• 한국생산제조학회지
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• 제21권6호
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• pp.871-877
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• 2012

New materials widely used for automobile related industry, aircraft, space development area are mostly high hardness materials. The hardness value of some hardened materials is over HRC45 and machining of this hardened materials is called as hard turning. Hard turning has its advantage on processing flexibility, cycle time and tool cost reduction. Also this process obtains high efficiency in processing and precise surface roughness through application of the CBN tools. In hard turning process with CBN tool, surface integrity is the important factor for considering the design of machine part and component under high stress and load conditions. A purpose of this study is to analyze optimal condition in hard turning process of AISI 52100 steel (HRC62) with high CBN and low CBN on turning characteristics, tool wear mechanism comparison and surface integrity.

• Tribology and Lubricants
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• 제18권3호
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• pp.228-234
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• 2002

Generally, space structures are subjected to severe situations, such as, sublimation, strong evaporation of lubricants, thermal stresses, high temperature gradients, irradiation, impacts by microscopic meteorites, and other factors. Recent]y, various kinds of coatings are applied to the parts under heavy contact stresses, in order to insure long wear-free lives and/or reduce friction coefficients. In space structures, molybdenum disulfide is using frequently. Moreover TiN, Al$_2$O$_3$, PTFE(Poly Tetra Fluor Ethylene) are introduced recently for space structure. In this part we are going to apply the partial model method, developed in reference[11] to analyze part with coated layer. In referencer[l1], we compute the reasonable size of partial model and aspect ratio. Using these data, we analyze the structures coated with TiN, Al$_2$O$_3$, PTFE under contact load, temperature and crack model . Beside, we consider the stress analysis under time dependent load and transient thermal effect.

• 한국표면공학회지
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• 제48권2호
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• pp.56-61
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• 2015

In this study, the wear performance of manganese phosphate coating on SM45C with addition agent of Tartaric acid and Citric acid were investigated. The Surface morphology of manganese phosphate coating was examined by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscopy (EDS). It is found that Mn, P, Fe, O and C. The crystal structure and thee composition was analysis and determined by using XRD. The XRD results indicated that manganese phosphate coatings are mainly composed of $(Mn,Fe)_5H_2(PO_4)_44H_2O$ and consists of a lot of close packed lump crystalline. Based on the time dependence of morphology and the weight of manganese phosphate coating, it shows that the phosphating process mainly includes three stages: corrosion of the substrate, creation and growth of phosphate crystal nucleus and thickening of manganese phosphate coating. The wear tests were performed in a ball on disc apparatus as per ASTM G-99 Standard. It was showed that the initial wear was quite high followed by low sludge.

• 한국정밀공학회지
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• 제18권8호
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• pp.107-115
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• 2001

Drilling torque was measured indirectly using the spindle motor current and controlled in real time through feedrate manipulation in a machining center. The PID controller designed in the previous paper was applied to drilling torque control. A series of cutting experiments were performed for various cutting conditions. Experimental results showed that the drilling torque was well regulated at a given reference level by feedrate manipulation in all cutting conditions. The increase in the cutting torque and temperature according to the increase in machining depth was suppressed and the risk of the drill failure and the drill flank wear were reduced remarkably through cutting torque control. Moreover, the suggested cutting torque control system doesn\`t disturb the cutting process and is practical for industrial environment. Therefore, the proposed culling torque control system will contribute to productivity improvement in drilling process.

• 한국의류학회지
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• 제29권9_10호
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• pp.1253-1264
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• 2005

The background, concept, and design characteristics of the Caports style, which comes into new domestic fashion trend of sportism, are discussed in this article. Analysis are performed with utilizing pictures, advertizements of fashion magazine such as Vogue Korea, Fashionbiz, Ceci, etc., and photographs from internet sites, domestic papers since 2002. The result of this study is as followings: New life style, arose from the change of social and cultural environment, such as increase in leisure time, fusion and well-being trend, begins to be reflected in caports style in the form of stress on utility and functionality. The caports style is a fusion style based on sports wear with character and fashion. And, it can be adapted as a sports wear and daytime wear. With respect to the form, it emphasizes healthy body line, and as for the material, it strikingly utilizes various and functional materials. It also shows active and cheerful image using bright color, and utilizes functional and decorative details such as line-tape, zipper, hood. The most important characteristic of the caports style is to present a new liberal style by mix & match, layering, and exposing

• 복식
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• 제57권8호
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• pp.75-88
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• 2007

Nowadays, geometrical form expressed on costume is recognizing as a part of modeling art, at the same time is working to develop it. Also the geometrical form is affording the coinciding lifestyle and sensitivity of customers keeping their pace. As a result, our study is researching on the geometrical form that is used in the pattern, silhouette, and detail of the costume to show the texture in sense of touch and the effect of optical illusion used in variable designs, in order to present the expansion our capability of infinite development included in the study of costume. Specially, geometrical form included in sports wear is very effective since the geometrical form includes short and simple beauty as well as practical design. Thus, this study is wishing to know if satisfying the practical and psychological urge of present human beings may be applied to the golf wear market, which is a type of sport that geometrical form is sent in the fastest way in domestic market. Also we are urged to know what type of design technique is the geometrical form nowadays used and changed to discriminate the artificial commerce and improve the identity of such unique brand. The source of this thesis is wishing to investigate the specialization and the most effective geometrical shape and preference of each type in domestic golf wear goods that applied geometrical goods in $2002{\sim}2006$ and analyze its way of expression.

