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        검색결과 28

        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study is to develop an comprehensive validation methodology for autonomous mobility-on-demand system with level 4 automated driving system. METHODS : The proposed method includes the quantitative techniques for validating both automated driving system and center system using each optimal indicators. In addition, a novel method for validating the whole system applying multi-criteria decision methodology is suggested. RESULTS : The relative weights for the vehicle system was higher than the center systems. Moreover, the relative weights of failure rate for validating the vehicle system was the highest, in addition to, a relative weight for accuracy of dynamic routing algorithm within center system was the highest. CONCLUSIONS : The proposed methodology will be applicable to validate the autonomous mobility on demand system quantitatively considering the relative weights for each systems.
        2020.12 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 노인의 자가운전 현황과 운전면허 관리제도에 대한 인식을 알아보고자 실시하였다. 연구 방법 : 지역사회에 거주하는 운전면허증을 소지한 60세 이상 노인을 대상으로 총 124부의 설문지를 배포하 였다. 배포한 설문지 중에서 총 93부를 회수하여 최종적으로 분석하였다. 결과 : 조사 대상자 중에서 현재 운전을 한다는 응답자가 76명(81.7%)이었고, 운전빈도는 주 1-2회가 26명(34.2%), 주 3-5회 23명(30.3%), 매일 19명(25%) 순으로 응답하였다. 운전하는 시간대는 오전 9시부터 오후 6시까지 낮 시 간대 운전이 61명(80.3)로 가장 많았다. 운전 시 가장 어려운 부분은 시력 저하라고 38명(50.0%)이 응답하였으며, 운전 중단 시기에 대해서는 ‘질환이나 장애가 발생했을 때’35명(46.1%), ‘주변에서 운전을 그만두라고 권유할 때’20명(26.3%) 순으로 응답하였다. 운전에 영향을 줄 수 있는 질환들 중에서 현재 가지고 있는 질환은 고혈압 35명(37.6%), 당뇨병(30.1%), 관절염 19명(20.4%) 순으로 많았다. 운전면허 자진반납제도, 운전기능검사, 교통안전 교육 실시에 대한 동의여부를 확인한 결과, 운전면허증 자진반납제도에 대해서는 반대의견이 73명(78.5%)으로 많았다. 반면에 운전기능검사에 대한 찬성의견은 70명(75.3%), 교통안전교육 찬성의견은 76명(81.7%)으로 반대보 다 많았다. 결론 : 본 연구를 통해 확인한 지역사회 노인들의 노인 운전자의 자가운전 현황과 새로운 운전면허 관리제도에 대한 인식에 대한 이해를 바탕으로 노인운전자들의 안전운전 증진의 방향을 모색하는 것이 필요할 것이다.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, bicycle has means of effective healthy transportation, and riding the bicycles is considered as popular recreational and sporting activities. Also, the saddle, steering system, driving device and braking device are researched briskly because of consumer’s need for driving performance and comfort. Especially, the importance of a cassette responsible for transmission function by transmitting power to the drive shaft through the chain is very focused. The writer conducted structural analysis for the sprocket of each level using the ANSYS widely used for the analysis. Speed shifting performance was enhanced by minimization / simplification of shifting point through a sort of tooth profile of the cassette. By partitioning a clear value type and other shifting point, it has been modified to enable smooth speed-shifting. In addition, as titanium precision forming process, this study studied the molding technique by blanking and dies forging for mass production of the cassette. so it could be expected that the entire drive train would utilize that in the future. The stamping process capability for thin materials for the mass production of the sprockets is applicable to producing automobile parts, so lightweight component production is likely to be possible through that, for the safety of driving.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study aimed to develop a proactive anti-icing system for driving zones at risk during winter. METHODS: An electric low power potable anti-icing system, operated with a battery and solar cell, was designed and fabricated. Potassium acetate was used as the anti-icing chemical. The developed anti-icing system was tested in the laboratory in advance to confirm its function. Potassium acetate was also tested both in the laboratory and outdoor (exposed to the sun) conditions. The anti-icing system was set up on the road for field testing. RESULTS: The 195 m spread distance of the anti-icing system was verified in the field test. CONCLUSIONS: The anti-icing system developed for safe driving on the road will be cost-effective and economical during installation and maintenance compared with currently used snow melting systems on vulnerable driving zones.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: Traffic safety facilities are used to prevent traffic accidents before they occur by providing drivers with information on traffic situations and the geometric design of roads. However, some facilities not defined in guidelines do not meet installation criteria, yet are being installed and used in order to increase efficiency in traffic flow and prevent traffic accidents in a specific expressway zone. In this study, we have evaluated the effect of delineation system which are not defined in the guideline criteria. METHODS : Different virtual scenarios were created for roads using expressway median barrier chevron signs, with a driving simulator used to evaluate the installation and operational effect of such signs. Ten experiments were performed with left- and right-curved roads at curve radius intervals of 500 m, from 500 m to 2,500 m. RESULTS: For sections with a curve radius of more than 1,500 m, drivers had a clear tendency toward stable driving regardless of delineation system. When a chevron sign is installed on a protection fence in the road curving left, an expanded installation is recommended up to the section with a curve radius of 1,000 m. According to the analysis results for the RHB (Relative High Beta spectrum), driving concentration also improved up to a curve radius of 1,000 m. CONCLUSIONS: The experiment result indicates the extent of biasing within a lane and the manipulation amount of steering handle, were analyzed and found to be affected by curve radius and road alignment regardless of delineation system.