• 한국가스학회지
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• 제26권6호
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• pp.24-29
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• 2022

이 논문은 LPG 자동차의 캠축베어링 시일의 오일누설, 컴퓨터커넥터 핀 손상에 의한 접촉불량, 베이퍼라이저 배부불량으로 인한 고장사례에 대하여 현상을 분석, 연구한 것이다. 첫 번째 사례는 실린더 헤드를 분해하여 확인한 결과 타이밍 시스템에서 가까운 엔진의 흡기캠축의 베어링과 시일의 조립부 손상으로 인해 이 부위로 엔진오일이 누설되는 것을 확인하였다. 두 번째 사례는 엔진컴퓨터로 공급되는 자동차의 시동을 제어하는 전원선의 커넥터 핀이 손상되어, 전원이 공급되지 않아 시동이 꺼진 것을 확인하였다. 세 번째 사례는 베이퍼라이저 내부에 이물질의 퇴적으로 인해 가스의 흐름이 원활하지 못하여 엔진의 부조화현상이 발생되었다. 결국, 베이퍼라이저에서 믹서로 적은 양의 가스를 공급하게 되고, 믹서의 스로틀 열림량을 제어하는 컴퓨터는 그 열림량만큼 공기를 공급하게 됨으로써 연소실에서 혼합기는 희박한 상태가 되어 엔진의 적정출력을 내지 못하는 것을 확인하였다. 따라서, 자동차가 최적의 운전조건이 될 수 있도록 자동차관련 시스템의 관리를 철저하게 해야한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.65-81
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• 2003

During the last few decades in Korea, the development of hillside or mountain areas has rapidly increased for infrastructure construction such as railroads, highways and housing. Many landslides have occurred during these constructions. Also, the amount and scale of damage caused by landslides have increased every year. In the case of Far East Asia including Korea, the damage of landslides is consequently reported during the wet season. In this paper, the effect of stabilizing piles on slope stability is checked and the behavior of slope soil and piles are observed throughout the year by field measurements in the large-scale cut slopes. In particular a large-scale cut slope situated on the construction site for the express highway in Donghae, Korea. First of all, The behavior of the slope soil was measured by inclinometers during slope modification. Landslides occurred in this area due to the soil cutting for slope modification. The horizontal deformations of slope soil gradually increased and rapidly decreased at depth of sliding surface indicating that the depth of sliding surface below the ground surface can be predicted. On the basis of being able to predict the depth of the sliding surface, stabilizing piles were designed and constructed in this slope. To ensure the stability of the reinforced slope using stabilizing piles, an instrumentation system was installed. The maximum deflection of piles is measured at the pile head and it is noted that the piles deform like deflection on a cantilever beam. The maximum bending stress of piles is measured at the soil layer. The pile above the soil layer is subjected to lateral earth pressure due to driving force of the slope, while pile below soil layer is subjected to subgrade reaction against pile deflection. As a result of research, the effect and applicability of stabilizing piles in large-scale cut slopes could be confirmed sufficiently.

• 대한소아치과학회지
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• 제26권1호
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• pp.151-156
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• 1999

1. 하순에 심한 self-mutilation wound를 야기한 Lesch-Nyhan syndrome 환아에서 상하악 유전치에 치관부 절단 및 치수 절제술을 시행하여 치아에 의한 자해를 방지하였다. 2. 장치를 이용한 치료가 어려운 경우 발치가 고려되기도 하나 본 증례에서는 발치보다 보존적인 술식으로 만족할 만한 결과를 얻었다.

