• 제목/요약/키워드: Line of Defence

검색결과 55건 처리시간 0.027초

Seismic performance of gravity-load designed concrete frames infilled with low-strength masonry

  • Siddiqui, Umair A.;Sucuoglu, Haluk;Yakut, Ahmet
    • Earthquakes and Structures
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    • 제8권1호
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    • pp.19-35
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    • 2015
  • This study compares the seismic performances of two reinforced concrete frame specimens tested by the pseudo-dynamic procedure. The pair of 3-storey, 3-bay frames specimens are constructed with typical characteristics of older construction which is lacking seismic design. One of the specimens is a bare frame while the other is infilled with low-strength autoclave aerated concrete (AAC) block masonry. The focus of this study is to investigate the influence of low strength masonry infill walls on the seismic response of older RC frames designed for gravity loads. It is found that the presence of weak infill walls considerably reduce deformations and damage in the upper stories while their influence at the critical ground story is not all that positive. Infill walls tend to localize damage at the critical story due to a peculiar frame-infill interaction, and impose larger internal force and deformation demands on the columns and beams bounding the infills. Therefore the general belief in earthquake engineering that infills develop a second line of defence against lateral forces in seismically deficient frames is nullified in case of low-strength infill walls in the presented experimental research.

한약재-식물성천연화학물질의 항산화 효능 및 기전 (Anti-Oxidant Efficiency and Memchanisms of Phytochemicals from Traditional Herbal Medicine)

  • 김종봉
    • 대한예방한의학회지
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    • 제12권1호
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    • pp.103-118
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    • 2008
  • Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species (ROS). Some ROS, such as superoxide and hydrogen peroxide, are normally produced in cells as by-products of biochemical reactions or as signaling molecules. When ROS-generating reactions are activated excessively, pathological quantities of ROS are released to create an imbalance between antioxidants and ROS, called as oxidative stress. Oxidative stress, which may result in cellular damage, has been linked to cardiovascular disease, diabetes, cancer, and other degenerative conditions. In humans the first line of antioxidant defence are the antioxidant enzymes, especially SOD, glutathione peroxidase (GPX), and to a lesser extent catalase, as well as the tripeptide glutathione(GSH). These enzymes will help destroy ROS(reactive oxygen species) such as hydroxyl radical, $H_2O_2$ and lipid peroxides, while GSH protects against oxidized protein. Many herbal medicines possess antioxidant properties. Herbal antioxidants may protect against these diseases by contributing to the total antioxidant defense system of the human body. Here, many herbal medicines including Ginseng, Licorice, Ligusticum Chuanxiong, Ginkgo biloba and many others was reviewed in terms of anti-oxidant efficiency related to their components.

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Unlimited Liability

  • Mckay, John S.
    • 항공우주정책ㆍ법학회지
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    • 제6권
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    • pp.137-147
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    • 1994
  • Clearly there are many legal arguments and criticisms surrounding the proposals for change in the Warsaw Convention and the need for a radical review. The question remains is unlimited liability the answer or should there be some other form of supplemental compensation and if so, what limits should be applicable. It does seem that the adopted limits of the Convention are seen by many as the first line of defence, which, dependent on political and cultural differences, the legal interpretation of contractual wording and the legal system globally have resulted in enormous differences in compensation paid whether or not the Convention limits were imposed. An example of this is in the United States, which highlights the significance of the problem in that domestic travellers without Convention Limits can, through the American legal system, obtain compensation in the multi-million dollar area for a death claim, whereas a passenger t1ying internationally would in the first instance be subject to Convention Limits. expensive legal action through litigation. To date, we can advise that insurers have not charged additional premium for unlimited liability coverage. Insurance rates as we have stated are hardening considerably. To date, average rate increases have been plus 56% for aircraft hull and plus 45% for liabilities. Insurers last year suffered global losses of around US $ 1.1 Billion against a premium income of US $ 800,000. The target premium income for 1993 is believed to be in the region of US $1.4 Billion.

