Effects of Pilger Rolling and Heat Treatment on Microstructure and Corrosion Resistance of Ag-electroplated 304 Stainless Steel Tubes

Hyun Park,Woo‑Jin Lee,Jae‑Han Son,Han‑Kyun Shin,Sung‑Kyu Hong,Hyo‑Jong Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

We introduce a cost-effective method that combines electroplating with metal cold working processes to manufacture compositetubes with robust corrosion resistance. First, a 3-step electroplating process was developed to form an adhesive anduniform Ag coating on the outer wall of a 304 stainless steel tube. The process consisted of a Ni-strike step for removing thepassivation layer of the initial 304 tube, Cu deposition for smoothing the surface by adding a buffer layer, and Ag deposition. To reinforce the interfacial adhesion between the electroplated layers and the 304 tube and increase the area of the Ag coating,a pilger rolling or pilger rolling + heat-treatment process was performed after the Ag electroplating process. Scanningelectron microscopy of the composite tubes after each process indicated that the as-deposited Ag coating changed fromhaving a rough to smooth surface after only pilger rolling and with additional heat treatment. Electron backscatter diffractionanalysis of the microstructures and textures of the tubes revealed that dynamic recrystallization occurred extensively duringpilger rolling, resulting in the formation of a relatively defect-free grain structure without heat treatment. Furthermore,electrochemical polarization curves determined that the Ag-coated composite tubes are superior to the uncoated 304 tubein terms of corrosion resistance under Cl−atmosphere, owing to the formation of a AgCl passivation layer during testing. Surface analysis of the composite tubes suggests that the properties of the AgCl passivation layer are related to the grainsize of the Ag coating and the density of plastic-deformation-induced defects.

The Functions of the English Utterance of Fighting! in Korean Discourse

Woo-hyun Jung 한국사회언어학회 2009 사회언어학 Vol.17 No.2

Jung, Woo-hyun 2009 The Functions of the English Utterance of fighting' in Korean Discourse The Sociolinguistic Journal of Korea 17(2). This study examines the functions of the English utterance, fighting', in Korean discourse, with special attention to how and when this expression is employed by Korean native speakers. To this end, this study collected data from naturally occurring situations and the scripts of some TV programs. The results showed that the expression, fighting', fulfills the primary function of encouraging the addressee, and that this pivotal function is extended to such functions as wishing; congratulating, thanking, promising, consoling, begging, and leave-taking, but not to as filling a pause. The findings of the study corroborated the widely-held claim that an utterance can fulfill plurivalent functions. The study also manifested other features fighting' can be verbalized, it can or cannot be responded, it can be employed reciprocally, and it can be used to highly value a thing as well as a person. These results will surely shed light on the study of discourse functional perspective of English loan-words in Korean discourse, thus, leading to a better understanding of the nativization of English into another language.

Transcriptome profiling of olive flounder responses under acute and chronic heat stress

Woo‑Jin Kim,이규빈,Dain Lee,Hyun‑Chul Kim,Bo‑Hye Nam,Hyungtaek Jung,이선주,Kyunghwan Kim 한국유전학회 2021 Genes & Genomics Vol.43 No.2

Background The olive founder (Paralichthys olivaceus) is a saltwater fsh, which is valuable to the economy. The olive founder strives to adapt to environmental stressors through physiological, biochemical, and transcriptional responses. The rise in water temperature threatens the growth, development, reproduction, and survival of olive founder. Each organ in the olive founder can diferentially respond to heat stress. Objectives The purpose of this study is to investigate organ-specifc transcriptional changes in olive founder tissues during heat stress. Methods In this study, transcriptome dynamics of the gill, liver, and muscle of olive founder to acute or chronic heat stress were investigated. Results Principal component analysis plotting revealed that the transcriptome of each organ is quite separated. K-means clustering, gene ontology, and Kyoto Encyclopedia of Genes and Genomes pathway analysis showed the diferential transcriptome responses of each organ to heat stress. Heat stress commonly afects the pathways involved in the correct protein folding, DNA repair, and cell cycle. Conclusion Our results may provide a valuable molecular basis of heat acclimation in fshes.

