• 한국자동차공학회논문집
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• 제8권6호
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• pp.142-155
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• 2000

A MIMO model reference control scheme incorporating the variable structure theory for a vehicle four wheel steering system(4WS) is proposed and evaluated for a class of continuous-time nonlinear dynamics with known or unknown uncertainties. The scheme employs an neural network to identify the plant systems, where the neural network estimates the nonlinear dynamics of the plant. By the Lyapunov direct method, the algorithm is proven to be globally stable, with tracking errors converging to the neighborhood of zero. The merits of this scheme is that the global system stability is guaranteed and it is not necessary to know the exact structure of the system. With the resulting identification model which contains the neural networks, it does not need higher degrees of freedom vehicle model than 3 degree of freedom model. Th proposed scheme is applied to the active four wheel system and shows the validity is used to investigate vehicle handing performances. In simulation of the J-turn maneuver, the reduction of yaw rate overshoot of a typical mid-size car improved by 30% compared to a two wheel steering system(2WS) case, resulting that the proposed scheme gives faster yaw rate response and smaller side angle than the 2WS case.

• 한국소음진동공학회논문집
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• 제16권6호
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• pp.582-592
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• 2006

This paper presents experimental and analytic methods to reduce interior noise generated by car axle. The test vehicle has a whine noise problem at passenger seats. In order to identify transfer path of interior axle noise, the vibration path analysis, the modal analysis and running modal analysis are systematically employed. By using these various methods, it has been founded that the interior noise generated by car axle was air borne noise. To reduce and predict axle noise, various structural modifications are performed by using FEM and BEM techniques, respectively. Through the modification of the axle structure, the air borne noise of the axle was reduced 3$\sim$4 dBA level.

• 산업경영시스템학회지
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• 제42권3호
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• pp.157-166
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• 2019

The study had subject to find out what factors Korean automobile consumer is considering in their decision to purchase cars in the situation of the growing competition in the domestic automobile market. In order to this end, the previous study was reviewed to select various factors considered in the process of buying cars. Based on this, Analytic Hierarchy Process was used to prioritize which factors were considered more important by consumers. In the result of study, we could find that performance had the highest priority, and the second ranking was the price. In contrast, image of brand and convenience of maintenance were shown to be relatively low in importance, ranking $3^{rd}$ and $4^{th}$, respectively. Beside, we could recognized the ranking of other detailed factors. This study has an academic implication in that it is able to grasp the latest tendency of consumers' purchase choice of car and to make conclusion by applying AHP analysis method to study of related subject. It also have practical significance that can be a basis for make sense what factors should be taken by the automobile industry to uprise the purchase of the consumers through the identification and preparation of the purchase selection criteria of domestic automobile buyers.

• 한국산업정보학회논문지
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• 제14권3호
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• pp.1-14
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• 2009

본 논문에서는 번호판 영역의 추출에 사용될 수 있는 특징 벡터와 이를 이용하여 문자와 비문자를 판별하고 숫자를 인식하는 방법을 제안한다. 제안하는 특징 벡터는 영상의 기울기 벡터에서 얻어지는 에지 영상의 방향 코드 히스토그램으로부터 추출된다. 추출된 특징 벡터를 MD로 구현되는 문자 및 비문자 인식기에 입력하여 문자와 비문자를 판별함으로써 번호판 영역의 위치를 추정하고, 숫자를 인식한다. 실험 결과 제안하는 방법이 문자와 비문자의 정확한 판별, 번호판 영역의 위치 추정 및 숫자의 인식에 유용하게 적용될 수 있음을 알 수 있었다.

• 한국자동차공학회논문집
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• 제14권6호
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• pp.143-150
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• 2006

In this paper, a new bushing model for vehicle dynamics analysis using Bouc-Wen hysteretic model is proposed. Bushing components of a vehicle suspension system are tested to capture the nonlinear behavior of rubber bushing elements using the MTS 3-axes rubber test machine. The results of the tests are used to define parameters in Bouc-Wen bushing model, which was employed to represent the hysteretic characteristics of the bushing. Bushing parameters are obtained by using genetic algorithms and sensitivity analysis of parameters are also carried out. ADAMS program was used for the identification process and VisualDOC program was employed to find the optimal parameters. A half-car simulation was carried out to show the usefulness of the developed bushing model.

