arXiv subjects

Qiang Fu

Publications and source records attributed to Qiang Fu.

At least 181 records · Page 10Linked to original sources

arXiv2017

Testing violation of the Leggett-Garg-type inequality in neutrino oscillations of the Daya Bay experiment

The Leggett-Garg inequality (LGI), derived under the assumption of realism, acts as the temporal Bell's inequality. It is studied in electromagnetic and strong interaction like photonics, superconducting qu-bits and nuclear spin. Until the weak interaction two-state oscillations of neutrinos affirmed the violation of Leggett-Garg-type inequalities (LGtI). We make an empirical test for the deviation of experimental results with the classical limits by analyzing the survival probability data of reactor neutrinos at a distinct range of baseline dividing energies, as an analog to a single neutrino detected at different time. A study of the updated data of Daya-Bay experiment unambiguously depicts an obvious cluster of data over the classical bound of LGtI and shows a $6.1σ$ significance of the violation of them.

hep-ph↗

arXiv2017

Coherent photoproductions of $J/Ψ$ and $Υ$ mesons in pp and PbPb ultraperipheral collisions from dynamical gluon distribution

We present calculations of coherent photoproduction of vector mesons ($J/Ψ$ and $Υ$) with leading-order parton distribution functions to check new kinds of corrections of the DGLAP equations and nuclear modifications. The input gluon distribution of the proton is the dynamical parton model from the DGLAP equations with GLR-MQ-ZRS (Gribov-Levin-Ryskin, Mueller-Qiu, Zhu-Ruan-Shen) modifications. From comparison between several other gluon distribution models, we find that the dynamical gluon distribution fits with the results of meson photoproduction experiments in the high energy region. The calculation of the differential cross sections using dynamical and other gluon distributions is compared with the experimental data from the HERA, ZEUS and LHCb Collaborations. Although there is little data for the rapidity distribution of vector meson photoproduction near zero rapidity, the dynamical gluon distribution works well with the data in the large rapidity region.

hep-ph↗

arXiv2017

Hyperspectral Light Field Stereo Matching

In this paper, we describe how scene depth can be extracted using a hyperspectral light field capture (H-LF) system. Our H-LF system consists of a 5 x 6 array of cameras, with each camera sampling a different narrow band in the visible spectrum. There are two parts to extracting scene depth. The first part is our novel cross-spectral pairwise matching technique, which involves a new spectral-invariant feature descriptor and its companion matching metric we call bidirectional weighted normalized cross correlation (BWNCC). The second part, namely, H-LF stereo matching, uses a combination of spectral-dependent correspondence and defocus cues that rely on BWNCC. These two new cost terms are integrated into a Markov Random Field (MRF) for disparity estimation. Experiments on synthetic and real H-LF data show that our approach can produce high-quality disparity maps. We also show that these results can be used to produce the complete plenoptic cube in addition to synthesizing all-focus and defocused color images under different sensor spectral responses.

cs.CV↗

arXiv2017

Code review and cooperative pair programming best practice

We need ways to improve the code quality. Programmers have different level of tenure and experience. Standard and programming languages change and we are forced to re-use legacy code with minimum revision. Programmers develop their habits and can be slow to incorporate new technologies to simplify the code or improve the performance. We rolled out our customized code review and pair programming process to address these issues. The paper discusses the about the improvement of mandatory code review and pair programming practiced in the commercial software development, and also proposes effective approaches to customize the code review and pair programming to avoid the pitfalls and keep the benefits.

cs.SE↗

arXiv2017

Global study of nuclear modifications on parton distribution functions

A global analysis of nuclear medium modifications of parton distributions is presented using deeply inelastic scattering data of various nuclear targets. Two obtained data sets are provided for quark and gluon nuclear modification factors, referred as nIMParton16. One is from the global fit only to the experimental data of isospin-scalar nuclei (Set A), and the other is from the fit to all the measured nuclear data (Set B). The scale-dependence is described by DGLAP equations with nonlinear corrections in this work. The Fermi motion and off-shell effect, nucleon swelling, and parton-parton recombination are taken into account together for modeling the complicated $x$-dependence of nuclear modification. The nuclear gluon shadowing in this paper is dynamically generated by the QCD evolution of parton splitting and recombination processes with zero gluon density at the input scale. Sophisticated nuclear dependence of nuclear medium effects is studied with only two free parameters. With the obtained free parameters from the global analysis, the nuclear modifications of parton distribution functions of unmeasured nuclei can be predicted in our model. Nuclear modification of deuteron is also predicted and shown with recent measurement at JLab.

