Tailless aircraft control using output subspace stabilization

Journal of Polymer Science Part A: Polymer ChemistryVolume 24, Issue 2 p. 375-378 Note Preparation of cyanuric-chloride activated poly(ethylene glycol) Steven G. Shafer, Steven G. Shafer Department of Chemistry, University of Alabama in Huntsville, Huntsville, Alabama 35899Search for more papers by this authorJ. Milton Harris, J. Milton Harris Department of Chemistry, University of Alabama in Huntsville, Huntsville, Alabama 35899Search for more papers by this author Steven G. Shafer, Steven G. Shafer Department of Chemistry, University of Alabama in Huntsville, Huntsville, Alabama 35899Search for more papers by this authorJ. Milton Harris, J. Milton Harris Department of Chemistry, University of Alabama in Huntsville, Huntsville, Alabama 35899Search for more papers by this author First published: February 1986 https://doi.org/10.1002/pola.1986.080240214Citations: 26AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume24, Issue2February 1986Pages 375-378 RelatedInformation

Po-Chedley and Fu investigated the difference in the magnitude of global temperature trends generated from the Microwave Sounding Unit (MSU) for the midtroposphere (TMT, surface to about 75 hPa) between the University of Alabama in Huntsville (UAH) and Remote Sensing Systems (RSS). Their approach was to examine the magnitude of a noise-reduction coefficient of one short-lived satellite, NOAA-9, which differed from UAH and RSS. Using radiosonde comparisons over a 2-yr period, they calculated an adjustment to the UAH coefficient that, when applied to the UAH data, increased the UAH global TMT trend for 1979–2009 by +0.042 K decade−1, which then happens to agree with RSS’s TMT trend. In studying their analysis, the authors demonstrate 1) the adjustment calculated using radiosondes is inconclusive when errors are accounted for; 2) the adjustment was applied in a manner inconsistent with the UAH satellite merging strategy, creating a larger change than would be generated had the actual UAH methodology been followed; and 3) that trends of a similar product that uses the same UAH coefficient are essentially identical to UAH and RSS. Based on the authors’ previous analysis and additional work here, UAH will continue using the NOAA-9 noise-reduction coefficient, as is, for version 5.4 and the follow-on version 5.5.

The field of Space Physics has significant recruitment potential. Almost everyone has been fascinated by space in one way or another since their early childhood. From this perspective, Space Physics might be expected to exhibit considerable diversity as a discipline. Regrettably, as in many STEM fields, the reality is quite different. Numerous reasons have been advanced about why the reality and the expectation diverge but one observation we have made over the years stands out, and, that is, that when students are given the opportunity, they are very eager to learn about Space Physics and enthusiastic about working on space physics projects. At The University of Alabama in Huntsville, we have developed a series of outreach programs, including summer programs, that are aimed at bringing students not typically exposed to space physics into the Space Physics community through working on real research projects that have the potential to produce journal publication results. These programs have been very effective in creating interest in Space Physics and have led to the recruitment of students that have been underrepresented historically into our research programs. In this paper, we summarize the various summer programs that the Center for Space Plasma and Aeronomic Research and Department of Space Science at The University of Alabama in Huntsville have been organizing in Space Physics for years and how these programs have contributed to increasing diversity in the field.

The success of systems engineering (SE) efforts to solve development issues benefit from the mutually advantageous relationship between academia and practice. This relationship can be threatened by lag in adoption and differences in focus between the two worlds. In an effort to help maintain alignment between SE research and practice, a 2‐day workshop was held at the University of Alabama in Huntsville on research needs in SE. The workshop was attended by individuals from academia, the Department of Defense, NASA, and the aerospace industry. This paper presents summaries of the discussions that took place, as well as possible research questions informed by the results of the workshop. The workshop consisted of an introductory roundtable and three breakouts sessions focusing on requirements, verification, and validation; configuration and data management; and systems acquisition and design. Several topics emerged as important concepts for future research, and research questions were developed relating to model‐based systems engineering (MBSE), requirements, modeling, sociotechnical issues, and education.

Author Affiliation: Associate Dean for Graduate Programs and Professor, College of Nursing, The University of Alabama in Huntsville. The author reports no conflicts of interest. Correspondence: Karen H. Frith, PhD, RN, NEA-BC, CNE, College of Nursing, The University of Alabama in Huntsville, 301 Sparkman Dr, Huntsville, AL 35899 ([email protected]).

