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WESCANEX 95. Communications, Power, and Computing. Conference Proceedings., IEEE

Date 15-16 May 1995

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  • IEEE WESCANEX 95. Communications, Power, and Computing. Conference Proceedings

    Publication Year: 1995
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    Freely Available from IEEE
  • List of keywords

    Publication Year: 1995
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    Freely Available from IEEE
  • List of authors

    Publication Year: 1995
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    Freely Available from IEEE
  • Using a VHF positioning system to map a native Indian reserve

    Publication Year: 1995 , Page(s): 451 - 455 vol.2
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    This paper discusses the use of Accutrak system's Agtrak 2020, a VHF radio based precise positioning and navigation system, to map the ThunderChild Native Indian Reserve in Saskatchewan, Canada. The VHF positioning system operates at the bottom of the VHF spectrum at 44 MHz, and has the advantage of bending and penetrating obstacles as compared to higher frequencies. This paper also highlights the principles of operation of the Accutrak system and the technique of obtaining accurate measurements using the phase of the carrier. The system was exceptionally useful in mapping roads and irregular shaped paths. It was less efficient in mapping structures and houses due to the antenna structure being large View full abstract»

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  • A digital signal processor based atomic force microscope controller

    Publication Year: 1995 , Page(s): 456 - 461 vol.2
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    This article describes the hardware architecture and software algorithms of a digital AFM controller that is built upon a digital signal processor DSP56001 from Motorola. The hardware of the digital controller includes a DSP board, a host-PC and a custom design analog/digital interface circuit board. The system has 0.4 Å/bit resolution in the vertical direction and 130 nm to 7000 nm field of view horizontally. The DSP is responsible for the operations of the AFM while the host-PC serves as a dual purpose graphical user interface for displaying the real time image and providing a menu driven panel to input the control parameters. The data communication between the DSP and the host-PC is done through hardware interrupt and is discussed in this article. Two scan algorithms are implemented and included in this article to show the flexibility of the digital controller View full abstract»

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  • A generalized method for distribution system reliability evaluation

    Publication Year: 1995 , Page(s): 349 - 354 vol.2
    Cited by:  Papers (1)
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    This paper presents a practical technique which can be used to simplify the procedure for determining the reliability indices of radial distribution systems with branches. A digital computer program has been developed using this technique. The paper illustrates the application of the developed program to two practical distribution system configurations View full abstract»

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  • A Faraday effect based clamp-on magneto-optical current transducer for power systems

    Publication Year: 1995 , Page(s): 329 - 333 vol.2
    Cited by:  Papers (2)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB)  

    A new type of Faraday effect based magneto-optical current transducer (MOCT) has been developed. This paper presents the theoretical background, engineering design, and test results of this clamp-on MOCT. The sensor consists of two separate clamp-on parts. This design avoids the need to break the current carrying circuit in order to have the conductor enclosed by the optical path while keeping the same measurement accuracy. A feedback scheme has been designed to stabilize the light source. The MOCT has two output stages, 1 kA, and 20 kA, so that it can provide current signals for both power system metering and relaying devices View full abstract»

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  • A wireless CMOS implantable receiver for neuromuscular microstimulators

    Publication Year: 1995 , Page(s): 383 - 385 vol.2
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    Describes an integrated CMOS power supply and demodulator for electromagnetic coupling dedicated for biotelemetry applications. The device receives a 40-MHz carrier RF signal carrying digital information. This signal is rectified and regulated to 5V-DC voltage. Digital information is extracted from the rectified signal. This circuit is completely integrated in CMOS 1.2-μm technology except for one diode View full abstract»

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  • A comparative study of multi-resolution image models

    Publication Year: 1995 , Page(s): 421 - 426 vol.2
    Cited by:  Papers (1)
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    The computational structures of three multifrequency decomposition image models, namely DCT, Laplacian pyramid, and wavelet transform are examined and compared in this paper. Their suitability for flexible subimage reconstruction is also discussed. The quality of reconstructed images from the three models is investigated with respect to image analysis. A basic and mostly used image processing process-edge detection-is applied to those images. Based on the results, some very interesting properties for each model are observed View full abstract»

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  • Birdsong recognition with DSP and neural networks

    Publication Year: 1995 , Page(s): 409 - 414 vol.2
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (400 KB)  

    Analysis of speech often begins with study of the vocal tract that created it. Bird vocalizations and human speech are generated by similar processes. This suggests that LPC coefficients extracted from birdsong samples could retain enough information to permit identification of species. In this paper we train a back-propagation neural network to recognize bird songs. We generated test and training data sets using 133 songs from six common bird species. Initially, identification performance was good for some species, and poor for others. We attributed this to a lack of temporal context information in the data. By changing the type of spectral information presented to the network, we were able to improve performance. We conclude that a neural network combined with digital preprocessing can be used to identify a bird by its song View full abstract»

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  • Evaluating interaction between high speed power system controllers

