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Systems Engineering, 1989., IEEE International Conference on

Date 24-26 Aug. 1989

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Displaying Results 1 - 25 of 146
  • IEEE International Conference on Systems Engineering (Cat. No.89CH2767-2)

    Publication Year: 1989
    Request permission for commercial reuse | PDF file iconPDF (170 KB)
    Freely Available from IEEE
  • Image segmentation from motion information

    Publication Year: 1989, Page(s):1 - 4
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (330 KB)

    Two schemes for segmentation from an image sequence are presented. The first scheme makes use of the fact that the second temporal derivative of the intensity function can be regarded as a motion weighted spatial Laplacian and only those parts of the image with motion have a nonzero value of the first derivative. However, this method is only applicable to single moving object situations. The secon... View full abstract»

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  • Stochastic learning automata for image estimation

    Publication Year: 1989, Page(s):5 - 8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (375 KB)

    Maximum posterior marginals (MPM) image estimation is examined in the framework of stochastic learning automata. An automaton is associated with each pixel, with the M gray levels possible at the pixel constituting the action set of the automaton. This distributed set of automata function in a cooperative manner with each automaton using an identical and predefined stochastic learning scheme to co... View full abstract»

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  • A practical method to extract image signals in a low signal environment

    Publication Year: 1989, Page(s):9 - 10
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (146 KB)

    A thresholding technique that can be used to extract image signals in a low signal environment is described. The technique is developed around commercially available machine vision systems. This method of determining the binarization threshold from a bimodal histogram does not require rigorous mathematical manipulation. For example, one does not need to fit two unimodal Gaussian distributions to t... View full abstract»

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  • A 3-D vision algorithm for robot applications

    Publication Year: 1989, Page(s):11 - 14
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (257 KB)

    A three-dimensional (3-D) vision algorithm using an off-shelf system with two cameras for robot applications is presented. The 3-D vision algorithm can be trained to recognize a 3-D object from a scene and input the center of location, the orientation, and the dimensions of the object to a robot control system. Taking advantage of the hard-wired fst blob analysis algorithm and the hard-wired fast ... View full abstract»

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  • A novel image sequence coding scheme

    Publication Year: 1989, Page(s):15 - 18
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (374 KB)

    An image sequence coding scheme, which emphasizes the use of temporal zero-crossings and edges of the sign image of interframe intensity changes, is presented. The advantages of using temporal zero-crossings and temporal edges of the sign image of interframe intensity changes are discussed. Several aspects of this scheme are described and the preliminary experimental results are given. Since only ... View full abstract»

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  • Adaptive image restoration using a rule-based knowledge system

    Publication Year: 1989, Page(s):19 - 22
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (308 KB)

    An image restoration method supported by a rule-based knowledge system that segments the image into a number of homogeneous regions and then applies a different restoration method for each of the regions is presented. It is pointed out that the actual implementation of the system involves two very unrelated fields: artificial intelligence and image restoration. The rule-based expert system solves ... View full abstract»

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  • Precision estimation of a fitted image line

    Publication Year: 1989, Page(s):23 - 26
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (265 KB)

    A simple and systematic treatment of the problem of estimating the precision of a fitted image is discussed. It is taken as an error propagation problem, and the general jacobian linearization approach is used to analyze it. Then, the formulas of the estimated precision of the fitted line are derived for two popular line fitting approaches: one is the least-squares line fitting, and the other is t... View full abstract»

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  • Convergence of bearing estimation for beamforming with known displaced sensors

    Publication Year: 1989, Page(s):27 - 31
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    The author studies convergence on the bearing estimate obtained when the trajectories of the sensor displacement are known and the bearing estimation from the shipboard beamformer is available. It is shown rigorously that under fairly general conditions this bearing estimate converges to the true bearing. Some computer simulations show that this convergence actually occurs in one iteration.<> View full abstract»

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  • A high resolution, near real-time frequency estimator for sub-microsecond pulses

    Publication Year: 1989, Page(s):33 - 38
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (507 KB)

    Based on analysis and simulation, a 7-bit, six-stage pipeline realization of an all-digital EW receiver is presented. The tentative design estimates frequencies of up to four radar pulses by means of the covariance algorithm. The covariance method generates the frequency estimate as roots of a polynomial equation whose coefficients are defined by a system of linear normal equations given in terms ... View full abstract»

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  • Target imaging using a synthesized bistatic radar

    Publication Year: 1989, Page(s):39 - 42
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (373 KB)

    The problem of radar imaging when the imaging system is composed of a group of phased arrays with arbitrary radiation patterns and coordinates (multistatic configuration) is discussed. Each phased array has a finite aperture and is used for transmitting and receiving functions, or both. A receiving phases array can make a synchronous or asynchronous detection of the backscattered signal. The appro... View full abstract»

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  • Estimation of source directions by eigenvector rotation and combined direction vectors-a least-squares approach

    Publication Year: 1989, Page(s):43 - 46
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (384 KB)

    Several previously published eigenvector rotation methods on multiple-source direction estimation using a sensor array (G. Vezzosi, 1982, D.R. Farrier, D.J. Jefferies, 1987) are further investigated in a correlated-source environment. It is demonstrated that one rotation method is basically limited to uncorrelated sources. To overcome this deficiency, an improved estimation procedure for dealing w... View full abstract»

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  • Estimating the direction of arrival at low signal to noise ratios using the principal-component-Burg cascaded system

    Publication Year: 1989, Page(s):47 - 50
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (271 KB)

