• Title/Summary/Keyword: 어가

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Enhancement of light reflectance and thermal stability in Ag-Mg alloy contacts on p-type GaN

  • Song, Yang-Hui;Son, Jun-Ho;Kim, Beom-Jun;Jeong, Gwan-Ho;Lee, Jong-Ram
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03a
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    • pp.18-20
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    • 2010
  • The mechanism for suppression of Ag agglomeration in Ag-Mg alloy ohmic contact to p-GaN is investigated. The Ag-Mg alloy ohmic contact shows low contact resistivity of $6.3\;{\times}\;10^{-5}\;{\Omega}cm^2$, high reflectance of 85.5% at 460 nm wavelength after annealing at $400^{\circ}C$ and better thermal stability than Ag contact The formation of Ga vacancies increase the net hole concentration, lowering the contact resistivity. Moreover, the oxidation of Mg atoms in Ag film increase the work function of Ag-Mg alloy contact and prevents Ag oxidation. The inhibition of oxygen diffusion by Mg oxide suppresses the Ag agglomeration, leading to enhance light reflectance and thermal stability.

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AN EXPERIMENT TO INDUCE SPAWNING OF CHINESE CARPS BY PITUITARY INJECTION (초어 및 백련의 인공 번식에 관한 연구)

  • Kim In-Bae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.3 no.1
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    • pp.19-26
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    • 1970
  • During the summer of 1969, a series of experiments on the spawning and development of the eggs of grass carp and silver carp was performed with the following results, but the complete development of eggs Iras not accomplished: 1. The season of maturity for both species is estimated to be from the end of June to the beginning of August. 2. Pituitary glands for the use of inducing maturation should be obtained before the maturation season of its donor. 3. Silver carp as small as 40 cm in body length (48 cm in total length) with an age of 6 years were found to have reached maturity, and the number of eggs in the ovaries were from about 23 to 26 thousand for those with body lengths of 40-44.5 cm. 4. The conical-shaped net cloth incubator worked better than others, and each incubator was most effective when installed in parallel series to the water supply pipe with a valve for each incubator to control water flow. 5. During the egg development, if any cell or cells were displaced, the eggs eventually died. 6. The proper manipulation of brood fish before the egg-taking seems to be very Important, and close care should be paid to feeding them well and keeping them in a pond of proper water depth.

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Feasibility of Enhancing Fishing Household Income Through Leports-fishing Development (레포츠피싱을 통한 어가소득 증대에 관한 연구)

  • Park, Seong Kwae;Kim, Soo Jin;Kim, Young Ja
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.2
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    • pp.180-196
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    • 2007
  • This study aims at analyzing the potential of leports-fishing for improving fishing household income. Leports-fishing is a composite concept which is combined with those of leisure, sports and fishing. Korean on-shore resources have also a composite characteristic. The properties of the east, west and south coastal waters are quite different in geography, biology and ecology. There is a array of leports-fishing development potentials of utilizing their characteristics. At present, angling forms a main activity of leports-fishing, but coastal seas would be an emerging space for the public. In order for them to be a ground of fun, enjoyment and festivals, it would be necessary to supply a wide range of activities and facilities including angling, scuba diving, fish barbecue, ecological experience, fishing experience, cruise, and so forth. As seen in the survey results, the participants have strong desire for fun and enjoyment through leports-fishing activities. The proportion of people participating in one or two times a year amounts to 40 percent. Most coastal places visited are close to medium/large cities and two-days leports-fishing/tourism accounts for some 77 percent. However, it turned out that conflicts between leports-fishing participants and fishermen are not serious. The results of expenditure function estimation appear that the elasticity of per capita income is very high with 1.2660 and that there are negative relationships between leports-fishing expenditure and transportation/food/lodging costs. Assuming the annual national economic growth rate of 4 percent, it is anticipated that Korean leports-fishing population will increase to 3.18 million in 2010 and 4.07 million in 2015. Korean leports-fishing market potential in 2015, which is calculated based on per capita expenditure on leports-fishing, appears to amount to 1,400 billion won~1,600 billion won. The contribution of such market potential to the fishing households is expected to be 62.3~74.2 percent(934.5 billion won~111.3 billion won).

