共查询到20条相似文献,搜索用时 31 毫秒
1.
《Electronic Commerce Research and Applications》2002,1(2):193-207
This paper presents a formal and executable approach to capture the behaviour of parties involved in a negotiation. A party is modeled as a negotiating agent composed of a communication module, a control module, a reasoning module, and a knowledge base. The control module is expressed as a statechart, and the reasoning module as a defeasible logic program. A strategy specification therefore consists of a statechart, a set of defeasible rules, and a set of initial facts. Such a specification can be dynamically plugged into an agent shell incorporating a statechart interpreter and a defeasible logic inference engine, in order to yield an agent capable of participating in a given type of negotiations. The choice of statecharts and defeasible logic with respect to other formalisms is justified against a set of desirable criteria, and their suitability is illustrated through concrete examples of bidding and multi-lateral bargaining scenarios. 相似文献
2.
提出Vague值向Fuzzy值转化的实用方法的定义。针对文献[6]中的一个Vague值向Fuzzy值转化的均值修正法,提出了加权均值修正法,并证明了这种方法同样是Vague值向Fuzzy转化的一种非常实用的方法。 相似文献
3.
A. I. Litvintsev 《Automation and Remote Control》2002,63(3):475-485
Mechanics is described and equations are given of the motion of an actively bending homogeneous body of a finite thickness in a channel with dry friction under conditions of a weak bending. Control is suggested of the motion of a body in a sinusoidal channel, which retains a continuous first derivative of the controlling moment and a bounded second derivative. A process is described of the maximization of the speed of motion by control and then by the choice of the best parameters of a channel. Control is also considered of other modes of the motion of a body in the same channel. 相似文献
4.
《Control Engineering Practice》2001,9(3):267-281
This paper describes a method for the state estimation of nonlinear systems described by a class of differential-algebraic equation models using the extended Kalman filter. The method involves the use of a time-varying linearisation of a semi-explicit index one differential-algebraic equation. The estimation technique consists of a simplified extended Kalman filter that is integrated with the differential-algebraic equation model. The paper describes a simulation study using a model of a batch chemical reactor. It also reports a study based on experimental data obtained from a mixing process, where the model of the system is solved using the sequential modular method and the estimation involves a bank of extended Kalman filters. 相似文献
5.
D.-S. KimAuthor Vitae J. RyuAuthor VitaeH.C. LeeAuthor Vitae H. ShinAuthor Vitae 《Computer aided design》2002,34(4):337-345
The evaluation of points and the computations of inflection points or cusps on a curve are often necessary in CAGD applications. When a curve is represented in a B-spline form, such computations can be made easier once it is transformed into a set of piecewise polynomial curves in power form. The usual practice of the transformation of a B-spline curve into a set of piecewise polynomial curves in power form is done either by a knot refinement followed by basis conversions, or by applying a Taylor expansion on each knot span of a B-spline curve.Presented in this paper is a new algorithm to convert a B-spline curve into a set of piecewise polynomial curves in power form. Experiment shows that the proposed algorithm significantly outperforms the conventional approach when one or more control points of a B-spline curve are continuously moving. 相似文献
6.
A tube is a solid bounded by the union of a one-parameter family of circles that may be decomposed into canal-surfaces and planar disks or annuli. A screw-sweep is the region swept by a shape during a screw motion. HelSweeper computes the boundary of a screw-sweep of an arbitrary union of tubes and polyhedra. To do so, it generates a superset of faces, splits them at their intersections, and selects the face portions that form the desired boundary. The novelty of the proposed approach lies in the fact that the faces contributed to this superset by a tube are each a screw-sweeps of a rigid curve (generator), which is the locus of grazing points, and that each grazing point is formulated as the intersection of a circle of the tube with a corresponding screw-plane. Hence, each such face is a one-parameter family of helices, each being the screw-sweep of a grazing point. 相似文献
7.
This paper is concerned with the controllability of a system with a time-varying delay. The system to be considered here is described by a linear differential-difference equation of a retarded type, where a time-varying delay is a certain class of a time-varying function. First, the concepts of controllability for linear differential-difference systems with a constant delay, introduced by Weiss (1987), are developed to the system with a time-varying delay. Second, necessary and sufficient conditions for controllability are obtained. Finally, the controllability of a stationary system with a constant delay is treated, including the results of Chyung and Lee (1966). 相似文献
8.
