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2,334 full-text articles. Page 97 of 101.

Sensorchestra: Collaborative Sensing For Symbolic Location Recognition, Heng-Tze Cheng, Feng-Tso Sun, Senaka Buthpitiya, Martin L. Griss 2011 Carnegie Mellon University

Sensorchestra: Collaborative Sensing For Symbolic Location Recognition, Heng-Tze Cheng, Feng-Tso Sun, Senaka Buthpitiya, Martin L. Griss

Martin L Griss

"Symbolic location of a user, like a store name in a mall, is essential for context-based mobile advertising. Existing fingerprint- based localization using only a single phone is susceptible to noise, and has a major limitation in that the phone has to be held in the hand at all times. In this paper, we present SensOrchestra, a col- laborative sensing framework for symbolic location recognition that groups nearby phones to recognize ambient sounds and images of a location collaboratively. We investigated audio and image features, and designed a classifier fusion model to integrate estimates from diff erent phones. We also …


Activity-Aware Mental Stress Detection Using Physiological Sensors, Feng-Tso Sun, Cynthia Kuo, Heng-Tze Cheng, Senaka Buthpitiya, Patricia Collins, Martin Griss 2011 Carnegie Mellon University

Activity-Aware Mental Stress Detection Using Physiological Sensors, Feng-Tso Sun, Cynthia Kuo, Heng-Tze Cheng, Senaka Buthpitiya, Patricia Collins, Martin Griss

Martin L Griss

"Continuous stress monitoring may help users better understand their stress patterns and provide physicians with more reliable data for interventions. Previously, studies on mental stress detection were limited to a laboratory environment where participants generally rested in a sedentary position. However, it is impractical to exclude the effects of physical activity while developing a pervasive stress monitoring application for everyday use. The physiological responses caused by mental stress can be masked by variations due to physical activity. We present an activity-aware mental stress detection scheme. Electrocardiogram (ECG), galvanic skin response (GSR), and accelerometer data were gathered from 20 participants across …


Omnisense: A Collaborative Sensing Framework For User Context Recognition Using Mobile Phones, Heng-Tze Cheng, Senaka Buthpitiya, Feng-Tso Sun, Martin L. Griss 2011 Carnegie Mellon University

Omnisense: A Collaborative Sensing Framework For User Context Recognition Using Mobile Phones, Heng-Tze Cheng, Senaka Buthpitiya, Feng-Tso Sun, Martin L. Griss

Martin L Griss

Context information, including a user’s locations and activities, is indispensable for context-aware applications such as targeted advertising and disaster response. Inferring user context from sensor data is intrinsically challenging due to the semantic gap between low-level signals and high-level human activities. When implemented on mobile phones, more challenges on resource limitations are present. While most existing work focuses on context recognition using a single mobile phone, collaboration among multiple phones has received little attention, and the recognition accuracy is susceptible to phone position and ambient changes. Simply putting a phone in one’s pocket can render the microphone muffled and the …


Room-Level Wi-Fi Location Tracking, Joshua Correa, Ed Katz, Patricia Collins, Martin Griss 2011 Carnegie Mellon University

Room-Level Wi-Fi Location Tracking, Joshua Correa, Ed Katz, Patricia Collins, Martin Griss

Martin L Griss

Context-aware applications for indoor intelligent environments require an appropriately accurate and stable interior positioning system to adapt services to the location of a mobile user or mobile device in a building. Different technologies provide a varying mix of resolution, accuracy, stability and challenges. In this paper we report on our experience using an existing Wi-Fi infrastructure without specialized hardware added to support location tracking. There are several approaches to track the location of Wi-Fi enabled devices within a building such as signal propagation models and signature matching. We found signature matching most effective in our environment. Signature matching is accomplished …


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 2011 University of Dayton

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

Electrical and Computer Engineering Faculty Publications

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 …


The Wireless Control Network: A New Approach For Control Over Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam 2011 University of Pennsylvania

The Wireless Control Network: A New Approach For Control Over Networks, Miroslav Pajic, Shreyas Sundaram, George Pappas, Rahul Mangharam

