可拼接式全柔性电容触觉阵列传感器设计与实验

针对现有机器人触觉传感器存在可穿戴性与可移植性差、不易维护及扩展等缺点,提出了一种可用于机器人仿生皮肤的全柔性电容式触觉传感器,并设计成12×12正方形触觉传感阵列和正六边形触觉模块两种可拼接式阵列结构.以炭黑填充硅橡胶作为电容式触觉传感器的弹性电介质,聚酰亚胺为柔性基体,有机硅导电银胶和金属膜为上下两柔性极板,共同构成压力敏感单元.介绍了电容式柔性触觉传感器的工作原理、结构设计及两种与之对应的电容触觉阵列无线数据采集与处理系统.实验结果表明,该全柔性电容式触觉阵列传感器及信号提取系统具有良好的稳定性与灵敏度,可用作人工皮肤实现全触觉感知.     

一种新型的触觉传感器及其应用

触觉传感器对智能机器人系统的设计越来越重要。本文叙述了触觉的机理和一种新型的触觉传感器的结构,以及感压可导橡胶的F-R特性,最后展望了这种传感器的应用领域。     

电容式柔性触觉传感器设计

为了实现对机器人指端触觉压力的检测,设计了一种电容式柔性触觉传感器,以PORON聚氨酯材料作为电容式触觉传感器电极间的弹性绝缘介质,导电膜在空间上呈垂直分布,分别交叉粘贴于 PORON聚氨酯材料上、下表面构成电容式触觉传感器的上、下电极,一起组成柔性电容传感单元,该触觉传感器制备工艺简单,材料成本低廉。测试结果表明,该触觉传感器及其信号采集与处理系统能够检测0~ 20Ｎ的触觉压力,曲线拟合最大误差为 6.44％,重复性误差为6.29％,能够实现触觉压力的检测,为在机器人指端实现触觉压力的检测提供一种参考。     

基于新型多模态触觉传感器的机器人交互物体分类

多模态传感融合对于机器人探索外界环境十分重要,而现有的触觉传感器只能收集一种触觉模态信息,其收集到的多模态信息存在弱配对问题,为了解决此问题,研究了一种基于触觉和视觉融合的多模态触觉传感器。该传感器可以利用一个感知层同时收集2种异构触觉模态信息,弥补了传统触觉传感器的缺陷,同时可以利用收集到的多模态信息对不同物体的几何形状进行分类,在研究过程中,通过按压实验收集了圆形、正方形、长方形和三角形4种形状物体的触觉信息,再利用K最近邻(KNN)算法进行几何形状分类,实验结果证明了该传感器在区分不同物体的形状上具有良好的效果。     

机器人用触觉传感器的研究

智能机器人通过视觉、触觉来识别周围的环境,工作对象和检测工作完成的情况。由于触觉装置控制简单,可直接检测物体的形状、光滑度、硬度等,因此触觉传感器是智能机器人的一个重要组成部分。 本文介绍三种国外的触觉传感器结构及其线路,在此基础上又探讨了光电触觉传感器以便为研制机器人的陈列触觉传感器奠定基础。     

基于Residual Networks的新型触觉传感器接触状态感知与识别

基于触觉信息识别不同接触状态对于人机交互的实现具有重要意义。本文提出一种基于残差网络(Residual Networks) 识别触觉传感器不同接触状态的方法。基于弹性体模板法制备了一款具有良好触觉感知能力的多孔石墨烯柔性触觉传感器。利用该触觉传感器采集了4种不同接触状态(拍打、重击、抚摸、推压)的时间序列数据,并对采集到的数据进行z-score标准化操作以及降采样处理。在此基础上,构建具有良好自适应性和泛化能力的Residual Networks模型对施加于该触觉传感器表面的4种接触状态进行分类识别,识别准确率为97.50%。实验结果表明：本文设计的多孔石墨烯柔性触觉传感器柔弹性好、灵敏度高、响应速度快,能够有效感知不同状态的接触力,Residual Networks模型可以高效地用于触觉传感器接触状态的分类识别。     

机器人触觉传感器的理论模型

本文从理论上探讨了机器人触觉传感器理论设计参数和实际制造参数的选择,给出了几种典型触觉传递矩阵,还讨论了触觉信号在计算机中的表示形式,最后对触觉传感器的噪声信号进行了简单的分析。     

