• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.975-983
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• 2020

Since the Fukushima Daiichi accident in 2011, concerns for the safety of multi-unit Nuclear Power Plant (NPP) sites have risen. This is because more than 70% of NPP sites are multi-unit sites that have two or more NPP units and a multi-unit accident occurred for the first time. After this accident, Probability Safety Assessment (PSA) has been considered in many countries as one of the tools to quantitatively assess the safety for multi-unit NPP sites. One of the biggest concerns for a multi-unit accident such as Fukushima is that the consequences (health and economic) will be significantly higher than in the case of a single-unit accident. However, many studies on multi-unit PSA have focused on Level 1 & 2 PSA, and there are many challenges in terms of public acceptance due to various speculations without an engineering background. In this study, two kinds of multi-unit Level 3 PSA for multi-unit site have been carried out. The first case was the estimation of multi-unit risk with conservative assumptions to investigate the margin between multi-unit risk and QHO, and the other was to identify the effect of time delays in releases between NPP units on the same site. Through these two kinds of assessments, we aimed at investigating the level of multi-unit risk and understanding the characteristics of risk in a multiunit context.

• Journal of Preventive Medicine and Public Health
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• v.43 no.5
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• pp.423-435
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• 2010

Objectives: The low benefit coverage rate of South Korea's health security system has been continually pointed out. A low benefit coverage rate inevitably causes catastrophic health expenditure, which can be the cause of the transition to poverty and the persistence of poverty. This study was conducted to ascertain the effect of catastrophic health expenditure on the transition to poverty and the persistence of poverty in South Korea. Methods: To determine the degree of social mobility, this study was conducted among the 6311 households that participated in the South Korea Welfare Panel Study in both 2006 and 2008. The effect of catastrophic health expenditure on the transition to poverty and the persistence of poverty in South Korea was assessed via multiple logistic regression analysis. Results: The poverty rate in South Korea was 21.6% in 2006 and 20.0% in 2008. 25.1 - 7.3% of the households are facing catastrophic health expenditure. Catastrophic health expenditure was found to affect the transition to poverty even after adjusting for the characteristics of the household and the head of the household, at the threshold of 28% or above. Conclusions: 25.1% of the households in this study were found to be currently facing catastrophic health expenditure, and it was determined that catastrophic health expenditure is a cause of transition to poverty. This result shows that South Korea's health security system is not an effective social safety net. As such, to prevent catastrophic health expenditure and transition to poverty, the benefit coverage of South Korea's health security system needs to the strengthened.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.115-121
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• 2019

Background: Due to the diversification and advancement of research, researchers have become to deal with a variety of chemical and biological harmful materials in the laboratories of universities and research institutes and the risk has increased as well. Therefore, it is necessary to strengthen the social safety net for laboratory accidents by strengthening the compensation to the level comparable to that of Korean Workers' Compensation & Welfare Service, when the researchers become physically disabled by laboratory accidents. The purpose of this study is to secure researchers' health rights and to create a research environment where researchers can work with confidence by strengthening the compensation to the level comparable to that of Korean Workers' Compensation & Welfare Service. Method: We analyzed the laboratory accidents by year, injury type, severity of accident and disability grade with the 6 year data from 2011 to 2016, provided by Laboratory Safety Insurance. Based on the analysis result, we predicted the financial impact on Laboratory Safety Insurance if we introduce a compensation annuity by disability grade which is similar to Injury-Disease Compensation Annuity of Korean Workers' Compensation & Welfare Service. Result :As of 2011, the insured number of Laboratory Safety Insurance was approximately 700,000. The Average premium per insured was KRW 3,339 and there were 158 claims. Total claim amount was KRW 130 million, whereas the premium was about KRW 2.3 billion. The loss ratio was very low at 5.75%. If we introduce a compensation annuity by disability grade similar to Injury-Disease Compensation Annuity of Korean Workers' Compensation & Welfare Service, the expected benefit amount for 1 case of disability grade 1 would be KRW 1.6 billion, assuming 2% of interest rate. Given current premium, the loss ratio, the ratio of premium income to claim payment, is expected 41.4% in 2017 and 151.6% in 2026. The increased loss ratio due to the introduce of the compensation annuity by disability grade is estimated to be 11.0% in 2017 and 40.4% in 2026. Conclusion: Currently, laboratories can purchase insurance companies' laboratory safety insurance that meets the standards prescribed by Act on the Establishment of Safe Laboratory Environment. However, if a compensation annuity is introduced, it would be difficult for insurance companies to operate the laboratory safety insurance due to financial losses from a large-scale accident. Therefore, it is desirable that one or designated entities operate laboratory safety insurance. We think that it is more desirable for laboratory safety insurance to be operated by a public entity rather than private entities.

