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2021

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Articles 211 - 240 of 827

Full-Text Articles in Aerospace Engineering

The Possible Use Of Telemedicine In Developing Countries, R. Wootton Oct 2021

The Possible Use Of Telemedicine In Developing Countries, R. Wootton

Online Journal of Space Communication

Since the place of telemedicine in the industrialized world is by no means properly worked out yet, it might seem premature to consider its use in developing countries. Nonetheless, there is interest in the possible use of telemedicine in developing countries, from at least two organizations:

  1. The Midjan group, an impromptu committee that was formed following the African Regional Telecommunications Development Conference in Abidjan in March 19963. This European telemedicine collaboration group aims to explore the use of telemedicine in developing countries. At present, the group includes representatives from 22 telecommunication and medical informatics suppliers, telecommunication operators, universities, hospitals and …


Streaming Instability With Multiple Dust Species-Ii. Turbulence And Dust-Gas Dynamics At Non-Linear Saturation, Chao-Chin Yang, Zhaohuan Zhu Oct 2021

Streaming Instability With Multiple Dust Species-Ii. Turbulence And Dust-Gas Dynamics At Non-Linear Saturation, Chao-Chin Yang, Zhaohuan Zhu

Physics & Astronomy Faculty Research

The streaming instability is a fundamental process that can drive dust-gas dynamics and ultimately planetesimal formation in protoplanetary discs. As a linear instability, it has been shown that its growth with a distribution of dust sizes can be classified into two distinct regimes, fast-and slow-growth, depending on the dust-size distribution and the total dust-To-gas density ratio . Using numerical simulations of an unstratified disc, we bring three cases in different regimes into non-linear saturation. We find that the saturation states of the two fast-growth cases are similar to its single-species counterparts. The one with maximum dimensionless stopping time τs,max = …


Frequency-Dependent Linearity Characterization And Uncertainty Analysis Of The Pace Oci Short-Wave Infrared Detection Assembly, Kenneth Squire, Jacob Hedelius, James Peterson, Eric Gorman, Gerhard Meister Oct 2021

Frequency-Dependent Linearity Characterization And Uncertainty Analysis Of The Pace Oci Short-Wave Infrared Detection Assembly, Kenneth Squire, Jacob Hedelius, James Peterson, Eric Gorman, Gerhard Meister

Space Dynamics Laboratory Publications

The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Ocean Color Instrument (OCI) will be used to collect data on the health of the planet’s oceans and atmosphere. Essential to OCI is its Short-Wave Infrared (SWIR) Detection Assembly (SDA), which measures light at discrete bands of interest. The linearity knowledge of the SDA detectors is crucial for collection of accurate and meaningful scientific data. This document presents the methodology employed in measuring the linearity response of the SDA to optical inputs at various modulation frequencies as well as the accompanying linearity uncertainty analysis.


Organizing Committee: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy Oct 2021

Organizing Committee: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy

Online Journal of Space Communication

Michael Beavin, Department of Commerce

Robert Bell, SSPI

Tamara Bond, SSPI

David Bross, Hannover Fairs Corporartion

Dean Henry Burdg, Auburn University

David Cavossa, Arrowhead Global Solutions

Scott Chase, Access Intelligence

Leonard David, Space.com

Kenneth Davidian, NASA

Don Flournoy, Ohio University

Tara Giunta, Paul Hastings Janofsky & Walker LLC

Ray Hamilton, Auburn University

Douglas Heydon, Consultant

Susan Irwin, Irwin Communications

Hussein Jirdah, Universities Space Research Association

Randy Johnson, Auburn University

David Logsdon, US Chamber of Commerce, Space Enterprise Project

Andrea Maleter, Futron Corporation

Ted Mallory, Astar Air Cargo

Joseph Pelton, George Washington University

Art Poland, George Mason University

Lon Rains, Space …


Sponsors: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy Oct 2021

Sponsors: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy

Online Journal of Space Communication

Sponsors of the Reach to Space Conference on Space Commercialization: A Celebration of 50 Years in Space


