• 제목/요약/키워드: Single layer structure

검색결과 692건 처리시간 0.034초

영상 인식을 위한 생리학적 퍼지 단층 학습 알고리즘 (Physiological Fuzzy Single Layer Learning Algorithm for Image Recognition)

  • 김영주
    • 한국지능시스템학회논문지
    • /
    • 제11권5호
    • /
    • pp.406-412
    • /
    • 2001
  • 본 논문은 기존의 퍼지 단층 퍼셉트론 알고리즘의 학습 시간과 수렴성을 개선하기 위해 인간 신경계의 생리학적 뉴런 구조를 분석하며 퍼지 논리를 이용한 새로운 뉴런 구조를 제시하고, 이를 바탕으로 생리학적 퍼지 단층 퍼셉트론(P-FLSP: Physiological Fuzzy Single Layer Perceptron)에 대한 학습 모형과 학습 알고리즘을 제안한다. 제안된 학습 알고리즘의 성능을 평가하기 위해 Exclusive OR 문제, 3-bit parity 문제 그리고 차량 번호판 인식 문제 등에 적용하여 피곤의 피지 단층 퍼셉트론 알고리즘과 성능을 비교, 분석하였다. 실험 결과에서는 제안된 학습 알고리즘(P-FSLP)이 기존의 퍼지 단층 학습 알고리즘보다 지역 최소화에 빠질 가능성이 감소하였으며 학습 시간과 수렴성도 개선되었을 뿐만 아니라, 영상 인식등에 대한 응용 가능성도 제시되었다.

  • PDF

UV 펄스 레이저 가공의 구리 박막 두께에 따른 열-구조 연성 해석 (Coupled Thermal-Structure Analysis of UV Laser Pulsing according to the Thickness of Copper Film on the Surface of Polyimide)

  • 신민재;신보성
    • 한국레이저가공학회지
    • /
    • 제16권2호
    • /
    • pp.7-11
    • /
    • 2013
  • Recently advanced laser processing is widely introduced to improve the efficiency of micro part production and to reduce the rate of inferior goods. In this paper the trend of delamination of single layer with both thin copper and polyimide according to the variation of copper thickness was investigated using the coupled thermal-structural analysis of ANSYS. From these analyses results, some conclusions were obtained. Firstly, the maximum temperature was increasing with respect to decrease of copper thickness. Secondly the maximum strain which was in general estimation the main effect of the delamination was observed in case of the copper thickness of $5{\mu}m$. Finally the trend of the delamination was decreasing with increasing the thickness of copper layer.

  • PDF

MEH-PPV와 TPB 다층박막의 광발광 및 전기적 특성 (Luminescent and electrical properties of MEH-PPV and 1,1,4,4-Tetraphenyl-1,3-butadiene Double Layer films)

  • 이명호;김영관;신동명;최종선;김정수
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
    • /
    • pp.163-166
    • /
    • 1997
  • Electroluminescent(EL) dcvice based on organic thin layers have attracted lots of interests because of thier possible application as large-area light-emitting displays. It was known that MEH-PPV and 1, 1, 4, 4, -Tetraphenyl-1, 3-butadiene(TPB) has red and blue emission peak at 580nm and 480nm, respectively. In this study, MEH-PPV films and TPB films were prepared by spin coating and vacuum deposition method, respectively. Films of MEH-PPV and TPB double layer were also prepared by the same method. Photoluminescent(PL) characteristics of these single and doubler layers were investigated, where a cell structure of glass substrate/ITO/MEH-PPV and/or TPB/Al was employed. It was found that the photoluminescent efficiency of TPB film was higher than that of MEH-PPV film with a single layer and also with a double structure. These films have also different I-V characteristics.

  • PDF

Design of an Antireflection Coating for High-efficiency Superconducting Nanowire Single-photon Detectors

  • Choi, Jiman;Choi, Gahyun;Lee, Sun Kyung;Park, Kibog;Song, Woon;Lee, Dong-Hoon;Chong, Yonuk
    • Current Optics and Photonics
    • /
    • 제5권4호
    • /
    • pp.375-383
    • /
    • 2021
  • We present a simulation method to design antireflection coating (ARCs) for fiber-coupled superconducting nanowire single-photon detectors. Using a finite-element method, the absorptance of the nanowire is calculated for a defined unit-cell structure consisting of a fiber, ARC layer, nanowire absorber, distributed Bragg reflector (DBR) mirror, and air gap. We develop a method to evaluate the uncertainty in absorptance due to the uncontrollable parameter of air-gap distance. The validity of the simulation method is tested by comparison to an experimental realization for a case of single-layer ARC, which results in good agreement. We show finally a double-layer ARC design optimized for a system detection efficiency of higher than 95%, with a reduced uncertainty due to the air-gap distance.

