In the first part, we consider general singular control problems for random fields given by a stochastic partial differential equation (SPDE). We show that under some conditions the optimal singular control can be identified with the solution of a coupled system of SPDE and a kind of reflected backward SPDE (RBSPDE).In the second part, existence and uniqueness of solutions of RBSPDEs are establ...

We consider a mixed stochastic control problem that arises in Mathematical Finance literature with the study of interactions between dividend policy and investment. This problem combines features of both optimal switching and singular control. We prove that our mixed problem can be decoupled in two pure optimal stopping and singular control problems. Furthermore, we describe the form of the opt...

Two linear-convex deterministic singular control problems in dimensions one and two are considered in this paper. They are solved using the dynamic programming method. The interest here is the explicitness of the results and the relation between the geometry of the drift along the free boundary of these problems and the principle of smooth t. The method of dynamic programming reduces the study ...

In this paper we study a two-phase free boundary problem for a semilinear elliptic equation on a bounded domain $Dsubset mathbb{R}^{n}$ with smooth boundary‎. ‎We give some results on the growth of solutions and characterize the free boundary points in terms of homogeneous harmonic polynomials using a fundamental result of Caffarelli and Friedman regarding the representation of functions whose ...

A new algorithmic setting is proposed for the discrete-time finite-horizon linear quadratic (LQ) optimal control problem with constrained or unconstrained final state, no matter whether the problem is cheap, singular, or regular. The proposed solution, based on matrix pseudoinversion, is completed and made practically implementable by a nesting procedure for welding optimal subarcs that enables...

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The present work deals with the optimal placement of piezoelectric actuators on a thin plate using Modified Control Matrix and Singular Value Decomposition (MCSVD) approach. The problem has been formulated using the finite element method using ten piezoelectric actuators on simply supported plate to suppress first six modes. The sizes of ten actuators are combined to outline one actuator by add...

abstract the use of water sources has increased due to extend of agricultural activity for answering food needs of increasing population. while because of exploitation and consumption of water, the use of this restricted resource is not appropriate. consequently in many districts of country the head level of ground water aquifers have been fallen and water level is negative. so, application of ...