• Journal of Korean Medical Science
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• v.33 no.48
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• pp.316.1-316.10
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• 2018

Background: Water pressure and muscle contraction may influence bone mineral density (BMD) in a positive way. However, divers experience weightlessness, which has a negative effect on BMD. The present study investigated BMD difference in normal controls and woman free-divers with vertebral fracture and with no fracture. Methods: Between January 2010 and December 2014, traditional woman divers (known as Haenyeo in Korean), and non-diving women were investigated. The study population was divided into osteoporotic vertebral fracture and non-fracture groups. The BMD of the lumbar spine and femoral neck was measured. The radiological parameters for global spinal sagittal balance were measured. Results: Thirty free-diving women and thirty-three non-diving women were enrolled in this study. The mean age of the divers was $72.1{\pm}4.7$ years and that of the controls was $72.7{\pm}4.0$ years (P = 0.61). There was no statistical difference in BMD between the divers and controls. In divers, cervical lordosis and pelvic tilt were significantly increased in the fracture subgroup compared to the non-fracture subgroup (P = 0.028 and P = 0.008, respectively). Sagittal vertical axis was statistically significantly correlated with cervical lordosis (Spearman's rho R = 0.41, P = 0.03), and pelvic tilt (Spearman's rho R = 0.46, P = 0.01) in divers. Conclusion: BMD did not differ significantly between divers and controls during their postmenopausal period. When osteoporotic spinal fractures develop, compensation mechanisms, such as increased cervical lordosis and pelvic tilt, was more evident in traditional woman divers. This may be due to the superior back muscle strength and spinal mobility of this group of women.

• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.457-464
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• 2019

Objectives: Quantitative structure-activity relationship (QSAR) is one of the effective alternatives to animal testing, but its credibility in terms of toxicity prediction has been questionable. Thus, this work aims to evaluate its predictive capacity and find ways of improving its credibility. Methods: Using $TOPKAT^{(R)}$, OECD toolbox, and $Derek^{(R)}$, all of which have been applied world-wide in the research, industrial, and regulatory fields, an analysis of prediction credibility markers including accuracy (A), sensitivity (S), specificity (SP), false negative (FN), and false positive (FP) was conducted. Results: The multi-application of QSARs elevated the precision credibility relative to individual applications of QSARs. Moreover, we found that the type of chemical structure affects the credibility of markers significantly. Conclusions: The credibility of individual QSAR is insufficient for both the prediction of chemical toxicity and regulation of hazardous chemicals. Thus, to increase the credibility, multi-QSAR application, and compensation of the prediction deviation by chemical structure are required.

• The Journal of Korean Physical Therapy
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• v.31 no.5
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• pp.279-285
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• 2019

Purpose: This study examined the effects of spinal stabilization exercises using visual feedback on the gross motor function and balance of the sitting posture in children with cerebral palsy. Methods: The subjects were 18 children with cerebral palsy aged 8-15 years in the I-III stages of the Gross Motor Function Classification System. The subjects were divided into an experimental group (n=9) and control group (n=9). The experimental group was treated with 30 minutes of neurodevelopmental treatment and 20 minutes of spinal stabilization exercises using visual feedback. The control group was treated with 30 minutes of neurodevelopmental treatment and 20 minutes of spinal stabilization exercises without visual feedback. Both groups participated in the experiment twice a week for eight weeks. The Gross Motor Function Measurement was performed to evaluate the changes between pre- and the post-intervention in gross motor function. The Seated Limit of Stability Surface Area was measured to evaluate the changes in trunk balance. Results: Both experimental and control groups showed a significant increase in the gross motor function and trunk balance (p<0.05). The experimental group showed a significant increase in gross motor function compared to the control group (p<0.05). The experimental group showed a significant increase in the dynamic trunk balance in all directions when measuring the Seated Limit of Stability Surface Area (p<0.05). Conclusion: Spinal stabilization exercises using visual feedback for the neurodevelopmental treatment of children with cerebral palsy can improve their gross motor function and trunk balance when in a sitting posture more effectively.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.675-687
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• 2010

