We present a new matrix-valued isospectral ordinary differential equation that asymptotically block-diagonalizes n × n zero-diagonal Jacobi matrices employed as its initial condition. This o.d.e. features a right-hand side with a nested commutator of matrices, and structurally resembles the double-bracket o.d.e. studied by R.W. Brockett in 1991. We prove that its solutions converge asymptotical...

The interaction of the dominant semidiurnalM2 internal tide with the large-scale subtidal flow is examined in an ocean model by propagating the tide through an ensemble of background fields in a domain centered on theHawaiianRidge. The background fields are taken from the SimpleOceanDataAssimilation (SODA) ocean analysis, at 2-month intervals from 1992 through 2001. Tides are computed with the ...

In this paper, the Adomian decomposition method for solving the linear and nonlinear parabolic equations is implemented with appropriate initial conditions. In comparison with existing techniques, the decomposition method is highly effective in terms of accuracy and rapid convergence. The numerical results obtained by this way have been compared with the exact solution to show the efficiency of...

A Cauchy problem for a one–dimensional diffusion–reaction equation is solved on a grid by a random walk method, in which the diffusion part is solved by random walk of particles, and the (nonlinear) reaction part is solved via Euler’s polygonal arc method. Unlike in the literature, we do not assume monotonicity for the initial condition. It is proved that the algorithm converges and the rate of...

We study the problem of finding the global Riemannian center of mass of a set of data points on a Riemannian manifold. Specifically, we investigate the convergence of constant stepsize gradient descent algorithms for solving this problem. The challenge is that often the underlying cost function is neither globally differentiable nor convex, and despite this one would like to have guaranteed con...

A simple analytical approach for formation-keeping of satellites in the presence of both orbital and attitude requirements is developed. A leader satellite is assumed to be in a J2-perturbed circular reference orbit and each follower satellite is required to stay in its prescribed, desired orbit with respect to the leader satellite, and at the same time, to point to an arbitrarily chosen specif...

We investigate the peaking phenomenon in the control of large-scale vehicular platoons. These systems are of considerable practical importance as they represent an example of systems on lattices in which different subsystems are dynamically coupled only through feedback controls. We demonstrate that imposing a uniform rate of convergence for all vehicles towards their desired trajectories may g...

Article history: Received 27 July 2007 Received in revised form 21 February 2008 Accepted 2 May 2008 Available online xxxx An ensemble smoother is used to estimate the initial conditions and mortality rates for a spatially explicit model of Alexandrium fundyense. The data assimilation procedure is effective at reducing model-data misfit in this strong constraint problem formulation. The skill o...

background & aims of the study: toluene-2, 4-diamine (tda) is a famous carcinogenic aromatic amine that is mostly employed as an intermediate in the production of dyes and toluene diisocyanate. in this study, degradation and mineralization of tda were investigated by uv/h2o2 process. materials & methods: this study is an experimental investigation on a laboratory scale. the study performed on s...

conclusions this case inspires consideration of hiv infection as a leading cause of thromboembolic event in individuals affected by the first episode of unprovoked one in whom diagnosis of hiv infection has not been established yet. case presentation a 27-year-old heterosexual smoker man was referred to our center due to a sudden-onset severe left lower extremity pain and claudication since thr...