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Using geotextiles in secondary roads to stabilize weak subgrades has been a well accepted practice over the past thirty years. However, from an economical point of view, a complete life cycle cost analysis (LCCA), which includes not only costs to agencies but also costs to users, is urgently needed to assess the benefits of using geotextile in secondary road flexible pavement. In this study, a comprehensive life cycle cost analysis framework was developed and used to quantify the initial and the future cost of 25 representative design alternatives. A 50 year analysis cycle was used to compute the cost-effectiveness ratio for the design methods. Four flexible pavement design features were selected to test the degree of influence of the frame's variables. The analysis evaluated these variables and examined their impact on the results. The study concludes that the cost effectiveness ratio from the two design methods shows that the lowest cost-effectiveness ratio using Al-Qadi's design method is 1.7 and the highest is 3.2. The average is 2.6. For Perkins' design method, the lowest value is 1.01 and the highest value is 5.7. The average is 2.1. The study also shows when user costs are considered, the greater TBR value may not result in the most effective life-cycle cost. Hence, for an optimum secondary road flexible pavement design with geotextile incorporated in the system, a life cycle cost analysis that includes user cost must be performed. / Master of Science

Abrasive waterjet (AWJ) cutting is one of the most recently developed nontraditional manufacturing technologies. It has been increasingly used in industry owing to its various distinct advantages over the other cutting technologies. However, many aspects of this technology require to be fully understood in order to increase its capability and cutting performance as well as to optimize the cutting process. This thesis contains an extensive literature review on the investigations of the various aspects in AWJ machining. It shows that while considerable work has been carried out, very little reported research has been found on the AWJ contouring process although it is a common AWJ cutting application. Because of the very nature of the AWJ cutting process, the changing nozzle traverse direction involved in AWJ contouring results in kerf geometrical or shape errors. A thorough understanding of the AWJ contouring process is essential for the reduction or elimination of these shape errors. It also shows that a lack of understanding of the AWJ hydrodynamic characteristics has limited the development of cutting performance models that are required for process control and optimization. Accordingly, a detailed experimental investigation is presented in this thesis to study the various cutting performance measures in AWJ contouring of an 87% alumina ceramic over a wide range of process parameters. For a comparison purpose, the study also considers AWJ straight-slit cutting. The effects of process parameters on the major cutting performance measures in AWJ contouring have been comprehensively discussed and plausible trends are amply analysed. It finds that the taper angles on the two kerf walls are in different magnitudes in AWJ contouring. The kerf taper on the outer kerf wall increases with the arc radius (or profile curvature), while that on the inner kerf wall decreases. Moreover, the depth of cut increases with an increase in arc radius and approaches the maximum in straight cutting for a given combination of parameters. The other process variables affect the AWJ contouring process in a way similar to that in straight cutting. The analysis has provided a guideline for the selection of process parameters in the AWJ contouring of alumina ceramics. In order to predict the cutting performance in process planning and ultimately optimize the cutting process, mathematical models for the major cutting performance measures in both straight-slit cutting and contouring are developed using a dimensional analysis technique. The models are then verified by assessing both qualitatively and quantitatively the model predictions with respect to the corresponding experimental data. It shows that the models can adequately predict the cutting performance measures and form the essential basis for developing strategies for selecting the optimum process parameters in AWJ cutting. To achieve an in-depth understanding of the jet dynamic characteristics such as the velocity and pressure distributions inside a jet, a Computational Fluid Dynamics (CFD) simulation is carried out using a Fluent6 flow solver and the simulation results are validated by an experimental investigation. The water and particle velocities in the jet are obtained under different input and boundary conditions to provide an insight into the jet characteristics and a good understanding of the kerf formation process in AWJ cutting. Various plausible trends and characteristics of the water and particle velocities are analysed and discussed, which provides the essential knowledge for optimizing the jet performance through optimizing the jetting and abrasive parameters. Mathematical models for the water and particle velocity distributions in an AWJ are finally developed and verified by comparing the predicted jet characteristics with the corresponding CFD simulation data. It shows that the jet characteristics models can yield good predictions for both water and particle velocity distributions in an AWJ. The successful development of these jet dynamic characteristics models is an essential step towards developing more comprehensive mathematical cutting performance models for AWJ cutting and eventually developing the optimization strategies for the effective and efficient use of this advanced manufacturing technology.

