• Coupled systems mechanics
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• 제7권4호
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• pp.441-453
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• 2018

Longitudinal fracture in a functionally graded beam configuration was studied analytically with taking into account the non-linear behavior of the material. A cantilever beam with two longitudinal cracks located symmetrically with respect to the centroid was analyzed. The material was functionally graded along the beam width as well as along the beam length. The fracture was studied in terms of the strain energy release rate. The influence of material gradient, crack location along the beam width, crack length and material non-linearity on the fracture behavior was investigated. It was shown that the analytical solution derived is very useful for parametric analyses of the non-linear longitudinal fracture behavior. It was found that by using appropriate material gradients in width and length directions of the beam, the strain energy release rate can be reduced significantly. Thus, the results obtained in the present paper may be applied for optimization of functionally graded beam structure with respect to the longitudinal fracture performance.

• 한국농공학회지
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• 제41권1호
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• pp.106-114
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• 1999

This paper explores the geometrical non-linear behavior of the simply supported tapered beams subject to the trapezoidal distributed load and end moments. In order to apply the Bernoulli -Euler beam theory to this tapered beam, the bending moment equation on any point of the elastical is obtained by the redistribution of trapezoidal distributed load. On the basis of the bending moment equation and the BErnoulli-Euler beam theory, the differential equations governging the elastical of such beams are derived and solved numerically by using the Runge-Jutta method and the trial and error method. The three kinds of tapered beams (i.e. width, depth and square tapers) are analyzed in this study. The numerical results of non-linear behavior obtained in this study from the simply supported tapered beams are appeared to be quite well according to the results from the reference . As the numerical results, the elastica, the stress resultants and the load-displacement curves are given in the figures.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 가을 학술발표회논문집
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• pp.201-208
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• 2000

This paper explores the non-linear behavior of tapered beam subjected to a floating concentrated load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastica is obtained from the final equilibrium state. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of clamped-roller beam are derived, and solved numerically. Three kinds of tapered beam types are considered. The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

• 한국농공학회지
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• 제42권2호
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• pp.108-114
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• 2000

This paper explores the non-linear behavior of tapered beam subjected to a floating concentration load. For applying the Bernoulli-Euler beam theory to this beam, the bending moment at any point of elastical is obtained from the final equilibrium stage. By using the bending moment equation and the Bernoulli-Euler beam theory, the differential equations governing the elastica of simple beam are derived , and solved numberically . Three kinds of tapered beam types are considered . The numerical results of the non-linear behavior obtained in this study are agreed quite well to the results obtained from the laboratory-scale experiments.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.449-450
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• 2006

Development of a feed drive system with high speed, positioning accuracy and thrust has been an important issue in modern automation systems and machine tools. Linear motors can be used as an efficient system to achieve such technical demands. By eliminating mechanical transmission mechanisms such as ball screw or rack-pinion, much higher speeds and greater acceleration can be achieved without backlash or excessive friction. However, an important disadvantage of linear motor system is its high power loss and heating up of motor and neighboring machine components on operation. For the application of the linear motors to precision machine tools an effective cooling method and thermal optimizing measures are required. In this paper presents an investigation into a thermal behavior of linear motor cooling plate. FVM employed to analyze the thermal behavior of the linear motor cooling plate, using the ANSYS-CFX.

• Computers and Concrete
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• 제23권1호
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• pp.11-23
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• 2019

Nowadays, the characterization of Ultra-High Performance Fiber-Reinforced Concrete (UHPFRC) tensile behavior still remains a challenge for researchers. For this purpose, a simplified closed-form non-linear hinge model based on the Third Point Bending Test (ThirdPBT) was developed by the authors. This model has been used as the basis of a simplified inverse analysis methodology to derive the tensile material properties from load-deflection response obtained from ThirdPBT experimental tests. In this paper, a non-linear finite element model (FEM) is presented with the objective of validate the closed-form non-linear hinge model. The state determination of the closed-form model is straightforward, which facilitates further inverse analysis methodologies to derive the tensile properties of UHPFRC. The accuracy of the closed-form non-linear hinge model is validated by a robust non-linear FEM analysis and a set of 15 Third-Point Bending tests with variable depths and a constant slenderness ratio of 4.5. The numerical validation shows excellent results in terms of load-deflection response, bending curvatures and average longitudinal strains when resorting to the discrete crack approach.

