in this article a graph theoretical approach is employed to study some specifications of dynamic systems with time delay in the inputs and states, such as structural controllability and observability. first, the zero and non-zero parameters of a proposed system have been determined, next the general structure of the system is presented by a graph which is constructed by non-zero parameters. the...

Adaptively secure Multi-Party Computation (MPC) is an essential and fundamental notion in cryptography. In this work, we construct Universally Composable (UC) MPC protocols that are adaptively secure against all-but-one corruptions based on LWE. Our protocols have a constant number of rounds and communication complexity dependant only on the length of the inputs and outputs (it is independent o...

let $r$ be a commutative ring with zero-divisor set $z(r)$. the total graph of $r$, denoted by$t(gamma(r))$, is the simple (undirected) graph with vertex set  $r$ where two distinct vertices areadjacent if their sum lies in $z(r)$.this work considers minimum zero-sum $k$-flows for $t(gamma(r))$.both for $vert rvert$ even and the case when $vert rvert$ is odd and $z(g)$ is an ideal of $r$it is s...

Let F be an r-uniform hypergraph. The chromatic threshold of the family of F free, r-uniform hypergraphs is the infimum of all non-negative reals c such that the subfamily of F -free, r-uniform hypergraphs H with minimum degree at least c (|V (H)| r−1 ) has bounded chromatic number. The study of chromatic thresholds of various graphs has a long history, beginning with the early work of Erdős-Si...

Causal and Noncausal discrete{time transfer functions for some discrete{time system with zero order hold (ZOH), rst order hold (FOH) or ideal sampler are distinguished and described. In the case of ZOH or FOH the discussed notions are essential for the system with a continuous time plant described by the rational proper transfer function with the order of numerator equal to that of the denomina...

It is commonly believed that Alcubierre’s warp drive works by contracting space in front of the warp bubble and expanding space behind it. We show that this expansion/contraction is but a marginal consequence of the choice made by Alcubierre, and explicitly construct a similar spacetime where no contraction/expansion occurs.