• 제목/요약/키워드: MOST150

검색결과 1,746건 처리시간 0.026초

150W LED등기구 방열을 위한 열 해석에 관한 연구 (A Study on Heat Simulation for Heat Radiation in 150W LED)

  • 소병문
    • 반도체디스플레이기술학회지
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    • 제15권4호
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    • pp.79-85
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    • 2016
  • For long life time and high efficiency, not necessary in improvement of LED chip structure, but also improve heat radiation for decrease heat in LED chip. In this study, efficiency decline factor has been investigated in LED lamp as study heat characteristic, luminance flux and heat resistance. When LED lamp temperature was increased, about 7% loss of luminance flux. In consequence of temperature analysis, width of fin was the most important factor of heat radiation. As a result, secure the enough heat path is very important factor of LED lamp design.

150℃이하 저온에서의 미세 접합 기술 (Low Temperature bonding Technology for Electronic Packaging)

  • 김선철;김영호
    • 마이크로전자및패키징학회지
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    • 제19권1호
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    • pp.17-24
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    • 2012
  • Recently, flip chip interconnection has been increasingly used in microelectronic assemblies. The common Flip chip interconnection is formed by reflow of the solder bumps. Lead-Tin solders and Tin-based solders are most widely used for the solder bump materials. However, the flip chip interconnection using these solder materials cannot be applied to temperature-sensitive components since solder reflow is performed at relatively high temperature. Therefore the development of low temperature bonding technologies is required in these applications. A few bonding techniques at low temperature of $150^{\circ}C$ or below have been reported. They include the reflow soldering using low melting point solder bumps, the transient liquid phase bonding by inter-diffusion between two solders, and the bonding using low temperature curable adhesive. This paper reviews various low temperature bonding methods.

공학인증 매뉴얼에서 콘텐츠 재사용을 위한 정보 아키텍처 모델링 (Modeling an Information Architecture for Content Reuse in Engineering Accreditation Manuals)

  • 구흥서
    • 전기학회논문지
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    • 제63권1호
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    • pp.150-155
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    • 2014
  • Content is often developed inconsistently in technical authoring environments, as new documents are created and existing documents are revised. The Darwin Information Typing Architecture(DITA) is an XML-based, end-to-end architecture for authoring, producing, and delivering technical documentations. The core of most advanced authoring and publishing systems is the concept of content reuse. In this paper, we describe to design and implement an authoring and producing system of different technical documentations for the accreditation programs of Engineering Education using DITA XML. It provide a content reuse method for accomplishing the improvement of content consistency and the speed-up of the production in technical documentations.

Effectiveness of different confining configurations of FRP jackets for concrete columns

  • Moretti, Marina L.
    • Structural Engineering and Mechanics
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    • 제72권2호
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    • pp.155-168
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    • 2019
  • This paper presents the results of an experimental investigation on the compressive strength of small scale concentrically axially loaded fiber-reinforced polymer (FRP) confined plain concrete columns, with cylinder concrete strength 19 MPa. For columns with circular (150-mm diameter) and square (150-mm side) cross sections wrapped with glass- and carbon-FRP sheets (GFRP and CFRP, respectively) applied with dry lay-up the effect of different jacket schemes and different overlap configurations on the confined characteristics is investigated. Test results indicate that the most cost effective jacket configuration among those tested is for one layer of CFRP, for both types of sections. In square sections the location of the lap length, either in the corner or along the side, does not seem to affect the confined performance. Furthermore, in circular sections, the presence of an extra wrap with FRP fibers parallel to the column's axis enhances the concrete strength proportionally to the axial rigidity of the FRP jacket. The recorded strains and the distributions of lateral confining pressures are discussed. Existing design equations are used to assess the lateral confining stresses and the confined concrete strength making use of the measured hoop strains.

착용감 구현을 위한 증강현실용 햅틱 상의(上衣) (Augmented Reality Haptic Upper Garment for Wear Sensation)

  • 임은혁;권지안;이수용
    • 로봇학회논문지
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    • 제14권2호
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    • pp.150-156
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    • 2019
  • Haptic systems have been widely used for both virtual reality and augmented reality application including game, entertainment, education and medical sectors. Clothing designers and retailers initiated using AR and VR technologies to help the consumers find style with the perfect fit. Most of the developed augmented reality shopping is implemented by overlapping the image of the clothes on the customer so that he/she can find the fit. However, those are only visual information and the customer cannot experience the real size and the stiffness of the clothes. In this paper, we present the haptic upper garment which provides the haptic feedback to the user using cables. By controlling the length of the cable, the size of the clothes is set and by stiffness control, the compliance of the fabric is implemented. The haptic garment is modeled for precise control and the distributed controller architecture is described. With the haptic upper garment, the user's experience of the virtual clothes is greatly enhanced.

