检索结果-内蒙古大学图书馆

computer Modeling in engineering & sciences 2021年第5期127卷 487-514页

作者： Yanlong Zhang Yanhui Zhou Jiming Wu Graduate School of China Academy of Engineering Physics Beijing100088China School of Data and Computer Science Sun Yat-Sen UniversityGuangzhou510275China Institute of Applied Physics and Computational Mathematics Beijing100088China

In this article,we study a 2D nonlinear time-fractional Rayleigh-Stokes problem,which has an anomalous subdiffusion term,on triangular meshes by quadratic finite volume element ***-fractional derivative,defined by Caputo fractional derivative,is discretized through L2−1σformula,and a two step scheme is used to approximate the time first-order derivative at time tn−α/2,where the nonlinear term is approximated by using a matching linearized difference scheme.A family of quadratic finite volume element schemes with two parameters are proposed for the spatial discretization,where the range of values for two parameters areβ1∈(0,1/2),β2∈(0,2/3).For testing the precision of numerical algorithms,we calculate some numerical examples which have known exact solution or unknown exact solution by several kinds of quadratic finite volume element schemes,and contrast with the results of an existing quadratic finite element scheme by drawing diversified comparison plots and showing the detailed data of L2 error results and convergence *** results indicate that,L2 error estimate of one scheme with parameters β_(1)=(3−√3)/6,β2=(6+√3−√21+6√3)/9 is O(h^(3)+△t^(2)),and L^(2) error estimates of other schemes are O(h^(2)+△t^(2)),where h and △t denote the spatial and temporal discretization parameters,respectively.

关键词： Quadratic finite volume element schemes anomalous sub-diffusion term L2 error estimate quadratic finite element scheme

Expressive probabilistic sampling in recurrent neural networks 23

学校读者我要写书评

暂无评论

Expressive probabilistic sampling in recurrent neural networ...

Proceedings of the 37th International Conference on Neural Information Processing Systems

作者： Shirui Chen Linxing Preston Jiang Rajesh P. N. Rao Eric Shea-Brown Department of Applied Mathematics University of Washington Seattle Paul G. Allen School of Computer Science & Engineering University of Washington Seattle Paul G. Allen School of Computer Science & Engineering and Center for Neurotechnology University of Washington Seattle Department of Applied Mathematics Computational Neuroscience Center University of Washington Seattle

In sampling-based Bayesian models of brain function, neural activities are assumed to be samples from probability distributions that the brain uses for probabilistic computation. However, a comprehensive understanding of how mechanistic models of neural dynamics can sample from arbitrary distributions is still lacking. We use tools from functional analysis and stochastic differential equations to explore the minimum architectural requirements for recurrent neural circuits to sample from complex distributions. We first consider the traditional sampling model consisting of a network of neurons whose outputs directly represent the samples (sampler-only network). We argue that synaptic current and firing-rate dynamics in the traditional model have limited capacity to sample from a complex probability distribution. We show that the firing rate dynamics of a recurrent neural circuit with a separate set of output units can sample from an arbitrary probability distribution. We call such circuits reservoir-sampler networks (RSNs). We propose an efficient training procedure based on denoising score matching that finds recurrent and output weights such that the RSN implements Langevin sampling. We empirically demonstrate our model's ability to sample from several complex data distributions using the proposed neural dynamics and discuss its applicability to developing the next generation of sampling-based Bayesian brain models.

