• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.212-219
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• 2015

Korea's first tram (so called "tram"), which was commenced the operation on May 4, 1899 of late Joseon Dynasty and run until 1968, played a pivotal role of public transportation. However, tram as new transportation mean is being recognized as traffic congestion problem becomes issue due to geometric automobile increase and reckless urban plan after stoppage of tram service. Tram has an advantage of inexpensive construction cost and eco-friendly means compared to existing and city railway, carrying more passengers rather than existing bus, excellent connectivity of existing transportation because of easy accessible to destination in the city center. Therefore, tram, what is called "Green Rvolution of Public Transportation", has a dreaming of revival and in the process of pushing. We suggest the accident type which might break out in the early stage of tram introduction and preventive measures by surveying the accident cases of tram advanced country, and study the crossing control measures.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.435-447
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• 1996

In this paper, we propose the method that extracts the speech feature using the hearing model through signal processing techniques. The proposed method includes the following procedure ; normalization of the short-time speech block by its maximum value, multi-resolution analysis using the discrete wavelet transformation and re-synthesize using the discrete inverse wavelet transformation, differentiation after analysis and synthesis, full wave rectification and integration. In order to verify the performance of the proposed speech feature in the speech recognition task, korean digit recognition experiments were carried out using both the DTW and the VQ-HMM. The results showed that, in the case of using DTW, the recognition rates were 99.79% and 90.33% for speaker-dependent and speaker-independent task respectively and, in the case of using VQ-HMM, the rate were 96.5% and 81.5% respectively. And it indicates that the proposed speech feature has the potential for use as a simple and efficient feature for recognition task

• Ecology and Resilient Infrastructure
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• v.4 no.2
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• pp.83-92
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• 2017

Increased investment in environment-friendly transport vehicles has led to rapid transit of railway tracks, double track program, linear improvements in railway lines, and moving railroad routes into the suburbs. They resulted in fast increase of railway yards. However, as the railroad yards being neglected, urban fine sites have been degraded. Local governments kept seeking ways to utilize the railway yards. In addition, Ministry of land, infrastructure and transport enacted "Guidelines for utilization of railway yards". The Guidelines categorized the railway yards into three types; conservation, utilized, and other sites in order to make efficient use of them. The railway yards have been converted and used for parks, rail bike trails, bike paths, and solar projects. It seems that studies are needed on diverse use of the yards and on post evaluation. This study investigated current uses of railway yards, domestic and foreign, and analyzed for the pertinent conditions on natural and cultural landscape, educational value, location and accessibility, potential for recreational area, and development opportunities. In this study, I proposed a quantitative evaluation method, and to find way to diversify the use of railway yards.

• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.160-170
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• 2020

Railroads and roads are typical linear projects, and their networks are expanding nationwide. To minimize the impact of their development on the environment, ecological disconnection due to the parallel lines of railroads and roads is to be avoided as much as possible. In this study, to examine the environmental impact of railroad and road development, the characteristics of railroads and roads and the differences between them were examined through a comparative analysis of key evaluation items. Based on the result, the road development, unlike the railroad project, suggests items for establishing an efficient land use plan and soil protection as the key evaluation items. There are no specific evaluation items and criteria that can be used to examine the environmental impact of railroad lines located adjacent to roads. In this study, eight evaluation items were suggested by reviewing the relevant literature. In particular, in the strategic environmental impact assessment stage, which examines the adequacy and location feasibility of the plan, the minimum separation distance criteria were proposed to examine in advance the environmental impact of railroads located adjacent to the existing roads. The distances were examined for the previously operated routes, and a distance of less than 200 m was suggested to minimize the environmental impact. The results were compared with those in other studies and analyzed. The results of this study can be used as a basis for examining alternative routes that can minimize the environmental impact of adjacent railroads and roads.

