• Title/Summary/Keyword: inexpensiveness

Search Result 15, Processing Time 0.026 seconds

Synthesis and photovoltaic performance of novel ionic dyes for the dye-sensitized solar cells (신규 유기염료를 적용한 염료감응 태양전지의 광전변환거동)

  • Jung, Mi Ran;Lee, Jeong Gwan;Kim, Sang Ah;Kim, Jae Hong
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.120.2-120.2
    • /
    • 2011
  • The improvement of solar energy-to-electricity conversion efficiency has continued to be an important research area of dye-sensitized solar cells (DSSCs). The mechanism of DSSCs is based on the injection of electrons from the photoexcited dye into the conduction band of nanocrystalline TiO2 or ZnO. Thus, the electronic structures, such as HOMO, LUMO, and HOMO-LUMO band gaps of dye moleculed in DSSC are deeply related to the electron transfer by photoexcitation and redox potential. Organic dyes, because of their many advantages, such as high molar extinction coefficients, convenience of customized molecular design for desired photophysical and photochemical properties, inexpensiveness with no transition metals contained, and environment-friendliness, are suitable as photosensitizers for DSSC. We believe that practically useful organic dye photosensitizers can be produced by exploiting electron donor/acceptor system with proper length of ${\pi}$-conjugation in a chromophore to control the absorption wavelength and enhance the photovoltaic performance. In this research, We designed and synthesized organic dyes also investigated the photoelectrochemical properties of a series of ionic dyes in DSSCs.

  • PDF

(Design and Implementation of a Web-Based Tool for Information Security Levelling with Multiple Weights) (다중 가중치를 적용한 웹 기반 정보보호수준 측정 도구 설계 및 구현)

  • Sung, Kyung;Choi, Sang-Yong;So, Woo-Young;Kim, Sung-Ok
    • Journal of the Korea Computer Industry Society
    • /
    • v.3 no.9
    • /
    • pp.1315-1328
    • /
    • 2002
  • Recently there has been increasing demand on developing methodologies and tools for measuring the information security level of organizations for the efficient security management, as the growth of security incidents. However, most methodologies from foreign countries are not realistic in constructing the checklists, moreover their tools provide neither the ease of use nor the inexpensiveness, and most domestic works are not properly considering the characteristics of the organizations. In this study, based on the recently developed standard for information security management, an information security levelling tool is designed and implemented which can be used before building an information security management system while considering the characteristics of organizations more efficiently. The efficiency comes from applying multiple variable weights for security levelling according to the characteristics of organizations.

  • PDF

An Information Security Levelling Toll using Fuzzy Technique (퍼지기법을 이용한 보안수준 측정 도구)

  • Sung, Kyung;Choi, Sang-Yong;So, Woo-Young
    • Convergence Security Journal
    • /
    • v.2 no.2
    • /
    • pp.123-135
    • /
    • 2002
  • As the development of information technology and thus the growth of security incidents, there has been increasing demand on developing methodologies and tools for measuring the information security level of organizations for the efficient security management. However, most works from foreign countries are not realistic in constructing the checklists, moreover their tools provide neither the ease of use nor the inexpensiveness, and most domestic works are not properly considering the characteristics of the organizations when measuring the information security level. In this study, an efficient information security levelling tool is suggested, which applies the multiple variable weights for security levelling according to the characteristics of organizations and the fuzzy technique to reduce the user's subjectivity.

  • PDF

A Study on Modeling Tool for Convergence of Smart Appliances (스마트 기기의 컨버전스를 위한 모델링 도구에 관한 연구)

  • Son, Hyun Seung;Kim, Woo Yeol;Kim, R. Young Chul
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.8 no.4
    • /
    • pp.119-125
    • /
    • 2008
  • The traditional way for convergence of smart appliances was software integrations on middleware. It is possible advantage to integrate easily and quickly with this way. But basically the middleware approach is slowly executed as it is huge the size of software. To solve this problem, we suggest a modeling tool for convergence. As we can execute and generate the automatic source code at the design phase with our modeling tool, it is possible to do software integration without the middleware. We use one example of U-Home environment to show the convergence for TV and the door lock system. With our approach, we will be able quickly to develop the convergent products what the customers desire with inexpensiveness, that is, the convergence of smart appliances without the middleware.

