• 제목/요약/키워드: knowledge bridge

검색결과 156건 처리시간 0.027초

Strouhal number of bridge cables with ice accretion at low flow turbulence

  • Gorski, Piotr;Pospisil, Stanislav;Kuznetsov, Sergej;Tatara, Marcin;Marusic, Ante
    • Wind and Structures
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    • 제22권2호
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    • pp.253-272
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    • 2016
  • The paper concerns with the method and results of wind tunnel investigations of the Strouhal number (St) of a stationary iced cable model of cable-supported bridges with respect to different angles of wind attack. The investigations were conducted in the Climatic Wind Tunnel Laboratory of the Czech Academy of Sciences in $Tel{\check{c}}$. The methodology leading to the experimental icing of the inclined cable model was prepared in a climatic section of the laboratory. The shape of the ice on the cable was registered by a photogrammetry method. A section of an iced cable model with a smaller scale was reproduced with a 3D printing procedure for subsequent aerodynamic investigations. The St values were determined within the range of the Reynolds number (Re) between $2.4{\cdot}10^4$ and $16.5{\cdot}10^4$, based on the dominant vortex shedding frequencies measured in the wake of the model. The model was oriented at three principal angles of wind attack for each of selected Re values. The flow regimes were distinguished for each model configuration. In order to recognize the tunnel blockage effect the St of a circular smooth cylinder was also tested. Good agreement with the reported values in the subcritical Re range of a circular cylinder was obtained. The knowledge of the flow regimes of the airflow around an iced cable and the associated St values could constitute a basis to formulate a mathematical description of the vortex-induced force acting on the iced cable of a cable-supported bridge and could allow predicting the cable response due to the vortex excitation phenomenon.

교량 현황정보 관리를 위한 인터넷 기반 정보시스템 개발 (Development of Road Bridge Information Management System based on Internet)

  • 박경훈;선종완
    • 한국산학기술학회논문지
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    • 제17권11호
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    • pp.716-723
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    • 2016
  • 국가 주요 사회기반시설물로서 전국 도로 교량의 현황 데이터를 효과적으로 수집하고, 데이터의 신뢰도를 증진시키며, 축적된 데이터를 분석하여 정책수립 지원을 위한 기초자료로 활용하기 위하여 전산화된 정보관리시스템이 필요하다. 데이터베이스와 GIS(Geographic Information Systems)를 포함하는 인터넷 기반 교량정보시스템(Bridge Information System; BIS)을 설계하고, GIS 기반 위치좌표와 교량 상태등급 정보 등 관리를 위한 필수 정보로 데이터 항목을 구성하였다. BIS는 관련 정보시스템과의 정보 연계가 가능하며, GIS 도입을 통해 교통량, 주소 정보 등의 현행화가 용이하도록 개발하였다. 현황정보의 신뢰도 향상을 위하여 입력 오류를 사전에 방지하기 위한 정보 검증 기능을 통해 데이터의 신뢰도를 향상시킬 수 있도록 하였다. 또한 축적된 데이터 분석을 바탕으로 기존에 불가능하던 다양한 지식정보를 제공하여 정책수립 지원이 용이하도록 하였으며, GIS를 바탕으로 직관적인 현황파악과 분석이 가능하도록 하였다. BIS의 현황정보 관리를 통해 유지관리 업무 효율성 향상, 정보 정확도 향상, 시계열에 따른 정보분석 등이 가능하여, 장래의 합리적인 국가 유지관리 정책 수립에 효과적으로 활용될 수 있을 것으로 판단된다.

The Use of Feed-forward and Feedback Learning in Firm-University Knowledge Development: The Case of Japan

  • Oh, In-Gyu
    • Asian Journal of Innovation and Policy
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    • 제1권1호
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    • pp.92-115
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    • 2012
  • The problem Japanese universities face is exactly the same as that of German universities: no international recognition in world rankings of universities despite their high levels of postwar economic and technological developments. This was indeed one reason why world-class Japanese firms, such as Toyota and Sony, have avoided working closely with Japanese universities for R&D partnership and new technology commercialization. To resolve this problem, the Japanese government has continuously implemented aggressive policies of the internationalization, privatization, liberalization, and privatization of universities since the onset of the economic recession in 1989 in order to revitalize the Japanese economy through radical innovation projects between universities and firms. National projects of developing medical robots for Japan's ageing society are some of the ambitious examples that emphasize feed-forward learning in innovation. However, this paper argues that none of these programs of fostering university-firm alliances toward feed-forward learning has been successful in promoting the world ranking of Japanese universities, although they showed potentials of reinforcing their conventional strength of introducing $kaizen$ through feedback learning of tacit knowledge. It is therefore argued in this paper that Japanese universities and firms should focus on feedback learning as a way to motivate firm-university R&D alliances.

