Computer Engineering Commons^™

Future Of Asynchronous Transfer Mode Networking, Fakhreddine Mohamed Hachfi

Theses Digitization Project

The growth of Asynchronous Transfer Mode (ATM) was considered to be the ideal carrier of the high bandwidth applications like video on demand and multimedia e-learning. ATM emerged commercially in the beginning of the 1990's. It was designed to provide a different quality of service at a speed up 100 Gbps for both real time and non real time application. The turn of the 90's saw a variety of technologies being developed. This project analyzes these technologies, compares them to the Asynchronous Transfer Mode and assesses the future of ATM.

A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw

Electrical Engineering and Computer Science - All Scholarship

The need for a robust predictive sensor communication network inspired this research. There are many critical issues in a communication network with different data rate requirements, limited power and bandwidth. Energy consumption is one of the key issues in a sensor network as energy dissipation occurs during routing, communication and monitoring of the environment. This paper covers the routing of a sensor communication network by applying an evolutionary algorithm- the ant system. The issues considered include optimal energy, data fusion from different sensor types and predicting changes in environment with respect to time.

Attack-Resistant Location Estimation In Wireless Sensor Networks, Dongdang Liu, Peng Ning, An Liu, Cliff Wang, Wenliang Kevin Du

Electrical Engineering and Computer Science - All Scholarship

Many sensor network applications require sensors’ locations to function correctly. Despite the recent advances, location discovery for sensor networks in hostile environments has been mostly overlooked. Most of the existing localization protocols for sensor networks are vulnerable in hostile environments. The security of location discovery can certainly be enhanced by authentication. However, the possible node compromises and the fact that location determination uses certain physical features (e.g., received signal strength) of radio signals make authentication not as effective as in traditional security applications. This paper presents two methods to tolerate malicious attacks against range-based location discovery in sensor networks. The …

Address Assignment In Ad-Hoc Networks, John Paul O'Grady

Theses

A wireless ad-hoc network is a collection of autonomous nodes or terminals that communicate with each other by forming a multi-hop radio network and maintaining connectivity in a decentralised manner. In an ad hoc network routing is used to find and maintain a path through the network. Routing requires each node to have a unique identifier, to ensure that packets sent to a particular node reach their intended destination. Most ad-hoc routing protocols assume that a node already has an address prior to its entry into a network and so the issue of address assignment is largely ignored. This however …

A New Look At The Multiclass Network Equilibrium Problem, Patrice Marcotte, Laura Wynter

Research Collection School Of Computing and Information Systems

The multiclass network equilibrium problem is expressed in general as a nonmonotone, asymmetric, variational inequality problem. We show that in spite of the nonmonotonicity of the cost operator, the problem may actually satisfy a weaker property, induced by the hierarchical nature of the travel cost interactions. This property allows a natural decomposition approach, not otherwise available, that admits provably convergent algorithms. We present one such algorithm, easily implementable using a solver for the single-class network equilibrium problem, together with a convergence proof.

Resource Harvesting Within The Oai-Pmh Framework, Herbert Van De Sompel, Michael L. Nelson, Carl Lagoze, Simeon Warner

Computer Science Faculty Publications

Motivated by preservation and resource discovery, we examine how digital resources, and not just metadata about resources, can be harvested using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). We review and critique existing techniques for identifying and gathering digital resources using metadata harvested through the OAI-PMH. We introduce an alternative solution that builds on the introduction of complex object formats that provide a more accurate way to describe digital resources. We argue that the use of complex object formats as OAI-PMH metadata formats results in a reliable and attractive approach for incremental harvesting of resources using the OAI-PMH.

Metadata And Buckets In The Smart Object, Dumb Archive (Soda) Model, Michael L. Nelson, Kurt Maly, Delwin R. Croom Jr., Steven W. Robbins

Computer Science Faculty Publications

We present the Smart Object, Dumb Archive (SODA) model for digital libraries (DLs), and discuss the role of metadata in SODA. The premise of the SODA model is to "push down" many of the functionalities generally associated with archives into the data objects themselves. Thus the data objects become "smarter", and the archives "dumber". In the SODA model, archives become primarily set managers, and the objects themselves negotiate and handle presentation, enforce terms and conditions, and perform data content management. Buckets are our implementation of smart objects, and da is our reference implementation for dumb archives. We also present our …

Development Of A Low Jitter Multiplying Delay Locked Loop, Ian Kennedy

Theses

The clock generator is a critical component in high-speed wireline communication systems. The clocks in these systems mark time at precise regular intervals. Any deviation of the clock edges from these ideal time points is called jitter and it degrades the overall integrity of the communication system. This thesis looks at both phase locked loops (PLLs) and delay locked loops (DLLs) and their ability to provide these precise clocks. Expressions for the thermal noise-induced jitter in both the PLL and DLL are compared. From this, the DLL is shown to possess the potential for better jitter performance. However, to realise …