abstract: The accurate prediction of pavement network condition and performance is important for efficient management of the transportation infrastructure system. By reducing the error of the pavement deterioration prediction, agencies can save budgets significantly through timely intervention and accurate planning. The objective of this research study was to develop a methodology for calculating a pavement condition index (PCI) based on historical distress data collected in the databases from Long-Term Pavement Performance (LTPP) program and Minnesota Road Research (Mn/ROAD) project. Excel™ templates were developed and successfully used to import distress data from both databases and directly calculate PCIs for test sections. Pavement performance master curve construction and verification based on the PCIs were also developed as part of this research effort. The analysis and results of LTPP data for several case studies indicated that the study approach is rational and yielded good to excellent statistical measures of accuracy. It is believed that the InfoPaveTM LTPP and Mn/ROAD database can benefit from the PCI templates developed in this study, by making them available for users to compute PCIs for specific road sections of interest. In addition, the PCI-based performance model development can be also incorporated in future versions of InfoPaveTM. This study explored and analyzed asphalt pavement sections. However, the process can be also extended to Portland cement concrete test sections. State agencies are encouraged to implement similar analysis and modeling approach for their specific road distress data to validate the findings. / Dissertation/Thesis / Masters Thesis Civil Engineering 2015

This thesis studies the area of virtualization. The focus is on the sub-area live migration, a technique that allows a seamless migration of a virtual machine from one physical machine to another physical machine. Virtualization is an attractive technique, utilized in large computer systems, for example data centers. By using live migration, data center administrators can migrate virtual machines, seamlessly, without the users of the virtual machines taking notice about the migrations. Manually initiated migrations can become cumbersome, with an ever-increasing number of physical machines. The number of physical and virtual machines is not the only problem, deciding when to migrate and where to migrate are other problems that needs to be solved. Manually initiated migrations can also be inaccurate and untimely. Two different strategies for automated live migration have been developed in this thesis. The Push and the Pull strategies. The Push strategy tries to get rid of virtual machines and the Pull strategy tries to steal virtual machines. Both of these strategies, their design and implementation, are presented in the thesis. The strategies utilizes Shannon's Information Entropy to measure the balance in the system. The strategies further utilizes a cost model to predict the time a migration would require. This is used together with the Information Entropy to decide which virtual machine to migrate if and when a hotspot occurs. The implementation was done with the help of OMNeT++, an open-source simulation tool. The strategies are evaluated with the help of a set of simulations. These simulations include a variety of scenarios with different workloads. Our results shows that the developed strategies can re-balance a system of computers, after a large amount of virtual machines has been added or removed, in only 4-5 minutes. The results further shows that our strategies are able to keep the system balanced when the system load is at medium. This while virtual machines are continuously added or removed from the system. The contribution this thesis brings to the field is a model for how automated live migration of virtual machines can be done to improve the performance of a computer system, for example a data center.

