共查询到20条相似文献,搜索用时 15 毫秒
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The Nb–Ni system is reassessed on the basis of a critical literature review involving recent experimental data. These newly published experimental data include the phase relation associated with the NbNi8 phase, phase transition temperatures resulting from selected alloys, all invariant reaction temperatures, and enthalpies of mixing of liquid, as well as the crystallographic data on the μ (Nb7Ni6) phase. A consistent thermodynamic data set for the Nb–Ni system is obtained by optimization of the selected experimental values. The calculated phase diagram, crystallographic properties and thermodynamic properties agree reasonably with the experimental data. Noticeable improvements have been made, compared with the previous thermodynamic optimizations. 相似文献
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ce and technology books to science and technology communication. The analyses show that the breeds and printing numbers of science and technology books are in good situation. They are of great variety, their printing numbers increase steadily; the contents of the books become rich and diversified. 相似文献
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One of the major issues banks are faced with in providing Internet Banking (IB) services is the adoption of these services
by the customers. This study seeks answer to the question that whether bank customers’ awareness of the services and advantages
of IB is effective in reducing the negative effect of customers’ perceived risk on their intention of IB adoption. To this
end, the two constructs of the dimensions of the perceived risk and IB awareness are simultaneously considered. Besides, in
the research model, the effect of IB awareness on each dimension of the perceived risk and the effect of these dimensions
on intention of IB adoption by the customers are investigated. The results indicate that IB awareness acts as a factor reducing
all dimensions of the perceived risk (including time, financial, performance, social, security, and privacy). In addition,
it was found out that except for social risk, other dimensions of the perceived risk have significantly negative effect on
the intention of IB adoption. Finally, proving the direct and positive effect of IB awareness on adoption intention, it was
concluded that the dimensions of customers’ perceived risk plays a mediating role in the positive effect of IB awareness on
IB adoption intention. In this respect, management approaches centered on the concept of IB awareness are offered for reducing
the dimensions of customers’ perceived risk. 相似文献
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Mihai Nadin 《国际通用系统杂志》2015,44(6):621-630
The knowledge domain of anticipation is still in the process of being defined, and is therefore subject to controversies. Science was never an endeavour of consensus but rather of debate. This additional argument to the debate integrates awareness of the early Soviet/Russian contributions to a science of anticipation. From this awareness derives the understanding of why anticipation faces opposition from established viewpoints. This article ascertains that anticipation advances a fundamental view of the living. Within this view, anticipation is always expressed in action. Short of this definitory condition, anticipation fades into the grey mass of speculative predictive methods. 相似文献
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Numerical Treatment of the Loss of Hyperbolicity of?the?Two-Layer Shallow-Water System 总被引:1,自引:0,他引:1
M. J. Castro-D��az E. D. Fern��ndez-Nieto J. M. Gonz��lez-Vida C. Par��s-Madro?al 《Journal of scientific computing》2011,48(1-3):16-40
This article is devoted to the numerical solution of the inviscid two-layer shallow water system. This system may lose the hyperbolic character when the shear between the layer is big enough. This loss of hyperbolicity is related to the appearance of shear instabilities that leads, in real flows, to intense mixing of the two layers that the model is not able to simulate. The strategy here is to add some extra friction terms, which are supposed to parameterize the loss of mechanical energy due to mixing, to get rid of this difficulty. The main goal is to introduce a technique allowing one to add locally and automatically an ??optimal?? amount of shear stress to make the flow to remain in the hyperbolicity region. To do this, first an easy criterium to check the hyperbolicity of the system for a given state is proposed and checked. Next, we introduce a predictor/corrector strategy. In the predictor stage, a numerical scheme is applied to the system without extra friction. In the second stage, a discrete semi-implicit linear friction law is applied at any cell in which the predicted states are not in the hyperbolicity region. The coefficient of this law is calculated so that the predicted states are driven to the boundary of the hyperbolicity region according to the proposed criterium. The numerical scheme to be used at the first stage has to be able to advance in time in presence of complex eigenvalues: we propose here a family of path-conservative numerical scheme having this property. Finally, some numerical tests have been performed to assess the efficiency of the proposed strategy. 相似文献
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《Information and Computation》2001,164(1):199-231
We present a natural deduction proof system for the propositional modal μ-calculus and its formalization in the calculus of inductive constructions. We address several problematic issues, such as the use of higher-order abstract syntax in inductive sets in the presence of recursive constructors, and the formalization of modal (sequent-style) rules and of context sensitive grammars. The formalization can be used in the system Coq, providing an experimental computer-aided proof environment for the interactive development of error-free proofs in the modal μ-calculus. The techniques we adopt can be readily ported to other languages and proof systems featuring similar problematic issues. 相似文献
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For the problem with H-criterion and uncertain nonlinear block with a regular part of the perturbation vector, equations of a class of controllers were obtained. These controllers can exert a sufficiently small influence of the regular component on the given output process. 相似文献
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《自动化学报》2006,32(6):F0002-F0002
