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Idoia Berges Jesús Bermúdez Alfredo Goñi Arantza Illarramendi 《Expert systems with applications》2013,40(7):2462-2475
Over the last years, there has been a change of perspective concerning the management of information systems, since they are no longer isolated and need to communicate with others. However, from a semantic point of view, real communication is difficult to achieve due to the heterogeneity of the systems. We present a proposal which, considering information systems are represented by software agents, provides a framework that favors a semantic communication among them, overcoming the heterogeneity of their agent communication languages. The main components of the framework are a suite of ontologies – conceptualizing communication acts – that will be used for generating the communication conversion, and an Event Calculus interpretation of the communications, which will be used for formalizing the notion of a satisfactory conversion. Moreover, we present a motivating example in order to complete the explanation of the whole picture. 相似文献
45.
Nickel manganite powder synthesized by calcination of a stoichiometric mixture of manganese and nickel oxide was additionally mechanically activated in a high energy planetary ball mill for 5-60 min in order to obtain a pure NiMn2O4 phase. The as-prepared powders were uniaxially pressed into disc shape pellets and then sintered for 60 min at 1200 °C. Changes in the particle morphology induced by mechanical activation were monitored using scanning electron microscopy, while changes in powder structural characteristics were followed using X-ray powder diffraction. The ac impedance spectroscopy was performed on sintered nickel manganite samples at 25 °C, 50 °C and 80 °C. It was shown that mechanical activation intensifies transport processes causing a decrease in the average crystallites size, while longer activation times can lead to the formation of aggregates, defects and increase of lattice microstrains. The observed changes in microstructures were correlated with measured electrical properties in order to define optimal processing conditions. 相似文献
46.
I. Miloševi? N. Kep?ijaE. Dobard?i? M. Damnjanovi?M. Mohr J. MaultzschC. Thomsen 《Materials Science and Engineering: B》2011,176(6):510-511
Symmetry based analysis of the Kohn anomaly is performed. Kohn phonon frequencies and displacements are calculated by force constant method. It is shown that Kohn phonon vibrations cause electronic band gap opening. 相似文献
47.
B. Škipina D.Lj. Mirjani?S.M. Vu?enovi? J.P. Šetraj?i?I.J. Šetraj?i? A.J. Šetraj?i?-Tomi?S.S. Pelemiš B. Markoski 《Optical Materials》2011,33(11):1578-1584
We have formulated a microscopic theory of optical properties of ultrathin molecular films (nanofilms), i.e. quasi 2D systems parallel to XY planes bounded by two surfaces. Exposure of nanofilms to the external electromagnetic fields has result in creation of excitons - but different than bulk ones. Harmonic exciton states were calculated using the method of two-time, retarded, temperature dependent Green’s functions. It has been shown that two types of optical excitations can occur: bulk and surface exciton states. Exciton energy dispersion law shows discrete behavior with non-zero values. Analysis of the dielectric properties of these crystalline systems for low exciton concentration shows that the permittivity strongly depends on boundary parameters and the thickness of the film. In addition, permittivity shows very narrow and discrete dependence of external electromagnetic field frequency, which is a consequence of both resonance and quantum size effects. Influences of boundary conditions on optical characteristics (through analyses of dynamical absorption coefficient) of these nanostructures were specially and in details explored. 相似文献
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The proposed procedure is implemented without breaking the loop with the controller in operation, by activating a cascade of band-pass filters in series with a relay in the inner loop and a notch filter in the outer loop. A highly accurate estimate of the critical point of a process Gp(s) is obtained in the presence of measurement noise and load disturbance. The effectiveness of the proposed procedure is illustrated using a test batch consisting of stable, integrating and unstable processes, including dead-time. 相似文献
49.
Arif Nesrullajev ?i?dem Y?rür-G?reci Belkis Bilgin-Eran 《International Journal of Thermophysics》2012,33(1):58-68
The synthesis and investigations of the mesomorphic, thermotropic, thermo-morphologic, and thermo-optical properties of two new salicylaldimine compounds, synthesized by our group, are reported in this work. Temperature transformations of specific textures of the smectic C mesophase, taking place in these compounds, and thermo-morphologic and thermotropic properties of the biphasic regions for direct and reverse phase transitions have been investigated. Temperature hysteresis and enlargement of the biphasic regions have been found. The character of texture transformations and temperature behavior of the optical birefringence indicate to the first order a smectic C–isotropic liquid-phase transition in these salicylaldimine compounds. 相似文献
50.
F. Cajner S. Kovačić H. Rafael A. Vugrinčić V. Šimunović B. Gržeta 《Materialwissenschaft und Werkstofftechnik》2015,46(1):69-77
Nitriding increases surface hardness and improves wear resistance of stainless steels. However, nitriding can sometimes reduce their corrosion resistance. In this paper, the influence of nitriding on the corrosion resistance of martensitic stainless steel was investigated. Plasma nitriding at 440 °C and 525 °C and salt bath nitrocarburizing were carried out on X17CrNi16‐2 stainless steel. Microhardness profiles of the obtained nitrided layers were examined. Phase composition analysis and quantitative depth profile analysis of the nitrided layers were preformed by X‐ray diffraction (XRD) and glow‐discharge optical emission spectrometry (GD‐OES), respectively. Corrosion behaviour was evaluated by immersion test in 1% HCl, salt spray test in 5% NaCl and electrochemical corrosion tests in 3.5% NaCl aqueous solution. Results show that salt bath nitrocarburizing, as well as plasma nitriding at low temperature, increased microhardness without significantly reducing corrosion resistance. Plasma nitriding at a higher temperature increased the corrosion tendency of the X17CrNi16‐2 steel. 相似文献