• Title/Summary/Keyword: Moving Time

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Adaptive Cell-Based Index For Moving Objects In Indoor

  • Shin, Soong-Sun;Kim, Gyoung-Bae;Bae, Hae-Young
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.7
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    • pp.1815-1830
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    • 2012
  • Existing R-tree that is based on a variety of outdoor-based techniques to manage moving objects have been investigated. Due to the different characteristics of the indoor and outdoor, it is difficult to management of moving object using existed methods in indoor setting. We propose a new index structure called ACII(adaptive Cell-based index for Indoor moving objects) for Indoor moving objects. ACII is Cell-based access structure adopting an overlapping technique. The ACII refines cells adaptively to handle indoor regional data, which may change its locations over time. The ACII consumed at most 30% of the space required by R-tree based methods, and achieved higher query performance compared with r-tree based methods.

WHEEL SLIP CONTROL WITH MOVING SLIDING SURFACE FOR TRACTION CONTROL SYSTEM

  • Chun, K.;Sunwoo, M.
    • International Journal of Automotive Technology
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    • v.5 no.2
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    • pp.123-133
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    • 2004
  • This paper describes a robust and fast wheel slip tracking control using a moving sliding surface technique. A traction control system (TCS) is the active safety system used to prevent the wheel slipping and thus improve acceleration performance, stability and steerability on slippery roads through the engine torque and/or brake torque control. This paper presents a wheel slip control for TCS through the engine torque control. The proposed controller can track a reference input wheel slip in a predetermined time. The design strategy investigated is based on a moving sliding surface that only contains the error between the reference input wheel slip and the actual wheel slip. The used moving sliding mode was originally designed to ensure that the states remain on a sliding surface, thereby achieving robustness and eliminating chattering. The improved robustness in driving is important due to changes, such as from dry road to wet road or vice versa which always happen in working conditions. Simulations are performed to demonstrate the effectiveness of the proposed moving sliding mode controller.

Moving Window Technique for Obstacle Detection Using Neural Networks (신경망을 사용한 장애물 검출을 위한 Moving Window 기법)

  • 주재율;회승욱;이장명
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.164-164
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    • 2000
  • This paper proposes a moving window technique that extracts lanes and vehicles using the images captured by a CCD camera equipped inside an automobile in real time. For the purpose, first of all the optimal size of moving window is determined based upon speed of the vehicle, road curvature, and camera parameters. Within the moving windows that are dynamically changing, lanes and vehicles are extracted, and the vehicles within the driving lanes are classified as obstacles. Assuming highway driving, there are two sorts of image-objects within the driving lanes: one is ground mark to show the limit speed or some information for driving, and the other is the vehicle as an obstacle. Using characteristics of three-dimension objects, a neural network can be trained to distinguish the vehicle from ground mark. When it is recognized as an obstacle, the distance from the camera to the front vehicle can be calculated with the aids of database that keeps the models of automobiles on the highway. The correctness of this measurement is verified through the experiments comparing with the radar and laser sensor data.

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Vibration Control of Quarter Vehicle ER Suspension System Using Fuzzy Moving Sliding Mode Controller (퍼지이동 슬라이딩모드 제어기를 이용한 1/4차량의 ER현가장치 진동제어)

  • Sung, Kum-Gil;Cho, Jae-Wan;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.644-649
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    • 2006
  • This paper presents a robust and superior control performance of a quarter-vehicle electrorheological (ER) suspension system. In order to achieve this goal, a moving sliding mode control algorithm is adopted, and its moving strategy is tuned by fuzzy logic. As a first step, ER damper is designed and manufactured for a passenger vehicle suspension system, and its field-dependent damping force is experimentally evaluated. After formulating the governing equation of motion for the quarter-vehicle ER suspension system, a stable sliding surface and moving algorithm based on fuzzy logic are formulated. The fuzzy moving sliding mode controller is then constructed and experimentally implemented. Control performances of the ER suspension system are evaluated in both time and frequency domains.

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Influence of a the Velocity of Moving Mass on Dynamic Behavior of Simple Beam Subjected to Uniformly Distributed Follower Forces (이동질량의 속도가 등분포종동력을 받는 단순보의 동특성에 미치는 영향)

  • Yoon, H.I.;Im, S.H.
    • Journal of Power System Engineering
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    • v.4 no.4
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    • pp.65-69
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    • 2000
  • On the dynamic behavior of a simple beam subjected to an uniformly distributed tangential follower force, the influences of the velocities and magnitudes of a moving mass have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving mass represented by the time functions. The uniformly distributed tangential follower force is considered within its critical value of a simple beam, and four values of velocity is also chosen. Their coupling effects on the deflections of a simple beam are inspected too. When a moving mass moves after middle zone of a simple beam at the low velocities, its deflection is increased by the coupling of an uniformly distributed tangential follower force and moving mass.

