• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.487-488
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• 2015

New inverter motor drive systems consume 30%~50% less energy compared to existing motor drive systems. For inverter motor drive systems, the development of a 1200V high side driver is critical. This paper presents an advanced 1200V high side driver with low power consumption and high ruggedness. This solution implements a high voltage level shifter which consumes low power by adding a clamped VGS LDMOS driver to the conventional short pulse generator. Moreover, this paper proposes a highly rugged 1200V LDMOS which improves SOA by limiting the hole current. This paper could be applied to smart power modules used for HVAC (heating, ventilation, and airconditioning) and industrial inverters. Consequently, this paper will provide design engineers with an understanding of how they can make a significant contribution to worldwide energy savings.

• 예술인문사회 융합 멀티미디어 논문지
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• 제9권9호
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• pp.721-736
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• 2019

본 논문에서는 대심도에 위치한 지하역사(지하 6층) 및 터널에서 화재가 발생했을 경우 제연설비 작동에 따른 연기의 거동을 측정하였다. 열풍기를 이용하여 열부력 효과를 구현한 연기발생장치를 이용하여 화재연기를 생성하였다. 화재발생 위치는 승강장 위 및 스크린도어 외부에 위치한 터널부의 승강장 위의 2가지 위치를 선정하였다. 승강장 화재발생시 승강장에 설치된 환기구를 통하여 연기가 배출되도록 하는 제연모드가 일반적인데 본 연구에서는 승강장 양단에 위치한 터널부의 환기구를 통한 배기도 같이 동작되도록 설정하여 실험을 수행하였다. 다양한 위치에서 연기농도 및 풍향풍속을 측정하였고 화면을 취득하여 연기의 이동 및 제연을 분석하였다. 승강장 내부에서 화재가 발생하였을 경우와 선로부에서 화재가 발생하였을 경우 승강장의 송풍기의 제연모드 동작과 터널의 송풍기의 배연 동작으로 인하여 연기배출이 원활하였고 화재 발생 인근 구역으로의 연기전파가 억제되었다. 본 연구에서 제시한 승강장 및 승강장 양단부의 터널에 적용되는 송풍기를 같이 운전하는 제연모드를 통하여 승강장 화재 및 화재열차 정차시 화재 연기로부터 승객들에게 보다 안전한 대피환경을 제공할 수 있을 것이다.

• 한국의류산업학회지
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• 제22권3호
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• pp.271-286
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• 2020

This study evaluated designs via the consumers' function and design preferences survey for using product design images, virtual avatar wearing images and product explanations that identified consumers' function and design preferences for knee protection pads as well as to develop movement assistive knee pad designs. We developed Design A for men and Design B for women. For Design A, the front of the knee supports muscles and alleviates pain with a hole. Mesh material with good ventilation was applied to enhance wearing comfort. The color was achromatic for a modern style, and the hook fastener and loops enabled easy wear and removal of the pad while controlling size and pressure strength. For Design B, taping details seamlessly support muscles in the knee area with fabrics less than 0.1 cm thick and with long sleeves in the diverse sizes. The design's satisfaction assessment showed that potential consumers were satisfied with Design A and Design B for overall design and functional features. Over 77% wanted to use/wear and purchase designs; in addition, over 78% expected it would help with walking and relieve knee pain. The results can be helpful for designers when deciding designs for manufacturing and commercializing kneepad products.

• 한국가스학회지
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• 제20권3호
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• pp.59-65
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• 2016

가스 사용 시설에서 폭발 위험성 평가 등급에 따라 적합한 방폭용 설비를 사용하는 것은 매우 중요하다. 가스 관련 법에서 가스 사용시설의 방폭 기준은 제시하고 있으나 폭발 위험장소 구분을 위한 기술 기준은 별도로 제시되어 있지 않다. 본 연구에서 한국산업표준 KS를 이용하여 저압 도시가스 배관시설에 대해 합리적인 폭발위험성 예측 방법을 제시하고자 한다. 누출공 크기, 누출압력에 따른 가상체적, 환기 유효성 등의 중요변수를 적용하여 폭발위험성이 예측되었다. 자연 환기 조건을 만족하는 실험 설비가 제작되어 도시 가스 누출 실험 결과와 KS 표준에 의해 예측된 폭발 위험성 예측 결과가 비교되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1326-1330
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• 2008

The failure mode of steel road wheels in a vehicle is cracks from ventilation hole through to contact plane on steel wheel's disc plate. But a number of cracks of Cornering Fatigue Limit Test is on contact plane near to wheel nut mounting area, even though it's satisfied with specified cycles. So this paper searches out causes to improve durability and reliability of C.F.T by uni-axial bending moment test. The verified cause is a "fretting" on contact area of steel wheel. In result, this paper suggests a solution to prevent a fretting by inserting a damping shim, 0.7mm between steel wheel contact areas. Therefore this paper makes it possible to move crack position of C.F.T in steel wheel from contact plane to vehicle's failure mode.

• 한국화재소방학회논문지
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• 제29권6호
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• pp.119-128
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• 2015

이 논문에서는 신축 후 약 2년이 경과한 전원주택에서 벽난로 가동 중에 벽난로로 인한 화재가 발생하여 전소된 사례에 대해 법원을 통해 소방서, 경찰서, 화재보험관련 조사기관, 주택을 시공한 건설회사와 벽난로를 시공한 벽난로제조업체로부터 제공받은 자료들을 분석하여 벽난로 옆 벽체의 목재기둥에 남아 있는 저온장기발화의 화재패턴을 근거로 벽난로 옆 벽체의 목재기둥에 벽난로 화실(火室)의 열이 전도되어 화재가 발생하였음을 입증하였다. 그리고 벽난로 옆의 목재기둥이 저온장기발화를 한 이유는 굴뚝에 환기를 위한 공기창을 설치하지 않았기 때문임을 화재시뮬레이션을 통해 입증하였다.

