The issues of solvability and construction of a solution of the Fredholm integral equation of the first kind are considered. It is done by immersing the original problem into solving an extremal problem in Hilbert spa...The issues of solvability and construction of a solution of the Fredholm integral equation of the first kind are considered. It is done by immersing the original problem into solving an extremal problem in Hilbert space. Necessary and sufficient conditions for the existence of a solution are obtained. A method of constructing a solution of the Fredholm integral equation of the first kind is developed. A constructive theory of solvability and construction of a solution to a boundary value problem of a linear integrodifferential equation with a distributed delay in control, generated by the Fredholm integral equation of the first kind, has been created.展开更多
The minimax path location problem is to find a path P in a graph G such that the maximum distance d_(G)(v,P)from every vertex v∈V(G)to the path P is minimized.It is a well-known NP-hard problem in network optimizatio...The minimax path location problem is to find a path P in a graph G such that the maximum distance d_(G)(v,P)from every vertex v∈V(G)to the path P is minimized.It is a well-known NP-hard problem in network optimization.This paper studies the fixed-parameter solvability,that is,for a given graph G and an integer k,to decide whether there exists a path P in G such that max v∈V(G)d_(G)(v,P)≤k.If the answer is affirmative,then graph G is called k-path-eccentric.We show that this decision problem is NP-complete even for k=1.On the other hand,we characterize the family of 1-path-eccentric graphs,including the traceable,interval,split,permutation graphs and others.Furthermore,some polynomially solvable special graphs are discussed.展开更多
Linear differential-algebraic equations (DAEs) with time-varying coefficients A(t)x’(t) + B(t)x(t) = q(t), which are tractable with a higher index, are discussed. Their essential properties are investigated. Some equ...Linear differential-algebraic equations (DAEs) with time-varying coefficients A(t)x’(t) + B(t)x(t) = q(t), which are tractable with a higher index, are discussed. Their essential properties are investigated. Some equivalent systems are given. Using them the paper shows how to state properly initial and boundary conditions for these DAEs. The eaistence and uniqueness theory of the solution of the initial and boundary value problems for higher index DAEs are proposed.展开更多
differential inclusion d u d t∈f(t,u) is presented. The convergence of the approximation solution and the existence of the solution for abstract evolution multivalued problem are discussed.
The integrability of the coupled, modified KdV equation and the potential Boiti-Leon-Manna-Pempinelli(mKdVBLMP) system is investigated using the Painleve analysis approach. It is shown that this coupled system possess...The integrability of the coupled, modified KdV equation and the potential Boiti-Leon-Manna-Pempinelli(mKdVBLMP) system is investigated using the Painleve analysis approach. It is shown that this coupled system possesses the Painleve property in both the principal and secondary branches. Then, the consistent Riccati expansion(CRE)method is applied to the coupled mKdV-BLMP system. As a result, it is CRE solvable for the principal branch while non-CRE solvable for the secondary branch. Finally; starting from the last consistent differential equation in the CRE solvable case, soliton, multiple resonant soliton solutions and soliton-cnoidal wave interaction solutions are constructed explicitly.展开更多
Applying constructed homotopy and its properties,we gel some sufficient conditions for the solvability of algebraic inverse eigenvalue problems,which are better than that of the paper [4] in some cases. Inverse eigenv...Applying constructed homotopy and its properties,we gel some sufficient conditions for the solvability of algebraic inverse eigenvalue problems,which are better than that of the paper [4] in some cases. Inverse eigenvalue problems,solvability,sufficient conditions.展开更多
This paper discusses problem IEP:Given n×m matrix X and m×m diagonal matrix A, find an n×n matrix A such that AX=XA.The new solvablily conditions for the problem IEP are obtained. The eigenvalue dislrib...This paper discusses problem IEP:Given n×m matrix X and m×m diagonal matrix A, find an n×n matrix A such that AX=XA.The new solvablily conditions for the problem IEP are obtained. The eigenvalue dislribulaion of the solutions for the problem IEP are described in detail.展开更多
