Engineering Commons^™

The Multiple Access Wiretap Channel Ii With A Noisy Main Channel, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

A two-transmitter multiple access wiretap channel II (MAC-WT-II) with a discrete memoryless (DM) main channel is investigated. Two models for the wiretapper, who chooses a fixed-length subset of the channel uses and observes erasures outside this subset, are proposed. In the first model, in each position of the subset, the wiretapper noiselessly observes either the first or the second user's symbol, while in the second model, the wiretapper observes a noiseless superposition of the two symbols. Achievable strong secrecy rate regions for the two models are derived. The achievability is established by solving a dual secret key agreement problem in …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• College Convocation 2016

A Smooth Toolpath Generation Method For Laser Metal Deposition, Renwei Liu, Zhiyuan Wang, Yunlu Zhang, Todd E. Sparks, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser metal deposition (LMD), also known as direct metal deposition (DMD) or laser engineered net shaping (LENS), which uses a laser beam to form a melt pool on a metallic substrate, into which powder or wire is fed. The conventional contour and zigzag toolpath pattern for LMD are discontinuous at turn points or corner points. The discontinuous toolpath causes uneven deposition, which brings height variation and porosity problems. This paper aims to develop a smooth toolpath generation method for LMD to improve the deposition quality. A parametric curve equation based on trigonometric functions is derived and built. It can be …

Modal Response As A Validation Technique For Metal Parts Fabricated With Selective Laser Melting, Joshua D. Pribe, Brian M. West, Michelle L. Gegel, Troy Hartwig, Toby Lunn, Ben Brown, Douglas A. Bristow, Robert G. Landers, Edward C. Kinzel

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper investigates modal analysis as a validation technique for additively manufactured parts. The Frequency Response Function (FRF) is dependent on both the geometry and the material properties of the part as well as the presence of any defects. This allows the FRF to serve as a “fingerprint” for a given part of given quality. Once established, the FRF can be used to qualify subsequently printed parts. This approach is particularly attractive for metal parts, due to the lower damping as well as use in high-value applications where failure is unacceptable. To evaluate the efficacy of the technique, tensile specimens …

Integration Of Voxel Based And Source Based Representation For Computer Aided Design Of Functional Gradient Materials, Fangquan Wang, Frank W. Liou, Todd E. Sparks

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Functionally Gradient Materials (FGMs) feature smooth transition from one material to another within a single object. FGMs modeling is considered to be one of the new challenges in Computer Aided Design area. To overcome this challenge, this paper presents the integration of a source-based and voxel-based approach to model FGMs. The input of STL format can be meshed and voxelized. The material composition and material varying information in each voxel can be generated from control sources. In addition, surface source is used to define default material information, and several filtering methods, including Gaussian filter, Average filter, are applied to blend …

The Quanta Image Sensor: Every Photon Counts, Eric Fossum, Jiaju Ma, Saleh Masoodian, Leo Anzagira, Rachel Zizza

Dartmouth Scholarship

The Quanta Image Sensor (QIS) was conceived when contemplating shrinking pixel sizes and storage capacities, and the steady increase in digital processing power. In the single-bit QIS, the output of each field is a binary bit plane, where each bit represents the presence or absence of at least one photoelectron in a photodetector. A series of bit planes is generated through high-speed readout, and a kernel or “cubicle” of bits (x, y, t) is used to create a single output image pixel. The size of the cubicle can be adjusted post-acquisition to optimize image quality. The specialized sub-diffraction-limit photodetectors in …

Practical Wired Digital Communications Link Analysis, Raymond Matthew Schmelzer

Dissertations and Theses

This thesis deals with the analysis of a Wired High Speed Serial Data Link (PAM2) which is commonly used throughout the data-communications and tele-communications industry. The goal of this study is to build a scalable simulation tool using Matlab that ultimately uses Receiver Bit Error Ratio (BER) as the metric for data link health. This study is also designed to aid in link specification development.

