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.

Thèse en cotutelle: Université Laval Québec, Canada et Université Blaise-Pascal, Clermont-Ferrand, France / Les systèmes Spatial On-Line Analytical Processing (SOLAP) permettent de prendre en charge l’analyse multidimensionnelle en ligne d’un très grand volume de données ayant une référence spatiale. Dans ces systèmes, le vague spatial n’est généralement pas pris en compte, ce qui peut être source d’erreurs dans les analyses et les interprétations des cubes de données SOLAP, effectuées par les utilisateurs finaux. Bien qu’il existe des modèles d’objets ad-hoc pour gérer le vague spatial, l’implantation de ces modèles dans les systèmes SOLAP est encore à l’état embryonnaire. En outre, l’introduction de tels modèles dans les systèmes SOLAP accroit la complexité de l’analyse au détriment de l’utilisabilité dans bon nombre de contextes applicatifs. Dans cette thèse nous nous proposons d’investiguer la piste d’une nouvelle approche visant un compromis approprié entre l’exactitude théorique de la réponse au vague spatial, la facilité d’implantation dans les systèmes SOLAP existants et l’utilisabilité des cubes de données fournis aux utilisateurs finaux. Les objectifs de cette thèse sont donc de jeter les bases d’une approche de conception de cube SOLAP où la gestion du vague est remplacée par la gestion des risques de mauvaises interprétations induits, d’en définir les principes d’une implantation pratique et d’en démontrer les avantages. En résultats aux travaux menés, une approche de conception de cubes SOLAP où le risque de mauvaise interprétation est considéré et géré de manière itérative et en adéquation avec les sensibilités des utilisateurs finaux quant aux risques potentiels identifiés a été proposée; des outils formels à savoir un profil UML adapté, des fonctions de modification de schémas multidimensionnels pour construire les cubes souhaités, et un processus formel guidant de telles transformations de schémas ont été présentés; la vérification de la faisabilité de notre approche dans un cadre purement informatique avec la mise en œuvre de l’approche dans un outil CASE (Computed Aided Software Engineering) a aussi été présentée. Pour finir, nous avons pu valider le fait que l’approche fournisse non seulement des cubes aussi compréhensibles et donc utilisables que les cubes classiques, mais aussi des cubes où le vague n’est plus laissé de côté, sans aucun effort pour atténuer ses impacts sur les analyses et les prises de décision des utilisateurs finaux. / SOLAP (Spatial On-Line Analytical Processing) systems support the online multi-dimensional analysis of a very large volume of data with a spatial reference. In these systems, the spatial vagueness is usually not taken into account, which can lead to errors in the SOLAP datacubes analyzes and interpretations end-users make. Although there are ad-hoc models of vague objects to manage the spatial vagueness, the implementation of these models in SOLAP systems is still in an embryonal state. In addition, the introduction of such models in SOLAP systems increases the complexity of the analysis at the expense of usability in many application contexts. In this thesis we propose to investigate the trail of a new approach that makes an appropriate compromise between the theoretical accuracy of the response to the spatial vagueness, the ease of implementation in existing SOLAP systems and the usability of datacubes provided to end users. The objectives of this thesis are to lay the foundations of a SOLAP datacube design approach where spatial vagueness management in itself is replaced by the management of risks of misinterpretations induced by the vagueness, to define the principles of a practical implementation of the approach and to demonstrate its benefits. The results of this thesis consist of a SOLAP datacube design approach where the risks of misinterpretation are considered and managed in an iterative manner and in line with the end users tolerance levels regarding those risks; formal tools namely a suitable UML (Unified Modeling Language) profile, multidimensional schemas transformation functions to help tailored the datacubes to end-users tolerance levels, and a formal process guiding such schemas transformation; verifying the feasibility of our approach in a computing context with the implementation of the approach in a CASE (Computed Aided Software Engineering) tool. Finally, we were able to validate that the approach provides SOLAP datacubes that are not only as comprehensible and thus usable as conventional datacubes but also datacubes where the spatial vagueness is not left out, with no effort to mitigate its impacts on analysis and decision making for end users.