• 한국의류학회지
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• 제44권6호
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• pp.1107-1119
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• 2020

This study analyzed a subject's body reaction and subjective sensation when wearing a gait-assistive rehabilitation robot. The research method measured skin and clothing surface temperatures for 'seating-standing' and 'walking in place' exercises after wearing a gait-assistive rehabilitation robot. In addition, subjective sensation and satisfaction were evaluated on a 7-point Likert scale. The study results showed that the average skin temperature during exercise while wearing the gait-assistive rehabilitation robot was within a comfortable range. However, during the 'seating-standing' exercise, the skin temperature was slightly lowered. Additionally, the clothing surface temperature tended to be lower than the pre-exercise temperature after all exercises. The subjective sensation evaluation results showed that the wear comfort of the waist part was low during mobility/activity. In addition, an overall improvement in the wear comfort of the robot is necessary. The short-time movement of wearing and walking in the gait-assistive rehabilitation robot did not interfere with the thermal comfort of the body. However, the robot needs to be ergonomically improved in consideration of the long wearing time along with improved material that to satisfy overall wearing comfort.

• 디지털콘텐츠학회 논문지
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• 제19권7호
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• pp.1225-1235
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• 2018

본 연구에서는 신체활동 모니터링이 가능한 스마트 의류와 연동되는 스마트 피트니스 콘텐츠와 관련하여 실용성을 갖춘 소비자 맞춤형 스마트 콘텐츠 개발 기획 연구의 일환으로, 타겟소비자의 잠재적 수요를 반영한 셀프트레이닝 지원용 스마트 피트니스 콘텐츠 개발의 구체적인 구현방향을 탐색하였다. 그 결과, 스마트 피트니스 콘텐츠에 대한 잠재적 수요는 시간 경과의 순서에 따라 '운동시작 전'의 단계에서는 '사용 접근성', '흥미유도', '다각적 스토리라인'의 범주어가 도출되었고, '운동수행 중'의 단계에서는 '실시간 음성코칭', '정확한 운동자세 모니터링', '개인 맞춤형 운동처방'이 도출되었다.'운동 직후'의 단계에서는 '실질적 보상제도', '등급제도', '체형변화 모니터링', '일상생활 모니터링'이 도출되었고, '다음 운동으로 연결'의 단계에서는 '동기유발', '높은 지속성' 이 도출되었다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1990년도 제11회 학술강연회초록집
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• pp.7-31
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• 1990

Tribologicsl diagnostics as the ensemble of means and methods of continuous monitoring of the state of friction characteristics of moving junctions is playing an ever important part in the development of friction, lubrication, and wear theory end practice. The scheme presenting the main areas of tribological diagnostics is given in Fig. I. This growing part of TD is determined by the general tendency of modern technology, expressed in an attempt to organically combine the functions of measuring, evaluating,and predicting the parameters and characteristics of the processee taking place in the operating device. The logical result of this integration in future is the closed system correcting its operation in accordance with sn established program. Unfortunately, tribotechnicsl devices are still very far from such an ideal system at the present time. While in the friction assemblies with hydrodynamic lubrication it is possible in the first approximation to realize feed-backs in the lubricant circulation system with the aid of monitoring of the pressure, temperature and filtration, in the systems operating without lubrication and with boundary lubricetion even the process of selection of the diagnostic parameters has not been completed.

• 한국안광학회지
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• 제20권1호
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• pp.43-49
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• 2015

목적: 콘택트렌즈 착용 경험이 있는 성인을 대상으로 콘택트렌즈 착용시간과 권장착용시간을 비교하여 올바른 콘택트렌즈 착용을 위한 자료를 제공하고자 한다. 방법: 콘택트렌즈 착용 경험이 있는 만 20세 이상의 성인남녀 611명(남성 39명, 여성 572명)을 대상으로 하였다. 일일 렌즈 착용시간, 착용 중인 렌즈의 종류, 일주일 중 렌즈 착용일수, 권장착용시간 인지와 준수여부를 설문하였다. 결과: 대상자의 일일 콘택트렌즈 착용시간은 평균 $7.97{\pm}3.60$ 시간으로 나타났다. 247명(40.4%)가 권장착용시간을 초과하여 착용하고 있었고, 36명(5.9%)은 일일 15시간 이상 착용하고 있는 것으로 조사되었다. 착용하고 있는 렌즈의 종류에 따른 착용시간은 3개월 착용 렌즈와 매일착용 렌즈가 각각 $9.79{\pm}2.68$ 시간과 $8.98{\pm}3.30$ 시간 이었다. 렌즈의 착용일수에 따라서는 주 5일 이상 착용하는 경우 평균 9시간 이상 착용하는 것으로 나타났다. 권장착용시간을 알고 있는 사람은 293명(48.0%), 모르는 사람 318명(52.0%)이었다. 권장착용시간을 알고 있는 사람의 56.7%가 착용시간을 준수한 반면, 모르는 사람은 22.3%가 착용시간을 준수하였다. 권장착용시간을 알면 권장착용시간을 지킬 확률이 4.55배 높았다. 결론: 콘택트렌즈를 착용하는 한국 직장인의 일일 평균 착용시간은 $7.97{\pm}3.60$ 시간(2~15시간)이며, 권장착용시간을 초과한 경우는 247명(40.4%)이었다. 권장착용시간에 대한 교육과 장시간 착용자에 대한 권고사항이 필요할 것으로 생각된다.