We study the solvability of two classes of Diophantine equations by using some new methods and new results in this paper. Let p be an odd prime and B n denote nth Bernoulli number. We prove that if p≡1(mod 4) and p...We study the solvability of two classes of Diophantine equations by using some new methods and new results in this paper. Let p be an odd prime and B n denote nth Bernoulli number. We prove that if p≡1(mod 4) and pB (p-1)/2 , then the equation x p+2 2m n 4=p ky 2, m,n,k∈[FK(W+3mm\.3mm][TPP107A,+3mm?3mm,BP], k>1, gcd (x,py)=1, and the equation x p+y 2=p kz 4, k∈[FK(W+3mm\.3mm][TPP107A,+3mm?3mm,BP], gcd (x,y)=1, k>1, 2|y have no integral solutions respectively.展开更多
In this paper, we are concerned with the solvability for a class of nonlinear sequential fractional dynamical systems with damping infinite dimensional spaces, which involves fractional Riemann-Liouville derivatives. ...In this paper, we are concerned with the solvability for a class of nonlinear sequential fractional dynamical systems with damping infinite dimensional spaces, which involves fractional Riemann-Liouville derivatives. The solutions of the dynamical systems are obtained by utilizing the method of Laplace transform technique and are based on the formula of the Laplace transform of the Mittag-Leffler function in two parameters. Next, we present the existence and uniqueness of solutions for nonlinear sequential fractional dynamical systems with damping by using fixed point theorems under some appropriate conditions.展开更多
In this paper, we investigate the effect of weight function in the nonlinear part on global solvability of the Cauchy problem for a class of semi-linear hyperbolic equations with damping.
This paper reinterprets the economic input-output equation as a description of a realized situation without considering decision making. This paper uses the equation that the self-sufficiency rate is added to the Leon...This paper reinterprets the economic input-output equation as a description of a realized situation without considering decision making. This paper uses the equation that the self-sufficiency rate is added to the Leontief type, and discusses its solvability. The equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. This condition means that commodities which a part of the relevant society possesses are not all inputted to its inside. Moreover, if the process of input and output is time irreversible, each part of the relevant society satisfies the space-time openness condition. Therefore, the solvability of the equation is guaranteed by time irreversibility. This proposition seems to be relevant to the grandfather paradox which is a type of time paradox.展开更多
We use the Bethe ansatz method to investigate the Schrdinger equation for a class of PT-symmetric non-Hermitian Hamiltonians. Elementary exact solutions for the eigenvalues and the corresponding wave functions are o...We use the Bethe ansatz method to investigate the Schrdinger equation for a class of PT-symmetric non-Hermitian Hamiltonians. Elementary exact solutions for the eigenvalues and the corresponding wave functions are obtained in terms of the roots of a set of algebraic equations. Also, it is shown that the problems possess sl(2) hidden symmetry and then the exact solutions of the problems are obtained by employing the representation theory of sl(2) Lie algebra. It is found that the results of the two methods are the same.展开更多
In this paper,a leader-follower stochastic differential game is studied for a linear stochastic differential equation with quadratic cost functionals.The coefficients in the state equation and the weighting matrices i...In this paper,a leader-follower stochastic differential game is studied for a linear stochastic differential equation with quadratic cost functionals.The coefficients in the state equation and the weighting matrices in the cost functionals are all deterministic.Closed-loop strategies are introduced,which require to be independent of initial states;and such a nature makes it very useful and convenient in applications.The follower first solves a stochastic linear quadratic optimal control problem,and his optimal closed-loop strategy is characterized by a Riccati equation,together with an adapted solution to a linear backward stochastic differential equation.Then the leader turns to solve a stochastic linear quadratic optimal control problem of a forward-backward stochastic differential equation,necessary conditions for the existence of the optimal closed-loop strategy for the leader is given by a Riccati equation.Some examples are also given.展开更多
