• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.939-944
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• 2002

PD phenomena can be regarded as a deterministic dynamical process where PD should be occurred if the local electric field be reached to be sufficiently high. And thus, its mathematical model can be described by either difference equations or differential equations using several state variables obtained from the time sequential measured data of PD signals. These variables can provide rich and complex behavior of detectable time series, for which Chaos theory can be employed. In this respect, a new PD pattern recognition method is proposed and named as 'Chaotic Analysis of Partial Discharges (CAPD)' for this work. For this purpose, six types of specimen are designed and made as the models of the possible defects that may cause sudden failures of the underground power transmission cables under service, and partial discharge signals, generated from those samples, are detected and then analyzed by means of CAPD. Throughout the work, qualitative and quantitative properties related to the PD signals from different defects are analyzed by use of attractor in phase space, information dimensions ($D_0$ and D2), Lyapunov exponents and K-S entropy as well. Based on these results, it could be pointed out that the nature of defect seems to be identified more distinctively when the CAPD is combined with traditional statistical method such as PRPDA. Furthermore, the relationship between PD magnitude and the occurrence timing is investigated with a view to simulating PD phenomena.

• Journal of the Korea Safety Management & Science
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• v.12 no.1
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• pp.59-62
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• 2010

At the present time, Musculo-Skeletal Disorders breaks out and it is increased in a high speed. It is a serious problem for the labors and managements. People becoming greatly interested in it. It is caused by the labor intensity which is according to the work form, hours of labor, and the labors and the labor unions have a correct understanding in it, and the labor powers becoming older, and the change of divisional social environment which is latent. Before working do the simple preparation gymnastics or operate insensitive exercise remedy without scientific verification only in the present circumstances. Although operate the Work-related Musculo-Skeletal Disorders exercise remedy, it can not get a sufficient effectiveness. So the study develop one type of exercise remedy which are divided the upper limbs exercise remedy, the trunk exercise remedy, the lower limbs exercise remedy. It can be done without using any exercise equipments and regardless places. We should also enable the exercise remedy to be easily applied to workers who are in different circumstances. To use EMG to measure the burden of exercise remedy. By doing so, employees can easily do exercises and it will help to prevent and even can treat MSD. It is just the objective of the research.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.1024-1033
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• 1997

The past several years have witnessed an ever-increasing acceptance and adoption of parallel processing, both for high performance scientific computing as well as for more general purpose applications. Furthermore with increasing needs to perform the complex flow calculations in an efficient manner, the use of the message passing model on distributed networks has emerged as an important alternative to the expensive supercomputers. This work attempts to provide a generic framework to enable the parallelization of all CFD-related works using the master-slave model. This framework consists of (1) input geometry, (2) domain decomposition, (3) grid generation, (4) flow computations, (5) flow visualization, and (6) output display as the sequential components, but performs computations for (2) to (5) in parallel on the workstation clustering. The flow computations are parallized by having multiple copies of the flow-code to solve a PDE on different spatial regions on different processors, while their flow data are exchanged across the region boundaries, and the solution is time-stepped. The Parallel Virtual Machine (PVM) is used for distributed communication in this work.

• Korean Journal of Adult Nursing
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• v.24 no.6
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• pp.627-634
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• 2012

Purpose: The purpose of this study was to identify registered nurses learning needs about physical assessment. Specifically, what are the perceived competency, frequency of skill use and the unmet training needs. Methods: The study was an exploratory survey study. The sample was 104 registered nurses. Data were collected through three instruments: The Perceived Competency in Physical Assessment Scale, the Frequency of Physical Assessment Scale, and the Training Needs of Physical Assessment Scale which incorporated 30 core Physical Assessment skills. Descriptive statistics, t-test, and Pearson's correlation coefficient were used to analyze the data. Results: Auscultation of heart and lung sounds and inspection of the spine were rated by the subjects as physical assessment skills they feel least competent and also were less frequently performed. The most competent area for physical assessment was neurological system. The respiratory and abdominal system was identified as two systems that more education would be needed. Nurses with less than one year of working experience reported needing more training. Nurses with more than five years of clinical work experience performed physical assessment more frequently than nurses with less than five year of work experience. The perceived competency was positively related to the frequency of physical assessment. Conclusion: Continuing education is necessary to further train registered nurses regarding physical assessment skills and the program needs to be focused on the area which nurses are less competent for and have high training need.

• Environmental Analysis Health and Toxicology
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• v.19 no.1
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• pp.1-24
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• 2004

Since dioxins became a serious concern in Korea, a significant number of investigations have been conducted to address diverse issues related to dioxins. However, the results have not been organized for ready access and use. The principal purposes of the work were to ⅰ) provide an archive of dioxin researches in Korea and ⅱ) give an overview of dioxin contamination. The focus of this work was placed on the contamination levels and characteristics concerning the waste incinerators emissions, environmental media, and biological samples(fishes/shellfishes, foods, and human body). Principal component analysis was conducted to identify common and/or unique features and the important variables associated with the congener patterns. From a comprehensive search of academic journals, research and monitoring project reports, dissertations, and periodicals of other forms, a total of 115 counts were found that met the purposes of this study. The contamination levels of various samples were summarized and compared to those reported in foreign literatures. The congener patterns varied largely with environmental media and distinguished particularly by OCDD, 1,2,3,4,6,7,8-HpCDF, and OCDF for the samples within the same media. The proximity to emission sources differentiated the congener patterns in air and soil samples by the fraction of OCDD.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.5
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• pp.487-496
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• 2020

