This paper presents work on piggyback cache validation (PCV), which addresses the problem of maintaining cache coherency for proxy caches. The novel aspect of our approach is to capitalize on requests sent from the proxy cache to the server to improve coherency. In the simplest case, whenever a proxy cache has a reason to communicate with a server it piggybacks a list of cached, but potentially...

In this paper, we present a detailed evaluation of cross wavelet analysis of bivariate time series. We develop a statistical test for zero wavelet coherency based on Monte Carlo simulations. If at least one of the two processes considered is Gaussian white noise, an approximative formula for the critical value can be utilized. In a second part, typical pitfalls of wavelet cross spectra and wave...

We show that trace distance measure of coherence is a strong monotone for all qubit and, so called, X states. An expression for the trace distance coherence for all pure states and a semi definite program for arbitrary states is provided. We also explore the relation between l1-norm and relative entropy based measures of coherence, and give a sharp inequality connecting the two. In addition, it...

Database Sharing (DB-sharing) refers to a general approach for building a distributed high performance transaction system. The nodes of a DB-sharing system are locally coupled via a high-speed interconnect and share a common database at the disk level. This is also known as a “shared dis~ approach. We compare database sharing with the database partitioning (shared nothing) approach and discuss ...

We present a piggyback server invalidation (PSI) mechanism for maintaining stronger cache coherency in Web proxy caches while reducing overall costs. The basic idea is for servers to piggyback on a reply to a proxy client, the list of resources that have changed since the last access by the client. The proxy client invalidates cached entries on the list and can extend the lifetime of entries no...

We propose an approach for quantifying the biological relatedness between gene products, based on their properties, and measure their similarities using exclusively statistical NLP techniques and Gene Ontology (GO) annotations. We also present a novel similarity figure of merit, based on the vector space model, which assesses gene expression analysis results and scores gene product clusters' bi...

In the context of non-Gaussian polarimetric clutter models, this paper presents an application of the recent advances in the field of Spherically Invariant Random Vectors (SIRV) modelling for coherency matrix estimation in heterogeneous clutter. The complete description of the POLSAR data set is achieved by estimating the span and the normalized coherency independently. The normalized coherency...

In this paper we provide generalizations of Specht’s Theorem which states that two n× n matrices A and B are unitarily equivalent if and only if all traces of words in two non-commuting variables applied to the pairs (A, A∗) and (B, B∗) coincide. First, we obtain conditions which allow us to extend this to simultaneous similarity or unitary equivalence of families of operators, and secondly, we...