We consider optimal birth control for the McKendrick equation of population dyna-mics.It consists of optimizing a system described by a first order partial differential equationwith nonlo-cal bilinear boundary control...We consider optimal birth control for the McKendrick equation of population dyna-mics.It consists of optimizing a system described by a first order partial differential equationwith nonlo-cal bilinear boundary control.Approximate minimum principles are obtained usingEkeland’s vari ational principle.展开更多
Dynamic programming(DP) is an effective query optimization approach to select an appropriate join order for relational database management system(RDBMS) in multi-table joins. This method was extended and made availabl...Dynamic programming(DP) is an effective query optimization approach to select an appropriate join order for relational database management system(RDBMS) in multi-table joins. This method was extended and made available in distributed DBMS(D-DBMS). The structure of this optimal solution was firstly characterized according to the distributing status of tables and data, and then the recurrence relations between a problem and its sub-problems were recursively defined. DP in D-DBMS has the same time-complexity with that in centralized DBMS, while it has the capability to solve a much more sophisticated optimal problem of multi-table join in D-DBMS. The effectiveness of this optimal strategy has been proved by experiments.展开更多
这份报纸讨论脉搏种痘策略的申请阻止并且控制传染疾病，它被组织年龄的先生描述在易受影响、恢复的个人到按年代先后的年龄在哪个被组织建模的一些，当感染的个人到感染年龄被组织时(持续时间自从感染) 。依赖没有疾病的平衡被决定的...这份报纸讨论脉搏种痘策略的申请阻止并且控制传染疾病，它被组织年龄的先生描述在易受影响、恢复的个人到按年代先后的年龄在哪个被组织建模的一些，当感染的个人到感染年龄被组织时(持续时间自从感染) 。依赖没有疾病的平衡被决定的时间，为哪个明确的表情存在。分析结果证明那在那里存在一种全球性稳定的没有感染的状况如果冲动的时期 T 和比例 p 满足 R 0 (p， T )< 1。最佳的问题被讨论：有在给定的 R 0 的最小的费用的脉搏种痘策略(p， T )< 1。展开更多
这篇论文被奉献给学习系统的唯一和存在由使用 C 0-semigroup 理论并且由分析讨论它的指数的稳定性的动态答案光谱系统操作员和它的伪紧密的分发。一些主要可靠性索引与系统操作员和最佳的假期时间的特徵函数被讨论得到最大的系统利润...这篇论文被奉献给学习系统的唯一和存在由使用 C 0-semigroup 理论并且由分析讨论它的指数的稳定性的动态答案光谱系统操作员和它的伪紧密的分发。一些主要可靠性索引与系统操作员和最佳的假期时间的特徵函数被讨论得到最大的系统利润在纸的结束被分析。展开更多
Considering the population evolution process of a community with a large population, suppose F(r, t) denotes the number of individuals aged less than r at the time t, p(r, t)=(?)F(r, t)/(?)r the age distribution or th...Considering the population evolution process of a community with a large population, suppose F(r, t) denotes the number of individuals aged less than r at the time t, p(r, t)=(?)F(r, t)/(?)r the age distribution or the state of the population. The evolution of the population state satisfies the following differential equation:展开更多
In this paper we present the accurate estimation of total fertility rates, prove the theorem of upper and lower bounds of double-edged limit and provide the formulas of upper and lower bounds of total fertility rates....In this paper we present the accurate estimation of total fertility rates, prove the theorem of upper and lower bounds of double-edged limit and provide the formulas of upper and lower bounds of total fertility rates. Based on these estimations and statistical data, we calculate the upper and lower bounds of the double-edged limit for 46 countries including China. Furthermore, we describe the positive growth rate, negative growth rate and zero growth rate of population development. These results are of great importance for us to control population not only in theory but also in practice.展开更多
In this paper we first establish the mathematical model of parity progressive population. Next, we study the spectrum of parity progressive population operator in the Hilbert space L2N+1[0,M] and prove that it generat...In this paper we first establish the mathematical model of parity progressive population. Next, we study the spectrum of parity progressive population operator in the Hilbert space L2N+1[0,M] and prove that it generates a positive co-semigroup. Finally, we discuss the existence and uniqueness of the solution to the equation of dynamics of parity progressive population and its asymptotic properties.展开更多
This paper considers global asymptotic properties for an age-structured model of heroin use based on the principles of mathematical epidemiology where the incidence rate depends on the age of susceptible individuals. ...This paper considers global asymptotic properties for an age-structured model of heroin use based on the principles of mathematical epidemiology where the incidence rate depends on the age of susceptible individuals. The basic reproduction number of the heroin spread is obtained. It completely determines the stability of equilibria. By using the direct Lyapunov method with Volterra type Lyapunov function, the authors show that the drug-free equilibrium is globally asymptotically stable if the basic reproduction number is less than one, and the unique drug spread equilibrium is globally asymptotically stable if the basic reproduction number is greater than one.展开更多
A nonlinear age-dependent population model,which allows for consideration of theeffects of crowding and resource limitation,is presented.The basic properties of solution,such asexistence,positivity,uniqueness,and ulti...A nonlinear age-dependent population model,which allows for consideration of theeffects of crowding and resource limitation,is presented.The basic properties of solution,such asexistence,positivity,uniqueness,and ultimate behavior,are discussed.Also,the condition of stabilityand controll-ability of the nonlinear population system is obtained.展开更多
The target of Hall for Workshop of Meta-synthetic Engineering (HWMSE) is to organically combine the human expert systems, machine systems and knowledge systems so as to realize meta-syntheses. The availability of HWMS...The target of Hall for Workshop of Meta-synthetic Engineering (HWMSE) is to organically combine the human expert systems, machine systems and knowledge systems so as to realize meta-syntheses. The availability of HWMSE embodies in capabilities of knowledge using and knowledge creation. In HWMSE the knowledge systems could be classed into two types: general knowledge system and object knowledge system. A highly strong and continually accumulated object knowledge system is essential for complex system problem solving. Systematic study of the object system is the foundation for knowledge system construction in HWMSE. It is important to design the knowledge system as a whole for systematic research while at the meanwhile open for accumulation through utilization. Case of object knowledge system construction and utilization in the project Research on the Man-machine Collaborated HWMSE Supporting Macroeconomic Policy Making is discussed.展开更多
基金This work was supported in part by a grant from the International Development Research Centre Ottawa,Canada
文摘We consider optimal birth control for the McKendrick equation of population dyna-mics.It consists of optimizing a system described by a first order partial differential equationwith nonlo-cal bilinear boundary control.Approximate minimum principles are obtained usingEkeland’s vari ational principle.
