Social media is impacting the practice of public relations inmany different ways, but the focus of this dissertation is on the power of big data from social media to identify and assess the relationship that stakeholders have with the organization. Social media analytics have tended to measure reactions to messages, rather than the strength of the relationship, even though public relations is responsible for building strong relationships with the organization’s stakeholders. Yet, social media provides insight into the conversations that stakeholders have with other stakeholders about the organization and thus can reveal insight into the quality of the relationship they have with the organization.<div><br></div><div>This dissertation takes a networked approach to understandthe strength of the relationship that the organization has with its stakeholders, meaning it acknowledges that the relationships two entities have with each other are influenced by the relationships those entities have with others in common. In this case, the relationship that a stakeholder has with the organizationis influenced by the relationship the stakeholder has with other stakeholders. Thus, one way to study the relationship that a stakeholder has with the organization is to look at the conversation and the postings on social media among the various stakeholders. The ultimate aim of the dissertation is to show how the relationship can be assessed, so the organization can create strategies that develop mutually beneficial relationships over time.<br></div><div><br></div><div>The context for the study is based on two major events where companies deliberately gather together their stakeholders to interact in person and onsocial media about issues and products related to the organization’sfuture. The first event is Adobe Creative Max, which Adobe hosts each year for creative professionals. The second context for the study is Dreamforce, which is hosted by Salesforce.com and includes so many attendees that the company has to bring in cruise ships to dock in the San Francisco Bay during the event since all the hotels in the area sell out far in advance. These two events provide a specific situation where stakeholders interact with other stakeholders outside of a crisis, which represents the majority of day-to-day public relations practice. Twitter data was collected during for each week of each conference, and all company tweets were filtered out of the data sample. Atext-mining approach was then used to examine the conversations among the stakeholders at the events.<br></div><div><br></div><div>Findings indicate that the strongest relationship was developed by Salesforce.com with its stakeholders at the Dreamforce 2018 event in large part because ofthe CEO’s keynote andthe organizational commitment to social justice and sustainability. Granted, Salesforce hadalready worked to develop a culture among employees and customers based on the concept, “family,”or “Ohana.” However, the text of the conversations reveal that the focus at this conference was on societal issues presented by the CEO. In contrast, the findings from the Adobe conference suggest the organization has a transactional relationship with its stakeholders, in part because the CEO keynote focused heavily on products and technology. The implications of these findings indicate that big data from social media can be used to assess relationships, especially when social media data represents conversations and interactions among stakeholders. The findings also show the influence of CEO communications on the relationship and the vital role that public relations practitioners play in setting that CEO communications agenda.</div>

Currently, digital signal processing systems typically assume that the signals are bandlimited. This is due to our knowledge based on the uniform sampling theorem for bandlimited signals which was established over 50 years ago by the works of Whittaker, Kotel'nikov and Shannon. However, in practice the digital signals are mostly of finite length. This kind of signals are not strictly bandlimited. Furthermore, advances in electronics have led to the use of very wide bandwidth signals and systems, such as Ultra-Wide Band (UWB) communication systems with signal bandwidths of several giga-hertz. This kind of signals can effectively be viewed as having infinite bandwidth. Thus there is a need to extend existing theory and techniques for signals of finite bandwidths to that for non-bandlimited signals. Two recent approaches to a more general sampling theory for non-bandlimited signals have been published. One is for signals with finite rate of innovation. The other introduced the concept of consistent sampling. It views sampling and reconstruction as projections of signals onto subspaces spanned by the sampling (acquisition) and reconstruction (synthesis) functions. Consistent sampling is achieved if the same discrete signal is obtained when the reconstructed continuous signal is sampled. However, it has been shown that when this generalized theory is applied to the de-interlacing of video signals, incorrect results are obtained. This is because de-interlacing is essentially a resampling problem rather than a sampling problem because both the input and output are discrete. While the theory for the resampling for bandlimited signals is well established, the problem of resampling without bandlimited constraints is largely unexplored. The aim of this thesis is to develop a resampling theory for non-bandlimited discrete signals and explore some of its potential applications. The first major contribution is the the theory and techniques for designing an optimal resampling system for signals in the general Hilbert Space when noise is not present. The system is optimal in the sense that the input of the system can always be obtained from the output. The theory is based on the concept of consistent resampling which means that the same continuous signal will be obtained when either the original or the resampled discrete signal is presented to the reconstruction filter. While comparing the input and output of a sampling/reconstruction system is relatively simple since both are continuous signals, comparing the discrete input and output of a resampling system is not. The second major contribution of this thesis is the proposal of a metric that allows us to evaluate the performance of a resampling system. The performance is analyzed in the Fourier domain as well. This performance metric also provides a way by which different resampling algorithms can be compared effectively. It therefore facilitates the process of choosing proper resampling schemes for a particular purpose. Unfortunately consistent resampling cannot always be achieved if noise is present in the signal or the system. Based on the performance metric proposed, the third major contribution of this thesis is the development of procedures for designing resampling systems in the presence of noise which is optimal in the mean squared error (MSE) sense. Both discrete and continuous noise are considered. The problem is formulated as a semi-definite program which can be solved effciently by existing techniques. The usefulness and correctness of the consistent resampling theory is demonstrated by its application to the video de-interlacing problem, image processing, the demodulation of ultra-wideband communication signals and mobile channel detection. The results show that the proposed resampling system has many advantages over existing approaches, including lower computational and time complexities, more accurate prediction of system performances, as well as robustness against noise.