The Matlab and theoretical development is broken up into three sections being Transmitter (TX), Channel (Hs) and Receiver (RX). Realistic noise impairments can be added to each section along the signal path creating signal stresses …

Performance Of Dynamically Simulated Reference Patterns For Cross Correlation Ebsd, Brian Jackson, Jordan Christensen, Saransh Singh, Marc De Graef, David T. Fullwood, Eric Richards Homer, Robert Wagoner

Faculty Publications

High-resolution (or \cross-correlation") electron backscatter diffraction analysis (HR-EBSD) utilizes cross-correlation techniques to determine relative orientation and distortion of an experimental electron backscatter diffraction pattern (EBSP) with respect to a reference pattern. The integrity of absolute strain and tetragonality measurements of a standard Si/SiGe material have previously been analyzed using reference patterns produced by kinematical simulation. While the results were promising, the noise levels were significantly higher for kinematically produced patterns, compared to real patterns taken from the Si region of the sample. This paper applies HR-EBSD techniques to analyze lattice distortion in a Si/SiGe sample, using recently developed dynamically simulated …

Lean Satellite Concept, Filippo Graziani, Mengu Cho

Small Satellite Conference

In 2014, International Academy of Astronautics (IAA) initiated Study Group (SG) 4.18, "Definition and Requirements of Small Satellites Seeking Low-Cost and Fast-Delivery". Its objectives of the study group are to examine the definitions of small satellites, identify the requirements every satellite should follow and then reflect some of the findings to an ISO standard draft ISO/WD/20991, "Space systems - Requirements for Small Spacecraft" that is being developed recently at ISO/TC20/SC14. The purpose of the present paper is to present the latest findings in the SG activity especially in terms of small satellite definition.

During the SG meeting in 2014, a …

Cubesat Model-Based Systems Engineering (Mbse) Reference Model –Model Distribution And Application –Interim Status #2, David Kaslow, Bradley Ayres, Michael Chonoles, Samuel Gasster, Laura Hart, Chris Massa, Rose Yntema

Small Satellite Conference

Model Based Systems Engineering (MBSE) is a key practice to advance systems engineering that can benefit CubeSat missions. MBSE creates a system model that helps integrate other discipline specific engineering models and simulations.

The International Council on Systems Engineering (INCOSE) established the MBSE Initiative to promote, advance, and institutionalize the practice of MBSE. The INCOSE Space Systems Working Group Challenge team has been investigating the applicability of MBSE for designing CubeSats since 2011.

Our application of MBSE uses System Modeling Language (SysML), a graphical modeling language, to model all aspects of a system either directly or through an interface with …

Introduction To Nasa's Academy Of Aerospace Quality, Alice Smith, Jeffrey Smith

Small Satellite Conference

The NASA Academy of Aerospace Quality (AAQ) is an internet-based public domain forum of quality assurance-related educational modules for students and faculty at academic institutions targeting those involved in aerospace research, technology development, and payload design and development including Cube Sats, Small Sats, Nano Sats, Rockets and High Altitude Balloons. The target users are university project and research teams but the academy has also been used by K-12 teams, independent space activists, NASA contractors and other governmental agencies including those abroad. The interactive - web portal contains a curriculum structure of 50 diverse technical topics such as workmanship, systems engineering, …

Enhancing Cubesat And Small Satellite Reliability Through Improved Thermal Management, Steven Isaacs, Diego Arias, Mike Hulse, Mark Lake, Derek Hengeveld

Small Satellite Conference

The interest in the use of CubeSat and small satellites for commercial, government and military applications continues to grow. Particularly in Low Earth Orbit, the successful deployment of commercial electronics has allowed dramatic reductions in cost and dramatic improvements in performance. These benefits leverage the R&D and production infrastructure of terrestrial electronics companies that dwarf the traditional space supply base. However, questions remain on the specific levels of reliability that can be achieved using hardware that was designed and tested for use in a very different environment compared to traditional space components that are designed for and tested to environmental …

