• 제목/요약/키워드: SKID

검색결과 185건 처리시간 0.036초

실차 실험을 통한 제동순시간에 의한 타이어-노면마찰계수에 관한 연구 (An Experimental Study of Tire-Road Friction Coefficient by Transient Brake Time)

  • 한창평;박경석;최명진;이종상;신운규
    • 한국정밀공학회지
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    • 제24권7호
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    • pp.106-111
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    • 2007
  • In this paper, the transient brake time was studied on the van type vehicle with accelerometer. Experiments were carried out on the asphalt(new and polished), unpacked road(earth and gravel) and on wet or dry road conditions. The transient brake time is not effected bzy the vehicle speed. The transient brake time is about 0.41$\sim$0.43second on the asphalt road surface and the error range is within 0.1$\sim$0.16second. For the asphalt road condition, the transient brake time is not effected by both new asphalt road surface and the polished asphalt road surface. With compared by dry and wet road surface condition, the transient brake time of wet condition is longer than dry road condition and compared with unpacked road condition and packed road condition, unpacked road condition is shorter than packed road condition. It is considered that the transient brake time is effected by the road surface fraction coefficient. In other words, the transients brake time increases as friction coefficient decreases.

포항가속기의 Reflective Memory를 이용한 독립형 BPM 제어시스템 개발 (Development of Independent BPM Control System Using Reflective Memory at PLS)

  • 윤종철;이진원;이은희;강흥식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.1697-1698
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    • 2008
  • PLS(Pohang Light Source) is 2.5 Gev synchrotron radiation source in Pohang, Korea, which is under operation since 1995. The hardware and software of the old BPM(Beam Position Monitor) data acquisition system for the PLS storage ring was completely upgraded to increase its performance and stability. The new BPM data acquisition system is based on VME-based EPICS (Experimental Physics and Instrument Control System) IOC system. We used 16-bit resolution analog-to-digital conversion board to digitize analog BPM signals. We developed a data average software to average raw BPM data using reflective memory board. We also developed device drivers for VME I/O boards used, IOC database for PV's(Process Variables). The new BPM data acquisition system is currently running for routine operation with good performance and stability. In this paper, we present the hardware and software of the new BPM data acquisition system DTL water skid cooling system and Resonant Control Cooling.

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KSLV-I 킥모터 개발을 위한 고공환경모사시험용 추력측정장치 (Thrust Measurement System for High Altitude Simulation Test of the KSLV-I Kick Motor)

  • 이정호;조상연;조기주;정동호;이한주;오승협;윤경렬;김동철
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.428-431
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    • 2008
  • Korea Aerospace Research Institute(KARI) is achieving the Korea Space Launch Vehicle(KSLV) program according to National Space Technology Development Program. KSLV-I will be composed to liquid propellant(first stage) and solid propellant(second stage) propulsion system. The propulsion system of KSLV-I second stage is solid kick motor with high expansion ratio and its starting altitude is 300km high. In order to verify the performance of upper stage propulsion system designed to operate in the upper atmosphere, test facility which can simulate high altitude is needed. High Altitude Simulation Test Facility is composed to Thrust Measurement System, Control & Measurement system, Diffuser, SKID for cooling water supply to diffuser, CCTV, fire protection system and so on. This paper introduces TMS adapted to High Altitude Simulation Test for KSLV-I Kick Motor Development and results of hot firing test for its performance verification.

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대형 PDP TV후방 판넬 금형 개발 (Development of Back Panel Dies for the Large Size PDP TV)

  • 안동규;김진석;한길영
    • 한국공작기계학회논문집
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    • 제15권6호
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    • pp.88-96
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    • 2006
  • The objective of this research works is to develop back panel dies of PDP TV with a large size. In order to design the geometry of the dies and an initial size of blank optimally, the finite element analysis has been carried out using AUTOFORM V4.2. The conner radius of the upper trimming area and the distance from the outer line of the blank holder to the outer line of the blank have been selected as design parameters to remove the wrinkling of the trimming area. The results of the analyses have been shown that a feasible product without wrinkles and skid lines can be obtained when the conner radius ranges from 6mm to 8mm and the distance lines in the range of 40-60mm. From the proposed design of the dies and an initial blank size, the final die set of the back panel has been successfully manufactured.