국방모델 개발을 위한 공통 모의논리 제안과 활용방안에 관한 연구 (A Suggestion of Common Analysts' Guidance and it's Utilisation)

  • 권혁래;구본임;이태억;임종원
    • 한국군사과학기술학회지
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    • 제15권6호
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    • pp.754-760
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    • 2012
  • To improve the efficiency and economics of national defence, the needs for defence M&S systems are greatly increased, but the lack of interoperability and reusability lowers the level of reliability in the existing simulations models. Recently, many research activities have been performed and some conceptual models, such as CMMS, DCMF, and KAMA, were introduced. However, these models don't support the whole process of defence M&S system development nor provide integrated domain knowledge and up-to-date data. In this paper, we analyzed the analysts' guidances and doctrines, which are the basic ingredients for the simulation system development, and proposed a systematic structure for all the defence M&S stakeholders to share the standardized domain knowledge, modeling algorithm and data. This will be a logical bridge between Mission Space and Simulation Space, and provide substantial data sets to build simulation systems.

불규칙형상 박판제품의 블랭킹용 네스팅 시스템 (A nesting system for blanking or piercing of irregular-shaped sheet metal products)

  • 최재찬;김병민;김철;김호관
    • 한국정밀공학회지
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    • 제14권11호
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    • pp.171-179
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    • 1997
  • This paper describes a nesting system of a computer-aided design of blanking and piercing for irregularly shaped sheet metal products. An approach to the system is based on knowledge-based rules. A nesting system is designed by considering several factors, such as utilization ratio which minimises the scrab for single or pairwise operation, bridge width, grain orientation and design requirements which maximise the strength of the part when subsequent bending is involve. Therefore this system which was implemented blank layout and strip layout module can carry out a nesting with a best utilization and a process planning for irregular shaped sheet metal products in single or pairwise operation and generate the blank layout and strip layout in graphic forms. Knowledges for a nesting and a process planning are extracted from plasticity theories, relevant references and empirical know-hows of experts in blanking industries. This provides its efficiency and effectiveness for nesting irregularly shaped sheet metal products.

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융합적 과학수업에 대한 초등교사의 인식론적 신념과 실행 -조사연구 및 자기연구- (Elementary Teachers' Epistemological Beliefs and Practice on Convergent Science Teaching: Survey and Self-Study)

  • 이수아;전영석
    • 한국과학교육학회지
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    • 제40권4호
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    • pp.359-374
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    • 2020
  • 본 연구는 조사연구와 자기연구의 복합 형태로 구성되었다. 조사연구로서 초등 교사의 융합 수업 및 융합 지식에 대한 인식론적 신념을 조사하였다. 그 결과를 대표하는 사례로서 교사이자 연구자인 "나"를 연구 참여자로 하여 융합 수업을 실행하는 교사로서 나의 융합 수업과 융합 지식에 대한 인식론적 신념을 살펴보고, 속력을 주제로 수학-과학-체육의 가족 유사성에 근거한 융합 과학수업 프로그램을 지도한 양상을 자기연구로 실행하였다. 초등 교사들의 융합 수업과 융합 지식에 대한 인식론적 신념에 대한 개방형 검사 문항을 초등 교사 28명에게 서면 질의 방법으로 조사하였다. 연구에 참여했던 초등 교사들은 융합 수업을 교과 활용적 접근 또는 다학문적 접근의 융합으로 생각하였다. 융합 지식을 개별 교과의 집합체로 인식하고 있었으며, 융합된 지식은 학생 스스로 문제를 해결하는 과정에서 습득할 수 있다는 인식론적 신념을 가지고 있었다. 교사이자 연구자인 나 역시 비슷한 신념을 지니고 있었다. 자기연구를 수행하는 동안 나는 가족유사성의 범주별 분석 결과와 그것에 근거한 융합 지식 체계를 반영하기 위해 노력하였으나, 간학문적 접근의 융합 활동을 구현하는데 어려움이 있었다. 수학의 단위, 비와 비율의 개념은 과학의 속력 개념과 연계되어 있어서 두 교과의 개념을 융합적으로 이해하는데 효과가 있었으며, 체육 활동은 수학과 과학 개념을 융합적으로 학습하기 위한 맥락을 제공하여 간학문적 접근의 융합 수업을 촉진시킬 수 있었다. 가족유사성에 근거한 간학문적 융합 지식 체계와 교사인 나의 인식론적 신념 간의 간극과 해결 양상에 대한 논의가 제시되었다.

