• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.184-188
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• 2008

It has been recognized that friction coefficient decreased with decreasing viscosity of oil in lubrication. In general, the more viscosity decreases, the more wear rate increases due to decrease load carrying capacity. It has been proposed that nano particles in oil decrease friction coefficient and wear rate. The purpose of this study is to apply oil of lower viscosity that mix with nano particles at the compressor used in a refrigerator to decrease friction coefficient keeping Load carrying capacity. Mineral oil of 8 cSt were used and mixed with nano particle. Friction coefficient was evaluated by a disk-on-disk tester. As a result, friction coefficient of nano oil decreased by 90% in comparison with raw oil. These results lead us to the conclusion that nano oil is new plan to raise efficiency of the compressor.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.194-202
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• 2008

In this study, we investigated the tribology behaviour of two different bearing materials. One of these alloys content is Cu(90)-Sn(10) alloy and is widely used in the automotive industry.The other is Al alloy. This bearing content is Al-Sn-Si-Cu. Therefore, it is required to study on the lublicating characteristics of bearing according to different materials. In this study, compressor bearings made by respectively "PTFE solid lubricant" and "AI alloy with superior load carrying capacity, rubbing and impact endurance", have gone through journal bearing test. Lubrication and abrasion characteristics are evaluated by analyzing the material characteristics of a scroll compressor bearing bush. The AI alloy bearing showed the most excellent lubrication and abrasion characteristics than Cu-Sn alloy under high load condition.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.292-297
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• 2008

Various types of refrigerators become popular in the market such as a common refrigerator, kimchi refrigerator and wine cellar. It is required to develop a multi function refrigerator which has different purposes in each evaporator. In this study, the performance of a multi type refrigerator system, which consists of one machine room and three evaporators, was measured in a bench type multi refrigerator. The multi type refrigerator system was tested by varying the number of refrigerator cabinet, refrigerant charge amount, temperature condition. Based on experimental data, the multi type refrigerator showed better performance than the conventional refrigerator(single type) At the same external load condition, the COP of the multi type refrigerator was $1.22{\sim}1.29$, but the COP of the single type refrigerator was 1.0.

• Proceedings of the Korean Reliability Society Conference
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• 2005.06a
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• pp.339-348
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• 2005

In evaluation of electronic reliability on the PCB(Printed Circuit Board),electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs In the environment of the high humidity and the high temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water drop acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity o of electrochemical migration depended on the temperature of water and the electrolyte quantity which included in the various waters.

• The korean journal of orthodontics
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• v.49 no.2
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• pp.116-123
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• 2019

As an alternative to the conventional fixed appliance that uses orthodontic brackets, a simple round tube without a bonding base can be bonded to the tooth surface by covering the tube with flowable resin. In this technique, bent wires cannot be inserted into the simple tubes; therefore, repositioning of the simple tubes is often required for adjustments. To reduce repositioning of simple tubes, a dome-shaped resin covering of the simple tube can be designed with a customized in-and-out compensation, using three-dimensional computer-aided design software based on digital simulation of orthodontic tooth movement. In the present case, the use of simple tubes bonded with customized resin coverings in a Class I nonextraction case is described in a 17-year-old male, in whom moderate crowding of the anterior teeth was treated over an 8-month period. This case shows that simple tubes can be used as an alternative to brackets in some Class I nonextraction cases, with the potential benefit of reducing decalcification.

• Journal of Intelligence and Information Systems
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• v.29 no.4
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• pp.395-413
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• 2023

This research studied the effect of customer experience characteristics in offline home appliance stores on perceived value and revisit intention. Among the offline distribution of home appliances with more than 100 stores nationwide, two home appliance retailers (HiMart, E-Land), three hypermarkets (E-Mart, Homeplus, Lotte Hi-Mart), and two home appliance stores (LG Best Shop, Samsung Digital Plaza) were selected, and a survey was conducted on men and women in their 20s or older in Seoul, Gyeonggi, and Incheon who had visited and purchased the home appliance store within the last 6 months. As a result of the survey, a statistical analysis was conducted on a total of 330 samples using the PLS (Partial Least Squares) structural equation model and SPSS statistical package. Through this study, the following research results can be obtained. First, educational experience, deviant experience, and aesthetic experience had a positive (+) effect on the functional value. However, entertainment experience did not affect functional value. Second, educational experience, deviant experience, and aesthetic experience all had a positive (+) effect on emotional value. Third, both functional and sensory values had a positive (+) effect on the revisit intention. Fourth, it was confirmed that brand loyalty had no moderating effect between functional value and sensory value revisit intention. The results of this study show the structural relationship between customer experience characteristics, perceived value (functional value, sensory value), and revisit intention. This result provides guidelines on what activities home appliance offline stores should do at a time when online channels threaten the survival of offline channels.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.413-416
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• 2003

