• Tribology and Lubricants
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• v.39 no.3
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• pp.118-122
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• 2023

In our study, we develop a finite element model based on Archard's wear law to predict the cumulative wear and the evolution of the tool profile in friction stir welding (FSW) applications. Our model considers the rotational and translational behaviors of the tool, providing a comprehensive description of the wear process. We validate the accuracy of our model by comparing it against experimental results, examining both the predicted cumulative wear and the resulting changes to the tool profile caused by wear. We perform a detailed comparison between the predictions of the model and experimental data by manipulating non-dimensional coefficients comprising model parameters, such as element sizes and time increments. This comparison facilitates the identification of a specific non-dimensional coefficient condition that best replicates the experimentally observed cumulative wear. We also directly compare the worn tool profiles predicted by the model using this specific non-dimensional coefficient condition with the profiles obtained from wear experiments. Through this process, we identify the model settings that yield a tool wear profile closely aligning with the experimental results. Our research demonstrates that carefully selecting non-dimensional coefficients can significantly enhance the predictive accuracy of finite element models for tool wear in FSW processes. The results from our study hold potential implications for enhancing tool longevity and welding quality in industrial applications.

• Journal of the Korea Fashion and Costume Design Association
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• v.20 no.1
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• pp.125-136
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• 2018

This study classified and analyzed the assignments for the Hanbok skill contests between 1998 and 2017 so that the Korean hanbok can be properly passed down. this study proposes a variety of useful values for the Hanbok culture industry by providing basic data on various Hanbok making techniques to the Hanbok artisan. The results of the analysis of 39 assignments for the Hanbok skill contest are as follows. Firstly, The 20 assignments presented in the Local Skills Competitions consisted of 13 tasks (65%) in formal wear and 7 tasks (35%) in casual wear. Formal wear is mainly comprised of men's and children's wear (85.7%). There are Pungcha Baji, Sagusam, Kkachi Durumagi, Jeonbok & Bokgeon, Durumagi, and others on the formal wear of men'schildren's wear. In casual wear, 66.7% of women's wear such as scarves, skirts, jeogori, Hwejang Jeogori & chima were on the list of assignments. Secondly, All of the 19 assignments presented in the National Skills Competitions were in adult suits. Thirteen tasks (68.4%) were in formal wear and 6 tasks (31.6%) were in casual wear. Nine out of the 13 formal wear tasks (69.2%) were men's clothes. In 6 assignments of the casual wear, men's and women's clothes were presented three times each. Formal wear that had many assignments was the men's Chulik, which was presented three times in 2006, 2008 and 2016. Thirdly, Eighteen (90%) of the 20 assignments presented at the Local Skills Competitions were for lined clothes, and the remaining 2 (10%) were for unlined clothes. Eleven tasks (57.9%) out of the 19 assignments presented in the National Skills Competitions were for lined clothes, and 8 tasks (42.1%) were for unlined clothes.

• International Journal of Costume and Fashion
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• v.4
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• pp.21-45
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• 2004

The rapid development of science technology during the 20th century has greatly lowered the hours for labour, thus giving members of society extra time for leisure. With the increasement of leisure activities, sports casual wear has become one of the foremost leading items in the fashion industry, and among such sports casual, down wear has become the F/W season's most popular item. Because it generates high profits, many recognize it as a very important factor in lady's wear. Since the 1990's, down wear was widely applied to various sections of lady's, men's, and children's wear, and it has ceased to be limited to sports casual only. The purpose of this study was to fully understand the characteristics of down, and to develop crossover garments design desired not only in the F/W season but also the S/S season. It has been taken into consideration that many restrictions in sewing technique and material selection in manufacturing down as a fashion product exist when choosing a means of manufacture. That was why this study focused on the history and characteristics of down while analysing the works of domestic and foreign designers to concretely applicate them in fashion products. This study has divided the resulting down wear products according to consumer preference： vest, jacket, coat, one-piece, and skirt to applicate design manufacture of lady's wear in general, while designing and making artistically expressed down wear. There were 48 works developed as a result of this study, of which 41 were ready-to-wear, and the remaining 7 works were creative art wear.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2581-2589
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• 2002

In this research, fretting tests were conducted in air to investigate the wear characteristics of fuel cladding materials with the fretting parameters such as normal load, slip amplitude, frequency and the number of cycles. A high frequency fretting wear tester was designed for this experiment by KAERI. After the experiments, the wear volume and the shape of wear contour were measured by the surface roughness tester. Tribologically transformed structures(TTS) were analysed by means of optical and scanning electron microscopes to identify the main wear mechanisms. The results of this study showed that the wear volume were increased with increasing slip amplitude, and the shape of wear contour was transformed V-type to W-type. Also, it was found that the critical slip amplitude was 168${\mu}{\textrm}{m}$. These phenomena mean that wear mechanism transformed partial slip to gross slip to accelerate wear volume. The wear depth increased with an increase of friction coefficient due to increase of normal load and frequency. The fretting wear mechanisms were believed that, after adhesion and surface plastic deformation occurred by relative sliding motion on the contact between two specimens, TTS creation was induced by surface strain hardening and wear debris were detached from the contact surface which were produced by the micro crack propagation and creation.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.296-303
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• 2001

