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Search results for: OPTIMAL DESIGN
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Optimal ECG lead for deriving respiratory signal
PublicationEDR is an interesting measuring technique that allows an indirect assessment of respiratory activity. This is an alternative solution to direct methods that are based on the measurement of air flow, which require a specialized sensor or even a system. However, due to inter-personal anatomical differences, the optimal ECG lead (placement of the electrodes) ensuring the best EDR signal quality is not fixed. An influence of ECG lead...
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Optimal control of multivariable ship propulsion system.
PublicationCelem pracy jest analiza i synteza algorytmu oraz struktury optymalnego regulatora wielowymiarowego układu napędowego statku na podstawie teorii sterowania optymalnego. W tym celu sformułowano oryginalny nieliniowy zero-wymiarowy ciągły w czasie i oparty na chwilowej wartości zmiennej stanu (w odróżnieniu od wartości średnich modelu matematycznego całego układu napędowego statku). Ten model zweryfikowano na podstawie wyników doświadczalnych...
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Optimal edge-coloring with edge rate constraints
PublicationWe consider the problem of covering the edges of a graph by a sequence of matchings subject to the constraint that each edge e appears in at least a given fraction r(e) of the matchings. Although it can be determined in polynomial time whether such a sequence of matchings exists or not [Grötschel et al., Combinatorica (1981), 169–197], we show that several questions about the length of the sequence are computationally intractable....
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Robust H- optimal synthesis of FDI systems
PublicationDetekcję błędów występujących w nadzorowanym obiekcie dynamicznym, stanowią-cą podstawę decyzji diagnostycznych, oprzeć można na analizie wektorów resz-towych, generowanych w układzie zawierającym odpowiednio zaprojektowany od-porny estymator stanu danego obiektu. Rozważano tylko zewętrzny aspekt syn-tezy generatora reszt optymalnych ze względu na normę tej przestrzeni H : toznaczy problem odprzęgania wektora resztowego od niemierzalnych...
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On optimal tracking of rapidly varying telecommunication channels
PublicationWhen parameters of mobile telecommunication channels change rapidly, classical adaptive filters, such as exponentially weighted least squares algorithms or gradient algorithms, fail to estimate them with sufficient accuracy. In cases like this, one can use identification methods based on explicit models of parameter changes such as the method of basis functions (BF). When prior knowledge about parameter changes is available the...
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Optimal state feedback controller for balancing cube
PublicationIn this paper, a nonlinear balancing cube system is considered, the concept for which is based on an inverted pendulum. The main purpose of this work was the modelling and construction of a balancing cube with the synthesis of the control system. The control objectives included swing-up and stabilization of the cube on its vertex at an unstable equilibrium. Execution of the intended purpose required, first, deriving a cognitive...
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An application of multi-agent system for ship’s power systems design
PublicationDesign process of transport ship power system consists of structure (topology) and component elements selection. Compliance with the requirements for static components does not guarantee optimal dynamic characteristics of entire power system. Design steps are difficult to formalize and as a consequence to this reason expert and multi-agent systems are used for solving selected design issues. In the paper distributed multi-agent...
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Expedited Multi-Objective Design Optimization of Miniaturized Microwave Structures Using Physics-Based Surrogates
PublicationIn this paper, a methodology for fast multi-objective design optimization of compact microwave circuits is presented. Our approach exploits an equivalent circuit model of the structure under consideration, corrected through implicit and frequency space mapping, then optimized by a multi-objective evolutionary algorithm. The correction/optimization of the surrogate is iterated by design space confinement and segmentation based on...
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Multi-fidelity aerodynamic design trade-off exploration using point-by-point Pareto set identification
PublicationAerodynamic design is inherently a multi-objective optimization (MOO) problem. Determining the best possible trade-offs between conflicting aerodynamic objectives can be computationally challenging when carried out directly at the level of high-fidelity computational fluid dynamics simulations. This paper presents a computationally cheap methodology for exploration of aerodynamic design trade-offs. In particular, point-by-point...