• Nuclear Engineering and Technology
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• v.51 no.1
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• pp.303-309
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• 2019

Tritium is an important nuclide that must be monitored for radiation safety management. In this study, HTO was orally administered to rats at the level of 37 kBq ($1{\mu}Ci$) or 370 kBq ($10{\mu}Ci$) to examine tissue distribution and excretion levels. After sacrifice, wet and dry tissue samples were weighed and analyzed for tissue free-water tritium (TFWT) and organically bound tritium (OBT). The mean tissue concentrations of TFWT (OBT) were 30.9 (17.8) and 4.4 (8.1) Bq/g on days 7 and 13 at the 37 kBq level and 30.8 (64.6) Bq/g on day 17 at the 370 kBq level. To assess the cytogenetic damage due to tritium exposure, a cytokinesis-blocked micronucleus (MN) assay was performed in blood samples from rats exposed to HTO for 14 and 21 days after oral administration. There was no significant difference in the MN frequencies between the control and exposed rats.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1718-1733
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• 2023

The virtual Frisch-grid method for room-temperature radiation detectors has been widely used because of its simplicity and high performance. Recently, side electrodes were separately attached to each surface of the detectors instead of covering the entire detector surface with a single electrode. The side-electrode structure enables the measurement of the three-dimensional (3D) gamma-ray interaction in the detector. The positional information of the interaction can then be utilized to precisely calibrate the response of the detector for gamma-ray spectroscopy and imaging. In this study, we developed a 3D position-sensitive 5 × 5 × 12 mm³ cadmium-zinc-telluride (CZT) detector and applied a flattening method to correct detector responses. Collimated gamma-rays incident on the surface of the detector were scanned to evaluate the positional accuracy of the detection system. Positional distributions of the radiation interactions with the detector were imaged for quantitative and qualitative evaluation. The energy spectra of various radioisotopes were measured and improved by the detector response calibration according to the calculated positional information. The energy spectra ranged from 59.5 keV (emitted by ²⁴¹Am) to 1332 keV (emitted by ⁶⁰Co). The best energy resolution was 1.06% at 662 keV when the CZT detector was voxelized to 20 × 20 × 10.

• Korean Journal of Health Education and Promotion
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• v.28 no.3
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• pp.31-42
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• 2011

Objectives: Busan had the highest mortality and the shortest life expectancy at birth among 16 provinces in Korea in 2008 and there were considerable health inequalities within the region. This study was performed to build up a priority setting framework in Healthy City Busan project. Methods: Analytic hierarchy process was used to determine the relative priority weight for different strategic and program dimensions along with the consistency of response. An on-site workshop-based meeting (calculating importance) and online survey (calculating risk) were conducted to obtain data from 8 experts. Results: The results showed that in strategic criteria "active health promotion & diseases prevention" and "building infrastructure for the Health City project" were two most important factors. In program criteria, considering both importance and risk scores, "making a healthy community" and "building community health centers" in disadvantaged areas were a top priority group. In addition, "enacting an ordinance for the Healthy City", "building the infrastructure for health impact assessment" and "making health care safety net for vulnerable population" were also higher priorities group. Conclusions: Our findings suggest that the Healthy City project in Busan should be focused on strengthening health equity and building infrastructure for sustainability of the project.

• Journal of Digital Convergence
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• v.16 no.7
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• pp.479-491
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• 2018

This study aims to figure out factors influencing health and moderating effect of social support resource between those factors and health of low income women in diverse spheres. The data of low income women were 239 cases and were utilized SPSS ver. 21 program. The main results of this study are as follows: firstly, health of low income women is identified medium level. Secondly, education level, self-efficacy and social support resource are related to the self-rated health of low income women. Especially, social support resource functions as moderators on between education and self-rated level of the health of low income women. Consequently, the findings suggest the need to expand the social intervention range to promote health of low income women from cost benefit to psychological support such as capacity building for self-management and establishment of safety-net to extend social support. And subsequently, the time attribute of the factors related to low-income women's health and the diverse characteristics of the subjects should be considered.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.87-87
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• 2019