关键词：

Unbiased and Multilevel Methods for a Class of Diffusions Partially Observed via Marked Point Processes

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Alvarez, Miguel Jasra, Ajay Ruzayqat, Hamza Applied Mathematics and Computational Science Program Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955 Saudi Arabia

In this article we consider the filtering problem associated to partially observed diffusions, with observations following a marked point process. In the model, the data form a point process with observation times that have its intensity driven by a diffusion, with the associated marks also depending upon the diffusion process. We assume that one must resort to time-discretizing the diffusion process and develop particle and multilevel particle filters to recursively approximate the filter. In particular, we prove that our multilevel particle filter can achieve a mean square error (MSE) of O(∈2) (∈ > 0 and arbitrary) with a cost of O(∈-2.5) versus using a particle filter which has a cost of O(∈-3) to achieve the same MSE. We then show how this methodology can be extended to give unbiased (that is with no time-discretization error) estimators of the filter, which are proved to have finite variance and with high-probability have finite cost. Finally, we extend our methodology to the problem of online static-parameter estimation. Key words: Unbiased Methods, Multilevel Monte Carlo, Non-Linear Filtering, Point Processes, Parameter *** Codes 60G55, 60G35, 62M20, 62F30 © 2023, CC BY.

关键词： Diffusion

Sarax: An Open-Source Software/Hardware Framework for Aerial Manipulators

学校读者我要写书评

暂无评论

Sarax: An Open-Source Software/Hardware Framework for Aerial...

International Conference on Unmanned Aircraft Systems (ICUAS)

作者： Ayham Alharbat Dion Zwakenberg Hanieh Esmaeeli Abeje Mersha Smart Mechatronics and Robotics research group Saxion University of Applied Science Enschede The Netherlands Robotics and Mechatronics research group Faculty of Electrical Engineering Mathematics & Computer Science University of Twente Enschede The Netherlands

ISBN: (数字)9798350357882

ISBN: (纸本)9798350357899

The use of Multi-Rotor Aerial Vehicles (MRAVs) in tasks that require physical interaction has been an active research field in the last decade which resulted in an increasing interest in Aerial Manipulators (AMs). This raises many challenges in the modeling, control, perception, and planning of these robots. However, designing and realizing an AM testbed is a complicated multi-disciplinary task, and there is a lack of standardization in the relatively new field of AMs. For this purpose, we introduce Sarax, an open-source hardware and software framework tailored for AMs research and innovation. The software of Sarax is built on top of open-source projects such as the Robot Operating System (ROS) and PX4 Autopilot, while the hardware is designed to be customizable, modular, and easily scalable through parameterized models. We verified and validated the proposed framework through indoor and outdoor experiments. We aim to open the door to accelerate AMs research and innovation, allow researchers and developers to focus on their core contributions, and take AMs technology to a higher readiness level.

关键词： Technological innovation Operating systems Standardization Manipulators Software Planning Open source hardware

Bayesian Parameter Inference for Partially Observed Stochastic Volterra Equations

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Jasra, Ajay Ruzayqat, Hamza Wu, Amin Applied Mathematics & Computational Science Program Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955 Saudi Arabia

In this article we consider Bayesian parameter inference for a type of partially observed stochastic Volterra equation (SVE). SVEs are found in many areas such as physics and mathematical finance. In the latter field they can be used to represent long memory in unobserved volatility processes. In many cases of practical interest, SVEs must be time-discretized and then parameter inference is based upon the posterior associated to this time-discretized process. Based upon recent studies on time-discretization of SVEs (e.g. [24]) we use Euler-Maruyama methods for the afore-mentioned discretization. We then show how multilevel Markov chain Monte Carlo (MCMC) methods [19] can be applied in this context. In the examples we study, we give a proof that shows that the cost to achieve a 4 mean square error (MSE) of O(ϵ2), ϵ > 0, is O(ϵ− 4/2H+1 ), where H is the Hurst parameter. If one uses a single level MCMC method then the cost is O(ϵ−2(2H+3)/ 2H+1 ) to achieve the same MSE. We illustrate these results in the context of state-space and stochastic volatility models, with the latter applied to real *** Codes 62F15, 62M20, 60J10, 60J22, 65C40 © 2023, CC BY.

