Systems and Communications Commons^™

Semantic Inference On Clinical Documents: Combining Machine Learning Algorithms With An Inference Engine For Effective Clinical Diagnosis And Treatment, Shuo Yang, Ran Wei, Jingzhi Guo, Lida Xu

Information Technology & Decision Sciences Faculty Publications

Clinical practice calls for reliable diagnosis and optimized treatment. However, human errors in health care remain a severe issue even in industrialized countries. The application of clinical decision support systems (CDSS) casts light on this problem. However, given the great improvement in CDSS over the past several years, challenges to their wide-scale application are still present, including: 1) decision making of CDSS is complicated by the complexity of the data regarding human physiology and pathology, which could render the whole process more time-consuming by loading big data related to patients; and 2) information incompatibility among different health information systems (HIS) …

Qos Recommendation In Cloud Services, Xianrong Zheng, Li Da Xu, Sheng Chai

Information Technology & Decision Sciences Faculty Publications

As cloud computing becomes increasingly popular, cloud providers compete to offer the same or similar services over the Internet. Quality of service (QoS), which describes how well a service is performed, is an important differentiator among functionally equivalent services. It can help a firm to satisfy and win its customers. As a result, how to assist cloud providers to promote their services and cloud consumers to identify services that meet their QoS requirements becomes an important problem. In this paper, we argue for QoS-based cloud service recommendation, and propose a collaborative filtering approach using the Spearman coefficient to recommend cloud …

Industrial Wireless Sensor Networks 2016, Qindong Sun, Schancang Li, Shanshan Zhao, Hongjian Sun, Li Xu, Arumugam Nallamathan

Information Technology & Decision Sciences Faculty Publications

The industrial wireless sensor network (IWSN) is the next frontier in the Industrial Internet of Things (IIoT), which is able to help industrial organizations to gain competitive advantages in industrial manufacturing markets by increasing productivity, reducing the costs, developing new products and services, and deploying new business models.

Power Budgets For Cubesat Radios To Support Ground Communications And Inter-Satellite Links, Otilia Popescu

Engineering Technology Faculty Publications

CubeSats are a class of pico-satellites that have emerged over the past decade as a cost-effective alternative to the traditional large satellites to provide space experimentation capabilities to universities and other types of small enterprises, which otherwise would be unable to carry them out due to cost constraints. An important consideration when planning CubeSat missions is the power budget required by the radio communication subsystem, which enables a CubeSat to exchange information with ground stations and/or other CubeSats in orbit. The power that a CubeSat can dedicate to the communication subsystem is limited by the hard constraints on the total …

Analysis And Implementation Of Communications Systems For Small Satellite Missions, Jason S. Harris

Electrical & Computer Engineering Theses & Dissertations

Nano satellites are becoming more and more popular space platforms due to their relatively low cost. Constellations of many of these small satellites are being launched for scientific and research purposes. This thesis has examined implementing a communications system for small satellites that can be used to maintain constant contact with satellites as they orbit the Earth. It analyzes the various components of a small satellite and how they integrate. It then discusses the different abstraction layers that will be required in order to support the same software architecture across various types of hardware. An orbital analysis was performed to …

Stability And Sensitivity Measures For Solutions In Complex, Intelligent, Adaptive And Autonomous Systems, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

Simulation has become a pivotal tool for the design, analysis, and control of complex, intelligent, adaptive and autonomous systems and its components. However, due to the nature of these systems, traditional evaluation practices are often not sufficient. As the components follow adaptive rules, the cumulative events often exploit bifurcation enabling events, leading to clusters of solutions that do not follow the usual rules for standard distributed events. When using simulation for design, analysis, and control of such systems, the evaluation needs to be richer, applying bifurcation and cluster analysis to understand the distribution, applying factor analysis to understand the important …

Classification Of Digital Communication Signal Modulation Schemes In Multipath Environments Using Higher Order Statistics, Meena Sreekantamurthy

Electrical & Computer Engineering Theses & Dissertations

Automatic identification and classification of modulation schemes in communication signals and decoding of information from the captured signals has assumed great importance recently in the wireless communication industry. Advancements in communications have introduced a large variety of modulation schemes in the transmitted signals; consequently, reliable detection of the modulation scheme in the intercepted signal has become an important issue in communications. It is the aim of this thesis to address this issue of reliable detection. Therefore, this research is focused on modeling and simulation of an automatic modulation classifier and, in particular, on the development of algorithms to use higher …

Camera Viewpoint Invariant Vehicular Traffic Segmentation And Classification, Jeffrey B. Flora

