• Journal of the Korean Association of Geographic Information Studies
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• 제7권2호
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• pp.37-46
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• 2004

In order to decrease the area damaged by forest fires and to prevent the occurrence of forest fires, we are making an effort to improve prevention measures for forest fires. The objective of this study is to classify hazard regions where forest fires occur based on the factors that contribute to the occurrence of forest fires. Forest fire sites in the Uiseong-gun, Gyeongsangbuk-do were surveyed according to the factors of forest type and topographic characteristics where the forest fires occurred. We used a correlation analysis to determine the forest fire occurrence factors and a conditional probability analysis and GIS to determine a forest fire danger index. The resulting forest fire danger index was used in the classification of forest fire occurrence risk regions.

• The Journal of the Korea institute of electronic communication sciences
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• 제12권2호
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• pp.255-260
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• 2017

In Korea, traffic accidents between pedestrians and vehicles in 2015 account for 38.8% of all accidents. This study proposes a system design that can measure the risk of conflict between a vehicle and a pedestrian. Firstly the systemdetect and estimate the position, speed, and directional data of the vehicle and the pedestrian. And then it estimate the conflict point between a vehicle and a pedestrian. The risk of conflict is quantified by estimating the pedestrian safety margin (PSM), which is the time difference between the arrival of the pedestrian at the crossing point to the point of conflict and the vehicle approaching the point. In this system each data is acquired through an external monitoring based evaluation module and an individual wearing module. In the future, such a system can be used for decision making such as the design of road hazard improvement facilities and the designation of the elderly protection area.

• Journal of the Korean Data and Information Science Society
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• 제28권2호
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• pp.349-359
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• 2017

In this paper, we conducted survival analyses by fitting the Cox proportional hazards model to stage III proximal colon cancer data obtained from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute. We investigated the effect of covariates on the hazard function for death from proximal colon cancer in stage III with surgery performed and estimated the survival probability for a patient with specific covariates. We showed that the proportional hazards assumption is satisfied for covariates that were used to analyses, using a test based on the Schoenfeld residuals and plots of the Schoenfeld residuals and $log[-log\{{\hat{S}}(t)\}]$. We evaluated the model calibration and discriminatory accuracy by calibration plot and time-dependent area under the ROC curve, which were calculated using 10-fold cross validation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제22권3호
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• pp.52-58
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• 2008

The importance of. identifying the causes of electrical faults cannot be overstated because of the accidents caused by over-current that take place at the home, the office and electrical facilities due to misuse, poor products and system faults. It is necessary to gather objective, scientific data pertaining to electrical fault investigation in a product liability(PL) environment. To date, no database(DB) has been built concerning the accurate cause analysis of faultyfacilities. In this paper, accident hazard and arc scattering when over-current flows in copper wire was investigated. It was found that when over-current flows in a copper wire, the copper wire became heated and bent and beads were scattered around the wire with a flash. It was determinedthat the fusing current and time was related to the current rise per second. For example, when the current rise per second was largethe fusing current was higher than when the current rise per second was small, and the beads dispersed along a wide area. Fusing time, however, was shorter. The possibility of electrical fault became highest when the fusing current was higher. As the current rise per second is short, the dendrite structure is distributed in the surface of the copper wire. These experimental results can be utilized for a fault process DB system in the investigation and the prevention of electrical faults.

• Korean Journal of Soil Science and Fertilizer
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• 제49권5호
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• pp.584-588
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• 2016

The current study was carried out to investigate total and inorganic arsenic (As) concentrations in 112 rice samples (husked rice and polished rice) grown around the abandoned mining areas and to estimate the potential health risk through dietary intake of rice in Korea. Mean concentrations of total As in husked rice and polished rice were 0.23 and $0.13mg\;kg^{-1}$, respectively. Also, average inorganic As concentrations in husked rice and polished rice were 0.09 and $0.05mg\;kg^{-1}$, respectively. These levels are lower than the standard guideline value ($0.2mg\;kg^{-1}$) for inorganic As in polished rice recommended by Korea Ministry of Food and Drug Safety and Codex. For health risk assessment, the average values of cancer risk probability was $5.7{\times}10^{-5}$ which was less than the acceptable cancer risk of $10^{-6}{\sim}10^{-4}$ for regulatory purpose. Also, hazard quotient values were lower than 1.0. Therefore, these results demonstrated that human exposure to inorganic As through dietary intake of rice collected from abandoned mining areas might not cause adverse health effects.

• Nuclear Engineering and Technology
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• 제47권6호
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• pp.700-711
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• 2015

Sodium-cooled fast breeder reactors use liquid sodium as a moderator and coolant to transfer heat from the reactor core. The main hazard associated with sodium is its rapid reaction with water. Sodium-water reaction (SWR) takes place when water or vapor leak into the sodium side through a crack on a heat-transfer tube in a steam generator. If the SWR continues for some time, the SWR will damage the surface of the defective area, causing it to enlarge. This self-enlargement of the crack is called "self-wastage phenomena." A stepwise numerical evaluation model of the self-wastage phenomena was devised using a computational code of multicomponent multiphase flow involving a sodium-water chemical reaction: sodiumwater reaction analysis physics of interdisciplinary multiphase flow (SERAPHIM). The temperature of gas mixture and the concentration of NaOH at the surface of the tube wall are obtained by a numerical calculation using SERAPHIM. Averaged thermophysical properties are used to assess the local wastage depth at the tube surface. By reflecting the wastage depth to the computational grid, the self-wastage phenomena are evaluated. A two-dimensional benchmark analysis of an SWAT (Sodium-Water reAction Test rig) experiment is carried out to evaluate the feasibility of the numerical model. Numerical results show that the geometry and scale of enlarged cracks show good agreement with the experimental result. Enlarged cracks appear to taper inward to a significantly smaller opening on the inside of the tube wall. The enlarged outer diameter of the crack is 4.72 mm, which shows good agreement with the experimental data (4.96 mm).