• 한국안전학회지
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• 제33권3호
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• pp.39-45
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• 2018

The occupational safety and health act defines how to evaluate the explosion hazardous areas according to KS (Korean Industrial Standards). Current KS have to follow IEC (International Electrotechnical Commission) 60079-10-1 1st edition and there has been no change since 2008. And its 2nd edition has been revised in 2015. In this study, IEC 1st Ed. (IEC 60079-10-1 1st edition) is compared with IEC 2nd edition. Total 112 case studies including four materials (methane, propane, benzene, methanol) are selected to test and explosion hazardous ranges evaluated by IEC 1st and 2nd Ed. are analyzed according to various leakage pressures and hole sizes. In order to verify the results calculated by them, PHAST, which is one of the most representative consequence analysis programs, is employed. As a result, it can be concluded that there are many differences between IEC 1st and 2nd Ed. due to the discharge and the ventilation parameters. As comparing with PHAST, it is confirmed that IEC 1st provides more conservative values than PHAST. Even if IEC 2nd Ed. provides more conservative for gases, this fails to provide more conservative values for liquids. Therefore, it is worth to note that a large value between the explosion hazardous ranges value calculated by the IEC 1st Ed. and 2nd Ed. should be selected until further investigation and analysis is made. Morevover, the full consideration for IEC 2nd Ed. have to be needed.

• 한국전자파학회논문지
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• 제16권3호
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• pp.311-318
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• 2005

평행평판 도파관의 윗면에 2차원적 주기적인 슬롯이 배열된 구조에서 회절특성에 중점을 두어 해석하였다. 주기적인 슬롯배열은 한 축은 무한 슬롯 배열로 두고 다른 축은 유한개의 슬롯 배열로 구성된다. 평행편판 도파관 내부로 입사되는 전자파는 일부 반사되고 일부는 슬롯을 통하여 복사되며 나머지는 주기적인 슬롯이 있는 영역을 넘어 투과하게 된다. 이러한 경우에 평행평판 도파관의 높이, 단일 슬롯의 크기, 그리고 슬롯 배열의 주기에 따라 반사, 복사 그리고 투과되는 전력을 수치 계산하여 살펴보았다. 이러한 연구는 TFT-LCD와 PDP 구조의 됫면에 장착되는 주기적인 원형개구 구조를 이용하는 환기구조 설계에 유익할 것으로 사료된다.

• 한국안전학회지
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• 제29권2호
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• pp.24-30
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• 2014

There have been controversies over whether explosion hazardous area(EHA) should be classified for facilities which use lighter-than-air gases such as city gas, hydrogen and ammonia. Two view points are confronting each other: an economic piont of view that these gases are lighter than air and disperse rapidly, hence do not form EHA upon release into the atmosphere, and a safety point of view that they are also inflammable gases, hence can form EHA although the extent is limited compared to heavy gases. But various standards such as KS, IEC, API, NFPA do not exclude light gases when classifying EHA and present examples of EHA for light gas facilities. This study calculates EHA using the hypothetical volume in the IEC code where the hole sizes required for the calculation were selected according to various nominal pipe sizes in such a way to conform to the EHA data in the API code and HSL. Then, 25 leakage scenarios were suggested for 5 different pipe sizes and 5 operating pressures that cover typical operating conditions of light gas facilities. The EHA for the minimum leakage scenario(25 mm pipe, 0.01MPa pressure) was found to correspond to a hypothetical volume larger than 0.1 $m^3$(medium-level ventilation). This confirms the validity of classifying EHA for facilities using lighter-than-air gases. Finally, a computer program called HACPL was developed for easy use by light gas facilities that classifies EHA according to operating pressures and pipe sizes.

• 복식문화연구
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• 제8권1호
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• pp.65-76
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• 2000

The purposes of this study were to claassify of clothing-wearing motives, to analyze tendency of fashion in campus, and to propose fashion merchandising plans and marketing strategies of companies for female college students. Research had been done during 1 week each on April and October in 1998 and 1999. Sixty-two students in spring semester and 54 student in fall semester were surveyed and analyzed. Their grades and majors were not considered in this study. Fashion Diary had been written by students and then their statements were analyzed by the means of the qualitative data analysis. Following conclusions were obtained from this study. 1. Clothing-wearing motives were classified with 'group depending on daily work', 'group depending on image', 'group depending on body supplement', 'group depending on weather', 'group of fashion following', 'group depending on courtesy', 'group depending on mood', and 'group of unconcerning'. 2. The fashion tendency of the students were layered look and they preferred casual styles, such as round t-shirts, jean pants, and cardigans. The color of white, black, and gray were prevalent for top wear, and the color of blue, black, beige for bottom wear in both seasons. For shoes, color of black, brown, white were popular. For bags, black, blue, and khaki color were prevailed. 3. The proposals obtained from this study are as follows : 1) Production of clothing enforced functional and practical base is wanted for 'group depending on daily work'. 2) Designs considering body parts such as hip, arm hole, shoulder, and thigh are needed. 3) Utilization of new materials such as waterproof with ventilation, opaque (means 'not see-through'), antipollution finishing process are required. 4) Simple designs of clothing which could be performed by herself with various accessories. Thermochromic materials are wanted for 'group of fashion following'. 5) Diversity of semi-suit is required for 'group depending on courtesy'.