• Title/Summary/Keyword: selective

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Pattern Classification Based on the Selective Perception Ability of Human Beings (인간 시각의 선택적 지각 능력에 기반한 패턴 분류)

  • Kim Do-Hyeon;Kim Kwang-Baek;Cho Jae-Hyun;Cha Eui-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.2
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    • pp.398-405
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    • 2006
  • We propose a pattern classification model using a selective perception ability of human beings. Generally, human beings recognize an object by putting a selective concentration on it in the region of interest. Much better classification and recognition could be possible by adapting this phenomenon in pattern classification. First, the pattern classification model creates some reference cluster patterns in a usual way. Then it generates an SPM(Selective Perception Map) that reflects the mutual relation of the reference cluster patterns. In the recognition phase, the model applies the SPM as a weight for calculating the distance between an input pattern and the reference patterns. Our experiments show that the proposed classifier with the SPM acquired the better results than other approaches in pattern classification.

Property Analysis of Solar Selective Coatings (태양 선택흡수막의 특성 분석)

  • Lee, Kil-Dong
    • Journal of the Korean Solar Energy Society
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    • v.33 no.4
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    • pp.31-38
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    • 2013
  • The chemical composition of the black Cr solar selective coatings electrodeposited were investigated for property analysis by using a XPS(X-ray photoelectron spectroscopy) before and after annealing in air at $300^{\circ}C{\sim}500^{\circ}C$ for 120 hours. Black Cr selective coating exposed by solar radiation for 5 months was compared with annealed sample. In addition, The Cu solar selective coatings were prepared by thermal oxidation method for low temperature application. The samples obtained were characterized by using the optical reflectance measurements by using a spectrometer. Optical properties of oxidized Cu solar coatings were solar absorptance $({\alpha}){\simeq}0.62$ and thermal emittance $({\epsilon}){\simeq}0.41(100^{\circ}C)$. In the as-prepared Cr black selective coating, the surface of the coating was found to have Cr hydroxide and Cr. The Cr hydroxide of the major component was converted to $Cr_2O_3$ or $CrO_3$ form after annealing at $500^{\circ}C$ with the desorption of water molecules. The black Cr selective coating was degraded significantly at temperature of $500^{\circ}C$. The main optical degradation modes of this coating were diffusion of Cu substrate materials.

Selective Emitter Formation of Borosilicate-Glass (BSG) Layer using UV Laser (UV Laser를 이용한 Borosilicate-Glass (BSG)층의 선택적 에미터 형성)

  • Kim, Ga Min;Chang, Hyo Sik
    • Korean Journal of Materials Research
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    • v.31 no.12
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    • pp.727-731
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    • 2021
  • In this study, we have investigated a selective emitter using a UV laser on BBr3 diffusion doping layer. The selective emitter has two regions of high and low doping concentration alternatively and this structure can remove the disadvantages of homogeneous emitter doping. The selective emitters were fabricated by using UV laser of 355 nm on the homogeneous emitters which were formed on n-type Si by BBr3 diffusion in the furnace and the heavy boron doping regions were formed on the laser regions. In the optimized laser doping process, we are able to achieve a highly concentrated emitter with a surface resistance of up to 43 Ω/□ from 105 ± 6 Ω/□ borosilicate glass (BSG) layer on Si. In order to compare the characteristics and confirm the passivation effect, the annealing is performed after Al2O3 deposition using an ALD. After the annealing, the selective emitter shows a better effect than the high concentration doped emitter and a level equivalent to that of the low concentration doped emitter.

The Simulation of Selective Emitter Formation for Crystalline Silicon Solar Cell by Growing Thermal Oxide (Thermal oxidation을 이용한 결정질 실리콘 태양전지의 selective emitter 형성 방법에 대한 simulation)

  • Choe, Yonghyon;Son, Hyukjoo;Lee, Inji;Park, Jeagun;Park, Yonghwan
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.53.1-53.1
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    • 2010
  • 결정질 실리콘 태양전지의 효율을 향상시키기 위하여 수광면에 서로 다른 도핑농도를 가지는 고농도 도핑영역과 저농도 도핑영역으로 이루어진 emitter를 형성하는 것이 요구되며 이를 selective emitter라 칭한다. Selective emitter를 형성하면 고농도 도핑영역에서 금속전극과 저항 접촉이 잘 형성되기 때문에 직렬 저항이 최소화되고 저농도 도핑영역에서는 전하 재결합의 감소로 인하여 태양전지의 변환효율이 상승하는 이점이 있다. Selective emitter의 형성방법은 이미 다양한 방법이 제안되고 있으나, 본 연구에서는 기존에 제시된 방법과는 다르게 열산화 시 dopant redistribution에 의한 Boron depletion 현상을 이용하여 selective emitter를 형성하는 방법을 제안하였고, 이를 Simulation을 통하여 검증하였다. 초기 emitter 확산 후 junction depth는 0.478um, 면저항은 $104.2{\Omega}/sq.$ 이었으며, nitride masking layer 두께는 0.3um로 설정하였다. $1100^{\circ}C$에서 30분간 습식산화 공정을 거친 후 nitride mask가 있는 부분의 junction depth는 1.48um, 면저항은 $89.1{\Omega}/sq$의 값을 보였고, 산화막이 형성된 부분의 junction depth는 1.16um, 면저항은 $261.8{\Omega}/sq$의 값을 보였다. 위 조건의 구조를 가진 태양전지의 변환 효율은 19.28%의 값을 나타내었고 Voc, Jsc 및 fill factor는 각각 645.08mV, $36.26mA/cm^2$, 82.42%의 값을 보였다. 한편 일반적인 구조로 설정한 태양전지의 변환 효율, Voc, Isc 및 fill factor는 각각 18.73%, 644.86mV, $36.26mA/cm^2$, 80.09%의 값을 보였다.

