• Proceedings of the KSR Conference
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• 2000.05a
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• pp.431-438
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• 2000

In recent years. the destructive force acting on the ballasted track is on the increase with the speed-up of trains and the number of trains, requiring more labor and expenditure to maintain the track in goof condition. Slab track has been developed to decrease the track maintenance work on earthworks. One type of slab track Rheda has Prefabricated track grid, consisting of rails. Prestressed concrete sleepers and reinforcement rods are aligned into position. and then concrete is then placed to integrate the sleepers into a reinforced concrete track slab. In this paper, a new analysis model for the system analysis of the slab track is presented. Then the analysis results are compared with requirements for slab track.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.362-369
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• 2005

In this paper, a research for the knowledge based configuration design software development of a train vehicle has been presented. Parametric design and knowledge based design concepts have been introduced for rapid design changes and analyses using a commercial CAD software, $CATIA^{/circledR}$ Knowledgeware module. Positions and dimensions of door, small window, large window, and number of seats were used as design parameters. It is crucial for train vehicle design because it enables rapid conceptual design by instant configuration changes. The results of this research can be used as one sub module of the multidisciplinary train vehicle design software and provide a basic data for rolling stock behavior and driver cab ergonomics of a train vehicle.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.376-380
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• 2006

There are several methods which estimate the behavior of the Structures. Recently, several displacement measuring instruments such a GPS are substantially developed. So, considering this technique, displacement measurement will be a very efficient method for estimating the behavior of the Structures and maintenance. Therefore we need to develop methods of structure maintenance & management by using displacement measuring instruments. In this study, I suggest to maintenance & management method by using displacements about simple beams and cantilever beams which are very important structure in civil engineering. The results show that the proposed method is capable of estimating the displacement and stress of the Beam Member by combining the proper number of measurement and optimum measurement points.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.478-483
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• 2006

In this study, as a part of research which is to make 50kg NSI turnout of PC sleeper, the main objective of this study is the optimization of PC sleeper's section, the number of PS tension wire. For this purpose, the finite element analysis was conducted to evaluate the serviceability and the safety of NSI PC sleeper developed. Analytical results showed that PC sleeper adapted in this study satisfied not only serviceability criterion but also safety criterion.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.179-186
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• 1998

Three phase squirrel cage induction motor is generally adopted as a traction motor to drive high speed trains because of its robustness for surrounding environment and easy maintenance. In the design of traction molar, reduction of weight is very important in order to reduce kinetic energy to accelerate the vehicle. Therefore, in this paper, design variables of a preliminary designed traction motor to minimize its weight is determined using the optimization technique. Before the optimization process, rotor slot number is determined to reduce vibration and noise by the analysis of magnetic force. As a result, a design example to reduce weight by 12% than that of the preliminary designed motor is presented.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1463-1472
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• 2008

The present paper to relate with the maintenance of the high-speed vehicle, KTX and is to treat a reliability evaluation. The reliability of the high-speed vehicle while operating between-failure average mileage (MKBSF) and parts between-failure average mileage (MKBF), 1,000,000 per km service failure number of items and availability and per km evaluated a maintenance expense. The reliability evaluation results and 2007 year reliability management indexes compared in 2006 years and they improved, per km the maintenance expense compared at 2006 and 36.6% was decreased. Reliability management activity leads and availability of the high-speed vehicle, safety improves and with the fact that will be able to decrease the maintenance expense which is an economic scale of railroad service is expected.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.103-109
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• 2024

A nonlinear numerical analysis of orientation and velocity fields of the full Ericksen-Leslie theory for a nematic liquid crystal under shear flow is given. We obtained for the first time the three-dimensional orientation and two component velocity profiles evolutions for both in- and out-of-shear plane orientation anchorings. Complex evolution routes to steady state were found even for shear aligning nematic. As the Ericksen number increases monotonic evolution of velocity and orientation shifts towards multi-region nucleating director rotation growth with complex secondary flow generations. We found that contrary to the in-shear-plane anchorings like homeotropic or parallel anchorings, binormal anchoring gives rise to substantial non-planar three-dimensional orientation with nonzero secondary flow.

• Steel and Composite Structures
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• v.48 no.1
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• pp.103-111
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• 2023

The caving property of top coal is a key factor to the success of top coal caving mining. The influence law of cyclic loading and unloading of hydraulic support on top coal caving is of great significance to improve the recovery rate of top coal. The similar simulation methods were used to study the dynamic evolution of the top coal cracks under the multi-cycle action of the support, and the parameters of top coal cracks were analyzed quantitatively in this paper. The results show that the top coal cracks can be divided into horizontal cracks and vertical cracks under the cyclic loading and unloading of the support. With the increase of the times of the support cycles loading and unloading, the load on the support decreases, the fractal dimension of the cracks increases, the number and total length of the top coal cracks increases, and the top coal caving is getting better. With the increase of the times of multi-cycle loading and unloading, the fractal dimension, total crack length and crack rate of top coal show a trend of rapid increase first and then increase slowly. Both the total length of the top coal cracks and the crack rate basically show linear growth with the change of the fractal dimension. The top coal caving can be well improved and the coal resource recovery rate increased through the multi-cycle loading and unloading.

• Journal of the Korean Institute of Rural Architecture
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• v.21 no.2
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• pp.27-34
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• 2019

This study explores the emergence of a modern form of Cheongju-eup townscape in the late 1930s by re-examining the 1960s restoration model of Seongan-dong and Jungang-dong in Cheongju, one of the historic cities in South Korea. According to the acquired data from the restoration model, it is found that the construction of a new urban area during the late 1930 was resulted from the following events: the development of a railroad station located outside of the north gate of Cheongju-eup since 1921, the completion of Musimcheon embankment outside the south gate in 1932, and the construction of Chungcheongbuk provincial office outside the eastern gate in 1937. In this period of development, which the author named 'Cheongju-eup period', the streets in the old castle, consisting only of two-story financial buildings, had been expanded from the existing area at the Seongan-gil intersection to the outside the east gate of Cheongju-eup. In addition, public government buildings, which were mainly located in both Seongan-gil and Yulgok-ro in the east-west direction, were newly constructed during the late 1930s in Seokgyo-dong, a new area in which a large number of commercial buildings including department stores, clothing stores, shoes shops, and watch stores were also built along the streets. Moreover, the modern form of Cheongju-eup was to be formed by several construction projects in the area of Jungang-ro in the late 1930s. Until the 1920s, the townscape outside the northern gate of Cheongju-eup, were composed of primary, agricultural, and female schools built on a largest site of Gyoseo-ro and Daeseong-ro as well as a transportation warehouse and a railway office near the Cheongju station. Then, entering the 1930s, new school buildings and domestic industrial shops and factories were built around the area of Jungang-ro ranging from the railway outside the northern gate to Bangadari. As a result, the expansion of townscape with newly constructed buildings in the late 1930s marked the emergence of a modern form of Cheongju-eup.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.490-497
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• 2011

When operating Express and Standard trains, which run with two different scheduled time, in a single line with limited number of side tracks for overtaking standard trains, it is required to have various modeling methodologies and simulations in order to calculate an optimum headway to maximize the capacity of the line with the best scheduled time. Especially it is inevitable that following trains have to slow down or stop in the middle of their operations due to the preceding trains, in case it is inappropriate controlled about either in which station an overtaking should be taken or how long it should be. This study is to analyze TPS data which have been produced with a simulation program which the team has invented to optimize Express and Standard mixed traffic plan and to introduce an algorism which shows detected conflict data, calculates appropriate dwell time after getting overtaken and helps to decide stations for overtaking.