关键词： Mean square error

Dispersive Vertex Guarding for Simple and Non-Simple Polygons

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Fekete, Sándor P. Mitchell, Joseph S.B. Rieck, Christian Scheffer, Christian Schmidt, Christiane Department of Computer Science TU Braunschweig Braunschweig Germany Department of Applied Mathematics and Statistics Stony Brook University Stony BrookNY United States Department of Electrical Engineering and Computer Science Bochum University of Applied Sciences Bochum Germany Department of Science and Technology Linköping University Norrköping Sweden

We study the Dispersive Art Gallery Problem with vertex guards: Given a polygon P, with pairwise geodesic Euclidean vertex distance of at least 1, and a rational number;decide whether there is a set of vertex guards such that P is guarded, and the minimum geodesic Euclidean distance between any two guards (the so-called dispersion distance) is at least . We show that it is NP-complete to decide whether a polygon with holes has a set of vertex guards with dispersion distance 2. On the other hand, we provide an algorithm that places vertex guards in simple polygons at dispersion distance at least 2. This result is tight, as there are simple polygons in which any vertex guard set has a dispersion distance of at most 2. Copyright © 2024, The Authors. All rights reserved.

关键词： Optimization

An Effective Exploration of Accessing 5G Mobile Communication That Affects E-Commerce Using IoT 8th

学校读者我要写书评

暂无评论

An Effective Exploration of Accessing 5G Mobile Communicatio...

8th International Conference on Information System Design and Intelligent Applications, ISDIA 2024

作者： Ljubimova, Elena Shichiyakh, Rustem Zakieva, Rafina Lydia, E. Laxmi Kumar, K. Vijaya Department of Mathematics and Applied Computer Science Kazan Federal University Elabuga Institute of KFU Yelabuga Russia Economic Sciences Department of Management Kuban State Agrarian University named after I.T. Trubilin Krasnodar Russia Pedagogical Sciences Department of Industrial Electronics and Lighting Engineering Kazan State Power Engineering University Kazan Russia Vijayawada520007 India Visakhapatnam India

ISBN: (纸本)9789819748945

To effectively answer these questions, your application's design needs to make a new user of your service feel at ease and not disoriented. This website is one of the most important parts of your marketing plan. If you have a fully functional, expert, and visually appealing website, it will be easier for consumers to do business with you. A user-friendly website will increase your revenue dramatically. It will be possible for your visitors to find the products on your website even more quickly than before. Many businesses have switched to selling their goods online, increasing the number of e-commerce platforms, thanks to COVID. In addition to retail and literature, e-commerce today supports a number of industries, such as books, home products, and cosmetics. Users will benefit from new features like augmented reality, chat capabilities, and recommended engines as 5G develops. Your business will get an immediate competitive edge over competitors by using these new features. Notwithstanding geographical disparities and the Covid pandemic, the business's target market has grown thanks to its offerings of groceries, essentials, and goods for the aged. These modifications suggest to people that e-commerce purchases now involve more commonplace needs than luxuries. By providing the best customer care possible at every point of contact, we at Clever Data prioritize the needs of our clients. With a team of dedicated developers and industry knowledge, it can provide you with the greatest solution for your clients’ comfort. They are thrilled to become a part of the intelligent Data family. 5G has a lot of potential and promises to help with these issues. Data processing and transmission speeds will soar to new heights with 5G. Thus, 5G will aid in the development and delivery of efficient online video advertising that can grab consumers’ interest and yield the most outcomes. Similarly, 5G networks guarantee that gadgets maintain their Internet connections while moving from o

关键词： Marketplaces

PDMA: Probabilistic service migration approach for delay-aware and mobility-aware mobile edge computing

学校读者我要写书评

暂无评论

PDMA: Probabilistic service migration approach for delay-awa...

