Computer Engineering Commons^™

Probabilistic Approaches To The Design Of Wireless Ad Hoc And Sensor Networks, Zhen Guo

Dissertations

The emerging wireless technologies has made ubiquitous wireless access a reality and enabled wireless systems to support a large variety of applications. Since the wireless self-configuring networks do not require infrastructure and promise greater flexibility and better coverage, wireless ad hoc and sensor networks have been under intensive research. It is believed that wireless ad hoc and sensor networks can become as important as the Internet. Just as the Internet allows access to digital information anywhere, ad hoc and sensor networks will provide remote interaction with the physical world.

Dynamics of the object distribution is one of the most important …

Multilevel Adaptive Security System, Hongwei Li

Dissertations

Recent trends show increased demand for content-rich media such as images, videos and text in ad-hoc communication. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such information over resource constrained ad hoc networks. In this work, traditional data security mechanisms, existing ad hoc secure routing protocols and multilevel security are first reviewed. Then a new system, called the Multilevel Adaptive Security System, which incorporates the multilevel security concept at both the application layer and the network layer, is proposed to provide adaptive security services for data and routing processes.

MLASS …

Design And Resource Management Of Reconfigurable Multiprocessors For Data-Parallel Applications, Xiaofang Wang

Dissertations

FPGA (Field-Programmable Gate Array)-based custom reconfigurable computing machines have established themselves as low-cost and low-risk alternatives to ASIC (Application-Specific Integrated Circuit) implementations and general-purpose microprocessors in accelerating a wide range of computation-intensive applications. Most often they are Application Specific Programmable Circuiits (ASPCs), which are developer programmable instead of user programmable. The major disadvantages of ASPCs are minimal programmability, and significant time and energy overheads caused by required hardware reconfiguration when the problem size outnumbers the available reconfigurable resources; these problems are expected to become more serious with increases in the FPGA chip size. On the other hand, dominant high-performance computing …

Hfo2 As Gate Dielectric On Si And Ge Substrate, Reenu Garg

Dissertations

Hafnium oxide HfO₂ has been considered as an alternative to silicon dioxide SiO₂ in future nano-scale complementary metal-oxide-semiconductor (CMOS) devices since it provides the required capacitance at the reduced device size because of its high dielectric constant. HfO₂ films are currently deposited by various techniques. Many of them require high temperature annealing that can impact device performance and reliability.

In this research, electrical characteristics of capacitors with HfO₂ as gate dielectric deposited by standard thermal evaporation and e-beam evaporation on Si and Ge substrates were investigated. The dielectric constant of HfO₂ deposited by thermal evaporation …

Online Clustering With Single-Pass Topology Based Fuzzy Clustering Algorithm, Abhishek Jaiantilal

Theses

Online clustering is of significant interest for real-time data analysis. Generic offline clustering methods such as K-Means, C-Means and others are computationally expensive. The computational burden of these methods increases non-linearly with the size of the data set. In addition these methods usually require a good amount of supervised knowledge yielding a non-unique solution. For real-time data analysis, there is an important tradeoff between accuracy and computational efficiency. An unsupervised one-pass clustering method that efficiently adapts to data distribution and evaluation is proposed. This method, Topology-Based Fuzzy Clustering (TFC), uses the topology of data to discover clusters. TFC uses the …

New Hybrid Automatic Repeat Request (Harq) Combining With Space Time Block Coding (Stbc) In Invariant And Variant Fading Channel, Guillem Ernest Malagarriga Vilella

Theses

Hybrid Automatic Repeat reQuest (HARQ) combining for space time block coding Multiple Input Multiple Output (MIMO) system consisting of N transmit antennas and M receive antennas (NxM) in a time invariant channel and in a time varying channel is proposed and its performance is analyzed. Based on the measured channel matrix, the receiver chooses the best retransmission order and communicated it to the transmitter.

The scheme, where this algorithm is performed, is a combination of a precombining HARQ scheme and the Multiple Alamouti Space-Time Block Coding (MASTBC), which is suitable for more than 2 transmit antennas. The combination of this …

Evaluation Of Coding Scheme For Mimo Radar, Suresh Kumar Harikrishnan

Theses

Multiple Input Multiple Output (MIMO) antenna systems have shown a great potential for wireless communication. These systems support high capacity, increased diversity and interference suppression. Recently it has been proposed MIMO constellations for Radar. MIMO Radar is not only a new research field, but also a very promising approach in terms of overcoming Radar Cross Section (RCS) fluctuations with diversity. This thesis explores the potential of coding schemes for MIMO Radar.