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Design of microstrip antenna subarrays: a simulation-driven surrogate-based approach
PublicationA methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (here, a corporate network) on the subarray side-lobe level and allows adjustment of both radiation and reflection responses of the structure under design within a single automated process. This process is realized as surrogate-based optimization that produces...
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Design of a Planar UWB Dipole Antenna with an Integrated Balun Using Surrogate-Based Optimization
PublicationA design of an ultra-wideband (UWB) antenna with an integrated balun is presented. A fully planar balun configuration interfacing the microstrip input of the structure to the coplanar stripline (CPS) input of the dipole antenna is introduced. The electromagnetic (EM) model of the structure of interest includes the dipole, the balun, and the microstrip input to account for coupling and radiation effects over the UWB band. The EM...
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Rotational Design Space Reduction for Cost-Efficient Multi-Objective Antenna Optimization
PublicationCost-efficient multi-objective design of antenna structures is presented. Our approach is based on design space reduction algorithm using auxiliary single-objective optimization runs and coordinate system rotation. The initial set of Pareto-optimal solutions is obtained by optimizing a response surface approximation model established in the reduced space using coarse-discretization EM simulation data. The optimization engine is...
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Power efficient thrust allocation algorithms in design of dynamically positioned ships
PublicationAssessment of power consumption on a Dynamically Positioned (DP) ship in the early design stage can assist crucial design choices. The study presents a comparison between two algorithms of optimal thrust allocation in a propulsion system for an over-actuated DP ship. Applied algorithms were Quadratic Programming (QP) and Non- dominated Sorting Genetic Algorithm II (NSGAII). Based on both approaches, tools were developed for ship...
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublicationTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublicationThe article introduces a design and analysis results of a prototype ORC (organic Rankine cycle) turbo generator rotor assembly of 300kW power, supported by tilting-pad bearings of original design. The calculations were performed for a prototype turbo generator rotor. The shaft of this machine is supported with two radial bearings, lubricated with an unusual lubricant – a low-boiling-point agent. The main objective of the presented...
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Optimal placement of IMU sensor for the detection of children activity
PublicationIn this paper an investigation to determine the optimal placement of IMU sensors for the purpose of children characteristic activity detection is presented. The article compares four different placement of two IMU sensors on human body. Ten healthy volunteers participated within the study. Data were collected firstly from two wireless 9-axial IMU sensors placed at the left and right wrists, then sensors were placed at lower back...
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Energy-Optimal Data Aggregation and Dissemination for the Internet of Things
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A new optimal algorithm for a time-dependent scheduling problem
PublicationIn this article a single machine time-dependent scheduling problem with total completion time criterion is considered. There are n given jobs j_1, ..., j_n and the processing time pi of the i-th job is given by p_i = 1 + b_is_i, where si is the starting time of the i-th job, i = 1, ..., n. If all jobs have different and non-zero deterioration rates and bi > bj => bi >= (b_min+1)/(b_min) b_j + 1/b_min, where b_min = min{b_i}, then...
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Motion stability during optimal control of the mobile platform
PublicationPraca przedstawia metodę badania stabilności robotów mobilnych podczas sterowania optymalnego na przykładzie 3-kołowej platformy mobilnej. Robot posiada więzy nieholonomiczne. Model matematyczny 3-kołowej platformy mobilnej opisuje skończona liczba nieliniowych równań różniczkowych. Stąd, prognozowanie stabilności ruchu takiego obiektu wymaga zastosowania efektywnych algorytmów.
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Optimal and safe control planning with the use of discrete optimization
PublicationW opracowaniu zaproponowano metodę projektowania optymalnych i tolerujących uszkodzenia systemów sterowania opartych na wykorzystaniu algorytmów optymalizacji dyskretnej. Publikacja przedstawia potencjalne wady i zalety metody. Główna idea proponowanego algorytmu sprowadza się do wykorzystania struktury grafu przepływowego w celu stworzenia reprezentacji dynamiki własnej danego procesu. Poszukiwana trajektoria optymalna, jeśli...