作者： Xu, Minxian Zhou, Qiheng Wu, Huaming Lin, Weiwei Ye, Kejiang Xu, Chengzhong Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen China Center for Applied Mathematics Tianjin University Tianjin China School of Computer Science and Engineering South China University of Technology Guangzhou China State Key Lab of IOTSC Department of Computer Science University of Macau China

As a key technology in the 5G era, mobile edge computing (MEC) has developed rapidly in recent years. MEC aims to reduce the service delay of mobile users, while alleviating the processing pressure on the core network. MEC can be regarded as an extension of cloud computing on the user side, which can deploy edge servers and bring computing resources closer to mobile users, and provide more efficient interactions. However, due to the user's dynamic mobility, the distance between the user and the edge server will change dynamically, which may cause fluctuations in Quality of Service. Therefore, when a mobile user moves in the MEC environment, certain approaches are needed to schedule services deployed on the edge server to ensure the user experience. In this article, we model service scheduling in MEC scenarios and propose a delay-aware and mobility-aware service management approach based on concise probabilistic methods. This approach has low computational complexity and can effectively reduce service delay and migration costs. Furthermore, we conduct experiments by utilizing multiple realistic datasets and use iFogSim to evaluate the performance of the algorithm. The results show that our proposed approach can optimize the performance on service delay, with 8%–20% improvement and reduce the migration cost by more than 75% compared with baselines during the rush hours. © 2021 John Wiley & Sons Ltd.

关键词： Mobile edge computing

Reduced-Dimension Stap Method for Conformal Array Based on Sequential Convex Programming

学校读者我要写书评

暂无评论

SSRN

SSRN 2024年

作者： Shi, Jingxi Yao, Xueqi Wang, Zhihang Cheng, Ziyang The School of Computer and Software Engineering Xihua University China The College of Applied Mathematics Chengdu University of Information Technology China The School of Information and Communication Engineering University of Electronic Science and Technology of China China

Compared with the uniform arrays, the conformal array can e ectively reduce the radar cross section and improve the utilization of the limited space in the aircraft. However, the special array structure aggravates the non-stationarity of the clutter, and the typical blocking matrix construction method in the space-time adaptive processing (STAP) is not appropriate any more. To address these issues, a reduced dimension STAP algorithm based on penalty sequential convex programming in the generalized sidelobe cancellation structure is proposed. The blocking matrix, channel selection vector and STAP weights can be optimized simultaneously in the algorithm framework. To tackle the resultant nonconvex problem, we formulate the original optimization function as a quasi-convex form and solve these parameters alternately within an iterative framework. Numerical simulations are provided to validate the proposed method and demonstrate its high performance. © 2024, The Authors. All rights reserved.

关键词： Space time adaptive processing

ON THE MAXIMUM SIZE OF VARIABLE-LENGTH NON-OVERLAPPING CODES

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Wang, Geyang Wang, Qi Department of Electrical and Computer Engineering Institute for Systems Research University of Maryland College ParkMD20742 United States Department of Computer Science and Engineering National Center for Applied Mathematics Shenzhen Southern University of Science and Technology Nanshan District Guangdong Shenzhen518055 China

Non-overlapping codes are a set of codewords such that the prefix of each codeword is not a suffix of any codeword in the set, including itself. If the lengths of the codewords are variable, it is additionally required that every codeword is not contained in any other codeword as a subword. Let C(n, q) be the maximum size of q-ary fixed-length non-overlapping codes of length n. The upper bound on C(n, q) has been well studied. However, the nontrivial upper bound on the maximum size of variable-length non-overlapping codes of length at most n remains open. In this paper, by establishing a link between variable-length non-overlapping codes and fixed-length ones, we are able to show that the size of a q-ary variable-length non-overlapping code is upper bounded by C(n, q). Furthermore, we prove that the average length of the codewords in a q-ary variable-length non-overlapping codes is lower bounded by ⌈logq C˜⌉, and is asymptotically no shorter than n−2 as q approaches ∞, where C˜ denotes the cardinality of q-ary variable-length non-overlapping codes of length up to *** Codes 94A45, 94B25 © 2024, CC BY.

关键词： C (programming language)