Proceedings of IEEE Pacific Rim Conference on Communications Computers and Signal Processing

19-21 May 1993

Go

Filter Results

Displaying Results 1 - 25 of 105
  • Formal description of a mobile data link protocol using Estelle

    Publication Year: 1993, Page(s):427 - 430 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (300 KB)

    An efficient mobile data link protocol (MDLP) based on a selective repeat Type II hybrid automatic repeat request scheme, using convolutional coding and code combining, is described in Estelle. Formal specifications are more complete and precise than descriptions in traditional methods such as natural language. A formalized description method provides a basis for performing testing and implementat... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Digital phase-locked loop with wide lock-in range using fractional divider

    Publication Year: 1993, Page(s):431 - 434 vol.2
    Cited by:  Papers (1)  |  Patents (4)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (256 KB)

    The authors propose a novel type of digital phase-locked loop (DPLL) with both a wide initial lock-in range and a fast initial acquisition time. In this DPLL, by using a fractional divider, it is possible for an initial fixed clock to be made as the adapting free-running frequency which is dependent on the input frequency. Therefore, one can obtain a wide initial lock-in range. Furthermore, removi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An approach toward automatic diagnosis of breast cancer from mammography

    Publication Year: 1993, Page(s):594 - 597 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (304 KB)

    An approach for extracting the exact shape of a breast cancer tumor from X-ray mammograms is proposed. High-intensity pixel clusters are obtained as initial candidate regions on the input image by using an image restoration technique. Then, scale-space filtering, in which one can trace edge elements from the lowest resolution to the highest one, is used. Delaunay arcs are used to get a connected c... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An alternate method for the recovery of band-limited sequences from nonuniformly decimated versions

    Publication Year: 1993, Page(s):362 - 365 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    Originally, the problem was addressed in the context of multirate signal processing, and methods based on polyphase filter banks have been proposed in the past. The procedure proposed here is based on the recovery of missing samples from an oversampled version of a bandlimited signal. Simulation results show that the power of the error in the recovery is on the order of 30 dB below the signal powe... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Automatic adjustment of the cutting position of a vision-based fish processing machine

    Publication Year: 1993, Page(s):702 - 705 vol.2
    Cited by:  Papers (1)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (304 KB)

    Several algorithms that can be used to locate the gill position where mechanical operations take place are described. The effect of adjustable parameters that are inherent to the hardware components and software algorithms on the performance of the vision system is discussed. To significantly improve the accuracy of the detection rate, a fuzzy-decision maker is developed. This procedure can genera... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • IIDT-type low-loss SAW filters used in wideband cellular radio systems

    Publication Year: 1993, Page(s):722 - 725 vol.2
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (268 KB)

    The design and performance of wideband low-loss surface-acoustic-wave (SAW) filters employing interdigitated interdigital transducers (IIDTs) suitable for cellular radio systems are described. The filters were fabricated on 36° YX-LiTaO3 substrates. A detailed design method which optimizes the IIDT configuration has been worked out. In the 500-MHz band, fractional bandwidths of up t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An object-oriented knowledge-based inspection planner

    Publication Year: 1993, Page(s):646 - 649 vol.2
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (340 KB)

    The authors present the development of an object-oriented inspection planner (OOIP) for integration of computer-aided design (CAD) and coordinate measuring machines (CMMs) using knowledge-based system techniques. The issues involved in CAD-directed inspection process planning are examined; the task of inspection process planning is decomposed into several subtasks. An inspection planning system is... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Mathematical channel models for spread spectrum data communications

    Publication Year: 1993, Page(s):782 - 785 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (252 KB)

    The results of an experimental investigation undertaken for direct sequence spread spectrum under controlled additive white Gaussian noise, multiuser and multipath conditions, employing coherent DQPSK (differential quadrature phase shift keying) as modulation scheme, is presented. A discrete partitioned Markov channel model, as proposed by Fritchman (1967) is parameterized to generate an error seq... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A method of extracting 3D patch information from object in image sequences: Volume Editor

