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In the postmodern-day organisation, acknowledgement of the facts today is that the retail sector has changed dramatically over the past ten years. Boom periods, surplus shopping and good times have ended. We have entered an era of harsh changes, business collapse, mergers, acquisitions and turbulent competitive environments that demand a constant review of business structure, financial performance, business practices and value creation to provide any hope of the ability to trade sustainably into the future. Responsiveness by retailers in this modern day driven by market need changes causes an almost instantaneous response by retailers to adapt and service the consumer demand. Thus, in evaluation of the underlying reasons for retail market shifts, one starting with the basic premise and rule of the law of natural selection – adapt to the environment, or die. No doubt that customer demand and the competitive landscape dictate effective and quick response from retailers, driving the form, shape, volume and nature of change. Present day marketplace forces are generally forming a worldwide consumer marketplace that will appear dramatically different since 2010, pushing retailers to bring about fundamental improvements to their methods and business models in order to survive. Conventional campaigns will stop being sufficient to deal with trends which may drive the retail markets into the realm of extreme conditions. Retailers in South Africa, albeit not directly, are impacted by global shifts and changes. In an environment with increasing competition and the growing demands for operational efficiencies, sustained profits and customer orientation, SA retailers are looking beyond their traditional business models and organisational boundaries to develop and leverage the resources and capabilities of international best practice to create superior value and drive competitive advantages in the marketplace. Value-add in making things work better for customers, albeit through various business enhancement and improvement initiatives, the longer their relationship will endure with the company. Thus the potential of adopting a deliberate creativity approach within the broader strategic planning process of a company, might well be the value-add activity that provides the catalyst for closing the performance gap, through bridging and integrating the core concepts of creativity and applying these concepts within real business operations, with the explicit aim of improving business profitability. To this end, the study originated from a need for a creativity-driven approach to enhance business performance in a retail organisation and not only challenge current paradigms, but redefine furniture retailing and create new furniture retailing operating models. In so doing, using a deliberate creativity-driven approach, that will catapult furniture retail onto a new performance curve that ultimately creates shareholder value through an enhanced customer proposition. The researcher embarked on a journey to establish whether a structured deliberate creativity change management framework could improve a company’s competitiveness, effectiveness and profitability; and to what degree a creativity framework can be used to enhance performance within a company. The research study results and findings, together with the financial performance results revealed that the creativity interventions deployed did in fact enhance business performance (financial, cultural, productivity and organisational behaviour) over the specific study period. The study also includes the design of a Conceptual Deliberate Creativity Framework, Conceptual Deliberate Creativity Strategy, Conceptual Deliberate Creativity Implementation Plan and an Integrated Beyonder Scorecard, which can be applied to any type of retail business across numerous diverse disciplines. / PhD (Business Administration), North-West University, Potchefstroom Campus, 2014

