Wyniki wyszukiwania - BazTech

1

Topological Synthesis of Tree Shaped Structures Based on a Building Blocks Hypothesis

Miazga P.

Journal of Telecommunications and Information Technology

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2011

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nr 4

45-49

EN

In this paper a new approach to evolutionary controlled creation of electronic circuit connection topology is proposed. Microwave circuits consisting of a tree like connection of ideal transmission lines are considered. Assuming that a reasonable number of transmission lines in a tree network ranges from 10 to 100, the number of connection combinations is immense. From the engineering practice comes the hypothesis that any device can be decomposed into some functional building blocks consisting of one to dozen transmission lines. The variety of linking combinations in a tree with a limited depth is confined to hundreds or thousands of shapes. Therefore we can decrease the dimensionality of research space, applying evolution to building blocks only. Evolutionary algorithm (EA) which processes simultaneously the population of λ functional blocks and population of ž circuits is proposed. A μ, λ selection scheme with tournament together with specific encoding of solutions, and custom operators is implemented. The μ, λ, α EA was tested on an example of the design of a microwave transistor matching circuit.

2

Simulation-based optimization - myths and reality

Miazga P.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2008

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z. 165

131-137

EN

The present paper discusses the influence of simulation model accuracy on the convergence of electromagnetic structure simulation-based optimization. Neither response surface approximation method nor the algorithm of moving window filtering, commonly used for simulation error compensation, is not fully capable of guaranteeing proper convergence. The non-expensive device model with coarse meshing and a modified error compensation method can yield satisfactory results in a reasonable time.

3

A meta-heuristics algorithm for the global optimization of expensive, simulator evaluated, objective function

Miazga P.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2006

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z. 156

273-280

EN

This paper presents the idea of a meta-heuristics algorithm called Evolutionary Controlled Clustering Algorithm (ECCA) designed for implementation in simulation optimization. The method focuses on localization of function optima neighborhoods. A Evolutionary Algorithm (EA) with soft selection and gene injection is used for finding basin of attraction. It operates over nodes of a grid created in a continuous parameter space. ECCA manipulates the grid density as well as the simulation accuracy. Clustered data is used for identification of the basin of attraction. Later, surrogate optimization is applied for local optima search. ECCA was optimized for operation in an uncertain and dynamically changing environment of simulation data. It was tested on the design of the shape of waveguide transition. The computer program can be executed concurrently on a multi-processor machine or on a grid of computers.

4

Global and local optimization algorithms in automated waveguide design

Miazga P., Kamola M.

Prace Naukowe Politechniki Warszawskiej. Elektronika

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2002

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z. 139

123--135

EN

An automated CAD design problem is presented. The automation is achieved by embedding simulation software in two optimization routines of different natures. The chapter first presents the optimization problem, the optimization algorithms and the sample results obtained. The discussion on the algorithms' accuracy and effectiveness is given. The example problem presented here, namely the optimization of waveguide bend, is one of the highly important design tasks in telecommunication networks.