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61.
Ewa Talik Marie-Emilie Lucas Wojciech Suski R. Tro 《Journal of Alloys and Compounds》2003,350(1-2):72-76
The XPS electronic structures of the AFe4Al8 (A=Sc, Y, U, Th) single crystals were measured. The valence band of UFe4Al8 exhibits domination of the U 5f states at the Fermi level, while for the other AFe4Al8 compounds the valence states are shifted by 0.5 eV toward higher binding energy. The multiplet structure of the U 4f and Th 4f states was analyzed in comparison with the U 4f states of U3Ge5 and UNiSb2. 相似文献
62.
Brett Abarbanel Bo Bernhard A. K. Singh Anthony Lucas 《Behaviour & Information Technology》2015,34(10):1005-1021
This study empirically tests a stimulus–organism–response (S–O–R) structural model that proposes that an online casino's atmospheric cues and functional qualities influence individuals' affective and cognitive responses, which in turn impact consumer behavioural intentions. Using self-reported data from a primarily US-based sample, analysed elements of the online gambling site stimulus included high and low task-relevant cues, financial trust, and gambling value. Demographic characteristics were found to moderate the relationship between the stimulus and internal satisfaction, with demographic group differences found among all stimulus constructs. Results emphasise the significant role that atmospherics and functional qualities play in generating positive behaviours from online gamblers, with additional implications in marketplace competitiveness and in responsible gambling practices. 相似文献
63.
Liu Hsu Marcelo Carvalho Minhoto Teixeira Ramon Romankevicius Costa Edvaldo Assunção 《Asian journal of control》2015,17(5):1484-1497
A Lyapunov design of multiple input, multiple output (MIMO) model‐reference adaptive control (MRAC) systems is proposed using new generalized passivity concepts based on WSPR and WASPR properties. The new design avoids control overparameterization and leads to the simplest unnormalized gradient algorithm by means of a passivating multiplier. To this end, a necessary and sufficient condition on the high frequency gain matrix to achieve the WASPR property is established. This condition is referred to as Positive Diagonal Jordan (PDJ) form. Based on the robustness WSPR and WASPR properties, a systematic determination of a robust passivating matrix multiplier is then presented. The advantages of the new design are illustrated by numerical simulation including a robotics adaptive visual servoing problem and a 4‐input‐4‐output dynamic system. © 2014 Chinese Automatic Control Society and Wiley Publishing Asia Pty Ltd 相似文献
64.
Lu??s Antunes Armando Matos Alexandre Pinto Andr?? Souto Andreia Teixeira 《Theory of Computing Systems》2013,52(1):162-178
We prove several results relating injective one-way functions, time-bounded conditional Kolmogorov complexity, and time-bounded conditional entropy. First we establish a connection between injective, strong and weak one-way functions and the expected value of the polynomial time-bounded Kolmogorov complexity, denoted here by?E(K t (x|f(x))). These results are in both directions. More precisely, conditions on?E(K t (x|f(x))) that imply that?f is a weak one-way function, and properties of?E(K t (x|f(x))) that are implied by the fact that?f is a strong one-way function. In particular, we prove a separation result: based on the concept of time-bounded Kolmogorov complexity, we find an interval in which every function?f is a necessarily weak but not a strong one-way function. Then we propose an individual approach to injective one-way functions based on Kolmogorov complexity, defining Kolmogorov one-way functions and prove some relationships between the new proposal and the classical definition of one-way functions, showing that a Kolmogorov one-way function is also a deterministic one-way function. A relationship between Kolmogorov one-way functions and the conjecture of polynomial time symmetry of information is also proved. Finally, we relate?E(K t (x|f(x))) and two forms of time-bounded entropy, the unpredictable entropy?H unp, in which ??one-wayness?? of a function can be easily expressed, and the Yao+ entropy, a measure based on compression/decompression schema in which only the decompressor is restricted to be time-bounded. 相似文献
65.
In this paper, we propose a new online identification approach for evolving Takagi–Sugeno (TS) fuzzy models. Here, for a TS model, a certain number of models as neighboring models are defined and then the TS model switches to one of them at each stage of evolving. We define neighboring models for an in-progress (current) TS model as its fairly evolved versions, which are different with it just in two fuzzy rules. To generate neighboring models for the current model, we apply specially designed split and merge operations. By each split operation, a fuzzy rule is replaced with two rules; while by each merge operation, two fuzzy rules combine to one rule. Among neighboring models, the one with the minimum sum of squared errors – on certain time intervals – replaces the current model.To reduce the computational load of the proposed evolving TS model, straightforward relations between outputs of neighboring models and that of current model are established. Also, to reduce the number of rules, we define and use first-order TS fuzzy models whose generated local linear models can be localized in flexible fuzzy subspaces. To demonstrate the improved performance of the proposed identification approach, the efficiency of the evolving TS model is studied in prediction of monthly sunspot number and forecast of daily electrical power consumption. The prediction and modeling results are compared with that of some important existing evolving fuzzy systems. 相似文献
66.