Structural Health Monitoring (SHM) is the science and technology of monitoring and assessing the condition of aerospace, civil and mechanical infrastructures using a sensing system integrated into the structure. Impedance-based SHM measures impedance of a structure using a PZT (Lead Zirconate Titanate) patch. This paper presents a low-power wireless autonomous and active SHM node called Autonomous SHM Sensor 2 (ASN-2), which is based on the impedance method. In this study, we incorporated three methods to save power. First, entire data processing is performed on-board, which minimizes radio transmission time. Considering that the radio of a wireless sensor node consumes the highest power among all modules, reduction of the transmission time saves substantial power. Second, a rectangular pulse train is used to excite a PZT patch instead of a sinusoidal wave. This eliminates a digital-to-analog converter and reduces the memory space. Third, ASN-2 senses the phase of the response signal instead of the magnitude. Sensing the phase of the signal eliminates an analog-to-digital converter and Fast Fourier Transform operation, which not only saves power, but also enables us to use a low-end low-power processor. Our SHM sensor node ASN-2 is implemented using a TI MSP430 microcontroller evaluation board. A cluster of ASN-2 nodes forms a wireless network. Each node wakes up at a predetermined interval, such as once in four hours, performs an SHM operation, reports the result to the central node wirelessly, and returns to sleep. The power consumption of our ASN-2 is 0.15 mW during the inactive mode and 18 mW during the active mode. Each SHM operation takes about 13 seconds to consume 236 mJ. When our ASN-2 operates once in every four hours, it is estimated to run for about 2.5 years with two AAA-size batteries ignoring the internal battery leakage.

• Safety and Health at Work
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• v.2 no.4
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• pp.336-347
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• 2011

Objectives: In Korea, an average of 258 workers claim compensation for their noise-induced hearing loss (NIHL) on an annual basis. Indeed, hearing disorder ranks first in the number of diagnoses made by occupational medical check-ups. Against this backdrop, this study analyzed the impact of 19 types of noise-generating machines and equipment on the sound pressure levels in workplaces and NIHL occurrence based on a 2009 national survey on work environments. Methods: Through this analysis, a series of statistical models were built to determine posterior probabilities for each worksite with an aim to present risk ratings for noise levels at work. Results: It was found that air compressors and grinding machines came in first and second, respectively in the number of installed noise-generating machines and equipment. However, there was no direct relationship between workplace noise and NIHL among workers since noise-control equipment and protective gear had been in place. By building a logistic regression model and neural network, statistical models were set to identify the influence of the noise-generating machines and equipment on workplace noise levels and NIHL occurrence. Conclusion: This study offered NIHL prevention measures which are fit for the worksites in each risk grade.

• Safety and Health at Work
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• v.2 no.4
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• pp.321-327
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• 2011

Objectives: To find out from an analysis of empirical data the levels of influence, which a labor union (LU) and Occupational Safety and Health Committee (OSHC) have in reducing the occupational injury and illness rate (OIIR) through their accident prevention activities in manufacturing industries with five or more employees. Methods: The empirical data used in this study are the Occupational Safety and Health Tendency survey data, Occupational Accident Compensation data and labor productivity and sales data for the years 2003 to 2007. By matching these three sources of data, a final data set (n = 280) was developed and analyzed using SPSS version 18 (SPSS Inc., Chicago, IL, USA). Results: It was found that a workplace with a LU has a lower OIIR than one without a LU. In manufacturing industries with five or more employees in 2007, the OIIR of the workplaces without a LU was 0.87%, while that of workplaces with a LU was much lower at 0.45%. In addition, workplaces with an established OSHC had a lower OIIR than those without an OSHC. Conclusion: It was found that the OIIR of workplaces with a LU is lower than those without a LU. Moreover, those with the OSHC usually had a lower OIIR than those without. The workplace OIIR may have an impact on management performance because the rate is negatively correlated with labor productivity and sales. In the long run, the OIIR of workplaces will be reduced when workers and employers join forces and recognize that the safety and health activities of the workplace are necessary, not only for securing the health rights of the workers, but also for raising labor productivity.

• Safety and Health at Work
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• v.5 no.4
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• pp.234-237
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• 2014

