방송 광고 방안을 제시하고자 한다. 매출 상승 효과를 높이기 위해, 방송중 주목, 흥미, 기억, 용인 등의 요인을 적용하여, 긍정적인 분위기로 시청자들의 창업점포를 각인시키고자 한다. 이를 통해, 온라인 방송으로 신규 창업점포를 광고 또는 임의 노출했을 때, 시청자들에게 미치는 영향을 측정하고 효율적인 광고를 하면서도 창업점포주들의 만족도를 높이기 위한 영향력을 미치는 변인과 효과적인 매체를 분석하고 조사하고자 한다. 실험연구 진행방법으로는 매주 금요일 JBS 방송, 페이스북, 유투브에 노출시켜 점포 매출 전*후를 조사하여 온라인 방송이 매출의 영향을 주는지 알아보고자 한다. 또한 매출에 영향이 미친다면 창업학도로서 큰 의미가 될 것으로 보여 논문 연구 진행중으로, 창업컨설턴트들에게 의미있는 연구를 진행할 것이다.

• 식물병연구
• /
• 제23권3호
• /
• pp.241-248
• /
• 2017

강원도 고랭지배추 포장에서 검출된 사탕무씨스트선충(H. schachtii)과 콩씨스트선충(H. glycines)을 구별할 수 있는 신속진단법을 개발하고자 하였다. 이를 위해 mtDNA COI 유전자 영역의 계통분석으로 동정된 사탕무씨스트선충 GC147, GC408, PM001 개체군과 콩씨스트선충 YS224, DA142, BC115 개체군을 대상으로 PCR-RFLP와 본 연구에서 개발한 특이 프라이머 세트를 이용한 PCR을 수행하였다. 사탕무씨스트선충과 콩씨스트선충 각각 3개 개체군의 mtDNA COI 영역 PCR 증폭산물에 8종류의 제한효소를 처리하여 DNA 절편길이다형성을 확인하였으며, 2종류의 제한효소 RsaI과 HinfI을 처리하면 DNA 밴드 양상의 차이로 사탕무씨스트선충과 콩씨스트선충 두 종을 구별할 수 있었다. 또한, 본 연구에서 개발한 프라이머 세트(JBS1, JBG1과 JB3R)는 사탕무씨스트선충 mtDNA COI 영역의 277과 339 bp, 콩씨스트선충의 339 bp의 특정 DNA 단편을 증폭시켰으며, 뿌리혹선충 3종과 뿌리썩이선충 2종의 식물기생선충은 증폭시키지 않았다. 따라서, 본 연구에서 개발한 프라이머 세트를 이용하여 PCR을 수행하면 사탕무씨스트선충과 콩씨스트선충을 구별할 수 있었다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2018년도 전력전자학술대회
• /
• pp.536-538
• /
• 2018

This paper introduces an enhanced interleaved (IL) PFC (Power Factor Correction) boost converter typed 650V Intelligent Power Module (IPM), which is fully optimized hybrid IGBT converter modules; Silicon (Si) IGBT and Silicon Carbide (SiC) diode, for up to 10kW HVAC (Heating, Ventilation, and Air Conditioning) systems. It utilizes newly developed $4^{th}$ Generation Field Stop (FS) trench IGBTs, $EXTREMEFAST^{TM}$ anti-paralleled diodes, SiC Junction Barrier Schottky (JBS) diodes, Bridge rectifiers, Multi-function LVIC, and Built-in thermistor provide good reliable characteristics for the entire system. This module also takes technical advantage of DBC (Direct Bonded Copper) substrate for the better thermal performance. It is shown that the Si IGBT/SiC diode hybrid IL PFC module can achieve excellent EMI performance and greatly enhance the power handling capability or switching frequency of various applications compared to the Si IGBT/Diode. This paper provides an overall description of the newly developed 650V/50A Hybrid SiC IL PFC IPM product.

