• Journal of the Korean Society for Precision Engineering
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• v.18 no.3
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• pp.143-151
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• 2001

Machine tool errors have to be characterized and predicted to improve machine tool accuracy. A real-time error compensation system has been developed based on volumetric error synthesis model which is composed of machine tool errors. This paper deals with new algorithm about verification of machine tool errors. This new algorithm uses a simplified volumetric error synthesis model. This simplified model is constructed with only main components among the error components of the machine. The main error components are analyzed by ball bar test of hemispherical helix. The novel measurement method using ball bar system has many advantages which are more efficient, easier to use than conventional measurement system.

• Culinary science and hospitality research
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• v.12 no.2 s.29
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• pp.1-17
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• 2006

This study is to develop a viable measurement tool of crowdedness in restaurants. First, to measure customer’s awareness of crowdedness related to each different environmental factor in a restaurant, 49 factors of crowdedness awareness were selected based on the previous studies and then properties of each factor affecting customer’s satisfaction for crowdedness were analyzed. To analyze effects of each factor upon the satisfaction rate, a Multiple Regression Analysis was conducted with the crowdedness awareness as an independent variable and satisfaction of crowdedness as a dependent variable. The results showed that when an analysis of the environmental factors in the crowdedness awareness was conducted in an effort to develop a measurement tool of crowdedness awareness in restaurants, that would be fit for the domestic food service market, based upon 49 factors of restaurant environment. Focusing on expectation and satisfaction rate, it was found that rating the satisfaction level would be a much more effective tool to measure crowdedness awareness because satisfaction rate appeared to be more closely related to the awareness than the results obtained from the Multiple Regression Analysis with a difference between expectation and satisfaction scores as an independent variable.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.5 s.176
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• pp.1343-1351
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• 2000

Thermally induced errors have been significant factors affecting the machine tool accuracy. In this paper, the spindle thermal error has been focused, where the 5 degree of freedom thermal error components are considered. An effective measurement system has been devised for the 5 DOF thermal errors, consisting of gap sensors and thermocouples around the micro-computer interfaced environment. Several thermal error modeling techniques are also implemented for the thermal error prediction: multiple linear regression, neural network and system identification methods, etc. The performance of the thermal error modeling techniques is evaluated and compared, giving the system identification method as the optimum model having the least deviation. The developed system for the thermal error measurement and modeling was practically applied to a CNC machining center, and the spindle thermal errors were effectively compensated around the micro computer-machine tool interfaced networks. The machine tool accuracy was improved about 4-5 times typically.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.4 s.97
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• pp.404-411
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• 2005

To increase accurateness and reliability of the evaluation of power tool vibration transmitted to an operator, it is necessary to measure the grip and feed forces during the measurement of hand-transmitted vibration. In the study a system was invented to measure the vibration and the grip and/or feed force, which consists of a measurement handle and a PC with a data acquisition system and the corresponding software. Strain gauges and an accelerometer were mounted on the handle surface for the simultaneous measurement of the forces and the vibration. The program in the system makes it possible to monitor the grip and feed force during the tool operation so that the operator keeps the applying forces within the pre-determined range. Investigating the vibration total values, frequency-weighted root-mean-square accelerations at the handle, obtained in repetition for each power tool with control of the grip and feed force showed more consistency than those measured without force control. By using the system the experimenter can reduce random error of the measured vibration.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1087-1093
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• 2013

In this study, a measurement method of double ball-bar is proposed to measure the geometric errors of an ultra-precision roll mold machine tool. A volumetric error model of the machine tool is established to investigate the effects of the geometric errors to a radius error and a cylindricity of the roll mold. A measurement path is suggested for the geometric errors, and a ball-bar equation is derived to represent the relation between the geometric errors and a measured data of the double ball-bar. Set-up errors, which are inevitable at the double ball-bar installation, also are analyzed and are removed mathematically for the measurement accuracy. In addition, standard uncertainty of the measured geometric errors is analyzed to determine the experimental condition. Finally, the proposed method is tested and verified through simulation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.375-378
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• 1995

Although laser interferometer measurement system has the advantage of range and accuracy, the traditional error measurement methods for geometric errors(two straightness and three angular errors) of a machine tool measures error components one at a time. It may also create an optical path difference and affect the measurement accuracy. In order to identify and compensate for geometric error of a moving body, an on-line measurement system for simultaneous detection of the five error components of a moving axis is required. An on-line measurement system with 5 degrees of freedom was developed for geometric error detection. Performance verification of the system was performed on an error generating mechanism. Experimental results show the feasibility of this system for identifying geometric errors of a side of machine tool.

