11,532 research outputs found
Segmental Spatiotemporal CNNs for Fine-grained Action Segmentation
Joint segmentation and classification of fine-grained actions is important
for applications of human-robot interaction, video surveillance, and human
skill evaluation. However, despite substantial recent progress in large-scale
action classification, the performance of state-of-the-art fine-grained action
recognition approaches remains low. We propose a model for action segmentation
which combines low-level spatiotemporal features with a high-level segmental
classifier. Our spatiotemporal CNN is comprised of a spatial component that
uses convolutional filters to capture information about objects and their
relationships, and a temporal component that uses large 1D convolutional
filters to capture information about how object relationships change across
time. These features are used in tandem with a semi-Markov model that models
transitions from one action to another. We introduce an efficient constrained
segmental inference algorithm for this model that is orders of magnitude faster
than the current approach. We highlight the effectiveness of our Segmental
Spatiotemporal CNN on cooking and surgical action datasets for which we observe
substantially improved performance relative to recent baseline methods.Comment: Updated from the ECCV 2016 version. We fixed an important
mathematical error and made the section on segmental inference cleare
Effect of user tastes on personalized recommendation
In this paper, based on a weighted projection of the user-object bipartite
network, we study the effects of user tastes on the mass-diffusion-based
personalized recommendation algorithm, where a user's tastes or interests are
defined by the average degree of the objects he has collected. We argue that
the initial recommendation power located on the objects should be determined by
both of their degree and the users' tastes. By introducing a tunable parameter,
the user taste effects on the configuration of initial recommendation power
distribution are investigated. The numerical results indicate that the
presented algorithm could improve the accuracy, measured by the average ranking
score, more importantly, we find that when the data is sparse, the algorithm
should give more recommendation power to the objects whose degrees are close to
the users' tastes, while when the data becomes dense, it should assign more
power on the objects whose degrees are significantly different from user's
tastes.Comment: 8 pages, 4 figure
Lack of correlation between expression of Epstein-Barr virus (EBV) latent membrane protein and bcl-2 oncoprotein in vivo
Aims - To evaluate whether there is any correlation between the expression of Epstein-Barr virus (EBV) latent membrane protein (LMP) and oncoprotein bcl-2 in the lymph node biopsy specimens of a Chinese patient with EBV-related reactive lymphoproliferation who later developed T cell lymphoma after a short period of time. Methods - Immunohistochemistry, with a standard alkaline phosphatase anti-alkaline phosphatase (APAAP) method and New Fuchsin as a chromogen, was used for single staining of bcl-2 or LMP. Double immunostaining combining APAAP and indirect immunofluorescence was performed for dual labelling of LMP and bcl-2. Results - bcl-2 was expressed in 10-30% of cells in the first lymph node biopsy specimen (EBV-associated lymphoproliferative disorder) and 30-50% of cells in the second lymph node biopsy specimen (T cell lymphoma). LMP was expressed in the first biopsy specimen but not in the second. Double immunostaining results showed that around 78% of LMP positive cells were bcl-2 negative and 94% bcl-2 positive cells were LMP negative. Among the very small fraction of LMP and bcl-2 double positive cells, the intensity of bcl-2 staining was heterogeneous and was not always stronger than that observed in LMP negative bcl-2 positive cells. Conclusions - The expression of bcl-2 protein is independent of LMP protein status in vivo. Several mechanisms may be involved in EBV associated lymphomagenesis, and bcl-2 induction may occur independently of LMP expression.published_or_final_versio
Uncoordinated cooperative forwarding in vehicular networks with random transmission range
© 2015 IEEE. This paper investigates cooperative forwarding in large highly dynamic vehicular networks. Unlike traditional coordinated cooperative forwarding schemes that require a large amount of coordination information to be exchanged before making the forwarding decision, this paper proposes an uncoordinated cooperative forwarding scheme where each node, a random transmission range, decides whether or not to forward a received packet independently based on a forwarding probability determined by its own location. Analytical results are derived on the successful end-to-end transmission probability and the expected number of forwarding nodes involved in the cooperative forwarding process. The multi-hop correlations and multi-path correlations, which constitute major challenges in the analysis, are carefully considered in our analysis. Simulations are conducted to establish the performance of the proposed scheme assuming different forwarding probability functions. In addition to developing an uncoordinated cooperative forwarding scheme, which is particularly suited for the highly dynamic vehicular networks, this paper also makes important theoretical contributions on analyzing the connectivity of networks with nodes of variable and random transmission ranges
Error microphone location study for an eight-channel ANC system in free space
© 25th International Congress on Sound and Vibration 2018, ICSV 2018: Hiroshima Calling. All rights reserved. The location of error microphones is one key factor that determines the performance of a multichannel active noise control (ANC) system in terms of global sound power reduction when the number and the location of secondary sources are fixed. In a single channel ANC system, the optimal error microphone location is on a line that is nearly perpendicular to the secondary and primary source axis and closer to the secondary source. This paper investigates the optimal location of the error microphones in an 8-channel ANC system in free space. It is demonstrated that good noise reduction performance can be achieved by placing the error microphones between the primary source and secondary sources and closer to the secondary sources in the low frequency range. Experiments conducted on a gearbox for low frequency noise control show that the averaged sound level reduction at the observation locations 2 meters away is 5.2 dB when the error microphones are placed at 0.2 m inside the secondary source surface
Lattice-Boltzmann model for axisymmetric thermal flows
In this brief report, a thermal lattice-Boltzmann (LB) model is presented for
axisymmetric thermal flows in the incompressible limit. The model is based on
the double-distribution-function LB method, which has attracted much attention
since its emergence for its excellent numerical stability. Compared with the
existing axisymmetric thermal LB models, the present model is simpler and
retains the inherent features of the standard LB method. Numerical simulations
are carried out for the thermally developing laminar flows in circular ducts
and the natural convection in an annulus between two coaxial vertical
cylinders. The Nusselt number obtained from the simulations agrees well with
the analytical solutions and/or the results reported in previous studies.Comment: 11 pages, 4 figure
- …