Real-Time and Embedded Systems Lab (mLAB)

We present a method to stabilize a plant with a network of resource constrained wireless nodes. As opposed to traditional networked control schemes where the nodes simply route information to and from a dedicated controller (perhaps performing some encoding along the way), our approach treats the network itself as the controller. Specifically, we formulate a strategy for each node in the network to follow, where at each time-step, each node updates its internal state to be a linear combination of the states of the nodes in its neighborhood. We show that this causes the entire network to behave as a …


In-Silico Hyperthermia Performance Of A Near-Field Patch Antenna At Various Positions On A Human Body Model, Sergio Curto, Terrence See, Patrick McEvoy, Max Ammann, Zhi Ning Chen 2011 Technological University Dublin

In-Silico Hyperthermia Performance Of A Near-Field Patch Antenna At Various Positions On A Human Body Model, Sergio Curto, Terrence See, Patrick Mcevoy, Max Ammann, Zhi Ning Chen

Articles

A compact patch applicator designed to enhance targeted energy coupling at 434 MHz is a key enabler for sensitizing temperature increments in body regions containing superficial tumours. A detailed FDTD body model is used to explore simulated RF coupling and temperature increments for typical clinical conditions. The antenna impedance matching, specific absorption rate and thermal distribution parameters are evaluated to identify applied performance outcomes. The analysis reveals physiological-RF coupling patterns for an optimised closely-coupled single element applicator.


Fluorinated Templates For Energy-Related Nanomaterials And Applications, Mohammed J. Meziani, Fushen Lu, Li Cao, Christopher E. Bunker, Elena A. Guliants, Ya-Ping Sun 2011 Clemson University

Fluorinated Templates For Energy-Related Nanomaterials And Applications, Mohammed J. Meziani, Fushen Lu, Li Cao, Christopher E. Bunker, Elena A. Guliants, Ya-Ping Sun

Electrical and Computer Engineering Faculty Publications

Fluorinated ionomer membranes, as represented by the commercially available Nafion films, are macroscopically homogeneous and optically transparent but microscopically inhomogeneous with the presence of nanoscale hydrophilic cavities. These cavities serve as nanoscale reactors for the synthesis of nanoparticles from a variety of materials. The membranes with embedded nanoscale semiconductors, still optically transparent, have been used as sheet-photocatalysts for energy conversion applications, while those with embedded reactive metals used as nano-energetic materials for hydrogen generation and beyond. This chapter provides an overview on the templated synthesis of nanomaterials in fluorinated ionomer membranes and the various energy-related applications of this unique class …


Special Issue On Wireless Sensor And Actuator Networks, Jiming Chen, Karl H. Johanson, Stephan Olariu, Ioannis Ch. Paschalidis, Ivan Stojmenovic 2011 Old Dominion University

Special Issue On Wireless Sensor And Actuator Networks, Jiming Chen, Karl H. Johanson, Stephan Olariu, Ioannis Ch. Paschalidis, Ivan Stojmenovic

Computer Science Faculty Publications

( First paragraph) WIRELESS Sensor Networks (WSNs), in their various shapes and forms, have greatly facilitated and enhanced the automated, remote, and intelligent monitoring of a large variety of physical systems. These networks consist of a large number of typically small devices, each incorporating sensing, processing, and wireless communications capabilities. Their use has penetrated a plethora of application domains from industrial and building automation, to environmental, wildlife, and health monitoring.


Management Of Change To Ensure Is Success: A Longitudinal Study, Pauline Ash Ray, Wenli Wang, Jerry Cha-Jan Chang, Geoffrey Hubona 2011 Thomas University

Management Of Change To Ensure Is Success: A Longitudinal Study, Pauline Ash Ray, Wenli Wang, Jerry Cha-Jan Chang, Geoffrey Hubona

Management, Entrepreneurship and Technology Faculty Publications

This paper aims to understand the effect of management of change on the success of information system (IS) implementation. Drawing on change management research and self-determination theory, a research model is developed. Data collected from a longitudinal field survey before, during, and after an enterprise-wide IS implementation are analyzed to test the proposed hypotheses. The results indicate that management of change can be used to increase readiness for change and end-user computing satisfaction during and after the implementation. Readiness for change positively impacts satisfaction during an implementation but not after. Contrary to the literature, No significant relationship exists between resistance …


