Assuming that the targeted microorganism's isothermal survival curves follow the Weibullian pattern, which describes a large number of microbial isothermal survival curves, a simple numerical algorithm was develop...
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Assuming that the targeted microorganism's isothermal survival curves follow the Weibullian pattern, which describes a large number of microbial isothermal survival curves, a simple numerical algorithm was developed to calculate the momentary survival ratio during non-isothermal thermal processes. The algorithm is based on a mathematical expression derived from a non-isothermal survival rate model proposed in the literature. Simulations indicated that the proposed algorithm generated the same results as those obtained from other non-isothermal models found in the literature. However, compared to the published models, the proposed algorithm has two advantages. One is that the calculation speed is very fast because only simple algebraic operations are involved, and the other is that it can be programmed very easily in different computer languages and spreadsheets. In addition, the algorithm provides an effective way to estimate changes of microbial survival ratio with time from product temperatures that are either directly measured during thermal processing or predicted by proper heat transfer models. Thus, the algorithm can also be easily incorporated into control systems of commercial thermal process equipment. (c) 2006 Elsevier Ltd. All rights reserved.
Non-obstructive particle damping (NOPD) is a new composite damping technology based on traditional partical damping and impacting damping, and it has good vibration-reduced results. Through studying thermodynamics con...
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ISBN:
(纸本)9783037850770
Non-obstructive particle damping (NOPD) is a new composite damping technology based on traditional partical damping and impacting damping, and it has good vibration-reduced results. Through studying thermodynamics constraint condition for non-inverse variation of inner tissue structure of the material, the endochronic theory obtained variation regularity of inner variable, further gave out evolution path of specific non-inverse thermodynamics variable under specific condition, and thus the constitutive relationship of the material was obtained. Based on endochronic theory, an incremental form of the endochronic constitutive relationship of discrete particle was derived, and then penalty element was introduced to solve the connection problem between structure and discrete particle, lastly finite element dynamics equation of NOPD composite structure was constructed. Based on the model of NOPD composite structure, simulation and experiment for response of NOPD free beam were made. It indicated that applying endochronic theory to analyze the response of NOPD is rational, which supplied an effective method for engineering application of NOPD.
In this paper, we introduce a new space of fuzzy numbers equipped with a scalar product defined in this space. The notion of a derivative of a fuzzy function in this space is defined. By employing these notions, an op...
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In this paper, we introduce a new space of fuzzy numbers equipped with a scalar product defined in this space. The notion of a derivative of a fuzzy function in this space is defined. By employing these notions, an optimal control problem with non-linear functional is formulated and an optimality condition is obtained in the form of maximum principle. Using this result, the numerical algorithm is offered for the solution of such problems.
numerical methods are proposed for constructing Nash and Stackelberg solutions in a two-player linear non-zero-sum positional differential game with terminal cost functionals and geometric constraints on the players...
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numerical methods are proposed for constructing Nash and Stackelberg solutions in a two-player linear non-zero-sum positional differential game with terminal cost functionals and geometric constraints on the players' controls. The formalization of the players' strategies and of the motions generated by them is based on the formalization and results from the theory of positional zero-sum differential games developed by N.N. Krasovskii and his school. It is assumed that the game is reduced to a planar game and the constraints on the players' controls are given in the form of convex polygons. The problem of finding solutions of the game may be reduced to solving nonstandard optimal control problems. Several computational geometry algorithms are used to construct approximate trajectories in these problems, in particular, algorithms for constructing the convex hull as well as the union, intersection, and algebraic sum of polygons.
This paper presents a functional approximation of the M/D/1/N built on a Taylor series approximation. numerical examples are carried out to illustrate the performance of our approach. (C) 2010 Published by Elsevier Ltd.
This paper presents a functional approximation of the M/D/1/N built on a Taylor series approximation. numerical examples are carried out to illustrate the performance of our approach. (C) 2010 Published by Elsevier Ltd.
In this paper we present magnetic control of a spacecraft using the Dichotomous Coordinate Descent (DCD) algorithm with box constraints. What is common for most work on magnetic spacecraft control is the technique for...