触觉传感技术述评

测量被测物和传感器之间触觉参数的触觉传感器是近年来才迅速发展起来的传感器件。它可感受众多的物理特性。检测所测物存在或不存在就是一种最简单的双态触觉传感器;较复杂的触觉传感器则由一个持续采样的二维排列的传感点组成。此类传感器可提供被测物的诸如尺寸、形状、位置、导热性和力的分布等数据。 触觉传感器的维度根据各个传感点的空间排列而定,可分为三种基本类型:     

三维柔性触觉/热觉传感器设计与仿真

针对目前触觉传感器研究中不能兼有柔韧性、多维力测量和热觉与触觉信号混杂等难题,设计了一种柔性多功能触觉/热觉传感器。介绍了该传感器的基本结构,并基于聚偏氟乙烯（ PVDF）薄膜的特性建立了三维力并行测量的数学模型。触觉检测基于PVDF的压电效应,热觉检测基于PVDF的热释电效应。通过对触觉和热觉信号做比例减法运算,从而彻底区分触觉和热觉信号。     

多感知机器人夹持器设计

介绍了一种具有力觉、触觉和位置信息的机器人夹持器设计。讨论了力觉传感器、触觉传感器和位置传感器的设计与实现，概述了夹持器的机械结构及其控制系统设计。     

QCDgrid: A Grid Resource for Quantum Chromodynamics

Quantum Chromodynamics (QCD) is an application area that requires access to large supercomputing resources and generates large amounts of raw data. The UK's national lattice QCD collaboration UKQCD currently stores and requires access to around five Tbytes of data, a figure that is growing dramatically as the collaboration's purpose built supercomputing system, QCDOC [P.A. Boyle, D. Chen, N.H. Christ, M. Clark, S.D. Cohen, C. Cristian, Z. Dong, A. Gara, B. Joo, C. Jung, C. Kim, L. Levkova, X. Liao, G. Liu, R.D. Mawhinney, S. Ohta, K. Petrov, T. Wettig and A. Yamaguchi, “Hardware and software status of QCDOC, arXiv: hep-lat/0309096”, Nuclear Physics. B, Proceedings Supplement, Vol. 838, pp. 129–130, 2004. See: http://www.ph.ed.ac.uk/ukqcd/community/qcdoc/; P.A. Boyle, D. Chen, N.H. Christ, M.A. Clark, S.D. Cohen, C. Cristian, Z. Dong, A. Gara, B. Joo, C. Jung, C. Kim, L.A. Levkova, X. Liao, R.D. Mawhinney, S. Ohta, K. Petrov, T. Wettig and A. Yamaguchi, “Overview of the QCDSP and QCDOC computers”, IBM Journal of Research and Development, Vol. 49, No. 2/3, p. 351, 2005] came into full production service towards the end of 2004. This data is stored on QCDgrid, a data Grid currently composed of seven storage elements at five separate UK sites.     

