• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.331-336
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• 2006

The rail clamp is the device to prevent that a crane slips along rails due to the wind blast as well as to locate the crane in the set position for loading and unloading containers. The wedge type rail clamp should be designed to consider the structural instability and the durability because it compresses both rail side with large clamping force by the wedge working as the wind speed increases. In this research, there are two methods which are design of experiment and variation technology in used commercial software and shape optimization was performed. The optimum results obtained by the two methods are compared and examined.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.185-191
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• 1998

Metro, as a kind of city rail transit, is a modem city passenger transit system with mass transportation and independent special rails. It has become a backbone of the traffic in the metropolis and an important modern symbol of a city. A modem traffic system is indispensable for Shanghai to be an international metropolis of finance, trade and economy. At present, Shanghai metro line No. 1 and its extension have been put into operation, metro line NO. 2 will be put into trial operation by the end of 1999, the Pearl Line, an elevated rail transit system is under construction and other lines will be constructed later according to the plan. But the funding of the city rail transit construction (both metro and light rail) is a big difficult problem to the infrastructure construction of the metropolises either at home or abroad, which is also a problem to restrict the development of the city rail transit of Shanghai. We have learned from the internal and external experiences of the rail transit construction that it is an important means to deal with the funds of the city rail transit construction to actively utilize foreign funds. It makes up the shortage of the internal funds on the one hand, the external advanced science and technology and the management experiences can be introduced on the other hand. In order to discuss and study conveniently with you together the new problems appearing in the metro construction and to open up a new train of thought, this article will give out a certain analysis and description to the funding method in the metro construction of Shanghai and the characteristics of utilizing foreign funds in the rail transit construction as well as the problems which we are faced with.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.401-406
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• 2019

The three-dimensional precision numerical analysis was performed using the finite element model applied with the railway track model consisting of rails, sleepers, and track elastic springs(ballast, rail pad). As a result of analyzing the track deformation level of the existing tracks due to the excavation work adjacent to the railway facilities, it was found that the track irregularity evaluation criteria (allowed values) of both conventional and high-speed railways lines were satisfied. Based on the numerical analysis using the track model, it was analyzed that the results of the prediction of the track irregularity due to the excavation work and the level of the track deformation occurring at the actual site could be approximated as closely as possible.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.540-545
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• 2007

The tilting train is able to tilt its body towards the center of the turning radius, preventing roll-over of the train as it runs on a curved rail at high-speed. This train, widely accepted for commercial purpose internationally, is very beneficial in that the operating time is shortened without much capital investment to the infrastructure where there are many curved rails. Over several years, the Korea Railroad Research Institute (KRRI) has developed such a train. In this paper, the safety of the Korean tilting train express (TTX) is investigated using a dynamic simulation model. Since proper safety standards have not been established for the TTX, those for the Korean train express (KTX) is employed to analyze the safety and ride comfort of the TTX. This study is useful in predicting the behavior of the TTX and ride comfort, and conforms that designed TTX is stable enough to satisfy the safety standards. It would be useful to recommend proper normal operating speed and determine the maximum safety speed, according to the result. Furthermore, it would be possible to provide basic reference data when analyzing the dynamic effect of the catenary system and the fatigue of the bogie.

• PNF and Movement
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• v.13 no.3
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• pp.127-134
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• 2015

Purpose: The current study seeks to examine the effect of coordinative pattern exercises of the upper and lower extremities using harnesses and walking rails on the walking and balance abilities of chronic stroke patients, and to develop effective programs and training methods to improve the functions of such patients. Methods: Subjects included 16 patients with hemiplegia caused by stroke. The subjects were randomly divided into an experimental group (n=8), on which coordinative pattern exercises of the upper and lower extremities were conducted, and a comparison group (n=8) that received typical exercise therapy. The experimental group underwent 30 minutes of typical exercise therapy and 30 minutes of coordinative pattern exercises of the upper and lower extremities, while the comparison group underwent typical exercise therapy for 30 minutes twice a day, five days per week for a six-week period. To evaluate walking ability, 10-m walking tests (10MWT) and 6-m walking tests (6MWT) were conducted. To assess balance ability, timed up and go tests (TUG) were performed. Results: After the intervention, significant (p<0.05) differences were seen in the 10MWT, 6MWT, and TUG in both the experimental and comparison groups. As for the 10MWT, the experimental group showed more significant improvement than the comparison group (p<0.05). In terms of the 6MWT, no significant differences were found between the groups, while the experimental group showed more significant differences than the comparison group in the TUG (p<0.05). Conclusion: The results from the current research indicate that training programs that apply coordinative pattern exercises of the upper and lower extremities with harnesses are extremely effective for improving the walking and balance abilities of chronic stroke patients.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.947-956
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• 2018