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경기 북부지역의 관광자원으로서 향토음식에 대한 고찰 (A Report on Utilizing Local Food as Tourism Resource of Northern Gyong-gi Province)

  • 남정혜;최태호
    • 한국식품영양학회지
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    • 제14권5호
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    • pp.479-484
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    • 2001
  • Gyong-gi province has been the political, social, economical center of Korea since the three Kingdom period, Koryo, Chosun dynasty. As a result, the area enjoys abundant local food culture. However, due to the truce line going through the province, it was divided into northern and southern region. Development of the northern Gyong-gi province has been restricted because of security and defence reasons. So, even though it has kept abundant local food heritage compared to other regions. local food products have not been fully developed. Furthermore, as bed towns of Seoul and new towns are constructed in this region, traditional and local culture has been vanished gradually and the regional uniqueness is disappearing. This report focuses on identifying unique local foods of northern Gyong-gj province where tourist site development is limited and finding out how to utilize these as international tourism resource in the 21$\^$th/ century, the era of reunified Korea. Now, we need to seek ways to overcome the current difficulties and utilize the heritage of food culture and develop It in a form that suits the taste of modern consumers.

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면역 알고리즘을 이용한 강건한 제어 시스템 설계 (On Designing a Robust Control System Using Immune Algorithm)

  • 서재용;원경재;김성현;조현찬;전홍태
    • 한국지능시스템학회논문지
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    • 제8권6호
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    • pp.12-20
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    • 1998
  • 제어 환경의 변화에 강건하게 대처할 수 있는 제어 시스템을 개발하기 위해서, 본 논문에서는 자연계의 면역 시스템과 다층 신경망을 결합한 제어 시스템을 제안한다. 제안한 제어 시스템은 면역 알고리즘을 이용하여 다층 신경망의 가중치를 조절한다. 면역 알고리즘은 초기 방어 단계인 선천성 면역 알고리즘과 적응 단계인 적응 면역 알고리즘으로 구성되어 있다. 과거에 학습한 경험이 있는 환경과 유사한 환경에 대해서 선천성 면역 알고리즘이 동작하고, 학습한 경험이 없는 새로운 제어 환경의 변하에 대해서는 적응 면역 알고리즘이 동작한다. 면역 알고리즘을 이용한 제어 시스템을 로봇 매니퓰레이터의 궤적 추종 제어에 적용하였으며, 컴퓨터 모의 실험을 통해 제어 시스템의 성능을 평가한다.

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MONITORING OF BAR TRANSFORMATION IN THE HAN RIVER ESTUARY USING RADARSAT/SAR IMAGES

  • Yang, Chan-Su;Han, Hee-Jeong;Park, Jin-Kyu;Ouchi, Kazuo
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.856-859
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    • 2006
  • In river with bar, the characteristics of its physical conditions have a close relationship with bar morphology. In this paper, a monitoring approach of bar transformation in the Han River Estuary is presented using RADARSAT/SAR Images. The estuary is divided into North and South Korea and its area is blocked by CCL(Civil Control Line). Satellite remote sensing, therefore, is uniquely suited to monitoring bar transformation. Based on SAR signatures for bars, bar transformation is investigated from 2000 to 2005, and monitoring of suspended-silt transportations from terrestrial runoff is tried to understand the morphology during the events of severe rain storm. SAR data did not reveal clearly the bar locations because of most of data acquisitions during high tides from 6.8 m to 9.0 m. Even though the problem, it could be said that in the estuary vegetated area and natural levees are developed well, but bars and shifted after an event like a flood. It is also showed that suspended solids such as silt transported through the estuary could contribute highly to a sedimentation environment around Incheon.

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A comparison of individual and combined $_L$-phenylalanine ammonia lyase and cationic peroxidase transgenes for engineering resistance in tobacco to necrotrophic pathogens

  • Way, Heather M.;Birch, Robert G.;Manners, John M.
    • Plant Biotechnology Reports
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    • 제5권4호
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    • pp.301-308
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    • 2011
  • This study tested the relative and combined efficacy of ShPx2 and ShPAL transgenes by comparing Nicotiana tabacum hybrids with enhanced levels of $_L$-phenylalanine ammonia lyase (PAL) activity and cationic peroxidase (Prx) activity with transgenic parental lines that overexpress either transgene. The PAL/Prx hybrids expressed both transgenes driven by the 35S CaMV promoter, and leaf PAL and Prx enzyme activities were similar to those of the relevant transgenic parent and seven- to tenfold higher than nontransgenic controls. Lignin levels in the PAL/Prx hybrids were higher than the PAL parent and nontransgenic controls, but not significantly higher than the Prx parent. All transgenic plants showed increased resistance to the necrotrophs Phytophthora parasitica pv. nicotianae and Cercospora nicotianae compared to nontransgenic controls, with a preponderance of smaller lesion categories produced in Prx-expressing lines. However, the PAL/Prx hybrids showed no significant increase in resistance to either pathogen relative to the Prx parental line. These data indicate that, in tobacco, the PAL and Prx transgenes do not act additively in disease resistance. Stacking with Prx did not prevent a visible growth inhibition from PAL overexpression. Practical use of ShPAL will likely require more sophisticated developmental control, and we conclude that ShPx2 is a preferred candidate for development as a resistance transgene.

