• Title/Summary/Keyword: time based risk level

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Analysis on Ampacity of Overhead Transmission Lines Being Operated

  • Yan, Zhijie;Wang, Yanling;Liang, Likai
    • Journal of Information Processing Systems
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    • v.13 no.5
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    • pp.1358-1371
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    • 2017
  • Dynamic thermal rating (DTR) system is an effective method to improve the capacity of existing overhead line. According to the methodology based on CIGRE (International Council on Large Electric systems) standard, ampacity values under steady-state heating balance can be calculated from ambient environmental conditions. In this study, simulation analysis of relations between parameters and ampacity is described as functional dependence, which can provide an effective basis for the design and research of overhead transmission lines. The simulation of ampacity variation in different rating scales is described in this paper, which are determined from real-time meteorological data and conductor state parameters. To test the performance of DTR in different rating scales, capacity improvement and risk level are presented. And the experimental results show that the capacity of transmission line by using DTR has significant improvement, with low probability of risk. The information of this study has an important reference value to the operation management of power grid.

Korean Caries Management by Risk Assessment (K-CAMBRA) (임상가를 위한 특집 1 - 우식위험도평가에 근거한 한국형 치아우식증 관리 모델)

  • Kim, Baek Il
    • The Journal of the Korean dental association
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    • v.52 no.8
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    • pp.456-463
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    • 2014
  • Caries Management by Risk Assessment (CAMBRA), published by California Dental Association in 2003, is a customized caries care system that classifies individuals' caries risk into 4 risk groups based on objective evidences and provides chemical treatments targeted for each caries risk level. However, this system was not only developed but also optimized for situation in the United States, resulting into many limitations to be used in Korea, and thus Korean CAMBRA (K-CAMBRA) that considers the clinical situation in Korea needs to be developed. K-CAMBRA includes various techniques that are newly developed in order to overcome the limitations. First, Q-ray, a new optical technology, is utilized in order to avoid the subjectivity of visual inspection during assessment of disease indicators and risk factors. Moreover, Cariview? that reflects the paradigm shift in cariology as a new form of caries assessment kit is used. In addition, considering the situation in Korea, where it is impossible to use high concentration fluoride product, Oral pack with a customized tray is added to increase the contact time of chemical substance. CAMBRA is believed to be the key clinical tool that overcomes the limitations of the paradigm of the conventional restoration-based surgical model of dentistry. Furthermore, it can be expected that Korean dentists can act as oral physicians who are able to control and care individuals' caries risk rather than operative experts who only care about the outcome of caries.

Safety Management System of Railway Logistics Based on Risk Analysis (리스크분석에 의한 철도물류 운영기관의 안전경영시스템에 관한 연구)

  • Lee, Ik-Seong
    • Journal of Applied Reliability
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    • v.10 no.1
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    • pp.73-91
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    • 2010
  • All activities relate to railway traffic involve risk and that these arise from a combination of the nature of operating activities. Proper management system is required to provide the organizational capability to reveal, analyse and address these weaknesses over time and in reasonably practicable ways, which will determine the rate at which risks can be further reduced. This paper presents a systematic risk analysis approach to safety planning and decision making, informed by a range of risk assessment techniques. An railway organization's safety management system is also presented that shows the approaches taken to minimize the external risks, and identify the shared risks and explain how they will be controlled through collaboration with others.

Validity of the scoring system for traumatic liver injury: a generalized estimating equation analysis

  • Lee, Kangho;Ryu, Dongyeon;Kim, Hohyun;Jeon, Chang Ho;Kim, Jae Hun;Park, Chan Yong;Yeom, Seok Ran
    • Journal of Trauma and Injury
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    • v.35 no.1
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    • pp.25-33
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    • 2022
  • Purpose: The scoring system for traumatic liver injury (SSTLI) was developed in 2015 to predict mortality in patients with polytraumatic liver injury. This study aimed to validate the SSTLI as a prognostic factor in patients with polytrauma and liver injury through a generalized estimating equation analysis. Methods: The medical records of 521 patients with traumatic liver injury from January 2015 to December 2019 were reviewed. The primary outcome variable was in-hospital mortality. All the risk factors were analyzed using multivariate logistic regression analysis. The SSTLI has five clinical measures (age, Injury Severity Score, serum total bilirubin level, prothrombin time, and creatinine level) chosen based on their predictive power. Each measure is scored as 0-1 (age and Injury Severity Score) or 0-3 (serum total bilirubin level, prothrombin time, and creatinine level). The SSTLI score corresponds to the total points for each item (0-11 points). Results: The areas under the curve of the SSTLI to predict mortality on post-traumatic days 0, 1, 3, and 5 were 0.736, 0.783, 0.830, and 0.824, respectively. A very good to excellent positive correlation was observed between the probability of mortality and the SSTLI score (γ=0.997, P<0.001). A value of 5 points was used as the threshold to distinguish low-risk (<5) from high-risk (≥5) patients. Multivariate analysis using the generalized estimating equation in the logistic regression model indicated that the SSTLI score was an independent predictor of mortality (odds ratio, 1.027; 95% confidence interval, 1.018-1.036; P<0.001). Conclusions: The SSTLI was verified to predict mortality in patients with polytrauma and liver injury. A score of ≥5 on the SSTLI indicated a high-risk of post-traumatic mortality.

