Engineering Commons^™

Data And Network Optimization Effect On Web Performance, Steven Rosenberg, Surbhi Dangi, Isuru Warnakulasooriya

Surbhi Dangi

In this study, we measure the effects of two software approaches to improving data and network performance: 1. Content optimization and compression; and 2. Optimizing network protocols. We achieve content optimization and compression by means of BoostEdge by ActivNetworks and employ the SPDY network protocol by Google to lower the round trip time for HTTP transactions. Since the data and transport layers are separate, we conclude our investigation by studying the combined effect of these two techniques on web performance. Using document mean load time as the measure, we found that with and without packet loss, both BoostEdge and SPDY …

Vanadium Oxide Thin-Film Variable Resistor-Based Rf Switches, Kuanchang Pan, Weisong Wang, Eunsung Shin, Kelvin Freeman, Guru Subramanyam

Guru Subramanyam

Vanadium dioxide (VO2) is a unique phase change material (PCM) that possesses a metal-to-insulator transition property. Pristine VO2 has a negative temperature coefficient of resistance, and it undergoes an insulator-to-metal phase change at a transition temperature of 68°C. Such a property makes the VO2 thin-film-based variable resistor (varistor) a good candidate in reconfigurable electronics to be integrated with different RF devices such as inductors, varactors, and antennas. Series single-pole single-throw (SPST) switches with integrated VO2 thin films were designed, fabricated, and tested. The overall size of the device is 380 μm × 600 μm. The SPST switches were fabricated on …

A High Performance Ceramic-Polymer Separator For Lithium Batteries, Jitendra Kumar, Padmakar Kichambare, Amarendra K. Rai, Rabi Bhattacharya, Stanley J. Rodrigues, Guru Subramanyam

Guru Subramanyam

A three-layered (ceramic-polymer-ceramic) hybrid separator was prepared by coating ceramic electrolyte [lithium aluminum germanium phosphate (LAGP)] over both sides of polyethylene (PE) polymer membrane using electron beam physical vapor deposition (EB-PVD) technique. Ionic conductivities of membranes were evaluated after soaking PE and LAGP/PE/LAGP membranes in a 1 Molar (1M) lithium hexafluroarsenate (LiAsF6) electrolyte in ethylene carbonate (EC), dimethyl carbonate (DMC) and ethylmethyl carbonate (EMC) in volume ratio (1:1:1). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques were employed to evaluate morphology and structure of the separators before and after cycling performance tests to better understand structure-property correlation. As compared …

Industry-University Collaboration: A University Of Dayton Model, Guru Subramanyam

Guru Subramanyam

This paper introduces industry-university collaboration activities currently in place at the University of Dayton's School of Engineering. These collaborations are important to prepare industry-ready graduates who excel in technical, entrepreneurial, and leadership skills. One of the key curricular components is the industry-sponsored multidisciplinary projects. Industry involvement in advisory committee, strategic research partnerships, and other forms are discussed.

Adaptive Beam Director For A Tiled Fiber Array, Mikhail Vorontsov, Jim F. Riker, Ernst Polnau, Svetlana Lachinova, Venkata S. Rao Gudimetla

Mikhail Vorontsov

We present the concept development of a novel atmospheric compensation system based on adaptive tiled fiber array architecture operating with target-in-the-loop scenarios for directed beam applications. The adaptive tiled fiber array system is integrated with adaptive beam director (ABD). Wavefront control and sensing functions are performed directly on the beam director telescope primary mirror. The beam control of the adaptive tiled fiber array aims to compensate atmospheric turbulence-induced dynamic phase aberrations and results in a corresponding brightness increase on the illuminated extended object. The system is specifically designed for tiled fiber system architectures operating in strong intensity scintillation and speckle-modulation …

Characterization Of Atmospheric Turbulence Effects Over 149 Km Propagation Path Using Multi-Wavelength Laser Beacons, Mikhail Vorontsov, Gary W. Carhart, Venkata S. Rao Gudimetla, Thomas Weyrauch, Eric Stevenson, Svetlana Lachinova, Leonid A. Beresnev, Jony Jiang Liu, Karl Rehder, Jim F. Riker

