• 제목/요약/키워드: large source

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바아지식 초대형 부유 구조물의 유탄성 응답 해석 (A Hydroelastic Response Analysis of a Very Large Floating Structure of Barge-Type in Waves)

  • 구자삼;조효제;김병현;이창호
    • 한국해양공학회지
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    • 제12권2호통권28호
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    • pp.43-56
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    • 1998
  • A barge-type structure has been recently watched since The Floating Structures Association of Japan proposed the new concept as the most suitable one of floating airports. In this paper, the method, which is based on a combination of a three-dimensional source distribution method and the wave interaction theory is applied to very large floating structure of barge-type. The calculated results show good agreement with the experimental and calculated ones by Yago and remarkable characteristics concerning the hydroelastic behavior of the very large floating structure on the effects of hydrodynamic interactions and choice of body modelling.

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벡터 양자화에서 시간 평균 왜곡치의 수렴 특성 I. 대수 법칙에 근거한 이론 (The Convergence Characteristics of The Time- Averaged Distortion in Vector Quantization: Part I. Theory Based on The Law of Large Numbers)

  • 김동식
    • 전자공학회논문지B
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    • 제33B권7호
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    • pp.107-115
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    • 1996
  • The average distortio of the vector quantizer is calcualted using a probability function F of the input source for a given codebook. But, since the input source is unknown in geneal, using the sample vectors that is realized from a random vector having probability function F, a time-average opeation is employed so as to obtain an approximation of the average distortion. In this case the size of the smple set should be large so that the sample vectors represent true F reliably. The theoretical inspection about the approximation, however, is not perfomed rigorously. Thus one might use the time-average distortion without any verification of the approximation. In this paper, the convergence characteristics of the time-average distortions are theoretically investigated when the size of sample vectors or the size of codebook gets large. It has been revealed that if codebook size is large enough, then small sample set is enough to obtain the average distortion by approximatio of the calculated tiem-averaged distortion. Experimental results on synthetic data, which are supporting the analysis, are also provided and discussed.

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Dietary Fiber and Large Bowel Cancer

  • Oku, Tsuneyuki
    • 한국식품영양과학회지
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    • 제25권3호
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    • pp.539-549
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    • 1996
  • Large bowel cancer correlates tightly to dietary factors such as dietary fiber and fat. Dietary fiber prevents the large bowel cancer in different modes of action which depend upon physicochemical and fermentable properties. Water-soluble fiber is fermented easily by intestinal microbes producing short chain fatty acids ; in contrast, water-insoluble fiber occurs effectively more rapid transit time due to greater bulk of gut content, though it is unfermentable. Not only short chain fatty acid is utilized in the proximal and distal colon as primary energy source, but also it lowers pH in the colon to normalize cellular differentiation and helps to stimulate peri staltic movement by acting as an osmotic laxative. In particular, butyric acid may also regulate gene expression and cell growth, though it is an important respiratory fuel for the colonocyte. Since dietary fiber and non-digestible oligosaccharides are the major source of butyric acid, this provides a possible link between dietary fiber and oligosaccharide and prevention of large bowel cancer. But, as with many links between dietary fiber and large bowel cancer, a direct casual association has not been established. In addition, RDA of dietary fiber which is 20~25g/day for adult Japanese, appears to be reasonable for the defecation once daily and the prevention of large bowel cancer.

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중·대형 디스플레이용 건식 식각(ICP Dry etcher) 설비의 플라스마 균일도 제어 기술 (Plasma Uniformity Control Technology for Dry Etching (ICP Dry etcher) Equipment for Medium and Large Displays)

  • 홍성재;전홍구;양호식
    • 반도체디스플레이기술학회지
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    • 제21권3호
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    • pp.125-129
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    • 2022
  • The current display technology tends to be highly integrated with high resolution, the element size is gradually downsized, and the structure becomes complicated. Inductively coupled plasma (ICP) dry etcher of various types of etching equipment is a structure that places a large multi-divisional antenna source on the top lid, passes current to the Antenna, and generates plasma using the induced magnetic field generated at this time. However, in the case of a device of a large area size, a support that can withstand a load structurally is necessary, and when these support portions are applied, arrangement of antenna becomes difficult, which causes reduction in uniformity. As described above, the development of antenna source of a large area having a uniform plasma density on the whole surface is difficult to restrict hardware (H/W). As a solution to this problem, we confirmed the change in uniformity of plasma by applying two kinds of specific shape faraday shield(FICP) to the lower part of the large area upper lid antenna of 6 and 8th more than that generation size. In this thesis, we verify the faraday shield effect which can improve plasma uniformity control of ICP dry etcher equipment applied to medium and large displays.