This research aims to develop a combined sense system that uses both the force feedback and visual feedback to establish the
shape of microscopic features of a microsample. It is thought that the efficiency of minute procedures would be improved if
the operator could obtain a sense of force while using a manipulator. We used a cantilever to touch a minute object and obtain
a reaction force from the degree of bending. We made a haptic device which gives a sense of that force to the operator, who
can feel the force when a user touches a sample with a cantilever. In addition, when the haptic device is used in simulations,
the user can feel a force just as if the user had touched a sample. 相似文献
9.
Bayesian recognition of local 3-d shape by approximating image intensity functions with quadric polynomials 总被引:2,自引:0,他引:2
The recognition in image data of viewed patches of spheres, cylinders, and planes in the 3-D world is discussed as a first step to complex object recognition or complex object location and orientation estimation. Accordingly, an image is partitioned into small square windows, each of which is a view of a piece of a sphere, or of a cylinder, or of a plane. Windows are processed in parallel for recognition of content. New concepts and techniques include approximations of the image within a window by 2-D quadric polynomials where each approximation is constrained by one of the hypotheses that the 3-D surface shape seen is either planar, cylindrical, or spherical; a recognizer based upon these approximations to determine whether the object patch viewed is a piece of a sphere, or a piece of a cylinder, or a piece of a plane; lowpass filtering of the image by the approximation. The shape recognition is computationally simple, and for large windows is approximately Bayesian minimum-probability-of-error recognition. These classifications are useful for many purposes. One such purpose is to enable a following processor to use an appropriate estimator to estimate shape, and orientation and location parameters for the 3-D surface seen within a window. 相似文献
10.
The paper sets forth a theory to explain how dimensions and views combine to specify the shape of a mechanical component. It provides a method to determine whether a component is under, over, or exactly defined by a given dimensioning scheme. Measures for assessing the quality of a scheme are proposed. A solution is offered to a problem of tolerancing: given a toleranced dimensioning scheme, find the resulting tolerances between undimensioned parts of a component. 相似文献
11.
Branching processes of Petri nets 总被引:1,自引:0,他引:1
Joost Engelfriet 《Acta Informatica》1991,28(6):575-591
Summary The notion of a branching process is introduced, as a formalization of an initial part of a run of a Petri net, including nondeterministic choices. This generalizes the notion of a process in a natural way. It is shown that the set of branching processes of a Petri net is a complete lattice, with respect to the natural notion of partial order. The largest element of this lattice is the unfolding of the Petri net. 相似文献
12.
Paul Pritchard 《Acta Informatica》1981,16(1):87-91
Summary Dijkstra has given a derivation of an efficient algorithm for a problem concerning monotonic subsequences, and extracted a proof of a related theorem from the algorithm. Here it is shown that a careful separation of concerns can lead to a beautiful conventional proof, a very different derivation of Dijkstra's algorithm, a more elegant proof from the algorithm, and the discovery of a duality property. 相似文献
13.
Christopher B. Smith Author VitaeAuthor Vitae Eugene John Author Vitae 《Computers & Electrical Engineering》2008,34(3):192-201
This paper presents a statistical approach to estimating the performance of a superscalar processor. Traditional trace-driven simulators can take a large amount time to conduct a performance evaluation of a machine, especially as the number of instructions increases. The result of this type of simulation is typically tied to the particular trace that was run. Elements such as dependencies, delays, and stalls are all a direct result of the particular trace being run, and can differ from trace to trace. This paper describes a model designed to separate simulation results from a specific trace. Rather than running a trace-driven simulation, a statistical model is employed, more specifically a Poisson distribution, to predict how these types of delay affects performance. Through the use of this statistical model, a performance evaluation can be conducted using a general code model, with specific stall rates, rather than a particular code trace. This model allows simulations to quickly run tens of millions of instructions and evaluate the performance of a particular micro-architecture while at the same time, allowing the flexibility to change the structure of the architecture. 相似文献
14.
The refined process structure tree 总被引:2,自引:0,他引:2
15.
