• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.223-232
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• 2017

Objectives: In response to increased interest in the safety of children's products, a risk management system is being prepared through exposure assessment of hazardous chemicals. To estimate exposure levels, risk assessors are using deterministic and probabilistic approaches to statistical methodology and a commercialized Monte Carlo simulation based on tools (MCTool) to efficiently support calculation of the probability density functions. This study was conducted to analyze and discuss the usage patterns and problems associated with the results of these two approaches and MCTools used in the case of probabilistic approaches by reviewing research reports related to exposure assessment for children's products. Methods: We collected six research reports on exposure and risk assessment of children's products and summarized the deterministic results and corresponding underlying distributions for exposure dose and concentration results estimated through deterministic and probabilistic approaches. We focused on mechanisms and differences in the MCTools used for decision making with probabilistic distributions to validate the simulation adequacy in detail. Results: The estimation results of exposure dose and concentration from the deterministic approaches were 0.19-3.98 times higher than the results from the probabilistic approach. For the probabilistic approach, the use of lognormal, Student's T, and Weibull distributions had the highest frequency as underlying distributions of the input parameters. However, we could not examine the reasons for the selection of each distribution because of the absence of test-statistics. In addition, there were some cases estimating the discrete probability distribution model as the underlying distribution for continuous variables, such as weight. To find the cause of abnormal simulations, we applied two MCTools used for all reports and described the improper usage routes of MCTools. Conclusions: For transparent and realistic exposure assessment, it is necessary to 1) establish standardized guidelines for the proper use of the two statistical approaches, including notes by MCTool and 2) consider the development of a new software tool with proper configurations and features specialized for risk assessment. Such guidelines and software will make exposure assessment more user-friendly, consistent, and rapid in the future.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.185-189
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• 2012

Objective: The aim of this paper is to introduces Hyundai Heavy Industry's ergonomic risk assessment tool, H-OWAS, which is considering work load and frequency compared to the OWAS. Background: As prevalence of work-related musculoskeletal disorders(WMSDs) in ship building industries has been much higher than that in other industries, most of the large scaled corporations have implemented their own prevention program since legislation on the prevention of WMSDs had introduced in 2003. Method: This paper introduces WMSDs prevention program, HEMP(HHI Ergonomics Management Program) which consists of risk assessment, improvement efforts of working environments, medical treatment and training/evaluation and describes how to operate the program. We also describe application of OWAS method considering work load and frequency for risk factor analysis(H-OWAS) and shows methodology for assessing the ergonomic risk factor. And comparison of the assessment results between OWAS and H-OWAS is carried out by statistical analysis. Result: There was statistically significant difference in the assessment results between OWAS and H-OWAS, and regression shows H-OWAS explains the borg's scale of perceived exertion more clearly than OWAS. Conclusion: H-OWAS has been proved more effective tool than OWAS to evaluate ergonomic risk factor under real working condition. Application: H-OWAS can be widely applied to the many other companies when implementing the ergonomics risk assessment.

• Journal of the Ergonomics Society of Korea
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• v.22 no.3
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• pp.75-91
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• 2003

Evaluation of repetitiveness for hand-intensive tasks is essential to determine the level of risk for upper-extremity musculoskeletal disorders at the workplace. Many measures and methods have been introduced for repetitiveness assessment: however, our understanding of the differences among these measures and methods is lacking. The present study compared the repetitiveness measures and measurement/analysis methods to help practitioners apply the proper repetitiveness assessment methodology in the workplace. By reviewing 51 studies of repetitiveness assessment, measures and corresponding measurement/analysis methods were surveyed. Of the repetitiveness measures, two types of dimensions (frequency and time) and corresponding types of analysis scopes were identified. According to the dimensional and analysis-scope types. the repetitiveness measures were categorized and then the surveyed studies were counted for each measure. It is identified that frequency measures have used 2.7 times higher than time measures and the frequency of wrist motions has been most frequently used in repetitiveness assessment. Furthermore, the measurement methods were categorized into objective and subjective methods, and the analysis methods into statistical and spectral methods. Lastly, eight factors (accuracy, reliability. sensitivity. efficiency. ease of use. applicability. interference. and robustness) were listed to be considered in selecting the appropriate assessment methodology.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.77-84
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• 2020