Electrical & Computer Engineering Theses & Dissertations

The goal of this intelligent transportation systems work is to develop a computer vision method that is view angle independent for segmenting and classifying vehicular traffic on highway systems. In order to achieve this goal, this work implements an algorithm for vehicle segmentation, feature extraction, and classification using the existing Virginia Department of Transportation (VDOT) infrastructure on networked traffic cameras. The VDOT traffic video is analyzed for vehicle detection and segmentation using an adaptive Gaussian mixture model algorithm. Speed estimation is performed using a single camera calibration. Size and shape features from morphological properties and texture features from histogram of …

Generator Polynomial Formulation For Parallel Counters With Applications, Lee A. Belfore Ii

Electrical & Computer Engineering Faculty Publications

Parallel counters have been studied for several decades as a component in high speed multipliers and multi-operand adder circuits. Using a generator polynomial as a formalism for describing parallel counters in the general case, parallel counter properties can be derived and inferred. Furthermore, the structure and decomposition of the generator polynomial can suggest different implementation strategies. These include simple implementations of (7,3) and (15,4) parallel counters. By grouping factors, the design of a fast (7,3) parallel counter is presented. Finally, the generator polynomial is extended to permit factors of different weights. This extension provides a means for describing the design …

Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald

Electrical & Computer Engineering Theses & Dissertations

Increasing numbers of wireless devices and mobile data requirements have led to a spectrum shortage. However spectrum utilization percentages are often low due to the current static spectrum allocation process where primary users (PUs) are given exclusive use to spectrum. Several mechanisms to increase spectrum utilization have been proposed including opportunistic spectrum access (OSA). Cognitive Radio (CR) is an emerging concept in wireless communication systems that aims to enable OSA in licensed frequencies by secondary users (SUs). CR systems are expected to sense the spectrum in order to determine if the PU is transmitting. Therefore OSA performance relies on the …

Time Synchronization For Ofdm Transmission With Applications To 4g Wimax Wireless Systems, Hamad Alhajri

Electrical & Computer Engineering Theses & Dissertations

Orthogonal Frequency Division Multiplexing (OFDM) has recently gained a lot of attention as a promising new technology for Broadband Wireless Access. OFDM-based communication systems decompose a high rate data stream into a set of lower data rate streams that are transmitted simultaneously over multiple subcarriers. WiMAX is an efficient and reliable wireless transmission standard that employs OFDM transmission. Due to its flexibility and mobility, WiMAX is becoming a preferred air interface for next generation broadband wireless systems. OFDM systems, including WiMAX, are very sensitive to time offsets introduced by radio signal propagation between transmitters and receivers. The lack of time …

A Study Of Diversity Techniques For Lte Wireless Systems, Ferhat Kaplan

Electrical & Computer Engineering Theses & Dissertations

The demand of attaining information and the wish to communicating anytime and anywhere has caused numerous innovations in the digital communication world. Today, approximately half of the people on earth somehow use wireless technology which is in every part of our lives. LTE (Long Term Evolution) and WIMAX (Worldwide Interoperability for Microwave Access) standards are the two leading wireless technologies, which support high data rates, multimedia applications, and voice video communications at very high speeds, also called 4G cellular systems in the global market.

These high expectations from wireless technology have revealed multiple antenna techniques which improve the performance and …

A Framework For Incident Detection And Notification In Vehicular Ad-Hoc Networks, Mahmoud Abuelela

Computer Science Theses & Dissertations

The US Department of Transportation (US-DOT) estimates that over half of all congestion events are caused by highway incidents rather than by rush-hour traffic in big cities. The US-DOT also notes that in a single year, congested highways due to traffic incidents cost over $75 billion in lost worker productivity and over 8.4 billion gallons of fuel. Further, the National Highway Traffic Safety Administration (NHTSA) indicates that congested roads are one of the leading causes of traffic accidents, and in 2005 an average of 119 persons died each day in motor vehicle accidents.

Recently, Vehicular Ad-hoc Networks (VANET) employing a …

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 …

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.

Fault-Injection Experiment For The Statistical Characterization Of Faults In Avionics Communication System, Amy M. Yates

Electrical & Computer Engineering Theses & Dissertations

Since flight control systems perform safety-critical functions, it is important to understand the possible effects on the closed-loop dynamical system's performance caused by these faults. The purpose of this project is to design the software and hardware needed to add fault-injection and monitoring capabilities to ROBUS-2, a flight communication system. ROBUS-2 is the current version of the fault-tolerant computer communication system used by the Scalable Processor-Independent Design for Enhanced Reliability (SPIDER), a general-purpose fault-tolerant integrated modular architecture (IMA) developed at the NASA Langley Research Center. The major components of SPIDER include processing elements (PEs) to perform calculations, bus interface units …

