186 resultados para MOO
Resumo:
Two lecture notes describe recent developments of evolutionary multi objective optimization (MO) techniques in detail and their advantages and drawbacks compared to traditional deterministic optimisers. The role of Game Strategies (GS), such as Pareto, Nash or Stackelberg games as companions or pre-conditioners of Multi objective Optimizers is presented and discussed on simple mathematical functions in Part I , as well as their implementations on simple aeronautical model optimisation problems on the computer using a friendly design framework in Part II. Real life (robust) design applications dealing with UAVs systems or Civil Aircraft and using the EAs and Game Strategies combined material of Part I & Part II are solved and discussed in Part III providing the designer new compromised solutions useful to digital aircraft design and manufacturing. Many details related to Lectures notes Part I, Part II and Part III can be found by the reader in [68].
Resumo:
These lecture notes describe the use and implementation of a framework in which mathematical as well as engineering optimisation problems can be analysed. The foundations of the framework and algorithms described -Hierarchical Asynchronous Parallel Evolutionary Algorithms (HAPEAs) - lie upon traditional evolution strategies and incorporate the concepts of a multi-objective optimisation, hierarchical topology, asynchronous evaluation of candidate solutions , parallel computing and game strategies. In a step by step approach, the numerical implementation of EAs and HAPEAs for solving multi criteria optimisation problems is conducted providing the reader with the knowledge to reproduce these hand on training in his – her- academic or industrial environment.
Resumo:
These lecture notes highlight some of the recent applications of multi-objective and multidisciplinary design optimisation in aeronautical design using the framework and methodology described in References 8, 23, 24 and in Part 1 and 2 of the notes. A summary of the methodology is described and the treatment of uncertainties in flight conditions parameters by the HAPEAs software and game strategies is introduced. Several test cases dealing with detailed design and computed with the software are presented and results discussed in section 4 of these notes.
Resumo:
The Raman spectra of NaLa(MoO4)2 single crystal have been recorded and interpreted on the basis of C4h symmetry. The observed fundamentals (internal and external) have been assigned unambiguously with the help of polarization data. All the group theoretically predicted Raman active fundamentals have been observed.
Resumo:
Scheelite type solid electrolytes, Li(0.5)Ce(0.5-x)Ln(x)MoO(4) (x = 0 and 0.25, Ln = Pr, Sm) have been synthesized using a solid state method. Their structure and ionic conductivity (a) were obtained by single crystal X-ray diffraction and ac-impedance spectroscopy, respectively. X-ray diffraction studies reveal a space group of I4(1)/a for Li(0.5)Ce(0.5-x)Ln(x)MoO(4) (x = 0 and 0.25, Ln = Pr, Sm) scheelite compounds. The unsubstituted Li0.5Ce0.5MoO4 showed lithium ion conductivity similar to 10(-5)-10(-3) Omega(-1)cm(-1) in the temperature range of 300-700 degrees C (sigma = 2.5 x 10(-3) Omega(-1) cm(-1) at 700 degrees C). The substituted compounds show lower conductivity compared to the unsubstituted compound, with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations.
Resumo:
The facile method of solution combustion was used to synthesize gamma(L)-Bi(2)MoO(6). The material was crystallized in a purely crystalline orthorhombic phase with sizes varying from 300 to 500 nm. Because the band gap was 2.51 eV, the degradation of wide variety of cationic and anionic dyes was investigated under solar radiation. Despite the low surface area (< 1 m(2)/g) of the synthesized material, gamma(L)-Bi(2)MoO(6) showed high photocatalytic activity under solar radiation due to its electronic and morphological properties. (C) 2011 Elsevier Ltd. All rights reserved.
Resumo:
Electrical double-layer capacitors owe their large capacitance to the formation of a double-layer at the electrode/electrolyte interface of high surface area carbon-based electrode materials. Greater electrical energy storage capacity has been attributed to transition metal oxides/nitrides that undergo fast, reversible redox reactions at the electrode surface (pseudo-capacitive behavior) in addition to forming electrical double-layers. Solution Precursor Plasma Spray (SPPS) has shown promise for depositing porous, high surface area transition metal oxides. This investigation explored the potential of SPPS to fabricate a-MoO 3 coatings with micro-structures suitable for use as super-capacitor electrodes. The effects of number of spray passes, spray distance, solution concentration, flow rate and spray velocity on the chemistry and micro-structure of the a-MoO 3 deposits were examined. DTA/TGA, SEM, XRD, and electrochemical analyses were performed to characterize the coatings. The results demonstrate the importance of post-deposition heating of the deposit by subsequent passes of the plasma on the coating morphology. © ASM International.
Resumo:
A new compound Ce(6-x)Ln(x)MoO(15-delta) has been synthesized by wet-chemistry method. Their crystal structure and oxide ionic conductivity were characterized by powder X-ray diffraction, Raman, IR spectrum and A.C. impedance technique. The XRD results showed that Ce6MO15-delta, Ce(5)LnMoO(15-delta) have cubic symmetry with Fm3m space group. The refined lattice parameters showed that their lattice constants decrease with the decrease of the ionic radius of Ln(3+). The electrochemical measurements showed that the ionic conductivity of resulting oxides Ce(6-x)Ln(x)MoO(15-delta) have an enhance, which may be a kind of promising material for SOFCs.
Resumo:
Tesis (Maestro en Ciencias de la Ingeniería Mecánica con Especialidad en Materiales) UANL, 2011.