Influence of Blurred Ways on Pattern Recognition of a Scale-Free Hopfield Neural Network

We investigate the influence of blurred ways on pattern recognition of a Barabasi-Albert scale-free Hopfield neural network （SFHN） with a small amount of errors. Pattern recognition is an important function of information processing in brain. Due to heterogeneous degree of scale-free network, different blurred ways have different influences on pattern recognition with same errors. Simulation shows that among partial recognition, the larger loading ratio （the number of patterns to average degree P/ （k） ） is, the smaller the overlap of SFHN is. The influence of directed （large） way is largest and the directed （small） way is smallest while random way is intermediate between them. Under the ratio of the numbers of stored patterns to the size of the network PIN is less than O. 1 conditions, there are three families curves of the overlap corresponding to directed （small）, random and directed （large） blurred ways of patterns and these curves are not associated with the size of network and the number of patterns. This phenomenon only occurs in the SFHN. These conclusions are benefit for understanding the relation between neural network structure and brain function.     

Pattern recognition and data mining software based on artificial neural networks applied to proton transfer in aqueous environments

In computational physics proton transfer phenomena could be viewed as pattern classification problems based on a set of input features allowing classification of the proton motion into two categories： transfer ＇occurred＇ and transfer ＇not occurred＇. The goal of this paper is to evaluate the use of artificial neural networks in the classification of proton transfer events, based on the feed-forward back propagation neural network, used as a classifier to distinguish between the two transfer cases. In this paper, we use a new developed data mining and pattern recognition tool for automating, controlling, and drawing charts of the output data of an Empirical Valence Bond existing code. The study analyzes the need for pattern recognition in aqueous proton transfer processes and how the learning approach in error back propagation （multilayer perceptron algorithms） could be satisfactorily employed in the present case. We present a tool for pattern recognition and validate the code including a real physical case study. The results of applying the artificial neural networks methodology to crowd patterns based upon selected physical properties （e.g., temperature, density） show the abilities of the network to learn proton transfer patterns corresponding to properties of the aqueous environments, which is in turn proved to be fully compatible with previous proton transfer studies.     

Novel homodyne frequency-shifting interference pattern locking system

We present a novel homodyne frequency-shifting interference pattern locking system to enhance the exposure contrast of interference lithography and scanning beam interference lithography(SBIL). The novel interference pattern locking system employs a special homodyne redundant phase measurement interferometer(HRPMI) as the sensor and an acousto-opto modulator(AOM) as the actuator. The HRPMI offers the highly accurate value as well as the direction recognition of the interference pattern drift from four quadrature interference signals. The AOM provides a very fine resolution with a high speed for phase modulation. A compact and concise system with a short optical path can be achieved with this new scheme and a small power laser head in tens of microwatts is sufficient for exposure and phase locking, which results in a relatively low-cost system compared with the heterodyne system. More importantly, the accuracy of the system is at a high level as well as having robustness to environmental fluctuation. The experiment results show that the short-time(4 s) accuracy of the system is 0.0481 rad e3σT at present. Moreover, the phase of the interference pattern can also be set arbitrarily to any value with a high accuracy in a relatively large range, which indicates that the system can also be extended to the SBIL application.     

Quantum spectra and classical periodic orbit in the cubic billiard

Quantum billiards have attracted much interest in many fields. People have made a lot of researches on the two-dimensional (2D) billiard systems. Contrary to the 2D billiard, due to the complication of its classical periodic orbits, no one has studied the correspondence between the quantum spectra and the classical orbits of the three-dimensional (3D) billiards. Taking the cubic billiard as an example, using the periodic orbit theory, we find the periodic orbit of the cubic billiard and study the correspondence between the quantum spectra and the length of the classical orbits in 3D system. The Fourier transformed spectrum of this system has allowed direct comparison between peaks in such plot and the length of the periodic orbits, which verifies the correctness of the periodic orbit theory. This is another example showing that semiclassical method provides a bridge between quantum and classical mechanics.     