Trains have been a major means of transport in Korea during these past decades. However, train facilities such as stations and repair shops are contaminated with organic and inorganic substances. There is a high probability of train facility contamination with polyaromatic hydrocarbons (PAHs). This study evaluated the PAH and heavy metal contamination of soil near railroads in the Kyungpook area. A total of 18 soil samples were collected from the railroads and analyzed for 16 PAHs and 6 heavy metal species. The contamination level of the top soil was found to be slightly higher than that of the subsoil for contamination with PAHs. The ratio of carcinogenic PAH concentration to the total PAH concentration was relatively high, with a maximum of 0.9. The toxicity equivalent (TEQ) of the PAHs were 500.6 ng/kg in the topsoil and 355.5 ng/kg in the subsoil. The ratio of low molecular PAHs (LPAHs) to high molecular PAHs (LPAHs) ranged from 6.7 to 29.5; this shows that contamination is primarily due to combustion of fuel rather than due to petroleum. The ratio of phenanthrene to anthracene and the ratio of fluoranthene to pyrene also show that contamination occurred due to combustion for transportation. The heavy metal contamination level was lower than the Korean standard, but higher than the background concentration; this indicates that the soil was affected by the operation of the railways.

• The Journal of the Convergence on Culture Technology
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• v.4 no.4
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• pp.393-399
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• 2018

The development of unmanned AI continues, and the development of AI unmanned is aimed at more efficiently, accurately, and speedily the work that has been resolved by manpower such as industry, welfare, and manpower. AI unmanned technology is evolving in various places, and it is time to switch to unmanned systems from many industries and factories. We take this into consideration, and use the Deep Learning technology, which is one of the core technologies of artificial intelligence (AI), not the manpower but the fruits that pour the rails at once in a large orchard. We want to study the unmanned fruit sorting machine that can be operated under manager's supervision without dividing the fruit by type and grade and dividing by country of origin and grade. This unmanned automated classification system aims to reduce the labor cost by minimizing the manpower and to improve the

• Structural Engineering and Mechanics
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• v.78 no.2
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• pp.163-174
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• 2021

Track-bridge interaction has become an essential part in the design of bridges and rails in terms of modern railways. As a unique ballastless slab track, the longitudinal continuous slab track (LCST) or referred to as the China railway track system Type-II (CRTS II) slab track, demonstrates a complex force mechanism. Therefore, a comprehensive track-bridge interaction study between multi-span simply supported beam bridges and the LCST is presented in this work. In specific, we have developed an integrated finite element model to investigate the overall interaction effects of the LCST-bridge system subjected to the actions of temperature changes, traffic loads, and braking forces. In that place, the deformation patterns of the track and bridge, and the distributions of longitudinal forces and the interfacial shear stress are studied. Our results show that the additional rail stress has been reduced under various loads and the rail's deformation has become much smoother after the transition of the two continuous structural layers of the LCST. However, the influence of the temperature difference of bridges is significant and cannot be ignored as this action can bend the bridge like the traffic load. The uniform temperature change causes the tensile stress of the concrete track structure and further induce cracks in them. Additionally, the influences of the friction coefficient of the sliding layer and the interfacial bond characteristics on the LCST's performance are discussed. The systematic study presented in this work may have some potential impacts on the understanding of the overall mechanical behavior of the LCST-bridge system.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.139-147
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• 2021

Numerical analysis was performed using FIMMWAVE to optimize the specifications of Si₃N₄/SiO₂ slot and ridge-slot optical waveguides based on confinement factor and effective mode area. The optimized specifications were confirmed based on sensitivity in terms of the refractive index of the analyte. The specifications of the slot optical waveguide, i.e., the width of the slot and the width and height of the rails, were optimized to 0.2 ㎛, 0.46 ㎛, and 0.5 ㎛ respectively. When the wavelength was 1.55 ㎛ and the refractive index of the slot was 1.3, the confinement factor and effective mode area of 0.2024 and 2.04 ㎛², respectively, were obtained based on the optimized specifications. The thickness of the ridge and the refractive index of the slot were set to 0.04 ㎛ and 1.1, respectively, to optimize the ridge-slot optical waveguide, and the confinement factor and effective mode area were calculated as 0.1393 and 2.90 ㎛², respectively. When the confinement coefficient and detection degree of the two structures were compared in the range of 1 to 1.3 of the analyte index, it was observed that the confinement coefficient and sensitivity were higher in the ridge-slot optical waveguide in the region with a refractive index less than 1.133, but the reverse situation occurred in the other region. Therefore, in the implementation of the integrated optical biochemical sensor, it is possible to propose a selection criterion for the two parameters depending on the value of the refractive index of the analyte.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.127-137
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• 2021

The method of utilizing the strain and vibration values of rails is primarily used to diagnose the condition of wheels and railroad facilities. The dynamic load is measured under the assumption that the strain of the rail and the load of the railroad vehicle are proportional. Wheel condition is measured under the assumption that the magnitude of the defect and the magnitude of the rail vibration are proportional. However, environmental factors affecting the strain and vibration of the rail such as vehicle speed, wheel load, climate, and track conditions are not reflected, many errors occur depending on the measurement conditions. In this study, the effect of track distortion, which is a major indicator of the track condition among the environmental factors that affect the strain and vibration of the rail, on the strain and vibration of the rail, was examined through dynamic simulation. As a measure to reduce the measurement deviation, the effect of securing additional measurement points was analyzed.