• Title/Summary/Keyword: 효율성 향상

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The characteristic analysis of TCO/p-layer interface in Amorphous Silicon Solar cell (비정질 실리콘 태양전지에서 투명전도막/p층 계면 특성분석)

  • Lee, Ji-Eun;Lee, Jeong-Chul;O, Byung-Sung;Song, Jin-Soo;Yoon, Kyung-Hoon
    • New & Renewable Energy
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    • v.3 no.4
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    • pp.63-68
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    • 2007
  • 유리를 기판으로 하는 superstrate pin 비정질 실리콘 태양전진에서 전면 투명전도막(TCO)과 p-층의 계면은 태양전지 변환효율에 큰 영향을 미친다. 면투명전도막(TCO)으로 현재 일반적으로 사용되는 ZnO:Al는 $SnO_2:F$보다 전기, 광학적으로 우수하고, 안개율 (Haze)높으며, 수소 플라즈마에서 안정성이 높은 특징을 갖고 있다. 그래서 박막 태양전지의 특성향상에 매우 유리하나, 태양전지로 제조했을 때, $SnO_2$보다 충진율(Fill Factor:F.F)과 $V_{oc}$가 감소한다는 단점을 가지고 있다. 본 실험실에서는 $SnO_2:F$dml F.F.가 72%이 나온 반면 ZnO:Al의 F.F은 68%에 그쳤다. 이들 원인을 분석하기 위해 TCO/p-layer의 전기적 특성을 알아 본 결과, $SnO_2:F$보다 ZnO:Al의 직렬저항이 높게 측정되었다. 이러한 결과를 바탕으로 p-layer에 $R=(H_2/SiH_4)=25$로 변화, p ${\mu}c$-Si:H/p a-SiC:H로 p-layer 이중 증착, p-layer의 boron doping 농도를 증가시키는 실험을 하였다. 직렬저항이 가장 낮았던 p ${\mu}c$-Si:H/p a-SiC:H 인 p-layer 이중 증착에서 $V_{oc}$는 0.95V F.F는 70%이상이 나왔다. 이들 각 p층의 $E_a$(Activiation Energy)를 구해본 결과, ${\mu}c$-Si:H의 Ea 가 가장 낮은 것을 관찰 할 수 있었다.

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Implementation of Pattern-Driven Web Test Automation Framework (패턴 중심의 웹 테스트 자동화 프레임워크의 구현)

  • Na, Jong-Chae;Jeong, Hyie-Soo;Ryoo, Seok-Moon
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.12
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    • pp.1239-1243
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    • 2010
  • The web environment is evolving rapidly. Testing in the web based software is an essential process to improve stability and productivity. Testing of complex web contents and ill(user interface) is most important thing. Implemented test cases are efficient when they are automated and reusable. But, most of the testing automation tools are focused on technical accessibility and functions still. A collaboration of the persons concerned and reusability of implemented test case are ignored. In this paper we propose an efficient way to design automated test case in web environment, and to share and pattern automated test cases we introduce testing framework called NTAF(NHN Test Automation Framework.). The NTAF is based on open source framework. It provides integrated testing environment that web testing cane be automated and managed continuously.

Analysis and Improvement Strategy of Library and Information Science Education Focusing on the Reference Service Curriculums (문헌정보학 교육의 현황 분석 및 개선방안 - 정보서비스(Reference Service) 관련 교과목을 중심으로 -)

  • Chung, Jae-Young
    • Journal of Korean Library and Information Science Society
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    • v.42 no.1
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    • pp.205-223
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    • 2011
  • This study is to suggest the ways to make the education in Library and Information Science more professional and more practical by going through the problems in the curriculum of Library and Information Science in the aspect of 'reference service'. For this purpose, the curriculum changes of 32 domestic universities offering Library and Information Science between 2005 and 2009 was analyzed and compared with the current situation of the U.S. The research has revealed some problems. First of all, it shows that the subjects such as the introduction of or the theory of library and information science still comprise a large portion of the domestic curriculum. Additionally, there seems to be much difference in the number of subjects between the universities. Lastly, there are few subjects which consist of the observation and understanding of the library field, and participation therein. Therefore, to operate the 'reference service' curriculum effectively, it is necessary to offer courses for understanding the users and subjects and for the reference service. In addition, it is necessary to strengthen the practical education through a close connection with the library field. Finally, it is urgent not only to expand the subjects for improving the ability of user education and communication but also to make the curriculum of each university specialized.

