• 무역상무연구
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• 제15권
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• pp.137-165
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• 2001

The study on the duration of risk in the marine insurance has been paid a great attention because the marine insurance has to provide several indemnity conditions including the one to be compensated the loss when the accident happens. The research examines as to how the duration of risk has been extended from the beginning period to now. The results show the duration of risk has been continually extended in terms of place and time by a dramatic change of environment related to the marine insurance including marine transportation, a variety of goods, development of marine communication, many different trading conditions, etc, and requirement of the assured. The validity of the duration of risk is effected when the ship leaves at the port and is terminated when the ship arrives at the final destination. It in the Lloyd's age has been started when the products was charged to the ship and terminated when the one was safely discharged to the destination. Recently, the duration of risk in England Marine Insurance attaches from the time the goods leave the warehouse or place of storage at the placed named for the commencement of the transit, continues during the ordinary course of transit and terminates on delivery to the consignees or other final warehouse or place of storage at the destination named. Further research on the extension of the duration of risk must be conducted according to the being large scale of the ship and goods.

• Journal of Preventive Medicine and Public Health
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• 제47권3호
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• pp.150-157
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• 2014

Objectives: The decrease or increase in sleep duration has recently been recognized as a risk factor for several diseases, including hypertension and obesity. Many studies have explored the relationship of decreased sleep durations and injuries, but few have examined the relationship between increased sleep duration and injury. The objective of this research is to identify the risk for injury associated with both decreased and increased sleep durations. Methods: Data from the 2010 Community Health Survey were used in this study. We conducted logistic regression with average sleep duration as the independent variable, injury as a dependent variable, and controlling for age, sex, occupation, education, region (cities and provinces), smoking, alcohol use, body mass index, hypertension, diabetes, arthritis, and depression. Seven categories of sleep duration were established: ${\leq}4$, 5, 6, 7, 8, 9, and ${\geq}10$ hours. Results: Using 7 hours of sleep as the reference, the adjusted injury risk (odds ratio) for those sleeping a total of ${\leq}4$ h/d was 1.53; 1.28 for 5 hours, for 1.11 for 6 hours, 0.98 for 8 hours, 1.12 for 9 hours, and 1.48 for ${\geq}10$ hours. The difference in risk was statistically significant for each category except for the 8 and 9 hours. In this study, risk increased as the sleep duration decreased or increased, except for the 8 and 9 hours. Conclusions: This research found that either a decrease or increase in sleep duration was associated with an increased risk for injury. The concept of proper sleep duration can be evaluated by its associated injury risk.

• 국제학술발표논문집
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• The 5th International Conference on Construction Engineering and Project Management
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• pp.397-402
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• 2013

In super-tall building construction projects, schedule risk factors which vertically change and are not found in the low and middle-rise building construction influence duration of a project by vertical attribute; and it makes hard to estimate activity or overall duration of a construction project. However, the existing duration estimating methods, that are based on quantity and productivity assuming activities of the same work item have the same risk and duration regardless of operation space, are not able to consider the schedule risk factors which change by the altitude of operation space. Therefore, in order to advance accuracy of duration estimation of super-tall building projects, the degree of changes of these risk factors according to altitude should be analyzed and incorporated into a duration estimating method. This research proposes a simulation model using Monte Carlo method for estimating activity duration incorporating schedule risk factors by weather conditions in a super-tall building. The research process is as follows. Firstly, the schedule risk factors in super-tall building are identified through literature and expert reviews, and occurrence of non-working days at high altitude by weather condition is identified as one of the critical schedule risk factors. Secondly, a calculating method of the vertical distributions of the weather factors such as temperature and wind speed is analyzed through literature reviews. Then, a probability distribution of the weather factors is developed using the weather database of the past decade. Thirdly, a simulation model and algorithms for estimating non-working days and duration of each activity is developed using Monte-Carlo method. Finally, sensitivity analysis and a case study are carried out for the validation of the proposed model.

• 한국경영과학회지
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• 제30권3호
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• pp.137-149
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• 2005

This study proposes a framework enhancing the accuracy of estimation for project duration by combining linear Bayesian updating scheme with the learning curve effect. Activities in a particular project might share resources in various forms and might be affected by risk factors such as weather Statistical dependence stemming from such resource or risk sharing might help us learn about the duration of upcoming activities in the Bayesian model. We illustrate, using a Monte Carlo simulation, that for partially repetitive projects a higher degree of statistical dependence among activity duration results in more variation in estimating the project duration in total, although more accurate forecasting Is achievable for the duration of an individual activity.

• 성인간호학회지
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• 제26권3호
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• pp.372-381
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• 2014

Purpose: This study investigated the prevalence of hypertension, explored sleep duration, and examined the related factors to hypertension in Korean middle-aged adults. Methods: Using raw data from the Korean National Health and Nutritional Examination Survey (KNHANES) conducted from 2008 to 2010, a secondary analysis was performed with data from 13,230 adults aged 30~64 years. ${\chi}^2$-test and multiple logistic regressions was used for the data analysis. Results: The prevalence of hypertension among Korean middle-aged adults was 21.8% and 40.3% among participants reported that their average sleep duration was below six hours a night. Risk factors for hypertension include: female (the odds ratio (OR) 1.66 for male), 50~64 years age group (OR 3.66 for 30~49 years age group), education level of elementary school (OR 1.84 for university level), low household income (OR 1.27 for upper), obesity (OR 2.41), high risk drinking (OR 1.64), and sleep duration${\leq}6$ hrs (OR 1.16 for 8 hrs of sleep). Conclusion: High risk population of hypertension could be male, aged, low education, and low income. Obesity, high risk drinking, and short sleep duration should be considered as risk factors for hypertension. Interventions for obesity management, adequate alcohol drinking and sleep duration could be considered for preventing hypertension.

