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Full-Text Articles in Digital Communications and Networking

Impact Of Primary User Activity On The Performance Of Energy-Based Spectrum Sensing In Cognitive Radio Systems, Sara L. Macdonald Apr 2013

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 …


Arraytrack: A Fine-Grained Indoor Location System, Jie Xiong, Kyle Jamieson Apr 2013

Arraytrack: A Fine-Grained Indoor Location System, Jie Xiong, Kyle Jamieson

Research Collection School Of Computing and Information Systems

With myriad augmented reality, social networking, and retail shopping applications all on the horizon for the mobile handheld, a fast and accurate location technology will become key to a rich user experience. When roaming outdoors, users can usually count on a clear GPS signal for accurate location, but indoors, GPS often fades, and so up until recently, mobiles have had to rely mainly on rather coarse-grained signal strength readings. What has changed this status quo is the recent trend of dramatically increasing numbers of antennas at the indoor access point, mainly to bolster capacity and coverage with multiple-input, multiple-output (MIMO) …


Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag Apr 2013

Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag

Computer Science Theses & Dissertations

Vehicular Ad Hoc Networks (VANETs) are a form of Mobile Ad Hoc Networks (MANETs) in which vehicles on the road form the nodes of the network. VANETs provide several services to enhance the safety and comfort of drivers and passengers. These services can be obtained by the wireless exchange of information among the vehicles driving on the road. In particular, the transmission of two different types of messages, safety/update and non-safety messages.

The transmission of safety/update message aims to inform the nearby vehicles about the sender's current status and/or a detected dangerous situation. This type of transmission is designed to …


Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh Mar 2013

Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh

College of Computing and Digital Media Dissertations

Voice over IP (VoIP) systems are gaining increased popularity due to the cost effectiveness, ease of management, and enhanced features and capabilities. Both enterprises and carriers are deploying VoIP systems to replace their TDM-based legacy voice networks. However, the lack of engineering models for VoIP systems has been realized by many researchers, especially for large-scale networks. The purpose of traffic engineering is to minimize call blocking probability and maximize resource utilization. The current traffic engineering models are inherited from the legacy PSTN world, and these models fall short from capturing the characteristics of new traffic patterns. The objective of this …


Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson Mar 2013

Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson

Theses and Dissertations

Cyber attacks are compromising networks faster than administrators can respond. Network defenders are unable to become oriented with these attacks, determine the potential impacts, and assess the damages in a timely manner. Since the observations of network sensors are normally disjointed, analysis of the data is overwhelming and time is not spent efficiently. Automation in defending cyber networks requires a level of reasoning for adequate response. Current automated systems are mostly limited to scripted responses. Better defense tools are required. This research develops a framework that aggregates data from heterogeneous network sensors. The collected data is correlated into a single …


Rootkit Detection Using A Cross-View Clean Boot Method, Bridget N. Flatley Mar 2013

Rootkit Detection Using A Cross-View Clean Boot Method, Bridget N. Flatley

Theses and Dissertations

In cyberspace, attackers commonly infect computer systems with malware to gain capabilities such as remote access, keylogging, and stealth. Many malware samples include rootkit functionality to hide attacker activities on the target system. After detection, users can remove the rootkit and associated malware from the system with commercial tools. This research describes, implements, and evaluates a clean boot method using two partitions to detect rootkits on a system. One partition is potentially infected with a rootkit while the other is clean. The method obtains directory listings of the potentially infected operating system from each partition and compares the lists to …


Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan Mar 2013

Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan

Theses and Dissertations

Today's computer networks are under constant attack. In order to deal with this constant threat, network administrators rely on intrusion detection and prevention services (IDS) (IPS). Most IDS and IPS implement static rule sets to automatically alert administrators and resolve intrusions. Network administrators face a difficult challenge, identifying attacks against a vast number of benign network transactions. Also after a threat is identified making even the smallest policy change to the security software potentially has far-reaching and unanticipated consequences. Finally, because the administrator is primarily responding to alerts they may lose situational awareness of the network. During this research a …


Automatic Detection Of Abnormal Behavior In Computing Systems, James Frank Roberts Jan 2013

Automatic Detection Of Abnormal Behavior In Computing Systems, James Frank Roberts

Theses and Dissertations--Computer Science

I present RAACD, a software suite that detects misbehaving computers in large computing systems and presents information about those machines to the system administrator. I build this system using preexisting anomaly detection techniques. I evaluate my methods using simple synthesized data, real data containing coerced abnormal behavior, and real data containing naturally occurring abnormal behavior. I find that the system adequately detects abnormal behavior and significantly reduces the amount of uninteresting computer health data presented to a system administrator.


