• Journal of Institute of Control, Robotics and Systems
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• v.7 no.2
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• pp.168-172
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• 2001

The accuracy problem of robot manipulators has long been one of the principal concerns in robot design and control. A practical and economical way of enhancing the manipulator accuracy, without affecting its hardware, is kinematic calibration. In this paper an effective and practical method is presented for kinematic calibration of Stewart platforms. In our method differential errors in kinematical parameters are linearly related to differential errors in the platform pose, expressed through the forward kinematics. The algorithm is tested using simulated measurement in which measurement noise is included.

• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.63-70
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• 2004

In this paper, we consider the adjustment of convergence on Color Display Tube (CDT). Convergence is a measure of how well the red, green and blue beams are physically aligned with each other to strike the same area on the screen. When misconvergence (convergence error) occurs, one way of compensating it is to attach several ferrite sheets on the inner part of Deflection Yoke (DY). We suggest an optimization model of misconvergence compensation process and report test results for 81 DY samples. As a result, more than 90% of the samples could be made to satisfy the required convergence criteria.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.1
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• pp.76-81
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• 1999

The degree of relative similarity between 2D patterns is obtained using Open-Ball Scheme. Open-Ball Scheme employs a method of transforming the geometrical information on 3D objects or 2D patterns into the features to measure the relative similarity for object(patten) recognition, with invariance on scale, rotation, and translation. The feature of an object is used to obtain the relative similarity and mapped into [0, 1] the interval of real line. For decades, Moment-Invariant Method has been used as one of the excellent methods for pattern classification and object recognition. Open-Ball Scheme uses the geometrical structure of patterns while Moment Invariant Method uses the statistical characteristics. Open-Ball Scheme is compared to Moment Invariant Method with respect to the way that it interprets two-dimensional patten classification, especially the paradigms are compared by the degree of closeness to human's intuitive understanding. Finally the effectiveness of the proposed Open-Ball Scheme is illustrated through simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.9
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• pp.1653-1667
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• 2011

Privacy is one of the most important and difficult research issues in ubiquitous computing. It is qualitative rather than quantitative. Privacy preserving mainly relies on policy based rules of the system, and users cannot adjust their privacy disclosure rules dynamically based on their wishes. To make users understand and control their privacy measurement, we present a scheme to quantize the personal privacy. We aim to configure the person's privacy based on the numerical privacy level which can be dynamically adjusted. Instead of using the traditional simple rule engine, we implement this scheme in a complex way. In addition, we design the scenario to explain the implementation of our scheme. To the best of our knowledge, we are the first to assess personal privacy numerically to achieve precision privacy computing. The privacy measurement and disclosure model will be refined in the future work.

• Journal of Korea Technology Innovation Society
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• v.13 no.1
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• pp.184-203
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• 2010

Based on the figure of Program's result, the measurement of National R&D Program efficiency cannot have reflected its characteristic. This study explores the way to integrate evaluators' recognition into program efficiency as a means of embodying its characteristic. As a way of integrating their recognition with evaluating efficiency, two methods are applied. One is AHP as for evaluators recognition and the other is DEA as for measuring efficiency. This study tries to show the effect of evaluators on program efficiency and compares the result with one which did not include their recognition. The study also implies that the recognition of evaluators should be considered when the program efficiency is measured. Furthermore, this study suggests that the participation and role of evaluators should be expanded into evaluation of program efficiency.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.11
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• pp.1136-1143
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• 2010

One-way laser ranging technology is applied for the precise orbit determination of LRO, which is the first trial for supporting the missions of lunar or planetary spacecraft. In this paper, LRO payload and ground system are discussed for LRO laser ranging, and some errors effecting on time of flight and tracking mount accuracy are analyzed. Additionally several technologies are also analyzed to make laser pulses shot from ground stations to arrive in the LRO earth window. Measurement data of LRO laser ranging verified that these technologies could be implemented for one-way laser ranging of lunar spacecraft.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.113-118
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• 2018

In this research, we conducted a questionnaire using the existing developed digital literacy checklist for analyzing the digital literacy level of Reserve Officers' Training Corps in K-University. In order to verify the validity and reliability of the measurement results collected on the basis of the response results, factor analysis of the question was carried out using the statistical analysis program SPSS 21.0, for each research group, the ability level by each factor was analyzed. Based on the results of analysis using frequency analysis, T-test and One-way ANOVA, we suggested measures to improve digital literacy level of school district officer candidates.

• Korean Journal of Child Studies
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• v.10 no.1
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• pp.26-42
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• 1989

This study was designed to investigate the relation between mother's interaction strategies and self-regulation of young children from a Vygotskian perspective. The hypotheses of this study were: 1) The self-regulation of young children will improve with increase in age, 2) the use of mothers' interaction strategies will increase as child's age decreases, 3) mothers' directiveness in the mother-child interaction depends on the age of child and socio-economic level, and 4) mothers' directiveness in the mother-child interaction will have negative relationship with child's self-regulation. The subjects of this study were 60 mother-child dyads with three different age-of-child groups (3-, 4-, and 5-year-olds). They were further divided into higher and lower socio-economic groups. A puzzle task was used for the measurement of self-regulation. The task consisted of two identical puzzles with one used as the model. The collected data were analyzed by ${\chi}^2$, one-way and two-way analysis of variance, and Pearson's r. Self-regulation of the young children improved with increase in age (P < .05). The use of mothers' interaction strategy decreased as the children's age increased (P < .05). Mothers' directiveness in the mother-child interaction was influenced by the age of child (P < .01) and by socioeconomic level (P < .05). There was a negative correlation (r=-.848) between the mothers' directiveness in the mother-child interaction and the child's self-regulation (P < .001).

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.1
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• pp.51-62
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• 2014

Purpose : The purpose of this work was to ascertain the effects of cervical traction on the pain, the range of motion and the quality of sleep of the older women with the tension headache. Method : 25 subjects between ages 66 and 82 who agreed on this experiment and diagnosed with tension headache participated in this study. All subjects were treated with air-pressure cervical traction while 20 minutes a day, 3 times per week, for 4 weeks. The effects of air-pressure cervical traction were evaluated by PSQI(Pittsburgh sleep quality index), a pain last a day, VAS, and four ROMs. In order to investigate the effect of age on the treatment, subjects were divided into two groups, of less and of over than age 75. The measured data were analyzed by using one-way repeated ANOVA and two-way repeated ANOVA. Result : 1) The group of less than age 75 showed the significant improvements in all measurement variables, PSQI, a pain last a day, VAS and four ROMs. 2) The group of over than age 75 showed the significant improvements in all measurement variables excluding the flexion ROM of cervical. 3) No significant differences between two groups were showed in all measurement variables, but the interaction effect between group and period was significant in only VAS. Conclusion : From the results of this study, a cervical traction intervention using an air-pressure cervical traction proved to be effective on the reduction of tension headache and the improvement of the quality of sleep.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.996-1003
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• 2021

The purpose of this study is to evaluate the reliability of repeated measurements of several dental scanners. Blue-lighted scanners, white-light scanners and optical-type scanners are used in the study of repeatability in this study. The measurement results were calculated as root mean square (RMS) and the significance level was confirmed by applying the 1-way ANOVA statistical technique (𝛼=.05). According to the statistical analysis, the scanner with the largest RMS value was Z-opt group (38.2 ㎛. Next, D-white was 35.2 ㎛ and the group with the lowest RMS value was I-blue (34.1 ㎛). The comparison of RMS means between each group was not significant (p>.05). From this result, the blue light had the lowest error in repeatability of dental scanners, but no statistical significance. The conclusion of this study is that the study results are clinically acceptable.