학문으로서의 한의학의 정의와 한의학의 과학화를 위한 논의 (A Study of Definition of Traditional Korean Medicine as Learning and Discussion for Scientization of Traditional Korean Medicine)

  • 김명현;김병수
    • 혜화의학회지
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    • 제23권2호
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    • pp.1-4
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    • 2015
  • Learning can be defined as its objects, main question for the objects, and its unique way to organize all the knowledge acquired as the results of the question. From the point of view like this, Traditional Korean Medicine(TKM) can be defined as learning for human body and its functions, health and diseases based on the theory of the Yin and Yang and of the five elements. Nowaday Many papers based on laboratory work publish for the name of scientization of TKM, but from the viewpoint of definition of learning, they have a problem that there is no basic theory. If TKM could be communicated with western natural science, it has to be solved. And oriental physiology has a same object and same questions with western physiology, so oriental physiology can be useful to make a bridge between TKM and western natural science.

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유아교육기관에서의 '이야기나누기시간'의 의미 - 현상학적 접근의 방법으로 - (A Study on the Meaning of Large-group Discussion Activities in the Kindergarten through Phenomenological Approach)

  • 유수경
    • 아동학회지
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    • 제28권3호
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    • pp.267-285
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    • 2007
  • This study was a phenomenological approach to the substance and meaning of large-group discussion activities in the kindergarten. Results of this study showed phenomena of the management of large-group discussion to be : 1) interchange in the natural fields of knowledge, 2) the fields of shared laughter and humor, 3) the exchange of glances individually between a teacher and children as well as children to children, 4) a bridge to connect one activity to another, 5) the guarantee of freedom in the limited space while keeping order, 6) the making of a way to connect individual children's inner self with the world, 7) conflicts between standardized themes and generated themes.

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Comparison of Structural Change Tests in Linear Regression Models

  • Kim, Jae-Hee
    • 응용통계연구
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    • 제24권6호
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    • pp.1197-1211
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    • 2011
  • The actual power performance of historical structural change tests are compared under various alternatives. The tests of interest are F, CUSUM, MOSUM, Moving Estimates and empirical distribution function tests with both recursive and ordinary least-squares residuals. Our comparison of the structural tests involves limiting distributions under the hypothesis, the ability to detect the alternative hypotheses under one or double structural change, and smooth change in parameters. Even though no version is uniformly superior to the other, the knowledge about the properties of those tests and connections between these tests can be used in practical structural change tests and in further research on other change tests.

Exact stochastic solution of beams subjected to delta-correlated loads

  • Falsone, G.;Settineri, D.
    • Structural Engineering and Mechanics
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    • 제47권3호
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    • pp.307-329
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    • 2013
  • The bending problem of Euler-Bernoulli discontinuous beams is dealt with, in which the discontinuities are due to the loads and eventually to essential constrains applied along the beam axis. In particular, the loads are modelled as random delta-correlated processes acting along the beam axis, while the ulterior eventual discontinuities are produced by the presence of external rollers applied along the beam axis. This kind of structural model can be considered in the static study of bridge beams. In the present work the exact expression of the response quantities are given in terms of means and variances, thanks to the use of the stochastic analysis rules and to the use of the generalized functions. The knowledge of the means and the variances of the internal forces implies the possibility of applying the reliability ${\beta}$-method for verifying the beam.