• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.291-303
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• 2003

This work is proposed an alternative identification method of outlying cell which is one of important issues in categorical data analysis. One finds that there is a strong relationship between the location of an outlying cell and the corresponding parameter estimates of the well-fitted log-linear model. Among parameters of log-linear model, an outlying cell is affected by interaction terms rather than main effect terms. Hence one could identify an outlying cell by investigating of parameter estimates in an appropriate log-linear model.

• 아동학회지
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• 제24권3호
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• pp.15-26
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• 2003

This research investigated young children's social interaction and task performance in dyadic collaboration. The independent variables were gender and social skill level(high/low groups). Twenty-four pairs each 4-year-old boys and 4-year-old girls(total 96 subjects) worked at a block reconstruction. Two researchers judged degree of dyadic collaboration. Data were processed by 2 way ANOVA and Pearson's product correlation. While no main effect for gender was found, the effect for social skill level(high/low groups)was significant for social interaction. There was positive correlation between social interaction and task performance.

• 한국유체기계학회 논문집
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• 제2권2호
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• pp.57-63
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• 1999

The flow through multistage turbomachinery is affected by the interaction between a rotor and a stator. The interaction is due to the inviscid potential effect and viscous effect between closely spaced rotor and stator airfoils. Three-dimensional, unsteady, incompressible Navier-Stokes equations with a standard $k-{\epsilon}$ model are solved using a non-staggered grid system. This method is applied to the flow through a multistage compressor measured by Stauter et al. The results have shown strong interaction between the rotating and stationary flow field. The decay of rotor wake and the pressure profiles agree very well with experimental data. The wake produced by rotor causes unsteady pressure on the surface of a stator. The rotor/stator interaction produces the unsteady pressure force on the rotor and stator blades.

• Structural Engineering and Mechanics
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• 제13권3호
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• pp.241-260
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• 2002

The effect of shear coupled with axial force variation on the inelastic seismic behaviour of reinforced concrete bridge piers is investigated in this paper. For this purpose, a hysteretic axial-shear interaction model was developed and implemented in a nonlinear finite element analysis program. Thus, flexure-shear-axial interaction is simulated under variable amplitude reversed actions. Comparative studies for shear-dominated reinforced concrete columns indicated that a conventional FE model based on flexure-axial interaction only gave wholly inadequate results and was therefore incapable of predicting the behaviour of such members. Analysis of a reinforced concrete bridge damaged during the Northridge (California 1994) earthquake demonstrated the importance of shear modelling. The contribution of shear deformation to total displacement was considerable, leading to increased ductility demand. Moreover, the effect of shear with axial force variation can significantly affect strength, stiffness and energy dissipation capacity of reinforced concrete members. It is concluded that flexure-shear-axial interaction should be taken into account in assessing the behaviour of reinforced concrete bridge columns, especially in the presence of high vertical ground motion.

• Asia pacific journal of information systems
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• 제6권1호
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• pp.39-74
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• 1996

Most of the research on a group decision support system [GDSS] has focused on directly examining its effect on the decision outcomes. Under this research framework, however, the role of group interaction process is largely ignored. This study focuses on the effect of the group interaction process on decision-making performance when a GDSS is used as the only medium for group interaction. Specifically, this study sought to determine whether significant relationships exist between the quality of the decision and the decision functions, contingent phases, and different decision paths. Natural interaction processes of decision -making groups was simulated in an experimental setting in which volunteer subjects from several business classes were assigned to dispersed three-person groups undertook the experimental task via a decision network. A baseline GDSS was developed for this setting. The results of this study confirmed earlier studies in a non - GDSS setting to suggest significant effects of decision functions and contingent phases on the quality of decision but no significant relationship between decision path and the quality of group decision.