Mikhail Vorontsov

We describe preliminary results of a set of laser beam propagation experiments performed over a long (149 km) near-horizontal propagation path between Mauna Loa (Hawaii Island) and Haleakala (Island of Maui) mountains in February 2010. The distinctive feature of the experimental campaign referred to here as the Coherent Multi-Beam Atmospheric Transceiver (COMBAT) experiments is that the measurements of the atmospheric-turbulence induced laser beam intensity scintillations at the receiver telescope aperture were obtained simultaneously using three laser sources (laser beacons) with different wavelengths (λ1 = 0.53 μm, λ2 = 1.06 μm, and λ3 = 1.55 μm). The presented experimental results on …

Comparison Of Turbulence-Induced Scintillations For Multi-Wavelength Laser Beacons Over Tactical (7 Km) And Long (149 Km) Atmospheric Propagation Paths, Mikhail Vorontsov, Venkata S. Rao Gudimetla, Gary W. Carhart, Thomas Weyrauch, Svetlana Lachinova, Ernst Polnau, Joseph Rierson, Leonid A. Beresnev, Jony Jiang Liu, Jim F. Riker

Mikhail Vorontsov

We report results of the experimental analysis of atmospheric effects on laser beam propagation over two distinctive propagation paths: a long-range (149 km) propagation path between Mauna Loa (Island of Hawaii) and Haleakala (Island of Maui) mountains, and a tactical-range (7 km) propagation path between the roof of the Dayton Veterans Administration Medical Center (VAMC) and the Intelligent Optics Laboratory (IOL/UD) located on the 5th floor of the University of Dayton College Park Center building. Both testbeds include three laser beacons operating at wavelengths 532 nm, 1064 nm, and 1550 nm and a set of identical optical receiver systems with …

Atmospheric Turbulence Compensation Of Point Source Images Using Asynchronous Stochastic Parallel Gradient Descent Technique On Amos 3.6 M Telescope, Mikhail Vorontsov, Jim F. Riker, Gary W. Carhart, Venkata S. Rao Gudimetla, Leonid A. Beresnev, Thomas Weyrauch

Mikhail Vorontsov

The Stochastic Parallel Gradient Descent Technique-based Adaptive Optics (SPGD-AO) system described in this presentation does not use a conventional wavefront sensor. It uses a metric signal collected by a single pixel detector placed behind a pinhole in the image plane to drive three deformable mirrors (DMs). The system is designed to compensate the image for turbulence effects. The theory behind this method is described in detail in [1]. However this technique, while widely simulated and tested in the laboratory, was not yet verified in astronomical field site experiments. During the month of May 2007, a series of experiments with SPGD-AO …

Pocket Deformable Mirror For Adaptive Optics Applications, Leonid A. Beresnev, Mikhail Vorontsov, Peter Wangsness

Mikhail Vorontsov

Adaptive/active optical elements are designed to improve optical system performance in the presence of phase aberrations. For atmospheric optics and astronomical applications, an ideal deformable mirror should have sufficient frequency bandwidth for compensation of fast changing wave front aberrations induced by either atmospheric turbulences or by turbulent air flows surrounding a flying object (air optical effects). In many applications, such as atmospheric target tracking, remote sensing from flying aircraft, boundary layer imaging, laser communication and laser beam projection over near horizontal propagation paths the phase aberration frequency bandwidth can exceed several kHz. These fast-changing aberrations are currently compensated using relatively …

Adaptive Optics Performance Over Long Horizontal Paths: Aperture Effects In Multi-Conjugate Adaptive Optical Systems, Miao Yu, Mikhail Vorontsov, Svetlana Lachinova, Jim F. Riker, Venkata S. Rao Gudimetla

Mikhail Vorontsov

We analyze various scenarios of the aperture effects in adaptive optical receiver-type systems when inhomogeneities of the wave propagation medium are distributed over long horizontal propagation path, or localized in a few thin layers remotely located from the receiver telescope pupil. Phase aberration compensation is performed using closed-loop control architectures based on phase conjugation and decoupled stochastic parallel gradient descent (DSPGD) control algorithms. Both receiver system aperture diffraction effects and the impact of wave-front corrector position on phase aberration compensation efficiency are analyzed for adaptive systems with single or multiple wave-front correctors.

