• Journal of the Korean Society of Industry Convergence
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• v.26 no.2_2
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• pp.333-340
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• 2023

Environmental regulations are being strengthened worldwide to solve global warming. For this reason, interest in eco-friendly gas fuels such as LNG and hydrogen is continuously increasing. However, when adopting eco-friendly gas fuel, liquefying at a cryogenic temperature is essential to ensure economic feasibility in storage and transportation. Although austenitic stainless steel is typically applied to store cryogenic liquefied gas, structural steel can experience sudden heat shrinkage in the case of leakage in the loading and unloading process of LNG. In severe cases, the phase of the steel may change, so care is required. This study conducted Charpy impact tests on steel material in nine different temperature ranges, from room to cryogenic temperatures, to analyze the effects of cryogenic liquefied gas leaks. As a result of the study, it was not easy to find variations in ductile to brittle transition temperature (DBTT) due to the leakage of cryogenic liquefied gas. Still, the overall impact toughness tended to decrease, and these results were verified through fracture surface analysis. In summary, brittle fracture of the steel plate may occur when a secondary load is applied to steel for hull structural use exposed to a cryogenic environment of -40 ℃ or lower. Therefore, it needs to be considered in the ship design and operating conditions.

• Journal of Environmental Impact Assessment
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• v.33 no.1
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• pp.42-51
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• 2024

Recently, as e-commerce has been activated and the demand for daily logistics services has increased due to the COVID-19 pandemic, the development of small logistics facilities has increased rapidly. Logistics facilities are concentrated in certain areas in Gyeonggi-do, where transportation is convenient, with large hinterland cities, showing a rapid increase. This study analyzed development characteristics such as development scale, development method, floor area ratio, and use area for a total of 259 logistics facilities developed in three local governments: Anseong, Yeoju, and Icheon. Logistics facilities developed in a specific area are developed in the form of undeveloped development in non-urban areas, causing damage to the national land environment and social conflict. This study proposed institutional improvement measures and evaluation guidelines for eco-friendly development that can solve problems such as indiscriminate development, environmental impact, and conflicts with residents caused by logistics facility development.

• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.548-559
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• 2016

Recent interests in both vehicle emissions and public health have facilitated the development of more eco-friendly transportation systems. This study proposed an integrated simulation approach for evaluating the effectiveness of speed management strategies from the various perspectives including safety, operational efficiency, and environmental compatability. Those simulation methods include driving simulation, traffic flow simulation, emissions simulation, and air dispersion simulation. An essence of the proposed simulation framework is to create the systematic connection of each simulation method toward the evaluation of effectiveness of speed management strategies. As an example, chicane and speed hump in residential area were evaluated by the proposed method. It is expected that the proposed simulation-based approach would be effectively used for the decision-making process in selecting better alternatives considering both safety and public health.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.68-72
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• 2015

The railway system has been recognized as one of the best eco-friendly advanced transportation systems. Furthermore, the improvement of the passenger transportation quality and the energy saving have been studied for being the most competitive transportation system. However, most of the studies have been mainly focused on the improvement of the transportation efficiency and energy saving because of the characteristics of the urban railway which serves the unspecified multiple passengers. In this paper, the 3-dimensional vibratory lateral acceleration has been measured in various environments for the automatic and manual operation modes of the general train and express train in the urban railway lines. In terms of the improvement of the passenger transportation quality, the comparison analysis of the ride quality is carried out based on the measured 3-dimensional vibratory lateral acceleration and the statistical techniques of UIC513R suggested by the International Union of Railways.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.156-161
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• 2016

An R&D project, 'Carbon Neutral Road Technologies Development', sponsored by the Korean Ministry of Land, Infrastructure, and Transport was performed and sustainable development is being discussed in relation to global climate change. A draft of the green highway certification system, the green highway design and construction technologies for making low carbon eco-friendly roads, and Green Highway Technology Investment Evaluation System (GTIES) for estimating and managing carbon emissions from roads have been developed from the results of the R&D project. A scheme for expanding the application of these technologies and building sustainable road systems by considering the concept of sustainability was proposed in this research.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.9
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• pp.1577-1582
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• 2016

