• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.776-780
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• 2015

In this paper, we have studied the effect of mechanical polishing to Ga-polar face for reducing the wafer bowing and strain in free-standing GaN. After the mechanical polishing to Ga-polar face, the bowing of the free-standing GaN substrate significantly decreased with increasing the size of diamond slurry, and eventually changed the bowing direction from concave to convex. Furthermore, the full width at half maximum (FWHM) of high-resolution X-ray diffraction (HR-XRD) were decreased, especially the FWHM of (1 0 2) reflection for $1.0{\mu}m$ size of diamond slurry was significantly decreased from 630 to 203 arcsec. In the case, we confirmed that the compressive strain in Ga-polar face was fully released by Raman measurement.

• The Journal of Korean Physical Therapy
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• 제23권4호
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• pp.1-6
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• 2011

Purpose: We investigated the effects of single-leg stance training on standing balance and mobility in patients with subacute hemiplegia. Methods: Seventeen matched subjects were assigned randomly to the experimental group or the control group. The experimental group comprising of 8 subjects received single-leg stance training and conventional physical therapy interventions 5 times per week for 4 weeks. The control group comprising of 9 subjects received only conventional physical therapy interventions 5 times per week for 4 weeks. Outcome measures were assessed before and after 4 weeks of intervention using the Berg Balance Scale (BBS), gait speed, and weight bearing index of the affected side. Results: Both the exercise groups showed significant improvements in BBS, gait speed, and weight bearing index (p<0.05). After 4 weeks of intervention, there were statistically significant differences in BBS and weight bearing index between the two groups (p<0.05). Conclusion: These findings suggest that conventional physical therapy interventions along with single-leg stance training could be more effective than conventional physical therapy alone for improving standing balance and mobility in patients with subacute hemiplegia.

• 한국전기전자재료학회논문지
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• 제29권1호
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• pp.30-34
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• 2016

In this paper, we report that selective etching on N-polar face by EC (electro-chemical)-etching effect on the reduction of bowing and strain of FS (free-standing)-GaN substrates. We applied the EC-etching to concave and convex type of FS-GaN substrates. After the EC-etching for FS-GaN, nano porous structure was formed on N-polar face of concave and convex type of FS-GaN. Consequently, the bowing in the convex type of FS-GaN substrate was decreased but the bowing in the concave type of FS-GaN substrate was increased. Furthermore, the FWHM (full width at half maximum) of (1 0 2) reflection for the convex type of FS-GaN was significantly decreased from 601 to 259 arcsec. In the case, we confirmed that the EC-etching method was very effective to reduce the bowing in the convex type of FS-GaN and the compressive stress in N-polar face of convex type of FS-GaN was fully released by Raman measurement.

• 대한기계학회논문집B
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• 제38권2호
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• pp.173-181
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• 2014

정상초음파장의 주파수 변이가 프로판/공기 예혼합화염의 전파거동 및 구조변이에 미치는 영향을 규명하기 위해 실험적 연구를 수행하였다. 다양한 당량비 조건에서 슐리렌 기법을 적용한 전파화염 가시화와 연소실 내부압력 측정을 통해 생성물 영역에서의 화염 구조변화 및 전파특성을 관찰하였다. 정상초음파가 존재할 경우 화염선단이 찌그러지고 기연부에서 횡방향 줄무늬가 생성되며, 이러한 구조변이는 정상초음파의 주파수에 종속한다. 또, 전파속도는 정상초음파가 교반하는 경우 증가되며, 화염전파 거동에 미치는 초음파의 영향은 주파수의 증가에 따라 보다 명확해진다는 사실도 확인되었다.

• 응용통계연구
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• 제24권6호
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• pp.1139-1148
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• 2011

프로야구 정규리그의 팀순위는 합리적인 기준에 따라 정해져야 함에도 불구하고 2011년 현재 한국 프로야구에서는 비합리적인 일본식 방식이 사용되고 있는 실정이다. 본 논문에서는 한국 프로야구에서 사용된 적이 있는 팀순위 결정 방식들의 장점들을 조합하여 만든 새로운 승률 계산 방식을 제안하였다. 또한 기존의 방식들과 제안된 방식을 과거와 현재의 한국 프로야구 자료에 적용하여 그 결과를 관찰하였다.

• 대한기계학회논문집B
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• 제39권2호
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• pp.161-168
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• 2015

정상초음파장의 구동 주파수가 메탄-공기 예혼합화염의 전파특성에 미치는 영향을 규명하고자 하는 실험결과를 제시한다. 고속카메라를 이용하여 화염의 전파영상을 획득하였으며, 영상 후처리를 통해 화염선단의 구조와 속도변이를 포함하는 화염의 거시적 거동을 상세히 관찰하였다. 정상초음파가 연소반응을 촉진시켜 화염 전파속도의 증대와 화염선단 구조의 변이를 유발한다는 사실에 더하여, 초음파구동 주파수와 당량비에 대한 화염거동의 종속성을 확인하였다.

