Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 124-138) Also available in print.

published_or_final_version / Computer Science / Master / Master of Philosophy

published_or_final_version / Computer Science and Information Systems / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 2005.

No keywords provided in dissertation / Cloud Computing has gained traction since its emergence and client organisations that want to benefit from the Cloud are looking for ways to migrate their on-premise applications to the Cloud. To assist client organisations with migration projects, researchers and practitioners have proposed various Cloud migration approaches. However, these approaches differ in applicability depending on the type of application being migrated and the Cloud Service Provider where the application is being migrated to. The various approaches to Cloud migration create complexity in Cloud migration decisions as client organisations have to consider various approaches depending on the migration project. The purpose of this dissertation is to create a universal Cloud migration approach that can be applied to every Cloud migration project. In this dissertation, a cloud migration decision framework is proposed; namely, A Holistic Cloud Migration Decision Framework (HCMDF). The research strategy that was followed is Design Science Research (DSR) and was selected since the output of the research is going to be an Information Technology (IT) research artefact. By applying the DSR strategy, the HCMDF was successfully developed and evaluated in the real world using an adaptive case study. The analysis of the results indicated that the HCMDF solves Cloud migration problem and that it can be applied to every Cloud migration project. Throughout the evaluation, areas of improvement were identified and these will be considered in future research. / School of Computing / M. Tech (Information Technology)

The ability to maintain continuous access to digital documents and artifacts is one of the most significant problems facing the archival, manuscript repository, and record management communities in the twenty-first century. This problem with access is particularly troublesome in the case of complex digital installments, which resist simple migration and emulation strategies. The Legacy Project, which was produced by the William Breman Jewish Heritage Museum in Atlanta, was created in the early 2000s as a means of telling the stories of Holocaust survivors who settled in metropolitan Atlanta. Legacy was an interactive multimedia kiosk that enabled museum visitors to read accounts, watch digital video, and examine photographs about these survivors. However, several years after Legacy was completed, it became inoperable, due to technological obsolescence. By using Legacy as a case study, I examine how institutions can preserve access to complex digital artifacts and how they can rescue digital information that is in danger of being lost.

Att arbeta med ett äldre så kallat legacy-system är en vanlig uppgift bland dagens programmerare men det saknas data om hur arbetsinsatsen är fördelad. Denna data vore användbar för att utvärdera hur kostsamt det är att vidareutveckla ett system kontra en omskrivning eller migration. För att åtgärda detta bidrar den här undersökningen med data som visar arbetsinsatsfördelningen vid migration av ett mindre legacy-system. Frågan som undersöks är ”Hur fördelas kostnaden i tid när man utvärderar och bygger om ett legacy-system?. Grunden för data i denna undersökning kommer ifrån utvecklingen av ett litet studentutvecklat system som använts på KTH och som var i stort behov av uppdatering. Det fanns mycket dokumentation om systemets krav och design, men den kod som fanns var ej användbar då den ej var dokumenterad och saknade klar struktur. Detta ledde till en omskrivning av systemet enligt de krav som tidigare formulerats. I det här projektet användes en vetenskaplig fallstudie med en kvantitativ metod för att få fram resultat. Tiden som lades ned på de moment som identifierats innan uppstart mättes och användes för att beräkna arbetsinsatsfördelningen. Resultatet av denna undersökning är en samling data som kan användas för uppskattningen av arbetsinsatsfördelningen vid omskrivningen av ett mindre legacy-system. I denna undersökning redovisas arbetsinsatsfördelningen som uppmätts under migrationen av ett legacy-system till en ny teknologi, då det existerande systemet inte betraktades som värt att uppdatera. Undersökningens slutsats är att om det finns ett bra förarbete som går att använda för att bygga om systemet så kommer majoriteten av arbetsarbetsinsatsen att läggas på implementeringen av systemet i kod. / Working with legacy-systems is a common task for programmers, and the development of these requires a great effort, but data regarding the distribution of this effort is scarce. This data would be valuable when evaluating the cost of continued development of a system compared to a rewrite or migration. To rectify this, we aim to provide a datapoint regarding the effort distribution for the migration of a small legacy-system. Our question is “How is the cost in time distributed when a legacy-system is evaluated and rebuilt?”. The data presented in this thesis comes from the development of a legacy-system developed by students at KTH. The system needed an update since it had ceased to function. There was a great amount of documentation with regards to requirement specifications and application design which could be used when redeveloping the system. The code, however, lacked any substantial documentation and structure, so it was decided early on that rewriting the system according to the existing documentation was going to be more efficient than working with the code for the current system. A scientific case study built on quantitative methods was used to collect data. To measure effort the time spent on each predefined moment was counted in minutes, and this was used to calculate the distribution of effort. The result of this thesis is a table of data and a review of the distribution of effort when working on a small legacy-system with clear requirements. The data produced in this thesis is based on the effort spent on rewriting a system that was not worth updating. The conclusion of this thesis is that most of the effort will be spent on implementing the code when a clearly defined system is rewritten from the ground up.

Thesis (M.Sc.(Computer Science))--University of Pretoria, 2009. / Includes bibliographical references.

Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...