• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.7-13
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• 2010

The integrity and accuracy of the drilling hole are decided by positional error, diameter error, the roundness, the straightness, the cylindericity, size of the burr, the surface roundness and others. Among these parameters, positional error and diameter error have the most important parameters. The diameter error has been widely studied, but there has been little research done about the positional error due to the difficulty of measuring it. The measurement of hole location and diameter would be performed by CMM(Coordinate Measurement Machine). However, the usage of CMM requires much time and cost. In order to overcome the difficulties, we have developed a hole location and diameter error measuring device using machine vision. The developed measurement device attached to a CNC machine can determine hole quality quickly and easily.

• The Journal of the Korea Contents Association
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• v.21 no.2
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• pp.594-603
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• 2021

This study explored the moderating effects of task difficulty for flow, learning motivation, and interesting in distant PBL classes of pre-service teachers. For this, the research model was constructed by analyzing previous studies. The research model verification was conducted by 105 students of taking courses in the curriculum. The distant PBL used a real-time video conference system. Cooperative activities were carried out in real time. After the end of the distant PBL activity, the level of learning motivation, interesting, flow, and task difficulty perception were measured. The collected data were analyzed using a test of the structural model invariance across the groups using a structural equation model. This analysis verifies the difference in path coefficients between measurement models. The control effect of task difficulty was verified through the difference in path coefficient. As a result, it was verified that interesting mediates the influence of learning motivation on flow. And the moderating effect of the perceived task difficulty appeared on the path from learning motivation to interesting.

• Journal of Families and Better Life
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• v.22 no.6 s.72
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• pp.201-218
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• 2004

The factors that affect the adjustment of the siblings of handicapped children were explored in this study. More specifically, how social and demographic variables affect the burdens the handicapped children's siblings experience, and how such burdens affect their adjustment in school and in the family were examined. The participants of this research were 139 students in elementary schools and middle schools, who have one or more handicapped siblings. The participants were recruited through their handicapped siblings who received services from social wet(are facilities in Daejon and Chungchong area. The scales used in this study were the measurement or Burdens for Handicapped children's siblings (Lee, Yoon Hwa, 2002), FACES (Olson et al, 1986). and The Measurement of Children's Adjustment in the School (Lim Jung Soon, 1993). The data were analyzed by frequency, percentage, average. standard deviation, T-test, one-way ANOVA, and multiple linear regression. 'rho results show that handicapped children's siblings have no difficulty in adjusting in the family if they have a religion, an elderly mother, and a high family income. They have no difficulty in adjusting in the family and in school, as long as they have no or little negative change in family relationship, low psychological burden, and no negative relational change for the handicapped sibling. Father's age and the family income their the only factors that affect their adjustment in school.

• Journal of the Ergonomics Society of Korea
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• v.24 no.3
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• pp.43-52
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• 2005

A two-dimensional posture measurement system was developed to evaluate the risks of work-related musculoskeletal disorders(MSDs) easily on various conditions of work. The posture measurement system is an essential tool to analyze the workload for preventing work-related musculoskeletal disorders. Although several posture measurement systems have been developed for workload assessment, some restrictions in industry still exist because of its difficulty on measuring work postures. In this study, an image recognition algorithm was developed based on a neural network method to measure work posture. Each joint angle of human body was automatically measured from the recognized images through the algorithm, and the measurement system makes it possible to evaluate the risks of work-related musculoskeletal disorders easily on various working conditions. The validation test on upper body postures was carried out to examine the accuracy of the measured joint angle data from the system, and the results showed good measuring performance for each joint angle. The differences between the joint angles measured directly and the angles measured by posture measurement software were not statistically significant. It is expected that the result help to properly estimate physical workload and can be used as a postural analysis system to evaluate the risk of work-related musculoskeletal disorders in industry.

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.23-35
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• 2023

Objective : This study is to examine the practical use of clinical observational evaluation of sensory integration therapy and the difficulty and importance of measuring results for each sub-item, and through this, to confirm the usefulness of the application of Artificial Intelligence measurement technology in clinical observational measurement and the need for application. Methods : The questionnaire consisted of the actual use of the sensory integration evaluation tool, the difficulty of measurement for each detailed item of clinical observation, the usefulness of AI measurement technology, the importance of evaluation for each detailed item, and the need for developing AI measurement technology. Results : The detailed items that were difficult to measure during clinical observation were the Finger-to-Nose Test and Postural control (71.0%), followed by Eye movement and Protective Extension Test (67.7%). 83.9% of the study subjects answered that it would be useful to apply AI measurement technology when observing images. Postural control (on the ball) (90.3%) was the highest item that answered that AI measurement technology was needed, followed by Eye movement (83.9%), and Prone Extension and Protective Extension Test (77.4%). Conclusion : The results confirmed the desire of therapists that clinical observation is an important evaluation tool in the field of child occupational therapy in Korea.