Multi-reserved Words Supporting System for Object-Oriented Educational Programming Language "Dolittle" (객체지향형 교육용프로그래밍언어 두리틀의 다중 예약어 지원 체계)

  • Choe, Hae-Sim;Kwon, Dae-Yong;Kim, Hyung-Shin;Yeum, Yong-Cheul;Yoo, Seoung-Wook;Lee, Won-Gyu
    • The Journal of Korean Association of Computer Education
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    • v.8 no.2
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    • pp.23-32
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    • 2005
  • Educational Programming Language (EPL) should be learner-friendly and easy to use. Dolittle, an object-oriented educational programming language (EPL), offers programming environment which can be programmed in Korean(Hangul). However, since some Dolittle commands are not appropriate to elementary and middle school students, it shows limitations for learners to express programming process. In this paper, we developed a set of 1:n multi-reserved words which are able to program with Korean linguistic characteristics as well as considering learners' differences, preferences, and applicable areas. The conclusion in the paper showed that programming with this 1:n multi-reserved words helped learners concentrate on problem solving regardless of the reserved words.

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Usability Evaluation of ICloud Calendar and Naver Calendar -Focused on Mobile Application- (iCloud 캘린더와 네이버 캘린더의 사용성 평가 -모바일 애플리케이션을 중심으로-)

  • Yoon, Kahee;Kim, Seung-In
    • Journal of Digital Convergence
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    • v.15 no.4
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    • pp.443-449
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    • 2017
  • Since usage of smartphone becomes popular, Ecology of smart media based on smartphone is creating new ecological system of information. This research is for evaluating usability and sustainability of application due to development of smartphone usage in these days. For the research, precedent researches were analyzed and hypothesis were set up based on those researches. Then, iCloud Calendar and Never Calendar, which are two major calendar applications, were evaluated by in-depth interview and measuring task performance time of interviewees, and used these results to verify hypothesis. Then verify hypothesis through the research and analyze which type of users focus on aesthetic impression, and which users focus on usability and practicality. This research is to analyze success and failure points of Calendar Applications' user experience design, and suggests guideline for future transformation of offline to online.

Diet Composition of Coilia nasus in the Coastal Waters off Gori, Korea (고리 주변해역에서 출현하는 웅어 (Coilia nasus)의 위내용물 조성)

  • Baeck, Gun-Wook;Park, Joo-Myun;Choo, Hyun-Gi;Huh, Sung-Hoi
    • Korean Journal of Ichthyology
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    • v.23 no.2
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    • pp.163-167
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    • 2011
  • The feeding habits of Coilia nasus were studied using 107 specimens collected from January to December 2005 in the coastal waters off Gori, Korea. The size of C. nasus ranged from 8.4 to 29.5 cm in standard length (SL). C. nasus was a carnivore that mainly consumed shrimps and copepods. Its diet also included small quantities of amphipods, euphausiids and chaetognaths. The feeding strategy graphical method reveled than C. nasus was specialized feeder and showed narrow niche width. Both small and large size class of C. nasus mainly consumed shrimps and copepods, and did not showed significant size-related changes in feeding habits. However, the mean number and weight of preys per stomach was higher than large size class than small size class.