Single-Inductor, Multiple-Input-Single-Output Converter Based Energy Mixer for Power Packet Distribution System

  • Reza, C.M.F.S.;Lu, Dylan Dah-Chuan;Qin, Ling;Qi, Jian
    • Journal of Power Electronics
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    • 제18권5호
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    • pp.1479-1488
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    • 2018
  • Power packet (PP) distribution system distributes power to different loads that share the same distribution cable in a packetized form. When compared with conventional power systems, a PP distribution system (PPDS) can reduce standby power, eliminate Point-of-Load (PoL) power conversion, and intelligently control the load demand from the source side. Due to the absence of PoL conversion, when multiple power sources at different voltage levels and conditioning requirements jointly send power to various loads at different voltage ratings, the generated voltage has an irregular shape. A large filter at each of the load sides is required to reduce such a large voltage ripple. In this paper, a single-inductor, multiple-input-single-output converter structure based multiple-energy-source mixer is proposed. It combines PP generation, maximum power point tracking (MPPT) of renewable energy sources (RESs) and filtering at the source side. To demonstrate the possible renewable energy integration, a PV panel is used as a power source together with other constant voltage sources. The PV power is approximately tracked using the constant voltage method and it is used for each of the PP generations. The proposed PP distribution system is experimentally verified and it is shown that a conventional PI controller is sufficient for stable system operation.

Analysis of inconsistent source sampling in monte carlo weight-window variance reduction methods

  • Griesheimer, David P.;Sandhu, Virinder S.
    • Nuclear Engineering and Technology
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    • 제49권6호
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    • pp.1172-1180
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    • 2017
  • The application of Monte Carlo (MC) to large-scale fixed-source problems has recently become possible with new hybrid methods that automate generation of parameters for variance reduction techniques. Two common variance reduction techniques, weight windows and source biasing, have been automated and popularized by the consistent adjoint-driven importance sampling (CADIS) method. This method uses the adjoint solution from an inexpensive deterministic calculation to define a consistent set of weight windows and source particles for a subsequent MC calculation. One of the motivations for source consistency is to avoid the splitting or rouletting of particles at birth, which requires computational resources. However, it is not always possible or desirable to implement such consistency, which results in inconsistent source biasing. This paper develops an original framework that mathematically expresses the coupling of the weight window and source biasing techniques, allowing the authors to explore the impact of inconsistent source sampling on the variance of MC results. A numerical experiment supports this new framework and suggests that certain classes of problems may be relatively insensitive to inconsistent source sampling schemes with moderate levels of splitting and rouletting.

대면적 CIGS 광흡수층 증착을 위한 선형증발원 개발 (Linear Source for Evaporating Large Area CIGS Absorber Layer)

  • 서제형;정승욱;이원선;최윤성;최명운;최진철;최광호
    • 한국진공학회지
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    • 제22권1호
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    • pp.1-6
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    • 2013
  • $600{\times}1,200mm$ 기판에 대면적 CIGS 광흡수층 증착을 위한 선형증발원 개발을 위해 다른 크기의 노즐과 일정한 노즐 간격을 가지는 선형증발원의 플럭스 밀도를 전산 모사하여 플럭스 균일도 ${\pm}5%$의 조건을 구하였다. 이를 바탕으로 제작된 선형증발원을 이용하여 Cu, In의 단일막 두께균일도를 확인하였고, CIGS 광흡수층을 동시증발법으로 증착하여 박막의 두께균일도 및 증착 조성의 균일도로 선형증발원을 평가하였다. XRF 조성 분석을 통해 구한 조성불균일도는 600 mm 폭에서 $$Cu{\leq_-}5%$$, $$In{\leq_-}7%$$, $$Ga{\leq_-}4%$$, $$Se{\leq_-}3%$$으로 균일한 조성비로 성막된 것을 확인하였고 SEM 분석을 통해 표면 결정립의 형상을 확인하였다. 또한 XRD측정을 통해 선형증발원 방향의 대면적 CIGS 광흡수층이 칼코피라이트 구조임을 확인하였다. 이를 통해서 개발된 하향 선형증발원이 CIGS 광흡수층 증착에 적합함을 확인하였다.