최대 칩두께를 이용한 쏘블레이드에서 칩핑과정의 역학적 모델링

김경우,김우순,최현민,김동현 한국공작기계학회 2001 한국공작기계학회 춘계학술대회논문집 Vol.2001 No.-

In order to establish the optimum process parameters and diamond saw blade composition for machining natural stone, the chip formation process and the wear process must be understood. Diamond saw blade is one of the most effective, versatile, and extensively used methods of processing rock and other hard materials, such as granite, marble, concrete and asphalt. For many years, it has been known that chip thickness is one of the most significant in the understanding of the sawing process, and other variables such as force and power have been correlated with it. In this study, mathematical relations of a material chipped by a single grit of the saw blade will be undertaken. The material chipping geometries have been mathematically defined and derived as maximum chip thickness.

순환식 운동프로그램이 대학 운동선수들의 전문체력 및 운동기능 향상에 미치는 영향

노동우(Noh, Dong?Woo),최현호(Choi, Hyun-Ho),이동준(Lee, Dong-Jun) 한국체육과학회 2019 한국체육과학회지 Vol.28 No.3

The purpose of this study was to investigate the effectiveness of elite volleyball players in improving their offense capabilities when combined with circuit training that improves their power and sense of balance that affects volleyball performance. In order to improve the power, agility and endurance of volleyball players, 10 volleyball players at M University were required to perform 13 moves twice a week in the six weeks after the league. As a results on the circuit exercise program, a significant improvement was shown in the extension-and-flexion muscular strength of the left, right pelvic limbs. Also, the back muscle strength and flexibility showed significant, sit-up to muscle endurance showed, side steps to agility were improved, standing height jumps, serve and spike speeds, which recognize the function of volleyball, showed a significant improvement after a circuit training program . These results suggest that the circuit exercise program will help improve the specific fitness and funcitional fitness of volleyball players.

스트라이프 패턴을 사용한 패션 디자인 이미지 분석 및 활용방안

정현 ( Jung¸ Hyun ),우주형 ( Woo¸ Ju Hyung ) 한국기초조형학회 2021 기초조형학연구 Vol.22 No.1

이 연구의 목적은 스트라이프 패턴을 사용한 패션 디자인의 이미지와 디자인 요소와의 관계를 분석하여 스트라이프 패턴 사용에 따른 특정 이미지의 디자인 전개를 위한 실질적인 아이디어를 제공하는 것이다. 연구방법은 2014년 S/S에서 2018년 S/S까지 패션 컬렉션에 등장한 패션 스타일 중 609점을 대상으로 8개 이미지 범주를 사용하여 패션 이미지를 분석하였고, 통계를 사용하여 디자인의 형태적 요소, 스트라이프의 표현요소, 배색 관계에서 패션 이미지와의 관련성을 도출하였다. 스트라이프 패턴 이 사용된 디자인의 이미지는 로맨틱, 모던, 에스닉, 매니시, 엘레강트, 아방가르드, 스포티, 클래식 순 의 빈도를 보였고, 패션 이미지와 디자인 요소의 연관성 분석, 즉 아이템, 도련 위치, 실루엣, 스트라이프 패턴의 선 방향, 선 모양, 반복 형태, 배색 관계 모두에서 패션 이미지에 따른 유의미한 차이가 발견되었다. 그 결과를 토대로 스트라이프 패턴을 사용한 패션 디자인의 이미지 활용방안을 제시하면 다 음과 같다. 로맨틱 이미지는 허벅지 길이의 X 실루엣 원피스 디자인에 고명도의 무채색과 유채색의 조합으로 이루어진 가로/혼합 방향의 선을 사용, 엘레강트 이미지는 풀렝스 원피스에 명도/채도차를 적게 둔 사선/혼합방향의 선, 클래식 이미지는 수트류에 저명도 중심의 전통적 선염 직물용 세로 방향 스트라이프를 사용, 모던 이미지는 간결한 원피스에 간격의 대비, 명도 차가 뚜렷한 무채색의 규칙적 인 세로 방향 스트라이프 사용, 매니시 이미지는 풀렝스 팬츠 아이템에 규칙적 세로 방향 스트라이프 사용, 스포티 이미지는 탑 & 팬츠/원피스 아이템에 채도차를 강조한 가로 방향 스트라이프 사용, 아방 가르드 이미지는 오벌 실루엣과 착시를 일으키는 불규칙적 반복/혼합 방향의 스트라이프 사용, 에스닉 이미지는 풀렝스 원피스에 가로 방향의 다양한 선들과 탁색조 중심의 멀티배색 등 시각적 복잡성을 강조하는 방향으로 활용하면 패션 이미지의 전달이 더욱 강화될 것으로 제안한다. The purpose of this research is to analyze the relationship between the image of fashion design using stripe patterns and design elements, and to provide practical ideas for the development of a specific image using stripe patterns. The research method was to analyze fashion images using 8 image categories targeting 609 fashion styles that appeared in the fashion collection from 2014 S/S to 2018 S/S. And the relationship between fashion image and formative elements of design, expressional elements of stripes, and color combinations was derived by statistical analysis. The fashion design image using stripe patterns among 609 fashion styles was used in the order of romantic, modern, ethnic, mannish, elegant, avant-garde, sporty, and classic. Significant differences were found according to the analysis of the relevance between fashion image and design elements, such as item, hem-line position, silhouette, line direction, line shape, line repetition, and color scheme. Based on the results, suggestions for utilization of the fashion image using stripe patterns are as follows. It can be enhanced that romantic image by X silhouette one-piece dress above knee-length using horizontal/mixed directional lines consisting of white and tinted color combination; elegant image by full-length dress using diagonal/mixed lines with similar value/saturation in colors; classic image by skirt/pants suits using traditional vertical stripes for yarn-dyed fabrics with low values in colors; modern image by simple one-piece dress using regular vertical stripes with clear intervals between lines and value contrast in achromatic colors; mannish image by full-length pants using regular vertical stripes; sporty image by pants/one-piece items using horizontal stripes with saturation contrast in colors; avant-garde image by oval silhouette items using irregularly repeated multi-directional stripes which cause optical illusion; and ethnic image by full-length one-piece dress using various horizontal lines such as zigzag with tone-downed multi-colors which cause visual complexity.

