• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.606-612
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• 2011

At the product design and development stage, the main criteria selecting a design alternative were performance aspect as well as cost aspect of a product. Ongoing new paradigm shifts such as low carbon green growth, climate change mitigation, sustainable society development urged considering environmental aspect of a product at the product design and development stage. Up to recently, only cost aspect except performance of a product was considered at the railway vehicle design process. Therefore, it is needed to develop a method that may consider environmental aspect of a product at the railway vehicle design process. Lee (2011) proposed that a method of an integration assessment of environmental aspect and cost aspect based on GHG emission instead of based on monetary value. This study conducted that apply the method of Lee (2011) to design alternative selection process of a railway vehicle. From the integrated view of environmental and cost aspect, the reference product and design alternatives are assessed and compared.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.589-594
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• 2004

In design of suspension system for KHST, it was applied the approximated optimization method using meta-models which called Response Surface Model and Neural Network Model for 29 design variables and 46 performance index. These models was coded using correlation between design variables and performance indices that is made by the 66 times iterative execution through the design of experimental table consisted orthogonal array L32 and D-Optimal design table. The results show that the optimization process is very efficient and simply applicable for complex mechanical system such as railway vehicle system. Also it was compared with the sensitivity of some design variables in order to know the characteristics of two models. This paper describes the general method for dynamic analysis and design process of railway vehicle system applied to KHST development, and proposed the efficient methods for vibration mode analysis process dealing with test data and the function based approximation method using meta-model applicable for a complex mechanical system. This method will be able to apply to the other railway vehicle system in oder to systematize and generalize the design process of railway vehicle dynamic system.

• 대한기계학회논문집A
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• 제28권3호
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• pp.267-273
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• 2004

The purpose of this paper is to develop a systematic design method for the suspension system hard points and compliance elements, which have great influence on the handling stability of a vehicle. In this paper, a method to optimize J-turn responses is presented based on the principles of design of experiments, multi-body dynamic analysis and optimum design technique. The design variables associated with the J-turn maneuver are selected through the experimental design sensitivity analysis using the perturbation method. An objective function is defined as an approximate function for the J-turn characteristics using the TSA(Taylor series approximation). The values of the design variables, which make the optimized J-turn characteristics, are obtained using the conjugate gradient method. The result of the J-turn simulation shows that the optimized vehicle has more improved handling stability than the optimized vehicle.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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• pp.191-198
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• 1994

The nonlinear dynamic behaviors of guardrail established on the local or high way have been investigated using BARRIER Ⅶ program with respect to four design variables such as section type of beams and posts, impact angle, impact velocity and vehicle weight. Computer simulation programs are sophisticated analytical models for analyzing dynamic vehicle/barrier interactions and provide a relatively inexpensive alternative to full scale crash testing. This study has been focused on the structural adequacy, occupant risk, and vehicle trajectory. For this purpose, the maximum deflection and impact force have been calculated to design the clear zone and to analyze effect of impact attenuation. Also, the acceleration of vehicle and exit angle after collision have been computed to estimate the occupant risk. From this study, it is suggested that we should strengthen the design criteria of guradrail to prevent from disastrous traffic accidents.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.111-122
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• 2002

European offset impact analysis of an electric vehicle was done using the robust design method. Section properties of some of the vehicle structure components which influence the european offset impact characteristics were chosen as the main factors fur the design. Eight factors were considered for the analysis: one with two level and seven with three level combinations comprising the L$\_$18/(2$^1$$\times$3$\^$7/) orthogonal array. It is shown that the sensitivities of the factors and the best combination of the factors can be obtained. One of the noteworthy results is that the design with the lower stiffness of the front components of engine room than the rear components can absorb more crash energy. Also it is shown that there exist interactions between some of factors considered.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.16-26
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• 1998

The major effective factors on the ride quality of a vehicle are the vibration and noise of the engine and drive system. Engine contributes about 80% of the vibration and noise in the vehicle, and exciting forces of the engine are transmitted onto the vehicle frame through the engine mount. This paper studies the vibration reduction of a vehicle through the improvement of the engine mount. A computer program for optimal design is developed and the engine mount conditions are optimized to reduce the WRMS of PSD of acceleration at the driver's seat, which are caused by the exciting forces at the idle speed. Design variables are selected as the stiffness, mount angle and the location of the engine mount rubber. It is shown through computer simulation that the PSD of acceleration at the driver's seat can be improved by redesigning the engine mount system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제21회 추계학술대회 논문집
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• pp.20-24
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• 2003

The feasibility of hybrid motor as a first stage of the air launch vehicle is investigated, and the result shows the hybrid motor can replace the solid motor. Optimal design study has been performed for the hybrid motor as a first stage of nanosat air launch vehicle. The first stage hybrid motor of the nanosat air launch vehicle, which uses the F-4E Phantom as a mother plane is designed for given mission requirements. Selected design variables are the number of ports, the initial oxidizer flux, the combustion chamber pressure, and the nozzle expansion ratio. The design results show that a hybrid motor can be successfully applicable to very small air launch vehicles which have severe physical constraints of length and diameter imposed by the mother plane.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.110-113
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• 2006

This paper describes the development process of body and full vehicle for reduced idle vibration through the data level of frequency and sensitivity. The vibration mode map is used to separate body structure modes from resonance of engine idle nm and steering system. This paper describes the analysis approach process to reduce the variation of uncertainties for idle vibration performance at initial design stage. The robust design method is performed to increase the stabilization performance under vehicle vibration. It is used to predict the effects of the stiffness deviation according to the spot welding condition of the body structure. The tolerance associated with hood over slam bumper is analyzed for the quality deviation of the moving system in full vehicle. And the glass sealant stiffness and weight difference is considered for the deviation characteristic. The design guideline is suggested considering sensitivity about body and full vehicle by using mother car at initial design stage. It makes possible to design the good NVH performance and save vehicles to be used in tests. These improvements can lead to shortening the time needed to develop better vehicles.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 춘계학술대회 논문집
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• pp.243-250
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• 2002

According to Ocean Korea 21, a basic plan established by the Ministry of Maritime Affairs and Fisheries (MOMAF) of Korea in May 2000, Korea Research Institute of Ships and Ocean Engineering (KRISO) proposed a program for the development of a deep-sea unmanned underwater vehicle (UUV) to explore deep sea for scientific purpose. KRISO has launched a project in May 2001 under the support of MOMAF. The deep-sea unmanned underwater vehicle will be applied to scientific researches in deep-sea as well as in shallow water. For operation of underwater vehicles in shallow water near the Korean Peninsula, a special design is required because of strong tidal current. In addition, MOMAF requires the vehicle to be designed for the purpose of long range survey, a long-term observation, and precise works in a specific area. Thus, KRISO has planned to design the system with the functional combination of both ROV and AUV. This paper presents the design of the deep-sea unmanned underwater vehicle.

• Advances in aircraft and spacecraft science
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• 제2권1호
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• pp.17-44
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• 2015

A modular multidisciplinary analysis and optimization framework has been built with the goal of performing conceptual design of an advanced efficient supersonic air vehicle. This paper addresses the specific challenge of designing this type of aircraft for a long range, supersonic cruise mission with a payload release. The framework includes all the disciplines expected for multidisciplinary supersonic aircraft design, although it also includes disciplines specifically required by an advanced aircraft that is tailless and has embedded engines. Several disciplines have been developed at multifidelity levels. The framework can be readily adapted to the conceptual design of other supersonic aircraft. Favorable results obtained from running the analysis framework for a B-58 supersonic bomber test case are presented as a validation of the methods employed.