• 제목/요약/키워드: 구기

검색결과 362건 처리시간 0.028초

Ethanol 및 그 Ester의 Fluorine Derivatives중(中) ${\beta}$-체(體)의 확인(確認) 및 정량(定量)에 관(關)한 연구(硏究) (Identification and Spectrophotometric Method for Determination of the ${\beta}-Fluorine$ Compounds in Fluorides of Ethanol and its Ester)

  • 심영기;이한표;구기서;김재백
    • Journal of Pharmaceutical Investigation
    • /
    • 제4권1_2호
    • /
    • pp.1-6
    • /
    • 1974
  • S-Benzylthiuronium chloride reacts with ethylene glycol, derived from hydrolysis of the fluorides, to produce a crystalline substances. Using this, the fluorides can be indentified by measuring melting point. And when the zirconium-alizarin solution reacts with ethylenefluoro hydrin or ${\beta}-fluoroethyl$ acetate, the red-violet color disappears to produce a yellow dye, which exhibits absorption maximum at about $530\;m{\mu}$ using the 250-microgram standard. Using these properties, the fluorine compounds can be determined conveniently by this method.

  • PDF

알루미나/텅스텐 동시소성에 의한 다층 팩키지 제조시 적층조건에 따른 camber의 변화 (Changes of Camber on Lamination Conditions in alumina/Tungsten Cofiring Multilayer Package)

  • 성재석;구기덕;윤종광;이상진;박정현
    • 한국세라믹학회지
    • /
    • 제34권6호
    • /
    • pp.601-610
    • /
    • 1997
  • In cofiring of multilayered alumina with tungsten, the change of camber with lamination condition was experimented and the effect of sintering shrinkage of alumina and tungsten was investigated. From the exact measurement of sintering shrinkage of tungsten thick film, as lamination pressure increased, the sintering shrinkage of alumina decreased but that of tungsten thick film was not changed. So it was though that the main factor which induced the sintering shrinkage difference between ceramics and metal with lamination condition was the change of sintering shrinkage of ceramics. In case of high lamination pressure, high green sheet density, the cofired specimen showed low camber due to low shrinkage difference between alumina and tungsten and there was a linear relation between camber and shrinkage difference. It was found that this shrinkage difference could change the thickness of tungsten film and the microstructure within via hole during cofiring.

  • PDF

암모니아-물 흡수식 시스템에서 유하액막식 발생기의 해석 (Analysis of Falling-film Generator in Ammonia-water Absorption System)

  • 김병주;손병후;구기갑
    • 설비공학논문집
    • /
    • 제13권5호
    • /
    • pp.422-430
    • /
    • 2001
  • In the present study, an evaporative generation process of ammonia-water solution film on the vertical plate was analysed. For the utilization of waste heat, hot water of low temperature was used as the heat source. The continuity, momentum, energy and diffusion equations for the solution film and vapor mixture were formulated in integral forms and solved numerically. Counter-current solution-vapor flow resulted in the refrigerant vapor of the higher ammonia concentration than that of co-current flow. Eve the rectification of refrigerant vapor was observed near the inlet of solution film in counter-current flow. For the optimum operation of generator using hot water, numerical experiments, based on the heat exchange and generation efficiencies. revealed the inter-relationships among the Reynolds number of the solution film and hot water, and the length of generator. Enhancement of heat and mass transport in the solution film was found to be very effective for the improvement of generation performance, especially at high solution flow rate.

  • PDF

모드유연도 행렬 변위를 이용한 전단빌딩의 정량적 손상평가 방법 (Damage quantification of shear buildings using deflections obtained by modal flexibility)

  • 성승훈;구기영;정형조
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2011년도 정기 학술대회
    • /
    • pp.44-47
    • /
    • 2011
  • 본 논문에서는 상사진동에서의 응답을 통해 구성된 모드유연도 행렬에 의해 추정되는 변위/변형을 이용해 전당빌딩의 손상을 정량적으로 평가하는 방법을 제시하였다. 제안된 방법은 전단빌딩의 손살발생 후의 층간변위와 손상발생 전 후의 층간변위 차이인 Damage-induced inter-story deflection(DI-ID)의 관계를 이용해 손상을 정량적으로 평가하는 방법이다. 구조물이 양전단력만을 발생시킴으로써 층간변위를 분명히 파악할 수 있도록 하는 양전단력 탐색하중(Positive Shear Inspection Load)을 통해 DI-ID를 산정한다. 제안된 방법의 검증을 위해 5층의 전단빌딩 축소모형을 대상구조물로 선정했으며, 단일손상과 다중손상의 모사를 위해 1층과 3층의 휨강성을 각각 10% 씩 저감시켰다. Static test와 modal test를 통해 각각의 결과를 비교하는 방법으로 제안된 방법의 성능검증을 수행했으며, 축소모형실험 결과, 두 실험간 평균오차 1% 이내로 정확도를 검증했다.

  • PDF

강박스 거더교의 FE 모델 개선을 위한 평균값 반복 신경망 (MINNs for FE model updating of a steel box girder bridge)

  • 트위 둥;취 진타오;김두기;구기영
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2011년도 정기 학술대회
    • /
    • pp.57-60
    • /
    • 2011
  • Updating model parameters are required in order to simulate the actual behavior of the dynamic structure. A new strategy, mean-iterative neural networks (MINNs) has been proposed in this paper for model parameter updating of a steel box girder bridge. With new strategy for structural dynamic model updating, it offers many advantages such as potential savings of computational effort, more consistent in reaching convergence. The dynamic response obtained from the experimental test on a two span continuous bridge is used as the target for model updating. And the presented algorithm is applied to update the model parameters. These results show a good possible of using MINNs in practice for dynamic model updating.

