Simplified formulations for two-dimensional TE-polarization fieldcomputations

Techniques in solving integrodifferential equations for two-dimensional transverse electric polarization field computations are discussed. Analytical simplifications are presented to efficiently and accurately evaluate the impedance elements, especially the diagonal ones, without loss of accuracy in the moment-method solution to the integral equations using pulse expansion and point matching. With such a choice, one can minimize the efforts in the software development of a two-dimensional electromagnetics code. Meanwhile, analytical simplifications on the evaluation of the impedance elements are developed based on the principle that the error due to simplifications is of a higher-order small argument than the error caused by the discretization     

An alternative method to share the initial fixed cost of a localarea network

The managers of local area networks must often determine how to share the initial fixed cost of the network among its users. The methods commonly used for this task are unsatisfactory. An alternative technique to solve this problem is presented and applied to the network of an actual corporation. The technique is based on four simplifications derived from the Shapley Value. The simplifications generate the same cost division as the Shapley Value and are easier to calculate. The results of the method are demonstrated and the network managers reaction is noted     

A simplified approach to determine the amplitude of the transientvoltage induced on a cable bundle

Studies the transient response of a multiconductor transmission line, by using the formalism of multiple reflections. This often requires an experimental characterization of the cable bundle that becomes tedious for a large number of conductors, In order to reduce the experimental task, the authors bring two simplifications: the first one is based on the approximation of totally degenerate modes, the second one on the approximation of semi-degenerate modes, Then, some experiments with real bundles have been achieved to validate these simplifications     

An extended soluble gas exchange model for estimating pulmonaryperfusion. I. Derivation and implementation

A dynamic model for respiratory exchange of blood soluble gas is described. This model includes a general treatment of tidal breathing, an inhomogeneous lung comprising multiple distensible compartments, and nonlinearities due to multiple-gas effects. The motivation for this new model is the continuing interest in estimating pulmonary perfusion from measurements of respiratory soluble gas exchange. Numerical simulation can be employed to investigate the errors that result from simplifications made in the derivations of simpler models used for this purpose. Examples of such simplifications are the assumptions that ventilation is constant and unidirectional, and that multiple soluble gases can be independently modeled. These results can delimit the boundaries within which perfusion estimates can be considered reliable. An example demonstrating the model and its numerical solution is presented.     

Current distribution on a cylindrical antenna in a plasma

A general solution for the current distribution on a cylinder in a cold magnetoplasma has been obtained. It is complicated, but for practical applications several simplifications occur. We present an outline of this solution and a sample of results.     

Efficient receiver structure for GSM mobile radio

The paper describes a receiver structure for the digital GSM mobile radio which is suitable for implementation using a DSP processor. The simulation results show that proposed simplifications have minor influence on the receiver performance and drastically reduce its computational complexity.     

p-n-p-n charge dynamics

A simple unified charge model applicable to both unsaturated and saturated p-n-p-n dynamic behavior is analyzed. Expressions are obtained for three important dynamic conditions: di/dt prior to saturation, voltage drop during turn-on, and reverse current during recovery. Comparison with measurement shows that interdigitated gate p-n-p-n devices match one-dimensional turn-on theory and closely approximate the behavior of p-i-n rectifiers under similar pulsed conditiom. The major analytical simplifications of the one-dimensional theory are examined in the Appendixes. The limitations imposed by these simplifications can be avoided by use of numerical integration techniques.     

A Comment on the Weiss–Weinstein Bound for Constrained Parameter Sets

The Weiss–Weinstein bound (WWB) provides a lower limit on the mean-squared error (MSE) achievable by an estimator of an unknown random parameter. In this correspondence, it is shown that some previously proposed simplified versions of the bound do not always hold for constrained parameters, i.e., parameters whose distribution has finite support. These simplifications can produce results which are no longer lower bounds on the MSE. Sufficient conditions are provided for the reductions to be valid.      

New Convolutional Codes--Part II

Part II presents a unified code-generation algorithm which contains new codes with rates from 14/15 to 49/50. For use with this class of codes, some simplifications of the weighted maximum likelihood decoding are suggested. An approximated error probability expression is set forth for using these codes in communications satellite channels, The measured results are remarkably close to the error rate calculations.     

A novel inverse dynamic model for 3-DoF delta robots

Delta Robots belong to a class of parallel robots widely used in industrial production processes, mostly for pick-and-place operations. The most relevant characteristics are the high speed and the extremely favorable ratio between the maximum payload and the weight of the robot itself. A reliable dynamic model is needed to implement torque controllers that reduce unnecessary high accelerations and so mechanical vibrations. The state-of-art inverse dynamic models exploit simplifications in order to facilitate the derivation of the equations of motion and their implementation. In this work, a novel and more rigorous inverse dynamic model is presented which does not rely on simplifications of the kinematic structure. The model has been validated comparing its estimations with real torques data collected moving a Delta Robot D3-1200 by SIPRO Srl; the computational complexity of the algorithm has also been investigated.     

Réception des messages biphase dans les systémes de télécommunications par fibres optiques

The author considers the problems relevant to the detection of unipolar split-phase signals in digital optical fiber communication systems. By use of simplifications concerning the fiber frequency response and the noise power spectrum, the error rate is computed in different kinds of signal processing. Compared to the theoretical optimum detection, the results are presented as a function of the practical receiver bandwidth.     