Hardness and Oxidation Resistance of Ti0.33Al0.67N/CrN Nano-multilayered Superlattice Coatings

  • Ahn, Seung-Su;Oh, Kyung-Sik;Chung, Tai-Joo;Park, Jong-Keuk
    • 한국세라믹학회지
    • /
    • 제56권1호
    • /
    • pp.49-55
    • /
    • 2019
  • $Ti_{0.33}Al_{0.67}N/CrN$ nano-multilayers, which are known to have excellent wear resistance, were prepared using an unbalanced magnetron sputter to have various periods of 2-5 nm. $Ti_{0.33}Al_{0.67}N$ had a hexagonal structure in a single layer, but converted to a cubic structure by forming a multilayer with CrN, which has a cubic structure. Thus, $Ti_{0.33}Al_{0.67}N$ formed a superlattice in the multilayer. The $Ti_{0.33}Al_{0.67}/CrN$ multilayer with a period of 2.5 nm greatly exceeded the hardness of the $Ti_{0.33}Al_{0.67}N$ and the CrN single layer, reaching 39 GPa. According to the low angle X-ray diffraction results, the $Ti_{0.33}Al_{0.67}N/CrN$ multilayer maintained its as-coated structure to a temperature as high as $700^{\circ}C$ and exhibited hardness of 30 GPa. The thickness of the oxide layer of the $Ti_{0.33}Al_{0.67}N/CrN$ multilayered coating was less than one-tenth of those of the single layers. Thus, $Ti_{0.33}Al_{0.67}N/CrN$ multilayered coating had hardness and oxidation resistance far superior to those of its constituent single layers.

반도체 패키지용 PCB의 구조 모델링 방법에 따른 패키지의 warpage 수치적 연구 (Numerical Study on Package Warpage as Structure Modeling Method of Materials for a PCB of Semiconductor Package)

  • 조승현;전현찬
    • 마이크로전자및패키징학회지
    • /
    • 제25권4호
    • /
    • pp.59-66
    • /
    • 2018
  • 본 논문에서는 수치해석을 사용하여 반도체용 패키지에 적용된 인쇄회로기판 (PCB(printed circuit board)) 구조를 다층 구조의 소재 특성을 모델링한 것과 단일 구조라고 가정한 모델링을 적용하여 warpage를 해석함으로써 단일 구조 PCB 모델링의 유용성을 분석하였다. 해석에는 3층과 4층 회로층을 갖는 PCB가 사용되었다. 또한 단일 구조 PCB의 재료 특성값을 얻기 위해 실제 제품을 대상으로 측정을 수행하였다. 해석 결과에 의하면 PCB를 다층 구조로 모델링한 경우에 비해 단일 구조로 모델링한 경우에 warpage가 증가하여 PCB 구조의 모델링에 따른 warpage 분석결과가 분명한 유의차가 있었다. 또한, PCB의 회로층이 증가하면 PCB의 기계적 특성인 탄성계수와 관성모멘트가 증가하여 패키지의 warpage가 감소하였다.

Prevention of P-i Interface Contamination Using In-situ Plasma Process in Single-chamber VHF-PECVD Process for a-Si:H Solar Cells

