Akademisk avhandling--Konstvetenskapliga institutionen--Göteborg, 1991. / Résumé en anglais.

Akademisk avhandling--Stockholm, 1997. / Résumé en anglais. Bibliogr. p. 374-381. Index.

Traditional networks are no longer sustainable, lacks in scalability and when more devices connect to it the process of troubleshooting becomes laborious and time-consuming. In order to reduce the complexity of traditional networks, Cisco developed the concept Software-defined access (SD-Access) which combines a number of features and protocols to create an automated solution to make it easier for network technicians. This thesis investigates the SD-Access concept and compares it to today's traditional networks to find which solution is least demanding when it comes to identifying and adjusting a network problem. We use an example scenario which compares the process of performing troubleshooting in today's traditional networks versus the futures SDA networks. Based on our example scenario, it is shown that troubleshooting in traditional networks is a labor-intensive process. The troubleshooting will be arduous because the majority of the work has to occur manually. SD-Access reduces the workload by dynamically locating the node that causes the problem and provides suggestions to solve the problem. Our comparison between the two solutions contributes to an increased understanding of how the troubleshooting process can be enhanced with SD-Access and in which scenario one of them is preferable to the other. / Traditionella nätverk är inte längre hållbara, nätverken brister i skalbarhet och när allt fler enheter är uppkopplade mot nätverket blir felsökningsprocessen arbetsam och tidskrävande. För att frångå den komplexitet traditionella nätverk medför utvecklade Cisco konceptet Software-defined access. SD-Access kombinerar flertalet funktioner och protokoll för att skapa en automatiserad lösning som underlättar för nätverkstekniker. Syftet med detta examensarbete är att jämföra felsökningsprocessen i traditionella nätverk och SD-Access, målet är att ta fram vilken lösning som är minst krävande när det kommer till att identifiera och åtgärda ett problem. Genom att utforma ett exempelscenario och jämföra processen för hur felsökningen genomförs, kan likheter och skillnader mellan de olika implementationsalternativen sammanställas. Utifrån exempelscenariot framgår det att felsökning i traditionella nätverk är en arbetsam uppgift. Felsökningen blir mödosam eftersom merparten av arbetet som krävs för att identifiera och åtgärda felet sker manuellt. SD-Access minskar arbetsbördan genom att dynamiskt lokalisera noden som orsakar problemet och tillhandahåller förslag som kan lösa problemet. Jämförelsen mellan de två lösningarna bidrar till en ökad förståelse kring hur felsökningsprocessen kan effektiveras med SD-Access och i vilka scenarion ena implementationsalternativet är att föredra över det andra.

