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排序方式: 共有287条查询结果,搜索用时 15 毫秒
1.
Macwan Richard Benezeth Yannick Mansouri Alamin 《Journal of Mathematical Imaging and Vision》2021,63(7):807-820
Journal of Mathematical Imaging and Vision - Remote photoplethysmography (rPPG) has been at the forefront recently, thanks to its capacity in estimating non-contact physiological parameters such as... 相似文献
2.
Spatial bound whale optimization algorithm: an efficient high-dimensional feature selection approach
Too Jingwei Mafarja Majdi Mirjalili Seyedali 《Neural computing & applications》2021,33(23):16229-16250
Neural Computing and Applications - Selecting a subset of candidate features is one of the important steps in the data mining process. The ultimate goal of feature selection is to select an optimal... 相似文献
3.
Lignin‐based wood adhesives are obtained that satisfy the requirements of relevant international standards for the manufacture of exterior‐grade wood particleboard. Formulations based on low molecular mass lignin and presenting an increase in the relative proportion of reactive points yield better results than the higher molecular mass lignin used in the past. These lignins allow a higher proportion of hydroxymethylation during preparation of methylolated lignins. These lignin‐based adhesives also yield acceptable results at particleboard pressing times that are sufficiently low to be of industrial significance. Lignin‐based wood adhesives, in which a nonvolatile nontoxic aldehyde (glyoxal) is substituted for formaldehyde in their preparation, are prepared and tested for application to wood panels such as particleboard. The adhesives yield good internal bond strength results for the panels, which are good enough to comfortably pass relevant international standard specifications for exterior‐grade panels. The adhesives also show sufficient reactivity to yield panels in press times comparable to that of formaldehyde‐based commercial adhesives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1690–1699, 2007 相似文献
4.
Matching of a LTB metric representing dust matter to a background FRW universe across a null hypersurface is studied. In general,
unrestricted matching is possible only if the background FRW is flat or open. There is in general no gravitational impulsive
wave present on the null hypersurface which is shear-free and expanding. Special cases of vanishing pressure or energy density
on the hypersurface are discussed. In the case of vanishing energy-momentum tensor of the null hypersurface, i.e., in the
case of a null boundary, it turns out that all possible definitions of the Hubble parameter on the null hypersurface, being
those of LTB or that of FRW, are equivalent, and that a flat FRW configuration can only be joined smoothly to a flat LTB one. 相似文献
5.
We study the use of high-order Sobolev gradients for PDE-based image smoothing and sharpening, extending our previous work
on this problem. In particular, we study the gradient descent equation on the heat equation energy functional obtained by
modifying the usual metric on the space of images, which is the L
2 metric, to a weighted H
k
Sobolev metric. We present existence and uniqueness results which show that the Sobolev diffusion PDE are well-posed both
in the forward and backward direction. Furthermore, we perform a Fourier analysis on the scale space generated by the Sobolev
PDE and show that as the order of the Sobolev metric tends to infinity, the Sobolev gradients converge to a Gaussian smoothed
L
2 gradient. We then present experimental results which exploit the theoretical stability results by applying the various Sobolev
gradient flows in the backward direction for image sharpening effects. Furthermore, we show that as the Sobolev order is increased,
the sharpening effects become more global in nature and more immune to noise. 相似文献
6.
Ubaid M. Al-Saggaf Ibrahim M. Mehedi Rachid Mansouri Maamar Bettayeb 《International Journal of Control, Automation and Systems》2017,15(6):2561-2569
In this paper, a fractional order control law is proposed and implemented for the evaluation of trajectory tracking performance of a rotary flexible-joint system. A state feedback based fractional integral control scheme is used in this proposed method. In this scheme, state feedback is responsible for stabilizing the system. The compensator, in series with the fractional integrator leads to obtain a similar closed-loop transient response like Bode’s ideal transfer function. The effectiveness of the proposed controller in tracking and being robust against parameter uncertainties is demonstrated through simulation. In addition, to show the usefulness of the proposed control scheme, the fractional controller is compared to an integer state feedback control by simulation and through experimentation on the Quanser’s rotary flexible-joint system. 相似文献
7.
