Investigation on chatter suppression effect with spindle speed variation

Soohyun Nam,Hyein Kim,Jaehyun Lee,Sung-Ho Nam,Kyung-Hee Park 한국생산제조학회 2024 한국생산제조시스템학회 학술발표대회 논문집 Vol.2024 No.4

Development of the light weight carbon composite tie bar

Nam, Soohyun,Lee, Dongyoung,Kim, Jinwhan,Lee, Dai Gil Elsevier 2015 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.134 No.-

<P><B>Abstract</B></P> <P>Stacks of energy conversion systems, such as proton exchange membrane fuel cells (PEMFCs), are composed of several hundreds of components, and they are compacted with tie bars to decrease electrical contact resistance and prevent the leakage of fuels. Since the sealing performance deteriorates over long operation times due to creep deformation of the stack, it is important to maintain a consistent clamping force under the creep deformation of the stack for long-term reliability.</P> <P>In this work, a light weight carbon composite tie bar was developed to replace the conventional steel tie bar. This new composite tie bar can achieve high elastic strain and provides a consistent compaction pressure to the stack over long operation time. To form the complex thread shape of the tie bar without compromising its tensile strength, different types of material were adopted for the thread and rod parts. A carbon fiber mat was used for the thread part because it has a higher drapability compared to other types of carbon fiber, such as unidirectional (UD) or the fabric type. The UD and fabric were adopted for the rod part for their high strength and elongation. Based on the tension test of the fabricated tie bar specimens, an optimum configuration of the carbon composite tie bar has been suggested.</P>

간호사가 경험하는 수평적 폭력이 간호사의 소진과 환자에 대한 공감에 미치는 영향: 의사소통의 조절효과를 중심으로

남수현(Soohyun Nam),황보영(Boyoung Hwang) 대한스트레스학회 2019 스트레스硏究 Vol.27 No.3

본 연구는 간호사가 경험하는 수평적 폭력이 간호사의 소진과 환자에 대한 공감에 미치는 영향에서 의사소통의 조절효과를 확인하기 위해 이차자료분석을 활용한 횡단적 서술연구이다. 일개 대학병원에 재직 중인 직원들을 대상으로 2019년 5월 20일부터 2주 간 온라인 설문조사를 통해 수집된 자료 중 직장에서 수평적 폭력을 경험한 간호사 211명의 자료를 위계적 다중회귀모형을 사용하여 분석하였다. 분석 결과, 의사소통의 조절효과는 수평적 폭력과 소진 간 관계에서 유의하게 나타났으나, 수평적 폭력과 환자에 대한 공감 간 관계에서는 유의하지 않았다. 따라서, 수평적 폭력으로 인한 간호사의 소진을 경감시키기 위해 의사소통 교육 프로그램을 개발, 활용하는 것이 필요하겠다. Background: Horizontal violence or lateral violence among nurses is a critical social issue given its global prevalence and frequency. In this study, we examined the effects of lateral violence on nurses’ burnout and empathy with patients by examining the moderating effect of communication in each relationship. Methods: This was a secondary analysis of data from a cross-sectional descriptive study, including a total of 211 registered nurses who had worked for more than six months at a medical institution in Seoul, South Korea. The data were collected between March 20, 2019 and June 1, 2019 using self-administered online surveys. Descriptive statistics and Pearson’s correlation coefficient were calculated, and hierarchical multiple regression analyses were performed. To test the moderating effect of communication, an interaction term was added to each model. Results: Communication negatively moderated the relationship between lateral violence and burnout. On the other hand, there was no significant moderating effect of communication on the relationship between lateral violence and empathy with patients. Conclusions: From these findings, we revealed the effect of communications between lateral violence and burnout. The higher the communication ability, the less the effect of lateral violence on burnout. Our findings highlight the importance of communication when developing interventions to reduce burnout in the presence of lateral violence.

