Application of Modern Fortran to Spacecraft Trajectory Design and Optimization

In this paper, applications of the modern Fortran programming language to the field of spacecraft trajectory optimization and design are examined. Modern object-oriented Fortran has many advantages for scientific programming, although many legacy Fortran aerospace codes have not been upgraded to use the newer standards (or have been rewritten in other languages perceived to be more modern). NASA's Copernicus spacecraft trajectory optimization program, originally a combination of Fortran 77 and Fortran 95, has attempted to keep up with modern standards and makes significant use of the new language features. Various algorithms and methods are presented from trajectory tools such as Copernicus, as well as modern Fortran open source libraries and other projects

Electrical impedance tomography applied to body-support interface pressure measurement

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN009081 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

State estimation and bad data detection in electrical power system

The thesis studies the subjects of bad data detection and state estimation in electrical power systems which are the processes whereby voltage, power flow and switch status measurements gathered continuously in real-time are used in conjunction with a model of the system to calculate the voltage levels at every node in the system. Traditionally the state estimation process requires two stages. The first stage is the pre-processing of the measurements by a bad data detector in an attempt to remove all the measurements which are grossly in error. The second is the calculation of the voltage levels by a state estimator from the remaining measurements which are likely to contain small random errors. Conventional state estimation algorithms are very sensitive to measurement errors, especially switch status errors, and unfortunately it is not possible to ensure that all the measurement errors are removed by the bad data detector. The thesis presents a new algorithm for state estimation utilising linear programming which is able to function in the presence of not only bad analogue measurements but also switch status measurement errors, thus removing the need for a bad data detector. The proposed method of state estimation is also able to include in its model of the system the individual busbars and bus-couplers within a substation. This feature enables the state estimation algorithm to process and provide additional network information thus leading to a more useful and reliable data base

PAN AIR: A computer program for predicting subsonic or supersonic linear potential flows about arbitrary configurations using a higher order panel method. Volume 4: Maintenance document (version 1.1)

The Maintenance Document is a guide to the PAN AIR software system, a system which computes the subsonic or supersonic linear potential flow about a body of nearly arbitrary shape, using a higher order panel method. The document describes the over-all system and each program module of the system. Sufficient detail is given for program maintenance, updating and modification. It is assumed that the reader is familiar with programming and CDC (Control Data Corporation) computer systems. The PAN AIR system was written in FORTRAN 4 language except for a few COMPASS language subroutines which exist in the PAN AIR library. Structured programming techniques were used to provide code documentation and maintainability. The operating systems accommodated are NOS 1.2, NOS/BE and SCOPE 2.1.3 on the CDC 6600, 7600 and Cyber 175 computing systems. The system is comprised of a data management system, a program library, an execution control module and nine separate FORTRAN technical modules. Each module calculates part of the posed PAN AIR problem. The data base manager is used to communicate between modules and within modules. The technical modules must be run in a prescribed fashion for each PAN AIR problem. In order to ease the problem of supplying the many JCL cards required to execute the modules, a separate module called MEC (Module Execution Control) was created to automatically supply most of the JCL cards. In addition to the MEC generated JCL, there is an additional set of user supplied JCL cards to initiate the JCL sequence stored on the system

A study of automatic contingency selection algorithms for steady-state security assessment of power systems and the application of parallel processing

The performance of various Contingency Selection methods has been investigated within the framework of accuracy for application to steady-state power system security assessment and suitability for execution in a real-time environment. In the study the following requirements have been considered: (a) Effectiveness: in identifying contingencies which may cause limit violations and discarding all others; (b) Adaptability: to model both permanent and temporary changes in the system; (c) Flexibility: to model any number and type of contingencies; (d) Computational efficiency: in terms of speed in selecting the sub-set of contingencies as well as in terms of storage requirements; (e) Ability: to update and augment on-line the list of contingencies given the actual system operating data. [Continues.

Adagio 4.18 user's guide.

Adagio is a Lagrangian, three-dimensional, implicit code for the analysis of solids and structures. It uses a multi-level iterative solver, which enables it to solve problems with large deformations, nonlinear material behavior, and contact. It also has a versatile library of continuum and structural elements, and an extensive library of material models. Adagio is written for parallel computing environments, and its solvers allow for scalable solutions of very large problems. Adagio uses the SIERRA Framework, which allows for coupling with other SIERRA mechanics codes. This document describes the functionality and input structure for Adagio

The Sixth Copper Mountain Conference on Multigrid Methods, part 2

The Sixth Copper Mountain Conference on Multigrid Methods was held on April 4-9, 1993, at Copper Mountain, Colorado. This book is a collection of many of the papers presented at the conference and so represents the conference proceedings. NASA Langley graciously provided printing of this document so that all of the papers could be presented in a single forum. Each paper was reviewed by a member of the conference organizing committee under the coordination of the editors. The multigrid discipline continues to expand and mature, as is evident from these proceedings. The vibrancy in this field is amply expressed in these important papers, and the collection clearly shows its rapid trend to further diversity and depth

Recent Experiences in Multidisciplinary Analysis and Optimization, part 2

The papers presented at the NASA Symposium on Recent Experiences in Multidisciplinary Analysis and Optimization held at NASA Langley Research Center, Hampton, Virginia, April 24 to 26, 1984 are given. The purposes of the symposium were to exchange information about the status of the application of optimization and the associated analyses in industry or research laboratories to real life problems and to examine the directions of future developments

Sierra/solid mechanics 4.22 user's guide.

Sierra/SolidMechanics (Sierra/SM) is a Lagrangian, three-dimensional code for the analysis of solids and structures. It provides capabilities for explicit dynamic and implicit quasistatic and dynamic analyses. The explicit dynamics capabilities allow for the efficient and robust solution of models subjected to large, suddenly applied loads. For implicit problems, Sierra/SM uses a multi-level iterative solver, which enables it to effectively solve problems with large deformations, nonlinear material behavior, and contact. Sierra/SM has a versatile library of continuum and structural elements, and an extensive library of material models. The code is written for parallel computing environments, and it allows for scalable solutions of very large problems for both implicit and explicit analyses. It is built on the SIERRA Framework, which allows for coupling with other SIERRA mechanics codes. This document describes the functionality and input structure for Sierra/SM

The Third Air Force/NASA Symposium on Recent Advances in Multidisciplinary Analysis and Optimization

The third Air Force/NASA Symposium on Recent Advances in Multidisciplinary Analysis and Optimization was held on 24-26 Sept. 1990. Sessions were on the following topics: dynamics and controls; multilevel optimization; sensitivity analysis; aerodynamic design software systems; optimization theory; analysis and design; shape optimization; vehicle components; structural optimization; aeroelasticity; artificial intelligence; multidisciplinary optimization; and composites