Datacubes are especially useful for answering efficiently queries on data warehouses. Nevertheless the amount of generated aggregated data is huge with respect to the initial data which is itself very large. Recent research work has addressed the issue of summarizing Datacubes in order to reduce their size. In this chapter, we present three different approaches. They propose structures which ma...

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...

In this work, the authors present observations of enhanced temporal coherency beyond that expected using the observations of the standard deviation of the Doppler velocities and the assumption of a family of exponentially decaying autocorrelation functions. The purpose of this paper is to interpret these observations by developing the complex amplitude autocorrelation function when both incoher...

A HREM study of small y-phase precipitates in P CEL-211-A1 single crystals is presented. The images taken at atomic resolution show the perfect coherency of the precipitates when they are embedded in the P austenitic phase. In this case, the precipitates are located at the antiphase boundaries of the matrix. In turn, several microdomains separated by internal antiphase-like boundaries are prese...

In shared-memory multiprocessor systems, the local caches which are used to tolerate the performance gap between processor and memory cause additional bus transactions to maintain the coherency of shared data. Especially, coherency misses and data traffic due to spatial locality and false sharing have a singificant effect on the system performance. In this approach, an adaptive cache coherence ...

In this paper previous works on calculating the output current of SBCNFET are reviewed and a new three capacitance model for estimating potential profile along the channel is proposed. Furthermore the transmission coefficient through the channel has studied and some new formulas considering the electron coherency in the channel are suggested. Electron coherency will results in resonant transmis...

We present a new model for distributed shared memory systems, based on remote data accesses. Such features are offered by network interface cards that allow one-sided operations, remote direct memory access and OS bypass. This model leads to new interpretations of distributed algorithms allowing us to propose an innovative detection technique of race conditions only based on logical clocks. Ind...

A major problem considering parallel computing is maintaining memory consistency and coherency, and ensuring ownership and access rights. These problems mainly arise from the fact that memory in parallel and distributed systems is still managed locally, e.g. using a combination of shared-busand directory-based approaches. As a result, such setups do not scale well with system size and are espec...

This paper presents main ideas of object consistency(OC) a new consistency model for distributed sharedmemory (DSM) systems. It was developed by ana-lyzing various sharing patterns in real parallel appli-cations as well as existing coherency models for bothat and object-based DSMs. OC is an attempt toe ectively integrate entry consistency (EC) and ver-sion consistenc...