Electroacoustic music has a unique ability to connect the listener to places, space and stories both real and imaginary. Each work within the portfolio explores specific objects, spaces and places. The intrinsic sonic qualities are explored and a musical narrative takes the listener through a newly composed imaginary space. Six original compositions are presented in this portfolio. The titles of these works are as follows: Lamenting, 192, All Along the Bell Tower, Oz, The Thing About Listening is…. and A Bit Closer to Home. Narrative structures that simulate a journey are used as a guide for the listener through immersive, virtual soundworlds. These spoken word and musical narratives also serve as a structural tool for the composer. Imagined and real sonic layers within stories and soundscapes are analysed, deconstructed and manipulated. These works convey a message, story or sense of place to the listener, while revealing sonic qualities that are not normally the focus of listening. My aim as a composer is to enhance the daily listening experiences of the listener, as they become more aware and appreciative of the sounds around them, through the sounds and spaces they experience in my music.

The Numidian Flysch Formation is a regionally extensive series of deep marine sandstones and mudstones which crop out in Spain, Morocco, Algeria, Tunisia, Sicily, and southern mainland Italy. The formation is dated as Oligocene to mid Miocene and represents an approximately linear series of submarine fans characterised by a quartz rich petrofacies. Their unique regional extent is nearly twice the length of the Angolan margin although issues surrounding provenance and basin context have hampered understanding. The Numidian Flysch Formation was deposited into the Maghrebian Flysch Basin (MFB) which was a foreland basin remnant of the neo-Tethys ocean in the western portion of the present day Mediterranean Basin. The basin was bordered to the north by an active margin which consisted of a southward verging accretionary prism, underlain by European crustal blocks which rode above northwards subducting oceanic crust. To the south, the African margin formed a passive-margin to the basin.The huge amount of geophysical and outcrop data which is becoming increasingly available suggests that submarine slope systems are more complex than previously thought, including topographically complex slopes, a wide variety of density flow types, and flow transformations. This thesis aims to review the sedimentology of the Numidian Flysch Formation in Sicily and Tunisia in light of these developments. Constraining the provenance and basin context of the formation is therefore of paramount importance, and this is also addressed.Commonly used evidence for the provenance of Numidian Flysch sandstones include its quartz rich petrology, an Eburnian and Pan-African age detrital zircon suite, its structural position within the foreland fold and thrust belt, and complex palaeocurrent orientations. when reviewd in their entirety and placed in context of other basin successions, the Numidian Flysch is constrained to a depositional location in the south of the basin, with polycyclic sediment sourced from African basement. The Numidian Flysch Formation is therefore a 'passive margin' sequence as opposed to a flysch sensu stricto. The timing of Numidian Flysch deposition is also coincidental with uplift of the Atlas chain in North Africa, during a period of significantly wetter conditions. A switch from carbonate to clastic deposition results from these conditions, and the Numidian Flysch Formation is considered an offshore extension of this regional sedimentation.Characterisation of outcrops in Sicily and Tunisia shows remarkably similar lithofacies and depositional elements. Sinuous upper slope channel complexes are entrenched within slope deposits to a depth of 100 m and occur within channel systems up to 5.7 km in width. They are filled predominantly with massive ungraded sandstones interpreted to aggrade through quasi-steady turbidity currents, interbedded with normally graded turbidites. Channel elements are subseismic in scale, are nested within complexes and show sinuosity. Coupled with lateral offset stacking, this strongly affects the architecture and facies heterogeneity of channel complexes. When compared to globally reviewed data, the thickness of channel elements as shown through their frequency distribution also suggests a fundamental control upon the degree of slope incision which is as yet unconstrained.In lower slope settings, channel complexes stack aggradationally with a width of over 1000 m. They are also predominantly filled with massive sandstones in fining upwards cycles, and show heterogeneous margins and large scale slumping. In central Sicily, large channel complexes are overlain by a stacked lobe complex, in turn overlain by a channel lobe transition zone. This progression coupled with palaeocurrent variability suggests intraslope deformation strongly impacts transiting flows through changes in flow capacity. Salt tectonics, present in Algeria and Tunisia is a possible forcing mechanism.Taken in context, the sections in Sicily record a proximal to distal palaeogeographic trend which is reconstructed towards the north/northeast once well constrained tectonic rotations are taken into account. Given regional similarities, controls upon slope architecture are interpreted to be similar throughout the basin, and deposits in Sicily therefore provide a good analogue for the remainder of the basin. These results therefore allow for a better constrained fan architecture, along with the allogenic controls upon them. Given the continental extent of this formation, the Numidian Flysch Formation provides a unique opportunity to study controls upon fan architecture once provenance and intraslope topography is factored in.

