Fundamental Mode Of Operation Research Articles

Broadbanding of a gyro-TWT by dielectric-loading through dispersion shaping

A general cylindrical waveguiding interaction structure with a dielectric rod at its axis and a dielectric lining at its wall is field-analyzed to obtain a cold dispersion relation. The results of the cold analysis are combined with the hot dispersion relation of a dielectric-free gyro-traveling wave tube (TWT) to obtain the hot dispersion relation of the dielectric-loaded gyro-TWT. The dispersion relation is interpreted to obtain the conventional TWT-type, Pierce-form gain equation. The dielectric parameters are chosen for a wideband coalescence between the beam end the waveguide modes. For a TE/sub 0n/-mode gyro-TWT, the fundamental mode of operation (n=s=1, where s is the beam-harmonic mode number), gives a higher gain which reduces as one goes for higher values of n=s. The second harmonic operation (n=s=2), however, gives a larger bandwidth. The present analysis also suggests a method to select the values of the hollow beam radius relative to the waveguide wall radius for enhancing both the device gain and bandwidth. This study shows the feasibility of a wideband amplification in a gyro-TWT using dielectric loading, at higher gain values than those obtainable from other broadbanding schemes such as simultaneous profiling of the waveguide cross section and the background dc magnetic flux density.

DATA-DRIVEN INDUCTIVE INFERENCE OF FINITE-STATE AUTOMATA

Within the field of structural pattern analysis, algorithms for inference of discrete mathematical models from samples are an important area of research. This paper gives an extensive survey of state-of-the-art methods for data-driven inductive inference of finite-state automata. In addition to providing notationally consistent descriptions of the methods’ fundamental mode of operation, aspects such as sequential learning, advantages and disadvantages, and the extension to stochastic automata are also addressed.

Analysis of MESFET injection-locked oscillators in fundamental mode of operation

In this paper, nonlinear analyses of MESFET oscillator in free-running and injection-locked states are studied based on the Volterra series method and stability analysis. The approach shown is capable of quantitatively analyzing the injection locking performance of oscillator using three-terminal devices in the fundamental mode of operation. Both the transmission-type and reflection-type injection locked oscillators (ILO) are simulated and experimentally verified. >

Fourier transform IR studies of alternate layer acid-amine Langmuir-Blodgett films with pyroelectric properties

The effects of heating acid-amine alternate Langmuir-Blodgett films on the molecular arrangement and head group interactions have been studied in relation to pyroelectric activity. We have shown how changes in the extent of proton transfer and head group rearrangements might lead to the necessary changes in polarization with temperature. Fourier transform IR methods are demonstrated to have the sensitivity and power needed to gather valuable information about the fundamental modes of operation of molecular electronic devices.

Ion channels and postsynaptic potentials

Neurotransmitters open transmembrane ion channels in target membranes. At the motor endplate, the open time of channels activated by acetylcholine determines the time course of the endplate current. Endplate channels are selective for cations and their conductance and open times are influenced by the nature of the permeating cation. Similar effects have been seen at anion-selective inhibitory synapses. Some 'blocking' drugs that depress postsynaptic responses to neurotransmitters produce effects not consistent with a simple model in which they block open channels. Channels activated by neurotransmitters can show subconductance states that may reflect the fundamental mode of operation of a variety of ion channels.

Design theory for rotary heat and mass exchangers—I. Wave analysis of rotary heat and mass exchangers with infinite transfer coefficients

A theory is presented for modeling rotary heat and mass exchangers with infinite transfer coefficients. The continuity and energy conservation equations for one-dimensional transient flow are established and analyzed. Solutions to the equations are obtained by the method of characteristics and the shock wave method. Both methods provide a set of analytical equations that allow performance prediction of the heat and mass exchanger with infinite transfer coefficients for any inlet and operating conditions. A regenerator-operating chart is introduced which shows the fundamental modes of operation for rotary heat and mass exchangers. Part II presents correlations for the effectiveness of rotary dehumidifiers with finite transfer coefficients.

Stability Analysis of Injection-Locked Oscillators in Their Fundamental Mode of Operation

Phase-lock stability of fundamental-wave injection-synchronized oscillators is investigated on the basis of a new time-domain approach. Starting from a quite general oscillator modeling and assuming single-frequency quasi-static operation, both exact and first-order approximate stability criteria are derived in a fully analytical form suitable for computer implementation. The examples worked out demonstrate good agreement of this theory with experimental observations available in the literature on multiple-tuned oscillators, whose behavior under large-signal injection was so far predictable only through graphical methods.

Silicon Waveguide Frequency Scanning Linear Array Antenna

The design and experimental findings of a novel approach a relatively simple low-cost frequency-scanning milliter-wave antenna are described. The antenna consists of a silicon dielectric rectangular rod with periodic metallic stripe perturbations on one side. The feasibility of electronically scanning through a range of angles by varying the frequency fed into the silicon rod is shown. CalcuIations were made to determine the allowable physical size of the silicon rod in order to maintain a single fundamental mode of operation and the effect which size variations and perturbation spacing have on the angle of radiation and the range of angular scan for a given frequency shift. Efforts covered the frequency range 55-100 GHz with specific points of interest at 60, 70, and 94 GHz. The results of the experiments conducted are compared with the theoretical calculations.

Solution of aerial triangulation problems using the N.R.C. analytical plotter

Combining the advantages of analog and analytical photogrammetric methods, the analytical plotter system is certainly the most flexible tool for the evaluation of diverse photogrammetric imagery, and at the same time an outstandingly powerful instrument in the field of aerial triangulation. The different techniques offered by this system for the accomplishment of aerial triangulation require corresponding formulations and solutions which, in turn, influence the design of appropriate programs. In this presentation, following a short description of the N.R.C. Analytical Plotter and its fundamental modes of operation, different solutions of aerial triangulation problems, concerning this system, are explained and discussed.

Survey of Flux-Responsive Magnetic Reproducing Heads

A magnetic reproducing head which generates signal voltage substantially proportional to the magnitude of the intercepted magnetic flux is commonly referred to as a flux-responsive or magnetostatic head. The fundamental mode of operation, the different approaches to practical solutions, and the characteristic features of this type of head are described. The explanations are illustrated by a number of cases which have been either proposed or practically executed by various organizations and investigators. References are given, including brief abstracts of pertinent patents and other publications.