• Journal of The Korean Astronomical Society
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• v.50 no.5
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• pp.139-149
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• 2017

The Korea Astronomy and Space Science Institute plans to develop a coronagraph in collaboration with National Aeronautics and Space Administration (NASA) and to install it on the International Space Station (ISS). The coronagraph is an externally occulted one-stage coronagraph with a field of view from 3 to 15 solar radii. The observation wavelength is approximately 400 nm, where strong Fraunhofer absorption lines from the photosphere experience thermal broadening and Doppler shift through scattering by coronal electrons. Photometric filter observations around this band enable the estimation of 2D electron temperature and electron velocity distribution in the corona. Together with a high time cadence (<12 min) of corona images used to determine the geometric and kinematic parameters of coronal mass ejections, the coronagraph will yield the spatial distribution of electron density by measuring the polarized brightness. For the purpose of technical demonstration, we intend to observe the total solar eclipse in August 2017 with the filter system and to perform a stratospheric balloon experiment in 2019 with the engineering model of the coronagraph. The coronagraph is planned to be installed on the ISS in 2021 for addressing a number of questions (e.g., coronal heating and solar wind acceleration) that are both fundamental and practically important in the physics of the solar corona and of the heliosphere.

• The Journal of the Korean bone and joint tumor society
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• v.3 no.2
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• pp.89-97
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• 1997

Twenty hundred and five out of 266 patients who were registered in Korea Cancer Center Hospital from Mar. 1985 to Jan. 1994, were analyzed in the aspect of survival and local recurrence. Fifty one patients were excluded due to inadequate data and follow up. Prognostic factors for survival were evaluated statistically. One hundred and four cases were male, 101 female. Average age was 39.7(range 1 to 77) year with a peak incidence around 4th decade. The most frequent diagnosis was malignant fibrous histiocytoma(MFH)(24.1%). Liposarcoma, synovial sarcoma, rhabdomyosarcoma, malignant peripheral nerve sheath tumor and fibrosarcoma were relatively common diagnostic entities, in decreasing order. In location, extremity was 179(87.3%) and trunk 26(12.7%). Average follow up period was 7.5 years(6 months to 10 years). Actuarial 5 years and 10 years survival rate were 64.0% and 40.8% respectively. In univariate analysis with log-lank test, significant differences in survival rate were noted in histopathological diagnosis, size(10 cm), stage and metastasis. Age, sex, tumor location, tumor depth and local recurrence didn't affect the survival rate. Adjuvant chemotherapy and/or radiotherapy did not affect overall survival rate, but lowered the local recurrence rate when compared with surgery only. Surgical margin did not affect the survival rate, but local recurrence rate was different according to each margin; 5.7% in more than wide; 39.5% in marginal; and 60.0% in intralesional excision. In multivariate analysis for results of univariate analysis with Cox's propotional model, metastasis was a meaningful factor for survival of soft tissue sarcoma.

• Journal of Korean Academy of Nursing
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• v.46 no.1
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• pp.29-38
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• 2016

Purpose: The Perinatal Post-Traumatic Stress Disorder Questionnaire (PPQ) was designed to measure post-traumatic symptoms related to childbirth and symptoms during postnatal period. The purpose of this study was to develop a translated Korean version of the PPQ and to evaluate reliability and validity of the Korean PPQ. Methods: Participants were 196 mothers at one to 18 months after giving childbirth and data were collected through e-mails. The PPQ was translated into Korean using translation guideline from World Health Organization. For this study Cronbach's alpha and split-half reliability were used to evaluate the reliability of the PPQ. Exploratory Factor Analysis (EFA), Confirmatory Factor Analysis (CFA), and known-group validity were conducted to examine construct validity. Correlations of the PPQ with Impact of Event Scale (IES), Beck Depression Inventory II (BDI-II), and Beck Anxiety Inventory (BAI) were used to test a criterion validity of the PPQ. Results: Cronbach's alpha and Spearman-Brown split-half correlation coefficient were 0.91 and 0.77, respectively. EFA identified a 3-factor solution including arousal, avoidance, and intrusion factors and CFA revealed the strongest support for the 3-factor model. The correlations of the PPQ with IES, BDI-II, and BAI were .99, .60, and .72, respectively, pointing to criterion validity of a high level. Conclusion: The Korean version PPQ is a useful tool for screening and assessing mothers' experiencing emotional distress related to child birth and during the postnatal period. The PPQ also reflects Post Traumatic Stress Disorder's diagnostic standards well.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.178-180
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• 2016