• 대한토목학회논문집
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• 제32권1B호
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• pp.53-57
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• 2012

본 연구에서는 하천에서 준설 웅덩이의 발달과정을 모의할 수 있는 수치모형을 제시하였다. 제시된 수치모형은 준정류 가정에 기초하는데, 이는 흐름은 정상류이고 하상은 시간에 따라 변한다고 가정하는 것이다. 준정류 모형은 흐름에 비해 하도 변형이 장기간에 걸쳐 진행된다는 사실에 근거한다. 총유사량 공식으로 Engelund and Hansen 공식과 Ackers and White 공식을 이용하여 수치실험을 실시하였다. Engelund and Hansen 공식을 사용하였을 때, Parker(2004)에 제시된 준설웅덩이의 되메움 과정을 정량적으로 유사하게 모의하는 것으로 나타났다. 제시된 모형의 적용성을 검토하기 위하여 선행 실내실험에 적용하였다. 전반적으로 준정류 모형이 실험수로에서 웅덩이의 발달과정을 잘 모의하는 것으로 확인되었다. 그러나 수치모형이 웅덩이 상류측으로 전파되는 두부침식 현상을 재현하지 못하며, 되메움 이후 하류로 전파되는 하상파를 과소 산정하는 것으로 나타났다.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.656-664
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• 2017

This paper presents the design and fabrication of a high power piezoelectric ultrasonic surgery unit for multi-purpose dental implantation. A conventional piezoelectric ultrasonic surgery units consists of a transducer and a tip. However, the drawback of this simple structure is that the output performance of the transducer considerably changes with the change of the tips. An ultrasonic surgery unit that has an additional booster between the transducer and the tip can solve this problem to some extent; for this, an optimal structural design for the transducer is required. We used the Bolted Langevin Transducer (BLT) as the basic transducer; it consists of piezoelectric ceramics and a metal body. It's structure was optimized using mathematical methods to determine the length and radius of the tail and head masses. Additionally, the booster was also subjected to the same methods. Using these mathematical methods, optimal results in terms of the resonance frequency (24.96 kHz), displacement ($14.27{\mu}m$), and pressure (2.8 MPa), could be obtained. The validity of this proposed surgery unit was confirmed experimentally, exhibiting a cutting force of around 7% higher than that of a conventional surgery unit.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2001년도 유체기계 연구개발 발표회 논문집
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• pp.159-164
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• 2001

An extensive range of pumping facilities are employed in the regional water supply system in metropolitan areas, and optimization and the systematic combination of the pump facilities have direct bearing on the stability and economy of the water supply system concerned. These systems must be able to guarantee stability, efficiency and offer high reliability. Preparation of metropolitan area regional water supply system construction project must include a basic plan which takes into account the suitability of pumping facilities to be used, the environment in which facilities will be installed, man-power requirements and basic operational and management policies. This paper contains over-all analysis of the management of metropolitan area regional water supply systems and highlights the cause of Inefficiency and energy waste and puts forward a remedial plan of action. In addition, pump/motor specification programs were developed using Visual Basic to assist selection of the same.

• 터널과지하공간
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• 제23권5호
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• pp.428-441
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• 2013

TBM을 적용하기 어려운 터널과 다양한 조건의 광산에서 기계 굴착장비인 로드헤더의 수요가 증가하고 있다. 하지만 우리나라에서 로드헤더의 적용 실적은 거의 전무하며, 일부 국가에서만 로드헤더의 설계 제작기술을 보유하고 있다. 따라서 본 연구에서는 로드헤더의 최적 선정과 설계를 위한 로드헤더의 굴착 원리 및 핵심설계항목들을 분석하였다. 또한 전 세계 143개의 로드헤더 설계 정보들을 데이터베이스화하고 로드헤더의 설계에 활용하기 위한 통계적인 상관관계들을 도출하였다. 마지막으로 데이터베이스에 기반하여 로드헤더를 설계하기 위한 절차를 제시하였다.

