By means of conceptual model prediction, two short-time strong precipitation processes in Xiamen on June 12th and 14th, 2008 were analyzed from the aspects of real precipitation, weather situation, physical parameter ...By means of conceptual model prediction, two short-time strong precipitation processes in Xiamen on June 12th and 14th, 2008 were analyzed from the aspects of real precipitation, weather situation, physical parameter and radar echo. The results showed that two short-time strong precipitation processes had complete different weather backgrounds, so physical quantities which could reflect atmospheric thermal and dynamic characteristic were different, as well as the characteristic and evolution process of radar echo, and it revealed that two short-time strong precipitation processes in Xiamen had various formation mechanisms and evolution processes. Therefore, many data should be combined to grasp different vantage points in precipitation forecast.展开更多
In this paper,a nonlinear time transformation method is presented for the analysis of strong nonlinear oscillation systems.This method can be used to study the limit cycle behavior of the autonomous systems and to ana...In this paper,a nonlinear time transformation method is presented for the analysis of strong nonlinear oscillation systems.This method can be used to study the limit cycle behavior of the autonomous systems and to analyze the forced vibration of a strong nonlinear system.展开更多
We dedicate to the 2D density-dependent nonhomogeneous incompressible Boussinesq equations with vacuum on . At infinity, if the attenuation of initial density and temperature is not very slow. And it is gained that th...We dedicate to the 2D density-dependent nonhomogeneous incompressible Boussinesq equations with vacuum on . At infinity, if the attenuation of initial density and temperature is not very slow. And it is gained that there is a global strong solution and is unique for the 2D Cauchy problem with the initial density which can allow vacuum conditions and even have compact support. Besides, the large time decay rates of the gradients of velocity, temperature and pressure can also be obtained which are also the same as those of the homogeneous case.展开更多
Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic ...Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic field's peak both in the time domain and in the frequency domain.With regard to this problem,after analyzing the time-domain and the frequency-domain characteristics of radar pulsed signals,we propose a new time-frequency combination test method based on the correction of the test parameters,as well as its correction method at different bandwidths.The test method is applied in a quick test of a high-power pulsed radar signal,and the corrected results have error less than 1 dB in both the time domain and the frequency domain,which indicates that the proposed time-frequency combined method is effective in testing strong and pulsed electromagnetic fields.展开更多
In this paper, single machine scheduling problems with variable processing time is discussed according to published instances of management engineering. Processing time of a job is the product of a “coefficient' ...In this paper, single machine scheduling problems with variable processing time is discussed according to published instances of management engineering. Processing time of a job is the product of a “coefficient' of the job on position i and a “normal' processing time of the job. The criteria considered is to minimize scheduled length of all jobs. A lemma is proposed and proved. In no deadline constrained condition, the problem belongs to polynomial time algorithm. It is proved by using 3 partition that if the problem is deadline constrained, its complexity is strong NP hard. Finally, a conjuncture is proposed that is to be proved.展开更多
The paper collects the records by the Fujian Digital Seismic Network of 40 shallow earthquakes in Taiwan with M_S≥5.0 from 1999 to 2013,analyzes the seismic phase(Pn,Sn phase)characteristics and travel-time rules,det...The paper collects the records by the Fujian Digital Seismic Network of 40 shallow earthquakes in Taiwan with M_S≥5.0 from 1999 to 2013,analyzes the seismic phase(Pn,Sn phase)characteristics and travel-time rules,determines travel-time models and develops a seismic phase travel-time equation based on the two-step fitting algorithm.With the deduction of processing time and network delay time,this method can provide an accurate estimation of early warning time of Taiwan earthquakes for the Fujian region,and has been officially employed in the earthquake early warning system of Fujian Province.展开更多
In this paper, we study the Cauchy problem of the density-dependent Boussinesq equations of Korteweg type on the whole space with a vacuum. It is proved that there exists a unique strong solution for the two-dimension...In this paper, we study the Cauchy problem of the density-dependent Boussinesq equations of Korteweg type on the whole space with a vacuum. It is proved that there exists a unique strong solution for the two-dimensional Cauchy problem established that the initial density and the initial temperature decay not extremely slow. Particularly, it is allowed to be arbitrarily large for the initial data and vacuum states for the initial density, even including the compact support. Moreover, when the density depends on the Korteweg term with the viscosity coefficient and capillary coefficient, we obtain a consistent priority estimate by the energy method, and extend the local strong solutions to the global strong solutions. Finally, when the pressure and external force are not affected, we deform the fluid models of Korteweg type, we can obtain the large time decay rates of the gradients of velocity, temperature and pressure.展开更多
