L. Sellami

United States Naval Academy, Annapolis, Maryland, United States

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Publications (28)6.71 Total impact

  • Louiza Sellami, Robert W. Newcomb, Surajit Sen
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    ABSTRACT: After a review of the coupled Newton's equations for a small alignment of grains with a fixed reflecting end wall, the equations are put into block diagrams of Simulink. Simulink simulations are given for 6 grain systems for cubic and Hertz intergrain potentials. The expected granular solitary waves are seen in the simulations. The block diagrams hence convert a single impulse into a traveling energy bundle of fixed width. This work forms the necessary first step for the eventual realization of the mathematical system represented by the granular chain as a Very Large Scale Integrated (VLSI) circuit.
    Modern Physics Letters B 05/2013; 27(13):50093-. · 0.48 Impact Factor
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    Louiza Sellami, Robert W. Newcomb
    VLSI Design, 01/2012; , ISBN: 978-953-307-884-7
  • Louiza Sellami, Kuan Wong, Robert W. Newcomb
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    ABSTRACT: Cochlea hair-cells act as neural interfaces of sound signals and, therefore, circuit representations are important to signal processing systems based upon characteristics of the ear. Here nonlinear semi-state equations for a bidirectional circuit representing a generic cochlea hair-cell are presented. The circuit can be specialized to inner or outer hair-cells depending upon the choice of circuit parameter values. Also developed are a canonical semi-state description for the hair-cell potassium and sodium channels, and circuits suitable for a transistorized hardware implementation. Circuit simulations are run with numerical data to correlate with the Howard–Hudspeth experiments.
    Journal of Circuits System and Computers 11/2011; 07(05). · 0.24 Impact Factor
  • Louiza Sellami, Robert W Newcomb
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    ABSTRACT: Sensors are becoming of considerable importance in several areas, particularly in health care. Therefore, the development of inexpensive and miniaturized sensors that are highly selective and sensitive, and for which control and analysis is present all on one chip is very desirable. These types of sensors can be implemented with microelectromechanical systems (MEMS), and because they are fabricated on a semiconductor substrate, additional signal processing circuitry can easily be integrated into the chip, thereby readily providing additional functions, such as multiplexing and analog-to-digital conversion. Here, we present a general framework for the design of a multisensor system on a chip, which includes intelligent signal processing, as well as a built-in self-test and parameter adjustment units. Specifically, we outline the system architecture and develop a transistorized bridge biosensor for monitoring changes in the dielectric constant of a fluid, which could be used for in-home monitoring of kidney function of patients with renal failure.
    Advances in experimental medicine and biology 01/2010; 680:701-8. · 1.83 Impact Factor
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    L. Sellami, R.W. Newcomb
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    ABSTRACT: Based on the equations of Keener, a novel and simple circuit model capable of generating chaotic activities similar to those that can occur in the heart is presented. The circuit consists of two RC cells, a mono-stable multi-vibrator, and a pulse generator, and is suitable for VLSI design. PSpice simulations are run to verify its performance. This model could be used to examine the possible reasons for the existence of these activities in the heart and will hopefully help to eliminate these causes.
    Biomedical Robotics and Biomechatronics, 2008. BioRob 2008. 2nd IEEE RAS & EMBS International Conference on; 11/2008
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    ABSTRACT: We present a MEMS, switched current mode circuit that realizes a multi-ear type system. A novel sensor, acts as a pressure transduction mechanism for input to cochlear-type processing. Z-transform computation of fluid motion in the tubules of the cochlea is realized with a switched current lattice cascade. We also describe how an array of MEMS-SI circuits can be placed for use as a multisensor, intended for sound-beam forming, accomplished with n-aural hearing
    Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on; 06/2001
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    ABSTRACT: We demonstrate a framework for eliminating significant perturbations along a cascade scattering model of the inner ear. This allows for the conception of a novel scheme of acute anti-noise stimulation at the cochlear level that can be particularly applicable to the class of tinnitus (ringing in the ear) that is aurally originated (peripheral). Peripherally induced tinnitus is often associated with the occurrence of spontaneous and evoked otoacoustic emissions, partially described by Kemp echoes, the basis of the scattering cochlea model (Sellami and Newcomb, IEEE Trans. Circuits and Systems-I, vol. 44, no. 2, pp 174-180, 1997). We propose that a refined version of the work presented here can be fit to individuals with hearing-loss induced tinnitus
