Engineering Commons^™

Marking Estimation In Petri Nets Using Dynamic Mode Decomposition, Aditya Kale

Theses

Petri Nets (PNs) are a well-established framework for modeling and analyzing complex systems with interacting, concurrent processes. This thesis extends traditional Petri Net methodologies by integrating Dynamic Mode Decomposition (DMD), a technique originally developed for fluid dynamics, to analyze Continuous Petri Nets (CPNs). By applying DMD to CPN marking evolution, this research constructs a reduced-order model that captures its dynamics through dynamic modes and eigenvalues, enabling prediction of future markings without detailed knowledge of transition firings or underlying deterministic models. The principal contribution of this research is extending the kit of tools available for analysis of CPN dynamics, providing insights …

Construction Of Multi-Mode Fiber Modes Using Phase Masks, Alexandre Tulikumwenayo

Theses

Transverse fiber modes are the distribution of electromagnetic fields in the cross-section of an optical fiber through which light propagates in the fiber. Research is being conducted to explore the usage of fiber modes with the purpose of increasing the capacity and reach of optical fibers. Mode Division Multiplexing, an area in which reseach is being conducted with the same purpose, is a multiplexing scheme used in optical networks that maps data channels onto different modes, and multiplexes these modes into one fiber for transmission. This thesis focuses on the study of modes in multi-mode fibers, and the simulation of …

Ultra Wideband Pulse Shaping, Pawel Rulikowski

Theses

Methods for shaping of sophisticated, transient, ultra wideband (UWB) waveforms and pulses are presented. The methods include novel circuits based on step recovery diodes (SRDs) and quasi-transversal filter concepts but the majority of the work focuses on UWB pulse shaping using completely passive nonuniform transmission lines (NUTLs). It is shown, for the first time, that NUTLs can be used to generate highly sophisticated arbitrary UWB pulse shapes, including modified Hermite polynomial (MHP) and approximate spheroidal wave function (APSWF) pulses which are not known to have been previously generated in practice, and a generalized methodology, verified by experiments, for design of …

Rf Mems Capacitors For Sdr, Yamuna Kuberappa

Theses

Micro electro mechanical systems (MEMS) applications in radio frequency (RF) and microwave electronics are revolutionizing the progress in wireless communications. In particular, MEMS switchable/tunable capacitors can facilitate the realization of multistandard software defined transceivers, offering better performance than existing solutions.

In this thesis, characterisation and RF modelling of MEMS switchable/tunable capacitors and the technical requirements for their application in multiband wireless transceiver circuits in a software defined radio (SDR) are described. The first device considered is a curled cantilever capacitive switch, configured in both shunt and series configuration where the capacitance is limited to two stable states. The second device, …

A Distributed Ai Approach For Large-Scale Wlan Design, Alan Mcgibney

Theses

The recent dramatic trend towards always-on-connectivity has driven the need for mobile ubiquitous computing environments with the advent of the Wireless Local Area Network (WLAN) seeing a shift from traditional wired networks to wireless networking. A WLAN typically contains a number of access points that allow wireless enabled clients access information and network resources such as the internet without the need for wires, offering flexibility and mobility to the users. Initial wireless networks were convenience based allowing users access to the primary wired network, and involved little planning prior to roll-out. The proliferation of low cost wireless devices combined wdth …

Lightweight Objective Quality Of Voice Estimation Through Machine Learning, Daniel Riordan

Theses

Communication systems are undergoing constant and rapid innovation, both at the design stage and in the field. This in turn has led to an inereasing need for fast, efficient, portable and economic methods for the testing of these systems. For voice carrying communication systems the quality of the transmitted voice that the system produces is a large factor in the overall performance rating of the system. This measure is known as the ‘Quality of Voice’ (QoV) and can be evaluated either subjectively or objectively.

Speech quality is a complex subjective phenomenon that can be best quantified by subjective testing. A …

Mesh Mac Enabling Mesh Networking Over Ieee 802.15.4 Mac Layer, Panneer Selvan Muthukumaran

Theses

Wireless sensor network is a network of sensor nodes that function in a cooperative manner to monitor the changes in the physical environment. Wireless sensor networks are used in environment and habitat monitoring, healthcare applications, building automation, and traffic control to name a few. Typically, wireless sensor node is a low power embedded device which consists of a microcontroller, sensors, wireless transceiver and a battery. These devices are usually distributed in a physical environment which makes it difficult to maintain the network manually.

The IEEE 802.15.4 and Zigbee are considered as standard protocols for wireless sensor networks. The IEEE 802.15.4 …

A Service Provisioning Platform For Beyond 3g - The Telecommunication Service Exchange, Donna Griffin

Theses

From the inception of mobile communications one of the most important factors contributing to its success has been a good understanding of user requirements. In the first generation, mobile networks offered subscribers the freedom to communicate regardless of their locations and the joy of instant access to voice telephony services. This provided a competitive edge over wire line communication networks and resulted in large revenue streams. However over the past decade, mobile network operators have been faced with a number of factors that have incurred significant costs and resulting reduced revenue. These factors include deregulation, increased competition and technological progress …

Adaptive Radio Resource Management For 2.5g Cellular Networks, Ken Murray

Theses

Recent years have seen a dramatic increase in demand for mobile communication services and with the introduction of 2.5G services such as general packet radio service, this trend is expected to increase further. These new services will introduce highly dynamic tele-traffic variations due to the inherent variability in resource usage of the new data services. The net effect will be considerable increase in load on the available radio resources. The currently employed fixed channel allocation scheme lacks the flexibility to support such traffic variations. A plethora of dynamic channel allocation schemes have been proposed in the past in an effort …