• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.4
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• pp.95-104
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• 2013

As global warming and depletion of fossil fuel are considered as urgent problems, the development of electric vehicle (EV) is getting more attention by automobile industry. However, the wide adoption of EVs is not coming yet, because of many issues such as long recharging time and high cost of batteries etc. As an alternative solution to the conventional battery charging EV, the idea of battery exchanging EV is introduced. To realize the battery exchanging business model, one should solve the issues of ownership and reliability of battery. To address such issues, the concept of battery sharing should be considered together with good traceability system. In this study, we studied RFID code structure to provide better visibility and traceability for shared EV batteries. The proposed RFID code and code generation system is based on GRAI-96 of EPCglobal and included factors such as chemical, physical, and manufacturing features. The designed code can be also used as the ID of each battery.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.739-744
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• 2010

As recent traffic policy focuses on reduction of congestion and environmental contamination, with a catch phrase, 'Green Traffic', Low Carbon Green Growth' and 'Sustainable Development', introducing the new eco-friendly transport means including railway has been emerging as critical issue. Included in the new transport means are BRT, Bimodal Tram and LRT, and this study was intended to evaluate and analyze Bimodal, among others, which generates less emission, noise and vibration thanks to hybrid type traction system employed by Bimodal Tram, which is considered a future-oriented system because of eco-friendly features and cost efficiency as well as punctuality and convenient accessibility to bus. Thus in this study, appropriateness of Bimodal Tram comparing to other system(BRT) was suggested, using conversion traffic from the road, traffic speed and CO2 emission at the metropolitan area and large provincial areas as the barometer in evaluation, and furthermore, the measures applicable to introduction strategy that will meet various functional aspects in urban area in the coming days were developed.

• Progress in Superconductivity
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• v.6 no.2
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• pp.118-123
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• 2005

A low cost YBCO oxide powder was employed as a starting precursor for MOD process. YBCO oxide is advantageous over metal acetates or TFA salts which are popular starting precursors for conventional MOD-TFA process because that YBCO oxide precursor is cheap and easy to control molar ratio. YBCO thin films were prepared by this oxide-precursor-based MOD process and annealing condition was optimized. The YBCO thin film annealed at below $780^{\circ}C$ shows no transport $I_c$ and poor microstructure. Raman spectroscopic study of YBCO thin film indicates that YBCO thin film prepared at below $780^{\circ}C$ contains a number of imperfections such as non-superconducting $BaCuO_2$ phase, cation disorder, etc. However, the YBCO thin film treated at above $800^{\circ}C$ shows improvement in microstructure and current transport properties. This research was supported by a grant from Center for Applied Superconductivity Technology of the 21st Century Frontier R&D Program funded by the Ministry of Science and Technology, Republic of Korea.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.83-93
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• 2010

The roundabout is a green transportation system which reduces the accident, the congestion cost and greenhouse effect. The purpose of the study is to analyze the multi-legged roundabout's efficiency. In pursuing the above, this study gives particular attention to building the optimal network of multi-legged roundabout and intersections, developing the scenarios for analysis reflected by the proportion of entering traffic volume of main and minor roads, and comparatively analyzing the average delay per car using VISSIM. The main results are as follows. First, when the entering traffic volume are less than 3,500pcph, the 5-legged single and double-lane roundabout are all analyzed to be more effective than intersection. Second, when the entering traffic volume are less than 3,600pcph, the 6-legged single-lane roundabout is analyzed to be more effective than intersection. The 6-legged double-lane roundabout is analyzed to be more effective than intersection. The 6-legged double-lane roundabout is analyzed to be more effective than intersection in all cases of entering volume.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.63-82
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• 2010

In spite of continuous road construction, traffic congestion has been worsening by radical vehicle's increase and development of surroundings near expressway. Thus, the necessity of traffic management and the needs of provision of traffic information to drivers are raised. In order to solve traffic problems, such as traffic congestion, search for optimal congestion management technique and evaluation of the effect of optimal solution should be examined prior to practice of optimal alternative. However, existing traffic analysis model and simulation programs as tools to search and evaluate optimal alternative are not sufficient to reflect traffic flow characteristics, domestic road and traffic conditions and to link up to Freeway Traffic Management Systems (FTMS). Hence, to use existing traffic analysis and simulation tools are followed by hard work to need a lot of time and cost. Therefore, in this research, Expressway TRaffic Analysis Model (ExTRAM) based on Freeway Traffic Management Systems (FTMS) was developed to apply it into congestion management easily.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.2
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• pp.100-109
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• 2008

Traffic accidents at night occur more than any other time because of improper road light facility and delineators. Therefore, cost-effective criteria of installing delineators are needed instead of expensive road light facility, especially, on rural road including light volume of traffic. This paper presents the criteria of installing 'Chevron Alignment Sign' considering driver's visual behavior characteristics and 'Raised Pavement Marker' considering critical encroachment angie of both straight section and curve one in order to reduce both the number of accidents on curve sections and the number of road encroachment accidents, respectively. The characteristics of visual behaviors can be expressed by visual angle involving curve radius and intersection angle. The estimated installing angles are $1^{\circ}{\sim}2.5^{\circ}$ by radii, which is based on changes in sensitivity across visual field by exogenous attention. Also, the raised pavement marker is installed every 2m, 3m, and 4m considering critical encroachment angles by radii.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.22-29
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• 2013

