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
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
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
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
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 carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based ...A carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based on the received training signals at each user＇s prescribed subcarder positions. Then, the re- ceived training signals were compensated by using the initial CFO estimates in the frequency domain and the multi-user interferences were estimated. Finally, the interference-cancelled training signals were used to reliably estimate each user＇s CFO. The CFO estimator performance was evaluated by the bit error rate per- formances of the CFO compensation-based receivers at the base station. Simulations show that with this optima CFO compensation receiver, the performance gain with the esti- mated CFO values is approximately 3 dB better at the 0.1% bit error rate than the initial CFO estimates.展开更多
The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental rese...The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental research on quantum information processing.Among various quantum platforms,a series of significant progresses have been made in photonic quantum chips and superconducting quantum chips,while both the number of qubits and the complexity of quantum circuits have been increasing.Although these two chip platforms have respective unique advantages and potentials,their shortcomings have been gradually revealed and need to be solved.By introducing phonon-integrated devices,it is possible to combine all unsuspended phononic,photonic,and superconducting quantum devices organi-cally on the same chip to achieve coherent coupling among them.Here,we provide a prospect and a short review on the integrated photonic,superconducting,and hybrid quantum chips for quantum information processing.展开更多
In this paper, we consider the low rank approximation solution of a generalized Lya- punov equation which arises in the bilinear model reduction. By using the variation prin- ciple, the low rank approximation solution...In this paper, we consider the low rank approximation solution of a generalized Lya- punov equation which arises in the bilinear model reduction. By using the variation prin- ciple, the low rank approximation solution problem is transformed into an unconstrained optimization problem, and then we use the nonlinear conjugate gradient method with ex- act line search to solve the equivalent unconstrained optimization problem. Finally, some numerical examples are presented to illustrate the effectiveness of the proposed methods.展开更多
Using a bounding technique, we prove that the fluid model of generalized Jackson network （GJN） with vacations is the same as a GJN without vacations, which means that vacation mechanism does not affect the dynamic p...Using a bounding technique, we prove that the fluid model of generalized Jackson network （GJN） with vacations is the same as a GJN without vacations, which means that vacation mechanism does not affect the dynamic performance of GJN under fluid approximation. Furthermore, in order to present the impact of vacation on the performance of GJN, we show that exponential rate of convergence for fluid approximation only holds for large N, which is different from a GJN without vacations. The results on fluid approximation and convergence fate are embodied by the queue length, workload, and busy time processes.展开更多
Understanding the multiple tectonic transformations during the Himalayan orogeny is significant in evaluating the evolution of Himalayan orogen.In the Gyirong area in south Tibet,deformed leucogranitic veins in the bi...Understanding the multiple tectonic transformations during the Himalayan orogeny is significant in evaluating the evolution of Himalayan orogen.In the Gyirong area in south Tibet,deformed leucogranitic veins in the biotite-plagioclase gneisses of Greater Himalayan crystalline complex(GHC) constitute south-vergent asymmetric folds.The reconstruction of the veins shows that they experienced two generations of deformation under different tectonic regimes:an earlier top-to-north extension and a later top-to-south thrusting,implying a tectonic transformation from N-S extension to N-S shortening.Zircons LA-ICP-MS U-Pb dating of the leucogranite shows that it was emplaced during 21.03-18.7 Ma.The data suggest that the tectonic transformation occurred after 18.7 Ma.The chronological data of South Tibet detachment system(STDS) and North-South trending rift(NSTR) from Gyirong and other areas indicate that the Himalayan orogeny was in a period of tectonic transformation from N-S extension to N-S shortening during 19-13 Ma.The transformation of tectonic regime was probably controlled by the India-Asia convergence rate.An increase in the convergence rate resulted in N-S shortening of the orogen,thrusting and folding,with coeval formation of the NSTR in Tibet.A decrease in the convergence rate led to N-S extension and reactivation of the STDS.展开更多
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.
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.
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.
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 .
