• Title/Summary/Keyword: selective

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CAM과 Selective Search를 이용한 확장된 객체 지역화 학습데이터 생성 및 이의 재학습을 통한 WSOL 성능 개선 (Expanded Object Localization Learning Data Generation Using CAM and Selective Search and Its Retraining to Improve WSOL Performance)

  • 고수연;최영우
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제10권9호
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    • pp.349-358
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    • 2021
  • 최근 CAM[1]을 이용해서 이미지의 객체에 대한 주의 영역 또는 지역화(Localization) 영역을 찾는 방법이 WSOL의 연구로서 다양하게 수행되고 있다. CAM을 이용한 객체의 히트(Heat) 맵에서 주의 영역 추출은 객체의 특징이 가장 많이 모여 있는 영역만을 주로 집중해서 객체의 전체적인 영역을 찾지 못하는 단점이 있다. 여기서는 이를 개선하기 위해서 먼저 CAM과 Selective Search[6]를 함께 이용하여 CAM 히트맵의 주의 영역을 확장하고, 확장된 영역에 가우시안 스무딩을 적용하여 재학습 데이터를 만든 후, 이를 학습하여 객체의 주의 영역이 확장되는 방법을 제안한다. 제안 방법은 단 한 번의 재학습만이 필요하며, 학습 후 지역화를 수행할 때는 Selective Search를 실행하지 않기 때문에 처리 시간이 대폭 줄어든다. 실험에서 기존 CAM의 히트맵들과 비교했을 때 핵심 특징 영역으로부터 주의 영역이 확장되고, 확장된 주의 영역 바운딩 박스에 대한 Ground Truth와의 IOU 계산에서 기존 CAM보다 약 58%가 개선되었다.

수중 다중경로 주파수 선택적 채널에서 최대우도추정을 적용한 선택적합성 주파수 다이버시티의 통신 성능 (Communication performance of selective combining frequency diversity with maximum likelihood estimation in underwater multipath frequency selective channels)

  • 이채희;박규칠;박지현
    • 한국음향학회지
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    • 제41권2호
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    • pp.143-149
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    • 2022
  • 본 논문은 최대우도추정(Maximum Likelihood Estimation, MLE)을 적용한 선택적 합성법(Selective Combining, SC)의 수중 주파수 다이버시티 통신성능을 평가하였다. 수중 다중경로 주파수 선택적 채널에서 수신 신호의 지연확산에 따른 상쇄 간섭 페이딩(destructive interference fading)은 수중 음향 통신 시스템의 오류 증가와 신호대잡음비(Signal to Noise Ratio, SNR)변동성에 영향을 준다. SC의 결정 값 추출을 위한 MLE 적용 해상실험에서 SC 주파수 다이버시티와 MLE-SC 주파수 다이버시티 성능을 평가하였다. SC보다 MLE-SC를 통해 추출한 결정 값을 적용한 경우 상대적으로 낮은 BER(Bit Error Rate) 특성을 확인하였다.

유튜브 정치동영상이 태도극화에 미치는 효과: 선택적 노출과 정치성향, 정치관심도의 상호작용효과를 중심으로 (The Effect of YouTube Political Videos on Attitude Polarization: Focusing on the Interaction Effect of Selective Exposure, Political Orientation, and Political Interest)

  • 이민규;이유민
    • 한국콘텐츠학회논문지
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    • 제22권8호
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    • pp.1-13
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    • 2022
  • 본 연구는 유튜브 정치동영상 이용자들을 대상으로 선택적 노출과 정치적 성향, 정치적 관심도의 태도극화에 대한 상호작용효과를 살펴보았다. 주요 결과를 제시하면 다음과 같다. 먼저 연구문제 1, 연구문제 2와 관련하여 유튜브 정치동영상 이용자들의 선택적 노출과 정치적 성향에 대한 태도극화, 선택적 노출과 정치적 관심도에 대한 태도극화를 살펴본 결과, 선택적 노출에서 동일하게 태도극화 '나'에 대한 주 효과가 발견되었다. 그러므로 유튜브 이용자들의 정치동영상에 대한 선택적 노출이 높아질수록 유튜브 이용자 자신의 태도극화가 강화되는 것으로 나타났다. 연구문제 3과 관련하여 유튜브 정치동영상 이용자들의 정치적 성향과 정치적 관심도에 대한 태도극화를 살펴본 결과, 정치적 성향과 정치적 관심도의 태도극화 '나' 에 대한 상호작용효과가 발견되었다. 따라서 진보적 성향이나 보수적 성향 모두 정치적 관심이 높을 때, 유튜브 이용자 자신의 태도극화도 강화되는 것으로 나타났다.