• International Area Studies Review
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• v.13 no.3
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• pp.501-525
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• 2009

Recent increase of academic interest in Born Globals has brought abundant researches, which accounts their causes and states, both in and out of the country. However, postulating that types of companies see the different perception of environment of global markets, and this difference will also bring different effects on enterprise capabilities and performance, this study implemented theoretical inquiry and evidential analysis. Technologically innovative SMEs, main subjects of this study, were categorized into Rapid Globals and Gradual Globals according to their internationalization speed, then followed by a CSA. This analysis has shown, regardless of corporate types, early perception of changes in global market environments, affects, in great amount, on marketing and R&D capabilities as well as performance. However, corporate types also showed difference in early perception of changes, marketing and R&D capabilities as well as performance. This evidential analysis provides enterprises pursuing internationalization in early stage with enforcement in their early perception of changes in global market environments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.599-604
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• 2017

Nowadays reactance method is being used as a technique for fault location in parallel feeding AC traction power system. However, implementation of this method requires a large number of field tests(ground fault) which is a huge burden on the operators. This paper presents a new estimation technique using quadratic interpolation to reduce number of times for field test and improves the accuracy of fault location. To verify a new technique, we solve AT feeding circuit and model it using PSCAD/EMTDC. Finally this paper conducts a comparative analysis of usefulness between a new technique and real field data.

• International Journal of Railway
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• v.5 no.4
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• pp.163-166
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• 2012

Many different types of floating slab track have been developed and installed around the world to reduce vibrations and noise originating in the surrounding environment. The main objective of this study is to examine the influence of slab length on behavior of floating slab track based on rail-slab-isolator interaction. The floating slab track is modeled by the connection between rail, slab, isolator, and slab mat in the transition zone. All elements were assembled in a simplified two-dimensional (2D) finite element model (FEM). The maximum length of FST is then investigated based on the maximum additional rail stress criterion as described in UIC 774-3R since no fully accepted design criteria for the slab length in FST systems currently exist.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.432-439
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• 2003

Tilting bogie system allow the train to pass curve at higher speed without affecting passenger comfort. As the tilting trains offer the optimum means of providing faster and more comfortable rail service with minimum of environmental disturbance and capital investment, more than 14 countries have now adopted or are about to adopt tilting train technology. The Korean National Railroad is also planing to apply faster tilting train to the areas where the High speed rail service are not provided. This paper describes the basic design and dynamic analysis of Bogie for 180 km/h Korean Tilting Train(TTX), which was done as a part of the Korean National R&D project.

• Journal of the Korean GEO-environmental Society
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• v.18 no.2
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• pp.5-19
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• 2017

Underground excavation for building construction in Korea is changing from conventional support method (Strut, Ground anchor) to inside permanent support method by stability, economic, circumstances around excavation and etc. This study was selected the sites of Top-down, New Top-down, S.P.S, S.T.D and B.R.D in general use. This study was compared and analyzed a construction cost and period between aforementioned methods and conventional support method. Also, this study was confirmed the stability of temporary retaining wall by analysis for measurement data under construction. As a result, this study can grasp that most improved permanent support method is excellent in economic and constructability than conventional support method in case of deep excavation and rapid appearance of bedrock.

• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.32-39
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• 2013

The next generation high-speed train(HEMU-430X) is Korea's first electric multiple unit type, high speed vehicle resulting from a national R&D project. Tests have been conducted on the Kyungbu High Speed Line running at speeds up to 354.64km/h, and analysis of the dynamic behavior of the train was carried out to evaluate its safety. In this study, a simplified method using an accelerometer(the method specified in UIC 518 OR) was chosen to analyze the safety of the train's dynamic behavior. The section chosen for analysis section was ${\pm}10{\sim}20km/h$ with respect to the maximum speed point. In addition, we analyzed the trend of this dynamic behavior with increasing speed by comparing the analyzed values with those of UIC 518 OR. The dynamic behavior results met the limit values of UIC 518 OR and the study indicates that this trend is predicted to continue at speeds above 354km/h.