Abstract Theoretical discussion concerning value creation has been popular in recent years in business studies, at both relationship and network levels. However, the body of research on value creation still clearly exhibits a dearth of empirical studies, especially at the level of networks. In this study, value-creating networks are empirically explored in a specific dynamic industrial setting, the software component business. The purpose of the research is to build an empirically grounded model that provides the elements that are involved in carrying out value creation processes related to software component business networks. Through the empirically grounded elements of the model and variations identified within them, a typology of value-creating networks related to the software component business is aimed to be provided as an empirical outcome of the study. First, a preliminary model of value-creating networks is built based on theoretical elaboration on the value creation and business network literature. The model is built upon the three interrelated elements of perceived end customer value, core competencies, and relationships. The preliminary model is then applied to the selected industrial setting. Based on the empirical findings, a fourth element is added at the heart of the model, namely the value system router. This fourth element characterise the importance of understanding the role of so-called system architecture in studying value creation and network structures in the software component business. System architecture provides the layered framework for integrating different components and subparts in order to build an effective total system solution for the end customer. System architecture acts as a value system router, as it gathers value streams from several suppliers at different system layers and then leads the value stream through the integration process to the end customer, which sees the system solution provided as being one value-creating entity. Although system architecture is not a new concept or area of consideration in the fields of technology and industrial management, its role both as a rationale for the specific value network structure and as a tool for understanding actor positioning, competence linking, and supplier portfolio management has not been taken into account in earlier studies.

Abstract The thesis is concerned with the development of gravure-offset-printing and low temperature co-fired ceramic (LTCC) technologies for the miniaturisation of electronic devices and components. The development work has been verified by several applications. Several aspects of gravure-offset-printing have to be optimised in order to make it suitable for fine-line printing and these have been addressed in the study with a focus on the printing inks and plates. Gravure-offset-printing inks were developed from commercial thick-film pastes. The effects of different ink characteristics on some properties of conductor lines, such as line width and resistivity, were studied. The dependence of the conductor lines on the quality of the engravings in the printing plates was also studied. The narrowest line widths obtained were about 30 μm with an accuracy of ±5 μm. Various LTCC compositions and processing steps involved in the production of integrated electronic devices, and the properties of several fabricated devices are discussed. The devices include inductors, band-pass filters and resistors for the 1–2 GHz frequency range. Miniaturisation has been the main focus of attention. For example, the integration of high-permittivity tapes in addition to low-permittivity tapes has made the miniaturisation of filter structures possible. Compatibility between these tapes during firing was found to be good. LTCC technology was further developed by adapting a modified LTCC-on-metal (LTCC-M) approach. A traditional way of guiding heat away from a component is to place a heat-sink under the component and utilise thermal vias and solder balls. In this study high- and low-permittivity tapes were attached directly on a heat-sink. Different heat-sink options were evaluated and the best performance was achieved with an AlN heat-sink which was deposited by screen-printing a Au layer on it. High-power chips were attached directly on the heat-sink through cavities in the LTCC tapes. This approach also restricted the shrinkage of the LTCC tapes. The fabricated test structures and components proved the viability of the approach although the compatibility between the pastes and tapes was not optimal.