A Sip Based Multimedia Messaging Service, Donna Griffin

Theses

The Session Initiation Protocol (SIP) is the protocol of choice for establishing multimedia sessions in Universal Mobile Telecommunications System (UMTS) networks as stated by 3GPP. SIP is a protocol that will merge together the cellular and Internet worlds and is also scalable, highly available and extensible. It enables mobile carriers to extend operations, administration, maintenance and provisioning (OAMP) in one application to all applications. In addition, while SIP permits presence. Instant Messaging, File Sharing etc., its ultimate value lies in seamlessly aggregating these applications in more powerful offerings, such as Multimedia Messaging, Push to Talk and Voice over IP.

Multimedia …

Performance Estimation Of A Sip Based Push-To-Talk Service For 3g Wireless Networks, Eoin O'Regan

Theses

Push To Talk (PTT) services have been in existence for several decades providing dispatch services via two-way radio such as walkie-talkies. For a number of years now PTT services have been available for use over mobile phone networks. These mobile PTT services have occupied a niche market with business users and have been provided on proprietary networks that do not enable roaming.

Over the past year there has been an explosion of interest in the concept of PTT provided over mobile networks using Internet Protocol (IP) technology. This service uses cellular access and radio resources more efficiently than circuit-switched cellular …

A Fit-Gap Analysis Of E-Business Curricula Vs. Industry Need, S. Davis, Keng Siau, K. Dhenuvakonda

Research Collection School Of Computing and Information Systems

The alignment of e-business academic programs with the e-business market is examined using a fit-gap analysis. Two high-end business schools, ranked independently by US News and Business Week, were chosen as sample. A total of 391 different e-commerce courses were identified, which were classified into 24 categories. Out of these, there are two broad and distinct tracks in e-business curricula, with one track paving the way for an e-business career with a prevailing focus on the business aspect and the other track leading to a career focusing on technology and Web-based systems development. Industry demand for e-business professionals and the …

Creating A Virtual Store Image, P. Katerattanakul, Keng Siau

Research Collection School Of Computing and Information Systems

A study was conducted to describe some of the factors that needed to be considered for a virtual store. It was revealed that the growth of e-commerce and online businesses has made it essential to understand the critical attributes of image for a virtual store. Store image was described as the way in which the store was defined by customers and several studies. The study compiled 77 designs and features into a list used to construct a survey. Four hundred and twenty-seven potential customers were requested to rate the significance of each item on the list. The information gathered identified …

A Communications Modeling System For Swarm-Based Sensors, Brian A. Kadrovach

Theses and Dissertations

Today's information age has exploded the amount of data available to decision makers at all levels of the control hierarchy. The miniaturization and proliferation of sensor technology has enabled extensive detection and monitoring and advances in computational capabilities have provided for embedded data analysis and the generation of information from raw data. Additionally, with the miniaturization of mechanical systems it is possible to provide platforms for sensor suites that are capable of mobility and limited autonomy. Swarming or bio-emergent behavior problems, provides a robust scalable mechanism for organizing large numbers of mobile sensor platforms. However, the mobility dynamics of swarm …

Low Interference Routing For Wireless Ad-Hoc Networks, Mohit Gupta

Theses

In this thesis the primary focus is on the problem of interference between messages. The thesis discusses why the messages are blocked in a system? How adding a message impacts the cost of all other available links, which can be established in the system.

This thesis analyzes how the availability of channels, increase in number of nodes and increase in the transmission range help in increasing the number of messages that can be handled in the network. It is also analyzes how critical is the selection of the maximum transmission range MTR, transmission range TR and required transmission range RTR. …

Hop-Limited Routing For Multihop Cellular Networks, Cem Dincer

Theses

In recent years, conventional cellular systems have experienced evolution in fields of data oriented services. During this period, the requirement for high data-rate stimulated new research proposals, which resulted in a new architecture: Multihop Cellular Networks (MCN), where multihop structure enables mobile stations to forward packets from other mobile stations to the base station on the uplink, and in turn, forward packets to other mobile stations from the base station on the downlink. In this thesis, a new routing algorithm is introduced for MCNs in order to limit the number of hops between the base station and the mobile stations …

Intrusion Detection System For Ad Hoc Mobile Networks Using Neighborhood Watch Theory, Ramani Rajagopalan