Now we are facing severe environmental issues such as global warming. Due to these, the concerns about eco-friendly energy have been increased. Kyoto protocol and Copenhagen climate change conference are circumstantial evidence of it. With these trends, the interests for the Electric Vehicles(EVs) which do not emit any harmful gases have gradually been raised. Unfortunately, however, massive connection of EVs to the power system could cause negative impacts such as voltage variations, frequency variations and increase of demand power. To prevent the mentioned issues, KEPCO adopts Time-of-Use(ToU) price for EVs charging. Nevertheless, it is important to verify the propriety of the charging system. In this paper, therefore, we used pre-introduced price elasticity concept to predict possible Demand Response(DR) on charging of EVs. And analyzed possible demand power increase according to various price elasticities. Simulation results show that given ToU based charging system would not enough to control the increase of demand power by EVs on the power system. It is concluded, therefore, additional methods and/or algorithms are required.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1886-1894
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• 2009

The widening national capital area of Korea has caused a traffic jam problem with increasing commuting hours. In addition, as the economic crisis goes on, the people moving to the outside of a city has increased. So we expect that the expansion of this metropolitan area will do grow and it will cause a more severe traffic jam in the near future. Therefore, We will study about 'Rapid Railroad Operation in Metropolitan Area' to solve this problem and improve rail's competitive power as a reasonable transportation method. The Rapid Railroad can sharply reduce commuting hours. Also, it is more eco-friendly transportation than the others. Through many cases revealed in both domestics and overseas, we will solve the problem of a traffic jam getting senous m metropolitan area. After studying successful cases of overseas, rapid railroad, such as France and Japan, we will study domestic cases of Yongsan$\sim$Dong-inchoen, Guro$\sim$Cheonan and Gaehwa$\sim$Sin-nonhyeon, and comparison will do made among these case. In conclusion, The introduction of Rapid Railroad show the effective plan for strengthen the competitiveness and solve the traffic problem.

• Journal of the Korean Society for Railway
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• v.19 no.5
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• pp.685-697
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• 2016

Railroad is considered as an eco-friendly transportation mode because it emits lower greenhouse gases and air pollutants and consumes less energy compared to trucking. To promote rail freight, many countries have implemented various policies, while South Korea has implemented few substantial policies. This study aims to compare and analyze rail freight policies of various countries in order to suggest policy implications to South Korea. We analyze relevant policies of 9 countries; these are classified into 5 categories, and we provide policy implications for facilitating rail freight infrastructure and equipments, grants for the transportation cost using freight rail, and road freight restriction policy.

• Journal of Institute of Convergence Technology
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• v.4 no.1
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• pp.21-27
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• 2014

White LEDs (light-emitting diodes) are promising new-generation light sources which can replace conventional lamps due to their high reliability, low energy consumption and eco-friendly effects. This paper briefly reviews recent progress of oxy/nitride host phosphor and quantum dot materials with broad excitation band characteristics for phosphor-converted white LEDs. Among oxy/nitride host materials, $M_2Si_5N_8:Eu^{2+}$, $MAlSiN_3:Eu^{2+}$ M-SiON(M=Ca, Sr, Ba), ${\alpha}/{\beta}-SiAlON:Eu^{2+}$ are excellent phosphors for white LED using blue-emitting chip. They have very broad excitation bands in the range of 440-460 nm and exhibit emission from green to red. In this paper, In this review we focus on recent developments in the crystal structure, luminescence and applications of the oxy/nitride phosphors for white LEDs. In addition, the application prospects and current trends of research and development of quantum dot phosphors are also discussed.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.2
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• pp.86-94
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• 2023

Tonnage taxation has contributed to developing the Korean maritime industry through tax relief for shipping companies. The current tonnage taxation relies on the net tonnage as an earning-capacity indicator in a merchant ship. Although the tonnage tax accords with horizontal equity, it does not match vertical equity because of the different taxable capacities of an individual company. Nowadays, maritime transport uses a dedicated vessel, and each shipping freight embeds a different value of time. It means the tonnage taxation regime should consider the added value of each shipping freight. Meanwhile, as the environmental regulations led by the International Maritime Organization are being strengthened, the Korean merchant fleet must be eco-friendly soon after. This study explores the alternative to renewing tonnage taxation by utilizing the Greenship certification and considering the ability-to-pay principle. Because the Greenship certification scheme encourages shipping decarbonization, maritime transport by a certified ocean-going vessel comes to be treated as an activity for the green economy. Special taxation for the green economy may contribute to shipping sustainability and market competitiveness.