• 제목/요약/키워드: Detection Systems

검색결과 6,016건 처리시간 0.031초

진동데이터 적용 모델기반 이상진단 (Model-based Fault Diagnosis Applied to Vibration Data)

  • 양지혁;권오규
    • 제어로봇시스템학회논문지
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    • 제18권12호
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    • pp.1090-1095
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    • 2012
  • In this paper, we propose a model-based fault diagnosis method applied to vibration data. The fault detection is performed by comparing estimated parameters with normal parameters and deciding if the observed changes can be explained satisfactorily in terms of noise or undermodelling. The key feature of this method is that it accounts for the effects of noise and model mismatch. And we aslo design a classifier for the fault isolation by applying the multiclass SVM (Support Vector Machine) to the estimated parameters. The proposed fault detection and isolation methods are applied to an engine vibration data to show a good performance. The proposed fault detection method is compared with a signal-based fault detection method through a performance analysis.

에지 영상의 분산을 이용한 비디오의 점진적 장면전환 검출 (Gradual Scene Change Detection Using Variance of Edge Image)

  • 류한진;유헌우;장동식;김문화
    • 제어로봇시스템학회논문지
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    • 제8권3호
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    • pp.275-280
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    • 2002
  • A new algorithm for gradual scene change detection in MPEG based frame sequences is proposed in this paper. The proposed algorithm is based on the fact that most of gradual curves can be characterized by variance distributions of edge information in the frame sequences. Average edge frame sequences are obtained by performing "sober" edge detection. Features are extracted by comparing variances with those of local blocks in the average edge frames. Those features are further processed by the opening operation to obtain smoothing variance curves. The lowest variance in the local frame sequences is chosen as a gradual detection point. Experimental results show that the proposed method provides 85% precision and 86% recall rate fur gradual scene changes.

Perturbation analysis for robust damage detection with application to multifunctional aircraft structures

  • Hajrya, Rafik;Mechbal, Nazih
    • Smart Structures and Systems
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    • 제16권3호
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    • pp.435-457
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    • 2015
  • The most widely known form of multifunctional aircraft structure is smart structures for structural health monitoring (SHM). The aim is to provide automated systems whose purposes are to identify and to characterize possible damage within structures by using a network of actuators and sensors. Unfortunately, environmental and operational variability render many of the proposed damage detection methods difficult to successfully be applied. In this paper, an original robust damage detection approach using output-only vibration data is proposed. It is based on independent component analysis and matrix perturbation analysis, where an analytical threshold is proposed to get rid of statistical assumptions usually performed in damage detection approach. The effectiveness of the proposed SHM method is demonstrated numerically using finite element simulations and experimentally through a conformal load-bearing antenna structure and composite plates instrumented with piezoelectric ceramic materials.

Effective Automatic Foreground Motion Detection Using the Statistic Information of Background

  • Kim, Hyung-Hoon;Cho, Jeong-Ran
    • 한국컴퓨터정보학회논문지
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    • 제20권9호
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    • pp.121-128
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    • 2015
  • In this paper, we proposed and implemented the effective automatic foreground motion detection algorithm that detect the foreground motion by analyzing the digital video data that captured by the network camera. We classified the background as moving background, fixed background and normal background based on the standard deviation of background and used it to detect the foreground motion. According to the result of experiment, our algorithm decreased the fault detection of the moving background and increased the accuracy of the foreground motion detection. Also it could extract foreground more exactly by using the statistic information of background in the phase of our foreground extraction.

시간지원 크랙잭션을 위한 충돌 검출 기법의 성능평가 (Performance Evaluation of Conflict Detection Schemes for Concurrent Temporal Tranactions)

  • 구경이;하봉옥;김유성
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제26권1호
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    • pp.80-80
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    • 1999
  • As Temporal DataBase Systems(TDBSs) manages both the historical versions and the current version of each data item, a temporal transaction may access more data records than atransaction in traditional database systems. Hence, the concurrency control subsystem of temporaldatabase management system should be able to correctly and efficiently detect actual conflicts amongconcurrent temporal transactions while the cost of detecting conflicts is maintained in low levelwithout detecting false conflicts which cause severe degradation of system throughput.In this paper, Two-Level Conflict Detection(TLCD) scheme is proposed for efficient conflictdetection between concurrent temporal transactions in TDBs. In the proposed TLCD scheme, sincechecking conflict between concurrent temporal transactions is performed at two levels, i, e., logicallevel and physical level, conflicts between concurrent temporal transactions are efficiently and correctlydetected,Furthermore, we also evaluate the performance of the proposed TLCD scheme with those oftraditional conflict detection schemes, logical-level conflict detection scheme and physical-level conflictdetection scheme by simulation approach, The result of the simulation study shows that the proposedTLCD scheme outperforms the previous conflict detection schemes with respect to the averageresponse time.