4륜 독립구동형 농업용 플랫폼의 주행 궤적 추종 성능 향상을 위한 휠 슬립 검출 및 보상제어 알고리즘 연구 (Slip Detection and Control Algorithm to Improve Path Tracking Performance of Four-Wheel Independently Actuated Farming Platform)

  • 김봉상;조성우;문희창
    • 로봇학회논문지
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    • 제15권3호
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    • pp.221-232
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    • 2020
  • In a four-wheel independent drive platform, four wheels and motors are connected directly, and the rotation of the motors generates the power of the platform. It uses a skid steering system that steers based on the difference in rotational power between wheel motors. The platform can control the speed of each wheel individually and has excellent mobility on dirt roads. However, the difficulty of the straight-running is caused due to torque distribution variation in each wheel's motor, and the direction of rotation of the wheel, and moving direction of the platform, and the difference of the platform's target direction. This paper describes an algorithm to detect the slip generated on each wheel when a four-wheel independent drive platform is traveling in a harsh environment. When the slip is detected, a compensation control algorithm is activated to compensate the torque of the motor mounted on the platform to improve the trajectory tracking performance of the platform. The four-wheel independent drive platform developed for this study verified the algorithm. The wheel slip detection and the compensation control algorithm of the platform are expected to improve the stability of trajectory tracking.

농촌 마을회관의 유니버설디자인 적용성 평가 - 전남 화순군 25개 마을회관을 중심으로 - (The Evaluation of the Village Community Center in Aspects of Universal Design Principles - Focused on 25 Village Community Centers in Hwasoon Province -)

  • 문인영;김미희
    • 한국실내디자인학회논문집
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    • 제23권1호
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    • pp.162-171
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    • 2014
  • This study aimed to evaluate how universal design principles are embodied in the village community center. It will provide preliminary data on constructing a physical space of village community center as small community space in agricultural districts. To achieving the purpose in this study, the research conducted inspection using checklist to 25 village community centers at Hwasoon, Jeonnam province. The conclusion of this study is as follows: Living room and kitchen/dining room by supportive design urgently need installation of Western Style furniture and solutions of stair gap by accessible design, and also the evaluation is unsuited on a fire-gas alarm system and prevention of electric shook system on safety-oriented design. Entrance evaluated in principle for insufficient on safety handle by supportive design and spare chair by adaptable design, and also it unsuited on the solutions of door sill by accessible design and non-skid by safety-oriented design. Bathroom is insufficient lever handle and safety grip by supportive design, sink isn't suitable by adaptable design. Outdoor space information legislation staircase ramp installation and horizontal installation of the staircase was not built.

불투수성 아스팔트 포장재료의 방수기능과 역학적 특성에 관한 연구 (A Study on the Mechanical Characteristics and Waterproof Performance of Impermeable Asphalt Pavement Materials)

  • Kim, Injoong;Kim, Kyeongjin;Lee, Seungyong
    • 한국재난정보학회 논문집
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    • 제12권3호
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    • pp.242-248
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    • 2016
  • 본 논문은 GMA(SIS, Stylene Isoprene Stylene) 고분자계 수지를 기반으로 제조된 아스팔트 바인더를 사용하여 플랜트에서 제조하는 혼합물로 방수기능을 갖도록 성능을 개선한 신개념의 불투수성 아스팔트 포장의 연구를 위해 수행하였다. GMA 고분자 수지 기반의 아스팔트는 유연성과 탄성을 바탕으로 중차량의 충격에 의한 영향을 받지 않으며, 우수 시에 포트 홀의 발생과 소성변형 등 여름철 온도 변화에도 안정적이다. 새롭게 제안된 열가소성 폴리머를 사용한 아스팔트 포장재료는 방수기능은 물론 역학적 특성을 검증하기 위해 KS기준과 ASTM기준에 맞게 안정도, 흐름값, 공극률, 동적 안정도, 인장강도비, 미끄럼 저항성 실험을 하여 역학적 특성을 분석 하였다.