The ambiguity functions measures related to MIMO Radar are used to evaluate how much diversity gain can be coherently achieved with certain coding schemes. The results of this analysis …

An Analytical Model Of Mac Protocol Dependant Power Consumption In Multi-Hop Ad Hoc Wireless Sensor Networks, Komlan Egoh

Theses

Power efficiency is the most constraining requirement for viable operation of battery-powered networked sensors. Conventionally, dynamic power management (DPM) is used to put sensor nodes into different states such as active, idle, and sleep, each consuming a certain level of power. Within the active state, communication operational states, such as receive and transmit consume different levels of nodal power. This thesis shows how DPM states and protocol operational states can be combined into a single stochastic model to finely evaluate the power consumption performance of a medium access control (MAC) protocol. The model is formulated as a semi-Markov decision process …

Security Information Management With Frame-Based Attack Presentation And First-Order Reasoning, Wei Yan

Dissertations

Internet has grown by several orders of magnitude in recent years, and this growth has escalated the importance of computer security. Intrusion Detection System (IDS) is used to protect computer networks. However, the overwhelming flow of log data generated by IDS hamper security administrators from uncovering new insights and hidden attack scenarios. Security Information Management (SIM) is a new growing area of interest for intrusion detection. The research work in this dissertation explores the semantics of attack behaviors and designs Frame-based Attack Representation and First-order logic Automatic Reasoning (FAR-FAR) using linguistics and First-order Logic (FOL) based approaches. Techniques based on …

A Versatile Programming Model For Dynamic Task Scheduling On Cluster Computers, Dejiang Jin

Dissertations

This dissertation studies the development of application programs for parallel and distributed computer systems, especially PC clusters. A methodology is proposed to increase the efficiency of code development, the productivity of programmers and enhance performance of executing the developed programs on PC clusters while facilitating improvement of scalability and code portability of these programs. A new programming model, named the Super-Programming Model (SPM), is created. Programs are developed assuming an instruction set architecture comprised of SuperInstructions (SIs). SPM models the target system as a large Virtual Machine (VM); VM contains functional units which are underlain with sub-computer systems and SIs …

Tcp Performance Enhancement In Wireless Networks Via Adaptive Congestion Control And Active Queue Management, Kai Xu

Dissertations

The transmission control protocol (TCP) exhibits poor performance when used in error-prone wireless networks. Remedy to this problem has been an active research area. However, a widely accepted and adopted solution is yet to emerge. Difficulties of an acceptable solution lie in the areas of compatibility, scalability, computational complexity and the involvement of intermediate routers and switches.

This dissertation rexriews the current start-of-the-art solutions to TCP performance enhancement, and pursues an end-to-end solution framework to the problem. The most noticeable cause of the performance degradation of TCP in wireless networks is the higher packet loss rate as compared to that …

Planar Visual Fusion Scintigraphy, Jacob Puthiamadathil

Theses

Planar scintigraphy, while providing useful information about the distribution of the radiopharmaceutical being used, often does not provide adequate information about the surrounding anatomical structures. A proposed method to solve this problem is by registering and fusing a scintigraphic image with a digital visual image. Fusing planar scintigraphic images with visual photographic images to supply an anatomic correlate to regions of radiopharmaceutical accumulation has been explored in this study. The digital visual image will provide a context for the relevant structures in the scintigraphic image. The validity of using one set of affine transformation parameters for registering all patient data …

Cluster-Based Wireless Mobile Ad-Hoc Network Security, Mandur Bajra Bajracharya

Theses

A wireless ad-hoc network is a cooperative communication network deployed with a specific purpose. It is characterized by dynamically changing topology with no fixed infrastructure which exhibits a perfectly vulnerable state for a number of different kinds of attacks.

This thesis proposes a novel technique of achieving security in wireless mobile ad hoc networks by integrating a simple clustering and a voting mechanism together. The purpose of forming a cluster is to facilitate security in the network and the voting is performed to support the decision making process in the cluster. A procedure of forming small homogenous clusters throughout the …

Enabling Cost Aware Routing With Auctions In Wireless Ad-Hoc Networks, Ali Yuksel

Theses

Battery power is a precious resource in wireless ad-hoc networks, and most routing protocols that have been proposed so far do not generate cost efficient routes. In this thesis, a novel auction-based cost-aware routing scheme, called CARA, is presented. CARA is designed as an extension of the MAC layer, and is shown to improve the cost efficiency of existing ad-hoc routing protocols through dynamic power control, while introducing only minimal additional overhead. The MAC layer at each node is given the capability to run local sealed-bid second-price auctions for the user data packets that need to be transmitted, and to …

Qos Constrained Cellular Ad Hoc Augmented Networks, Chi-Tung Chen

Dissertations

In this dissertation, based on different design criteria, three novel quality of service (QoS) constrained cellular ad hoc augmented network (CAHAN) architectures are proposed for next generation wireless networks. The CAHAN architectures have a hybrid architecture, in which each MT of CDMA cellular networks has ad hoc communication capability. The CAHAN architectures are an evolutionary approach to conventional cellular networks. The proposed architectures have good system scalability and high system reliability.