In the postmodern-day organisation, acknowledgement of the facts today is that the retail sector has changed dramatically over the past ten years. Boom periods, surplus shopping and good times have ended. We have entered an era of harsh changes, business collapse, mergers, acquisitions and turbulent competitive environments that demand a constant review of business structure, financial performance, business practices and value creation to provide any hope of the ability to trade sustainably into the future. Responsiveness by retailers in this modern day driven by market need changes causes an almost instantaneous response by retailers to adapt and service the consumer demand. Thus, in evaluation of the underlying reasons for retail market shifts, one starting with the basic premise and rule of the law of natural selection – adapt to the environment, or die. No doubt that customer demand and the competitive landscape dictate effective and quick response from retailers, driving the form, shape, volume and nature of change. Present day marketplace forces are generally forming a worldwide consumer marketplace that will appear dramatically different since 2010, pushing retailers to bring about fundamental improvements to their methods and business models in order to survive. Conventional campaigns will stop being sufficient to deal with trends which may drive the retail markets into the realm of extreme conditions. Retailers in South Africa, albeit not directly, are impacted by global shifts and changes. In an environment with increasing competition and the growing demands for operational efficiencies, sustained profits and customer orientation, SA retailers are looking beyond their traditional business models and organisational boundaries to develop and leverage the resources and capabilities of international best practice to create superior value and drive competitive advantages in the marketplace. Value-add in making things work better for customers, albeit through various business enhancement and improvement initiatives, the longer their relationship will endure with the company. Thus the potential of adopting a deliberate creativity approach within the broader strategic planning process of a company, might well be the value-add activity that provides the catalyst for closing the performance gap, through bridging and integrating the core concepts of creativity and applying these concepts within real business operations, with the explicit aim of improving business profitability. To this end, the study originated from a need for a creativity-driven approach to enhance business performance in a retail organisation and not only challenge current paradigms, but redefine furniture retailing and create new furniture retailing operating models. In so doing, using a deliberate creativity-driven approach, that will catapult furniture retail onto a new performance curve that ultimately creates shareholder value through an enhanced customer proposition. The researcher embarked on a journey to establish whether a structured deliberate creativity change management framework could improve a company’s competitiveness, effectiveness and profitability; and to what degree a creativity framework can be used to enhance performance within a company. The research study results and findings, together with the financial performance results revealed that the creativity interventions deployed did in fact enhance business performance (financial, cultural, productivity and organisational behaviour) over the specific study period. The study also includes the design of a Conceptual Deliberate Creativity Framework, Conceptual Deliberate Creativity Strategy, Conceptual Deliberate Creativity Implementation Plan and an Integrated Beyonder Scorecard, which can be applied to any type of retail business across numerous diverse disciplines. / PhD (Business Administration), North-West University, Potchefstroom Campus, 2014

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / The design of a telemetry tracking system is generally centered around its desired RF performance which is typically specified in terms of beamwidth, gain and/or G/T. These parameters determine the size of the reflector used in a given application and consequently dictate the required size and performance of the associated pedestal. Any subsequent improvement in the RF performance of such a system is primarily achieved by increasing the size of its reflector. The magnitude of the improvement realized is therefore limited by the load handling capability of the pedestal. In most instances, the substitution of a larger reflector with its increased inertia and wind loading causes a significant degradation in the dynamic performance of the tracking system. This paper describes how the figure of merit (G/T) of a specific dual axis telemetry tracking system can be improved by a minimum of 7.3 dB/K° without impacting its dynamic performance or increasing its weight. These impressive results are made feasible by the innovative pairing of a unique design planar reflector with a novel implementation of the conical scanner technology. The FLAPS™ reflector incorporates a newly developed concept which features lightweight construction and very low wind load coefficients [1, 2]. The conical scanner is a lightweight version of the DECS tracking feed system described in the referenced technical paper [3].