Optimal power flow (OPF) has been considered as an important problem in power systems. Although several excellent algorithms, such as Newton method and interior point method, have been developed to solve the OPF probl...Optimal power flow (OPF) has been considered as an important problem in power systems. Although several excellent algorithms, such as Newton method and interior point method, have been developed to solve the OPF problem, divergences still often occur. Till now, few works have focused on the solv- ability identification and feasibility restoring of divergent OPF problems. In this paper, we propose a systematic approach to identify the solvability of divergent OPF problems, and restore a feasible solu- tion for unsolvable OPF cases. The proposed approach consists of two phases: solvability identifica- tion phase (SIP) and feasibility restoring phase (FRP). In SIP, a novel methodology based on problem transformation and active set is adopted to identify the solvability of divergent OPF problem. If a fea- sible solution can be obtained in SIP, then this divergent OPF problem is solvable, otherwise, FRP is used to restore a feasible or optimal solution by relaxing soft constraints and load shedding. In FRP, a feasibility restoring model is presented, and a priority-listing strategy of restoring actions is proposed to restore the unsolvable OPF problems. Numerical studies indicate that the proposed SIP and FRP are reliable to diagnose the solvability of the divergent OPF problems, give an index to measure the un- solvability, and restore an unsolvable OPF case.展开更多
The main purpose of the present paper is to examine the existence and local uniqueness of solutions of the implicit equations arising in the application of a weakly algebraically stable general linear methods to dissi...The main purpose of the present paper is to examine the existence and local uniqueness of solutions of the implicit equations arising in the application of a weakly algebraically stable general linear methods to dissipative dynamical systems, and to extend the existing relevant results of Runge-Kutta methods by Humphries and Stuart(1994).展开更多
This paper studies the following two problems:Problem Ⅰ. Given X, B ∈ Rnxm, find A ∈ Ps,n, such that AX = B, where Ps, n = {A ∈ SRnxn|XTA>0,STX = 0, for given S ∈ R}.Problem Ⅱ. Given A* ∈ Rnxn, find A ∈ SE,...This paper studies the following two problems:Problem Ⅰ. Given X, B ∈ Rnxm, find A ∈ Ps,n, such that AX = B, where Ps, n = {A ∈ SRnxn|XTA>0,STX = 0, for given S ∈ R}.Problem Ⅱ. Given A* ∈ Rnxn, find A ∈ SE, such that ||A*-A|| = infA∈SE||A* -A|| where SE denotes the solution set of Problem Ⅰ.The necessary and sufficient conditions for the solvability of Problem Ⅰ, the expression of the general solution of Problem Ⅰ and the solution of Problem Ⅱ are given for two cases. For the general case, the equivalent form of conditions for the solvability of Problem Ⅰ is given.展开更多
W. Feit has ever beautifully proved the following theorem by the abstract group theoretic method.Theorem 1. Let G be an arbitrary finite group with a cyclic Sylow p-subgroup. If there exists a normal subgroup N of G s...W. Feit has ever beautifully proved the following theorem by the abstract group theoretic method.Theorem 1. Let G be an arbitrary finite group with a cyclic Sylow p-subgroup. If there exists a normal subgroup N of G such that P|(|N|, |G/N|), then G is psolvable.展开更多
We consider the higher-order Cauchy problem (ACP<sub>n</sub>) x<sup>n</sup>(t)=sum from i=0 to n-1 B<sub>i</sub>x<sup>i</sup>(t)<sub>1</sub>x<sup>...We consider the higher-order Cauchy problem (ACP<sub>n</sub>) x<sup>n</sup>(t)=sum from i=0 to n-1 B<sub>i</sub>x<sup>i</sup>(t)<sub>1</sub>x<sup>i</sup>(0)=x<sub>i</sub> for 0≤i≤n-1,where B<sub>i</sub>(0≤i≤n-1) are closed linear operators on a Banach space X such that D=∩ i=0 n-1 D(B<sub>i</sub>)is dense in X. It is well known that the solvability and the well-posedness of (ACP<sub>n</sub>)were studied only in some special cases, such as D(B<sub>n-1</sub>)?D(B<sub>i</sub>) for 0≤i≤n-2 by F. Neu-brander and a factoring case by J. T. Sandefur. In this paper, by using some new results ofvector valued Laplace transforms given by W. Arenddt, we obtain some characterizations ofthe solvability and some sufficiency conditions of the well-posedness for general (ACP<sub>n</sub>),which generalize F. Neubrander’s results and the famous results for (ACP<sub>1</sub>)展开更多