Speaker Biographies: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy Oct 2021

Speaker Biographies: Reach To Space Conference On Space Commercialization: A Celebration Of 50 Years In Space, D. Flournoy

Online Journal of Space Communication

Speaker Biographies: Reach to Space Conference on Space Commercialization: A Celebration of 50 Years in Space

Edward D. Horowitz

Phillip Spector

John Mattingly

Robert Bell

Joseph N. Pelton

Courtney Stadd

Gregg Maryniak

J. Steven Newman

Lon Rains

Don M. Flournoy

John Ordway


Conference Program, D. Flournoy Oct 2021

Conference Program, D. Flournoy

Online Journal of Space Communication

CONFERENCE ON SPACE COMMERCIALIZATION

CELEBRATION OF 50 YEARS IN SPACE

AND LOOKING TO THE FUTURE

CONFERENCE PROGRAM

Monday, November 12, 2007


Space And Defense – Volume Twelve – Number Two – Summer 2021, Space And Defense Journal Oct 2021

Space And Defense – Volume Twelve – Number Two – Summer 2021, Space And Defense Journal

Space and Defense

No abstract provided.


Nusat I: History, Robert J. Twiggs Oct 2021

Nusat I: History, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "NUSat I: History" from October 5, 2021.


Nusat I: History, Robert J. Twiggs Oct 2021

Nusat I: History, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "NUSat I: History" from October 5, 2021.


Survivability Analysis In The Shadow Of Apollo: Part I - Cislunar Debris Propagation And Spacecraft Vulnerability, Nathan R. Boone, Robert A. Bettinger Oct 2021

Survivability Analysis In The Shadow Of Apollo: Part I - Cislunar Debris Propagation And Spacecraft Vulnerability, Nathan R. Boone, Robert A. Bettinger

Faculty Publications

Although the reality of routine travel and sustained operations and habitation in space likely remains several decades away, the building blocks of space exploration and space system development necessary to realize this reality are currently being laid by peer, near-peer, and emerging space-faring nations. Traditionally, global space operations were notionally limited to near-Earth space, with mission altitudes extending to geosynchronous or even highly elliptical orbits. During the 2010s, however, space operations began moving beyond this paradigm to encompass cislunar space with reinvigorated U.S. initiatives to return to the Moon via the Artemis program, planned commercial space projects, and an accelerated …


Assessment Of Conventional And Air-Jet Wheel Deflectors For Drag Reduction Of The Drivaer Model, Sandra K. S. Boetcher, Kaloki L. Nabutola Oct 2021

Assessment Of Conventional And Air-Jet Wheel Deflectors For Drag Reduction Of The Drivaer Model, Sandra K. S. Boetcher, Kaloki L. Nabutola

Publications

Aerodynamic drag is a large resistance force to vehicle motion, particularly at highway speeds. Conventional wheel deflectors were designed to reduce the wheel drag and, consequently, the overall vehicle drag; however, they may actually be detrimental to vehicle aerodynamics in modern designs. In the present study, computational fluid dynamics simulations were conducted on the notchback DrivAer model—a simplified, yet realistic, open-source vehicle model that incorporates features of a modern passenger vehicle. Conventional and air-jet wheel deflectors upstream of the front wheels were introduced to assess the effect of underbody-flow deflection on the vehicle drag. Conventional wheel-deflector designs with varying heights …


Viability And Application Of Mounting Personal Pid Voc Sensors To Small Unmanned Aircraft Systems, Cheri Marcham Oct 2021

Viability And Application Of Mounting Personal Pid Voc Sensors To Small Unmanned Aircraft Systems, Cheri Marcham

Publications

Small Unmanned Aerial Systems in Emergency Response

Current sUAS Uses

  • Search and rescue
  • Thermal imaging
  • Evaluating structural stability
  • Spread of wildfires
  • Storm damage


