共查询到20条相似文献，搜索用时 62 毫秒
1.
杨必成 《上海大学学报(英文版)》2010,14(6):391-395
Through using weight function, we give a new Hilbert-type integral inequality with two independent parameters and two pair of conjugate exponents, which is a best extension of a Hilbert-type integral inequality with the homogeneous kernel of 0-degree. The equivalent form, the reverses and some particular results are considered. 相似文献
2.
The lower bound for the volume of the zonotope for John-basis had been given by Ball. In this paper, a simple proof of Ball＇s inequality was first provided, then the result of Ball was generalized from John-basis to a sequence of non-zero vectors which are full rank. Furthermore, the upper bound for the volumes of zonotopes was given. Finally the inequalities were deduced for the inradius and circumradius of a certain zonotope. 相似文献
3.
We now consider an inequality of the form
f1（x） 〉f2（x）.
Every numerical value x0 taken from the domain of admissible values is called a solution of the inequality, if, when x0 is substituted into both sides of the inequality, the result is a true numerical inequality. constitute All the the solution solutions of an inequality set of the inequality. 相似文献
4.
One of the oldest customs of mankind is the celebration of the new year. Some people say the Chinese were the first to start it, others believe it was the ancient Germans, and still others claim it was the Romans. We know that the Chinese have always had a great festival at the time of their new year that comes later than ours. The Chinese New Year festival lasts several days.The ancient Germans established a new year festival be- 相似文献
5.
《天津大学学报(英文版)》2018,(6)
In this study, a new mass model involving superheat, initial temperature, liquid height, evaporator diameter, and flashing time is established to describe the flash evaporation process of water film. Of 469 sets of flash experimental data from three previous researches, 305 sets were applied to optimize parameters, and the other 164 sets were used to verify the practicability of the model. The results showed that the mean relative error between the literature data and the model values was less than 16.3%, and the model statistics proved that the model was well-posed. Then, the kinetic model was obtained using the time derivative of the new mass model. Computational fluid dynamics simulation of water film flash evaporation was studied based on a user-defined function program of the new evaporation kinetic model. The new kinetic model shows more consistency with the experimental phenomena in terms of evaporated mass and temperature compared with the evaporation–condensation model in Fluent software and Gopalakrishna's model. This new kinetic model can be extended to describe the flash process of water solution under other conditions. 相似文献
6.
Accuracy and fastness of iris localization are very important in automatic iris recognition. A new fast iris localization algorithm based on improved generalized symmetry transform (GST) was proposed by utilizing iris symmetry. GST was improved in three aspects: 1 ) A new distance weight function is defined. The new weight function, which is effective in iris localization, utilized the characteristic of irises that the iris is a circular object and it has one inner boundary and one outer boundary. 2) Each calculation of the symmetry measurement of a pair of symmetry points was performed by taking one point of a pair as the starting point of the transformation. This is the most important reason for fast iris localization, due to which, repetitious computation was largely excluded. 3) A new phase weight function was proposed to adjust GST to locate circle target much better because the inner part of iris is darker than the outer part. The edge map of iris image was acquired and GST was only implemented on the edge point, which decreased computation without loss of accuracy. The modification of distance weight function and phase weight function leads to the accuracy of localization, and other ideass peed up the localization. Experiments show that the average speed of new algorithm is about 7.0-8.5 times as high as traditional ones including integro-differential operator and Hough transform method. 相似文献
7.
A theorem for osculatory rational interpolation was shown to establish a new criterion of interpolation.On the basis of this conclusion a practical algorithm was presented to get a reduction model of the linear systems.Some numerical examples were given to explain the result in this paper. 相似文献
8.
The step-size procedure is very important for solving optimization problems. The Armijo step-size rule, the Armijo-Goldstein step-size rule and the Wolfe-Powell step-size rule are three well-known line search methods. On the basis of the above three types of line search methods and the idea of the proximal point methods, a new class of step-size rules was proposed. Instead of a single objective function f, f ＋1/2（x - xk）^TBk（x-Xk） was used as the merit function in iteration k, where Sk is a given symmetric positive definite matrix. The existence of the steplength for the new rules was proved. Some convergence properties were also discussed. 相似文献
9.