    The problem of estimating the direction of arrival (DOA) of plane waves is considered. The principal component (PC) method has a threshold of 7 dB, below which the mean square error is too large for the estimate to be considered reliable. The PC method is cascaded with the Burg algorithm (BA) to yield estimates of DOAs at signal-to-noise ratios (SNRs) as low as -5 dB. For a single source, this cas... View full abstract»

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  • A fast sequential block-processing instrumental variable algorithm and its FFT implementation

    Publication Year: 1989, Page(s):51 - 54
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (321 KB)

    The authors present a method to efficiently implement the recursive instrumental variable (RIV) algorithm, which is often encountered in many practical applications. A sequential block-processing algorithm is derived, and its fast Fourier transform (FFT) implementation is discussed. Under several easily met conditions, this method can offer a remarkable computational advantage over the previous fa... View full abstract»

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  • Strapdown gyro contribution to coning motion errors

    Publication Year: 1989, Page(s):55 - 58
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (331 KB)

    The authors present an overview of coning motion errors, with particular emphasis on the contribution of nonideal strapdown gyro characteristics. An analytical derivation of drift errors due to both undetected motion and imperfect gyros is provided with the expression for gyro effects representing a new result. Typical compensation techniques which are used to correct for undetected coning motion ... View full abstract»

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  • An approach for coordinating mobility and manipulation

    Publication Year: 1989, Page(s):59 - 63
    Cited by:  Papers (15)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    The authors discuss the problem of planning a task for a robotic system that consists of a manipulator mounted on a mobile base. The task planning problem is formulated as a nonlinear optimization problem. The cost of point-to-point motion in three-dimensional Cartesian space is decomposed into two components representing the qualitative difference between motion due to the mobile base and motion ... View full abstract»

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  • Mapping processes to processors for space based robot systems

    Publication Year: 1989, Page(s):65 - 68
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (440 KB)

    A stepwise process is shown that maps a logical description of a system architecture onto a functional computer architecture based on a description of the application at hand and the response times required for that application. The response times are broken into execution and communication times to partially separate the application-dependent issues from the technology-dependent issues. An exampl... View full abstract»

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  • Control of intelligent robot systems

    Publication Year: 1989, Page(s):69 - 72
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (290 KB)

    A coherent framework for the implementation of intelligent robot control and a paradigm demonstrating the concepts of target state redefinition and task-level feedback are presented. The model-based robot control problem is reviewed, and the standard robotics terminology is introduced. The target state is defined using task-level feedback concepts. Then, the visual-feedback paradigm to outline the... View full abstract»

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  • Robust control of flexible manipulators

    Publication Year: 1989, Page(s):73 - 76
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (271 KB)

    A robust control scheme is presented for a single link flexible manipulator under parameter uncertainties. State feedback is determined from the knowledge of the range in which the open-loop system parameters lie. The state feedback so obtained provides a minimal desired damping under parameter uncertainties. To account for residual modes, a low-pass filter is used in the forward path. The filter ... View full abstract»

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  • A comparison of adaptive order statistic filters using different images

    Publication Year: 1989, Page(s):77 - 80
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (369 KB)

    Histogram windowing, a local statistic-based edge detector, an adaptive window size, and a median filter are compared to the median filter, the SAM filter, and the moving average filter. The five filters are compared using the peak-to-peak signal-to-noise ratio (PSNR). Four different images are used for comparison: (1) Lenna, (2) geometrical, (3) harbour, and (4) face. Three noise types are used: ... View full abstract»

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  • Image smoothing based on local image models

    Publication Year: 1989, Page(s):81 - 83
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (317 KB)

    On the basis of an algorithm which identifies the neighborhood of a pixel as constant, oriented, or irregular based on the spatial relationship among the pixels inside this neighborhood, the use of different smoothing schemes according to the neighborhood surrounding each pixel is proposed. This approach is applied to images corrupted with additive Gaussian noise and impulse speckle noise. The fla... View full abstract»

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  • An adaptive order statistic constant false alarm rate detector

    Publication Year: 1989, Page(s):85 - 88
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (403 KB)

    An adaptive order statistic (AOS) detector is proposed which acts as an order statistic detector but whose parameter k is chosen according to the outcome of a hypothesis test that attempts to detect the presence of a clutter power transition within each reference window. The AOS detector is analyzed in exponentially distributed stationary clutter, and it is shown that it is indeed a constant-false... View full abstract»

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  • Analysis of median type detail preserving filters

    Publication Year: 1989, Page(s):89 - 92
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (295 KB)

    The authors study detail preserving median filters for image processing. Multilevel FIR median hybrid (FMH) filters are analyzed, and it is shown that some multilevel structures can be expressed as single weighted FMH filters. The in-place growing median concept, which has shown promising results with one-dimensional signals, is extended into image processing.<> View full abstract»

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  • Projection filters for image and signal restoration

    Publication Year: 1989, Page(s):93 - 97
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (502 KB)

    Projection filters are reviewed, and a version called the partial projection filter is introduced. It allows images to be restored to a subspace which can be chosen for practical problems. Finally, a localized version of the filter is presented. Results of the various filters are given on restoration of images containing text and natural objects that are blurred by Gaussian defocusing blur.<> View full abstract»

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  • Robust stability bounds for discrete system reduced-order dynamic compensator designs

    Publication Year: 1989, Page(s):99 - 102
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (264 KB)

    Stability robustness is discussed for optimal reduced-order dynamic compensator designs for linear discrete systems. Robust stability of the controller design in the presence of perturbations (modeling errors) of the system matrices is investigated. These results are based on a recently developed bound on elemental (structured) time-varying perturbations of an asymptotically stable linear time-inv... View full abstract»

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