• Title/Summary/Keyword: Weight function theory

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Calculation of weight functions in single edge notched specimen (SEN시편에서의 무게함수 계산)

  • 안득만
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.604-610
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    • 1991
  • In this paper, the weight functions for the Mode I and Mode II in SEN(single edge notched) specimen are obtained by superposition of the displacement in the singular field of the Buckner type and the displacements by opposite tractions induced by the singular field. The stress intensity factors, $K_{I}$ and $K_{II}$ are calculated by the weight function theory in SEN specimen under the loading equivalent to uniform tension and shear at infinity in Griffith crack. And the results are compared with the exact solutions.s.

Minimum Weight Design of Stiffened Laminated Composite Cylindrical Panel with R Type Stiffener (R형 보강재로 보강된 복합적층 원통형패널의 최소중량화설계)

  • 원종진;이종선;홍석주
    • Proceedings of the KAIS Fall Conference
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    • 2001.05a
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    • pp.103-107
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    • 2001
  • This study is simulation about buckling behavior under axial compression which is cylindrical panel laminated USN125 and USN150 made by various winding angle. And also this study compare with linear and nonlinear FDEM theory, and FEM theory. To solve the objective function and the design variables, this study use the linear and nonlinear buckling theories or FDEM and nonlinear search optimum design method of ADS for minimum weight design on which stiffened laminated composite cylindrical panel with stiffener that R-type section.

Ranking Decision on Assessment Indicator of Natural Resource Conservation Area Using Fuzzy Theory - Focused on Site Selection for the National Trust - (퍼지이론을 이용한 자연자원 보전지역의 평가지표 순위 결정 - 내셔널 트러스트 후보지 선정을 중심으로 -)

  • You Ju-Han;Jung Sung-Gwan;Park Kyung-Hun;Oh Jeong-Hak
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.4 s.111
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    • pp.97-107
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    • 2005
  • This study was carried out to construct accurate and scientific system of assessment indicators in selection of National Trust conservation areas, which was new concept of domestic environment movement and offer the raw data of new analytic method by introducing the fuzzy theory and weight for overcoming the uncertainty of ranking decision. To transform the Likert's scale granted to assessment indicators into the type of triangular fuzzy number(a, b, c), there was conversion to each minimum(a), median(b), and maximum(c) in applying membership function, and in using the center of gravity and eigenvalue, there was to decide the ranking. The rankings of converted values applied a mean importance and weight were confirmed that they were generally changed. Therefore, the ranking decision was better to accomplish objective and rational ranking decision by applying weight that was calculated in grouping of indicator than to judge the singular concept and to be useful in assessment of diverse National Trust site. In the future, because AHP, which was general method of calculating weight, was lacked, there was to understand the critical point to fix a pertinent weight, and to carry out the study applying engineering concept like fuzzy integral using $\lambda-measure$.

A robust nonlinear mathematical programming model for design of laterally loaded orthotropic steel plates

  • Maaly, H.;Mahmoud, F.F.;Ishac, I.I.
    • Structural Engineering and Mechanics
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    • v.14 no.2
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    • pp.223-236
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    • 2002
  • The main objective of the present paper is to address a formal procedure for orthotropic steel plates design. The theme of the proposed approach is to recast the design procedure into a mathematical programming model. The objective function to be optimized is the total weight of the structure. The total weight is function of its layout parameters and structural element design variables. Mean while the proposed approach takes into consideration the strength and rigidity criteria in addition to other dimensional constraints. A nonlinear programming model is developed which consists of a nonlinear objective function and a set of implicit/explicit nonlinear constraints. A transformation method is adopted for minimization strategy, where the primal model constrained problem is transformed into a sequence of unconstrained minimization models. The search strategy is based on the well-known Fletcher/Powell algorithm. The finite element technique is adopted for discretization and analysis strategies. Mindlin theory is selected to simulate the finite element model and a selective reduced integration scheme is exploited to avoid a shear lock problem.

EXISTENCE OF POSITIVE SOLUTIONS FOR GENERALIZED LAPLACIAN PROBLEMS WITH A PARAMETER

  • Kim, Chan-Gyun
    • East Asian mathematical journal
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    • v.38 no.1
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    • pp.33-41
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    • 2022
  • In this paper, we study singular Dirichlet boundary value problems involving ϕ-Laplacian. Using fixed point index theory, the existence of positive solutions is established under the assumption that the nonlinearity f = f(u) has a positive falling zero and is either superlinear or sublinear at u = 0.