WLAN 시스템에 적용 가능한 그라운드 슬롯과 stub를 갖는 변형된 링 안테나 설계와 제작 (Design and Manufacture of Modified Ring antenna with Stub and Ground Slot for WLAN Applications)

  • 구융서;임대수
    • 한국정보통신학회논문지
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    • 제17권10호
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    • pp.2265-2272
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    • 2013
  • 본 논문에서는 WLAN 시스템에 적용 가능한 이중 공진을 갖는 변형된 원형 링 안테나를 설계 및 제작 하였다. 제안된 안테나는 평면형 모노폴 설계를 기본으로 원형 링 모양의 구조와 변형된 급전선로, 그리고 접지면의 사각 슬롯으로 구성함으로서 이중대역 특성을 갖도록 설계하였다. 최적화된 파라메타를 얻기 위해 상용 툴(HFSS)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 작용하는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 제작하였으며 WLAN 대역에서 반사손실, 이득, 방사패턴의 특성을 측정하였다.

GTEM 셀 설계를 위한 전자파 모델링 및 회로망 해석 기법 연구 (A Study on the Electromagnetic Modeling and Network Analysis for GTEM Cell Design)

  • 이우상
    • 한국전자파학회논문지
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    • 제19권7호
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    • pp.791-799
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    • 2008
  • 본 논문에서는 $DC{\sim}18\;GHz$에서 동작하는 GTEM 셀 설계를 위한 전자파 모델링과 회로망 해석 기법을 제시하였다. GTEM 셀의 동축선 입력 급전부의 모드 변환기, 전송선 길이가 5미터인 확장형 사각 동축선 그리고 전송부 동축선의 전류와 입력단으로부터 입사되는 전자파를 정합시킬 수 있는 종단 부하로 구성되는 3차인 전자파 수치 해석 모델을 제시하였다. GTEM cell의 급전부, 전송선부, 종단 부하부에 대한 등가 회로망 모델을 제시하였으며, 이를 이용하여 전자파 수치 해석 모델에서 구해진 산란 계수로부터 GTEM cell의 성능 평가 지수인 입력 반사 계수를 계산할 수 있도록 하였다. $DC{\sim}18\;GHz$에서 동작하는 $5.0{\times}2.5{\times}1.7\;m$ 크기의 GTEM cell을 설계, 제작, 성능 평가하여 제안한 기법의 효용성을 입증하였다.

비동기 양상태 소나의 표적 거리 추정 오차 분석 (Analysis of the range estimation error of a target in the asynchronous bistatic sonar)

  • 정의철;김태환
    • 한국음향학회지
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    • 제39권3호
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    • pp.163-169
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    • 2020
  • 비동기 양상태 소나는 음원 방향에서 수신되는 직접파를 탐지하고 직접파가 수신된 시간을 추정하여 반사파의 거리를 산출한다. 따라서 동기식에 비해 직접파 수신 시간 추정 오차가 표적 거리 추정 오차에 더하여 나타난다. 특히, 직접파는 다중경로 신호에 의해 정합필터 출력이 여러 개의 첨두치로 나타나는데 문턱치를 넘는 첫 번째 첨두치로 직접파 도달시간을 추정하는 기법과 가장 큰 첨두치로 직접파 도달시간을 추정하는 기법에 대하여 분석하였다. 실험은 공간적으로 분리된 음원과 해저에 매설된 선배열 수신센서로 구성된 양상태 소나를 이용하여 모의 반향기에서 반향되는 유사 표적 신호를 획득하는 방식으로 진행되었다. 실험결과 첫 번째 첨두치로 직접파 도달시간을 추정하는 기법이 표적 거리 추정 오차가 더 작은 것을 확인하였다. 도출된 결과는 비동기 양상태 소나의 표적 추적 기법에 활용할 예정이다.