Two-Dimensional Node-Line Semimetals in a Honeycomb-Kagome Lattice

Recently, the concept of topological insulators has been generalized to topological semimetals, including threedimensional(3 D) Weyl semimetals, 3 D Dirac semimetals, and 3 D node-line semimetals(NLSs). In particular,several compounds(e.g.,certain 3 D graphene networks, Cu_3 PdN,Ca_3 P_2) were discovered to be 3 D NLSs, in which the conduction and valence bands cross at closed lines in the Brillouin zone.Except for the two-dimensional(2 D)Dirac semimetal(e.g.,graphene), 2 D topological semimetals are much less investigated. Here we propose a new concept of a 2 D NLS and suggest that this state could be realized in a new mixed lattice(nawed as HK lattice)composed by Kagome and honeycomb lattices. It is found that A_3 B_2(A is a group-ⅡB cation and B is a group-VA anion) compounds(such as Hg_3 As_2) with the HK lattice are 2 D NLSs due to the band inversion between the cation Hg-s orbital and the anion As-p_z orbital with rcespect to the mirror symmetry, Since the band inversion occurs between two bands with the same parity, this peculiar 2 D NLS could be used as transparent conductors.In the presence of buckling or spin-orbit coupling, the 2 D NLS state may turn into a 2 D Dirac semimetal state or a 2 D topological crystalline insulating state. Since the band gap opening due to buckling or spin-orbit coupling is small, Hg_3 As_2 with the HK lattice can still be regarded as a 2 D NLS at room temperature.Our work suggests a new route to design topological materials without involving states with opposite parities.     

Spectrum warping based on sub-glottal resonances in speaker-independent speech recognition

To reduce degradation in speech recognition due to varied characteristics of different speakers,a method of perceptual frequency warping based on subglottal resonances for speaker normalization is proposed.The warping factor is extracted from the second subglottal resonance using acoustic coupling between subglottis and vocal tract.The second subglottal resonance is independent of the speech content,which reflects the speaker characteristics more than the third formant.The perceptual minimum variation distortionless response(PMVDR) coefficient is normalized,which is more robust and has better anti-noise capability than MFCC. The normalized coefficients are used in the speech-mode training and speech recognition.Experiments show that the word error rate,as compared with MFCC and the spectrum warping by the third formant,decreases by 4%and 3%respectively in clean speech recognition,and by 9%and 5%respectively in a noisy environment.The results indicate that the proposed method can improve the word recognition accuracy in a speaker-independent recognition system.     

Numerical study of heat-transfer in two-and quasi-two-dimensional Rayleigh–Bénard convection

A detailed comparative numerical study between the two-dimensional(2 D) and quasi-two-dimensional(quasi-2 D)turbulent Rayleigh–B′enard(RB) convection on flow state, heat transfer, and thermal dissipation rate(TDR) is made. The Rayleigh number(Ra) in our simulations ranges up to 5×10~(10) and Prandtl number(Pr) is fixed to be 0.7. Our simulations are conducted on the Tianhe-2 supercomputer. We use an in-house code with high parallelization efficiency, based on the extended PDM–DNS scheme. The comparison shows that after a certain Ra, plumes with round shape, which is called the "temperature islands", develop and gradually dominate the flow field in the 2 D case. On the other hand, in quasi-2 D cases, plumes remain mushroom-like. This difference in morphology becomes more significant as Ra increases, as with the motion of plumes near the top and bottom plates. The exponents of the power-law relation between the Nusselt number(Nu) and Ra are 0.3 for both two cases, and the fitting pre-factors are 0.099 and 0.133 for 2 D and quasi-2 D respectively,indicating a clear difference in magnitude of the heat transfer rate between two cases. To understand this difference in the magnitude of Nu, we compare the vertical profile of the horizontally averaged TDR for both two cases. It is found that the profiles of both cases are nearly the same in the bulk, but they vary near boundaries. Comparing the bifurcation height zb with the thermal boundary layer thickness dq, it shows that zb δ_θ(3 D) δ_θ(2 D) and all three heights obey a universal power-law relation z ~Ra~(-0.30). In order to quantify the difference further, we separate the domain by zb, i.e., define the area between two zb(near top and bottom plates respectively) as the "mid region" and the rest as the "side region", and integrate TDR in corresponding regions. By comparing the integral it is found that most of the difference in TDR between two cases, which is connected to the heat transfer rate, occurs within the thermal boundary layers. We also compare the ratio of contributions to total heat transfer in BL–bulk separation and side–mid separation.     

Four-dimensional parameter estimation of plane waves using swarming intelligence

This paper proposes an efficient approach for four-dimensional(4D) parameter estimation of plane waves impinging on a 2-L shape array. The 4D parameters include amplitude, frequency and the two-dimensional(2D) direction of arrival,namely, azimuth and elevation angles. The proposed approach is based on memetic computation, in which the global optimizer, particle swarm optimization is hybridized with a rapid local search technique, pattern search. For this purpose,a new multi-objective fitness function is used. This fitness function is the combination of mean square error and the correlation between the normalized desired and estimated vectors. The proposed hybrid scheme is not only compared with individual performances of particle swarm optimization and pattern search, but also with the performance of the hybrid genetic algorithm and that of the traditional approach. A large number of Monte–Carlo simulations are carried out to validate the performance of the proposed scheme. It gives promising results in terms of estimation accuracy, convergence rate, proximity effect and robustness against noise.     