Wireless Physical-Layer Security Performance Of Uwb Systems, Miyong Ko 2011 University of Massachusetts Amherst

Wireless Physical-Layer Security Performance Of Uwb Systems, Miyong Ko

Masters Theses 1911 - February 2014

Traditionally, spread-spectrum systems have been employed to provide low probability-of-intercept (LPI) and low probability-of-detection (LPD) performances at the physical layer, but the messages transmitted over such a system are still encrypted with a powerful cipher to protect their secrecy. Our challenge is to find a solution to provide an additional level of security at the physical layer so that simple systems such as RFID tags with limited resources can be secure without using standard encryption. It has recently been suggested that the cryptographic security of the system can be enhanced by exploiting physical properties of UWB signals. With an eavesdropper …


Integrated Cmos Iq Upconverter/Downconverter For An X-Band Phased-Array Radar Application, Ryan C. Johnson 2011 University of Massachusetts Amherst

Integrated Cmos Iq Upconverter/Downconverter For An X-Band Phased-Array Radar Application, Ryan C. Johnson

Masters Theses 1911 - February 2014

This thesis describes the design and measurement of an X-band IQ up/down converter that has been fabricated on a 180nm RF CMOS process. This converter includes components for mixing, frequency doubling, quadrature generation, amplification, and limiting. The specific circuit topologies used include passive double-balanced mixers, RC polyphase filters, and injection locked LC oscillators.

The converter is part of a transceiver chain that will make up the dedicated circuitry for each active antenna element of a phased-array radar. An active antenna element combines a radiator with its own transceiver subsystem. A phased-array radar, NetRad, is under development at the University of …


Addressing/Exploiting Transceiver Imperfections In Wireless Communication Systems, Lihao Wang 2011 University of Massachusetts Amherst

Addressing/Exploiting Transceiver Imperfections In Wireless Communication Systems, Lihao Wang

Masters Theses 1911 - February 2014

This thesis consists of two research projects on wireless communication systems. In the first project, we propose a fast inphase and quadrature (I/Q) imbalance compensation technique for the analog quadrature modulators in direct conversion transmitters. The method needs no training sequence, no extra background data gathering process and no prior perfect knowledge of the envelope detector characteristics. In contrast to previous approaches, it uses points from both the linear and predictable nonlinear regions of the envelope detector to hasten convergence. We provide a least mean square (LMS) version and demonstrate that the quadrature modulator compensator converges.

In the second project, …


Simulating A Universal Geocast Scheme For Vehicular Ad Hoc Networks, Benjamin L. Bovee 2011 University of Massachusetts Amherst

Simulating A Universal Geocast Scheme For Vehicular Ad Hoc Networks, Benjamin L. Bovee

Masters Theses 1911 - February 2014

Recently a number of communications schemes have been proposed for Vehicular Ad hoc Networks (VANETs). One of these, the Universal Geocast Scheme (UGS) proposed by Hossein Pishro-Nik and Mohammad Nekoui, provides for a diverse variety of VANET-specific characteristics such as time-varying topology, protocol variation based on road congestion, and support for non line-of-sight communication. In this research, the UGS protocol is extended to consider inter-vehicle multi-hop connections in intersections with surrounding obstructions along with single-hop communications in an open road scenario. Since UGS is a probabilistic, repetition-based scheme, it supports the capacity-delay tradeoffs crucial for periodic safety message exchange. The …


Audio-To-Optical Conversion And Transmission, Jason Moritz 2011 California Polytechnic State University - San Luis Obispo

Audio-To-Optical Conversion And Transmission, Jason Moritz

Electrical Engineering

The purpose of this project is to understand free-space optical transmission of signals in the application of transmitting an audio signal. An audio signal will be taken from the headphone output of a computer and used to modulate a current source driving an LED and a laser diode. The optical signal will then be transmitted through free space as well as two different focal length lenses and converted back to an audio signal to measure any attenuation or gain in the original signal. My experimental results showed that the LED was able to transmit up to 10 dB more power …


Aether, Thomas Cameron, Kristine Colton, Daren Childers 2011 California Polytechnic State University - San Luis Obispo

Aether, Thomas Cameron, Kristine Colton, Daren Childers

Electrical Engineering

Aether is a RC-style autonomous air vehicle that utilizes GPS positioning along with a wireless communication system to achieve a computer-controlled flight.

