• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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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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• v.18 no.3
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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.

• Journal of the Korean institute of surface engineering
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• v.48 no.2
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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.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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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.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.9_10 s.146
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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

• Journal of the Korean Society of Costume
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• v.57 no.8
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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.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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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.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1225-1235
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• 2018

In this study, as a part of practical and customized smart contents development planning research related to smart fitness contents associated with smart wear that can monitor physical activity, we investigated the potential needs for smart fitness contents through research. As a result, the potential needs for smart fitness contents is 'accessibility to use', 'inducement of interest', 'diverse story line' were derived at the stage of 'before exercise', 'Real - time voice coaching', 'accurate exercise posture monitoring', and 'personalized exercise prescription' were derived at the stage of 'during exercise'. At the stage of 'after exercise', 'substantial reward system', 'grading system', 'body figure change monitoring' and 'everyday life monitoring' were derived. At the stage of 'connection to the next exercise', 'triggering exercise motivation', 'high sustainability' wear derived.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1990.06a
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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.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.1
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• pp.43-49
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• 2015

Purpose: This study was to compare the habitual soft contact lens wear to recommended wearing schedule for subjects and suggest a clinical guideline for prescribing contact lens. Methods: 611 adults (39 men and 572 women) with contact lens experience took part in this study. The survey collected information about current wearing schedule (hours/day and days/week), types of lenses worn and awareness of recommended wear schedule. Results: The subjects wore the daily contact lens for $7.97{\pm}3.60$ hours/day in average. Of these, 247 subjects (40.4%) exceeded the recommended wear schedule and 36 (5.9%) wore for over 15 hours. It turned out that subjects with 3-month extended contact lenses and the ones with the conventional daily wear wore for $9.79{\pm}2.68$ hours and $8.98{\pm}3.30$ hours/day, respectively. For subjects wearing contact lenses longer than five days/week it tended to wear for over 9 hours. Those who were aware of the wear schedule were 293 (48.0%), and those not were 318 (52.0%). 56.7% of subjects who were aware of the wear schedule respected the recommendation whereas only 22.3% of those unaware of it were found to respect it. The possibility to respect the wear schedule was 4.55 times higher when wearers were aware of it. Conclusions: Korean office workers wearing contact lenses wore for $7.97{\pm}3.60$ hours/day. 247 (40.4%) of subjects wore contact lens longer than recommended wear schedule. This implies that it will need to educate contact lens wearer about recommended wear schedule and advice for the long time wearer.