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Supported by the National Key Basic Research and Development (973) Program of China (No. 2007CB310601)
文摘A carrier frequency offset （CFO） estimator was developed based on an interference cancellation scheme for an orthogonal frequency division multiplex access uplink. An initial CFO estimate was first ob- tained based on the received training signals at each user＇s prescribed subcarder positions. Then, the re- ceived training signals were compensated by using the initial CFO estimates in the frequency domain and the multi-user interferences were estimated. Finally, the interference-cancelled training signals were used to reliably estimate each user＇s CFO. The CFO estimator performance was evaluated by the bit error rate per- formances of the CFO compensation-based receivers at the base station. Simulations show that with this optima CFO compensation receiver, the performance gain with the esti- mated CFO values is approximately 3 dB better at the 0.1% bit error rate than the initial CFO estimates.
基金supported by the National Key Research and De-velopment Program of China(Grant No.2017YFA0304303)National Nat-ural Science Foundation of China(Grant Nos.11874342,12061131011,92165209,11925404,11922411)+1 种基金Key-Area Research and Development Program of Guangdong Province Grant No.2020B0303030001China Postdoctoral Science Foundation(Grant No.BX2021167).
文摘The integration of qubits with long coherence times and functional quantum devices on a single chip,and thus the realization of an allsolidstate quantum computing chip,is an important goal in current experimental research on quantum information processing.Among various quantum platforms,a series of significant progresses have been made in photonic quantum chips and superconducting quantum chips,while both the number of qubits and the complexity of quantum circuits have been increasing.Although these two chip platforms have respective unique advantages and potentials,their shortcomings have been gradually revealed and need to be solved.By introducing phonon-integrated devices,it is possible to combine all unsuspended phononic,photonic,and superconducting quantum devices organi-cally on the same chip to achieve coherent coupling among them.Here,we provide a prospect and a short review on the integrated photonic,superconducting,and hybrid quantum chips for quantum information processing.
文摘In this paper, we consider the low rank approximation solution of a generalized Lya- punov equation which arises in the bilinear model reduction. By using the variation prin- ciple, the low rank approximation solution problem is transformed into an unconstrained optimization problem, and then we use the nonlinear conjugate gradient method with ex- act line search to solve the equivalent unconstrained optimization problem. Finally, some numerical examples are presented to illustrate the effectiveness of the proposed methods.
文摘Using a bounding technique, we prove that the fluid model of generalized Jackson network （GJN） with vacations is the same as a GJN without vacations, which means that vacation mechanism does not affect the dynamic performance of GJN under fluid approximation. Furthermore, in order to present the impact of vacation on the performance of GJN, we show that exponential rate of convergence for fluid approximation only holds for large N, which is different from a GJN without vacations. The results on fluid approximation and convergence fate are embodied by the queue length, workload, and busy time processes.
基金supported by the National Natural Science Foundation of China (41172176 and 41121062)China Geological Survey (1212011121066)
文摘Understanding the multiple tectonic transformations during the Himalayan orogeny is significant in evaluating the evolution of Himalayan orogen.In the Gyirong area in south Tibet,deformed leucogranitic veins in the biotite-plagioclase gneisses of Greater Himalayan crystalline complex(GHC) constitute south-vergent asymmetric folds.The reconstruction of the veins shows that they experienced two generations of deformation under different tectonic regimes:an earlier top-to-north extension and a later top-to-south thrusting,implying a tectonic transformation from N-S extension to N-S shortening.Zircons LA-ICP-MS U-Pb dating of the leucogranite shows that it was emplaced during 21.03-18.7 Ma.The data suggest that the tectonic transformation occurred after 18.7 Ma.The chronological data of South Tibet detachment system(STDS) and North-South trending rift(NSTR) from Gyirong and other areas indicate that the Himalayan orogeny was in a period of tectonic transformation from N-S extension to N-S shortening during 19-13 Ma.The transformation of tectonic regime was probably controlled by the India-Asia convergence rate.An increase in the convergence rate resulted in N-S shortening of the orogen,thrusting and folding,with coeval formation of the NSTR in Tibet.A decrease in the convergence rate led to N-S extension and reactivation of the STDS.