  • PDF

Organic Sensitizers based on Bis-carbazole for Dye-Sensitized Solar Cells (비스-카바졸 유기염료를 이용한 염료감응태양전지)

  • Kim, Hyo-Jeong;Byun, Yeo-Jin;Nam, Jung-Eun;Kim, Dae-Hwan;Kang, Jin-Kyu
    • 한국태양에너지학회:학술대회논문집
    • /
    • 2012.03a
    • /
    • pp.397-399
    • /
    • 2012
  • Dye-sensitized solar cells (DSSCs) have received considerable attention as the most promising candidates for renewable energy systems in recent years. Among these, organic dyes which have many advantages such as large absorption coefficients, customized molecular design for desired photophysical and photochemical properties, inexpensiveness and environment-friendliness, are suitable as photosensitizers for DSSCs. We have studied on the design and synthesis of two organic dyes (BECZ 1 and BECZ 2) with a 9-ethyl-9H-carbazole core for dye-sensitized solar cells (DSSCs). Two organic dyes comprised of two 9-ethyl-9H-carbazole moiety as electron-donor, two types of cyanoacrylic acid moiety acting as acceptor. In addition, n-ethyl unit introduced for increasing the solubility and the donating power. The obtained organic dyes were comprehensively characterized by NMR, GC-MS, FAB-MS and UV/Vis spectroscopies. DSSCs sensitized by the dyes BECZ1 and BECZ2 produced ${\eta}$ value 3.31% and a ${\eta}$ value 3.21%.

  • PDF

Musculoskeletal Ultrasound Intervention: Principles & Cautions (초음파를 이용한 침습적 치료: 원칙과 주의점)

  • Oh, Gun-Myung;Lee, Kyung Jae;Min, Byung-Woo;Kim, Dong-Wan
    • The Journal of Korean Orthopaedic Ultrasound Society
    • /
    • v.6 no.1
    • /
    • pp.38-44
    • /
    • 2013
  • The ultrasound can be used primarily to guide exact needle placement for aspirations of fluids, injections of steroid, and biopsies in musculoskeletal field. Recently, ultrasound-guided intervention is widely used because of several advantages such as real-time performance, relatively inexpensiveness, and getting multiple images without additional radiations. However, the modality is operator dependent and requires detailed knowledge of the relevant anatomy and there have been also reported serious complications related to the procedure. So, authors will discuss about the basic techniques, principles and cautions for the use of ultrasound-guided intervention in musculoskeletal field.

  • PDF

Web-Based Information Security Leveling Tool (웹 기반 정보보안 수준 측정 도구 설계)

  • Sung, Kyung
    • Journal of the Korea Society of Computer and Information
    • /
    • v.10 no.4 s.36
    • /
    • pp.375-384
    • /
    • 2005
  • As the development of information communication technology and thus the growth of security incidents, there has been increasing demand on developing methodologies and tools for measuring the information security level of organizations for the efficient security management. However, most works from foreign countries are not realistic in constructing the checklists, moreover their tools provide neither the ease of use nor the inexpensiveness, and most domestic works are not properly considering the characteristics of the organizations when measuring the information security level. In this study, an efficient information security levelling tool is suggested, which applies the multiple variable weights for security levelling according to the characteristics of organizations and the fuzzy technique to reduce the user's subjectivity and the genetic algorithm to establish the security countermeasure.

  • PDF

Highly Efficient and Stable Organic Photo-Sensitizers based on Triphenylamine with Multi-anchoring Chromophore for Dye-sensitized Solar Cells (트리페닐아민을 이용한 염료감응형 태양전지 고효율 염료합성)