文摘Dynamic programming(DP) is an effective query optimization approach to select an appropriate join order for relational database management system(RDBMS) in multi-table joins. This method was extended and made available in distributed DBMS(D-DBMS). The structure of this optimal solution was firstly characterized according to the distributing status of tables and data, and then the recurrence relations between a problem and its sub-problems were recursively defined. DP in D-DBMS has the same time-complexity with that in centralized DBMS, while it has the capability to solve a much more sophisticated optimal problem of multi-table join in D-DBMS. The effectiveness of this optimal strategy has been proved by experiments.
基金supported by Natural Science Foundation of Henan Province under Grant No.092300410206Science and Technology Program of Educational Department of Henan Province under Grant No. 2009A110015
文摘这份报纸讨论脉搏种痘策略的申请阻止并且控制传染疾病，它被组织年龄的先生描述在易受影响、恢复的个人到按年代先后的年龄在哪个被组织建模的一些，当感染的个人到感染年龄被组织时(持续时间自从感染) 。依赖没有疾病的平衡被决定的时间，为哪个明确的表情存在。分析结果证明那在那里存在一种全球性稳定的没有感染的状况如果冲动的时期 T 和比例 p 满足 R 0 (p， T )< 1。最佳的问题被讨论：有在给定的 R 0 的最小的费用的脉搏种痘策略(p， T )< 1。
文摘Considering the population evolution process of a community with a large population, suppose F(r, t) denotes the number of individuals aged less than r at the time t, p(r, t)=(?)F(r, t)/(?)r the age distribution or the state of the population. The evolution of the population state satisfies the following differential equation:
文摘In this paper we present the accurate estimation of total fertility rates, prove the theorem of upper and lower bounds of double-edged limit and provide the formulas of upper and lower bounds of total fertility rates. Based on these estimations and statistical data, we calculate the upper and lower bounds of the double-edged limit for 46 countries including China. Furthermore, we describe the positive growth rate, negative growth rate and zero growth rate of population development. These results are of great importance for us to control population not only in theory but also in practice.
文摘In this paper we first establish the mathematical model of parity progressive population. Next, we study the spectrum of parity progressive population operator in the Hilbert space L2N+1[0,M] and prove that it generates a positive co-semigroup. Finally, we discuss the existence and uniqueness of the solution to the equation of dynamics of parity progressive population and its asymptotic properties.
基金supported partially by the National Natural Science Foundation of China under Grant Nos.1127131411371305
文摘This paper considers global asymptotic properties for an age-structured model of heroin use based on the principles of mathematical epidemiology where the incidence rate depends on the age of susceptible individuals. The basic reproduction number of the heroin spread is obtained. It completely determines the stability of equilibria. By using the direct Lyapunov method with Volterra type Lyapunov function, the authors show that the drug-free equilibrium is globally asymptotically stable if the basic reproduction number is less than one, and the unique drug spread equilibrium is globally asymptotically stable if the basic reproduction number is greater than one.
文摘A nonlinear age-dependent population model,which allows for consideration of theeffects of crowding and resource limitation,is presented.The basic properties of solution,such asexistence,positivity,uniqueness,and ultimate behavior,are discussed.Also,the condition of stabilityand controll-ability of the nonlinear population system is obtained.
基金This work was supported by National Natural Science Foundation of China under Grant No. 79990580. The original version was presented at the Congress of the IFSR2005.
文摘The target of Hall for Workshop of Meta-synthetic Engineering (HWMSE) is to organically combine the human expert systems, machine systems and knowledge systems so as to realize meta-syntheses. The availability of HWMSE embodies in capabilities of knowledge using and knowledge creation. In HWMSE the knowledge systems could be classed into two types: general knowledge system and object knowledge system. A highly strong and continually accumulated object knowledge system is essential for complex system problem solving. Systematic study of the object system is the foundation for knowledge system construction in HWMSE. It is important to design the knowledge system as a whole for systematic research while at the meanwhile open for accumulation through utilization. Case of object knowledge system construction and utilization in the project Research on the Man-machine Collaborated HWMSE Supporting Macroeconomic Policy Making is discussed.
