Implementation and analysis of a Navier-Stokes algorithm on parallel computers

The results of the implementation of a Navier-Stokes algorithm on three parallel/vector computers are presented. The object of this research is to determine how well, or poorly, a single numerical algorithm would map onto three different architectures. The algorithm is a compact difference scheme for the solution of the incompressible, two-dimensional, time-dependent Navier-Stokes equations. The computers were chosen so as to encompass a variety of architectures. They are the following: the MPP, an SIMD machine with 16K bit serial processors; Flex/32, an MIMD machine with 20 processors; and Cray/2. The implementation of the algorithm is discussed in relation to these architectures and measures of the performance on each machine are given. The basic comparison is among SIMD instruction parallelism on the MPP, MIMD process parallelism on the Flex/32, and vectorization of a serial code on the Cray/2. Simple performance models are used to describe the performance. These models highlight the bottlenecks and limiting factors for this algorithm on these architectures. Finally, conclusions are presented

Solving the Cauchy-Riemann equations on parallel computers

Discussed is the implementation of a single algorithm on three parallel-vector computers. The algorithm is a relaxation scheme for the solution of the Cauchy-Riemann equations; a set of coupled first order partial differential equations. The computers were chosen so as to encompass a variety of architectures. They are: the MPP, and SIMD machine with 16K bit serial processors; FLEX/32, an MIMD machine with 20 processors; and CRAY/2, an MIMD machine with four vector processors. The machine architectures are briefly described. The implementation of the algorithm is discussed in relation to these architectures and measures of the performance on each machine are given. Simple performance models are used to describe the performance. These models highlight the bottlenecks and limiting factors for this algorithm on these architectures. Conclusions are presented

The World Bank's role in shaping Third World population policy

Since the World Bank became involved in population work in 1969, it has sought to influence Third World population policy by undertaking several types of activity: lending, policy dialogue, economic and sector work, analysis and research, and collaboration with other international agencies. The Bank's comparative advantage lies in policy development. It uses three main strategies: policy dialogue, sector work, and policy-oriented research. Policy dialogue occurs with government officials and program managers, mainly through discussions, Bank-sponsored seminars, and project development. Population sector work, which analyzes the population sector in a particular country, provides a base for operational activities and for initiating policy dialogue with program managers. Population research in recent years has focused on alternative policy and program strategies. The Bank's work in policy development has contributed greatly to shifts in government population policy in many countries, and its operational strategies have helped shape population programs in others. Its work program in the coming years will continue to stress policy work.Demographics,Agricultural Research,Country Population Profiles,Health Indicators,Health Information&Communications Technologies

Additive decompositions for rings of modular forms

We study rings of integral modular forms for congruence subgroups as modules over the ring of integral modular forms for the full modular group. In many cases these modules are free or decompose at least into well-understood pieces. We apply this to characterize which rings of modular forms are Cohen--Macaulay and to prove finite generation results. These theorems are based on decomposition results about vector bundles on the compactified moduli stack of elliptic curves.Comment: Complete revision. Comments welcome. arXiv admin note: text overlap with arXiv:1609.0926

A Petrified Lepidophyte Cone From The Pennsylvanian Of Michigan

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141101/1/ajb204938.pd

Insurance-State Regulation-Unauthorized Insurers False Advertising Process Act

Recent Illinois legislation subjects foreign insurers who are not authorized to do business in Illinois and who circulate false advertising there to the jurisdiction of the state courts and the State Insurance Commissioner. When the Insurance Commissioner is informed of false or misleading advertising, he is to notify the supervisory insurance official of the domicile state of the foreign insurer. If this notice does not result in the cessation of the activity, the Commissioner may proceed against the insurer under the state\u27s Unfair Trade Practice Act. Since the typical mail order insurer will not have agents or property within the state, the mere solicitation of business, by mail or otherwise, is made the equivalent of an appointment of the Insurance Commissioner as the insurer\u27s agent for all service of process. Unauthorized Insurer\u27s False Advertising Process Act, ILL. ANN. STAT. ch. 73, § 735.1 (Smith-Hurd Supp. 1961)

The Persian period of Old Testament history and religion

Thesis (M.A.)--Boston University, 1939. This item was digitized by the Internet Archive

Damage from Collapsed Backfill Rock and Soils Behind Retaining Walls Caused by Earthquake Shaking

The 17 January 1994 Northridge Earthquake caused extensive damage to thousands of buildings and condominiums throughout the San Fernando Valley. Not only to the buildings’ structure, but also to the foundations and subdrain systems. This author investigated and documented hundreds of cases where condominium units experienced similar symptoms of damage resulting from collapsed backfill rock and soils from the earthquake forces. A typical condominium building investigated was of three story construction with an 8 to 10 foot high retaining wall on three sides of the 4 to 10 unit building to contain the garages and utility rooms. Some building slabs and other ancillary features, ie. patios, wing walls, decks, steps, walks were constructed directly over the backfill rock and soil. The earthquake shaking especially the vertical acceleration caused the backfill behind the retaining walls to collapse as much as eight inches resulting in failure not only to the retaining walls and surface features, but also to the underlying subdrain pipes behind the building’s retaining wall. Detailed subsurface investigations found in almost every case collapsed backfill rock and cracked, crushed or deformed perforated and solid PVC drain pipes. Other investigations suggested that the crushed pipes were caused by improper installation during original construction. This author conduced lab testing and full scale field testing to demonstrate that the resulting failures were caused by the earthquake shaking and not installation. These failures resulted in millions of dollars in insurance claims and reconstruction of retaining wall backfills and reinstallation of subdrains

On The Radial Pitting In Callixylon

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141185/1/ajb209490.pd

A Lycopodiaceous Strobilus From The Pocono Sandstone Of Pennsylvania

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141572/1/ajb208877.pd