  • Yang, Hyunsik;Jung, Daeyoung;Jung, Miran;Kim, Jaehong
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2010.06a
    • /
    • pp.88.1-88.1
    • /
    • 2010
  • Organic dyes, because of their many advantages, such as high molar extinction coefficients, convenience of customized molecular design for desired photophysical and photochemical properties, inexpensiveness with no transition metals contained, and environment-friendliness, are suitable as photosensitizers for the Dye-sensitized Solar Cell (DSSC). The efficiency of DSSC based on metal-free organic dyes is known to be much lower than that of Ru dyes generally, but a high solar energy-to-electricity conversion efficiency of up to 8% in full sunlight has been achieved by Ito et al. using an indoline dye. This result suggests that smartly designed and synthesized metal-free organic dyes are also highly competitive candidates for photosensitizers of DSSCs with their advantages mentioned above. Recently, the performance of DSSC based on metal-free organic dyes has been remarkably improved by several groups. We had reported the novel organic dye with double electron acceptor chromophore, which was a new strategy to design an efficient photosensitizer for DSSC. To verify the strategy, we synthesized organic dyes whose geometries, electronic structures and optical properties were derived from preceding density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. In this paper, we successfully synthesized the chromophore containing multi-acceptor push-pull system from triphenylamine with thiophene moieties as a bridge unit. Organic dyes with a single electron acceptor and double acceptor system were also synthesized for comparison purposes. The photovoltaic performances of these dyes were compared, and the recombination dark current curves and the incident photon-to-current (IPCE) efficiencies were also measured in order to characterize the effects of the multi-anchoring groups on the open-circuit voltage and the short-circuit current. In order to match specifications required for practical applications to be implemented outdoors, light soaking and thermal stability tests of these DSSCs, performed under $100mWcm^{-2}$ and $60^{\circ}C$ for 1000h.

  • PDF

Motivators and Demotivators of Chat Reference Service (채팅을 통한 정보봉사 서비스의 이용자 동기화 및 비동기화 요인)

  • Lee, Seong-Sin
    • Journal of the Korean Society for information Management
    • /
    • v.25 no.2
    • /
    • pp.115-125
    • /
    • 2008
  • The Purpose of this study was to discover the factors which motivate academic library users to use chat reference service and which demotivate academic library users to use chat reference service. To achieve the study purposes, this study conducted interview with the selected participants (Information Studies graduate students at Florida State University(FSU)) through email in April and May 2007. This study found that 1) convenience, 2) anonymity, and 3) inexpensiveness of the service served as incentives(motivators) for chat reference service consumers to use the service. On the other hand, chat reference service consumers mentioned the following factors as obstacles (demotivators) for using the service: 1) waiting time, 2) accessibility, 3) interface design, and 4) difficulties with expressing themselves in a virtual space.

한국상사중재의 국제화와 경쟁력

  • Jo, Jeong-Gon
    • Journal of Arbitration Studies
    • /
    • v.7 no.1
    • /
    • pp.411-446
    • /
    • 1997
  • This paper reports the results of an experimental companson of the winning rates in arbitral awards between the Korean Commercial Arbitration Board and the Japan Commercial Arbitration Association, and analyzed the comparative advantages of KCAB in international arbitration compared with ICC. There are so many factors to analyze the level of internationalizaton and competitiveness in the arbitration. From the recent lituratures, arbitration experts reported and debated tremendous elements which is vital to have a competition in the international arbitration market. Arbitration factors such as fairness, reliability, awareness, extension, enforcement, inexpensiveness, closed and expedited proceedings, arbitrators, expert knowledge, service, arbitral award, etc. are very important to appraise the level of the globalization and competitiveness of arbitration organizations Using these factors, I appraised current level of the globalization and competitiveness of the Korean Commercial Arbitration Board, unique arbitration organization in South Korea. Next, we are able to compare the level of fairness using the concept of 'winning rate' All over the world, only several arbitration organizations published and opened their own arbitral awards even In anonymity. The Japanese arbitration institutions published it regularly as well as the Korean When compared with these two institutions' "winning rates". there is similiar tendency in favor of domestic corporations That is to say, the winning rates in domestic arbitration cases are greater than those in international arbitration cases. This embarks an implication of unequality, a part of unfairness, in these two countries' arbitration. Finally, an analysis was conducted between the statistics of KCAB and ICC, especially to the focus on the number of arbitration cases, arbitration tribunals, arbitration places, parties' nationalities. the types of contents, the amount of arbitration, arbitration costs. There are two meanings to keep in mind for advancement of Korean arbitration. One is to establish new strategy specializing in small amount arbitration less than US$200,000. The other is to rearrange the panel of arbitration, especially in increasing field of arbitration cases such as the disputes of license, technology transfer, patent, etc.

  • PDF