    Circuits and Systems, 2001. MWSCAS 2001. Proceedings of the 44th IEEE 2001 Midwest Symposium on; 02/2001
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    ABSTRACT: An inner ear degree-two cochlea section, which encompasses complex transmission zeros, is realized completely in hardware. In doing this, standard complex two port filters are extracted to a real four port network. A new digital switched current circuit is used with improved clock feed through delay portions. A complex lattice portion is simulated in both Spice and Matlab with accurate results
    Circuits and Systems, 2000. Proceedings of the 43rd IEEE Midwest Symposium on; 02/2000
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    ABSTRACT: A five transistor nonlinear load line is presented for use in analog CMOS circuit design. The load line can be adjusted, possibly dynamically, by an external voltage to fit the situation. In this paper the load-line circuit is presented along with design equations and an example of its use in the realization of a neural type cell. Other uses are in relaxation oscillator and chaos generator design
    Circuits and Systems, 2000. Proceedings of the 43rd IEEE Midwest Symposium on; 02/2000
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    ABSTRACT: The internal auditory system emits slightly detectable sounds (Kemp echoes) as a response to the auditory input. This response is able to be mimicked via a cascade of two-port lattices and has been previously simulated with analog amplifiers. This paper presents a digital implementation scheme using fixed-point, two's complement arithmetic with the wordlength and decimal precision based on generic parameters. The advantages are in accuracy and cancellation of initial cycle oscillations due to initial conditions normally present in both numerical and continuous implementations
    Circuits and Systems, 2000. Proceedings of the 43rd IEEE Midwest Symposium on; 02/2000
  • Robert W. Newcomb, Louiza Sellami
    Wiley Encyclopedia of Electrical and Electronics Engineering, 12/1999; , ISBN: 9780471346081
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    ABSTRACT: Switched current circuits are used here to design real degree-one discrete time lattices for use in modeling the inner ear portion of ear-type networks. This lattice is characterized as an electrical two port system and is, therefore, described by a transfer scattering matrix relating input and output signals. This matrix is degree-one and requires only one delay function, which we realize with a switched current circuit containing only one delay. This circuit uses a new sampling switch that substantially reduces the distortion occurring due to the clock feed through in conventional MOS based switches. Spice simulation results are included to support the theory
    Circuits and Systems, 1999. 42nd Midwest Symposium on; 02/1999
  • L. Sellami, R.W. Newcomb
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    ABSTRACT: This paper presents a MOSFET based biosensor circuit for the monitoring of such things as creatinine in patients with renal failure. Its VLSI layout is presented for 1.2 μ or for 2.0 μ MOSIS CMOS processes. The proposed biosensor circuit is a capacitive gap sensor where the device consists of a bridge made of three standard PMOS devices connected either as resistors or capacitors and forming three arms of the bridge. The fourth arm is a similar PMOS transistor but with a gap between the channel and a raised poly layer in which a fluid, such as creatinine, or a gas, can be placed. PSpice simulations and Spice extractions from the layout are included to demonstrate the operation of the circuit
    Circuits and Systems, 1999. ISCAS '99. Proceedings of the 1999 IEEE International Symposium on; 02/1999
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    ABSTRACT: We present analog VLSI circuits for the learning rate adaptation in self-organizing neural networks using the Mulier-Cherkassky learning rate adapted to the continuous-time case. The circuit design uses the solution of the Riccati equation as a basis for implementing the learning rate schedule
    Neural Networks Proceedings, 1998. IEEE World Congress on Computational Intelligence. The 1998 IEEE International Joint Conference on; 06/1998
  • Louiza Sellami, R.W. Newcomb