Distributed Efficient Channel Allocation Technique For Multi-Radio Multichannel Interference-Aware Multi-Path Routing Protocol In Wireless Mesh Networks., Shreenidhi. P. L, Puttamadappa. C

Innovative Research Publications IRP India

The major change in the wireless network standards has attracted researchers to utilize benefits of several data services in various applications. Wireless Mesh Networks which follows 802.11 standards are very best alternative to Local Area Networks and Metropolitan Area Networks. There is a need for better utilization of the 802.11 spectrum in Mesh Networks environment when transmitting data through mesh networks. Recent work shows the increase in utilization of 802.11 spectrum for wireless mesh networks. An effort has been made to design and develop a distributed, self healing, self stabilizing protocol that’s assigns channels to mesh nodes in large wireless …

Parallel Computation In Communication And Signal Processing, Amean Al_Safi, Bradley Bazuin, Liqaa Alhafadhi

Amean S Al_Safi

The powerful computation of GPU has increased the computation speed up of many systems. This paper summarize some of the most important work in the field of communication and signal processing using GPU

Testimony Before The House Committee On National Security And The House Committee On Oversight And Government Reform, George H. Baker Iii

George H Baker

The Commission to Assess the threat to the United States from Electromagnetic Pulse, on which I served as principal staff, made a compelling case for protecting critical infrastructure against the nuclear electromagnetic pulse (EMP) and geomagnetic disturbances (GMD) caused by severe solar storms. Their 2008 Critical Infrastructure Report explains EMP effects, consequences, and protection means for critical infrastructure sectors. EMP and GMD are particularly challenging in that they interfere with electrical power and electronic data, control, transmission, and communication systems organic to nearly all critical infrastructures. The affected geography may be continental in scale. EMP and GMD events thus represent …

The Openorbiter Cubesat As A System-Of-Systems (Sos), Sofiane Chaieb, Michael Wegerson, Jeremy Straub, Ronald Marsh, Benjamin Kading, David Whalen

Jeremy Straub

This paper discusses the use of the system-of-systems (SoS) methodology and SoS engineering (SoSE) to the challenge of the design and operation of a CubeSat-class spacecraft. It considers this in the context of one critical component system, the electrical power system (EPS) which interacts with virtually all other systems onboard the spacecraft. The spacecraft is also considered in the context of being a system-component of a larger mission system-of-systems. The efficacy of SoSE use for this endeavor is considered and recommendations are made for the use of SoS and SoSE by other small spacecraft and, more broadly, spacecraft developers.

Supervisory Control And Data Acquisition (Scada) Control Optimization, Garrett Johnson, Jeremy Straub, Eunjin Kim

Jeremy Straub

SCADA systems are generally used to monitor and control multiple systems of the same type to allow them to be remotely controlled and monitored. Water plants, for example, could be controlled and monitored by a SCADA system. This project seeks to optimize a SCADA system using Artificial Intelligence. A constraint satisfaction / optimization algorithm is used to maximize performance relative to weighted system goals.

A Software Defined Radio Communications System For A Small Spacecraft, Michael Hlas, Jeremy Straub, Ronald Marsh

Jeremy Straub

Software defined radios (SDRs) are poised to significantly enhance the future of small spacecraft communications. They allow signal processing to be performed on a computer by software rather than requiring dedicated hardware. The OpenOrbiter SDR (discussed in [1] and refined in [2]) takes data from the flight computer and converts it into an analog signal that is transmitted via the spacecraft antenna. Because the signal processing is done in software, the radio can be easily reconfigured. This process is done in reverse for incoming transmissions, which are received by the SDR and decoded by software. Figures 1 and 2 provide …

Creating A Low-Cost Radio For An Open Cubesat, Michael Wegerson, Jeremy Straub, Ronald Marsh

Jeremy Straub

A reliable communication system is key to the success of a CubeSat mission, allowing for data to be trans-mitted to the ground station and commands to be up-loaded to the satellite. To satisfy this need, the OpenOrbiter satellite (a 1-U CubeSat [1], being devel-oped with a target parts budget of under $5,000 [2]) is leveraging previously space-tested [3], low-cost trans-ceiver design which is based on the SI 4463 IC unit. This board design will be included in the publically available Open Framework for Educational Nanosatel-lites (OPEN) allowing others to modify, enhance and/or make use of the design in the future.