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In this paper we present magnetic control of a spacecraft using the Dichotomous Coordinate Descent (DCD) algorithm with box constraints. What is common for most work on magnetic spacecraft control is the technique for solving for the control variables of the magnetic torquers where a cross product is included which is well known to be singular. The DCD algorithm provides a new scheme which makes it possible to use a general control law and then adapt it to work for magnetic torquers including restrictions in available magnetic moment, instead of designing a specialized controller for the magnetic control problem. A non-linear passivity-based sliding surface controller is derived for a fully actuated spacecraft and is then implemented for magnetic control by utilizing the previous mentioned algorithm. Results from two simulations are provided, the first comparing the results from the DCD algorithm with older results, and the second showing how easily the derived sliding surface controller may be implemented, improving our results.
We propose a new interpolation technique for the CIP method applied to curvilinear coordinates. The CIP method can hardly maintain third-order accuracy on curvilinear coordinates. The reason for the degeneracy in accu...
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We propose a new interpolation technique for the CIP method applied to curvilinear coordinates. The CIP method can hardly maintain third-order accuracy on curvilinear coordinates. The reason for the degeneracy in accuracies has not been discussed in detail. This paper reveals the problems of the CIP method on curvilinear coordinates and presents an improved CIP method to solve the advection equation accurately. The features of the presented method are: (1) the metric computation on the upwind stencil is defined in the same manner as in the advection phase of the CIP method;and (2) gradient values in the physical domain in the computation on the curvilinear coordinates are used. Various test problems show that the improved CIP method has approximate third-order accuracy. (C) 2010 Elsevier Inc. All rights reserved.
作者:
Lane, R. O.QinetiQ
Malvern Technol Ctr Malvern WR14 3PS Worcs England
Super-resolution of signals and images can improve the automatic detection and recognition of objects of interest. However, the uncertainty associated with this process is not often taken into consideration. This is i...
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Super-resolution of signals and images can improve the automatic detection and recognition of objects of interest. However, the uncertainty associated with this process is not often taken into consideration. This is important because the processing of noisy signals can result in spurious estimates of the scene content. This study reviews a variety of super-resolution techniques and presents two non-parametric Bayesian super-resolution algorithms that not only take uncertainty into account, but also retain knowledge about the output uncertainty in the form of a full probability distribution. One of the two Bayesian techniques is based on an analytical calculation re-interpreted as super-resolution, and the other is a novel numerical algorithm. Although the algorithms are presented as stand-alone techniques for image analysis, such Bayesian super-resolution algorithms can increase automatic target recognition performance over standard super-resolution.
Modeling of of material behaviour has significant influence on design and optimization of mechanical structures and consequently calculation of their lifetime. When using complex constitutive material model that descr...
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Modeling of of material behaviour has significant influence on design and optimization of mechanical structures and consequently calculation of their lifetime. When using complex constitutive material model that describes elastic-plastic behaviour of the cyclically loaded material and takes into account damage occurrence and accumulation, the process of parameter identification from experimental data is very complex and time-consuming. In this paper the damage occurrence and accumulation within the material are described by means of models of Bauschinger effect, kinematic and isotropic hardening (or softening) according to Chaboche material model and mean stress relaxation according to Ohno-Wang material model. Since the material model is highly non-linear, its parameter identification requires complex numerical procedures, carefully chosen algorithms and numerical operators, followed by software solution development. The developed automated system for material model parameter identification is validated by comparing the calculated with experimental response of the material. Its usage can make material behaviour modeling for numerous materials accurate, fast and user-friendly. (C) 2010 Elsevier B.V. All rights reserved.
In this paper we review fourth-order approximations of the biharmonic operator in one, two and three dimensions. In addition, we describe recent developments on second and fourth order finite difference approximations...
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In this paper we review fourth-order approximations of the biharmonic operator in one, two and three dimensions. In addition, we describe recent developments on second and fourth order finite difference approximations of the two dimensional Navier-Stokes equations. The schemes are compact both for the biharmonic and the Laplacian operators. For the convective term the fourth order scheme invokes also a sixth order Pade approximation for the first order derivatives, using an approximation suggested by Carpenter-Gottlieb-Abarbanel (J. Comput. Phys. 108:272-295, 1993). We also introduce the derivation of a pure streamfunction formulation for the Navier-Stokes equations in three dimensions.
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