  • Han, Seung-Hee;Jeon, Jun-Hong;Choi, Jin-Young;Park, Won-Woong
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.204-205
    • /
    • 2011
  • In thin film silicon solar cells, p-i-n structure is adopted instead of p/n junction structure as in wafer-based Si solar cells. PECVD is a most widely used thin film deposition process for a-Si:H or ${\mu}c$-Si:H solar cells. For best performance of thin film silicon solar cell, the dopant profiles at p/i and i/n interfaces need to be as sharp as possible. The sharpness of dopant profiles can easily achieved when using multi-chamber PECVD equipment, in which each layer is deposited in separate chamber. However, in a single-chamber PECVD system, doped and intrinsic layers are deposited in one plasma chamber, which inevitably impedes sharp dopant profiles at the interfaces due to the contamination from previous deposition process. The cross-contamination between layers is a serious drawback of a single-chamber PECVD system in spite of the advantage of lower initial investment cost for the equipment. In order to resolve the cross-contamination problem in single-chamber PECVD systems, flushing method of the chamber with NH3 gas or water vapor after doped layer deposition process has been used. In this study, a new plasma process to solve the cross-contamination problem in a single-chamber PECVD system was suggested. A single-chamber VHF-PECVD system was used for superstrate type p-i-n a-Si:H solar cell manufacturing on Asahi-type U FTO glass. A 80 MHz and 20 watts of pulsed RF power was applied to the parallel plate RF cathode at the frequency of 10 kHz and 80% duty ratio. A mixture gas of Ar, H2 and SiH4 was used for i-layer deposition and the deposition pressure was 0.4 Torr. For p and n layer deposition, B2H6 and PH3 was used as doping gas, respectively. The deposition temperature was $250^{\circ}C$ and the total p-i-n layer thickness was about $3500{\AA}$. In order to remove the deposited B inside of the vacuum chamber during p-layer deposition, a high pulsed RF power of about 80 W was applied right after p-layer deposition without SiH4 gas, which is followed by i-layer and n-layer deposition. Finally, Ag was deposited as top electrode. The best initial solar cell efficiency of 9.5 % for test cell area of 0.2 $cm^2$ could be achieved by applying the in-situ plasma cleaning method. The dependence on RF power and treatment time was investigated along with the SIMS analysis of the p-i interface for boron profiles.

  • PDF

라이즈비에 따른 단층 및 복층 래티스 돔의 좌굴특성에 관한 비교연구 (A Comparative Study on the Buckling Characteristics of Single-layer and Double-layer Lattice Dome According to Rise ratio)

  • 권영환;정환목;석창목;박상훈
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1998년도 가을 학술발표회 논문집
    • /
    • pp.283-289
    • /
    • 1998
  • In the latticed domes which is a set of space frame, buckling is derived if the external force reaches a limitation by the lightness of the material and the minimization of the member section area. these are concerned with a geometric shape, network pattern, the number of layer, and so on. Most of all, the number of layer of the lattice dome is a important factor from the viewpoint of initial and structure design. Therefore this study compared buckling characteristics of single-layer with double-layer latticed domes and investigated the relativity of buckling-stress-ratio and member-density-ratio according to rise ratio to improve that designers could extend the range of .design selection

  • PDF

스페이서층 두께변화에 따른 공명터널링 다이오드에서 전류-전압 특성의 자기무모순법에 의한 해석 (Dependence of the Thickness of Spacer Layers on the Current Voltage Characteristics of DB Resonant Tunneling Diodes Analyzed with a Self-Consistent Method)

  • 김성진;이상훈;성영권
    • 전자공학회논문지A
    • /
    • 제31A권3호
    • /
    • pp.46-52
    • /
    • 1994
  • We investigated theoretically the current-voltage characteristics of resonant tunneling diodes with a single quantum well structure. using a self-consistent method. This method is a numerical analysis which is able to include the effects of the undoped spacer layer and the band bending by charge accumulation and depletion on the contact layers which have not been considered in the flat-band model reported by Esaki. so that it is better suited to explain experimental results. The structure used is an $AL_{0.5}Ga_{0.5}AS/GaAs/Al_{0.5}Ga_{0.5}AS$ single quantum well. In this work. we estimate the theoretical current-voltage characteristics of the same structure, and then, the dependence of the current-voltage curves on the thickness of undoped spacer layers sandwiched between the barrier and highly n-doped GaAs contact layer.

  • PDF

A Neural Fuzzy Learning Algorithm Using Neuron Structure

  • Yang, Hwang-Kyu;Kim, Kwang-Baek;Seo, Chang-Jin;Cha, Eui-Young
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
    • /
    • pp.395-398
    • /
    • 1998
  • In this paper, a method for the improvement of learning speed and convergence rate was proposed applied it to physiological neural structure with the advantages of artificial neural networks and fuzzy theory to physiological neuron structure, To compare the proposed method with conventional the single layer perception algorithm, we applied these algorithms bit parity problem and pattern recognition containing noise. The simulation result indicated that our learning algorithm reduces the possibility of local minima more than the conventional single layer perception does. Furthermore we show that our learning algorithm guarantees the convergence.

  • PDF