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

Date 24-24 Feb. 2000

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Displaying Results 1 - 25 of 80
  • 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
  • Atomic force microscope image enhancement using human visual system model properties and adaptive filters

    Publication Year: 2000, Page(s):K1/1 - K1/8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    Atomic force microscope (AFM) images are usually of poor quality and need to be interpreted visually. The human visual system (HVS) is generally modeled as an adaptive, multichannel and highly non-linear system. This paper proposes an adaptive image enhancement systems for improving the quality of the AFM images. The proposed method is based on a combination of an adaptive low pass filter and a si... View full abstract»

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  • Performance of FHMA, MFSK over Rician fading channel under MTJ

    Publication Year: 2000, Page(s):E1/1 - E111
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    In this paper, the effect of multitone jamming (MTJ) on an FHMA/MFSK system is investigated. The channel under consideration is a Rician fading channel, with AWGN included in the analysis. The system capacity is considered as an indicator of the system performance and is calculated for different situations. The capacity is shown to be affected by channel fading state. For no fading, the capacity i... View full abstract»

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  • Cancellation of the communication channel interference

    Publication Year: 2000, Page(s):E2/1 - E2/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    In this paper a scheme is presented for enhancing speech that is severely interfered with by undesired periodic interference. The proposed scheme structure depends on the estimation of the interference using an adaptive line enhancer whose output represents a reference input to an adaptive noise canceller. The output of the noise canceller represents a course estimate of the desired speech signal ... View full abstract»

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  • Synthesis of self-timed FIFO circuit from signal transition graphs (STGs)

    Publication Year: 2000, Page(s):C9/1 - C9/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (452 KB)

    As we build faster digital switching circuits, the ability to accomplish global synchronization with a high-speed clock becomes a limiting factor to system throughput. Self-timed circuit design is an active research area and synthesis of self-timed control circuits using signal transition graphs is a promising approach. Our goal is to construct a FIFO circuit that does not require the distribution... View full abstract»

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  • Two partially adaptive antenna array techniques for interference elimination

    Publication Year: 2000, Page(s):B15/1 - B15/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    Fully or partially adaptive antenna array (AAA) techniques are designed to reduce the effect of interference and jamming signals. This is done by automatically steering nulls in the array field pattern directed towards the direction of arrival of the interfering signal. We present two simple and easy-to-implement partially AAA techniques to eliminate the effect of interfering signal when its direc... View full abstract»

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  • Optical fiber wavelength division multiplexer based on two-mode interference

    Publication Year: 2000, Page(s):F1/1 - F110
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (400 KB)

    An optical fiber wavelength division multiplexer based on two-mode interference has been analyzed. A theoretical model based on solution of the wave equation for a two-mode optical waveguide by computing their propagation characteristics is used. In addition, the coupled power between these two modes has been investigated. The dependence of the coupled power on the wavelength, the core radius and ... 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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  • 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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  • 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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  • Neural network based spread spectrum PN code acquisition system

    Publication Year: 2000, Page(s):C30/1 - C3011
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (584 KB)

    A neural network based direct sequence spread spectrum code synchronization system is proposed. The's system is based on training a recurrent random neural network (RNN) model on all the possible phases of the used spreading code. The trained network can then be used at the receiver for the initial coarse alignment of the local code phase and the received code. One advantage of this technique over... View full abstract»

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  • HF electric field effect on Buneman's instability in a relativistic plasma waveguide

    Publication Year: 2000, Page(s):H1/1 - H1/6
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (224 KB)

    The stabilizing effect of a strong HF (pump) electrical field on the Buneman instability in a plane relativistic plasma waveguide is investigated. A new mathematical technique, the separation method, is applied to the two-fluid plasma model to separate the equations, which describe the system, into two parts: temporal and space parts. The temporal (dynamical) part enables us to determine the frequ... View full abstract»

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  • Generation of an approximate TE electromagnetic X-wave in free space and in a planar layered medium using a finite array of electric dipoles

    Publication Year: 2000, Page(s):B10/1 - B1012
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (704 KB)

    The problem of generating an approximate transverse electric (TE) electromagnetic X-wave using a finite circular array of electric dipoles is investigated as an extension of Huygens' aperture solution. A comparison is first made between the dominant term of the time domain far field radiated from an electric dipole and from the elementary point source term in Huygens' formula. The result of this c... 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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  • Two mixed methods for the analysis of a multimode optical rib waveguide

    Publication Year: 2000, Page(s):B17/1 - B1711
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (524 KB)

    A new technique is developed for calculating the dispersion characteristics and field distribution of a multimode rib optical waveguide. The technique is based on the combination of the effective index and the variational methods. An algorithm is implemented to study the effect of the structure parameters and dimensions on the dispersion curves for quasi-TE and TM-modes of a rib optical waveguide.... View full abstract»

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  • Reference-free adaptive interference cancellation using cross-coupled scheme

    Publication Year: 2000, Page(s):C1/1 - C111
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (836 KB)

    This paper deals with the reference-free adaptive interference cancelling techniques. A new cross-coupled adaptive interference canceller (CC-AIC), with only a single input is introduced. This scheme is capable for cancelling narrow-band interference (NBI) from a broadband signal or wideband noise from a narrow-band signal with a significantly better cancellation performance than the conventional ... View full abstract»

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  • Neural network face recognition using statistical feature extraction

    Publication Year: 2000, Page(s):C31/1 - C31/8
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (708 KB)

    Recognition method of human face using statistical analysis feature extraction and a neural network algorithm is proposed. In the preprocessing step we detect the edges of the face image by using the Sobel algorithm. Then we propose a new method to transform the two-dimension black and white image to a one-dimension vector. Finally, based on the statistical analysis, we extract seven features. In ... 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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  • A fingerprint classification technique using multilayer SOM

    Publication Year: 2000, Page(s):C26/1 - C26/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (532 KB)

    This paper presents an automatic fingerprint classification technique similar to that reported by Ongun and Halici (see Proc. of IEEE vol.84, no.10, p.1497-12, 1996) but, an inverse filtering technique was introduced to restore the distorted parts of the images prior to the feature extraction stage. The results have shown that introducing the inverse filtering stage has improved the percentage of ... 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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  • Integrating Fourier descriptors and PCA with neural networks for face recognition

    Publication Year: 2000, Page(s):C22/1 - C22/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (620 KB)

    A new approach to the face recognition problem is presented through combining Fourier descriptors with principal component analysis (PCA) and neural networks. Here the faces are vertically oriented frontal view with scaling, orientation, expression, and illumination changes. There are many research activities on face recognition using the face space which is described by a set of eigenfaces. Each ... View full abstract»

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  • Impact of the current global revolution in communication systems and networks on the social and economic lives in the Middle East

    Publication Year: 2000, Page(s):INV1/1 - INV1/8
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    We have demonstrated, in this paper, the potential of the knowledge-based society, opportunities, challenges and risks. It was noted, that there are many open issues, which need to be well evaluated in order to select the appropriate option for our region. Special emphasis, should be given to improve the infrastructure of the Internet backbone to be able to cope with the growing demand for high ca... 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 novel technique for improving the performance of Salisbury screen

    Publication Year: 2000, Page(s):C27/1 - C27/8
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (332 KB)

    The most common and simple structure to reduce the level of the reflected power from a metallic surface is the single layer structure known as Salisbury screen which is a sheet of porous material impregnated with graphite and spaced a quarter-wavelength off a metallic backing plate. The main disadvantage of this mechanism is the narrow frequency bandwidth. Many techniques have been reported to imp... View full abstract»

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