In this paper, we developed a damage evaluation technique that can determine the damage location of a long-sized structure such as a cable-stayed bridge, and verified the performance of the developed technique through experiments. The damage assessment method aims to extract data that can evaluate the damage of the structure without the undamage data and can determine the damage location only by analyzing the response data of the structure. To complete this goal, we developed a damage assessment technique that considers variability based on the IMD theory, which is a statistical pattern recognition technique, to identify the damage location. To complete this goal, we developed a damage assessment technique that considers variability based on the IMD theory, which is a statistical pattern recognition technique, to identify the damage location. To evaluate the performance of the developed technique experimentally, cable damage experiments were conducted on model cable-stayed bridges. As a result, the damage assessment method considering variability automatically outputs the damageless data according to external force, and it is confirmed that the performance of extracting information that can determine the damage location of the cable through the analysis of the outputted damageless data and the measured damage data is shown.

• Journal of People, Plants, and Environment
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• v.23 no.5
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• pp.521-535
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• 2020

Background and objective: This study investigated plant type and color preference and conducted a psychological assessment for gardening activities of firefighters in a high-risk occupational group. Methods: A survey was conducted on 117 firefighters aged 39.01±9.17 in Sunchang in March 2020 to examine their preferences in plant type and color and conduct a psychological assessment of firefighters on gardening activities. Results: For plant experience and awareness, plant-related event showed the highest score, followed by plant preference tendency and plant growing experience. The level of plant gardening activities was higher among older age and higher job position. As a result of examining the quality of life according to the demographic characteristic with WHOQOL-BREF (World Health Organization Quality of Life Assessment Instrument), it was found that the quality of life was higher among the 20s-30s than 50s, firefighter position than fire lieutenant or higher, those with higher average monthly income, and the singles group than married (p < .05). The administration group showed lower scores than the fire suppression group working in the field, showing statistical significance. Most firefighters showed high preference for herbal plants among the 12 types of flowering plants, in the order of Rosmarinus officinalis>Lavandula spp.>Mentha piperita, Calendula officinalis. Pelargonium spp. was preferred the least out of the flowering plants, Lycopersicon esculentum was preferred the most out of 12 types of vegetable plants, while Angelica acutiloba was preferred the least statistical significance. For the preference of plant colors, yellow was the most preferred color, followed by white, blue, orange, red, and green, showing statistical significance. For the psychological survey responses of emotion words toward 6 plants colors, it was found that 'bright' was the emotion felt most strongly by the white, yellow, and orange groups, 'calm' and 'comfortable' by the green and blue groups, and 'fancy' by the red group. Conclusion: The effect of agro-healing programs can be increased by using mostly yellow plants when creating indoor healing gardens at the workplaces of fire officials in a high-risk occupational group, and using herbal plants and Lycopersicon esculentum in the gardens for agro-healing activities.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.50-56
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• 2007

Impact of thermal discharge of nuclear power plant on marine environment is naturally reflected in biogeochemical changes of seawater. Until now, many investigation activities and reports of impact analysis of marine environment were occasionally inadequate to provide sufficient justification in resolving controversial conflict of interests related with thermal discharge of nuclear power plant. From the scrutinized examination of recent 17 reports published in Korea between 2002 and 2004, the most apparent issue was inadequacy of sampling design and absence of significance of many measured parameters. In many cases, lack of statistical interpretation of raw data incurred subjective or ambiguous assessment results, which failed in deducing mutual concurrence between the parties of interest. In overall all, the main reasons for impairing integrity of previous reports seem to be inconsistency of environmental investigation procedures between research institutions, inadequate sampling design at the discretion of institutions and lack of objectivity of impact assessment based on statistical interpretation. Therefore, the primary goal of this study is to (1) discuss the blown issues on previous routine practice of seawater quality assessment procedures, and to (2) provide improved investigation procedures and rational standard criteria strictly based on statistical analysis for the better seawater quality assessment, which could be supported by scientific community, public agency, investigation institution and the other parties of interest.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.229-229
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• 2015