陈登福 《重庆大学学报(英文版)》2007,6(4):242-248
The mathematical model of high-efficiency continuous billet casting was developed, incorporating the effective spraying water coefficient and the effective specific spraying water flowrate of secondary cooling. To realize uniform cooling in secondary cooling zones, the spraying cooling structure and the arrangement of nozzles were redesigned and optimized, and an additional spraying cooling zone was used. A new secondary cooling model of spraying water was built. It was found that the required spraying water flowrate of a cooling zone was related with the casting speed, the casting temperature, the compositions of liquid steel and the cooling water temperature of secondary cooling. The operation of the reformed caster proved that the spraying cooling structure and the new secondary cooling model were suitable, and the casting speed was greatly enhanced. The highest casting speed was (3.8 to 4.0) m/min for billet with a section of 150×150 mm2. The quality and the output of the billet were improved, and the economical benefit was heightened. 相似文献
10.
杨小平 《中学生英语读写(高中版)》2003,(10)
The search for a new Canadian Flag started inearnest1 in 1925 when a committee2 of the Privy Council3began to research possible designs for a national flag.However,the work of the committee was never finished.Later, in 1946, a select parliamentary4 committee was 相似文献
11.
Due to low carrying capacity and short life of current ring reducer, we proposed a new planetary gearing with internal gear ring, which consisted of two stages. One was an involute planetary drive and the other was an N-type planetary drive with small teeth difference. The kinematic calculation was conducted based on the analysis of structural composition and working principle. Formulas of backlash calculation for the new planetary gearing were derived by using probabilistic theory and the analytical model was created at the same time. Then, main factors that affect the systematic backlash were introduced and the effects of manufacture error, misaligments and roller bearing parameters on the distribution of backlash were presented. The influence of gear backlash on systematic return difference was performed based on the backlash mathematic model proposed. The results show that the backlash is a little large, of which the backlash of bearing takes a greater part than two gearing stages. So we presented some practical methods to reduce the systematic backlash. 相似文献
12.
GUChuan－qing 《上海大学学报(英文版)》2001,5(1):11-14
A recursive rational algorithm for matrix exponentials was botained by making use of the generalized inverse of a matrix in this paper.On the basis of the n-th convergence of thiele-type continued fraction expansion,a new type of the generalized inverse matrix-valued pade approximant(GMPA)for matrix exponentials was defined and its remainder formula was proved.The resuts of this paper were illustrated by some examples. 相似文献
13.
不可压各向异性超弹性材料中的空穴生成 总被引：3，自引：0，他引：3
The cavitation problem in a solid sphere composed of an incompressible anisotropic hyper-elastic material under a univroms radial tensile dead load was examined.A new analytical solution was obtained.The stress contruibutions were given and the jumping and concentration of stresses were discussed.The stability of solutions and the effect of the degree of ainsotropy of the material were analyzed. 相似文献
14.
We now consider an inequality of the formf_1(x)>f_2(x).Every numerical value x_0 taken from the domain ofadmissible values is called a solution of theinequality,if,when x_0 is substituted into both sidesof the inequality,the result is a true numericalinequality.All the solutions of an inequalityconstitute the solution set of the inequality.Forinstance,the inequality x~2<1 has for its solution setthe open interval(-1,1).Sometimes,for the sakeof brevity,we loosely say that the solution of the 相似文献
15.
