ETD Collection

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Author: search.filters.author.Middleton, Sarah

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    Toxic leadership, social support and individual and organisational outcomes
    (2018) Middleton, Sarah
    Growing numbers of studies point to the negative impact and stress of Toxic Leadership (TL) on employees, both in their personal and work wellbeing. Such negatives include high levels of stress, reduced self-esteem and increases in alcohol and drug abuse. TL has also been found to reduce job satisfaction, organisational commitment behaviour and organisational citizenship behaviours. In addition, TL has been thought to result in severe health outcomes including; post-traumatic stress disorder, suicidal ideation and extreme forms of physical illness such as cancer and heart attacks. This South African study, based on a sample of 258 employees working across a wide range of industries, was conducted to explore Toxic Leadership and its effect on three dependant/outcomes variables. These outcome variables included Voluntary Turnover Intention, Work Engagement and Organisational Commitment Behaviour. In addition, Social Support and its role as a moderator was investigated. Consenting participants filled out six questionnaires namely; a Self-Developed Demographic Questionnaire, Schmidt’s Toxic Leadership scale (2008), Kantor’s (2013) Voluntary Turnover Intention (VTI) Scale, Utrecht Work Engagement Scale (UWES), Mowday, Steers & Porter (1979) Organisational Commitment Behaviour Questionnaire (OCQ) and Procidano and Heller’s (1983) Perceived Social Support Scale (PSI) (Adapted version). The results of the study indicated that Toxic Leadership was significantly correlated to the outcome variables. The simple regression also showed that Toxic Leadership raised levels of Voluntary Turnover Intention and lowered levels of Work Engagement, Organisational Commitment Behaviour and Social Support. While Social Support was directly related to the three dependant/outcomes variables with it having a positive effect on Work Engagement and Organisational Commitment Behaviour and decreasing levels of Voluntary Turnover Intention within the regressions. However, within the moderated multiple regressions, Toxic leadership relationship with Social Support actually had an inverse effect on the outcome variables. This is because instead of improving levels of Voluntary Turnover Intention, Work Engagement and Organisational Commitment Behaviour, it made negative effects of Toxic Leadership even worse. Some possible reasons for this was argued in this research. Finally, in addition to these findings, limitations and further contributions for future research into Toxic Leadership was also discussed.
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    The design and implementation of an acoustic phased array transmitter for the demonstration of MIMO techniques
    (2011-11-07) Middleton, Sarah
    MIMO radar algorithms are the latest generation of techniques that can be applied to array radars. They offer the potential to improve the radar resolution, increase the number of targets that can be identified and give added flexibility in beampattern design. However, little experimental data demonstrating MIMO radar is available because radar arrays are already expensive systems and MIMO extends the com- plexity and cost further. An acoustic array, which works on the same principles as a radio frequency radar array, can be built at a fraction of the cost of a real radar system. The novel contribution of this project was the demonstration ofMIMO radar techniques on an acoustic array, which was designed and built for this purpose. To achieve the project objectives, the theory of traditional phased array radar techniques and MIMO techniques was researched. The phased array and MIMO techniques were also simulated under narrowband and wideband conditions, and the strengths and weaknesses of each were highlighted. This was followed by the design and implementation of a low cost audible acoustic transmitter array to be used with an existing receiver array to demonstrate the investigated array radar techniques. Finally, the techniques were tested on the hardware platform. The simulation and hardware test results were used to evaluate and compare the performance of phased array and MIMO radar techniques. The beampattern design flexibility that is offered by MIMO radar was demonstrated with the transmission and measurement of omnidirectional, single-lobed and multi-lobed MIMO beampat- terns. Also, parameter estimation experiments were performed where phased array and MIMO radar signals were transmitted. Phased array techniques were shown to be simple, effective and robust. The MIMO Capon, APES and GLRT parameter estimation techniques were shown to be sensitive to the type of signals transmitted, and in most cases, the added complexity of these techniques did not lead to improved target parameter estimation results. However, the MIMO technique of transmitter beamforming on reception gave high resolution target range and angle estimates, living up to the expectations placed on MIMO radar.