• 제목/요약/키워드: captive

검색결과 226건 처리시간 0.052초

Experimental Investigation of the Hydrodynamic Characteristics of a Ship due to Bank Effect

  • Vo, Anh Khoa;Mai, Thi Loan;Jeon, Myungjun;Yoon, Hyeon Kyu
    • 한국항해항만학회지
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    • 제46권2호
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    • pp.82-91
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    • 2022
  • When a ship moves in the proximity of the lateral bank, bank suction forces are generated due to bank effects. Thus, hydrodynamic forces can significantly impact the ship's maneuverability and navigation safety. In this study, model tests were performed to investigate the hydrodynamic forces exerted on a ship, especially suction forces caused by bank effects, using captive model and bank effect tests. A low-speed condition was selected in this study, because of the perilous situation as the ship moves close to the bank. The accuracy of the hydrodynamic forces exerted on the hull was verified, by comparing the results of the static drift test with the results obtained from other institutes at design speed. The straight simulation caused by bank effects was then implemented using estimated hydrodynamic coefficients.

Uterine leiomyosarcoma in a captive female capybara (Hydrochoerus hydrochaeris): a case report

  • Lee, Hany;Kim, Soo-Hyeon;Bae, Min-Kyung
    • 대한수의학회지
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    • 제62권2호
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    • pp.11.1-11.4
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    • 2022
  • A captive female capybara (Hydrochoerus hydrochaeris) of unknown age discharged a bloody mass from the vaginal region. A histopathology examination revealed the mass to be a reproductive leiomyosarcoma, and an ovariohysterectomy was performed. The histopathology examination confirmed that the excised tissue was a uterine leiomyosarcoma. The purpose of this report is to describe clinical history and histopathological diagnosis of leiomyosarcoma in capybaras. This report is novel because it describes the first diagnosis of uterine leiomyosarcoma in a capybara. Since clinical data about capybaras are rare, this case report will help to diagnosis and treat reproductive diseases of this species.

단어 임베딩 모델 기반 캡티브 포털 메뉴 추천 시스템 (Captive Portal Recommendation System Based on Word Embedding Model)

  • 여동훈;황병일;김동주
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2023년도 제68차 하계학술대회논문집 31권2호
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    • pp.11-12
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    • 2023
  • 본 논문에서는 상점 내 캡티브 포털을 활용하여 수집된 주문 정보 데이터를 바탕으로 사용자가 선호하는 메뉴를 추천하는 시스템을 제안한다. 이 시스템은 식품 관련 공공 데이터셋으로 학습된 단어 임베딩 모델(Word Embedding Model)로 메뉴명을 벡터화하여 그와 유사한 벡터를 가지는 메뉴를 추천한다. 이 기법은 캡티브 포털에서 수집되는 데이터 특성상 사용자의 개인정보가 비식별화 되고 선택 항목에 대한 정보도 제한되므로 기존의 단어 임베딩 모델을 추천 시스템에 적용하는 경우에 비해 유리하다. 본 논문에서는 실제 동일한 시스템을 사용하는 상점들의 구매 기록 데이터를 활용한 검증 데이터를 확보하여 제안된 추천 시스템이 Precision@k(k=3) 구매 예측에 유의미함을 보인다.

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Optimization and Mathematical Modeling of the Transtubular Bioreactor for the Production of Monoclonal Antibodies from a Hybridoma Cell Line

  • Halberstadt, Craig R.;Palsson, Bernhanrd O.;Midgley, A.Rees;Curl, Rane L.
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제7권3호
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    • pp.163-170
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    • 2002
  • This report describes the use of a transtubular bioreactor to study the relative effects of diffusion versus perfusion of medium on antibody production by a hybridoma cell line. The study was performed with a high-density cell culture maintained in a serum-free, low-protein medium for 77 days. It was determined that the reactor possessed a macro-mixing pattern residence time distribution similar to a continuous stirred tank reactor (CSTR), However, due to the arrangement of the medium lines in the reactor, the flow patterns for nutrient distribution consist of largely independent medium path lengths ranging from short to long. When operated with cyclic, reversing, transtubular medium flow, some regions of the reactor (with short residence times) are more accessible to medium than others (with long residence times). From this standpoint, the reactor can be divided into three regions: a captive volume, which consists of medium primarily delivered via diffusion; a lapped volume, which provides nutrients through unilateral convection; and a swept volume, which operates through bilateral convection. The relative sizes of these three volumes were modified experimentally by changing the period over which the direction of medium flow was reversed from 15 min (larger captive volume) to 9 h (larger swept volume). The results suggest that antibody concentration increases as the size of the diffusion-limited (captive) volume is increased to a maximum at around 30 min with a sharp decrease thereafter. As reflected by changes in measured consumption of glucose and production of lactate, no significant difference in cellular metabolism occurred as the reactor was moved between these different states. These results indicate that the mode of operation of the transtubular bioreactor may influence antibody productivity under serum-free, low-protein conditions with minimal effects on cellular metabolism.