A Method For Identifying Personalized Representations In Web Archives, Mat Kelly, Justin F. Brunelle, Michele C. Weigle, Michael L. Nelson Jan 2013

A Method For Identifying Personalized Representations In Web Archives, Mat Kelly, Justin F. Brunelle, Michele C. Weigle, Michael L. Nelson

Computer Science Faculty Publications

Web resources are becoming increasingly personalized — two different users clicking on the same link at the same time can see content customized for each individual user. These changes result in multiple representations of a resource that cannot be canonicalized in Web archives. We identify characteristics of this problem by presenting a potential solution to generalize personalized representations in archives. We also present our proof-of-concept prototype that analyzes WARC (Web ARChive) format files, inserts metadata establishing relationships, and provides archive users the ability to navigate on the additional dimension of environment variables in a modified Wayback Machine.


Communications And Energy-Harvesting In Nanosensor Networks, Michele C. Weigle Nov 2012

Communications And Energy-Harvesting In Nanosensor Networks, Michele C. Weigle

Computer Science Presentations

PDF of a powerpoint presentation from the National Science Foundation (NSF) Workshop on Biological Computations and Communications in Boston, Massachusetts, November 9, 2012. Also available on Slideshare.


A Probabilistic Graphical Model For Topic And Preference Discovery On Social Media, Lu Liu, Feida Zhu, Lei Zhang, Shiqiang Yang Oct 2012

A Probabilistic Graphical Model For Topic And Preference Discovery On Social Media, Lu Liu, Feida Zhu, Lei Zhang, Shiqiang Yang

Research Collection School Of Computing and Information Systems

Many web applications today thrive on offering services for large-scale multimedia data, e.g., Flickr for photos and YouTube for videos. However, these data, while rich in content, are usually sparse in textual descriptive information. For example, a video clip is often associated with only a few tags. Moreover, the textual descriptions are often overly specific to the video content. Such characteristics make it very challenging to discover topics at a satisfactory granularity on this kind of data. In this paper, we propose a generative probabilistic model named Preference-Topic Model (PTM) to introduce the dimension of user preferences to enhance the …


On Heterogeneous User Demands In Peer-To-Peer Video Streaming Systems, Zhipeng Ouyang Jul 2012

On Heterogeneous User Demands In Peer-To-Peer Video Streaming Systems, Zhipeng Ouyang

School of Computing: Dissertations, Theses, and Student Research

A Peer-to-Peer (P2P) video streaming system usually consists of a large number of peers, which have heterogeneous physical properties. Orthogonal to the physical heterogeneity, there is another type of heterogeneity called demand heterogeneity. Namely, peers have their own demands on the quality and type of the streaming service. The problem of demand heterogeneity has received little attention and as a result current P2P video streaming systems cannot achieve satisfactory performance due to demand heterogeneity. In this dissertation, we study how to design efficient P2P video streaming systems with heterogeneous user demands.

First, we study the problem of heterogeneous user demands …


Meta-Heuristics Analysis For Technologically Complex Programs: Understanding The Impact Of Total Constraints For Schedule, Quality And Cost, Henry Darrel Webb Jul 2012

Meta-Heuristics Analysis For Technologically Complex Programs: Understanding The Impact Of Total Constraints For Schedule, Quality And Cost, Henry Darrel Webb

EMSE Doctoral Projects

Program management data associated with a technically complex radio frequency electronics base communication system has been collected and analyzed to identify heuristics which may be utilized in addition to existing processes and procedures to provide indicators that a program is trending to failure. Analysis of the collected data includes detailed schedule analysis, detailed earned value management analysis and defect analysis within the framework of a Firm Fixed Price (FFP) incentive fee contract.