The Effects of Regular Walking Exercise on Metabolic Syndrome, Cardiovascular Risk Factors, and Depressive Symptoms in the Elderly with Diabetic Mellitus (노인 당뇨병 환자의 규칙적 걷기운동 프로그램이 대사증후군, 심혈관 위험도 및 우울정도에 미치는 효과)

  • Sung, Ki-Wol;Lee, Ji-Hyun
    • Research in Community and Public Health Nursing
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    • v.21 no.4
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    • pp.409-418
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    • 2010
  • Purpose: This study aimed to estimate the effects of a regular walking exercise program on metabolic syndrome, cardiovascular risk factors, and depressive symptoms among the elderly with diabetic mellitus (DM) based on the Theory of Reasoned Action (TRA). Methods: This study has randomized and stratified experimental design with experimental and control groups. We developed a regular walking exercise program suitable for the elderly with DM based on the guidance of AAHPERD. The experimental group participated in the regular walking exercise program, which contains walking exercise 3 times a week and 50 minutes each time for 3 months and education on controlling diet and preventing complications once a week and 20 minutes each time for 4 weeks. Post-test was conducted after 3 months to estimate metabolic syndrome, cardiovascular risk factors, and depressive symptoms. Results: The regular walking exercise program was effective for decreasing the waist size, the level of fasting blood glucose (FBG) and triglyceride (TG), cardiovascular risk factors and the severity of depressive symptoms among the elderly with DM. Conclusion: The incidence of complications would be decreased by applying a regular walking exercise program.

Hydraulic Model for Real Time Forecasting of Inundation Risk (실시간 범람위험도 예측을 위한 수리학적 모형의 개발)

  • Han, Geon-Yeon;Son, In-Ho;Lee, Jae-Yeong
    • Journal of Korea Water Resources Association
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    • v.33 no.3
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    • pp.331-340
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    • 2000
  • This study aims to develop a methodology of real time forecasting of mundation risk based on DAMBRK model and Kalman filter. The model is based on implicit, nonlinear finite difference approximatIons of the one-dimensional dynamic wave equations. The stochastic estimator uses on extended Kalman filter to provide optimal updating estimates. These are accomplished by combining the predictions of the determurustic model with real time observauons modified by the Kalman filter gain ractor. Inundation risks are also estimated by applying Monte Carlo simulation to consider the variability in cross section geometry and Manning's roughness coefficient. The model calibrated by applying to the floods ot South Han River on September, 1990 and August, 1995. The Kalman tilter model indicates that significant improvement compared to deteriministic analysis in flood routing predictions in the river. Overtopping risk of levee is also presented by comparing levee height with simulated flood level. level.

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Dietary and Lifestyle Habits and Dietary Behaviors According to Level of Smartphone Addiction in University Students in Kyungnam Province (경남 일부 대학생들의 스마트폰 중독이 식습관, 생활습관 및 식행동에 미치는 영향)

  • Park, Kyung-Ae
    • Journal of the Korean Dietetic Association
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    • v.23 no.4
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    • pp.408-430
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    • 2017
  • The purpose of this study was performed to investigate dietary and lifestyle habits, dietary behaviors, and food frequency according to the level of smartphone addiction among 408 university students in Kyungnam province. Statistical analyses were performed using the SPSS software package. Based on using the Smartphone Addiction Poneness Scale, 28.4% were potential-risk smartphone users and while 13.2% were high-risk smartphone users. The levels of depression (P<0.05) and stress (P<0.05) and frequency of snacks (P<0.01) were higher in high-risk and potential-risk groups than in the normal group, and meal frequency was highest in the high-risk group (P<0.01). Percentages of using a smartphone at meal time (P<0.01) and snacking while using a smartphone (P<0.01) were higher in potential-risk and high-risk groups than in the normal group. Percentages of skipping meals (P<0.001) and slow eating speed (P<0.01) due to using a smartphone were higher in high-risk and potential-risk groups than in the normal group, and percentages of taste change (P<0.05) were higher in the high-risk group than in the potential-risk and normal groups. Percentages of exercise reduction (P<0.01), body weight increase (P<0.05), sleep disturbance (P<0.001), and increase in stress (P<0.01) due to using a smartphone were higher in the high-risk group than in the normal group. Scores of dietary behaviors avoiding salty food (P<0.01) and excessive drinking (P<0.001) were higher in the high-risk group than in the normal group. Scores for frequency of oil or nuts (P<0.05) and fatty meats (P<0.01) were highest in the high-risk group. Our results suggest that effective nutrition education programs are needed to solve unhealthy dietary and lifestyle habits from high-risk smartphone users in university students.

