• Clean Technology
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• v.29 no.2
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• pp.95-101
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• 2023

An experiment was conducted to produce vaterite-type precipitated calcium carbonate from waste oyster shells in order to use them as recyclable resources. Calcined oyster shells containing calcium oxide as their main component were prepared at a temperature of 800℃ for 24 h. The oyster shells were dissolved in nitric acid or hydrochloric acid solution to make 0.1 M calcium nitrate or calcium chloride aqueous solution, and a carbonation reaction was performed using a 0.1 M sodium carbonate aqueous solution under various experimental conditions, which included varying the amount of aspatic acid additive, the amount of NH₄OH added, the reaction time, the reaction temperature, the stirring speed, and the type of dissolved acid. The XRD, SEM, and size distributions were analyzed and the vaterite content was calculated. Spherical precipitated calcium carbonate with a vaterite content of 95.9% was synthesized by adding 0.1 mol aspatic acid/1 mol CaO and 2 cm³ of NH₄OH, and reacting for 1 h at 25℃ while stirring at 600 rpm. The average particle diameter was found to be 12.11 ㎛. Calcium carbonate contatining high vaterite is used as high value added calcium carbonate for medical, food, inke additiver, etc.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.215-229
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• 2023

Objectives: To validate the effectiveness of a real-time chemical exposure monitoring system developed by KOSHA (Korea Occupational Safety and Health Agency), we applied the system to a workplace in the electronics industry for 153 days. Methods: The monitoring system consisted of a PID chemical sensor, a LTE communication equipment, and a web-based platform. To monitor chemical exposure, four sets of sensors were placed in two manufacturing tasks - inspection and jig cleaning - which used TCE as a degreasing agent. We reviewed previous reports of work environment measurements and conducted a new work environment measurement on one day during the period. The PID sensor systems detected the chemical exposure levels in the workplace every second and transmitted it to the platform. Daily average and maximum chemical exposure levels were also recorded. Results: We compared the results from the real-time monitoring system and the work environment measurement by traditional methods. Generally, the data from the real-time monitoring system showed a higher level because the sensors were closer to the chemical source. We found that 28% of jig cleaning task data exceeded the STEL. Peak exposure levels of sensor data were useful for understanding the characteristics of the task's chemical use. Limitations and implications were reviewed for the adoption of the system for preventing poisoning caused by chemical substances. Conclusions: We found that the real-time chemical exposure monitoring system was an efficient tool for preventing occupational diseases caused by chemical exposure, such as acute poisoning. Further research is needed to improve the reliability and applicability of the system. We also believe that forming a social consensus around the system is essential.

• Journal of Marine Life Science
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• v.1 no.2
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• pp.109-116
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• 2016

We determined the effects of different water temperatures (15, 20, and 25℃) and photoperiod cycles (24L:0D, 12L:12D, and 0L:24D) on the oxygen consumption of the offspring of a cultured Japanese strain (JJ), a selected Korean strain (KK), and intraspecific hybrid strains (JK and KJ) of red seabream, Pagrus major, under starvation conditions. The different fish strains, water temperatures, and photoperiod cycles had effects on the mean oxygen consumption of fish. Oxygen consumption increased with increasing water temperatures for all photoperiod treatments (p<0.001). Fish held in continuous darkness (0L:24D) used consistently less oxygen than fish exposed to continuous light (p<0.05). The oxygen consumption of fish exposed to the light phase in a 12L:12D photoperiod was higher than that of fish in the dark phase of the 12L:12D cycle, and differences were significant in three of the strains: JJ (15℃), KK (15 and 20℃), and KJ (25℃). The oxygen consumption of the inbred (JJ and KK) and intraspecific hybrid (JK and KJ) strains varied with differing water temperatures and photoperiod cycles. The JK strain displayed significantly higher oxygen consumption than the other strains under all experimental conditions except 15℃ with a 0L:24D photoperiod. The JK and KJ strains usually showed the highest and lowest oxygen consumption values, respectively, whereas the inbred strains exhibited intermediate values. Oxygen consumption in the JJ and JK strains was usually higher than that of the KK and KJ strains. We propose that differences in the thermal sensitivity and photosensitization properties of the strains contribute to differences in their ability to adapt to changes in water temperature and photoperiod, thus resulting in differences in the amplitude of their metabolic rates.

