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101.
Quite often in database search, we only need to extract portion of the information about the satisfying item. We consider
this problem in the following form: the database of N items is separated into K blocks of size b = N / K elements each and
an algorithm has just to find the block containing the item of interest. The queries are exactly the same as in the standard
database search problem. We present a quantum algorithm for this problem of partial search that takes about 0.34 fewer iterations than the quantum search algorithm. 相似文献
102.
Andrey V. Kikhtenko Vladimir B. Goncharov Kirill I. Zamaraev 《Catalysis Letters》1993,21(3-4):353-360
Gas phase reactions of Mo+ and W+ ions with the molecules of various oxidants (NO, O2, N2O, CH2O, C2H4O) were studied using ion cyclotron resonance. In oxidation with N2O the mono-, di- and trioxide metal cations are formed consecutively. The trioxide MO3
+ ions of both metals react with CO to form CO2 and MO2
+ ions. In this way, catalytic reaction N2O + CO N2 + CO2 occurs in the gas phase with MoO3
+ /MoO2
+ and WO3
+/WO2
+ couples as catalysts. The rate constants have been measured for both stages of the catalytic cycle as well as for the stages of the catalyst preparation. Metal-oxygen bond energies were estimated for MoOx
+ and WOx
+ species with various x. The mechanism of CO oxidation with MoOx
+ and WOx
+ cations as catalysts in the gas phase is discussed in comparison with that for the oxidation over classical solid oxide catalysts. 相似文献
103.
Water productivity (WP) and water footprint (WFP) are popular concepts in research and discourses on water management. Yet there are concerns about their theoretical validity and practical value. This paper shows that the water production function, the concept with a sound theoretical foundation, is the basis for WP. Total WFP is the reciprocal of WP. The practical value of WP and WFP depends on the context of water use and stress. Maximizing WP, not a panacea to all water problems, mainly suits arid rainfed areas. In other regions, economic and marginal WP for increasing overall production should take precedence in water management and policy decisions. 相似文献
104.
Vladimir Shestak Edwin K.P. Chong Anthony A. Maciejewski Howard Jay Siegel 《Journal of Parallel and Distributed Computing》2012
The problem of finding efficient workload distribution techniques is becoming increasingly important today for heterogeneous distributed systems where the availability of compute nodes may change spontaneously over time. Resource-allocation policies designed for such systems should maximize the performance and, at the same time, be robust against failure and recovery of compute nodes. Such a policy, based on the concepts of the Derman–Lieberman–Ross theorem, is proposed in this work, and is applied to a simulated model of a dedicated system composed of a set of heterogeneous image processing servers. Assuming that each image results in a “reward” if its processing is completed before a certain deadline, the goal for the resource allocation policy is to maximize the expected cumulative reward. An extensive analysis was done to study the performance of the proposed policy and compare it with the performance of some existing policies adapted to this environment. Our experiments conducted for various types of task-machine heterogeneity illustrate the potential of our method for solving resource allocation problems in a broad spectrum of distributed systems that experience high failure rates. 相似文献
105.
106.
The concept of games with incompetence has been introduced to better represent games where players may not be capable of executing strategies that they select. In particular this paper introduces incompetence into bimatrix games and investigates the properties of such games. The results obtained describe both the general dependence of “extreme Nash equilibrium payoffs” on incompetence and special behaviour arising in particular cases. The dependence of the payoffs can be complex and include non-linearities and transition points. Transition points occur when kernels change and may result in the number of “extreme Nash equilibria” changing. Understanding these changes allows the determination of the benefits of regimes that seek to decrease a player’s incompetence. While the games we consider are normally static, in our context there is a hidden dynamics resulting from the fact that players will strive to improve their equilibrium payoffs by changing their incompetence levels. This might require training, in the case of games like tennis, or it might require the purchase of new equipment costing billions of dollars, in the case of military applications. 相似文献
107.
Igor Goldfarb Vladimir Gol’dshtein J. Barry. Greenberg Ann Zinoviev 《Journal of Engineering Mathematics》2006,56(2):129-142
Recent experimental evidence has uncovered the peculiar behavior of certain gel droplets which, under appropriate ambient
thermal conditions, evaporate and burn in an oscillatory fashion. In this work a preliminary foray is made into the theoretical
analysis of the nature of the evolution of a hot gas mixture containing organic gel fuel droplets with oscillatory evaporation
within the context of thermal-explosion theory. The problem is modeled as a system of highly nonlinear singularly perturbed
ordinary differential equations. Non-dimensionalization of the equations enables identification of the parameters that play
a major role in determining the dynamical regimes of the system of equations. The method of integral manifolds is exploited
for the analysis and it is found, that for certain parametric regions, the system exhibits new dynamical behavior that is
quite different from that found for conventional liquid droplets. 相似文献
108.
A new meshless method for computing the dynamic stress intensity factors (SIFs) in continuously non-homogeneous solids under a transient dynamic load is presented. The method is based on the local boundary integral equation (LBIE) formulation and the moving least squares (MLS) approximation. The analyzed domain is divided into small subdomains, in which a weak solution is assumed to exist. Nodal points are randomly spread in the analyzed domain and each one is surrounded by a circle centered at the collocation point. The boundary-domain integral formulation with elastostatic fundamental solutions for homogeneous solids in Laplace-transformed domain is used to obtain the weak solution for subdomains. On the boundary of the subdomains, both the displacement and the traction vectors are unknown generally. If modified elastostatic fundamental solutions vanishing on the boundary of the subdomain are employed, the traction vector is eliminated from the local boundary integral equations for all interior nodal points. The spatial variation of the displacements is approximated by the MLS scheme. 相似文献
109.
110.