• 대한지리학회지
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• 제48권5호
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• pp.615-628
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• 2013

하천의 유로가 급격하게 변경되는 하도 변위로 형성된 신하도에서는 상 하류간의 고도차로 인해 폭포 가 발생될 수 있다. 본 연구는 우리나라의 7개 폭포를 대상으로 하여, 하도 변위에 의한 폭포의 형성 유형과 과정을 설명하고, 폭포의 후퇴 속도와 영향 요인을 분석하였다. 울진군 불영 폭포, 영덕군 용추 폭포, 양구군 직연 폭포, 울진군 광품 폭포는 자연적인 감입 곡류 절단에 의해 형성되었다. 태백시 삼형제 폭포, 남원시 구룡 폭포는 하천 쟁탈의 과정에서 형성된 것이고, 충주시 팔봉 폭포는 농경지 확보를 위한 인위적인 하도 절단으로 형성되었다. 폭포는 두부 침식으로 인해 시간이 갈수록 위치가 상류 쪽으로 이동하였는데, 폭포의 형성 시기를 추정할 수 있는, 불영, 용추, 직연, 삼형제 폭포의 후퇴 속도는 3~4m/ka로 측정되었다. 이들 4개 폭포의 후퇴 속도는 유역 면적, 강수량, 기반암의 용식 및 풍화 가능성, 초기 폭포의 높이와 뚜렷한 양의 상관관계를 갖는 것으로 분석되었다.

• 한국안전학회지
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• 제29권3호
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• pp.79-84
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• 2014

Human error is one of the major contributors to the accidents. A lot of risk assessment techniques have been developed for prevention of accidents. Nevertheless, most of them were interested in physical factors, because quantitative evaluation of human errors was difficult quantitatively. According to lack of risk assessment techniques about human errors, most of industrial risk assessment for human errors were based on data of accident analysis. In order to develop an effective countermeasure to reduce the risk caused by human errors, a systematic analysis is needed. Generally, risk assessment system is composed of 5 step(classification of work activity, identification of hazards, risk estimation, evaluation and improvement). This study aimed to develop a risk identification technique for human errors that could mainly be applied to industrial fields. In this study, Ergo-HAZOP and Comprehensive Human Error Analysis Technique were used for developing the risk identification technique. In the proposed risk identification technique, Ergo-HAZOP was used for broad-brush risk identification. More critical risks were analysed by Comprehensive Human Error Analysis Technique. In order to verify applicability, the proposed risk identification technique was applied to the work of pile head cutting. As a consequence, extensive hazards were identified and fundamental countermeasures were established. It is expected that much attention would be paid to prevent accidents by human error in industrial fields since safety personnel can easily fint out hazards of human factors if utilizing the proposed risk identification technique.

• 한국의류학회지
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• 제40권6호
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• pp.1085-1099
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• 2016

This article is designed to establish fundamental design criterion for theme park cast costumes in accordance with play type and space. There is an understanding that theme parks act as a play space that is designed to meet diverse playing desires. To analyze cast costumes, the theme park - 'Everland' in South Korea as an example, area was divided into attraction space and non-attraction space. Attraction space is mainly for full-scale play content areas and the non-attraction space is to enforce the attraction space experience. Roger Caillois's play theory states that there are 4 play types; Illinx, Mimicry, $Ag{\hat{o}}n$, and Alea. All 4 play types were shown through attraction and Mimicry at non-attraction. Each cast costume was analyzed in terms of apparel design elements - silhouette, textile, color, detail, and props - related to play type facility and cast role. Criteria for theme park cast costume designs were suggested based on the results. Illinx cast members who fulfill a safety-checking role wear high chroma warm color costumes with the accent on details in bodice cutting lines, collar edges, pockets, buttons and decorative ornaments. A complementary contrast is also used. The guidance cast in Illinx may wear a suit in bright/vivid color. Mimicry guidance cast costumes show meticulous perfection in imitation with the figure in its space. From head to toe, color, textile, and silhouette - every detail and even props should match the character. $Ag{\hat{o}}n$ cast costumes are strictly limited in detail and decorative ornament usage as well as in color, since they are in charge of the management and operation of a competition. Alea cast's role is a self-demonstrator. Alea cast members should be a real tarot card reader. However, a manual should control their costumes. A total of 10 cast roles at a non-attraction space should be designed to show job patterns clearly in accordance with the whole theme at the park.