The study examines the challenges and critical success factors for effective incubation of ICT start-up firms. Information and communication technology (ICT) start-up firms are internationally acknowledged for their contribution to economic growth, improving the quality of life and job creation. The selected case site is the Innovation Hub which hosts a hi-tech incubator called Maxum. The Innovation Hub is an internationally accredited science park located in Tshwane, Pretoria which was launched by the Gauteng Provincial Government in year 2002. The Innovation Hub’s challenge is that its incubation programme is similar to those employed in the developed world. The off-the-shelve programme has not been customised for use within the South African socio-economic context. However, the Innovation Hub is a relatively high performing incubator which has met the prescribed precursors for success. The critical success factors include the hands-on professional services provided to entrepreneurs, value networks and government support. In order to improve the success rate of the incubation of ICT start-up firms, there is a need to adopt a long-term approach towards innovation support and to establish an incentive funding mechanism that fosters job creation by entrepreneurs. The objectives of the study were achieved. The researcher has extended Kumar & Kumar framework and added three critical success factors. The findings of the study cannot be generalised but can be replicated. These findings are of value to the incubator managers and also to the policy-makers when developing and enacting policies that promote incubation of ICT start-up firms. / Thesis (M.Com.)-University of KwaZulu-Natal, Westville, 2010.

Society is increasingly on the move, mobile devices are commonly being used to coordinate group actions, and group communication features are rapidly being added to existing technologies. Despite this, little is known about how mobile groups act, or how communications technologies should be designed to augment existing behaviour. This is partially due to minimal research being done on the topic, but also to the lack of research methods available to study the topic with. Mobile groups are challenging to study because of frequent and long-duration movement, frequent distribution, and the rapidly changing environments they operate within. To address these issues, this research focuses on methodological issues surrounding the development of mobile devices for mobile groups and communities. More specifically it addresses backpackers, who are a relevant example of this type of community. The research primarily explores the convergence of computer supported cooperative work (CSCW) and the field of mobile device development. This enables the combination of emphasis on designing technologies for groups, social implications, mobile device design, and mobile settings. Major research outcomes presented in this thesis lie in three areas: 1) methods, 2) technology designs, and 3) backpacker culture. Five studies of backpacker behaviour and requirements form the core of the research. The methods used are in-situ and exploratory, and apply both novel and existing techniques to the domain of backpackers and mobile groups. Methods demonstrated in this research include: field trips for exploring mobile group behaviour and device usage, a social pairing exercise to explore social networks, contextual postcards to gain distributed feedback, and blog analysis which provides post-hoc diary data. Theoretical contributions include: observations on method triangulation, a taxonomy of mobility research, method templates to assist method usage, and identification of key categories leading to mobile group requirements. Design related outcomes include: 57 mobile tourism product ideas, a format for conveying product concepts, and a design for a wearable device to assist mobile researchers. Our understanding of backpacker culture has also improved as a consequence of the research. It has also generated user requirements to aid mobile development, methods of visualising mobile groups and communities, and a listing of relevant design tensions. Additionally, the research has added to our understanding of how new technologies such as blogs, SMS and iPods are being used by backpackers and how mobile groups naturally communicate.

