Extended multi bottom–up tree transducers

Extended multi bottom–up tree transducers are defined and investigated. They are an extension of multi bottom–up tree transducers by arbitrary, not just shallow, left-hand sides of rules; this includes rules that do not consume input. It is shown that such transducers, even linear ones, can compute all transformations that are computed by linear extended top–down tree transducers, which are a theoretical model for syntax-based machine translation. Moreover, the classical composition results for bottom–up tree transducers are generalized to extended multi bottom–up tree transducers. Finally, characterizations in terms of extended top–down tree transducers and tree bimorphisms are presented.     

Intelligent Human-Machine Interaction Based on Dynamic Bayesian Networks Probabilistic Intention Recognition

In this article, a novel human–machine interaction based on the machine intention recognition of the human is presented. This work is motivated by the desire that intelligent machines as robots imitate human–human interaction, that is to minimize the need for classical direct human–machine interface and communication. A philosophical and technical background for intention recognition is discussed. Here, the intention–action–state scenario is modified and modeled by Dynamic Bayesian Networks to facilitate for probabilistic intention inference. The recognized intention, then, drives the interactive behavior of the machine such that it complies with the human intention in light of the real state of the world. An illustrative example of a human commanding a mobile robot remotely is given and discussed in details.     

Age differences rendezvousing: reminders for side-stepping

This paper reports a diary study of the use of mobile telephones for rendezvousing by young adults (aged 18–30) and mature adults (aged 31–45) in the UK. A number of age differences were found. Specifically, 31–45s more frequently: (1) attributed problems rendezvousing to the overrunning of previous activities, and to the spontaneous performance of additional tasks (‘side-stepping’); (2) reported that ‘problem’ rendezvous resulted in unnecessary sacrifices; and (3) changed plans for the rendezvous. These differences arose, because additional family commitments encouraged 31–45s to pack their daily programme of activities more tightly than 18–30s. Mobile phones might better target 31–45s, if they, for example, enhanced To Do Lists with context-sensitive reminders, in the first instance, reminders triggered by location (GSM network cellID) and logging off from PCs.

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Numerical analysis on electroosmotic flows in a microchannel with rectangle-waved surface roughness using the Poisson–Nernst–Planck model

The present study has numerically investigated two-dimensional electroosmotic flows in a microchannel with dielectric walls of rectangle-waved surface roughness to understand the roughness effect. For the study, numerical simulations are performed by employing the Nernst–Planck equation for the ionic species and the Poisson equation for the electric potential, together with the traditional Navier–Stokes equation. Results show that the steady electroosmotic flow and ionic-species transport in a microscale channel are well predicted by the Poisson–Nernst–Planck model and depend significantly on the shape of surface roughness such as the amplitude and periodic length of wall wave. It is found that the fluid flows along the surface of waved wall without involving any flow separation because of the very strong normal component of EDL (electric double layer) electric field. The flow rate decreases exponentially with the amplitude of wall wave, whereas it increases linearly with the periodic length. It is mainly due to the fact that the external electric-potential distribution plays a crucial role in driving the electroosmotic flow through a microscale channel with surface roughness. Finally, the present results using the Poisson–Nernst–Planck model are compared with those using the traditional Poisson–Boltzmann model which may be valid in these scales.     

Empirical Characterization of Session–Based Workload and Reliability for Web Servers

The growing availability of Internet access has led to significant increase in the use of World Wide Web. If we are to design dependable Web–based systems that deal effectively with the increasing number of clients and highly variable workload, it is important to be able to describe the Web workload and errors accurately. In this paper we focus on the detailed empirical analysis of the session–based workload and reliability based on the data extracted from actual Web logs of eleven Web servers. First, we introduce and rigourously analyze several intra–session and inter–session metrics that collectively describe Web workload in terms of user sessions. Then, we analyze Web error characteristics and estimate the request–based and session–based reliability of Web servers. Finally, we identify the invariants of the Web workload and reliability that apply through all data sets considered. The results presented in this paper show that session–based workload and reliability are better indicators of the users perception of the Web quality than the request–based metrics.     

A Discontinuous Galerkin Scheme Based on a Space–Time Expansion. I. Inviscid Compressible Flow in One Space Dimension

In this paper, we propose an explicit discontinuous Galerkin scheme for conservation laws which is of arbitrary order of accuracy in space and time. The basic idea is to use a Taylor expansion in space and time to define a space–time polynomial in each space–time element. The space derivatives are given by the approximate solution at the old time level, the time derivatives and the mixed space–time derivatives are computed from these space derivatives using the so-called Cauchy–Kovalevskaya procedure. The space–time volume integral is approximated by Gauss quadrature with values at the space–time Gaussian points obtained from the Taylor expansion. The flux in the surface integral is approximated by a numerical flux with arguments given by the Taylor expansions from the left and from the right-hand side of the element interface. The locality of the presented method together with the space–time expansion gives the attractive feature that the time steps may be different in each grid cell. Hence, we drop the common global time levels and propose that every grid zone runs with its own time step which is determined by the local stability restriction. In spite of the local time steps the scheme is locally conservative, fully explicit, and arbitrary order accurate in space and time for transient calculations. Numerical results are shown for the one-dimensional Euler equations with orders of accuracy one up to six in space and time.     