hep-ph↗

arXiv2015

The comultiplication of modified quantum affine $\frak{sl}_n$

Let $\dot{\mathbf{U}}(\widehat{\frak{sl}}_n)$ be the modified quantum affine $\frak{sl}_n$ and let ${\bf U}(\widehat{\frak{sl}}_N)^+$ be the positive part of quantum affine $\frak{sl}_N$. Let $\dot{\mathbf{B}}(n)$ be the canonical basis of $\dot{\mathbf{U}}(\widehat{\frak{sl}}_n)$ and let $\mathbf{B}(N)^{\mathrm{ap}}$ be the canonical basis of ${\bf U}(\widehat{\frak{sl}}_N)^+$. It is proved in \cite{FS} that each structure constant for the multiplication with respect to $\dot{\mathbf{B}}(n)$ coincide with a certain structure constant for the multiplication with respect to $\mathbf{B}(N)^{\mathrm{ap}}$ for $n<N$. In this paper we use the theory of affine quantum Schur algebras to prove that the structure constants for the comultiplication with respect to $\dot{\mathbf{B}}(n)$ are determined by the structure constants for the comultiplication with respect to $\mathbf{B}(N)^{\mathrm{ap}}$ for $n<N$. In particular, the positivity property for the comultiplication of $\dot{\mathbf{U}}(\widehat{\frak{sl}}_n)$ follows from the positivity property for the comultiplication of ${\bf U}(\widehat{\frak{sl}}_N)^+$.

math.QA↗

arXiv2015

On the hyperalgebra of the loop algebra ${\widehat{\frak{gl}}_n}$

Let $\widetilde{\mathcal U}_{\mathbb Z}({\widehat{\frak{gl}}_n})$ be the Garland integral form of ${\mathcal U}(\widehat{\frak{gl}}_n)$ introduced by Garland \cite{Ga}, where ${\mathcal U}(\widehat{\frak{gl}}_n)$ is the universal enveloping algebra of ${\widehat{\frak{gl}}_n}$. Using Ringel--Hall algebras, a certain integral form ${\mathcal U}_{\mathbb Z}(\widehat{\frak{gl}}_n)$ of ${\mathcal U}(\widehat{\frak{gl}}_n)$ was constructed in \cite{Fu13}. We prove that the Garland integral form $\widetilde{\mathcal U}_{\mathbb Z}({\widehat{\frak{gl}}_n})$ coincides with ${\mathcal U}_{\mathbb Z}(\widehat{\frak{gl}}_n)$. Let ${\mathpzc k}$ be a commutative ring with unity and let ${\mathcal U}_{\mathpzc k}(\widehat{\frak{gl}}_n)={\mathcal U}_{\mathbb Z}(\widehat{\frak{gl}}_n)\otimes{\mathpzc k}$. For $h\geq 1$, we use Ringel--Hall algebras to construct a certain subalgebra, denoted by ${\mathtt{u}}_{\!\vartriangle\!}(n)_h$, of ${\mathcal U}_{\mathpzc k}(\widehat{\frak{gl}}_n)$. The algebra ${\mathtt{u}}_{\!\vartriangle\!}(n)_h$ is the affine analogue of ${\mathtt{u}}({\frak{gl}}_n)_h$, where ${\mathtt{u}}({\frak{gl}}_n)_h$ is a certain subalgebra of the hyperalgebra associated with ${\frak{gl}}_n$ introduced by Humhpreys \cite{Hum}. The algebra ${\mathtt{u}}({\frak{gl}}_n)_h$ plays an important role in the modular representation theory of ${\frak{gl}}_n$. In this paper we give a realization of ${\mathtt{u}}_{\!\vartriangle\!}(n)_h$ using affine Schur algebras.

math.RT↗

arXiv2015

Noise Robust IOA/CAS Speech Separation and Recognition System For The Third 'CHIME' Challenge

