• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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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.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.617-623
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• 2020

다수의 승객을 운송하는 도시철도 전동차는 도시 철도교통시스템의 핵심이다. 따라서 차량의 동적성능이 확보가 차량 안전 확보 및 승객서비스 차원에서 선행되어야 한다. 철도차량의 진동, 승차감과 같은 동적거동은 현가시스템 구조 및 현가요소에 따라 크게 영향을 받는다. 철도차량의 현가시스템은 윤축과 대차간 1차현가시스템, 대차와 차체간 2차현가시스템으로 구성되어 있다. 본 논문에서는 국내에서 운용되고 있는 전동차 현가구조에 따른 전동차의 동적거동에 대하여 분석하고자 한다. 현가구조가 상이한 2종류의 전동차에 대하여 실제 선로에서 동일 주행조건으로 주행시험을 수행하였으며 차량의 진동을 계측하였고 진동과 승차감, 진동감쇠율과 같은 동적거동 특성을 분석하였다. 시험결과, 차체 진동성능은 좌우방향은 B대차가, 상하방향은 A대차가 상대적으로 우수하게 나타났다. 승차감은 전반적으로 A대차가 B대차에 비하여 우수하게 나타났다. 진동감쇠율을 보면, 1차현가시스템은 고무스프링이 적용된 A대차에 비하여 코일스프링이 적용된 B대차의 진동감쇠 성능이 우수하며 2차현가시스템은 코일스프링에 비하여 공기스프링이 적용된 A대차의 진동감쇠 성능이 우수하다. 본 논문의 결과는 향후 철도차량 신차 설계 과정에서 현가구조 설계 및 현가요소 선정 시, 유용한 자료로 활용될 것이라 기대된다.

• 동의신경정신과학회지
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• 제21권2호
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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.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.84-90
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• 2018

철도차량의 거동을 해석하기 위하여 다물체 동역학 모델을 구성함에 있어 현가시스템을 구성하는 스프링, 댐퍼와 같은 현가요소에 대한 스프링강성이나 감쇠계수와 같은 물성치 파악은 매우 중요하다. 그 중 1차, 2차 현가시스템에 주로 활용되고 있는 코일스프링에 대한 동역학 모델을 구성함에 있어 축방향 강성은 도면이나 설계자료에 명확하게 명시되어 있지만 횡방향에 대한 물성은 명시되어 있지 않아 동역학 해석 모델 구성에 어려움을 안고 있다. 따라서 본 논문에서는 철도차량의 현가시스템에 폭 넓게 적용되고 있는 코일스프링에 대한 횡강성을 해석하기 위한 모델에 대하여 검토하고자 한다. 코일스프링 시료에 대한 횡강성을 해석하고자 유한요소해석 방법을 수행하였고 Krettek와 Sobczak의 코일스프링 횡강성 해석모델을 적용하여 수치해석을 수행하였다. 그리고 코일스프링 시료를 대상으로 횡강성 특성시험을 수행하여 해석모델과의 적합성을 검토하였다. 시험결과와 비교한 결과, Krettek와 Sobczak의 코일스프링 횡강성 해석모델을 적용하고 보정계수를 수정한 결과가 시험결과에 근사한 결과를 얻을 수 있었다.

• 대한피부과학회지
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• 제56권9호
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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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.