Economic Optimization Of Offshore Wind Farms Using The Geometric Algorithm, Mahidhar Nandigam

Electrical & Computer Engineering Theses & Dissertations

The research project related to this thesis focuses on the optimization of electrical systems for offshore wind farms for a given capacity. The optimal design and planning is a critical issue for developing cost effectively Offshore Wind Farms in energy systems. The Geometric Optimization Algorithms approach has been adopted to develop an optimization program, where the main components of the electrical system of an offshore wind farm and key technical specifications are used as parameters to be optimized for a minimum cost with necessary constraints. The effectiveness of the optimization program can be evaluated with real-time comparison between offshore wind …

Embedding Gps Data Into Speech Signal, Kagan Can

Electrical & Computer Engineering Theses & Dissertations

Communication between deployed troops is very important on a battlefield. The real time knowledge of the location of the communicating patter is also very important in many situations because if you do not know the exact position of your units you cannot give correct orders. A minor error in an order can cause fatal results or lead to defeat. In many cases the position of the units is given through the speech channel by simply speaking the coordinates of the location. This can cause misunderstandings due to misinterpretation of the speech and makes it unsafe to rely on such communications. …

A Novel Digital Audio Watermarking Approach By Embedding Coefficients In Discrete Cosine Transform Domain, Erol Duymaz

Electrical & Computer Engineering Theses & Dissertations

Watermarking is a basic secure communication method. It is used for embedding a recognizable pattern in media in such a manner that modification of the media also modifies the pattern, thus making it easy to detect the modification. This technique and its variants have many practical applications pertaining to secure communications, media verification, etc. Digital audio watermarking is a technique for embedding data within an audio signal in such a way that the original and the modified audio signals are essentially identical. The embedded data can be used for various purposes such as secure communication in military applications, owner identification …

A Smart-Phone Application For Improving Communication Skills In Children With Autism, Lakshmi Padmaja Battagiri

Electrical & Computer Engineering Theses & Dissertations

The prevalence of autism, a complex neurobiological disorder, has grown at a staggering rate in the recent past. Today, one out of 150 American children is diagnosed with autism. Generally, the disorder appears during an individual's first three years of life of and persists through his/her entire life span. The individual faces various social interaction, communication and behavioral problems. Developmental disabilities, extreme withdrawal, lack of social behaviour, severe language and attention deficits, repetitive behaviours and limited interests are the characteristics of this disorder. There is no verified cure yet, but several therapies and intervention systems especially focused on the early …

A Simulation Study Of Convergence Speed For Distributed Codeword Adaptation Algorithms In Cdma Wireless Systems, Sahana Maharjan

Electrical & Computer Engineering Theses & Dissertations

In this thesis we present a side-by-side comparison of interference avoidance (IA) algorithms for distributed codeword adaptation in Code Division Multiple Access (CDMA) systems. In CDMA systems, the interference is determined by the values of the cross-correlation of codewords assigned to users, and various algorithms can be used for codeword optimization. The IA algorithms for codeword adaptation considered are the eigen-algorithm, the Minimum Mean Square Error (MMSE) update, and the adaptive IA algorithm, for which we investigate convergence speed using the extensive simulations of several uplink CDMA system scenarios. The results of this thesis were presented at the Fourth IEEE …

Implementation Requirements For The Notice Architecture In Vehicular Communications, Dusadee Treeumnuk

Electrical & Computer Engineering Theses & Dissertations

Many studies have been focusing on Vehicular Ad-Hoc Networking (VANET) in order to increase the quality of traffic and life on the road. An important aspect in vehicular communications is maintaining the privacy and security of VANET. NOTICE is an emerging architecture promising efficient traffic notification as well as strong immunity to malicious attacks, leading to improvement of safety and reduction of traffic congestion on roadways. To enable secure traffic notification, the NOTICE system employs vehicle-to-infrastructure (V2I) communication rather than vehicle-to-vehicle (V2V) communication like in traditional VANET. The infrastructure consists of sensor belts which are embedded in the roadway and …

Kilovolt Blumlein Pulse Generator With Variable Pulse Duration And Polarity, Andrea De Angelis, Juergen F. Kolb, Luigi Zeni, Karl H. Schoenbach

Bioelectrics Publications

A Blumlein pulse generator which utilizes the superposition of electrical pulses launched from two individually switched pulse forming lines has been designed and tested. By using a power metal-oxide-semiconductor field-effect transistor as a switch on each end of the Blumlein line, we were able to generate pulses with amplitudes of 1kV across a 100Ω load. Pulse duration and polarity can be controlled by the temporal delay in the triggering of the two switches. Using this technique, we have demonstrated the generation of pulses with durations between 8 and 60ns. The lower limit in pulse duration was determined by the switch …