Small Satellite Communication System Creation At The University Of North Dakota, Michael Hlas, Jeremy Straub, Ronald Marsh

Jeremy Straub

Software defined radios (SDRs) are poised to significantly enhance the future of small spacecraft communications. They allow signal processing to be performed on a computer by software rather than requiring dedicated hardware. The OpenOrbiter SDR (discussed in [1] and refined in [2]) takes data from the flight computer and converts it into an analog signal that is transmitted via the spacecraft antenna. Because the signal processing is done in software, the radio can be easily reconfigured. This process is done in reverse for incoming transmissions, which are received by the SDR and decoded by software. Figures 1 and 2 provide …

Impact Of Srs In Wdm Systems And Its Mitigation By Maximum Likelihood Sequence Detection, Innovative Research Publications Irp India, T. Sabapathi, G. Jaya Brindha

Innovative Research Publications IRP India

Non linear effects play a major role in hindering the progress of optical communication systems in terms of higher data rates and long haul transmissions. Maximum Likelihood Sequence Detection (MLSD) has been proposed to combat the nonlinear effects in optical channels. The main objective is to extract the original signal from the received signal which is distorted due to the non linear effects arising in the fiber. MLSD is an optimum detector as it uses the Viterbi detection through the Trellis structure. In this paper, the impact of SRS in the transmitted signal and its mitigation by MLSD are analyzed. …

Structural Similarity Based Image Quality Assessment Using Full Reference Method, Innovative Research Publications Irp India, Suneet Betrabet, Chetan Kumar Bhogayta

Innovative Research Publications IRP India

This paper presents an objective quality assessment for digital images that have been degraded by noise. Objective quality assessment is crucial and is generally used in image processing. The main objective of this paper is to analyse various statistical properties and their measurements and finally compare them. The statistical properties that are included are mean square error (MSE), root mean square error (RMSE), signal to noise ratio (SNRQ), peak signal to noise ratio (PSNR) and certain frequency parameters like spectral magnitude distortions and spectral phase distortions. But it is observed that MSE and PSNR yield poor results therefore a new …

Blind Source Separation Using Ica For Additive Mixing In Time And Frequency Domain, Innovative Research Publications Irp India, Swapnil Mohan Mahajan, Suneet Kishore Betrabet

Innovative Research Publications IRP India

This paper presents BSS for additive mixing where every recordings consist of differently weighted signal. Therefore, by using ICA for both time-domain and frequencydomain, we are going to separate source signals from mixed signal. The main aim of our analysis is to perform undetermined convolutive BSS via frequency bin-wise clustering and permutation alignment where convolutive mixture are most delayed and weighted. So, ICA in timedomain is fails to separate signals. Hence, instead of this we use ICA in frequency-domain which playing vital role in separation of audio signals by using MATLAB which is our future work

A Low-Cost Radio For An Open Cubesat, Michael Wegerson, Jeremy Straub, Ronald Marsh

Jeremy Straub

The OpenOrbiter small spacecraft development program aims to develop a template that can be used by colleges and universities world-wide to ‘jumpstart’ their own CubeSat development program. It is doing this through the development of designs (and implementations to test the designs functionality) of all basic CubeSat subsystems. A CubeSat can prospectively perform elements of a mission that would otherwise have required the development and deployment of a multi-million dollar satellite, thus, interest in CubeSats in industry and government is strong as well. The Open Prototype for Educational Nanosats (OPEN) design being produced by the OpenOrbiter program may, thus, be …

The Creation Of A Communication Systems For A Small Satellite At The University Of North Dakota, Michael Hlas, Jeremy Straub, Ronald Marsh

Jeremy Straub

Software defined radios (SDRs) are poised to significantly enhance the future of small spacecraft communications. They allow signal processing to be performed on a computer by software rather than requiring dedicated hardware. The SDR takes data from the flight computer and converts it into an analog signal that is transmitted via the spacecraft antenna. Because the signal processing is done in software, the radio can be easily reconfigured.

Data is prepared for transmission by TCP stack software onboard the OpenOrbiter Spacecraft and placed in a queue while the spacecraft is listening for a signal from a ground station. When a …

Design Of An Onboard Distributed Multiprocessing System For A Cubesat, Michael Wegerson, Jeremy Straub, Ronald Marsh

Jeremy Straub

The OpenOrbiter program aims to develop a low-cost framework to facilitate the development of CubeSat-class spacecraft (small spacecraft with nominal dimensions of 10 cm x 10 cm x 10 cm) for a parts cost of less than $5,000. To validate the framework that has been developed, a prototype unit will also be fabricated and tested in low-Earth orbit. In addition to validating the development of Open Prototype for Educational Nanosats (OPEN) framework, the spacecraft will perform on-orbit science. One aspect of the science mission will be to demonstrate and characterize the efficacy of two types of image processing. To this …

