• Journal of the Korean Institute of Navigation
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• v.21 no.2
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• pp.1-9
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• 1997

This paper presented a method of evaluating navigational safety of a ship by means fo the integrted seakeeping performance index(ISPI). The ISPI is defined by measuring only any one factor through the medium of relative dangerousness of the other factors for evaluating seakeeping performance. This evaluation method can be applied to the ships for any types and loading conditions. In devloping the practical evaluation system of navigational safety, it is expected to be useful to solve the difficulties in measuring factors by sensors. The results are also useful for devloping the optimum type of ship by applying at the initial design phase.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.378-391
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• 2002

A 250mm stroke aerostatic stage, which detects position with laser scale and is driven by linear motor, is made and analyzed positioning error in 20$\pm$ 0.5 $^{\circ}C$ controlled atmosphere, aiming at investigating positioning characteristic of ultra-precision stage. We prove this aerostatic stage has a 10nm micro step resolution by experiment. By means of analyzing laser interferometer system, the scale of measuring error is about 0.2-0.4$\mu\textrm{m}$ according to refractive index error from missing the temperature change. To improve laser interferometer system, compensate refractive index error using measuring data from thermocouple. And, confirm 0.10$\mu\textrm{m}$ repeatability and 0.13 $\mu\textrm{m}$ positioning accuracy using the compensating refractive index. Also, we confirm 0.07 ${\mu}{\textrm}{m}$ repeatability of the stage using capacitive displacement sensor.

• Journal of Korean Society for Quality Management
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• v.27 no.2
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• pp.47-56
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• 1999

In this paper, we analyzed two methodologies to evaluate the total quality management activities comparatively. One of them is the traditional scoring system (TSS) by analytic hierarchy process (AHP) and the other is the efficiency measuring system (EMS) by data envelop analysis (DEA). It is demonstrated that the index by TSS and the efficiency index by EMS are not correlated. Also, the efficiency index by EMS in terms of company characteristics such as the size of company and ISO certifications is different from the index by TSS. The result implies that to evaluate the quality activities by EMS is needed as a supplementary methodology.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2001.05a
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• pp.473-492
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• 2001

This paper presents an econometric model for measuring basic research capacity index(BRCI) of each OECD countries and analyses the gap in terms of time lag measured and forecasted in connection with factor analysis and BRCI progress function. Based on the analysis, gross domestic expenditure on R&D(GERD), total R&D personnel, higher education expenditure on R&D(HERD) and number of science and technical papers based on SCI are more effective than other factors to BRCI. Also, BRCI progress function shows that 29 years is needed for Korea to catch up the level of German's BRCI of year 1998. But, it's impossible for Korea to catch up US and Japan. Therefore, with restricted scientific resources, Korea's own strategy for strengthening basic research capacity is going to be more important in 21st century.

• Proceedings of the Safety Management and Science Conference
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• 2011.04a
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• pp.701-705
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• 2011

The paper reviews Cronbaha's coefficient to measure a single source of error. On the contrary to classical measurement theory, the generalizability study can be used in the social survey design to calculate Generalizability Index (GI) and Dependability Index (DI) for measuring multiple sources of errors of behavior evaluation. The study proposes application guidelines to implement R:($A{\times}B$) mixed models that are composed of random factor and fixed factor.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.755-760
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• 1998

This study was performed to improve the evaluation of the longitudinal roughness index for various profilometers at airport runway. Especially, a laser type of profilemeter subjected to the longitudinal roughness index has been focused. The test result show that a new type of profile index, IRI(International roughness index) resulted from a laser type of profilometer was profitable for airport runway etc.. The present study provides useful results for the improvement of evaluation of the conventional profile index.