본 연구에서는 백색가전 제품의 특성에 맞는 임베디드 시스템 플랫폼 디자인을 제안한다. 프로세서는 최근 더욱 각광을 받고 있는 ARM 계열의 디바이스를 사용하였으며 운영체제는 임베디드 시장에서 급부상하고 있는 리눅스를 대상으로 한다. 본 연구는 백색가전 제품군 전체를 대상으로 하고 전자레인지를 이용하여 시제품을 구현하였다. 특히 백색가전은 제품의 특성상 제조원가에 민감한 제품이므로 메모리 등 시스템의 자원 사용을 최소화하여 제조원가를 낮추는 방향으로 디자인의 방향을 정해야 한다. 하드웨어 비용은 현실적으로 거의 시장에서 정해진 비용의 범주를 크게 벋어나지 못하겠으나 소프트웨어의 크기는 접근하는 방법에 따라 차이가 날 수 있다. 이에 본 논문은 가능한 탑재될 리눅스의 커널 크기를 줄이며 파일시스템 및 기타 라이브러리의 크기를 최소화하여 백색가전에 적합한 플랫폼을 제시하는데 주목적이 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1104-1113
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• 2007

As there have recently been a rapid development in a supercomputer network infrastructure and an increase in the use of wireless terminals such as a PDA and cellular phone, people realize that it is highly required that they develope a various types of application services to integrate wireless network and engage them. On top of that, because current appliances are being converted into digital domestic appliances, and network and such appliances react upon each other, domestic appliances are now evolving to Internet appliances. Thus, people eager to establish a home network, which can offer a various sorts of services to customers because such appliances can share and send the data when such appliances are connected to power lines, telephone wires, and IEEE1394. Along with this, people are also enthusiastically conducting a study on Internet Application, which monitor and control the internet appliances triggered by connecting home network and supercomputer network. This study focuses on designing and developing an integrated wireless home server by effectively integrating wire and wireless network: It can approach and control each internet appliance connected with the home network inside and outside the house. In this study we also test it with an internet appliance simulator.

• The korean journal of orthodontics
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• v.28 no.6 s.71
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• pp.905-914
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• 1998

The goals of this study were to present presurgical naso-alveolar molding (PNAM) appliance in unilateral cleft lip and palate treatment and to evaluate the effects of PNAM appliance on alveolar molding. Samples were consisted of 4 unilateral cleft lip and palate infants (3 males and 1 female, mean age=23.2 days after birth) who were treated with PNAM appliances in Department of Orthodontics, Seoul National University Dental Hospital. Average alveolar cleft gap between the greater and lesser segment was 8.27mm and average duration of alveolar molding treatment was 9.7 weeks. These patients' models were obtained at initial visit (T1) and alter successful alveolar molding (T2). Seven linear and five angular variables were measured by using photometry and digital caliper. All statistical analyses were performed by SPSS win ver. 7.5 program. Paired t-test was used to compare the mean values. 1. The posterior part of alveolar segments are the stable structures during alveolar molding treatment period in infants. 2. Forward growth of the greater segment may be hindered by the action of alveolar molding. 3. The closure of cleft gap during alveolar molding were usually due to inward and backward bending of the anterior part of the greater segment and outward bending of the whole lesser segment.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.389-395
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• 2020

This study is about finding effects of home appliances to home furnishing. Recently, home appliances go beyond smart by technology development to show design integrated with furniture. Accordingly, this study is First, from the perspective of home furnishing, I examined the meaning of living space for millennial. Second, I investigated home appliances that recently released for millennial, and analyzed appliances trends, focused on product concepts and styling keyword. Third, conducted in-depth interview focusing on four parts : meaning of space, experience of home- furnishing, appliance and interior, feeling of current appliances. Research has shown that design considered space relevance can make home appliances the main of interior. Future studies will need to validate quantified statistical data. Through this study, I hope that will help to set the role and design direction of home appliances in the future.