Within the UK, levels of timber processing are set to increase as the plantation grown forest resource reaches financial maturity. Made up predominately of exotic coniferous species, this resource has been the focus of many recent studies as wood users look to improve their fundamental knowledge of the primary characteristics that will enable them to make more appropriate decisions and capitalise on future opportunities. As a further contribution to this knowledge base, it was the aim of this thesis to determine moisture content variation within Sitka spruce (Picea sitchensis (Bong.) Carr) standing trees and roundwood logs. Within standing trees, moisture content was found to vary significantly in both the longitudinal and radial directions (P<0.001). Longitudinally, the base and top of the trees contained higher quantities of moisture than did the lower and mid sections. Radially, the moisture content at the centre of each disk was very low and this extended outwards before rapidly increasing mid-radius and then reaching a plateau near to the cambium. A sigmoid regression model successfully explained two-thirds of the radial moisture content variation as well as explaining the longitudinal moisture content variation. The radial variation with tree height was described by a shortening of the low moisture content extending outwards from the pith and a softening of the steepness of the increase with the duration extending as tree height increased. Seasonal variation within standing spruce trees was assessed within a plantation forest in northern England. Removing samples from 81 trees throughout a period covering 42 calendar weeks of 2012 revealed no significant effect of season on the moisture content although a link was identified with short-term variation in temperature. However, further analysis on the radial sections confirmed that when the moisture content data were converted to a percentage of total lumen saturation, a significant effect of seasonal variation was observed within the outer sapwood region (P<0.001). Whilst the standing trees as a whole did not demonstrate seasonal variation in moisture content, variation due to seasonal weather did have an effect on the drying of roundwood within the forest. Analysis of c. 25,000 samples, collected over a 6-year period, confirmed that season (dormant or growing) had a significant effect on sample moisture content (P<0.001). Temperature was recorded as having the greatest effect on moisture variation within roundwood whilst the effect of rainfall was not significant, due principally to the unpredictable nature of this variable throughout the year. To identify the radial and longitudinal moisture content change of roundwood during drying, an experiment was carried out to accelerate the drying process on short logs using an industrial oven at a constant temperature (40°C). Total drying time varied between 7 and 28 days prior to post drying analysis of the logs to determine the longitudinal and radial moisture profiles. All logs lost a constant quantity of moisture each day with the logs dried for 28 days losing more than 50% of their starting weight. Longitudinally, moisture was lost from all points along the length of each log with the log ends remaining driest, although these dry areas only accounted for 40% of the total log length. Radially, moisture declined across the log with the greatest amount removed from the outer radius. In order to provide some relevance of the impact moisture content variation has on the forest industry value chain, data collected from a working timber harvesting operation confirmed that variation existed between volume to weight conversions of different products. Within this even-aged Sitka spruce clearfell, volume to weight conversion factors ranged from 1.02 to 1.19. Differences of this magnitude can not only lead to a lack of understanding of between tree variation within a single site, but can also result in an impact on the optimum value recovery expected by each of the parties engaged within the value chain. The results presented within this thesis will help guide timber growers, agents, managers and purchasers in their future decision making when considering the most suitable markets for standing trees or roundwood logs. Improving knowledge of spatial and temporal moisture content variation will potentially result in maximising the forestry value chain and enable the forestry sector in the UK to make more from wood.

Large wood and its accumulations are poorly understood despite being an important feature in the functioning of forested river channels and floodplains. Large wood has previously been removed from rivers in order to reduce flow resistance and increase channel conveyance. However, recently there has been an appreciation of the role of large wood accumulations in creating important aquatic habitat, increasing geomorphic diversity, re-connecting river channels to their floodplains and in the development of multi-channel anastomosed river patterns. This thesis examines the role that large wood plays at a range of scales in a low-order forested stream in the New Forest, Southern England. The study river was subject to restoration measures, involving the addition of large wood to the river channel, as part of an EU LIFE III project. An empirical and Froude-scaled flume approach is taken to determine the role of large wood accumulations upon the reach-scale flow resistance values. Large wood accumulations from a variety of environments are assessed to determine the hydraulic effects of accumulations of different architecture in different environments. Field data from the study catchment is used to show the role of large wood in increasing the frequency and duration of reach-scale, floodplain inundation. Hydrological data shows the impact the restoration has upon both flood peak magnitude and flood peak travel time highlighting the potential benefits of large wood to downstream flood risk. A 2-Dimensional model is produced which simulates the effect of a range of large wood accumulations upon the inundation extent. An approach using spatial diversity metrics, widely used in ecological sciences, is conducted in an attempt to quantify the flow depth and flow velocity diversity, which can influence flow habitat diversity. Results show that large wood can initiate an anastomosing flow pattern which allows increases flow depth diversity by up to 49% and flow velocity diversity by up to 48%

