Radio Science Conference, 2000. 17th NRSC '2000. Seventeenth National

24-24 Feb. 2000

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  • Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)

    Publication Year: 2000
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    Freely Available from IEEE
  • Author list

    Publication Year: 2000, Page(s):705 - 708
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    Freely Available from IEEE
  • A genetic algorithm for joint optimization of capacity and flow assignment in packet switched networks

    Publication Year: 2000, Page(s):C5/1 - C5/6
    Cited by:  Papers (2)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    One of the design problems concerning packet switched computer communication networks is the joint optimization of capacity and flow assignment (CFA). In this problem the topology of the network and the traffic requirements between node pairs are given, and the objective is to find the flows on the different links and their capacities that minimize the total network cost and keep its average delay... View full abstract»

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  • Influence of carrier-temperature gradients on the transport of hot carriers across semiconductor junctions

    Publication Year: 2000, Page(s):D2/1 - D2/8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (624 KB)

    On the basis of the hydrodynamic model the transport of hot carriers in the p-i-n diode is investigated over a large scale of reverse-bias voltage. the electric field distribution and the total current density which we obtained by both the drift-diffusion model and the hydrodynamic model are approximately identical before the breakdown region. So, the electric field distribution is not severely pe... View full abstract»

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  • Solution of the non-uniformly spaced array problem using neural networks

    Publication Year: 2000, Page(s):B21/1 - B21/8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    A neural network algorithm used in a non-conventional way to solve the non-uniformly spaced array problem is demonstrated. Using this algorithm, the problem of uniformly spaced and non-uniformly excited arrays was solved. Comparison between this method and the Dolph-Chebyshev method demonstrated its capability of producing lower sidelobe levels for same beamwidth and number of elements. Moreover, ... View full abstract»

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  • Analysis of circuits containing nonlinear elements using neural networks and genetic algorithm

    Publication Year: 2000, Page(s):C4/1 - C4/8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (340 KB)

    The use of a neural network model to analyze electronic circuits is a promising new technique in the field of circuit analysis. This new technique allows the electronic circuits to be analyzed without the need to solve the physical equations describing the circuit. This paper introduces a novel technique to solve electronic circuits that contain linear and non-linear elements. The non-linear eleme... View full abstract»

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  • Theory of nonlinear transport of hot carriers across semiconductor junctions

    Publication Year: 2000, Page(s):D1/1 - D1/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (536 KB)

    In this paper we investigate analytically the transport mechanisms of both electrons and holes across semiconductor p-n junctions in view of the hydrodynamic model. We present a novel analytical solution of the set of hydrodynamic equations across semiconductor p-n junctions. In addition, we show whether the hydrodynamic model actually adds new information to our knowledge about carrier transport ... View full abstract»

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  • Adaptive space-time processing for interference suppression in phased array radar systems. II. Tracking radar

    Publication Year: 2000, Page(s):B9/1 - B9/7
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    For pt.I see ibid., p.B8/1-B8/8 (2000). In phased array radar systems, a tracking process is performed using an electronic scan of a predetermined sector to provide a continuous information about the detected targets. In practice, the presence of interference (noise, clutter, and jamming signals) either prevent or deceive the tracking circuit to follow the real targets, and consequently, the track... View full abstract»

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  • A new proposed method for the design of broadband microwave planar diode detectors

    Publication Year: 2000, Page(s):D6/1 - D618
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (748 KB)

    A new proposed CAD method for the design of broadband microwave planar square law diode detectors is presented. In this method, the proposed broadband (low-Q) short circuit passive networks are used to contribute in diode matching. This method produces diode detectors with low VSWR over the useful broad bandwidth without using diode biasing (self bias) and without using resistance in the diode mat... View full abstract»

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  • Pitch detection algorithm using a wavelet correlation model

    Publication Year: 2000, Page(s):C33/1 - C33/8
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (364 KB)

    A new algorithm for pitch detection of the speech signal is introduced. The technique is based on the discrete wavelet transform to classify the speech signal into voiced and unvoiced segments. The wavelet parameters of the voiced segments in two frequency bands are extracted and crosscorrelation is performed to generate a correlation function. Then, a peak detection is applied to extract the pitc... View full abstract»

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  • Adaptive space-time processing for interference suppression in phased array radar systems. I. Search radar

    Publication Year: 2000, Page(s):B8/1 - B8/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (580 KB)

    This paper presents an adaptive technique of filtering to suppress the interference in phased array search radar systems. This interference includes noise, clutter, and jamming signals. Unlike the time processing techniques, our filtering process is based upon the target Doppler shift as well as the interference spatial distribution to suppress adaptively the undesired signals. This can be achieve... View full abstract»

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  • ATROS: a simulator for the design and analysis of ATM networks and protocols

    Publication Year: 2000, Page(s):C13/1 - C13/7
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (736 KB)

    This paper introduces a simulation tool that could be used for the design and analysis of ATM networks and protocols. The simulator was developed in C++ programming language and compiled on a DOS/Windows platform. It is a discrete-event simulator that has a user-friendly graphical user interface (GUI). The simulator has been tested and validated under different operational scenarios and... View full abstract»

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  • Exact generalized polynomial array synthesis

    Publication Year: 2000, Page(s):B20/1 - B20/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    This paper is concerned with the symmetric excitation design of linear array antennas. Exact solutions for broadside array antenna synthesis are extended to cover evaluating the system of excitation coefficients producing general predetermined radiation patterns View full abstract»

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  • Modular neural networks for face detection

    Publication Year: 2000, Page(s):C3/1 - C3/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (680 KB)