AC8A-T6 알루미늄 合金材의 切削加工 特性에 關한 硏究

최현민,김경우,김우순,김용환,김동현,채왕석 한국공작기계학회 2002 한국공작기계학회 추계학술대회논문집 Vol.2002 No.-

In this study, examined the cutting characteristics of alumuminum alloy AC8A-T6 that is used to present car piston materials. And in been holding materials machining empirically escape as result that experiment comparison changing the cutting speed and feed on various condition to choose efficient machining condition. The following results can be summarized from this research. 1.As the cutting speed decreased, principal cutting force and thrust cutting force is increased, and reason that cutting force interacts greatly in the low cutting speed is thought by result by BUE's stabilization. 2.The feed speed and cutting speed increase, friction factor is decrescent and the cause appeared the thrust cutting force is fallen than cutting force relatively because chip flow according to increase of the feed rate is constraint. 3.Though specific cutting resistance grows cutting area and the feed rate are few, the cause was expose that shear angle decreases by rake face of tool gets into negative angle remarkably as wear of a cutting tool or defect part of workpiece is cut. 4.Cutting speed do greatly depth of cut is slow, surface roughness examined closely through an experiment that becomes bad, and know that it can get good surface that process cutting speed because do feed rate by 0.1㎜/rev low more than 250m/min to get good surface roughness can.

