• 전자공학회논문지C
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• 제34C권7호
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• pp.1-7
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• 1997

VHDL simulation requires both analysis and elaboration processes. Reducing the time taken by these processes shorten design cycles. We propose an incremental analysis and elaboration algorithm for VHDL, which minimizes the number of design units to be re-analyzed and re-elaborated after an incremental change, thereby reducing the desing cycle time. Experimental results show about four times performance improvement in analysis and 1.25 times in elaboration over the conventional method.

• Steel and Composite Structures
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• 제35권3호
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• pp.327-341
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• 2020

The use of high-strength steel and concrete in the construction industry has been gaining increasing attention over the past few decades. With it comes the need to utilise high-strength structural bolts to ensure the design load to be transferred safely through joint regions, where the space is limited due to the reduced structural dimensions. However, research on the behaviour of high-strength structural bolts under various loading combinations is still insufficient. Most of the current design specifications concerning high-strength structural bolts were established based on a very limited set of experimental results. Moreover, as experimental programs normally include limited design parameters for investigation, finite element analysis has become one of the effective methods to assist the understanding of the behaviour of structural components. An accurate and simple full-range stress-strain model for high-strength structural bolts under different loading combinations was therefore developed, where the effects of bolt fracture was included. The ultimate strength capacities of various structural bolts obtained from the present experimental program were compared with the existing design provisions. Furthermore, design recommendations concerning the pure shear and tension, as well as combined shear and tension resistance of Grade 10.9 high-strength structural bolts were provided.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.971-976
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• 2006

This paper presents a design technique of steel structures subjected to static and dynamic loadings using practical nonlinear inelastic analysis software. The beam-column approach using the stability functions and the plastic hinge concept enables the software to suitably predict second-order effects and inelastic behavior of beam-columns. For dynamic analysis. the incremental from of the equation of motion is solved by the use of a step-by-step numerical integration procedure in which the assumption of constant acceleration over a small time step is employed. The accuracy of the analysis program is validated using the results of ABAQUS program and experimental tests. A user-friendly graphic interface of the software is developed to facilitate the modeling process and result interpretation of the problem. A design example of large span bridge is presented to detail the direct design process using the practical advanced analysis software.

• 한국정밀공학회지
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• 제19권9호
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• pp.118-124
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• 2002

The use of ceramic inserts in hot extrusion dies offers significant technical and economic advantages over other forms of manufacture. In this paper, process simulation and stress analysis are thus combined during the design, and a data exchange program has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process. The shrink fit analysis has been performed that enables optimal design of the dies taking into account the elastic deflections which generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the die design. The stress analysis of the dies is used to determine the stress conditions on the ceramic insert by considering contact and interference effects under both mechanical and thermal loads. The results are compared with the experimental ones for verification.

• 복식문화연구
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• 제12권3호
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• pp.379-391
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• 2004

The purpose of this study was to examine the effects of uniform's color and motif on nurse's impression formation. The experimental design was 5×3×2(uniform color×motif ×perceiver's gender) factorial design with a between-subjects design. The experimental materials developed for the study were a set of stimuli and a response scale. The subjects were 738 undergraduate students of Daejon and Chungnam province. The SPSS package was used for data analysis which includes factor analysis, two-way ANOVA, Duncan's multiple range test, and Cronbach's α to measure the reliability. Results were as follows; The image or the stimulus was consisted of the 4 different dimensions(evaluation, sociability, ability, potency). All the independent variables showed some significant impression effects on selected dimensions. The motif and perceiver's gender also showed significant main effects as well as some interaction effects with the color variable on some selected impression dimension and the impression effects of the three variables in relationship to perceiving nurses' images. On a conclusion, these results supported the Gestalt theory.