• The Journal of KAIRB
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• v.2 no.1
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• pp.6-22
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• 2020

Purpose: Clinical studies require institutional review board (IRB) approval based on the ethical principle and regulations. While the number of clinical studies has been increased and diversified, duplicated IRB review for multi-center studies has become a major issue. Therefore, single IRB system has been suggested in revised Common Rule. This study aimed to identify and assess the current status of single IRB in Korea and the anticipated needs of single IRB from researchers and IRB member or administrators. Methods: We developed 14 questions including perceived advantages and disadvantages of single IRB, and anticipated problems. The online survey collected opinions on single IRB from researchers, IRB members and IRB administrators. We also interviewed five IRB administrators who have an experience of single IRB. Results: A total of 80 responses were analyzed in this study. Although efficiencies were suggested for the advantages of single IRB in terms of reducing burden of duplicated review, respondents also perceived that the different review criteria between single IRB and each IRB would be a major hurdle for adopting single IRB system. Therefore, the standardization of standard of procedures (SOP) and the standardization of IRB submission materials should be preceded. According to the small group experiences of single IRB in Korea, we also observed the similar anticipated problems of single IRB. Conclusion: Single IRB system has many advantages for conducting multi-center trial. However, many specialists still have a lot of concerns about introducing a single IRB system in Korea. Therefore, a gradual, step-by-step process for conducting a single IRB system in Korea will be needed. Many studies for improving currently suggested single IRB system and the improvement of awareness about the essential of single IRB system would be needed.

• 한국노년학
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• v.30 no.4
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• pp.1129-1143
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• 2010

The purposes of this study were to investigate the major determinants influencing on health promoting behaviors(HPB) of the elderly living in Seoul. The conceptual framework of the study was Pender's health promoting model and the ecological perspectives. The study was conducted with 495 elderly persons whom 60 years old. For the analysis of data, descriptive statistics and hierarchical regression were used for the statistical analysis with SPSS program. The results were as following: 1) The mean score of the HPB was 3.11(SD=0.41). 2) Hierarchical regression analysis found that ModelIV accounted for 55.7% of the variance in HPB. 3) The Major determinants on HPB among the elderly persons were prior related perceived benefits of action, social support, perceived self-efficacy, community environment, perceived health status, education, and age. In conclusions, first, we should develop to various levels of educational and supportive programs for the HPB among the elderly persons. Second, we should examine more with environment, the accessibility to senior welfare agencies. Third, we should be organized the self-help groups for the elderly persons to improve health promoting behaviors. Fourth, the government should established more secure environment for the HPB, and find better solutions that are provided by various social welfare agencies connected with the coordination of the services in the local communities. Finally, we should develop professional education training programs of the HPB for the practitioners in the field of Gerontological Social Work.

• 한국노년학
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• v.31 no.2
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• pp.259-276
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• 2011

If frail elderly could use home care services adequately, quality of their life might improve and their costs of service would be decreased. The purpose of this study is to examine the factors on institutionalization of elderly using home care services in Korean long-term care insurance system. This study used the data of '2009 satisfaction survey of Korean long-term care system'. The survey proceeded using sampling data by region, level of long-term care need, and insurance type among beneficiaries from August 2009 to September 2010. The onset dates of institutionalization of 1,230 participants were ascertained from long-term care insurance claim data. This study calculated hazard ratio through Cox Proportional Hazard Model. The results showed that if elderly using home care services suffer a fracture, the hazard ratio of institutionalization is higher significantly. Although not significant, if older persons have more items of damaged cognitive functions, the hazard ratio of institutionalization is higher. The results have policy implications to supplement of home care service system and postpone institutionalization of elderly.

• The Journal of Korean Academy of Sensory Integration
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• v.21 no.2
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• pp.35-44
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• 2023

Objective : This study sought to explore occupational therapy students' awareness of Developmental Rehabilitation Services (DRSs) and the certification of Sensory Developmental Rehabilitation Service Providers (SDRSPs). Moreover, it also aimed to examine the differences in students' awareness based on general characteristics. The findings were intended to provide a foundation for research on sensory developmental rehabilitation. Methods : An online survey was conducted among 199 occupational therapy students nationwide from October 4 to November 5, 2022. Frequency analysis was used to assess the general characteristics and additional items. Both descriptive statistics and frequency analysis were employed to assess the students' awareness of DRSs and SDRSP certification. Any differences in the students' awareness based on their general characteristics were examined using t-tests and an analysis of variance. Results : The students' awareness of DRSs was moderate (4.50 ± 2.40), while their awareness of SDRSP certification was also moderate (4.22 ± 2.55). The awareness of DRSs varied significantly based on the students' academic year and child-related practice experience. Similarly, the awareness of SDRSP certification differed significantly based on the students' academic program, academic year, recognition by the related department, and child-related practice experience. Conclusion : The occupational therapy students expressed a strong intention to provide DRSs and become certified as SDRSPs. However, their awareness levels were moderate. These findings emphasize the importance of educational efforts and the provision of relevant information about DRSs and SDRSP certification in universities to foster the development of competent SDRSPs.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1139-1147
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• 2023

