• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.6
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• pp.618-629
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• 2001

This paper presents a result of failure analysis and reliability evaluation for high voltage ceramic capacitors. The failure modes and failure mechanisms were studied in two ways in order to estimate component life and failure rate. The causes of failure mechanisms for zero resistance phenomena under withstanding voltage test in high voltage ceramic capacitors molded by epoxy resin were studied by establishing an effective root cause failure analysis. Particular emphasis was placed on breakdown phenomena at the ceramic-epoxy interface. The validity of the results in this study was confirmed by the results of accelerated testing. Thermal cycling test for high voltage ceramic capacitor mounted on a magnetron were implemented. Delamination between ceramic and epoxy, which might cause electrical short in underlying circuitry, can occur during curing or thermal cycle. The results can be conveniently used to quickly identify defective lots, determine $B_{10}$ life estimation each lot at the level of inspection, and detect major changes in the vendors processes. Also, the condition for dielectric breakdown was investigated for the estimation of failure rate with load-strength interference model.

• Journal of Gifted/Talented Education
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• v.15 no.2
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• pp.101-125
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• 2005

We applied functional magnetic resonance imaging (fMRI) techniques to examine whether general intelligence (g) could be assessed using a neurobiological signal of the brain. Participants were students in a national science academy and several local high schools. They were administered diverse intelligence (RAPM and WAIS) and creativity tests (TTCT-figural and TTCT-verbal). Forty of them were scanned using fMRI while performing complex and simple g tasks. In brain regions of greater blood flow in complex compared with simple g tasks, the gifted group with an exceptional g level was not significantly different from the average group with an ordinary g level: both of them activated the lateral prefrontal, anterior cingulate, posterior parietal cortices. However, the activation levels of the gifted group were greater than those of the average group, particularly in the posterior parietal cortex. Correlation analysis showed that the activity of the posterior parietal cortex has the highest correlation ($(r=0.73{\sim}0.74)$) with individual g levels and other regions also have moderate correlation ($(r=0.53{\sim}0.66)$). On the other hand, two-sample t test showed a striking contrast in intelligence tests scores between the gifted and the average group, whereas it did not show in creativity tests scores. These results suggest that it is within the bounds of possibility that a neurobiological signal of the brain is used in the assessment of the gifted and also suggest that creativity has to be given a great deal of weight on the assessment of the gifted.

• Anxiety and mood
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• v.9 no.1
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• pp.31-37
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• 2013

Objective : The PDSQ is a brief and psychometrically strong self-report scale designed to screen for common DSM-IV Axis I disorders in clinical settings. In this study, the K-PDSQ was compared with the M.I.N.I.-Plus (Mini-International Neuropsychiatric Interview-Plus) for diagnostic validity and availability of the K-PDSQ as a part of standardization of the K-PDSQ. Methods : The 640 patients were evaluated with the K-PDSQ and the M.I.N.I.-Plus. Diagnosing with the M.I.N.I.-Plus, the diagnostic correspondence, administering time, sensitivity, specificity, ROC curve, and AUC of the K-PDSQ were evaluated. Results : For the diagnostic correspondence of the K-PDSQ, Cohen's kappa coefficient was .66 between the K-PDSQ and the M.I.N.I.-Plus. The administering time of the K-PDSQ was $18.2{\pm}11.80$ minutes. Both sensitivity and specificity of the K-PDSQ were higher: the mean sensitivity across 10 subscales of K-PDSQ was 86%; the mean specificity was 84%. All AUCs of each subscale were above .80, which were statistically significant. Conclusion : The K-PDSQ is valid and available as a diagnostic screening tool. It will be widely used in clinical settings for screening DSM-IV Axis I diagnosis because of its simplicity and high reliability.

• Horticultural Science & Technology
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• v.30 no.3
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• pp.308-324
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• 2012

The aim of this study is to develop and construct the elements of a new evaluation tool to assess the effectiveness of a horticultural therapy. Delphi method was applied to classify the realms of evaluation and specify their components and constituting items. Delphi process was performed through three rounds and 24 professionals attended all the rounds as panel members. Some of the items were revised or removed according to the results of such tests as content validity ratio, agreement rate, convergency and stability of each item. On the contrary, a few new items were added by accepting the opinions of the professional panels. Previous to the Delphi, the realms of evaluation were classified into physical, cognitional, psycho-emotional and social ones on the basis of literature review, professionals' consultation and in-depth interview with practitioners. At the first round, 112 items constituting four realms were reviewed. The numbers of items to be reviewed were reduced to 107 at the second round and to 102 at the third round. As a result, 98 items in 4 realms were decided as proper evaluation points of horticultural therapy. The compositions of the four respective realms are as follows: 5 components and 27 items in physical realm; 4 components and 25 items in cognitional realm; 2 components and 24 items in psycho-emotional realm; and 4 components and 22 items in social realm. These realms, components and specific items derived from this study constitute indices to evaluate the effectiveness of horticultural therapy. In addition, they might be utilized as good guidelines for planning horticultural therapy programs.

