9,816 research outputs found
Topological Influence-Aware Recommendation on Social Networks
Users in online networks exert different influence during the process of information propagation, and the heterogeneous influence may contribute to personalized recommendations. In this paper, we analyse the topology of social networks to investigate usersâ influence strength on their neighbours. We also exploit the user-item rating matrix to find the importance of usersâ ratings and determine their influence on entire social networks. Based on the local influence between users and global influence over the whole network, we propose a recommendation method with indirect interactions that makes adequate use of usersâ relationships on social networks and usersâ rating data. The two kinds of influence are incorporated into a matrix factorization framework. We also consider indirect interactions between users who do not have direct links with each other. Experimental results on two real-world datasets demonstrate that our proposed framework performs better than other state-of-the-art methods for all users and cold-start users. Compared with node degrees, betweenness, and clustering coefficients, coreness constitutes the best topological descriptor to identify usersâ local influence, and recommendations with the measure of coreness outperform other descriptors of user influence.</jats:p
The Microsoft 2017 Conversational Speech Recognition System
We describe the 2017 version of Microsoft's conversational speech recognition
system, in which we update our 2016 system with recent developments in
neural-network-based acoustic and language modeling to further advance the
state of the art on the Switchboard speech recognition task. The system adds a
CNN-BLSTM acoustic model to the set of model architectures we combined
previously, and includes character-based and dialog session aware LSTM language
models in rescoring. For system combination we adopt a two-stage approach,
whereby subsets of acoustic models are first combined at the senone/frame
level, followed by a word-level voting via confusion networks. We also added a
confusion network rescoring step after system combination. The resulting system
yields a 5.1\% word error rate on the 2000 Switchboard evaluation set
The Microsoft 2016 Conversational Speech Recognition System
We describe Microsoft's conversational speech recognition system, in which we
combine recent developments in neural-network-based acoustic and language
modeling to advance the state of the art on the Switchboard recognition task.
Inspired by machine learning ensemble techniques, the system uses a range of
convolutional and recurrent neural networks. I-vector modeling and lattice-free
MMI training provide significant gains for all acoustic model architectures.
Language model rescoring with multiple forward and backward running RNNLMs, and
word posterior-based system combination provide a 20% boost. The best single
system uses a ResNet architecture acoustic model with RNNLM rescoring, and
achieves a word error rate of 6.9% on the NIST 2000 Switchboard task. The
combined system has an error rate of 6.2%, representing an improvement over
previously reported results on this benchmark task
The quark orbital angular momentum from Wigner distributions and light-cone wave functions
We investigate the quark orbital angular momentum of the nucleon in the
absence of gauge-field degrees of freedom, by using the concept of the Wigner
distribution and the light-cone wave functions of the Fock state expansion of
the nucleon. The quark orbital angular momentum is obtained from the
phase-space average of the orbital angular momentum operator weighted with the
Wigner distribution of unpolarized quarks in a longitudinally polarized
nucleon. We also derive the light-cone wave function representation of the
orbital angular momentum. In particular, we perform an expansion in the nucleon
Fock state space and decompose the orbital angular momentum into the -parton
state contributions. Explicit expressions are presented in terms of the
light-cone wave functions of the three-quark Fock state. Numerical results for
the up and down quark orbital angular momenta of the proton are shown in the
light-cone constituent quark model and the light-cone chiral quark-soliton
model.Comment: 26 pages, 4 figure
Lattice Boltzmann Approach to High-Speed Compressible Flows
We present an improved lattice Boltzmann model for high-speed compressible
flows. The model is composed of a discrete-velocity model by Kataoka and
Tsutahara [Phys. Rev. E \textbf{69}, 056702 (2004)] and an appropriate
finite-difference scheme combined with an additional dissipation term. With the
dissipation term parameters in the model can be flexibly chosen so that the von
Neumann stability condition is satisfied. The influence of the various model
parameters on the numerical stability is analyzed and some reference values of
parameter are suggested. The new scheme works for both subsonic and supersonic
flows with a Mach number up to 30 (or higher), which is validated by well-known
benchmark tests. Simulations on Riemann problems with very high ratios
() of pressure and density also show good accuracy and stability.
Successful recovering of regular and double Mach shock reflections shows the
potential application of the lattice Boltzmann model to fluid systems where
non-equilibrium processes are intrinsic. The new scheme for stability can be
easily extended to other lattice Boltzmann models.Comment: Figs.11 and 12 in JPEG format. Int. J. Mod. Phys. C (to appear
Effects of tai chi on postural control during dual-task stair negotiation in knee osteoarthritis : a randomised controlled trial protocol
Stair ascent and descent require complex integration between sensory and motor systems; individuals with knee osteoarthritis (KOA) have an elevated risk for falls and fall injuries, which may be in part due to poor dynamic postural control during locomotion. Tai chi exercise has been shown to reduce fall risks in the ageing population and is recommended as one of the non-pharmocological therapies for people with KOA. However, neuromuscular mechanisms underlying the benefits of tai chi for persons with KOA are not clearly understood. Postural control deficits in performing a primary motor task may be more pronounced when required to simultaneously attend to a cognitive task. This single-blind, parallel design randomised controlled trial (RCT) aims to evaluate the effects of a 12-week tai chi programme versus balance and postural control training on neuromechanical characteristics during dual-task stair negotiation. Sixty-six participants with KOA will be randomised into either tai chi or balance and postural control training, each at 60âmin per session, twice weekly for 12 weeks. Assessed at baseline and 12 weeks (ie, postintervention), the primary outcomes are attention cost and dynamic postural stability during dual-task stair negotiation. Secondary outcomes include balance and proprioception, foot clearances, self-reported symptoms and function. A telephone follow-up to assess symptoms and function will be conducted at 20 weeks. The findings will help determine whether tai chi is beneficial on dynamic stability and in reducing fall risks in older adults with KOA patients in community. Ethics approval was obtained from the Ethics Committee of the Affiliated Rehabilitation Hospital of Fujian University of Traditional Chinese Medicine (#2018KY-006-1). Study findings will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals. ChiCTR1800018028. [Abstract copyright: Š Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
In-situ marginalisation : social impact of Chinese mega-projects
This study offers a detailed analysis of an underâresearched social problem of inâsitu marginalisation and its causes by drawing on the concept of state entrepreneurialism. Our empirical data stem from the Lingang mega project in Shanghai and one of its neighbourhoods named Neighbourhood No.57 where we find that the residents have not been relocated but are instead suffering from declining public services and environmental quality from surrounding industrial developments. The root cause of this problem is the municipal governmentâs prioritisation of its strategic objectives of economic development over the livelihood of local residents. The strategic vision of the municipality has led to mass relocation in its early phases of development but in its later stages leaves many residents waiting for relocation whilst being gradually surrounded by industrial developments. Despite continued residential complaints and petitions, inâsitu marginalisation is not resolved due to the institutional arrangement of Lingang, which has centralised planning and financing powers to newly created projectâoriented state organisation. Social responsibilities have been relegated to lowerâtiered governments in Lingang which have neither planning power nor the financial resources to resolve the problems of residents. By examining the case of Lingang, this paper provides a different analytical framework for explaining the social problems emerging from Chinaâs mega urban developments
Enhancing Transient Stability of PLL-Synchronized Converters by Introducing Voltage Normalization Control
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