The first proposed architecture is the QoS constrained minimum-power cellular ad hoc augmented network architecture (QCMP CAHAN). The QCMP CAHAN can find the optimal minimum-power routes under the QoS …

Scalable Wide Area Ad-Hoc Networking, Nithin Bose

Theses

The scalability problem of routing algorithms in Mobile Ad-hoc networks (MANET) has conventionally been addressed by introducing hierarchical architectures, clusters, and neighborhood zones. In all of these approaches, some nodes are assigned different routing related roles than others. Examples include cluster heads, virtual backbones and border nodes. The selection of these nodes on a fixed or dynamic basis adds complexity to the routing algorithm, in addition to placing significant demands on mobility and power consumption of these nodes. Furthermore, the scalability achieved with hierarchical architectures or partitions is limited.

This thesis demonstrates that location awareness can greatly aid in MANET …

A Co-Processor Design To Support Mpi Primitives In Configurable Multiprocessor Designs, Rohan Bafna

Theses

The Message-Passing Interface (MIPI) is a widely used standard for inter-processor communication in parallel computers. This standard is normally implemented in software, thus resulting in large communication latencies. A hardware implementation can reduce communication latencies significantly, thereby increasing the bandwidth. However, this approach cannot be applied in practice to the very large set of functions in MPI.

Reconfigurable computing has reached levels where entire parallel systems can be built inside one or more FPGAs (Field-Programmable Gate Arrays). In this scheme, specialized components must be built for inter-processor communication and the resulting code is difficult to port to other reconfigurable platforms. …

An Autonomous Router-Based Solution To Detect And Defend Low Rate Ddos Attacks, Karunakar Anantharam

Theses

Internet security was not a concern when the Internet was invented, but we cannot deny this fact anymore. Since all forms of businesses and communications are aligned to the Internet in one form or the other, the security of these assets (both infrastructure and content) is of prime importance. Some of the well known consequences of an attack include gaining access to a network, intellectual property thefts, and denial of service.

This thesis focuses on countering flood-type attacks that result in denial of service to end users. A new classification of this denial of service attacks, known as the low …

Ultra Wideband Communication Link, Preeti Singh

Theses

Ultra-wideband communication (UWB) has been a topic of extensive research in recent years especially for its short-range communication and indoor applications. The preliminary objective of the project was to develop a description and understanding of the basic components of the communication link at microwave frequencies in order to achieve the primary objective of establishing a communication setup at a bandwidth of 2.5 GHz for testing Ultra Wideband (UWB) antennas. This was achieved with the aid of commercially available optical system which was modified for the purpose. Beginning with the generation of baseband narrow pulses with energy spanning over a broad …

Mobile Agent Based Distributed Network Management : Modeling, Methodologies And Applications, Jian Ye

Dissertations

The explosive growth of the Internet and the continued dramatic increase for all wireless services are fueling the demand for increased capacity, data rates, support of multimedia services, and support for different Quality of Services (QoS) requirements for different classes of services. Furthermore future communication networks will be strongly characterized by heterogeneity. In order to meet the objectives of instant adaptability to the users' requirements and of interoperability and seamless operation within the heterogeneous networking environments, flexibility in terms of network and resource management will be a key design issue. The new emerging technology of mobile agent (MA) has arisen …

Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar

Theses

Deadlock occurrence is a critical problem for any computer network. Various solutions have been proposed over last two decades to solve problem of deadlocks in networks using different routing schemes, like up/down routing algorithm used in Myrinet switches. However, most of existing approaches for deadlock-free routing either try to eliminate any possibility of deadlock occurrence, which can result in putting extra restrictions on the routing in the networks or put no restrictions on routing, which leads to other approach namely deadlock recovery. In this thesis emphasis is on developing hybrid approach for routing in wormhole networks, wherein some prohibition is …

Ip Traceback With Deterministic Packet Marking Dpm, Andrey Belenky

Dissertations

In this dissertation, a novel approach to Internet Protocol (IP) Traceback - Deterministic Packet Marking (DPM) is presented. The proposed approach is scalable, simple to implement, and introduces no bandwidth and practically no processing overhead on the network equipment. It is capable of tracing thousands of simultaneous attackers during a Distributed Denial of Service (DDoS) attack. Given sufficient deployment on the Internet, DPM is capable of tracing back to the slaves for DDoS attacks which involve reflectors. Most of the processing is done at the victim. The traceback process can be performed post-mortem, which allows for tracing the attacks that …

