检索结果-内蒙古大学图书馆

ON COMPUTING 3-FINGER FORCE-CLOSURE GRASPS OF POLYGONAL OBJECTS

IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION 1995年第6期11卷 868-881页

作者： PONCE, J FAVERJON, B UNIV ILLINOIS BECKMAN INST URBANA IL 61801 USA ALEPH TECHNOL F-38400 ST MARTIN DHERES FRANCE

This paper addresses the problem of computing stable grasps of 2-D polygonal objects. We consider the case of a hand equipped with three hard fingers and assume point contact with friction. We prove new sufficient conditions for equilibrium and force closure that are linear in the unknown grasp parameters. This reduces computing the stable grasp regions in configuration space to constructing the three-dimensional projection of a five-dimensional polytope. We present an efficient projection algorithm based on linear programming and variable elimination among linear constraints. Maximal object segments where fingers can be positioned independently while ensuring force closure are found by linear optimization within the grasp regions. The approach has been implemented and several examples are presented.

关键词： Fingers Friction Sufficient conditions Space technology Computer science USA Councils projection algorithms Mechanical factors Robots Resists

来源：评论

学校读者我要写书评

暂无评论

Achievable Rate Maximization for Underlay Spectrum Sharing MIMO System With Intelligent Reflecting Surface

引用

IEEE WIRELESS COMMUNICATIONS LETTERS 2022年第8期11卷 1758-1762页

作者： Kumar, Vaibhav Flanagan, Mark F. Zhang, Rui Tran, Le-Nam Univ Coll Dublin Sch Elect & Elect Engn Dublin D04 V1W8 4 Ireland Natl Univ Singapore Dept Elect & Comp Engn Singapore Singapore

In this letter, the achievable rate maximization problem is considered for intelligent reflecting surface (IRS) assisted multiple-input multiple-output (MIMO) systems in an underlay spectrum sharing scenario, subject to interference power constraints at the primary users. The formulated non-convex optimization problem is challenging to solve due to its non-convexity as well as coupling design variables in the constraints. Different from existing works that are mostly based on alternating optimization (AO), we propose a penalty dual decomposition based gradient projection (PDDGP) algorithm to solve this problem. We also provide a convergence proof and a complexity analysis for the proposed algorithm. We benchmark the proposed algorithm against two known solutions, namely a minimum mean-square error based AO algorithm and an inner approximation method with block coordinate descent. Specifically, the complexity of the proposed algorithm grows linearly with respect to the number of reflecting elements at the IRS, while that of the two benchmark methods grows with the third power of the number of IRS elements. Moreover, numerical results show that the proposed PDDGP algorithm yields considerably higher achievable rate than the benchmark solutions.

关键词： MIMO communication Approximation algorithms Couplings Convergence Benchmark testing Wireless communication projection algorithms Intelligent reflecting surface underlay spectrum sharing MIMO penalty dual decomposition gradient projection

来源：评论

学校读者我要写书评

暂无评论

Reducing the Cost of Mesh-to-Mesh Data Transfer

引用

IEEE TRANSACTIONS ON MAGNETICS 2014年第2期50卷 7010704-1-7010704-4页

作者： Journeaux, Antoine Alexandre Bouillault, Frederic Roger, Jean Yves Lab Genie Elect Paris F-91192 Gif Sur Yvette France EDF Res & Dev F-92141 Clamart France

Mesh-to-mesh data transfer methods are evaluated in terms of not only accuracy but also the cost of computing time. Interpolation is a widely used method because of its simplicity. However, it suffers from a lack of precision when Lagrange elements are considered. projection methods, which are more complex, are thus preferred, although they significantly increase the computational time as well as the memory cost. We propose a comparison between these two methods (interpolation and projection) applied to curl-conforming and div-conforming elements. It appears that interpolation is advantageous because of its simplicity and speed while giving results of the same order as the projection method. A process to accurately compute circulations along edges and fluxes through faces is proposed. It relies on an adaptive quadrature scheme which provides reliable results regardless of the variation of the initial solution.

关键词： Computational efficiency computational geometry function approximation magnetic fields projection algorithms scientific computing

来源：评论

学校读者我要写书评

暂无评论

Bi-Orthonormal Polynomial Basis Function Framework With Applications in System Identification

引用

IEEE TRANSACTIONS ON AUTOMATIC CONTROL 2016年第11期61卷 3285-3300页

作者： van Herpen, Robbert Bosgra, Okko Oomen, Tom Eindhoven Univ Technol Dept Mech Engn Control Syst Technol Grp NL-5612 AZ Eindhoven Netherlands

Numerical aspects are of central importance in identification and control. Many computations in these fields involve approximations using polynomial or rational functions that are obtained using orthogonal or oblique projections. The aim of this paper is to develop a new and general theoretical framework to solve a large class of relevant problems. The proposed method is built on the introduction of bi-orthonormal polynomials with respect to a data-dependent bi-linear form. This bi-linear form generalises the conventional inner product and allows for asymmetric and indefinite problems. The proposed approach is shown to lead to optimal numerical conditioning (kappa = 1) in a recent frequency-domain instrumental variable system identification algorithm. In comparison, it is shown that these recent algorithms exhibit extremely poor numerical properties when solved using traditional approaches.