• Earthquakes and Structures
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• 제14권6호
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• pp.577-587
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• 2018

The quantitative assessment of the seismic collapse risk of a structure requires the usage of an optimal intensity measure (IM) which can adequately characterise the severity of the ground motion. Research suggests that the average spectral acceleration ($Sa_{avg}$) may be an efficient and sufficient alternate IM as compared to the more traditional first mode spectral acceleration, $Sa(T_1)$, particularly during seismic collapse risk estimation. This study primarily presents a comparative evaluation of the sufficiency of the average spectral acceleration with respect to ground motion duration, and secondarily assesses the impact of ground motion duration on collapse risk estimation. By assembling a suite of 100 historical ground motions, incremental dynamic analysis of 60 different inelastic single-degree-of-freedom (SDF) oscillators with varying periods and ductility capacities were analysed, and collapse risk estimates obtained. Linear regression models are used to comparatively quantify the sufficiency of $Sa_{avg}$ and $Sa(T_1)$ using four significant duration metrics. Results suggests that an improved sufficiency may exist for $Sa_{avg}$ when the period of the SDF system increases, particularly beyond 0.5, as compare to $Sa(T_1)$. In reference to the ground motion duration measures, results indicated that the sufficiency of $Sa_{avg}$ is more sensitive to significant duration definitions that consider almost the full wave train of an accelerogram ($SD_{a5-95}$ and $SD_{v5-95}$). In order to obtain a reduced variability of the collapse risk estimate, the 5-95% significant duration metric defined using the Arias integral ($SD_{a5-95}$) should be used for seismic collapse risk estimation in conjunction with $Sa_{avg}$.

• 대한불안의학회지
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• 제14권1호
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• pp.21-27
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• 2018

Objective : The purpose of this study was to examine the relationship between self-reported sleep duration and depression or suicidal ideation in Korean adolescents. Methods : The data obtained from the 11th Korea Youth Risk Behavior Web-Based Survey (KYRBWS) were analysed. 68,043 students from 797 schools participated in this nationwide survey. Results : 53.7% of male students and 68.4% of female students had reported that a weekday sleeping duration of less than 6 hours. When the depression and suicidal ideation were analyzed by age, the odds ratio was higher in middle-school students than in high-school students. Both male and female students showed a higher risk of depression and suicidal ideation when sleeping duration was less than 5 hours and the risk was slightly higher in boys than in girls. Conclusion : Insufficient sleep duration in Korean adolescents increases depression and suicidal ideation, and these results differ according to age and gender.

• 지역사회간호학회지
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• 제26권2호
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• pp.100-107
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• 2015

Purpose: To explore the association between sleep and the risk of accidental injury at school among Korean adolescents. Methods: From the database of the Ninth Korea Youth Risk Behavior Web-based Survey (KYRBS), the researcher selected 63,307 adolescents who responded to a survey on sleep hours. We conducted logistic regression with sleep duration and fatigue after sleep as independent variables, the risk of injury at school as a dependent variable, and gender, grade, school type, economic status, parents' education level, number of participations in physical education, and current smoking and drinking as control variables. Results: Using 9 hours of sleep as the reference, the adjusted injury risk (odds ratio) was 1.74 for those sleeping less than 5 hours a day, 1.61 for 5 hours, 1.45 for 6 hours, 1.31 for 7 hours, 1.13 for 8 hours, and 1.40 for 10 hours or longer. The difference between each pair of groups was statistically significant. In this study, injury risk increased as sleep duration decreased and fatigue after sleep increased. Conclusion: The findings suggest that a short nightly duration of sleep and fatigue after sleep can be considered potential risk factorsfor unintentional injuries at school among Korean adolescents.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.577-581
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• 2009

The fixed duration test has been widely used in the reliability demonstration test for rolling stocks. This article deals with how to design the test statistics, acceptance criteria and the fixed duration of the MTBF(Mean Time Between Failures) demonstration test considering the consumer risk. Numerical examples are given to illustrate the dependence of the consumer risk on the test duration and MTBF requirement.

• 대한수의학회지
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• 제59권1호
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• pp.25-31
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• 2019

The aim of this study was to determine predictive risk factors implicated in complications in dogs with esophageal foreign bodies. Medical records of 72 dogs diagnosed with esophageal foreign bodies by endoscopy were reviewed retrospectively. Factors analyzed included age; breed; gender; body weight, location, dimension, and type of foreign body; and duration of impaction. To identify risk factors associated with complications after foreign body ingestion, categorical variables were analyzed using the chisquare or Fisher's exact tests and multivariate analysis, as appropriate. Complications secondary to esophageal foreign body ingestion included megaesophagus, esophagitis, perforation, laceration, diverticulum, and pleuritis. Univariate analysis revealed that the location and duration of impaction after foreign body ingestion were associated with an increased risk of esophageal laceration and perforation. Multivariate analysis showed that age, duration of impaction, and foreign body dimension were significant independent risk factors associated with the development of complications in dogs with esophageal foreign bodies. In conclusion, these results showed that longer duration of impaction and larger foreign body dimensions may increase the risks of esophageal laceration, perforation, and plueritis in dogs.