期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators
1
作者 XU Xiu-Wei REN Ting-Qi LIU Shu-Yan MA Qiu-Ming LIU Sheng-Dian 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第1期41-44,共4页
Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary m... Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators (BEQPO's)I we present the analytic expression of arbitrary matrix elements for BEQPO's. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO's. 展开更多
关键词 Boson exponential quadratic polynomial operator matrix element P representation partition function of Boson quadratic polynomial system
下载PDF
A sludge volume index (SVI) model based on the multivariate local quadratic polynomial regression method 被引量:4
2
作者 Honggui Han Xiaolong Wu +1 位作者 Luming Ge Junfei Qiao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期1071-1077,共7页
In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to ... In this study, a multivariate local quadratic polynomial regression(MLQPR) method is proposed to design a model for the sludge volume index(SVI). In MLQPR, a quadratic polynomial regression function is established to describe the relationship between SVI and the relative variables, and the important terms of the quadratic polynomial regression function are determined by the significant test of the corresponding coefficients. Moreover, a local estimation method is introduced to adjust the weights of the quadratic polynomial regression function to improve the model accuracy. Finally, the proposed method is applied to predict the SVI values in a real wastewater treatment process(WWTP). The experimental results demonstrate that the proposed MLQPR method has faster testing speed and more accurate results than some existing methods. 展开更多
关键词 Sludge volume index Multivariate quadratic polynomial regression Local estimation method Wastewater treatment process
下载PDF
Universal sums of three quadratic polynomials
3
作者 Zhi-Wei Sun 《Science China Mathematics》 SCIE CSCD 2020年第3期501-520,共20页
Let a,b,c,d,e and f be integers with a≥ c≥ e> 0,b>-a and b≡a(mod 2),d>-c and d≡c(mod 2),f>-e and f≡e(mod 2).Suppose that b≥d if a=c,and d≥f if c=e.When b(a-b),d(c-d) and f(e-f) are not all zero,we p... Let a,b,c,d,e and f be integers with a≥ c≥ e> 0,b>-a and b≡a(mod 2),d>-c and d≡c(mod 2),f>-e and f≡e(mod 2).Suppose that b≥d if a=c,and d≥f if c=e.When b(a-b),d(c-d) and f(e-f) are not all zero,we prove that if each n∈N={0,1,2,...} can be written as x(ax+b)/2+y(cy+d)/2+z(ez+f)/2 with x,y,z∈N then the tuple(a,b,c,d,e,f) must be on our list of 473 candidates,and show that 56 of them meet our purpose.When b∈[0,a),d∈[0,c) and f∈[0,e),we investigate the universal tuples(a,b,c,d,e,f) over Z for which any n∈N can be written as x(ax+b)/2+y(cy+d)/2+z(ez+f)/2 with x,y,z∈Z,and show that there are totally 12,082 such candidates some of which are proved to be universal tuples over Z.For example,we show that any n∈N can be written as x(x+1)/2+y(3y+1)/2+z(5z+1)/2 with x,y,z∈Z,and conjecture that each n∈N can be written as x(x+1)/2+y(3y+1)/2+z(5z+1)/2 with x,y,z∈N. 展开更多
关键词 representations of integers universal sums quadratic polynomials
原文传递
The classification of bi-quintic parametric polynomial minimal surfaces
4
作者 LI Cai-yun ZHU Chun-gang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2017年第1期14-26,共13页
Parametric polynomial surface is a fundamental element in CAD systems. Since the most of the classic minimal surfaces are represented by non-parametric polynomial, it is interesting to study the minimal surfaces repre... Parametric polynomial surface is a fundamental element in CAD systems. Since the most of the classic minimal surfaces are represented by non-parametric polynomial, it is interesting to study the minimal surfaces represented in parametric polynomial form. Recently,Ganchev presented the canonical principal parameters for minimal surfaces. The normal curvature of a minimal surface expressed in these parameters determines completely the surface up to a position in the space. Based on this result, in this paper, we study the bi-quintic isothermal minimal surfaces. According to the condition that any minimal isothermal surface is harmonic,we can acquire the relationship of some control points must satisfy. Follow up, we obtain two holomorphic functions f(z) and g(z) which give the Weierstrass representation of the minimal surface. Under the constrains that the minimal surface is bi-quintic, f(z) and g(z) can be divided into two cases. One case is that f(z) is a constant and g(z) is a quadratic polynomial, and another case is that the degree of f(z) and g(z) are 2 and 1 respectively. For these two cases,we transfer the isothermal parameter to canonical principal parameter, and then compute their normal curvatures and analyze the properties of the corresponding minimal surfaces. Moreover,we study some geometric properties of the bi-quintic harmonic surfaces based on the B′ezier representation. Finally, some numerical examples are demonstrated to verify our results. 展开更多
关键词 polynomial parametric curvature canonical compute quadratic satisfy isothermal acquire verify
下载PDF
Improved response surface method and its application in stability reliability degree analysis of tunnel surrounding rock 被引量:10
5
作者 苏永华 张鹏 赵明华 《Journal of Central South University of Technology》 EI 2007年第6期870-876,共7页