Infonorma is a multi-agent system that provides its users with recommendations of legal normative instruments they might be
interested in. The Filter agent of Infonorma classifies normative instruments represented as Semantic Web documents into legal
branches and performs content-based similarity analysis. This agent, as well as the entire Infonorma system, was modeled under
the guidelines of MAAEM, a software development methodology for multi-agent application engineering. This article describes
the Infonorma requirements specification, the architectural design solution for those requirements, the detailed design of
the Filter agent and the implementation model of Infonorma, according to the guidelines of the MAAEM methodology. 相似文献
67.
68.
Josiele S. Teixeira Diego C. Knupp Antônio J. Silva Neto 《Inverse Problems in Science & Engineering》2017,25(6):909-935
The present work addresses the problem of structural damage identification built on the statistical inversion approach. Here, the damage state of the structure is continuously described by a cohesion parameter, which is spatially discretized by the finite element method. The inverse problem of damage identification is then posed as the determination of the posterior probability densities of the nodal cohesion parameters. The Markov Chain Monte Carlo method, implemented with the Metropolis–Hastings algorithm, is considered in order to approximate the posterior probabilities by drawing samples from the desired joint posterior probability density function. With this approach, prior information on the sought parameters can be used and the uncertainty concerning the known values of the material properties can be quantified in the estimation of the cohesion parameters. The assessment of the proposed approach has been performed by means of numerical simulations on a simply supported Euler–Bernoulli beam. The damage identification and assessment are performed considering time domain response data. Different damage scenarios and noise levels were addressed, demonstrating the feasibility of the proposed approach. 相似文献
69.
Vibratory finishing is a widely-used manufacturing process in which a vibrating container filled with granular media becomes fluidized. The resulting bulk flow entrains workpieces and exposes their surfaces to the impacts resulting from the small-scale media vibrations. The bulk flow is responsible for entrainment and mixing, while the media vibration does work on the surfaces. The selection of machine vibration parameters is commonly based on experience due to the difficulty in predicting the fluidized bed behavior. In this work, a discrete element method was used to investigate how the bulk flow in an actual tub finisher filled with steel balls depends on the tub motion parameters through a parametric study. The underlying mechanisms that create and drive the bulk flow were identified by examining the relationships between the bulk flow rates and the wall forces. Finally, the connection between the wall motion and the wall forces was investigated. The tub frequency was the most effective control parameter and there was an optimal phase difference between the horizontal and vertical vibrations to maximize bulk flow. The relationship between the media packing at the walls and the tangential forces between the walls and the media explained the formation and speed of the bulk flow. Lastly, it was shown that the tangential wall forces, unlike the normal forces, cannot be obtained from the known wall motion alone since they also depend on the media velocities relative to the walls. 相似文献
70.
Vibratory finishing (VF) employs vibrationally-fluidized granular media to finish the surfaces of workpieces that are entrained in the flowing media. Its application has been based mostly on experience and trial-and-error due to the complexity of the granular material behavior. The present study used discrete element modeling (DEM) to investigate how the movement of a commercial two-dimensional tub finisher influenced the average particle speed of the media in a bed of smooth, steel, spherical particles, and thus the work that would be done on an entrained workpiece. The parameters governing the tub wall motion (frequency, in-plane amplitudes, and phases of vibration) and the coefficient of friction between the media and the wall were systematically varied in 71 three-dimensional DEM simulations. The average particle speed was affected mostly by the vertical amplitude of tub motion rather than by the frequency, and was mostly independent of other parameters of motion and of the wall friction. A strong relationship was found between the average particle speed and the work done by the wall per cycle of vibration. The normal force on the wall was also found to correlate strongly with the normal component of the wall velocity. Together, these relationships offer the potential to enable the analytical prediction of the average particle speed based on the motion parameters of the tub alone. The paper provides a set of practical guidelines for the control of the average particle speed in VF that are explained by the forces between the media and walls of the tub finisher. 相似文献