인지행동치료 프로그램이 대학생의 지각된 스트레스와 신체 증상에 미치는 효과

남수현(Soohyun Nam),황보영(Boyoung Hwang) 대한스트레스학회 2017 스트레스硏究 Vol.25 No.3

본 연구에서는 스트레스로 인해 신체 증상을 호소하는 대학생들에게 인지행동치료 프로그램을 적용하여 지각된 스트레스, 신체 증상, 부정적 자동적 사고, 역기능적 태도에 미치는 효과를 검증하였다. 지방 소재 1개 대학교에 재학 중인 학생들 중 신체 증상 설문 총점 7점 이상인 대상자를 선별하여 참여를 원하는 집단을 선택하도록 하였다. 실험군(17명)은 매주 60분 간 총 5회기에 걸친 집단 중재에 참여하였고 대조군(15명)은 참여하지 않았다. 두 군간 결과변수의 전후 변화 차이는 반복측정 분산분석을 사용하여 분석하였다. 실험군의 지각된 스트레스, 신체 증상, 부정적 자동적 사고 점수의 중재 전후 변화량이 대조군의 변화량보다 유의하게 컸으나, 역기능적 태도 점수의 변화 양상은 실험군, 대조군 간 유의한 차이가 없었다. Background: The purpose of this study was to evaluate the effects a cognitive behavioral intervention on perceived stress, somatic symptoms, automatic negative thoughts and dysfunctional attitudes in college students. Methods: This was a quasi-experimental study with a nonequivalent control group design. Students who agreed to participate in the study and had a total score of 7 or greater on the Patient Health Questionnaire-15 were asked to choose one of the two groups to attend: Experimental and control groups. Students in the experimental group (N=17) received 5-weekly group sessions of the intervention, each of which lasted 60 minutes. The interventions were not provided to the control group (N=15). Students in both groups were asked to complete a set of questionnaires at baseline and five weeks. Descriptive statistics were calculated, and t-test, Mann-Whitney U test and repeated measures ANOVA were performed. Results: There was a significant interaction between time and group for perceived stress, somatic symptoms and automatic negative thoughts. Dysfunctional attitudes, on the other hand, were not significantly different by group. Conclusions: The findings showed that the intervention was effective for college students suffering from perceived stress and somatic symptoms. In particular, the significant decrease in automatic negative thoughts among students in the intervention group suggests that the effect of the cognitivebehavioral intervention was mediated by the cognitive factors of somatic symptoms.

Fabrication and factory acceptance test of ITER sector sub-assembly tool

Nam, Kyoungo,Bae, Jinho,Ha, Minsu,Jung, Sikun,Park, Soohyun,Jung, Wooho,Shin, Daewang,Moon, Jaehwan,Yang, Hyungyeol North-Holland 2019 Fusion engineering and design Vol.146 No.1

<P><B>Abstract</B></P> <P>An ITER Tokamak machine with a torus shape is composed of nine units of 40◦ sectors. The sector sub-assembly tool (SSAT) is dedicated assembly tool to integrate vacuum vessel (VV) sector, VV thermal shield (VVTS) segments, VVTS port shrouds, two toroidal field coils (TFC) and various intercoil structures into 40◦ sector. For the sub-assembly process of 40° sector, SSAT shall have sufficient strength to support and handle heavy components up to 1250 t. And fine alignment system to adjust components considering assembly tolerance should be designed and verified by appropriate means. Although the structural analysis and mock-up tests were completed, structural stability and alignment system should be verified through factory acceptance test with real component and system. In this paper, the factory acceptance test results of the sector sub-assembly tool including VV load simulation and partial load test of VVTS outboard (OB) sector frame will be presented to verify the structural assessment and adjustment of the component.</P>

Characterization and cDNA cloning of the purified novel antimicrobial peptide form sea urchin, Heliocidaris crassispina

Soohyun Park,Wonjeong Park,Hye Young Oh,Hye-jin Go,Anastasia Kubarova,Nam Gyu Park 한국수산과학회 양식분과 2022 한국수산과학회 양식분과 학술대회 Vol.2022 No.10

LSTM 구조의 순환 신경망을 이용한 음향 환경 분류

배수현(Soohyun Bae),이철민(Chul Min Lee),최인규(Inkyu Choi),김남수(Nam Soo Kim) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.1

A report of 28 unrecorded bacterial species, phylum Bacteroidetes, in Korea

Maeng, Soohyun,Baek, Chaeyun,Bae, Jin-Woo,Cha, Chang-Jun,Jahng, Kwang-Yeop,Joh, Ki-seong,Kim, Wonyong,Seong, Chi Nam,Lee, Soon Dong,Cho, Jang-Cheon,Yi, Hana The National Institute of Biological Resources 2018 Journal of species research Vol.7 No.2

In order to investigate indigenous prokaryotic species diversity in Korea, various environmental samples from diverse ecosystems were examined. Isolated bacterial strains were identified based on 16S rRNA gene sequences, and those exhibiting at least 98.7% sequence similarity with known bacterial species, but not reported in Korea, were selected as unrecorded species. 28 unrecorded bacterial species belonging to the phylum Bacteroidetes were discovered from various habitats including wastewater, freshwater, freshwater sediment, wet land, reclaimed land, plant root, bird feces, seawater, sea sand, tidal flat sediment, a scallop, marine algae, and seaweed. The unrecorded species were assigned to 18 different genera in five families: Flavobacterium, Epilithonimonas, Dokdonia, Gillisia, Flavicella, Chryseobacterium, Algibacter, Aquimarina, Lacinutrix, Gaetbulibacter, Cellulophaga, Tenacibaculum, and Maribacter of Flavobacteriaceae, Dyadobacter of Cytophagaceae, Draconibacterium of Draconibacterium_f, Sunxiuqinia of Prolixibacteraceae, and Fulvivirga of Fulvivirga_f. The selected isolates were subjected to further taxonomic characterization including analysis of Gram reaction, cellular and colonial morphology, biochemical activities, and phylogenetic trees. Descriptive information of the 28 unrecorded species is provided.