Building on work in the field of rural geography, this thesis considers the changes which have taken place to the ways in which woods are managed and how the market for woodfuel has evolved following the considerable growth in demand for firewood and woodchip over the past decade. Through the use of in-depth interviews and field visits to woods and woodfuel businesses across the Midlands, it is demonstrated that the growth of the market has encouraged private woodland owners to carry out more management. This is a significant change from the latter half of the 20th Century when falling timber prices, and the lack of a market for wood products generally, resulted in many woodlands being neglected. In particular, the woodfuel markets have stimulated the removal and restoration of ‘Plantation on Ancient Woodland Sites’ (PAWS) by creating a market for the products of first and second thinning operations. Woodland owners are now able to make small, but significant, profits from their woods which is a marked change from a decade ago. A principal driver of the woodfuel market is the ‘Renewable Heat Incentive’ (RHI), whereby the Government is subsidising the use of woodchip-fed biomass boiler systems as part of the transition towards a greater use of renewable energy sources. Whilst the Forestry Commission’s principal objective remains the production of high quality timber, this thesis demonstrates it is reviewing how it may contribute to the woodfuel market’s growing share of the UK’s energy sector. In the thousands of small, privately-owned woods across England, the majority of which are owned for amenity and wildlife purposes, the thesis explores how the growing demand for firewood and woodchip is encouraging greater management. The many ways in which woodfuel management is complementary to other management objectives like timber production, wildlife and shooting are highlighted. The changes which have taken place to the UK’s forestry sector with the growing use of woodfuel is contextualised by exploring the extent to which they typify a ‘post-productivist’ shift. In many ways, the UK’s forestry sector appears to have entered a post-productivist era, with less emphasis placed on timber production since the 1980s and more policies to promote wildlife. The doctrine has been widely critiqued by examining the changes to agriculture but the forestry sector has been largely neglected, barring the work of Mather et al. (2006) who claim it has undergone a post-productivist shift. This view is contested by exploring how the growth of the woodfuel markets is promoting greater timber harvesting, as well as affecting how public and private woodland owners view their woods as money-making assets. The market from the perspective of the woodfuel merchants is also explored. Their histories and backgrounds are presented, revealing a diverse community of people with different business aims. Following an analysis of the ways in which merchants operate, from the types of machinery used to the methods of delivery, a typology of merchants is proposed. Whilst a ‘professionalisation’ of the sector has taken place over the past decade, with more standardised units of sale and improved customer service, an informal firewood market exists whereby some customers are unwillingly sold unseasoned firewood. With wood burning becoming a more popular activity in the UK following a surge in the use of dedicated wood burners, people are becoming more knowledgeable about the burning properties of different species of wood. However, the growth in demand for wood has led merchants to question whether the UK’s woods and forests can continue supplying the market at the current rate. Many merchants struggle to source timber for woodfuel and this had led them to supplement their stocks by purchasing from European suppliers. A contrasting view, however, is that the UK has a surplus of timber across its many unmanaged woods, as demonstrated by the Forestry Commission’s most recent national survey. The thesis therefore highlights a perception amongst merchants that the country’s timber supplies are at risk from the growing demand for woodfuel.

This thesis is an intersectional study of forest rights of forest-dwellers in the tribal territory of Koraput, India. The thesis is developed around a piece of path-breaking legislation, the Forest Rights Act (FRA) of India 2006, under which land titles and resource use rights are being granted to many forest-dwelling households and communities. This work exclusively deals with the individual title holders of forest land under the FRA. It explores three important questions: 1) what is the history of forest-rights delineation in Koraput?, 2) how are the rights of forest-dwelling people being settled under FRA? and, 3) what are the complexities of land use in these tribal forestlands?} The thesis has used a mixed-methods approach to build and connect its three focus areas. Historical aspects of local forest rights have been explored through the lens of colonial and post-colonial forest policy analysis. The investigation of the various aspects of FRA implementation and ground realities combines cross-disciplinary approaches from political and gendered micro geography. The analysis of emerging land use on forest lands allotted under FRA is influenced by the Sen’s theory of entitlements, endowments and capabilities {Sen, 2001}. A multi-approach assessment methodology has been used by analysing a wide range of data streams including historical documents, household surveys, interviews, participatory maps, observations, group discussions and secondary data sets. Key findings that have emerged from this thesis are, 1) the consequences of the implementation of colonial and post-colonial forest policy measures on Koraput's forest-dwellers are substantial and unique geography of Koraput has produced new insights to the existing knowledge of history of forest rights in India, 2) FRA is a promising piece of legislation that has achieved significant political and bureaucratic collaboration in Koraput, but it is marred by major operational inefficiencies, and 3) the newly created FRA-lands will provide opportunities for policy makers and title owners to reconsider many existing norms including legal versus illegal occupation of forest land, forest-farming practices on FRA lands, and a need for renewed forest and land management goals for FRA territories in tribal India.

