• 한국자동차공학회논문집
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• 제7권9호
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• pp.146-157
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• 1999

Safety systems for road vehicles have been rapidly developed in recent years. Especially, the VDC(Vehicle dynamics Control) system is a new active safety system for road vehicles which controls its dynamic vehicle motion in emergency situations . In the case of configuring the VDC system by utilizing the ABS(Anti-lock Brake System), the role of a control logic which directly influences the vehicle motion is very important. In this study the performance of the VDC vehicle was compared to the performances of the CBS (Conventional Brake system )and ABS vehicle. For various driving conditions , the simulation of vehicle dynamics with known VDC control logics was performed. Analysis results showed the VDC vehicle could stably perform even on the road of low coefficient of friction. In addition it was shown that the basic control logic for the VDC system could outstandingly improve driving stability in the case of braking as well as constant speed cruising.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 추계학술대회 논문집
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• pp.139-140
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• 2013

본 연구는 군 항공용 레이더 프로세서 유닛용 다중 출력 스위칭 전원공급기 개발 과제의 효율 요구조건 만족을 위해 선행 연구 과제로 실시되었다. 전원공급기의 다중 출력 전원 중 출력 전력이 크고, 효율 측면에서 구현 난이도가 높은 +3.3VDC/55A 전원을 대상으로 선정하였다. 주요 개발 목표 사양은 입력전압 범위 230VDC~330VDC, 전압 안정도 ${\pm}2%$, 효율 85% 이상이다. 이를 만족하기 위해 DC/DC 컨버터의 메인 토폴로지는 하프 브릿지 컨버터이며, 효율 특성 개선을 위하여 동기정류방식을 적용하였다. 본 논문은 DC/DC 컨버터의 설계와 Prototype을 제작하고, 고찰된 실험결과를 제시한 내용으로, 230VDC~330VDC 범위의 입력 조건 및 +3.3VDC/55A 출력 조건에서 최대 89%의 효율 특성을 확인한 내용을 기술한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.707-710
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• 1998

This paper presents a new voltage down converter(VDC) for low power, high speed DRAM. This VDC Consists of RVG(Reference Voltage Generator) and Driver Circuit. And it is independent of temperature variation, and Supply Voltage. Using weak inversion region, this RVG dissipates low power. Internal Voltage Source of this VDC is stable in spite of high speed operation of memory array. This circuit is designed with a $0.65\mu\textrm{m}$ nwell CMOS technology. In HSPICE simulation results, Temperature dependency of this RVG is $20\muV/^{\circ}C,$ supply voltage dependency is $\pm0.17%,$ $VCC=3.3V\pm0.3V,$ and current dissipation is $5.22\muA.$ Internal voltage source bouncing of this VDC is smaller than conventional VDC.

• 한국인터넷방송통신학회논문지
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• 제13권6호
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• pp.123-129
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• 2013

안드로이드 파일시스템은 임의적 접근제어 방식을 사용하여 시스템의 자원에 접근할 수 있는 오픈 시스템이기 때문에 상대적으로 저장장치에 대한 제어가 필요하다. 이러한 특성으로 인해 안드로이드의 VDC를 통해서 접근제어를 하는 경우 안드로이드가 VDC 기능을 제공하는 경우에만 가능하다는 문제점이 있다. 이를 개선하는 방법으로는 VDC의 기능을 시스템 콜(system call)을 통하여 직접 구현함으로써 OS와는 별도로 연동 모듈을 만들어 저장장치 제어기능을 추가하여야 한다. 본 논문에서는 일반적인 저장장치의 마운트 시스템에 대하여 VDC 기능을 이용하여 사용자에 대한 접근을 제어하는 방법을 제안하였다. SD, UMS 와 같은 저장장치에 대한 접근제어를 마운트 방식에 의하여 구현하였고 제안된 기법이 제어가 설정된 저장장치에 파일을 복사/저장하려면 쓰기가 금지되어 제어가 수행됨을 실험을 통하여 검증하였다.

