Electrical and Computer Engineering Commons^™

Online Parameter Estimation Under Non-Persistent Excitations For High-Rate Dynamic Systems, Jin Yan, Simon Laflamme, Jonathan Hong, Jacob Dodson

Civil, Construction and Environmental Engineering Publications

High-rate dynamic systems are defined as systems experiencing dynamic events of typical amplitudes higher than 100 g_n for a duration of less than 100 ms. They are characterized by 1) large uncertainties on the external loads; 2) high levels of nonstationarity and heavy disturbance; and 3) generation of unmodeled dynamics from changes in mechanical configuration. To fully enable these systems, feedback capabilities must be developed. This includes computationally fast software and low latency hardware. This paper presents a pure time-based online parameter estimation algorithm for high-rate dynamic systems with real-time applicability. The algorithm is based on a model reference ...

Array-Based Guided Wave Source Location Using Dispersion Compensation, Andrew Downs, Ronald A. Roberts, Jiming Song

Electrical and Computer Engineering Publications

An important advantage of guided waves is their ability to propagate large distances and yield more information about flaws than bulk waves. Unfortunately, the multi-modal, dispersive nature of guided waves makes them difficult to use for locating flaws. In this work, we present a method and experimental data for removing the deleterious effects of multi-mode dispersion allowing for source localization at frequencies comparable to those of bulk waves. Time domain signals are obtained using a novel 64-element phased array and processed to extract wave number and frequency spectra. By an application of Auld’s electro-mechanical reciprocity relation, mode contributions are ...

Motivation Dynamics For Autonomous Composition Of Navigation Tasks, Paul B. Reverdy, Vasileios Vasilopoulos, Daniel E. Koditschek

Departmental Papers (ESE)

We physically demonstrate a reactive sensorimotor architecture for mobile robots whose behaviors are generated by motivation dynamics. Motivation dynamics uses a continuous dynamical system to reactively compose low-level control vector fields using valuation functions which capture the potentially competing influences of external stimuli relative to the system's own internal state. We show that motivation dynamics 1) naturally accommodates external stimuli through standard signal processing tools, and 2) can effectively encode a repetitive higher-level task by composing several low-level controllers to achieve a limit cycle in which the robot repeatedly navigates towards two alternatively valuable goal locations in a commensurately ...

Alternative Doppler Extraction For Indoor Communication Signals, Thomas L. Bradshaw

All Graduate Theses and Dissertations

Radar is a common detection system for detecting the speed and velocity of moving objects. Radar is performed by transmitting a radio signal in the direction of a moving object and then processing the received reflected radio waves. The radar system processes the received signal to extract the Doppler frequency of the reflected waves, which reveals information about the velocity of the object. In traditional radar, the system uses one antenna for both the transmitter and the receiver.

In passive bistatic radar, the transmit antenna and receiver antenna are separated. In addition, the radar system has no control over the ...

Dynamic Planning Networks, Norman Tasfi, Miriam A M Capretz

Electrical and Computer Engineering Publications

We introduce Dynamic Planning Networks (DPN), a novel architecture for deep reinforcement learning, that combines model-based and model-free aspects for online planning. Our architecture learns to dynamically construct plans using a learned state-transition model by selecting and traversing between simulated states and actions to maximize information before acting. DPN learns to efficiently form plans by expanding a single action conditional state transition at a time instead of exhaustively evaluating each action, reducing the number of state-transitions used during planning. We observe emergent planning patterns in our agent, including classical search methods such as breadth-first and depth-first search. DPN shows improved ...

Issue 7: Contributors, David Hartshorn, Martin Jarrold

Online Journal of Space Communication

List of Issue 7 Contributors.

Future Solutions: Universal Access, David Hartshorn

Online Journal of Space Communication

Today, the nations of the world have an immediate opportunity to advance essential telecommunication policy objectives through harmonisation of regulations governing the use of fixed satellite-based network solutions.

Future Solutions: Access To Ict: A Tale Of Three Briefings, David Hartshorn

Online Journal of Space Communication

If your inbox is anything like mine, then you already know that the publication of satellite communications reports has become an industry unto itself. But that's not to say that it's always an end unto itself. On the contrary.

Regulatory Reform: Strengthening Access To Information & Communications Technologies: Guidelines To Facilitate Policy & Regulation For Satellite Services, Global Vsat Forum

Online Journal of Space Communication

This document was prepared by GVF, an association of organisations engaged in the delivery of advanced broadband and narrowband satellite services to consumers, and commercial and government enterprises worldwide.

Regulatory Reform: In The Land Of The 'Coffeenet', Martin Jarrold

Online Journal of Space Communication

Sitting down to write this article at a desk some 30 miles south of central London, and less than one degree west of the Greenwich meridian, I became immediately more conscious than usual of geography. The frequently interwoven use of such western-centric cartographic labels as Middle East, and Far East, with the geographically more precise terms of Western or Central Asia, and East and South-East Asia, sometimes causes us to confuse the actual proximity of Europe's, much larger, near-neighbour.