The vibration control problem for flexible structures is examined within the context of overall controller performance and power reduction. First, the issue of optimal sensor and actuator placement is considered along with its associated control robustness aspects. Then the option of alternately activating subsets of the available devices is investigated. Such option is considered in order to better address the effects of spatiotemporally varying disturbances acting on a flexible structure while reducing the overall energy consumption. Towards the solution to the problem of optimal device placement, three different approaches are proposed. First, a computationally efficient scheme for the simultaneous placement of multiple devices is presented. The second approach proposes a strategy for the optimal placement of sensors and collocated sensor/actuator pairs, taking into account the influence of the spatial distribution of disturbances. The third approach provides a solution to the actuator location problem by incorporating considerations with respect to preferred spatial regions within the flexible structure. Then the second problem named above is considered. Activating a subset of the available and optimally placed actuators and sensors in a flexible structure provides enhanced performance with reduced energy consumption. Such approach of switching on and off different actuating devices, depending on their local-in-time authority, results in a hybrid system. Therefore the proposed work draws on existing results on hybrid systems and includes an additional degree of freedom, whereby both the actuating devices and the control signals allocated to them are switched in and out. To enable this switching an activation strategy, which insures also that stability-under-switching is guaranteed, is required. Three different strategies are considered for such actuators allocation: first a cost-to-go index is considered, then a cost function based on the mechanical energy of the flexible structure and finally a performance index based on the maximum deviation of the transverse displacement. A flexible aluminum plate was chosen to validate and test the proposed approaches. The set up utilized four pairs of collocated piezoceramic patches that serve to provide sensing and actuating capabilities. Extensive numerical simulations were performed for both the placement strategies and the switching policies proposed, in order to predict the behavior of the flexible plate and provide the optimal actuator and sensor locations that were to be affixed on the flexible structure. Finally, to complete the validation process a sequence of experimental tests were performed. The objective of these tests was to compare the performance of the proposed hybrid control system to traditional non switched control schemes. In order to provide a repeatable perturbation, four of the piezoceramic patches were allocated to simulate a spatiotemporally varying disturbance, while the remaining four patches were used as sensors and controlling actuators. The experimental results showed a significant performance improvement for the switched controller over the traditional controller. Moreover the switched controller exhibited improved robustness towards spatiotemporally varying disturbances while the traditional controller showed a significant loss of controller performance. The improvement achieved in vibration control problems could be extended to a wider range of applications. In particular, although this study was concentrated on a rectangular thin plate, the proposed strategies can be applied to emph{any} structure and more generally to any plant whose dynamics can be represented by a second order linear system. For example, by removing the restriction of spatially fixed actuators and sensors, the proposed theory can be applied to the problem of unmanned vehicles control.

Transmission Control Protocol (TCP) is the dominant transport protocol in the Internet and supports many of the most popular Internet applications, such as the World Wide Web (WWW), file transfer and e-mail. TCP congestion control algorithms dynamically learn the network bandwidth and delay characteristics of a network and adapt its performance to changes in traffic so as to avoid network collapse. TCP is designed to perform well in traditional wireline networks with the assumptions that packet losses are mainly due to network congestion and random bit error rate (BER) is negligible. However, networks with wireless links suffer from significant packet losses due to random bit errors and handoffs. Hence TCP performs poorly in networks with wireless links because it treats any packet loss in the network to be a result of network congestion and slows down its transmission rate, or even cause the TCP sender to experience unnecessary timeouts, further reducing its performance. The development of advance wireless networks, such as WiFi, UMTS and WiMAX, make it necessary to find ways to improve TCP's efficiency and resource utilization, as well as improve the user's experience and reduce latency times. In order to find effective solutions to this effect, packet losses across wireless links should be distinguished from congestion related packet losses. In this thesis, we concentrate on two main strategies for enabling the TCP congestion control mechanism to determine the cause for a packet loss. One is a proxy-based mechanism that monitors the radio network interface and sends radio network feedback (RNF) to the TCP sender with the status of the wireless link. The other one is an