In order to solve the problem of early estimation of moderately strong aftershock duration time in an earthquake sequence,this study has been conducted.First,the definition of the strong aftershock has been given.It i...In order to solve the problem of early estimation of moderately strong aftershock duration time in an earthquake sequence,this study has been conducted.First,the definition of the strong aftershock has been given.It is pointed out that there is a difference in the strong aftershock duration time between the main shock type sequence and the strong earthquake swarm sequence.After dividing the three cases,i.e.,a strong aftershock duration time larger than 1 day,smaller than 1 day,and no strong aftershock occurred in a main shock type sequence by using the pattern recognition method,we gave the rough correlation relation between strong aftershock duration time and first large shock magnitude for two types of sequences.Finally,the judgment index and method of estimating strong aftershock duration times for different sequence types have been given.展开更多
We construct optimal k-step, 5- to 10-stage, explicit, strong-stability-preserving Hermite-Birkhoff (SSP HB) methods of order 12 with nonnegative coefficients by combining linear k-step methods of order 9 with 5- to 1...We construct optimal k-step, 5- to 10-stage, explicit, strong-stability-preserving Hermite-Birkhoff (SSP HB) methods of order 12 with nonnegative coefficients by combining linear k-step methods of order 9 with 5- to 10-stage Runge-Kutta (RK) methods of order 4. Since these methods maintain the monotonicity property, they are well suited for solving hyperbolic PDEs by the method of lines after a spatial discretization. It is seen that the 8-step 7-stage HB methods have largest effective SSP coefficient among the HB methods of order 12 on hand. On Burgers’ equations, some of the new HB methods have larger maximum effective CFL numbers than Huang’s 7-step hybrid method of order 7, thus allowing larger step size.展开更多
President Xi Jinping said that to tackle the intricate and complex problems facing the world,we need to uphold multilateralism and build a community with a shared future for mankind.CAFIU has actively participated in ...President Xi Jinping said that to tackle the intricate and complex problems facing the world,we need to uphold multilateralism and build a community with a shared future for mankind.CAFIU has actively participated in multilateral activities,such as the sessions of the United Nations Human Rights Council,NGO Conference,C20 and Global Summit of Women,sending a strong message for improving international cooperation in a multilateral way.展开更多
Since the 20 thcentury,the time intervals of M ≥6.7 strong earthquakes in the SichuanYunnan region show obvious regularity.Using the years of the strong events,a twodimensional time coordinate system is generated,bas...Since the 20 thcentury,the time intervals of M ≥6.7 strong earthquakes in the SichuanYunnan region show obvious regularity.Using the years of the strong events,a twodimensional time coordinate system is generated,based on which,the time prediction model is constructed for strong earthquakes in the Sichuan-Yunnan region.Prediction analysis shows that there is risk of generating four earthquakes with M ≥ 6.7 in the Sichuan-Yunnan region in the future 16 years,and there are strong signals for M ≥6.7earthquakes for periods 2012-2021 and 2025-2029.The strong earthquakes may occur around 2014-2015,2019 and 2027.展开更多
The infinite generator of α-times Integrated C semigroups and the properties of resolvent are given. At the same time, we discuss the relationship between the existence of strong solution of a class of nonhomogeneous...The infinite generator of α-times Integrated C semigroups and the properties of resolvent are given. At the same time, we discuss the relationship between the existence of strong solution of a class of nonhomogeneous abstract Cauchy problem and α-times integrated C semigroups, and a sufficient and necessary condition is obtained.展开更多
在机会网络中,节点的行为模式会表现出一定的社交特征,节点往往因相似的移动模式和固定的活动范围,在动态异构网络中表现出一定的集群特性,形成一个个拥有相似社会特征的独特小团体.节点的社会属性表现出长期的稳定性,可以有效应用在路...在机会网络中,节点的行为模式会表现出一定的社交特征,节点往往因相似的移动模式和固定的活动范围,在动态异构网络中表现出一定的集群特性,形成一个个拥有相似社会特征的独特小团体.节点的社会属性表现出长期的稳定性,可以有效应用在路由中.针对这一思想,本文提出了基于社交圈划分和相遇时间预测的机会网络路由算法SCEP(Social Circle division and Encounter time Prediction).该算法关注两个节点形成的直接关系与节点的社会属性特征,定义了基于强社交关系的熟悉集合拓扑,基于熟悉集合的概念以分布式方式开发社区,节点社区的合并受某些规则的约束,并对过时节点进行拓扑剪裁.同时,本文基于节点间相遇的时间间隔序列建模,利用节点间相遇历史数据预测下一次通信的时间.消息的路由通过利用社区、亲密节点集和可预测的通信时间等因素来实现.仿真实验结果表明,与EpSoc,CARA,SAAD,Prophet、NBAPR这5种算法相比,SCEP的性能更好.展开更多
