Analysis Of Linear Networks Research Articles

System design of orifice pulse-tube refrigerator using linear flow network analysis

A linear flow network model was developed for the system analysis of an orifice pulse-tube refrigerator (OPT). The flow network analysis considers the pressure as the electric voltage and the mass flow as the electric current. The linear governing equations for the flow network are derived from the continuity and the momentum equations and are analytically solved simultaneously with the energy equation derived to account for the thermal effect in the flow network. The thermal performance calculation can thus be greatly simplified by solving the equivalent circuit of the OPT using a sinusoidal signal analysis. To minimize the analytical errors, an equivalent pulse tube temperature T̄ ptm was introduced with a weighting factor W F which was determined experimentally. The linear flow network analysis provides a powerful tool for the system performance analysis of an OPT.

Simulation of dispersive multiconductor transmission lines by Pade approximation via the Lanczos process

A mathematical model for dispersive, multiconductor transmission lines is introduced that makes possible the utilization of the Pade approximation via the Lanczos (PVL) process to the analysis of linear networks that contain transmission line systems. The mathematical model is based on the use of Chebyshev polynomials for the representation of the spatial variation of the transmission-line voltages and currents. A simple collocation procedure is used to obtain a matrix representation of the transmission line equations with matrix coefficients that are first order polynomials in the Laplace-transform variable s and in which terminal transmission-line voltages and currents appear explicitly. Thus, the model is compatible with both the PVL algorithm and the modified nodal analysis formalism. Results from the numerical simulation of both digital interconnect-type and microwave circuits are presented to demonstrate the validity and discuss the efficiency of the proposed model.

Real-time linear time-domain network analysis using picosecond photoconductive mixer and samplers

Ion-implanted GaAs photoconductive (PC) switches have been used as an optical-microwave frequency mixer and electrical waveform samplers in a real-time sampling system. This high fidelity system has a bandwidth of 100-GHz, time resolution of 4-ps and a measurement sensitivity of 5-/spl mu/V//spl radic/(Hz). Because of this high sensitivity capability, the magnitude of the testing signal can be maintained sufficiently small to allow network analysis of a device or circuit in the linear mode without signal distortion. In this paper, a linear time-domain network analysis of a broadband monolithic microwave integrated circuit (MMIC) amplifier has been demonstrated in real-time by the optoelectronic technique. A measurement time of less than 40 /spl mu/s is used to acquire waveform data. The dynamic range of the system can be further improved to 40 dB by reducing the repetition rate of the step recovery diode. Since the PC switches are fabricated with processes compatible to MMIC manufacturing, this real-time system is well-suited for on-wafer MMIC characterization.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Linear network analysis of regenerator in a cyclic-flow system

A linear dynamics model of Darcy's form for a regenerator is first derived, from which a linear network analysis is employed to study the dynamic response of the regenerator in a cyclic-flow system. It is shown that the dynamic response of the regenerator is determined by the design of the load impedance Z 2( s). The amplitude attenuation and phase shift between the mass flow and the pressure wave due to the effects of the regenerator configuration and the load impedance can be clearly seen from the present linear network analysis. It is found that introduction of load impedance will reduce the bandwith of a regenerator and increase the phase lag of the mass flow with respect to the pressure wave.

On a self‐optimizing algebraic approach to symbolic analysis

AbstractIn this paper a new approach to the symbolic analysis of linear networks is presented. A computer programme based on this approach is briefly described. It is shown that this method in computer applications considerably reduces the number of operations needed, the number of components in the final results and thus the computer time. the method is based on the tableau description of the analysed closed network. Descriptions of elements of the network are optimally chosen successively during the operation of the algorithm. the method presented seems to be the best so far among direct methods of fully symbolic analysis and considerably enhances the possibility of such an analysis.

Linear network analysis of split-type stirling refrigerator

A linear network model is developed for split-type Stirling refrigerators. We obtain an equivalentnetwork and two transfer-function functions from which the system performance can be evaluated. Implementation of the linear network model in the system design analysis of split-type Stirling refrigerator is shown satisfactory.

Allowance for wideband parameter fluctuations in linear inertial networks

A method is developed for analysis of linear inertial networks that undergo parameter fluctuations over a wide detuning range (up to the carrier frequency). Frequency fluctuations caused by reactive-parameter perturbations in LC and tapped-capacitor oscillators are determined as an illustration.

Qualitative analysis of electronic linear programming neural networks

One of the problems that can be solved by neural networks is the linear programming problem. Tank and Hopfield designed an electronic neural network and showed that the network is stable. A more general electronic neural network that solves the linear programming problem is presented herein and its error is analysed. A design with the lowest possible error is shown, detailed transient analysis of the network's outputs together with geometrical interpretations is performed. It is also shown how the network solutions depend on change of the network parameters. Some experimental examples are given.

