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991.
992.
When a new editorial team takes over responsibility for the important task of overseeing the production of a journal, it is critical, for both readers and those interested in publishing their scholarly work in the journal, that they clearly present their vision for the direction of the journal. Such a statement provides an opportunity for the editors to illustrate their plans for interpreting the journal's mandate in a manner that ensures continuity with previous volumes of the journal while also emphasizing areas of the mandate that may not have received the attention they deserve. This editorial is designed with these purposes in mind. In the following paragraphs, we will provide information on the structure and scope of the journal for the next four years, as well as practical information on how authors should interpret the mandate of the journal and submit their work to the journal. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
In this article we discuss recent work on coarse-graining methods for microscopic stochastic lattice systems. We emphasize
the numerical analysis of the schemes, focusing on error quantification as well as on the construction of improved algorithms
capable of operating in wider parameter regimes. We also discuss adaptive coarse-graining schemes which have the capacity
of automatically adjusting during the simulation if substantial deviations are detected in a suitable error indicator. The
methods employed in the development and the analysis of the algorithms rely on a combination of statistical mechanics methods
(renormalization and cluster expansions), statistical tools (reconstruction and importance sampling) and PDE-inspired analysis
(a posteriori estimates). We also discuss the connections and extensions of our work on lattice systems to the coarse-graining of polymers. 相似文献
994.
Several publications (e.g., Smil, Reynolds) have shown the links between civilisation and the efficiency of energy options. As a general rule, human progress was supported by more and more efficient energy options. One indicator of this efficiency is the energy payback, the ratio of energy produced to energy invested. From the earliest use of wood to the massive use of oil in the 1970s, energy payback ratios (EPRs) have improved significantly. 相似文献
995.
Simultaneous Object Recognition and Segmentation from Single or Multiple Model Views 总被引:3,自引:0,他引:3
Vittorio Ferrari Tinne Tuytelaars Luc Van Gool 《International Journal of Computer Vision》2006,67(2):159-188
We present a novel Object Recognition approach based on affine invariant regions. It actively counters the problems related
to the limited repeatability of the region detectors, and the difficulty of matching, in the presence of large amounts of
background clutter and particularly challenging viewing conditions. After producing an initial set of matches, the method
gradually explores the surrounding image areas, recursively constructing more and more matching regions, increasingly farther
from the initial ones. This process covers the object with matches, and simultaneously separates the correct matches from
the wrong ones. Hence, recognition and segmentation are achieved at the same time. The approach includes a mechanism for capturing
the relationships between multiple model views and exploiting these for integrating the contributions of the views at recognition
time. This is based on an efficient algorithm for partitioning a set of region matches into groups lying on smooth surfaces.
Integration is achieved by measuring the consistency of configurations of groups arising from different model views. Experimental
results demonstrate the stronger power of the approach in dealing with extensive clutter, dominant occlusion, and large scale
and viewpoint changes. Non-rigid deformations are explicitly taken into account, and the approximative contours of the object
are produced. All presented techniques can extend any view-point invariant feature extractor.
This research was supported by EC project VIBES, the Fund for Scientific Research Flanders, and the IST Network of Excellence
PASCAL. 相似文献
996.
The concept of a valveless acoustic micropump was investigated. Two-dimensional, time-varying, axisymmetric, incompressible
viscous flows through a planar diffuser-nozzle element were analyzed for applications in valveless acoustic micropumps. The
diffuser divergence half-angles (θ), and the maximum pressure amplitudes (P) were independently varied. The inflow was periodic and the excitation frequency (f) was varied over the range 10 kHz ≤ f ≤ 30 kHz. The net time-averaged volume flux and the rectification capability of the diffuser were found as functions of
θ, f, and P. The phase difference between pressure and velocity waveforms, the life time and the size of large scale flow recirculation
regions inside the microdiffuser, and energy losses were found to be strongly frequency dependent. 相似文献
997.