Comparative Studies on Heating and Cooling Loads' of a Building Varied by Annual Weather Data (연도별 기상데이터를 활용한 건물의 냉.난방부하 특성 비교)

  • Lee, Ji-Hoon;Hwang, Kwang-Il
    • Journal of Navigation and Port Research
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    • v.35 no.3
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    • pp.265-270
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    • 2011
  • The purpose of this study is to compare and analyze the differences of a building's heating and cooling loads depending on the weather variation. Followings are the results. The temperature, humidity and wind speeds of standard year are bigger than those of 2006~2009. The 2006~2009's total horizontal solar irradiance is greater than that of standard year, and the direct solar irradiance of standard year is bigger in winter and vice versa in summer. As results of simulation on heating and cooling loads, it is difficult to find out the bilateral influences between maximum thermal loads and annual's. The equivalent-time operating ratio(EOR) is defined on this study to estimate the differences between year and year, and the EOR of standard year shows low value comparing to 2006~2009 years'.

A Study on an Improvement of Network Monitoring Performance by Adding Time Variables in SNMP PDU (SNMP PDU의 시간변수 추가를 통한 네트워크 모니터링 성능 향상에 관한 연구)

  • 윤천균;정일용
    • Journal of Korea Multimedia Society
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    • v.6 no.7
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    • pp.1266-1276
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    • 2003
  • Multimedia information containing voice and image is transmitted on Internet, which is ten times or hundred times larger than ordinary information. Analysis types for network management in this environment consist of a real time analysis, a basic analysis and an intensive analysis. The intensive analysis is useful for gathering the trend information of specific objects periodically for certain period in order to monitor network status. When SNMP is applied to collect the trend information of intensive analysis, it brings on the increase of network load, the delay of response time and the decrease of data collection accuracy since an agent responds to manager's every polling. In this paper, an efficient SNMP is proposed and implemented to add time variables in the existing SNMP PDU. It minimizes unnecessary traffic in the intensive analysis between manager and agent, and collects trend information more accurately. The results of experiments show that it has compatibility with the existing SNMP, decreases the amount of network traffic greatly and increases the accuracy of data collection.

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Playback Quantity-based Proxy Caching Scheme for Continuous Media Data (재생량에 기반한 연속미디어 데이터 프록시 캐슁 기법)

  • Hong, Hyeon-Ok;Im, Eun-Ji;Jeong, Gi-Dong
    • The KIPS Transactions:PartB
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    • v.9B no.3
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    • pp.303-310
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    • 2002
  • In this paper, we propose a proxy caching scheme that stores a portion of a continuous media object or an entire object on the Internet. The proxy stores the initial fraction of a continuous media object and determines the optimal size of the initial fraction of the continuous media object to be cached based on the object popularity. Under the proposed scheme, the initial latency of most clients and the data transferred from a remote server can be reduced and limited cache storage space can be utilized efficiently. Considering the characteristics of continuous media, we also propose the novel popularity for the continuous media objects based on the amount of the data of each object played by the clients. Finally, we have performed trace-driven simulations to evaluate our caching scheme and the popularity for the continuous media objects. Through these simulations, we have verified that our caching scheme, PPC outperforms other well-known caching schemes in terms of BHR, DSR and replacement and that popularity for the continuous media objects based on the amount of the playback data can enhance the performance of caching scheme.