This study introduces how GISs (Geographic Information Systems) are used to assess spatial disparities in urban green spaces in the Chicago. Green spaces provide us with a variety of benefits, namely environmental, economic, and physical benefits. This study seeks to explore socioeconomic relationships between green spaces and their surrounding communities and to evaluate spatial disparities from a variety of perspectives, such as health-related, socioeconomic, and physical environment factors. To achieve this goal, this study used spatial statistics, such as optimized hotspot analysis, network analysis, and space-time cluster analysis, which enable conclusions to be drawn from the geographic data. In particular, 12 variables within the three factors are used to assess spatial disparities in the benefits of the use of green spaces. Finally, the variables are standardized to rank the community areas and identify where the most vulnerable community areas or parks are. To evaluate the benefits given to the community areas, this study used the z- and composite scores, which are compared in the three different combinations. After identifying the most vulnerable community area, crime data is used to spatially understand when and where crimes occur near the parks selected. This work contributes to the work of urban planners who need to spatially evaluate community areas in considering the benefits of the uses of green spaces.

• Safety and Health at Work
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• v.2 no.4
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• pp.375-379
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• 2011

Control Banding (CB) strategies to prevent work-related illness and injury for 2.5 billion workers without access to health and safety professionals has grown exponentially this last decade. CB originates from the pharmaceutical industry to control active pharmaceutical ingredients without a complete toxicological basis and therefore no occupational exposure limits. CB applications have broadened into chemicals in general - including new emerging risks like nanomaterials and recently into ergonomics and injury prevention. CB is an action-oriented qualitative risk assessment strategy offering solutions and control measures to users through "toolkits". Chemical CB toolkits are user-friendly approaches used to achieve workplace controls in the absence of firm toxicological and quantitative exposure information. The model (technical) validation of these toolkits is well described, however firm operational analyses (implementation aspects) are lacking. Consequentially, it is often not known if toolkit use leads to successful interventions at individual workplaces. This might lead to virtual safe workplaces without knowing if workers are truly protected. Upcoming international strategies from the World Health Organization Collaborating Centers request assistance in developing and evaluating action-oriented procedures for workplace risk assessment and control. It is expected that to fulfill this strategy's goals, CB approaches will continue its important growth in protecting workers.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.1
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• pp.1-10
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• 2019

Naval ship design and related other activities can be characterized by the complexity of the interactions among products, activities, and disciplines. Such complexities often result in inferior designs, cost overrun, and late-delivery. Hence there exist tremendous interests in both improving the design process itself and optimizing the interactions among design activities. This paper looks at the complexity of designing naval ships thereby leading to the innovation of current ship design practices using design structure matrix. It can be used to induce the optimal ordering of design activities as well as identify sources of complexities. The method presented here identifies coupled design activities useful for reducing the complexity of naval ship design as well as optimally reordering design activities. This paper recommends the use of design structure matrix method suitable for numerically optimizing the concept design process of naval ship, and reducing cost and time required in designing naval ships by modeling and analyzing the design activities and engineering tasks, defined in systems engineering planning documents.

• Safety and Health at Work
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• v.10 no.2
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• pp.188-195
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• 2019

Background: Mine workers in South Africa face challenges relating to poor health and safety, including fatigue risks, and poor socioeconomic and living conditions. Fatigue results in impaired mental and physical performance. The aim of this study was to assess contributors to fatigue of mine workers in South Africa. Methods: Data collection took place at four gold mines and one platinum mine in South Africa. A total of 21 focus groups were held with individuals in management, union representatives, and mine workers, and 564 questionnaires were completed by mine workers to gather information about fatigue and potential contributors to fatigue at these mines. Results: Qualitatively (through focus groups), fatigue was attributed to extended working hours, harsh working conditions, high workloads, production pressure, and resource constraints, along with aspects relating to demographic and socioeconomic factors, living conditions, lifestyle, health, and wellness. Greater fatigue was significantly associated with younger age, indebtedness, a lack of exercise, poor nutrition, less sleep, increased alcohol use, poor self-reported health, more sick leave, higher stress, and lower job satisfaction. Conclusion: The aim of the study was achieved; numerous work-, sociodemographic-, lifestyle-, and wellness-related factors were linked to fatigue in the participating mine workers. Contributors to fatigue should be addressed to improve health, safety, and sustainability in the industry.

• Journal of Korean Biological Nursing Science
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• v.21 no.1
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• pp.37-45
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• 2019

Purpose: This descriptive research was on hand dermatitis in clinical nurses. Nurses often have a high rate of hand dermatitis with several factors associated with the dermatitis. The factors analyzed in this study included; general characteristics, work-related factors, hand washing, and allergies relate to hand dermatitis. Methods: Data were collected from April to May 2016. The subjects were nurses who had worked 12 months or more in a University Hospital. They voluntarily gave their consent for the research. The Symptombased questionnaires were sent to 220 nurses and 199 responses were returned. Collected data were analyzed using frequency, percentage, mean, standard deviation, ${\chi}^2-test$, and logistic regression analysis using SPSS 23.0. Results: Prevalence of dermatitis in nurses was 48.2%. Nurses who had worked for over three years were twice more likely to suffer hand dermatitis than nurses who had worked for 3 years or less (adjusted odds ratio [adj. OR]= 1.97, p= .036). Nurses who used alcohol sponge swabs more than 20 times per shift were 2.5 times more likely to suffer hand dermatitis as compared to those who used them less times (adj. OR = 2.51, p= .023). Conclusion: Results revealed that about a half of the clinical nurses suffered from hand dermatitis, hence it is crucial to find appropriate interventions for dermatitis prevention. This concern needs to be addressed especially in nurses who have more work experience and use more alcohol sponge swabs.