228 resultados para AK43-4880


Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper, a novel cortex-inspired feed-forward hierarchical object recognition system based on complex wavelets is proposed and tested. Complex wavelets contain three key properties for object representation: shift invariance, which enables the extraction of stable local features; good directional selectivity, which simplifies the determination of image orientations; and limited redundancy, which allows for efficient signal analysis using the multi-resolution decomposition offered by complex wavelets. In this paper, we propose a complete cortex-inspired object recognition system based on complex wavelets. We find that the implementation of the HMAX model for object recognition in [1, 2] is rather over-complete and includes too much redundant information and processing. We have optimized the structure of the model to make it more efficient. Specifically, we have used the Caltech 5 standard dataset to compare with Serre's model in [2] (which employs Gabor filter bands). Results demonstrate that the complex wavelet model achieves a speed improvement of about 4 times over the Serre model and gives comparable recognition performance. © 2011 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Our group recently reproduced the water-assisted growth method, so-called "SuperGrowth", of millimeter-thick single-walled carbon nanotube (SWNT) forests by using C2H4/H2/H2O/Ar reactant gas and Fe/Al2O3, catalyst. In this current work, a parametric study was carried out on both reaction and catalyst conditions. Results revealed that a thin Fe catalyst layer (about 0.5 nm) yielded rapid growth of SWNTs only when supported on Al2O3, and that Al2O3 support enhanced the activity of Fe, Co, and Ni catalysts. The growth window for the rapid SWNT growth was narrow, however. Optimum amount of added H2O increased the SWNT growth rate but further addition of H2O degraded both the SWNT growth rate and quality. Addition of H2 was also essential for rapid SWNT growth, but again, further addition decreased both the SWNT growth rate and quality. Because Al2O3 catalyzes hydrocarbon reforming, Al2O3 support possibly enhances the SWNT growth rate by supplying the carbon source to the catalyst nanoparticles. The origin of the narrow window for rapid SWNT growth is also discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The probe tip is pivotal in determining the resolution and nature of features observed in the Scanning Tunnelling Microscope (STM). We have augmented a conventional Pt/Ir metallic tip with a hydrothermally grown ZnO nanowire (NW). Atomic resolution imaging of graphite is attained. Current-voltage (IV) characteristics demonstrate an asymmetry stemming from the unintentional n-type doping of the ZnO NW, whereas the expected Schottky barrier at the ZnO-Pt/Ir interface is shown to have negligible effect. Moreover the photoconductivity of the system is investigated, paving the way towards a photodetector capable of atomic resolution.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The last few years have seen considerable progress in pedestrian detection. Recent work has established a combination of oriented gradients and optic flow as effective features although the detection rates are still unsatisfactory for practical use. This paper introduces a new type of motion feature, the co-occurrence flow (CoF). The advance is to capture relative movements of different parts of the entire body, unlike existing motion features which extract internal motion in a local fashion. Through evaluations on the TUD-Brussels pedestrian dataset, we show that our motion feature based on co-occurrence flow contributes to boost the performance of existing methods. © 2011 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

本文研究稀有鲫的胚胎发育过程以及水温变化对其发育速度的影响,首次报道了鱼类卵壳内,包裹于胚胎外的似膜结构和伴随的胚胎蜕膜现象。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

宽带社区接入网是下一代网络研究的主要领域之一.RBISN(社区宽带综合业务网络系统)研究使用交换式以太网提供数字电视、IP电话和Internet接入服务.需要解决用户隔离、组播、服务质量的问题.本文介绍了这一系统中交换机采用的关键技术.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Macduff, J. H., Humphreys, M. O., Thomas, Howard (2002). Effects of a stay-green mutation on plant nitrogen relations in Lolium perenne during N starvation and after defoliation. Annals of Botany, 89 (1), 11-21. Sponsorship: BBSRC RAE2008

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper introduces the concept of adaptive temporal compressive sensing (CS) for video. We propose a CS algorithm to adapt the compression ratio based on the scene's temporal complexity, computed from the compressed data, without compromising the quality of the reconstructed video. The temporal adaptivity is manifested by manipulating the integration time of the camera, opening the possibility to realtime implementation. The proposed algorithm is a generalized temporal CS approach that can be incorporated with a diverse set of existing hardware systems. © 2013 IEEE.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The one-step dispersion of HiPco single-walled carbon nanotubes in aqueous media with the use of a synthetic lyso-phosphatidylcholine was studied. Solubilization occurs through wrapping of lipid molecules around the circumference of the tubes, yielding lipid monolayers on the graphitic sidewalls as evidenced by atomic force microscopy imaging and dynamic light scattering measurements. Raman spectroscopy showed that the dispersion and centrifugation process leads to an effective enrichment of the stable aqueous suspension in carbon nanostructures with smaller diameters.

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Based on the premise that the history of the representation in drama of the Ulster "Troubles" has been characterised by a move from direct to metaphorical engagement, this paper seeks to explore the signficance of Brian Friel's Translations as a "Troubles Drama" with reference to a production of the play I directed for the Hungarian Theater of Cluj in the Fall of 2001. Interpreting a play about language in a language other than the one in which it was originally written proved to have many implications for the rehearsal process and led me to experiment with the image theatre techniques of Augusto Boal. The nature of Cluj/Kolozsvar as a bi-lingual city added to the complexities of the process, as did my own status as an English-speaking director in a Hungarian-speaking environment. The extraordinary neautre of the wider geopolitical context at the time of the production proved to be the final ingredient in what became an exceptional empirical process of discovery. The discussion of the particular production is placed in the wider context of an exposition of a theory of "cultural gravity" as an alternative to "liminality" in helping to assess the cultural signficance of geopolitical boundaries.