关键词： Least-squares approximations numerical analysis polynomials projection algorithms system identification

来源：评论

学校读者我要写书评

暂无评论

Novel algorithms for Blind Sensing of Signals With Variable Bandwidths in Cognitive Radio

引用

IEEE SYSTEMS JOURNAL 2020年第3期14卷 4272-4283页

作者： De, Parthapratim Inst Infocomm Res Singapore 138632 Singapore

In a cognitive radio, an interface is designed for use by secondary users (SUs) on a noninterfering basis in spectrum allocated to the primary user (PU). However, to prevent interference to the PU, the SU cognitive radio needs to detect the presence of the PU at very low signal-to-noise ratio (SNR), due to multipath and shadowing on its way to the SU. Wideband spectrum sensing is considered here. The main contribution of this article is a blind algorithm for blindly sensing PU signals, of varying bandwidths, at very low SNRs. A novel oblique projection (involving the oversampled received signal) is used. The effect of PU signal bandwidth on the performance of the blind spectrum sensing algorithms is investigated in this article, which has not been done earlier. Unlike existing blind spectrum sensing algorithms, whose performance depends on the bandwidth of the PU signal, the oblique projection-based novel method adapts itself to the varying bandwidths of the PU signal to maintain the constant level of superior performance for all bandwidths of PU signals;this is solely due to the oblique projection sensing method, which also exploits the correlation between the PU signals on the different receiver oversampled branches.

关键词： Bandwidth Sensors Correlation Signal to noise ratio Cognitive radio Multipath channels Databases Adaptive signal detection blind equalizers cognitive radio estimation theory parameter estimation projection algorithms

来源：评论

学校读者我要写书评

暂无评论

Convergence analysis of a global optimization algorithm using stochastic differential equations

引用

JOURNAL OF GLOBAL OPTIMIZATION 2009年第1期45卷 95-110页

作者： Parpas, Panos Rustem, Berc Univ London Imperial Coll Sci Technol & Med Dept Comp London SW7 2AZ England

We establish the convergence of a stochastic global optimization algorithm for general non-convex, smooth functions. The algorithm follows the trajectory of an appropriately defined stochastic differential equation (SDE). In order to achieve feasibility of the trajectory we introduce information from the Lagrange multipliers into the SDE. The analysis is performed in two steps. We first give a characterization of a probability measure (I ) that is defined on the set of global minima of the problem. We then study the transition density associated with the augmented diffusion process and show that its weak limit is given by I .

关键词： Stochastic global optimization Simulated annealing Stochastic differential equations Fokker-Planck equation Laplace's method projection algorithms

来源：评论

学校读者我要写书评

暂无评论

Publishing Node Strength Distribution With Node Differential Privacy

引用

IEEE ACCESS 2020年 8卷 217642-217650页

作者： Liu, Ganghong Ma, Xuebin Li, Wuyungerile Inner Mongolia Univ Inner Mongolia Key Lab Wireless Networking & Mobi Hohhot 010000 Peoples R China

The challenge of graph data publishing under node-differential privacy mainly comes from the high sensitivity of the query. Compared with edge-differential privacy that can only protect the relationship between people, node-differential privacy can protect both the relationship between people and personal information. Therefore, Node-differential privacy must pay attention to the protection of personal information. This paper studies the release of node strength distribution under node-differential privacy by reducing sensitivity. We propose two algorithms to publish node strength distribution: Alternate-histogram (ALT-histogram) and Density-histogram (DEN-histogram). Experimental results show that compared with the existing node strength histogram publishing algorithm, our proposed algorithm has advantages in L1-error and KS-distance, make the noise node strength distribution closer to that of the original graph. We also propose an introspective analysis to understand the influence of the projection algorithm on the node strength distribution, experiments to prove that the projection algorithm plays an important role in the node strength distribution.

