Three-dimensional (3D) diffuse optical tomography is known to be a nonlinear, ill-posed and sometimes under-determined problem, where regularization is added to the minimization to allow convergence to a unique solution. In this work, a generalized least-squares (GLS) minimization method was implemented, which employs weight matrices for both data-model misfit and optical properties to include ...

This work compares several node (and network) criticality measures quantifying to which extend each node is critical with respect to the communication flow between nodes of the network, and introduces a new measure based on the Bag-of-Paths (BoP) framework. Network disconnection simulation experiments show that the new BoP measure outperforms all the other measures on a sample of Erdős-Rényi an...

Here we present an implementation of Primal-Dual Affine scaling method to solve linear optimisation problem on GPU based systems. Strategies to convert the system generated by complementary slackness theorem into a symmetric system are given. A new CUDA friendly technique to solve the resulting symmetric positive definite subsystem is also developed. Various strategies to reduce the memory tran...

This paper presents the application of Genetic Algorithm (GA) to assess and enhance Total Transfer Capability (TTC) using Flexible AC Transmission System (FACTS) devices during power system planning and operation. Conventionally TTC is assessed using Repeated Power Flow (RPF) or Continuation Power Flow (CPF) or Optimal Power Flow (OPF) based methods which normally uses Newton Raphson (NR) metho...

The scattering matrix for multi-component systems is recalculated using the extended form of the Sherman-Morisson formula. The matrix elements are given explicitly in closed form. The Gibbs-Duhem relation separates the density and composition contributions.

We investigate multitarget search on complex networks and derive an exact expression for the mean random cover time that quantifies the expected time a walker needs to visit multiple targets. Based on this, we recover and extend some interesting results of multitarget search on networks. Specifically, we observe the logarithmic increase of the global mean random cover time with the target numbe...

In this paper we present a new incomplete factorization of a square matrix into triangular factors in which we get standard LU or LDL T factors (direct factors) and their inverses (inverse factors) at the same time. Algorithmically, we derive this method from the approach based on the Sherman-Morrison formula [18]. In contrast to the RIF algorithm [11], the direct and inverse factors here direc...

where A = [uVlnxn with aU = 6i,ji + hi_ ,,j, C = I n-‘J, I is the n x n identity matrix and J is the n x n matrix of all 1’s. This determinant arises in the calculation of cumulants of a statistic analogous to Pearson’s chisquared for a multinomial sample (Sibson [5]), and its value has been conjectured by Good [2]. In this paper we use enumerative methods to prove Good’s conjecture. The partic...

An algorithm to compute efficiently the first two derivatives of (very) large multideterminant wavefunctions for quantum Monte Carlo calculations is presented. The calculation of determinants and their derivatives is performed using the Sherman-Morrison formula for updating the inverse Slater matrix. An improved implementation based on the reduction of the number of column substitutions and on ...

This paper presents a needle-tissue interaction model that is a 3D extension of prior work based on needle and tissue models discretized using the Finite Element Method. The use of flexible needles necessitates remeshing the tissue during insertion, since simple mesh-node snapping to the tip can be detrimental to the simulation. In this paper, node repositioning and node addition are the two me...