This report will incorporate the acquisition, design, integration, implementation and testing phases of the UAV development. Furthermore a discussion of troubleshooting as well as improvements for future projects will be included.


Ultra Wideband Pulse Shaping, Pawel Rulikowski 2011 NIMBUS Centre for Embedded Systems Research

Ultra Wideband Pulse Shaping, Pawel Rulikowski

Theses

Methods for shaping of sophisticated, transient, ultra wideband (UWB) waveforms and pulses are presented. The methods include novel circuits based on step recovery diodes (SRDs) and quasi-transversal filter concepts but the majority of the work focuses on UWB pulse shaping using completely passive nonuniform transmission lines (NUTLs). It is shown, for the first time, that NUTLs can be used to generate highly sophisticated arbitrary UWB pulse shapes, including modified Hermite polynomial (MHP) and approximate spheroidal wave function (APSWF) pulses which are not known to have been previously generated in practice, and a generalized methodology, verified by experiments, for design of …


Special Issue On Information Dissemination And New Services In P2p Systems, Min Song, Sachin Shetty, Wenbin Jiang, E. K. Park 2011 Old Dominion University

Special Issue On Information Dissemination And New Services In P2p Systems, Min Song, Sachin Shetty, Wenbin Jiang, E. K. Park

Electrical & Computer Engineering Faculty Publications

Information dissemination is an important P2P application that has received considerable research attention in recent years. P2P information dissemination systems range from simple file sharing applications to more complex systems that allows users to securely and efficiently publish, organize, index, search, update and retrieve data in a distributed storage medium. For complex P2P information dissemination systems, there is a need for features which include security, anonymity, fairness, scalability, resource management, and organization capabilities. For effective information dissemination, following features of P2P systems and infrastructure need to be updated: distributed object location and routing mechanisms, novel approaches to content replication, caching …


Model-Driven Safety Analysis Of Closed-Loop Medical Systems, Miroslav Pajic, Rahul Mangharam, Oleg Sokolsky, David Arney, Julian M. Goldman, Insup Lee 2011 University of Pennsylvania

Model-Driven Safety Analysis Of Closed-Loop Medical Systems, Miroslav Pajic, Rahul Mangharam, Oleg Sokolsky, David Arney, Julian M. Goldman, Insup Lee

Departmental Papers (CIS)

In modern hospitals, patients are treated using a wide array of medical devices that are increasingly interacting with each other over the network, thus offering a perfect example of a cyber-physical system. We study the safety of a medical device system for the physiologic closed-loop control of drug infusion. The main contribution of the paper is the verification approach for the safety properties of closed-loop medical device systems. We demonstrate, using a case study, that the approach can be applied to a system of clinical importance. Our method combines simulation-based analysis of a detailed model of the system that contains …


Separation Distance Reduction In Mimo Systems Using End-Fire Antenna Arrays, Amean Al_Safi 2010 Western Michigan University

Separation Distance Reduction In Mimo Systems Using End-Fire Antenna Arrays, Amean Al_Safi

Amean S Al_Safi

The main problem in Multiple Input-Multiple Output (MIMO) systems is the separation distance between antennas which must be greater than or equal to half wavelength. Satisfying this separation is difficult or impossible especially at mobile communication, therefore this paper study the capability to reduce these separation distance by using End-Fire antenna arrays. Each antenna at the transmitter and receiver side is replaced by a set of antennas work as an array with a radiation pattern directed toward the axes of the arrays. The separation between elements in these arrays is fixed at quarter wavelength in order to have one main …


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