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排序方式: 共有2145条查询结果,搜索用时 15 毫秒
41.
42.
Nicholas A. Yaraghi Nicolás Guarín‐Zapata Lessa K. Grunenfelder Eric Hintsala Sanjit Bhowmick Jon M. Hiller Mark Betts Edward L. Principe Jae‐Young Jung Leigh Sheppard Richard Wuhrer Joanna McKittrick Pablo D. Zavattieri David Kisailus 《Advanced materials (Deerfield Beach, Fla.)》2016,28(32):6835-6844
43.
Qi Jia Xin Ou Manuel Langer Benjamin Schreiber Jörg Grenzer Pablo F. Siles Raul D. Rodriguez Kai Huang Ye Yuan Alireza Heidarian René Hübner Tiangui You Wenjie Yu Kilian Lenz Jürgen Lindner Xi Wang Stefan Facsko 《Nano Research》2018,11(7):3519-3528
A nanofabrication method for the production of ultra-dense planar metallic nanowire arrays scalable to wafer-size is presented. The method is based on an efficient template deposition process to grow diverse metallic nanowire arrays with extreme regularity in only two steps. First, III–V semiconductor substrates are irradiated by a low-energy ion beam at an elevated temperature, forming a highly ordered nanogroove pattern by a “reverse epitaxy” process due to self-assembly of surface vacancies. Second, diverse metallic nanowire arrays (Au, Fe, Ni, Co, FeAl alloy) are fabricated on these III–V templates by deposition at a glancing incidence angle. This method allows for the fabrication of metallic nanowire arrays with periodicities down to 45 nm scaled up to wafer-size fabrication. As typical noble and magnetic metals, the Au and Fe nanowire arrays produced here exhibited large anisotropic optical and magnetic properties, respectively. The excitation of localized surface plasmon resonances (LSPRs) of the Au nanowire arrays resulted in a high electric field enhancement, which was used to detect phthalocyanine (CoPc) in surface-enhanced Raman scattering (SERS). Furthermore, the Fe nanowire arrays showed a very high in-plane magnetic anisotropy of approximately 412 mT, which may be the largest in-plane magnetic anisotropy field yet reported that is solely induced via shape anisotropy within the plane of a thin film. 相似文献
44.
Aitor Almeida Pablo Orduña Eduardo Castillejo Diego López-de-Ipiña Marcos Sacristán 《Personal and Ubiquitous Computing》2011,15(4):419-429
As the dependence on mobile devices increases, the need for supporting a wider range of users and devices becomes crucial.
Elders and people with disabilities adopt new technologies reluctantly, a tendency caused by the lack of adaptation of these
technologies to their needs. To address this challenge, this paper describes a framework, Imhotep, whose aim is to aid developers
in the accessible application creation process, making the creation of user-centered applications easier and faster. Our framework
allows to easily adapt the applications to the constraints imposed by the user capabilities (sensorial, cognitive, and physical
capabilities) and device capabilities by providing a repository that will manage the compilation and deployment of applications
that include a set of preprocessor directives in the source code. These directives are enhanced with concepts that are automatically
adjusted to the current trends of mobile devices by using a Fuzzy Knowledge-Eliciting Reasoner. Our final goal is to increase
the number of applications targeted to elders and people with disabilities providing tools that facilitate their development.
The paper also describes the evaluation of both the accuracy of the fuzzy terms generated for mobile devices and the usability
of the proposed platform. 相似文献
45.
Oscar M. Bonastre Marie-José Montpetit Pablo Cesar 《Multimedia Tools and Applications》2011,53(3):481-485
The move to IP Protocol Television (IPTV) has challenged the traditional television industry by opening the Internet to high
quality real time television content delivery. Thus it has provided an enabling set of key technologies to understand and
foster further innovations in the multimedia landscape and to create dynamics in the TV value chain. This editorial provides
a brief overview of this special issue. It begins with a short introduction to IPTV Technology and then summarizes the main
contributions of the selected papers for this special issue, highlighting their salient features and novel results. 相似文献
46.
Virginia Francisco Pablo Gervás Federico Peinado 《Knowledge and Information Systems》2010,25(3):421-443
With the advent of affective computing, the task of adequately identifying, representing and processing the emotional connotations
of text has acquired importance. Two problems facing this task are addressed in this paper: the composition of sentence emotion
from word emotion, and a representation of emotion that allows easy conversion between existing computational representations.