TMDE(Test Measurement and Diagnostic Equipment) which is using in the military weapon system should perform the periodic calibration to maintain a measurement reliability during the life cycle, organizations are faced with increasing pressures to minimize costs while improving the reliability of test equipment. Previous studies suggest that reliability models are determined by considering simple size and characteristics of equipment, however an applying single Model may not be fit well maintenance data of many kinds of TMDEs. This paper presents that recommending an optimal calibration interval through the goodness of fit test with verifying statistical significance level among the several intervals which are computed with using major reliability models. According to the result of applying the actual proposed of calibration interval analysis method for various types of equipment, reliabilities are maintained for the end of calibration intervals.

• Perspectives in Nursing Science
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• v.9 no.1
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• pp.51-60
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• 2012

Purpose: The purpose of this study was to develop a self-directed e-learning program for ICU nurses and to evaluate how the proposed e-learning program affects the level of knowledge, nursing performance and job satisfaction of ICU nurses. Methods: The e-learning program was developed with the Computer Assisted Instruction Design Model using sources of self-efficacy which included the inactive attainment, vicarious experience, and verbal persuasion of ICU nurses. The program was evaluated by experts. Following the revision of the program, it was applied to a total of 59 ICU nurses (experimental group n=29, control group n=30) from three hospitals. Four weeks later, we measured the level of knowledge, nursing performance and job satisfaction. Results: The level of knowledge significantly improved in the experimental group (t=5.691, p<.001). Moreover, the level of nursing performance significantly increased in the areas of circulatory diagnostic test (t=2.143, p=.039), EKG (t=2.911, p=.006), aortic balloon pump (t=2.491, p=.017), and nebulizer therapy (t=2.085, p=.044). Overall, job satisfaction did not significantly increase (t=1.664, p=.105); however, job satisfaction in terms of relationships with coworkers (t=2.371, p=.023) and the needs of nursing performance (t=2.940, p=.006) were significantly increased. Conclusion: The results showed that the proposed e-learning program using sources of self-efficacy from ICU nurses was an effective learning method to increase the level of knowledge and nursing performance. The propose de-learning program would be a useful teaching tool for ICU nurses improving the quality of ICU patient care.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.69-77
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• 2007

Purpose: To evaluate the accuracy of the imaging reformation of cone beam computed tomography for the assessment of bone defect healing in rat model. Materials and Methods: Sprague-Dawley strain rats weighing about 350 gms were selected. Then critical size bone defects were done at parietal bone with implantation of collagen sponge. The rats were divided into seven groups of 3 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, and 8 weeks. The healing of surgical defect was assessed by multi planar reconstruction (MPR) images and three-dimensional (3-D) images of cone beam computed tomography, compared with soft X-ray radiograph and histopathologic examination. Results: MPR images and 3-D images showed similar reformation of the healing amount at 3 days, 1 week, 2 weeks, and 8 weeks, however, lower reformation at 3 weeks, 4 weeks, and 6 weeks. According to imaging-based methodologies, MPR image revealed similar reformation of the healing amount than 3-D images compare with soft X-ray image. Among the four threshold values for 3-D images, 400-500 HU revealed similar reformation of the healing amount. Histopathologic examination confirmed the newly formed trabeculation correspond with imaging-based methologies. Conclusion: MPR images revealed higher accuracy of the imaging reformation of cone beam computed tomography and cone beam computed tomography is a clinically useful diagnostic tool for the assessment of bone defect healing.