This paper presents the contribution to the third 'CHiME' speech separation and recognition challenge including both front-end signal processing and back-end speech recognition. In the front-end, Multi-channel Wiener filter (MWF) is designed to achieve background noise reduction. Different from traditional MWF, optimized parameter for the tradeoff between noise reduction and target signal distortion is built according to the desired noise reduction level. In the back-end, several techniques are taken advantage to improve the noisy Automatic Speech Recognition (ASR) performance including Deep Neural Network (DNN), Convolutional Neural Network (CNN) and Long short-term memory (LSTM) using medium vocabulary, Lattice rescoring with a big vocabulary language model finite state transducer, and ROVER scheme. Experimental results show the proposed system combining front-end and back-end is effective to improve the ASR performance.

cs.SD↗

arXiv2015

IsoDAR Neutrino Experiment Simulation with Proton and Deuteron Beams

In this paper we consider high-intensity source of electron antineutrinos from the production and subsequent decay of 8Li. It opens a wide range of possible searches for beyond standard model physics via studies of the inverse beta decay interaction. In IsoDAR experiments Lithium 8 is a short lived beta emitter producing a high intensity anti-neutrinos, which is very suitable for making several important neutrino experiments. In this paper we used the GEANT4 program. to simulate neutrino production using proton and deuteron beams. We find that the neutrino production rate is about 3 times from deuteron beam than from proton beam in low energy region.

physics.ins-det↗

arXiv2015

Presenting affine Schur Algebras

The universal enveloping algebra ${\mathcal U}({\widehat{\frak{gl}}_n})$ of ${\widehat{\frak{gl}}_n}$ was realized in \cite[Ch. 6]{DDF} using affine Schur algebras. In particular some explicit multiplication formulas in affine Schur algebras were derived. We use these formulas to study the structure of affine Schur algebras. In particular, we give a presentation of the affine Schur algebra ${\mathcal S}_{\!\vartriangle}(n,r)_{\mathbb Q}$.

math.RT↗

arXiv2015

Bayesian De-quantization and Data Compression for Low-Energy Physiological Signal Telemonitoring

We address the issue of applying quantized compressed sensing (CS) on low-energy telemonitoring. So far, few works studied this problem in applications where signals were only approximately sparse. We propose a two-stage data compressor based on quantized CS, where signals are compressed by compressed sensing and then the compressed measurements are quantized with only 2 bits per measurement. This compressor can greatly reduce the transmission bit-budget. To recover signals from underdetermined, quantized measurements, we develop a Bayesian De-quantization algorithm. It can exploit both the model of quantization errors and the correlated structure of physiological signals to improve the quality of recovery. The proposed data compressor and the recovery algorithm are validated on a dataset recorded on 12 subjects during fast running. Experiment results showed that an averaged 2.596 beat per minute (BPM) estimation error was achieved by jointly using compressed sensing with 50% compression ratio and a 2-bit quantizer. The results imply that we can effectively transmit n bits instead of n samples, which is a substantial improvement for low-energy wireless telemonitoring.

cs.IT↗

arXiv2014

Positivity properties for canonical bases of modified quantum affine $\frak{sl}_n$

The positivity property for canonical bases asserts that the structure constants of the multiplication for the canonical basis are in ${\mathbb N}[v,v^{-1}]$. Let $\mathbf U$ be the quantum group over ${\mathbb Q}(v)$ associated with a symmetric Cartan datum. The positivity property for the positive part ${\mathbf U}^+$ of ${\mathbf U}$ was proved by Lusztig. He conjectured that the positivity property holds for the modified form $\dot{\mathbf U}$ of ${\mathbf U}$. In this paper, we prove that the structure constants for the canonical basis of $\dot{\mathbf U}(\widehat{\frak{sl}}_n)$ coincide with certain structure constants for the canonical basis of ${\mathbf U}(\widehat{\frak{sl}}_N)^+$ for $n<N$. In particular, the positivity property for $\dot{\mathbf U}(\widehat{\frak{sl}}_n)$ follows from the positivity property for ${\mathbf U}(\widehat{\frak{sl}}_N)^+$.

math.QA↗

arXiv2014

Calibration of Multiple Fish-Eye Cameras Using a Wand

Fish-eye cameras are becoming increasingly popular in computer vision, but their use for 3D measurement is limited partly due to the lack of an accurate, efficient and user-friendly calibration procedure. For such a purpose, we propose a method to calibrate the intrinsic and extrinsic parameters (including radial distortion parameters) of two/multiple fish-eye cameras simultaneously by using a wand under general motions. Thanks to the generic camera model used, the proposed calibration method is also suitable for two/multiple conventional cameras and mixed cameras (e.g. two conventional cameras and a fish-eye camera). Simulation and real experiments demonstrate the effectiveness of the proposed method. Moreover, we develop the camera calibration toolbox, which is available online.