• Physical Therapy Rehabilitation Science
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• 제3권2호
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• pp.125-133
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• 2014

Objective: The aim of this study is to investigate the effect of patellar taping on balance and gait abilities in chronic stroke patients. Design: Randomized placebo-controlled trial. Methods: Thirty chronic stroke patients who have been diagnosed at least six months or before were recruited from R hospital. These study subjects were randomized to the experimental group (n=15) or placebo group (n=15). In the experimental group, patellar taping was applied while for the placebo group, placebo taping was applied. The Balance System SD was used for measuring dynamic standing balance in these two groups. In addition, the GAITRite (CIR System Inc.) system was utilized for calculating gait performance in these patients. Results: After application of taping, the patellar taping group showed a significant decrease in dynamic standing balance in their sway area (p<0.05). However, in the placebo group, there was no significant difference in dynamic standing balance ability and gait ability before and after application of taping. Comparison of the patellar taping group and placebo group showed significant differences in dynamic standing balance ability and gait performance (p<0.05). Conclusions: From the results of this study, it appears that application of patellar taping in chronic stroke patients significantly improved dynamic standing balance ability and gait ability in these patients. Based on these results, patellar taping is thought to be useful in real clinical settings where there are many chronic patients who are in need of improvement in their balance and gait ability.

• 산업융합연구
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• 제20권7호
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• pp.1-11
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• 2022

본 논문에서는 여러 연구기관에서 논의하고 있는 데이터 기반 평가 방법론 중 토픽모델링 기법을 이용하여 계량적인 값을 도출하고 그 과정에서 실제 전문가들이 수행하는 국가연구개발사업과제와 이를 법률과 정책실무에서 다루는 국회 상임위원회 간의 정책적 인식 차이가 있는지 ICT 분야를 중심으로 파악해 보고자 한다. 먼저 HAN 모델로 사업과제 데이터를 학습하여 ICT 문서를 분류하는 모델을 만들고, 해당 모델을 통해 분류된 ICT 문서를 대상으로 LDA 토픽모델링 분석을 수행하여 국가연구개발사업과제 데이터와 국회 상임위원회 회의록에서 도출된 토픽과 분포를 비교한다. 구체적으로 총 26개의 토픽이 도출되었으며, 각 토픽이 포함하는 단어와 문서 분포 비율을 살펴봤을 때, 국가사업과제는 상대적으로 전문적인 주제의 문서가 많았으며, 국회 상임위원회는 상대적으로 사회적이고 대중적인 문제를 다루는 것으로 나타나 인식에 다소 차이가 있는 것으로 보였다. 인식의 차이를 수치적으로 확인할 수 있는 만큼, 향후 정책이나 과제 평가에 사용할 수 있는 지표에 대한 기초연구로 활용 가능할 것이다.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2004년도 춘계학술대회
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• pp.98-112
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• 2004

Nowadays science and technology analyses appeared as standing on the basis of the scope and quantity of literature in the field of rapidly progressed science and technology. And using both of them, it is named 'bibliometric'\;or\;'scientometrics'. These analysis results answer emergence in science and technology and provide researchers, responsible persons, technological information specialists, and planners with useful value. Accordingly, the purpose of this research is to suggest schematized change aspects and new research directions hidden in bibliographical phenomenon of a paper in the science and technology field to science and technology researchers and policy planners. For this, the field this paper researche is the next generation OLED field. The reason to choose this field is due to the importance of the next generation OLED, and wide scope connected by various fields. Besides, to measure application and technological fields by using bibliographical method and technology is as important as in a basic research field.

• Safety and Health at Work
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• 제9권1호
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• pp.79-83
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• 2018

Background: Lower-limb varicose veins (VVs) are common and known to have a higher prevalence among people who work in occupations requiring prolonged standing. In the Republic of Korea, however, VV-related occupational factors have seldom been examined. This study was conducted to assess the prevalence of VVs among nurses, an occupational group considered to be at high risk of VVs, and determine the occupational risk factors of prolonged standing. Methods: Between March and August 2014, a questionnaire survey coupled with Doppler ultrasonography was conducted on the nurses working at a university hospital. Results: A total of 414 nurses participated in the survey and diagnostic testing. From the survey analysis and test results, the prevalence of VVs in nurses was estimated to be 16.18%. Significant factors for venous reflux were age [odds ratio (OR) = 1.06, 95% confidence interval (CI) = 1.03-1.10], pregnancy (OR = 2.15, 95% CI = 1.17-3.94), and delivery (OR = 2.02, 95% CI = 1.08-3.78). The statistical significance of these factors was verified after risk adjustment for sociodemographic factors (OR = 3.40, 95% CI = 1.27-9.09). Conclusion: Factors significantly associated with venous reflux were increasing age and prolonged working hours (${\geq}4hours$) in a standing position (OR = 2.80, 95% CI = 1.08-7.25), even after risk adjustment for sociodemographic factors. This study is significant in that an objective diagnosis of VVs preceded the analysis of the risk factors for VV incidence, thus verifying objectively that VVs are associated with occupations requiring prolonged hours of working in a standing position.