This project develops heuristics and provides recommendations for analysis of complex project management efforts such as those discussed herein. The analysis of the effects of the constraints on …


Extended Pcr Rules For Dynamic Frames, Florentin Smarandache, Jean Dezert Jul 2012

Extended Pcr Rules For Dynamic Frames, Florentin Smarandache, Jean Dezert

Branch Mathematics and Statistics Faculty and Staff Publications

In most of classical fusion problems modeled from belief functions, the frame of discernment is considered as static. This means that the set of elements in the frame and the underlying integrity constraints of the frame are fixed forever and they do not change with time. In some applications, like in target tracking for example, the use of such invariant frame is not very appropriate because it can truly change with time. So it is necessary to adapt the Proportional Conflict Redistribution fusion rules (PCR5 and PCR6) for working with dynamical frames. In this paper, we propose an extension of …


An Extensible Framework For Creating Personal Archives Of Web Resources Requiring Authentication, Matthew Ryan Kelly Jul 2012

An Extensible Framework For Creating Personal Archives Of Web Resources Requiring Authentication, Matthew Ryan Kelly

Computer Science Theses & Dissertations

The key factors for the success of the World Wide Web are its large size and the lack of a centralized control over its contents. In recent years, many advances have been made in preserving web content but much of this content (namely, social media content) was not archived, or still to this day is not being archived,for various reasons. Tools built to accomplish this frequently break because of the dynamic structure of social media websites. Because many social media websites exhibit a commonality in hierarchy of the content, it would be worthwhile to setup a means to reference this …


Visualizing Digital Collections At Archive-It, Kalpesh Padia Jul 2012

Visualizing Digital Collections At Archive-It, Kalpesh Padia

Computer Science Theses & Dissertations

Archive-It, a subscription service from the Internet Archive, allows users to create,maintain, and view digital collections of web resources. The current interface of Archive-It is largely text-based, supporting drill-down navigation using lists of URIs.While this interface provides good searching capabilities, it is not efficient for browsing. In the absence of keywords, a user has to spend large amount of time trying to locate a web page of interest. In order to provide a better visual experience to the user, we have studied the underlying characteristics of Archive-It collections and implemented six different visualizations (treemap, time cloud, bubble chart, image plot, …


Wireless Sensor Network For Wine Fermentation, Kerry Scharfglass, Andrew Lehmer Jun 2012

Wireless Sensor Network For Wine Fermentation, Kerry Scharfglass, Andrew Lehmer

Computer Engineering

This project implements an automated temperature monitoring system for wine fermentation which is affordable, easy to use, and scalable to typical small winery setups. To realize these requirements, we implemented the system as a wireless sensor network utilizing commercial off-the-shelf hardware. Temperature and system diagnostic information is communicated wirelessly in a peer-to-peer network topology such that all information flows toward an aggregating server. The server makes the temperature information available over the Internet via a web application and alerts the winemaker by email when the temperature has left acceptable bounds that the winemaker may configure. This project also involved materials …


Energy-Efficient Continuous Activity Recognition On Mobile Phones: An Activity-Adaptive Approach, Zhixian Yan, Vigneshwaran Subbaraju, Dipanjan Chakraborty, Archan Misra, Karl Aberer Jun 2012

Energy-Efficient Continuous Activity Recognition On Mobile Phones: An Activity-Adaptive Approach, Zhixian Yan, Vigneshwaran Subbaraju, Dipanjan Chakraborty, Archan Misra, Karl Aberer

Research Collection School Of Computing and Information Systems

Power consumption on mobile phones is a painful obstacle towards adoption of continuous sensing driven applications, e.g., continuously inferring individual’s locomotive activities (such as ‘sit’, ‘stand’ or ‘walk’) using the embedded accelerometer sensor. To reduce the energy overhead of such continuous activity sensing, we first investigate how the choice of accelerometer sampling frequency & classification features affects, separately for each activity, the “energy overhead” vs. “classification accuracy” tradeoff. We find that such tradeoff is activity specific. Based on this finding, we introduce an activity-sensitive strategy (dubbed “A3R” – Adaptive Accelerometer-based Activity Recognition) for continuous activity recognition, where the choice of …


Extending The Hybridthread Smp Model For Distributed Memory Systems, Eugene Anthony Cartwright Iii May 2012

Extending The Hybridthread Smp Model For Distributed Memory Systems, Eugene Anthony Cartwright Iii