• Journal of the Korean Society for Nondestructive Testing
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• v.23 no.1
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• pp.21-29
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• 2003

It is very important to reduce the computational time in estimating the parameters of vision control algorithm for robot's position control in real time. Unfortunately, the batch estimation commonly used requires too murk computational time because it is iteration method. So, the batch estimation has difficulty for robot's position control in real time. On the other hand, the Extended Kalman Filtering(EKF) has many advantages to calculate the parameters of vision system in that it is a simple and efficient recursive procedures. Thus, this study is to develop the EKF algorithm for the robot's vision control in real time. The vision system model used in this study involves six parameters to account for the inner(orientation, focal length etc) and outer (the relative location between robot and camera) parameters of camera. Then, EKF has been first applied to estimate these parameters, and then with these estimated parameters, also to estimate the robot's joint angles used for robot's operation. finally, the practicality of vision control scheme based on the EKF has been experimentally verified by performing the robot's position control.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.259-267
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• 2004

A finite element method is used to simulate interaction of laser-based ultrasounds with surface breaking tracks in elastic media. The laser line source focused on the surface of semi-infinite medium is modeled as a shear dipole in 2-D plane strain finite elements. The shear dipole-finite clement model is found to give correct directivity patterns for generated longitudinal and shear waves. The interaction of surface waves with surface breaking cracks (2-D machined slot) is considered in two ways. Both the source and receiver are fixed with respect to the cracks in the first case, while the source is moving in another case. It is shown that the crack depth tested in the range of 0.3-5.0mm $({\lambda}_R/d=0.21{\sim}3.45)$ can be measured using the corner reflected waves produced by the fixed laser source. The moving laser source is found to cause a large amplitude change of reflected waves near crack, and the crack whose depth is one order lower than the wavelength ran be detected from this change.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.54-61
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• 2016

Studies on assessment tools for predicting cardiovascular disease risk (CDR), along with the studies to prevent CDR have been consistently reported. The validity of the Framingham risk score (FRS), a commonly known tool, has been verified through the precedent studies. In this study, we examined the differences of FRS according to the application of categories of LDL cholesterol (LDL-C) or Total cholesterol (TC), and attempted to evaluate the agreement of 10 yr CHD risk judgment based on the above-mentioned application. Excluding those diagnosed as cardiovascular diseases, data on subjects (755 men and 775 women) from the 2011 Korean National Health and Nutrition Examination Survey were used. We found differences of FRS and 10 yr CHD risk depending on the application of categories of LDL cholesterol (LDL-C) or Total cholesterol (TC). FRS of TC points were higher than those of LDL-C in both men and women. In classification of low risk (<10%), intermediate risk (10~19%), and high risk (${\geq}20%$), there were disagreements for 106 men and 26 women. Women showed almost perfect agreement from Coefficient of Cohen's Kappa (0.718 in men, and 0.884 in women). In assessment of 10 yr CHD risk, R-squared value from regression including TC was higher than that of LDC-C in both men and women (0.972 vs 0.885). From this result, we can draw a conclusion that correlation coefficients of FRS and CHD risk including TC were higher than those of LDC-C, and women showed a greater degree of agreement than men.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.156-161
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• 2007

Pediatric dentists are frequently encountered with fractured root fragments of primary teeth caused either by the traumatic injuries or by the accidental fractures during the procedure of tooth extractions. In these situations, we often hesitate which method to choose, extract or retain it. In general, it is recommended to retain apical fragments, as the attempts to extract the apical fragments might harm the developing permanent tooth germ. This study was designed to ensure the validity of intentional retention of the root fragments of primary teeth in the situations described above. 6 children with intentionally root fragments who experienced root fracture in primary anterior teeth were available Periodic radiographic assessment was performed at 3 months interval for $7{\sim}37$ months. The results of this study showed that apical fragments had been resorbed through physiologic process in 5 patients. Apical fragment had been gingival emergence along with the erupting permanent tooth in 1 patient. There were no evidence of interference with eruption of permanent successors. In summary we have been ensured the validity of intentionally retention of the root fragments of primary teeth. Children with being remained apical root fragment should be recalled regularly for assessment and parents should be thoroughly informed about the situation with special emphasis on the necessity of periodic check-up.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.576-582
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• 2018

At present, universities in Korea are trying to raise the competency of university students by preparing them with abilities and attitudes required in society, and many universities are carrying out "core competency based education." Therefore, there is a need to evaluate the core competencies of students and verify educational performance. M University, which trains students in specialized marine topics, also conducts core competency based education, reflecting the specificity of the university. The purpose of this study was to develop and validate a tool to measure the core competencies of M University students. First, preliminary questions were developed based on a literature review. Second, item analysis and exploratory factor analysis were conducted. As a result, six factors were identified. Finally, a total of 50 items were extracted from the final test, and validity was confirmed. The scale developed on the basis of this study can not only diagnose the core competency of students overall but also connect programs by diagnosing individual core competencies. It will be possible to use these results as basic data for honing the differentiated talents of universities specialized in maritime and ocean-related topics.

• Journal of Korean Library and Information Science Society
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• v.49 no.2
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• pp.201-220
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• 2018

The purpose of this study is to explore problems within bibliotherapy research of the 15 thesis papers aimed at improving self esteem, and then to explore development plan. In the current study on bibliotherapy, the problems with bibliotherapy are presented in five aspects. First, there is a lack of professionalism and role of counselor who plays the most important role in bibliotherapy. Second, the situation of the internalizer as an internalizer of bibliotherapy was not reflected in the bibliotherapy program. Third, the lack of diversity in the bibliotherapy program does not keep the reader's interest in bibliotherapy. Fourth, bibliotherapy reading material is limited to text material, which lacks the use of various media. Fifth, there is insufficient validity for the test paper that measures the effectiveness of the reader's bibliotherapy in terms of research methods. Several development plan are proposed based on the factors that affect bibliotherapy. First, it is necessary to develop and train teaching materials to secure expertise of bibliotherapy counselors. Second, it is necessary to develop data on the various media on suitable for bibliotherapy material. Third, it is necessary to review the test paper that can accurately measure the effectiveness of bibliotherapy.