• Transactions on Electrical and Electronic Materials
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• v.7 no.6
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• pp.313-318
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• 2006

This paper introduces a partial discharge (PD) severity metric, S, based on the evaluation of time-sequence PD data capture and resulting Time-Sequence-Analysis Discharge (TSAD) level distributions. Basically based on an IEC60270 measurement technique, each PD event is time stamped and the discharge level noted. By evaluating the time differences between a previous and subsequent discharge, a 3D plot of time-sequence activity and discharge levels can be produced. From these parameters a measurement of severity, which takes into account dynamic or instantaneous variations in both the time of occurrence and the level of discharge, rather than using standard repetition rate techniques, can be formulated. The idea is to provide a measure of the severity of PD activity for potentially measuring the state of insulation within an item of plant. This severity measure is evaluated for a simple point-plane geometry in $SF_{6}$ as a function of gap distance and applied high voltage. The results show that as the partial discharge activity increases, the severity measure also increases. The importance of future investigations, quantifications and evaluations of the robustness, sensitivity and importance of such a severity measurement, as well as comparing it with typical repetition rate assessment techniques, and other monitoring techniques, are also very briefly discussed.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.62-69
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• 2019

Korean shipbuilding companies have taken many efforts for safety over the years by developing Health, Safety & Environment (HSE) Management Systems, Procedures, Training, and studying Programs for prevention of incidents. As a result, the shipbuilding industry has succeeded in reducing overall injury rates. Nevertheless, the industry also noticed that incident rates are still not at zero and more importantly, serious injuries and fatalities are still occurring. One factor that may be attributing to this is the lack of managing potential severity during incident investigations, most incident investigations are implemented based on the actual result. Generally, each shipbuilding company develops their customized incident investigation programs and these are also commonly being focused on actual result. This study aimed to develop a shift in strategy toward safety to classify the criteria of potential severity from any incidents and manage that to prevent any recurrence or causing any serious injuries or fatalities in the shipbuilding industry. Several global energy companies have already developed potential severity management tools and applied them in their incident investigations. In order to verify the necessity of improvement for current systems, a case study and comparative analysis between a domestic shipbuilding company and several global energy companies from foreign countries was implemented and comparison of two incident investigation cases from specific offshore projects was conducted to measure the value of a potential severity system. Also, a checklist was established from the data of fatalities and serious injuries in recent 5 years that occurred in Korea shipbuilding industry and a proposal to verify high potential incidents in the incident investigation process and comparative analysis between the assessment by appling proposed checklist and the assessment from a global energy company by using their own system was implemented. As a measure to prevent any incidents, it is required to focus on potential severity assessment during the incident investigation rather than to only control actual result. Hence, this study aims to propose a realistic plan which enables to improve the existing practices of incident investigation and control in the shipbuilding industry.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.3
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• pp.9-15
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• 2011

This study analyzed contributing factors affecting leg injury severity in pedestrian-vehicle crashes. A Binary Logistic Regression (BLR) method was used to identify the factors. Independent variables include characteristics for pedestrian, vehicle, road, and environmental conditions. The leg injury severity is classified into two classes, which are dependent variables in this study, such as 'severe' and 'minor' injuries. Pedestrian age, collision speed, and the height of vehicle were identified as significant factors for the leg injury. The probabilistic outcome of predicting leg injury severity can be effectively used in not only deriving pedestrian-related safety policies but also developing advanced vehicular technologies for pedestrian protection.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.151-156
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• 2012

Objective: In 2010, the rate of injuries and illnesses in the shipbuilding industry was 1.20, about 1.74 times higher than the average of overall industries(0.69). Musculoskeletal disorders(MSDs) became a major problem since 2000 in shipbuilding industry. The purpose of this study was to provide efficient implementation management through evaluating the economic effectiveness of the Musculoskeletal Disorders Prevention Program(MDPP). Successfully implementing the MDPP in the workplace may decrease the risk of MSDs and therefore reduce MSDs related costs. Methods: Occupational accident index (frequency rate, severity rate, and frequency severity indicator), estimated direct costs, and total occupational accident occurrence rate were provided by analysis of MSDs, statistical analysis of MDPP decreed companies, and data analysis of implementation. Results: The study shows the number of MSDs for MDPP decreed companies decreased 76.2% from 2,319 in 2004 to 551 in 2008. Above all, the number of MSDs decreased 78.7% in Shipbuilding industries. Forty companies (85.1%) showed a decreasing tendency and 27.7% of those had an $R^2$ > 0.7. Similar results were found in severity rate and frequency severity indicator. From these results, it appears there are a number of advantages in implementing the MDPP. Conclusion: MDPP effectiveness was demonstrated by analysing implementation and occupational accident index. A more effective and efficient implementation would take into account business sector, size, policy, and organization of the company.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.3
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• pp.69-76
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• 2018

General workers who assist various technicians in different fields with their work across the whole construction sites without having a particular skill are at risk of the highest accident rate and their accident form becomes varied. Accordingly, this study was conducted to identify the relationship between form of safety accident and influence factor in general workers and analyze accident severity by influence factor. The followings are the results from this study. First, as a result of analyzing major form of accident and influence factors in general workers with network analysis methodology, nine forms of accident and seventeen influence factors were drawn. Second, it was found that in accident severity among general workers, collapsing, among various forms of accident, appeared the highest, followed by fall, electric shock, fire, hit by an object, bumped against, trip, scission getting cut chopped in order. Third, main points of special, concentrated, and permanent management were presented in order to reduce the safety accident in general workers effectively.