Application of the new pattern recognition system in the new e-nose to detecting Chinese spirits

We present a new pattern recognition system based on moving average and linear discriminant analysis （LDA）, which can be used to process the original signal of the new polymer quartz piezoelectric crystal air-sensitive sensor system we designed, called the new e-nose. Using the new e-nose, we obtain the template datum of Chinese spirits via a new pattern recognition system. To verify the effectiveness of the new pattern recognition system, we select three kinds of Chinese spirits to test, our results confirm that the new pattern recognition system can perfectly identify and distinguish between the Chinese spirits.     

Tunneling of Bose-Einstein condensate and interference effect in a harmonic trap with a Gaussian energy barrier

The tunneling effect of Bose-Einstein condensate (BEC) in a harmonic trap with a Gaussian energy barrier is studied in this paper. The initial condensate evolves into two separate moving condensates after the tunneling time under certain conditions. The interference pattern between the two moving condensates is given as a comparison and as a further demonstration of the existence of the global phase.     

Theoretical analysis and experimental results of interference striation pattern of underwater target radiated noise in shallow water waveguide

Waveguide invariant in shallow water is an attractive topic in recent three decades. The interference phenomena of direct wave of radiated noise of underwater target and reflection wave from sea surface and sea bottom can be considered as a typical case of shallow water waveguide.The interference striation pattern of direct wave and its reflection is the effective and comprehensive figure for better understanding the essence of shallow water waveguide invariant.The theoretical analysis of interference phenomena generated by direct wave of radiated noise of underwater target and its reflection wave from sea surface and sea bottom is presented in this paper.It is shown that the interference wave resulted by sea surface reflection will produce striation pattern centered at high frequency band.But the interference of nulling frequency resulted by sea bottom reflection may be at low frequency or high frequency, it strongly depends on the acoustic behavior of sea bottom.The relationship between main parameters of interference striation pattern and target,receiver,and environment is derived.It is shown that the interference striation have the shape of hyperbolic curve.The equation set of the hyperbolic curve and its asymptotic line is presented.The at sea experiment carried out in South China sea shows some interesting results.A part of data processing results are illustrated in this paper.The results expressed in this paper show that the interference striation pattern can be used,in some conditions,as a potential means for target recognition.     

Neural Approach for Calculating Permeability of Porous Medium

Permeability is one of the most important properties of porous media. It is considerably difficult to calculate reservoir permeability precisely by using single well-logging response and simple formula because reservoir is of serious heterogeneity, and well-logging response curves are badly affected by many complicated factors underground. We propose a neural network method to calculate permeability of porous media. By improving the algorithm of the back-propagation neural network, convergence speed is enhanced and better results can be achieved. A four-layer back-propagation network is constructed to effectively calculate permeability from well log data. Spontaneous potential, resistivity of deep lateral log, resistivity of micro-gradient log, resistivity of micro-normal log, Interval transit time of acoustic log and resistivity of shallow lateral log are selected as the inputs, and permeability is selected as the output. There are 35 and 40 units used in the two hidden layers, respectively. During the training course, the correlation coefficient between the calculated permeability and the standard pattern is as high as 0.9937, the average absolute error between them is 0.046μm^2 and the average relative error is only 1.93%. for practical applications, the average relative error between the calculated permeability and actual permeability is also as low as about 10.0%.     

Large and anisotropic linear magnetoresistance in bulk stoichiometric Cd3As2 crystals

Cd3As2 was recently identified as a novel three-dimensional(3D)topological semimetal hosting the long-pursuing 3D Dirac Fermion.Crystals of Cd3As2 grown preferentially along the[100]and[112]directions were obtained through the modified chemical vapor transfer growth method,thus allowing the examination of transport anisotropy.The resistivity and magnetoresistance(MR)are basically linear with respect to magnetic field(H)in the measured temperature range of 2–300 K irrespective of the directions.The linear resistivity and MR are significantly anisotropic not only along[100]and[112]directions but also with respect to tilt angle between the growth directions and H,thus providing transport signatures of the 3D Dirac Fermion as well as the possible linear and anisotropic change of Weyl Fermi surface in H.Very large MR along the[100]direction is observed,even approaching 3100%at 2 K and 14 k Oe(1 Oe=79.5775 A m-1).The results would be helpful in renewing interest in studying emergent phenomena arising from bulk 3D Dirac Fermion as well as in paving the way for Cd3As2 to be used in magnetoelectronic sensors.     

