We consider the problem of recovering a signal observed in Gaussian noise. If the set of signals is convex and compact, and can be specified beforehand, one can use classical linear estimators that achieve a risk within a constant factor of the minimax risk. However, when the set is unspecified, designing an estimator that is blind to the hidden structure of the signal remains a challenging pro...

We study the problem of aggregation of estimators when the estimators are not independent of the data used for aggregation and no sample splitting is allowed. If the estimators are deterministic vectors, it is well known that the minimax rate of aggregation is of order log(M), where M is the number of estimators to aggregate. It is proved that for affine estimators, the minimax rate of aggregat...

An orbit determination Kalman filter has been developed that uses two types of measurements of time division multiple access (TDMA) L-Band signals from satellites in low Earth orbit, a carrier phase measurement and a biased pseudorange measurement. This algorithm will enable precise orbit determination of satellites broadcasting TDMA signals not originally intended for navigation. The TDMA stru...

In the linear regression models with AR (1) error structure when collinearity exists, stochastic linear restrictions or modifications of biased estimators (including Liu estimators) can be used to reduce the estimated variance of the regression coefficients estimates. In this paper, the combination of the biased Liu estimator and stochastic linear restrictions estimator is considered to overcom...

In this paper, the equations of motion for geodesics in the neutral rotating Black Ring metric are derived and the separability of these equations is considered. The bulk of the paper is concerned with sets of solutions where the geodesic equations can be examined analytically specifically geodesics confined to the axis of rotation, geodesics restricted to the equatorial plane, and geodesics th...

‎in this paper‎, ‎we study spectral element approximation for a constrained‎ ‎optimal control problem in one dimension‎. ‎the equivalent a posteriori error estimators are derived for‎ ‎the control‎, ‎the state and the adjoint state approximation‎. ‎such estimators can be used to‎ ‎construct adaptive spectral elements for the control problems.

Our key aim is to propose effective estimators for the conditional probability density of a scalar response variable given functional co-variable, where considered have missing data at random. Such are constructed by combining approaches local linear method and kernel nearest neighborhood. The main feature this estimation possibility model phenomena. Under less restrictive conditions, we show s...

in this study, simple, fast and reliable cyclic voltammetry (cv), linear sweep voltammetry (lsv), square wave voltammetry (swv) and differential pulse voltammetry (dpv) methods were developed and validated for determination of bosentan in pharmaceutical preparations. the proposed methods were based on electrochemical oxidation of bosentan at platinum electrode in acetonitrile solution containin...

the concepts of structural optimization was introduced about sixty years ago. smiths from the university of los angeles (california) for the first time has offered the combination of finite element method and optimization techniques to design optimum structures (1960). at present time, this techniques are generally understood and many softwares for this perpose have been developed. in this pape...