end-to-end mechanism, in which the packet error pattern is used as the system metric to fine-tune the congestion control mechanism. It also presents an analytical model of TCP with enhanced recovery mechanism for wireless environments. In a proxy-based mechanism, TCP sender is explicitly informed of any effects caused by wireless links. However, the implementation technique is network dependent. We have proposed and developed three proxy-based schemes; the radio network feedback (RNF) scheme over an 802.11 WLAN network, the radio network controller (RNC) feedback over a UMTS network and a wireless enhancement proxy (WENP) over both the 802.11 WLAN and UMTS networks. The RNF scheme is introduced at the 802.11 WLAN base station that monitors the TCP packet flows over the wireless links, detects wireless packet losses and provides feedback to the TCP sender using one of the TCP header reserved control bits, called RNF flag. TCP Reno is modified to utilize the radio network feedback to distinguish the losses due to wireless effects form the congestion and fine-tuned to perform wireless enhanced fast retransmit and fast recovery mechanisms. The RNF scheme is implemented using the OPNET tool, and the simulation results show that the TCP performance is significantly improved. The RNC feedback mechanism, similar to the RNF scheme, is developed and implemented in a UMTS network. The GPRS Tunneling Protocol (GTP) layer of the UMTS Radio Network Control (RNC) protocol stack was modified to detect and notify the TCP sender of the wireless packet losses, which is the main difference between the RNF and RNC mechanisms. The simulation results shows that the RNC feedback mechanism significantly improves the TCP performance compared to that of standard TCP over UMTS. The wireless enhancement proxy (WENP) is developed to minimize spurious TCP timeouts over wireless networks and implemented in both 802.11 WLAN and UMTS networks. WENP extends the proposed RNF and RNC feedback mechanisms to detect both wireless packet losses and large delays across the wireless link, and to notify the TCP sender of these events with the aid of two reserved bits in the TCP header. TCP Reno is further modified to utilize the WENP feedback to distinguish both wireless packet losses from congestion losses and spurious timeouts from normal timeouts. It is also fine-tuned to perform both the wireless enhanced fast retransmit and fast recovery mechanism and the timeout mechanism. The simulation results demonstrate that the proposed scheme markedly improves the TCP performance compared to that of standard WLAN and UMTS implementations. An end-to-end early packet loss recovery (EPLR) mechanism that modifies the TCP Reno fast retransmit algorithm to detect packet losses early and to speed up the packet recovery process to reduce the number of TCP timeouts over networks with heavy packet losses, such as wireless networks is also presented. TCP Reno with EPLR scheme is implemented in a UMTS network and its performance is compared with that of TCP Reno and New Reno. Simulation results shows that Reno with EPLR improves the TCP performance and application response time significantly compared to that of both Reno and New Reno by reducing the TCP timeouts, which is the main cause of degradation of the TCP performance in a wireless environment. Finally, we develop an analytical TCP throughput model with enhanced TCP Reno fast retransmit algorithm to avoid timeouts. The model captures the TCP fast retransmit mechanism and expresses the steady state congestion window and throughput as a function of network utilization factor, round trip time (RTT) and loss rate. Another new feature added to the model is dynamic adjustment of the congestion window size depending on the packet drop rates. This speeds up the packet recovery process and reduces the number of TCP timeouts over networks with heavy packet losses. The proposed model is implemented over a UMTS network and its performance is compared with that of TCP Reno. Simulation results show that the proposed model reduces the TCP timeouts and improves the TCP performance compared to that of TCP Reno. It is also found that the model provides a very good match to the steady-state congestion window behavior.

Poor employee performance is one of employer’s most common challenges. The study aims to explore the effectiveness of a Performance Enhancement Programme (PEP) used within an electricity supply company and identifying the contributing factors for managers and supervisors not utilizing the programme. The research method consists of two parts, a literary review and an empirical study. The empirical study was done by means of a survey conducted on a sample of 210 Eskom supervisors and managers of the North Western Region of Eskom. The measuring instrument consisted of a structured questionnaire, developed by the researcher. The results revealed that supervisors and managers are using PEP and that they see it as a good tool to manage poor performance. Respondents indicated very clearly that they need training to be able to address poor performance. The findings concerning the effectiveness of the PEP were inconclusive. The small sample size was a limitation to the study. The questionnaire proved to be lacking in determining the effectiveness of the Performance Enhancement Programme. The sample only included supervisors and managers in the North Western Region of Eskom. Further research needs to be conducted with a larger sample including employees on all levels. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2012.