Reduced gravity undergraduate student flight experiment - Liquid transfer in reduced gravity

This paper describes an effort by industry and university partners to centralize manufacturing decision making through the development of generic simulation tools. This ongoing, cooperative process improvement initiative between the Industrial and Systems Engineering faculty at the University of Alabama in Huntsville (UAH) and Chrysler’s Huntsville Electronics Division (HED) permits the involved faculty to broaden their experience and technical expertise in electronics fabrication, while the industry partner benefits from the transfer of technical knowledge and advanced analysis methodologies from the university. The focus of the project is the definition of generic electronic manufacturing models that can be easily defined and implemented through common user-oriented interfaces, allowing users who are not familiar with simulation and simulation languages to address the needs of their particular functional areas.

This study evaluates source attribution of ozone (O3) in the southeast United States (US) within O3 lamina observed by the University of Alabama in Huntsville (UAH) Tropospheric Ozone Lidar Network (TOLNet) system during June 2013. This research applies surface-level and airborne in situ data and chemical transport model simulations (GEOS-Chem) in order to quantify the impact of North American anthropogenic emissions, wildfires, lightning NOx, and long-range/stratospheric transport on the observed O3 lamina. During the summer of 2013, two anomalous O3 layers were observed: (1) a nocturnal near-surface enhancement and (2) a late evening elevated (3–6 km above ground level) O3 lamina. A “brute force” zeroing method was applied to quantify the impact of individual emission sources and transport pathways on the vertical distribution of O3 during the two observed lamina. Results show that the nocturnal O3 enhancement on 12 June 2013 below 3 km was primarily due to wildfire emissions and the fact that daily maximum anthropogenic emission contributions occurred during these night-time hours. During the second case study it was predicted that above average contributions from long-range/stratospheric transport was largely contributing to the O3 lamina observed between 3 and 6 km on 29 June 2013. Other models, remote-sensing observations, and ground-based/airborne in situ data agree with the source attribution predicted by GEOS-Chem simulations. Overall, this study demonstrates the dynamic atmospheric chemistry occurring in the southeast US and displays the various emission sources and transport processes impacting O3 enhancements at different vertical levels of the troposphere.

*† ‡ This report presents the methodology used in the estimation of uncertainties associated with testing of the LE-7A rocket engine and discusses the results of the uncertainty analysis. The analysis was part of a coordinated effort between the Japan Aerospace Exploration Agency (JAXA) and the University of Alabama in Huntsville (UAH) to develop a detailed uncertainty analysis of the acceptance testing of the LE-7A engine. The primary products of this effort include uncertainty estimates for single tests, multiple tests on the same engine, and multiple engines at the same facility. The analysis focused on the uncertainties associated with the rocket performance parameters of thrust, vacuum thrust, specific impulse, and vacuum specific impulse. The analysis revealed that random uncertainty caused by unsteadiness in the engine firing was the dominant source of uncertainty. The systematic uncertainties present in the system were negligible for single value uncertainties, but were the dominant source for mean value uncertainties.

A miniaturized Scanning Electron Microscope (mini-SEM) for in-situ lunar investigations is being developed at NASA Marshall Space Flight Center with colleagues from the University of Alabama in Huntsville (UAH), Advanced Research Systems (ARS), and the University of Tennessee in Knoxville (UTK). Scanning Electron Microscopes (SEMs) can provide information on the size, shape, morphology and chemical composition of lunar regolith. Understanding these basic properties will allow us to better estimate the challenges associated with In-Situ Resource Utilization and to improve our basic science knowledge of the lunar surface (either precluding the need for sample return or allowing differentiation of unique samples to be returned to Earth.) Miniaturization (and power reduction) of an SEM appropriate for in-situ planetary investigations has warranted several novel re-designs of traditional SEM components. As such, this research has been centered on these principle elements and includes: an electron gun, beam defining and focusing system, and deflection/scanning/imaging system. Of these, the electron gun development, which is the focus of this paper, is of particular importance as it dictates the design and operation of the remaining components.

