• Korean Journal of Applied Biomechanics
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• v.22 no.4
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• pp.421-428
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• 2012

The purpose of this study was to verify the effects of developed assisting wear which maximize trunk(back) muscle's stretch-shortening effect during backswing and downswing for increasing golf ball carrying distance. Design and fabrication of assistive wear were performed based on the results of analyzed data of trunk EMG activity from the golf drive swings of elite professional male golfers during back swing and downswing phases. After the prototype of wear was produced, surface EMG and Flight scope tests were conducted to verify the effectiveness of the wear for increasing distance to the professional golfers. Results indicated that wearing trial showed significant longer carry distance than the non-wearing trial(p<.001). The carry distance of wearing trial showed an average 229 m compared to the non-wearing trial, the average 225 m. The swing with wearing also produced significantly faster ball speed than the trial without wearing(p<.05). Average 245 Km/h and 244 Km/h were produced for the swing with and without wearing trails, respectively. EMG results also indicated that the muscle activity of left psoas was significantly increased for wearing trial during downswing and near the impact. Thus, this may affect positively to increase club head speed. The activity of the left latissimus dorsi was dramatically increased during the final stage of swing. This generates elongation effect for longer follow-through and increased impulse between club and ball so eventually valid assistance to increase carry distance. Therefore, the developed assisting wear was proved to be effective tool for increasing golf ball carry distance with maximizing trunk(back) muscle's stretch-shortening effect during backswing and downswing.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.415-420
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• 2005

Korea High Speed Railway of which wheels have been excessively worn during the trial operation prior to opening was additionally applied with solid lubricant besides the existing oil lubricant in order to overcome such excessive wear. Therefore, it was shown that wear status has been improved in the test by which railway system including vehicles and tracks was stabilized during a year's commercial operation, comparing to that with excessive wear in the trial operation prior to opening to the public. In this connection, wheel's wear per mileage was analyzed, based on vehicles in service in order to make out the wheel's wear at present, from which the useful data relating to wheel maintenance could be obtained.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.11
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• pp.1369-1380
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• 2005

This study suggests a strategy of providing apparel product information from the wearers' perspective on Internet shopping malls, as a way of compensating for the lack of opportunities to try on the actual product. On an actual Internet shopping mall that sells apparel product, the 'trial-experience information' (the experiential information provided by the fit models who tried on the products) was provided for 83 different items from four women's wear brands. The traffic and sales performances (number of visitors, page view, gross sales of goods, conversion rate, and the numbers of customer transactions) of the apparel product websites that contain trial-experience information were compared to the performances of the brand's websites before this information was implemented. The changes in percent contribution of these brands in women's wear category were also noted. The specific results are as follows: First, all the four performance measures as well as the percent contribution of the experiment products in women's wear category increased noticeably throughout the experiment period (11 to $103\%$). Second, when the percent contribution of these brands in women's wear category in terms of traffic and sales performances were compared to the previous year, these measures increased between $497\%\;and\;2851\%$. Third, the amount of customer transactions also increased after the trial-information was provided, yet to a relatively smaller extent $(29.04\%\;to\;55.25\%)$. The findings showed that trial-experience information provided on the Internet shopping malls may reduce customers' risk perception and lead to increased sales of apparel product and improve the site use ratio.

• Journal of the Korean Society for Railway
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• v.8 no.5
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• pp.477-482
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• 2005

Through a year's commercial operation, Korea High Speed Railway has solved defectives from several breakages at the beginning and is going into the stage of stable operation. Among issues, wheel wear becomes a matter of primary concerns in view of vehicle's stability and maintenance. It was understood as above that wear status has been improved in the test by which railway system including vehicles and tracks was stabilized during a year's commercial operation, comparing to that with excessive wear in the trial operation prior to opening to the public. To make out wheel's wear status and characteristics of equivalent conicity at present when the service has been introduced a year ago and the average cumulative mileage of vehicles reach almost 500,000km, wheel's wear types were analyzed with the current vehicles in service.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.207-215
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• 2004

There are various characteristics called for in work roll and intermediate rolls for cold rolling mills. Among these characteristics, the two main requirements are to ensure the quality of the rolled products and to reduce roll cost. To achieve these needs, resistance to wear, to thermal shock and to contact fatigue are especially important. This paper describes that new material(named DSR1) for intermediate rolls which greatly increases rolling campaign and improves resistance to wear has been developed. DSR1 was successfully manufactured and has been used in the cold rolling mill. It showed that Trial product was homogenous in hardness distribution and sufficient usable diameter. Also in service test, trial product is much more excellent rolling performance than conventional $5\%Cr$.

