• 한국공작기계학회논문집
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• 제10권6호
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• pp.63-70
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• 2001

This study is concerned with Finite Element Analysis on welded part of control link fur automobile. For analysis, control link was modeled into two parts, ring and rod. Heating condition, temperature distributions and fatigue fracture strength were analyzed using "HEAT III" and "NDURE" module of NISA II. Metal flow in the process of welding was simulat- ed by $DEFORM^{TM}2D$.The analyzed results were compared with experimental inspection. Quality of welded part was able to be improved by controlling metal flow in the process of welding by increase the friction constant of ring part. Heat transfer analysis and flow simulations were in good agreement wish welding experiments.

• 한국생산제조학회지
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• 제25권4호
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• pp.290-294
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• 2016

A finite element method (FEM) study was performed on micro-scale blanking of an AL6061-T6 foil with negative clearance. ABAQUS/explicit was used to prepare a simulation model of negative clearance blanking with tools having an edge radius comparable to the foil thickness. The Johnson-Cook plastic flow model was used in the simulations for the material flow. The FEM model was used to study the effects of various blanking parameters on the negative clearance blanking process and quality of the blank. In particular, the projecting edge on the bottom of the blank was observed. Research on negative blanking at the micro-scale is summarized and discussed.

• 소성∙가공
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• 제21권1호
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• pp.24-29
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• 2012

Precision control of the width of slabs is vital for product quality and production economy in steel rolling mills. However, the formation of so called 'dog-bone' at the edge of the slab would affect the final width during the horizontal rolling that follows. Therefore, it is essential to predict and control the dog-bone shape. In this paper, a model is derived by using a number of finite element simulations for edge rolling and a least square regression analysis. The prediction accuracy of the proposed model is examined by comparing the predictions from finite element simulation with experiment results in the literature.

• Structural Engineering and Mechanics
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• 제5권2호
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• pp.137-148
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• 1997

In computing eigenvalues for a large finite element system it has been observed that the eigenvalue extractors produce eigenvectors that are in some sense more accurate than their corresponding eigenvalues. From this observation the paper uses a patch type technique based on the eigenvector for one mesh quality to provide an eigenvalue error indicator. Tests show this indicator to be both accurate and reliable. This technique was first observed by Stephen and Steven for an error estimation for buckling and natural frequency of beams and two dimensional in-plane and out-of-plane structures. This paper produces and error indicator for the more difficult problem of three dimensional brick elements.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.901-904
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• 2002

The cutting thickness of ultra-precision machining is generally very small, only a few micrometer or even down to the order of a flew manometer. In such case, a basic understanding of the mechanism on the micro-machining process is necessary to produce a high quality surface. When machining at very small depths of cut, metal flow near a rounded tool edge become important. In this paper a finite element analysis is presented to calculate the stagnation point on the tool edge or critical depth of cut below which no cutting occurs. From the simulation, the effects of the cutting speed on the critical depths of cut were calculated and discussed. Also the transition of the stagnation point according to the increase of the depths of cut was observed.

• Educational Technology International
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• 제16권1호
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• pp.1-30
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• 2015

The purpose of this research is to propose a novel social LMS developed for group collaborative learning with a think-aloud tool integrated for sharing cognitive processes in order to improve group collaborative learning performance. In this developmental research, the system was designed with three critical elements: the think-aloud element supports learners through shared cognition, the social network element improves the quality of collaborative learning by forming a structured social environment, and the learning management element provides a understructure for collaborative learning for student groups. Moreover, the three critical elements were combined in an educational context and applied in three directions.

• 품질경영학회지
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• 제45권1호
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• pp.11-24
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• 2017

Purpose: This study is on the priority for improving students satisfaction in university educational service. It explores the dimension of service quality and analyzes the relationship among quality elements, service satisfaction, and loyalty. Methods: This paper performs empirical studies by questionnaire survey. The Timko model is used for finding the degree of possible improvement of quality elements, and structural equation and regression models are used to analyze the effect of them on service satisfaction and loyalty. Also, explanatory factor analysis is used to investigate the quality determinants. Results: The quality dimension is composed of curriculum, employment support, interaction with outsiders, start-up support, learning support, counselling, and administration service. Curriculum, learning support, and administration service are positively correlated with service satisfaction, and service satisfaction has a positive effect on loyalty. Counselling service is an attractive element, and curriculum, start-up support, and learning support are indifferent elements. Conclusion: Comprehensive analysis shows that curriculum, academic advisor, and administration service have high priorities for improving educational service satisfaction.

• Spatial Information Research
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• 제11권4호
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• pp.327-340
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• 2003

공간데이터베이스의 품질평가는 공간데이터베이스의 특징에 따라 적절한 품질요소와 평가방법이 적용되어야 한다. 본 연구에서는 공간데이터베이스의 하나인 토지데이터베이스에 대한 구체적인 품질평가 방안을 제시하는데 목적을 두고 있다. 이를 위하여 토지데이터베이스를 구성하는 지형데이터베이스, 지적데이터베이스, 용도지역지구 데이터베이스의 구축 단계별 품질요소를 선정하고, 선정된 품질요소에 대하여 평가방법을 제시하였다. 토지데이터베이스의 품질요소는 위치정확성, 속성정확성, 일관성, 완결성, 시간정확성, 신뢰성, 이력 등이며, 다양한 통계적 및 수학적 방법들을 검토하여 각 품질요소의 객관적인 측정방법을 제안하였다.

• 간호행정학회지
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• 제16권4호
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• pp.497-506
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• 2010

Purpose: The purpose of this study was to examine the causal relationships among quality of health care service, service value, satisfaction and loyalty as perceived by hospital inpatients. Methods: A survey using a structured questionnaire was conducted with 654 hospital inpatients. Analysis of the data was done with both SPSS Win 17.0 for descriptive statistics and AMOS 18.0 for the structural equation model. Results: The modified model yielded Chi-square=7.96 (p=.019), df=2, $x^2$/df=3.98, GFI=.99, AGFI=.96, RMSEA=.07, NFI=.99, CFI=.99, TLI=.98 and showed good fit indices. Three dimensions of quality had significant direct effects on service value. Functional quality, technical quality and service value had significant direct effects on customer satisfaction. Technical quality, service value, and customer satisfaction had significant direct effects on customer loyalty. Conclusion: These results suggest that quality of health care is an important element in service value, and through both quality and service value, customer satisfaction and customer loyalty can be enhanced. Further study with a larger sample from various hospitals and a longitudinal design is necessary.

• East Asian mathematical journal
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• 제34권2호
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• pp.103-125
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• 2018

This study was conducted as a part of the project to evaluate the quality of mathematics instruction in the national curriculum system. The purpose of this study is to measure the consistency between teaching goals of mathematics curriculum, contents presentation of textbooks, and testing including adequacy of each element in mathematics instruction for 8th grade. To do this, we used MIQP (instructional quality profile for Mathematics) developed basing on the instructional quality profile (IQP) in the previous research of the project. First, the quality of textbooks' content presentation for 8th grade was found that the desirable levels in number and operation area and geometric area was relatively less compared to other areas, but it was generally good. Second, it was found that the quality of mathematics testing for 8th grade was good in terms of consistency with the curriculum's teaching goals, consistency with the content presentation of textbooks, and adequacy of testing. However, regional differences in the quality of testing showed that there were some deficiencies in regions outside the metropolitan.