Theses

This study describes several experiments to simulate and study temperature sensor networks. The ultimate goal of this study is to accurately predict a temperature sensor failure in a sensor network, using Network Neighborhood Watch theory. Simulated temperature measurements are used to compare the results of accuracy, and quickness in detecting a failure in a malfunctioning sensor node. This is done by changing the intervals between temperature sampling, by considering different rates of temperature raise, as well as varying the number of nodes in the network neighborhood (deployment density). The thesis studies the threshold for temperature sensor failure by computing a …

Reduction Of False Positives In Fault Detection System Using A Low Pass Data Filter, Ranjit Salunkhe

Theses

Network traffic is bursty in nature and exhibits the property of self-similarity, the degree of which is measured by the Hurst parameter. Now, in any network there is always the possibility of the occurrence of fault traffic that can be caused due to faults or malfunction of a network component. Fault Detection Systems that check for traffic anomalies can trigger off an alert on the detection of any traffic behavior that deviates from normal. Such deviation is usually caused when a fault occurs. But in network traffic sudden bursts may occur due to the inherent behavior of a network application. …

Building Customer Trust In Mobile Commerce, Keng Siau, Zixing Shen

Research Collection School Of Computing and Information Systems

Customer trust, which is crucial for the growth and success of mobile commerce, is discussed. Building customer trust is a complex process that involves technology and business practices as well as movement from initial trust formation to continuous trust development. Gaining customer trust involves consideration of its three components: competence trust, predictability trust and goodwill trust. From a customer's perspective, competence trust in e-commerce is built upon the Internet vendor's skills, expertise and operational abilities.

Wlan Csma/Ca Performance In A Bluetooth Interference Environment, Randall B. Noel

Theses and Dissertations

IEEE 802.11 WLANs and Bluetooth piconets both operate in the 2.4 GHz Industrial Scientific and Medical (ISM) radio band. When operating in close proximity, these two technologies interfere with each other. Current literature suggests that IEEE 802.11 (employing direct sequence spread spectrum technology) is more susceptible to this interference than Bluetooth, which uses frequency hopping spread spectrum technology, resulting in reduced throughput. Current research tends to focus on the issue of packet collisions, and not the fact that IEEE 802.11 may also delay its transmissions while the radio channel is occupied by a Bluetooth signal. This research characterizes previously neglected …

Characterizing Data Streams Over Ieee 802.11b Ad-Hoc Wireless Networks, John T. Wagnon

Theses and Dissertations

Soon, advancements in data encryption technology will make real-time decryption of the contents of network packets virtually impossible. This research anticipates this development and extracts useful information based on packet level characteristics. Distinguishing characteristics from e-mail, HTTP, print, and FTP applications are identified and analyzed. The analysis of collected data from an ad-hoc wireless network reveals that distinguishing characteristics of network traffic do indeed exist. These characteristics include packet size, packet frequency, inter-packet correlation, and channel utilization. Without knowing the contents of packets or the direction of the traffic flow, the applications accessing the wireless network can be determined.

Enterprise Integration With Erp And Eai, Jinyoul Lee, Keng Siau, Soongoo Hong

Research Collection School Of Computing and Information Systems

The Integration of enterprise with the ERP (enterprise resource planning) and EAI (enterprise application integration) is discussed. The ERP supports the centralized business strategy while EAI accomodates the decentralized business processes. The changes brought in by the internet technology led the internalization and extrenalization to move together. The agility and the flexibility in the organizations would be achieved by a greater degree of communication, coordination and cooperation in human factors and information technologies. The enterprise integration fulfills the needs of both internal business processes and external customer by internalization and externalization.

The Mediated Data Integration (Medint) : An Approach To The Integration Of Database And Legacy Systems, Suvimol Mukviboonchai

Theses: Doctorates and Masters

The information required for decision making by executives in organizations is normally scattered across disparate data sources including databases and legacy systems. To gain a competitive advantage, it is extremely important for executives to be able to obtain one unique view of information in an accurate and timely manner. To do this, it is necessary to interoperate multiple data sources, which differ structurally and semantically. Particular problems occur when applying traditional integration approaches, for example, the global schema needs to be recreated when the component schema has been modified. This research investigates the following heterogeneities between heterogeneous data sources: Data …

Automated Distribution And Management Of Software And Hardware Configurations For Heterogeneous Wireless Devices, Grainne Foley

Theses

The continuing evolution of wireless networks and services has increased the complexity and diversity of wireless networks and devices, placing significant emphasis on the need for flexible device configuration management. Widely varying wireless technologies currently operate independently worldwide, making global wireless network access for the mobile user confusing and unwieldy. New technologies, network access methodologies and improved services further obscure the evolving environment. The focus of effort for this thesis is the development of a system to automate the distribution and management of software and hardware configurations that enable different levels of wireless device reconfiguration. The scope of investigation will …

