• Title/Summary/Keyword: Time estimation

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Investigation on the Real-Time Environment Recognition System Based on Stereo Vision for Moving Object (스테레오 비전 기반의 이동객체용 실시간 환경 인식 시스템)

  • Lee, Chung-Hee;Lim, Young-Chul;Kwon, Soon;Lee, Jong-Hun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.3 no.3
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    • pp.143-150
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    • 2008
  • In this paper, we investigate a real-time environment recognition system based on stereo vision for moving object. This system consists of stereo matching, obstacle detection and distance estimation. In stereo matching part, depth maps can be obtained real road images captured adjustable baseline stereo vision system using belief propagation(BP) algorithm. In detection part, various obstacles are detected using only depth map in case of both v-disparity and column detection method under the real road environment. Finally in estimation part, asymmetric parabola fitting with NCC method improves estimation of obstacle detection. This stereo vision system can be applied to many applications such as unmanned vehicle and robot.

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A Modified Velocity Estimation Scheme in AAS (Adaptive Antenna System) (AAS(적응형 안테나 시스템)에서의 이동체 속도 추정 방안)

  • Chung, Young-Uk;Choi, Yong-Hoon;Lee, Hyuk-Joon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.2
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    • pp.100-107
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    • 2009
  • Velocity estimation is one of important issues for efficient system management in mobile cellular systems. In this paper, a modified velocity estimation scheme which works in Adaptive Antenna System (AAS) is proposed. The proposed scheme estimates user velocity based on moving distance information and sojourn time information. From numerical results, it is shown that the proposed scheme can estimate user velocity accurately with low cost.

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Real-Time Estimation of Radial and Axial Depth of Cuts in End Milling Using the Cutting Forces (절삭력을 이용한 엔드밀링 공정의 실시간 축방향 및 반경방향 절삭깊이 추정)

  • 김승철
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.34-39
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    • 1999
  • If the on-line cutting conditions (e.g. speed, feedrate, radial and axal depth of cuts) can be identified in an end milling process, much information about cutting forces will be estimated from the cutting force model. Therefore, those estimated conditions can be applied to monitoring and control areas. In this paper, a real-time estimation algorithm for radial and axial depth of cuts is studied in end milling using the averaging cutting forces per tooth. The analytical estimation models of depth of cuts are derived from the geometric cutting force model. The validity of the estimation models is verified on a horizontal machining center through the experiments in various cutting conditions.

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An Estimation method for Characteristic Parameters in a Low Frequency Signal Transformed by High Frequency Signals (고주파 신호에 의하여 변형된 저주파신호에서의 특성변수 추정 기법)

  • Yoo, Kyung-Yul
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.2
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    • pp.86-88
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    • 2002
  • An estimation method for the characteristic parameters in the low frequency signal is proposed in this paper. A low frequency signal is assumed to be modulated or distorted by high frequency terms. The algorithm proposed in this paper is designed to select set of local maximums in a successive manner, hence it is denoted as the iterative peak picking(IPP) algorithm. The IPP algorithm is operating in the time domain and is using only the comparison operation between two neighboring samples. Therefore, its computational complexity is very low and the delay caused by the computation is negligible, which make the real-time operation possible with economic hardware. The proposed algorithm is verified on the pitch estimation of speech signal and blood pulse estimation.

An Study on Basis for Demand Estimation of Lifetime Sports Facilities (생활체육시설의 수요예측을 위한 기초적 연구)

  • Min, Young-Gi
    • Journal of The Korean Digital Architecture Interior Association
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    • v.3 no.1
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    • pp.15-22
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    • 2003
  • The purpose of this study was to analyze basic conditions for the demand estimation erection of lifetime sports facilities. This is described the whole concept of lifetime sports(sport for all) for helping the understanding of its concept correctly. Firstly, second chapter was examined the significance, function and role of lifetime sports in modern society. Secondly, third and forth chapter was examined demand and participation of lifetime sports activities for demand estimation of lifetime sports facilities. Participation rate is on the rise by the increase in income and leisure time to some extent, but after that it stops rising. In other words, the same participation rate persists without additional increase in participation by the changes in time deepening and in the patterns of demand for lifetime sports activities.