Graduate Theses and Dissertations

Memory Hierarchy is of growing importance in system design today. As Moore's Law allows system designers to include more processors within their designs, data locality becomes a priority. Traditional multiprocessor systems on chip (MPSoC) experience difficulty scaling as the quantity of processors increases. This challenge is common behavior of memory accesses in a shared memory environment and causes a decrease in memory bandwidth as processor numbers increase. In order to provide the necessary levels of scalability, the computer architecture community has sought to decentralize memory accesses by distributing memory throughout the system. Distributed memory offers greater bandwidth due to decoupled …


Spatial Queries In Wireless Broadcast Environments [Keynote Speech], Kyriakos Mouratidis May 2012

Spatial Queries In Wireless Broadcast Environments [Keynote Speech], Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

Wireless data broadcasting is a promising technique for information dissemination that exploits the computational capabilities of mobile devices, in order to enhance the scalability of the system. Under this environment, the data are continuously broadcast by the server, interleaved with some indexing information for query processing. Clients may tune in the broadcast channel and process their queries locally without contacting the server. In this paper we focus on spatial queries in particular. First, we review existing methods on this topic. Next, taking shortest path computation as an example, we showcase technical challenges arising in this processing model and describe techniques …


Node Filtering And Face Routing For Sensor Network, Umang Amatya Apr 2012

Node Filtering And Face Routing For Sensor Network, Umang Amatya

College of Engineering: Graduate Celebration Programs

Main Contributions

•Efficient Algorithms for identifying Redundant Sensor Nodes

•New Technique for Filtering Redundant Nodes in Sensor Network

•Reliable Algorithm for Message Routing - Forwarding

•User Friendly Prototype Implementation in Java

•Results of Experimental Investigation


Towards Fine-Grained Radio-Based Indoor Location, Jie Xiong, Kyle Jamieson Feb 2012

Towards Fine-Grained Radio-Based Indoor Location, Jie Xiong, Kyle Jamieson

Research Collection School Of Computing and Information Systems

Location systems are key to a rich experience for mobile users. When they roam outdoors, mobiles can usually count on a clear GPS signal for an accurate location, but indoors, GPS usually fades, and so up until recently, mobiles have had to rely mainly on rather coarse-grained signal strength readings for location. What has changed this status quo is the recent trend of dramatically increasing numbers of antennas at the indoor AP, mainly to bolster capacity and coverage with multiple-input, multiple-output (MIMO) techniques. In the near future, the number of antennas at the access point will increase several-fold, to meet …


Erasure Techniques In Mrd Codes, Florentin Smarandache, W.B. Vasantha Kandasamy, R. Sujatha, R.S. Raja Durai Jan 2012

Erasure Techniques In Mrd Codes, Florentin Smarandache, W.B. Vasantha Kandasamy, R. Sujatha, R.S. Raja Durai

Branch Mathematics and Statistics Faculty and Staff Publications

In this book the authors study the erasure techniques in concatenated Maximum Rank Distance (MRD) codes. The authors for the first time in this book introduce the new notion of concatenation of MRD codes with binary codes, where we take the outer code as the RD code and the binary code as the inner code. The concatenated code consists of the codewords of the outer code expressed in terms of the alphabets of the inner code. These new class of codes are defined as CRM codes. This concatenation techniques helps one to construct any CRM code of desired minimum distance …


Neutrosophic Masses & Indeterminate Models Applications To Information Fusion, Florentin Smarandache Jan 2012

Neutrosophic Masses & Indeterminate Models Applications To Information Fusion, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper we introduce the indeterminate models in information fusion, which are due either to the existence of some indeterminate elements in the fusion space or to some indeterminate masses. The best approach for dealing with such models is the neutrosophic logic.


A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube Sep 2011

A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube

Theses and Dissertations

The rapid transition of critical business processes to computer networks potentially exposes organizations to digital theft or corruption by advanced competitors. One tool used for these tasks is malware, because it circumvents legitimate authentication mechanisms. Malware is an epidemic problem for organizations of all types. This research proposes and evaluates a novel Malware Target Recognition (MaTR) architecture for malware detection and identification of propagation methods and payloads to enhance situation awareness in tactical scenarios using non-instruction-based, static heuristic features. MaTR achieves a 99.92% detection accuracy on known malware with false positive and false negative rates of 8.73e-4 and 8.03e-4 respectively. …


