• Structural Engineering and Mechanics
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• 제18권6호
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• pp.731-744
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• 2004

Modified virtual crack closure integral (MVCCI) technique has become very popular for computation of strain energy release rate (SERR) and stress intensity factor (SIF) for 2-D crack problems. The objective of this paper is to propose a numerical integration procedure for MVCCI so as to generalize the technique and make its application much wider. This new procedure called as numerically integrated MVCCI (NI-MVCCI) will remove the dependence of MVCCI equations on the type of finite element employed in the basic stress analysis. Numerical studies on fracture analysis of 2-D crack (mode I and II) problems have been conducted by employing 4-noded, 8-noded (regular & quarter-point), 9-noded and 12-noded finite elements. For non-singular (regular) elements at crack tip, NI-MVCCI technique generates the same results as MVCCI, but the advantage for higher order regular and singular elements is that complex equations for MVCCI need not be derived. Gauss numerical integration rule to be employed for 8-noded singular (quarter-point) element for accurate computation of SERR and SIF has been recommended based on the numerical studies.

• Structural Engineering and Mechanics
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• 제60권1호
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• pp.111-130
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• 2016

Two new elements with six degrees of freedom are proposed by applying the equilibrium conditions and strain-displacement equations. The first element is formulated for the infinite ratio of beam radius to thickness. In the second one, theory of the thick beam is used. Advantage of these elements is that by utilizing only one element, the exact solution will be obtained. Due to incorporating equilibrium conditions in the presented formulations, both proposed elements gave the precise internal forces. By solving some numerical tests, the high performance of the recommended formulations and also, interaction effects of the bending and axial forces will be demonstrated. While the second element has less error than the first one in thick regimes, the first element can be used for all regimes due to simplicity and good convergence. Based on static responses, it can be deduced that the first element is efficient for all the range of structural characteristics. The free vibration analysis will be performed using the first element. The results of static and dynamic tests show no deficiency, such as, shear and membrane locking and excessive stiff structural behavior.

• Structural Engineering and Mechanics
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• 제36권3호
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• pp.301-319
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• 2010

The paper seeks to explore some aspects of the current state of knowledge on progressive collapse in the technical literature covering blast loads and structural analysis procedure applicable to reinforced concrete (RC) buildings. The paper describes the progressive collapse analysis of a commercial RC building located in the city of Riyadh and subjected to different blast scenarios. A 3-D finite element model of the structure was created using LS-DYNA, which uses explicit time integration algorithms for solution. Blast loads were treated as dynamic pressure-time history curves applied to the exterior elements. The inherent shortcomings of notional member removal have been taken care of in the present paper by simulating the damage of structural elements through the use of solid elements with the provision of element erosion. Effects of erosion and cratering are studied for different scenarios of the blast.

• 한국게임학회 논문지
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• 제20권2호
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• pp.75-90
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• 2020

본 연구의 목적은 PC게임을 구성하는 주요한 요소 중 하나인 음악의 기능적 역할을 알아보는데 있다. 이를 위해 PC 게임의 장르별 테마음악을 분석 유목을 통해 구분한 후 다중 대응일치분석을 사용하여 '음악종류', '음악의 구조적 요소', '이미지' 간의 거리를 시각적으로 위치화하여 변인간의 관련성을 분석하였다. 그 결과 게임 장르별 음악의 종류와, 음악의 구조적 요소, 이미지의 특성별 공간의 위치적 차이가 있음을 확인하였다.

• 정보화연구
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• 제10권1호
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• pp.71-77
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• 2013

XML 스키마 매칭은 두 스키마의 엘리먼트들 간의 의미적인 유사성을 찾는 작업이다. XML 스키마 매칭은 스키마 통합, 데이터 통합, 데이터 웨어하우징, 데이터 변환, P2P 데이터 관리, 시멘틱 웹 등과 같은 응용체계에서 중요한 역할을 한다. 본 논문은 룰과 구조적 속성에 기반한 XML 엘리먼트 매칭 알고리즘을 제안한다. 제안한 알고리즘에서는 먼저 XML 문서의 구조적 속성을 이용하여 엘리먼트들이 unique와 non-unique로 분류되며, 이후 룰에 따라 엘리먼트의 매칭여부를 결정한다. 제안 알고리즘의 효과성을 보이기 위해 인터넷에 공개된 XML 스키마를 이용하여 성능을 평가하였다. 또한 제안 알고리즘은 문서의 구조적 속성을 이용함으로써 사용자 주관성을 배제하고 객관성을 보장하며 특정 유형이 아닌 다양한 형태의 XML에 적용이 가능하다.