The purpose of this paper is to present and evaluate the performance of a method for controlling the dose for optimal image acquisition while minimizing patient exposure by applying a small-sized Photomultiplier(SiPM) sensor inside a portable detector. Portable detectors have the advantage of being able to quickly access the patient's location for rapid diagnosis, but this mobility comes with the challenge of dose control. This paper presents a method to identify the dose that can have the DQE and optimal image quality of the detector through image evaluation based on IEC62220-1-1, an international standard for X-ray imaging devices, and to identify the optimal dose by matching the ADU of the image and the output of the SiPM Sensor. The Skull AP image was acquired by implementing the detector manufacturer's reference dose. The optimal dose was 342.8 µGy, and the optimal controlled dose was 148.3 µGy, which is 57 % of the manufacturer's reference dose. The Chest AP image was 81.9 µGy and the optimal controlled dose was 27.9 µGy, which is a high dose reduction effect of 66 %. In addition, the two images were analyzed by five radiologists and found to have no clinically significant difference in anatomical delineation.

• Health Policy and Management
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• v.33 no.4
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• pp.450-456
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• 2023

Background: This study aims to develop a "Predictive Model for the Possibility of Collection Delinquent Health Insurance Contributions" for the National Health Insurance Service to enhance administrative efficiency in protecting and collecting contributions from livelihood-type defaulters. Additionally, it aims to establish customized collection management strategies based on individuals' ability to pay health insurance contributions. Methods: Firstly, to develop the "Predictive Model for the Possibility of Collection Delinquent Health Insurance Contributions," a series of processes including (1) analysis of defaulter characteristics, (2) model estimation and performance evaluation, and (3) model derivation will be conducted. Secondly, using the predictions from the model, individuals will be categorized into four types based on their payment ability and livelihood status, and collection strategies will be provided for each type. Results: Firstly, the regression equation of the prediction model is as follows: phat = exp (0.4729 + 0.0392 × gender + 0.00894 × age + 0.000563 × total income - 0.2849 × low-income type enrollee - 0.2271 × delinquency frequency + 0.9714 × delinquency action + 0.0851 × reduction) / [1 + exp (0.4729 + 0.0392 × gender + 0.00894 × age + 0.000563 × total income - 0.2849 × low-income type enrollee - 0.2271 × delinquency frequency + 0.9714 × delinquency action + 0.0851 × reduction)]. The prediction performance is an accuracy of 86.0%, sensitivity of 87.0%, and specificity of 84.8%. Secondly, individuals were categorized into four types based on livelihood status and payment ability. Particularly, the "support needed group," which comprises those with low payment ability and low-income type enrollee, suggests enhancing contribution relief and support policies. On the other hand, the "high-risk group," which comprises those without livelihood type and low payment ability, suggests implementing stricter default handling to improve collection rates. Conclusion: Upon examining the regression equation of the prediction model, it is evident that individuals with lower income levels and a history of past defaults have a lower probability of payment. This implies that defaults occur among those without the ability to bear the burden of health insurance contributions, leading to long-term defaults. Social insurance operates on the principles of mandatory participation and burden based on the ability to pay. Therefore, it is necessary to develop policies that consider individuals' ability to pay, such as transitioning livelihood-type defaulters to medical assistance or reducing insurance contribution burdens.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.526-532
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• 2023

Falls are fatal accidents that occur more than 420,000 times a year worldwide. Therefore, to study patients with falls, we found the association between extrinsic injury codes and principal diagnosis S-codes of patients with falls, and developed a prediction model to predict extrinsic injury codes based on the data of principal diagnosis S-codes of patients with falls. In this study, we received two years of data from 2020 and 2021 from Institution A, located in Gangneung City, Gangwon Special Self-Governing Province, and extracted only the data from W00 to W19 of the extrinsic injury codes related to falls, and developed a prediction model using W01, W10, W13, and W18 of the extrinsic injury codes of falls, which had enough principal diagnosis S-codes to develop a prediction model. 80% of the data were categorized as training data and 20% as testing data. The model was developed using MLP (Multi-Layer Perceptron) with 6 variables (gender, age, principal diagnosis S-code, surgery, hospitalization, and alcohol consumption) in the input layer, 2 hidden layers with 64 nodes, and an output layer with 4 nodes for W01, W10, W13, and W18 exogenous damage codes using the softmax activation function. As a result of the training, the first training had an accuracy of 31.2%, but the 30th training had an accuracy of 87.5%, which confirmed the association between the fall extrinsic code and the main diagnosis S code of the fall patient.