Hardware Design For An Intelligent Attitude Determination And Control System (Adcs), Michael Wegerson, Matt Partridge, Nathan Crocker, David Schindele, Broc Friend, Levi Lewis, Ben Johnson, Jeremy Straub, Ronald Marsh

Jeremy Straub

Attitude determination and control is one of the most important subsystems on any satellite, allowing the spacecraft to sense and control its orientation while in orbit. Attitude sensing is achieved by measuring the satellite’s acceleration, rotation, and it’s alinement to Earth’s magnetic field. With its orientation determined, a satellite can use one or several different techniques to regulate its motion. One methods is to use of a pseudo-passive system of electromagnets (called magnetorquers) powered at specific times to use magnetic fields generated by the Earth to exert force on the spacecraft, thereby controlling the rotation of the satellite and facilitating …

Analysis Of A ‘Turn-Key’ No Hardware Space Mission Using The Orbital Services Model, Jeremy Straub

Jeremy Straub

Many applications that would benefit from access to space cannot afford the cost of spacecraft development, launch and operations. Other operations require only a fraction of a spacecraft or complete use of a spacecraft for a limited period of time. This paper considers the value of a ‘turn-key’ style space mission. It considers what types of missions could be reasonably conducted using this approach. The economics of being a service provider are considered. Then, a prospective mission concept for one OSM ‘turn-key’ mission is presented. The value proposition of this mission is assessed and the hardware and other capabilities required …

Analyzing Wi­Fi P2p In The Context Of A Hangman Game, William L. Honig

William L Honig

Wi­Fi P2P , which complies with the Wi­Fi Alliance's Wi­Fi Direct™ certification

2 3

program, is a relatively new addition to wireless communications systems. It is now

supported in Android operating system (since version 4.0). In theory, Wi­Fi Direct offers

advantages for ad hoc communications between mobile apps. A key goal of this project

was to evaluate the ability of Wi­Fi P2P for interconnecting mobile apps by using a

common game suitable to mobile screens and devices.

The application allows the user to interconnect two devices using Wi­Fi P2P and

play the classic hangman game. The players search for devices …

Variable Attenuator Blends Dynamic Range, Linearity, Chin-Leong Lim

Chin-Leong Lim

A voltage variable attenuators (VVA) with compact dimensions and high linearity can be realized by connecting PIN diodes in the form of a π network. However this VVA's maximum frequency is limited to ~1 GHz because of signal leakage through the series diodes' parasitic capacitances. The ceiling frequency can significantly raised by resonating the parasitic capacitance with a parallel inductor. This technique has been previously demonstrated on a discrete design. To reduce component count and size, this work extends the technique to a standalone, highly-integrated module. This paper reports the performances achieved at 3.5 GHz.

The prototype's attenuation is adjustable …

Reducing Magneto-Inductive Positioning Errors In A Metal-Rich Indoor Environment, Orfeas Kypris, Traian Abrudan, Andrew Markham

Orfeas Kypris

Ferrous objects distort magnetic fields and can significantly increase magneto-inductive positioning errors in indoor environments. In this work, we use image theory in order to formulate an analytical channel model for the magnetic field of a quasi-static magnetic dipole positioned above a perfectly conducting half-space. The proposed model can be used to compensate for the distorting effects that metallic reinforcement bars (rebars) impose on the magnetic field of a magneto-inductive transmitter node in an indoor environment. Good agreement is observed between the analytical solution and numerical solutions obtained from 2-D finite element simulations when the transmitter node is located more …

Limiters Protect Adcs Without Adding Harmonics, Chin-Leong Lim

Chin-Leong Lim

High-speed Analogue to Digital Converters (ADC) are used for sampling at either the intermediate frequency (IF) or the radio frequency of wireless receivers. When the transmitter is nearby, the sampled signal can exceed the ADC’s maximum input level. So, amplitude limiting is necessary to prevent ADC damage or degradation. While automatic gain control is effective for controlling IF amplitude excursion in traditional single-carrier systems, it is not desirable in modern multi-carrier applications. One solution is to cap the IF amplitude excursion with a limiter. Unfortunately, a new problem is created – the strong non-linearity that is required of a good …