• Health Policy and Management
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• v.23 no.4
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• pp.434-444
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• 2013

Background: Regional Cardiocerebrovascular Centers (RCC) were established for the prevention and treatment of cardiocerebrovascular disease and funded by the Ministry of Health and Welfare. The purpose of this study was to develop and validate the measurement tool of public benefits in RCC. Methods: Through the intensive literature review, experts surveys and their repetitive feedback, we selected the 46 items about the public benefits in RCC. Development of measurement tool involved content validity test using Content Validity Index (CVI), construct validity test through factor analysis and reliability test. Results: Thirty-five items were selected by content validity test, which CVI was 0.08 or higher. Through the construct validity test, 32 items in 7 factors were derived. And Cronbach's alpha was 0.951. Finally, public benefits measurement tool is composed of 32 items in 7 factors which are comprehensiveness of health care services, market complement, emergency care, cost, governance, quality improvement, and government control. Conclusion: Though we developed the measurement tool of public benefits in RCC, it would be utilized to measure the public benefits of various health agencies.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.3
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• pp.311-332
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• 2015

This study aims at developing the measurement tool of reading motivation using self-determination theory (SDT). SDT is not simply divided into the intrinsic and extrinsic motivation. SDT resides along a continuum, with amotivation, external regulation, introjected regulation, identified regulation, integrated regulation, intrinsic motivation. SDT addresses the process of internalization of various extrinsic motives. This study analyzed motivation factor of the measurement tool such as MRQ (motivations for reading questionnaire), MRP (motivation to read profile) ERAS (elementary reading attitude survey, RSCS (reading self-concept scale). The study re-classified analysis results based on SDT. Ultimately, this study was proposed measurement tool of reading motivation using SDT has 6 area, 30 items.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.111-128
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• 2005

This paper examines the validity of the newly developed IT consulting SERVQUAL measurement tool. In an attempt to measure Ire IS customers' expectations and perceived quality of the services they received, the researchers developed a diagnostic tool of SERVQUAL based on the solid theoretical background, which can specifically be applied to the IT consulting service sector. This on-going research so far, has been applied to six (6) different organizations that have received IT consulting services over the past years. From the preliminary data collected, the correlation and the factor analyses were conducted to understand the underlying concept and refinement of the measurement tool. Although the correlation analysis showed a little tendency of collinearity among some of the variables, all showed sound relationship of the proposed hypotheses. The exploratory factor analytic approach was chosen because it does not set any priori constraints on the estimation of components or the number of components to be extracted. The number of different factor solutions was extracted and tested to see which solution represents better grouping of the variables. The Crombach's Alpha was computed on different combinations of the factor solutions to ensure validity. The results show 8-dimensional IT consulting SERVQUAL measures which they are, assurance, knowledge & skill, customer relationship, support, empathy, process management, expertise, and education, seem more appropriate than the originally proposed 6 dimensions. The study approach was non-experimental cross-sectional research design. The longitudinal design of follow-up studies to periodically revise and refine current measure is strongly recommended for fine tuning of the tool.

• Journal of the Korea Society of Computer and Information
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• v.24 no.12
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• pp.191-199
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• 2019

In this paper, we propose to develop a diagnosis tool for measuring digital competence for university student. To this end, 223 students participated for the survey research. Based on the survey by 6 domain and 40 questions, 6 factors and 18 questions for digital competence measurement were drawn throughout the factors analysis. The results of the confirmatory factor analysis showed the fact that 6 factors and 18 questions that satisfied the model-fit indexes statistically were finally confirmed. And the developed tool demonstrated good results in reliability and validity verification, which were suitable for measuring digital competence for university students. The developed measurement tool of digital competence for university students consisted of 6 sub-components such digital device operation, communication and collaboration, information searching, processing, and management, problem solving and learning, security, digital ethics. The digital competence measuring tool developed in this study is expected to be used to identify the current level of competences for university student, and to enhance their own digital competences through educational supports.