• Korean Journal of Biological Psychiatry
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• v.16 no.2
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• pp.69-75
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• 2009

Objectives : The detrended fluctuation analysis is one of the nonlinear methods for the investigation of biological time series. It quantifies the fractal scaling properties and is known to be useful in the evaluation of long-range correlations in time series. The heart rate variability(HRV) of obstructive sleep apnea syndrome (OSAS) patients during nighttime was analyzed by detrended fluctuation analysis to assess its relationship with the severity of the symptoms. Methods : Fifty nine untreated male OSAS patients with moderate to severe symptoms(mean age=45.4${\pm}$11.7 years, apnea-hypopnea index, AHI${\geq}$15) underwent nocturnal polysomnography. Moderate(AHI=15-30, N=22) and severe(AHI>30, N=37) OSAS patients were compared for the indices derived from detrended fluctuation analysis and frequency domain analysis of HRV. Results : In the detrended fluctuation analysis, the alpha values were 0.75${\pm}$0.11 and 0.82${\pm}$0.07 for the severe and the moderate OSAS groups respectively. The difference was significant(p<.01). The alpha value had negative correlation with AHI(r=-.425, p=.001). Negative correlation coefficients were also found in the relationships between the alpha values and very low frequency(VLF)(r=-.425, p=.001), low frequency(LF)(r=-.633, p= <.001) and the LF/HF ratio(r=-.305, p=.019) respectively. LF/HF ratio(p=.005) was higher in the severe OSAS group compared to that of the moderate OSAS group. Conclusion : In this study, the detrended fluctuation analysis showed the significant difference between the two OSAS groups classified according to their severity of symptoms. The scaling exponent showed the negative correlation with AHI and indicies of frequency domain analysis. This result suggests that detrended fluctuation analysis can be helpful to estimate the severity of OSAS.

• Journal of Korean Society for Quality Management
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• v.44 no.2
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• pp.373-388
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• 2016

Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.

• Child Health Nursing Research
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• v.13 no.2
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• pp.136-146
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• 2007

Purpose: The purpose of this study was to develop a tool to assess the severity of illness in high risk newborns. Method: The research design was a methodological study. The tool was developed in 4 stages: first, preliminary items were developed based on a questionnaire about the severity of illness index that was given to 8 health professionals in Neonatal Intensity Care Units (NICU) second, a panel of specialists reduced the preliminary items using 3 validity tests; third, final items were selected from the results of a pre-test. Finally, from July 2005 to May 2006, reliability and validity were tested with a sample of 160 high risk newborns admitted to the NICU. Results: The final tool to identify the severity of illness index in high risk newborns consisted 39 items and Cronbach's alpha coefficient for internal consistency was .922. Using factor analysis, 4 factors were extracted and these factors explained 54.451% of the total variance. Conclusion: The instrument for assessing the severity of illness in high risk newborns developed in this study was identified as a tool with a high degree of reliability and validity. In this sense, this tool can be effectively utilized for assessing and implementing care for high risk newborns.

• Safety and Health at Work
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• v.15 no.2
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• pp.200-207
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• 2024

Background: Workers are often exposed to hazardous heat due to their work environment, leading to various injuries. As a result of climate change, heat-related injuries (HRIs) are becoming more problematic. This study aims to identify critical contributing factors to the severity of occupational HRIs. Methods: This study analyzed historical injury reports from the Occupational Safety and Health Administration (OSHA). Contributing factors to the severity of HRIs were identified using text mining and model-free machine learning methods. The Multinomial Logit Model (MNL) was applied to explore the relationship between impact factors and the severity of HRIs. Results: The results indicated a higher risk of fatal HRIs among middle-aged, older, and male workers, particularly in the construction, service, manufacturing, and agriculture industries. In addition, a higher heat index, collapses, heart attacks, and fall accidents increased the severity of HRIs, while symptoms such as dehydration, dizziness, cramps, faintness, and vomiting reduced the likelihood of fatal HRIs. Conclusions: The severity of HRIs was significantly influenced by factors like workers' age, gender, industry type, heat index , symptoms, and secondary injuries. The findings underscore the need for tailored preventive strategies and training across different worker groups to mitigate HRIs risks.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.3
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• pp.391-398
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• 2019

In general, truck-involved crashes increase severity in terms of both injury level and crash impact level. Recently, although the frequency and fatality of truck-involved crashes in Korea are rising, their associative studies are very limited. Therefore, the objective of this study is to identify critical factors influencing on injury severity of truck-involved crashes on Korean freeway system. To carry out this objective, this study uses an ordered probit model (OPM) based on a 6-year crash dataset from 2012 to 2017. From the analysis, eight variables were found to have a great effect on injury severity: older driver, crash speed, rear-end collision, number of vehicles involved, drowsy driving, nighttime (0:00 to 6:00) driving, overturn or rollover, and vehicle's fire after crash. However, injury severity was less severe in crashes under snowy condition and crashes to traffic facilities (i.e., crash alone).