Chapter 1 Introduction. The magnetic field lines that emerge from the polar regions extend to great distances from the earth. The auroral zone closely approximate the boundary between those field lines that are closed within the magnetosphere and those that form the geomagnetic tail. the field lines int he tail may be open or possibly joined with the interplanetary field. this introduces considerable coupling between the polar ionosphere and the distant regions of the earth's atmosphere. High energy charged particles from the sun and disturbances in the magnetosphere, therefore cause large changes in the polar ionosphere, with auroral displays and regions of increased or irregular ionisation. Increasing attention is therefore, being paid to studies of the polar ionosphere to gain some insight into the changes occurring at great heights.

Work began in March 1967 with the design and construction of the fixed interferometer (described in Chapter 2) for measuring the elevation angle of arrival of 20MHz signals from the satellite Beacon-B. Also during this first year most of the computing was completed for the theoretical calculations on ray paths presented in Chapter 5; these results along with some previously obtained experimental results form the basis of a paper accepted by Radio Science. Records were obtained from the interferometer from April 1968 to the end of the transmitting life of Beacon-B in January 1970. The analysis of the phase traces from the two aperture interferometer was complicated by the automatic antenna switching procedures; each transit had to be annotated and the useful chart delineated manually before the analysts recorded the phase at intervals of a few seconds on a semi-automatic digital recording system. The antenna switching was designed to save electronics and one channel on the chart recorder, but lead to a computer programming effort which may have been more costly in time and lost transits than the saving achieved by avoiding two separate interferometers (Chapter 2). While this programming and analysis were going on, the computing delays on the University’s overworked IBM 1130 gave time to follow up the idea of recording the fast Faraday fading on 20 MHz signals from a satellite near to or even below the horizon. This project was simplified by the availability of an easily converted 20 MHz receiver and a digital recording system. The report on this project is given in Chapter 4 and also in a short paper. The elevation angle measurements from the interferometer were converted to virtual height increment versus equivalent vertical frequency plots and thence to electron density profiles (Chapter 3, Part I). This analysis was developed from ideas given originally by Titheridge (1964). The interpretation of the resulting values of the scale height at the peak (Chapter 3, Part II) in terms of ionosphere morphology depended heavily on the total content hourly values maintained on computer disk by Dr Titheridge. The results and discussion in Chapter 3 will be presented as a separated paper. Chapter 6 is a review of the effects of the ionosphere on transmitted satellite signals and in particular gives a wider view of Faraday fading than is normally taken. Because of its general nature Chapter 6 can serve as an introduction to satellite radio propagation techniques; it appears at the end of this thesis as common ground after the diversions of Chapters 4 and 5. Since this work falls into three separate projects of ray elevation angle measurements, fast Faraday fading, and second order Faraday rotation calculations, the reports on each have been written with minimal cross referencing; this should facilitate reading but has resulted in a small amount of repetition.

The single-polynomial method for ionogram analysis is adapted to give a least-squares procedure in which the number of scaled virtual heights is greater than the number of terms in the real-height polynomial. The general principles are described in detail and the procedure is applied to the valley problem in bottomside ionogram analysis. It is shown that only a single parameter, the integrated valley ionisation, is obtainable from typical ionograms. The least-squares technique is then applied to the problem of topside ionogram analysis where the facility for using any mixture of ordinary and extraordinary ray virtual depth data is very useful. The method is shown to offer many advantages over the more traditional methods. The effects of horizontal ionisation gradients on bottomside and topside ionograms are extensively investigated by a new technique for synthesising ionograms corresponding to a given model of a moving disturbance in the ionosphere. A number of interesting and important ionogram characteristics are identified and explained. Finally, the specific problem of a large disturbance seen on total electron content records during summer nights is briefly re-examined using topside ionogram data. It is suggested that the disturbance is not primarily a topside phenomenon as originally supposed.

