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Full-Text Articles in Systems and Communications

An Rf Cmos Implementation Of An Adaptive Filter For Narrow-Band Interferer Suppression In Uwb Systems, Markus Both Dec 2011

An Rf Cmos Implementation Of An Adaptive Filter For Narrow-Band Interferer Suppression In Uwb Systems, Markus Both

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Ultra-wideband (UWB) technology is a new type of technology for wireless communication that is based on the transmission of low power sub-nanosecond pulses. UWB communication utilizes a large bandwidth that overlaps and is coexistent with other wireless communication standards that can be also considered as narrow-band interferers. Because UWB systems are highly susceptible to narrow-band interferers, there is a demand for interferer suppression. An adaptive filter consisting of a two-element diversity receiver that performs minimum mean square error combining (MMSE) by the LMS algorithm is proposed. Thereby the elements of the LMS algorithm as well as the receiver LNA were …


Auto-Tuning Antenna, John Chen, Jennifer Tighe Dec 2011

Auto-Tuning Antenna, John Chen, Jennifer Tighe

Electrical Engineering

Radio transmitters and antennas have differing impedances at the output and feedpoint, depending on frequency. Modern antenna tuning methods involve manual or automatic resistance and reactance network adjustment to match transmitter and antenna impedance. This reduces power reflections to the transmitter, but introduces losses and prevents full transmitter power from being radiated at the antenna. This project utilizes a variable length antenna element to tune and match transmitter and antenna impedances, allowing efficient power transfer to the antenna. The antenna length varies from 0 to 30.5 inches. The method involves an RF signal with a maximum power of 2 watts …


Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang Sep 2011

Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang

Ray Bareiss

As emergency first responders and commanders increasingly use mobile phones, tablets, and social media to communicate, coordinate, and manage information during disasters, we see a need and opportunity to provide a mobile device-appropriate semantic layer to a geographically-based common operating picture. The challenge is to provide a simple, usable structure for a rapidly growing body of information to simplify the development of situational awareness in an unfolding disaster. We use a hyperlinked structure based on the ASK model to organize information in a readily accessible form. In this paper we describe our initial design and experience with an Android-based prototype, …


Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang Sep 2011

Semantic Geotagging: A Location-Based Hypermedia Approach To Creating Situational Awareness, Ray Bareiss, Martin Griss, Steven Rosenberg, Yu Zhang

Martin L Griss

As emergency first responders and commanders increasingly use mobile phones, tablets, and social media to communicate, coordinate, and manage information during disasters, we see a need and opportunity to provide a mobile device-appropriate semantic layer to a geographically-based common operating picture. The challenge is to provide a simple, usable structure for a rapidly growing body of information to simplify the development of situational awareness in an unfolding disaster. We use a hyperlinked structure based on the ASK model to organize information in a readily accessible form. In this paper we describe our initial design and experience with an Android-based prototype, …


Laser Cursor, Michael Liman Jun 2011

Laser Cursor, Michael Liman

Electrical Engineering

A user controls a cursor on a computer screen using a laser pointer. A camera picks up the laser pointer’s position and sends the data to the computer to move the cursor in the correct position.


Discrete Alarm Clock, Travis Moore, Collin Barth Jun 2011

Discrete Alarm Clock, Travis Moore, Collin Barth

Electrical Engineering

The standard alarm clock, as used daily by millions worldwide, has clear room for modification and improvement. This paper documents an implementation that rectifies many of these flaws. Improvements include adjustable snooze length, an IR remote for ease of use, and an RF headset for discrete alarm use or potential incorporation into a device much like a hearing aid. The processes involved in creating a digital alarm clock, as well as the obstacles met in the implementation of the enhanced design, are detailed within.


An Exploration Of Knowledge And Skills Transfer From A Formal Software Engineering Curriculum To A Capstone Practicum Project, Ray Bareiss, Ed Katz Apr 2011

An Exploration Of Knowledge And Skills Transfer From A Formal Software Engineering Curriculum To A Capstone Practicum Project, Ray Bareiss, Ed Katz

Ray Bareiss

Students at Carnegie Mellon Silicon Valley complete a team-based practicum project for an industrial sponsor as the capstone of their master’s education in software engineering. Over time, the faculty member who typically serves as advisor for such projects has been disturbed by the failure of several student teams to transfer some relevant knowledge and skills from the formal curriculum to the relatively unstructured practicum project environment. We conducted a survey of all 2010 software engineering students to ascertain the most significant selfreported shortcomings. This paper presents the survey data and then discusses the results in terms of a theory of …


Imirok: Real-Time Imitative Robotic Arm Control For Home Robot Applications, Heng-Tze Cheng, Zheng Sun, Pei Zhang Mar 2011

Imirok: Real-Time Imitative Robotic Arm Control For Home Robot Applications, Heng-Tze Cheng, Zheng Sun, Pei Zhang

Zheng Sun

Training home robots to behave like human can help people with their daily chores and repetitive tasks. In this paper, we present Imirok, a system to remotely control robotic arms by user motion using low-cost, off-the-shelf mobile devices and webcam. The motion tracking algorithm detects user motion in real-time, without classifier training or predefined action set. Experimental results show that the system achieves 90% precision and recall rate on motion detection with blank background, and is robust under the change of cluttered background and user-to-camera distance.