Afin d’obtenir un positionnement GPS de précision centimétrique, il est important de bien modéliser les erreurs telles que les délais ionosphérique et troposphérique ainsi que les erreurs d’horloge et d’éphémérides. Pour une solution de précision centimétrique utilisant des mesures de phase, il est également important d’être en mesure de détecter et de corriger les sauts de cycle, car ceux-ci introduisent des biais artificiels dans la solution, qui peuvent entraîner des erreurs dans l’estimation des coordonnées. Les sauts de cycle sont causés par la perte de réception des signaux occasionnée par des obstructions entre les satellites et l’antenne. Que ce soit pour un positionnement temporel relatif GPS qui n’utilise qu’un seul récepteur (aucune station de référence) ou en mode relatif conventionnel ou le PPP (Precise Point Positioning), les sauts de cycle obligent l’utilisateur à recommencer la période d’initialisation lorsqu’il reste moins de 4 satellites non obstrués. Le but de ce projet est d’évaluer l’apport d’une méthode pour détecter et corriger les sauts de cycle dans une solution GPS mono-fréquence en utilisant des mesures complémentaires provenant d’un gyro-accéléromètre. Le modèle utilisé lors des tests est le AHRS400CC-100 de la compagnie CrossBow. Avec cette méthode, il est possible de comparer, pour chaque satellite, la différence d’ ambigüités, calculée à partir des observations GPS et celle prédite à partir de la position calculée avec les mesures du gyro-accéléromètre. Dans le cadre de ce projet, plusieurs étapes ont dû être réalisées. La première étape était de valider la précision des observations du AHRS400CC-100, puis de quantifier pour chacun de ses capteurs, la marche aléatoire et l’instabilité du biais. Ensuite, d’exploiter les mesures du gyro-accéléromètre afin de calculer une solution de navigation, et d’identifier les limites de précision de l’instrument en mode statique et cinématique. La dernière étape était de combiner la solution de navigation du gyro-accéléromètre à celle du GPS pour évaluer pendant combien de temps le gyro-accéléromètre maintient un positionnement avec suffisamment de précision pour détecter et corriger un saut de cycle. Les résultats ont démontré que des sauts de cycle pourraient être détectés et corrigés instantanément après une coupure du signal GPS d’une durée de 10 secondes pour un positionnement statique et pouvant atteindre 5 secondes en mode cinématique dans des conditions idéales sinon 1 à 2 secondes. Pour augmenter l’efficacité de l’application de détection et de correction de sauts de cycle, l’implémentation d’un filtre de Kalman pour effectuer la fusion des observations GPS et du gyro-accéléromètre pourrait être réalisée dans le cadre de travaux futurs. / In order to achieve centimetre precision using GPS, one must use the carrier phase measurements. It is also important to minimise the impact of the many errors that affect GPS measurements: ionosphere and tropospheric delays, orbit and clocks errors. Another essential part of a precise GPS measurement, is the detection and correction of cycle slips. These slips, caused by the interruption of the GPS signal, introduce artificial biases in the measurement that result in erroneous coordinate estimates. For different GPS solution such as Real Time Kinematic (RTK), Time Relative positioning (TRP) or Precise Point positioning (PPP), to correct cycle slips, the user must restart the initialisation process. In this research, a method to detect and correct cycle slip in monofrequence GPS solution is explored. This methode uses inertial data provided by an attitude and heading reference system (AHRS). The model that is used here is Crossbow’s AHRS400CC-100. With this method, it is possible to compare, for each observed satellite, the ambiguity difference between the ambiguity values calculated from GPS observations and those predicted by the navigation solution calculated from the AHRS observations. It is effective to integrate AHRS to GPS. An AHRS can potentially be used for cycle slip detection and fixing. Using the AHRS measurements, one can achieve centimetre level precision for short periods of time. This method of positioning can be used during GPS signal loss to maintain the navigation solution. Once the GPS signal is retrieved, it is possible to compare the ambiguity difference between satellite line of view vector of each satellite calculated using GPS observations and satellite line of view vector calculated from the last AHRS position GPS observations. For this research project, the initial task was to validate the precision of the AHRS400CC-100 observations, and to quantify random walk error and bias instability for each of the instruments sensors using static data sets. The next task was to use the AHRS measurements to calculate a navigation solution and to identify the instruments limitations of position precision using static and kinematic data. The last task was to combine AHRS and GPS observations, to obtain an integrated navigation solution. Once the solution implemented, simulated data gaps were added to the data set in order to evaluate the maximum duration of GPS data loss after which it is possible to detect and correct GPS cycle slips using the autonomous AHRS navigation solution. According to the results of the experiments using the method proposed in this paper, AHRS positioning appears to maintain adequate precision for cycle slip detection and fixing for up to 10 seconds for static positioning and up to 5 seconds for kinematic positioning in ideal conditions.