The effect of source-sink relationships on the performance of tomato and hot pepper was investigated in glasshouse experiments by pruning tomato trusses and hot pepper fruit from plants trained to a single stem. The objectives were to characterize the effect of time, method and intensity of pruning on the yield and quality of tomato and hot pepper. Pruning at anthesis as compared to pruning at fruit-set had little effect on yield and fruit quality of both crops. Yield per truss increased steadily with intensity of pruning in tomato, due to increase in fruit size and fruit number per truss. Thus, total yield was not affected by pruning. In hot pepper fruit size increased with intensity of pruning but total yield was significantly reduced and total plant dry mass depressed at higher source : sink ratios (two and three fruit pruned out of a total of six). Occurrence of fruit disorders such as blossom-end rot and fruit cracking increased with increasing source: sink ratio. Pruning of one truss in tomato and one fruit in hot pepper gave the best fruit quality in terms of fruit size, pericarp thickness and freedom from defects, without decreasing total and marketable yield. Removing a middle truss of tomato (third truss) gave the highest yield as compared to removing the youngest truss (sixth truss) or the oldest truss (first truss). The yield increase (relative to the control) in the remaining individual trusses tended to decrease with increasing distance of the trusses from the pruned truss. In hot pepper removal of the youngest fruit (sixth fruit) resulted in the highest yield in comparison to removal of the middle fruit (third fruit) and the oldest fruit (first fruit). The quantity of yield increase in the remaining individual fruits had no consistent trend regarding the relative distance of the fruits from the pruned fruit. Two pruning methods were tried on hot pepper and tomato to compare yield and fruit quality. The first method involved pruning of the first three consecutive trusses of tomato and the first three consecutive fruit of hot pepper out of a total of six. The second method involved pruning of three alternating tomato trusses or hot pepper fruit. Yield and yield components did not differ significantly for the two methods, but pruning alternate trusses of tomato and fruit of hot pepper reduced occurrence of fruit disorders. / Dissertation (MSc (Agric) Agronomy)--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Raman spectroscopy is a vibrational spectroscopic technique. It gives a unique combination of non-destructive analysis, high spatial resolution and phase characterisation. In the current study Raman spectroscopy was used as the primary technique during the study of chemical components in archaeological earthenware samples (i.e. low temperature fired clay pottery) of South African and Chinese origin, and characterisation of iron oxides derived from mill scale. One shard from each of the South African archaeological sites (Rooiwal, Lydenburg, Makahane and Graskop) was analysed by Raman spectroscopy, FT-IR spectroscopy, X-ray fluorescence (XRF) spectroscopy and X-ray diffractometry (XRD). The common features observed were montmorillonite (Mg3(Si,Al)4(OH)2.4.5H2O[Mg]0.35), kaolin (Al2Si2O5(OH)5), quartz (α-SiO2), feldspar (K- and NaAlSi3O8), hematite (α-Fe2O3), calcium silicate (CaSiO3) and illite (KAl4(Si7AlO20)(OH)4). Gypsum (CaSO4.2H2O) and calcium carbonates (CaCO3) were detected in Lydenburg, Makahane and Graskop shards. Amorphous carbon was observed in Lydenburg and Makahane shards while rutile appeared only in Makahane shard. The Lydenburg and Rooiwal shards showed the presence of anhydrite (CaSO4). The Chinese clay samples investigated by Raman spectroscopy were from the J A Van Tilburg museum at the University of Pretoria. The large red shard was recovered from the 1552 Portuguese shipwreck, São João, found around Port Edward, South Africa. Four other shards (two red and two gray) were recovered from the 1622 Portuguese shipwreck, the São João Baptista, found around Kenton-on-Sea off the South African coast. A 19th century Chinese teapot was also analysed. Hematite, kaolin, quartz, amorphous carbon and aluminosilicates were observed in all three red shards. All these components, except quartz, were also observed in the teapot. The gray shards showed the presence of quartz, kaolin, amorphous carbon and aluminosilicates. The pigments identified were hematite (in red samples) and black amorphous carbon (in all samples). Magnetite and goethite were precipitated from mill scale-derived precursors in aqueous media. Hematite was then prepared from the calcination of goethite at 750°C and maghemite from the thermal treatment of magnetite at 200°C. The iron oxides were characterised by Raman spectroscopy, XRD, surface area determination and scanning electron microscopy (SEM). They were generally composed of very small sized particles showing high surface area values. / Thesis (PHD)--University of Pretoria, 2008. / Chemistry / unrestricted

Wide cracks in land-based Ni- or Co-base superalloy turbine components are difficult to repair successfully using conventional welding or brazing techniques. This project examined the feasibility of liquid phase diffusion brazing using novel Ni- and Co-base braze alloys containing Hf or Zr as melt point depressant for the repair of wide cracks in turbine components. An optimized braze cycle was developed and the joints were evaluated using various metallographic techniques and mechanical tests (elevated temperature tensile tests, creep rupture tests and low cycle fatigue tests). Microstructural examination revealed the presence of Hf- or Zr-rich intermetallic phases (most likely Ni7Hf2 or Ni5Zr) in Ni-base braze joints. These intermetallic compounds were, however, observed to be significantly softer than the boride phases routinely found in commercially available braze alloys with boron as melt point depressant. As a result, the novel wide gap brazed joints displayed excellent mechanical properties (ranging from 80% to 100% of the base metal’s properties). The low cycle fatigue properties of wide gap braze joints performed using a combination of MarM247 superalloy powder and Ni-Cr-Hf or Ni-Cr-Zr braze filler metals were found to be superior to those of the widely used Ni-Cr-B braze filler metals. Wide gap braze repair of FSX-414 Co-base superalloy using novel MarM509/MarM509B and MarM509/Co-Hf braze alloys resulted in high temperature tensile properties equivalent to those of weld repairs in the same parent material (using Nozzalloy filler metal). The creep rupture and low cycle fatigue (LCF) properties of the braze joints were superior to those of welds performed using MarM918 filler metal. / Thesis (PhD)--University of Pretoria, 2008. / Materials Science and Metallurgical Engineering / unrestricted

With an increasing number of students enrolling at higher education institutions in South Africa, it has become important to investigate whether these institutions are using their resources adequately. This study uses data envelopment analysis (DEA) to estimate the efficiency of 23 South African tertiary education institutions based on both teaching and research outputs. Using DEA we are able to rank South African universities according to their use of resources in these two areas. These rankings can identify institutions which are performing well and also those which require improvement. The effect that merging institutions has on this efficiency is also determined. Owing to the limited sample size, variable reduction techniques, including the efficiency contribution measure (ECM) and principal components analysis (PCA-DEA), were used to improve the discrimination of the analysis.