Downscaling is a fundamental procedure in the assessment of the future climate change impact at regional and watershed scales. Hence, it is important to investigate the spatial variability of the climate conditions that are constructed by various downscaling methods in order to assess whether each method can model the climate conditions at various spatial scales properly. This study introduces a fundamental research from Jang and Kavvas(2015) that precipitation variability from a popular statistical downscaling method (BCSD) and a dynamical downscaling method (MM5) that is based on the NCAR/NCEP reanalysis data for a historical period and on the CCSM3 GCM A1B emission scenario simulations for a projection period, is investigated by means of some spatial characteristics: a) the normalized standard deviation (NSD), and b) the precipitation change over Northern California region. From the results of this study it is found that the BCSD method has limitations in projecting future precipitation values since the BCSD-projected precipitation, being based on the interpolated change factors from GCM projected precipitation, does not consider the interactions between GCM outputs and local geomorphological characteristics such as orographic effects and land use/cover patterns. As such, it is not clear whether the popular BCSD method is suitable for the assessment of the impact of future climate change at regional, watershed and local scales as the future climate will evolve in time and space as a nonlinear system with land-atmosphere feedbacks. However, it is noted that in this study only the BCSD procedure for the statistical downscaling method has been investigated, and the results by other statistical downscaling methods might be different.

• Communications for Statistical Applications and Methods
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• v.18 no.3
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• pp.287-294
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• 2011

Peer assessment is an educational valuation system that involves studying with a colleague and granting value to the progress made by the colleague. Although this method has many merits, there is also a drawback pertaining to calculating the mean of the scores that were granted to the levels of contribution. However, this has been improved upon by a diversified study. However, the concept of the chi-square test and p-value used in the preceding study is not easy individuals engaged in the industrial engineering field or education when using peer assessment. This study uses simple statistics like standard deviation, in addition to, investigating the availability of a suggested method as well as examples of utility and application. This study can contribute to increase the convenience of users through the use of convenience analysis and with this method.

• Journal of the Korean Society for Railway
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• v.19 no.2
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• pp.187-194
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• 2016

It is necessary to determine reliability indexes of existing railway bridges prior to setting up a proper target reliability index that can be used to introduce a reliability based limit state design method to design practice. Reliability is evaluated for a six PSC-I girder railway bridge, which is one of many representative types of double-track railway bridges. The reliability assessment is carried out for an edge girder subjected to bending moment. In the assessment, the flexural resistance and the fixed-load effect were obtained using existing statistical values from previous research on the introduction of limit state design to road bridge design. On the other hand, the live-load effect was determined using statistical values obtained from field measurement for the Joong-ang corridor, on which heavy freight trains are frequently passing. The reliability assessment is performed by AFOSM(Advanced First Order Second Moment method) for the limit state equation, and a sensitivity analysis for the reliability is performed for each factor of the load and resistance effects.

• Korea Journal of Hospital Management
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• v.25 no.3
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• pp.78-86
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• 2020

Purposes: This study purposed to identify factors influencing the composite quality score from the quality assessment program for long-term care hospitals Methodology: The study variables was obtained from HIRA(Health Insurance Review and Assessment Service): the composite quality scores and hospital variables such as number of doctors, nurses, beds, medical technicians, medical equipments, administrative region, ownerships from 3rd (2010) to 7th (2018) quality assessment program. National Statistical Portal(www.kosis.go.kr) provided the number of senior citizens aged over 65 in city·county·district area. SAS 9.4 was used for the data processing and used to analyze the data. Findings: The results showed that composite quality score increased past 9 years. Hospital variables such as number of doctor, nurse, medical technicians, bed and public hospitals had significant positive relationship with the composite quality score. Administrative region(district) showed higher scores compare to that of city. Compare to the score of quality assessment year(2010), as the assessment year move to 2012, 2013, 2015, 2018, results showed higher significant positive coefficients. Practical Implication: Continuously improve the performance of long-term care hospitals, current quality assessment program are needed to update their system such as adopting indicators measuring the service process, or compensating the cost for quality assessment program. It will enable to provide more reasonable and accurate performance assessment scores.