• 제목/요약/키워드: Impediments

검색결과 103건 처리시간 0.029초

Performance Improvement of All Solution Processable Organic Thin Film Transistors by Newly Approached High Vacuum Seasoning

  • Kim, Dong-Woo;Kim, Hyoung-Jin;Lee, Young-Uk;Hong, Mun-Pyo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.470-470
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    • 2012
  • Organic thin film transistors (OTFTs) backplane constitute the active elements in new generations of plastic electronic devices for flexible display. The overall OTFTs performance is largely depended on the properties and quality of each layers of device material. In solution based process of organic semiconductors (OSCs), the interface state is most impediments to preferable performance. Generally, a threshold voltage (Vth) shift is usually exhibited when organic gate insulators (OGIs) are exposed in an ambient air condition. This phenomenon was caused by the absorbed polar components (i.e. oxygen and moisture) on the interface between OGIs and Soluble OSCs during the jetting process. For eliminating the polar component at the interface of OGI, the role of high vacuum seasoning on an OGI for all solution processable OTFTs were studied. Poly 4-vinly phenols (PVPs) were the material chosen as the organic gate dielectric, with a weakness in ambient air. The high vacuum seasoning of PVP's surface showed improved performance from non-seasoning TFT; a $V_{th}$, a ${\mu}_{fe}$ and a interface charge trap density from -8V, $0.018cm^2V^{-1}s^{-1}$, $1.12{\times}10^{-12}(cm^2eV)^{-1}$ to -4.02 V, $0.021cm^2V^{-1}s^{-1}$, $6.62{\times}10^{-11}(cm^2eV)^{-1}$. These results of OTFT device show that polar components were well eliminated by the high vacuum seasoning processes.

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항공기 비상사태에 대한 객실안전조치에 관한 연구 -객실승무원의 안전업무와 승객의 객실안전정보 인식을 중심으로- (A Study on the Improvement Methods on Cabin Safety Actions in Aircraft Accidents -Focused on Cabin Crew Safety Performances & Passenger Perceptions of Cabin Safety Information -)

  • 유경인;유광의;이춘기
    • 한국항공운항학회지
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    • 제21권4호
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    • pp.126-136
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    • 2013
  • Aircraft accidents these days, following the mega sizing trend of the aircraft, result in enormous losses of human lives apart from those of property, which cannot be replaced by any means. As most recently, in April 20, 2012, a Boeing 737 passenger plane departed Karachi on an augural flight to Islamabad, Pakistan, crashed close to an express highway on final approach, all 121 passengers and 6 crew members were killed. As such a large number of fatalities have been recorded in aircraft accidents while accident investigation results show that more than 95% of aircraft accidents are now survivable. There are three basic stages in surviving the aircraft accident: surviving the crash impact, the evacuation process and the hostile post evacuation environmental elements. These stages require the cabin crew's expeditious and appropriate actions on the basis of systematic and thorough cabin safety training in order to increase occupants' survivability, along with the passengers' preparedness. In this aspect, this paper examines the issues acting as the impediments to the passenger survival in inflight emergency situations, that are the deficiencies with cabin crew safety training, related performances and the shortcomings in passengers' knowledge on inflight safety information, leading to their inappropriate responses to emergency situations. These issues are analyzed and the root causes are identified, suggesting the resolving countermeasures.

Effect of genistein administration on the recovery of spermatogenesis in the busulfan-treated rat testis

  • Chi, Heejun;Chun, Kangwoo;Son, Hyukjun;Kim, Jonghyun;Kim, Giyoung;Roh, Sungil
    • Clinical and Experimental Reproductive Medicine
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    • 제40권2호
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    • pp.60-66
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    • 2013
  • Objective: Impairment of spermatogenesis has been identified as an inevitable side effect of cancer treatment. Although estrogen treatment stimulates spermatogenic recovery from the impaired spermatogenesis by suppressing the intra-testicular testosterone (ITT) level, side effects of estrogen are still major impediments to its clinical application in humans. Soybeans are rich in genistein, which is a phytoestrogen that binds to estrogen receptors and has an estrogenic effect. We investigated the effects of genistein administration on ITT levels, testis weight, and recovery of spermatogenesis in rats treated with a chemotherapeutic agent, busulfan. Methods: Busulfan was administered intraperitoneally to rats, and then a GnRH agonist was injected subcutaneously into the back, or genistein was administered orally. Results: The weight of the testes was significantly reduced by the treatment with busulfan. The testis weight was partially restored after busulfan treatment by additional treatment with either the GnRH agonist or genistein. Busulfan also induced atrophy of a high percentage of the seminiferous tubules, but this percentage was decreased by additional treatment with either the GnRH agonist or genistein. Treatment with genistein was effective at suppressing and maintaining ITT levels comparable to that in the GnRH agonist group. Conclusion: Genistein effectively suppressed ITT levels and stimulated the recovery of spermatogenesis in rats treated with a chemotherapeutic drug. This suggests that genistein may be a substitute for estrogens, for helping humans to recover fertility after cancer therapy without the risk of side effects.