Quasi-Optimum Digital Phase-Locked Loops

Quasi-optimum digital phase-locked loops (DPLL) are derived utilizing nonlinear estimation theory. Nonlinear approximations are employed to yield realizable loop structures. Baseband equivalent loop gains are derived, which, under high signal-to-noise ratio conditions may be calculated off line. Additional simplifications are made that permit the application of the Kalman filter algorithms to determine the minimum mean-square error (MSE) loop filter. Consideration is given to sampling rate and implementation requirements. Performance is evaluated by a theoretical analysis and by simulation. Theoretical and simulated results are discussed and a comparison to analog results is made.     

A small-signal analysis of the modulation response of high-speedquantum-well lasers: effects of spectral hole burning, carrier heating,and carrier diffusion-capture-escape

We present a small-signal analysis of the modulation response by simultaneously considering the effects of spectral hole burning, carrier heating, and carrier diffusion capture-escape. An explicit form of the small-signal modulation response is obtained and the nonlinear gain coefficients associated with each physical process are defined. Further simplifications in our results will give analytical forms for calculating the resonant frequency and damping rate of the modulation response. One of the simplified versions of our results is shown to agree with previous investigations. The effects of the carrier dephasing time, energy relaxation time, and diffusion-capture-escape times on the high-speed performance of QW lasers are theoretically investigated     

Paraxial approximation effect on a dielectric interface analysis

We are presenting a fast new method of analysing a dielectric interface which is assumed to be cylindrically symmetrical. It is based on a multimode Gaussian beam development. Then two different cases are considered and we show the kind of results we can expect from this process. Finally, we explain in detail the relationships between the paraxial approximation and further justified simplifications which lead to an important calculation time decrease.     

A Vector Derivation Useful in Impedance Plethysmographic Field Calculations

A vector relationship similar to Green's theorem incorporating simplifications which can be made for impedance plethysmography is derived. The mathematics involved are simplified by the use of current density instead of electric field. Geselowitz's lead theory result [1] is rederived and a limitation of such proofs is discussed.     

Numerical Analysis of a Very Long-Wavelength HgCdTe Pixel Array for Infrared Detection

In this paper we present numerical simulations of pixel arrays for detection of very long-wavelength (≥14 μm) infrared radiation. The drift-diffusion equations are solved on a three-dimensional finite element grid; this approach avoids errors typically introduced by one- or two-dimensional simplifications which are difficult to quantify. We simulate the device structure and compare our numerical results with values measured on fabricated and characterized devices. The aim is to test the quality of the HgCdTe material model and derive insights for geometry optimization of pixel array detectors grown by liquid-phase epitaxy.     

Mixed-Mode Chain Scattering Parameters: Theory and Verification

Chain scattering parameters or T-parameters are a useful tool for calculating cascaded two-ports. With the increasing importance of mixed-mode S-parameters, a need for converting the T-parameters from their unbalanced form into a balanced form emerges for suiting both common and differential mode waves, as well as the mode conversion. This paper presents the derivation of the equations for transformations between mixed-mode S- and T-parameters for a mixed-mode two-port. Although derived in a way very similar to monomode T-parameters, no simplifications were necessary. Measurement results exemplify the quality of the T-parameter transformation under real-life conditions.     

Model of temperature dependence for gain shape of erbium-dopedfiber amplifier

The problem of modeling the temperature dependence of erbium-doped fiber amplifier (EDFAs) is important for multichannel optical WDM systems. A physical model is presented in this paper, which could be used to predict the gain change under temperature variations for such systems. Some of the input parameters for the model are the erbium energy sublevel density, excitation coefficients from lower sublevels to upper sublevels of erbium ions, and electron distribution over energy levels. It is difficult to measure these parameters. In order to use the model for gain shape calculations, some simplifications are demonstrated. These simplifications lead to two numerical models, which are shown to be consistent with experimental data with reasonable accuracy, and are based only on two spectral measurements for different temperatures. Both numerical models were tested for the signal band and the 980 nm pump band of a typical erbium-doped fiber     

An automated sensor nodes’ speed estimation for wireless sensor networks

Wireless sensor networks (WSNs) have become more and more notorious thanks to their numerous advantages. But, some of the WSN weaknesses, inherent to sensor nodes’ particularities (low memory, finite battery, etc.), make these networks vulnerable especially for some particular scenarios such as nodes’ mobility which alters the correct network functioning and completely compromises its normal behavior. Thus, we propose in this paper a novel mobility prediction model called the general Bayesian-based mobility prediction (G-BMP) model where sensor nodes’ speed values are derived based on a Bayesian inference paradigm and upon the occurrence of “expired links” and “non-expired links” events. Moreover, to make the implementation of G-BMP possible on sensor devices, we introduce some simplifications during the computation and the transmission of speed distributions. The evaluation of G-BMP using python illustrates the accuracy of the model in deriving the correct speed values in a timely manner. We also compare the performance of G-BMP to the native BMP model that only considers the expired link events when updating the nodes’ speed distributions. The results show that the convergence to real speed values within sensor nodes is faster with G-BMP than that with the native BMP model. In addition, all the simulations illustrate the accuracy of the simplifications used to reduce the overhead generated by the frequent exchange of speed distributions.