Sweep method in analysis optimal control for rendez-vous problems

This paper deals with determining the sufficient conditions of minimum for the class of problems in which the necessary conditions of optimum are satisfied in the strengthened form Legendre-Clebsch. To this paper, we shall use the sweep method which analysis the conditions of existence of the conjugated points on the optimal trajectory. The study we have done evaluates the command variation on the neighboring optimal trajectory. The sufficient conditions of minimum are obtained by imposing the positivity of the second variation. The results that this method offers are applied to the problem o the orbital rendez-vous for the linear case of the equations of movement.     

Optimal control policies for resource allocation in an activity network

In the paper a class of project-scheduling problems concerning the allocation of continuously divisible resources is considered. It is assumed that performing speeds of activities are continuous functions of the resource amount, and that the initial and terminal states of activities are known. For such mathematical models of project activities the problem of time-optimal resource allocation under instantaneous and integral constrains on a resource, and the problem of cost-optimal resource allocation with fixed project duration are formulated and a general solution concept is proposed. Necessary and sufficient conditions for the existence of a solution in particular cases are derived and properties of optimal schedules are given. The control policies for resource allocation are constructed for the example of the cost-optimal problem.     

Strong solutions and trajectory attractors to the thin-film equation with absorption

We prove local and global in time existence of non-negative weak solutions to the thin-film equation with absorption and obtain sufficient conditions for extra regularity of these solutions. Moreover, for the class of global strong solutions, we show existence of a trajectory attractor.     

Tensor conditions for the existence of a common solution to the Lyapunov equation

Necessary and sufficient conditions for the existence of a common solution to the Lyapunov equation for two stable complex matrices are derived. These conditions are applied to the cases when a common weak solution to the Lyapunov equation exists. Conditions for the existence of a common solution to the Lyapunov equation for two complex 2 × 2 and two complex 3 × 3 matrices are derived.     

Symmetries in Projective Multiresolution Analyses

We give an equivariant version of Packer and Rieffel’s theorem on sufficient conditions for the existence of orthonormal wavelets in projective multiresolution analysis. Suppose that the scaling functions are invariant with respect to some finite group action. We give sufficient conditions for the existence of wavelets with similar invariance. Research supported in part by the Research Council of Norway, project number NFR 154077/420. Some of the final work was also done with the support from the project NFR 170620/V30.     

Investment in electric energy storage under uncertainty: a real options approach

In this paper we develop a real options approach to evaluate the profitability of investing in a battery bank. The approach determines the optimal investment timing under conditions of uncertain future revenues and investment cost. It includes time arbitrage of the spot price and profits by providing ancillary services. Current studies of battery banks are limited, because they do not consider the uncertainty and the possibility of operating in both markets at the same time. We confirm previous research in the sense that when a battery bank participates in the spot market alone, the revenues are not sufficient to cover the initial investment cost. However, under the condition that the battery bank also can receive revenues from the balancing market, both the net present value (NPV) and the real options value are positive. The real options value is higher than the NPV, confirming the value of flexible investment timing when both revenues and investment cost are uncertain.     

On period-$k$ solution for a population system with state-dependent impulsive effect

The period-$k$ solutions of population differential system with state-dependent impulsive effect are investigated by the theory of discontinuous dynamical system. Through $G$-function theory, the necessary and sufficient conditions are obtained for trajectory direction of a population differential system, and the results are better than the previous work. Also, the local stability of period-$k$ solutions is studied by the mapping structure and the theory of eigenvalue analysis. Furthermore, the existence of period-1 solution is investigated for a special impulsive population differential system, and the analytical condition is established. Finally, the trajectory of period-1 solution and the relationship between different parameters and the module of eigenvalues are illustrated.     

具亚线性功能反应函数的捕食模型的定性分析

研究了一类食饵具常数存放且功能反应函数为亚线性函数的食饵-捕食者模型,获得了正平衡点全局渐近稳定,极限环存在惟一的充分条件.     

一类具有功能反应函数捕食-食饵模型的定性分析

本文讨论了一类具有功能反应函数的捕食食饵模型.通过定性分析,得到了系统轨线全局稳定性,闭轨线的存在性和极限环唯一性的一些充分条件.     

Factorization in the Wiener algebra of a class of 2×2 matrix functions

In this paper the problem of the factorization in the Wiener algebra of a class of 2×2 matrix functions of Daniele type is considered. For these matrix functions necessary and sufficient conditions for the existence of a canonical factorization are obtained and, provided these conditions are fulfilled, the factors of such factorization can be derived in an explicit form.     