The solvability of quadratic optimal control via output feedback is studied. It has been concluded that every optimal output feedback is a derivative solution to the corresponding optimal-state feedback, and the linea...The solvability of quadratic optimal control via output feedback is studied. It has been concluded that every optimal output feedback is a derivative solution to the corresponding optimal-state feedback, and the linear matrix equation that determines the existence of the optimal output feedback is generally unsolvable. The output matrix C with some parameters is discussed, and the necessary condition for the existence of the optimal output feedback is given. Moreover, for the single-input system, the condition is proved almost sufficient.展开更多
文摘The issues of solvability and construction of a solution of the Fredholm integral equation of the first kind are considered. It is done by immersing the original problem into solving an extremal problem in Hilbert space. Necessary and sufficient conditions for the existence of a solution are obtained. A method of constructing a solution of the Fredholm integral equation of the first kind is developed. A constructive theory of solvability and construction of a solution to a boundary value problem of a linear integrodifferential equation with a distributed delay in control, generated by the Fredholm integral equation of the first kind, has been created.
文摘The minimax path location problem is to find a path P in a graph G such that the maximum distance d_(G)(v,P)from every vertex v∈V(G)to the path P is minimized.It is a well-known NP-hard problem in network optimization.This paper studies the fixed-parameter solvability,that is,for a given graph G and an integer k,to decide whether there exists a path P in G such that max v∈V(G)d_(G)(v,P)≤k.If the answer is affirmative,then graph G is called k-path-eccentric.We show that this decision problem is NP-complete even for k=1.On the other hand,we characterize the family of 1-path-eccentric graphs,including the traceable,interval,split,permutation graphs and others.Furthermore,some polynomially solvable special graphs are discussed.
基金Project supported by the National Natural Science Foundation of China by Jiangsu Provincial Natural Science Foundation
文摘Linear differential-algebraic equations (DAEs) with time-varying coefficients A(t)x’(t) + B(t)x(t) = q(t), which are tractable with a higher index, are discussed. Their essential properties are investigated. Some equivalent systems are given. Using them the paper shows how to state properly initial and boundary conditions for these DAEs. The eaistence and uniqueness theory of the solution of the initial and boundary value problems for higher index DAEs are proposed.
基金the National Natural Science Foundation of China(No.197710 62 )
文摘differential inclusion d u d t∈f(t,u) is presented. The convergence of the approximation solution and the existence of the solution for abstract evolution multivalued problem are discussed.
基金Supported by the Natural Science Foundation of Zhejiang Province of China under Grant No LY14A010005
文摘The integrability of the coupled, modified KdV equation and the potential Boiti-Leon-Manna-Pempinelli(mKdVBLMP) system is investigated using the Painleve analysis approach. It is shown that this coupled system possesses the Painleve property in both the principal and secondary branches. Then, the consistent Riccati expansion(CRE)method is applied to the coupled mKdV-BLMP system. As a result, it is CRE solvable for the principal branch while non-CRE solvable for the secondary branch. Finally; starting from the last consistent differential equation in the CRE solvable case, soliton, multiple resonant soliton solutions and soliton-cnoidal wave interaction solutions are constructed explicitly.
文摘Applying constructed homotopy and its properties,we gel some sufficient conditions for the solvability of algebraic inverse eigenvalue problems,which are better than that of the paper [4] in some cases. Inverse eigenvalue problems,solvability,sufficient conditions.