무기체계의 효과적인 개발을 위한 항공탑재시험용 POD 시스템 설계 (Captive Flight Test POD System Design for Effective Development in Weapon System)

  • 박정수
    • 한국융합학회논문지
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    • 제9권6호
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    • pp.25-31
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    • 2018
  • 항공탑재시험은 복잡해지는 무기체계 개발과정에서 데이터 획득을 위해 수행하는 중요한 시험 중 하나이다. 본 논문은 무기체계 개발 과정중 수행하는 항공탑재시험용 POD 시스템에 대한 설계 내용 및 시험 결과를 소개한다. 항공탑재시험용 POD는 좌 우 2개의 POD가 설계 및 제작되었고 각각의 POD는 항공기 연료탱크와 동일한 외형과 질량특성을 갖도록 하여 감항인증 절차를 생략할 수 있도록 하였다. 또한 무기체계 개발에 필요한 표적 영상 데이터 계측, 항법 데이터 획득, 알고리듬 검증 및 분석에 필요한 기준 데이터를 획득할 수 있도록 구성품들을 적절하게 배치하였다. 항공탑재시험용 POD 시스템은 기계적, 전기적 요소들이 모두 반영된 복합적인 시스템이며 개발된 POD 시스템은 반복적으로 항공탑재시험에 사용되어 무기체계 개발에 필요한 다양한 데이터를 성공적으로 획득하였다.

Use of the foraging area by captive bred oriental storks (Ciconia boyciana) in a closed semi natural paddy field

  • Yoon, Jong-Min;Na, Sang-Hee;Kim, Su-Kyung;Park, Shi-Ryong
    • Journal of Ecology and Environment
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    • 제35권2호
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    • pp.149-155
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    • 2012
  • Rice paddy fields have been recognized as an alternative habitat for avian wetland foragers, and fish-rice farms have become a new tool in improving the abundance of aquatic animals. However, the use of the habitats by avian foragers, particularly by oriental storks ($Ciconia$ $boyciana$), was not well understood. In the present study, we investigated how a fish-rice farm influenced the abundance of aquatic animals and documented the foraging behavior of the two captive bred oriental storks in a closed semi-natural paddy field. Our results showed that the fish refuge pond (water depth 40 cm) had a higher abundance of fish whereas the areas planted with rice (water depth 20 cm) had more tadpoles and some aquatic insects. The two captive bred oriental storks captured mostly fish and aquatic insects in the rice-planted area and mostly fish in the fish refuge pond. The two oriental storks had higher foraging success and spent more time for foraging in the rice-planted area than in the fish refuge pond. This result suggests that the oriental storks might prefer foraging in the area with fish, aquatic insects, and amphibians under a greater success rate presumably due to shallow water depth in the paddy fields with a fish-rice farm.

탑재비행시험 영상을 적용한 통합비행 시뮬레이션 기법 연구 (Study on Integrated-Flight Simulation Method Using CFT Imagery)

  • 정동길;윤효석;박진현
    • 한국시뮬레이션학회논문지
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    • 제27권1호
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    • pp.111-117
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    • 2018
  • 영상탐색기가 적용된 유도무기체계의 경우 영상 추적 성능이 체계 성능에 큰 영향을 미치기 때문에 유도탄 비행 중 강인한 영상 추적 성능을 확보하는 것이 필수적이다. 유도탄의 실사격 비행시험이 실제 영상 추적 성능을 확인하기 위한 가장 확실한 방법이나, 실사격 시험만으로 영상 추적기법을 실험 및 수정/보완할 경우 매우 큰 비용 손실이 발생하게 된다. 따라서 영상탐색기를 유도탄 비행 궤적을 모의할 수 있는 비행체에 탑재 후 추적 성능을 시험하는 탑재비행시험(CFT; Captive Flight Test)을 수행하게 된다. 하지만 탐색기를 탑재하는 항공기가 유도탄의 완벽한 거동을 모의하는 것은 불가능하기 때문에 탑재 비행시험만으로 체계 성능을 확인할 수는 없다. 본 논문에서는 기존 영상추적기법 단독 성능 확인에만 한정되어 있던 탑재비행시험 영상을 통합비행 시뮬레이션에 적용하여 체계 성능 확인이 가능하도록 한 기법 연구 결과에 대하여 기술하였다. 이 연구는 탑재비행시험 영상의 활용도를 증대시킬 뿐만 아니라, 기존 합성영상 기반의 통합비행 시뮬레이션 기법의 사실성을 보완할 수 있어 다양한 측면에서 체계 성능 검증을 가능하게 하였다.