Recent advances in minimally invasive surgery for gynecologic indications

  • Koo, Yu-Jin
    • Journal of Yeungnam Medical Science
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    • 제35권2호
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    • pp.150-155
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    • 2018
  • Recently, an increasing interest in less invasive surgery has led to the advent of laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES). LESS and NOTES could be technically challenging, but available literature has demonstrated the feasibility and safety of LESS for benign gynecologic diseases. However, the evidence is not strong enough to recommend the use of LESS over that of conventional multiport laparoscopic surgery (MLS). As per the results of the most recently published meta-analysis, the majority of surgical outcomes are equivalent between LESS and MLS, except for the longer operative time in LESS for both adnexal surgery and hysterectomy. Although an increasing number of studies have reported on robotic LESS, NOTES, and LESS for gynecologic malignancy, definite conclusions have not been drawn owing to the lack of sufficient information.

A Case of Lobular Capillary Hemangioma at the False Vocal Cord With Intermittent Stridor

  • Park, Sang-Wook;Cho, Ki Ju;Won, Seongjun;Park, Jung Je
    • 대한후두음성언어의학회지
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    • 제32권3호
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    • pp.150-152
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    • 2021
  • Lobular capillary hemangioma (LCH) is a type of benign vascular tumor. It arises from vascular endothelial cells and contains capillaries arranged in a lobular pattern. In the head and neck, the most common presenting location of LCH is the lips, and presentation in the larynx is very rare. LCH might not be distinct from granuloma in macroscopic views. We report a 71-year-old female with LCH of the larynx that was totally resected via laryngeal microsurgery with a CO2 laser and briefly review the literature.

Deep Neck Infection Caused by Infected Dentigerous Cyst: A Case Report

  • Kim, Gyeong-Mi;Oh, Ji-Su;You, Jae-Seek;Moon, Seong-Yong;Choi, Hae-In
    • Journal of Oral Medicine and Pain
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    • 제46권4호
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    • pp.150-154
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    • 2021
  • Deep neck infection (DNI) is a potentially serious pathology that can lead to serious complications and high rate of mortality. Since DNI affects the cervical spaces, which can compromise airway, aggressive antibiotic administration and prompt surgical drainage are essential for recovery. Although most causes of DNI are known to be dental infections, developmental cysts such as dentigerous cysts are relatively few causes. In this case, we report a rare patient with severe deep neck space infection caused by infected third molar with dentigerous cyst.

Evaluation of Water Suction for Compacted Bentonite Buffer Under Elevated Temperature Conditions

  • Yoon, Seok;Lee, Deuk-Hwan;Cho, Won-Jin;Lee, Changsoo;Cho, Dong-Keun
    • 방사성폐기물학회지
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    • 제20권2호
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    • pp.185-192
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    • 2022
  • A compacted bentonite buffer is a major component of engineered barrier systems, which are designed for the disposal of high-level radioactive waste. In most countries, the target temperature required to maintain safe functioning is below 100℃. If the target temperature of the compacted bentonite buffer can be increased above 100℃, the disposal area can be dramatically reduced. To increase the target temperature of the buffer, it is necessary to investigate its properties at temperatures above 100℃. Although some studies have investigated thermal-hydraulic properties above 100℃, few have evaluated the water suction of compacted bentonite. This study addresses that knowledge gap by evaluating the water suction variation for compacted Korean bentonite in the 25-150℃ range, with initial saturations of 0 and 0.22 under constant saturation conditions. We found that water suction decreased by 5-20% for a temperature increase of 100-150℃.

포장 콘크리트의 크기 효과에 따른 휨 강도 특성 분석에 관한 실험적 연구 (An Experimental Study on Size-effect for Characteristic of Flexural Strength of Pavement Concrete)

  • 이현기;오홍섭;심종성;심재원
    • 대한토목학회논문집
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    • 제35권2호
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    • pp.299-306
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    • 2015
  • 국내 포장 콘크리트의 품질관리는 KS 규정에 따라 재령 28일 휨 인장강도를 기준으로 평가되고 있으며, 현재 대부분 사용되고 있는 휨 인장강도 시험체는 상대적으로 큰 $150{\times}150{\times}550mm$ 시험체를 사용하고 있다. 이에 따라 시험체의 취급이 어렵고 양생조의 활용도가 떨어지고 있는 실정이다. 이에 따라 본 연구는 휨 인장강도 시험체를 줄여 이 같은 문제점을 해결하고자 하였다. 이를 위해 KS에서 규정되고 있는 시험체 크기의 내에서 로그 스케일에 따른 압축강도 및 휨 강도 시험을 실시하고, 시험체 크기를 변수로 설정하여 강도 및 표준편차를 분석하였다. 또한 이와 같은 실내 실험을 바탕으로 Bazant가 제안한 크기 효과 법칙(Size effect law, SEL)의 예측식을 사용하여 비교 분석함으로써 시험체 크기간의 상관성을 검토하여 콘크리트 포장의 품질 평가시 시험체 크기 축소를 위한 기초자료로 활용하고자 한다.