Accuracy vs. Lifetime: Linear Sketches for Aggregate Queries in Sensor Networks

The in–network aggregation paradigm in sensor networks provides a versatile approach for evaluating aggregate queries. Traditional approaches need a separate aggregate to be computed and communicated for each query and hence do not scale well with the number of queries. Since approximate query results are sufficient for many applications, we use an alternate approach based on summary data–structures. We consider two kinds of aggregate queries: location range queries that compute the sum of values reported by sensors in a given location range, and value range queries that compute the number of sensors that report values in a given range. We construct summary data–structures called linear sketches, over the sensor data using in–network aggregation and use them to answer aggregate queries in an approximate manner at the base–station. There is a trade–off between accuracy of the query results and lifetime of the sensor network that can be exploited to achieve increased lifetimes for a small loss in accuracy. Most commonly occurring sets of range queries are highly correlated and display rich algebraic structure. Our approach takes full advantage of this by constructing linear sketches that depend on queries. Experimental results show that linear sketching achieves significant improvements in lifetime of sensor networks for only a small loss in accuracy of the queries. Further, our approach achieves more accurate query results than the other classical techniques using Discrete Fourier Transform and Discrete Wavelet Transform. This work was supported in part by NASA under Cooperative Agreement NCC5–315.     

A priori determination of bounds for the optimal value of variables in integer linear programming problems

The paper outlines a simple technique for determining a narrower interval containing the coordinates of the optimal solution to integer linear programming problems. Computational experiments show that the lengths of the given ranges of variables decreases by 30–90% on average. __________ Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 86–93, March–April 2006.     

Deontic logics for prioritized imperatives

When a conflict of duties arises, a resolution is often sought by use of an ordering of priority or importance. This paper examines how such a conflict resolution works, compares mechanisms that have been proposed in the literature, and gives preference to one developed by Brewka and Nebel. I distinguish between two cases – that some conflicts may remain unresolved, and that a priority ordering can be determined that resolves all – and provide semantics and axiomatic systems for accordingly defined dyadic deontic operators. A preliminary version was presented to the working group “Law and logic’ of the XXII. World Congress of Philosophy of Law and Social Philosophy (IVR 2005), 24–29 May 2005, Granada, Spain.     

Design and fabrication of microfluidic mixer from carbonyl iron�CPDMS composite membrane

This paper introduces a carbonyl iron–PDMS (CI–PDMS) composite magnetic elastomer in which carbonyl iron (CI) particles are uniformly distributed in a PDMS matrix. The CI particles and the PDMS were mixed at different weight ratios and tested to determine the influence of CI concentration. The magnetic and mechanical properties of the magnetic elastomers were characterized, respectively, by vibrating-sample magnetometer and by tensile testing using a mechanical analyzer. The elastomer was found to exhibit high magnetization and good mechanical flexibility. The morphology and deformation of the CI–PDMS membrane also were observed. A magnetically actuated microfluidic mixer (that is, a micromixer) integrated with CI–PDMS elastomer membranes was successfully designed and fabricated. The high efficiency and quality of the mixing makes possible the impressive potential applications of this unique CI–PDMS material in microfluidic systems.     

Modelling the Evolution of National Economies Based on Input–Output Networks

Uncovering the evolutionary dynamics of economies is helpful for us to design economic policy. This paper develops an economic evolution model by examining the coupled dynamics of industry growth and interindustry structure. For each industry, its economic properties (mainly characterized by price and quantity) are incorporated into the model. The input–output relationships among different industries are described as input–output networks, in which nodes represent industries, and weights represent technological and economic constraints between pairing industries. By measuring the dynamic importance of each node, we find that all the nodes in the input–output networks have the same dynamic importance. On the basis of this empirical regularity and the rational expectation assumption, we show that the coupled dynamics of the economic properties of nodes and input–output networks can explain the evolutionary dynamics of national economies.     

A Note on the Stability of Gauss–Jordan Elimination for Diagonally Dominant Matrices

Peters and Wilkinson [2] state that “it is well known that Gauss–Jordan is stable” for a diagonally dominant matrix, but a proof does not seem to have been published [1]. The present note fills this gap. Gauss–Jordan elimination is backward stable for matrices diagonally dominant by rows and not for those diagonally dominant by columns. In either case it is forward stable. Received February 28, 2000     

Effect algebras with the subsequential interpolation property

We prove Brooks–Jewett, Vitali–Hahn–Saks and NikodymBoundedness theorems for modular measures on lattice-ordered effect algebras with the subsequential interpolation property. Supported by G.N.A.M.P.A.     

