• Journal of the Korean Society of Safety
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• v.31 no.6
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• pp.84-92
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• 2016

Since the mankind started its space mission, the number of artificial space objects has been increasing exponentially. It contains not just the space machines which are in use but the machines which are out of order. Meantime, those dead machines are being a serious danger, a real threat to human's lives and property because of it could re-enter into the earth's atmosphere and fall to the ground causing mega-disaster. As the number of space activities gets growing so far, the re-entry of the space objects will be a lot more happened in the future. Therefore, not just natural space object like asteroids but the artificial space object like artificial satellite and space station can cause the disaster by falling to the ground. To protect our nation and our property, the government has set up the space disaster management center in Korea astronomy and Space science Institute. In this study, we surveyed public's recognition of the space object's re-entry situation and analyzed it to contribute building national space disaster management policy.

• Journal of Korean Society of Disaster and Security
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• v.9 no.1
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• pp.25-32
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• 2016

Technical development have broaden human activity ranges and make human possible to defend the disasters which was undependable in the past. However, human's space activity brought a new kind of disaster to human. In the past, natural space objects was the only concern from the space, like the asteroid fallen on Chelyabinsk, Russia. But, nowadays, by the increasing number of the man-made space objects, these space kind of threat have diversified and become very real. So, nationwide safety strategy should be established to protect the people. In this paper, we suggest three points to make the decision for establishing the strategy based on the AHP analysis results.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.161-172
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• 2007

Vehicles transporting hazardous materials can make huge damage to people, properties and environment by traffic accidents. Therefore, transporting hazardous materials is a big issue with the cutting edge technology of communications in these days. However, despite this situation, Korean government gives limited efforts for systematic management, research and investment about hazardous materials. Accordingly, this research suggests the key path finding algorithm about management of real-time schedule and routes for vehicles transporting hazardous materials. Besides, the case study is progressed in transportation networks of Seoul in order to evaluate the reality of algorithm. Specifically, time-space network transformation is performed for time window attributes. In addition, this study proposes the techniques searching for non-dominated paths considering schedule by the multiobjective shortest path algorithm based on dynamic programming in dynamic transportation networks including multiobjective attributes.

• Safety and Health at Work
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• v.6 no.1
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• pp.18-24
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• 2015

Background: In 2006, three farmers died at the bottom of an agricultural shallow well where the atmosphere contained only 6% oxygen. This study aimed to document the variability of levels of oxygen and selected hazardous gases in the atmosphere of wells, and to identify ambient conditions associated with the low-oxygen situation. Methods: A cross-sectional survey, conducted in June 2007 and July 2007, measured the levels of oxygen, carbon monoxide, hydrogen sulfide, and explosive gas (percentage of lower explosive limit) at different depths of the atmosphere inside 253 wells in Kamphaengphet and Phitsanulok provinces. Ambient conditions and well use by farmers were recorded. Carbon dioxide was measured in a subset of wells. Variables independently associated with low-oxygen condition (<19.5%) were identified using multivariate logistic regression. Results: One in five agricultural shallow wells had a low-oxygen status, with oxygen concentration decreasing with increasing depth within the well. The deepest-depth oxygen reading ranged from 0.0% to 20.9%. Low levels of other hazardous gases were detected in a small number of wells. The low-oxygen status was independently associated with the depth of the atmosphere column to the water surface [odds ratio (OR) = 13.5 for 8-11 m vs. <6 m], depth of water (OR = 0.17 for 3-<8 m vs. 0-1 m), well cover (OR = 3.95), time elapsed since the last rainfall (OR = 7.44 for >2 days vs. <1 day), and location of well in sandy soil (OR = 3.72). Among 11 wells tested, carbon dioxide was detected in high concentration (>25,000 ppm) in seven wells with a low oxygen level. Conclusion: Oxygen concentrations in the wells vary widely even within a small area and decrease with increasing depth.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.47-51
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• 2006

Modern residing equipment developed much quantitatively along with economic growth but improvement for agreeable residing space of indoor environment is insufficient situation yet. Also, the latest sick-building syndrome discharging room contaminant such as Formaldehyde, toluene, radon etc. built house or buildings newly human body threaten. Radon of them is real condition that raise origination of lung cancer next to smoke. So, wish to in this research by one of solution way of these problems adsorption performance and specie performance excellent activated carbon to concrete bricks for deconstipating suppository that is room finish fare mix and examine closely after grasp physical, mechanical special quality, hazardous substance and specie performance effect. According to result that estimate environment efficiency evaluation, the $CO_2$ absorption amount displayed decrease effect more than about 90% in activated carbon metathesis rate 40% and radon release amount displayed tendency that decrease about $76{\sim}96%$ in activated carbon metathesis rate 40%.

• Journal of the Korea Institute of Building Construction
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• v.6 no.2 s.20
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• pp.105-109
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• 2006

Modern residing equipment developed much quantitatively along with economic growth but improvement for agreeable residing space of indoor environment is insufficient situation yet. Also, the latest sick-building syndrome discharging room contaminant such as Formaldehyde, toluene, radon etc. built house or buildings newly human body threaten. Radon of them is real condition that raise origination of lung cancer next to smoke. So, wish to in this research by one of solution way of these problems adsorption performance and specie performance excellent activated carbon to mortar for deconstipating suppository that is room finish fare mix and examine closely after grasp physical, mechanical special quality, hazardous substance and specie performance effect. According to result that estimate friendly-environment performance, the $CO_2$ absorption amount displayed decrease effect more than about 90% in activated carbon metathesis rate 80% and radon release amount displayed tendency that decrease about $75{\sim}85%$ in activated carbon metathesis rate 80%.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.173-184
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• 2018

As the portable traffic information collection system using probe vehicles spreads, it is becoming possible to collect road hazard information such as portholes, falling objects, and road surface freezing using in-vehicle sensors in addition to existing traffic information. In this study, we developed a integration and decision algorithm that integrates time and space in real time when multiple probe vehicles detect events such as road hazard information based on GPS coordinates. The core function of the algorithm is to determine whether the road hazard information generated at a specific point is the same point from the result of detecting multiple GPS probes with different GPS coordinates, Generating the data, (3) continuously determining whether the generated event data is valid, and (4) ending the event when the road hazard situation ends. For this purpose, the road risk information collected by the probe vehicle was processed in real time to achieve the conditional probability, and the validity of the event was verified by continuously updating the road risk information collected by the probe vehicle. It is considered that the developed hybrid processing algorithm can be applied to probe-based traffic information collection and event information processing such as C-ITS and autonomous driving car in the future.