Advanced Web Services Retrieval System using Matchmaking Algorithm (매치메이킹 알고리즘을 이용한 개선된 웹서비스 검색 시스템)

  • Choi, Ok-Kyung;Han, Sang-Yong;Lee, Jung-Woo
    • Journal of Intelligence and Information Systems
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    • v.13 no.3
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    • pp.1-15
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    • 2007
  • Recently, semantic web technology, represented by ontology building, is being combined with web services technology, creating 'Semantic Web Services' as a new promising field in information retrieval research. Accordingly, many brokering and matchmaking agents are being developed and used in the field. However, literature review revealed that most models do not take QoS(Quality of Services) into consideration. In this study, a QoS-augmented matchmaking algorithm is developed based on service availability, response time, maximum transaction amount, reliability, accessibility and price as critical QoS items. A prototype for Intelligent Semantic Web Services System is developed using publicly available data. Performance test was conducted and reported at the end.

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Preparation and Electrochemical Characterization of ZrO2/Ti Electrode by ESD Coating Method (ESD 코팅법에 의한 ZrO2/Ti 전극의 제조 및 전기화학적 특성)

  • Kim, Han-Joo;Hong, Kyeong-Mi;Sung, Bo-Kyung;Park, Soo-Gil
    • Journal of the Korean Electrochemical Society
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    • v.11 no.2
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    • pp.95-99
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    • 2008
  • This study has made the electrode that is coated zirconium oxide on the titanium by ESD(Electrostatic spray deposition) coating methode. It has investigated the effects of the etching method of a Ti substrate as the preparation, making of zirconium oxide film and electrochemical characteristics of the electrode that is etched on the titanium. The HCl etching develops a fine and homogeneous roughness on the Ti substrate. Fabrication and material properties of the metal oxide electrode, which is known to be so effective to generate ozone and hypochlorous acid (HOCl) as power oxidant, were studied. A proper metal oxide material is focus zirconium oxide through reference. A coating method to enhance the fabrication reproducibility of the zirconium oxide electrode was used ESD coating method by zirconium oxychloride. Zirconium oxide films on the Ti substrate were tested using SEM, XRD, Cyclic voltammetry.

A study on Road Ski Design of Air-Inflated Tires (공기주입식 로드스키 디자인에 관한 연구)

  • 윤재우
    • Archives of design research
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    • no.18
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    • pp.53-60
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    • 1996
  • A Human desire to improve the quality of living, intends to share, along with increase of the income, more importance(in the form of money and time) on the leisure and sport activity. This study has been motivated to create a design a tool(product) which will effectively and variously improve the joy of leisure and sports activity In the course of the design work; 1 We collected and reviewed all the On-Land Runni'ng leisure and sports products in the country, 2 We investigated life styles of various ages of the end users and the consumers' environmental change, to find a market pOSSibility, and 3. A good deal of consideration has been made to find the Korean folk (traditlonal)pastlme culture and to apply It into a possibility of globalization The investigation and analysis work provided a base to designing of "Air-Inflated Road Ski ", Which is completely a new form of leports product. which will help well balanced strengthening of the body, and which is enjoyable in and out-door in various ways and by everybody old or young and man or womann or woman.

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A Convergent Study on Flow at Rotor of Washing Machine (세탁기 내부의 회전날개에서의 유동에 관한 융합 연구)

  • Choi, Kye-Kwang;Cho, Jae-Ung
    • Journal of the Korea Convergence Society
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    • v.11 no.10
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    • pp.237-241
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    • 2020
  • The flow analyses in this study were executed on the three washing machine models with the rotors like real shapes. On the pressures and speeds for the left, right and bottom planes of rotors, model C was generally found to have the greatest pressure on the flow, more than twice as much as model A, and in order of model B and model A. At the streamline velocities of flow on the side of the rotating blades of models A, B and C, model C had the greatest rate of flow overall, which was 1.7 times higher than model A, followed by model B and model A. In case of model C, the number of blades is smaller than model A or model B, but the thickness of lower rotor becomes thicker. It can be seen that model C improves the washing performance due to the high flow pressure and high flow rate. Also, it is seen that this study is adequate at the efficient design with durability of the washing machine rotor practically and the aesthetic convergence of the rotor.