Le Lean est une démarche qui consiste à éliminer les opérations à non-valeur ajoutée, utiliséepar les entreprises pour améliorer la performance des activités de production. Les entreprisesappliquant cette démarche observent des gains rapides sur le plan opérationnel mais,progressivement, certaines observent une chute des résultats opérationnels voire une dégradation dela santé des opérateurs. Nous cherchons à pallier ces limites et nous nous interrogeons sur la capacitédes acteurs de l’entreprise à les anticiper et à prendre des actions correctives. Pour cela, nous posonsla question du modèle de performance et de la prise de décision adoptés par les acteurs pour déployerle Lean. Nous proposons que les acteurs évaluent l’efficience des activités de production, transforméespar la démarche Lean, en prenant en compte non seulement la dimension opérationnelle de laperformance, mais aussi la dimension humaine intégrant l’activité de travail. Nous définissons unmodèle de performance qui supporte cette vision de l’Homme au travail « acteur ». Pour aider lesacteurs des entreprises à faire évoluer leur modèle de performance Lean existant, nous proposons uneméthodologie d’accompagnement basée sur une démarche de réingénierie intégrant unaccompagnement qui favorise l’évolution des représentations des acteurs au moyen d’unapprentissage sociocognitif. Cette méthodologie s’appuie sur un cadre et des outils de modélisationqui permettent de représenter les impacts de ce nouveau modèle de performance sur la prise dedécision et sur la pérennisation des bénéfices du lean. / Lean is an approach aiming at eliminating non-value added operations, used by companies to improve the performance of their production activities. Companies applying this approach are observing rapid gains in operational terms but gradually some observe a fall in operating results or a degradation of the health of work force. We seek to overcome these limits and we ask about the ability of those of the company to anticipate and to take corrective actions. For this, we question about the performance model and the decision adopted by corporate actors to deploy Lean. We propose thatcorporate actors evaluate the efficiency of production, processed by the Lean approach, taking into account not only the operational level of performance, but also the human dimension integrating realwork activity. We define a performance model that supports a kind of “actor” vision of man at work.To help corporate actors to change their existing model of Lean performance, we offer a support methodology based on a reengineering approach integrating coaching aimed at changing there presentations of the actors by a sociocognitive learning. This methodology is based on a framework and modeling tools to represent the impacts of this new performance model on the decision and on the sustainability of the lean benefits.

The thesis is focused on the definition of performance and individual methods of measuring company performance. Furthermore, thesis deals with evaluation of company performance for Čegan Ltd. company using the START model. The actions for improve the company performance are proposed based on the START model and financial analysis.

Group work and online discussions are not new terms in education and are important activities for Information Systems students. It has become important because it encourages creative thinking and provides more efficient problem-solving approaches. Online social networking sites, like Facebook, have pedagogical potential and the consideration of its academic application should not be ignored by lecturers or students. The main problem identified in this thesis is that the awareness and application of the emerging pedagogical potential of online social networking sites, like Facebook, especially for the purpose of group work and online discussions, is limited among Information Systems lecturers and students. The purpose of this study is to determine the level of awareness and application of Facebook as an academic tool by Information Systems lecturers and students, and whether it can enhance the learning experience of students, related to the effectiveness of group work and online discussions. The perceptions of both Information Systems lecturers and students were recorded by means of questionnaires and interviews. It was found that most lecturers and students were aware of Facebook’s pedagogical potential. However, the consideration and application of Facebook as an academic tool, by lecturers and students, are limited. From a cultural perspective, it was found that students from a private institution, where no Learning Management System was implemented, as well as black students, showed increased levels of utilisation and performance, in terms of enhanced learning experienced, on the academic groups on Facebook. The researcher developed a model for the academic application of Facebook for Information Systems students, based on the Task-Technology Fit and the Social Software Performance Model theories. This study concludes with the recommendation that Information Systems lecturers and students should become increasingly aware of and consider the pedagogical potential of Facebook as a supplementary tool and with suggestions for future research. / Dissertation (MCom)--University of Pretoria, 2010. / Informatics / unrestricted

