• Title/Summary/Keyword: Probablistic method

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Quasi-linearization of non-linear systems under random vibration by probablistic method (확률론 방법에 의한 불규칙 진동 비선형 계의 준선형화)

  • Lee, Sin-Young;Cai, G.Q.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.785-790
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    • 2008
  • Vibration of a non-linear system under random parametric excitations was evaluated by probablistic methods. The non-linear characteristic terms of a system were quasi-linearized and excitation terms were remained as they were given. An analytical method where the square mean of error was minimized was ysed. An alternative method was an energy method where the damping energy and rstoring energy of the linearized system were equalized to those of the original non-linear system. The numerical results were compared with those obtained by Monte Carlo simulation. The comparison showed the results obtained by Monte Carlo simulation located between those by the analytical method and those by the energy method.

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Implementation of Smart Video Surveillance System Based on Safety Map (안전지도와 연계한 지능형 영상보안 시스템 구현)

  • Park, Jang-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.1
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    • pp.169-174
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    • 2018
  • There are many CCTV cameras connected to the video surveillance and monitoring center for the safety of citizens, and it is difficult for a few monitoring agents to monitor many channels of videos. In this paper, we propose an intelligent video surveillance system utilizing a safety map to efficiently monitor many channels of CCTV camera videos. The safety map establishes the frequency of crime occurrence as a database, expresses the degree of crime risk and makes it possible for agents of the video surveillance center to pay attention when a woman enters the crime risk area. The proposed gender classification method is processed in the order of pedestrian detection, tracking and classification with deep training. The pedestrian detection and tracking uses Adaboost algorithm and probabilistic data association filter, respectively. In order to classify the gender of the pedestrian, relatively simple AlexNet is applied to determine gender. Experimental results show that the proposed gender classification method is more effective than the conventional algorithm. In addition, the results of implementation of intelligent video security system combined with safety map are introduced.

Development of a Knowledge Representation Scheme and Diagnosis Mechanism for Heterogeneous Distributed Fault Diagnosis (이종분산 고장 진단을 위한 지식표현 방법 및 진단 방법의 개발)

  • 안영애;박종희
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.12
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    • pp.1687-1696
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    • 1995
  • An integrated fault diagnosis system for heterogeneous manufacturing environments is developed. This system has a contrast with existing diagnosis systems in the respect that they are mostly for diagnosing faults on individual machines. In addition to the usual (e.g., audio, electrical) diagnostic signals, the characteristics of products from the machines are considered as the unifying diagnostic parameters among heterogeneous machines in the diagnosis. The system is composed of a knowledge representation scheme and a diagnostic query processing mechanism. Its knowledge representation scheme allows the diagnostic knowledges from heterogeneous unit diagnostic systems to be uniformly expressed in terms of the causal relations among relevant data items. It is flexible in the sense that causes for one relation can be effects for another may be reflected on our knowledge representation scheme. The diagnosis mechanism is based on a probabilistic inferencing method. This probablistic diagnosis mechanism provides more general diagnosis than existing ones in that it accommodates multiple causes and takes complication among causes into account. These scheme and mechanism are applied to a typical example to demonstrate how our system works.

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A Study on the Harmonics Measurement, Assessment and Simulation of the High Speed Electric Train Loads (고속철 부하의 고조파 측정, 평가 및 시뮬레이션에 관한 연구)

  • Kim, Kyung-Chul;Jin, Seong-Eun;Lee, Joo-Hong;Lee, Il-Moo;Kim, Joo-Rak
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2006.05a
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    • pp.272-277
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    • 2006
  • High speed electric trains have nonlinear loads including converters and inverters for the contol synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE std. 519-1992, and harmonics simulation using EDSA program for the case study.

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A Study on the Hormonic Characteristics of Typical Household Loads by Field Measurements (현장 측정에 의한 가정집 부하의 고조파 특성에 관한 연구)

  • Kim, Kyung-Chul;Oh, Kyung-Hoon;Choi, Hyoung-Bumb
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.4
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    • pp.100-106
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    • 2008
  • Typical household load have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads and harmonics simulation using EDSA program for the case study.