• Science of Emotion and Sensibility
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• v.14 no.1
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• pp.83-92
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• 2011

Because of the development of digital technologies and information-oriented products, the importance of user interface design and usability are increasing in recent year. So we need a systematic and rational way to measure and manage how effective the improvement of user interface is. The purpose of this study is to develop measurable ‘Usability Improvement Index' which signify how much usability has improved in user interface design. First, I made the framework of measuring and evaluating usability through analysis of existing usability metrics and previous studies. Then, I suggested the process of calculating 'Usability Improvement Index' based on categorizing characteristics of measurable usability and definition of usability metrics. The process is as in the following : measuring the present level of usability, analysis of problems, making alternative user interface design, measuring the improved level of usability, calculating Usability Improvement Index. For verification, the case study on application of Usability Improvement Index to usability improvement of application software of digital camcorder presented. This study is expected to assist 'goal oriented user interface design' and to manage usability systematically.

• The Korean Journal of Rehabilitation Nursing
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• v.9 no.2
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• pp.126-133
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• 2006

Purpose: The purpose of this study was to investigate Laughter Index, depression and anxiety in middle-aged women. Method: The data were collected from 622 middle-aged women by means of structured questionnaire. The data were analyzed using descriptive analysis, t-test, one-way ANOVA, Pearson correlation analysis by SPSS version 10. Results: The measuring of respondents' laughter index revealed they scored an average of 94.75 (${\pm}16.13$) of the full score 150. The measuring of respondents' depression showed they marked an average of 42.69 (${\pm}7.72$) of the full score 80. The measuring of respondents' anxiety showed they marked an average of 42.03 (${\pm}9.48$) of the full score 80. Respondents statistically showed the significant difference in their laughter index depending on age(t=.917, p=.000), and economic status(F=21.710, p=.000). Respondents statistically revealed the significant difference in depression depending on religion(F=3.396, p=.018), economic status(F=13.660, p=.000). Respondents statistically revealed the significant difference in anxiety depending on religion(F=5.557, p=.001), economic status(F=16.79, p=.000). The laughter index related to depression and anxiety in middle-aged women were significantly correlated. Conclusion: This study showed that laughter index in middle-aged women was correlated negatively depression and anxiety. Further research is regarded as necessary to evaluate and to compare effects of laughter with physical health status.

• Journal of the Korean Society for information Management
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• v.24 no.4
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• pp.173-189
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• 2007

By measuring satisfaction index of the users of Information System, it is possible not only to estimate ROI(Return on Investment) but also to draw the device for the efficiency and improvement of the System. This study tries to give User Satisfaction Index Model for the System, and present operators and managers of the system with the method for improving satisfaction and efficiency by measuring the User Satisfaction Index of representative information systems. For this, the survey was carried out for the representative information systems. On the basis of the analysis, Satisfaction Index was drawn and through Matrix Analysis, the strategy for system improvement was derived.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.9
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• pp.167-173
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• 2004

The heterodyne He-Ne laser interferometer is the most widely used sensing unit to measure the position error. It measures the positioning error from the displacement of a moving reflector in terms of the wave length. But, the wave length is affected by the variation of atmospheric temperature. Temperature variation of 1$^\circ C$ results in the measuring error of 1ppm. In this paper, for measuring more accurately the position error of the ultra precision stage, the refractive index compensation method is introduced. The wave length of the laser interferometer is compensated using the simultaneously measured room temperature variations in the method. In order to investigate the limit of compensation, the stationary test against two fixed reflectors mounted on the zerodur$\circledR$ plate is performed firstly. From the experiment, it is confirmed that the measuring error of the laser interferometer can be improved from 0.34${\mu}m$ to 0.11${\mu}m$ by the application of the method. Secondly, for the verification of the compensating effect, it is applied to estimate the positioning accuracy of an ultra precision aerostatic stage. Two times of the refractive index compensation are performed to acquire the positioning error of the stage from the initially measured data, that is, to the initially measured positioning error and to the measured positioning error profile after the NC compensation. Although the positioning error of an aerostatic stage cannot be clarified perfectly, it is known that by the compensation method, the measuring error by the laser interferometer can be improved to within 0.1${\mu}m$.