In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independentl...In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independently of the meshsize. For convenience, we only discuss Jacobi relaxation as smoothing operator in detail.展开更多
In the article, we present some refinements of three classes of transformation inequalities for zero-balanced hypergeometric functions by use of the updated monotonicity criterion for the quotient of power series.
Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life （RUL） for the deteriorating systems. This paper presents a method based on probabilistic and stochas...Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life （RUL） for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically moni- tored degradation processes with dynamic time-varying operational conditions and condition- specific failure zones. The method assumes that the degradation rate is influenced by specific oper- ational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditioqs are assumed to evolve as a discrete-time Markov chain （DTMC）. The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUE estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with exist- ing methods for the same dataset.展开更多
We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined o...We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined on [0, 1]_k. The anwser is affirmative.展开更多
In the past decade,the e-government affairs keep developing,which prom otes the reform of governmental affairs and the enhancement of administrative efficiency.However,the phenomenon of inform ation silo has bad influ...In the past decade,the e-government affairs keep developing,which prom otes the reform of governmental affairs and the enhancement of administrative efficiency.However,the phenomenon of inform ation silo has bad influence upon the governm ental information resources sharing and the efficiency of the e-government affairs,hindering inform ation connectivity,so that the government management cannot meet the need of society,nor can the e-governm ent develop in the long run.This paper attempts to analyze the embodiment and causes of the phenomenon of information silo,putting forward measures of solving the problem of inform ation silo.展开更多
A new die design for equal channel angular pressing （ECAP） of square cross-section billet was proposed by a 45° rotation of the inlet and outlet channels around the channel axes. ECAP utilizing the rotated and ...A new die design for equal channel angular pressing （ECAP） of square cross-section billet was proposed by a 45° rotation of the inlet and outlet channels around the channel axes. ECAP utilizing the rotated and conventional dies was simulated in three dimensions using the finite element method. Conditions with different material properties and friction coefficients were studied. The billet deformation behavior was evaluated in terms of the spatial distribution of equivalent plastic strain, plastic deformation zone and load history. The results show that the rotated die appears to produce billets with a smaller deformation inhomogeneity over the entire cross- section and a greater average of equivalent plastic strain at the cost of a slightly larger working load. The billet deformdtion enters into a Steady s^ate earlier in the case of the rotated die than the conventional die under the condition of a relatively large friction coefficient.展开更多
A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The re...A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .展开更多
基金This work was supported by China State Major Key Project for Basic Researches
文摘In this paper we describe a multi-grid algorithm for mixed problems with penalty by the linear finite element approximation. It is proved that the convergence rate of the algorithm is bound ed away from 1 independently of the meshsize. For convenience, we only discuss Jacobi relaxation as smoothing operator in detail.
基金supported by the Natural Science Foundation of China(61673169,11401191,11371125)the Tianyuan Special Funds of the Natural Science Foundation of China(11626101)the Natural Science Foundation of the Department of Education of Zhejiang Province(201635325)
文摘In the article, we present some refinements of three classes of transformation inequalities for zero-balanced hypergeometric functions by use of the updated monotonicity criterion for the quotient of power series.
基金supported by the Fundamental Research Funds for the Central Universities(No.YWF-14-ZDHXY-16)
文摘Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life （RUL） for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically moni- tored degradation processes with dynamic time-varying operational conditions and condition- specific failure zones. The method assumes that the degradation rate is influenced by specific oper- ational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditioqs are assumed to evolve as a discrete-time Markov chain （DTMC）. The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUE estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with exist- ing methods for the same dataset.
文摘We investigate the following problem in this paper: where there is an unique 1-periodic discrete quadratic spline s∈S(3, p, h) satisfying certain interpolatory condition for a 1-periodic discrete function de- fined on [0, 1]_k. The anwser is affirmative.
文摘In the past decade,the e-government affairs keep developing,which prom otes the reform of governmental affairs and the enhancement of administrative efficiency.However,the phenomenon of inform ation silo has bad influence upon the governm ental information resources sharing and the efficiency of the e-government affairs,hindering inform ation connectivity,so that the government management cannot meet the need of society,nor can the e-governm ent develop in the long run.This paper attempts to analyze the embodiment and causes of the phenomenon of information silo,putting forward measures of solving the problem of inform ation silo.
基金financially supported by the National Natural Science Foundation of China (No. 50871040)
文摘A new die design for equal channel angular pressing （ECAP） of square cross-section billet was proposed by a 45° rotation of the inlet and outlet channels around the channel axes. ECAP utilizing the rotated and conventional dies was simulated in three dimensions using the finite element method. Conditions with different material properties and friction coefficients were studied. The billet deformation behavior was evaluated in terms of the spatial distribution of equivalent plastic strain, plastic deformation zone and load history. The results show that the rotated die appears to produce billets with a smaller deformation inhomogeneity over the entire cross- section and a greater average of equivalent plastic strain at the cost of a slightly larger working load. The billet deformdtion enters into a Steady s^ate earlier in the case of the rotated die than the conventional die under the condition of a relatively large friction coefficient.
文摘A new high accuracy 6D ( Dimension ) wide range measuring technology and the method of coordinate transformations have been developed in a project for automobile body-in- white measurement in Michigan , U S A . The requirements and the special features about the measured objective are mainly stated. The main instruments used in the project are introduced. The 6D measuring system , the method for coordinate transformations and the design of 3D optical target with hollow tetrahedron are described in detail . The 6D system and the technology can be certainly used in many other kinds of geometric mea- suring projects .
