Metascheduling of HPC Jobs in Day-Ahead Electricity Markets

High performance grid computing is a key enabler of large scale collaborative computational science. With the promise of exascale computing, high performance grid systems are expected to incur electricity bills that grow super-linearly over time. In order to achieve cost effectiveness in these systems, it is essential for the scheduling algorithms to exploit electricity price variations, both in space and time, that are prevalent in the dynamic electricity price markets. In this paper, we present a metascheduling algorithm to optimize the placement of jobs in a compute grid which consumes electricity from the day-ahead wholesale market. We formulate the scheduling problem as a Minimum Cost Maximum Flow problem and leverage queue waiting time and electricity price predictions to accurately estimate the cost of job execution at a system. Using trace based simulation with real and synthetic workload traces, and real electricity price data sets, we demonstrate our approach on two currently operational grids, XSEDE and NorduGrid. Our experimental setup collectively constitute more than 433K processors spread across 58 compute systems in 17 geographically distributed locations. Experiments show that our approach simultaneously optimizes the total electricity cost and the average response time of the grid, without being unfair to users of the local batch systems.Comment: Appears in IEEE Transactions on Parallel and Distributed System

A STUDY ON CHRONIC OTITIS MEDIA ACTIVE MUCOSAL TYPE WITH SINUSITIS AS FOCAL SEPSIS

AIM : To establish the role of Sinusitis as Focal sepsis in Chronic Otitis media active mucosal disease, to emphasizethe need of proper diagnostic endoscopic evaluation and improvement in middle ear mucosal disease status afterfunctional endoscopic sinus surgery.METHODS : 60 Patients in the age groups of 18-49 years Chronic otitis media active mucosal disease wereidentified and screened for evidence of Focal Sepsis in Pasanasal sinus by Diagnostic Nasal endoscopy andcomputed tomography of paranasal diseases. Then Functional endoscopic sinus surgery was done to clear sinusitisand middle ear mucosal disease status assessed.RESULTS :Evaluation revealed that sinusitis in these patients was the cause for persistent discharge. All patients hadone or more evidence of sinusitis like pus in middle meatus, deviated nasal septum and turbinoseptal deformities,prominent enlarged bullae, enlarged middle turbinate on DNE and CT. The otoendoscopy showed inflamed andboggy middle ear mucosal status. All patients underwent septoplasty/FESS depending on findings. Out of 60patients 52 patient had improvement in middle ear mucosal status with surgery.In the adult population sinusitis is the most important focal sepsis in case of persistent ear discharge in ChronicOtitis Media active mucosal type of disease.A proper diagnostic nasal evaluation of all Chronic Otitis Media activemucosal type of patients is necessary in comprehensive management of the disease. The clearance of sinusitis hasimproved the middle ear mucosal status. Unilateral ear discharge is associated with sinusitis only on thecorresponding side, which is in concurrence with our study. Functional endoscopic sinus surgery has emerged as thebest procedure for clearance of sinusitis.

On Strong Centerpoints

Let $P$ be a set of $n$ points in $\mathbb{R}^d$ and $\mathcal{F}$ be a family of geometric objects. We call a point $x \in P$ a strong centerpoint of $P$ w.r.t $\mathcal{F}$ if $x$ is contained in all $F \in \mathcal{F}$ that contains more than $cn$ points from $P$, where $c$ is a fixed constant. A strong centerpoint does not exist even when $\mathcal{F}$ is the family of halfspaces in the plane. We prove the existence of strong centerpoints with exact constants for convex polytopes defined by a fixed set of orientations. We also prove the existence of strong centerpoints for abstract set systems with bounded intersection

Small Strong Epsilon Nets

Let P be a set of n points in $\mathbb{R}^d$. A point x is said to be a centerpoint of P if x is contained in every convex object that contains more than $dn\over d+1$ points of P. We call a point x a strong centerpoint for a family of objects $\mathcal{C}$ if $x \in P$ is contained in every object $C \in \mathcal{C}$ that contains more than a constant fraction of points of P. A strong centerpoint does not exist even for halfspaces in $\mathbb{R}^2$. We prove that a strong centerpoint exists for axis-parallel boxes in $\mathbb{R}^d$ and give exact bounds. We then extend this to small strong $\epsilon$-nets in the plane and prove upper and lower bounds for $\epsilon_i^\mathcal{S}$ where $\mathcal{S}$ is the family of axis-parallel rectangles, halfspaces and disks. Here $\epsilon_i^\mathcal{S}$ represents the smallest real number in $[0,1]$ such that there exists an $\epsilon_i^\mathcal{S}$-net of size i with respect to $\mathcal{S}$.Comment: 19 pages, 12 figure