An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mend... An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward. The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function(PDF) of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not itemtive circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method, whose workload is only 30% of classical method and its accuracy is comparative. 展开更多
关键词 response surface method Rosenbluth method statistic moment entropy density function quadratic polynomial
下载PDF
Image Interpolation Through Surface Reconstruction 被引量:2
6
作者 ZHANG Ling LI Xue-mei 《Computer Aided Drafting,Design and Manufacturing》 2013年第4期25-29,共5页
Reconstructing an HR (high-resolution) image which preserves the image intrinsic structures from its LR (low-resolution) counterpart is highly challenging. This paper proposes a new surface reconstruction algorith... Reconstructing an HR (high-resolution) image which preserves the image intrinsic structures from its LR (low-resolution) counterpart is highly challenging. This paper proposes a new surface reconstruction algorithm applied to image interpolation. The interpolation surface for the whole image is generated by putting all the quadratic polynomial patches together. In order to eliminate the jaggies of the edge, a new weight fimction containing edge information is incorporated into the patch reconstruction procedure as a constraint. Extensive experimental results demonstrate that our method produces better results across a wide range of scenes in terms of both quantitative evaluation and subjective visual quality. 展开更多
关键词 quadratic polynomial patch weight function interpolation surface
下载PDF
Three-dimensional Information Decoupling System Based on PSD and Deviation Correction
7
作者 YAN Chao-chao LU Jin YANG Hai-ma 《International English Education Research》 2015年第3期101-107,共7页
Three-dimensional Information Decoupling System Based on PSD were designed based on LabVIEW, in order to achieve precision, timeliness, reliability require-ments of the PSD used in the ATP system of Satellite Earth qu... Three-dimensional Information Decoupling System Based on PSD were designed based on LabVIEW, in order to achieve precision, timeliness, reliability require-ments of the PSD used in the ATP system of Satellite Earth quantum communication. Firstly, the laser light source was driven by a stepper motor to scan on the PSD photosensitive surface, and the voltage value was collected and calculated to get the spot position. Analyzing the cause of nonlinear, a mathematical model was built between the actual value and the measured value by using binary quadratic polynomial method, PSD nonlinear correction function would be got. Then, the object micro displacement and angle offset were measured by combining optical triangulation method, and the error of the measurement results was corrected. Experimental results showed that, after the correction, the measuring deviation could be significantly reduced, the PSD performance calibration requirements was achieved, the efficiency of the system was developed greatly by using LabVIEW. 展开更多
关键词 Position sensitive detector (PSD) Three-dimensional Information Decoupling System Binary quadratic polynomial method Microdisplacement measurement Angle Measurement
下载PDF
Determining knots by optimizing the bending and stretching energies 被引量:1
8
作者 ZHANG Fan QIN Xue-ying +1 位作者 LI Xue-mei CHENG Fu-hua 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2017年第1期53-67,共15页
For a given set of data points in the plane, a new method is presented for computing a parameter value(knot) for each data point. Associated with each data point, a quadratic polynomial curve passing through three a... For a given set of data points in the plane, a new method is presented for computing a parameter value(knot) for each data point. Associated with each data point, a quadratic polynomial curve passing through three adjacent consecutive data points is constructed. The curve has one degree of freedom which can be used to optimize the shape of the curve. To obtain a better shape of the curve, the degree of freedom is determined by optimizing the bending and stretching energies of the curve so that variation of the curve is as small as possible. Between each pair of adjacent data points, two local knot intervals are constructed, and the final knot interval corresponding to these two points is determined by a combination of the two local knot intervals. Experiments show that the curves constructed using the knots by the new method generally have better interpolation precision than the ones constructed using the knots by the existing local methods. 展开更多
关键词 optimizing interpolation bending freedom stretching quadratic chord polynomial optimize Associated
下载PDF
Liouvillian and Analytic Integrability of the Quadratic Vector Fields Having an Invariant Ellipse 被引量:2
9
作者 Jaume LLIBRE Claudia VALLS 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2014年第3期453-466,共14页
