• Safety and Health at Work
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• v.13 no.3
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• pp.357-363
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• 2022

Background: Refractory ceramic fibers (RCFs) are a suspected carcinogen but have been widely used as insulations. Depending on the temperature, RCFs can transform into crystalline SiO₂, which is a carcinogen that can be present in the air during bulk RCF handling. This study analyzed the physicochemical and morphological characteristics of RCFs at high temperatures and determined the exposure levels during the semiconductor scrubber maintenance. Methods: Sampling was conducted at a company that manufactures semiconductor scrubbers using RCFs as insulation. Bulk RCF samples were collected both before and after exposure to a scrubber temperature of 700℃. Airborne RCFs were collected during scrubber maintenance, and their characteristics were analyzed using microscopes. Results: The components of bulk RCFs were SiO₂ and Al₂O₃, having an amorphous structure. Airborne RCFs were morphologically different from bulk RCFs in size, which could negatively affect maintenance workers' health. 58% of airborne RCFs correspond to the size of thoracic and respirable fibers. RCFs did not crystallize at high temperatures. The exposure caused by airborne RCFs during the scrubber frame assembly and insulation replacement was higher than the occupational exposure limit. Conclusion: Workers conducting insulation replacement are likely exposed to airborne RCFs above safe exposure limits. As RCFs are suspected carcinogens, this exposure should be minimized through prevention and precautionary procedures.

• Advances in concrete construction
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• v.11 no.5
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• pp.375-386
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• 2021

In this paper, a study of stability and health of a newly-built railway tunnel is presented. The field test was implemented to monitor the secondary lining due to the significant cracking behaviors influenced the stability and health of the tunnel structure. Surface strain gauges were installed for monitoring the status of crack openings, and the monitoring outputs demonstrated that the cracks were still in the developing stage. Additionally, adjacent tunnel and poor condition of surrounding rock were identified as the causes of the lining cracking by systematically characterizing the crack spatial distribution, tunnel site and surrounding rock conditions. Reconstruction of partial lining and reconstruction of the whole secondary lining were designed as the maintenance projects for different cracking regions based on the construction feasibility. For assessing the health conditions of the reinforced lining, embedded strain gauges were set up to continuously measure the strain and the internal force of the reconstructed structures. For the partially reconstructed lining, the outputs show the maximum tensile elongation is 0.018 mm during 227 days, which means the structure has no obvious deformation after maintenance. The one-year monitoring of full-section was implemented in the other two completely reconstructed cross-sections by embedded strain gauge. The outputs show the reconstructed secondary lining has undertaken the pressure of surrounding rock with the time passing. According to the calculated compressive and tensile safety factors, the completely reconstructed lining has been in reliable and safe condition during the past year after reinforcement. It can conclude that the aforementioned maintenance projects can effectively ensure the stability and health of this tunnel.

• Journal of muscle and joint health
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• v.23 no.3
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• pp.206-213
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• 2016

Purpose: The aim of this study was to identify the closeness, self-esteem and intention of exercise maintenance in the elderly participants of the BeHaS exercise program. Methods: Thirty-one elderly participated in the BeHaS exercise program which held 1 hour a week for 8 weeks. Data were collected by self-report questionnaires. Analysis of data was done using UCINET 6.0 for closeness and SPSS 22.0 program for frequency and Wilcoxon signed rank test. Results: The score of closeness, self-esteem and intention of exercise maintenance in pretest were significantly higher than those of posttest relatively(p<.001, p=.040, p=.007). Conclusion: These findings suggest that the BeHaS exercise program for elderly can be effective nursing care to improve closeness, self-esteem and intention of exercise maintenance.

• Child Health Nursing Research
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• v.18 no.3
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• pp.135-142
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• 2012

Purpose: The purpose of this study was to examine the effects of structured nursing intervention for caregivers on maintenance of intravenous (IV) infusions in infants. Methods: The structured nursing intervention was developed through the processes of interviews with nurses from pediatric wards. To identify the effects of the developed nursing intervention, a non-synchronized non-equivalent control group pretest-posttest design study was conducted with caregivers from the pediatric ward from a hospital in Seoul. Of 100 admitted infants, 50 caregivers were assigned to the intervention group and received the structured nursing intervention for maintenance of intravenous infusions in infants. The others were assigned control group and received routine care. Data were collected on patient factors, IV insertion factors, treatments, and IV related complications. The form developed for the structured nursing intervention was used by staff nurses. Results: Compared to the control group, IV insertion frequency in experimental group infants was significantly lower and IV related complications decreased (p<.05). Conclusion: These results suggest that the structured nursing intervention for caregivers on maintenance of intravenous infusions may have effects on maintenance of intravenous infusions in infants, and decreasing IV related complications. This nursing intervention can be used to improve IV related problems of admitted infants.

• Journal of Korean society of Dental Hygiene
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• v.17 no.3
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• pp.479-492
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• 2017

Objectives: The purpose of this study is to understand the practices of the dental implant maintenance care according to knowledge and attitude toward dental implant in the dental service consumers. Methods: T-test, ANOVA, and cross tabulation were carried out to understand the knowledge and attitude toward the dental implant, the experiences of the treatments, and the practices of their maintenance care depending on the general characteristics and the oral-health education experience. The collected data were analyzed using by SPSS Windows Program 23.0. Results: The actual state of the implant maintenance care was revealed to be high in the use of oral care products with 83.9% and in the professional maintenance care with 86.0%. In terms of the implant-related experiences, the participation and the participation frequency in the professional maintenance care were resulted to be higher especially in those with more cases of surgical procedures and in those with more failure experiences. Examining the practices of management according to knowledge and attitude toward dental implant, the higher in knowledge and attitude led to the higher uses of oral care products. The periodically professional maintenance care was indicated to be received even if being taken high management cost. Conclusions: Effective education methods and programs are necessary to be developed and executed so that information and knowledge can lead the correct practices in the dental service consumers.

