• 제목/요약/키워드: structural understanding

검색결과 1,350건 처리시간 0.201초

차실 내부소음의 특성과 저감에 관한 실험적 고찰(상)

  • 정주화
    • 오토저널
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    • 제5권2호
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    • pp.15-20
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    • 1983
  • The nature and the sources of sound in cars is discussed in the light of many previous works, and the importance of the system resonances inside cars is suggested. An investigation of a 'boom' problem in a small size passenger car is described. It was established that the 'boom' frequencies coincided with engine firing frequency and also with several system resonances. To find out main transmission path of the noise to the car interior, various possible sources were eliminated from the investigation by means of simple modification to the vehicle. Data on the structural modes of the body, and the acoustic modes of the passenger compartment at various forcing cases were obtained to provide better understanding of the problem. It was found that the acoustic resonance responsible for the boom was controlled largely the bending motion of the floor. To investigate the effect of the structural modification to the acoustic response, center floor of the car was reinforced. a great reduction of the noise inside the car especially at the offending speed range, was achieved by this modification.

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중형버스의 전복 강도해석 (An Analysis for Rollowver Strength of a Medium Bus)

  • 민한기;김택
    • 한국자동차공학회논문집
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    • 제7권7호
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    • pp.195-201
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    • 1999
  • In Rollover crashes, the development of bus structure to ensure the maintenance of survival space for passengers is very important . So, this paper focuses on understanding the possibility of efficient structural development considering rollover strength through computer simulation using the commercial code, LS-DYNA3D at the initial stage of vehicle development structural members, and impact boundary conditions required by ADR59(Australian Design Rule 59)were applied. In order to confirm the validity of the computational results, the test results. After the usefulness of this method of analysis was confirmed , we have proposed the effective modificationfor rollover strength.

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온라인 쇼핑환경에서 상호작용성의 역할 (The Role of Interactivity in Online Shopping Environments)

  • 박민정
    • 복식문화연구
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    • 제16권1호
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    • pp.145-157
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    • 2008
  • The purpose of this study was to examine the effect of interactivity on consumers' mental imagery, attitude toward a product, confidence in evaluation and purchase intention. The proposed model was examined by conducting an experiment using mock apparel websites. A total of 1,009 female college students enrolled at a major midwestern university in the USA participated in the experiment. A structural equation model was used to test the model. The results of the study indicate that interactivity positively influenced mental imagery, attitudes toward a product imagery, and confidence in evaluation. The structural equation model also revealed that mental imagery positively influenced attitude toward a product and confidence in evaluation. Finally, the results show that attitude toward a product and confidence in judgment positively affected purchase intention. The study provides valuable theoretical perspectives which aide in the understanding of the effect of interactivity on consumers' cognitive and behavioral responses, and helps retailers develop effective marketing strategies.

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Mitochondrial Fission: Regulation and ER Connection

  • Lee, Hakjoo;Yoon, Yisang
    • Molecules and Cells
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    • 제37권2호
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    • pp.89-94
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    • 2014
  • Fission and fusion of mitochondrial tubules are the main processes determining mitochondrial shape and size in cells. As more evidence is found for the involvement of mitochondrial morphology in human pathology, it is important to elucidate the mechanisms of mitochondrial fission and fusion. Mitochondrial morphology is highly sensitive to changing environmental conditions, indicating the involvement of cellular signaling pathways. In addition, the well-established structural connection between the endoplasmic reticulum (ER) and mitochondria has recently been found to play a role in mitochondrial fission. This minireview describes the latest advancements in understanding the regulatory mechanisms controlling mitochondrial morphology, as well as the ER-mediated structural maintenance of mitochondria, with a specific emphasis on mitochondrial fission.

방호울타리의 충돌해석에 관한 연구 (A Study on The Crash Analysis of Guard Rail)

  • 민한기;정종안;김택;국진선
    • 한국생산제조학회지
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    • 제20권5호
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    • pp.598-604
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    • 2011
  • In guard rail crashes, the development of guard rail structure to ensure the maintenance of safety for passengers is very important. So, this paper focuses on understanding the possibility of efficient structural development considering crash strength of guard rail through computer simulation using the commercial code, LS-DYNA3D at the initial stage of guard rail development. For this study, guard rail structure was modeled using shell elements to represent major structural members and passenger car was modeled using plate elements of simple shape to do not have the drawing, and impact boundary conditions required by regulation was applied. In order to confirm the validity of the computational results, they were compared with the test results.

