• 한국산업보건학회지
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• 제28권2호
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• pp.230-239
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• 2018

Objective: The purpose of this study is to identify the kinds and exposure levels of health hazards in the metalworking process in relation to acute poisoning accidents caused by methanol in 2016. Methods: The number of industries, workplaces, exposed workers, regional distribution, and exposure level of health hazards in metalworking process were investigated based on employee exposure assessment database provided by KOSHA (the Korea Occupational Safety and Health Agency), which was collected from workplace hazard evaluation programs in Korea. Exposure metrics for methanol were assessed by RCR (risk characterization ratio). Results: The numbers of processes, workplaces, and exposed workers of metalworking, which include CNC (computer numerical control) were 25, 14,405, and 169,102 respectively. The numbers of samples of chemical hazards including methanol were 91,325, and it was found that workers in metalworking were exposed to 249 kinds of chemical hazards. There were 16 kinds of special controlled substances including beryllium. It is estimated that the number of workplaces involving CNC process was 2,537, and the number of exposed workers was 27,976. In CNC process, the total number of workplaces handling methanol was 36, and 298 workers were estimated to be exposed. There was no exceeded that surpassed the OEL and 49% of samples were below the limit of detection. Methanol exposure concentrations in Gyeonggido Province were statistically significantly higher than in other areas (p <0.0001). Conclusions: In the metalworking process including CNC, there is exposure to a wide variety of health hazards. There was no sample exceeding the OEL for methanol. Therefore, it is necessary to recognize the limits of the employee exposure assessment system and urgently improve measures to prevent the occurrence of events like methanol poisoning.

• 한국의료질향상학회지
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• 제15권2호
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• pp.107-120
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• 2009

Background : To estimate fall incidence rate and associated factors in inpatients from a general hospital. Method : The data were collected from 104 fall incident reports developed by the patient safety committee in a general hospital in Seoul from 01 January 2007 to 31 December 2008. Information included general characteristics of patients, factors related to fall, types, places, circumstances and outcomes of fall. Result : The incidence rate of fall, which was 4.4 per 1,000 total discharged patients and 0.5 per 1,000 patient-days, was much lower than that of several hospitals in the United States. The difference may reflect the different incidence reporting system of each hospital. Fall-prone patients were, in general, $$\geq_-$$65 years of age, had an alert mental status, were ambulatory with some assistance, and were dependent on and ambulatory device. High incidence of falls was associated with patients with circulatory disease. The majority of fall events usually occurred in bed or at the bedside in the patient's room, and occurred more often during the night than during the day or evening. Risk factors of fall were use of drugs (antihypertensive or neuropsychiatric drugs) and environmental factors (e.g., overly high bed height, surrounding objects, inadequate fitness shoes and slippery floor). Physical injury occurred in 43.3% of fall events, which typically required diagnosis of injury and treatment such as suturing. Risk factors for repeated falls were use of a neuropsychiatric drug (odds ratio=13.9) and gait disturbance (odds ratio=91.2). Risk factors for fall-related injury were alert mental status (odds ratio=3.3 times more likely to fall than those who were drowsy or in a stupor) and general weakness(odds ratio=3.3 times more likely to fall than those who were not generally weak). Conclusion : Medical and nursing staff should be aware of the fall risk factors of hospitalized patients and should intensively pursue preventative strategies. Development of fall prevention education based on these results is recommended.

• Smart Structures and Systems
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• 제31권2호
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• pp.183-197
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• 2023

For long-span bridges with a structural health monitoring (SHM) system, environmental temperature-driven responses are proved to be a main component in measurements. However, anomalous structural behavior may be hidden incomplicated recorded data. In order to receive reliable assessment of structural performance, it is important to study therelationship between temperature and monitoring data. This paper presents an application of the cointegration based methodology to detect anomalies that may be masked by temperature effects and then forecast the temperature-induced deflection (TID) of long-span suspension bridges. Firstly, temperature effects on girder deflection are analyzed with fieldmeasured data of a suspension bridge. Subsequently, the cointegration testing procedure is conducted. A threshold-based anomaly detection framework that eliminates the influence of environmental temperature is also proposed. The cointegrated residual series is extracted as the index to monitor anomaly events in bridges. Then, wavelet separation method is used to obtain TIDs from recorded data. Combining cointegration theory with autoregressive moving average (ARMA) model, TIDs for longspan bridges are modeled and forecasted. Finally, in-situ measurements of Xihoumen Bridge are adopted as an example to demonstrate the effectiveness of the cointegration based approach. In conclusion, the proposed method is practical for actual structures which ensures the efficient management and maintenance based on monitoring data.