• Safety and Health at Work
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• v.10 no.1
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• pp.87-94
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• 2019

Background: Lead (Pb) exposure in shooting ranges has been reduced by various measures such as jacketed ammunition and lead-free primers. Nevertheless, this may lead to exposure to other metals, potentially resulting in adverse health effects. Methods: In a cross-sectional study, 35 subjects from seven different shooting ranges were studied: four shooting instructors, 10 police officers, 15 Special Forces, and six maintenance staff members. Metals and metalloids were determined in blood and urine by inductively coupled plasma-mass spectrometry. Results: The concentrations of most elements did not differ significantly between groups or compared to reference values, except for Sb and Pt in urine and Pb in blood. Mean values for Sb were considerably higher in urine from the Special Forces ($0.34{\mu}g/L$), the maintenance staff ($0.13{\mu}g/L$), and shooting instructors ($0.32{\mu}g/L$) compared to the police officers before shooting ($0.06{\mu}g/L$) and a Belgian reference value ($0.04{\mu}g/L$). For Pt, the Special Forces showed higher mean urinary concentrations ($0.078{\mu}g/L$) compared to a Belgian reference value (<$0.061{\mu}g/L$). Mean values for blood lead were markedly higher in the Special Forces ($3.9{\mu}g/dL$), maintenance staff ($5.7{\mu}g/dL$), and instructors ($11.7{\mu}g/dL$) compared to police officers ($1.4{\mu}g/dL$). One instructor exceeded the biological exposure index for blood Pb ($38.8{\mu}g/dL$). Conclusion: Since both Pb and Sb were found to be higher in shooting range employees, especially among frequent shooters, it is advisable to provide appropriate protective equipment, education, and medical follow-up for shooting range personnel in addition to careful choice of ammunition.

• Journal of Preventive Medicine and Public Health
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• v.16 no.1
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• pp.105-112
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• 1983

To characterize the diet and physical exercise patterns of bank personnel for the health maintenance, a questionnaire was administered to all the employess (1,249) of Daegu Bank in June 1983 among whick 78.1% (976) responded. Three quarters of the respondents were between 20 and 34 years old. About 30% of 20-24 years old group were male compared with 73.1% of 25-39 years old group. Major findings of the survey are as follows: 1) The most concerned chronic disease of the respondents were in the order of cancer (27.4%), psychiatric disease (15.1%), hypertension (14.1%), heart disease (13.7%) and tuberculosis (7.9%). 2) For the prevention of adulthood disease and obesity, 53.4% of the respondents were restricting sugar intake; 40.9%, salt: and 35.1%, fat-rich food. 3) Among all the respondents 36.9% were making effort to reduce body weight and 17.7% were trying to gain body weight. 4) The proportion of respondents who practice physical exercise for the health maintenance was 82.9% in male and 62.5% in female.

• International Journal of High-Rise Buildings
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• v.12 no.4
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• pp.321-333
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• 2023

Structural health monitoring is a technology or research field that extends the service life of structures and contributes to the prevention of disaster accidents by continuously evaluating the safety, stability, and serviceability of structures as well as allowing timely and proper maintenance. However, the contact-type sensors used for it require considerable time, cost, and labor for installation and maintenance. As an alternative, computer vision has attracted attention recently. Computer vision has the potential to make quality, deformation, and damage monitoring for structures contactless and automated. In this study, research cases in which computer vision was utilized for structural health monitoring are introduced, and its effects and limitations are summarized. Therefore, the applicability and future research directions of computer vision-based structural health monitoring are discussed.

• Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.119-127
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• 2015

In the case of a high-valuable asset, the Operation and Maintenance (O&M) phase requires heavy charges and more efforts than the installation (construction) phase, because it has long usage life and any accident of an asset during this period causes catastrophic damage to an industry. Recently, with the advent of emerging Information Communication Technologies (ICTs), we can get the visibility of asset status information during its usage period. It gives us new challenging issues for improving the efficiency of asset operations. One issue is to implement the Condition-Based Maintenance (CBM) approach that makes a diagnosis of the asset status based on wire or wireless monitored data, predicts the assets abnormality, and executes suitable maintenance actions such as repair and replacement before serious problems happen. In this study, we have addressed several aspects of CBM approach: definition, related international standards, procedure, and techniques with the introduction of some relevant case studies that we have carried out.

• Journal of KIBIM
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• v.8 no.4
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• pp.34-40
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• 2018

As the number of aged bridges increases, the development of efficient bridge maintenance techniques is becoming more important. Particularly, there have been many studies on digital-twin models of bridges for maintenance and SHM (Structure Health Monitering). However, in order to use the digital-twin model for maintenance of the bridge, the model updating process that matches the structural response between the real bridge and the digital-twin bridge model must be done. This study presents a model updating method that adjusts bridge's stiffness and boundary condition with genetic algorithm (GA) using static displacements and verified proposed updating method through field test on PSC girder bridge. This study also proposes a conceptual idea to construct an efficient bridge maintenance system by applying the updated numerical analysis model to the digital-twin model.