Leveraging Mobile Context For Effective Collaboration And Task Management In Disaster Response, Faisal Luqman, Martin L. Griss Mar 2011

Leveraging Mobile Context For Effective Collaboration And Task Management In Disaster Response, Faisal Luqman, Martin L. Griss

Martin L Griss

Collaboration and task management is challenging in distributed, dynamically-formed teams, typical in large scale disaster response scenarios. Ineffective collaboration may result in poor performance and possible loss of life. In this paper, we present Overseer, an agent-based system that exploits context information from mobile devices to facilitate collaboration and task allocation. We describe our system architecture and show how mobile context can be used to create dynamic role-based assignments to support collaboration and effective task management.


Anubis: An Attestation Protocol For Distributed Context-Aware Applications, Senaka Buthpitiya, Feng-Tso Sun, Heng-Tze Chen, Patrick Tague, Martin L. Griss, Anind K. Dey Jan 2011

Anubis: An Attestation Protocol For Distributed Context-Aware Applications, Senaka Buthpitiya, Feng-Tso Sun, Heng-Tze Chen, Patrick Tague, Martin L. Griss, Anind K. Dey

Martin L Griss

Sharing sensitive context information among multiple distributed components in mobile environments introduces major security concerns. The distributed sensing, processing and actuating components of these applications can be compromised and modified or impersonated to extract private and confidential information or to inject false information. In this paper we present the Anubis protocol for remote code attestation and access control of distributed components using remote execution of trusted code. Our Anubis protocol leverages previous work in the fields of wireless sensor networks and secure web browsing. Anubis allows new components to be introduced to the environment without updating existing components. Our implementation …


Mobile Context-Aware Personal Messaging Assistant, Senaka Buthpitiya, Deepthi Madamanchi, Sumalatha Kommaraju, Martin L. Griss Jan 2011

Mobile Context-Aware Personal Messaging Assistant, Senaka Buthpitiya, Deepthi Madamanchi, Sumalatha Kommaraju, Martin L. Griss

Martin L Griss

A previous study shows that busy professionals receive in excess of 50 emails per day of which approximately 23% require immediate attention, 13% require attention later and 64% are unimportant and typically ignored. The flood of emails impact mobile users even more heavily. Flooded inboxes cause busy professionals to spend considerable amounts of time searching for important messages, and there has been much research into automating the process using email content for classification; but we find email priority depends also on user context. In this paper we describe the Personal Messaging Assistant (PMA), an advanced rule-based email management system which …


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

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 Jan 2011

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 Jan 2011

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 Jan 2011

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 …


Contextualized Mobile Support For Learning By Doing In The Real World, Ray Bareiss, Natalie Linnell, Martin Griss Dec 2010

Contextualized Mobile Support For Learning By Doing In The Real World, Ray Bareiss, Natalie Linnell, Martin Griss

Ray Bareiss

This research addresses the use of mobile devices with both embedded and external sensors to provide contextualized help, advice, and remediation to learners engaged in real-world learn-by-doing tasks. This work is situated within the context of learning a complex procedure, in particular emergency responders learning to conduct urban search and rescue operations. Research issues include the design and delivery of contextualized performance support and the inferring of learner actions and intentions from sensor data to ensure that the right support is delivered just in time, as it is relevant to what the learner is doing.


Fpga Implementation Of Pipeline Digit-Slicing Multiplier-Less Radix 2 2 Dif Sdf Butterfly For Fast Fourier Transform Structure, Yazan Samir, Rozita Teymourzadeh, Masuri Othman, Shabiul Islam Dec 2010

Fpga Implementation Of Pipeline Digit-Slicing Multiplier-Less Radix 2 2 Dif Sdf Butterfly For Fast Fourier Transform Structure, Yazan Samir, Rozita Teymourzadeh, Masuri Othman, Shabiul Islam

Dr. Rozita Teymourzadeh, CEng.

The need for wireless communication has driven the communication systems to high performance. However, the main bottleneck that affects the communication capability is the Fast Fourier Transform (FFT), which is the core of most modulators. This paper presents FPGA implementation of pipeline digit-slicing multiplier-less radix 22 DIF (Decimation In Frequency) SDF (single path delay feedback) butterfly for FFT structure. The approach taken; in order to reduce computation complexity in butterfly multiplier, digit-slicing multiplier-less technique was utilized in the critical path of pipeline Radix-22 DIF SDF FFT structure. The proposed design focused on the trade-off between the speed and active silicon …


Optimised Toolbox For The Design Of Rotary Reluctance Motors, Grace I, Rozita Teymourzadeh, Bright S, Aravind Cv Dec 2010

Optimised Toolbox For The Design Of Rotary Reluctance Motors, Grace I, Rozita Teymourzadeh, Bright S, Aravind Cv

Dr. Rozita Teymourzadeh, CEng.

Operation of the rotary reluctance machine is highly affected due to the sequential attraction-repulsion principle of the adjacent phase excitation. The problem has been identified and addressed by various researchers in the past decades. Effective magnetic design is one way of minimizing the effect. However it is tedious and time consuming as the design procedure involve higher analytical derivation and calculations. This paper presents a simpler graphical user interface toolbox to use for the design of reluctance motors. The developed interface calculates the analytical values of the aligned, unaligned and intermediate inductance values so that the user can interpret the …