Large Square-Loop Antenna Deployment From Cubesats, Angela Cleri, Ralen Toledo, Austin Fruithandler, Brandon Goudy, Jacob Mingear, Norman Fitz-Coy

Small Satellite Conference

The small-scale nature of CubeSats presents a challenge for researchers looking to integrate large antennas that are suited for experiments using very low frequencies (VLF, 3-30 kHz). Loop antennas hold several advantages over monopole and dipole voltage probes because they are not subject to the same size restrictions. Monopoles and dipoles have to be larger to achieve the same gain and performance as loop antennas. Conversely, loop antennas hold a disadvantage in that they require stiffeners to maintain the loop structure which poses challenges in both stowage and deployment. To address these challenges, the University of Florida has been developing …

Energy-Cognizant Scheduling Of Store-And-Forward Communications With Multiple Priority Levels In Nanosatellite Systems, Cherry Y. Wakayama, Peter J. Yoo, Zelda B. Zabinsky

Small Satellite Conference

We derive an autonomous scheduling system for low earth orbiting store-and-forward communications nanosatellites (nanosats). Nanosats receive messages of different sizes and priorities, and the nanosat scheduling system determines when to deliver complete or partial messages to associated destinations. The optimal schedule considers nanosat limitations in terms of size, power, onboard data storage, energy capacity and contact time windows. In this paper, we first formulate a binary linear program to optimize a single-satellite resource-constrained message delivery schedule. Since a large-scale binary integer program is computationally intensive, we develop an approximation algorithm based on a time-indexed formulation and mean busy time objective …

Ors Responsive Manufacturing 6u Spacecraft, Jillian Marsh, Eric Stroka, George Moretti, Quinn Young, Jim Perry, Dean Wada, Matt Jeppesen, Matt Felt, Bryan Hansen

Small Satellite Conference

The Operationally Responsive Space Office is developing a small satellite capability and small satellite design specifically for advanced manufacturing and assembly methods for a semi-automated assembly and test facility. Designing a small satellite to be assembled and tested with this novel and innovative approach enables reduced costs, schedule, and risk. This presentation will discuss the implementation, unique design features, lessons learned, and challenges associated with developing for this new rapid-assembly capability as well as the unique benefits and challenges of assembly and test using automated, robotic systems. The presentation will also include discussions of the role that design-for-manufacturing, modular open …

Robust, Radiation Tolerant Command And Data Handling And Power System Electronics From Nasa Goddard Space Flight Center, Hanson Nguyen, James Fraction, Melyane Ortiz-Acosta, George Dakermanji, Bradford P. Kercheval, Amri Hernandez-Pellerano, Leonine S. Lee, David S. Kim, David S. Jung, Steven E. Meyer, Udayan Mallik, Kurt D. Rush, Faramarz Farid, James C. Olsen, Pietro A. Sparacino

Small Satellite Conference

In today's rapidly advancing technology roadmap for space applications there is an emphasis on completing missions faster and cheaper than previous large-scale missions at the National Aeronautics and Space Administration (NASA) such as the Lunar Reconnaissance Orbiter (LRO) or the Magnetospheric Multiscale (MMS) mission. As part of this effort, focus has shifted from using mostly radiation-tolerant or radiation-hardened parts to more commercial-off-the-shelf (COTS) components for missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the command and data handling (C&DH) system and the Electrical Power Systems (EPS) that …

Project: Lunasonde, Jeremiah Pate

Small Satellite Conference

LunaSonde is a 6U CubeSat mission with the objective of exploring the moon while testing several new technologies. It is also a potential contender for the NASA CubeQuest Challenge. Although low earth orbit has been revolutionized by nanosatellite design, deep space/ lunar exploration have varied little from multimillion dollar missions. In order to expand the scope of planetary exploration, we have designed an adaptable lunar nanosatellite which leverages several new technologies such as 3-D printed construction, photonic integrated chips, and a miniaturized optical communication package. LunaSonde will analyze the lunar surface with a thermal and multispectral imager, demonstrating planetary exploration …