• 디지털산업정보학회논문지
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• 제13권1호
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• pp.69-78
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• 2017

As the smartphone-based devices are diffused and developed rapidly, they provide the convenience to the users. The abovementioned sentence technologies are being used not only in the existing sensor and wireless network technology but also in the application services of the diverse fields application services such as smart appliance, smart car, smart health care, etc. and the new fusion paradigm from the industry is presented by undertaking the researches in diverse area by the enterprises and research institutions. However, the smart environment exposes its weaknesses in the mobile terminal area, existing wireless network and IT security area. In addition, due to new and variant ways of attack, not only the critical information are disclosed However also the financial damages occur. This paper proposed the protocol to perform the smartphone-based safe device monitoring and safe communication. The proposed protocol designed the management procedure of registration, identification, communication protocol and device update management protocol and the safety against the attack techniques such as the an-in-the-middle-attack, impersonation attack, credential threat, information leaks and privacy invasion was analyzed. It was observed that the proposed protocol showed the performance improved by approximately 52% in the communication process than the existing system.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.635-644
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• 2004

A method of identifying structural parameters such as stiffness and damping coefficients at interfacial points of vibro-acoustic systems is suggested using an optimization technique. To identify the parameters using a numerical optimization algorithm, cost functions are defined. The cost function should be zero at the correct parameter values. To minimize the cost functions using an optimization technique, a design sensitivity analysis procedure is developed in the framework of the multi-domain FRF-based substructuring method. As a numerical example, a ladder-like structure problem is introduced. With known parameter values and different initial guesses of the parameters, convergence characteristics to the exact value are compared f3r the three cost functions. Investigating the contours of the cost functions, we find the first cost function has the largest convergent region to the correct value. As another practical problem, stiffnesses of engine mounts and bushings in a passenger car are identified. The numerical examples show that the proposed method is efficient and accurate far realistic problems.

• 한국소음진동공학회논문집
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• 제14권6호
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• pp.536-545
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• 2004

A method of identifying structural parameters such as stiffness and damping coefficients at interfacial points of vibro-acoustic systems is suggested using an optimization technique. To identify the parameters using a numerical optimization algorithm, cost functions are defined. The cost function should be zero at the correct parameter values. To minimize the cost functions using an optimization technique, a design sensitivity analysis procedure is developed in the framework of the multi-domain FRF-based substructuring method. As a numerical example, a ladder-like structure problem is introduced. With known parameter values and different initial guesses of the parameters, convergence characteristics to the exact value are compared for the three cost functions. Investigating the contours of the cost functions, we find the first cost function has the largest convergent region to the correct value. As another practical problem, the stiffnesses of engine mounts and bushings in a passenger car are identified. The numerical examples show that the proposed method is efficient and accurate for realistic problems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.501-509
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• 2003

A method of identifying structural parameters such as stiffness and damping coefficients at interfacial points of vibro-acoustic systems is suggested using an optimization technique. To identify the parameters using a numerical optimization algorithm, cost functions are defined. The cost function should be zero at the correct parameter values. To minimize the cost functions using an optimization technique, a design sensitivity analysis procedure is developed in the framework of the multi-domain FRF-based substructuring method. As a numerical example, a ladder-like structure problem is introduced. With known parameter values and different initial guesses of the parameters, convergence characteristics to the exact value are compared for the three cost functions. Investigating the contours of the cost functions, we find the first cost function has the largest convergent region to the correct value. As another practical problem, stiffnesses of engine mounts and bushings in a passenger car are identified. The numerical examples show that the proposed method is efficient and accurate even when applied to realistic problems.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.55-64
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• 2021

In the last few years, the massive development in wireless networks, high internet speeds and improvement in car manufacturing has shifted research focus to Vehicular Ad-HOC Networks (VANETs). Consequently, many related frameworks are explored, and it is found that security is the primary issue for VANETs. Despite that, a small number of research studies have taken into consideration the identification of performance standards and parameters. In this paper, VANET security frameworks are explored, studied and analysed which resulted in the identification of a list of performance evaluation parameters. These parameters are defined and categorized based on the nature of parameter (security or general context). These parameters are identified to be used by future researchers to evaluate their proposed VANET security frameworks. The implementation paradigms of security frameworks are also identified, which revealed that almost all research studies used simulation for implementation and testing. The simulators used in the simulation processes are also analysed. The results of this study showed that most of the surveyed studies used NS-2 simulator with a percentage of 54.4%. The type of scenario (urban, highway, rural) is also evaluated and it is found that 50% studies used highway urban scenario in simulation.