• 농촌의학ㆍ지역보건
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• 제48권1호
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• pp.13-27
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• 2023

Objectives: The purpose of this study is to investigate changes in public health-related perceptions of residents of Gangwon province after the outbreak of Coronavirus disease-19(COVID-19) of the public. Methods: We performed paired T-test analysis to measure the change in public health-related perceptions before and after COVID-19. We also utilized generalized estimating equations to identify demographic factors correlated with public health-related perceptions. Results: The public perceived public health as 'All citizens can use medical care and protect/promote health.' The concept was the most popular, from 94.3% in 2019 to 95.5% in 2020. In addition, after COVID-19, residents of Gangwon province's satisfaction with medical services increased, but the overall level was not high. Among the eight essential healthcare needs after COVID-19, cardiovascular disease and injury services have emerged as preferred services. However, by sociodemographic factors, distinctive responses were detected. Conclusions: Through COVID-19, Gangwon residents' awareness of the public's health rights has increased. Those living in vulnerable areas or with unmet medical care, supported strengthening public health care. In addition, although medical satisfaction has increased, it is not satisfied, so listening to the voices of the population group with low satisfaction is essential. Lastly, since the necessity of essential health care may change due to specific events, the local government needs to plan health projects reflecting the needs of residents. Therefore, when designing the public health care strategy in Gangwon province, the local government should consider not only political factors but also environmental factors, demographic and conceptual factors.

• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2371-2376
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• 2021

As the γ-ray energy increases, a reconstructed image becomes noisy and blurred due to the penetration of the γ-ray through the coded mask. Therefore, the thickness of the coded mask was increased for high energy regions, resulting in severely decreased the performance of the detection efficiency due to self-collimation by the mask. In order to overcome the limitation, a modified uniformly redundant array γ-ray imaging system using dual anti-mask method was developed, and its performance was compared and evaluated in high-energy radiation region. In the dual anti-mask method, the two shadow images, including the subtraction of background events, can simultaneously contribute to the reconstructed image. Moreover, the reconstructed images using each shadow image were integrated using a hybrid update maximum likelihood expectation maximization (h-MLEM). Using the quantitative evaluation method, the performance of the dual anti-mask method was compared with the previously developed collimation methods. As the shadow image which was subtracted the background events leads to a higher-quality reconstructed image, the reconstructed image of the dual anti-mask method showed high performance among the three collimation methods. Finally, the quantitative evaluation method proves that the performance of the dual anti-mask method was better than that of the previously reconstruction methods.

• Safety and Health at Work
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• 제10권1호
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• pp.54-60
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• 2019

Background: Increasing the establishment of integrated management systems (IMSs) is done with the purpose of leaving traditional management methods and replacing them with modern management methods. Thus, the present study sought to analyze the events and investigate the impact of IMS on health and safety performance indices in an Iranian combined cycle power plants. Methods: This case study was conducted in 2012 in all units of the Yazd Combined Cycle Power Plant on accident victims before and after the implementation of IMS. For data analysis and prediction of indices after the implementation of IMS, descriptive statistics and Kolmogorov-Smirnov test, Chi-square, linear regression, and Cubic tests were conducted using SPSS software. Results: The number of people employed in the power plant in an 8-year period (2004-2011) was 1,189, and 287 cases of work-related accidents were recorded. The highest accident frequency rate and accident severity rate were in 2004 (32.65) and 2008 (209), respectively. Safe T-score reached to below -3 during 2010-2011. In addition, given the regression results, the relation between all predictor variables with outcomes was significant (p < 0.05), except for the variable $X^1$ belonging to the accident severity rate index. Conclusion: The implementation of safety programs especially that of IMS and its annual audits has had a significant impact on reducing accident indices and improving safety within the study period. Accordingly, health and safety management systems are appropriate tools for reducing accident rate, and the use of regression models and accident indices is also a suitable way for monitoring safety performance.

• 한국환경보건학회지
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• 제32권6호
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• pp.543-555
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• 2006

