检索结果-内蒙古大学图书馆

Piecewise Linear Approximation by the Method of Worst Segment Division

LOBACHEVSKII JOURNAL OF MATHEMATICS 2021年第12期42卷 2969-2979页

作者： Sukiasyan, H. S. Natl Acad Sci Republ Armenia Inst Math Yerevan 0019 Armenia Natl Polytech Univ Armenia Yerevan Armenia

The finite element method for numerical solving two-dimensional boundary value problem is based on domain triangulation and piecewise linear approximation. The present paper describes how to minimize the number of triangulation vertices without exceeding the given level of the approximation error. The paper proposes a method for constructing piecewise linear approximations for continuous two-dimensional functions by dividing the ''worst'' segment. The possibilities of applying the proposed method in solving boundary value problems are investigated. The main theorem gives a sufficient condition on the minimized functional so that the best mesh would be the Delaunay triangulation. An example of a numerical solution of the Maxwell equation of the electromagnetic field using the method of the worst segment division with Delaunay triangulation is given.

关键词： boundary value problem finite element method piecewise linear approximation Dealaunay triangulation recursive algorithm

来源：评论

学校读者我要写书评

暂无评论

Pricing maximum-minimum bidirectional options in trinomial CEV model

引用

Journal of Economics, Finance and Administrative Science 2016年第41期21卷 50-55页

作者： Peng, Bin Peng, Fei SEME Beijing University of Civil Engineering and Architecture Beijing China Electrical & Computer Engineering UBC Vancouver Canada

Maximum-minimum bidirectional options are a kind of exotic path dependent options. In the constant elasticity of variance (CEV) model, a combining trinomial tree was structured to approximate the non-constant volatility that is a function of the underlying asset. On this basis, a simple and efficient recursive algorithm was developed to compute the risk-neutral probability of each different node for the underlying asset reaching a maximum or minimum price and the total number of maxima (minima) in the trinomial tree. With help of it, the computational problems can be effectively solved arising from the inherent complexities of different types of maximum-minimum bidirectional options when the underlying asset evolves as the trinomial CEV model. Numerical results demonstrate the validity and the convergence of the approach mentioned above for the different parameter values set in the trinomial CEV model. © 2016

关键词： Maximum-minimum bidirectional options recursive algorithm Trinomial CEV model

来源：评论

学校读者我要写书评

暂无评论

Probability Distribution on Rooted Trees

Probability Distribution on Rooted Trees

引用

IEEE International Symposium on Information Theory (ISIT)

作者： Nakahara, Yuta Saito, Shota Kamatsuka, Akira Matsushima, Toshiyasu Waseda Univ Ctr Data Sci Tokyo 1698050 Japan Gunma Univ Fac Informat Gunma 3718510 Japan Shonan Inst Technol Dept Informat Sci Fujisawa Kanagawa 2518511 Japan Waseda Univ Dept Appl Math Tokyo 1698555 Japan

ISBN: (纸本)9781665421607;9781665421591

The hierarchical and recursive expressive capability of rooted trees is applicable to represent statistical models in various areas, such as data compression, image processing, and machine learning. On the other hand, such hierarchical expressive capability causes a problem in tree selection to avoid overfitting. One unified approach to solve this is a Bayesian approach, on which the rooted tree is regarded as a random variable and a direct loss function can be assumed on the selected model or the predicted value for a new data point. However, all the previous studies on this approach are based on the probability distribution on full trees, to the best of our knowledge. In this paper, we propose a generalized probability distribution for any rooted trees in which only the maximum number of child nodes and the maximum depth are fixed. Furthermore, we derive recursive methods to evaluate the characteristics of the probability distribution without any approximations.

关键词： Bayes decision theory Bayes statistics recursive algorithm rooted trees

来源：评论

学校读者我要写书评

暂无评论

On adaptive threshold intervals for stopping recursive least squares in the space of parameters

引用

Informatica (Netherlands) 1995年第3期6.0卷 299-312页

作者： Pupeikis, Rimantas Institute of Mathematics and Informatics Vilnius 2600 Akademijos St. 4 Lithuania

In the papers (Kaminskas, 1972;Kaminskas and Nemura, 1975;Yin, 1989) the stopping rules of recursive least squares (RLS) are worked out using the ellipsoidal confidence region for the respective parameter vector of a linear dynamic system. The aim of the given paper is the development of the technique for calculating threshold intervals of respective criterions, used in a stopping rule, which are presented in Kaminskas (1972). In this connection adaptive threshold intervals based on the Cramer- Rao lower bound are proposed here. The results of numerical simulation by IBM PC/AT are given. © 1995 IOS Press. All rights reserved.