DOAS tomography for the retrieval of trace gas profiles from satellite-based UV-Vis limb spectra

A new method is employed for retrieving the profiles of trace gas number densities from satellite-based ultraviolet-visible (UV-Vis) spectra of scattered sunlight, which are recorded from the limb atmosphere over a range of tangent heights. The slant column abundances of trace gas along the lines of sight (LOSs) are obtained by differential optical absorption spectroscopy (DOAS), and the tomographic technique is applied to such column abundances to retrieve two-dimensional (2D) concentration profiles. For validation of the tomographic technique, the slant column abundances are simulated by a tested 2D NO2 profile set with latitudes from 90°S to 90°N between altitudes of 0 and 100 km, and the retrieval of number density profiles on 1-km grids is performed. The results suggest that between ±80°, the retrieved structure is almost the same as the test data. According to the comparison of the selected cross sections of the vertical profiles between retrieved and true concentrations, the NO2 number densities have been retrieved with an accuracy of 15% or better and 5% for altitudes between 25 and 40 km. The validation of the retrieved data shows good agreement between the retrieved and true profiles.     

Function Projective Synchronization of Discrete-Time Chaotic and Hyperchaotic Systems Using Backstepping Method

In this paper, a function projective synchronization scheme is developed to investigate the function projective synchronization between the discrete-time driven chaotic system and the discrete-time response chaotic system. With the aid of symbolic-numeric computation, we use the scheme to study the function projective synchronization between 2D Lorenz discrete-time system and Hdnon discrete-time system, as well as that between 3D discrete-time hyperchaotic system and Henon-like map via three scalar controllers, respectively. Moreover numerical simulations are used to verify the effectiveness of the proposed scheme.     

Reliable iris localization using integral projection function and 2D-shape properties

Iris recognition technology recognizes a human based on his/her iris pattern.However,the accuracy of the iris recognition technology depends on accurate iris localization.Localizing a pupil region in the presence of other low-intensity regions,such as hairs,eyebrows,and eyelashes,is a challenging task.This study proposes an iris localization technique that includes a localizing pupillary boundary in a sub-image by using an integral projection function and two-dimensional shape properties(e.g.,area,geometry,and circularity).The limbic boundary is localized using gradients and an error distance transform,and the boundary is regularized with active contours.Experimental results obtained from public databases show the superiority of the proposed technique over contemporary methods.     

Features of underwater echo extraction based on the stationary wavelet transform and singular value decomposition

A feature extraction method of underwater echo is proposed, which uses the redundancy property of SWT (the Stationary Wavelet Transform) and the steady property of SVD (Singular Value Decomposition). Since using singular values of SWT coefficients matrix as feature vectors, with the K-L transform to multi-subspace signal obtained from SWT, it is a feature compression method essentially. In contrast to the method of sub-bands energy feature based on discrete orthogonal wavelet transform (DWT), better results of lake trial data are acquired with this method: (1) Under the same sample and distance within-class, distance between-class is larger than former; (2) Correct recognition rates are also higher than former, whether the training and testing samples are chosen from the same lake trail or not; (3) Sample sets varying, the variation range of correct recognition rates is far less than the former. Thus this method can obtain more robust, effective features and better correct recognition results.     

Grain Crush and Its Evolution in Granular Material： a Two-Dimensional Distinct Element Model Approach

A crush criterion and a simplified post-crush process for spherical grains are introduced into the traditional distinct element model (DEM). The crush criterion is based on Herzian comtact, and it indicates a negative relation between critical force Fcr and radius R via Fcr ∝ R^-3/2. Effects of grain crush on deformation pattern and statistical features of crush evolution for samples under uniaxial strain load are intensively investigated. Influences of maximum crush times and particle size distribution (PSD) are also discussed. It is found that: (1) Grain crush will blur the localization of deformation. (2) Crush is prone to occur in larger grains, due to force concentration and lower critical force Fcr for larger grains. (3) Grain crush only temporarily reduces contact force, which results in the most rapid increase of the number of grains with maximum crush time.     

Acoustic analysis of the vowel system in Hotan dialect and its contribution to dialect recognition of Uyghur dialects

Based on the actual needs of speech application research such as speech recognition and voiceprint recognition,the acoustic characteristics and recognition of Hotan dialect were studied for the first time.Firstly,the Hetian dialect voice was selected for artificial multi-level annotation,and the formant,duration and intensity of the vowel were analyzed to describe statistically the main pattern of Hetian dialect and the pronunciation characteristics of male and female.Then using the analysis of ...