• Structural Engineering and Mechanics
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• 제13권1호
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• pp.103-116
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• 2002

A solution based on the linear three-dimensional theory of elasticity is developed for vibration and elastostatic problems of hollow toroids. The theory is developed for transversely isotropic toroids of arbitrary thickness, and has the potential to validate some vehicle and aircraft tire models in the linear range. In the semi-analytical method that is adopted Fourier series are written in the circumferential direction, forming a set of two-dimensional problems. These problems are solved using the differential quadrature method. A commercial finite element program is used to determine alternative solutions. For validation both problems of vibration and elastostatics are considered. Finally results are determined for local surface loading problems, and conclusions are drawn.

• 한국경영과학회지
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• 제39권3호
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• pp.41-49
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• 2014

Several developed countries have recently provided electric vehicle consumers and producers with financial subsidies. There has been some empirical research on the impact of government subsidies on the consumers' purchase of electric cars. However, little analytical research on the government subsidies for the electric car market exists. This research analyzes the impact of the government financial subsidies on the electric car price and technology level as well as the consumers' adoption of electric cars. This research also suggests that the government should subsidize only the electric car market to further improve the electric car technology.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1253-1258
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• 2004

The system safety must be ensured before customization. There was no specific requirement representing system safety in Korea until now. So we should draw safety requirements to guarantee system safety for the first time. In this paper, the Preliminary Hazard Analysis (PHA) to derive the safety requirements on the train control system was carried out. To analyze hazard, we have to deduce system functions, identify related hazards, derive the effects of the hazards, analyze current risks, define the target risks of the system, and deduce the alternative plans to reduce the effects of the hazards. For the case study, the detailed analysis on vehicle collision that was a main hazard of the train control system was carried out.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.295-298
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• 1996

In this paper, a self-tuning optimal control algorithm is proposed to retain the optimal performance of an active suspension system, when the vehicle has some time varying parameters and parameter uncertainties. We consider a 2 DOF time-varying quarter car model which has the parameter variation of sprung mass, suspension spring constant and suspension damping constant. Instead of solving algebraic riccati equation on line, we propose a neural network approach as an alternative. The optimal feedback gains obtained from the off line computation, according to parameter variations, are used as the neural network training data. When the active suspension system is on, the parameters are identified by the recursive least square method and the trained neural network controller designer finds the proper optimal feedback gains. The simulation results are represented and discussed.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.393-396
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• 2005

Due to the fast growing rate of the global container trade, every major port is under the pressure of meeting the projected capacity demand. As a result, alternative solutions have been sought for improving capacity and meeting the growing demand for container storage area and terminal capacity. Moreover, material handling process re-engineering is now a critical issue for logistics and supply chain managers of airline, shipping lines, terminal and warehousing enterprises around the world. Therefore, the purpose of this paper is to develop the 3D simulator for executing performance valuation of port transportation systems. The developed 3D simulator system is to measure the effectiveness of the proposed total system and compare it with existing practices. The performance analysis variables are also defined for these comparisons

• 한국수학교육학회지시리즈D:수학교육연구
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• 제20권1호
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• pp.31-38
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• 2016

WHAT we teach, and HOW students experience it, are the primary factors that shape students' understanding and beliefs of what mathematics is all about. Further, students pick up their sense of mathematics from their experience with it. We have seen the results of the approach to "break the subject into pieces and make students master it bit by bit. As an alternative, we strive to create a teaching environment in which students are DOING mathematics and thereby engender selected aspects of "mathematical culture" in the classroom. The vehicle for doing this is the so-called Japanese Open-ended approach to teaching mathematics. We will discuss three aspects of the open-ended approach - process open, end product open, formulating problems open - and the associated approach to assessing learning.

• 대한안전경영과학회지
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• 제16권3호
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• pp.185-194
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• 2014

Internal engine is the main power source of vehicle and is the main source of air pollution. To satisfy this getting rigorous emission regulation, it must be solved simultaneously the dilemma of reducing emission gas and increasing heat efficiency. Diesel engine is preferred compare with gasoline engine in aspect of energy consumption but it must be solved reducing the containing of NOx, CO and HC. In this study: 1. Looking for alternative of performance improvement of Exhaust Gas Recirculation(EGR) which is emission gas reduction system. 2. Reducing malfunction of controlling emission gas. 3. Made possible precision control.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.858-863
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• 2007

With increase of load power the case it will not be able to supply the power which is necessary to the vehicle, it establishes dosage increase of main transformer of substation or power compensation equipment, and must supply the power which is necessary. But like this method the expense and the hour when it is considerable are necessary. As an alternative plan, if neighborhood substation can supply power through parallel feeding then it can supply power applying the equipment of existing. So we investigate the possibility of parallel feeding method between neighboring substations through measuring results of voltage phase difference and analysing feeding circuit,

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1105-1114
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• 2007

Recently the urban railroad which is under plan and construction in domestic is under consideration Light Rail Transit mostly with the alternative against excess of working expenses of Midium Rail Transit(subway), inefficient transportation problem etc. It come to a conclusion that the application of the light rail transit is proper from reserve feasibility study and approval process of Master plan in Daegu urban railroad Line No.3 Based on hereupon, carried out the detail investigation for optimum system selection which suitable for Daegu urban circumstance in process of master plan can satisfy the working expenses decided in national expenditure support project.

• 전기학회논문지
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• 제63권12호
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• pp.1759-1763
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• 2014

In this paper, we were performed a structural analysis and durability analysis for an integral frame with an axle according to development of the electric locomotive traction motor. In terms of the structural stability, as a result of the analysis modeling with coupling conditions of beam element and an alternative element of three-dimensional, the maximum von-Mises stress of the locking screw mounting frame were similar as 50MPa and 51MPa. Also A comparison of the natural frequency and the exciting frequency while driving of the electric locomotive No. 8200, the natural frequency is 627.05Hz~856.9Hz while the exciting frequency is not more than most 30Hz or 553Hz, 1110Hz. Therefore, it is possible to avoid the resonance.