Syftet med denna studie är att tolka och förstå hur individen som väljer att rösta påsverigedemokraterna upplever att hen behandlas av sin omgivning till följd av sin politiskaröst. I den tidigare forskningen lyfter jag upp att sverigedemokraterna på politisk nivåbetraktats som något annorlunda. Vidare lyfter jag upp forskning som har gjorts kringavvikande och stigmatisering, hur detta sker och hur det påverkar individen i sitt vardagligaliv. Arbetet tolkas med hjälp av Goffmans tanke kring stigmatisering och Beckers tankarkring avvikande. I arbetet utgår jag från ett hermeneutiskt förhållningsätt, för att fånga inindividernas upplevelse av fenomenet. Studien grundar sig på fem intervjuer med individersom skulle rösta på sverigedemokraterna om det var val idag. I arbetets resultatdel lyfts upphur de som intervjuas upplever att de blir bemötta, och vidare hur det finns ett stigma kring attvara sverigedemokrat på många håll, och att det även lett till negativa handlingar motindividen. Studien visar även att det finns anledning att inte vara öppen med sin politiska rösti en del sammanhang, då risken att misskrediteras är för stor. Upplevelsen av hur man bemötssom sverigedemokrat tycks dock vara mångtydig och situationsberoende.

Le Positionnement Ponctuel Précis (PPP) est une technique de positionnement qui utilise un seul récepteur GNSS. Cette approche diffère nettement des méthodes différentielles qui sont largement utilisées et qui nécessitent deux ou plusieurs récepteurs. Le PPP est une technique économique, autonome par station, avec une précision centimétrique qui a ouvert la possibilité à une large gamme d'applications. Cependant, dans les applications qui nécessitent une convergence rapide et une haute précision, la performance du PPP n'est pas encore suffisante. Le PPP peut prendre jusqu’à 30 minutes pour converger vers des solutions avec une précision décimétrique. Cette longue période d’initiation est principalement consacrée à la stabilisation des ambiguïtés de phase vers des valeurs flottantes constantes. Compte tenu de ce problème, il est démontré que la Résolution des Ambigüités (RA) améliore la stabilité du modèle d’estimation, réduit le temps de convergence et améliore la précision des coordonnées. Cette étude vise donc à améliorer la performance du PPP pour obtenir une meilleure précision plus rapidement. À cette fin, les biais de phase des satellites qui perturbent la résolution des ambiguïtés sont estimées du côté producteur et résolues du côté utilisateur. Une modélisation judicieuse de paramètres et une sélection rigoureuse des modèles de correction sont effectuées afin de réduire la propagation des erreurs non-corrigées dans les biais de phase des satellites estimés. Du côté producteur, une nouvelle approche modulaire à deux étapes est proposée et implémentée comprenant l'estimation de biais de phase des satellites à partir de chaque site et l'intégration séquentielle des solutions. Ces deux étapes ont des structures simples et elles permettent d'estimer précisément les biais de phase de chaque satellite. L’algorithme de l’intégration séquentielle garde un bon compromis entre la charge de calcul, la charge et la capacité de mémoire de l’ordinateur, l'efficacité du traitement des paramètres et la précision des estimations. Du coté producteur, chaque observation est modélisée individuellement et intégrée dans le processus d'estimation. Ceci facilite l'intégration des fréquences supplémentaires (par exemple, la troisième fréquence L5 ou des observations multi-GNSS) pour améliorer davantage la performance de PPP en fonction de la modernisation du GNSS. Du côté utilisateur, un modèle d’observation de plein rang au niveau de récepteur mono-fréquence est proposé et implémenté. Cela donne de la flexibilité aux utilisateurs avec les récepteurs mono-fréquence pour utiliser notre solution PPP-RA lorsque les produits d'ionosphère de haute précision sont disponibles. Le modèle proposé est compatible avec les horloges de satellite standards actuelles fournies par IGS, CODE, JPL, par exemple. Le délai ionosphérique est corrigé et estimé en parallèle. Cela permet à l'utilisateur d’utiliser une correction ionosphérique de faible ou de haute précision et obtenir une performance améliorée en ajustant uniquement la précision de l'estimation de ce paramètre. La performance du PPP-RA du côté utilisateur a été comparée au PPP conventionnel en termes du temps de convergence et de la précision des coordonnées. En résumé, on a obtenu une amélioration importante en temps de convergence (jusqu'à 80 %) et en précision planimétrique (jusqu'à 60 %) par rapport au PPP conventionnel. De plus, une étude comparative est effectuée pour distinguer les caractéristiques de notre approche des autres méthodes PPP-RA. L’avantage de notre PPP-RA est aussi démontré par son approche unique à éliminer