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Influence of Two Moving Masses on Dynamic Behavior of a Simple Beam (두 이동질량이 단순보의 동특성에 미치는 영향)

  • Yoon, H.I.;Choi, C.S.;Im, S.H.
    • Journal of Power System Engineering
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    • v.4 no.4
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    • pp.70-77
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    • 2000
  • On the dynamic behavior of a simple beam the influences of the velocities and distance of two moving masses have been studied by numerical method. The instant amplitude of a simple beam is calculated and analyzed for each position of the moving masses represented by the time functions. As increasing the velocties of two moving masses on the simple beam, the amplitude of the transverse vibration of the simple beam is decreased and the frequency of the transverse vibration of the simple beam is increased. As the distance between two moving masses increase, the transverse displacement of the simple beam is decrease. The simple beam is very stable in second mode at $\bar{a}=0.5$ and in third mode at $\bar{a}=0.3$.

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BLDC Motor Cogging Torque Calculation with the Moving Material Method in the Finite Element Method

  • Won, Sung-Hong;Choi, Jae-Hoon;Lee, Ju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.3
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    • pp.74-78
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    • 2008
  • Conventionally, when we need to know about the dynamic characteristics of motors, the moving band method has been the first considerable technique. In this paper, we have investigated the moving material method that moves the property of the material in moving area elements of BLDC motors, instead of moving mesh elements of the rotor. From this method, we can reduce the demanded HDD memory for FEM analysis and the calculation time with same results.

Decentralized Moving Average Filtering with Uncertainties

  • Song, Il Young
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.418-422
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    • 2016
  • A filtering algorithm based on the decentralized moving average Kalman filter with uncertainties is proposed in this paper. The proposed filtering algorithm presented combines the Kalman filter with the moving average strategy. A decentralized fusion algorithm with the weighted sum structure is applied to the local moving average Kalman filters (LMAKFs) of different window lengths. The proposed algorithm has a parallel structure and allows parallel processing of observations. Hence, it is more reliable than the centralized algorithm when some sensors become faulty. Moreover, the choice of the moving average strategy makes the proposed algorithm robust against linear discrete-time dynamic model uncertainties. The derivation of the error cross-covariances between the LMAKFs is the key idea of studied. The application of the proposed decentralized fusion filter to dynamic systems within a multisensor environment demonstrates its high accuracy and computational efficiency.

Algorithm for Detection of Fire Smoke in a Video Based on Wavelet Energy Slope Fitting

  • Zhang, Yi;Wang, Haifeng;Fan, Xin
    • Journal of Information Processing Systems
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    • v.16 no.3
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    • pp.557-571
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    • 2020
  • The existing methods for detection of fire smoke in a video easily lead to misjudgment of cloud, fog and moving distractors, such as a moving person, a moving vehicle and other non-smoke moving objects. Therefore, an algorithm for detection of fire smoke in a video based on wavelet energy slope fitting is proposed in this paper. The change in wavelet energy of the moving target foreground is used as the basis, and a time window of 40 continuous frames is set to fit the wavelet energy slope of the suspected area in every 20 frames, thus establishing a wavelet-energy-based smoke judgment criterion. The experimental data show that the algorithm described in this paper not only can detect smoke more quickly and more accurately, but also can effectively avoid the distraction of cloud, fog and moving object and prevent false alarm.

Vibration Control of Quarter Vehicle ER Suspension System Using Fuzzy Moving Sliding Mode Controller (퍼지이동 슬라이딩모드 제어기를 이용한 1/4차량의 ER현가장치 진동제어)

  • Sung, Kum-Gil;Cho, Jae-Wan;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.8 s.113
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    • pp.822-829
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    • 2006
  • This paper presents a robust and superior control performance of a quarter-vehicle electrorheological (ER) suspension system. In order to achieve this goal, a moving sliding mode control algorithm is adopted, and its moving strategy is tuned by fuzzy logic. As a first step, ER damper is designed and manufactured for a passenger vehicle suspension system, and its field-dependent damping force is experimentally evaluated. After formulating the governing equation of motion for the quarter-vehicle ER suspension system, a stable sliding surface and moving algorithm based on fuzzy logic are formulated. The fuzzy moving sliding mode controller is then constructed and experimentally implemented. Control performances of the ER suspension system are evaluated in both time and frequency domains.