A Framework For Aggregating Network Performance In Distributed Brokering Systems, Gurhan Gunduz, Shrideep Pallickara, Geoffrey C. Fox

Electrical Engineering and Computer Science - All Scholarship

The Internet is presently being used to support increasingly complex interaction models as a result of more and more applications, services and frameworks becoming network-centric. Efficient utilization of network and networked resources is of paramount importance. Network performance gathering is a precursor to any scheme that seeks to provide adaptive routing capabilities for interactions. In this paper we present a network performance aggregation framework that is extensible and appropriate for distributed messaging systems that span multiple realms, disparate communication protocols and support different applications.

Wireless Local Area Network Security : An Investigation Into Security Tool Usage In Wireless Networks, Susan Webb

Theses : Honours

Many organisations and individuals installing wireless local area networks (WLANs), which are based on the IEEE 802.11 b standard, have little understanding of the security issues that surround this technology.

This study was initiated to determine how WLAN security issues affect organisations in Perth, Western Australia. The scope of the study was restricted to 802.llb WLANs operating in infrastructure mode, where all traffic is transmitted by wireless access points (APs). This study was conducted in two phases. The general aims of the first phase were to determine the number of detectable WLANs in the Perth Central Business District (CBD) and …

Frequency-Hopped Multiple-Access Communications With Noncoherent M-Ary Ofdm-Ask, A. Al-Dweik, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

A noncoherent, bandwidth-efficient modulation scheme is proposed for frequency-hopping multiple-access (FH-MA) networks. The proposed scheme is a combination of noncoherent M-ary amplitude-shift keying (NMASK) and orthogonal frequency-division multiplexing (OFDM). Using this scheme minimizes the required data bandwidth. The number of frequency slots available to the users increases significantly for a fixed spread-spectrum bandwidth (BW_SS). The effect of the multiple-access interference is reduced. Simple and accurate bit error rate expressions have been derived for FH-OFDM-MASK in additive white Gaussian noise channels and for FH-OFDM-ASK in Rayleigh fading channels.

Mobile Communications And Mobile Services, Keng Siau, Z. Shen

Research Collection School Of Computing and Information Systems

As wireless technologies evolve, the coming mobile revolution will bring dramatic and fundamental changes to the world. This revolution has already begun and is gaining momentum. The revolution will impact numerous facets of our daily lives and the way business is conducted. It will provide important data in real time to assist decision makers, exert great influence on communications between businesses and their customers, and transform the way we live our lives. This paper examines issues in providing services via wireless technologies, i.e. mobile services. The paper discusses the challenges facing mobile services, such as changes in business strategies, investment …

Report On The Third Acm/Ieee Joint Conference On Digital Libraries (Jcdl), Michael L. Nelson

Computer Science Faculty Publications

The Third ACM/IEEE Joint Conference on Digital Libraries (JCDL 2003) was held on the campus of Rice University in Houston, Texas, May 27 - 31. Regarding the merging of the ACM and IEEE conference series, in the JCDL 2002 conference report published last year in D-Lib Magazine Edie Rasmussen noted, "Perhaps by next year...no one will remember that it wasn't always so" [1]. Judging by the number of participants I met who did not know that the ACM and IEEE used to hold separate digital library conferences, Rasmussen's prediction has come to pass.

A Multilevel Neural Network Architecture For Digital Implementation Of A Face Recognition System Based On Eigenface Approach, Linda Rajan

Electrical & Computer Engineering Theses & Dissertations

The design and development of the digital implementation of a multilevel feed forward neural network architecture for face recognition based on statistical features representing Eigenfaces is presented in this thesis. The architecture is divided into three parts: feature extractor, classifier and identifier, The Eigenface extractor architecture is developed based on an efficient design strategy in which all the M weight values corresponding to the Eigenfaces are generated simultaneously from M images representing the Eigen vectors and the test input image. The multilayer neural network classifier is trained using error backpropagation algorithm. A novel multilevel digital architecture is developed for the …

Training Radial Basis Neural Networks With The Extended Kalman Filter, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

Radial basis function (RBF) neural networks provide attractive possibilities for solving signal processing and pattern classification problems. Several algorithms have been proposed for choosing the RBF prototypes and training the network. The selection of the RBF prototypes and the network weights can be viewed as a system identification problem. As such, this paper proposes the use of the extended Kalman filter for the learning procedure. After the user chooses how many prototypes to include in the network, the Kalman filter simultaneously solves for the prototype vectors and the weight matrix. A decoupled extended Kalman filter is then proposed in order …