ACC(Adaptive Cruise Control) 평가프로그램 개발 (Development of Evaluation Programs for Adaptive Cruise Control System)

  • 문영준;박유경
    • 한국ITS학회 논문지
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    • 제1권1호
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    • pp.70-78
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    • 2002
  • 치관 국제적으로 전방차량을 따라 순항하거나 전방 장애물을 인식해 경고를 주는 등 교통 및 도로 상황에 대응하여 운전자에게 안전운전을 지원하는 기능을 갖춘 첨단안전차량(Advanced Safety Vehicle: ASV)이 개발되어 시판되고 있다. 국제표준기구(ISO) ITS기술위원회(TC2O4)의 도로/차량 경고 및 제어시스템(Vehicle/Roadway Warning and Control System) 분야(WGl4)에서는 ASV의 각종 기능과 관련한 국제표준을 제정하기 위한 작업이 활발히 진행되고 있다. 또한 각 국가들은 ASV 핵심기능들을 대상으로 그 나라의 도로 및 교통 환경 하에서 실차 주행시험을 통해 기능의 안전도 및 적합성을 평가하는 연구개발을 진행하고 있다 우리나라에서도 건설교통부 ITS 연구개발사업을 통해 ASV 핵심 기능의 하나인 감응식순항제어(Adaptive Cruise Control: ACC)에 대한 국내의 주행 적합성을 평가하기 위한 종합 시험평가 프로그램이 개발 제시되었다. 본 논문에서는 진행중인 국제표준을 근거로 국내의 도로/교통조건에 따른 차량주행 시나리오를 통해 개발된 ACC 종합시험평가 프로그램을 소개하고 이에 따라 실시된 시험결과를 분석한다 이를 통해 결과적으로 ACC의 곽내 주행을 위한 안전기준의 필요성을 제시한다.

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Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus

  • Phung, Manh Hung;Wattanachai, Pongnak;Kasem, Soytong;Poeaim, Supattra
    • Mycobiology
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    • 제43권3호
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    • pp.288-296
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    • 2015
  • Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of $2.6{\sim}101.4{\mu}g/mL$. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

자연자원관리를 위한 핵심도구: 적응관리 (Adaptive Management: a key tool for natural resource management)

  • 박영철;유재원;정수영;오태건;김종렬;최미경;최옥인
    • 한국습지학회지
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    • 제21권4호
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    • pp.267-280
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    • 2019
  • 적응관리는 불확실성이 존재하는 상황에서 자연자원을 관리하는 최적의 관리방법들 중의 하나이다. 여러 가지 한계에도 불구하고, 자연자원 관리에 대한 정책 및 계획수립에 있어 적응관리방법 활용의 필요성은 국제적으로 증가하고 있다. 그러나 우리나라의 자연자원 관리분야에서는 적응관리의 활용사례가 매우 드물다. 본 연구에서는 적응관리의 정의, 절차, 장애요인들과 적용시 고려할 점에 대한 고찰 및 적응관리방법에서 필수적인 요소인 생태모델에 대하여 리뷰하였다. 또한, 적응관리의 도입이 권장되는 바다숲, 연안습지 및 수산자원관리분야에 적응관리방법을 적용할 경우 고려해야 할 사항들에 대하여도 고찰하였다.

한.중간 부가가치물류 활성화방안에 관한 연구 - 산동성을 중심으로 - (A Study on Promotion of Value Added Logistics(VAL) Activities between Korea and China)

  • 이정민;이충배
    • 한국항만경제학회지
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    • 제25권3호
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    • pp.385-406
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    • 2009
  • 한중 국교가 수립된 이래 한국과 중국간의 무역규모는 매년 급속도로 증대되고 있다. 두 국가간 경제 및 물류협력은 경제관계의 발전뿐만 아니라 부가가치 물류의 활성화를 위해서 중요하다. 그럼에도 불구하고 양국가간 운송 및 관세절차 등에 있어 물류네트워크와 관리에 장애적 요소가 여전히 존재하고 있다. 본 연구의 목적은 한국과 중국의 산동성간의 부가가치 물류활성화를 위한 방안을 제시하는 데 있다. 이를 위해 양 지역간 무역구조와 물류네트워크의 분석을 통해 부가가치 물류비즈니스 모델을 제안하였다. 아웃바운드 비즈니스 모델은 우리나라 물류기업의 중국으로의 진출방안으로 현재 영세할 뿐만 아니라 경험이 적은 관계로 정책적 지원을 통해 위험요소를 최소화할 수 있는 방안의 수립이 요구된다. 인바운드 비즈니스 모델로는 중국의 저렴한 비용에 의해 생산된 제품을 한국으로 수입하여 품질 및 브랜드 가치를 높일 수 있도록 하기 위한 항만 및 공항배후단지의 개발 및 중국 기업과의 협력체제가 중요하다. 결론적으로 양국간 부가가치 물류활성화를 도모하기 위해서는 무엇보다 양국가간 무역 및 물류분야의 협력체제 구축이 중요한 과제가 되고 있다.