• 반도체디스플레이기술학회지
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• 제12권4호
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• pp.9-13
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• 2013

Lapping is a very complicated and random process resulting from the variation of abrasive grains in its sizes and shapes and from the numerous factors having an effect on the process quality. This paper presents a study of a $2^4$ full factorial experimental design and analysis to optimize surface quality in lapping operation. The optimization of the factors to obtain minimum surface roughness was carried out by incorporating effect plots, main effect plots, interaction plots, analysis of variance(ANOVA), surface plots, and contour plots. The statistical design experiments, designed to reduce the total number of experiments required, indicated that, within the selected conditions, all the parameters influenced at a significance level of 5%. In addition, some of the possible interactions between these parameters also influenced the lapping process, especially those that were of third order. A regression model was suggested and fitted the experimental data very well.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.88-97
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• 1999

In this study, a systematic approach for roll pass design in bar rolling was studied. To minimize the trial and errors in the process design, a roll CAD system and a FE analysis system were combined. Based on the system, a methodology for roll pass design by FEM was studied. At first, designed process was compared with the FE analysis results and process redesign based on the FEM results was performed to obtain the specified final geometry. Then, empirical formula for roll speed set-up was compared with the FE analysis results. Further study on various simulations for bar rolling will help in making up for the inaccuracy in the currently used empirical roll speed rules. In addition, verification of the accuracy of the FE analysis system must be performed using experimental data in the industry.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.989-992
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• 2002

This paper presents a procedure far design, modeling and analysis of a fine positioning stage. The stage considered here is composed of flexure hinges, piezoelectric actuators and their peripherals. Through a series of analysis, the structural analysis model is simplified as a rigid body(the moving part) and springs (the flexure hinges). An experimental design procedure is applied to determine optimum design variables for flexure hinges. The optimum variables are validated through a numerical test. A sensitivity analysis on the notch positions is also performed to obtain a guideline of fabrication accuracy for the stage.

• 보건교육건강증진학회지
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• 제21권4호
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• pp.15-33
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• 2004

With growing significance of psychological well-being in the worksite, the purpose of this analysis was to overview the empirical studies on worksite stress management and to identity the overall effect of worksite health promotion programs on stress management through meta-analysis. Literature retrieval was conducted on-line first in MEDLINE, EBSCOhost Academic Search Premier, and PSYCHINFO databases in public health, psychology, sociology, and human resource management areas. All studies written in English and published in the peer-reviewed journals during 1990 and 2002 were recruited. Key words used in literature retrieval were 'worksite,' 'intervention,' 'program,' 'work stress,' 'strain,' 'burnout,' 'management,' 'prevention,' 'education,' and 'health promotion.' A total of 18 worksite intervention studies with 48 effect sizes were analyzed and the results were as follows. Approximately 60％ of the studies had quasi-experimental design and were conducted in manufacturing company and public sector. General psychological strains and burnout were frequently used measures of psychological stress. The lecturing and discussion typed intervention and the participatory problem-solving typed intervention were employed more than others in the studies. The average effect (r: pearson's simple correlation coefficient) weighted by sampling error was -0.14 (-0.32 to 0.05). In the conventional category of effects this is a small effect ranging from -0.59 to 0.05. Binomial effect size showed that success rates increased from 43％ without intervention to 57％ after an intervention. Sampling error explained 47.14％ of the observed variance and its effectiveness on stress management were heterogeneous. In regression analysis with suspected moderating factors affecting the worksite interventions, research design was the only significant moderating factor. The studies with quasi-experimental design had greater effects than the studies with experimental design.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.619-626
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• 2018

Most publications confirm that an ecological interface is a very efficient tool to supporting operators in recognition of complex and unusual situations and in decision-making. The present article describes the experience of implementation of an ecological interface concept for visualization of material balance in a drum separator of RBMK-type NPPs. Functional analysis of the domain area was carried out and revealed main factors and contributors to the balance. The proposed ecological display was designed to facilitate execution of the most complicated cognitive operations, such as comparison, summarizing, prediction, etc. The experimental series carried out at NPPs demonstrated considerable reduction of operators' mental load, time of reaction, and error rate.