• Journal of Periodontal and Implant Science
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• v.46 no.1
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• pp.10-21
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• 2016

Purpose: This study evaluated the predictive performance of a combination of self-report questionnaires, salivary hemoglobin levels, and age as a non-invasive screening method for periodontitis. Methods: The periodontitis status of 202 adults was examined using salivary hemoglobin levels, responses to 10 questions on a self-report questionnaire, and the Community Periodontal Index (CPI). The ability of those two variables and the combination thereof with age to predict the presence of CPI scores of 3-4 and 4 was assessed using logistic regression and receiver operating characteristic (ROC) curve analysis. Results: CPI scores of 3-4 and 4 were present among 79.7% and 46.5% of the sample, respectively. The area under the ROC curves (AUROCs) of salivary hemoglobin levels for predicting prevalence of CPI scores of 3-4 and 4 were 0.63 and 0.67, respectively (with sensitivity values of 71% and 60% and specificity values of 56% and 72%, respectively). Two distinct sets of five questions were associated with CPI scores of 3-4 and 4, with AUROCs of 0.73 and 0.71, sensitivity values of 76% and 66%, and specificity values of 63% and 69%. The combined model incorporating both variables and age showed the best predictive performance, with AUROCs of 0.78 and 0.76, sensitivity values of 71% and 65%, and specificity values of 68% and 77% for CPI scores of 3-4 and 4, respectively. Conclusions: The combination of salivary hemoglobin levels and self-report questionnaires was shown to be a valuable screening method for detecting periodontitis.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.3
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• pp.187-196
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• 2000

This study was performed to offer convenience to determine the vertical dimension of occlusion of edentulous patients by investigating the interocclusal distances at physiologic rest position, at speaking of /m/ sound, and some korean short sounds, that is, /mem/ and /beb/ sounds, which were found in our previous study with dentulous subjects. Ten edentulous subjects - 6 men and 4 women - were selected for this study. The frequencies at speaking of /m/, /mem/, and /beb/ sounds were analyzed with Computerized speech lab($CSL^{TM}$, Model 4300B, Software version 5.X, Kay Elemetrics Co. U.S.A.). And the interocclusal distances at physiologic rest position and at speaking of /m/, /mem/, and /beb/ sounds were measured with K6 diagnostic system(Myo-tronics, Inc. U.S.A.). The results of this study were as follows ; 1. In the acoustic analysis by Computerized speech lab, frequencies of sounds of edentulous subjects with complete denture at speaking of /m/, /mem/, and /beb/ were similar to those of dentulous subjects. 2. In the linear correlation by Pearson's correlation coefficient, the interocclusal distance at physiologic rest position was most similar to those of speaking /mem/ sound, secondly /m/ sound, and thirdly /beb/ sound(p<0.05). In reliability by Cronbach's alpha, the results were reliable with alpha value 0.97. 3. It was found by Levene's test for equality of variance that the difference between men and women in the interocclusal distances at physiologic rest position and at speaking of /m/, /mem/, and /beb/ sounds was not statistically significant(p>0.05).

• Journal of the Korean Solar Energy Society
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• v.39 no.6
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• pp.55-65
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• 2019

With the rapid development of the national industry, the importance of electrical safety was recognized because of a lot of new electrical equipment are installing and the electrical accidents have been occurring annually. Today, the electrical equipments is inspect by using the portable Infrared thermal imaging camera. but the most negative element of using the camera is inspected for only state of heating, the reliable diagnosis is depended with inspector's knowledge, and real-time monitoring is impossible. This paper present the infrared thermal imaging safety diagnosis system. This system is able to monitor in real time, predict the state of fault, and diagnose the state with analysis of thermal and power data. The system consists of a main processor, an infrared camera module, the power data acquisition board, and a server. The diagnostic algorithm is based on a mathematical model designed by analyzing the Pearson's Correlation Coefficient between temperature and power data. To test the prediction algorithm, the simulations were performed by damaging the terminals or cables on the switchboard to generate a large amount of heat. Utilizing these simulations, the developed prediction algorithm was verified.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.46-51
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• 2004

his paper presents a novel design technique for the TS fuzzy classifier via linear matrix inequalities(LMI). To design the TS fuzzy classifier built by the TS fuzzy model, the consequent parameters are determined to maximize the classifier's performance. Differ from the conventional fuzzy classifier design techniques, convex optimization technique is used to resolve the determination problem. Consequent parameter identification problems are first reformulated to the convex optimization problem. The convex optimization problem is then efficiently solved by converting linear matrix inequality problems. The TS fuzzy classifier has the optimal consequent parameter via the proposed design procedure in sense of the minimum classification error. Simulations are given to evaluate the proposed fuzzy classifier; Iris data classification and Wisconsin Breast Cancer Database data classification. Finally, simulation results show the utility of the integrated linear matrix inequalities approach to design of the TS fuzzy classifier.