    Publication Year: 1995 , Page(s): 270 - 275 vol.2
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    Control coordination of fast acting voltage devices is considered of great significance in the electric utility industry as the existing transmission systems are expected to operate at higher loadings. Coordination of the controls of static VAr compensators, DC transmission systems and power system stabilizers will maximize the loading capability of the network. The available study tools are identified along with how they might be applied to coordinate controls. A procedure for coordinating controls for electromechanical and electromagnetic interactions is presented. A “global gain margin” is defined View full abstract»

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  • A new positive sequence directional element for numerical distance relays

    Publication Year: 1995 , Page(s): 334 - 339 vol.2
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    This paper describes a new positive sequence directional element for use in numerical distance relays. Results are shown for the performance of the element in relays on the Manitoba Hydro network during disturbances and from tests on the Real Time Digital Simulator (RTDS) in the Power Systems Laboratory at the University of Manitoba View full abstract»

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  • Guiding principles in controlling small automated vehicles

    Publication Year: 1995 , Page(s): 366 - 370 vol.2
    Cited by:  Papers (1)
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    This paper describes the principles of a control program that was used to drive a self-propelled, 25 HP lawnmower. The course to follow was predetermined and an integral part of the software program. It consisted of straight lines, 90 and 180 degree turns. The two critical pieces of information were the offset error and the angle the mower was, relative to the desired course. Determination of the angle was difficult and was achieved with limited success. The lawnmower was able to follow the course with an error of less than 8 cm (first standard deviation). The author discusses the Accutrak Positioning System, the control computers, and steering control View full abstract»

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  • RTDS-a fully digital power system simulator operating in real time

    Publication Year: 1995 , Page(s): 300 - 305 vol.2
    Cited by:  Papers (33)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (564 KB)  

    This paper presents details on the design, architectural features and applications of a real-time digital simulator (RTDS) developed at the Manitoba HVDC Research Centre (Winnipeg, Canada). Custom hardware and software have been developed and collectively applied to the simulation and study of electromagnetic transients phenomenon in power systems in real-time. The combination of real-time operation, flexible I/O, graphical user interface and an extensive library of accurate power system component models make the RTDS an ideal simulation tool with a wide range of applications View full abstract»

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  • Ray-tracing studies in a perturbed atmosphere

    Publication Year: 1995 , Page(s): 386 - 391 vol.2
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    We report the development of a new ray-tracing simulation tool having the potential of the full characterization of a radio link through the accurate study of the propagation path of the signal from the transmitting to the receiving antennas across a perturbed atmosphere. The ray-tracing equations are solved, with controlled accuracy, in three dimensions (3D) and the propagation characteristics are obtained using various refractive index models. The launching of the rays, the atmospheric medium and its disturbances are characterized in 3D. The software evaluates the ray trajectory, beam spreading, the transmitted/received power taking account of the radiation pattern and orientation of the antennas and finally, the polarization state of the beam. The novelty in the approach stems from the use of special numerical techniques dealing with so called stiff differential equations without which no solution of the ray-tracing equations is possible. Some previously known results are presented for comparative purposes and new results are presented as well as some of the capabilities of the software View full abstract»

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  • Heterodyne electrostatic force microscopy used as a new non-contact test technique for integrated circuits

    Publication Year: 1995 , Page(s): 483 - 488 vol.2
    Cited by:  Patents (2)
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    In this paper a new high-resolution non-contact scanned probe voltage measurement technique for integrated circuits is presented. Voltages are extracted by sensing the localized electrostatic force between an energized probe and a point on the circuit being tested. Using a nulling method, the technique is capable of accurate magnitude measurements of high frequency signals without complex calibration requirements. An instrument based on the developed technique has been constructed and RF vector waveform measurement of a GaAs MMIC at 1 GHz as well as arbitrary waveform sampling of a CMOS circuit is demonstrated View full abstract»

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  • Application of electromagnetic transient simulation for the solution of HVDC control problems

    Publication Year: 1995 , Page(s): 283 - 288 vol.2
    Cited by:  Papers (2)
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    The paper describes how an electromagnetic transient simulation program (EMTPDC) was used in the design of modifications to the controls of an HVDC converter that was experiencing commutation failures from AC voltage disturbances. These events were reviewed by the valve supplier and two control modifications were proposed. The purpose of the simulation study was first to reproduce measurements recorded at site, and then to select the best control strategy to eliminate the problem View full abstract»

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  • Evaluation of harmonic impedance presented by a thyristor controlled AC load

    Publication Year: 1995 , Page(s): 258 - 263 vol.2
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    The growing use of thyristor controlled loads in AC distribution systems is a major cause of increased level of harmonics which have many other detrimental effects on power system operation. One aspect of interest to the electric utility is the harmonic impedance presented by the power converter/load to the distribution system. In this preliminary investigation, the harmonic impedance of a power converter/load as a function of the power converter delay angle is evaluated View full abstract»

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  • High speed analog signal tester

    Publication Year: 1995 , Page(s): 377 - 382 vol.2
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    This paper describes a new high speed analog signal testing technique that can be used to characterize high speed analog signals in an integrated circuit (IC). The procedure can be implemented on an IC to be tested with the addition of two simple components. The end result is that high speed analog signals can be sampled and brought off-chip to be stored in some manner. The authors discuss the CMOS4S and BiCMOS analog signal testers View full abstract»