Background: Inhalation of asbestos fibers can lead to adverse health effects on the lungs. This study describes lung function profiles among individuals with nonmalignant asbestos-related disorders (ARDs). Methods: The study population was from the Workers' Compensation (Dust Diseases) Board of New South Wales, Sydney, Australia. Lung function measurements were conducted in males with asbestosis (n = 26), diffuse pleural thickening (DPT; n = 129), asbestosis and DPT (n = 14), pleural plaques only (n = 160) and also apparently healthy individuals with a history of asbestos exposure (n = 248). Standardized spirometric and single-breath diffusing capacity for carbon monoxide ($DL_{CO}$) measurements were used. Results: Mean age [standard deviation (SD)] was 66.7 (10.3) years for all participants. Current and ex-smokers among all participants comprised about 9.0% and 54.8%, respectively. Median pack-years (SD) of smoking for ex- and current-smokers were 22.7 (19.9). Overall 222 participants (38.6%) and 139 participants (24.2%) had forced expiratory volume in 1 second ($FEV_1$) and forced vital capacity (FVC) measurements < 80% predicted, and 217 participants (37.7%) had $FEV_1/FVC$ results < 70%. A total of 249 individuals (43.8%) had DLCO values < 80% predicted and only 75 (13.2%) had DLCO/VA results < 80% predicted. A total of 147 participants (25.6%) had peak expiratory flow (PEF) measurements < 80% predicted. The presence of ARDs lowered the lung function measurements compared to those of healthy individuals exposed to asbestos. Conclusion: Lung function measurement differs in individuals with different ARDs. Monitoring of lung function among asbestos-exposed populations is a simple means of facilitating earlier interventions.

• Journal of East-West Nursing Research
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• v.27 no.2
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• pp.104-113
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• 2021

Purpose: The purpose of this study was to investigate the status of emotional labor of nursing personnel working in comprehensive nursing service ward and to suggest the way service improvement can be achieved. Methods: A total of 28 nurses working in comprehensive nursing service ward were divided into four groups to conduct focus group interview. All interviews were recorded and transcribed after the interview to perform data analysis in the order of data classification, topic categorization, and keyword derivation. Results: The five categories of subjects and relating keywords drawn from the focus group interviews are as follows: 1) Emotional labor experience: suppressing emotions, expressing emotions or actions that are different from reality, 2) Situations of emotional labor: verbal abuse and assault, sexual harassment, personal needs and errands, 3) Responses to emotional labor: responding directly, responding directly, receiving senior's help, using the organizational system, persevering, 4) Problems caused by emotional labor: work exhaustion, job change intention, job stress, 5) Protection plan against emotional labor: manual or education for nurses, education for patients and carers, compensation, tough sanctions though system strengthening. Conclusion: This study shows that although nurses working in comprehensive nursing service ward generally experience high levels of emotional labor, the problem solving of them relies mainly on personal response. Therefore, it is necessary to develop various measures to protect nurses in an organizational level response, thus to improve the comprehensive nursing service system.

• Journal of the Korean Society of Safety
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• v.36 no.4
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• pp.99-107
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• 2021

This study analyzes the differences in definitions and concepts of terms used in the statistical indicators of fatal occupational injuries per 100,000 workers among countries included in the ILOSTAT data explorer. In addition, improvement measures focusing on the limitations in international comparison are proposed. Five countries-the Republic of Korea, Germany, Japan, United Kingdom, United States-- were comparatively analyzed. These countries were selected according to the significance of differences in their definitions of workplace injuries, workers, and compensation insurance, and their reporting systems. Considering these differences before directly comparing statistical indicators of fatal occupational injuries per 100,000 workers among countries is necessary because the range of comparison groups and the definition of fatal occupational injury are different for each country. While one can also compare trends by country, it is necessary to investigate beforehand whether the criteria and methods for processing statistics have changed. Misinterpretation can be minimized by properly understanding the process and limitations of fatal occupational statistical indicators that may differ from country to country.

• Safety and Health at Work
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• v.11 no.4
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• pp.418-424
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• 2020

Background: According to the previous studies, the work-related accident rate decreased in Korea after the introduction of occupational health and safety management system (OHSMS), but there were several disasters in Korea such as subway worker's death at Guui station in 2016 and the Taean thermal power plant accident in 2018, which escalated the social demand for safety. In 2018, OHSMS became an international standard, as ISO45001 was announced. Methods: A survey was conducted to research the implementation status of OHSMS and changes in people's perception, and the results were compared with those of a past survey. Results: Enhanced social demand and various stakeholders' (not only buyer) needs, and social responsibility are perceived as the motivation for the introduction of OHSMS rather than legal compliance or customer demand. In the questionnaire about problems with the implementation of OHSMS, the factors with higher response rate in 2018 than 2004 were "excessive cost" and "complicated documentation management." In the questionnaire about how to promote OHSMS in organizations, most people answered "reduction of workers' compensation insurance rate" in 2004, but most people answered "exemption from health and safety supervision" in 2018. Conclusion: For the effective implementation of ISO45001, emphasis is placed on social demand, training to recognize health and safety as a part of management, and the reduction of certification and consulting costs to promote the introduction of OHSMS. Incentives such as insurance premium cuts and exemptions from health and safety supervision are needed.