• The Korean Journal of Community Living Science
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• v.27 no.3
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• pp.419-435
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• 2016

The purpose of the present study was to suggest the design requirements for Korean naval duty uniforms by evaluating the physiological and psychological comfort while wearing the uniforms. Two sets of wear trials were conducted with summer uniforms(eight young males) and winter uniforms(seven other young males). The summer wear trial consisted of 10-min rest, 60-min exercise, and 10-min recovery at an air temperature($T_{air} $) of $33^{\circ}C$ and 62%RH, followed by 10-min recovery at a $T_{air} $ of $23^{\circ}C$ and 64%RH(total 90 min). The winter wear trial consisted of 20-min rest at $T_{air} $ $20^{\circ}C$ and 55%RH, 25-min rest, 30-min exercise, and 35-min recovery at a $T_{air} $ of 0oC and 43%RH(total 110 min). Rectal and seven skin temperatures, clothing microclimate, heart rate, oxygen consumption, total sweat rate, and subjective perceptions were measured during the wear trials. By evaluating the experimental results from the wear trials, we extracted the following psycho-physiological design requirements to improve the current Korean naval uniforms: (1) It is important to maintain the skin temperatures within their comfort range, which depends on the body region (higher than $30^{\circ}C$ in winter, but less than $35^{\circ}C$ in summer). (2) In summer, the feet should be protected from the high heat of the ship floor surface. (3) In summer, sweat from the back should be sufficiently absorbed and allowed to dry quickly.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.1
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• pp.11-21
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• 2009

It is remarkable that the children's wear market has been growing instead of declining birth rate. The parents are willing to pay more when they find children's wear of better design and improved quality. For better quality, it is necessary to research on the pattern making of children's wear. After the interview with the 10 leading children's brands, we found that they develop individual design pattern based on each items middle block pattern which characterize the brands design line. Most frequently used middle block is for casual pants. Through interview with pattern designers, comparative study of patterns drafting methods, wearing test of trial garments and altering and adjustment of patterns, we developed the casual pants block pattern for 7 years old boys.

• Korean Journal of Human Ecology
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• v.12 no.2
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• pp.253-263
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• 2003

The purposes of this study were to find out an evaluation scale that could predict wear comfort and to investigate the effect of the skin-contacting fiber type on the subjective sensation and microclimate. Sensorial evaluation was basically followed by the Human Perception Analysis (HPA) interviewing 144 consumers. Sixteen female subjects were participated in the sleeve wear test with and without wearing vapor permeable water repellent outerwear. Experimental sleeves were constructed using the same double knit by turning inside out to control other material effects except the skin-contacting fiber type, hence each different side of double knit, cotton side and the cotton/polypropylene blend side, was next to skin in each trial of the experiment. As results, it was noted that the term representing a combined feeling of thermal and wetness sensation, and muggy appeared to be a powerful language to measure perceptual responses of human subject among five dimensions of evaluation. although the ordinary users did not use the term very often. As for the comfort properties of double knits, it seemed that subjects slightly more preferred polypropylene/cotton blend to cotton as the skin-contacting fiber type when they wore outerwear and their skin were covered with sweat, although the result was rot statistically significant and need to be confirmed under higher work load.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.16-21
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• 2002

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation fer the HMC is not sufficiently performed and the efficient cutting conditions aren't selected, a great loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented from the analysis of acceleration in idling. The Machinability fur the TiAlN coated flat end mill and STD11( $H_{R}$C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions and slenderness ratio and a low response of tool dynamometer in high speed is proved. The resonance spindle speed is identified through the tool wear and natural frequency test.t.

• Transactions of Materials Processing
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• v.11 no.2
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• pp.165-170
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• 2002

The preform design of forging processes plays a key role in improving product qualities, such as defect prevention, dimensional accuracy and mechanical strengths. In the industry, preforms are generally designed by the iterative trial-and-error approach, but it results in significant tooling cost and time. It is thus necessary to minimize lead-time and human intervention through an effective preform design method. In this paper, the equi-potential lines designed in the electric field are introduced to find the preform shape, and then the optimization process is used to choose the equi-potential lines that will keep the die wear to a minimum Because, in the forging process, the die wear is a function of various important factors, such as forming stress and strain, microstructure and mechanical properties of a Product.