Relative Pose Uncertainty Quantification Using Lie Group Variational Filtering, Christopher W. Hays Oct 2021

Relative Pose Uncertainty Quantification Using Lie Group Variational Filtering, Christopher W. Hays

Doctoral Dissertations and Master's Theses

The applications of visual sensing techniques have revolutionized the way autonomous systems perceive their environment on Earth. In space, the challenge of accurate perception has proven to be a difficult task. Due to adverse lighting conditions, high-noise images are common and degrade the performance of traditional feature-based estimation and perception algorithms. This work explores the applications of a variational filtering scheme founded in Lie Group theory to an autonomous rendezvous, proximity operations and docking problem. Two methodologies, a Monte Carlo approach and an Unscented Transform, for propagating uncertainty using a Lie Group Variational Filter are introduced and developed.


Rf Fingerprinting Unmanned Aerial Vehicles, Norah Ondus Oct 2021

Rf Fingerprinting Unmanned Aerial Vehicles, Norah Ondus

Doctoral Dissertations and Master's Theses

As unmanned aerial vehicles (UAVs) continue to become more readily available, their use in civil, military, and commercial applications is growing significantly. From aerial surveillance to search-and-rescue to package delivery the use cases of UAVs are accelerating. This accelerating popularity gives rise to numerous attack possibilities for example impersonation attacks in drone-based delivery, in a UAV swarm, etc. In order to ensure drone security, in this project we propose an authentication system based on RF fingerprinting. Specifically, we extract and use the device-specific hardware impairments embedded in the transmitted RF signal to separate the identity of each UAV. To achieve …


Integration Of Process Planning Into The Automated Fiber Placement Design For Manufacturing Cycle, Alex Brasington Oct 2021

Integration Of Process Planning Into The Automated Fiber Placement Design For Manufacturing Cycle, Alex Brasington

Theses and Dissertations

Automated Fiber Placement (AFP) is a composite manufacturing technique utilizing a robotic or gantry-based system and an attached fiber placement head to lay a prescribed number of strips of composite material, additively forming large composite structures. This technique has enabled increased throughput with increased accuracy and reliability when compared with prior composite manufacturing methods. However, even with the current state-of-the-art AFP process which employs advanced computer simulations and complex robotic operations, the data from various levels of the manufacturing lifecycle is isolated. This results in an incoherent system between the initial design phase and final part completion with limited ability …


Development Of A Converging-Channel Drop Tower For Sphere Symmetric Isolated Single Droplet Combustion, Nicholas Alexander Demaio Oct 2021

Development Of A Converging-Channel Drop Tower For Sphere Symmetric Isolated Single Droplet Combustion, Nicholas Alexander Demaio

Theses and Dissertations

The dawn of a new Space Age is upon us; Microgravity combustion of hydrocarbon fuels is a popular method of research and characterization. This allows for a one-dimensional analysis by suppressing the buoyancy forces produced by gravity and the large temperature differential between the flame boundary and the surrounding air. The current testing methods are expensive and require extensive preparation on the researchers behalf. There is a need to investigate an alternative method that is inexpensive, repeatable, and comparable to the other approaches that coincides with the literature.

A low-cost converging-channel drop tower was designed and fabricated for sphero-symmetric single …


Nonlinear Intelligent Model Predictive Control Of Mobile Robots, Benjamin Albia Oct 2021

Nonlinear Intelligent Model Predictive Control Of Mobile Robots, Benjamin Albia

Theses and Dissertations

This thesis presents a framework for an artificial neural network (ANN) model-based nonlinear model predictive control of mobile ground robots. A computer vision analysis module was first developed to extract quantitative position information from onboard camera feed with respect to a prescribed path. Various strategies were developed to construct nonlinear physical plant models for model predictive control (MPC), including the physics-based model (PBM), the ANN trained on PBM-generated data, the ANN trained on test-captured data, and the ANN initially trained on PBM-generated data and then retrained with captured data. All the models predict physical states and positions of the robot …