A New Vehicle Detection Method based on Color Integral Histogram

  • Hwang, Jae-Pil;Ryu, Kyung-Jin;Park, Seong-Keun;Kim, Eun-Tai;Kang, Hyung-Jin
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제8권4호
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    • pp.248-253
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    • 2008
  • In this paper, a novel vehicle detection algorithm is proposed that utilizes the color histogram of the image. The color histogram is used to search the image for regions with shadow, block symmetry, and block non-homogeneity, thereby detecting the vehicle region. First, an integral histogram of the input image is computed to decrease the amount of required computation time for the block color histograms. Then, shadow detection is performed and the block symmetry and block non-homogeneity are checked in a cascade manner to detect the vehicle in the image. Finally, the proposed scheme is applied to both still images taken in a parking lot and an on-road video sequence to demonstrate its effectiveness.

암의 조기진단을 위한 계수변화 검출에 관한 연구 (On the Detection of Parameter Changes in Dynamical Systems for an Early Diagnosis of Cancer)

  • 이권순;배종일;전재록
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 B
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    • pp.748-750
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    • 1995
  • An early detection of cancer is very important for the complete cure of cancer. Therefore, it is considered a diagnosis of cancer via the detection of an abrupt change from the healthy state to the cancerous state. It includes the development of algorithm for the detection of parameter change for conditionally-linear stochastic systems for the cancer diagnosis. The statistical testing is proposed to implement a parameter change algorithm. The detection algorithm studied in this research is based on sequential hypotheses testing in a so-called local asymptotic framework. Here a simple numerical example is provided to highlight some of the concepts and to provide a basis for further investigation. Despite its simplicity this research may have practical application in clinical oncology.

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Blind Adaptive Multiuser Detection for the MC-CDMA Systems Using Orthogonalized Subspace Tracking

  • Ali, Imran;Kim, Doug-Nyun;Lim, Jong-Soo
    • ETRI Journal
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    • 제31권2호
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    • pp.193-200
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    • 2009
  • In this paper, we study the performance of subspace-based multiuser detection techniques for multicarrier code-division multiple access (MC-CDMA) systems. We propose an improvement in the PASTd algorithm by cascading it with the classical Gram-Schmidt procedure to orthonormalize the eigenvectors after their sequential extraction. The tracking of signal subspace using this algorithm, which we call OPASTd, has a faster convergence as the eigenvectors are orthonormalized at each discrete time sample. This improved PASTd algorithm is then used to implement the subspace blind adaptive multiuser detection for MC-CDMA. We also show that, for multiuser detection, the complexity of the proposed scheme is lower than that of many other orthogonalization schemes found in the literature. Extensive simulation results are presented and discussed to demonstrate the performance of the proposed scheme.

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스마트 홈을 위한 CAN 기반 화재 감지 시스템의 구현 (Implementation of CAN-based Fire Detection System for Smart Home)

  • 이경창;김정희;이홍희
    • 제어로봇시스템학회논문지
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    • 제10권8호
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    • pp.734-741
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    • 2004
  • This paper presents a network based fire detection system using CAN, in order to evaluate feasibility of home automation protocol for smart home. In general, because a traditional fire detection system has an analog transmission method with 4-20mA current, it has several shortcomings such as weakness to noise. Hence, as an alternative to the traditional system, this paper presents the architecture of CAN based fire detection system and the design method of CAN communication network. Also, the performance of the suggested system is evaluated through an experimental testbed. Especially, CAN has several advantages such as low cost and easiness of implementation compared to Ethernet or ARCNET, which are low layer of BACNet. Therefore, if CAN is adopted as low layer of BACNet, the home automation system is implemented more effectively.

머신 비젼을 이용한 졸음 감지 시스템 개발 (Development of a Drowsiness Detection System using Machine Vision)

  • 강수민;허경무
    • 제어로봇시스템학회논문지
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    • 제22권4호
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    • pp.266-270
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    • 2016
  • In this paper, we propose a technique of drowsiness detection using machine vision. The drowsiness of vehicle driver is often the primary cause of motor vehicle accidents. Therefore, the checking of eye images for detecting drowsiness status of driver is critical for preventing these accidents. In our suggested method, we analyze the changes of histogram and edge of eye region images which are acquired using CCD camera. We developed a drowsiness detection system using the histogram and edge change information. The experimental results show that our proposed method enhances the accuracy of detecting drowsiness nearly to 98%, and can be used for preventing vehicle accidents due to the drowsiness of drivers.