Components and Interfaces of a Process Management System for Parallel Programs

Parallel jobs are different from sequential jobs and require a different type of process management. We present here a process management system for parallel programs such as those written using MPI. A primary goal of the system, which we call MPD (for multipurpose daemon), is to be scalable. By this we mean that startup of interactive parallel jobs comprising thousands of processes is quick, that signals can be quickly delivered to processes, and that stdin, stdout, and stderr are managed intuitively. Our primary target is parallel machines made up of clusters of SMPs, but the system is also useful in more tightly integrated environments. We describe how MPD enables much faster startup and better runtime management of parallel jobs. We show how close control of stdio can support the easy implementation of a number of convenient system utilities, even a parallel debugger. We describe a simple but general interface that can be used to separate any process manager from a parallel library, which we use to keep MPD separate from MPICH.Comment: 12 pages, Workshop on Clusters and Computational Grids for Scientific Computing, Sept. 24-27, 2000, Le Chateau de Faverges de la Tour, Franc

A Parallel Array Scanning Algorithm

Suppose we are given a vector X of n real numbers and we want to find the maximum sum found in any contiguous subvector of X. In Jon Bentley\u27s article [l] on algorithm design and technique, a simple vector scanning problem and a series of progressively more efficient algorithms to solve this problem were discussed in some detail. Clearly, any algorithm must visit each location of X at least once and consequently a lower bound on the running time for problem is 0(n), which is in fact attainable as Bentley’s paper illustrates. However, the original motivation for this problem was the analagous two dimensional problem for an n x n array. That is, find the maximum sum contained in any contiguous rectangular subarray. Currently, the fastest algorithm obtained for this problem is O(n3)[2] ; the theoretical lower bound would be at least 0(n2). In this note, we will present a parallel processing approach to this problem which results in excess of one order of magnitude speed up for large problems in the 0(n3) algorithm

A survey of practices, procedures, and time allotments devoted to the National Lunch Program by the principals, teachers, and lunchroom workers of the elementary public schools of Essex County

Thesis (Ed.M.)--Boston Universit

The Sandtown-Winchester Neighborhood Transformation Initiative: Lessons Learned About Community Building & Implementation

Describes challenges in implementing a ten-year community building initiative in Baltimore. Includes community capacity investment, early decision-making, power relationships, race and class issues, and neighborhood leadership

Universality and template synthesis of cosmic ray air shower radio emission

Accurate prediction of the radio emission from cosmic ray air showers relies on computationally demanding Monte Carlo simulations such as CoREAS. We aim to expedite this process via a semi-analytical synthesis model while maintaining high accuracy by using simulated radio pulses as templates. We present our key concept for template processing focusing on the development of the particle cascade and its empirical effect on the locally produced radio signal. In this context the universality of the radio emission from small sections of an air shower also becomes important where most previous studies focus on integral quantities observable at far distances.Comment: Proceedings of the 36th ICRC, Madison, USA, PoS(ICRC2019)29

Template synthesis approach for radio emission from extensive air showers

We present a novel way to synthesise the radio emission from extensive air showers. It is a hybrid approach which uses a single microscopic Monte-Carlo simulation to generate the radio emission from a shower with a different longitudinal evolution, primary particle type and energy. The method employs semi-analytical relations which only depend on the shower parameters to transform the radio signal in the simulated antennas. We apply this method to vertical air showers with energies ranging from 10$^{17}$eV to 10$^{19}$eV and compare the results with CoREAS using two different metrics. In order to gauge the performance over our simulation set, we subsequently use every shower in the set as a template to synthesise the emission from the other showers. Depending on the scoring metric, template synthesis reconstructs the radio emission with an accuracy of 5 to 10%

An Algorithm for Parallel Subsumption

Many current automated theorem provers use a refutation procedure based on some version of the principle of resolution. These methods normally lead to the generation of large numbers of new clauses. Subsumption is a process that eliminates the superfluous clauses from the clause space, thus speeding up the proof. The research presented in this thesis is concerned with the design and implementation of a subsumption algorithm which exploits the parallelism provided by a multiprocessor. For portability, all coding is done in the programming language C. Monitors are used as the synchronization mechanism. Correct performance in both a multiprocessor and uniprocessor mode is stressed. The parallel tests are run on a Denelcor HEP located at Argonne National Laboratory