The consumption of herbal medicine and related products (herbal products) have increased in South Korea. At the same time the quality, safety, and efficacy of herbal products is being raised. Currently, the herbal products are standardized and controlled according to the requirements of the Korean Pharmacopoeia, the National Institute of Health and the Ministry of Public Health and Social Affairs. The validation of herbal products and their medicinal component is important, since many of these herbal products are composed of two or more medicinal plants. However, there are no tools to support the validation process. Interest in deep learning has exploded over the past decade, for herbal medicine using algorithms to achieve herb recognition, symptom related target prediction, and drug repositioning have been reported. In this study, individual images of four herbs (Panax ginseng C.A. Meyer, Atractylodes macrocephala Koidz, Poria cocos Wolf, Glycyrrhiza uralensis Fischer), actually sold in the market, were achieved. Certain image preprocessing steps such as noise reduction and resize were formatted. After the features are optimized, we applied GoogLeNet_Inception v4 model for herb image recognition. Experimental results show that our method achieved test accuracy of 95%. However, there are two limitations in the current study. Firstly, due to the relatively small data collection (100 images), the training loss is much lower than validation loss which possess overfitting problem. Secondly, herbal products are mostly in a mixture, the applied method cannot be reliable to detect a single herb from a mixture. Thus, further large data collection and improved object detection is needed for better classification.

• Smart Structures and Systems
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• v.29 no.1
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• pp.77-91
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• 2022

Various monitoring systems have been implemented in civil infrastructure to ensure structural safety and integrity. In long-term monitoring, these systems generate a large amount of data, where anomalies are not unusual and can pose unique challenges for structural health monitoring applications, such as system identification and damage detection. Therefore, developing efficient techniques is quite essential to recognize the anomalies in monitoring data. In this study, several machine learning techniques are explored and implemented to detect and classify various types of data anomalies. A field dataset, which consists of one month long acceleration data obtained from a long-span cable-stayed bridge in China, is employed to examine the machine learning techniques for automated data anomaly detection. These techniques include the statistic-based pattern recognition network, spectrogram-based convolutional neural network, image-based time history convolutional neural network, image-based time-frequency hybrid convolution neural network (GoogLeNet), and proposed ensemble neural network model. The ensemble model deliberately combines different machine learning models to enhance anomaly classification performance. The results show that all these techniques can successfully detect and classify six types of data anomalies (i.e., missing, minor, outlier, square, trend, drift). Moreover, both image-based time history convolutional neural network and GoogLeNet are further investigated for the capability of autonomous online anomaly classification and found to effectively classify anomalies with decent performance. As seen in comparison with accuracy, the proposed ensemble neural network model outperforms the other three machine learning techniques. This study also evaluates the proposed ensemble neural network model to a blind test dataset. As found in the results, this ensemble model is effective for data anomaly detection and applicable for the signal characteristics changing over time.

• Journal of dental hygiene science
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• v.20 no.1
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• pp.16-24
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• 2020

Background: Dental treatment has shifted to the center of the community, and the public policy of the country has expanded to support the vulnerable classes such as the disabled. The dental profession needs education regarding oral health services for persons with disabilities, and it is necessary to derive the competencies for this. Therefore, we conducted this study to derive the normative ability to understand the role of a dental hygienist in the oral health service for persons with disabilities and improvement plans for education. Methods: We conducted a qualitative analysis for deriving competencies by analyzing the data collected through in-depth interviews with experts in order to obtain abilities through practical experience. Based on the competency criterion, relevant competency in the interview response was derived using the priori method, and it was confirmed whether the derived ability matched the ability determined by the respondent. Results: The professional conduct competencies of dental hygienists, devised by the Korean Association of Dental Hygiene, consists of professional behavior, ethical decision-making, self-assessment skills, lifelong learning, and accumulated evidence. Also, core competencies of the American Dental Education Association competencies for dental hygienist classification such as ethics, responsibility for professional actions, and critical thinking skills were used as the criterion. The dental hygienist's abilities needed for oral health care for people with disabilities, especially in the detailed abilities to fulfill these social needs, were clarified. Conclusion: To activate oral health care for people with disabilities, it is necessary for dental hygienists to fulfill their appropriate roles, and for this purpose, competency-based curriculum restructuring is indispensable. A social safety net for improving the oral health of people with disabilities can be secured by improving the required skills-based education system of dental hygienists and strengthening the related infrastructure.