Chapter 1 Introduction. The magnetic field lines that emerge from the polar regions extend to great distances from the earth. The auroral zone closely approximate the boundary between those field lines that are closed within the magnetosphere and those that form the geomagnetic tail. the field lines int he tail may be open or possibly joined with the interplanetary field. this introduces considerable coupling between the polar ionosphere and the distant regions of the earth's atmosphere. High energy charged particles from the sun and disturbances in the magnetosphere, therefore cause large changes in the polar ionosphere, with auroral displays and regions of increased or irregular ionisation. Increasing attention is therefore, being paid to studies of the polar ionosphere to gain some insight into the changes occurring at great heights.

Work began in March 1967 with the design and construction of the fixed interferometer (described in Chapter 2) for measuring the elevation angle of arrival of 20MHz signals from the satellite Beacon-B. Also during this first year most of the computing was completed for the theoretical calculations on ray paths presented in Chapter 5; these results along with some previously obtained experimental results form the basis of a paper accepted by Radio Science. Records were obtained from the interferometer from April 1968 to the end of the transmitting life of Beacon-B in January 1970. The analysis of the phase traces from the two aperture interferometer was complicated by the automatic antenna switching procedures; each transit had to be annotated and the useful chart delineated manually before the analysts recorded the phase at intervals of a few seconds on a semi-automatic digital recording system. The antenna switching was designed to save electronics and one channel on the chart recorder, but lead to a computer programming effort which may have been more costly in time and lost transits than the saving achieved by avoiding two separate interferometers (Chapter 2). While this programming and analysis were going on, the computing delays on the University’s overworked IBM 1130 gave time to follow up the idea of recording the fast Faraday fading on 20 MHz signals from a satellite near to or even below the horizon. This project was simplified by the availability of an easily converted 20 MHz receiver and a digital recording system. The report on this project is given in Chapter 4 and also in a short paper. The elevation angle measurements from the interferometer were converted to virtual height increment versus equivalent vertical frequency plots and thence to electron density profiles (Chapter 3, Part I). This analysis was developed from ideas given originally by Titheridge (1964). The interpretation of the resulting values of the scale height at the peak (Chapter 3, Part II) in terms of ionosphere morphology depended heavily on the total content hourly values maintained on computer disk by Dr Titheridge. The results and discussion in Chapter 3 will be presented as a separated paper. Chapter 6 is a review of the effects of the ionosphere on transmitted satellite signals and in particular gives a wider view of Faraday fading than is normally taken. Because of its general nature Chapter 6 can serve as an introduction to satellite radio propagation techniques; it appears at the end of this thesis as common ground after the diversions of Chapters 4 and 5. Since this work falls into three separate projects of ray elevation angle measurements, fast Faraday fading, and second order Faraday rotation calculations, the reports on each have been written with minimal cross referencing; this should facilitate reading but has resulted in a small amount of repetition.

The single-polynomial method for ionogram analysis is adapted to give a least-squares procedure in which the number of scaled virtual heights is greater than the number of terms in the real-height polynomial. The general principles are described in detail and the procedure is applied to the valley problem in bottomside ionogram analysis. It is shown that only a single parameter, the integrated valley ionisation, is obtainable from typical ionograms. The least-squares technique is then applied to the problem of topside ionogram analysis where the facility for using any mixture of ordinary and extraordinary ray virtual depth data is very useful. The method is shown to offer many advantages over the more traditional methods. The effects of horizontal ionisation gradients on bottomside and topside ionograms are extensively investigated by a new technique for synthesising ionograms corresponding to a given model of a moving disturbance in the ionosphere. A number of interesting and important ionogram characteristics are identified and explained. Finally, the specific problem of a large disturbance seen on total electron content records during summer nights is briefly re-examined using topside ionogram data. It is suggested that the disturbance is not primarily a topside phenomenon as originally supposed.