Based on spin-unrestricted hartree fock theory, we present the spin unrestricted multi- configuration time dependent hartree lock theory （UMCTDHF） to describe the electron correlation dynamics of systems interacting...Based on spin-unrestricted hartree fock theory, we present the spin unrestricted multi- configuration time dependent hartree lock theory （UMCTDHF） to describe the electron correlation dynamics of systems interacting with laser field. The positive spin orbitals and the negative spin orbitals are propagated in their own subspace respectively. The spin orbital in the spin-down subspace acts with that in the spin-up subspace by the reduced density matrix and mean field operator. The ground energy is acquired by propagating the trial wave function in the imaginary time by using spin-restricted MCTDHF （RMCTDHF） and UMCTDHF respectively. Then the ionization probabilities and the electrons energies are calculated by using RMCTDHF and UMCTDHF when the laser field is present. The ionization probability calculated with UMCTDHF agrees with the previous theoretical reports very well. The UMCTDHF method is accurate and applicable for open shell system beyond the capability of the RMCTDHF method.展开更多
文摘By means of conceptual model prediction, two short-time strong precipitation processes in Xiamen on June 12th and 14th, 2008 were analyzed from the aspects of real precipitation, weather situation, physical parameter and radar echo. The results showed that two short-time strong precipitation processes had complete different weather backgrounds, so physical quantities which could reflect atmospheric thermal and dynamic characteristic were different, as well as the characteristic and evolution process of radar echo, and it revealed that two short-time strong precipitation processes in Xiamen had various formation mechanisms and evolution processes. Therefore, many data should be combined to grasp different vantage points in precipitation forecast.
基金The project partly supported by the Foundation of Zhongshan University Advanced Research Center
文摘In this paper,a nonlinear time transformation method is presented for the analysis of strong nonlinear oscillation systems.This method can be used to study the limit cycle behavior of the autonomous systems and to analyze the forced vibration of a strong nonlinear system.
文摘We dedicate to the 2D density-dependent nonhomogeneous incompressible Boussinesq equations with vacuum on . At infinity, if the attenuation of initial density and temperature is not very slow. And it is gained that there is a global strong solution and is unique for the 2D Cauchy problem with the initial density which can allow vacuum conditions and even have compact support. Besides, the large time decay rates of the gradients of velocity, temperature and pressure can also be obtained which are also the same as those of the homogeneous case.
文摘Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic field's peak both in the time domain and in the frequency domain.With regard to this problem,after analyzing the time-domain and the frequency-domain characteristics of radar pulsed signals,we propose a new time-frequency combination test method based on the correction of the test parameters,as well as its correction method at different bandwidths.The test method is applied in a quick test of a high-power pulsed radar signal,and the corrected results have error less than 1 dB in both the time domain and the frequency domain,which indicates that the proposed time-frequency combined method is effective in testing strong and pulsed electromagnetic fields.
文摘In this paper, single machine scheduling problems with variable processing time is discussed according to published instances of management engineering. Processing time of a job is the product of a “coefficient' of the job on position i and a “normal' processing time of the job. The criteria considered is to minimize scheduled length of all jobs. A lemma is proposed and proved. In no deadline constrained condition, the problem belongs to polynomial time algorithm. It is proved by using 3 partition that if the problem is deadline constrained, its complexity is strong NP hard. Finally, a conjuncture is proposed that is to be proved.
基金funded by the Spark Program of Earthquake Sciences (XH13012)China Earthquake Administration,and a Key Scientific and Technological Program of Earthquake Administration of Fujian Province (201202)
文摘The paper collects the records by the Fujian Digital Seismic Network of 40 shallow earthquakes in Taiwan with M_S≥5.0 from 1999 to 2013,analyzes the seismic phase(Pn,Sn phase)characteristics and travel-time rules,determines travel-time models and develops a seismic phase travel-time equation based on the two-step fitting algorithm.With the deduction of processing time and network delay time,this method can provide an accurate estimation of early warning time of Taiwan earthquakes for the Fujian region,and has been officially employed in the earthquake early warning system of Fujian Province.
文摘In this paper, we study the Cauchy problem of the density-dependent Boussinesq equations of Korteweg type on the whole space with a vacuum. It is proved that there exists a unique strong solution for the two-dimensional Cauchy problem established that the initial density and the initial temperature decay not extremely slow. Particularly, it is allowed to be arbitrarily large for the initial data and vacuum states for the initial density, even including the compact support. Moreover, when the density depends on the Korteweg term with the viscosity coefficient and capillary coefficient, we obtain a consistent priority estimate by the energy method, and extend the local strong solutions to the global strong solutions. Finally, when the pressure and external force are not affected, we deform the fluid models of Korteweg type, we can obtain the large time decay rates of the gradients of velocity, temperature and pressure.