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    ABSTRACT: A new method fur converting a lossless cascade lattice realization of a real, stable, single-input, single-output (ARMAn, n) filter, with a lossy constant terminating one-port section, to a lossy realization is proposed. The conversion process is carried out through the factorization of the transfer scattering matrix of a two-port equivalent of the terminating section and the distribution of the loss term, embedded in this matrix, among the lossless lattice sections according to some desirable pattern. The cascade is then made computable through the extraction of right-matched I-unitary normalization sections. The technique applies to both degree-one and degree-two lattice sections, and is rendered systematic owing to the particular lossless lattice structure used. The motivation for this work lies in the synthesis of a pipeline of digital cochlea lattices with loss suitable for hearing impairment diagnosis via Kemp echoes
    IEEE Transactions on Circuits and Systems II Analog and Digital Signal Processing 05/1998;
  • L Sellami, R W Newcomb
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    ABSTRACT: The Hollis-Paulos artificial neural network (HPANN) is convenient in terms of its possibility for realization of variable weight artificial neural networks (ANN's) in very large scale integration (VLSI) by MOS transistor circuits, though it is nondynamical and not driven by external inputs. Here we introduce dynamics and inputs into the HPANN and show that over the range of operation covered by the Hollis-Paulos theory the system has an inverse. In particular, we derive that inverse, in semistate form, and give simulation results on its operation, showing how well the input to the original HPANN can be recovered from the output of the HPANN when fed into the inverse system. A comparison is made with the previous inverse of the Hopfield ANN. Possible applications of these inverse systems are to decoding of transmitted ANN signals and to inverse filtering for the extraction of input signals from processed signals.
    IEEE Transactions on Neural Networks 02/1998; 9(5):979-86. · 2.95 Impact Factor
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    ABSTRACT: Two novel CMOS circuit designs implementing floating resistors are introduced, using the structure of a two-transistor CMOS bilateral linear resistor in the first configuration and two two-transistor CMOS bilateral linear resistors and cascode current mirrors in the second configuration. Linearity is achieved through nonlinearity cancellation via current mirrors over an applied range of ±5V. PSpice simulation results using parameters of MOSIS transistors are presented to verify the theory. These floating resistors can be used for coupling weights in VLSI neural-type cell arrays.
    Journal of Circuits System and Computers 01/1998; 8:559-569. · 0.24 Impact Factor
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    ABSTRACT: A means of modulating information signals in both additive and multiplicative ways by chaotic signals is considered. The chaotic signals are obtained from neural type cells set to their chaotic oscillation mode. The information containing signals are modulated by these chaotic signals by introducing each as the input to a differential pair
    Circuits and Systems, 1998. ISCAS '98. Proceedings of the 1998 IEEE International Symposium on; 01/1998
  • Louiza Sellami, Robert W. Newcomb
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    ABSTRACT: A synthesis algorithm for a pipelined lattice implementation of cochlea-like digital filters is presented, based upon the properties of real, lossless lattice synthesis of ARMA filters. The algorithm operates on a simplified characterization of elementary lattice sections of degree one or degree two. This leads to a structure that is recursively designed and for which each lattice is precisely implemented by a pair of complex conjugate transmission zeros via Richard's function extractions. Except for zeros of transmission on the unit circle, all other types and multiplicities are allowed. Necessary and sufficient conditions are derived for the degree-two lattices to guarantee computability, i.e., realizability with no delay-free loops. In addition to being suitable for VLSI realization, the structure enables a systematic cochlea assessment from the scattering ear parameters.
    Circuits Systems and Signal Processing 12/1997; 17(1):103-116. · 0.98 Impact Factor
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    ABSTRACT: Applications involving speech coding and phonetic classification are introduced as educational tools for reinforcing signal processing concepts learned in senior level communication classes at the US Naval Academy. These applications utilize the software packages MATLAB and NeuralWorks and are used to explore the concepts of impulse sampling, Fourier transforms, data windowing, and homomorphic filtering
    Frontiers in Education Conference, 1997. 27th Annual Conference. 'Teaching and Learning in an Era of Change'. Proceedings.; 12/1997

Publication Stats

53 Citations
6.71 Total Impact Points

Institutions

  • 1996–2013
    • United States Naval Academy
      • Department of Electrical and Computer Engineering
      Annapolis, Maryland, United States
  • 2000
    • Universidad Politécnica de Madrid
      Madrid, Madrid, Spain
  • 1995–2000
    • University of Maryland, College Park
      • Department of Electrical & Computer Engineering
      College Park, MD, United States