We present Neumann-Neumann domain decomposition preconditioners for the solution of elliptic linear quadratic optimal control problems. The preconditioner is applied to the optimality system. A Schur complement formulation is derived that reformulates the original optimality system as a system in the state and adjoint variables restricted to the subdomain boundaries. The application of the Schu...

In the transport layer of the TCP/IP protocol suite, both TCP and UDP use internet checksum to protect headers and data. Internet checksum uses 1’s complement arithmetic to detect errors in the content delivered by the data-link layer. Both research and experience have shown that there are a wide variety of error sources which can not be detected by this lower layer. The error detecting perform...

We deal with the problem of preserving various versions of completeness in (< κ)–support iterations of forcing notions, generalizing the case “S–complete proper is preserved by CS iterations for a stationary costationary S ⊆ ω1”. We give applications to Uniformization and the Whitehead problem. In particular, for a strongly inaccessible cardinal κ and a stationary set S ⊆ κ with fat complement ...

The problem of nding the minimum topology of multipro-cessing substrates supporting parallel execution of any given neighbourhood constrained system is proposed and possible optimal strategies are investigated based on the relationship between Barbosa's scheduling by edge reversal-SER-distributed algorithm and the minimum clique covering problem. It is shown that from any given clique covering ...

The second author’s ω, ∆, χ conjecture proposes that every graph satisties χ ≤ d 1 2 (∆ + 1 + ω)e. In this paper we prove that the conjecture holds for all claw-free graphs. Our approach uses the structure theorem of Chudnovsky and Seymour. Along the way we discuss a stronger local conjecture, and prove that it holds for claw-free graphs with a three-colourable complement. To prove our results ...

The objective of this article is to study the problem of generating implications with negation when only a set of purely positive implications related to a formal context K = (G,M, I) is provided. To that end, we define a sound and complete inference system which includes a characterization of implications whose left-hand side is a key in the context K|K̃ representing the apposition of the conte...

Super-efficiency model in the presence of negative data is a relatively neglected issue in the DEA field. The existing super-efficiency models have some shortcomings in practice. In this paper, a novel VRS radial super-efficiency DEA model based on Directional Distance Function (DDF) is proposed to provide a complete ranking order of units (including efficient and inefficient ones). The propose...

The methane negative chemical ionization (NCI) mass spectra of the medically important 1,3-dihydro-5-phenyl-1,4-benzodiazepin-2-ones generally consisted solely of M- and (M-H)- ions. Attempts to find the location of the H lost in the generation of the (M-H)- ion were unsuccessful, although many possibilities were eliminated. A Hammett correlation analysis of the relative sensitivities of a seri...