Condition Based Maintenance (CBM) is based on the assessment of equipment state which is obtained by measuring some indicators. When there is uncertainty concerning the state of the equipment, the measurements gathered are called imperfect. In this case the equipment aging and degradation process is assumed to follow a Markov process and is modeled by a Hidden Markov Model (HMM). This article describes a general procedure that can be used to estimate the parameters of the HMM. It is based on the Expectation-Maximization (EM) algorithm. The procedure deals with independent as well as correlated maintenance observations. The latter are most common in CBM applications. Simulated examples are presented. 相似文献
998.
In order to lower the short-circuit effect due to the measurement contacts, Vertical Hall Devices (VHDs) are generally designed either in bulky N-type silicon or in the deep N-well of high-voltage CMOS technologies. In this last case, VHD can benefit from on chip circuitry for offset and 1/f noise reduction, but HVCMOS remains a costly technology. Using spinning-current, HVCMOS compatible VHDs with a resolution of 76 μT rms over a 1.6-kHz bandwidth have been demonstrated. The VHD presented here is designed in the shallow N-well of a low-cost 0.35 μm standard CMOS technology. Unlike conventional VHD, its measurement contacts are located outside the sensor active area. FEM simulations and experimental results show that the new geometry suppresses the short-circuit effect and strongly reduces the intrinsic offset and noise. Thus, without any noise and offset reduction method, this new small VHD (63 μm2) reaches a resolution of 79 μT rms over a (5 Hz–1.6 kHz) bandwidth, and opens the way to the integration of 3D Hall sensors in low-cost standard CMOS technologies. 相似文献
999.
Hugo Centomo David Amarantini Luc Martin Fran?ois Prince 《IEEE transactions on neural systems and rehabilitation engineering》2007,15(2):258-265
It has been demonstrated that below-knee amputee (BKA) subjects use specific compensation strategies to overcome their physical limitations. Biomechanical studies emphasize that the motor strategies adopted by BKA adults differ between their amputated limb and their nonamputated limb and from those employed by able-bodied (AB) subjects. The purpose of this investigation was to compare the motor solutions used by control AB and BKA children during a stepping-in-place (SIP) task and to assess how they regulate the coordination of their nonamputated and amputated limbs during this task. Eight BKA children and eight AB children paired for gender, age, weight and height participated in our study. One-way analysis of variances (ANOVAs) were performed on peaks of angular excursion, moment, and power at the hip, knee, and ankle to compare motor strategies between the BKA and AB groups. The main results of our experiment showed that even if BKA and AB children did the task with almost the same kinematics, the kinetic data revealed completely different mechanisms of the two groups to achieve the SIP task, and BKA children had a symmetrical interlimb strategy. SIP, a simple task compared to gait at the level of neuro-musculoskeletal demands, could thus offer a transition task to physical therapists for below-knee recently-amputated children. 相似文献
1000.
Lucía Pérez Amaro Bernabé L. Rivas Serena Coiai Elisa Passaglia Sylvain Augier Francesco Ciardelli 《应用聚合物科学杂志》2009,113(1):290-298
Polypropylene (PP) was modified by radical grafting of acrylic acid (AA) in the melt by using dicumyl peroxide (DCP) as initiator. To reach a high grafting degree (GD) without substantially modifying PP‐chain structure, a few runs were carried out by employing butyl 3‐(2‐furanyl)propenoate (BFA), which is a coagent able to preserve the molecular weight (MW) of PP macromolecules in the presence of radical grafting reagents. All the samples were extracted with selective solvents to remove unreacted chemicals and free poly(acrylic acid) (PAA), and the GD was accurately determined by using the FTIR methodology. The GD ranged from 1.51 to 4.67 mol %. High‐temperature size permeation chromatography analysis was used to evaluate MW behavior, confirming the control exerted by the presence of BFA on the degradation reactions. DSC, TGA, and SEM analyses were performed to analyze the chemical modification effects on the polymer products' thermal and morphological properties. Finally, selected samples, with a particle size distribution in the range 100–850 μm, were tested as metal ion adsorption resins. Al(III), Cr(III), Zn(II), Cd(II), Pb(II), and Hg(II) were studied, and the highest adsorption efficiency values (in percentage) were obtained for Al(III) (15–20%) and Hg(II) (25–30%). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献