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Exploration on the Organization of High School Home Economics Selective Curriculum for the Fourth Industrial Revolution (4차 산업혁명을 대비한 고등학교 가정과 선택 교육과정 편성 방안 탐색)

  • Park, Mi Jeong
    • Human Ecology Research
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    • v.55 no.5
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    • pp.539-553
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    • 2017
  • This study explored the organization of high school Home Economics (HE) selective curriculum for the Fourth Industrial Revolution. We critically review the change process of HE curriculum as well as problems based on the understanding of the Fourth Industrial Revolution. The results were as follows. First, regarding the characteristic consistently shown in the revision process of high school curriculum, the huge increase of the number of subject organized resulted from the intensification of the selective-centered curriculum strengthening the choice for school and students. However, HE was reduced to some 'Technology-Home Economics' subject and a single subject 'HE Science' as a selective subject was subsequently combined with Technology after the $7^{th}$ curriculum period. Consequently, HE hard to organize the career-focused curriculum, emphasized by the revised 2015 curriculum due to the insufficient number of subjects. Second, the choice of HE in high school curriculum should be expanded as measures to organize the HE curriculum of high school to cope with changes that result from the Fourth Industrial Revolution. For the operation of the career-focused curriculum, career selective subjects and specialized subjects should be more diversely established. In accordance with changes in a future society that results from the Fourth Industrial Revolution, the HE education community should be prepared in advance to be organized as a selective subject when revising a subsequent curriculum, by newly establishing subjects necessary to students through collective intelligence and deliberation with pedagogists and scholars for subject content as well as by producing/getting approval from government-recognized textbooks.

Evaluation of Process and Satisfaction for Selective Courses in a Medical School (의과대학 선택교육과정의 운영절차와 만족도 평가)

  • Kim, Do-Hwan;Choi, Young-Hyu;Han, Sang Yun;Shin, Jwa-Seop;Lee, Seunghee
    • Korean Medical Education Review
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    • v.19 no.2
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    • pp.90-100
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    • 2017
  • The necessity of embracing selective courses in medical curriculum is increasing due to the expansion of medical knowledge and changes in the health care environment. In contrast to the abundant evidence regarding elective or selective courses during the clinical phase, articles focusing on the preclinical period are relatively scarce. This study aims to explore the development, implementation, and evaluation of newly-adopted selective courses in the first-year medical curriculum in a medical school which recently underwent a major curricular revision. First of all, the Curriculum Committee established goals and operating principles of the courses, and then the committee encouraged all participating professors to attend a related faculty development workshop after finalizing the list of courses. A survey was conducted at the end of each course for evaluation. Of the 36 courses opened in 2016, the overall satisfaction of students was $4.98{\pm}1.06$ (out of 6) and showed a strong correlation with students' previous expectations, reasoning- and participation-oriented teaching, and outcome of the courses including increased motivation. In the open-ended responses, students and professors described not only intended outcomes such as acquisition of medical knowledge and increased interest in new topics, but also unintended outcomes including positive impression for selective courses and even high satisfaction and rewarding experiences, especially from the teachers' perspective. Although long-term outcomes remain to be seen, the results of this study show the feasibility and impact of selective courses and will contribute to effective implementation in other medical schools.

Computer Generated Hologram for Beam Control of LCOS based Wavelength Selective Switch (LCOS기반의 파장선택스위치 빔제어용 컴퓨터 생성 홀로그램)

  • Lee, Yong-Min;Han, Chang Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.6
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    • pp.744-749
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    • 2016
  • This paper presents the design of a computer-generated hologram for beam control of an LCOS-based wavelength selective switch, which is the core technology for next-generation ROADM. By introducing a computer-generated hologram instead of general grating patterns to control the LCOS device, we contribute to building a more efficient wavelength selective switch. With the use of phase modulation properties of LCOS devices, we designed the hologram for five-port output and a 40-channel wavelength selective switch. We applied a multi-level phase modulation technique with the Gerchberg-Saxton algorithm to produce the hologram, which is easily scalable to any different type of wavelength selective switch. With an experimental setup, we verified the usability of the hologram designed for five-port output. We also suggest a hologram design technique for beam control of a 40-channel wavelength selective switch.