Empirical Modeling Of Tilt-Rotor Aerodynamic Performance, Michael C. Stratton Oct 2021

Empirical Modeling Of Tilt-Rotor Aerodynamic Performance, Michael C. Stratton

Mechanical & Aerospace Engineering Theses & Dissertations

There has been increasing interest into the performance of electric vertical takeoff and landing (eVTOL) aircraft. The propellers used for the eVTOL propulsion systems experience a broad range of aerodynamic conditions, not typically experienced by propellers in forward flight, that includes large incidence angles relative to the oncoming airflow. Formal experiment design and analysis techniques featuring response surface methods were applied to a subscale, tilt-rotor wind tunnel test for three, four, five, and six blade, 16-inch diameter, propeller configurations in support of development of the NASA LA-8 aircraft. Investigation of low-speed performance included a maximum speed of 12 m/s and …


Aerospace Mechanics And Controls, Carlos Montalvo Sep 2021

Aerospace Mechanics And Controls, Carlos Montalvo

Textbooks

This report represents aerospace mechanics and controls for CubeSats, quadcopters and aircraft. A CubeSAT is a small satellite on the order of 10 centimeters along each axis. A 1U satellite is a small cube with 10 cm sides. These satellites are used for a variety of missions and created by a variety of different organizations. When deployed from a rocket, a CubeSAT may obtain a large angular velocity which must be reduced before most science missions or communications can take place. Maximizing solar energy charging also involves better pointing accuracy. To control the attitude of these small satellites, reaction wheels, …


Combined Devices Of Facts Technology, Bahrom Ravshanovich Normuratov Associate Lecturer, Misrikhan Misrikhanov, Shukhrat Khamidov Sep 2021

Combined Devices Of Facts Technology, Bahrom Ravshanovich Normuratov Associate Lecturer, Misrikhan Misrikhanov, Shukhrat Khamidov

Technical science and innovation

FACTS - Flexible Alternative Current Transmission System technology is a family of devices, each of which can be used individually and in concert with other devices to control the interrelated parameters of the electrical power system. The mission of FACTS technology is to improve the control of power flows in both steady-state and transient modes of EPS. Flexibility of Electric Power Transmission, applied as "The ability to adapt to changes in transmission system or operating conditions while maintaining sufficient operating limits in steady-state and transient modes". Controlled Flexible AC Transmission Lines - Flexibility from Electric Power Transmission means "AC Power …


The Return To Anisotropy Across A Jet In Crossflow, Gregory P. Sakradse Sep 2021

The Return To Anisotropy Across A Jet In Crossflow, Gregory P. Sakradse

Dissertations and Theses

With data from experiments on a jet of air emitting from an orifice flush with the floor of a wind tunnel providing a transverse flow, analysis is conducted to extract information about the state of anisotropy in the Reynolds stress tensor. Inflow velocities are modulated across two distinct turbulence intensity regimes while holding jet exit conditions constant, providing an opportunity to isolate effects of both jet to crossflow velocity ratio, r and the effects of the turbulence carried by the crossflow. Anisotropy in the Reynolds stress tensor is examined through anisotropy invariant maps and evolution of the function F, …


Start With Simple Spacecraft: Cansat & Cricketsat, Robert J. Twiggs Sep 2021

Start With Simple Spacecraft: Cansat & Cricketsat, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Start with Simple Spacecraft: CanSat & CricketSat" from September 22, 2021.