Damage assessment of linear structures by a static approach, I: Theory and formulation

  • Tseng, Shih-Shong
    • Structural Engineering and Mechanics
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    • 제9권2호
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    • pp.181-193
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    • 2000
  • The objective of this research is to propose a new global damage detection parameter, termed as the static defect energy (SDE). This candidate parameter possesses the ability to detect, locate and quantify structural damage. To have a full understanding about this parameter and its applications, the scope of work can be divided into several tasks: theory and formulation, numerical simulation studies, experimental verification and feasibility studies. This paper only deals with the first part of the task. Brief introduction will be given to the dynamic defect energy (DDE) after systematically reviewing the previous works. Process of applying the perturbation method to the oscillatory system to obtain a static expression will be followed. Two implementation methods can be used to obtain SDE equations and the diagrams. Both results are equally good for damage detection.

전단에 파괴되는 철근콘크리트 보의 해석적 연구 (FRACTURE ANALYSIS OF REINFORCED CONCRETE BEAMS FALING IN SHEAR)

  • 김우종
    • 전산구조공학
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    • 제1권2호
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    • pp.111-120
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    • 1988
  • 이 연구는 철근콘크리트보의 전단파괴 매카니즘에 대한 근본적인 성질을 밝히기 위해서 전단균열의 생성 및 진행과정을 해석적으로 연구하였다. 유한요소법에 파괴역학(fracture mechanics)을 결합시킨 program을 이용하여서, 철근 콘크리트 보에서 균열이 진행함에 따라 바꿔지는 내부응력상태와 균열정점에서의 stress intensity factors 등을 조사하여서, 전단균열의 생성 및 진행의 근본적인 이유를 밝히고자 하였다. 해석결과로 밝혀진 사실들을 간단한 실험으로 비교 검증하였다.

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The Emergence of the Diagrid - It's All About the Node

  • Boake, Terri Meyer
    • 국제초고층학회논문집
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    • 제5권4호
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    • pp.293-304
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    • 2016
  • The diagrid structural system for constructing tall buildings is a recent invention. Debuting in 2004 with the construction of the Swiss Re Tower in London, this aesthetically driven structural system has centered the perfecting of its technology on the development of the nodes that form its innovative deviation from standard steel tall framing methods. The paper examines variations in node design, understanding the linked dependence the modularity and the choice to expose the steel in the building, as well as on advances in digital modelling that allow an increasingly seamless line of communication from the engineering design through to the actual fabrication of the nodes. This advanced design and fabrication technology will be seen to have resulted in the expanded use of the technical term "node" to inform the design and construction of a range of other applications in the structuring of tall buildings, including the use of steel castings.

Theoretical Determination of Transfer Length in Pretensioned Members Using Thick Cylinder Theory

  • Oh, Byung-Hwan;Kim, Eui-Sung
    • KCI Concrete Journal
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    • 제12권2호
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    • pp.31-43
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    • 2000
  • The extensive usage of pretensioned prestressed concrete component in modem construe- tion as structural members mandates precise understanding of its mechanism. Especially, an adequate transfer of prestressing force from steel tendons to concrete around the end regions of the member is a critical issue. Due to the importance of the topic, several investigators have formulated equations modeling the transfer bond length based on various bonding mechanism between steel and concrete. However, the existing models are still inadequate in predicting the bond development in pretensioned prestressed concrete members. Therefore, this study presents a model of transfer bond length based on rational theory that can simulate experimental results. The model is developed into solid mechanics based structural analysis computer program. The program is validated by comparing the analysis results with experimental results of bond stress distribution, concrete strain profiles, and transfer length in pretensioned prestressed concrete members. The proposed analytical procedure in this study can be utilized as a useful tool for realistic evaluation of transfer length in pretensioned prestressed concrete members.

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Mechanochemistry: from Mechanical Degradation to Novel Materials Properties

  • Sepelak, V.;Becker, K.D.
    • 한국세라믹학회지
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    • 제49권1호
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    • pp.19-28
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    • 2012
  • High-energy mechanical action applied to solid leads to destruction and diminution to the nanosize level. But on the other hand, it can induce structural changes at the nanoscale and at the atomic level which can result in novel materials properties. In this contribution, case studies will be presented concerned with the tailoring of magnetic properties of mechanically treated nanomaterials. Emphasis is placed on materials that have been synthesized by mechanochemical means and on an improved understanding of their nanomagnetism in general. The associated local structural changes of the iron containing magnetic materials discussed in the examples have been studied most suitably by $^{57}Fe$ Mossbauer nuclear probe spectroscopy whose results are supplemented by measurements of the magnetic properties of the mechanosynthesized nanomaterials.