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  • Effect of system imperfections on BER performance of CDMA receiver with multipath diversity combining

    Publication Year: 1995 , Page(s): 392 - 397 vol.2
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    The bit error rate performance of a multipath combining type code division multiple access receiver with imperfections in power control, channel parameter estimation and spreading code phase estimation is analyzed. Imperfection in power control is taken into account by modeling the received signal power as a log normally distributed random variable. The estimate errors are modeled as zero mean Gaussian random variables. It is shown that the performance of such a receiver significantly degrades when variance of power control imperfection is above 0 dB, mean square error in channel parameter estimation is above 0.01 and standard deviation of the code phase error is above 0.1 View full abstract»

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  • An algebraic construction method for cellular neural networks

    Publication Year: 1995 , Page(s): 427 - 431 vol.2
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    An algebraic method for construction of a cellular neural network (CNN) is derived. Using this method, CNNs for connected component detection and the maze problem are given in detail. Because the transition of states is included in the algebraic equations during the construction of the network, the network arrives at a unique solution in either a synchronous or an asynchronous operation process, and the solution is stable. The cellular neural network has important potential applications in such areas as image processing and pattern recognition. Its continuous time feature allows real-time signal processing and its local interconnection feature makes it easy for VLSI implementation View full abstract»

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  • Neural code-excited linear prediction for low power speech compression

    Publication Year: 1995 , Page(s): 415 - 420 vol.2
    Cited by:  Papers (1)
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    In this paper, we discuss the use of artificial neural learning methods for low bit-rate speech compression, potentially in non-stationary environments. Unsupervised learning algorithms are particularly well-suited for vector quantization (VQ) which is used in many speech compression applications. We discuss two unsupervised learning algorithms: frequency-sensitive competitive learning and Kohonen's self-organizing maps which have both been investigated for learning the codebook vectors in an adaptive vector quantizer. In contrast with earlier work, we have employed these learning rules in VQ of the linear predictive coding (LPC) prediction residual. The performance of these unsupervised learning algorithms in speaker-dependent and speaker-independent speech compression are presented. Our results compare favourably with those of code-excited linear prediction (CELP) requiring reduced computational power with a tolerable reduction in speech quality. We also explore the effects of limited precision on classification and learning in competitive learning algorithms for low power VLSI implementations View full abstract»

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  • Autonomous power management system for a small satellite

    Publication Year: 1995 , Page(s): 312 - 317 vol.2
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    An argument that a fuzzy system design methodology is better suited for the design of autonomous power systems than the currently used classical expert system methodology is presented. An architecture that incorporates fuzzy systems is developed for designing autonomous power management systems. The architecture was designed to meet both present and projected future technological requirements for satellite autonomy. Systems with varying degrees of autonomy can be implemented by varying the number of modules and their complexity. Detailed design, based on the proposed architecture, is given of a system with Level 5 autonomy. This system was implemented on a low cost 8-bit microprocessor and required less than 6 kBytes of memory. The power management system implemented was shown to perform the required autonomy functions through experiments in which it was required to follow a sequence of commands given in the form of a load switching schedule. After the power management system passed the command execution test, faults were introduced in the load to test its fault tolerance capabilities. The system was able to detect, identify and take appropriate action whenever an anomaly was introduced View full abstract»

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  • HVDC transmission system models for power system reliability evaluation

    Publication Year: 1995 , Page(s): 501 - 507 vol.2
    Cited by:  Papers (1)
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    High voltage direct current transmission (HVDC) systems are finding increased use for long distance transmission of electrical energy from remote hydro electric generating stations to the load centers. The area of reliability evaluation of HVDC transmission systems has not attracted much attention in the past. The situation is changing as more and more DC links are being built, the need to develop methods for assessing the impact of these links on the overall system adequacy is increasing. This paper illustrates a technique for modeling the HVDC links. These models were then integrated into the overall system reliability studies. A simple system example was used to illustrate the technique. Practical system studies incorporating the developed model are illustrated. Finally the data requirements for modeling HVDC links in reliability studies are discussed View full abstract»

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  • Transient analysis and genetic algorithms for classification

    Publication Year: 1995 , Page(s): 432 - 437 vol.2
    Cited by:  Papers (4)
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    This paper presents a method of generating unique fingerprints of radio transmitter turn-on transients. The fingerprinting system consists of the application of multiresolution wavelet analysis used to characterize the features contained in the transient followed by the use of a genetic algorithm to extract the wavelet coefficients that represent critical features of the transient. To measure the ability of the system to generate efficient and unique fingerprints, a neural network is used to classify the transients by their fingerprints. To test the noise sensitivity of the system, noisy transients were applied to a trained neural network, the network was able to positively classify noisy transients with 20 dB signal to noise ratios (SNR) and up. Experiments with real radio transients show that the system is able generate uniqiue fingerprints for absolute classification by a neural network for radios of differing model type as well as radios of the same model type View full abstract»

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