关键词： Privacy Differential privacy Sensitivity Histograms projection algorithms Publishing Databases Differential privacy private graph publishing node strength

来源：评论

学校读者我要写书评

暂无评论

Uninformative variable elimination for improvement of successive projections algorithm on spectral multivariable selection with different calibration algorithms for the rapid and non-destructive determination of protein content in dried laver

引用

ANALYTICAL METHODS 2011年第8期3卷 1790-1796页

作者： Wu, Di Chen, Xiaojing Zhu, Xiangou Guan, Xiaochun Wu, Guichu Wenzhou Univ Coll Phys & Elect Engn Informat Chashan Univ Town Wenzho 325035 Zhejiang Prov Peoples R China Zhejiang Univ Coll Biosyst Engn & Food Sci Hangzhou 310058 Zhejiang Peoples R China

The potential of using partial least square based uninformative variable elimination algorithm (UVEPLS) on successive projections algorithm (SPA) for spectral multivariable selection was evaluated. A case study was done on the visible and shortwave-near infrared (Vis-SNIR) spectroscopy for the rapid and non-destructive determination of protein content in dried laver. Three calibration algorithms, namely multiple linear regression (MLR), partial least square regression (PLS) and least-square support vector machine (LS-SVM), were used for the model establishment based on the selected variables of SPA, UVEPLS and UVEPLS-SPA, respectively. A total of 175 samples were prepared for the calibration (n = 117) and prediction (n = 58) sets. The performances of different pretreatments were compared. Both linear calibration algorithms of MLR and PLS and non-linear calibration algorithms of LS-SVM with linear kernel and RBF kernel obtained similar results based on certain variable selection strategies of SPA, UVEPLS and UVEPLS-SPA. The average improvement percentage of RPD values of four calibration algorithms was 38.66% by calculating SPA on UVEPLS processed variables. Therefore there was much improvement of using UVEPLS on SPA spectral multivariable selection with both linear and nonlinear calibration algorithms in this case. Moreover, the RPD values of both linear and non-linear models based on the thirteen selected variables of UVEPLS-SPA show that coarse quantitative predictions of the protein determination in dried laver is possible based on Vis-SNIR spectra. We hope that the results obtained in this study will help both further chemometric (multivariate selection and calibration analysis) investigations and investigations in the sphere of applied vibrational (Near infrared, Mid-infrared and Raman) spectroscopy of sophisticated multicomponent systems.

关键词： protein content Multivariable projection algorithms algorithms non-destructive Nori protein determination Variable

来源：评论

学校读者我要写书评

暂无评论

TIME-COMPLEXITY OF A PATH FORMULATED OPTIMAL ROUTING ALGORITHM (2ND PRINTING)

引用

IEEE TRANSACTIONS ON AUTOMATIC CONTROL 1994年第9期39卷 1839-1844页

作者： ANTONIO, JK TSAI, WK HUANG, GM TEXAS A&M UNIV DEPT ELECT ENGNCOLLEGE STNTX 77843 UNIV CALIF IRVINE DEPT ELECT ENGNIRVINECA 92717

A detailed analysis of convergence rate is presented for an iterative path formulated optimal routing algorithm. In particular, it is quantified, analytically, how the convergence rate changes as the number of nodes in the underlying graph increases. The analysis is motivated by a particular path formulated gradient projection algorithm that has demonstrated excellent convergence rate properties through extensive numerical studies. The analytical result proven in this note is that the number of iterations for convergence depends on the number of nodes only through the network diameter.

关键词： computational complexity convergence of numerical methods data communication systems graph theory iterative methods optimisation telecommunication network routing convergence rate gradient projection algorithm iterative path formulated optimal routing al complexity classes convergence of numerical methods iterative methods Graph theory telecommunication network routing DATA TRANSMISSION SYSTEMS projection algorithms Routing algorithms Converge

来源：评论

学校读者我要写书评

暂无评论

Mpemba-Like Behavior in Carbon Nanotube Resonators

引用

METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE 2011年第13期42A卷 3907-3912页

作者： Greaney, P. Alex Lani, Giovanna Cicero, Giancarlo Grossman, Jeffrey C. MIT Dept Mat Sci & Engn Cambridge MA 02139 USA Ecole Polytech Solides Irradies Lab F-91128 Palaiseau France Polytech Torino INFM I-10129 Turin Italy Polytech Torino Dept Phys I-10129 Turin Italy

Surprising Mpemba-like dissipation is observed during computer simulated ring-down of the flexural modes of a single-walled carbon nanotube resonator. Vibrations are made to decay to zero faster by adding a larger initial excitation. We liken this counterintuitive observation to the well-known Mpemba effect in which hot water freezes faster that cold water. In both cases, the system seems to pose a memory of its thermal history;a paradoxical result that is reconciled if the dissipative state of the system is not described uniquely by the system's average temperature. A vibrational mode projection algorithm is used to track the dissipation pathway, showing that dissipation is dependent strongly on the development of an athermal phonon population. The implications of Mpemba-like behavior in more general, and continuously driven, nanomechanical systems are discussed.

关键词： thermal history flexural mode Resonator Device Component ring-down Computers Depletion Carbon Nanotubes Vibrations modes projection algorithms cold water

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：