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Nuclear fusion offers the potential of almost limitless energy from sea water and lithium without the dangers of carbon emissions or long term radioactive waste. At the forefront of fusion technology are the tokamaks, toroidal magnetic confinement devices that contain miniature stars on Earth. Nuclei can only fuse by overcoming the strong electrostatic forces between them which requires high temperatures and pressures. The temperatures in a tokamak are so great that the Deuterium-Tritium fusion fuel forms a plasma which must be kept hot and under pressure to maintain the fusion reaction. Turbulence in the plasma causes disruption by transporting mass and energy away from this core, reducing the efficiency of the reaction. Understanding and controlling the mechanisms of plasma turbulence is key to building a fusion reactor capable of producing sustained output. The extreme temperatures make detailed empirical observations difficult to acquire, so numerical simulations are used as an additional method of investigation. One numerical model used to study turbulence and diffusion is CENTORI, a direct two-fluid magneto-hydrodynamic simulation of a tokamak plasma developed by the Culham Centre for Fusion Energy (CCFE formerly UKAEA:Fusion). It simulates the entire tokamak plasma with realistic geometry, evolving bulk plasma quantities like pressure, density and temperature through millions of timesteps. This requires CENTORI to run in parallel on a Massively Parallel Processing (MPP) supercomputer to produce results in an acceptable time. Any improvements in CENTORI’s performance increases the rate and/or total number of results that can be obtained from access to supercomputer resources. This thesis presents the substantial effort to optimise CENTORI on the current generation of academic supercomputers. It investigates and reviews the properties of contemporary computer architectures then proposes, implements and executes a benchmark suite of CENTORI’s fundamental kernels. The suite is used to compare the performance of three competing memory layouts of the primary vector data structure using a selection of compilers on a variety of computer architectures. The results show there is no optimal memory layout on all platforms so a flexible optimisation strategy was adopted to pursue “portable” optimisation i.e optimisations that can easily be added, adapted or removed from future platforms depending on their performance. This required designing an interface to functions and datatypes that separate CENTORI’s fundamental algorithms from repetitive, low-level implementation details. This approach offered multiple benefits including: the clearer representation of CENTORI’s core equations as mathematical expressions in Fortran source code allows rapid prototyping and development of new features; the reduction in the total data volume by a factor of three reduces the amount of data transferred over the memory bus to almost a third; and the reduction in the number of intense floating point kernels reduces the effort of optimising the application on new platforms. The project proceeds to rewrite CENTORI using the new Application Programming Interface (API) and evaluates two optimised implementations. The first is a traditional library implementation that uses hand optimised subroutines to implement the library functions. The second uses a dynamic optimisation engine to perform automatic stripmining to improve the performance of the memory hierarchy. The automatic stripmining implementation uses lazy evaluation to delay calculations until absolutely necessary, allowing it to identify temporary data structures and minimise them for optimal cache use. This novel technique is combined with highly optimised implementations of the kernel operations and optimised parallel communication routines to produce a significant improvement in CENTORI’s performance. The maximum measured speed up of the optimised versions over the original code was 3.4 times on 128 processors on HPCx, 2.8 times on 1024 processors on HECToR and 2.3 times on 256 processors on HPC-FF.

Master of Science / Department of Computing and Information Sciences / Mitchell L. Neilsen / The computer industry has seen a growth in the development of mobile applications over the last few years. Tablet/Mobile applications are preferred over their desktop versions due to their increased accessibility and usability. Android is the most popular mobile OS in the world. It not only provides a world-class platform for creating several apps, but also consists of an open marketplace for distributing them to Android users everywhere. This openness has led to it being a favorite for consumers and developers alike, thereby leading to a strong growth in app consumption. The main objective of the project is to design and develop an Android software application for USDA (U.S. Department of Agriculture) structural design that can be used on Android tablets. The different components of USDA that can be designed using this application are SingleCell, TwinCell, Cchan, Cbasin and Drpws3e. The USDA (U.S. Department of Agriculture) structural design application was previously developed using FORTRAN. But FORTRAN is not supported by Android Tablets. So, F2J Translator software was used to convert the FORTRAN source files to java source files which are supported by Android. Also, many other formatters such as CommonIn, CommonOut, and SwapStreams were used to translate some common blocks of FORTRAN code that cannot be translated by F2J Translator. The developed Android software allows users to access all different components of USDA structural design. Users can either directly enter the data in the forms provided or upload a file that already has data stored in it. When the application is run, the output can be accessed as a PDF file. Users can even send the output of a particular component to their personal email address. This output provided by the software application is helpful for design engineers to implement new structural designs.

Typescript, etc. / Digitized by Kansas Correctional Industries

Neste trabalho abordam-se alguns aspectos numéricos relacionados ao movimento de uma partícula carregada em um fluido ionizado, constituindo assim o fenômeno de eletroforese. A equação de Navier-Stokes governa a hidrodinâmica do sistema, sendo atribuída a esta um termo forçante relacionado a equação de Poisson-Boltzmann que descreve a interação com o campo elétrico. A simulação foi realizada utilizando a linguagem Fortran 90 e as discretizações foram feitas pelo método de diferenças finitas junto as equações governantes. Para descrever a posição da partícula foi usada a técnica de fronteira virtual, onde são criados pontos lagrangeanos sobre,o contorno da partícula formando uma espécie de segunda malha. Foram feitos testes com objetivo de validar as equações governantes e identificar a influencia das condições de contorno direção da partícula. / In this work we study some of the numerical aspects related to the motion of a charged particle in an ionized fluid, known as the phenomenon of electrophoresis. The Navier-Stokes equations models the ,hydrodynamics of the system, with the addition of a forcing term, related to the Poisson-Boltzmann equation, which describes the interaction of the electric field. The simulation was performed using Fortran 90 and discretizations were made by the method of finite differences applied to the governing equations. To describe the position of the particle the technique of virtual boundary is used, where Lagrangean points are created around the circumference of the particle forming a sort of second mesh. Tests were made with the objective of validating the governing equations and to identify the influence of boundary conditions in the direction of the particle.

Typescript, etc. / Digitized by Kansas Correctional Industries

Typescript, etc. / Digitized by Kansas Correctional Industries

This creative project is a FORTRAN language computer program, DIET.FOR, two auxilary programs, CODR.FOR and FOODR.FOR, and accompanying documentation. DIET.FOR is a dietary analysis program in which the user enters the foods which a subject has eaten. The program then calculates the results. The auxilary programs create the data files on which the nutritional analysis is based. The documentation is designed as a tutorial to aid the user.Ball State UniversityMuncie, IN 47306