교차로 교통사고 자동감지를 위한 사고음의 음향특성 분석 (Acoustic Characteristic Analysis of the accident for Automatic Traffic Accident Detection at Intersection)

  • 박문수;김재이
    • 한국산학기술학회논문지
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    • 제7권6호
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    • pp.1142-1148
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    • 2006
  • 실제적으로, 현재의 교통사고 검지시스템은 주로 교차로에서의 영상정보와 디지털 영상처리기술에만 거의 의존하고 있기 때문에 교차로에서의 혼잡한 상황하에서는 정확한 판별의 제한이 잔존하고 있다. 이러한 문제점을 보완하기 위하여, 본 논문은 교차로에서의 교통사고 자동검지율의 향상을 위해 검토되어야 할 사고음의 음향특성을 분석함으로써 현재 기술수준과 실현가능성을 가늠해 보는 것을 목적으로 한다. 교차로 주변에 차량의 소통이 거의 없을 때는 자동차사고 스키드음은 1[KHz]$\sim$3[KHz] 대역에서 특정패턴을 보였다. 또한, 차량 충돌음의 주파수 대역은 500[Hz]이하에서 사고가 발생하지 않은 시점보다 높은 30[dB] 이상의 음압차이를 보였다.

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Implementation of Intelligent Electronic Acupuncture Needles Based on Bluetooth

  • Han, Chang Pyoung;Hong, You Sik
    • International journal of advanced smart convergence
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    • 제9권4호
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    • pp.62-73
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    • 2020
  • In this paper, we present electronic acupuncture needles we have developed using intelligence technology based on Bluetooth in order to allow anyone to simply receive customized remote diagnosis and treatment by clicking on the menu of the smartphone regardless of time and place. In order to determine the health condition and disease of patients, we have developed a software and a hardware of electronic acupuncture needles, operating on Bluetooth which transmits biometric data to oriental medical doctors using the functions of automatically determining pulse diagnosis, tongue diagnosis, and oxygen saturation; the functions are most commonly used in herbal treatment. In addition, using fuzzy logic and reasoning based on smartphones, we present in this paper an algorithm and the results of completion of hardware implementation for electronic acupuncture needles, appropriate for the body conditions of patients; the algorithm and the hardware implementation are for a treatment time duration by electronic acupuncture needles, an automatic determinations of pulse diagnosis, tongue diagnosis, and oxygen saturation, a function implementation for automatic display of acupuncture point, and a strength adjustment of electronic acupuncture needles. As a result of our simulation, we have shown that the treatment of patients, performed using an Electronic Acupuncture Needles based on intelligence, is more efficient compared to the treatment that was performed before.

금속 그레이팅의 높이변화에 따른 최적치수 설계 및 안정성 해석 (Optimal Dimension Design and Stability Analysis of Non-slip Steel Grating)

  • 손인수
    • 한국산업융합학회 논문집
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    • 제25권3호
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    • pp.357-363
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    • 2022
  • In this study, in order to develop an non-slip metal grating, the stability of the grating according to the span of the grating and the gap and height of the bearing bar was evaluated. The optimal shape design of the grating was performed using the results of determining the stability of the grating. The purpose of this study is to determine the stability according to the spacing and height of the bearing bar by applying the design pressure at the design stage to develop the anti-skid grating, and to design the optimal shape for cost reduction. In the optimal design, the target variable was set as the mass, and the optimal design of the grating was performed based on about 20%. Regardless of the height of the bearing bar of the grating, the stress and deformation of the span and the grating showed a proportional tendency to each other, and it was found that the stress decreased as the height of the bearing bar increased. Based on the structural analysis results, an optimal design was performed using mass as the objective variable, and the existing 2mm thickness was changed to 1.6mm, reducing the mass by about 19%. The stress increased by about 4.4% compared to the maximum stress of the existing grating, but the minimum safety factor was 3.1, indicating that the optimally designed grating was stable.