• Title/Summary/Keyword: concentrated structure

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비균질 Pasternak 지반위에 얹혀진 박판의 자유진동 해석 (Free Vibration Analysis of Thin Plate on Inhomogeneous Pasternak Foundation)

  • Kim, Il-Jung;Lee, Young-Soo;Oh, Soog-Kyoung;Lee, Hoy-Jin
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문초록집
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    • pp.395.2-395
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    • 2002
  • Recently, as size of building structure becomes larger, mat area of building structure is supported on Inhomogeneous foundation. The equipment machineries in building are mostly on basement story. The slab of the lowest basement story with equipment machineries is considerded as concentrated masses on plate supported on foundation. In this paper. vibration analysis of rectangular thin plate is done by use of rectangular finite element with 4 nodes. (omitted)

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2차원 구조물의 최적형상설계에 관한 연구 (A Study on the Optimal Shape Design of 2-D Structures)

  • 김홍건;양성모;노홍길;나석찬;유기현;조남익
    • 한국공작기계학회논문집
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    • 제12권2호
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    • pp.9-16
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    • 2003
  • A strategy of the optimal shape design with FEA(Finite Element Analysis) for 2-D structure is proposed by comparing subproblem approximation method with first order approximation method. A cantilever beam with two different loading conditions, a concentrated load and an evenly distribute load, and truss structure with a concentrated loading condition are implemented to optimize the shape. It gives a good design strategy on the optimal truss structure as well as the optimal cantilever beam shape. It is found that the convergence is quickly finished with the iteration number below ten. Optimized shapes of cantilever beam and truss structure are shown with stress contour plot by the results of the subproblem approximation method and the first order approximation methd.

수정개별요소법을 이용한 구조물의 파괴거동에 관한 연구 (A Study on Failure Behavior of Structures by Modified Distinct Element Method)

  • 김문겸;오금호;김상훈;김우진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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    • pp.210-217
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    • 1996
  • Under strong shock loads including earthquake or blast, structures may start to crack in stress concentrated members. The continuous behavior of the structure changes to the discontinuous. In this study, numerical method analyzing continuous and discontinuous behavior of a structure is developed using a modified distinct element method. Equations of motion of each distinct element are integrated using the central difference method, one of the finite difference methods. Interactions between he elements are considered by an element and pore spring. The forces acting in the center of an element include contact stress transferred by element spring; tensile stress by pore spring; and external traction such as earthquake or blast load. To verify the proposed method, the behavior of the cantilever beam subject to the quasi-static concentrated force at the end is investigated. The failure behavior of the simply supported beam subject to the strong shock at the center is studied. The proposed method can predict the failure behavior of the structure due to the shock loading and the post-failure discontinuous behavior of the structure.

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Microstructure and shear modulus in concentrated dispersions of bidisperse charged spherical colloids

  • Chun, Myung-Suk;Lee, Sangwoo;Lee, Tae-Seok;Cho, Jae-Seol
    • Korea-Australia Rheology Journal
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    • 제16권1호
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    • pp.17-26
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    • 2004
  • We examine rigorous computations on microstructural as well as rheological properties of concentrated dispersions of bidisperse colloids. The NVT Monte Carlo simulation is applied to obtain the radial distribution function for the concentrated system. The long-range electrostatic interactions between dissimilar spherical colloids are determined using the singularity method, which provides explicit solutions to the linearized electrostatic field. The increasing trend of osmotic pressure with increasing total particle concentration is reduced as the concentration ratio between large and small particles is increased. From the estimation of total structure factor, we observe the strong correlations developed between dissimilar spheres. As the particle concentration increases at a given ionic strength, the magnitude of the first peak in structure factors increases and also moves to higher wave number values. The increase of electrostatic interaction between same charged particles caused by the Debye screening effect provides an increase in both the osmotic pressure and the shear modulus. The higher volume fraction ratio providing larger interparticle spacing yields decreasing high frequency limit of the shear modulus, due to decreasing the particle interaction energy.

교각구조물의 유지보수 (Maintenance & Repairs of pier Structure)

  • 김규린
    • 기술사
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    • 제34권1호
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    • pp.35-43
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    • 2001
  • This paper Is described for the maintenance and repair method for the pier structure currently under repair works in the Han river bridges. During the economic growth period from the year 1960 to 1980, our engineer was concentrated only for study of the construction method of bridge. We have neglected the importance for the maintenance & repair method of construction structure. Therefore this paper will give you some ideas of repair and maintenance method.

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집중권 방식 영구자석 동기전동기의 냉각특성 개선에 관한 연구 (A Study for Improving a Thermal Performance of Liquid Cooled Permanent Magnet Synchronous Machine with Concentrated Winding)

  • 강경호;안수홍;윤영득;유석진;안효철
    • 전기학회논문지
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    • 제61권4호
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    • pp.555-566
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    • 2012
  • This paper presents a thermal analysis of an interior PM synchronous machine with concentrated winding for electric vehicle. The conventional thermal equivalent network model has been used for a long time for calculation of the temperature rises in electrical machines. In spite of being popular, this method can not be applied correctly for elements with complicated cooling structure like liquid cooled housing. To overcome this drawbacks, in this paper, a hybrid thermal model using the result of CFD analysis partly. Using this method, to improve a thermal performance of PMSM with concentrated winding, the effects of two design parameters are analysed. Finally, the accuracy of this model has been verified by experiments for the developed 21kW motor.