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2005년 이전 생성되어 동결보관중인 배아의 처리 (Disposition of Cryopreserved Embryos Generated before the Year of 2005)

  • 이경훈;최영민
    • Clinical and Experimental Reproductive Medicine
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    • 제36권3호
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    • pp.209-217
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    • 2009
  • 목 적: 2005년 생명윤리법 시행 이전에 생성되어 동결보관중인 배아 (이후 '2005년 이전에 생성된 잔여 배아')의 처리에 관련된 문제점을 논의하고, 문제 해결을 위한 방안을 모색하고자 하였다. 연구방법: 2009년 12월 31일 이후 폐기되어야 하는 '2005년 이전에 생성된 잔여 배아'의 재이용에 관련한 각 이해 당사자들 사이의 의견 차이를 예측하였다. 또한 "2005년 이전에 생성된 잔여 배아 폐기" 및 "동의서 획득" 과정에 필연적으로 부각하게 될 여러 문제점을 파악하였다. 결 과: 관계 당국에서는 2006년 11월 23일 '국가생명윤리심의위원회'에서 심의, 의결한 '법 시행 이전에 생성된 배아 관리 지침'을 마련해 놓았으나, 이후 뚜렷한 후속 조치가 없는 것으로 파악되고 있다. 결 론: '2005년 이전에 생성된 잔여 배아'의 처리와 관련된 동의서 취득 방식에 대한 국가적 또는 사회적인 공론화 과정이 형성되지 않는다면, 생명윤리법이 궁극적으로 지키고자 하는 인간의 존엄과 가치가 침해될 가능성이 있다. '2005년 이전에 생성된 잔여 배아'에 관련된 동의서 획득 과정에 필연적으로 제기될 "합리적이고 정당한 합의 절차"를 시급히 마련하여 향후 지속적으로 제기될 생명윤리 관련 문제들에 대한 해결의 시발점이 되어야 한다.

가습기살균제 참사에 관한 학술연구의 비판적 검토와 다양한 관점의 이해 (Critical Reviews of Academic Research and Perspectives for Understanding the Humidifier Disinfectant Disaster)

  • 김지원;방예원;박문영;조경이;최예용
    • 한국환경보건학회지
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    • 제45권4호
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    • pp.340-357
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    • 2019
  • The purpose of this paper is to help develop a comprehensive understanding of the humidifier disinfectant disaster from diverse perspectives based on a critical review of the relevant academic research papers published so far in the fields of both natural and social science. The authors reviewed pertinent articles in the six academic areas of law, social science, humanities, medicine, toxicology, and environmental health. A proper understanding of the issue of humidifier disinfectant is a challenging task because diverse aspects of it have become related over the more than two decades since such products were first released to the market in 1994. Technical and esoteric issues such as the complex system for relief and compensation for health damages and the approval of chemical toxicity are known to be major impediments to viewing the bigger picture regarding this tragedy. The authors believe that experts need to consider a comprehensive perspective going beyond their individual research arena to gain a better understanding of this issue, especially since it was an alarm signal on ethics and the role of experts and scholars in Korean society. Besides the two professors arrested by the prosecutor's office, it should be remembered that medical doctors recommended patients use humidifiers and disinfectants, and the media was inactive in reporting on this issue. Furthermore, the current paucity of examination of the social and political implications of this tragedy calls for more active engagement by researchers in the humanities and social sciences. In this regard, this paper is a work of self-examination and self-criticism by the authors that could resonate with the overall academic community.

Direction Of Trade Of Major Agricultural Commodities From India

  • Kumar, K. Nirmal Ravi
    • Agribusiness and Information Management
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    • 제12권1호
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    • pp.36-49
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    • 2020
  • This study pertains to direction of exports direction of major agricultural commodities viz., rice, maize, bengal gram, chillies and cotton from India. In the ensuing next decade during 21st century, India is likely to witness changes in the export pattern of these commodities due to both internal and external constraints. One of the major internal constraints is mounting cost of production. Similarly, one of the most important external constraints include excessive subsidization by importing countries that makes Indian commodities less competitive in the international market. So, the important research question is to analyse the direction of exports of major agricultural commodities from India during post-WTO regime. The dynamic nature of trade pattern of the selected commodities was analyzed by employing the first order Markov process by examining gains and losses in respect of export shares of major Indian agricultural commodities to different countries. During the post-WTO regime, it was found that Saudi Arabia for rice, Bangladesh for maize, Pakistan for bengal gram, Malaysia for (dry) chillies, China, mainland for cotton are the loyal destinations for the commodities. The increasing demand for the selected commodities in countries like Saudi Arabia, Côte d'Ivoire for rice; Malaysia for maize; Pakistan and Algeria for Bengal gram; USA and Sri Lanka for (dry) chillies and Vietnam, Pakistan and Indonesia for cotton need to be explored for augmenting the exports. In order to achieve this goal, it is essential that consumer preferences in newer markets, market intelligence and impediments for augmenting exports need to be researched. It is also high time to analyze the export competitiveness of selected commodities across these importing countries.