Optimal And Intelligent Decision Making In Sustainable Development Of Electronic Products, Meimei Gao

Dissertations

Increasing global population and consumption are causing declining natural and social systems. Multi-lifecycle engineering and sustainable development address these issues by integrating strategies for economic successes, environmental quality, and social equity. Based on multi-lifecycle engineering and sustainable development concepts, this doctoral dissertation aims to provide decision making approaches to growing a strong industrial economy while maintaining a clean, healthy environment. The research develops a methodology to complete both the disassembly leveling and bin assignment decisions in demanufacturing through balancing the disassembly efforts, value returns, and environmental impacts. The proposed method is successfully implemented into a demanufacturing module of a Multi-LifeCycle …

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. …

Internet Traffic Over Wide Area Network - Statistical Modeling And Analysis, Yan Yi Lee

Theses

This thesis provides results on trace data collecting and modeling of the Internet traffic over a Wide Area Network. The study is based on extensive data, gathered by tracing the actual packet exchange at the interfaces of devices on the WAN of BCCLS (Bergen County Cooperative Library System). A powerful network monitoring system WhatsUp Gold was employed to monitor the WAN, and logged the byte rates and packet rates sent and received at the interfaces. Different statistical distributions were employed to model the data traces. In comparison with some other statistical models - normal, lognormal, Weibull, and Pareto, which are …

Tree Based Reliable Topology For Distributing Link State Information, Ram Narayan Krishnan

Theses

Finding paths that satisfy the performance requirements of applications according to link state information in a network is known as the Quality-of- Service (QoS) routing problem and has been extensively studied. However, distributing link state information may introduce a significant protocol overhead on network resources. In this thesis, the issue on how to update link state information efficiently and effectively is investigated. A theoretical framework is presented, and a high performance link state policy that is capable of minimizing the false blocking probability of connections under a given update rate constraint is proposed. Through theoretical analysis, it is shown that …

Efficient Resource Allocation And Call Admission Control In High Capacity Wireless Networks, Jiongkuan Hou

Dissertations

Resource Allocation (RA) and Call Admission Control (CAC) in wireless networks are processes that control the allocation of the limited radio resources to mobile stations (MS) in order to maximize the utilization efficiency of radio resources and guarantee the Quality of Service (QoS) requirements of mobile users. In this dissertation, several distributed, adaptive and efficient RA/CAC schemes are proposed and analyzed, in order to improve the system utilization while maintaining the required QoS.

Since the most salient feature of the mobile wireless network is that users are moving, a Mobility Based Channel Reservation (MBCR) scheme is proposed which takes the …

Fpga Implementation Of A Cholesky Algorithm For A Shared-Memory Multiprocessor Architecture, Satchidanand G. Haridas

Theses

Solving a system of linear equations is a key problem in the field of engineering and science. Matrix factorization is a key component of many methods used to solve such equations. However, the factorization process is very time consuming, so these problems have traditionally been targeted for parallel machines rather than sequential ones. Nevertheless, commercially available supercomputers are expensive and only large institutions have the resources to purchase them or use them. Hence, efforts are on to develop more affordable alternatives. This thesis presents one such approach.

The work presented here is an implementation of a parallel version of the …

Detecting Malfunction In Wireless Sensor Networks, Pablito C. Lake

Theses

The objective of this thesis is to detect malfunctioning sensors in wireless sensor networks. The ability to detect abnormality is critical to the security of any sensor network. However, the ability to detect a faulty wireless sensor is not trivial. Controlled repeatable experiments are difficult in wireless channels. A Redhat Linux. 7.0 Wireless Emulation Dynamic Switch software was used to solve this problem.

Six nodes were configured with a node acting as a base station. The nodes were all part of a cell. This means that every node could communicate with all other nodes. A client-server program simulated the background …

Soft Fault Detection Using Mibs In Computer Networks, Sachin Arora

Theses

To improve network reliability and management in today's high-speed communication system, a statistical anomaly network intrusion detection system (NIDS) has been investigated, for network soft faults using the Management Information Base (Mm) traffic parameters provided by Simple Network Management Protocol (SNMP), for both wired and wireless networks. The work done would be a contribution to a system to be designed MIB Anomaly Intrusion Detection, a hierarchical multi-tier and multiobservation-window Anomaly Intrusion Detection system. The data was derived from many experiments that had been carried out in the test bed that monitored 27 MIB traffic parameters simultaneously, focusing on the soft …