文摘This paper discusses problem IEP:Given n×m matrix X and m×m diagonal matrix A, find an n×n matrix A such that AX=XA.The new solvablily conditions for the problem IEP are obtained. The eigenvalue dislribulaion of the solutions for the problem IEP are described in detail.
文摘We study the solvability of two classes of Diophantine equations by using some new methods and new results in this paper. Let p be an odd prime and B n denote nth Bernoulli number. We prove that if p≡1(mod 4) and pB (p-1)/2 , then the equation x p+2 2m n 4=p ky 2, m,n,k∈[FK(W+3mm\.3mm][TPP107A,+3mm?3mm,BP], k>1, gcd (x,py)=1, and the equation x p+y 2=p kz 4, k∈[FK(W+3mm\.3mm][TPP107A,+3mm?3mm,BP], gcd (x,y)=1, k>1, 2|y have no integral solutions respectively.
文摘In this paper, we are concerned with the solvability for a class of nonlinear sequential fractional dynamical systems with damping infinite dimensional spaces, which involves fractional Riemann-Liouville derivatives. The solutions of the dynamical systems are obtained by utilizing the method of Laplace transform technique and are based on the formula of the Laplace transform of the Mittag-Leffler function in two parameters. Next, we present the existence and uniqueness of solutions for nonlinear sequential fractional dynamical systems with damping by using fixed point theorems under some appropriate conditions.
文摘In this paper, we investigate the effect of weight function in the nonlinear part on global solvability of the Cauchy problem for a class of semi-linear hyperbolic equations with damping.
文摘This paper reinterprets the economic input-output equation as a description of a realized situation without considering decision making. This paper uses the equation that the self-sufficiency rate is added to the Leontief type, and discusses its solvability. The equation has a unique solution if and only if each part of the relevant society satisfies the space-time openness condition. This condition means that commodities which a part of the relevant society possesses are not all inputted to its inside. Moreover, if the process of input and output is time irreversible, each part of the relevant society satisfies the space-time openness condition. Therefore, the solvability of the equation is guaranteed by time irreversibility. This proposition seems to be relevant to the grandfather paradox which is a type of time paradox.
文摘We use the Bethe ansatz method to investigate the Schrdinger equation for a class of PT-symmetric non-Hermitian Hamiltonians. Elementary exact solutions for the eigenvalues and the corresponding wave functions are obtained in terms of the roots of a set of algebraic equations. Also, it is shown that the problems possess sl(2) hidden symmetry and then the exact solutions of the problems are obtained by employing the representation theory of sl(2) Lie algebra. It is found that the results of the two methods are the same.
基金This work was supported by National Key Research&Development Program of China under Grant No.2022YFA1006104National Natural Science Foundations of China under Grant Nos.11971266,11831010Shandong Provincial Natural Science Foundations under Grant Nos.ZR2022JQ01,ZR2020ZD24,ZR2019ZD42.
文摘In this paper,a leader-follower stochastic differential game is studied for a linear stochastic differential equation with quadratic cost functionals.The coefficients in the state equation and the weighting matrices in the cost functionals are all deterministic.Closed-loop strategies are introduced,which require to be independent of initial states;and such a nature makes it very useful and convenient in applications.The follower first solves a stochastic linear quadratic optimal control problem,and his optimal closed-loop strategy is characterized by a Riccati equation,together with an adapted solution to a linear backward stochastic differential equation.Then the leader turns to solve a stochastic linear quadratic optimal control problem of a forward-backward stochastic differential equation,necessary conditions for the existence of the optimal closed-loop strategy for the leader is given by a Riccati equation.Some examples are also given.