Analysis of Prescriptions from Taepyeonghyeminhwajegukbang, Somunsunmyungronbang and Nansilbijang based on Herb weight ratio grade (본초 비율의 순위를 이용한 문헌의 특징 분석 방법 - 태평혜민화제국방(太平惠民和劑局方), 난실비장(蘭室秘藏), 소문선명론방(素問宣明論方)을 중심으로 -)

  • Kim, Ki-Wook;Kim, Thae-Yul;Lee, Byung-Wook
    • Journal of Korean Medical classics
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    • v.27 no.4
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    • pp.73-84
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    • 2014
  • Objectives : I'd like to mimic JunChenZuoShe Theory as Herb weight ratio grade. And than analyze the characteristics of the prescription based on the Herb weight ratio grade from Taepyeonghyeminhwajegukbang, Somunsunmyungronbang and Nansilbijang. Methods : At first, we have changed herb informations to Herb weight ratio. The second we have decided the ranking of herb weight ratio. The third we have entered herb weight ratio grade. Finally we have counted frequency of first grade herb from the Taepyeonghyeminhwajegukbang, Somunsunmyungronbang and Nansilbijang. Results : We could use a new search function to find prescription by herb weight ratio grade. And than we could find out prescription efficacy rate of the ancient documents. Conclusions : We have entered herb weight ratio grade values by herb weight ratio ranking of top 10%, 30%, 60%. So we could find out that buqi(補氣) efficacy is used most often in the Taepyeonghyeminhwajegukbang, Somunsunmyungronbang and Nansilbijang. In the rate of qingrezaoshi(淸熱燥濕) efficacy, fasanfengre(發散風熱) efficacy, fasanfenghan(發散風寒) efficacy, Nansilbijang is higher than Taepyeonghyeminhwajegukbang. In the rate of qingrezaoshi(淸熱燥濕) efficacy, gongxia(攻下) efficacy, Somunsunmyungronbang is higher than Taepyeonghyeminhwajegukbang.

Size and Shape Discrete Optimum Design of Planar and Spacial Steel Structures Using Fuzzy-Genetic Algorithms (퍼지-유전자알고리즘에 의한 평면 및 입체 강구조물의 단면/형상 이산화 최적설계)

  • Park, Choon-Wook;Yuh, Baeg-Youh;Kim, Su-Won
    • Proceeding of KASS Symposium
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    • 2005.05a
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    • pp.236-245
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    • 2005
  • This paper was developed the discrete optimum design program by the refined fuzzy-genetic algorithms based on the genetic algorithms and fuzzy theory. The optimum design of this paper can perform both size and shape optimum design for planar and spacial steel structures. In this paper, the objective function is the weight of steel structures and the constraints are the design limits defined by design and buckling strengths, displacements and thicknesses. The design variables are dimensions and coordinates of steel sections. Design examples are given to show the applicability of the discrete optimum design program of this paper.

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Smart modified repetitive-control design for nonlinear structure with tuned mass damper

  • ZY Chen;Ruei-Yuan Wang;Yahui Meng;Timothy Chen
    • Steel and Composite Structures
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    • v.46 no.1
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    • pp.107-114
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    • 2023
  • A new intelligent adaptive control scheme was proposed that combines observer disturbance-based adaptive control and fuzzy adaptive control for a composite structure with a mass-adjustable damper. The most important advantage is that the control structures do not need to know the uncertainty limits and the interference effect is eliminated. Three adjustable parameters in LMI are used to control the gain of the 2D fuzzy control. Binary performance indices with weighted matrices are constructed to separately evaluate validation and training performance using the revalidation learning function. Determining the appropriate weight matrix balances control and learning efficiency and prevents large gains in control. It is proved that the stability of the control system can be ensured by a linear matrix theory of equality based on Lyapunov's theory. Simulation results show that the multilevel simulation approach combines accuracy with high computational efficiency. The M-TMD system, by slightly reducing critical joint load amplitudes, can significantly improve the overall response of an uncontrolled structure.

A Theory on Phase Behaviors of Diblock Copolymer/Homopolymer Blends

  • 윤경섭;박형석
    • Bulletin of the Korean Chemical Society
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    • v.16 no.9
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    • pp.873-885
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    • 1995
  • The local structural and thermodynamical properties of blends A-B/H of a diblock copolymer A-B and a homopolymer H are studied using the polymer reference interaction site model (RISM) integral equation theory with the mean-spherical approximation closure. The random phase approximation (RPA)-like static scattering function is derived and the interaction parameter is obtained to investigate the phase transition behaviors in A-B/H blends effectively. The dependences of the microscopic interaction parameter and the macrophase-microphase separation on temperature, molecular weight, block composition and segment size ratio of the diblock copolymer, density, and concentration of the added homopolymer, are investigated numerically within the framework of Gaussian chain statistics. The numerical calculations of site-site interchain pair correlation functions are performed to see the local structures for the model blends. The calculated phase diagrams for A-B/H blends from the polymer RISM theory are compared with results by the RPA model and transmission electron microscopy (TEM). Our extended formal version shows the different feature from RPA in the microscopic phase separation behavior, but shows the consistency with TEM qualitatively. Scaling relationships of scattering peak, interaction parameter, and temperature at the microphase separation are obtained for the molecular weight of diblock copolymer. They are compared with the recent data by small-angle neutron scattering measurements.