결정질 실리콘 태양전지의 고효율 화를 위한 Selective emitter 구조 및 Ni/Cu plating 전극 구조 적용에 관한 연구 (PA study on selective emitter structure and Ni/Cu plating metallization for high efficiency crystalline silicon solar cells)

  • 김민정;이재두;이수홍
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.91.2-91.2
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    • 2010
  • The use of plated front contact for metallization of silicon solar cell may alternative technologies as a screen printed and silver paste contact. This technologies should allow the formation of contact with low contact resistivity a high line conductivity and also reduction of shading losses. The better performance of Ni/Cu contacts is attributed to the reduced series resistance due to better contact conductivity of Ni with Si and subsequent electroplating of Cu on Ni. The ability to pattern narrower grid lines for reduced light shading combined with the lower resistance of a metal silicide contact and improved conductivity of plated deposit. This improves the FF as the series resistance is deduced. This is very much required in the case of low concentrator solar cells in which the series resistance is one of the important and dominant parameter that affect the cell performance. A selective emitter structure with highly dopes regions underneath the metal contacts, is widely known to be one of the most promising high-efficiency solution in solar cell processing. This paper using selective emitter structure technique, fabricated Ni/Cu plating metallization cell with a cell efficiency of 17.19%.

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전하선택형 태양전지의 연구개발 동향 (Research and Development Trend of Carrier Selective Energy Contact Solar Cells)

  • 조은철;조영현;이준신
    • Current Photovoltaic Research
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    • 제6권2호
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    • pp.43-48
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    • 2018
  • The traditional silicon heterojunction solar cells consist of intrinsic amorphous silicon to prevent recombination of the silicon surface and doped amorphous silicon to transport the photo-generated electrons and holes to the electrode. Back contact solar cells with silicon heterojunction exhibit very high open-circuit voltages, but the complexity of the process due to form the emitter and base at the backside must be addressed. In order to solve this problem, the structure, manufacturing method, and new materials enabling the carrier selective contact (CSC) solar cell capable of achieving high efficiency without using a complicated structure have recently been actively developed. CSC solar cells minimize carrier recombination on metal contacts and effectively transfer charge. The CSC structure allows very low levels of recombination current (eg, Jo < 9fA/cm2), thereby achieves high open-circuit voltage and high efficiency. This paper summarizes the core technology of CSC solar cell, which has been spotlighted as the next generation technology, and is aiming to speed up the research and development in this field.

감각의 순응을 이용한 선택적 감각유발 가능성 (Adaptation of Sensory Nerve Afferents for Selective Elicitation of Tactile Sensations)

  • 안보영;마주형;황선희;송동진;강곤
    • 한국정밀공학회지
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    • 제32권10호
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    • pp.845-850
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    • 2015
  • This study was designed to investigate the feasibility of utilizing an adaptation for selective elicitation of tactile sensations by means of transcutaneous electrical stimulation. We conducted the first experiment to investigate how the stimulation frequency affected the adaptation. Twenty healthy subjects participated in the second experiment to confirm our proposal that the perception intensity of the low-frequency vibration can be enhanced after a high-frequency adaptation, and vice versa. It was found that (1) a low-frequency stimulation did not adapt the nerve afferents responsible for the high-frequency vibration, (2) a high-frequency stimulation affected the nerve afferents responsible for the low-frequency vibration, but adapted to the pressure sensation more intensely, and (3) more than 62% of the subjects reported a more clear selective sensation after the adaptation had lessened or depressed the unwanted sensation. The observations showed that adaptation of the nerve afferent could be utilized for selective elicitation of tactile sensations.

Selective Vapor-Phase Deposition of Conductive Poly(3,4-ethylenedioxythiophene) Thin Films on Patterned FeCl3 Formed by Microcontact Printing

  • Lee, Bo H.;Cho, Yeon H.;Shin, Hyun-Jung;Kim, Jin-Yeol;Lee, Jae-gab;Lee, Hai-won ;Sung, Myung M.
    • Bulletin of the Korean Chemical Society
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    • 제27권10호
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    • pp.1633-1637
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    • 2006
  • We demonstrate a selective vapor-phase deposition of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin films on patterned $FeCl_3$. The PEDOT thin films were grown on various substrates by using the vapor-phase polymerization of ethylenedioxythiophene (EDOT) with $FeCl_3$ catalytic layers at 325 K. The selective deposition of the PEDOT thin films using vapor-phase polymerization was accomplished with patterned $FeCl_3$ layers as templates. Microcontact printing was done to prepare patterned $FeCl_3$ on polyethyleneterephthalate (PET) substrates. The selective vapor-phase deposition is based on the fact that the PEDOT thin films are selectively deposited only on the regions exposing $FeCl_3$ of the PET substrates, because the EDOT monomer can be polymerized only in the presence of oxidants, such as $FeCl_3$, Fe($CIO_4$), and iron(II) salts of organic acids/inorganic acids containing organic radicals.

