• 제목/요약/키워드: A to Zoo

검색결과 359건 처리시간 0.024초

콘크리트의 불안정 균열성장에 관한 연구 (A Study on the Unstable Crack Growth of Concrete)

  • 고영주;배주성
    • 대한토목학회논문집
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    • 제11권3호
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    • pp.29-36
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    • 1991
  • 본 연구에서는 ASTM E561-80에서 제안한 방법과는 달리, 반복하중시 측정된 각각의 compliance를 상호비교인자로 활용하여 증가 균열길이를 간접적으로 구하고, 이 값들을 균혈성장 동안에 흡수된 비탄성 에너지를 고려한 변형에너지 해방율개념에 적용하여 구한 저항곡선의 해석으로부터 콘크리트의 불안정 균열성장 개시점을 구하였으며, 또한 굵은골재 최대수치와 시편의 두께변화가 임계파괴인성치에 미치는 영향 등을 고찰하였다.

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Non-data Aided Timing Phase Recovery Scheme for Digital Equalization of Chromatic Dispersion and Polarization Mode Dispersion

  • Park, Jang-Woo;Chung, Won-Zoo;Park, Jong-Sun;Kim, Sung-Chul
    • Journal of the Optical Society of Korea
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    • 제13권3호
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    • pp.367-372
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    • 2009
  • In this paper we propose an electronic domain timing phase selection scheme for the optical communication systems suffering from inter-symbol-interference (ISI) distortion due to chromatic dispersion (CD) or polarization mode dispersion (PMD). In the presence of CD/PMD a proper timing phase selection is important for discrete time domain equalizers, since different timing phases produce different nonlinear ISI channels of different severity. The proposed timing phase recovery scheme based on dispersion minimization (DM) practically approximates the optimal minimum mean squared error (MMSE) timing phase without training signals which reduces overall throughput substantially, especially in time-varying channels such as PMD. The simulation results show that the proposed DM timing agrees with MMSE timing phase, under proper normalization of the received signals, for various dispersion and OSNR.

GIS용 광 CT 센서부의 위치와 각도변화에 따른 출력 특성 (A study on characteristic of out-put signal according to angle and sensing position for optical current sensor for GIS)

  • 박정환;지승욱;이광식;김민수;김정배;박원주
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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    • pp.418-421
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    • 2006
  • 현재 국내 외에서 GIS(Gas Insulated Switchgear)용 광 CT(optical current transformer)가 활발히 연구 개발되고 있다. 이러한 광 CT는 전력선에 발생하는 자기장에 의해 레이저 빛의 파장 각도가 변하는 현상인 Faraday Effect를 기련 원리로 한 전류측정용 기기이다. 본 논문에서는 GIS용 광 CT 개발을 목적으로 한 기초적 연구로써 자기장이 발생하는 전력선에 장착되는 센서부가 도선을 중심으로 해서 어떻게 위치하느냐에 따른 광 CT의 출력신호를 측정하여 연구하였다.

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유우목장에서 빠르고 정확한 발정탐지를 위한 숫송아지의 음경전위술 (Penile Translocation Surgery of a Calf for Exact and Quick Detection of Estrus on a Dairy Farm)

  • 김성기;김성하;권보현;용환율
    • 한국임상수의학회지
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    • 제26권4호
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    • pp.376-378
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    • 2009
  • 2007년 8월 26일 생인 7개월된 숫송아지에게 음경전위술을 실시했다. 음경의 방향을 바꿔 정상적인 교미를 불가능하게 함으로써 경산우와 처녀우군에 도입이 되면 후각을 이용하여 발정을 탐지하게 되고 수의사에게 인공수정 혹은 수정란이식의 최적시간을 제공하게 될 것이다. 본 보고는 어린 숫송아지에게 실시되는 음경전위술법을 설명한 것이다.