The rapidly intensifying adoption of the Internet channel for marketing and sales by incumbent bricks-and-mortar retailers underscores the importance of assessing the impact of the online channel strategies on firm performance in the dynamic competitive environment. At the time when store-based retailers increasingly dominate online sales the questions of when and how an incumbent retailer should adopt an online channel to achieve and sustain a competitive advantage are of utmost interest for both marketing scholars and practitioners. This dissertation investigates the role of two strategic decisions in affecting firm performance: (a) the order of adopting an online channel by incumbent retailers and (b) the degree of coordination between store and online sales channels. The resource-based view and the dynamic capabilities approach are used as theoretical foundations for the study. Following resource-based logic and applying a contingency perspective, this research proposes that firm-specific resource endowments determine the success of the order of online entry strategy for incumbent retailers. This dissertation utilizes the dynamic capabilities approach to propose that the strategy of inter-channel channel coordination leads to higher performance when core, unique dynamic capabilities pertaining to e-commerce are developed in-house, as opposed to being outsourced. By posing and answering the research questions regarding the role of strategic decisions of order of online entry and channel coordination in enhancing long-term financial and operational performance, this dissertation contributes to the development of strategic theory in the nascent areas of electronic commerce and multi-channel retailing, provides further empirical support to resource-based theory of competitive advantage, and assists managers in formulating more informed strategic objectives for achieving multi-channel competitive advantage.

The future wireless communication systems are required to meet the growing demands of reliability, bandwidth capacity, and mobility. However, as corruptions such as fading effects, thermal noise, are present in the channel, the occurrence of errors is unavoidable. Motivated by this, the work in this dissertation attempts to improve the system performance by way of exploiting schemes which statistically reduce the error rate, and in turn boost the system throughput. The network can be studied using a simplified model, the two-way relay channel, where two parties exchange messages via the assistance of a relay in between. In such scenarios, this dissertation performs theoretical analysis of the system, and derives closed-form and upper bound expressions of the error probability. These theoretical measurements are potentially helpful references for the practical system design. Additionally, several novel transmission methods including block relaying, permutation modulations for the physical-layer network coding, are proposed and discussed. Numerical simulation results are presented to support the validity of the conclusions.

This thesis investigates multiple-input-multiple-output (MIMO) channel modelling for a wideband indoor environment. Initially the theoretical basis of geometric modelling for a typical indoor environment is looked at, and a space-time model is formulated. The transmit and receive antenna correlation is then separated and is expressed in terms of antenna element spacing, the scattering parameter, mean angle of arrival and number of antenna elements employed. These parameters are used to analyze their effect on the capacity for this environment. Then the wideband indoor channel operating at center frequencies of 2.4 GHz and 5.2 GHz is investigated. The concept of MIMO frequency scaling is introduced and applied to the data obtained in the measurement campaign undertaken at the University of Pretoria. Issues of frequency scaling of capacity, spatial correlation and the joint RX/TX double direction channel response for this indoor environment are investigated. The maximum entropy (ME) approach to MIMO channel modelling is investigated and a new basis is developed for the determination of the covariance matrix when only the RX/TX covariance is known. Finally, results comparing this model with the established Kronecker model and its application for the joint RX/TX spatial power spectra, using a beamformer, are evaluated. Conclusions are then drawn and future research opportunities are highlighted. / Thesis (PhD)--University of Pretoria, 2008. / Electrical, Electronic and Computer Engineering / unrestricted

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The epithelial sodium channel, ENaC, forms the rate-limiting step for sodium reabsorption in the cortical collecting duct of the kidney. It is known that ENaC is important in maintaining fluid homeostasis and ultimately blood pressure as mutations in ENaC result in inherited forms of hyper- and hypotension (Liddle's syndrome and Pseudohypoaldosteronism (PHA type I), respectively). Clinically, ENaC activity can be blocked by treatment with the potassium sparing diuretic amiloride. However, due to difficulties in dosing and the transient nature of channel block, treatment goals are seldom achieved. It is, therefore, necessary to better understand the function and regulation of ENaC activity. ENaC is a member of the DEG/ENaC family of ion channels. Each family member is composed of multiple subunits - each subunit contains two transmembrane domains, short cytoplasmic amino and carboxy termini, and a relatively large extracellular domain. ENaC is a heterotrimer of homologous subunits Α-,Β-, and ΓENaC. ENaC is a constitutively active ion channel. It is not ligand gated or voltage activated. However, channel activity can be modulated by a variety of stimuli. I hypothesize that the extracellular domain functions as a sensor, allowing the channel to detect and respond to changes in extracellular conditions. To test this, we expressed human ΑΒΓENaC in Xenopus oocytes and used the two-electrode voltage clamp technique to measure changes in ENaC activity in response to changing extracellular conditions. Using this technique, I identified several novel means of regulating ENaC activity. I found that ENaC activity can be rapidly and reversibly stimulated or suppressed in response to extracellular acidification depending on the balance of extracellular sodium and chloride concentrations and have identified several key residues involved. I found that extracellular chloride inhibits ENaC activity through putative binding sites in the extracellular domain located between the Α- and Β- and Β- and ΓENaC subunits. This allowed us to determine that ENaC adopts an ΑΓΒ channel architecture. Additionally, I have made progress in understanding channel movement by identifying length dependent intersubunit interactions that alter channel gating. Based on our data we conclude that the extracellular domain is integral to modulation of channel activity. The work described herein has significantly advanced the field by improving our understanding of ENaC structure and function.

