Adaptive structured parallelism for computational grids

Algorithmic skeletons abstract commonly-used patterns of parallel computation, communication, and interaction. They provide top-down design composition and control inheritance throughout the whole structure. Parallel programs are expressed by interweaving parameterised skeletons analogously to the way sequential structured programs are constructed. This design paradigm, known as structured parallelism, provides a high-level parallel programming method which allows the abstract description of programs and fosters portability. That is to say, structured parallelism requires the description of the algorithm rather than its implementation, providing a clear and consistent meaning across platforms while their associated structure depends on the particular implementation. By decoupling the structure from the meaning of a parallel program, it benefits entirely from any performance improvements in the systems infrastructure

Dynamic weight parameter for the Random Early Detection (RED) in TCP networks

This paper presents the Weighted Random Early Detection (WTRED) strategy for congestion handling in TCP networks. WTRED provides an adjustable weight parameter to increase the sensitivity of the average queue size in RED gateways to the changes in the actual queue size. This modification, over the original RED proposal, helps gateways minimize the mismatch between average and actual queue sizes in router buffers. WTRED is compared with RED and FRED strategies using the NS-2 simulator. The results suggest that WTRED outperforms RED and FRED. Network performance has been measured using throughput, link utilization, packet loss and delay

Using eSkel to Implement the Multiple Baseline Stereo Application

We give an overview of the Edinburgh Skeleton Library eSkel, a structured parallel programming library which offers a range of skeletal parallel programming constructs to the C/MPI programmer. Then we illustrate the efficacy of such a high level approach through an application of multiple baseline stereo. We describe the application and show different ways to introduce parallelism using algorithmic skeletons. Some performance results will be reported

Variance and Sample Size Calculations in Quality-of-Life-Adjusted Survival Analysis (Q-TWiST)

The Quality-Adjusted Time Without Symptoms or Toxicity (Q-TWiST) statistic previously introduced by Glasziou, Simes and Gelber (1990, Statistics in Medicine 9 , 1259–1276) combines toxicity, disease-free survival, and overall survival information in assessing the impact of treatments on the lives of patients. This methodology has received positive reviews from clinicians as intuitive and useful, but to date, the variance of this statistic has remained unspecified. We review aspects of the Q-TWiST method for analyzing clinical trial data, extend the method to accommodate multiple treatment arms, and provide closed-form asymptotic variance formulas. We also provide a framework for designing Q-TWiST clinical trials with sample sizes determined using the derived asymptotic variance formulas. Trials currently collecting quality of life data did not have the benefit of these sample size calculation techniques in designing their studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65778/1/j.0006-341X.2000.00173.x.pd

Tests on the efficiency of the power plant at the Kansas State Agricultural College

Citation: Fockele, Glick and Cole, Murray S. Tests on the efficiency of the power plant at the Kansas State Agricultural College. Senior thesis, Kansas State Agricultural College, 1902.Morse Department of Special CollectionsIntroduction: The plant is designed to furnish heat and power for the various departments at the Kansas State Agricultural College of Manhattan, Kansas. It was originally intended by the writers to include in their work, tests on the heating power of the plant, but the arrangement of their other college work during the year, made it impossible for them to conduct the experiments at a time when the heating plant was in operation. Another drawback was the absence of suitable apparatus for the determination of the calorific power of the coal. The heating plant consists of six externally fired, horizontal, multitubular boilers, designated as No. 1, 2, 3, 4, 5 and 6. Five are of 60 nominal horsepower and one, No. 6, is of 100 nominal horsepower. The tests were conducted upon No. 1, for the reason that it was the only high pressure boiler which was piped for individual feed water, and with this boiler is our interest concerned. None of the connections with other boilers could possibly affect results of these tests except in the test on April 28th, when No. 3 was turned in on account of the heavy load on the engine. In this case neither boiler made more steam than the engine could use, so the pressure in neither one was affected in the least and the conditions of the test were kept uniform. The boiler itself is 54” diameter, with 34 flues 3-3/4 inches in diameter and 16 feet long. The grates are 4-1/2’ by 4-1/2’. The boiler was built by Joseph Bromich of Topeka, Kansas. It was installed in 1896. It was in very good condition for all tests. The fuel used was the coal furnished by the state for use in the institution, and was of very poor quality. It comes from the state mines near Leavenworth, and is mined by the prisoners from the state penitentiary

The Integration of Task and Data Parallel Skeletons

We describe a skeletal parallel programming library which integrates task and data parallel constructs within an API for C++. Traditional skeletal requirements for higher orderness and polymorphism are achieved through exploitation of operator overloading and templates, while the underlying parallelism is provided by MPI. We present a case study describing two algorithms for the travelling salesman problem