Experimental assessment of post-earthquake retrofitted reinforced concrete frame partially infilled with fly-ash brick

  • Kumawat, Sanjay R.;Mondal, Goutam;Dash, Suresh R.
    • Earthquakes and Structures
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    • 제22권2호
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    • pp.121-135
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    • 2022
  • Many public buildings such as schools, hospitals, etc., where partial infill walls are present in reinforced concrete (RC) structures, have undergone undesirable damage/failure attributed to captive column effect during a moderate to severe earthquake shaking. Often, the situation gets worsened when these RC frames are non-ductile in nature, thus reducing the deformable capability of the frame. Also, in many parts of the Indian subcontinent, it is mandatory to use fly-ash bricks for construction so as to reduce the burden on the disposal of fly-ash produced at thermal power plants. In some scenario, when the non-ductile RC frame, partially infilled by fly-ash bricks, suffers major structural damage, the challenge remains on how to retrofit and restore it. Thus, in this study, two full-scale one-bay, one-story non-ductile RC frame models, namely, bare frame and RC partially infilled frame with fly-ash bricks in 50% of its opening area are considered. In the previous experiments, these models were subjected to slow-cyclic displacement-controlled loading to replicate damage due to a moderate earthquake. Now, in this study these damaged frames were retrofitted and an experimental investigation was performed on the retrofitted specimens to examine the effectiveness of the proposed retrofitting scheme. A hybrid retrofitting technique combining epoxy injection grouting with an innovative and easy-to-implement steel jacketing technique was proposed. This proposed retrofitting method has ensured proper confinement of damaged concrete. The retrofitted models were subjected to the same slow cyclic displacement-controlled loading which was used to damage the frames. The experimental study concluded that the hybrid retrofitting technique was quite effective in enhancing and regaining various seismic performance parameters such as, lateral strength and lateral stiffness of partially fly-ash brick infilled RC frame. Thus, the steel jacketing retrofitting scheme along with the epoxy injection grouting can be relied on for possible repair of the structural members which are damaged due to the captive column effect during the seismic shaking.

Does Visitation Dictate Animal Welfare in Captivity? : A Case Study of Tigers and Leopards from National Zoological Park, New Delhi

  • Gupta, Avni;Vashisth, Saurabh;Sharma, Mahima;Hore, Upamanyu;Lee, Hang;Pandey, Puneet
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제3권2호
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    • pp.103-114
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    • 2022
  • Zoological Parks house exclusive animal species, thus creating a source of education and awareness for visitors. Big cats like tigers and leopards are among the most visited species in zoos globally. However, they often display stressful or stereotypic behaviours. Such behaviours are influenced by multiple factors including visitors, animal history, and captive environment. To understand this impact, we investigated the behavioural response of tigers and leopards to visitation, captive, and biological factors. The behaviour of eight big cats housed in the National Zoological Park, New Delhi, was monitored using focal sampling technique during May and June 2019. We recorded the captive and biological factors and visitor density for the subjects. The study revealed high proportions of inactive and stereotypic behaviours amongst the species. Tigers and leopards were found to perform stereotypic behaviours for 22% and 28% of their time, respectively. Generalised Linear Models revealed a significant variation of stereotypy in association with the factors. Stereotypy was influenced by visitor density, age, sex, breeding history, coat colour, and enclosure design. Adults, males, white-coated, previously bred, and those housed in smaller and simple enclosures display more stereotypy than young, females, normal-coated, unbred, and those housed in larger and complex enclosures, respectively. A high density of visitors induced more stereotypic behaviours amongst the big cats. As providing entertainment and awareness amongst the public is one of the fundamental objectives of the zoo, visitors can not be avoided. Thus, we suggest providing appropriate enrichments that would reduce stereotypies and promote naturalistic behaviours.