Weaker convergence for Newton's method under Hölder differentiability

We use more precise majorizing sequences than in earlier studies such as [J. Appell, E. De Pascale, J.V. Lysenko, and P.P. Zabrejko, New results on Newton–Kantorovich approximations with applications to nonlinear integral equations, Numer. Funct. Anal. Optim. 18 (1997), pp. 1–17; I.K. Argyros, Concerning the ‘terra incognita’ between convergence regions of two Newton methods, Nonlinear Anal. 62 (2005), pp. 179–194; F. Cianciaruso, A further journey in the ‘terra incognita’ of the Newton–Kantorovich method, Nonlinear Funct. Anal. Appl. 15 (2010), pp. 173–183; F. Cianciaruso and E. De Pascale, Newton–Kantorovich approximations when the derivative is Hölderian: Old and new results, Numer. Funct. Anal. Optim. 24 (2003), pp. 713–723; F. Cianciaruso, E. De Pascale, and P.P. Zabrejko, Some remarks on the Newton–Kantorovich approximations, Atti Sem. Mat. Fis. Univ. Modena 48 (2000), pp. 207–215; E. De Pascale and P.P. Zabrejko, Convergence of the Newton–Kantorovich method under Vertgeim conditions: A new improvement, Z. Anal. Anwendvugen 17 (1998), pp. 271–280; J.A. Ezquerro and M.A. Hernández, On the R-order of convergence of Newton's method under mild differentiability conditions, J. Comput. Appl. Math. 197 (2006), pp. 53–61; J.V. Lysenko, Conditions for the convergence of the Newton–Kantorovich method for nonlinear equations with Hölder linearizations (in Russian), Dokl. Akad. Nauk BSSR 38 (1994), pp. 20–24; P.D. Proinov, New general convergence theory for iterative processes and its applications to Newton–Kantorovich type theorems, J. Complexity 26 (2010), pp. 3–42; J. Rokne, Newton's method under mild differentiability conditions with error analysis, Numer. Math. 18 (1971/72), pp. 401–412; B.A. Vertgeim, On conditions for the applicability of Newton's method, (in Russian), Dokl. Akad. N., SSSR 110 (1956), pp. 719–722; B.A. Vertgeim, On some methods for the approximate solution of nonlinear functional equations in Banach spaces, Uspekhi Mat. Nauk 12 (1957), pp. 166–169 (in Russian); English transl.: Amer. Math. Soc. Transl. 16 (1960), pp. 378–382; P.P. Zabrejko and D.F. Nguen, The majorant method in the theory of Newton–Kantorovich approximations and the Pták error estimates, Numer. Funct. Anal. Optim. 9 (1987), pp. 671–684; A.I. Zinc?enko, Some approximate methods of solving equations with non-differentiable operators (Ukrainian), Dopovidi Akad. Nauk Ukraïn. RSR (1963), pp. 156–161] to provide a semilocal convergence analysis for Newton's method under Hölder differentiability conditions. Our sufficient convergence conditions are also weaker even in the Lipschitz differentiability case. Moreover, the results are obtained under the same or less computational cost. Numerical examples are provided where earlier conditions do not hold but for which the new conditions are satisfied.     

Isogeometric variational multiscale modeling of wall-bounded turbulent flows with weakly enforced boundary conditions on unstretched meshes

In this work, we combine (i) NURBS-based isogeometric analysis, (ii) residual-driven turbulence modeling and iii) weak imposition of no-slip and no-penetration Dirichlet boundary conditions on unstretched meshes to compute wall-bounded turbulent flows. While the first two ingredients were shown to be successful for turbulence computations at medium-to-high Reynolds number [I. Akkerman, Y. Bazilevs, V. M. Calo, T. J. R. Hughes, S. Hulshoff, The role of continuity in residual-based variational multiscale modeling of turbulence, Comput. Mech. 41 (2008) 371–378; Y. Bazilevs, V.M. Calo, J.A. Cottrell, T.J.R. Hughes, A. Reali, G. Scovazzi, Variational multiscale residual-based turbulence modeling for large eddy simulation of incompressible flows, Comput. Methods Appl. Mech. Engrg., 197 (2007) 173–201], it is the weak imposition of no-slip boundary conditions on coarse uniform meshes that maintains the good performance of the proposed methodology at higher Reynolds number [Y. Bazilevs, T.J.R. Hughes. Weak imposition of Dirichlet boundary conditions in fluid mechanics, Comput. Fluids 36 (2007) 12–26; Y. Bazilevs, C. Michler, V.M. Calo, T.J.R. Hughes, Weak Dirichlet boundary conditions for wall-bounded turbulent flows. Comput. Methods Appl. Mech. Engrg. 196 (2007) 4853–4862]. These three ingredients form a basis of a possible practical strategy for computing engineering flows, somewhere between RANS and LES in complexity. We demonstrate this by solving two challenging incompressible turbulent benchmark problems: channel flow at friction-velocity Reynolds number 2003 and flow in a planar asymmetric diffuser. We observe good agreement between our calculations of mean flow quantities and both reference computations and experimental data. This lends some credence to the proposed approach, which we believe may become a viable engineering tool.     

Book reviews

CALCULUS AND THE COMPUTER (An Approach to problem solving) by T. V. Fossum and R. W. Gatterdam, 1980, pub. by Scott, Forrseman & Co., Glenview, Illinois, 217pp+Index. $6.95 (only U.S. Price available).

KNOWLEDGE BASED PROGRAM CONSTRUCTION, by David R. Barstow, The Computer Science Library, Programming Languages Series No. 6. North-Holland, 1979. $10.

NUMERICAL ANALYSIS OF SEMICONDUCTOR DEVICES. Proceedings of the NASECODE 1 Conference held at Trinity College, Dublin, from 27th-29th June 1979, edited by B.T. Browne and J. J. H. Miller, pub. by Boole Press Ltd., P.O. Box No. 5, 51 Sandycove Road, Dunlaoghaire, Co. Dublin, Ireland, August 1979, XII + 303 pages, Cloth £20 (U.S. $42) ISBN 0-906783-003.     

