• Title/Summary/Keyword: driving method

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Method for Current-Driving of the Loudspeakers with Class D Audio Power Amplifiers Using Input Signal Pre-Compensation (입력 신호의 전치 보상을 이용한 D 급 음향 전력 증폭기의 스피커 전류 구동 방법)

  • Eun, Changsoo;Lee, Yu-chil
    • Journal of Korea Multimedia Society
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    • v.21 no.9
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    • pp.1068-1075
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    • 2018
  • We propose a method for driving loudspeakers from class D audio power amplifiers in current mode, instead of in conventional voltage mode, which was impossible with the feedback circuitry. Unlike analog audio amplifiers, Class D audio power amplifiers have signal delay between the input and output signals, which makes it difficult to apply the feedback circuitry for current-mode driving. The idea of the pre-distortion scheme used for the compensation of the non-linearity of RF power amplifiers is adapted to remedy the impedance variation effect of the loudspeakers for current driving. The method uses the speaker model for the pre-distorter to compensate for the speaker impedance variation with frequency. The simulation and test results confirms the validity of the proposed method.

JV Rock Driving Method (JV 공법)

  • Kim, Kwang-Il;Inoue Hajimu;Toshio Teraoka;Yeo, Byung-Chul
    • Proceedings of the Korean Geotechical Society Conference
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    • 1995.10a
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    • pp.41.1-44
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    • 1995
  • The JV method is an epochal civil engineering style that boasts of significant pile driving power through low-vibration works by ideally combining the high pressure water injected from the water jet cutter and the vibrations combining from the vibratory pile driver extractors. As a result, you are ensured stable and safe pile driving and extraction in bedrocks that were previously impossible with conventional machines and methods. The other advantage is its high performance and a low-pollution characteristis that is ensured by suppressing ground vibrations. This is a very important factor since it often becomes an issue upon civil engineering in the city. With the addition of this method. the range of steel pipe pile, steel sheet pile and other steel pile use has been drastically expanded. Other advantages of this method incldes accurate works, shortening of the construction period and improved work performance. Since the minimun amount of high pressure water is used to drill the ground, it not only loosens the ground, but also cuts the ground at the tip of the pile to improve driving works.

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Study on Characteristics of Write Discharge with Single Sustain Waveform in AC Plasma Display Panel (교류형 플라즈마 디스플레이에서 단일 유지 파형을 가지는 기입 방전의 특성의 연구 )

  • Byung-Gwon Cho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.1
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    • pp.56-61
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    • 2023
  • The characteristics of write discharge were investigated when the conventional driving method with the unipolar sustain voltages, and the single sustain driving method applying the bipolar sustain voltage were applied in an AC plasma display. In the case of having a single sustain waveform, the strength of the write discharge is weakened compared to the conventional driving method during the address period, because the wall charge inside the panel is more dissipated by the lower scanning voltage. In the driving method with a single sustain waveform, the bias voltage of the other electrodes was changed to improve the write discharge characteristics. As a result, the intensity of the discharge was enhanced by 32% and the delay time was shortened by 60 ㎲.

A Study on the Benefit of Driving Amenity Based on Highway Density (도로 밀도에 따른 운전쾌적성 편익에 관한 연구)

  • Cho, Hanseon
    • Journal of Korean Society of Transportation
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    • v.31 no.5
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    • pp.48-59
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    • 2013
  • Normally the benefits concerned in the feasibility study for highway constructions are travel time saving, vehicle operation cost, etc. which can be calculated using the simulation tool(EMME3). However, there must be extra benefits of driving amenity improvement that drivers can perceive through decreasing driving fatigue and improving driving comfortability. In this study, the definition of driving amenity was established and a method of estimation for the benefit of driving amenity improvement was developed. Highway type (urban/rural highway) and highway density was considered to estimate the driving amenity. And Double-bounded Dichotomous Choice among Contingent Valuation Method(CVM) was applied to survey the willingness-to-pay of drivers when highway density decreases. Finally the value of driving amenity was estimated using the results of survey and logit medel. As the existing highway density is high, willingness-to-pay increases in both urban and rural highways. Even though the changing rates of highway density are same, willingness-to-pay is different based on the existing highway density.

Motion Profile Generation Method for Absolute Angular Error Control Mode of Gun/Turret Driving System (포/포탑 구동 시스템의 절대 각 오차 제어 모드에 대한 모션 프로파일 생성 기법)

  • Eom, Myunghwan;Song, Sinwoo;Park, Ilwoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.5
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    • pp.674-686
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    • 2019
  • In this paper, we will discuss the absolute angular error control mode for the Gun/Turret driving system. The Gun/Turret driving controller receives absolute angular error calculated from the fire control system (FCS). Thus, the Gun/Turret driving controller is subjected to step command to cause residual vibration and system unstable. In order to reduce residual vibration and to ensure the system stability, we propose an error motion profile method with two types of trapezoidal and S-Curve. The validity of the proposed error motion profile method is confirmed via simulation by observing that the resulting position error, driving power, and power density satisfied the control performance.