• 한국정보통신학회논문지
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• 제9권6호
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• pp.1402-1406
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• 2005

차량 안정성에 관한연구는 전자제어시스템의 발달과 더불어 급속한 발전을 이룩하였다. 이러한 장치들은 ABS, TCS등이 있고, 현재 활발히 연구되고, 실용화 단계에 있는 VDC이 있다. 그러나 이러한 장치들은 제동력이나 엔진 토크의 감소로 제어되므로 운전자의 의지와는 상관이 없는 차량의 운동이 발생하게 된다. 본 논문에서는 ATC의 동적성능 해석을 수행 하였다.

• 한국자동차공학회논문집
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• 제7권9호
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• pp.212-219
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• 1999

This paper describes the NANDO VDC (Vehicle Dynamics Control) system for the vehicle stability enhancement and consists of the control strategies , computer simulation and tests on the various road surface. This VDC system controls the dynamic vehicle motion in the emergency situation such as the final oversteer/understeer andallows the vehicle to follow the course as desired by the driver. The system is based on an active yaw control and its performance verified by the test is shown. Also the comparison between the MANDO VDC System and a competitor is carried out.

• 한국자동차공학회논문집
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• 제11권3호
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• pp.184-191
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• 2003

HILS(Hardware-ln-the-Loop Simulation) is a scheme that incorporates hardware components of primary concern in the numerical simulation environment. Due to its advantages over actual vehicle test and pure simulation, HILS is being widely accepted in automotive industries as test benches for vehicle control units. Developed in this study is a HILS system for VDC(Vehicle Dynamics Control) with a valve control system that modulates the brake pressures at low wheels. Two VDC control logics were developed and tested in the HILS system. Test results under various driving conditions are presented in this paper.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.115-122
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• 2004

Evaluation of active safety control systems usually relies heavily on field testing and is time-consuming and costly. Advances in computer simulations make it possible to perform exhaustive design trials and evaluations before field testing, and promise to dramatically reduce development cost and cycle time. In this paper, a comprehensive simulation-based evaluation procedure is proposed, which combines standard evaluation maneuvers, worst-case techniques, and a driver model for closed-loop path following evaluations. A vehicle dynamic controller (VDC) for a popular Sport Utility Vehicle is evaluated using the proposed procedure. Simulation results show that the proposed procedure can be used to assess the performance of the VDC under various conditions and provides valuable information for the re-design of the VDC.

• 제어로봇시스템학회논문지
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• 제13권5호
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• pp.414-421
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• 2007

This paper presents a engine/brake integrated VDC(Vehicle Dynamic Control) system using neural network algorithm methods for wheel slip and yaw rate control. For stable performance of vehicle, not only is the lateral motion control(wheel slip control) important but the yaw motion control of the vehicle is crucial. The proposed NNPI(Neural Network Proportional-Integral) controller operates at throttle angle to improve the performance of wheel slip. Also, the suggested NNPID controller performs at brake system to improve steering performance. The proposed controller consists of multi-hidden layer neural network structure and PID control strategy for self-learning of gain scheduling. Computer Simulation have been performed to verify the proposed neural network based control scheme of 17 dof vehicle dynamic model which is implemented in MATLAB Simulink.

• International Journal of Precision Engineering and Manufacturing
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• 제4권3호
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• pp.28-35
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• 2003

The objective of the Vehicle Dynamics Control (VDC) system is to maintain vehicle stability under critical lateral motions, It has a good potential of becoming one of the chassis control necessities since the system can be realized with little additional cost on top of the ABS/TCS system, Developed in this research is a hardware-in-the-loop simulator for VDC with a valve control system that modulates the brake pressures at four wheels: Two VDC control logics, a simple control logic and an LQR control logic, have been developed and incorporated in the HILS system. Their performance under various driving conditions was tested in the HILS system and the results are presented.