基金Supported by the National Natural Science Foundation of China (Grant No. 50507018)the Key Project of Chinese Ministry of Education (Grant No. 107063)the Natural Science Fund of Zhejiang Province (Grant No. R1080089)
文摘Optimal power flow (OPF) has been considered as an important problem in power systems. Although several excellent algorithms, such as Newton method and interior point method, have been developed to solve the OPF problem, divergences still often occur. Till now, few works have focused on the solv- ability identification and feasibility restoring of divergent OPF problems. In this paper, we propose a systematic approach to identify the solvability of divergent OPF problems, and restore a feasible solu- tion for unsolvable OPF cases. The proposed approach consists of two phases: solvability identifica- tion phase (SIP) and feasibility restoring phase (FRP). In SIP, a novel methodology based on problem transformation and active set is adopted to identify the solvability of divergent OPF problem. If a fea- sible solution can be obtained in SIP, then this divergent OPF problem is solvable, otherwise, FRP is used to restore a feasible or optimal solution by relaxing soft constraints and load shedding. In FRP, a feasibility restoring model is presented, and a priority-listing strategy of restoring actions is proposed to restore the unsolvable OPF problems. Numerical studies indicate that the proposed SIP and FRP are reliable to diagnose the solvability of the divergent OPF problems, give an index to measure the un- solvability, and restore an unsolvable OPF case.
基金a grant !(No. 19871070) from NSF of China a grant!(No. A757D9I0) from Academy of Mathematics and System Sciences, Academy o
文摘The main purpose of the present paper is to examine the existence and local uniqueness of solutions of the implicit equations arising in the application of a weakly algebraically stable general linear methods to dissipative dynamical systems, and to extend the existing relevant results of Runge-Kutta methods by Humphries and Stuart(1994).
文摘This paper studies the following two problems:Problem Ⅰ. Given X, B ∈ Rnxm, find A ∈ Ps,n, such that AX = B, where Ps, n = {A ∈ SRnxn|XTA>0,STX = 0, for given S ∈ R}.Problem Ⅱ. Given A* ∈ Rnxn, find A ∈ SE, such that ||A*-A|| = infA∈SE||A* -A|| where SE denotes the solution set of Problem Ⅰ.The necessary and sufficient conditions for the solvability of Problem Ⅰ, the expression of the general solution of Problem Ⅰ and the solution of Problem Ⅱ are given for two cases. For the general case, the equivalent form of conditions for the solvability of Problem Ⅰ is given.
基金Project supported by Fok Ying Tung Education Foundation.
文摘W. Feit has ever beautifully proved the following theorem by the abstract group theoretic method.Theorem 1. Let G be an arbitrary finite group with a cyclic Sylow p-subgroup. If there exists a normal subgroup N of G such that P|(|N|, |G/N|), then G is psolvable.
文摘We consider the higher-order Cauchy problem (ACP<sub>n</sub>) x<sup>n</sup>(t)=sum from i=0 to n-1 B<sub>i</sub>x<sup>i</sup>(t)<sub>1</sub>x<sup>i</sup>(0)=x<sub>i</sub> for 0≤i≤n-1,where B<sub>i</sub>(0≤i≤n-1) are closed linear operators on a Banach space X such that D=∩ i=0 n-1 D(B<sub>i</sub>)is dense in X. It is well known that the solvability and the well-posedness of (ACP<sub>n</sub>)were studied only in some special cases, such as D(B<sub>n-1</sub>)?D(B<sub>i</sub>) for 0≤i≤n-2 by F. Neu-brander and a factoring case by J. T. Sandefur. In this paper, by using some new results ofvector valued Laplace transforms given by W. Arenddt, we obtain some characterizations ofthe solvability and some sufficiency conditions of the well-posedness for general (ACP<sub>n</sub>),which generalize F. Neubrander’s results and the famous results for (ACP<sub>1</sub>)
基金Project supported by the National Natural Science Fundation of China.
文摘The solvability of quadratic optimal control via output feedback is studied. It has been concluded that every optimal output feedback is a derivative solution to the corresponding optimal-state feedback, and the linear matrix equation that determines the existence of the optimal output feedback is generally unsolvable. The output matrix C with some parameters is discussed, and the necessary condition for the existence of the optimal output feedback is given. Moreover, for the single-input system, the condition is proved almost sufficient.