• Journal of Korean Academy of Nursing
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• v.45 no.1
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• pp.107-117
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• 2015

Purpose: The purpose of this study was to evaluate the psychometric properties of the Korean version of the Alzheimer's Disease Knowledge Scale (ADKS-K) to determine its applicability to Korean adults. Methods: Cross-cultural validity was performed according to Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN). The Kuder-Richardson Formula 20 for internal consistency and Intraclass Correlation Coefficient (ICC) for test-retest reliability were conducted. Content validity, criterion related validity and construct validity were evaluated. The Classical Test Theory (CTT) model and the Item Response Theory (IRT) model were applied in performing the item analysis. Results: The KR 20 was .71, and the ICC was .90, indicating that the ADKS-K has internal consistency and stability reliability. Thirty items of the ADKS-K had significant Content Validity Ratio (CVR) values, i.e., mean of 0.82 and range of 0.60~1.00. Mean item difficulty and discrimination indices calculated by TestAn program were 0.63 and 0.23, respectively. Mean item difficulty and discrimination indices calculated by BayesiAn program were -0.60 and 0.77, respectively. These tests indicate that ADKS-K has an acceptable level of difficulty and discriminating efficiency. Conclusion: Results suggest that ADKS-K has the potential to be a proper instrument for assessing AD knowledge in Korean adults.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.8
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• pp.863-872
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• 2012

The squareness measurement of driving axes of a machine tool is very important to evaluate the performance of the machine. Laser interferometer measurement system is one of the most reliable equipment to measure the squareness. However, squareness measurement using laser system with an optical square result in restriction of straightness optics setup and Abbe's offset. This offset combines with angular errors during the motion of an axis to cause Abbe's error. In addition, the difficulty in optical square setup causes restriction of other optics and limitation of measurable range. In this paper, mathematical approaches are presented to eliminate the Abbe's error and to estimate squareness for full range by using the best fit of straightness data measured without an optical square. Experiments for squareness measurement of 3 axis machine tool were conducted and the proposed techniques were used for squareness evaluation with elimination of Abbe's error and squareness estimation for the full travel range.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.16-21
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• 2008

The demand for three-dimensional (3D) shape measurements is increasing in a variety of fields, including the manufacture of molds and dies. The most popular technology for 3D shape measurement is the coordinate measuring machine (CMM) with a contact trigger probe. Although a CMM provides a high degree of accuracy, it is inefficient due to its long measuring time. It also has difficulty measuring soft objects that can be deformed by the touch of the contact probe. In addition, a CMM cannot digitize areas that are difficult to reach, and cannot capture very minute details on the surface of complex parts. For these reasons, optical non-contact measurement techniques are receiving more attention since they eliminate most of the problems associated with contact methods. Laser scanning is emerging as one of the more promising non-contact measurement techniques. This paper describes various acquisition considerations for laser scanning, including the accuracy of the 3D scan data, which depends on the charge-coupled device (CCD) gain and noise. The CCD gain and noise of a 3D laser scanner are varied while keeping the other conditions constant, and the measurement results are compared to the dimensions of a standard model. The experimental results show that a considerable time savings and an optimum degree of accuracy are possible by selecting the proper CCD gain and noise.

• Journal of the Korea Society of Computer and Information
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• v.24 no.3
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• pp.123-133
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• 2019

Bicycle fitting used to depend on empirical adherence of bicycle Peter and intuitive judgment by hand, but recent developments in industry and the Fourth Industrial Revolution have continuously developed other related tools that can be applied to bicycle fitting. Depending on these circumstances, bicycle fitting technology is also developing, and due to the difficulty of the technicians, there is a limit to popularizing. The Bicycle Integrated Fitting System has the need for this study to make these problems easy for anyone to operate by the system of manual. The purpose of this study is to examine the methods of physical sizing among the various stages of developing these systems. Accurate physical measurements can improve the efficiency of bicycle riding and minimize the injury of bicycle risers issued by incorrect fittings. Thus, in this study, physical measurement methods for bicycle fitting were derived by body region and applied to the post-measurement fitting as well as the location and method of measurement. It has prepared a basis for establishing a core database for physical measurement of development of integrated bicycle fitting system. Research was conducted to enhance understanding and utilization of users after system development and results were derived for the purpose of the study. Research was conducted to establish a database for the development of a bicycle integrated fitting system, and future research on bicycle fitting methods, application of the system, and hardware development should be carried out.

• Current Optics and Photonics
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• v.4 no.1
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• pp.44-49
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• 2020

In this paper, a new method is presented to measure the refractive index of single plain glass or multilayered materials, based on a laser frequency-shifted confocal feedback microscope. Combining the laser frequency-shifted feedback technique and the confocal effect, the method can attain high axial-positioning accuracy, stability and sensitivity. Measurements of different samples are given, including N-BK7 glass, Silica plain glass, and a microfluidic chip with four layers. The results for N-BK7 glass and Silica plain glass show that the measurement uncertainty in the refractive index is better than 0.001. Meanwhile, the feasibility of this method for multilayered materials is tested. Compared to conventional methods, this system is more compact and has less difficulty in sample processing, and thus is promising for applications in the area of refractive-index measurement.