Guo R Li SB Zhao LN Zhao YS Lu W Yuan P Deng P Liao F 《Journal of Zhejiang University. Science. B》2007,8(12):867-874
There was a slow-relaxing tail of skeletal muscles in vitro upon the inhibition of Ca^2＋-pump by cyclopiazonic acid （CPA）. Herein, a new linearly-combined bi-exponential model to resolve this slow-relaxing tail from the fast-relaxing phase was investigated for kinetic analysis of the isometric relaxation process of Bufo gastrocnemius in vitro, in comparison to the single exponential model and the classical bi-exponential model. During repetitive stimulations at a 2-s interval by square pulses of a 2-ms duration at 12 V direct currency （DC）, the isometric tension of Bufo gastrocnemius was recorded at 100 Hz. The relaxation curve with tensions falling from 90% of the peak to the 15th datum before next stimulation was analyzed by three exponential models using a program in MATLAB 6.5. Both the goodness of fit and the distribution of the residuals for the best fitting supported the comparable validity of this new bi-exponential model for kinetic analysis of the relaxation process of the control muscles. After CPA treatment, however, this new bi-exponential model showed an obvious statistical superiority for kinetic analysis of the muscle relaxation process, and it gave the estimated rest tension consistent to that by experimentation, whereas both the classical bi-exponential model and the single exponential model gave biased rest tensions. Moreover, after the treatment of muscles by CPA, both the single exponential model and the classical bi-exponential model yielded lowered relaxation rates, nevertheless, this new bi-exponential model had relaxation rates of negligible changes except much higher rest tensions. These results suggest that this novel linearly-combined bi-exponential model is desirable for kinetic analysis of the relaxation process of muscles with altered Ca2^＋-pumping activity. 相似文献
16.
张宏 《高等教育与学术研究》2006,(2)
The term, culture shock, was introduced for the first time in 1958 to describe the anxiety produced when a person moves to a completely new environ- ment. This term expresses the lack of direction, the feeling of not knowing what to do or how to do things in a new environment, and not knowing what is appro- priate or inappropriate. The feeling of culture shock generally sets in after the first few weeks of coming to a new place. "Coming to America is like jumping into cold water," says an inte… 相似文献
17.
Novel approach for determining the optimal axial preload of a simulating rotary table spindle system
This paper presents a new theoretical model to determine the optimal axial preload of a spindle system, for challenging the traditional method which relies heavily on experience of engineers. The axial preloading stiffness was treated as the sum of the spindle modal stiffness and the framework elastic stiffness, based on a novel concept that magnitude of preloads can be controlled by measuring the resonant frequency of a spindle system. By employing an example of a certain type of aircraft simulating rotary table, the modal stiffness was measured on the Agilent 35670A Dynamic Signal Analyzer by experimental modal analysis. The equivalent elastic stiffness was simulated by both finite element analysis in ANSYS? and a curve fitting in MATLAB?. Results showed that the static preloading stiffness of the spindle was 7.2125×107 N/m, and that the optimal preloading force was 120.0848 N. Practical application proved the feasibility of our method. 相似文献
18.
Based on microscope and image processing, a new method of auto tool setting for micro milling was presented. Firstly, a realtime image of tool setting area was obtained by microscope and CCD camera, then image processing was carried out on this image and the gap between the tool and workpiece was calculated. The gap measurement was sent to motion controlling card to make the tool approach to the surface of workpiece. These steps were repeated until the gap is zero, which means that tool setting was finished. Moreover, a reliability verification test was conducted. Results indicated that the precision of tool setting is satisfactory. 相似文献
19.
In late 1989,I had bought a house in the eastside neighborhood of Los Angeles,which was being transformed by waves of new immigrants, and I was convinced racial harmony was impossible.Statistics said that each year,tens of thousands of new immigrants,mostly from Latin America and Asia,were pouring into Southern California,yet most whites never lived with the results of these statistics. 相似文献
20.
An alternative Monte Carlo strategy for the computation of global illumination problem was presented.The proposed approach provided a new and optimal way for solving Monte Carlo global illumination based on the zero variance importance sampling procedure. A new importance driven Monte Carlo global illumination algorithm in the framework of the new computing scheme was developed and implemented. Results, which were obtained by rendering test scenes, show that this new framework and the newly derived algorithm are effective and promising. 相似文献