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The optimal construction of fiber-optic Fabry-Perot interferometer
PublicationTematem artykułu jest optymalizacja sensorów światłowodowych, wykorzystujących interferometer Fabry-Perota, pracujących w modzie odbiciowym. Celem optymalizacji była maksymalizacja rozdzielczości i dokładności sensora. Autorzy przedstawili analizę teoretyczną oraz wyniki eksperymentalnej optymalizacji światłowodowego interferometru Fabry-Perota, zaprojektowanego i zrealizowanego w laboratorium KOiSE PG.
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Optimal backbone coloring of split graphs with matching backbones
PublicationFor a graph G with a given subgraph H, the backbone coloring is defined as the mapping c: V(G) -> N+ such that |c(u)-c(v)| >= 2 for each edge uv \in E(H) and |c(u)-c(v)| >= 1 for each edge uv \in E(G). The backbone chromatic number BBC(G;H) is the smallest integer k such that there exists a backbone coloring with max c(V(G)) = k. In this paper, we present the algorithm for the backbone coloring of split graphs with matching backbone.
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Optimal asynchronous estimation of 2D Gaussian-Markov processes
PublicationW artykule rozważa się problem estymacji trajektorii dwuwymiarowych ciągłoczasowych procesów Gaussa-Markowa na podstawie zaszumionych pomiarów wykonywanych w nierównomiernie rozłożonych chwilach czasu. W przypadku takiego problemu, w każdym cyklu pracy algorytmu należy dokonać dyskretnoczasowej predykcji (analogicznie jak w przypadku filtru Kalmana). Niestety zadanie to może być złożone obliczeniowo. Aby rozwiązać ten problem,...
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Optimal linear control theory in power system application
PublicationPrzedstawiono syntezę stabilizatora systemowego przy wykorzystaniu metodyki Hinf. Zaprojektowany regulator umożliwia uzyskanie lepszych rezultatów w porównaniu z regulatorem odniesienia w szerokim zakresie zmian punktu pracy.
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The spindle speed optimal control in modern milling operations.
PublicationPraca dotyczy modeli obrabiarek ze sprzężeniem zwrotnym, w przypadku których istotne znaczenie mają drgania samowzbudne typu chatter. Opis układu drgającego przedstawiono w postaci dynamiki układu sterowanego, przy czym sygnałem sterującym jest chwilowa zmiana prędkości obrotowej wrzeciona. Rozważano frezowanie czołowe smukłym frezem trzpieniowym na pionowym cent rum frezarskim. Przedstawiono rezultaty przykładów symulacji komputerowych....
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Chatter surveillance with the creation of a map of optimal spindle speeds
PublicationW pracy przedstawiono metodę nadzorowania drgań samowzbudnych typu chatter. Wyznaczono wartości optymalnych prędkości obrotowych wrzeciona dla poszczególnych punktów na powierzchni przedmiotu obrabianego, wykorzystując rożne techniki analizy modalnej. Badania eksperymentalne wykazały, że otrzymana w ten sposób mapa optymalnych prędkości obrotowych wrzeciona jest skutecznym narzędziem do eliminacji drgań chatter w procesie obróbki...
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Optimal configuration of an electrode array for measuring ventricles' contraction
PublicationAn influence of an electrode-array configuration on an impedance signal composition for a fixed spatial distribution of its sources is examined in the paper. The Finite Element Method and Geselowitz relationship were used for examining three different electrode-arrays. A sensitivity approach was used to evaluate each configuration assuming that localization of the signal source is known. A conductivity change, thus the source of...
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Design space reduction and variable-fidelity EM simulations for feasible Pareto optimization of antennas
PublicationA computationally efficient procedure for multi-objective optimization of antenna structures is presented. In our approach, a response surface approximation (RSA) model created from sampled coarse-discretization EM antenna simulations is utilized to yield an initial set of Pareto-optimal designs using a multi-objective evolutionary algorithm. The final Pareto front representation for the high-fidelity model is obtained using surrogate-based...