Stricter regulations and evolving environmental concerns have been exerting ever-increasing pressure on the automotive industry to produce low carbon vehicles that reduce emissions. As a result, increasing numbers of alternative powertrain architectures have been released into the marketplace to address this need. However, with a myriad of possible alternative powertrain configurations, which is the most appropriate type for a given vehicle class and duty cycle? To that end, comparative analyses of powertrain configurations have been widely carried out in literature; though such analyses only considered limited types of powertrain architectures at a time. Collating the results from these literature often produced findings that were discontinuous, which made it difficult for drawing conclusions when comparing multiple types of powertrains. The aim of this research is to propose a novel methodology that can be used by practitioners to improve the methods for comparative analyses of different types of powertrain architectures. Contrary to what has been done so far, the proposed methodology combines an optimisation algorithm with a Modular Powertrain Structure that facilitates the simultaneous approach to optimising multiple types of powertrain architectures. The contribution to science is two-folds; presenting a methodology to simultaneously select a powertrain architecture and optimise its component sizes for a given cost function, and demonstrating the use of multi-objective optimisation for identifying trade-offs between cost functions by powertrain architecture selection. Based on the results, the sizing of the powertrain components were influenced by the power and energy requirements of the drivecycle, whereas the powertrain architecture selection was mainly driven by the autonomy range requirements, vehicle mass constraints, CO2 emissions, and powertrain costs. For multi-objective optimisation, the creation of a 3-dimentional Pareto front showed multiple solution points for the different powertrain architectures, which was inherent from the ability of the methodology to concurrently evaluate those architectures. A diverging trend was observed on this front with the increase in the autonomy range, driven primarily by variation in powertrain cost per kilometre. Additionally, there appeared to be a trade-off in terms of electric powertrain sizing between CO2 emissions and lowest mass. This was more evident at lower autonomy ranges, where the battery efficiency was a deciding factor for CO2 emissions. The results have demonstrated the contribution of the proposed methodology in the area of multi-objective powertrain architecture optimisation, thus addressing the aims of this research.

This research project deals with dynamic field testing of light-frame wood buildings with wood based shear walls. The primary objective of the investigation is to evaluate the code formula for estimating light wood frame building’s fundamental period, through intensive field testing and numerical modelling. The project also aims to propose an alternative simplified rational approach where applicable. The thesis provides insight to the ambient vibration testing procedures of light-frame wood buildings and explains the protocol adopted for the current research program. Ambient vibration (AV) field tests were conducted on several multi-storey wood and beam-and-post buildings in Canada. Modal parameters of measured buildings, such as natural frequency, mode shapes and equivalent structural damping were obtained from Frequency Domain (FD) analysis of ambient motion records. Experimental and numerical investigations were performed to evaluate the effect of non-structural components, and the connectivity between firewall-separated buildings, on dynamic properties of light-frame wood buildings. The study provides a reliable expression for building period estimate based on field testing and numerical modeling.

This study analyzed the effects of a training package containing response constraint, self-evaluation, reinforcement, and a fading procedure on written letter components and whole letter writing in four elementary school participants. The effect on accuracy of written components was evaluated using a multiple-baseline-across components and a continuous probe design of components, as well as pre-test, baseline, and post-test measures. The results of this study show that response constraint and self-evaluation quickly improved students' performance in writing components. Fading of the intervention was achieved quickly and performance maintained. Results also show that improvement in component writing improved whole letter and full name writing and letter reversals in the presence of a model were corrected.

[pt] Tradicionalmente, o processo de desenvolvimento de sistemas paralelos enfatiza o desempenho em detrimento de melhores abstrações de programação, o que acarreta problemas como excessiva complexidade de código e redução da manutenibilidade do software. Novas técnicas tem se mostrado interessantes na construção de software paralelo, tais como as tecnologias de componentes de software. Este trabalho realizou um estudo do mecanismo de comunicação paralela entre componentes conhecido como Interfaces Coletivas. Como parte desse estudo, foi realizada uma implementação desse mecanismo no middleware de componentes SCS, onde foram projetados e implementados dois conectores para sincronizaçãoe comunicação paralela. Essa implementação viabilizou uma análise dos requisitos para a integração das Interfaces Coletivas em um middleware orientado a componentes e possibilitou a identificação dos desafios de implementar esse mecanismo em uma linguagem como C++, amplamente usada em aplicações científicas. / [en] Traditionally, the development process of parallel systems emphasizes performance at the expense of better programming abstractions, which causes problems such as excessive code complexity and reduced software maintainability. New techniques have shown expressive results in building parallel software, such as software components technologies. This work conducted a study of the mechanism of parallel communication between components known as Collective Interfaces. As part of this study, we performed an implementation of this mechanism in the SCS middleware, where two connectors were designed and implemented for parallel synchronization and communnication. This implementation allowed us to analyze the requirements for the integration of Collective Interfaces in a component oriented middleware and to identify the challenges of implementing this mechanism in a language as C++, widely used in scientific applications.