N-Methylthiobenzyl-Chitosan Bead의 합성과 금속이온의 선택적 흡착능력 (Synthesis of N-Methylthiobenzyl-Chitosan Beads and It's Selective Adsorption Abilities of Metal Ions)

  • 최한영;한상문;안병제;이성호;유국현;이승진
    • 환경위생공학
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    • 제16권2호
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    • pp.91-99
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    • 2001
  • Cross linked chitosan beads showed high selective adsorption abilities in order of $Au^{3+}$ > $Hg^{2+}$ > $Cu^{2+}$ > $Cd^{2+}$ > $Pt^{4+}$ > ${UO_2}^{2+}$ ions in mixed solution of various metal ions at pH 4.5. N-methyltyiobenzylated chitosan beads(MTB-chitosan beads) were prepared treating with p-(methylthio) benzaldehyde after cross linking of chitosan beads to give them a high selectivity in adsorption of metal ions. The MTB-chitosan beads demonstrated their selectivity on precious metals among various metal ions distinctively. Particularly, the MTB-chitosan had a peculiar selective adsorption on $Pd^{2+}$, $Au^{2+}$, and $Hg^{2+}$ions whilst the cross linked chitosan beads showed its high adsorption on $Pd^{2+}$ at pH 1.1. On the other hand, the cross linked chitosan beads showed its superiority in selective adsorption on $Au^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ions to the MTB-chitosan at pH 4.5 of the test solution. Thus metal selectivities were given to chitosan beads through chemical modifications.

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Enhanced Activity for Oxygen Evolution Reaction of Nanoporous IrNi thin film Formed by Electrochemical Selective Etching Process

  • Park, Shin-Ae;Shim, Kyubin;Kim, Kyu-Su;Moon, Young Hoon;Kim, Yong-Tae
    • Journal of Electrochemical Science and Technology
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    • 제10권4호
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    • pp.402-407
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    • 2019
  • Water electrolysis is known as the most sustainable and clean technology to produce hydrogen gas, however, a serious drawback to commercialize this technology is due to the slow kinetics in oxygen evolution reaction (OER). Thus, we report on the nanoporous IrNi thin film that reveals a markedly enhanced OER activity, which is attained through a selective etching of Os from the IrNiOs alloy thin film. Interestingly, electrochemical selective etching of Os leads to the formation of 3-dimensionally interconnected nanoporous structure providing a high electrochemical surface area (ECSA, 80.8 ㎠), which is 90 fold higher than a bulk Ir surface (0.9 ㎠). The overpotential at the nanoporous IrNi electrode is markedly lowered to be 289 mV at 10 mA cm-2, compared with bulk Ir (375 mV at 10 mA cm-2). The nanoporous IrNi prepared through the selective de-alloying of Os is promising as the anode material for a water electrolyzer.

Construction of Probability Identification Matrix and Selective Medium for Acidophilic Actinomycetes Using Numerical Classification Data

  • Seong, Chi-Nam;Park, Seok-Kyu;Michael Goodfellow;Kim, Seung-Bum;Hah, Yung-Chil
    • Journal of Microbiology
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    • 제33권2호
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    • pp.95-102
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    • 1995
  • A probability identification matrix of acidophilic Streptomyces was constructed. The phenetic data of the strains were derived from numerical classification described by Seong et al. The minimum number of diagnostic characters was determined using computer programs for calculation of different separation indices. The resulting matrix consisted of 25 clusters versus 53 characters. Theoretical evaluation of this matrix was achieved by estimating the chuster overlap and the identification scores for the Hypothetical Median Organisms (HMO) and for the representatives of each cluster. Cluster overlap was found to be relatively small. Identification scores for the HMO and the randomly selected representatives of each cluster were satisfactory. The matrix was assessed practically by applying the matrix to the identification of unknown isolates. Of the unknown isolates, 71.9% were clearly identified to one of eight clusters. The numerical classification data was also used to design a selective isolation medium for antibiotic-producing organisms. Four chemical substances including 2 antibiotics were determined by the DLACHAR program as diagnostic for the isolation of target organisms which have antimicrobial activity against Micrococcus luteus. It was possible to detect the increased rate of selective isolation on the synthesized medium. Theresults show that the numerical phenetic data can be applied to a variety of purposes, such as construction of identification matrix and selective isolation medium for acidophilic antinomycetes.

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