基金This project was sponsored by the Jiont Earthquake Science Foundation (91012), China
文摘In order to solve the problem of early estimation of moderately strong aftershock duration time in an earthquake sequence,this study has been conducted.First,the definition of the strong aftershock has been given.It is pointed out that there is a difference in the strong aftershock duration time between the main shock type sequence and the strong earthquake swarm sequence.After dividing the three cases,i.e.,a strong aftershock duration time larger than 1 day,smaller than 1 day,and no strong aftershock occurred in a main shock type sequence by using the pattern recognition method,we gave the rough correlation relation between strong aftershock duration time and first large shock magnitude for two types of sequences.Finally,the judgment index and method of estimating strong aftershock duration times for different sequence types have been given.
文摘We construct optimal k-step, 5- to 10-stage, explicit, strong-stability-preserving Hermite-Birkhoff (SSP HB) methods of order 12 with nonnegative coefficients by combining linear k-step methods of order 9 with 5- to 10-stage Runge-Kutta (RK) methods of order 4. Since these methods maintain the monotonicity property, they are well suited for solving hyperbolic PDEs by the method of lines after a spatial discretization. It is seen that the 8-step 7-stage HB methods have largest effective SSP coefficient among the HB methods of order 12 on hand. On Burgers’ equations, some of the new HB methods have larger maximum effective CFL numbers than Huang’s 7-step hybrid method of order 7, thus allowing larger step size.
文摘President Xi Jinping said that to tackle the intricate and complex problems facing the world,we need to uphold multilateralism and build a community with a shared future for mankind.CAFIU has actively participated in multilateral activities,such as the sessions of the United Nations Human Rights Council,NGO Conference,C20 and Global Summit of Women,sending a strong message for improving international cooperation in a multilateral way.
文摘Since the 20 thcentury,the time intervals of M ≥6.7 strong earthquakes in the SichuanYunnan region show obvious regularity.Using the years of the strong events,a twodimensional time coordinate system is generated,based on which,the time prediction model is constructed for strong earthquakes in the Sichuan-Yunnan region.Prediction analysis shows that there is risk of generating four earthquakes with M ≥ 6.7 in the Sichuan-Yunnan region in the future 16 years,and there are strong signals for M ≥6.7earthquakes for periods 2012-2021 and 2025-2029.The strong earthquakes may occur around 2014-2015,2019 and 2027.
文摘The infinite generator of α-times Integrated C semigroups and the properties of resolvent are given. At the same time, we discuss the relationship between the existence of strong solution of a class of nonhomogeneous abstract Cauchy problem and α-times integrated C semigroups, and a sufficient and necessary condition is obtained.
文摘在机会网络中,节点的行为模式会表现出一定的社交特征,节点往往因相似的移动模式和固定的活动范围,在动态异构网络中表现出一定的集群特性,形成一个个拥有相似社会特征的独特小团体.节点的社会属性表现出长期的稳定性,可以有效应用在路由中.针对这一思想,本文提出了基于社交圈划分和相遇时间预测的机会网络路由算法SCEP(Social Circle division and Encounter time Prediction).该算法关注两个节点形成的直接关系与节点的社会属性特征,定义了基于强社交关系的熟悉集合拓扑,基于熟悉集合的概念以分布式方式开发社区,节点社区的合并受某些规则的约束,并对过时节点进行拓扑剪裁.同时,本文基于节点间相遇的时间间隔序列建模,利用节点间相遇历史数据预测下一次通信的时间.消息的路由通过利用社区、亲密节点集和可预测的通信时间等因素来实现.仿真实验结果表明,与EpSoc,CARA,SAAD,Prophet、NBAPR这5种算法相比,SCEP的性能更好.
文摘Based on spin-unrestricted hartree fock theory, we present the spin unrestricted multi- configuration time dependent hartree lock theory （UMCTDHF） to describe the electron correlation dynamics of systems interacting with laser field. The positive spin orbitals and the negative spin orbitals are propagated in their own subspace respectively. The spin orbital in the spin-down subspace acts with that in the spin-up subspace by the reduced density matrix and mean field operator. The ground energy is acquired by propagating the trial wave function in the imaginary time by using spin-restricted MCTDHF （RMCTDHF） and UMCTDHF respectively. Then the ionization probabilities and the electrons energies are calculated by using RMCTDHF and UMCTDHF when the laser field is present. The ionization probability calculated with UMCTDHF agrees with the previous theoretical reports very well. The UMCTDHF method is accurate and applicable for open shell system beyond the capability of the RMCTDHF method.