    Publication Year: 1993, Page(s):630 - 633 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (252 KB)

    A method for the extraction of 3-D patch information from an object in image sequences on a VTR is proposed. The stationary object is filmed on the VTR. The system, in cooperation with a human operator, helps to estimate 3-D patch information of the object accurately and flexibly. The 3-D patch information of the object is expressed as both a rough 3-D shape and fine 2-D texture in the object imag... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A memory ARQ scheme with soft decision and low reliability zone detectors

    Publication Year: 1993, Page(s):435 - 438 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    The performance improvement of a memory ARQ (automatic repeat request) scheme using soft decision and reliability zone detectors is analyzed. A number of probable error patterns are generated whenever a packet is detected in error. The formation of the error patterns is governed by the reliability weights assigned to the received bits. It is shown that the probability of repeat request is signific... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Some applications in forestry of biological digital image processing

    Publication Year: 1993, Page(s):598 - 601 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (292 KB)

    It is shown that chromatin (DNA) distribution patterns in the nuclei of insect cells provide predictors related to the future development of the insect population. The patterns are extracted from digital images of the nuclei. The systems described have been implemented at the Pacific Forestry Centre. In previous reports this has been demonstrated in laboratory populations; here it is demonstrated ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Efficient implementation of SVD-updating algorithms for subspace tracking

    Publication Year: 1993, Page(s):366 - 369 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (260 KB)

    An efficient parallel implementation of the SVD (singular value decomposition) updating algorithm is addressed. The modifications applied to the algorithm are: approximation of Kogbetliantz's SVD algorithm, approximation of the SVD-rotation evaluations, and factorization of the rotations. This results in a square root and division free SVD-updating algorithm, which combines the speedups and hardwa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • CHIP in plain logic

    Publication Year: 1993, Page(s):742 - 746 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (312 KB)

    The programming language Prolog allows succinct representation of a wide variety of scheduling problems. To speed up execution, a new version called CHIP (Constraint Handling In Prolog) was introduced that maintains the programming advantages of Prolog. CHIP achieves its speed by keeping track of the sets of possible values for each variable. In this way, a search can be abandoned as soon as any s... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance evaluation on the design of a direct sequence spread spectrum system

    Publication Year: 1993, Page(s):682 - 685 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (240 KB)

    The authors evaluate the performance of a direct sequence spread spectrum system based on a differential-encoding binary phase shift keying (DE-BPSK) scheme. A non-coherent sequence tracking loop and a squaring loop are used at the receiver for sequence synchronization and carrier recovery, respectively. The performance evaluation considers the degradation related to the tracking loop and the squa... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic time slot assignment in reservation protocols for multiaccess channels

    Publication Year: 1993, Page(s):451 - 454 vol.2
    Cited by:  Papers (5)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (320 KB)

    The authors discuss the dynamic control of time slot access in reservation protocols for multiaccess channels employing frame structures similar to those investigated by L. G. Roberts (1973) and others. Fixed length frame is dynamically divided on a frame-by-frame basis into a reservation subframe with minislots for reservation requests by contention, and a data subframe with reserved time slots f... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Efficient design of recursive filters satisfying prescribed magnitude and phase specifications

    Publication Year: 1993, Page(s):398 - 401 vol.2
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (228 KB)

    A method for the design of recursive filters satisfying prescribed specifications using a least-squares approach is presented. In this method, a weighted mean-square error based on the difference between desired and actual frequency responses is formulated in a quadratic form. Quadratic programming is employed wherein the constraint on stability is accommodated. The proposed method is compared wit... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Sub-pixel detection of active targets

    Publication Year: 1993, Page(s):470 - 473 vol.2
    Cited by:  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (292 KB)