• Computers and Concrete
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• 제3권2_3호
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• pp.123-144
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• 2006

Reinforced concrete corbels are structural elements widely used in practical engineering. The complex response of these elements is described in design codes in a simplified manner. These formulations are not sufficient to show the real behavior, which, however, is an essential prerequisite for the manufacturing of numerous elements. Therefore, a deterministic and probabilistic study has been performed, which is described in this contribution. Real complex structures have been modeled by means of the finite element method supported primarily by experimental works. The main objective of this study was the detection of uncertainties effects and safety margins not captured by traditional codes. This aim could be fulfilled by statistical considerations applied to the investigated structures. The probabilistic study is based on advanced Monte Carlo simulation techniques and sophisticated nonlinear finite element formulations.

• Computers and Concrete
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• 제25권4호
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• pp.327-341
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• 2020

Advanced forms of structural design (e.g., displacement-based methods) require knowledge of the non-linear force-displacement behavior of both the overall building and individual lateral load resisting elements, i.e., walls or building cores. Similarly, understanding the non-linear behaviour of the elements in a structure can also allow for a less conservative structural response to be calculated by better understanding the cracked (i.e., effective) properties of the various RC elements. Calculating the non-linear response of an RC section typically involves using 'black box' analysis packages, wherein the user may not be in complete control nor be aware of all the intricate settings and/or decisions behind the scenes. This paper introduces a user-friendly and transparent analysis program for predicting the back-bone force displacement behavior of slender (i.e., flexure controlled) RC walls, building cores or columns. The program has been validated and benchmarked theoretically against both commonly available and widely used analysis packages and experimentally against a database of 16 large-scale RC wall test specimens. The program, which is called WHAM, is written using Microsoft Excel spreadsheets to promote transparency and allow users to further develop or modify to suit individual requirements. The program is available free-of-charge and is intended to be used as an educational tool for structural designers, researchers or students.

• Computers and Concrete
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• 제11권5호
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• pp.475-492
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• 2013

Since the beginning of the 90 s, depending on the growth of the industrial sector in Turkey, factory constructions have been increased. The cost of precast concrete buildings is lower than the steel ones for this reason the precast structural systems are used more. Precast concrete structural elements are mostly as strong as not to have damage in the earthquake but weakness of connections between elements causes unexpected damages of structure during earthquake. When looking at the previous researches, it can be seen that there is a lack of studies about socket type base connections although there were many experimental and analytical studies about the connections of precast structural elements. The aim of this study is to investigate the stress transfer mechanism between column and the socket base wall with finite element method. For the finite element analysis ANSYS software was used. A finite element model was created which is the simulation of experimental research executed by Canha et al. (2009) under vertical and horizontal forces. Results of experimental research and finite element analysis were compared to create a successful simulation of experimental program. After determining the acceptable parameters, models of socket bases were created. Model dimensions were chosen according to square section column sizes 400, 450, 500, 550 and 600 mm which were mostly used in industrial buildings. As a result of this study, stress distribution at center section of the socket base models were observed and it is found that stress distribution affects triangular at the half of socket bottom and top.

• 한국경영과학회지
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• 제37권4호
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• pp.181-196
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• 2012

The purpose of this study is to evaluate of the perception, elements and quality level of business strategy in domestic hospitals. We analyze survey data about strategy. Significantly, we find that domestic hospitals were greatly feeling about the necessity and importance of strategy, but elements and quality level of actual execution strategy is much lower. When evaluating level on the perception, elements and quality of strategy within each of Miles and Snow's strategy type, PA(prospector+analyzer) was higher than DR(defender+reactor). And result of structural equation modeling(SEM), elements had a significant influence on the quality of the strategy, a positive relationship between the components and the PA have been identified. Therefore, we propose that to increase the elements level in order to improve the quality level of strategy, and hospital administrators are need to be PA rather than DR.

• Structural Engineering and Mechanics
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• 제10권2호
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• pp.93-110
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• 2000

An alternative interpretation of the completeness requirements for the higher order elements is presented. Apart from the familiar condition, $\sum_iN_i=1$, some additional conditions to be satisfied by the shape functions of higher order elements are identified. Elements with their geometry in the natural form, i.e., without any geometrical distortion, satisfy most of these additional conditions inherently. However, the geometrically distorted elements satisfy only fewer conditions. The practical implications of the satisfaction or non-satisfaction of these additional conditions are investigated with respect to a 3-node bar element, and 8- and 9-node quadrilateral elements. The results suggest that non-satisfaction of these additional conditions results in poorer performance of the element when the element is geometrically distorted. Based on the new interpretation of completeness requirements, a 3-node element and an 8-node rectangular element that are insensitive to mid-node distortion under a quadratic displacement field have been developed.