les défauts de rang et résoudre les ambiguïtés libre-de-biais. / Precise Point Positioning (PPP) is a single receiver GNSS positioning technique developed in contrast to broadly used differential methods that require two or more receivers. Employing a single receiver makes PPP a cost-effective and per-site autonomous technique with centimetre precision that has opened up the possibility of a wide range of applications. In many applications where short time period is required to reach high precisions, the performance of PPP is not yet sufficient. Typically, PPP takes up to 30 minutes in order to converge to coordinate solutions with acceptable precision. This limitation is mostly due to the long period required for stabilizing the float carrier phase ambiguities to constant values. Given this problem, it is showed that Ambiguity Resolution (AR) improves drastically the stability of the estimation model that in turn reduces the convergence time, and increases the precision of estimated coordinates. Thus, this study seeks to enhance the performance of PPP to obtain higher precision at a faster convergence time. For this reason, the hardware dependent satellite phase biases are estimated at the producer-side and by applying them as corrections the integer ambiguities can be resolved at the user-side. A judicious modelling of all parameters and a careful selection of the correction models is accomplished to reduce the impact of error propagation on the precision of parameters estimation. At the producer-side, a novel modular approach is proposed and established including the per-site satellite phase bias estimation and the sequential integration of the solutions. The two-steps of the producer-side have simple structures and allows for estimating the satellite phase biases. The proposed sequential network solution, keeps a good compromise between the computational burden, the computer memory load, the efficiency of handling parameters and the precision of estimations. In addition, all observables are modelled individually and integrated in the estimation process that facilitates the extension of algorithms for integrating additional frequencies or mutli-GNSS observables with respect to the GNSS modernization. At the user side, a novel full rank design matrix in the single frequency level is proposed and implemented. This gives the flexibility to the users with single-frequency receivers to benefit from our PPP-AR while the high precision ionosphere products are available. The proposed model is compatible with the current standard satellite clocks available, for example, from IGS, CODE, and JPL. The ionosphere is corrected and estimated at the same time. This gives the user the possibility to take advantage of low or high precision ionosphere products for obtaining an enhanced performance with our PPP-AR by only adjusting the precision of the ionosphere delay estimation. The performance of our PPP-AR user-side is then compared to the conventional PPP in terms of convergence time and coordinate precision. A substantial improvement has been obtained in terms of planimetric precision (up to 60%) and the convergence time (up to 80%) compared to the conventional PPP method. In addition, the characteristics of our PPP-AR are compared in detail with other PPP-AR methods. The advantage of our method is discussed by its unique approach of removing the rank deficiencies and resolving bias-free ambiguities.

La géologie a exprimé, face à la géomatique, le besoin de modéliser les objets géologiques en 3D et d'analyser ces modèles pour prendre des décisions plus éclairées. La géomatique répond relativement bien à certain de ces besoins comme celui de construire des modèles géologiques tridimensionnels. Cependant, les systèmes géomatiques (tels que les systèmes d'information géographique) ne sont pas adaptés à la gestion explicite des relations topologiques s'exprimant dans un univers 3D. Ce projet de maîtrise vise à développer une structure de stockage qui régularise les relations spatiales entre des objets tridimensionnels, permettant d'élargir les possibilités d'analyse d'un modèle géologique 3D. Pour réaliser ce projet, quatre étapes ont été nécessaires : 1) inventaire des structures topologiques 2D et 3D, 2) création d'une structure de données géométriques 3D, 3) création d'un prototype et, finalement, 4) réalisation de tests avec le prototype. Avec ces développements, une requête montrant la relation spatiale contient entre des unités géologiques et des fractures a été réalisée en 3D. Les résultats obtenus montrent le grand potentiel de cette approche pour l'analyse de modèle géologique. De plus, la création d'une nouvelle structure topologique de données appliquée aux données géologiques est certes un avancement pour l'application de la géomatique au domaine des sciences de la terre.