195,999 research outputs found
Ground tests of a rendezvous maneuver based on visual servoing
No full textThe problem of autonomous space rendezvous and docking is faced from both a numerical and an experimental point of view. A 2D free floating chaser platform has been equipped with a docking system and a camera dedicated to relative navigation with respect to a target platform. The image processing and filtering algorithms are processed in real time so that the target is identified and tracked, and the relative longitudinal and lateral displacements are evaluated. The GNC algorithms are first tested by means of a numerical tool where a multibody plant is modeled, so that contact forces and relevant post-contact dynamics can be accurately predicted. The experimental tests of the same GNC algorithms show the accuracy of the vision-based navigation, and the robustness of the docking strategy even with respect to some disturbances, such as the plume impingement effect, that were not included in the numerical model. © 2014 IEEE
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Control parameters transition during deploying operations of a space flexible structure via multi-body approach
No full textThe need to model very complex spacecraft has induced many researchers to develop different methodologies for their study, depending on the type of analysis to be performed. In the ease of structural analysis a classical finite element approach is used to describe in detail each component. In the case of flight mechanics a simple rigid spacecraft can be used for studying guidance, navigation and control laws. On the contrary for studying deploying mechanisms it is necessary to define models of joints and actuators. The necessity to reduce time and cost of the development of new space platforms requires the integration of these different design models and processes. In recent years new methodologies, based on the so-called multibody approach, have been introduced for modeling mechanical systems. Complex space structures are divided into sub-elements (rigid or flexible) connected to each other through joints. With this approach, a very detailed multibody model of a spacecraft can be easily adapted to face different disciplines. Unfortunately, when dealing with elastic bodies the number of degrees of freedom (DOFs) drastically increases. The approach here suggested to keep the number of DOF low is to employ a hybrid approach where a limited number of bodies is chosen, depending on the values of their inertial and elastic properties. In the present work a very large flexible satellite is modeled via multibody technique. In particular the deployable solar arrays and the bus are represented with only three elastic bodies. The deployment phase of the solar panels is simulated through a time sequence of panels models with different geometries. For each configuration the inertial and modal properties are evaluated, and eventually these parameters are interpolated in order to determine their values when a continuous movement of the panels is simulated. On account of the geometry variation we can observe not only a variation on the values of the natural frequencies, but also an exchange on the ranking of the relevant modal shapes and hence on the relevant modal participation factors. A re-ordering of the modal shapes is mandatory before doing any interpolation. A robust and easy to implement re-ordering criteria is presented in the paper together with a number of numerical simulations showing that the proposed hybrid approach can be considered as a valid alternative to simulate a deployable structure with a reduced number of elements and hence of a reduced computational cost. Copyright © (2012) by the International Astronautical Federation
Intern experience at CH���M Hill, Inc.: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
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