황토미장재 성능개선을 위한 실험적 연구 (A fundamental Study on the Performance Improvement of Hwangto plaster)

  • 황혜주;이종국;강남이
    • KIEAE Journal
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    • 제5권3호
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    • pp.49-56
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    • 2005
  • Recently the Volatile Organic Compound, HCHO, a harmful object spout from the construction materials is made an issue of social problem. Also the appearance of the building where the confidentiality is high was interior air pollution and it was brought about a huge problem. The government research facility and a relation industry sector conducts a many effort to improves like this actual condition. The Diverse ability building material which contains the natural material of the jade, the charcoal and the hwangto instead of the finish material which contains the harmful chemical material, is becoming development and utility. Hereupon the study have carried out research on hwangto plaster that was composed of hwangto and rice straw. The result of test that is deduced by basic proportion is properly appeared with suitable ratio of the hwangto and the sand to 4:6~5:5 by the compressive strength and crack control, workability. The result of test, that adds the rice straw to basic blending for a crack control, appeared with the fact that it is most suitable 3%to add the rice straw that has a length of 0.5cm~2cm. The result of test that plaster over the large size to compare a cement plaster with a hwangto plaster show a similar efficiency by workability. Also it controlled the crack and peeling off actual condition which is discovered from the hwangto plaster of existing perfectly.

흙타설 벽체의 현장 시공 가능성 검토 (Evaluation as to whether field pour earth wall construction is possible)

  • 황혜주;강남이;양준혁
    • KIEAE Journal
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    • 제12권1호
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    • pp.99-104
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    • 2012
  • In event of selecting construction materials, taking ones found easily around make embodied energy saved. The earth construction could be an eco-friendly engineering from a views of keeping the embodied energy. The pour earth method construction, as one of earth constructions, improves liquidity of earth-mixed properties to build walls or foundations. This study is aimed at evaluating possibilities as to machinery constructions using pumping cars or excavators to be applied on natural non-dried earth which are purchased from sites neighboring to subject building. The study showed that the pumping car used construction was smoothly carried out without any remarkable difficulties and further, a compressed strength was found to keep a certain degree to possibly construct low-story buildings. However, it showed some different levels as to a compressed strength by locations of buildings. In the construction course, we couldn't use remicon plants or a remicon due to field conditions and we are forced to take excavators in compounding or mixing works. But, it is evaluated that actually liquidity or compressed strength will be better than in case of using machineries like remicon plants. These results make us determine that the wall construction using machineries is possible.

An Automatic Strabismus Screening Method with Corneal Light Reflex based on Image Processing

  • Huang, Xi-Lang;Kim, Chang Zoo;Choi, Seon Han
    • 한국멀티미디어학회논문지
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    • 제24권5호
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    • pp.642-650
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    • 2021
  • Strabismus is one of the most common disease that might be associated with vision impairment. Especially in infants and children, it is critical to detect strabismus at an early age because uncorrected strabismus may go on to develop amblyopia. To this end, ophthalmologists usually perform the Hirschberg test, which observes corneal light reflex (CLR) to determine the presence and type of strabismus. However, this test is usually done manually in a hospital, which might be difficult for patients who live in a remote area with poor medical access. To address this issue, we propose an automatic strabismus screening method that calculates the CLR ratio to determine the presence of strabismus based on image processing. In particular, the method first employs a pre-trained face detection model and a 68 facial landmarks detector to extract the eye region image. The data points located in the limbus are then collected, and the least square method is applied to obtain the center coordinates of the iris. Finally, the coordinate of the reflective light point center within the iris is extracted and used to calculate the CLR ratio with the coordinate of iris edges. Experimental results with several images demonstrate that the proposed method can be a promising solution to provide strabismus screening for patients who cannot visit hospitals.

Minimally traumatic extraction of fractured bilateral maxillary canine teeth using a piezoelectric surgical unit in an African lion (Panthera leo)

