Nested loops are normally the most time intensive tasks in computer algorithms. These loops often include multiple dependencies between arrays that impose communication constraints when used in multiprocessor systems. These dependencies may be between dependent arrays (loop dependencies), or between independent arrays (data dependencies). In this paper, reducing the communication caused by data...

We consider how to partition and distribute sparse matrices among processors to reduce communication cost in sparse matrix computations, in particular, sparse matrix-vector multiplication. We consider 2d distributions, where the distribution is not constrained to just rows or columns. We present a new model and an algorithm based on vertex separators and nested dissection. Preliminary numerical...

We describe a method to explore the configurational phase space of chemical systems. It is based on the nested sampling algorithm recently proposed by Skilling (AIP Conf. Proc. 2004, 395; J. Bayesian Anal. 2006, 1, 833) and allows us to explore the entire potential energy surface (PES) efficiently in an unbiased way. The algorithm has two parameters which directly control the trade-off between ...

In this paper a numerical investigation is performed to study the effects of different nanofluids on convective heat transfer enhancement in a partitioned square cavity subject to different shapes of nanoparticle using water-SiO2 nanofluid. This study has been carried out to analyze the effects of SiO2 nanoparticle, its volumetric fraction between 2 and 4%, and nanoparticle shape (i.e. blades, ...

One of the approaches used to partition inputs consists in modifying and limiting the input set using an external transcoder. This method is strictly related to output coding. This paper presents an optimal output coding in PAL-based programmable transcoders. The algorithm can be used to implement circuits in PAL-based CPLDs.

Joins are arguably the most important relational operators. Poor implementations are tantamount to computing the Cartesian product of the input relations. In a temporal database, the problem is more acute for two reasons. First, conventional techniques are designed for the optimization of joins with equality predicates, rather than the inequality predicates prevalent in valid-time queries. Seco...

Wireless charging coupled with computation offloading in edge networks offers a promising solution for realizing power-hungry and intensive applications on user-devices. We consider multi-access computing (MEC) system collocated MEC server base-station/access point (AP), each equipped massive MIMO antenna array, supporting multiple users requesting data wireless charging. The goal is to minimiz...

We propose a simple level set method for the Dirichlet k-partition problem which aims to partition an open domain into K different subdomains as minimize sum of smallest eigenvalue Laplace operator in each subdomain. first formulate nested minimization functional function and eigenfunction defined As approximation, we simply replace by so that can then be converted single problem. apply standar...