• 대한안전경영과학회지
• /
• 제16권1호
• /
• pp.119-127
• /
• 2014

This study tried to develop a basis for quantitative index of working postures associated with WMSDs (Work-related Musculoskeletal Disorders) that could overcome realistic restriction during application of typical checklists for WMSDs evaluation. The baseline data(for a total of 603 jbs) for this study was obtained from automobile manufacturing company. Specifically, data for back posture was analyzed in this study to have a better and more objective method in terms of job relevance than typical methods such as OWAS, RULA, and REBA. Major statistical tools were clustering, logistic regression and so on. The main results in this study could be summarized as follows; 1) The relationship between working posture and WMSDs symptom at back was statistically significant based on the results from logistic regression, 2) Based on clustering analysis, three levels for WMSDs risk at back were produced for flexion as follows: low risk(< $18.5^{\circ}$), medium risk($18.5^{\circ}{\sim}36.0^{\circ}$), high risk(> $36.0^{\circ}$), 3) The sensitivities on risk levels of back flexion was 93.8% while the specificities on risk levels of back flexion was 99.1%. The results showed that the data associated with back postures in this study could provide a good basis for job evaluation of WMSDs at back. Specifically, this evaluation methodology was different from the methods usually used at WMSDs study since it tried to be based on direct job relevance from real working situation. Further evaluation for other body parts as well as back would provide more stability and reliability in WMSDs evaluation study.

• 대한치과기공학회지
• /
• 제22권1호
• /
• pp.179-198
• /
• 2000

Since dental prosthesis is made possible only when dental technicians give themselves to the study of knowledge and the acquisition of updated skills, continuing education is of great importance in that it makes up for the efforts of dental technicians. Accordingly, continuing education relates to a system designed to contribute to the enhancement of the talents of dental technicians and the dental health of the nation. Specialized knowledge and information may work as the best weapon to preserve their jbs. This is true of this modern society where no one can expecth to survive without acquiring knowledge and information constantly for work is getting more classified and more divirsifide. This paper is dedicated to take a look at the current condition of the continuing education of dental technicians and to come up with measure to make general evaluation and to improve continuing education. This research resorts to 609 questionnaires among 6433 copies save unfaithfully responded 34 copos with 6.431 dental technicians as the subjects enrolled in the Dental technician Association. The collected questionnaires consist of 365 dental technicians living in Seoul and of 244 ones, Which account for 11.8 percent of dental technicians enrolled in the association. Because dental technicians live more in local areas than Seoul, the generalization of this survey leaves something to be desired. I have come up with the following findings. 1. 6,431 dental technicians, or 36.3 percent of an total of 14,956 licensed dental technicians, were admitted as numbers of the Dental Tachnician Association as of October 31, 1999. In the '98 continuing education. 4,141 dental technicians among 4,711 dental technicians got relevant training, and in the '99 continuing education, 4,075 technicians, or 75.9 percent of 5,365 technicians got relevant training while 1,290 technicians or 24.2 percent, fail to get relevant training. 2. The survey has it that 38.1 percent of dental technicians are ignorant of the laws on continuing education, and that technicians staying in local communities(146 persons, or 61.6%) take more part in education than those living in the capital of Korea(159 persons, or 146%), and that the older they are, the more money they earn, the more carrer they have, the higher position they hold, the more part they take in education 3. According to the survey, those who have the experience of getting training more than three times account for 52 persons(16.8%) in Seoul and 47 persons(22.4%) in local districts(p<0.01). In terms of sanctions in relation to continuing education, 26 dental technicians(4.6%) say that they have ever gotten sanctions, and 533 dental technicians(95.4%) say that they haven't. And those who were absent from continuing education(72 technicians : 13.51%) didn't get any sanction. 4. In terms of the degree of understanding continuing education, local technicians(46.8% : 110 persons) have a higher understanding of continuing education than their countparts staying in Seoul(36.0% : 130). Continuing education is not the ultimate goal itself. It should be changed to motivate those who get education to be willing to take part in contunuing education, and to help dental technicians in a practical and specific way. And the branch societies should be developde to engage in more specialized and classified expert fields. Of course, the curriculum should be so selected that the conceptions of dental technicians may be reflected to the maximum extent, and the ultimate effores should be made to effect diversity in the ways of educational methods and to perfect the preparation of continuing education on the part of instructors. Regulations should be established in relation to continuing education with a veiew to enhancing the participation of continuing education and its effectiveness. The supervision of the Ministry of Health and Welfare is of great importance in this context. The regulation of continuing education is not administrative regulation, but the expression of national will to guarantee the medical service of the nation at highest level. Therefore, it is necessary that the Ministry of Health and Welfare should change their understanding of the needs for the continuing education of dental experts, and that the expertise of government employees in charge of continuing education should be expanded. It goes without saying that the government should suppory continuing education in a financial way so as to supply the person in charge of public welfare and control the quality of national medicine.