We characterize the Liouvillian and analytic integrability of the quadratic polynomial vector fields in R2 having an invariant ellipse.More precisely,a quadratic system having an invariant ellipse can be written into ... We characterize the Liouvillian and analytic integrability of the quadratic polynomial vector fields in R2 having an invariant ellipse.More precisely,a quadratic system having an invariant ellipse can be written into the form x=x2+y2-1+y(ax+by+c),y=x(ax+by+c),and the ellipse becomes x2+y2=1.We prove that(i) this quadratic system is analytic integrable if and only if a=0;(ii) if x2+y2=1 is a periodic orbit,then this quadratic system is Liouvillian integrable if and only if x2+y2=1 is not a limit cycle;and(iii) if x2+y2=1 is not a periodic orbit,then this quadratic system is Liouvilian integrable if and only if a=0. 展开更多
关键词 Liouvillian integrability quadratic planar polynomial vector fields invariant ellipse
原文传递
Enlarging Image by Constrained Least Square Approach with Shape Preserving 被引量:4
10
作者 张帆 张新 +1 位作者 秦学英 张彩明 《Journal of Computer Science & Technology》 SCIE EI CSCD 2015年第3期489-498,共10页
From a visual point of view, the shape of an image is mainly determined by the edges. Conventional polynomial interpolation of image enlarging methods would produce blurred edges, while edge-directed interpolation bas... From a visual point of view, the shape of an image is mainly determined by the edges. Conventional polynomial interpolation of image enlarging methods would produce blurred edges, while edge-directed interpolation based methods would cause distortion in the non-edge areas. A new method for image enlarging is presented. The image is enlarged in two steps. In the first step, a fitting surface is constructed to interpolate the image data. To remove the zigzagging artifact for each pixel, a fitting patch is constructed using edge information as constraints. The combination of all the patches forms the fitting surface which has the shape suggested by image data. Each point on the fitting surface can be regarded as a sampling point taken from a unit square domain, which means that when the fitting surface is used to enlarge the image, each sampling domain of the enlarged pixels is also a unit square, causing the enlarged image to lose some details. To make the enlarged image keep the details as many as possible, the sampling domain of the enlarged pixels should be less than a unit square. Then, in the second step, using the points taken from the fitting surface, new pixels are computed using constrained optimization technique to form the enlarged image, and the size of the sampling domain of the enlarged pixels is inversely proportional to the size of the enlarged image. The image enlarged by the new method has a quadratic polynomial precision. Comparison results show that the new method produces resized image with better quality. 展开更多
关键词 image resizing FITTING quadratic polynomial shape preserving edge information
原文传递
LTE turbo decoder design 被引量:1
11
作者 杨乐 叶甜春 +1 位作者 吴斌 张瑞齐 《Journal of Semiconductors》 EI CAS CSCD 2015年第7期119-123,共5页
This paper presents a turbo decoder supporting all 188 block sizes in 3GPP long term evolution (LTE) standard which can be employed in the LTE micro-eNodB system. The design allows 1, 2, 4, 8 or 16 soft-in/softout ... This paper presents a turbo decoder supporting all 188 block sizes in 3GPP long term evolution (LTE) standard which can be employed in the LTE micro-eNodB system. The design allows 1, 2, 4, 8 or 16 soft-in/softout (SISO) decoders to concurrently process each block size, and the number of iterations can be adjusted. By adding a register in core structure add-compare-select-add, this article proposes an improved SISO algorithm and interleaving design, calculated forward state matrix and backward state matrix alternately, and the branch transition probability can be used in the Turbo decode process directly just after one clock delay. The structure enables a decoder processing radix-2 algorithm with high speed, instead of radix-4 as the conventional decoder. Moreover, the paper details an interleaver/de-interleaver, which is combined by two operational steps. One is column address mapping and the other is intra-row permutation. Decoder realizes interleaving by loading data from memories whose address is generated by column mapping and then lets data passing through inter-row permutation. For de-interleaving, the system can adopt reverse operation. 展开更多
关键词 LTE turbo decoder quadratic polynomial permutation) QPP interleaver
原文传递
The local Hlder exponent for the entropy of real unimodal maps In Memory of Lei Tan
12
作者 Giulio Tiozzo 《Science China Mathematics》 SCIE CSCD 2018年第12期2299-2310,共12页
We consider the topological entropy h(θ) of real unimodal maps as a function of the kneading parameter θ(equivalently, as a function of the external angle in the Mandelbrot set). We prove that this function is local... We consider the topological entropy h(θ) of real unimodal maps as a function of the kneading parameter θ(equivalently, as a function of the external angle in the Mandelbrot set). We prove that this function is locally Hlder continuous where h(θ) > 0, and more precisely for any θ which does not lie in a plateau the local Hlder exponent equals exactly, up to a factor log 2, the value of the function at that point.This confirms a conjecture of Isola and Politi(1990), and extends a similar result for the dimension of invariant subsets of the circle. 展开更多
关键词 ENTROPY unimodal maps quadratic polynomials Hlder exponent
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部