• 가정과삶의질연구
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• 제23권5호
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• pp.103-122
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• 2005

The purpose of this study was to examine the influences of their money attitudes to spending behaviors of middle, high, and college students. The total number of students selected for this study were 1,252. Factor analysis, Cronbach' ${\alpha}$, two-way ANOVA, Duncan' multiple range test, Pearson correlation analysis, and multiple regression were used for statistical analysis. The results were summarized as followings: 1) The tendency of attitude that money is good was highest. Also, the tendency of attitude that money represents freedom and power was slightly high. On the other hand the attitudes that money represents achievement, and that money is evil were low. Especially the attitude that money represents respect was lowest. 2) Resulting from two-way ANOVA, the attitudes that money is good and represents achievement showed significant interaction effects between sex and age. The altitude that money is good showed significant differences by sex especially among middle and high school students. The altitude that money represents achievement showed significant differences by age among the male students. Three types of attitudes that money is evil, money represents respect, and money represents both freedom and power showed significant main effects in different age groups. Also the attitude that money represents freedom and power showed significant main effect by different sexes. 3) Four different types of measuring spending behaviors scored slightly low mark. 4) Resulting from two-way ANOVA, four different spending behaviors showed significant difference only by sexes and ages. Planned spalding behavior and conscious spending behavior showed significant differences in ages and sexes separately. While impulsive spending behavior by different age groups resulted in significant differences. Excessive spending behavior by sexes resulted in significant differences. 5) Regression analysis showed that planned spending behavior had the linear relationships in no, sex, self-esteem, and attitude that money is good. Conscious spending behavior had the linear relationships in ses, and attitudes that money represent achievement. respect, and freedom. Impulsive spending behavior had the linear relationships in age, self-esteem, and attitudes that money is good and that money is evil, and attitude that money represent freedom, Excessive spending behavior had the linear relationships in sex, self-esteem, and attitudes that money represent achievement, respect and freedom.

• 한국컴퓨터정보학회논문지
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• 제22권9호
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• pp.125-132
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• 2017

The purpose of this study was to examine the factors influencing career preparation behavior based on the perception of college students from the perspective of social cognitive career theory and to examine the effect of career barriers and career decision self - efficacy on career preparation behavior And career - decision self - efficacy. The results of the study are as follows. First, career barriers perceived by college students showed a significant positive correlation with career decision self - efficacy and career preparation behavior(-), and career decision efficacy showed a statistically significant correlation with career preparation behavior(+). Second, as a result of linear regression analysis to examine the effect of career barriers on career preparation behavior, lack of self - clarification, lack of job information, and lack of recognition of need were subordinate factors of career barriers. Third, as a result of linear regression analysis to examine the effect of career decision - making self - efficacy on career preparation behavior, goal setting and job information, which are sub - factors of career decision self - efficacy, were analyzed. Fourth, mediating effects of career decision self - efficacy on career barriers and career preparation behavior were analyzed by hierarchical regression analysis. The results of this study confirm that the level of career barrier, which is an important factor in career preparation behavior of college students, should be lowered and career decision self - efficacy should be increased.

• KSBB Journal
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• 제14권3호
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• pp.279-283
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• 1999

본 연구에서는 난백에 포함된 라이소자임의 컬럼 크로마토그래피에서의 breakthrough behavior 실험을 통해 최적 크로마토그래피 분리조건을 결정하였다. 다양한 양이온 교환수지의 라이소자임 breakthrough behavior를 비교한 결과 Cellufine C-200(Amicon, USA)이 라이소자임 흡착에 가장 우수한 성능을 보였다. Cellufine C-200 수지에서 이온강도, pH, 선속도 등이 난백 라이소자임의 breakthrough behavior에 미치는 영향을 비교한 결과 conductivity 2.75 mS/cm, pH 7, 선속도 0.635cm/min의 최적 조건을 얻었다. 본 최적조건에서 prep 규모 컬럼 크로마토그래퍼를 이용 난백으로부터 라이소자임을 분리하였다. 정제된 라이소자임과 Sigma 라이소자임의 specific activity는 비슷하였으며 SDS-PAGE 분석 결과 본 연구에서 정제된 라이소자임이 Sigma 라이소자임보다 impurity 단백질들을 적게 포함하고 있음을 확인하였다.

• 한국터널지하공간학회 논문집
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• 제2권2호
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• pp.72-85
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• 2000

암석은 지질학적 생성과정으로 인해 잠재적으로 많은 구조적 결함을 내포하고 있는 재료이다. 이러한 구조적 결함으로 인해 압축하중을 받고 있는 암석의 변형거동 및 파괴는 비선형적이다. 지금까지의 연구들에서는 암석의 비선형 거동을 모사하기 위해 균열모형, 즉 활주균열모형 (Sliding crack model) 과 전단균열모형 (Shear crack model) 을 사용하였다. 이 연구들에서는 암석의 비선형 응력-변형률 곡선과 균열성장으로 인해 발생되는 유효탄성정수들 ($E_1$, $E_2$, ${\nu}_1$, ${\nu}_2$, $G_2$) 의 변화와 같은 여러 가지 암석 거동을 모사하였다 (Kemeny, 1993; Jeon, 1996, 1998). 대부분의 이러한 연구들은 주로 균열모형의 암석거동의 적용에 대한 타당성을 검증하는데 그쳤으며 지하공간이나 사면설계 등의 실제적인 수치해석을 목적으로 균열모형을 적용한 연구는 그다지 많지 않다. 본 연구에서는 암석의 비선형 응력 변형률 곡선을 모사함으로써 균열모형의 암석에의 적용에 대한 타당성을 검증하며 실제적인 수치해석, 즉 상용되고 있는 유한요소해석 프로그램에 균열모형을 적용하였다.