cs.CV↗

arXiv2014

Stochastic parallel gradient descent optimization based on decoupling of the software and hardware

We classified the decoupled stochastic parallel gradient descent (SPGD) optimization model into two different types: software and hardware decoupling methods. A kind of software decoupling method is then proposed and a kind of hardware decoupling method is also proposed depending on the Shack-Hartmann (S-H) sensor. Using the normal sensor to accelerate the convergence of algorithm, the hardware decoupling method seems a capable realization of decoupled method. Based on the numerical simulation for correction of phase distortion in atmospheric turbulence, our methods are analyzed and compared with basic SPGD model and also other decoupling models, on the aspects of different spatial resolutions, mismatched control channels and noise. The results show that the phase distortion can be compensated after tens iterations with a strong capacity of noise tolerance in our model.

astro-ph.IM↗

arXiv2014

Experimental study on Modified Linear Quadratic Gaussian Control for Adaptive Optics

To achieve high resolution imaging the standard control algorithm used for classical adaptive optics (AO) is the simple but efficient proportional-integral (PI) controller. The goal is to minimize the root mean square (RMS) error of the residual wave front. However, with the PI controller one does not reach this minimum. A possibility to achieve is to use Linear Quadratic Gaussian Control (LQG). In practice, however this control algorithm still encounters one unexpected problem, leading to the divergence of control in AO. In this paper we propose a Modified LQG (MLQG) to solve this issue. The controller is analyzed explicitly. Test in the lab shows strong stability and high precision compared to the classical control.

astro-ph.IM↗

arXiv2014

The Integral quantum loop algebra of $\mathfrak{gl}_n$

We will construct the Lusztig form for the quantum loop algebra of $\mathfrak{gl}_n$ by proving the conjecture \cite[3.8.6]{DDF} and establish partially the Schur--Weyl duality at the integral level in this case. We will also investigate the integral form of the modified quantum affine $\mathfrak{gl}_n$ by introducing an affine stabilisation property and will lift the canonical bases from affine quantum Schur algebras to a canonical basis for this integral form. As an application of our theory, we will also discuss the integral form of the modified extended quantum affine $\mathfrak{sl}_n$ and construct its canonical basis to verify a conjecture of Lusztig in this case.

math.QA↗

arXiv2014

Energy Efficient Telemonitoring of Physiological Signals via Compressed Sensing: A Fast Algorithm and Power Consumption Evaluation

Wireless telemonitoring of physiological signals is an important topic in eHealth. In order to reduce on-chip energy consumption and extend sensor life, recorded signals are usually compressed before transmission. In this paper, we adopt compressed sensing (CS) as a low-power compression framework, and propose a fast block sparse Bayesian learning (BSBL) algorithm to reconstruct original signals. Experiments on real-world fetal ECG signals and epilepsy EEG signals showed that the proposed algorithm has good balance between speed and data reconstruction fidelity when compared to state-of-the-art CS algorithms. Further, we implemented the CS-based compression procedure and a low-power compression procedure based on a wavelet transform in Filed Programmable Gate Array (FPGA), showing that the CS-based compression can largely save energy and other on-chip computing resources.

cs.IT↗

arXiv2014

Technology Parks Potential for Small and Medium Enterprises

Being one of the most important factors of economic growth of the country, innovations became one of the key vectors in Russian economic policy. In this field technology parks are one of the most effective instruments which can provide growth of innovative activity in sectors, regions and economies. In this paper, we made a model that allows us to evaluate the effect of technology parks in the economy of the country and its potential for small and medium enterprises. The model is based on a system of coupled equations, whose parameters are estimated on the statistical data that reflect the activity of the economic entity, in an environment of this entity the technology parks are acting. Typically, there are regression equations linking a number of economic factors with some output indicators. We analyzed the property of increasing the share of surviving small and medium enterprises for Russian conditions as one of the effect of technology parks and built a working model for estimating the maximum (limit) values of the effect.

q-fin.GN↗