• Title/Summary/Keyword: visible-LED

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Color Filter Based on a Sub-wavelength Patterned Metal Grating (광파장 이하 주기를 갖는 금속 격자형 컬러필터)

  • Lee, Hong-Shik;Yoon, Yeo-Taek;Lee, Sang-Shin;Kim, Sang-Hoon;Lee, Ki-Dong
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.383-388
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    • 2007
  • A color filter was demonstrated incorporating a patterned metal grating in a quartz substrate. The filter is created in a metal layer perforated with a symmetric two-dimensional array of circular holes, with the pitch smaller than the wavelength of the visible light. A finite-difference time-domain simulation was performed to analyze the device by investigating the effect of structural parameters like the grating height, the period, the hole size, and the refractive index of the hole-filling material on its performance. The device performance was especially optimized by controlling the refractive index of the material comprising the holes of the grating. And two different devices were fabricated by means of the e-beam direct writing with the following design parameters: the grating height of 50 nm, the two pitches of 340 nm for the red color and 260 nm for the green color. For the prepared device with the period of 340 nm, the center wavelength was 680 nm and the peak transmission 57%. And for the other device with the pitch of 260 nm, the center wavelength was 550 nm and the peak transmission was 50%. The filling of the hole with a material whose refractive index is matched to that of the substrate has led to an increase of ${\sim}15%$ in the transmission efficiency.

Microfluidic Assisted Synthesis of Ag-ZnO Nanocomposites for Enhanced Photocatalytic Activity (광촉매 성능 강화를 위한 미세유체공정 기반 Ag-ZnO 나노복합체 합성)

  • Ko, Jae-Rak;Jun, Ho Young;Choi, Chang-Ho
    • Clean Technology
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    • v.27 no.4
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    • pp.291-296
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    • 2021
  • Recently, there has been increasing demand for advancing photocatalytic techniques that are capable of the efficient removal of organic pollutants in water. TiO2, a representative photocatalytic material, has been commonly used as an effective photocatalyst, but it is rather expensive and an alternative is required that will fulfill the requirements of both high performing photocatalytic activities and cost-effectiveness. In this work, ZnO, which is more cost effective than TiO2, was synthesized by using a microreactor-assisted nanomaterials (MAN) process. The process enabled a continuous production of ZnO nanoparticles (NPs) with a flower-like structure with high uniformity. In order to resolve the limited light absorption of ZnO arising from its large band gap, Ag NPs were uniformly decorated on the flower-like ZnO surface by using the MAN process. The plasmonic effect of Ag NPs led to a broadening of the absorption range toward visible wavelengths. Ag NPs also helped inhibit the electron-hole recombination by drawing electrons generated from the light absorption of the flower-like ZnO NPs. As a result, the Ag-ZnO nanocomposites showed improved photocatalytic activities compared with the flower-like ZnO NPs. The photocatalytic activities were evaluated through the degradation of methylene blue (MB) solution. Scanning electron microscopy (SEM), x-ray diffraction (XRD), and energy-dispersive x-ray spectroscopy (EDS) confirmed the successful synthesis of Ag-ZnO nanocomposites with high uniformity. Ag-ZnO nanocomposites synthesized via the MAN process offer the potential for cost-effective and scalable production of next-generation photocatalytic materials.

Current Status and Needs Assessment for Obesity Prevention and Management Project at Public Health Centers (보건소 비만예방관리 사업 현황 및 요구도 분석)