Design And Development Of A Multi-Mode Monopropellant Electrospray Mircropropulsion System, Steven P. Berg, Joshua L. Rovey

Small Satellite Conference

Multi-mode spacecraft propulsion is the use of two or more types of propulsive devices on a spacecraft that share some commonality in terms of either hardware or propellant. An example is the Mars Global Surveyor, which made use of hydrazine as both a monopropellant for attitude control and a bipropellant for primary maneuvering. Specific to this study is a multi-mode propulsion system making use of a high-thrust chemical mode and a high-specific impulse electric mode. Using these two modes can be beneficial in two primary ways. One way is by designing a mission such that the high-thrust and high-specific impulse …

Iitmsat: Innovative Packet Protocol And Concept Of Operations, Akshay Gulati, Sourbh Bhadane, Joseph Samuel, Harishankar Ramachandran, R. David Koilpillai

Small Satellite Conference

No abstract provided.

Microscope, A Cnes Microsatellite To Check Einstein Equivalence Principle, And Its Rf Equipments, Clement Dudal, Romain Mathieu, Yves André, Marie Vialard, Hervé Guillon, M. Fernandez, Anis Latiri, G. Guillois, Y. Richard, P. Bataille

Small Satellite Conference

No abstract provided.

Characterizing Chromatic Effects In Small Star Trackers, Tom Dzamba, John Enright, Doug Sinclair

Small Satellite Conference

No abstract provided.

Targeting All Of Stem In The Primary School : Engineering Design As A Foundational Process, Lyn English

2009 - 2019 ACER Research Conferences

With the increased national and international focus on advancing STEM education, it is important to ensure all of its disciplines are represented in the curriculum. To-date, the STEM acronym has been used largely in reference to science, with less emphasis on the remaining disciplines – especially engineering. Yet engineering design, a core component of engineering education, is now seen internationally as a foundational process linking the STEM disciplines, not just confined to engineering. Engineering concepts, design processes, representing, modelling, and innovative design-based problem-solving are all featured within the new Design and Technologies Curriculum. This paper will explore the nature and …

Development Of A Low-Flying Cubesat Mission For F-Region Characterization, Jonathan Black, Gregory Earle, Robert Mcgwier, Anthony Wolosik

Small Satellite Conference

Plasma irregularities in the F-region (200-800 km) of the night-time equatorial ionosphere have been shown to significantly influence the performance and reliability of space borne and ground based radio communication systems. Equatorial Spread-F (ESF) episodes may cause the disruption of satellite operations, communications, and navigation due to backscatter and radar scintillation. Current records of rocket, satellite, and radar data are not of sufficient quantity to allow for accurate models and predictions of the spectrum of irregularities. To provide a better understanding and predict F-region phenomena that may disrupt communications, it is important to perform in situ, or local, real-time measurements …

The Conceptual Design Of Cubesat Based System For Gnss Radio Occultation/Reflective Mission, Jer Ling, Chen-Tsung Lin

Small Satellite Conference

The Global Navigation Satellite System (GNSS) Radio Occultation/Reflective (RO/R) instrument collects global atmospheric data and oceanic wind speed data for weather prediction and climate researches. This paper proposes the conceptual design of the satellite constellation and the satellite to realize the GNSS-RO/R mission based on the cubesat platform, with the goal to achieve cost effectiveness and minimum deployed schedule. The cubesat considered in the study is 6U and within 10 kilogram. The proposed innovative constellation consists of 12 (minimum required) plus 6 (backup) satellites on three 500 km altitude sun synchronous planes, 6 satellites even phasing on each plane. It …