A Study on the Car Audio Sound Quality Enhancement under Vehicle Noise and Its Subjective Evaluation (차량 주행소음을 고려한 자동차 오디오 음질 개선 및 주관적 음질평가 연구)

    • The Journal of the Acoustical Society of Korea
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    • v.18 no.8
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    • pp.108-115
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    • 1999
  • In this study we suggested a digital filter method to enhance car audio sound quality against the sound distortion due to cabin's acoustic characteristics and car driving noises. The digital filters designed were based on the characteristics on car driving noises and cabin acoustic characteristics. Car driving noises were analyzed by two ways; one is an objective method, octave band frequency analysis method. The other is a subjective method; sensory evaluation method, NCB method. On these results, seven sets of modified coefficients of eleven band digital filters were obtained. To find optimum audio sound quality among nine sound samples filtered by designing seven types of digital filters, which were mixed car driving noises at 100km/h, subjective evaluation method was used, paired comparison method; Scheffe' seven point method.

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Estimation of Real Driving Fuel Consumption Rate of a Vehicle When Driving on Road Including Grade (경사가 포함된 도로의 주행시 실제 주행연비 예측)

  • 박진호;박영일;이장무
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.65-76
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    • 2000
  • To measure the fuel consumption rate of a vehicle, a car is tested on chassis dynamometer following given driving mode. But the fuel consumption rate measured by this method may be somewhat different from that measured in on-road driving conditions. It may be due to not considering road grade in driving modes. In this study, new driving modes which include road grade are proposed, and the simulation program to estimate the real driving fuel consumption rate of a vehicle is developed. On-road car tests to verify the simulation program are carried out and the results of the simulation are analysed and compared with those of the experiments.

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An Analysis of Driving Property of a Reflective Electronic Display Fabricated by Using Filtering Method of Non-moving Particles

  • Kim, Young-Cho
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.5
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    • pp.233-236
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    • 2012
  • The driving properties of a particle-insertion method that filters non-moving particles are analyzed, by measuring its optical and electrical properties. An area that is occupied by the moved particles is proposed, as a desirable evaluation method for a reflective display. To compare the driving property of the particle-moving method with that of the reported simple particle-loading method, two panels are fabricated, according to the different particle-insertion methods, in the same panel condition, of which the width of ribs is $30{\mu}m$, the cell size is $220{\mu}m{\times}220{\mu}m$, the cell gap is $116-120{\mu}m$, the q/m value of the black particles is $+1.8{\mu}C/g$ and that for the white particles is $-4.3{\mu}C/g$. The particle-moving method has a filtering effect which excludes the non-moving particles, inserting only movable particles into the respective cell, so that a panel fabricated by the particle-moving method can drive most of the particles in a cell. Also, most of the particles move at the threshold voltage of 40 V, with enhanced reflectivity. The driving property is also verified by measurement of the occupation rate of the moved particles.

Path Tracking for AGV using Laser guidance system (레이저 유도 시스템을 이용한 AGV의 경로추적)

  • Park, Jung-Je;Kim, Jung-Min;Do, Joo-Cheol;Kim, Sung-Shin;Bae, Sun-Il
    • The Journal of Korea Robotics Society
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    • v.5 no.2
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    • pp.120-126
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    • 2010
  • This paper presents to study the path tracking method of AGV(autonomous guided vehicle) which has a laser guidance system. An existing automatic guided vehicles(AGVs) which were able to drive on wired line only had a automatic guidance system. However, the automatic guidance systems that those used had the high cost of installation and maintenance, and the difficulty of system change according to variation of working environment. To solve such problems, we make the laser guidance system which is consisted of a laser navigation and gyro, encoder. That is robust against noise, and flexible according to working environment through sensor fusion. The laser guidance system can do a perfect autonomous driving. However, the commercialization of perfect autonomous driving system is difficult, because the perfect autonomous driving system must recognize the whole environment of working space. Hence, this paper studied the path tracking of AGV using laser guidance system without wired line. The path tracking method is consisted of virtual path generation method and driving control method. To experiment, we use the fork-type AGV which is made by ourselves, and do a path tracking experiments repeatedly on same experimental environment. In result, we verified that proposed system is efficient and stable for actual fork-type AGV.

The Effects of Driving Rehabilitation Functional Training on Visual Perception and Driving Reaction Velocity (운전시뮬레이터 훈련이 시 지각 및 운전 반응 속도에 미치는 효과)

  • Lee, Jungsook;Kim, Sungwon
    • Journal of The Korean Society of Integrative Medicine
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    • v.5 no.4
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    • pp.77-81
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    • 2017
  • Purpose : This study examined the effects of driving rehabilitation functional training on visual perception ability and driving reaction velocity. Those subjects were put under MVPT-3 test to see their visual perceptual functions before and after the 4weeks' driving rehabilitation function training and then put to TMT A-type test to see their driving reaction velocity performance. The followings are the results of this study. Methods : Using a driving simulator, driving rehabilitation functional training was performed targeting men and women aged in 20s 20 minutes per time, two times per week, for a month. Results : As for the change in visual perception, the Raw Score of MVPT-3 very significantly increased (p<.01), and the Standard Score also very significantly increased (p<.01). As for the change in reaction velocity, TMT A-type very significantly decreased (p<.01), and TMT B-type also very significantly decreased (p<.01). Conclusion : It could be found that driving rehabilitation functional training should be effective for both visual perception and reaction velocity. Consequently, the driving rehabilitation function training can be applied to clinics as training method for functional recovery and improvement of visual perceptual functions and driving reaction velocity performance ability of the patients. Thus, various functional programs should be studied in the future.