Network Security: A Review Of Salient Security Aspects Of The Universal Mobile Telecommunication System (Umts), F. Imran, M. Hussain Jul 2011

Network Security: A Review Of Salient Security Aspects Of The Universal Mobile Telecommunication System (Umts), F. Imran, M. Hussain

International Conference on Information and Communication Technologies

Wireless communication is known as key to global development. Wireless and mobile communication is gaining more importance in our life. Protecting information is one the aspects which we need to focus on the wireless networks. Universal mobile telecommunication system (UMTS) is evolution of the third generation mobile communication system. It was built on the success of global system for mobile communication (GSM). Universal mobile telecommunication system's security is also built on global system for mobile communication (GSM). The paper reviews the literature of the security aspects of the Universal mobile telecommunication system. A critical evaluation of the proposed solutions is …


Networks - Ii: Modified On Demand Transmission Power Control For Wireless Sensor Networks, Mirza M Yasir Masood, Ghufran Ahmed, Noor M. Khan Jul 2011

Networks - Ii: Modified On Demand Transmission Power Control For Wireless Sensor Networks, Mirza M Yasir Masood, Ghufran Ahmed, Noor M. Khan

International Conference on Information and Communication Technologies

On Demand Transmission Power Control (ODTPC) is a well known transmission power control strategy that is used to reduce high power consumption in wireless sensor networks (WSNs). In this paper, we propose an extension to ODTPC and thus, a modified version of ODTPC is proposed named MODTPC. Simulation results show that performance of MODTPC is better than ODTPC in terms of efficiency and energy saving.


Network Security: A Secure Architecture For Open Source Voip Solutions, Fahad Sattar, M. Hussain, Kashif Nisar Jul 2011

Network Security: A Secure Architecture For Open Source Voip Solutions, Fahad Sattar, M. Hussain, Kashif Nisar

International Conference on Information and Communication Technologies

Voice over IP “VoIP” is a form of voice speech that uses data networks, for transmission of voice traffic over IP-based networks to transmit voice signals. The signal is correctly encoded at one end of the communication channel, sent as packets through the data network, then decoded at the receiving end and transformed back into a voice signal. It has a potential and offering a choice to the traditional telephony systems due to its high resource utilization and cost efficiency. Meanwhile, Wireless Local Area Networks (WLANs) have become an ever present networking technology that has been deployed around the world. …


Networks - I: Interference Mitigation In 4g System Using Smart Antenna, Asad Ali Siddiqui, Muhammad Mazhar Manzoor, Aamir Ijaz, Adnan Umar Khan, Imran Ahmed Awan, Sangita Lal Chand Jul 2011

Networks - I: Interference Mitigation In 4g System Using Smart Antenna, Asad Ali Siddiqui, Muhammad Mazhar Manzoor, Aamir Ijaz, Adnan Umar Khan, Imran Ahmed Awan, Sangita Lal Chand

International Conference on Information and Communication Technologies

Emerging trends of mobile communication and ever growing demand of mobile users with high speed data requirements and migrating towards 4G, Co-Channel interference and multipath in urban/dense urban environment will limit the capacity of the network. Smart antenna is now recognized by its higher user capacity in 4G wireless networks by efficiently reducing multipath and co-channel interference. Smart Antenna use adaptive beam forming algorithms in a dynamic environment continuously adjusting the weight of antenna arrays for creating a beam to track desired users automatically, and minimize interference from other users by placing nulls in their directions. This research work provides …


Artificial Intelligence – I: A Preliminary Framework For Human-Agent Communication In Electronic Negotiations, Moez Ur Rehman, Nosheen Riaz Jul 2011

Artificial Intelligence – I: A Preliminary Framework For Human-Agent Communication In Electronic Negotiations, Moez Ur Rehman, Nosheen Riaz

International Conference on Information and Communication Technologies

Electronic negotiations are business negotiations conducted via electronic means using information and communications technologies (ICT). Two dominant types of electronic negotiation systems are automated negotiation systems for software agents and negotiation support systems (NSSs) for humans. However, the integration of two types for human-agent negotiations is an important task. In this paper, an extended communication model for human-agent business negotiations is presented. For this purpose, the underlying communication models of automated negotiations and NSSs are analyzed. The extended communication model is based on a common negotiation ontology which captures the negotiation agenda and paves the way for such hybrid communication, …