  • Park, Jiyoung;Im, Mihae;Baek, Seolhyang;Park, Chongwon;Hwang, Gahui;Kim, Wansoo;Oh, Yumi;Cho, A Ra;Jo, Jieun
    • Research in Community and Public Health Nursing
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    • v.32 no.3
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    • pp.368-381
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    • 2021
  • Purpose: The obesity prevention and management program led by public health centers are important in the community. This study aims to identify the current status of obesity prevention and management programs at public health centers and perceptions regarding facilitators and barriers when implementing programs. Methods: This study used a concurrent mixed methods design. A survey was conducted to investigate the current status and infrastructure of the obesity prevention and management program at eighty-three public health centers nationwide. Nine program managers and six local residents with experience in the program were interviewed by using a semi-structured questionnaires. Results: Most of the infrastructure facilities for the program were inadequate, and insufficient budgets and lack of professional staff were identified as barriers. Facilitators included diversification of program delivery methods, operator competence, and visible outcomes and rewards. For the effectiveness of the program, it is vital to have adequate assistants, a sufficient budget, various promotional methods, and connections with various institutions in the community. On this basis, it is acknowledged that the public health center serves as a platform for preventing and managing obesity in the community. Conclusion: It is expected that infrastructure improvements in public health centers and the link with community resources are needed. In addition, there is an urgent need to set standards for obesity prevention and management programs implemented in public health centers to 'resolve regional disparities'.

The Effect of Startup Support Policy on Entrepreneurship: Focusing on TIPS Support Projects by the Ministry of SMEs and Startups (창업지원정책이 기업가정신에 미치는 영향: 중소벤처기업부 팁스(TIPS) 지원사업을 중심으로)

  • Kim, Mijoo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.3
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    • pp.1-17
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    • 2022
  • This study studied the effect of the TIPS support project of the Ministry of SMEs and Startups on the entrepreneurship of TIPS start-ups. The Tips start-up company, which is the subject of the study, was selected for the TIPS support project, participated in all commercialization funds, incubation facilities, and capacity building programs, and was selected as a company that received private investment. One-on-one in-depth interviews were conducted for about eight weeks from January 14, 2022 to March 11, 2022. For this study, the TIPS support project was subdivided into four categories: commercialization funds, incubation facilities, capacity building programs, and private investment attraction, and entrepreneurship factors were classified into four categories: innovation, challenge spirit, leadership, and risk-taking. As a result of the in-depth interview, the influence of the TIPS support project on entrepreneurship factors was in the order of challenge spirit, innovation, risk-taking, and leadership. Specifically, it was found that commercialization funds influenced innovation and risk-taking, incubation facilities had a challenge spirit and risk-taking, competency-building programs had a challenge spirit and leadership, and attracting private investment had an influence on innovation and challenge spirit. The implications of this study are that the TIPS support project, a private investment-led technology start-up support program, was introduced in 2013 and as of the end of March 2022, and a report was prepared focusing on visible performance such as private investment performance and employment rate. However, through this study, by analyzing whether the TIPS support project contributed to the cultivation of entrepreneurship for TIPS start-ups, it was found that it had a positive influence not only on quantitative growth but also on qualitative growth.

A Case Study of ART Counseling on Maladjusted Children's Self-Respect and Social Ability Development (부적응 아동의 자아존중감 및 사회성 발달을 위한 미술상담 사례연구)

  • Hong, Mi-Young;Cho, Bung-Hwan
    • The Korean Journal of Elementary Counseling
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    • v.8 no.1
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    • pp.109-122
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    • 2009
  • The purpose of this study was to put an art counseling program in the elementary school maladjusted child and helped the school life adjustment of the maladjusted child's self-respect and social ability development. For this purpose, picked out 4 people children who are the lowest score in the child where the total score is below 100 points sorted 6 grades of Y elementary school in Daejeon. The art counseling program as a reconstruction of the prior study to meet an object of this study was provided to children in experimental group at the researcher's classroom after school for 12 session, two sessions per week. For analyze the study result. First, for quantitatively analysis of an maladjusted behavior compared pre and post test of conduct of school life adjustments test. Second, for confirm the change of self-respect and social ability development pre and post test and analyzed comparison. Third, recognizing trial state change of an maladjusted children put a KSD pre and post test and analyzed comparison with contents of a picture. Fourth, every session of the qualitative analysis which describes the conduct quality of each child led and the maladjusted child should have been visible what kind of change after the art counseling program execution criminal record, compared. The result of the study is the art counseling program decreased the maladjust conduct of the maladjusted child and is effective to self-respect and social ability development of the maladjusted child. And the art counseling program letting induces the change which is affirmative psychologically with the maladjusted child. As a result, the art counseling program to help the self-respect of the maladjusted child and social ability development, and it will be more effective in the school life adjustment for the maladjusted child.