NASA is intent on exploiting the unique perspective of space-based remote optical instruments to observe and study large-scale environmental processes. Emphasis on smaller and more affordable missions continues to force the remote sensing instruments to find innovative ways to reduce the size, weight, and cost of the sensor package. This is a challenge because many of the proposed instruments incorporate a high quality meter-class telescope that can be a significant driver of total instrument costs. While various methods for telescope weight reduction have been achieved, many of the current approaches rely on exotic materials and specialized manufacturing techniques that limit availability or substantially increase costs. A competitive lightweight telescope technology that is especially well suited to space-based coherent Doppler wind lidar has been developed through a collaborative effort involving NASA Marshall Space Flight Center (MSFC) through the Global Hydrology and Climate Center (GHCC) and the University of Alabama in Huntsville (UAH) at the Center for Applied Optics (CAO). The new lightweight optics using metal alloy shells and surfaces (LOMASS) fabrication approach is suitable for high quality metal mirrors and meter-class telescopes. Compared to alternative materials and fabrication methods the new approach promises to reduce the areal density of a meter-class telescope to less than 15-kg/sq m; deliver a minimum VIO-RMS surface optical quality; while using commercial materials and equipment to lower procurement costs. The final optical figure and finish is put into the mirrors through conventional diamond turning and polishing techniques. This approach is especially advantageous for a coherent lidar instrument because the reduced telescope weight permits the rotation of the telescope to scan the beam without requiring heavy wedges or additional large mirrors. Ongoing investigations and preliminary results show promise for the LOMASS approach to be successful in demonstrating a novel alternative approach to fabricating lightweight mirrors with performance parameters comparable with the Space Readiness Coherent Lidar Experiment (SPARCLE). Development and process characterization is continuing with the design and fabrication of mirrors for a 25-cm telescope suitable for a lidar instrument.

Qualis Corporation, recognized for leading efforts in the incorporation of next generation management processes, recently was engaged in an effort to exercise a multiplidisciplinary design optimization project applicable to Space Exploration, Resources and Colonization for the need to demonstrate an approach for meeting the challenges where operations outside the atmosphere and on extraterrestrial surfaces frequently encounter serious and unique challenges. A design optimization tool just now becoming available to industry was chosen for this project. VdotTM is a process management tool that provides the ability to define, deploy, and execute desktop processes for distributed teams. It was realized that Vdot automated the manual integration process executed as part of the informal systems integration process implemented by the Vehicle Integrated Performance Analysis (VIPA) methodology developed at NASA’s Marshall Space Flight Center (MSFC), where Qualis Corporation has a significant presence. A contract was initiated in early 2007 from the University of Alabama in Huntsville (UAH) Modeling and Simulation Center to the Qualis Corporation to study the utility of using Vdot to manage the VIPA processes and demonstrate a tool to enable Lunar Robotics designs.

The NASA Systems Engineering Research Consortium was established to understand the theory of systems engineering. In this pursuit, a principal research topic has been understanding preferences that exist in engineering and how they impact design decisions. Value models are one form of mathematical representation of preferences that enable optimization and value-based engineering approaches. Work at the University of Alabama in Huntsville (UAH), within the consortium, has examined how to form value models and how to execute systems engineering with value models. This paper discusses four value models built by UAH researchers for the NASA consortium. This paper describes, briefly, the content, concept, mathematical or conceptual basis, and future of the models. The research shows promising improvements to systems engineering if value models can be formed and illustrates challenges to forming them.

An induction generator (IG) speed drive with the application of a sliding mode controller and a proposed fuzzy neural network (FNN) controller is introduced in this paper. Grid connected wind energy conversion system (WECS) present interesting control demands, due to the intrinsic nonlinear characteristic of wind mills and electric generators. The FNN torque compensation is feedforward to increase the robustness of the wind driven induction generator system. A multivariable controller is designed to drive the turbine speed to extract maximum power from the wind and adjust to the power regulation. Moreover, a sliding mode speed controller is designed based on an integral-proportional (IP) sliding surface. When sliding mode occurs on the sliding surface, the control system acts as a robust state feedback system.

IERUS Technologies, Inc. and the University of Alabama in Huntsville have partnered to perform characterization and development of algorithms and hardware for adaptive optics. To date the algorithm work has focused on implementation of the stochastic parallel gradient descent (SPGD) algorithm. SPGD is a metric-based approach in which a scalar metric is optimized by taking random perturbative steps for many actuators simultaneously. This approach scales to systems with a large number of actuators while maintaining bandwidth, while conventional methods are negatively impacted by the very large matrix multiplications that are required. The metric approach enables the use of higher speed sensors with fewer (or even a single) sensing element(s), enabling a higher control bandwidth. Furthermore, the SPGD algorithm is model-free, and thus is not strongly impacted by the presence of nonlinearities which degrade the performance of conventional phase reconstruction methods. Finally, for high energy laser applications, SPGD can be performed using the primary laser beam without the need for an additional beacon laser. The conventional SPGD algorithm was modified to use an adaptive gain to improve convergence while maintaining low steady state error. Results from laboratory experiments using phase plates as atmosphere surrogates will be presented, demonstrating areas in which the adaptive gain yields better performance and areas which require further investigation.