In nuclear power steam generators, high flow rates can induce vibration of the tubes resulting in fretting wear damage due to contacts between the tubes and their supports. In this paper the fretting wear tests and the sliding wear tests were performed using the steam generator tube materials of Inconel 690 against STS 304. Sliding tests with the pin-on-disk type tribometer were done under various applied loads and sliding speeds at air and water environment. Fretting tests were done under various vibrating amplitudes, applied normal loads and various temperatures. From the results of sliding and fretting wear tests, the wear of Inconel 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and often drastically different wear rates can occur. At room temperature, the wear coefficient K of Inconel 690 is 7.57${\times}$10$\^$13/Pa$\^$1/ in air and it is 1.93${\times}$10$\^$13/Pa$\^$1/ in water. At room temperature, it is found that the wear volume in air is more than in water. In water, the wear coefficient K at 50$^{\circ}C$ and 80$^{\circ}C$ is 4.35${\times}$10$\^$-13/Pa$^1$ and 5.81${\times}$10$\^$-13/Pa$^1$ respectively, Therefore, it is found that the wear volume extremely increases by increasing on temperature in water. This study shows that the dissolved oxygen with temperature increment increases and the wear due to fluidity is severe.

• Journal of the Korea Fashion and Costume Design Association
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• v.26 no.1
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• pp.45-60
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• 2024

This study analyzes the athleisure wear purchase status, wearing conditions, and design preferences of men in their 20s and 30s and provides basic data for the development of men's athleisure wear that reflects consumer preferences. An online survey was conducted on 200 men from August 23 to August 27, 2023. The questionnaire consisted of a total of 48 questions, including 8 questions about the respondent's general information, 19 questions about the purchase status of athleisure wear, 6 questions about the status of wearing athleisure wear, and 15 questions about athleisure wear design preferences. The survey results are as follows. The most common motive for exercise participation was 'maintaining health.' 'Nike' was the most preferred and purchased brand among athleisure wear brands, and the main place of purchase of athleisure wear was 'Internet and mobile shopping malls', reflecting the recent purchasing trend of the MZ generation. When purchasing athleisure wear, the most common selection criterion was 'design', followed by 'fitting comfort', 'possibility to use as daily wear', and 'price'. The most common route to obtain purchase information was 'Internet search', and the 'overall satisfaction' with athleisure wear was found to be satisfactory with an average of 3.83. The most common reason for wearing athleisure wear was 'because it is comfortable to do activities', followed by 'because it can be used as everyday wear'. Lastly, 'black', 'short-sleeved t-shirt', 'short length' sleeve, 'round neckline', 'waist length', and 'relaxed loose fit' were preferred for the top design, and 'black', 'shorts', 'full elastic type' waistband, 'regular fit that fits the body well' were preferred for the bottom design.

• 한국기계연구소 소보
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• s.19
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• pp.69-79
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• 1989

Cutting tool life monitoring is a critical element needed for designing unmanned machining systems. This paper describes a tool wear measurement system using computer vision which repeatedly measures flank and crater wear of a single point cutting tool. This direct tool wear measurement method is based on an interactive procedure utilizing a image processor and multi-vision sensors. A measurement software calcultes 7 parameters to characterize flank and crater wear. Performance test revealed that the computer vision technique provides precise, absolute tool-wear quantification and reduces human maesurement errors.

• Proceedings of the KWS Conference
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• 2001.05a
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• pp.245-247
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• 2001

In this study, the effects of dilution on the wear behavior of PTAW (Plasma Transferred Arc Welding) Inconel 625, Inconel 718 and Stellite 6 overlays on Nimonic 80A were investigated. Inorder to evaluate the wear performance, two-body and three-body abrasive wear test, and dry sliding wear test were performed. According to wear tests, the wear rate of deposit with dilution 30% was higher than that of dilution 10% by 10%, and it was also found the plastic deformation near worn surface.

• Tribology and Lubricants
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• v.16 no.5
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• pp.357-364
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• 2000

In this study, the sliding wear in spur gears, using Archard's wear model, is analyzed. Formulas of tooth sliding wear depth along the line of action are derived. The tooth profile is modified Id make a smooth transmission of the normal loads and the cylinder profile for reducing the pressure spike is suggested. The sliding wear rate is calculated with these profiling results. We expect these modification methods to contribute to the reduction of sliding wear not only in the root, but the tip of tooth and tooth edge.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.04b
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• pp.126-132
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• 1996

A laboratory scale hot strip rolling wear simulator(HRWS) was developed for the purpose of investigating the tribological phenomena occurred in production hot strip rolling mills. The HRWS' main parts are the electric heater, the mechanical descaler, tandem type 2-4Hi rolling mill stands, the cooling chamber, the tension controller and coiler. By simulating the tribelogical phenomena in rolling process at laboratory, wear patterns, cracks, cat-ear wear, black film, effect of hot rolling oil lubrication, etc. were reproduced, and discussed on the performace of simulator.