An approach to solution uniqueness in game problems

A new concept of strong conflict equilibrium is proposed that supplements the well-known fundamental system of conflict equilibria and considerably increases the possibility of finding a unique strongest equilibrium (solution) in any game problem. The efficiency of this new equilibrium is illustrated by static and dynamic game problems. This work was carried out under the program “Basic foundations of information technologies and systems” of the Russian Academy of Science (Project No. 1–3). Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 116–127, March–April 2009.     

Bioinspired computing nets for directionality in vision

Directional selectivity to local visual stimuli appears in various levels of the visual pathway, being in the retina very conspicuous. Neurophysiology suggests that directionality (as well as other local and quasi-global filtering properties) are based in the space–time interactions of processes with different “memory” (latency). We draw inspiration from the corresponding underlying biological mechanisms to propose two general schemes for directionality computation in nets, compatible with other space–time filtering properties. First, a connectivistic mechanism based on bipolar–amacrine–ganglion cell interaction is proposed, by formalizing the classical proposals of early vision neurophysiologists. Second, inspired initially in the more recently described intrinsic directionality of amacrines, novel schemes are proposed where directionality appear as the computing consequence of adding memory to spatial filtering structures. The mathematical formulations are achieved by means of Newton Filters and Hermite Functionals.     

Thinking About Evolution in Terms of Cellular Computing

The past five decades of molecular genetics have produced many discoveries about genome structure and function that can only be understood from an informatic perspective: – distinct sequence codes to mark the individual steps in packaging, expression, replication, transmission, repair and restructuring of DNA molecules; – modularity of data files for RNA and protein products; – combinatoric organization of signals to format the genome for differential functioning during cellular and organismal cycles; – direct participation of DNA in the execution of biological algorithms (formation of highly structured nucleoprotein complexes); – hierarchical organization of genomic subsystems to form higher level system architectures. This review will discuss aspects of genome organization and genome change that require a more formal computational analysis. We will see how modern results indicate that genome evolution has many similarities to computer system engineering. The ability of cells to control the function of natural genetic engineering systems is central to the genome’s potential as a Read–Write information storage system.     

On the numerical solution of nonlinear systems of Volterra integro-differential equations with delay arguments

Particular cases of nonlinear systems of delay Volterra integro-differential equations (denoted by DVIDEs) with constant delay τ > 0, arise in mathematical modelling of ‘predator–prey’ dynamics in Ecology. In this paper, we give an analysis of the global convergence and local superconvergence properties of piecewise polynomial collocation for systems of this type. Then, from the perspective of applied mathematics, we consider the Volterra’s integro-differential system of ‘predator–prey’ dynamics arising in Ecology. We analyze the numerical issues of the introduced collocation method applied to the ‘predator–prey’ system and confirm that we can achieve the expected theoretical orders of convergence.      

Some principles of coordinated decision making in distributed systems

Conclusion The proposed approach leads to flexible decision support algorithms and procedures that easily adapt to changing requirements. The application of the proposed principles is illustrated in [12] with the object of allowing for the specific features of the problem and accelerating convergence of distributed decision support systems. The application of these principles to the construction of various control procedures and decision support scheme is demonstrated in [13–19]. At the present time, in connection with active transition to the market and operation in a rapidly changing reality, we can expect an increase in demand for algorithms, procedures, and schemes that divide the domains of competence, sharply delineate the domains of responsibility, and clearly separate the fields of action of the “center” and the “periphery” [11]. The need for such procedures will also be felt in financial management support [26–27] and in macro/micro economic modeling and forecasting [20–26]. This is due to the fact that in our rapidly changing world we are often unable to identify several separate criteria for optimization. We are often forced to look for a decision which is admissible by a whole range of formal and informal criteria and is stable under small perturbations of both the criteria and the external conditions [28–30]. Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 161–175, March–April, 1996.     

A Bradley–Terry artificial neural network model for individual ratings in group competitions

A common statistical model for paired comparisons is the Bradley–Terry model. This research re-parameterizes the Bradley–Terry model as a single-layer artificial neural network (ANN) and shows how it can be fitted using the delta rule. The ANN model is appealing because it makes using and extending the Bradley–Terry model accessible to a broader community. It also leads to natural incremental and iterative updating methods. Several extensions are presented that allow the ANN model to learn to predict the outcome of complex, uneven two-team group competitions by rating individuals—no other published model currently does this. An incremental-learning Bradley–Terry ANN yields a probability estimate within less than 5% of the actual value training over 3,379 multi-player online matches of a popular team- and objective-based first-person shooter.