Input Range Testing for the General Mission Analysis Tool (GMAT)

This document contains a test plan for testing input values to the General Mission Analysis Tool (GMAT). The plan includes four primary types of information, which rigorously define all tests that should be performed to validate that GMAT will accept allowable inputs and deny disallowed inputs. The first is a complete list of all allowed object fields in GMAT. The second type of information, is test input to be attempted for each field. The third type of information is allowable input values for all objects fields in GMAT. The final piece of information is how GMAT should respond to both valid and invalid information. It is VERY important to note that the tests below must be performed for both the Graphical User Interface and the script!! The examples are illustrated using a scripting perspective, because it is simpler to write up. However, the test must be performed for both interfaces to GMAT

General Mission Analysis Tool (GMAT): Mission, Vision, and Business Case

The Goal of the GMAT project is to develop new space trajectory optimization and mission design technology by working inclusively with ordinary people, universities businesses and other government organizations; and to share that technology in an open and unhindered way. GMAT's a free and open source software system; free for anyone to use in development of new mission concepts or to improve current missions, freely available in source code form for enhancement or future technology development

General Mission Analysis Tool (GMAT)

The General Mission Analysis Tool (GMAT) is a space trajectory optimization and mission analysis system developed by NASA and private industry in the spirit of the NASA Mission. GMAT contains new technology and is a testbed for future technology development. The goal of the GMAT project is to develop new space trajectory optimization and mission design technology by working inclusively with ordinary people, universities, businesses, and other government organizations, and to share that technology in an open and unhindered way. GMAT is a free and open source software system licensed under the NASA Open Source Agreement: free for anyone to use in development of new mission concepts or to improve current missions, freely available in source code form for enhancement or further technology development

Analysis Of Conservation Practices In The Blackland Prairie Region Of Mississippi And Construction Of A Predictor For Locating New Sites For Conservation Efforts

Mississippi’s Blackland Prairie has been reduced below 10% of pre-Columbian extent, with few conservation practices in place. To determine efficacy of current restoration practices, plant species at remnant sites were compared with those at restoration sites. Analyses using multivariate statistical approaches revealed no generalizable patterns among four available remnants versus two available restoration sites. Thus, the aim of this project shifted to evaluating methods of identifying Blackland Prairie remnants or potential restoration sites. Location data for Blackland Prairie plant species and potentially informative environmental variables were used to develop geographic information system (GIS)-based habitat models. The best models were selected for validation against a second set of data collected from random points on public lands across the survey region. Validation surveys also were used to explore trends in predictive success and to aid in increasing accuracy through inclusion of other variables. Models incorporating soil characteristics had the highest predictive success

A miniature flame for atomization in continuum excited atomic fluorescence spectrometry

Call number: LD2668 .T4 1979 H83Master of Scienc

A Simple, Powerful Method for Optimal Guidance of Spacecraft Formations

One of the most interesting and challenging aspects of formation guidance law design is the coupling of the orbit design and the science return. The analyst's role is more complicated than simply to design the formation geometry and evolution. He or she is also involved in designing a significant portion of the science instrument itself. The effectiveness of the formation as a science instrument is intimately coupled with the relative geometry and evolution of the collection of spacecraft. Therefore, the science return can be maximized by optimizing the orbit design according to a performance metric relevant to the science mission goals. In this work, we present a simple method for optimal formation guidance that is applicable to missions whose performance metric, requirements, and constraints can be cast as functions that are explicitly dependent upon the orbit states and spacecraft relative positions and velocities. We present a general form for the cost and constraint functions, and derive their semi-analytic gradients with respect to the formation initial conditions. The gradients are broken down into two types. The first type are gradients of the mission specific performance metric with respect to formation geometry. The second type are derivatives of the formation geometry with respect to the orbit initial conditions. The fact that these two types of derivatives appear separately allows us to derive and implement a general framework that requires minimal modification to be applied to different missions or mission phases. To illustrate the applicability of the approach, we conclude with applications to two missions: the Magnetospheric Multiscale mission (MMS) , and the Laser Interferometer Space Antenna (LISA)

Reflections on the Use of Grounded Theory in Interpretive Information Systems Research

In Information Systems research there are a growing number of studies that must necessarily draw upon the contexts, experiences and narratives of practitioners. This calls for research approaches that are qualitative and may also be interpretive. These may include case studies or action research projects. For some researchers, particularly those with limited experience of interpretive qualitative research, there may be a lack of confidence when faced with the prospect of collecting and analysing the data from studies of this kind. In this paper we reflect on the lessons learned from using Grounded Theory in an interpretive case study based piece of research. The paper discusses the lessons and provides guidance for the use of the method in interpretive studies

The use of gel-cast ceramic foams as diesel particulate filters

Interest in diesel particulate reduction technologies has been revived over the past few years as a result of the increased popularity in Europe of diesel passenger cars, due to their superior fuel efficiency and advances made in performance, along with new legislation requiring the reduction of exhaust emission products. A number of technologies have been commercialised in this growing market sector including the use of filtration media to clean the exhaust gases. In fact during the course of this work the first Diesel Particulate Filtration (DPF) system to be fitted on a passenger car was introduced by the car manufacturer Peugeot. One of the many previously studied technologies for the reduction of diesel particulate emissions was through the use of reticulated ceramic foam filters. A more recent alternative approach to the production of porous ceramics is via gel casting. [Continues.

The Nonlinear Evolution of Instabilities Driven by Magnetic Buoyancy: A New Mechanism for the Formation of Coherent Magnetic Structures

Motivated by the problem of the formation of active regions from a deep-seated solar magnetic field, we consider the nonlinear three-dimensional evolution of magnetic buoyancy instabilities resulting from a smoothly stratified horizontal magnetic field. By exploring the case for which the instability is continuously driven we have identified a new mechanism for the formation of concentrations of magnetic flux.Comment: Published in ApJL. Version with colour figure