Determinants of Capital Structure:The Case in Vietnam

  • VU, Thu Minh Thi;TRAN, Chung Quang;DOAN, Duong Thuy;LE, Thang Ngoc
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.159-168
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    • 2020
  • This is a quantitative research, underpinned by the philosophy of natural science and deduction approach that examines the impact of the various aspects of corporate governance mechanism on the choice of capital structure of Vietnamese listed firms. We focus on the effect of factors such as the board size, the board independence, and especially different ownership structures, which include the managerial ownership, the state ownership, the concentrated ownership, and the foreign ownership. They are the main scopes of corporate governance and are supposed to be relevant to determine the corporate financing choice. To explain the causal relationship between factors, we construct the regression model and then test it by using different statistical method approaches, including the pooled OLS, the fixed effects model, and the random effects model. Data are collected from 336 firms with shares listed in the Ho Chi Minh City Stock Exchange in Vietnam, totaling 1583 observations. Overall, the results reveal that the board size, state ownership, and concentrated ownership have positive impact on the firm's capital structure, whereas foreign ownership appears to have negative influence on the capital structure. The research does not find evidence of a the correlation between board independence, managerial ownership and corporate capital struture.

The Impact of Ownership Structure and Audit Quality on Carbon Emission Disclosure: An Empirical Study from Indonesia

  • TARIGAN, Bahagia;PRAMONO, Agus Joko;RUSMIN, Rusmin;ASTAMI, Emita Wahyu
    • The Journal of Asian Finance, Economics and Business
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    • 제9권4호
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    • pp.251-259
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    • 2022
  • This study investigates the impact of ownership structures and audit quality on carbon emission disclosure. It also examines how audit quality affects the relationship between ownership structures and carbon emission disclosure. This research includes 106 standalone sustainability reports from non-financial companies that were listed on the Indonesia Stock Exchange (IDX) between 2015 and 2018. Our findings show that family and concentrated ownerships convey less information about carbon emissions. Our results fail to demonstrate that disclosure of carbon emissions could be a corporation's approach to respond to stakeholder pressure and public visibility and to provide legitimacy for its existence. We also find a positive and significant association between high-quality (Big4) auditors and carbon emission performance. Our further result suggests that Big4 auditors seem to compromise their high standard quality on auditing family and concentrated ownership firms. They fail to influence their family and concentrated ownership clients to be socially responsible. Policymakers should support the existence of Big4 auditors as a driver of carbon emission performance. Top management should be proactive to tackle carbon emission issues by adopting stakeholder-driven mechanisms and establishing legitimacy with society. Nevertheless, the involvement of family and highly concentrated shareholders in decision-making processes and information disclosure should not be encouraged.

낙차공이 있는 복단면 수로에서 사주거동의 수치분석 (Numerical Analysis of the Behavior of Bars in a Compound Channel with a Drop Structure)

  • 김기정;장창래
    • Ecology and Resilient Infrastructure
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    • 제3권1호
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    • pp.14-21
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    • 2016
  • 본 연구에서는 2차원 수치모형을 이용하여 복단면 하도에서 낙차공을 고려하여 하도 변화와 사주의 거동 특성을 분석하였다. 교호사주에 의하여 흐름이 분리되며, 사주의 선단부에서 흐름이 집중되고 수충부가 형성되었다. 낙차공에 의하여 흐름은 하도 전체에 균등하게 분산되었으며, 낙차공 하류에서는 흐름이 집중되고 하상고가 낮아졌다. 그러나 사주의 형상은 낙차공 상류의 영향을 받아 교호사주의 형상을 유지되었다. 하폭 대 수심이 증가하면서 교호사주, 중앙사주, 복렬사주가 형성되었으며, 사주의 수가 증가하였다. 낙차공에 의하여 흐름이 집중되어 낙차공 상류에서 사주길이보다 낙차공 하류에서 사주길이가 더 짧게 나타났다.

설비하중을 고려하는 단층래티스돔의 좌굴특성에 관한 연구 (A Study on the Buckling Characteristics of Single-Layer Latticed Domes under Equipment-Loading)

  • 박지영;정환목;권영환
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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    • pp.83-88
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    • 1994
  • Recently, the equipments of the structure are increasing remarkably. It is very important to evaluate the stability of the domes under concentrated loading such as a large-scale illuminating, visional, and sound equipment. The paper is aimed at investigating the buckling characteristics of single-layer latticed domes with triangular network under the uniformly distributed vertical-loading and the partially concentrated equipment-loading. The results show that the effects of the equipment-loading on the buckling strength is much more sensitive in domes of overall buckling than in domes of member buckling.

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