Poor employee performance is one of employer’s most common challenges. The study aims to explore the effectiveness of a Performance Enhancement Programme (PEP) used within an electricity supply company and identifying the contributing factors for managers and supervisors not utilizing the programme. The research method consists of two parts, a literary review and an empirical study. The empirical study was done by means of a survey conducted on a sample of 210 Eskom supervisors and managers of the North Western Region of Eskom. The measuring instrument consisted of a structured questionnaire, developed by the researcher. The results revealed that supervisors and managers are using PEP and that they see it as a good tool to manage poor performance. Respondents indicated very clearly that they need training to be able to address poor performance. The findings concerning the effectiveness of the PEP were inconclusive. The small sample size was a limitation to the study. The questionnaire proved to be lacking in determining the effectiveness of the Performance Enhancement Programme. The sample only included supervisors and managers in the North Western Region of Eskom. Further research needs to be conducted with a larger sample including employees on all levels. / Thesis (MBA)--North-West University, Potchefstroom Campus, 2012.

Recent developments in the practice control field have heightened the need for performance enhancement. The designed controller should not only guarantee the variables to follow their set point values, but also ought to focus on the performance of systems like quality, efficiency, etc. Hence, with the fact that the inevitable noises are widely existing during industry processes, the randomness of the tracking errors can be considered as a critical performance to improve further. In addition, due to the fact that some controllers for industrial processes cannot be changed once the parameters are designed, it is crucial to design a control algorithm to minimise the randomness of tracking error without changing the existing closed-loop control. In order to achieve the above objectives, a class of novel algorithms are proposed in this thesis for different types of systems with unmeasurable states. Without changing the existing closed-loop proportional integral(PI) controller, the compensative controller is extra added to reduce the randomness of tracking error. That means the PI controller can always guarantee the basic tracking property while the designed compensative signal can be removed any time without affecting the normal operation. Instead of just using the output information as PI controller, the compensative controller is designed to minimise the randomness of tracking error using estimated states information. Since most system states are unmeasurable, proper filters are employed to estimate the system states. Based on the stochastic system control theory, the criterion to characterise the system randomness are valid to different systems. Therefore a brief review about the basic concepts of stochastic system control contained in this thesis. More specifically, there are overshoot minimisation for linear deterministic systems, minimum variance control for linear Gaussian stochastic systems, and minimum entropy control for non-linear and non-Gaussian stochastic systems. Furthermore, the stability analysis of each system is discussed in mean-square sense. To illustrate the effectiveness of presented control methods, the simulation results are given. Finally, the works of this thesis are summarised and the future work towards to the limitations existed in the proposed algorithms are listed.

For pianists working within the western art music tradition, the ability to perform a large and complex repertoire from memory is almost a prerequisite for a successful career. Memorising and maintaining this repertoire requires considerable practice and can lead to physical overuse syndromes. Additionally, automated motor memory developed via physical practice is not always sufficient for secure recall, often leading to performance anxiety. It is important therefore for professionals to identify optimal practice strategies, and mental rehearsal has been widely advocated as a potential means of enhancing memorisation and performance fluency while at the same time avoiding physical overuse. The results of three studies that examined mental imagery rehearsal by expert pianists, adopting a mixed methods approach, are presented in this thesis. The first was a participant observation study of a course at which eleven advanced pianists learned to use a memorisation technique incorporating deliberate imagery; the study aimed to describe the teaching and learning of specific imagery techniques and to examine the potential advantages and drawbacks of this approach. The second study was an online questionnaire survey of thirty six piano students at UK conservatoires designed to investigate the teaching and implementation of mental rehearsal techniques at advanced training levels; the survey found that despite a widespread awareness of imagery rehearsal as a potentially effective strategy, training in specific techniques was not consistently available, and recommended mental practice strategies were adopted much less consistently than strategies involving physical practice. Finally, an fMRI study of fourteen expert pianists aimed to determine the neural correlates of imagery rehearsal and simulated piano playing. Differences observed in brain activation between tasks suggested increased involvement of working memory processes during mental imagery. The thesis concludes that mental imagery rehearsal techniques are acquired skills that can be taught and improved over time and which have specific advantages over motor learning, but that more pedagogical training is needed in order for these techniques to become fully effective and widely adopted.