• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.6-14
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• 2019

There are about 38,977 CNG cars and 247 natural gas vehicle charging stations in operation in order to improve the urban air environment. With the introduction of natural gas vehicles, the atmospheric environment, which was the main cause of air pollution in the metropolitan area, was remarkably improved. However, unlike these positive effects, CNG bus accidents, which occurred more than 10 times since 2005, have caused concern among the majority of citizens using public transportation. It is necessary to make a judgment on the feasibility and future direction of CNG pressure vessel safety management that can safeguard the safety of CNG pressure vessel at the time of starting. In this study, we investigates production and use of CNG vessel, the current status of safety management of CNG bus transportation companies & charging stations and then proposes measures to prevent accident recurrence and safety management based on the actual situation investigation and analysis.

• The Science & Technology
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• v.8 no.12 s.79
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• pp.61-64
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• 1975

An expression for the vibrational frequency of diatomic molecular is obtained by using molecular gas temperature T and molecular gas mean-free path λ. And when λ/T →2.59, beca use of the damped vibration, a diatomic molecular gas is Impeded about transportation. If transfortation is not attained with this condition, rectilinear motion of a diatomic molecular gas can't maintain for the equilibrium state.

• Journal of the Korean Society of Safety
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• v.32 no.4
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• pp.129-136
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• 2017

This study investigated the probability of possible accident through qualitative and quantitative analysis of the pressure safety valve types installed in facilities using high pressure gas to compare the installation domestic and foreign pressure safety valve standards sought the safety characteristics and safety improvement direction accordingly. The three types are the case where the shut-off valve is not installed at the front of the PSV (Case A), If a shut-off valve is installed at the front of the PSV for inspection (Case B) and If a shut-off valve is installed in front of PSV (C.S.O), PSV is installed in parallel (Case C). Three types of cases were compared with FTA and HAZOP. The results of study of the possible accidents due to over-pressure safety valve installation type, used in a high-pressure gas facilities was shows in the following order Case B > Case A > Case C. The results of analysis through FTA was in order to protect the reservoir for the possible occurring of accident the safety valve installation is depend on its type. In the FTA analysis, defects in the device itself which attached to the storage tank as a substitute for analysis of the probability of operator mistakes was Case B with as high as $2.01{\times}10^{-6}$. Depending on the type of installation analysis of Case B in order to ensure safety is prohibited to install shut-off valve and believes that mandatory regulations are needed. Rationally installing of pressure safety valve in the high pressure using facilities will be expected to improve the industrial safety from severe accidents such as high-pressure gas fire explosion.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.591-598
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• 2017

To prolong the shelf-life of strawberry, samples were treated with gel packs containing slow-released chlorine dioxide($ClO_2$) gas at 3~7 ppm for 6 days at room temperature. The weight loss and decay ratio as well as changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples decreased slightly, but the weight of the control changed faster than those of the $ClO_2$ gas treated samples during the storage period. The decay ratio of control was higher than those of the $ClO_2$ gas treatments since 4 days of storage. The pH and acidity in the control and in the $ClO_2$ gas treated samples were no differences during storage period. The lightness of strawberry decreased during storage, but there was no difference in lightness among the treatments even when storage time was extended. The redness and yellowness of the control showed higher change than those of the $ClO_2$ gas treatments during 6 days. The firmness of the control changed more rapidly than those of the $ClO_2$ gas treatments during 6 days. Especially, the samples treated 3 and 5 ppm $ClO_2$ gas were the least changed. And the scores for appearance, firmness and overall acceptance control and 7 ppm $ClO_2$ gas treatment decreased more rapidly than those of 3 and 5 ppm treatment.