The platform safety door is difficult to install in platform because the doors of railway vehicles and existing Passenger Safety doors should be alined. To be able to solve this problem, we propose the use of Rope Type Platform Safe Door (RPSD) which is a vertically retractable platform that is designed to close from top to bottom. This platform has installed safety gate pillars at intervals of 20-40 m which accommodates different types of train regardless of train length, gate opening and location. In this paper, we reviewed the application of existing PSD and RPSD in various train stops in Seoul Gyeongbu Line platform. The results of the review showed that the existing PSD may cause problem in construction, safety and cost efficiency. The use of RPSD however shows that minimal problems will be encountered.

• Journal of the Korean Institute of Navigation
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• v.18 no.3
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• pp.81-103
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• 1994

Increasing costs and competition in the global trade and transportation arena have led to a search for effient, cost-effective, particularly through the application of computer and information technologies. Most recently the introduction of Electronic Data Interchange(EDI) technologies in both trading and trade facili-tation activitiess have bagun to change the complextion of the international transport space. Korea as well as the other developing countries has become aware of the need to embrace EDI strate-gies in order to maintain a competitive market position with their more technologically advanced neighbou-ring and international trading partners. A way of EDI implementation, KMPA has invested large budgets in the research of the EDI since 1990. As the result of study in EDI of transport, KL-Net(Korea Logistics Network) was organized for the EDI business in cargo logistics. In spite of these KMPA's activities, the development plan of container logistics data interchange is not good and useful. So a new model of EDI in transportation is required by using the concepts of cargo data sharing. The purpose of this paper is to suggest a new way of container logistics data interchange model. This paper therefore analyze the information flow in the current container logistics and find the problem in the area to derive a new model. The followings are the results of this paper : (1) There are many problems and user's requirements in container logistics data interchange in Korea. (2) Many messages of UN/EDIFACT are able to be used in container logistics data interchange. (3) The container cargo data are stored in Container Logistics Network(CL-Net) database. And when necessary by requesting message transmission, the container logistics data interchange is possible. (4) Customs cargo clearance system and PORT-MIS can be linked to CL-Net. If the systems, however, are to introduce EDI in data interchange, the quality of user's software has to be assured.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.320-320
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• 2014

Amorphous silicon alloy (a-Si) solar cells and modules have been receiving a great deal of attention as a low-cost alternate energy source for large-scale terrestrial applications. Key to the achievement of high-efficiency solar cells using the multi-junction approach is the development of high quality, low band-gap materials which can capture the low-energy photons of the solar spectrum. Several cell designs have been reported in the past where grading or buffer layers have been incorporated at the junction interface to reduce carrier recombination near the junction. We have investigated profiling the composition of the a-SiGe alloy throughout the bulk of the intrinsic material so as to have a built-in electrical field in a substantial portion of the intrinsic material. As a result, the band gap mismatch between a-Si:H and $a-Si_{1-x}Ge_x:H$ creates a barrier for carrier transport. Previous reports have proposed a graded band gap structure in the absorber layer not only effectively increases the short wavelength absorption near the p/i interface, but also enhances the hole transport near the i-n interface. Here, we modulated the GeH4 flow rate to control the band gap to be graded from 1.75 eV (a-Si:H) to 1.55 eV ($a-Si_{1-x}Ge_x:H$). The band structure in the absorber layer thus became like a U-shape in which the lowest band gap was located in the middle of the i-layer. Incorporation of this structure in the middle and top cell of the triple-cell configuration is expected to increase the conversion efficiency further.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.61-63
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• 2003

A major research objective related to proton exchange membrane(PEM) for DMFC is to achieve high proton conductivity over 10$^{-2}$ S/cm, high hydrolytic stability and low methanol permeability with low cost base materials. for the purpose, a lot of thermoplastic polymers such as polysulfones, polyethersulfone, polyetherketones, polyimides, polyoxadiazole, polyphosphazene and polybenzimidazol have been investigated. Amongst those polymers, polyimides have been suggested as a potential PEM due to their excellent thermal, chemical stability and good mechanical properties. Generally, polyimides are synthesized by polycondensation with numerious diamines and dianhydriedes. In our study, polyimide was prepared using non-sulfonated diamine, sulfonated diamine directly synthesized by fuming sulfuric acid, and naphthalenic dianhydride to improve the hydrolysis stability under acidic condition. Through monomer sulfonation-subsequent polymerization method, the high proton conducting capability and the desired sulfonation level were effectively controlled at the same time. To reduce severe methanol transport through the membrane, the chemical crosslinking among polymer chains was introduced using various crosslinking agents with different chain lengths. The crosslinked sulfonated polyimide membranes showed high proton conductivity up to 8.09$\times$10$^{-2}$ S/cm and from crosslinking effect methanol transport through the membranes was considerably reduced as compared with unmodified membranes. For increase of chain length of crosslinker, methanol permeability was adversely reduced to 10$^{-8}$ $\textrm{cm}^2$/s due to decrease of IEC and increase of crosslinking desity.