As the globalisation process accelerates there is a growing need for individual countries to understand the bases for effective performance in international trade. Because it makes up such a large share of world trade, it is especially important to understand what determines effectiveness in exporting. Despite much empirical research, especially over recent decades, the state of knowledge on this topic remains fragmented, unclear and unsatisfactory. The motivation for the present study was therefore twofold: dissatisfaction with the present state of knowledge in this vital area and the importance to the UK economy of improving its export performance in a world of increasing competition. Its aim was to contribute to the resolution of both. In addition to finding what appeared to be quite serious methodological problems in a group of earlier studies, our review of the literature indicated that the best prospects for identifying the determinants of effective exporting were to be found, not at national or sectoral level but at that of the individual firm. Accordingly, an empirical survey research project was developed. To minimise unquantifiable inter-sectoral variability, it was focused on a single sector of industry. For a range of reasons, including the limited amount of information available about its current export activity and prospects, the UK knitted apparel industry was chosen. Special care having been taken to assemble the fullest possible sampling frame and to develop a suitable instrument (which included an export performance model), a mail survey in the form of a stratified random sample of exporting UK manufacturers of knitted apparel was carried through from late 2000. Persistent follow-up by mail and telephone generated a response rate of 70 per cent, comprising close to half of the sampling frame, that was representative of all company size bands, levels of exporting and products. The overall quality of the responses was good; tests of non-response did not find any indications of non-response bias. Data analysis, designed to test thoroughly our 10 export-determinants hypotheses, relied primarily on Pearsonian correlation at the bivariate level then sequentially on Multiple Regression Analysis, Canonical Correlation Analysis and Partial Least Squares. A perhaps slightly novel aspect of the research was that it was not solely cross-sectional in format; a longitudinal element was provided by drawing on the researcher's earlier surveys ; and a panel element by following-up, in 2007, the main 2000 field survey. Where possible, these data were drawn upon in the analysis and interpretation. There did not appear to be any conflict between the three multivariate techniques employed and indeed their findings were not dissimilar. The outcome of the data analysis was to uphold, to varying degrees, most of our hypotheses about the determinants of effective or successful exporting. Those that did not find support were three: firm size, product adaptation, and price determination method. Most strongly supported as determinants were promotional intensity, serving many markets and visits to trade fairs/exhibitions; others which were statistically significant, included management commitment, special staff skills and the use of Commission Agents. While the conclusions must remain a bit tentative they are encouraging.

Bakgrund: Taximarknaden har varit, och är, under förändring. Till följd av den teknologiska utvecklingen har nya aktörer och substitut etablerat sig på marknaden. Uber, Bzzt och Lime är endast tre av de företag som vuxit fram under de senare åren. De nya företagen bidrar inte endast med nya, innovativa substitut till traditionell taxi, utan även ökad konkurrens vad gäller tillgänglighet via digitala plattformar. Syfte: Syftet med uppsatsen är att analysera den teknologiska utvecklingens betydelse för taximarknadens struktur och funktion, med fokus på Stockholm. Metod: Uppsatsens referensram är Structure-Conduct-Performance modellen. För djupare analys och förståelse har intervjuer med: Bzzt, Svenska Taxiförbundet och Taxi Stockholm, genomförts. Uppsatsen innefattar även två egna undersökningar om taxiföretagens prisnivå och tillgänglighet. De taxiföretagen som inkluderas i uppsatsen är: Sverigetaxi, TaxiKurir, Taxi Stockholm, TOPCAB samt Uber. Slutsats: Den teknologiska utvecklingen har en stor betydelse för taximarknadens struktur och funktion, i det avseende att den bidrar till en mer kundcentrerad och effektivare marknad. Marknadsstrukturen i Stockholm liknar en hybridmarknad mellan oligopol och fullständig konkurrens, beroende på de storleksmässiga skillnader som finns mellan aktörerna. Marknaden har en jämn prisnivå och bra tillgänglighet, varav det sistnämnda har förbättrats till följd av utvecklandet av taxiföretagens egna applikationer. / Background: The taxi market has been, and is, undergoing a transformation. As a result of the technological development, new companies and substitutes have been established on the market. Uber, Bzzt and Lime are only three of all the new companies that have emerged in the recent years, and not only contribute with new, innovative substitutes for traditional taxi, but also increased competition in terms of accessibility through digital platforms. Purpose: The purpose of the essay is to analyze the influence of the technological development on the taxi market’s structure and function, with focus on Stockholm. Completion: The main framework of the essay is the Structure-Conduct-Performance model. For a more profound analysis three interviews were conducted with: Bzzt, Svenska Taxiförbundet and Taxi Stockholm. The essay also includes a study of the price level and a study of the accessibility to a taxi. The included companies are: Sverigetaxi, TaxiKurir, Taxi Stockholm, TOPCAB and Uber. Conclusions: The technological development have a large impact on the structure and function of the taxi market, since it contributes to a more customer-centered and efficient market. The market structure in Stockholm is similar to a hybrid market of an oligopoly and perfect competition, depending on the difference in size of the existing companies. The market has a uniform price level and a good accessibility, of which the latest has improved as a result of the development of the taxi companies own applications.