A Review of Studies on personal information (개인정보 연구동향과 과제)

  • Bang, Min Seok;Oh, Cheol H.
    • Informatization Policy
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    • v.21 no.1
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    • pp.3-16
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    • 2014
  • The personal information is now considered more valuable and important topic in this highly improved knowledge information society. In this research, 50 research papers and government reports between 2000 and 2013 are analysed to understand a trend of academic research of the personal information. To summarize of the result of the analysis, firstly, there are many discussions and emphases to governmental protections of the personal information, mainly in the qualitative and legal system level. Secondly, there are insufficient researches of the personal information, particularly in the academic field rather than government and national research institutes. Thirdly, there are not sufficient investigations to approach influential reasons and relations of cause and effect, though there are much enough researches on the actual and present conditions of the protection of the personal information. To develop the investigation of the personal information, it needs to be considered to research more about systematic approach to the issue of personal information, expansion of research area considering the changeable IT environment, diverse methodological experiment like a metrical way, reformation of investigation system, and improved information management in the private sector.

Dynamic Analysis of Long-span Arch Bridge by Fracturing Hangers (장대 아치교 행어 파단에 의한 동적 해석)

  • Yhim, Sung-Soon;Kong, Min-Sik;Yoo, Yi-Seul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.2
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    • pp.113-120
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    • 2010
  • Recently, various evaluations concerning structural stability under construction step and completely constructed step have been executed during a Long-span Arch Bridge designing procedure. However, the breakage of cable-hangers of arched bridge in unexpected accident or periodic cable-replacement has not been considered. Therefore, the purpose of this study is that analyzing structural safety of arched bridge when the cable-hangers being fractured by that reasons. Dynamic analysis are performed by idealizing impact load to three types of impact functions as fracturing the cables. Consequently, when the hangers are fractured, the maximum tensile force by dynamic analysis is larger than those by static analysis. Therefore, the dynamic analysis is demanded to accurately obtain the responses for the structural stability with a realistic impact loading model in the breakage and replacement of cable hangers of long-span arched bride. Moreover, the analysis method and results in this study can be used to basic criteria in design.

Removal Characteristics of Dissolved Uranium by Shewanella p. and Application to Radioactive Waste Disposal (스와넬라균(Shewanella p.)에 의한 용존우라늄 제거 특성 및 방사성폐기물 처분에의 응용)

  • Lee, Seung-Yeop;Baik, Min-Hoon;Song, Jun-Kyu
    • Economic and Environmental Geology
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    • v.42 no.5
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    • pp.471-477
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    • 2009
  • An experimental removal of dissolved uranium (U) exsiting as uranyl ion (${UO_2}^{2+}$) was carried out using Shewanella p., iron-reducing bacterium. By the microbial reductive reaction, initial U concentration ($50{\mu}M$) was constantly decreased, and most U were removed from solution after 2 weeks. Major mechanism that U was removed from the solution was adsorption, precipitation and mineralization on the microbe surface. Under the transmission electron microscopy, the U adsorbed on the microbe was observed as being crystallized and eventually enlarged to several ${\mu}m$ sizes of minerals by combining with individual microbes and organic exudates. It seems that such U growth and mineralization on the microbial surface could affect the U behavior in a radioactive waste disposal site. Thus, the biogechemical reaction of metal-reducing bacteria observed in this experiment could give an affirmative measure that the microbial activity may retard U movement in subsurface environment.

Fishes Growth Process System using Morphing Techniques (모핑기술을 이용한 어류 성장과정 시스템)

  • Ryu, NamHoon;Seo, SeungWan;Ban, KyeongJin;Song, SeungHeon;Kim, EungKon
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.653-657
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    • 2008
  • Industry related to digital contents is growing rapidly and is noticed as a higher value-added business. In digital reflex contents industry, computer graphics techniques are core techniques. Because they make production or scene that is difficult to photograph possible with real camera, expand a range of contents making. Lately, computer graphics techniques apply various fields such as blockbuster movie, game, educational contents, simulation etc, and there are many studies about movement of each object made up of contents or automation of object change. This paper shows the process of fishes growth, from spawn to a full-grown fish making use of 3D morphing techniques and want to plan fish growth process system that can know difference between fishes that are applied to 3D morphing techniques and normal full-grown fishes according to various environmental factors that affect growth.

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