Flexible Mold For Microstructures Replication, Zefu Ren, Dae Won Kim Sep 2021

Flexible Mold For Microstructures Replication, Zefu Ren, Dae Won Kim

Student Works

Space debris has been a growing concern in space exploration sector. To combat this issue, biomimicry is utilized to create a gecko’s feet microstructure that will be attached to a gripper or robotic arm. This will enable capture of debris through the use of dry adhesive microstructure. However, the production of such microstructures is expensive which hinders their implementation. The objective of this research is to develop an advanced fabrication process to mass produce gecko’s feet microstructure with soft polymer mold. The possibility of using different coating methods with coating materials will be justified. The process of fabricating mold and …


Issue 12: Contributors, Don Flournoy Sep 2021

Issue 12: Contributors, Don Flournoy

Online Journal of Space Communication

Biographical information on the Issue 12 contributors.


Usdla: An Instructional Media Selection Guide For Distance Learning, Jolly T. Holden, Philip Westfall Sep 2021

Usdla: An Instructional Media Selection Guide For Distance Learning, Jolly T. Holden, Philip Westfall

Online Journal of Space Communication

Purpose and Use of the Media Selection Guide


Increasingly, educators and trainers are challenged within their respective
organizations to provide for the efficient distribution of instructional con-
tent using instructional media. The appropriate selection of instructional
media to support distance learning is not intuitive and does not occur as a
matter of personal preference. On the contrary, instructional media selec-
tion is a systematic sequence of qualitative processes based on sound in-
structional design principles. Although media selection is often mentioned
when studying the discipline of instructional technology or Instructional
Systems Design (ISD), it is sometimes overlooked when applying the …


U.S. Government Education And Training Network, Philip Westfall Sep 2021

U.S. Government Education And Training Network, Philip Westfall

Online Journal of Space Communication

The U.S. Government Education and Training Network is a network of networks operated by a consortium of 17 federal agencies. With over 10,000 scheduled hours of broadcasting each year (4,500 from ATN alone), from 15 uplinks reaching out to over 1,500 receive sites, GETN offers high-quality, low-cost ITV with virtually limitless distribution capability within the US today and overseas.


A Critical Perspective On The Indian Experience, K. P. Madhu Sep 2021

A Critical Perspective On The Indian Experience, K. P. Madhu

Online Journal of Space Communication

Growth in the use of satellites for education has been phenomenal in India. Beginning in the 1970s with the SITE project (Satellite Instructional Television Experiment) using a borrowed US satellite, then in the 1980s having its own indigenous INSAT satellite for educational TV, to having a full fledged educational channel on national TV in the 1990s, to the potential of 72 educational channels on EDUSAT at the beginning of the 21st century, shows long-term interest and commitment to this sector.


Distance Education Projects In Kyrgyzstan, Aida Aidakyeva Sep 2021

Distance Education Projects In Kyrgyzstan, Aida Aidakyeva

Online Journal of Space Communication

Kyrgyzstan is a landlocked country in Central Asia, one of the former Soviet Union republics, endowed with few natural resources, but it has a tremendously advantageous location on the major crossroads between Asia and Europe. Under the Soviet system the educational level of the population used to be very high in Kyrgyzstan. Recently the quality of education has started to worsen due to the continuous migration of the nation's specialists to more economically developed countries.


Distance Education Via Satellite: An Early Case Study Of The Indonesian Distance Education Satellite System, Willard D. Shaw Sep 2021

Distance Education Via Satellite: An Early Case Study Of The Indonesian Distance Education Satellite System, Willard D. Shaw

Online Journal of Space Communication

In 1980, the U.S. Agency for International Development initiated the AID Rural Satellite Program (RSP) to explore the potential of telecommunications as a means of extending scarce expert resources and expanding educational opportunities to remote and rural areas. Building on simple, interactive, and inexpensive telephone-based technologies, the Program developed teleconferencing systems for use as a development tool. Three pilot projects-in Indonesia, the West Indies, and Peru-were implemented to test and demonstrate that audioteleconferencing could reliably and affordably support development activities in education, health and agriculture.

The abstract of this paper is available in Bahasa Indonesia. See supplemental files below.