    The problem of accurately detecting the location of active targets using low-cost machine vision systems is presented, with a requirement for location accuracies greater than 0.5 pixels. Methods of locating bloblike images of active targets are presented, including the calculation of the centroid of binarized versions of the blob, and the fitting of a parametric model to the blobs intensity distri... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Soft-decision algorithm and readable erasure correction for a BFSK demodulator

    Publication Year: 1993, Page(s):419 - 422 vol.2
    Cited by:  Papers (1)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (220 KB)

    A soft decision algorithm is described for a tangent lock loop based BFSK (binary frequency shift keying) modem. The performance of DSP (digital signal processing)-based modems can be improved by making use of the "quality" of individual bits in a demodulated bitstream, where a confidence level can be assigned to bits by recording the parameter(s) used by a soft decision algorithm. Sample test res... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Auto-alignment of acoustic transducers in a multipath environment

    Publication Year: 1993, Page(s):714 - 717 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (248 KB)

    A system incorporating a priori information and various estimation algorithms to continuously point an ultrashort baseline (USBL) array toward the first arrival of a sound pulse in a multipath environment has been developed. The system was designed for use underwater to establish and maintain a narrow-beam acoustic telemetry channel between two communicating stations that may or may not be station... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A case study of isosurface generation in 3D visualization

    Publication Year: 1993, Page(s):622 - 625 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (232 KB)

    The authors explore the problem of the redundancy of the marching-cube algorithm which is widely used as an isosurface generation technique of 3-D visualization. The redundancy occurs when the pixel value from input volumetric data is equal to the isovalue chosen. A modified version of the marching-cube algorithm is also proposed. The results show that the modified algorith thus can increase the e... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Image stabilization for a camera on a moving platform

    Publication Year: 1993, Page(s):734 - 737 vol.2
    Cited by:  Papers (3)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (284 KB)

    An image stabilization system for use with a camera mounted on a moving vehicle is presented. This system has been designed to produce steady image sequences from signals which have been received from such a vehicle. Initial tests have verified the validity of the motion detection algorithm, and substantial stabilization of recorded images has been observed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A performance evaluation of tree-based coherent distributed shared memory

    Publication Year: 1993, Page(s):390 - 393 vol.2
    Cited by:  Papers (1)  |  Patents (70)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (268 KB)

    The system is organized based on the tree-based coherent algorithm, in which the coherence is maintained at the network nodes, in a fully distributed and localized manner. The system has an overlapped tree structure, where the processors are located on the leaves. The proposed coherence protocol relies only on one-to-one message passing. Simulation shows that, in a matrix multiplication program, t... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Use of image processing in the development of a dynamic model for fish processing

    Publication Year: 1993, Page(s):706 - 709 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (228 KB)

    The development of a finite element model of the fish-machine interactions is required for the analysis of parameters which affect the performance of a fish processing machine. Standard image processing techniques are used to determine the geometric parameters necessary to build the model, and to verify the simulation results. The image processing techniques are tested on Pacific salmon, and are i... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Model reference impedance control of robotic manipulators

    Publication Year: 1993, Page(s):614 - 617 vol.2
    Cited by:  Papers (5)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (368 KB)

    A model reference impedance controller which requires neither a dynamic model of the robot nor torque controlled actuators has been implemented on an industrial manipulator. The controller has been implemented on a six-degree-of-freedom industrial arm. No model of the manipulator dynamics was required, just an underlying controller capable of tracking a specified path in joint space. The bandwidth... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the use of Fourier transform with acoustical fields

    Publication Year: 1993, Page(s):726 - 729 vol.2
    Request permission for commercial reuse | Click to expandAbstract |PDF file iconPDF (112 KB)

    The authors present a theoretical introduction to the possibility of using the Fourier transform to study the fields produced by distributions, either continuous or discrete, of acoustic source distributions. With this approach one can develop and simplify methods of analysis and synthesis of fields produced by acoustic sources. The procedure is based on the theorem of the small complex translatio... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.