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The Abuse and Invention of Tradition from Maintenance Process of Historic Site No.135 Buyeo Gungnamji Pond (사적 제135호 부여 궁남지의 정비과정으로 살펴본 전통의 남용과 발명)

  • Jung, Woo-Jin
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.2
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    • pp.26-44
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    • 2017
  • Regarded as Korea's traditional pond, Gungnamj Pond was surmised to be "Gungnamji" due to its geological positioning in the south of Hwajisan (花枝山) and relics of the Gwanbuk-ri (官北里) suspected of being components to the historical records of Muwang (武王)'s pond of The Chronicles of the Three States [三國史記] and Sabi Palace, respectively, yet was subjected to a restoration following a designation to national historic site. This study is focused on the distortion of authenticity identified in the course of the "Gungnamji Pond" restoration and the invention of tradition, whose summarized conclusions are as follows. 1. Once called Maraebangjuk (마래방죽), or Macheonji (馬川池) Pond, Gungnamji Pond was existent in the form of a low-level swamp of vast area encompassing 30,000 pyeong during the Japanese colonial period. Hong, Sa-jun, who played a leading role in the restoration of "Gungnamji Pond," said that even during the 1940s, the remains of the island and stone facilities suspected of being the relics of Gungnamji Pond of the Baekje period were found, and that the traces of forming a royal palace and garden were discovered on top of them. Hong, Sa-jun also expressed an opinion of establishing a parallel between "Gungnamji Pond" and "Maraebangjuk" in connection with a 'tale of Seodong [薯童說話]' in the aftermath of the detached palace of Hwajisan, which ultimately operated as a theoretical ground for the restoration of Gungnamj Pond. Assessing through Hong, Sa-jun's sketch, the form and scale of Maraebangjuk were visible, of which the form was in close proximity to that photographed during the Japanese colonial period. 2. The minimized restoration of Gungnamji Pond faced deterrence for the land redevelopment project implemented in the 1960s, and the remainder of the land size is an attestment. The fundamental problem manifest in the restoration of Gungnamji Pond numerously attempted from 1964 through 1967 was the failure of basing the restorative work in the archaeological facts yet in the perspective of the latest generations, ultimately yielding a replication of Hyangwonji Pond of Gyeongbok Palace. More specifically, the methodologies employed in setting an island and a pavilion within a pond, or bridging an island with a land evidenced as to how Gungnamji Pond was modeled after Hyangwonji Pond of Gyeongbok Palace. Furthermore, Chihyanggyo (醉香橋) Bridge referenced in the designing of the bridge was hardly conceived as a form indigenous to the Joseon Dynasty, whose motivation and idea of the misguided restoration design at the time all the more devaluated Gungnamji Pond. Such an utterly pure replication of the design widely known as an ingredient for the traditional landscape was purposive towards the aesthetic symbolism and preference retained by Gyeongbok Palace, which was intended to entitle Gungnamji Pond to a physical status of the value in par with that of Gyeongbok Palace. 3. For its detachment to the authenticity as a historical site since its origin, Gungnamji Pond represented distortions of the landscape beauty and tradition even through the restorative process. The restorative process for such a historical monument, devoid of constructive use and certain of distortion, maintains extreme intimacy with the nationalistic cultural policy promoted by the Park, Jeong-hee regime through the 1960s and 1970s. In the context of the "manipulated discussions of tradition," the Park's cultural policy transformed the citizens' recollection into an idealized form of the past, further magnifying it at best. Consequently, many of the historical sites emerged as fancy and grand as they possibly could beyond their status quo across the nation, and "Gungnamji Pond" was a victim to this monopolistic government-led cultural policy incrementally sweeping away with new buildings and structures instituted regardless of their original space, and hence, their value.