• Structural Engineering and Mechanics
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• 제13권4호
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• pp.455-464
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• 2002

There is a growing demand to assess the remaining strength and endurance of existing composite steel and concrete bridge beams due to the aging infrastructure, increases in permissible vehicle weights and increases in their frequencies. As codes are generally dedicated to the design of new structures, new procedures are required to aid in the assessment of existing bridges to ensure that they are utilised to the full. In this paper, simple expressions are presented to perform partial-interaction analyses directly from full-interaction analyses, so that the beneficial effect of partial-interaction on the shear forces on the shear connectors can be utilised in assessment to extend the fatigue life of simply supported bridge beams and to determine the effect of remedial work if necessary. Use of the assessment technique is described by way of an illustrative example.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.363-370
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• 2001

A computationally efficient algorithm to analyze a group pile behavior is proposed by consideration of both soil-pile and pile-cap interactions. Using toad transfer method the nonlinear characteristics of the soil-pile interaction for a single pile is modeled by piecewise linear soil springs (p-y, t-z, and q-z curves). Beam-column method, one of the most practical approaches, is used for numerical modeling of the soil-pile system. In addition to the group effect resulting from the soil-pile-soil interaction, for a more realistic analysis it is essential to consider the effect of pile-cap interaction including geometric configuration of the piles in a group and conectivity conditions between piles and the cap. This paper mainly focuses on the pile-cap interaction and the development of a rational numerical procedure of its incorporation with the beam-column method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.820-825
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• 1994

It is improtant to examine life or crack propagation behavior of structures because of its safety evaluation. The purpose of this study is to investigate the effect of crack-crack interaction to evaluate fatigue life and crack behavior. In this study, the behavior of the interaction of two cracks is studied by experiment. The vertical distance of two cracks is varied to make different interaction stress field. In addition, the effect of plastic zone is considered to examine crack propagation path and propagation rate.

• Journal of Information Technology Applications and Management
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• 제13권4호
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• pp.197-214
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• 2006

This study explores factors to facilitate web-based collaborative learning and the effect of learning, based on the PBL(Problem Based Learning) from the constructivist approach in e-learning. A research model, using the key variables such as situations, interactions, and systems, was developed. In order to test this proposed model, experimental design and post-survey was conducted to the learners who took on-line and off-line course with team project. In the research model, situation category was divided into instructor's support, unstructured problem, and self-directed learning. Interaction category was divided into three factors; 'interaction between learners', 'interaction between learner and instructor', and 'interaction between learner and technology'. System category was divided into.monitoring and incentives. As a result, it was found that collaborative learning can be improved by situations, interactions, and systems, and the effectiveness of learning can be improved by situations and interactions in PBL.

• Nuclear Engineering and Technology
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• 제42권6호
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• pp.680-689
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• 2010

The crack-tip stress fields and fracture mechanics assessment parameters for a surface crack, such as the elastic stress intensity factor or the elastic-plastic J-integral, can be affected significantly by the adjacent cracks. Such a crack interaction effect due to multiple cracks can alter the fracture mechanics assessment parameters significantly. There are many factors to be considered, for instance the relative distance between adjacent cracks, the crack shape, and the loading condition, to quantify the crack interaction effect on the fracture mechanics assessment parameters. Thus, the current assessment codes on crack interaction effects (crack combination rules), including ASME Sec. XI, BS7910, British Energy R6 and API 579-1/ASME FFS-1, provide different rules for combining multiple surface cracks into a single surface crack. The present paper investigates crack interaction effects by evaluating the elastic stress intensity factor and the elastic-plastic J-integral of adjacent in-plane surface cracks in a plate through detailed 3-dimensional elastic and elastic-plastic finite element analyses. The effects on the fracture mechanics assessment parameters of the geometric parameters, the relative distance between two cracks, and the crack shape are investigated systematically. As for the loading condition, an axial tension is considered. Based on the finite element results, the acceptability of the crack combination rules provided in the existing guidance was investigated, and the relevant recommendations on a crack interaction for in-plane surface cracks are discussed. The present results can be used to develop more concrete guidance on crack interaction effects for crack shape characterization to evaluate the integrity of defective components.