The emotion of a sentence of text should be derived by composition of the emotions of the words in the sentence, but no method
has been proposed so far to model this compositionality. Of the various existing approaches for representing emotions, some
are better suited for some problems and some for others, but there is no easy way of converting from one to another. This
paper presents a system that addresses these two problems by reasoning with two ontologies implemented with Semantic Web technologies:
one designed to represent word dependency relations within a sentence, and one designed to represent emotions. The ontology
of word dependency relies on roles to represent the way emotional contributions project over word dependencies. By applying
automated classification of mark-up results in terms of the emotion ontology the system can interpret unrestricted input in
terms of a restricted set of concepts for which particular rules are provided. The rules applied at the end of the process
provide configuration parameters for a system for emotional voice synthesis. 相似文献
47.
Pablo Quintía Roberto Iglesias Miguel A. Rodríguez Carlos V. Regueiro 《Robotics and Autonomous Systems》2010,58(12):1306-1315
One of the main problems of robots is the lack of adaptability and the need for adjustment every time the robot changes its working place. To solve this, we propose a learning approach for mobile robots using a reinforcement-based strategy and a dynamic sensor-state mapping. This strategy, practically parameterless, minimises the adjustments needed when the robot operates in a different environment or performs a different task.Our system will simultaneously learn the state space and the action to execute on each state. The learning algorithm will attempt to maximise the time before a robot failure in order to obtain a control policy suited to the desired behaviour, thus providing a more interpretable learning process. The state representation will be created dynamically, starting with an empty state space and adding new states as the robot finds new situations that has not seen before. A dynamic creation of the state representation will avoid the classic, error-prone and cyclic process of designing and testing an ad hoc representation. We performed an exhaustive study of our approach, comparing it with other classic strategies. Unexpectedly, learning both perception and action does not increase the learning time. 相似文献
48.
Jonathan Pietarila Graham Darryl D. Holm Pablo Mininni Annick Pouquet 《Journal of scientific computing》2011,49(1):21-34
The subfilter-scale (SFS) physics of regularization models are investigated to understand the regularizations’ performance
as SFS models. Suppression of spectrally local SFS interactions and conservation of small-scale circulation in the Lagrangian-averaged
Navier-Stokes α-model (LANS-α) is found to lead to the formation of rigid bodies. These contaminate the superfilter-scale energy spectrum with a scaling
that approaches k
+1 as the SFS spectra is resolved. The Clark-α and Leray-α models, truncations of LANS-α, do not conserve small-scale circulation and do not develop rigid bodies. LANS-α, however, is closest to Navier-Stokes in intermittency properties. All three models are found to be stable at high Reynolds
number. Differences between L
2 and H
1 norm models are clarified. For magnetohydrodynamics (MHD), the presence of the Lorentz force as a source (or sink) for circulation
and as a facilitator of both spectrally nonlocal large to small scale interactions as well as local SFS interactions prevents
the formation of rigid bodies in Lagrangian-averaged MHD (LAMHD-α). LAMHD-α performs well as a predictor of superfilter-scale energy spectra and of intermittent current sheets at high Reynolds numbers.
It may prove generally applicable as a MHD-LES. 相似文献
49.
Pablo Irarrazaval Carlos Lizama Vicente Parot Carlos Sing-Long Cristian Tejos 《Computers & Mathematics with Applications》2011,62(3):1576-1590
The fractional Fourier transform (FrFT) is revisited in the framework of strongly continuous periodic semigroups to restate known results and to explore new properties of the FrFT. We then show how the FrFT can be used to reconstruct Magnetic Resonance (MR) images acquired under the presence of quadratic field inhomogeneity. Particularly, we prove that the order of the FrFT is a measure of the distortion in the reconstructed signal. Moreover, we give a dynamic interpretation to the order as time evolution of a function. We also introduce the notion of ρ-α space as an extension of the Fourier or k-space in MR, and we use it to study the distortions introduced in two common MR acquisition strategies. We formulate the reconstruction problem in the context of the FrFT and show how the semigroup theory allows us to find new reconstruction formulas for discrete sampled signals. Finally, the results are supplemented with numerical examples that show how it performs in a standard 1D MR signal reconstruction. 相似文献
50.
Pablo Cascón Andrés Ortiz Julio Ortega Antonio F. Díaz Ignacio Rojas 《The Journal of supercomputing》2011,58(3):302-313
Hosts with several, possibly heterogeneous and/or multicore, processors provide new challenges and opportunities to accelerate
applications with high communications bandwidth requirements. Many opportunities to scale these network applications with the increase in the link bandwidths are related to the exploitation of the available parallelism provided by the presence
of several processing cores in the servers, not only for computing the workload of the user application but also for decreasing
the overhead associated to the network interface and the system software. 相似文献