Regulatory Reform: Asia's Great Step Forward, David Hartshorn

Online Journal of Space Communication

This paper was presented at Connect-World Asia Pacific, June 2002.

Forget about a great leap forward. All that's needed to facilitate communications in Asia are a few small steps. Indeed, today all nations of the world have an immediate opportunity to advance essential telecommunication policy objectives through harmonisation of regulations governing the use of telecommunications solutions.

Regulatory Reform: Wanted: A Bridge For Africa's Digital Divide Apply: Pretty Much Anywhere In Africa Quote Reference: Vsat, Martin Jarrold

Online Journal of Space Communication

For Africa, and for the economy of the whole planet, those hundreds of millions of people across the continent who are currently denied reasonable access to even simple voice service represent a vast untapped pool of creativity. This very large and potentially very powerful economic dynamo demands access to more than the simplest tools of communication, and requires the means to unleash the potential productivity of its own knowledge-base into an increasingly connected world. The International Telecommunications Union acknowledges this, as does its sister organisation, the United Nations. The Global VSAT Forum enjoins you to acknowledge it too.

Overview: A+B+C = Vsat, Martin Jarrold

Online Journal of Space Communication

The benefits of VSAT systems and services are being realised in all spheres across the globe, both private and public. Banks, government departments, schools, hospitals, home offices, small enterprises, multi-national corporates, and rural telephony… all sectors are seizing upon the opportunity to get connected through satellite communications.

Overview: Satellite Communication In Ghana - Challenges And Prospects, Kwasi Boateng

Online Journal of Space Communication

Busy Internet is a Ghanaian ISP that uses satellite connectivity to bring Internet to West Africans. The operations of this ISP illustrate the reliability, versatility and efficiency of, VSAT, (Very Small Aperture Terminal) networks in delivering fast broadband Internet services.

Overview: The View From 22,300 Miles High, David Hartshorn

Online Journal of Space Communication

Asia's geography, claiming many of the world's highest peaks, has provided a dramatic setting for a climbing expedition that began decades ago, when the satellite communications community took its first step on the lower slopes of the mountain.

Overview: Politics And Technology Converge: Case Studies On The Effects Of Regulatory Reform On Vsat Adoption In Developing Countries, Emmanuel Adugu, Kwasi Boateng, D. Flournoy, Eric Gavua, Wencelous Kaswoswe, Miao Zhang

Online Journal of Space Communication

Developing countries are actively implementing satellite data networks, and have undertaken policy reforms to facilitate such networks. This research examines how regulatory changes have resulted in the removal of barriers relating to the deployment of access technologies and growth in connectivity, especially in VSAT installations for low cost Internet access. In addition, this research seeks to identify the socio-economic impact of emerging data network applications in government, business, health and education. In some cases, government offices have been the driver of change; in other cases, businesses have been the ones to initiate and press these developments forward.

Overview: Pipelines Of The Skies, Errol Olivier

Online Journal of Space Communication

Advances in fixed satellite technology are enabling oil and gas concerns to enhance the efficiency of offshore operations with cost-effective voice and data network solutions.

Issue 7: From The Guest Editors, David Hartshorn, Martin Jarrold

Online Journal of Space Communication

During the past 15 years, the international satellite communications industry has been developing and refining network solutions such that today, there are more than one million so-called Very Small Aperture Terminal (VSAT) systems installed and operating in more than 120 countries.

Review Of Biomedical Application Examples Of Sinh-Domain Filters, Fatma Zuhal Adalar, Ali Kırçay

Dicle University Journal of Engineering

In this study, a review of biomedical application examples of sinh-domain filters is presented. Increasing living standards in developed countries and the combination of low-cost and practical health solutions determine the progress of biomedical systems. The design strategies of today's biomedical systems are aimed at achieving higher speed and wide dynamic range, lower power consumption and portable design. Therefore, sinh-domain filters, which have positive properties such as offering a wide dynamic range at low supply voltage, electronically adjusting the frequency characteristic, providing linearity and low power consumption, and the requirement for small chip area, are becoming increasingly important for ...

Effect Of Rotor Geometry On Performance Of 6/4 Switched Reluctance Motors, Ahmet Fenercioglu, Merve Şen Kurt, Altan Şahin, Hüseyin Zafer Keleş, Tuba Kocaer

Dicle University Journal of Engineering

This study investigates the effect of rotor geometry on performance in switched reluctance motors (SRM) using models analyzed by the 2-D Finite Element Method (FEM). All models have the same stator geometry, winding features, and air gap, but have different rotor geometries. The SRM model operates at nominal speed of 3000 rpm; with 6/4 pole and 150 W output power. Magnetic model analysis was undertaken for the 3 different rotor models. Electrical performance characteristics; speed, phase current, source current, efficiency, electromagnetic torque, and load torque were determined. Magnetic flux density and flux lines in the stator and rotor and ...