Benzene and Leukemia: The 0.1 ppm ACGIH Proposed Threshold Limit Value for Benzene

  • Infante Peter F.
    • 대한예방의학회:학술대회논문집
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    • 1994.02a
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    • pp.681-691
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    • 1994
  • The American Conference of Governmental Industrial Hygienists (ACGIH) has proposed a threshold limit value (TLV) for benzene of 0.1 ppm. Individuals representing the American Petroleum Institute (API)and the Chemical Manufacturers Association (CMA) have argued that 1) the risk assessment by Rinsky .et al. which ACGIH partially relied upon for its proposed TLV overestimates the risk; however, at the exposures levels of interest - (e.g., 0.1 to 1.0 ppm) for establishing a benzene TLV, the Rinsky et al. assessment provides lower estimates of leukemia risk than most others; 2) ACGIH should not use the Dow study for direct observational evidence of leukemia risk associated with low-level benzene exposure because of confounding exposure; however, it is unlikely that confounding exposures played a role in the excess of leukemia demonstrated in the study, and the Dow cohort was exposed to an average benzene concentration of about 5.5 ppm benzene for 7.11 years (31:1.5 ppm-years), while some of the individuals in the study who died from leukemia were exposed to an average of only 1.0 ppm without the opportunity for highpeak exposures; 3) the Occupational Safety and Health Administration (OSHA) established an 8-hour time-weighted average (TWA) of 1.0 ppm in 1987, and there is no new evidence that would justify reducing the TWA below that level; however, the OSHA TWA of 1.0 ppm was based on economic feasibility and the level of excess risk remaining at 1.0 ppm, i.e., 10 excess leukemia deaths per 1000 workers over an occupational lifetime (45 years) according to OSHA's preferred estimate leaves behind I risk considered significant by OSHA. In addition, chromosomal studies among workers and in animals exposed to benzene indicate that low-level exposure, i.e., 1.0 ppm, is associated with elevated Cytogenetic damage. On the basis of adverse health effects data alone, in this author's opinion, it would be poor science and poor public health policy to establish a benzene TLV greater than 0.1 ppm.

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A Method for Determining the Peak Level of Risk in Root Industry Work Environment using Machine Learning (기계학습을 이용한 뿌리산업 작업 환경 위험도 피크레벨 결정방법)

  • Sang-Min Lee;Jun-Yeong Kim;Suk-Chan Kang;Kyung-Jun Kim
    • The Journal of the Korea institute of electronic communication sciences
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    • v.19 no.1
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    • pp.127-136
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    • 2024
  • Because the hazardous working environments and high labor intensity of the root industry can potentially impact the health of workers, current regulations have focused on measuring and controlling environmental factors, on a semi-annual basis. However, there is a lack of quantitative criteria addressing workers' health conditions other than the physical work environment. This gap makes it challenging to prevent occupational diseases resulting from continuous exposure to harmful substances below regulatory thresholds. Therefore, this paper proposes a machine learning-based method for determining the peak level of risk in root industry work environments and enables real-time safety assessment in workplaces utilizing this approach.

Expression of Enterotoxin Genes in Staphylococcus aureus Isolates Based on mRNA Analysis

  • Lee, Young-Duck;Moon, Bo-Youn;Park, Jong-Hyun;Chang, Hyo-Ihl;Kim, Wang-June
    • Journal of Microbiology and Biotechnology
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    • v.17 no.3
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    • pp.461-467
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    • 2007
  • Staphylococcus aureus strains are important foodborne pathogens that produce various toxins. To evaluate the risk of the enterotoxins, four S. aureus strains from kimbap and two clinical samples were isolated and identified, and their expression of the enterotoxin genes were analyzed using a reverse transcription real-time PCR. Various enterotoxin genes were detected, including sea, seg, seh, sei, sen, seo, and sem, where each isolate contained one or two. When the mRNA detection of the enterotoxin genes was analyzed using a reverse transcriptase PCR, various levels of expression were found depending on the species and enterotoxin gene. Therefore, it is reasonable to suggest that the poisoning risk of S. aureus can be effectively evaluated based on the gene expression at the mRNA level.