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To overcome recent emission regulation, various hybrid systems are being developed. In the E-4WD(electric four wheel drive) system, the engine and transmission drive the front wheel, electric motor and single reduction gear drive the rear wheel. As the gear ratio of the reduction gear set determines the electric motor's operating point, the gear ratio is important to enhancement efficiency of hybrid system. This study is to analyze motor reduction gear ratio's influence on E-4WD hybrid system for optimized efficiency and driving performance. Fuel economy, operating point of power source and hybrid mode are analyzed using simulation developed with dynamic programming method.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 컬러정보와 깊이정보를 사용하여 얼굴을 검출하고 추적한 후 항해사의 졸음을 탐지하는 방법을 제안한다. 이 방법은 얼굴검출 과정과 얼굴추적 과정으로 구성된다. 얼굴검출 과정에서는 기존의 방법 중 가장 좋은 성능을 보이는 Adaboost 알고리즘을 사용하며, Adaboost로 입력되는 영상의 영역을 사람이 존재하는 영역으로만 제한하여 얼굴을 검출한다. 얼굴검출 과정에서 얼굴이 검출되면 그것을 템플릿으로 하여 얼굴추적 과정이 수행된다. 제안한 방법의 성능을 평가하기 위하여 실험영상을 이용하여 실험을 수행하였다. 실험결과 제안한 졸음탐지 방법은 기존의 방법에 비해 약 23 %의 수행시간을 보였으며, 또한 졸음탐지 방법은 추적시간과 추적 정확도에 있어서 상보적인 관계를 가지며, 특별한 경우를 제외한 모든 경우에서 약 1 %의 낮은 추적오차율을 보였다.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Engine power of industrial vehicle is used to control the driving load, steering load and operating load. In other words, one power source need to transmit part of power through several power transmission paths. To achieve this performance, we consider a gear box which have one input shaft and several output shaft. In this study, the performance of gear box is analyzed to find out the reliable test process in dynamometer. With test results, the validity of study is verified.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many countries of the world has been devoting a lot of effort to reduce carbon emission. In order to reduce carbon emission, the high efficiency engine has been studied in the automotive industry. Of these, the spread and research of the diesel engine in Europe center are active. However the combustion characteristic of diesel engines have disadvantages of much NOx and soot emissions. In this study, the optimum regeneration point of the forced regeneration type DPF(Diesel Particulate Filter) that was equipped in medium-duty diesel vehicles using a mechanical fuel injection system have studied. DPF that is applied to the medium-duty diesel vehicle has a bent inlet pipe. The flow distribution characteristics of DPF according to the influence of the bent pipe have investigated. The flow distribution characteristics of DPF according to variation of the engine operating condition is considered to be useful data In order to decide the optimum regeneration point.
        2013.10 구독 인증기관 무료, 개인회원 유료
        In this paper, we developed a power amplifier system for driving a solenoid coil. The developed system consists of three units; control unit, drive unit and coil. The control unit generates a drive signal of sinusoidal wave type, monitors an operating status of the drive unit and vibration characteristics of the coil. The drive unit drives a solenoid coil in response to command from the control unit. The coil was fabricated with the size of diameter in 1.5 cm and length in 1.7 cm using electric copper wire. 4 types of drive unit were tested with thermal and vibration characteristics of the coil using temperature sensor and 3-axis accelerometer, respectively. From the result, the developed system has many advantages with respect to simple control algorithm, small size, and operates stably up to 68 watts driving condition.
        2013.08 구독 인증기관 무료, 개인회원 유료
        Flexible Driving System(FDS)는 제조업(주로 자동차 생산공장 및 전자제품 생산공장, 식품공장 등) 생산공장에서 사용되는 무인 자동화 운반설비를 말한다. 지금으로부터 200년전 James Ford가 개발했던 공장자동화의 역사는 산업혁명을 거치면서 발전을 거듭하였으며 최근에는 작업자의 안전 및 돌발적 사고로 인한 생산성 급감이 생산공장에서는 중요한 이슈로 떠오르고 있으며, 이를 보완하기 위한 기존 시스템의 운반설비 시스템에 더욱 스마트한 기능을 더한 자동화설비에 대한 필요성이 증대되었다. 이를 위해 먼저 현재 생산중인 제어부 전차반의 크기를 기존 대비 30 % 정도 compact하게 재설계하여 소형화함으로써 종래의 기어방식의 컨베이어 시스템의 대용으로 사용되며, 향후 전문화 될 경우 Electrical Moving System(EMS)가 널리 사용되게 될 전망이다.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Driving mechanism, the central part of a robot, was designed in this study. Power for the motive drive was acquired by directly connecting the motor shaft in worm shape of the low-end DC motor, car window motor, to a decelerator. The decelerator consists of a worm gear to receive power from the motor shaft, a pinion gear to be connected in line with the worm gear, and an output shaft to be engaged to the pinion gear. Motion driving is achieved by the power from the motor shaft with the designed gears, transferred to the deceleration mechanism and to the output gear
        2008.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        섬유기계산업은 생산성의 극대화를 위해 고속/정밀화를 추구하고 있으며 수요자의 요구에 따라 높은 내구성과 안정성, 신뢰성을 가진 기계를 요구하고 있다 본 연구에서는 워터제트직기를 대상으로 실제 운전 시 구동계에 토크센서를 부착하여 모듈별로 직기에 영향을 미치는 부하량을 측정 및 분석하였다 또한, 워터제트직기에 대한 동역학적 해석을 수행한 결과와 비교함으로서 섬유기계의 구동계에 대한 토크와 진동에 대한 계측 및 분석기술을 개발하고, 내구성과 안정성이 뛰어난 고부가가치의 섬유기계 개발에 대한 기초자료를 제시하였다.
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