마이크로솔더링을 이용한 정전류다이오드 회로 자외선 LED 광원모듈 제작 (Fabrication Of Ultraviolet LED Light Source Module Of Current Limiting Diode Circuit By Using Flip Chip Micro Soldering)

  • 박종민;유순재;카완 안일
    • 한국전기전자재료학회논문지
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    • 제29권4호
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    • pp.237-240
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    • 2016
  • The improvement of irradiation intensity and irradiation uniformity is essential for large area and high power UVA light source application. In this study, large number of chips bonded by micro soldering technique were driven by low current, and current limiting diodes were configured to supply constant current to parallel circuits consisting of large number of series strings. The dimension of light source module circuit board was $350{\times}90mm^2$ and 16,650 numbers of 385 nm flip chip LEDs were used with a configuration of 90 parallel and 185 series strings. The space between LEDs in parallel and series strings were maintained at 1.9 mm and 1.0 mm distance, respectively. The size of the flip chip was $750{\times}750{\mu}m^2$ were used with contact pads of $260{\times}669{\mu}m^2$ size, and SAC (96.5 Sn/3.0 Ag/0.5 Cu) solder was used for flip chip bonding. The fabricated light source module with 7.5 m A supply current showed temperature rise of $66^{\circ}C$, whereas irradiation was measured to be $300mW/cm^2$. Inaddition, 0.23% variation of the constant current in each series string was demonstrated.

대용량 파일 전송 소프트웨어의 동일성 감정 방법 (Appraisal Method for Similarity of Large File Transfer Software)

  • 전병태
    • 한국소프트웨어감정평가학회 논문지
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    • 제17권1호
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    • pp.11-16
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    • 2021
  • 정보통신의 발달로 인하여 소프트웨어의 중요성이 증대되고 있으며, 이에 따른 소프트웨어 저작권 분쟁도 증가하는 추세에 있다. 본 논문은 제출된 프로그램들의 소스와 관련하여 프로그램 수행에 필요한 파일들을 감정범위로 하였다. 분석 대상인 대용량 파일 전송 솔루션 프로그램은 데이터에 대한 전자서명 및 암호화를 통하여 기밀성, 무결성, 사용자 인증, 부인방지 기능 등의 부가 기능을 제공하고 있다. 본 논문에서는 프로그램 A, 프로그램 B, 프로그램 C 3개에 대하여 분석을 수행한다. 프로그램 유사율을 산출하기 위하여 다음과 같은 내용을 분석한다. 패키지의 구조, 패키지 이름, 각 패키지 내 소스파일 이름, 소스파일 내 변수명, 함수명, 함수구현 소스코드, 제품의 환경변수 정보에 대하여 유사 여부를 분석하고 프로그램의 전체 유사율을 산출한다. 패키지 구조 및 패키지 이름이 일치되는 정도를 확인하기 위해, 폴더 구조를 비교하여 유사도 판단을 하였다. 또한 패키지 구조 및 패키지 이름이 어느 정도 일치하는지와 각 패키지 내 소스 파일(클래스) 이름이 어느 정도 일치하는지에 대한 분석을 하였다.

백그라운드 제거후 신호의 세기에 대하여 (ON THE BACKGROUND-SUBTRACTED INTENSITY)

  • 선광일
    • 천문학논총
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    • 제20권1호
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    • pp.109-116
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    • 2005
  • When we measure a source signal in the presence of a background rate that has been independently measured, the usual approach is to obtain an estimate of the background rate by observing an empty part of the sky, and an estimate of the source signal plus background rate by observing the region where a source signal is expected. The source signal rate is then estimated by subtracting the background rate from the source signal plus background rate. However, when the rates or their observation times are small, this procedure can lead to negative estimates of the source signal rate, even when it should produce a positive value. By applying the Bayesian approach, we solve the problem and prove that the most probable value of source signal rate is zero when the observed total count is smaller than the expected background counts. It is also shown that the results from the conventional method is consistent with the most probable value obtained from the Bayesian approach when the source signal is large or the observation time is long enough.