A Study on the Harmonics and Flickers Measurement of High Speed Electric Train Loads (고속열차 부하의 고조파 및 플리커 측정에 관한 연구)

  • Kim, Kyung-Chul;Kim, You-June
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.2
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    • pp.71-77
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    • 2007
  • High speed electric trains have time-varying nonlinear loads causing voltage fluctuations to the power system. A cumulative probablistic approach is the most commonly used method to solve time varying loads. Flicker can be defined as the effect produced on the human visual perception by a changing emission of light lamps subjected to magnitude fluctuations of their supply voltage. This paper provides an in depth analysis on harmonics and flickers measurement of the high speed electric train loads. And the measurement results are evaluated by the IEC 61000-3-6 and IEC 61000-3-7.

A Survey of the Harmonics Level on a Typical Household Loads by Field Measurements (현장 측정에 의한 일반 가정집 부하의 고조파 수준 조사)

  • Kim, Kyung-Chul;Oh, Kyung-Hoon;Choi, Hyoung-Bumb;Hong, Sa-Guen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.95-102
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    • 2008
  • Typical household loads have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads for one year period and the survey is conducted with the objectives to identify the trends of harmonic distortion level present and indentify the future trends of metering in the presence of nonsinusoidal current and voltage waveforms in the system.

Development of New Probabilistic Seismic Hazard Analysis and Seismic Coefficients of Korea Part II: Derivation of Probabilistic Site Coefficients (신(新) 확률론적 지진분석 및 지진계수 개발 Part II: 확률론적 지진계수 도출)

  • Kwak, Dong-Yeop;Jeong, Chang-Gyun;Lee, Hyunwoo;Park, Duhee
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.7
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    • pp.111-115
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    • 2009
  • In Korea, the probabilistically developed seismic hazard maps are used with deterministically derived seismic site coefficients in developing the design response spectrum of a specific site. Even though the seismic hazard maps and seismic site coefficients are incompatible, the current design code ignores such incompatibility. If the seismic hazard map and seismic coefficients are both developed in identical probabilistic framework, such problems can be solved. Unfortunately, the available method cannot be use to derive "true" probabilistic site coefficients. This study uses the ground motion time histories, which were developed as the result of a new probabilistic seismic hazard analysis in the companion paper, as input motions in performing one-dimensional equivalent linear site response analyses, from which the uniform hazard response spectra are generated. Another important characteristic of the hazard response spectra are that the uncertainties and randomness of the ground properties are accounted for. The uniform hazard spectra are then used to derive probabilistic site coefficients. Comparison of probabilistic and deterministically site coefficients demonstrate that there is a distinct discrepancy between two coefficients.

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A Study on the Time-varying Harmonics Measurement, Assessment and Simulation of the Electric Arc Furnace Loads (시간에 따라 변하는 전기로 부하의 고조파 측정, 평가 및 시뮬레이션에 관한 연구)

  • Kim, Kyung-Chul;Jin, Seong-Eun;Lee, Joo-Hong;Jeon, Young-Soo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.5
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    • pp.9-17
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    • 2006
  • Large steel industries have nonlinear loads such as electric arc furnaces. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time-varying harmonics. Harmonic simulations are performed to evaluate the harmonic voltage and current distortions throughout the system. This paper provides an in depth analysis on harmonics field measurement of the electric arc furnace loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519 and harmonic simulation for the time-varying harmonics. The EDSA program was used as a simulation tool for the case study.

A Study on the Harmonics Simulation of the High Speed Electric Train Loads by Field Tests (현장시험에 의한 고속전철 부하의 고조파 시뮬레이션에 관한 연구)

  • Kim, Kyung-Chul;Kim, You-June
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.40-47
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    • 2007
  • High speed electric trains have nonlinear loads including converters and inverters for the control synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. Harmonic simulations are performed to evaluate the harmonic voltage and current distortions throughout the system. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519-l992, and harmonics simulation using EDSA program for the case study.