Papers by Keyword: Interval Arithmetic

Abstract: For long time span, the impact of many factors, uncertainties and other characteristics of mid-long term load forecasting, as well as the over-estimation of interval arithmetic, a mid-long term load forecasting method based on interval Taylor model algorithm was presented. In order to avoid misjudgment of the relationship between variables, reducing over-estimation problem, a global variable named Taylor model ID was presented to identify the independent variables and the dependent variable. The same independent variables construct the interval Taylor model only once. Use Maclaurin formula to derive the interval Taylor model of correlation function formula, and then get a quadratic exponential smoothing method based on interval the Taylor model. The proposed method has been tested on a provincial calculation. The results demonstrated the effectiveness and practical value of the approach by comparing with the results of Monte Carlo simulation and interval method.

Abstract: Based on the existing cable failure problems, two features of cable failure problems areput forward. The cablescannot be measured precisely and their characteristics cannot be predicted certainly. In order toanalyze the reliability of cables more reasonably, non-probabilistic reliability theory and its development status are introducedin this article. And the theory of modified one dimensional optimization algorithm is appliedto thereliability analysis of stayed-cable. Its results are comparedwith the results of the probabilistic reliability analysis of stayed-cable. Then the parameters analyses of cableare taken, as a result, the main factors that haveobviouslyinfluence on the reliability of the cable are presented in the article.

Abstract: The paper presents chosen traditional (based on probability theory) and non-traditional (based on possibility theory) computational tools for analysis of the material, geometric or loading uncertainties in mechanical structures. Uncertainties are introduced as bounded possible values intervals or as fuzzy sets, assuming possibility theory and as random parameters in the case of the probability theory. The main goal was to propose numerical algorithms for fuzzy analysis of stochastic oscillated FE model (truss structure) and to predict fuzzy fatigue damage considering fuzzy S/N curve.

Abstract: This paper deals with the application of interval arithmetic in internal model control (IMC) for suspension systems. The IMC problem is expressed as an optimization of filter parameters. And the optimization can be solved by branch-and-bound scheme with interval arithmetic techniques. We present the algorithm for the model of suspension systems. The effectiveness of the algorithm is demonstrated through simulation results.

Abstract: Using the generalized interval arithmetic we give a generalized cholesky decomposition. Generalized intervals (intervals whose bounds are not constrained to be increasingly ordered) extend classical intervals providing better algebraic properties. In particular, the generalized interval arithmetic is a group for addition and for multiplication of zero free intervals. These properties allow one constructing a cholesky decomposition of a generalized interval matrix A: the computed generalized interval matrix L satisfy A=LL^T with equality instead of the weaker inclusion obtained in the context of classical intervals.

Abstract: Everyday engineering work is rife with uncertainty and complexity. Some of the uncertainty stems from highly variable natural phenomena such as wind and earthquakes. More prevalent is the uncertainty that arises from a simple lack of knowledge, especially in complex problems. This paper describes the key considerations of designing, manufacturing, and installing large amusement devices, with characteristics complex and uncertain by nature. A range of techniques for engineering decision-making and reasoning in the presence of uncertainty and complexity are described. The techniques may be applied throughout the design and manufacturing process, but are particularly effective in the early or conceptual stages, which are characterized by greater uncertainty than the latter design phases. The techniques described include qualitative reasoning, adaptive interval plotting, design space mapping, and design space reliability estimation. These methods allow the engineer to solve and visualize the design space. In contrast to engineering problem-solving approaches which find a single point configuration, a design space may include a large number of feasible solutions. The range of solutions may be used effectively in engineering decision making.

Abstract: Array bound is a concealed security defect. It generally cannot be found in the compiling progress, so it is extremely easy to cause a system crash. In this paper, we describe a static array bound checker, which concentrates on the defect of interprocedural array bound. This method is achieved by using the technology of static analysis, interval arithmetic and procedure summary, so it can detect the faults before the progress running. We finally give an experiment to verify the effectiveness and the high precision of this method. The method has been applied to practical projects.

Abstract: This paper considers the performance of radial basis function neural networks for the purpose of data classification. The methods are illustrated using a simple two class problem. Two techniques for reducing the rate of misclassifications, via the introduction of an “unable to classify” label, are presented. The first of these considers the imposition of a threshold value on the classifier outputs whilst the second considers the replacement of the crisp network weights with interval ranges. Two network training techniques are investigated and it is found that, although thresholding and uncertain weights give similar results, the level of variability of network performance is dependent upon the training approach