한우 거세 1<SUP>+</SUP>등급육의 대·소분할 부위별 일반성분, 무기질 및 비타민 조성

조수현(Soohyun Cho),최용민(Yongmin Choi),설국환(Kuk-Hwan Seol),강선문(Sun Moon Kang),Hoa Ban Va,김윤석(Yoon-Seok Kim),김진형(Jin-Hyoung Kim),성필남(Pil-Nam Seong),문성실(Sung-Sil Moon),서현우(Hyun-Woo Seo) 한국식품영양과학회 2021 한국식품영양과학회지 Vol.50 No.4

본 연구의 목적은 한우고기 거세 1<SUP>+</SUP>등급육의 10개 대분할과 37개 소분할 부위에 대한 칼로리, 일반성분, 비타민 및 무기질 조성을 조사하여 소비자들에게 부위별 기초 영양정보를 제공하고자 수행하였다. 10개 대분할육 간 비교에서 등심, 채끝, 양지와 갈비는 에너지 함량(288.17~336.41 kcal) 및 지방 함량(23.61~29.36%)이 다른 부위들보다 유의적으로 높았다(P<0.05). 단백질 함량은 우둔육(22.14%)이 가장 높았고 갈비(16.05%)가 가장 낮았다(P<0.05). 10개 대분할육에 포함된 각 소분할육 간의 특성 비교는 다음과 같았다. 대분할 등심육 내 살치살은 에너지, 지방, 콜레스테롤 함량이 유의적으로 가장 높았다(P<0.05). 대분할 우둔육과 설도육 내에서 단백질 함량은 보섭살과 설깃살이 다른 소분할 부위 보다 유의적으로 높았고, 지방 함량은 설깃머리살과 삼각살이 유의적으로 높았다(P<0.05). 대분할 갈비육 내에서 제비추리는 수분, 단백질, 회분 함량이 가장 높았고, 지방과 콜레스테롤 함량은 가장 낮았다(P<0.05). 철은 우둔(우둔살 2.64 mg), 설도(보섭살 2.87; 설깃머리살 2.75; 도가니살 2.86 mg), 양지(양지머리살 2.40; 업진안살 2.44; 치마살 2.46; 앞치마살 2.31 mg), 갈비(토시살 3.38; 안창살 3.25 mg)가 높았다(P<0.05). 티아민 함량은 설도육 0.062 mg으로 가장 많았고 리보플라빈 함량은 안심육이 0.231 mg으로 가장 많았다(P<0.05). 판토텐산 함량은 사태육이 2.89 mg으로 가장 높았다. 이러한 한우고기의 부위별 영양성분 분석 결과는 소비자들이 한우고기 섭취를 위한 부위 선택 시 유용하게 활용될 수 있을 것으로 생각된다. The objective of this study was to compare the nutritional composition (e.g., calories, vitamins, and minerals) of 10 primal cuts and 37 retail cuts of 1<SUP>+</SUP> grade Hanwoo beef. Out of 10 primal cuts, loin, striploin, brisket, and rib cuts had the highest energy (288.17∼336.41 kcal) and fat (23.61∼29.36%) content. Significantly lower and higher protein content was found in the ribs (16.05%) and top round (22.14%), respectively, compared to the other cuts in the 10 primal cuts studied. An analysis of the retail cuts in each primal cut showed that the chuck flap had significantly higher energy, fat, and cholesterol than the loin cut. While studying the top round and bottom round cuts, no significant variations were observed among the retail cuts in terms of the energy and cholesterol content but higher protein content was found in the rump (21.82%) and the outside round (21.50%) and higher fat content in the outside round head (13.81%) and the tri-tip (13.74%). In the rib cuts, the neck chain was higher in protein (21.13%) and lower in fat and cholesterol than the other retail cuts. Among the primal cuts studied, the top round (top inside round, 2.64 mg), bottom round (rump, 2.87; outside round head, 2.75; knuckle, 2.86 mg) and ribs (hanging tender, 3.38; outside skirt, 3.25 mg) had significantly higher iron content than the other retail cuts in the same primal cuts. A study of the vitamin content showed that the highest thiamin, riboflavin, and pantothenic acid levels were found in the bottom round (0.062 mg), tenderloin (0.231 mg), and shank (2.89 mg) among 10 primal cuts, respectively. These results would be helpful in selecting retail cuts of Hanwoo beef based on nutritional information.

University Students’ Perceptual Lecture Evaluation of Online Lectures During the COVID-19 Situation

Sangzo Nam,Soohyun Cho 한국콘텐츠학회 2022 International Journal of Contents Vol.18 No.1