Najme Mansouri Gholam Hosein Dastghaibyfard Ehsan Mansouri 《Journal of Network and Computer Applications》2013,36(2):711-722
Data Grid is a geographically distributed environment that deals with large-scale data-intensive applications. Effective scheduling in Grid can reduce the amount of data transferred among nodes by submitting a job to a node, where most of the requested data files are available. Data replication is another key optimization technique for reducing access latency and managing large data by storing data in a wisely manner. In this paper two algorithms are proposed, first a novel job scheduling algorithm called Combined Scheduling Strategy (CSS) that uses hierarchical scheduling to reduce the search time for an appropriate computing node. It considers the number of jobs waiting in queue, the location of required data for the job and the computing capacity of sites. Second a dynamic data replication strategy, called the Modified Dynamic Hierarchical Replication Algorithm (MDHRA) that improves file access time. This strategy is an enhanced version of Dynamic Hierarchical Replication (DHR) strategy. Data replication should be used wisely because the storage capacity of each Grid site is limited. Thus, it is important to design an effective strategy for the replication replacement. MDHRA replaces replicas based on the last time the replica was requested, number of access, and size of replica. It selects the best replica location from among the many replicas based on response time that can be determined by considering the data transfer time, the storage access latency, the replica requests that waiting in the storage queue and the distance between nodes. The simulation results demonstrate the proposed replication and scheduling strategies give better performance compared to the other algorithms. 相似文献
8.
In this article, we try to better understand the relationship between learning and crisis through the analysis of recurrent crises. Our study focused on two successive and similar crises experienced by the same organization, namely two hostile takeover bids a French bank (Société Générale) had to cope with in 1988 and 1999. From a literature review within the fields of organizational learning and management crisis, we proposed an analytical grid making it possible to get a better understanding of crisis‐induced lesson‐drawing processes. We then used that grid to analyse and compare the learning processes implemented during the two crises under study. This comparison leads us to suggest that lack of organizational learning is one factor that accounts for crisis recurrence. Conversely, proactive crisis management behaviour – resulting from double‐loop learning – seems to be the most fruitful behaviour to adopt in order to prevent a recurrent crisis and produce long‐term effects in the organization. 相似文献
9.
Investigation of Heat‐Induced Degradation of Virgin Olive Oil Using Front Face Fluorescence Spectroscopy and Chemometric Analysis 下载免费PDF全文
Yvon Mbesse Kongbonga Hassen Ghalila Youssef Majdi William Mbogning Feudjio Zohra Ben Lakhdar 《Journal of the American Oil Chemists' Society》2015,92(10):1399-1404
A simple setup using a 365‐nm light‐emitting diode coupled to a USB spectrometer through an optical fiber, in a front‐face fluorescence configuration, was used to investigate the heat‐induced deterioration of virgin olive oil at different heating temperatures and times. The samples were heated for 30, 60, 120 and 180 min for every temperature setting of 140, 160 and 180 °C, respectively. Two important results are reported in this article. First, a neo‐formed compound around 665 nm due to the degradation of chlorophyll was observed. This new peak was attributed to pyropheophytins. The second result showed an important rise of the peak around 489 nm, which corresponded to the oxidation products. The correlation obtained between the peroxide value and the 489 nm peak using principal component analysis revealed the mechanism of the oxidation process. It further showed that the peak around 489 nm is a direct consequence of the degradation of hydroperoxide. 相似文献
10.
Mahsa Barzegar Rabi Behrooz Hamid Reza Mansouri Saeed Kazemi Najafi Linda F. Lorenz Charles R. Frihart 《Journal of the American Oil Chemists' Society》2020,97(12):1371-1383
Canola is widely grown in the northern latitudes for its vegetable oil, generating large quantities of residual, low value canola flour used as animal feed. The common wood adhesive poly(diphenylmethylene diisocyanate) (pMDI) should react with the wide variety of functional groups in proteins. Therefore, it would seem that canola flour with added pMDI could be an effective adhesive. Two main questions are addressed in this study: How do the wood adhesive properties of canola flour compare to the better-studied soy flour? How well do proteins, which contain an abundance of functional groups, cure with the very reactive pMDI? These questions were addressed using the small-scale adhesive strength test ASTM D-7998, with various adhesive formulations and bonding conditions for canola flour plus pMDI compared to soy adhesives. The more challenging wet cohesive bond strength was emphasized because the dry strengths were usually very good. Generally, soy adhesives were better than canola ones, as was the polyamidoamine-epichlorohydrin cross-linker compared to pMDI, but these generalizations can be altered by the conditions selected. Three-ply plywood tests supported the small-scale test results. 相似文献