• Proceedings of the KSR Conference
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• 1998.05a
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• pp.572-579
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• 1998

In this paper, an analytical model for analyzing the interaction between train and floating slab track is presented. Train is modelled by 4-lumped masses system which are composed of a carbody supported by secondary suspension, a bogie frame supported by primary suspension, and two wheelsets supported by nonlinear Hertzian springs. In the track model, rail is considered to have a distributed mass and to be supported discretely at sleepers above ballast on slab. The slab supported by discrete isolators put on fixed floor is modelled by finite beam elements. Numerical analyses are carried out to examine anti-vibration effect of the GERB slab track which is same type laid in Puchon station on the subway No. 7 Line.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.387-392
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A train dynamic modeling is modified with the one car model presented in the previous conference and it was extended to 6cars models having the same suspensions and added some connection's characteristics between the cars with Vampire program. It is used to analyze the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics in the condition of 6 cars configuration. The results would be useful to manage the potential risks in the next stage of basic and critical design that will be done by the manufacturing company.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.617-623
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• 2020

Urban railroad vehicles carry many passengers and are the core of an urban railroad transportation system. Therefore, the dynamic performance of the vehicle must be ensured. Dynamic behaviors such as the vibration and ride comfort of railway vehicles are affected by the structure of the suspension system. We analyzed the dynamic behavior of a railway vehicle according to the suspension system of an urban railway vehicle, which is mainly operated in Korea. For two types of vehicles with different suspension structures, the vibration of the vehicles on railway tracks was measured, and dynamic behavior characteristics such as vibration, ride, and vibration reduction rate were analyzed. The result of the test shows that the vibration performance of the body is superior to that of B-bogie in the lateral direction and that of A-bogie in the vertical direction. Overall, the ride quality of the A-bogie car is superior to that of B-bogie. When analyzing the vibration attenuation rate of primary suspension system, the vibration attenuation performance of B-bogie with coil spring was superior to that of A-bogie with a conical rubber spring. The secondary suspension system has better vibration attenuation performance for A-bogie with air springs compared to coil springs.

• Journal of Oriental Neuropsychiatry
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• v.21 no.2
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• pp.61-73
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• 2010

Objectives : The purpose of this study was to assess anti-depressive effects of Bee Venom(BV) on an Animal Model of Depression induced immobility stress. Methods : There was 2 pre-experiments MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and Western blot test and 3 main experiments ; forced swimming test, tail suspension test and Y-maze task. Male rats were used for main experiment. The subject was divided into 4 groups(1. control group injected only saline, without immobility stress 2. Negative group injected saline after 2 hours immobility stress 3. Positive group injected Amitriptyline after 2 hours immobility stress 4. BV group injected Bee Venom after 2 hours immobility stress). Each group consisted of 6 rats. Forced swimming test, tail suspension test, Y-maze task were used to evaluate anti-depressive effect of Bee Venom. Results : In MTT assay, as the density of BV increased, the existence rate of primary neuronal cell increased. In Western blot test, the density of CREB and AKT was increasing as time went by. In forced swimming test, BV group showed immobility decreased more than Normal group and Positive group. In tail suspension test, Normal group and Positive group showed immobility decreased more than BV group. In Y-maze task, BV group showed immobility decreased more than Normal group, but Positive group showed immobility decreased more than BV group. Conclusions : These results suggest that Bee Venom may have anti-depressive effect on depression.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.84-90
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• 2018

In constructing the multi-body dynamics model to analyze the behavior of the railway vehicle, it is very important to understand the properties of the suspension elements that constitute the suspension system. Among them, coil springs, which are mainly used in primary and secondary suspension systems, clearly show the axial stiffness in the drawings, but the lateral properties of the coil springs are not specified clearly, making it difficult to construct a dynamic analysis model. Therefore, in this paper, the model for analyzing the lateral stiffness of the coil spring is examined. A finite element method was applied to analyze the lateral stiffness of the coil spring and numerical analysis was performed by applying the coil spring lateral stiffness analysis model proposed by Krettek and Sobczak. And the test to analyze the lateral stiffness of coil spring was conducted. As a result of comparing with the test results, it was found that the results obtained by applying the lateral stiffness analysis model of Krettek and Sobczak and correcting the correction coefficient are similar to those of the test results.

• Korean journal of dermatology
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• v.56 no.9
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• pp.552-555
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• 2018

Vitiligo is a commonly acquired cutaneous depigmentation disorder that affects 0.5~1% of the population worldwide. While phototherapy is the primary treatment for vitiligo, surgical methods can be used for treating patients who are refractory to conventional treatments. Herein, we present the case of a 14-year-old Korean girl who developed vitiligo after hematopoietic stem cell transplantation for the treatment of acute lymphoblastic leukemia. She had multiple depigmented patches on her lower legs that did not respond to narrow-band ultraviolet B phototherapy for 7 months. The depigmented patches were successfully treated by transplantation of non-cultured epidermal cell suspension from the epidermal roof of the suction blister in the right inner thigh. No adverse event, such as secondary infection or scarring in both the donor and recipient sites, was noted. We recommended that non-cultured epidermal cell suspension transplantation using the suction blister method would be a safe and effective option for the treatment of refractory vitiligo.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1631-1638
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• 2007

In this paper, a modeling for the dynamic behavior of a train vehicle is suggested for the prediction of the braking characteristics. In the dynamic modeling, effects of the primary and secondary suspension elements are considered and interactions between two vehicles are also estimated. This study can offer some fundamental results for a further research to enhance the braking performance using active braking control.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1134-1135
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• 2006

In this paper, dynamic simulation results for magnetically-levitated vehicles are resented. The dynamic equation and models for a half-bogie system are derived. The system includes primary suspension system, magnet module, spring-damper system and cabin. Also, the dynamic characteristics for the derived models are analysed. Using the results, levitation control algorithm can be designed to meet the performance requirements.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.124-131
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• 1999

The axle spring is used in primary suspension component of railway vehicles. The most important factor of axle spring is to have adequate spring constant for comfortable feeling of ride. The non-linear properties of rubber which were important parameter to evaluate of rubber components, were determined by the characteristic test. The finite element analysis of the axle spring are executed to predict the behavior of deformation and stiffness by using commercial FEA code.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.474-481
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• 1998

Metal bonded rubber spring is used in primary suspension component of the high speed train. The aim of this study is to establish a finite element analysis technique for the metal bonded rubber spring. Some theoretical analyses were performed on the hyperelastic behavior in rubber material and test are carried out to acquire the constants in strain energy function for it. Also, finite element analysis were executed to evaluate the design parameter and behavior of deformation and stress distribution using by the commercial finite element code.