수면량과 집중력의 상관관계

김병우,류지근,박우진,박계원,김미정,임지은,백대현,최재덕,최윤호,이가현,이관,김덕수 東國大學校醫學硏究所 2002 東國醫學 Vol.9 No.1

수면, 기억 그리고 학습의 연관성은 실제 매우 복잡하다. 많은 연구에도 불구하고 명확한 연구결과는 아직 없다. 우리는 이 연구에서 평소와는 달리 시험 전날 수면 변화 양상이 집중력에 어느 정도 영향력을 미치는지 알아보고자 하였고, 이를 이용해 효율적인 수면 관리를 할 수 있는 기초자료로 삼고자 하였다. 동국대 의대 본과 1학년생 중 지원자 30명과 본과 2학년생 10명을 대상으로 평상시 상태와 시험 직후 수면이 부족한 상태에서 각각 K-PES TEST를 실시하여 총 8항목에 걸쳐 암기력, 판단력, 단순반응의 변화정도를 검사하였다. 또 설문조사를 병행하여 결과에 영향을 미칠 수 있는 다른 인자들도 파악하였다. 수면량에 대한 부호 숫자 짝짓기(순간 판단력)을 검사한 결과, 인간의 최대 생리학적 기능은 꼭 수면부족에 의해 좌우되는 것은 아니다. 그러나, 수면감소는 피로를 증가시키고, 동기부여를 감소시키나 단, 새로운 사실을 학습하는 데에는 큰 영향을 끼치지 않는다. 즉, 수면부족으로 장시간 깨어있는 것은 정확성과 반응성을 떨어뜨린다. 흡연에 대한 부호 숫자 짝짓기(순간 판단력)을 검사한 결과, 니코틴의 수면에 대한 상호관계는 알려지지 않았고, 인간의 감정이나 의식, 인식에 영향을 주는 것으로 알고있지만, 장기적은 측면에서 흡연이나 알코올은 인식능력과 무관한 것 같다. 카페인에 대한 숫자 외우기(암기력)검사 결과, 카페인은 spacial selective attention에는 특별한 영향을 주지 않지만 지각과정이나 주의 집중에 큰 효과를 주며, 인간의 의식 수행에 긍정적인 효과를 준다. 즉 카페인은 활력, 혼란, 피로상태를 변화시키고 visual analog scales에서 휴식상태에 가까운 양상을 나타낸다. 또 48시간 동안 수면을 취하지 않은 사람에게 카페인은 집중력과 장시간의 좋은 기분을 유지하게 하였다. 그러나 규칙적, 비규칙적으로 먹는 사람간에는 인지수행력의 차이를 보이지 않으며 상용자에서는 상당한 내성이 보인다. 수면패턴에 대한 숫자 더하기(순간 판단력)검사 결과, 집중력은 수면패턴에 의해서도 영향을 받고, 수면패턴이 바뀌게 되면 순간판단력을 저하시킨다. This study was performed to evaluate relationship of sleep and attention, and to control sleep effectively. We conducted a K-PES test of 40 medical students. K-PES contains eight elements, for example, simple response, selective response, color pairing, OddEven discrimination, number addition, number-symbol matching, memory, right-tapping, left tapping. Through these, we tested changes of memory, judgement, simple response. And we conducted a questionnaire survey to exclude bias. Results are as follows. As a results of number-symbol matching test, we know that sleeplessness is not complete responsible for physiologic function for humans. But, decreased sleep increases fatigue and decreases motivation, but no influence on learning new materials. So, long term sleeplessness decreases precision and responsibility. As a results of number-symbol matching test on smoking, a relationship of nicotine and sleep is not certain. A point of view in long term period, smoking and drinking is not related cognition, even if we know that those influence mood, consciousness and cognition. As a results of memory work test on caffeine, caffeine does not influence spacial selective attention, but mainly does perception, attention and consiousness process. Namely caffeine changes energetic activities, chaos, fatigue states and shows resting state in visual analog scales In sleeplessness for 48 hours, caffeine produced attention and good mood for a long time. But, in case of cognitive process no significance shows in regular or irregular diet. Regular diet shows high resistance. As a results of number addition test on sleep patterns, seep patterns influence attention, changes of sleep patterns decrease a moment judgement.

내동정맥루술후의 수지운동이 동정맥루의 혈류와 개존에 미치는 영향

신현석,조원현,이성문,우성구,김현철 大韓脈管外科學會 1995 大韓脈管外科學會誌 Vol.11 No.1

국내 한의학 학술지에 발표된 동의보감 연구 현황 조사

한창현(Chang-hyun Han),박상영(Sang-young Park),권오민(Oh-min Kwon),안상영(Sang-young Ahn),안상우(Sang-woo Ahn) 한국의사학회 2009 한국의사학회지 Vol.22 No.2

Background : To understand Korean medicine it is crucial to first understand medical aspect of ‘DongUiBoGam’. It is also meaningful that it became one of the influential book even to posterity. Also based on the apprehension, we can take a view of development of Korean medicine led by ‘DongUiBoGam’. Objectives : This study aims to review the status, study field, specialist of DongUiBoGam. In the process, this review will grasp trends in this field of studies and will direct further researches into the right direction. Method : The computerized Korean databases were searched from their respective inceptions up to December 2008. The search terms used were ‘DongUiBoGam’ and random or Korean language terms related to DongUiBoGam. Several specialized journals were also manually searched for relevant articles. Result : Since the 2000s, DongUiBoGam papers in the Korean Literature is increased. Published 58 papers on The Korean Journal of Oriental Medical Prescription were more than the other journals. 58 papers published in The Korean Journal of Oriental Medical Prescription are the best in many areas related to Korean medicine. Most people have submitted papers related to DongUiBoGam was Woo-yeal Jeong. Conclusions : ‘DongUiBoGam’ research is conducted and current tendency and outlook for ‘DongUiBoGam’ is carried out focusing on several associations.