关键词： Dynamic system Least squares recursive algorithm Threshold

来源：评论

学校读者我要写书评

暂无评论

Event-Triggered Fault Estimation for Nonlinear Systems with Missing Measurements 33

Event-Triggered Fault Estimation for Nonlinear Systems with ...

引用

33rd Chinese Control Conference (CCC)

作者： Liu, Yang Wang, Zidong He, Xiao Zhou, Donghua Tsinghua Univ Dept Automat Beijing 100084 Peoples R China Brunel Univ Dept Comp Sci Uxbridge UB8 3PH Middx England Tsinghua Univ TNList Beijing 100084 Peoples R China

ISBN: (纸本)9781479947249

In this paper, the joint fault and state estimation problem is investigated for a class of nonlinear systems with event-triggered transmissions and missing measurements. In the proposed event-triggered transmission scheme, in order to reduce unnecessary network traffic, the current measurement is released only when it changes greatly from the previously transmitted one. A Bernoulli distributed sequence taking values on 0 or 1 is introduced to govern possible missing measurements in the transmission. Special effort is made to obtain and then minimize certain upper bound of the estimation error covariance in the simultaneous presence of the linearization errors and imperfect measurement transmissions. It is noticeable that, in the proposed method, the traditional assumption on the availability on the probability density functions of the states and the innovations conditional on the measurements is no longer needed, and therefore the application scope is much widened. Moreover, the fault and states can be jointly estimated, thereby providing a way of simultaneously monitoring the system and diagnosing the faults. The estimator gain is calculated via solving two recursive matrix equations, and the corresponding algorithm is therefore suitable for online applications. An illustrative example is provided to show the effectiveness of the proposed algorithm.

关键词： Event-triggered transmission missing measurements nonlinear systems fault estimation recursive algorithm

来源：评论

学校读者我要写书评

暂无评论

A Two-Dimensional Mode-Matching Technique for Wake-Interaction Tonal Noise Including Rotor-Stator Coupling

A Two-Dimensional Mode-Matching Technique for Wake-Interacti...

引用

AIAA Aviation Forum

作者： Girier, Leo Roger, Michel Lafitte, Anthony Posson, Helene Univ Claude Bernard Lyon 1 Univ Lyon Ecole Cent Lyon CNRSLab Mecan Fluides & AcoustUMR 5509INSA Lyo 36 Ave Guy de Collongue F-69134 Scully France Safran Aircraft Engines F-77550 Moissy Cramayel France

ISBN: (数字)9781624107047

ISBN: (纸本)9781624107047

Noise generated by the impingement of rotor wakes on guide vanes is still widely studied in the context of turbofan noise. However, analytical models are often limited to an isolated stator made of flat-plate vanes, neglecting the presence of the rotor. The present work proposes an iterative procedure based on successive applications of a mode-matching technique on the stator and the rotor to model the acoustically coupled rotor-stator system, including vane camber. This allows one to study the "shielding" effect of the rotor and the occurrence of inter-stage trapped modes, in order to better predict the relative balance between upstream and downstream sound powers, as well as modal and frequency contents. The influence of interstage distance and rotor rotational speed on sound generation and propagation is investigated in this paper. It appears that the additional scattering by the rotor can have a significant impact on the emerging tones by redistributing sound through frequencies. The ratio of downstream to upstream acoustic power tends to increase compared to the single stator computation, as previously reported in the literature, even if an artificial swirl is imposed upstream of the compressor stage in the present study. However, the total sound power with and without the rotor scattering remains the same in the performed test cases.

关键词： Camber Aircraft Noise Pollution Compressor Design Rotor Wake Rotor Stator Interactions Acoustic Excitation Conservation of Mass recursive algorithm Acoustic Scattering Stagnation Enthalpy

来源：评论

学校读者我要写书评

暂无评论

Removal of High Density Salt-And-Pepper Noise by recursive Enhanced Median Filtering 2

Removal of High Density Salt-And-Pepper Noise by Recursive E...