Analysis of linear networks with inconsistent initial conditions

The authors present a new method for analyzing time-invariant linear networks that allows for the existence of inconsistent initial conditions. Their method is based on the use of distributions and state equations. Any time-invariant linear network, including networks involving any kinds of pure or controlled sources, can be analyzed. Also, the transferences of energy that occur at t=0 are determined, and the concept of connection energy is introduced. The algorithms are easily implemented in a computer program.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

More efficient algorithms for symbolic network analysis: supernodes and reduced loop analysis

In this paper, two efficient approaches will be discussed that support linear network analysis: supernode analysis (SNA) and reduced loop analysis (RLA). By means of some selected example networks, these methods will be demonstrated and, thus, it will be shown that calculations can be dramatically simplified. In this way, all network situations can be handled. There are obvious advantages to SNA as it combines the MNA and the straightforward manual processing of the network. A very efficient solution strategy is obtained without source shifting and other common, less directed methods being used. SNA/RLA and symbolic algebra fit extremely well together. Thus an algorithm that supports the symbolic calculation of networks by means of supernodes which has been conceptualized and implemented in the analog design expert system EASY will be presented in detail. Above the educational aspect, it should be noted that the computer can now take a systematic approach to MNA and network analysis in general.

Parallel Processing Implications for Management Scientists

As parallel processing systems become more accessible, management scientists need to be aware of their implications for algorithm design. Parallel processing systems can simultaneously execute several programs and can be categorized by the number of processors available or the number of data streams that can be used. Efficient interprocessor communication is essential. Fine-grained parallel programs explicitly make use of these communication functions to improve speed, while coarse-grained programs interact less frequently and distribute similar subprograms among processors. In either case, procedures can be used to enable serial programs to execute on parallel processors. Management scientists have used these systems to investigate linear programming problems, simulation models, and network analysis. They offer users opportunities to address problems whose solutions were previously limited by serial-processing architectures.

Thevenin's theorem

The equivalent generator theorem is discussed. It is commonly called Thevenin's theorem, in honor of Leon Charles Thevenin, a French telegraph engineer and educator who proposed it in 1883, but in fact Hermann von Helmholtz proposed it first, in an 1853 paper. Although originally introduced to facilitate the analysis of linear networks of resistances and voltage sources, the theorem subsequently was defined in terms of impedances and voltage sources. As a tool for circuit analysis, it is allied to the superposition theorem. The history of the theorem and how it came to be named for Thevenin are described. >

Analysing networks containing current conveyors

The (second generation) current conveyor is a building block that can be used to design linear circuits. Current conveyors have been used to design oscillators, filters and simulated inductors. This paper presents a simple procedure for analysing circuits that contain current conveyors. The procedure is well suited for manual calculations. It is also easily programmed and is compatible with a previously published algorithm for the computer analysis of linear networks. An important feature of the procedure is that it can be used to analyse networks containing non-ideal current conveyors.

A Framework for Teaching OR Techniques

A five-stage approach to mathematical modelling is reviewed. It is shown how this can be used as a framework for introducing the teaching of simple stock control and distribution, financial modelling and planning, linear programming, decision trees, network analysis and discrete-event simulation. The framework puts emphasis on the conceptualization and verbalization stages, which provides a unifying link for the techniques described and is found substantially to improve formulation skills.

A Framework for Teaching OR Techniques

A five-stage approach to mathematical modelling is reviewed. It is shown how this can be used as a framework for introducing the teaching of simple stock control and distribution, financial modelling and planning, linear programming, decision trees, network analysis and discrete-event simulation. The framework puts emphasis on the conceptualization and verbalization stages, which provides a unifying link for the techniques described and is found substantially to improve formulation skills.

Multiple-Model OR Packages

Multiple-model OR packages (MMORPs) are software packages which incorporate algorithms for the solution of a wide range of OR models. In this paper we consider 15 such packages which are currently available for the IBM-PC. A detailed review of these packages with respect to six common OR models [linear programming, integer programming, assignment, transportation, network analysis (PERT/CPM) and Markov processes] is presented. Criteria for choosing a MMORP are highlighted and a subjective judgement made as to whether each package is worth considering for purchase or not.

Multiple-Model OR Packages

Multiple-model OR packages (MMORPs) are software packages which incorporate algorithms for the solution of a wide range of OR models. In this paper we consider 15 such packages which are currently available for the IBM-PC. A detailed review of these packages with respect to six common OR models [linear programming, integer programming, assignment, transportation, network analysis (PERT/CPM) and Markov processes] is presented. Criteria for choosing a MMORP are highlighted and a subjective judgement made as to whether each package is worth considering for purchase or not.

Primary subgraph method for linear active network analysis

This paper introduces the concept of the primary subgraph of a composite graph associated with a linear active network, and presents a new and efficient topological method, called the primary subgraph method, for linear active network analysis. This method is an improvement and unification of the complete tree method and directed tree method. It thoroughly solves the sign evaluation problem and cancellation term problem.

Computer-aided noise analysis of linear multiport networks

The limitations of the noise figure computation algorithm for linear multiports are discussed. The results obtained during analysis of two different circuits were selected to put into evidence the effects on accuracy of both matrix inversions and the ‘extraction re-embedding’ procedure.

D.C. ANALYSIS OF PIECEWISE LINEAR NETWORKS USING THE GAUSS‐SEIDEL METHOD

Analysis of piecewise linear resistive networks, described by nodal equations, using the Gauss‐Seidel method is presented in the paper. The conditions which guarantee the existence of a unique solution and convergence of the iterative technique are formulated. An algorithm is described and a numerical example is demonstrated.