Banking through insufficiently coordinated and non-integrated channels (Multi-Channel) is slowly being discarded. With Omni-Channel banking, where channels are integrated and data and information are shared across cross channels, customers are in control of the channels they wish to use. Factors influencing the organisational decision to transition from Multi-Channel to Omni-Channel hasn't been fully explored. Is this decision responding to internal factors like efficiency improvements, or is it driven by external factors like customer demands, trying to enhance customer experience, gaining competitive advantage over the competitors, expanding the business by introducing new business models, or trying to gain access to smart technologies for financial benefit? This dissertation presents research findings into the investigation of factors that influence the organisational decision to transition from Multi-Channel to Omni-Channel banking. A positivist case study with inductive reasoning was adopted. Qualitative data was collected from a single organisation through interviews together with observations of the strategy documents between January 2019 and April 2019. An initial conceptual model was derived from the literature review to guide data collection, after which thematic analysis was used to analyse the data and develop an emergent theory. The key findings from the research study are that a customer centric approach informs the decision to transition. The customer is at the centre of the omni-channel strategy: that is through an enhanced customer experience or timeously responding to customer demands. Other factors are either enabling this strategy, like technological innovations, and efficiency improvements or are the outcome of the strategy like customer satisfaction, revenue or cost optimisation, and competitive advantage. The key implications are that organisations must pay more attention to the customer journey and ensure that they advance in the Customer Experience Capability Maturity Model. Most successful business transitions to the Omni-Channel strategy require a transformation in organizational culture, operations and processes, and the underlying technologies.

Given the exponentially increasing number of connected devices to the network which will lead to a larger number of installed celluar towers and base stations that are in closer proximity to one another when compared to the current cellular network setup, and the increasing demand of higher data rates by end users, it becomes essential to investigate new methods that will more effectively mitigate the larger interference introduced by the more packed celluar grid and that result in higher data rates. This paper investigates using Device-to-Device communication where neighboring users can cooperate to mitigate the correlated interference they both receive, where one user acts as a relay and the other as the intended destination of a broadcast message sent by the source base station. The setup studied utalizes a non-orthogonal multiple access (NOMA) scheme and a combined decode-forward and compress-forward relaying scheme. We show that this combined scheme outperforms the individual schemes for some channels and network setups, or reduces to either scheme when the combination does not offer any achievable rate gains. The performance of each scheme is measured with respect to the locations of the base station and the two devices, and to the capacity of the digital link between the users.

Underwater communication systems are in high demanded for subaquatic environment activities as the sea is an enormous and mostly unexplored place. The ten-meter long and few giga-bit per second range optical communication technique is feasible and has bright future compared to the mature but low data rate (few kilobits per second) acoustic technology and short distance (several meters) radio-frequency signaling schemes. The underwater wireless optical communication (UWOC) technique takes advantage of wide bandwidth, low attenuation effect in the visible range for multiple applications such as seafloor and offshore exploration, oil pipe control and maintenance, and pipeline leak detection. Nowadays, visible light-emitting diode (LED)-based and laser diode (LD)-based UWOC system are attractive and much related research is being conducted in the field. However, the major challenges of developing UWOC systems are the attenuation, scattering and turbulence effects of the underwater environment. The temperature gradient, salinity gradient, and bubbles make underwater optical channel predictable challenging and degrade the optical beam propagating distance and quality. Most studies focus on the statistical distribution of intensity fluctuations in underwater wireless optical channels with random temperature and salinity variations as well as the presence of air bubbles. In this thesis, we experimentally investigate the reciprocity nature of underwater turbulence caused by the turbidity, air bubbles, temperature variations, and salinity. Bit error rate measurement and statistical data analysis reveal the high reciprocal nature of turbulence that can be induced by the presence of bubbles, temperature, and salinity. The mitigation strategies for the different turbulence scenarios are discussed.