引用

2nd IEEE International Conference on Emerging Technology Trends in Electronics, Communication and Networking (ET2ECN)

作者： Sharma, Abhishek Chaurasia, Vijayshri Maulana Azad Natl Inst Technol Bhopal India

ISBN: (纸本)9781479969869

In many applications the existence of impulsive noise in the acquired images is one of the most common problems. In present scenario median filters are very functional solution for the removal of impulse noise in the images. In general procedure firstly the noise is detected and then removed secondly. This paper proposes a novel method with two thresholds (Minimum threshold and maximum threshold) which detects noise more efficiently. Further the enhanced median value is use to replace the noisy pixels recursively. It furnishes a better Peak Signal to Noise Ratio (PSNR) as compared to many existing median filter based image de-noising methods.

关键词： Impulse noise Median filter recursive algorithm Enhanced median Noise detection

来源：评论

学校读者我要写书评

暂无评论

Improved algorithm to evaluate the reliability of a circular consecutive 2-out-of-r-from-n:F system

Improved algorithm to evaluate the reliability of a circular...

引用

35th SICE International Annual Conference (SICE 96)

作者： Higashiyama, Y Kraetzl, M Caccetta, L EHIME UNIV DEPT ELECT & ELECT ENGNMATSUYAMAEHIME 790JAPAN

ISBN: (纸本)0780337514

A circular consecutive k-out-of-r-from-n:F system consists of n components ordered on a cycle. The system fails if and only if there are r consecutive components at least k of which are failed. The time complexity of a recently published algorithm for circular consecutive k-out-of-r-from-n:F system is O(nr). This paper proposes a method to improve upon this O(nr) algorithm.

关键词： circular consecutive 2-out-of-r-from-n:F system exact reliability recursive algorithm

来源：评论

学校读者我要写书评

暂无评论

Estimating box-dimension by sign counting

Estimating box-dimension by sign counting

引用

28th International Conference on Information Technology Interfaces

作者： Veleva, Sanja Kocic, Ljubisa Fac Elect Engn Skopje Karpos II BB Skopje 1000 Macedonia Univ Nis Fac Elect Engn Nish Serbia

ISBN: (纸本)9537138054

In this article we examine the possibility of improving the recursive algorithm for computation of box-dimension of complex sets. The known method of box-counting is simplified down to the simple sign counting operation. Our target set is a "cloud" of amorphous points since many fractal sets are given in this form. The key of the algorithm are affine transformations from the world coordinate system to the parametric one and renormalization using as elementary operations as binary dilatation and unit shift transformations. The verification of the quality of results of the generated algorithm is established in the testing phase of the algorithm.

关键词： box-dimension fractal sets recursive algorithm

来源：评论

学校读者我要写书评

暂无评论

Sojourn Time Analysis for Processor Sharing Loss Queuing System with Service Interruptions and MAP Arrivals 19th

Sojourn Time Analysis for Processor Sharing Loss Queuing Sys...

引用

19th International Conference on Distributed Computer and Communication Networks (DCCN)

作者： Samouylov, Konstantin Sopin, Eduard Gudkova, Irina RUDN Univ Dept Appl Probabil & Informat Miklukho Maklaya Str 6 Moscow 117198 Russia FRC CSC RAS Inst Informat Problems Vavilova Str 44 Moscow 119333 Russia

ISBN: (纸本)9783319519173;9783319519166

Processor sharing (PS) queuing systems are widely investigated by research community and applied for the analysis of wire and wireless communication systems and networks. Nevertheless, only few works focus on finite queues with both PS discipline and service interruptions. In the paper, compared with the previous results we analyze a finite capacity PS queuing system with Markovian arrival process, unreliable server, service interruptions, and an upper limit of the number of customers it serves simultaneously. For calculating the mean sojourn time, unlike a popular but computational complex technique of inverse Laplace transform we use an effective method based on embedded Markov chain. A practical example concludes the paper.

关键词： Queuing system Processor sharing Egalitarian processor sharing Unreliable server Interruption Probability distribution recursive algorithm Sojourn time Absorbing Markov chain

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：