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Kriging-assisted hybrid reliability design and optimization of offshore wind turbine support structure based on a portfolio allocation strategy
PublicationIn recent years, offshore wind power generation technology has developed rapidly around the world, making important contributions to the further development of renewable energy. When designing an Offshore Wind Turbine (OWT) system, the uncertainties in parameters and different types of constraints need to be considered to find the optimal design of these systems. Therefore, the Reliability-Based Design Optimization (RBDO) method...
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Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size deter-mination
PublicationIn this paper, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement...
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Machine Learning Techniques in Concrete Mix Design
PublicationConcrete mix design is a complex and multistage process in which we try to find the best composition of ingredients to create good performing concrete. In contemporary literature, as well as in state-of-the-art corporate practice, there are some methods of concrete mix design, from which the most popular are methods derived from The Three Equation Method. One of the most important features of concrete is compressive strength, which...
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Dynamic Positioning Capability Assessment for Ship Design Purposes
PublicationThe article focuses on solving a problem of optimal thrust distribution over the actuators in a ship Dynamic Positioning, according to DNV-ST-0111 standard, Level 1. The classic Quadratic Programming approach is combined with the numerical solusion used to handle the propeller with the rudder constraints in the optimization task and the influence between thrusters and skeg. It is presented as an efficient method of minimizing the...
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Market Regeneration in Line with Sustainable Urban Development
PublicationThis article presents the study of the optimal design solutions for regeneration of marketplaces. It examines the design variants for the revitalisation of the marketplace, in particular, investment in their modernisation in order to find the most optimal model for transforming these public spaces to have a significant impact on the city’s development. The research is a comparative analysis of the implementation of regeneration...
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Optimal Multivariable Control for Modified Z-source Based IPT
PublicationThis paper describes Z-source based inductive power transfer topologies control approaches. The goal of this work is a multi-variable control approach which involves a constant voltage/constant current control along with an optimal frequency control to obtain maximum efficiency. This control is applied to the wireless power transfer system based on a modified Z-source topology. The description of the control method along with simulation...
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Optimal Multivariable Control for Modified Z-source Based IPT
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Which airways management technique is optimal for trauma patient ventilation?
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Necessary conditions for optimal control of general N-D model
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Generation of Optimal Process Plan Alternatives for Manufacturing Mechanical Components
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Chatter vibration surveillance by the optimal-linear spindle speed control
PublicationArtykuł dotyczy drgań samowzbudnych typu chatter podczas obróbki szybkościwowej frezami kulistymi. Opisano w nim niestacjonarny model procesu skrawania oraz przeprowadzono analizy dynamiki układu z opóźniającym sprzężeniem zwrotnym. W celu zredukowania drgań zaproponowano zmiany prędkości obrotowej wrzeciona. Przedstawiono także procedurę nadzorowaia drgań z wykorzystaniem opisanej metody. Dla wybranych przypadków, w artykule przedstawiono...
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Sub-optimal fault-tolerant control by means of discrete optimization
PublicationOpracowanie przedstawia metodę projektowania sterowania optymalnego i odpornego na uszkodzenia z zastosowaniem algorytmów optymalizacji dyskretnej. Poszukiwana trajektoria, jeśli istnieje, jest reprezentowana przez najtańszą ścieżkę w grafie przepływowym, kodującym właściwości danego procesu dynamicznego. Metoda umożliwia zdefiniowanie obszarów zastrzeżonych dla punktu pracy, mogących reprezentować uszkodzenia systemu wykryte wcześniej.
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Sub-optimal fault-tolerant control with the use of discrete optimization
PublicationW pracy prezentuje się koncepcję projektowania układów sterowania z tolerancją usterek poprzez zastosowanie podejścia suboptymalnego. Przyjąwszy przestrzenno-stanową reprezentację nieliniowego procesu dynamicznego we wstępnej fazie projektowania (off-line) poszukuje się optymalnej trajektorii punktu pracy w przestrzeni stanu (ograniczanej do pewnej przestrzeni roboczej). Na poszukiwaną trajektorię można łatwo narzucać dowolne ograniczenia,...
