Inverse airfoil design procedure using a multigrid Navier-Stokes method

The Modified Garabedian McFadden (MGM) design procedure was incorporated into an existing 2-D multigrid Navier-Stokes airfoil analysis method. The resulting design method is an iterative procedure based on a residual correction algorithm and permits the automated design of airfoil sections with prescribed surface pressure distributions. The new design method, Multigrid Modified Garabedian McFadden (MG-MGM), is demonstrated for several different transonic pressure distributions obtained from both symmetric and cambered airfoil shapes. The airfoil profiles generated with the MG-MGM code are compared to the original configurations to assess the capabilities of the inverse design method

Applications of FEM and BEM in two-dimensional fracture mechanics problems

A comparison of the finite element method (FEM) and boundary element method (BEM) for the solution of two-dimensional plane strain problems in fracture mechanics is presented in this paper. Stress intensity factors (SIF's) were calculated using both methods for elastic plates with either a single-edge crack or an inclined-edge crack. In particular, two currently available programs, ANSYS for finite element analysis and BEASY for boundary element analysis, were used

Assessing Student Oral Language Proficiency: Cost-Conscious Tools, Practices & Outcomes

Second language teachers have an ever increasing abundance oftechnology choices for assessment of student oral proficiency through theadaption of consumer electronics and multimedia devices. The purpose ofthis article is two-fold: (1) to address the benefits and ease of usingdifferent multimedia tools to assess students' oral language proficiencyregardless of grade level and (2) to report the findings of an orallanguage assessment study. Results from the empirical study (N = 128)show that there are manifold benefits of using technology for oralproficiency assessment for both students and instructors. Additionally, thisresearch emphasizes the importance of maximum use of the targetlanguage in the classroom and the importance of aligning assessmentrubrics to the American Council on the Teaching of Foreign Language'sspeaking proficiency guidelines

Circular 78

Historically, sales of exotic meats have been limited only by supply. As supply has increased in recent years, national and international exotic game markets have grown rapidly. In the United States, growth has occurred primarily in the restaurant section, although over-the-counter sales have also increased. The Alaskan reindeer industry is exploring the potential of expanding its meat sales as well as antler sales. Meat production increased from 320,000 pounds in 1987 to 432,000 pounds in 1988. This production increase is reflected in a 27 percent increase in dollar value (Alaska Crop and Livestock Reporting Service, 1989). Under current management procedures, potential meat production has been estimated at 500,000 pounds (Pearson and Lewis, 1988). Any future market expansion is likely to occur in urban Alaska and in areas outside the state (Jones, 1988)

Shared memory as a basis for conservative distributed architectural simulation

Journal ArticleThis paper describes experience in parallelizing an execution-driven architectural simulation system used in the development and evaluation of the Avalanche distributed architecture. It reports on a specific application of conservative distributed simulation on a shared memory platform. Various communication-intensive synchronization algorithms are described and evaluated. Performance results on a bus-based shared memory platform are reported, and extension and scalability of the implementation to larger distributed shared memory configurations are discussed. Also addressed are specific characteristics of architectural simulations that contribute to decisions relating to the conservatism of the approach and to the achievable performance

Message passing support in the Avalanche widget

Journal ArticleMinimizing communication latency in message passing multiprocessing systems is critical. An emerging problem in these systems is the latency contribution costs caused by the need to percolate the message through the memory hierarchy (at both sending and receiving nodes) and the additional cost of managing consistency within the hierarchy. This paper, considers three important aspects of these costs: cache coherence, message copying, and cache miss rates. The paper then shows via a simulation study how a design called the Widget can be used with existing commercial workstation technology to significantly reduce these costs to support efficient message passing in the Avalanche multiprocessing system

PPE interface and functional specification

Journal ArticleThis document describes the interface and functional specification of a Protocol Processing Engine (PPE) for workstation clusters. The PPE is intended to provide the support necessary to implement low latency protocols requiring only low resource (cpu and bus bandwidth) consumption

PPE-level protocols for carpet clusters

Journal ArticleWe describe the lowest level of a suite of protocols for workstation cluster multicomputers: the parts implemented in hardware by a Protocol Processing Engine (PPE) and the software level immediately above the PPE. The stated goal of this work is extremely low end-to-end latency communications on independent workstations connected by a packet switching communication fabric. The workstations are expected to run a commercial operating system and must present the same security characteristics as traditional protocols. We begin with a realization of sender-based protocols. Such protocols can avoid much of the copying that slows down traditional approaches and can also reduce the overhead involved in demultiplexing packet streams and notification of recipients. Finally, we present some measurements of an early prototype