Comparative Evaluation of Selective Chromogenic Media for Coliforms Bacteria Isolated from Food (식품 유래 대장균군의 발색 배지 분리 효율 비교)

  • Lee, Da-Yeon;Kim, Hee-Eon;Lee, Jin-Sung;Kim, Keun-Sung;Cho, Yong-Sun
    • Journal of Food Hygiene and Safety
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    • v.31 no.3
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    • pp.222-225
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    • 2016
  • In this study, the performance of five selective media for coliform bacteria was evaluated. In total, 83 coliform isolates from ready-to-eat food and 21 reference strains were inoculated in five agar media : Chromocult coliform agar (Merck Millipore), HiCrome coliform agar (Sigma), CHROMagar ECC chromogenic media, Brilliance E. coli/coliform selective agar (OXOID), and endo agar (Merck Millipore). Coliform isolates and reference strains were inoculated on the selective media to test media sensitivity and specificity. The tested media showed the following sensitivities for the isolated strains: Chromocult coliforms agar and HiCrome coliform agar, 94%; Brilliance E. coli/coliform selective agar, 93%; CHROMagar ECC chromogenic media, 92%; and endo agar, 74%. In addition, all media showed 100% specificity, except for endo agar (71%). Moreover Chromocult coliform agar and HICrome coliform agar showed high levels recovery. Taken together, these results identified Chromocult coliform agar and HICrome coliform agar as an effective selective medium for coliforms with higher sensitivity and specificity compared to other media tested in this study.

Analysis of Judgements on the validity of selective/unilateral Arbitration Agreement - In case of the Supreme Court's Judgements - (선택적 중재합의의 유효성에 대한 판례분석 - 대법원 판례를 중심으로 -)

  • Chung, Young-Hwan
    • Journal of Arbitration Studies
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    • v.19 no.3
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    • pp.3-24
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    • 2009
  • This article discusses the validity of selective/unilateral arbitration agreement that provides arbitration as one of several dispute resolution methods. The Supreme Court has held selective/unilateral arbitration agreement that is conditional invalidity since the judgement of 2003Da318 decided on Aug. 22, 2003: In the following judgements of 2004Da42166 decided on Nov. 11, 2004 and 2005Da12452 decided on May 27, 2005, the Court stated that the selective/unilateral arbitration agreement that stipulates to resolve a dispute through arbitration or mediation would be valid as an effective arbitration agreement only if a party elects and proceeds an arbitration proceeding and another party responses to the arbitration proceeding without any objection. The definition of arbitration agreement, the formation of selective/unilateral arbitration agreement, the summary of relative judgements and academic theories will be reviewed in order to examine the appropriateness of the series of judgements of the Supreme Court. Based on such reviews, this article will investigate the adequacy of the Supreme Court judgements from the perspectives of i) the principle of party autonomy, ii) the structure of dispute resolution methods, iii) legal provisions of Arbitration Act, iv) legal stability, and v) the policy to revitalize the use of arbitration. At conclusion, this article will suggest the change of precedents of the Supreme Court's judgements with regard to the selective arbitral agreement.

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Performance Evaluation of Selective Coatings for Solar Thermal Collectors (태양열 집열기에 사용될 선택흡수막의 성능 평가)

  • Lee, Kil-Dong
    • Journal of the Korean Solar Energy Society
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    • v.32 no.4
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    • pp.43-50
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    • 2012
  • Metal-metal oxide (M-M oxide) cermet solar selective coatings with a double cermet layer film structure were deposited on the Al-deposited glass substrate by using a directed current (DC) magnetron sputtering technology. M oxide (CrO and ZrO) was used as the ceramic component in the cermets, and Cr and Zr used as the metallic components. In addition, black Cr (Cr-$Cr_2O_3$ cermet) solar selective coatings were deposited on the Ni-plated Cu substrate by using a electroplating method for comparison. The thermal stability tests were carried out for performance evaluation of solar coatings. Reflectance measurements were used to evaluate both solar absorptance(${\alpha}$) and thermal emittance (${\epsilon}$) of the solar coatings before and after thermal testing by using a spectrometer. Optical properties of optimized cermet solar coatings were ${\alpha}{\simeq}0.94-0.96$ and ${\epsilon}{\simeq}0.1$ ($100^{\circ}C$). The results of thermal stability test of M-M oxide solar coatings showed that the Cr-CrO cermet solar selective coatings were more stable than the Zr-ZrO cermet selective coatings at temperature of both $400^{\circ}C$ in air and $450^{\circ}C$ in vacuum. The black Cr solar selective coatings were degraded in air at temperature of $400^{\circ}C$. The main optical degradation modes of these coatings were diffusion of metal atoms, and oxidation.