单时期证券市场的最优投资组合

考虑了单时期金融市场模型的最优投资组合问题,并对一般的效用函数,给出了最优投资组合问题有解的一个充分条件.     

具常数存放的非线性功能反应捕食模型的定性分析

研究一类食饵具常数存放且功能反应函数为次线性函数的食饵-捕食者模型,获得了一些平衡点全局渐近稳定,极限环存在惟一的充分条件.利用数值仿真检验了我们的结论.     

Monotone solutions of second-order nonlinear differential equations

Necessary and sufficient conditions are obtained for existence of monotone solutions of a nonlinear differential equation. As applications, several existence criteria and comparison theorems are derived.     

具次线性功能反应函数的食饵-捕食者模型的定性分析

本文研究了一类食饵具常数存放且功能反应函数为次线性函数的食饵-捕食者模型.利用常微分方程定性理论和稳定性理论的分析方法,获得了一些平衡点全局渐近稳定,极限环存在唯一的充分条件.     

Leakage delays in BAM

A well known bidirectional associative memory (BAM) model is generalized with the introduction of discrete time delays in the leakage (or forgetting) terms. By using a model transformation, the system is converted to one of a neutral delay system. Two sets of delay dependent sufficient conditions are derived for the existence of a unique equilibrium as well as its asymptotic and exponential stability. The methods of degenerate Lyapunov-Kravsovskii functionals and inequalities together with some properties of M-matrices are used in the derivation of sufficient conditions. In the absence of leakage delays, the sufficient conditions lead to some known sufficient conditions.     

Riemann problem in non-ideal gas dynamics

In this paper we consider the Riemann problem for gas dynamic equations governing a one dimensional flow of van der Waals gases. The existence and uniqueness of shocks, contact discontinuities, simple wave solutions are discussed using R-H conditions and Lax conditions. The explicit form of solutions for shocks, contact discontinuities and simple waves are derived. The effects of van der Waals parameter on the shock and simple waves are studied. A condition is derived on the initial data for the existence of a solution to the Riemann problem. Moreover, a necessary and sufficient condition is derived on the initial data which gives the information about the existence of a shock wave or a simple wave for a 1-family and a 3-family of characteristics in the solution of the Riemann problem.     

Coefficient criteria for the existence of a limit cycle in a two-dimensional system with hysteresis

Necessary and sufficient conditions for existence of a limit cycle in a two-dimensional system with hysteresis nonlinearity are derived in terms of the system coefficients.     

An approach for an algorithmic solution of discrete optimal control problems and their game-theoretical extension

We consider time discrete systems which are described by a system of difference equations. The related discrete optimal control problems are introduced. Additionally, a gametheoretic extension is derived, which leads to general multicriteria decision problems. The characterization of their optimal behavior is studied. Given starting and final states define the decision process; applying dynamic programming techniques suitable optimal solutions can be gained. We generalize that approach to a special gametheoretic decision procedure on networks. We characterize Nash equilibria and present sufficient conditions for their existence. A constructive algorithm is derived. The sufficient conditions are exploited to get the algorithmic solution. Its complexity analysis is presented and at the end we conclude with an extension to the complementary case of Pareto optima.Dmitrii Lozovanu was Supported by BGP CRDF-MRDA MOM2-3049-CS-03.     

Weakly nonlinear boundary-value problems for differential systems with pulse influence

The coefficient sufficient conditions for the existence of solutions and the iteration algorithm of constructing these solutions are obtained for weakly nonlinear boundary-value problems for systems of ordinary differential equations with pulse influence in the general case in which the number of boundary conditions does not coincide with the order of the differential system. The equation is derived for generating amplitudes of these boundary-value problems. This equation determines the amplitude of a solution, which can be regarded as generating for the required solution, and gives necessary conditions for the existence of this solution.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 45, No. 2, pp. 221–225, February, 1993.     

时标上带有反馈控制的两种群竞争系统的概周期解

研究了一类时标上带有反馈控制的两种群竞争系统的概周期解的存在性与稳定性.首先应用微分不等式和比较原理得到了该系统的持久性.在此基础上,通过构造了一个合适的Lyapunov泛函,得到该系统存在唯一一致渐近稳定正概周期解的充分条件.文中对以前的相关文献研究结果进行了推广.