Miniaturized Phonon Trap Timing Units For Pnt Of Cubesats, Mina Rais-Zadeh, Adam Peczalski, Serhat Altunc, Yun Zheng, Obadiah Kegege, Harry Shaw, Greg Heckler

Small Satellite Conference

This research is directed towards development of a chip-scale timing unit (clock) to be used in new systems that aim to improve the quantity and quality of data transmittal from small spacecrafts. The quantity and quality of data transmission are directly influenced by the speed and accuracy of the on-board clock. NASA roadmap identifies major technical challenges for space clocks using current technologies (i.e., quartz resonators), namely sensitivity to on-board thermal environment conditions and susceptibility to g-force, and ionizing radiation effects. The timing units developed under this project will enhance the current Small Satellites capabilities. With this technology Small Sats …

Modular Payload-Centered Cubesat, Saleh Al-Shidhani

Small Satellite Conference

CubeSats gained a lot of popularity recently after many successful missions and due to the availability of pico-components for these satellites. Although miniaturizing the electronic circuits, sensors and attitude control hardware are progressing very well, there are other components that cannot be miniaturized such as imaging lenses while maintaining spacial resolution. As results, bigger CubeSats were introduced. To maintain smaller size we developed a new Cubesat structure that's likely to reduce the size by 50%. The frame structure design offers the demanded rigidity around the payload and surrounded with eight slots for other components. the slots offer direct access to …

2015-2016 Eraudb Aiaa Design/Build/Fly Technical Report, Trevor W. Perrott

Student Works

The economic potential of small unmanned aerial vehicles (SUAVs) has been well documented and reported. According to the Association for Unmanned Vehicle Systems International (AUVSI), there is an associated economic impact from the growth of the UAV industry. The goal of the American Institute of Aeronautics and Astronautics Design/Build/Fly Competition Research Program (AIAA DBF CRP) is to investigate design and manufacturing methods for application to SUAVs within the scope of the AIAA DBF Competition.

Students were engaged in the application of aerospace engineering knowledge for the production of a dual-aircraft system. Through the use of Computational Fluid Dynamics (CFD), Computer …

Utilizing Electroencephalography Measurements For Comparison Of Task-Specific Neural Efficiencies: Spatial Intelligence Tasks, Benjamin J. Call, Wade Goodridge, Idalis Villanueva, Nicholas Wan, Kerry Jordan

Engineering Education Faculty Publications

Spatial intelligence is often linked to success in engineering education and engineering professions. The use of electroencephalography enables comparative calculation of individuals' neural efficiency as they perform successive tasks requiring spatial ability to derive solutions Neural efficiency here is defined as having less beta activation, and therefore expending fewer neural resources, to perform a task in comparison to other groups or other tasks. For inter-task comparisons of tasks with similar durations, these measurements may enable a comparison of task type difficulty. For intra-participant and inter-participant comparisons, these measurements provide potential insight into the participant's level of spatial ability and different …

Hybrid Flow Battery And Mn/Mn Electrolyte System, Stephen M. Lipka, Christopher R. Swartz

Center for Applied Energy Research Faculty Patents

An electrolyte system for a hybrid flow battery has a manganese based anolyte and a manganese based catholyte.

Hybrid Process Using A Membrane To Enrich Flue Gas Co2 With A Solvent-Based Post-Combustion Co2 Capture System, Kunlei Liu, Reynolds A. Frimpong, Kun Liu

Center for Applied Energy Research Faculty Patents

A process for recovery of CO₂ from a post-combustion gas includes pre-concentrating a CO₂ component of the post-combustion flue gas by passing the post-combustion gas through a CO₂-selective membrane module to provide a CO₂-enriched permeate stream and a CO₂-lean reject stream. Next, in a CO₂ absorber, both the CO₂-enriched permeate stream and CO₂ lean reject stream, fed to separate feed locations on the CO₂ absorber, are contacted with a scrubbing solvent to absorb CO₂ and provide a carbon-rich scrubbing solvent. Finally, absorbed CO₂ is stripped …