  • PDF

온도변화에 자유로운 임피던스 기반 국부 손상검색 (Temperature Effect-free Impedance-based Local Damage Detection)

  • 구기영;박승희;이종재;윤정방
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
    • /
    • pp.21-26
    • /
    • 2007
  • This paper presents an impedance-based structural health monitoring (SHM) technique considering temperature effects. The temperature variation results in a significant impedance variation, particularly both horizontal and vertical shifts in the frequency domain, which may lead to erroneous diagnostic results of real structures. A new damage detection strategy has been proposed based on the correlation coefficient (CC) between the reference impedance data and a concurrent impedance data with an effective frequency shift which is defined as the shift causing the maximum correlation. The proposed technique was applied to a lab-sized steel truss bridge member under the temperature varying environment. From an experimental study, it has been demonstrated that a narrow cut inflicted artificially to the steel structure was successfully detected using the proposed SHM strategy.

  • PDF

중국(中國)의 한중(韓中) 자유무역협정(自由貿易協定) 추진전략(推進戰略)과 정책적(政策的) 시사점(示唆點) (The China's Strategy against Korea-China FTA and its Policy Implications)

  • 구기보;홍정륜
    • 무역상무연구
    • /
    • 제35권
    • /
    • pp.223-247
    • /
    • 2007
  • This paper focused on analyzing the effect against the Chinese Economy of Korea-China FTA and the trend of China-launching FTAs. And then this paper intended to deduce policy implications against the negotiations of Korea-China FTA. The points that Korea should consider in the process of the research and negotiations of Korea-China FTA are as follows: First, it is necessary that Korea should negotiate with China only in terms of the economic sector, excluding non-economic sectors which includes politics, national securities and so on. Second, Korea should put on the lists the every possible sectors that Korea has comparative advantages in. It is essential that the sectors include services in trade, TRIPs, ect. Third, the Korean government should put investment arrangements on the negotiating lists and ask China to afford a special favor to Korean investment In China. Forth, the Korean government should set the level of its tariff, considering the nation's trade deficit that Korea-China FTA will bing about.

  • PDF

축구손상과 예방 (Football Injury & Prevention)

  • 김현철;김헝수
    • 대한정형외과스포츠의학회지
    • /
    • 제3권1호
    • /
    • pp.42-48
    • /
    • 2004
  • 대중적 구기종목인 축구는 동호회원의 증가로 환자 발생이 많아지는 추세에 있다. 축구에 대한 전반적인 이해를 돕고, 축구 기술의 생체역학적인 면과 손상과의 관계를 고찰하여 예방조치를 취하는데 도움이 되고자 하였다. 실외축구, 풋살, 여자축구 등과 Kick, Pass, Heading 등 기술과 관련된 손상, 특히 최근 논란이 되고 있는 머리부상에 대해서도 문헌고찰 등을 통해 검토하였다.

  • PDF

도루묵 수산자원회복계획 하에서 동해구기선저인망어업의 최적 어획노력량과 어획량 수준 결정에 관한 탐색적 연구 (An Exploratory Study on Determining Optimal Fishing Effort and Production Levels of Danish Seine Fishery under the Sandfish Stock Rebuilding Plan)

  • 최종열;김도훈
    • 수산경영론집
    • /
    • 제43권1호
    • /
    • pp.1-9
    • /
    • 2012
  • Based on Clark and Munro's theory of dynamic optimization between fishery resources and production, this study is aimed to take an empirical analysis of optimal production level to the Danish Seine fishery under the sandfish stock rebuilding plan. For empirical analysis, it examined the optimal fish stock size, production and fishing effort levels and it also made an additional evaluation of optimal production changes on main variables by sensitivity analyses. When a 4% of the discount rate is assumed, the optimal sandfish production of Danish Seine fishery would be 3,049 t, and the sandfish optimal stock size is evaluated to be 19,016 t. In addition, the optimal fishing effort is estimated to be 4,368 days. Accordingly, to achieve the optimal production level, current fishing efforts should be reduced while the fish stock size should be increased up to the optimal level.

농구 학습을 위한 웨어러블 센서 기반의 동작 인식 기법 (A Gesture Recognition Mechanism Based on Wearable Sensors for Basketball Learning)

  • 이준서;박정현;이준형;장명호;김희주;송충건;유헌창
    • 한국컴퓨터교육학회 학술대회
    • /
    • 한국컴퓨터교육학회 2018년도 동계학술대회
    • /
    • pp.137-140
    • /
    • 2018
  • 대한민국의 대표적인 구기 종목 중 하나인 농구는 입문 시 기본 동작에 적응하고 기본 규칙을 이해하기 위해 많은 시간이 소비된다. 또한 기존 농구 학습 분야에서 평가 수행 시 평가 대상자의 실력을 정량적으로 도출하는 것이 힘들어 중 고등학교 체육교과의 수행평가에서 객관적인 평가가 이루어지기 힘들었다. 본 연구에서는 이러한 농구 학습의 한계점을 해결하기 위하여 3축 자이로 센서와 스위치가 적용된 웨어러블 시스템을 기반으로 농구 학습을 도와주는 동작인식 기법을 제안한다. 그리고 실험을 통하여 제안하는 동작인식 기법의 성능을 검증하였으며, 생활체육 활성화를 통한 국민 건강증진과 객관적인 수행평가 실현에 기여할 것으로 기대된다.

  • PDF