New shape-based auroral oval segmentation driven by LLS-RHT

A new method that exploits shape to localize the auroral oval in satellite imagery is introduced. The core of the method is driven by the linear least-squares (LLS) randomized Hough transform (RHT). The LLS-RHT is a new fast variant of the RHT suitable when not all necessary conditions of the RHT can be satisfied. The method is also compared with the three existing methods for aurora localization, namely the histogram-based k-means [C.C. Hung, G. Germany, K-means and iterative selection algorithms in image segmentation, IEEE Southeastcon 2003 (Session 1: Software Development)], adaptive thresholding [X. Li, R. Ramachandran, M. He, S. Movva, J.A. Rushing, S.J. Graves, W. Lyatsky, A. Tan, G.A. Germany, Comparing different thresholding algorithms for segmenting auroras, in: Proceedings of the International Conference on Information Technology: Coding and Computing, vol. 6, 2004, pp. 594-601], and pulse-coupled neural network-based [G.A. Germany, G.K. Parks, H. Ranganath, R. Elsen, P.G. Richards, W. Swift, J.F. Spann, M. Brittnacher, Analysis of auroral morphology: substorm precursor and onset on January 10, 1997, Geophys. Res. Lett. 25 (15) (1998) 3042-3046] methods. The methodologies and their performance on real image data are both considered in the comparison. These images include complications such as random noise, low contrast, and moderate levels of key obscuring phenomena.     

A DAFT DL_POLY distributed memory adaptation of the Smoothed Particle Mesh Ewald method

The Smoothed Particle Mesh Ewald method [U. Essmann, L. Perera, M.L. Berkowtz, T. Darden, H. Lee, L.G. Pedersen, J. Chem. Phys. 103 (1995) 8577] for calculating long ranged forces in molecular simulation has been adapted for the parallel molecular dynamics code DL_POLY_3 [I.T. Todorov, W. Smith, Philos. Trans. Roy. Soc. London 362 (2004) 1835], making use of a novel 3D Fast Fourier Transform (DAFT) [I.J. Bush, The Daresbury Advanced Fourier transform, Daresbury Laboratory, 1999] that perfectly matches the Domain Decomposition (DD) parallelisation strategy [W. Smith, Comput. Phys. Comm. 62 (1991) 229; M.R.S. Pinches, D. Tildesley, W. Smith, Mol. Sim. 6 (1991) 51; D. Rapaport, Comput. Phys. Comm. 62 (1991) 217] of the DL_POLY_3 code. In this article we describe software adaptations undertaken to import this functionality and provide a review of its performance.     

Response to the comments on "Fundamental limits of reconstruction-based superresolution algorithms under local translation"

Wang and Feng (IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 28, no. 5, p 846, May 2006) pointed out that the deduction in (Z. Lin and H. Y. Shum, IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 26, no. 1, pp. 83-97, Jan. 2004) overlooked the validity of the perturbation theorem used in (Z. Lin and H. Y. Shum, IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 26, no. 1, pp. 83-97, Jan. 2004). In this paper, we show that, when the perturbation theorem is invalid, the probability of successful superresolution is very low. Therefore, we only have to derive the limits under the condition that validates the perturbation theorem, as done in (Z. Lin and H. Y. Shum, IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 26, no. 1, pp. 83-97, Jan. 2004).     

A counterexample of a theorem by Tsolas et al. and an independentresult by Zaborszky et al. [with reply]

Recent results on the composition of the stability boundary by N.A. Tsolas et al. (IEEE Trans. Circuits Syst., vol.CAS-32, no.10, pp.1041-9, Oct. 1985) and J. Zaborszky et al. (Proc. IFAC Symp. Power Syst. Power Plant. Contr., Beijing, China, Aug. 1986, pp.597-603) claimed that it consisted of the stable manifolds of index-one unstable equilibria and their closures. A counterexample shows the potential existence of additional structures within the boundary. This finding invalidates numerous theorems published in the literature. The author concedes that the counterexample to the theorem in the paper by N.A. Tsolas et al. is unassailable and identifies the error in his proof     

Comparison of computational approaches for predicting the effects of missense mutations on p53 function