    A new concept for detection of human faces is presented. An efficient approach to reduce the computation time taken by neural networks for the searching process is introduced. We combine both Fourier and wavelet transforms with cooperative modular neural networks (MNNs) to enhance the performance of the detection process. Such an approach is applied to identify human faces automatically in clutter... View full abstract»

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  • Design of radiation hard CMOS APS image sensors for space applications

    Publication Year: 2000, Page(s):D5/1 - D5/9
    Cited by:  Papers (2)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (904 KB)

    The overall objective the research work described in this paper was to design a radiation hard CMOS active pixel sensor (APS), which is intended for use in imaging systems flown on future NASA space missions in the era of ever decreasing mass and power budgets. The radiation hard designs of essential circuits required to enable the design of an experimental radiation hard CMOS APS image sensor are... View full abstract»

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  • Antenna synthetic beam imaging using chirp algorithm

    Publication Year: 2000, Page(s):B12/1 - B1210
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (476 KB)

    A MATHCAD code is developed for simulating the scatterer complex image for specific user requirements. The effect of the transmitted frequency is illustrated. The synthetic beamwidth, the chirp rate, and the scene size window are determined. These parameters impose some constraints or modifications on the transmitted signal from the synthetic aperture radar (SAR) View full abstract»

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  • A 2.2-V BiCMOS controlled current conveyor and high-Q current-mode band-pass filter application

    Publication Year: 2000, Page(s):C15/1 - C15/7
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    A 2.2-V BiCMOS second-generation current-controlled conveyor with a positive current transfer from X to Z (CCCII+) and unity voltage gain between Y and X ports is proposed and simulated. This conveyor is used as a basic building block of a tunable current-mode band-pass filter. The filter is electronically tuned to select a certain signal frequency by controlling the conveyors-bias curr... View full abstract»

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  • Restoration of multichannel images with limited a priori information using multichannel parallel-like adaptive filters

    Publication Year: 2000, Page(s):C18/1 - C1810
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (692 KB)

    We introduce a heuristic method for adaptive multichannel restoration of degraded multispectral images when there is limited knowledge about the undegraded images and the noise. The proposed structure aims at reversing the action of the blur function on the image. The system uses number of channels equal to the number of multispectral images L. Each channel consists of L subchannel structures of t... View full abstract»

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  • A modified fuzzy Sobel edge detector

    Publication Year: 2000, Page(s):C32/1 - C32/9
    Cited by:  Papers (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (628 KB)

    A modified fuzzy Sobel method for edge detection and enhancement is proposed. This method is a modification of the fuzzy Sobel method proposed by Kuo, Lee and Liu see (IEEE Conference on Fuzzy Systems, p.1069-74, 1997). The proposed method overcomes the drawbacks of the conventional gradient methods for edge detection such as Prewitt and Sobel methods. It automatically obtains four threshold value... View full abstract»

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  • Effect of turbulence on underwater targets recognition

    Publication Year: 2000, Page(s):F2/1 - F2/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (844 KB)

    This paper provides an analysis of the echo structures returning from underwater targets, then it describes the effect of turbulence on underwater target recognition. The sonar signal recognition system deals with the echoes received from complex geometrical shapes of underwater targets. Practical measurements were carried out in the Naval Research Center (NRC) in Alexandria that is supported by a... View full abstract»

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  • A convenient calibration procedure of four-port reflectometers: application on six-port reflectometer and heterodyne network analyzer

    Publication Year: 2000, Page(s):B7/1 - B7/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (304 KB)

    This paper presents a millimeter-wave six-port reflectometer in the W-frequency band (75-110 GHz). A convenient calibration technique requiring two standards is described. The measurement performance of this method is compared with the results of a dual six-port network analyzer using the LRL calibration procedure. Moreover, characterization of some components by the heterodyne network analyzer in... View full abstract»

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  • Modelling and analysis of coplanar waveguide for LiNbO3 optical modulators

    Publication Year: 2000, Page(s):B16/1 - B1611
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    Hybrid-mode analysis is carried out for coplanar waveguide applicable to Z-cut Ti:LiNbO3 optical modulators. The analysis is based on the integral equations. Generalized trial quantities are introduced as virtual adjustable sources in the equivalent network representation of the structure. The microwave effective index and the characteristic impedance as a function of the operating freq... View full abstract»

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  • NNFRM: neuro-new fuzzy reasoning model interpreted as general case of fuzzy reasoning model

    Publication Year: 2000, Page(s):C29/1 - C29/8
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (404 KB)

    An interpretation of the new fuzzy reasoning model (NFRM) is developed. This interpretation makes the traditional fuzzy reasoning model (FRM) a special case under certain conditions. In addition, a neural network is constructed to represent the NFRM. The proposed neuro-new fuzzy reasoning model (NNFRM) optimizes the parameters of the NFRM by using the well-known backpropagation concept. The parame... View full abstract»

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  • Chiral absorbing material

    Publication Year: 2000, Page(s):B3/1 - B3/8
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (336 KB)

    The paper presents the analysis for plane wave scattering from a grounded chiral substrate that is loaded by an array of square patches for the sake of minimizing the radar cross section (RCS) for the equipment covered by them. The analysis includes a chiral substrate with different electromagnetic parameters. It shows moderate frequency bands of good absorption for the structures presented View full abstract»

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  • Laser altimetry and its application in geographic scanning

    Publication Year: 2000, Page(s):D4/1 - D4/5
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (352 KB)

    Laser altimetry is a technique whereby reflections of a laser beam are used to measure the altitude of an aircraft above the ground based on a round trip delay measurement. With current improvements in short laser pulse generation and high resolution time and amplitude measurements, the same technique is now used to measure topographical features of the ground surface. In addition to surface eleva... View full abstract»

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