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A Study on Individual Tap-Power Estimation for Improvement of Adaptive Equalizer Performance

  • Kim, Nam-Yong
    • Journal of electromagnetic engineering and science
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    • v.4 no.1
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    • pp.23-29
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    • 2004
  • In this paper we analyze convergence constraints and time constant of IT-LMS algorithm and derive a method of making it's time constant independent of signal power by using input variance estimation. The method for estimating the input variance is to use a single-pole low-pass filter(LPF) with common smoothing parameter value, θ. The estimator is with narrow bandwidth for large θ but with wide bandwidth for small θ. This small θ gives long term average estimation(low frequency) of the fluctuating input variance well as short term variations (high frequency) of the input power. In our simulations of multipath communication channel equalization environments, the method with large θ has shown not as much improved convergence speed as the speed of the original IT-LMS algorithm. The proposed method with small θ=0.01 reach its minimum MSE in 100 samples whereas the IT-LMS converges in 200 samples. This shows the proposed, tap-power normalized IT-LMS algorithm can be applied more effectively to digital wireless communication systems.

Study on DAS-Based Time Synchronization for Improving Reliability of Section Load Estimation

  • Lee, In-tae;Lee, Ji-Hoon;Jung, Nam-Joon;Jung, Young-Beom;Lee, Byung-sung
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.61-65
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    • 2015
  • For effective distribution planning and operation, we need a reliable estimation of operation capacity. But it is difficult to ensure reliability due to the low accuracy of section load data, which is used as a basis in estimating the operation capacity. This paper discusses how to improve the accuracy of section load data by analyzing the existing method of estimating the section load, using statistical techniques to adjust the acquired data, and using the section load estimation algorithm to estimate the section load based on the adjusted data.

A study on development of program for estimation the Lifetime of insulating materials (절연재료의 수명예측을 위한 프로그램개발에 관한 연구)

  • 박성민;배덕권;정인재;박우현;이기식;이준웅
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.699-702
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    • 2000
  • Today, electrical machine is being large capacitor and EHV(Extra High Voltage) of power equipment is a need of high reliability of insulating matetials. Therefore, it is a need of fixed appraisement of lifetime to used data of breakdown. This paper studied a development of the program for estimation the lifetime of insullating materials and the long-time breakdown voltage by experimentation. The estimation program is based on the "Inverse Power Law", defined V$\^$n/t is constant. After gaining the life exponent n, it is mapping the long-time breakdown voltages. On the base of life exponent, the estimation of lifetime and usefulness of the insulation systems are possible, furthermore easy calculation is possible.

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Real-Time Estimation of the Boost Inductance in a Single-phase AC/DC parallel PWM converter for High-speed EMU (동력분산형 고속철도의 단상 병렬 AC/DC PWM 컨버터를 위한 승압형 인덕턴스의 실시간 추정)

  • Jung, Hwan-Jin;Park, Byoung-Gun;Hyun, Dong-Seok
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.259-264
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    • 2009
  • This paper proposes a real-time estimation of the boost inductance in a single-phase AC/DC parallel PWM converter for high-speed EMU. The estimation procedure of the boost inductance is only based on the variation of input current and the input AC voltage measurement. The estimated boost inductance is optimized by the least square method. This estimation technique can improve the performance of current controller and reduce the harmonics of the input current in the feed-forward controller. The validity of proposed technique is verified through the MATLAB SIMULINK simulation results.

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THE OPEN-CIRCUIT VOLTAGE STATE ESTIMATION OF THE BATTERY

  • LEE, SHINWON
    • Journal of applied mathematics & informatics
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    • v.39 no.5_6
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    • pp.805-811
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    • 2021
  • Currently, batteries use commonly as energy sources for mobile electric devices. Due to the high density of energy, the energy storage state of a battery is very important information. To know the battery's energy storage state, it is necessary to find out the open state voltage of the battery. The open state voltage calculates with a mathematical model, but the computation of the real time state is complicated and requires many calculations. Therefore, the state observer designs to estimate in real time the battery open-circuit voltage as disturbance including model error. Using the estimated open voltage and applying it to the state estimation algorithm, we can estimate the charge. In this study, we first estimate the open-circuit voltage and design an estimation algorithm for estimating the state of battery charge. This includes errors in the system model and has a robust characteristic to noise. It is possible to increase the precision of the charge state estimation.