We present a goal-oriented a posteriori error estimator for finite element approximations of a class of homogenization problems. As a rule, homogenization problems are defined through the coupling of a macroscopic solution and the solution of auxiliary problems. In this work we assume that the homogenized problem is known and that it depends on a finite number of auxiliary problems. The accuracy in the goal functional depends therefore on the discretization error of the macroscopic and the auxiliary solutions. We show that it is possible to compute the error contributions of all solution components separately and use this information to balance the different discretization errors. Additionally, we steer a local mesh refinement for both the macroscopic problem and the auxiliary problems. The high efficiency of this approach is shown by numerical examples. These include the upscaling of a periodic diffusion tensor, the case of a Stokes flow over a porous bed, and the homogenization of a fuel cell model which includes the flow in a gas channel over a porous substrate coupled with a multispecies nonlinear transport equation. 相似文献
16.
《Journal of Systems and Software》1986,6(3):251-259
We have built a system, Patchwork, that allows programs to be organized according to a dataflow model. In our implementation, application programs use Patchwork to assemble complex microcode programs for a graphics processor from a library of microcode modules. We describe a simple and efficient implementation, in which the only overhead incurred is a single extra level of indirection when invoking a module or when a module accesses inputs, outputs, or local storage. The implementation depends on being able to describe a distinct execution tree for the network, which obviates the need both for run-time monitoring of the execution and for movement of data. Thus, neither dataflow hardware nor a dataflow language is needed for the implementation. Patchwork supports flow-of-control constructs such as looping and branching, the assembly of complex modules from simpler ones, modules written in a variety of languages for a variety of different devices, the interleaved execution of several programs on a single processor, and the execution of a single program on a set of processors in parallel. An analysis showed that Patchwork contributed between 2 and 5% to the total running time of sample microcode programs. 相似文献
17.
刘文艳 《数字社区&智能家居》2007,(11):672-673,702
在剖析青少年网上银行犯罪本质特征和主要特点的基础上,进一步探讨了青少年网上银行犯罪产生的根源,并据此提出一些根本的打击防范对策.有助于进一步确保网上银行的运行安全。 相似文献
18.
K. V. Vorontsov 《Pattern Recognition and Image Analysis》2010,20(3):269-285
Three general methods for obtaining exact bounds on the probability of overfitting are proposed within statistical learning
theory: a method of generating and destroying sets, a recurrent method, and a blockwise method. Six particular cases are considered
to illustrate the application of these methods. These are the following model sets of predictors: a pair of predictors, a
layer of a Boolean cube, an interval of a Boolean cube, a monotonic chain, a unimodal chain, and a unit neighborhood of the
best predictor. For the interval and the unimodal chain, the results of numerical experiments are presented that demonstrate
the effects of splitting and similarity on the probability of overfitting. 相似文献
19.
Inductive behaviours may be classified according to their aim. We intend to show that there are at least two kinds of inductive behaviours. Most of the publications seem to take into consideration only one of these: to copy as exactly as possible the behaviour of a probability process. After a brief discussion to explain the necessity of a learning criterion and a recall about one criterion, representative of most of them, we shall define a new criterion, and show why it is better fitted to learn the laws of a deterministic process from a set of observations.This criterion has been used to implement a program which builds an acceptor of natural language sentences in a CAI environment using a tutorial strategy, and then for a question answering device. As attractive as the results are, their improvement requires a semantic model. We give the basic principles of a model which we currently develop, and whose main feature is approximation. 相似文献
20.
This paper proposes a recovery plan for managing disruptions in a three-stage production-inventory system under a mixed production environment. First, a mathematical model is developed to deal with a disruption at any stage while maximizing total profit during the recovery-time window. The model is solved after the occurrence of a disruption event, with changed data used to generate a revised plan. We also propose a new and efficient heuristic for solving the developed mathematical model. Second, multiple disruptions are considered, where a new disruption may or may not affect the recovery plans of earlier disruptions. The heuristic, developed for a single disruption, is extended to deal with a series of disruptions so that it can be implemented for disruption recovery on a real-time basis. We compare the heuristic solutions with those obtained by a standard search algorithm for a set of randomly generated disruption test problems, and that show the consistent performance of our developed heuristic with lower computational times. Finally, some numerical examples and a real-world case study are presented to demonstrate the benefits and usefulness of our proposed approach. 相似文献