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An optimal abstraction model for hardware multithreding in modern processor architectures.
PublicationPrzegląd technologii implementacji wątków sprzętowych. Propozycja abstrakcji maszyny wirtualnej SIMD (On-Demand Virtual Single Instruction Multiple Data machine) do optymalnego użycia wątków sprzętowych.
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The spindle speed optimal control as a mean of chatter vibration surveillance
PublicationNowa metoda nadzorowania drgań wirujących narzędzi w nowoczesnych frezarkach polega na wykorzystaniu sterowania optymalnego w układach niestacjonarnych przy energetycznym wskaźniku jakości. W rezultacie, sygnałem sterującym jest chwilowa zmiana prędkości obrotowej wrzeciona. Rozważano frezowanie czołowe smukłym frezem trzpieniowym. Wyniki symulacji komputerowych potwierdziły praktyczne uzasadnienie proponowanej metody. Drgania...
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Efficient Multi-Objective Simulation-Driven Antenna Design Using Co-Kriging
PublicationA methodology for fast multi-objective antenna optimization is presented. Our approach is based on response surface approximation (RSA) modeling and variable-fidelity electromagnetic (EM) simulations. In the design process, a computationally cheap RSA surrogate model constructed from sampled coarse-discretization EM antenna simulations is optimized using a multi-objective evolutionary algorithm. The initially determined Pareto...
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Pareto Ranking Bisection Algorithm for EM-Driven Multi-Objective Design of Antennas in Highly-Dimensional Parameter Spaces
PublicationA deterministic technique for fast surrogate-assisted multi-objective design optimization of antennas in highly-dimensional parameters spaces has been discussed. In this two-stage approach, the initial approximation of the Pareto set representing the best compromise between conflicting objectives is obtained using a bisection algorithm which finds new Pareto-optimal designs by dividing the line segments interconnecting previously...
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Fast Multi-Objective Optimization of Narrow-Band Antennas Using RSA Models and Design Space Reduction
PublicationComputationally efficient technique for multi-objective design optimization of narrow-band antennas is presented. In our approach, the corrected low-fidelity antenna model (obtained through coarse-discretization EM simulations) is enhanced using frequency scaling and response correction, sampled, and utilized to obtain a fast response surface approximation (RSA) antenna surrogate. The RSA model is constructed in the reduced design space....
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EM-Driven Multi-Objective Optimization of Antenna Structures in Multi-Dimensional Design Spaces
PublicationFeasible multi-objective optimization of antenna structures is presented. An initial set of Pareto optimal solutions is found using a multi-objective evolutionary algorithm (MOEA) working with a fast surrogate antenna model obtained by kriging interpolation of coarse-discretization EM simulation data. To make the surrogate construction computationally feasible in multi-dimensional design space, the space subset containing non-dominated...
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Rapid multi-objective design optimisation of compact microwave couplers by means of physics-based surrogates
PublicationThe authors introduce a methodology for fast multi-objective design optimisation of miniaturised microwave couplers. The approach exploits the surrogate-based optimisation paradigm with an underlying low-fidelity model constructed from an equivalent circuit of the structure under consideration, corrected through implicit and frequency space mapping. A fast prediction tool obtained this way is subsequently optimised by a multi-objective...
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Low-cost multi-objective design of compact microwave structures using domain patching
PublicationA good compromise between size and electrical performance is an important design consideration for compact microwave structures. Comprehensive information about size/performance trade-offs can be obtained through multi-objective optimization. Due to considerable electromagnetic (EM) cross-couplings in highly compressed layouts, the design process has to be conducted at the level of high-fidelity EM analysis which is computationally...
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Evolutionary Algorithms in MPLS network designing
PublicationMPLS technology become more and more popular especially in core networks giving great flexibility and compatibility with existing Internet protocols. There is a need to optimal design such networks and optimal bandwidth allocation. Linear Programming is not time efficient and does not solve nonlinear problems. Heuristic algorithms are believed to deal with these disadvantages and the most promising of them are Evolutionary Algorithms....