one of the problems in the ground-based circular synthetic aperture radar is the dependence of the azimuth resolution to the antenna rotation radius and operational limitation of increasing it. to enhance the image quality in azimuth, model-based image formation through three methods: matched filter, inverse filter and optimum filter is suggested and analyzed. for the purpose of comparison, thr...

We study the problem of matrix estimation and matrix completion under a general framework. This framework includes several important models as special cases such as the gaussian mixture model, mixed membership model, bi-clustering model and dictionary learning. We consider the optimal convergence rates in a minimax sense for estimation of the signal matrix under the Frobenius norm and under the...

short-selling prohibition has been one of the primary assumptions of markowitz mean-variance model. solving markowitz quadratic model creates investment efficient frontier by considering only two return and budget constraints. in order to develop a more realistic portfolio selection model, in this paper, a new mathematical model is developed to allow short-selling under some practical constrain...

The present paper deals with development of a simulation model for the performance evaluation of feed water system of a thermal power plant using Markov Birth-Death process and probabilistic approach. In present paper, the feed water system consists of four subsystems. After drawing transition diagram for feed water system, differential equations are developed and then solved recursively using ...

The microstructure of dual phase steels can be considered as a matrix of ferrite phase reinforced by martensite particles. Recent measurements show that the mechanical properties of the ferrite phase are changed with the distance from the martensite grains. In this paper, a new method has been proposed to consider this phenomenon in finite element modeling of dual phase steels microstructure. I...

‎In this paper, we present a two-stage model for ranking of decision making units (DMUs) using interval analytic hierarchy process (AHP). Since the efficiency score of unity is assigned to the efficient units, we evaluate the efficiency of each DMU by basic DEA models and calculate the weights of the criteria using proposed model. In the first stage, the proposed model evaluates decision making...

this research presents a numerical tool to estimate the green's function operator matrix of intraplate faults. having this matrix and its inverse, spatial distribution of fault slippage could be investigated through the inverse analysis of geodetic data. this information could be employed to predict the location of future powerful earthquakes. to implement fault sliding in fe calculations,...

matrix analysis of corrosion inhibition phenomena (macip), in which an inhibitor isconsidered as a point in a multi-dimensional virtual efficiency space, was performed on somepyridine derivatives. the needed molecular parameters such as homo and lumo energylevels, charge densities on hetero atom, dipole moment, heat of formation, and total energyvalues were obtained by means of semi-empirical q...