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排序方式: 共有2917条查询结果,搜索用时 15 毫秒
201.
Delli Priscoli Francesco Di Giorgio Alessandro Lisi Federico Monaco Salvatore Pietrabissa Antonio Celsi Lorenzo Ricciardi Suraci Vincenzo 《International Journal of Control, Automation and Systems》2017,15(2):892-904
International Journal of Control, Automation and Systems - In the framework of the Future Internet, the aim of the Quality of Experience (QoE) Control functionalities is to track the personalized... 相似文献
202.
Convex piecewise-linear fitting 总被引:1,自引:1,他引:0
We consider the problem of fitting a convex piecewise-linear function, with some specified form, to given multi-dimensional
data. Except for a few special cases, this problem is hard to solve exactly, so we focus on heuristic methods that find locally
optimal fits. The method we describe, which is a variation on the K-means algorithm for clustering, seems to work well in practice, at least on data that can be fit well by a convex function.
We focus on the simplest function form, a maximum of a fixed number of affine functions, and then show how the methods extend
to a more general form. 相似文献
203.
Simone Ceriani Giulio Fontana Alessandro Giusti Daniele Marzorati Matteo Matteucci Davide Migliore Davide Rizzi Domenico G. Sorrenti Pierluigi Taddei 《Autonomous Robots》2009,27(4):353-371
A trustable and accurate ground truth is a key requirement for benchmarking self-localization and mapping algorithms; on the
other hand, collection of ground truth is a complex and daunting task, and its validation is a challenging issue. In this
paper we propose two techniques for indoor ground truth collection, developed in the framework of the European project Rawseeds, which are mutually independent and also independent on the sensors onboard the robot. These techniques are based, respectively,
on a network of fixed cameras, and on a network of fixed laser scanners. We show how these systems are implemented and deployed,
and, most importantly, we evaluate their performance; moreover, we investigate the possible fusion of their outputs. 相似文献
204.
Aline G. Cunha Angelo A. T. da Silva Mateus G. Godoy Rodrigo V. Almeida Alessandro B. C. Simas Denise M. G. Freire 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2013,88(2):205-211
BACKGROUND: The response surface methodology was successfully applied to the optimization of the reaction variables for the kinetic resolution of a precursor of high‐value myo‐inositols, ( ± )‐1,2‐O‐isopropylidene‐3,6‐di‐O‐benzyl‐myo‐inositol (( ± )‐1), by Novozym 435. The resolutions were run separately, with two acylating agents, ethyl acetate and vinyl acetate, in a solvent‐free system. The variables analyzed were reaction temperature, substrate concentration, water concentration and enzyme activity. A statistical model was employed for the evaluation of the influence of the variables on conversion and enantiomeric excess (ee). RESULTS: The optimal conditions for this resolution using vinyl acetate as acylating agent were 45 °C, 5 mg mL?1 of substrate, 71 U of enzyme activity and 0%w/w of water concentration. The high conversion (49.2 %) and ee (>99%) reached in the chemoenzymatic synthesis of acylated product, L‐(?)‐5‐O‐Acetyl‐3,6‐di‐O‐benzyl‐1,2‐O‐isopropylidene‐myo‐inositol, secure the efficient synthesis of the D enantiomorph present in the original racemic mixture (( ± )‐1) as well. CONCLUSIONS: The use of the experimental design strategy was productive, leading to a 14‐fold increase in the productivity of the reaction compared with the non‐optimized conditions. Both derivative L‐(?)‐2 and remaining substrate D‐(+)‐1 were obtained at high ee. © 2012 Society of Chemical Industry 相似文献
205.
Laguerre-Gauss and Bessel-Gauss beams in uniaxial crystals 总被引:1,自引:0,他引:1
Cincotti G Ciattoni A Palma C 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(8):1680-1688
A simple correspondence between the paraxial propagation formulas along the optical axis of a uniaxial crystal and inside an isotropic medium is found in the case of beams with linearly polarized circularly symmetric boundary distributions. The electric fields of the ordinary and the extraordinary beams are related to the corresponding expressions in a medium with refractive index n(o) and n(e)2/n(o), where n(o) and n(e) are the ordinary and the extraordinary refractive indexes, respectively. Closed-form expressions for Laguerre-Gauss and Bessel-Gauss beams propagating through an anisotropic crystal are given. 相似文献
206.
Karol Mikula Alessandro Sarti Fiorella Sgallari 《Computing and Visualization in Science》2006,9(1):23-31
We introduce semi-implicit complementary volume numerical scheme for solving the level setformulation of Riemannian mean curvature
flow problem arising in image segmentation, edge detection, missing boundary completion and subjective contour extraction.
The scheme is robust and efficient since it is linear, and it is stable in L_∞ and weighted W
1,1 sense without any restriction on a time step. The computational results related to medical image segmentation with partly
missing boundaries and subjective contours extraction are presented. 相似文献
207.
Alessandro Chiuso Author Vitae Author Vitae 《Automatica》2005,41(3):377-391
We study statistical consistency of two recently proposed subspace identification algorithms for closed-loop systems. These algorithms may be seen as implementations of an abstract state-space construction procedure described by the authors in previous work on stochastic realization of closed-loop systems. A detailed error analysis is undertaken which shows that both algorithms are biased due to an unavoidable mishandling of initial conditions which occurs in closed-loop identification. Instability of the open loop system may also be a cause of trouble. 相似文献
208.
A robust deconvolution scheme for fault detection and isolation of uncertain linear systems: an LMI approach 总被引:1,自引:0,他引:1
Alessandro Casavola Author Vitae 《Automatica》2005,41(8):1463-1472
Optimal H∞ deconvolution filter theory is exploited for the design of robust fault detection and isolation (FDI) units for uncertain polytopic linear systems. Such a filter is synthesized under frequency domain conditions which ensure guaranteed levels of disturbance attenuation, residual decoupling and deconvolution performance in prescribed frequency ranges. By means of the Projection Lemma, a quasi-convex formulation of the problem is obtained via LMIs. A FDI logic based on adaptive thresholds is also proposed for reducing the generation of false alarms. The effectiveness of the design technique is illustrated via a numerical example. 相似文献
209.
Pietro Cenciarelli Alessandro Tiberi 《Electronic Notes in Theoretical Computer Science》2005,127(5):3
We present a case study where Synchronising Graphs, a system of parallel graph transformation, are used to solve the syntactic unification problem for first order rational terms (with possibly infinite unifier). The solution we offer is efficient, that is quasi-linear, and simple: a program of 28 characters. 相似文献
210.
Christian Monzio Compagnoni Alessandro S. Spinelli Andrea L. Lacaita Sabina Spiga 《Microelectronic Engineering》2006,83(10):1927-1930
We present a detailed experimental investigation of transient currents in HfO2 capacitors in the short timescale. We show that the transient currents flowing through the capacitor plates when the gate voltage is reset to zero after a low voltage stress period follow a power-law time dependence t−α (with α ? 1) over more than eight decades of time and down to the μs timescale. As transient currents in HfO2 are largely increased with respect to the SiO2 case, these results confirm that transient effects can be a severe issue for the successful integration of high-k dielectrics. 相似文献