We applied our recently developed kinetic computational mutagenesis (KCM) approach [L.T. Chong, W.C. Swope, J.W. Pitera, V.S. Pande, Kinetic computational alanine scanning: application to p53 oligomerization, J. Mol. Biol. 357 (3) (2006) 1039–1049] along with the MM-GBSA approach [J. Srinivasan, T.E. Cheatham 3rd, P. Cieplak, P.A. Kollman, D.A. Case, Continuum solvent studies of the stability of DNA, RNA, and phosphoramidate-DNA helices, J. Am. Chem. Soc. 120 (37) (1998) 9401–9409; P.A. Kollman, I. Massova, C.M. Reyes, B. Kuhn, S. Huo, L.T. Chong, M. Lee, T. Lee, Y. Duan, W. Wang, O. Donini, P. Cieplak, J. Srinivasan, D.A. Case, T.E. Cheatham 3rd., Calculating structures and free energies of complex molecules: combining molecular mechanics and continuum models, Acc. Chem. Res. 33 (12) (2000) 889–897] to evaluate the effects of all possible missense mutations on dimerization of the oligomerization domain (residues 326–355) of tumor suppressor p53. The true positive and true negative rates for KCM are comparable (within 5%) to those of MM-GBSA, although MM-GBSA is much less computationally intensive when it is applied to a single energy-minimized configuration per mutant dimer. The potential advantage of KCM is that it can be used to directly examine the kinetic effects of mutations.     

On the estimation of the general parameter

In this paper, we first discuss the origin, developments and various thoughts by several researchers on the generalized linear regression estimator (GREG) due to Deville and Särndal [Deville, J.C., Särndal, C.E., 1992. Calibration estimators in survey sampling. J. Amer. Statist. Assoc. 87, 376-382]. Then, the problem of estimation of the general parameter of interest considered by Rao [Rao, J.N.K., 1994. Estimating totals and distribution functions using auxiliary information at the estimation stage. J. Official Statist. 10 (2), 153-165], and Singh [Singh, S., 2001. Generalized calibration approach for estimating the variance in survey sampling. Ann. Inst. Statist. Math. 53 (2), 404-417; Singh, S., 2004. Golden and Silver Jubilee Year-2003 of the linear regression estimators. In: Proceedings of the Joint Statistical Meeting, Toronto (Available on the CD), 4382-4380; Singh, S., 2006. Survey statisticians celebrate Golden Jubilee Year-2003 of the linear regression estimator. Metrika 1-18] is further investigated. In addition to that it is shown that the Farrell and Singh [Farrell, P.J., Singh, S., 2005. Model-assisted higher order calibration of estimators of variance. Australian & New Zealand J. Statist. 47 (3), 375-383] estimators are also a special case of the proposed methodology. Interestingly, it has been noted that the single model assisted calibration constraint studied by Farrell and Singh [Farrell, P.J., Singh, S., 2002. Re-calibration of higher order calibration weights. Presented at Statistical Society of Canada conference, Hamilton (Available on CD); Farrell, P.J., Singh, S., 2005. Model-assisted higher order calibration of estimators of variance. Australian & New Zealand J. Statist. 47 (3), 375-383] and Wu [Wu, C., 2003. Optimal calibration estimators in survey sampling. Biometrika 90, 937-951] is not helpful for calibrating the Sen [Sen, A.R., 1953. On the estimate of the variance in sampling with varying probabilities. J. Indian Soc. Agril. Statist. 5, 119-127] and Yates and Grundy [Yates, F., Grundy, P.M., 1953. Selection without replacement from within strata with probability proportional to size. J. Roy. Statist. Soc. Ser. 15, 253-261] estimator of the variance of the linear regression estimator under the optimal designs of Godambe and Joshi [Godambe, V.P., Joshi, V.M., 1965. Admissibility and Bayes estimation in sampling finite populations—I. Ann. Math. Statist. 36, 1707-1722]. Three new estimators of the variance of the proposed linear regression type estimator of the general parameters of interest are introduced and compared with each other. The newly proposed two-dimensional linear regression models are found to be useful, unlike a simulation based on a couple of thousands of random samples, in comparing the estimators of variance. The use of knowledge of the model parameters in assisting the estimators of variance has been found to be beneficial. The most attractive feature is that it has been shown theoretically that the proposed method of calibration always remains more efficient than the GREG estimator.