13,476 research outputs found

    Variable neural networks for adaptive control of nonlinear systems

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    This paper is concerned with the adaptive control of continuous-time nonlinear dynamical systems using neural networks. A novel neural network architecture, referred to as a variable neural network, is proposed and shown to be useful in approximating the unknown nonlinearities of dynamical systems. In the variable neural networks, the number of basis functions can be either increased or decreased with time, according to specified design strategies, so that the network will not overfit or underfit the data set. Based on the Gaussian radial basis function (GRBF) variable neural network, an adaptive control scheme is presented. The location of the centers and the determination of the widths of the GRBFs in the variable neural network are analyzed to make a compromise between orthogonality and smoothness. The weight-adaptive laws developed using the Lyapunov synthesis approach guarantee the stability of the overall control scheme, even in the presence of modeling error(s). The tracking errors converge to the required accuracy through the adaptive control algorithm derived by combining the variable neural network and Lyapunov synthesis techniques. The operation of an adaptive control scheme using the variable neural network is demonstrated using two simulated example

    Regional social infrastructure management in the system of tools used for improving the quality of life for regional population

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    This paper analyzes the processes in the social sphere and the performance of operating the social infrastructure to improve the population’s quality of life in the Russian regions. Particular attention has been paid to the role of organizational and administrative components, which include the regulation of social infrastructure institutions, planning, and programming that affect the performance of infrastructure facilities utilization. The goal of this study was to evaluate the effectiveness of social infrastructure management through the congruence of immediate results (dynamics of indicators for social services) and final results (parameters of the population’s quality of life). The working hypothesis of the study was a breach of infrasystemic principle in the infrastructural support for improving the population’s quality of life in the constituent entities of the Russian Federation because of the insufficient effectiveness of public administration. The work on this paper involved using a set of methodological approaches, such as structured, factorial, systemic, and evolutionary approaches, to substantiate the conceptual framework, prepare the method-based approaches, and determine the impact made by the changes in the parameters of social infrastructure facilities on provided services and shifts in the indicators of the population’s quality of life. The paper proposes a method-based approach to quantifying the effectiveness of organizational and administrative components by using the diagnostics of sufficiency in the implementation of infrasystemic principle for the operation of social infrastructure based on elasticity coefficients. The proposed approach and analytical data obtained in the areas, such as health care, education, trade, housing & utilities, culture & sport, allowed ranking the regions of the Ural Federal District and identifying the areas of insufficient effectiveness in the organizational and administrative mechanism used for improving the population’s quality of life as the basis for developing practical recommendations for the executive branch of constituent entities of the Russian Federation and adjustment of socioeconomic policies

    Fusion to green fluorescent protein improves expression levels of Theileria parva sporozoite surface antigen p67 in insect cells

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    East Coast fever (ECF) is a fatal disease of cattle caused by the protozoan parasite Theileria parva. The development of a subunit vaccine, based on the sporozoite-specific surface antigen p67, has been hampered by difficulties in achieving high-level expression of recombinant p67 in a near-authentic form. Therefore two sets of recombinant baculovirus vectors were constructed. The first set, encoding various regions of p67, produced low levels of the corresponding p67 domains in High Five™ cells, despite the presence of large amounts of p67 RNA. The second, consisting of p67 domains fused to the carboxy-terminus of GFP expressed significantly higher levels of p67 protein. The GFP[ratio]p67 fusion proteins were recognized by a sporozoite-neutralizing monoclonal antibody (TpM12) raised against native p67 whereas non-fused full length p67 expressed in insect cells was not recognized. GFP-tagging therefore, appeared to enhance the stability of p67 and to conserve its folding. The high-level expression of p67 domains in a more authentic form is an important step towards the development of an effective subunit vaccine against ECF

    Nondeterministic Instance Complexity and Proof Systems with Advice

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    Motivated by strong Karp-Lipton collapse results in bounded arithmetic, Cook and Krajíček [1] have recently introduced the notion of propositional proof systems with advice. In this paper we investigate the following question: Given a language L , do there exist polynomially bounded proof systems with advice for L ? Depending on the complexity of the underlying language L and the amount and type of the advice used by the proof system, we obtain different characterizations for this problem. In particular, we show that the above question is tightly linked with the question whether L has small nondeterministic instance complexity

    Connection between horizons and algebraic type

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    We study connections between both event and quasilocal horizons and the algebraic type of the Weyl tensor. The relation regarding spacelike future outer trapping horizon is analysed in four dimensions using double-null foliation.Comment: 4 pages, to appear in Proceedings of Spanish relativity meeting 201

    Response of sweet maize (Zea mays L. Saccharata strut) and soil chemical properties to compost in Asaba, Delta State

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    Experiment was conducted in Delta State University, Asaba Campus during the early and late seasons of 2016 to monitor the response of sweet maize and soil chemical properties to compost. The compost was formulated with rice husk and cowdung at a ratio of 7:3. The compost was applied at 0 (control), 5, 10 and 15 t/ha to 15kg soil per polythene bag. The soil was analyzed to determine the initial nutrient content. The bags were arranged in a completely randomized design in three replicates and maize variety Sammaz 37 was used. Four seeds were sown and later thinned to one stand two weeks after sowing. Plant height, leaf area, stem girth, dry mater, weight of green ear and weight of dehusked green ear were measured. Soil samples were collected after harvest for post harvest soil analysis. Data were subjected to analysis of variance and means were separated with Duncan Multiple Range Test at 5% level of probability. Results revealed that treated plant had outstanding performance than untreated, 15 t/ha of compost had higher plant height (144.5±7.3 and 146.8±16.6 cm), stem girth (8.3±0.43 and 8.6±0.47 cm), leaf area (247.5±41.5 and 148.8±30.3 cm2), dry matter (2.9±0.82 and 3.2±1.0 t/ha), weight of green ear (0.24±0.04 and 0.30±0.01 kg) and weight of dehusked green ear (0.16±0.03 and 0.16±0.4 kg) in both seasons respectively. It also had higher soil chemical properties. Therefore, the compost could be recommended at 15 t/ha in the study area.Keywords: sweet maize, soil fertility, rice husk, cowdung, compos

    Fluence and polarisation dependence of GaAs based Lateral Photo-Dember terahertz emitters

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    We characterise THz output of lateral photo-Dember (LPD) emitters based on semi-insulating (SI), unannealed and annealed low temperature grown (LTG) GaAs. Saturation of THz pulse power with optical fluence is observed, with unannealed LTG GaAs showing highest saturation fluence at 1.1 ± 0.1 mJ cm-2. SI-GaAs LPD emitters show a flip in signal polarity with optical fluence that is attributed to THz emission from the metal-semiconductor contact. Variation in optical polarisation affects THz pulse power that is attributed to a local optical excitation near the metal contact

    Constraint algebra for Regge-Teitelboim formulation of gravity

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    We consider the formulation of the gravity theory first suggested by Regge and Teitelboim where the space-time is a four-dimensional surface in a flat ten-dimensional space. We investigate a canonical formalism for this theory following the approach suggested by Regge and Teitelboim. Under constructing the canonical formalism we impose additional constraints agreed with the equations of motion. We obtain the exact form of the first-class constraint algebra. We show that this algebra contains four constraints which form a subalgebra (the ideal), and if these constraints are fulfilled, the algebra becomes the constraint algebra of the Arnowitt-Deser-Misner formalism of Einstein's gravity. The reasons for the existence of additional first-class constraints in the canonical formalism are discussed.Comment: LaTeX, 12 pages; in this version the misprints in eq. (37) and (41) was correcte
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