During a twenty-day period in 2005, a nine-stage Andersen cascade impactor was used to determine the seasonal size distribution of atmospheric particles and its inorganic ion species sampled for 24hr in Iksan city, located southwest of the Korean peninsula. Samples were analyzed for major water-soluble ion species using Dionex-100 ion chromatograph. Average fine and coarse mass concentrations of atmospheric particles were, respectively, 31.4 and $82.6{\mu}g\;m^{-3}$ in spring and 35.8 and $73.4{\mu}g\;m^{-3}$ in fall-winter during the sampling period of 2005, while measurements of 69.8 and 9.9 were obtained in the sampling period of summer, The size distribution of particulate mass concentration during the non-Asian dust period was generally bimodal, whereas the size distribution of particulate mass concentration during the Asian dust period was unimodal due to the significant increase of coarse particles, which originated from long-range transport of soil dust particles from loess regions of the Asian continent. Among ionic species, $SO{_4}^{2-},\;NH{_4}^+,\;K^+$ were mainly distributed in fine particles due to their characteristics of emission sources and gas-to-particle conversion, while $Na^+,\;Mg^{2+}\;and\;Ca^{2+}$ were dominantly in coarse particles. However, $NO_3{^-}\;and\;Cl^-$ were distributed in both coarse particles and fine particles. Although $SO{_4}^{2-}$ was mainly distributed in fine particles, the size distributions of $SO{_4}^{2-}$ in coarse mode were significantly increased during the Asian dust events compared to those during the non-Asian dust period. $Ca^{2+}$ showed the most abundant species in the atmospheric particles during the Asian dust period. $NH{_4}^+$ was found to mainly exist as $(NH_4)_2SO_4$ in fine particles.

• 식품보건융합연구
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• 제6권3호
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• pp.31-41
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• 2020

The caregivers of elderly people with dementia suffer an affectation in the psychological and social order due to the low probability of total rehabilitation of the elderly and the progressive course of this pathology. In the municipality of Guisa, Granma Province there is a health problem regarding this problem since family caregivers of the elderly with dementia constantly go to the Psychology and Psychiatry consultations, in search of specialized help because they report feeling depressed. For this reason, this research was carried out with the objective of determining the main manifestations of depression in these caregivers. The results emanating from the triangulation of methods (scientific observation) and techniques (questionnaire, interviews and inventory Beck), employees at three stages of work where it was found that the main manifestations of depression of these caregivers are: poss of interest or the ability to enjoy activities that were previously pleasurable, loss of emotional reactivity to pleasant environmental events and circumstances, sleep disturbances, marked loss of appetite, weight loss, irritability, muscular tension, feelings of sadness unmotivated that produces discomfort and sufferings, ansiety, entities of handicap, blame, loss of self-confidence and feelings of inferiority, gloomy perspective of the future.

• 생태와환경
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• 제46권1호
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• pp.1-9
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• 2013

Algal blooms in potable water supplies are becoming an increasingly prevalent and serious water quality problem around the world. In addition to precipitating taste and odor problems, blooms damage the environment, and some classes like cyanobacteria (blue-green algae) release toxins that can threaten human health, even causing death. There is a recognized need in the water industry for models that can accurately forecast in real-time algal bloom events for planning and mitigation purposes. In this study, using data for an interconnected system of rivers and reservoirs operated by a New Jersey water utility, various ANN models, including both discrete prediction and classification models, were developed and tested for forecasting counts of three different algal classes for one-week and two-weeks ahead periods. Predictor model inputs included physical, meteorological, chemical, and biological variables, and two different temporal schemes for processing inputs relative to the prediction event were used. Despite relatively limited historical data, the discrete prediction ANN models generally performed well during validation, achieving relatively high correlation coefficients, and often predicting the formation and dissipation of high algae count periods. The ANN classification models also performed well, with average classification percentages averaging 94 percent accuracy. Despite relatively limited data events, this study demonstrates that with adequate data collection, both in terms of the number of historical events and availability of important predictor variables, ANNs can provide accurate real-time forecasts of algal population counts, as well as foster increased understanding of important cause and effect relationships, which can be used to both improve monitoring programs and forecasting efforts.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1393-1398
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• 2018

In conventional single-photon emission computed tomography (SPECT), only the photoelectric events in the detectors are used for image reconstruction. However, if the $^{131}I$ isotope, which emits high-energy radiations (364, 637, and 723 keV), is used in nuclear medicine, both photoelectric and Compton scattering events can be used for image reconstruction. The purpose of our work is to perform simulations for Compton SPECT by using the Geant4 application for tomographic emission (GATE). The performance of Compton SPECT is evaluated and compared with that of conventional SPECT. The Compton SPECT unit has an area of $12cm{\times}12cm$ with four gantry heads. Each head is composed of a 2-cm tungsten collimator and a $40{\times}40$ array of CdZnTe (CZT) crystals with a $3{\times}3mm^2$ area and a 6-mm thickness. Compton SPECT can use not only the photoelectric effect but also the Compton scattering effect for image reconstruction. The correct sequential order of the interactions used for image reconstruction is determined using the angular resolution measurement (ARM) method and the energies deposited in each detector. In all the results of simulations using spherical volume sources of various diameters, the reconstructed images of Compton SPECT show higher signal-to-noise ratios (SNRs) without degradation of the image resolution when compared to those of conventional SPECT because the effective count for image reconstruction is higher. For a Derenzo-like phantom, the reconstructed images for different modalities are compared by visual inspection and by using their projected histograms in the X-direction of the reconstructed images.