• International Journal of Highway Engineering
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• v.16 no.3
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• pp.75-84
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• 2014

PURPOSES : Traffic congestions which occur in the intersections of arterials lead to mobility and environment problem, and then traffic agencies and engineers have been struggling for mitigating congestions with greenhouse gas emissions. As an alternative of solving theses problems, this study is to introduce a low-cost and high-effectiveness countermeasure as unconventional intersections which are successfully in operation in U.S.. The main feature of unconventional intersections is to reroute turning movement on an approach to other approach, which consequently more green time is available for the progression of through traffic. Due to improved progression, this unique geometric design contributes to reduce delays with greenhouse gas emission and provides a viable alternative to interchanges. This study is to evaluate the potential operation and environment benefits of unconventional intersections. METHODS : This study used the VISSIM model with Synchro and EnViVer. Synchro is to optimize signal phases and EnViVer model to estimate the amount of greenhouse gas emissions by each condition. RESULTS : The result shows that unconventional intersections lead to increase the capacity and to reduce greenhouse gas emissions, compared to existing intersections. CONCLUSIONS : Unconventional intersections have the ability to positively impact operations and environments as a low-cost and high-effectiveness countermeasure.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.2 s.140
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• pp.142-150
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• 2005

Recently, the gas transportation system for CNG(Compressed Natural Gas) has been developed and several innovative approaches are presented from the aspects of commercial demand. In this study, a new type of 20ft container shape CNG tank with two and four cylinder intersections by using the intersecting spheres has been proposed. And the structural analysis of CNG tank with Mildsteel, API High Tensile Steel, Al-alloy and FRP has been carried out to compare the different types of pressure vessels of materials used. The analysis result shows that the proposed intersectional cylindrical type of CNG tank can be applied to the gas transportation system. And further study on the commercial analysis and associated equipments should be carried out for the practical applications.

• Journal of Climate Change Research
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• v.7 no.3
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• pp.289-297
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• 2016

In this study, we researched the emission source category and it was calculated emissions estimates from existing research or literature review related to port. In addition, we have created the basis for a policy that can reduce greenhouse gas emissions calculation based on the results of the harbor. Greenhouse gas emissions estimation results, we proposed a method for allocating the GIS space. In this study, we confirmed based on the calculated greenhouse gas emissions by sources resulting in the GIS Map Port result of the expression construct for space allocation. Based on these results, it tries to provide the basic data that can be used when you want to create a local government measures to reduce scenario in the future.

• Proceedings of the KOR-KST Conference
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• 2007.02a
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• pp.114-120
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• 2007

• Environmental and Resource Economics Review
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• v.29 no.3
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• pp.389-418
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• 2020

Some OECD countries are showing signs of decoupling in the transportation sector. In terms of sustainable development, the decoupling of economic activities and greenhouse gas emissions in the transportation sector is very important. This study calculated a decoupling index of greenhouse gas emissions in the transportation sector for 25 OECD countries. Also this study analyzed the impact of energy transition on decoupling regimes. According to the analysis, a considerable number of countries have reached the decoupling phase, and some countries have shown strong decoupling regime in which greenhouse gas emissions are reduced despite economic growth. From ordered panel logit analysis, energy transition had significant impact on achieving decoupling phase. Electrification of transport had a positive effect on the decoupling, while the gasification was not significant. In addition, small traffic, high urbanization rates, strong environmental policies, and high trade opening have had significant effects on achieving decoupling.

• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.1-12
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• 2018

The purpose of this study is to establish a methodology for evaluating quantitative effects of transportation GHG (greenhouse gas) reduction-related policies that were implemented based on the reduction goals of transportation GHG and effective implementation plans. This study uses a modal utility function and demand estimation models as well as a GHG emission basic unit estimation model by each transportation mode based on actual traffic and emission data. The results showed that the effects of GHG reduction policies such as electric vary from region to region, and from vehicle to vehicle. It is also confirmed that an eco-drive promotion policy, one of the lowest budget policies, is expected to contribute to high reduction in GHG. In addition, not only automobile emission improvement policies but also the promotion policies of public transportation are expected to highly reduce GHG as confirmed quantitatively in this study. The results of this study are expected to be useful for national and local governments' evaluation of GHG reduction policies to cope with the post 2020.