Distributed Cluster-Based Outlier Detection In Wireless Sensor Networks, Swetha Gali

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks find several potential applications in a variety of fields, such as environmental monitoring and control, battlefields, surveillance, smart buildings, human health monitoring, etc. These sensor networks consist of a large number of very tiny, inexpensive, and low power sensor nodes, which are deployed in a variety of harsh environments that may result in the sensor data getting corrupted. It is thus critical to detect and report these abnormal values in the sensor data, in order to have a better understanding of the monitored environment. Detection of the abnormal values is of special interest for the sensor network …

Performance Analysis Of Ieee 802.11b Devices In The Presence Of Interference Aware Scheduling-Adaptive Frequency Hopping Enabled Bluetooth Devices, Deepthi Gopalpet

Electrical & Computer Engineering Theses & Dissertations

Wireless Local Area networks (WLAN) and Wireless Personal Area Networks (WPAN) provide complimentary services using the same unlicensed radio frequency band of operation. The 802.11b WLAN operates in the 2.4 GHz band and uses a Direct Sequence Spread Spectrum technique. It is designed to cover large areas ranging up to 100 meters in diameter, which may connect hundreds of computers. Bluetooth (BT) WPAN also operates in the same frequency band as the IEEE 802.lib and it uses a Frequency Hopping Spread Spectrum technique. BT is primarily used for communications between notebooks, palm units and other personal computing devices within relatively …

Fault Arrangements And Their Effect On The Performance Of Wireless Sensor Networks, Dwayne Sayone Blai

Electrical & Computer Engineering Theses & Dissertations

Wireless sensor networks face many reliability challenges. The networks are deployed in open, hostile environments, making them easily susceptible to network failure. As a result, there are countless faults that can occur in sensor networks, from component failure to outside attacks. Outside attacks take place when an adversary gains control over a node or set of nodes in the network. Outside attackers can destroy a network in numerous ways such as random attacks, clustering attacks, search-based attacks, etc. The method and strategy used in each of these attacks directly affects the network's reliability. Understanding how these adversaries are positioned is …

An Operational Model For Mobile Sensor Cloud Management, Indrajeet Kalyankar

Electrical & Computer Engineering Theses & Dissertations

Mobile sensors provide a safe, cost effective method for gathering information in hazardous environments. When the hazardous environment is either unexplored, such as the surface of Mars, or unanticipated, such as the result of chemical contamination, it is desirable for a system to gather information with a minimal amount of outside control (localization, decision control, etc.) and prepositioned sensors. If one takes a look at the number of the sensors deployed on a scale, at the lower end is the sole, multipurpose sensor unit. The upper end deals with hordes of inexpensive, expendable sensors. In the middle, a cluster of …

Mobius: An Omnidirectional Robotic Platform And Software Architecture For Network Teleoperation, Samuel Aaron Miller

Electrical & Computer Engineering Theses & Dissertations

The following thesis presents the results of a project to develop and test an omnidirectional robotic system (hardware and software) at NASA Langley Research Center's Robotics and Intelligent Machines Lab. The impetus for the project was the unique capabilities of omnidirectional systems. Some of the many potential benefits these systems have include improved material-handling capabilities in constrained environments (such as might be found in extraterrestrial manned habitats), efficient camera-based vehicle teleoperation, and simplified route planning for autonomous robot operations.

The project's focus was to design, build, and test a system that used Mecanum wheels to achieve omnidirectional motion. In addition …

The Reliability Of The Computer Communication Networks Including Mobile Nodes, Sahin Yasar

Electrical & Computer Engineering Theses & Dissertations

The wireless computer networks have an uncertainty in their structures aside from their big advantages for the users. The environmental conditions, changing locations of the mobile hosts and the changing components in the system can easily affect their reliability. In order to know a system capability performing its functions, keep the reliability at a certain level and/or detect the deficiency of the system, it is necessary to analyze the reliability of a computer communication network including the wired and wireless parts. But the above reasons also make the analysis and a unique solution difficult so a set of algorithms is …

Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan

Computer Science Theses & Dissertations

Localization in wireless networks refers to a collection of tasks that, collectively, determines the location of a mobile user, striving to hide the effects of mobility from the user and/or application. Localization has become an important issue and has drawn considerable attention, as many applications including E-911, cargo tracking, locating patients, location-sensitive billing, etc., require knowledge of the location of user/objects. It was realized, quite a while back, that extending emergency 911-like services (E-911) to continually growing mobile population is one of the extremely important localization applications. The bulk of the proposed solutions to emergency location management in wireless environments …