A simple formula for the group inverse of a 2× 2 block matrix with a bipartite digraph is given in terms of the block matrices. This formula is used to give a graph-theoretic description of the group inverse of an irreducible tridiagonal matrix of odd order with zero diagonal (which is singular). Relations between the zero/nonzero structures of the group inverse and the Moore-Penrose inverse of...

This paper derives an inequality relating the p-norm of a positive 2×2 block matrix to the p-norm of the 2×2 matrix obtained by replacing each block by its p-norm. The inequality had been known for integer values of p, so the main contribution here is the extension to all values p ≥ 1. In a special case the result reproduces Hanner’s inequality. As an application in quantum information theory, ...

Active Constellation Extension (ACE) is one of techniques introduced for Peak to Average Power Ratio (PAPR) reduction for OFDM systems. In this technique, the constellation points are extended such that the PAPR is minimized but the minimum distance of the constellation points does not decrease. In this paper, an iterative ACE method is extended to spatially encoded OFDM systems. The proposed m...

This paper derives an inequality relating the p-norm of a positive 2×2 block matrix to the p-norm of the 2×2 matrix obtained by replacing each block by its p-norm. The inequality had been known for integer values of p, so the main contribution here is the extension to all values p ≥ 1. In a special case the result reproduces Hanner’s inequality. A weaker inequality which applies also to non-pos...

We answer Blass' question from 1989 of whether the inequality u < g is strictly stronger than the lter dichotomy principle [6, page 36] a rmatively. We show that there is a forcing extension in which every non-meagre lter on ω is ultra by nite-to-one and the semilter trichotomy does not hold. This trichotomy says: every semi lter is either meagre or comeagre or ultra by nite-to-one. The trichot...

Khazad is a new block cipher initially proposed as a candidate to the NESSIE project. Its design is very similar to Rijndael, although it is a 64-bit block cipher. In this paper, we propose a new attack that can be seen as an extension of the Square attack. It takes advantage of redundancies between the round key derivation and the round function, and also exploits some algebraic observations o...

In this paper, we describe a phrase-based unigram model for statistical machine translation that uses a much simpler set of model parameters than similar phrasebased models. The units of translation are blocks – pairs of phrases. During decoding, we use a block unigram model and a word-based trigram language model. During training, the blocks are learned from source interval projections using a...

The wide-awake approach to flexor tendon repair has decreased our rupture and tenolysis rates, and permitted us to get consistently good results in cooperative patients. We no longer perform flexor tendon repair with the tourniquet, sedation and muscle paralysis of general or block (Bier or axillary) anesthesia. Injection of only lidocaine with epinephrine wherever incisions will be made in the...

We prove that a Z d-action by automorphisms of a compact, abelian group is Bernoulli if and only if it has completely positive entropy. The key ingredients of the proof are the extension of certain notions of asymptotic block independence from Z-actionsto Z d-action and their equivalence with Bernoullicity, and a surprisingly close link between one of these asymptotic block independence propert...

Device-level interfaces in operating systems present a very useful cut-point for researchers to experiment with new ideas. By virtualizing these interfaces, developers can create soft devices, which are used in the same way as normal hardware devices, but provide extra functionality in software. Recent years have shown this approach to be of considerable interest: a few examples of block device...