• Fire Science and Engineering
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• 제27권4호
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• pp.13-20
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• 2013

Buildings in Korea have been getting higher recently and been being changed environmentally since the Korean fire standard was released in 1968. It should be established to make a appropriate correspondence of fire fighting against the those environmental changes. Most of all, fire water capacity which is basis of fire fighting service is a very significant factor. In this paper, the Korean fire water capacity and fire water duration were compared with China, Japan and the United states. Furthermore, fire water capacity, fire water duration, flow rate were compared by hazard classification, occupant use, number of floor and area with water based fire suppression system. This study has been surveyed to show what are difference, similarity, advantage and disadvantage on fire water capacity in the Korean standard comparing with neighboring countries like China, Japan as well as the United states. This study could be found what level the Korean fire water capacity is. So it suggests about more developed standard on fire water capacity with the result of analysis and comparison.

• Journal of Korea Society of Industrial Information Systems
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• 제5권2호
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• pp.1-8
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• 2000

Manual material handling(MMH)is major factor which causing physical injuries of worker at working area and frequency of low back pain(LBP) is increasing industrial accidents. Especially, working in bad circumstance such as farm, orchard, harbor loading and unloading, logging place and mining place which located in inclined slope can cause much possibility of hazard and absence of working balance can cause injuries of musculoskeletal system such as joint, bone, ligament. So, this study used EMG system to measure and evaluate muscle force information and fatigue of worker when lifting on slope. The result of measuring averaged integrated EMG(AEMG) shows multifidus muscle be used more than anything else in force. neck extensors are used at 15°, 20°frequently. generally the AEMG result shows multifidus muscle be used in force. Commonly, muscle fatigue of multifidus is higher than other muscle by analysis mean power frequency(MPF). The result of load sharing rate shows multifidus and erectorspinae which are deep spinal muscles is relatively high and neck extensor is low.

• Journal of Fashion Business
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• 제24권3호
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• pp.30-39
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• 2020

This study was conducted to identify problems in domestic flame-retardant performance specifications. Currently, the domestic wallcovering anti-inflammatory regulations are not prepared for damage caused by smoke, with the carbonized area as the main function. In particular, given that smoke is the main cause of human casualties and injuries in a fire, it is reasonable that the flame density and toxicity of the wallcovering should also be the main performance indicators. The scope and method of research in this study were as follows. First, a prior study related to fire on various wallcoverings was considered. Second, it raised questions about the effects of smoke in the event of a fire and domestic anti-inflammatory performance tests. Third, textile wallcovering samples were manufactured with viscose rayon for experimental verification of the problems and tested by Korean and EU standards without flame retardant processing to analyze the differences between each regulation. Fourth, the performance of flame retardant wallcovering according to Korean standards was evaluated using smoke density and harmful gas testing methods. The results of each test were as follows. Non-fire retardant wallcovering was rejected by Korea standards. However, B-s1.d0 in Europe. Smoke density testing and harmful gas by domestic combustion processing on the same sample showed that the smoke density increased about 4.3 times more than before, and the harmful gas test showed that the suspension of the post-processing sample slowed earlier than the non-processed sample.

• Journal of Preventive Medicine and Public Health
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• 제49권3호
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• pp.176-182
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• 2016

Objectives: Prospective evaluations of the associations between depressive symptoms and suicide deaths have been mainly performed in high-risk populations, such as individuals with psychiatric disorders or histories of self-harm. The purpose of this study was to prospectively examine whether more severe depressive symptoms assessed using the Geriatric Depression Scale (GDS) were associated with a greater risk of death from suicide in a general-risk population. Methods: A total of 113 478 men from the Korean Veterans Health Study (mean age, 58.9 years) who participated in a postal survey in 2004 were followed up for suicide mortality until 2010. Results: Over 6.4 years of follow-up, 400 men died by suicide (56.7 deaths per 100 000 person-years). More severe depressive symptoms were associated with greater risk of suicide death (p for trend <0.001). The unadjusted hazard ratios (HRs) in comparison to the absence of depression were 2.18 for mild depression, 2.13 for moderate depression, 3.33 for severe depression, and 3.67 for extreme depression. After adjusting for potential confounders, men with a potential depressive disorder had an approximate 90% higher mortality from suicide (adjusted HR, 1.92; 95% confidence interval [CI], 1.38 to 2.68; p<0.001) than men without depression. Each five-point increase in the GDS score was associated with a higher risk of death by suicide (adjusted HR, 1.22; p<0.001). The value of the area under the receiver operating characteristics curve of GDS scores for suicide deaths was 0.61 (95% CI, 0.58 to 0.64). Conclusions: Depressive symptoms assessed using the GDS were found to be a strong independent predictor of future suicide. However, the estimate of relative risk was weaker than would be expected based on retrospective psychological autopsy studies.