In recent years, there have been rapid advances in sensor, sensor-on-a-chip, MEMS and wireless communication technologies. Now. massively distributed sensor networks are capable of linking people and the physical world together, providing platforms for information to be collected, shared, and processed in unprecedented ways. It is commonly recognized that sensor network research will lead to smart sentient spaces for our home and environment, work and leisure. It can help us to fight against disasters, protect us from hazards, and strengthen our defense. For the past few years, sensor networks research 相似文献
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By J. E. RUBIO 《International journal of control》2013,86(1):69-78
The uniqueness of the solution of the differential equations derived from Pontryagin's Maximum Principle is considered for a general control problem with a freo right end of the trajectory and fixed terminal time. Under several restrictive conditions on the controlled system and performance criterion, it is proved that those equations have a unique solution. This is done by embedding the problem into a class of similar problems by means of the introduction of a positive parameter ? multiplying the performance criterion, and then making use of the uniqueness properties of an associated autonomous system together with the continuity of the solutions of the differential equations with respect to the parameter ? An example that illustrates the range of applicability of the theorems proved is also presented. 相似文献
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《Information & Management》2019,56(5):640-656
IT organizations use strategic IT benchmarking (SITBM) to improve business-IT alignment or for developing IT strategies. However, SITBM often does not result in the desired outcomes. Because the extant literature does not contribute to improving SITBM success, we conduct a deductive-inductive study to understand which factors distinguish successful and unsuccessful SITBM. We find that traditional project-level factors do not explain SITBM success; they are necessary but not sufficient. Rather, we show that the individual level is instrumental for explaining SITBM success, especially by ensuring the buy-in of relevant project team members – a perspective not yet discussed by pertinent literature. 相似文献
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L. I. Timchenko N. I. Kokryatskaya A. A. Yarovyy V. V. Melnikov G. L. Kosenko 《Cybernetics and Systems Analysis》2013,49(5):785-795
This paper presents a prediction method using a parallel–hierarchical (PH) network and hyperbolic smoothing of empirical data. The average prediction error is 0.55% for the developed method and 1.62% for neural networks; therefore, this method is more efficient as applied to real-time systems than traditional neural networks due to the use of the PH network and hyperbolic smoothing in implementing the operation of predicting the positions of energy centers of laser beam spot images for optical communication systems. 相似文献
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A lambda system with algebraic operators,Lambda-plus system,is introduced.After giving the definitions of the system,we present a sufficient condition for formulating a model of the system.Finally,a model of such system is constructed. 相似文献
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Simulation and Improvement of the Processing Subsystem of the Manchester Dataflow Computer
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The Manchester dataflow computer is a famous dynamic dataflow computer.It is centralized in architecture and simple in organization.Its overhead for communication and scheduling is very small.Its efficiency comes down,when processing elements in the processing subsystem increase.Several articles evaluated its performance and presented improved methods.The authors studied its processing subsystem and carried out the simulation.The simulation results show that the efficiency of the processing subsystem drops dramatically when average instruction execution microcycles become less and the maximum instruction execution rate is nearly attained.Two improved methods are presented to oversome the disadvantage.The improved processing subsystem with a cheap distributor made up of a bus and a two-level fixed priority circuit possesses almost full efficiency no matter whether the average nstruction execution microcycles number is large or small and even if the maximum instruction execution rate is approached. 相似文献
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We solve Burgers’ equation with random Riemann initial conditions. The closed solution allows simple expressions for its statistical moments. Using these ideas we design an efficient algorithm to calculate the statistical moments of the solution. Our methodology is an alternative to the Monte Carlo method. The present approach does not demand a random numbers generator as does the Monte Carlo method. Computational tests are added to validate our approach. 相似文献
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《国际计算机数学杂志》2012,89(1-4):7-14
In a class of categories, including E. Manes's assertional ones, the control structures if-then-else and repeat-until are modeled as natural transformations of suitable functors. This context show how the three basic pieces of any structured programming language (concatenation, conditional and recursion) share naturality. 相似文献
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《Card Technology Today》2000,12(5):14-15
The slow but increasing spread of chip-based payment cards, the introduction of the euro and the recent flurry of panic over the security of the smart card payment system in France offers new opportunities to point-of-sale terminal manufacturers. 相似文献
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The Shortley–Weller method is a standard central finite-difference-method for solving the Poisson equation in irregular domains with Dirichlet boundary conditions. It is well known that the Shortley–Weller method produces second-order accurate solutions and it has been numerically observed that the solution gradients are also second-order accurate; a property known as super-convergence. The super-convergence was proved in the \(L^{2}\) norm in Yoon and Min (J Sci Comput 67(2):602–617, 2016). In this article, we present a proof for the super-convergence in the \(L^{\infty }\) norm. 相似文献