L (Logarithmic space) versus NL (Non-deterministic logarithmic space) is one of the great open problems in computational complexity theory. In the paper “Bounds on monotone switching networks for directed connectivity”, we separated monotone analogues of L and NL using a model called the switching network model. In particular, by considering inputs consisting of just a path and isolated vertice...

We present explicit formulae for the eccentric connectivity index and Wiener index of 2-dimensional square and comb lattices with open ends. The formulae for these indices of 2-dimensional square lattices with ends closed at themselves are also derived. The index for closed ends case divided by the same index for open ends case in the limit N →&infin defines a novel quantity we call compression...

Let P = (p,,) and Q = (qij) be m x n integral matrices, R and S be integral vectors. Let Nf(R, S) denote the class of all m x n integral matrices A with row sum vector R and column sum vector S satisfying P < A < Q. For a wide variety of classes ‘%$I( R, S) satisfying our main condition, we obtain two necessary and sufficient conditions for the existence of a matrix in @(R, 5). The first charac...

Introduction: Medial temporal sclerosis (MTS) is a form of mesial temporal lobe epilepsy (mTLE). It is typically characterized by structural alterations in hippocampus (HC) and related mesial temporal lobe (MTL) network. Resting state functional connectivity (RSFC) is considered an ideal technique in quantifying the dysfunction and maladaptation in MTL network. It is well- dem...

Let M and N be internally 4-connected binary matroids such that M has a proper N -minor, and |E(N)| ≥ 7. As part of our project to develop a splitter theorem for internally 4-connected binary matroids, we prove the following result: if M\e has no N -minor whenever e is in a triangle of M , and M/e has no N -minor whenever e is in a triad of M , then M has a minor, M ′, such that M ′ is internal...

We prove that if N is an internally 4-connected minor of an internally 4-connected binary matroid M with E(N) ≥ 4, then there exist matroids M0,M1, . . . ,Mn such that M0 ∼= N , Mn = M , and, for each i ∈ {1, . . . , i}, Mi−1 is a minor of Mi, |E(Mi−1)| ≥ |E(Mi)| − 2, and Mi is 4-connected up to separators of size 5.

We characterize the size of monotone span programs computing certain “structured” boolean functions by the Nullstellensatz degree of a related unsatisfiable Boolean formula. This yields the first exponential lower bounds for monotone span programs over arbitrary fields, the first exponential separations between monotone span programs over fields of different characteristic, and the first expone...