  • Se Eun Kim;Yoocheol Jeong
    • Journal of Veterinary Science
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    • 제25권4호
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    • pp.50.1-50.6
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    • 2024
  • Importance: Canine extraction of large carnivores can pose significant risk due to extensive tissue damage during aggressive bone reduction. This report highlights a rare instance in which the use of a piezoelectric surgical unit (PSU) for maxillary canine extraction in a large carnivore resulted in successful outcomes with minimal tissue damage. Case presentation: A 10-year-old male African lion presented with decreased appetite because of bilateral maxillary canine fractures. Intraoral radiographs revealed enlarged root canals and periapical radiolucency of the fractured canines, leading to a diagnosis of periapical periodontitis and pulpitis. To extract the right maxillary canine, conventional method using hand instrument failed to achieve adequate luxation, necessitating the use of the flat blade of the PSU to sever the periodontal ligament. The left maxillary canine was extracted using PSU from the beginning, and the extraction time was markedly shortened by using PSU without additional alveolar bone damage or bleeding. Conclusion and Relevance: This case demonstrated that utilizing PSU for canine extraction in a lion resulted in periodontal ligament separation, reducing damage to the alveolar bone and shortening surgical time. It suggests the promising application of PSU in tooth extraction for large wild animals, indicating its potential significance in veterinary dentistry.

Application of an Optical Current Transformer For Measuring High Current

  • Kim, Yeong-Min;Park, Won-Zoo
    • 조명전기설비학회논문지
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    • 제24권11호
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    • pp.9-16
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    • 2010
  • This paper examines the temperature characteristics of an Optical CT (optical current transformer) using the Faraday effect for measuring high current in a super high voltage-power apparatus. It is performed as follows by the sensor for embodying Faraday effect. $\cdot$ A single-mode optical fiber capable of maintaining a polarization state is used. $\cdot$ A light source is applied at 1310[nm] to a Laser Diode. $\cdot$ The Linear of Faraday effect to a large current is evaluated and $\cdot$ A possible application using an Optical CT was shown. An Influence of Faraday effect to the surrounding temperature measured -40~50[$^{\circ}C$], and the characteristic of the current sensitivity was reported. An application using the results of the temperature compensation system was used in order to compensate for surrounding temperatures. A possibility of applying Optical CT for electric power apparatus was advanced further. We were able to confirm that this temperature calibration method can minimize the fluctuation of the output signal depending on the temperature conditions.

공간정보 웹 서비스에서 OGC WPS 2.0 적용 (Application of OGC WPS 2.0 to Geo-Spatial Web Services)

  • 윤구선;이기원
    • 한국지리정보학회지
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    • 제19권3호
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    • pp.16-28
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    • 2016
  • 공간정보 웹 서비스 기술과 응용 분야의 발전에 따라 서로 다른 운영 플랫폼과 브라우저 환경들에서의 호환성과 상호운용성을 위한 기술적 고려가 필요한 상황이다. 또한 웹 시스템 구현에 필요한 공통요소 및 지원요소의 중복성 문제가 발생하는 경우도 있다. 이러한 문제에 대하여 국제표준기구인 OGC에서 개발한 공간정보와 관련된 표준들을 이해하고 적용하는 것이 적절한 해결 방안이 될 수 있다. 따라서 현재 공간정보 웹 서비스 설계와 개발에서 서비스 목적과 환경에 적합하도록 OGC 표준들을 적용하는 것은 핵심 고려사항이다. 특히 목표 시스템이 웹상에서의 실제 공간정보 처리기능을 지원하는 경우에는 WPS를 고려해야 한다. 그러나 최근에 발표된 WPS 2.0 표준에 대한 연구는 아직 초기 응용단계이다. 본 연구에서는 WPS 2.0의 주요 특징이라고 할 수 있는 다양한 프로세스의 동시 처리를 가능하게 하는 비동기식 처리기능을 제공하는 기초 운영 환경 구축에 주안점을 두고 웹 기반 공간정보 분석서비스를 위한 시험 시스템을 구현하였다. Binary thresholding 알고리즘을 적용한 사례를 제시하였으며 향후 다중 사용자의 다중 알고리즘 동시 사용요청에 대한 실험을 계속 연구로 수행할 예정이다. 예시 시스템은 jQuery와 OpenLayers를 이용한 클라이언트 시스템과 Spring 프레임워크를 기반으로 ZOO 프로젝트와 Geoserver등의 오픈소스를 적용한 서버 시스템으로 구성하였다. 이번 연구에서 제시된 모델과 처리 결과는 실제 사용자 환경에서 WPS 적용성과 확장성을 위한 참고모델로 이용될 수 있다.