in this study, the problem of determining an optimal trajectory of a nonlinear injection into orbit problem with minimum time was investigated. the method was based on orthogonal polynomial approximation. this method consists of reducing the optimal control problem to a system of algebraic equations by expanding the state and control vector as chebyshev or legendre polynomials with undetermined...

purpose: to report the clinical, radiological, pathological and therapeutic features of a case of recurrent cavernous hemangioma. case report: a 32 year old lady with progressive decrease of vision in her right eye associated with blepharoptosis was diagnosed to have orbital cavernous hemangioma which was excised. 10 years later she presented with recurrent proptosis and progressive eye deviati...

we propose to use a mathematical method based on stochastic comparisons of markov chains in order to derive performance indice bounds‎. ‎the main goal of this paper is to investigate various monotonicity properties of a single server retrial queue with first-come-first-served (fcfs) orbit and general retrial times using the stochastic ordering techniques‎.