Regular path queries (RPQ’s) are given by means of regular expressions and ask for matching patterns on labeled graphs. RPQ’s have recently received great attention in the context of semistructured data, which are data whose structure is irregular, partially known, or subject to frequent changes. One of the most important problems in databases today is the integration of semistructured data from multiple sources modeled as views. In this setting, the database is not available, and given a user query, the system has to answer based solely on the information provided by the views. The problem is computationally hard, and the well-known algorithm for solving it runs in 2EXPTIME. In this paper, we provide practical evidence that this algorithm performs poorly on the average as well. Then, we propose automata- theoretic techniques which make the view-based answering of RPQ’s more feasible in practice.

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Den globala biologiska mångfalden minskar på grund av kraftig mänsklig exploatering av resurser. Ett sådant exempel är diversitetens nedgång i Fennoskandias skogar. Denna studie sökte att undersöka om skogsbruket negativt påverkar mångfalden i en svensk skog i förhållande till dess vedlevande lavar och mossor, med hjälp av träsubstratets kvaliteter som jämförelse och oberoende variabel. 21 vedlevande mossor och lavar var grunden för dessa jämförelser. Studien jämförde två ursprungligen likadana produktionsskogar, där den ena blev ett naturreservat för nästan 100 år sedan. De ligger sydost om Linköping stad, nära BjärkaSäby. Tio 300 m2transekter med slumpmässigt genererade startpunkter och riktningar etablerades i varje skog. Kvantiteten av, deras diameter, deras höjd/längd och deras arttillhörighet för levande och döda träd över en meter i höjd noterades. Nedbrytningsstadier för liggande död ved bredare än 5 centimeter noterades. Ett Wilcoxon-rank-summa-test avslöjade signifikant högre medelvärden av förekomster för vedlevande arter inuti reservatet. Oparade t-tester avslöjade signifikant högre medelvärden för de vedlevande arternasarttäckning och för volymen död ved i reservatet. Pearsons chi-två test avslöjade signifikanta fördelningsskillnader hos levande tallars och lövträdsdiametrar mellan de två områdena men inte mellan fördelningen av nedbrytningsstadier eller hos diametrarna för levande granar. Logistiska regressioner avslöjade att de flesta av de vedlevande arterna med över 10 förekomster i båda områdena över lag hade åtminstone en signifikant korrelation med dess substrats egenskaper. Fynden tyder på att modernt skogsbruk påverkar vedlevande arter negativt, främst på grund av den lilla mängden substrat tillgängligt i produktionsskogen snarare än på grund av substratens variation av egenskaper. / Global biodiversity is declining due to human exploitation, such as seen with its decline within Fennoscandian forests. This study aimed to see if forestry negatively impacts diversity in a Swedish forest in relation to its wood-living lichens and mosses, using the wooden substrate qualities as a point of comparison. 21 saproxylic mosses and lichens formed the basis of these comparisons. The study compared two originally equal production forests, where one became a reserve almost 100 years ago. They are located south-east of Linköping City, near Bjärka-Säby. Ten 300 m2 transects with randomly generated placements and directions were established in each forest. The quantity, diameter, height/length, and species of living and deadtrees over one meter tall were noted. Decay stages for lying dead wood broader than 5 centimeters was noted. A Wilcoxon-rank-sum-test revealed significantly higher meanoccurrences of saproxylic species in the reserve. Unpaired t-tests revealed significantly higher means of saproxylic species coverage and volume of dead wood in the reserve. Pearson’s chi-square test revealed significant distribution differences of living pines and deciduous tree diameters between the two areas but not in the distribution of wood decay stages or in the diameters of living spruces. Logistic regressions revealed that most of the saproxylic specieswith over 10 occurrences in both areas over all had at least one significant correlation with its substrate’s properties. Findings indicate that modern forestry negatively impacts wood-dwelling species mostly due to the small amount of substrate in the managed forest rather than due to their variety

Dry, boreal, forest ecosystems have been shown to alternate due to reindeer presence by changing the field layer. This affects the temperature of the soil, changes the microclimate and the nutrients of soil and field layer. By removal of biomass and trampling stress the ground lichen mats reduce in cover and thickness. In this thesis two dry, boreal pine forests in Northern Finland were studied, to see how the nutrient stocks in the field layer are impacted by reindeer presence. A comparison of the same site, with >20 years in between was studied to see how year-round grazing affect the carbon storage in the field layer compared to winter grazing.    I found that reindeer grazing reduces the vegetation carbon storage, however, the impact on the vegetation nitrogen storage differs with site. Furthermore, the lichens and shrubs had lower C:N ratios because of increased nitrogen content in the plant tissue and unaffected carbon content. These results show that reindeer actively changes the vegetation quantity and quality which will have implications for the soil carbon storage.

Approved for public release, distribution is unlimited / The Marine Corps is fielding the MTVR Truck as a replacement for its aging fleet of five-ton cargo trucks. The MTVR is an Acquisition Category II program that was a multi-service Army-Marine Corps program. The purpose of this thesis is to examine the effectiveness of having an Army Product Office execute a Marine Corps Program. The study analyzes the effectiveness of the timing of the program's transition from the Army to the Marine Corps. A detailed literature search, as well as information gathered from attending various IPRs and conducting interviews with program officials and contractors, provided the basis for the in-depth background study presented. Analysis of the data gathered led to a justification for multi-service managed programs, as well as to recommendations on the timing of the MTVR program transition. / Civilian, United States Army

Upon consultation with NPS faculty, the School has determined that this thesis may be released to the public, its distribution is unlimited effective August 25, 2011. / One result of the break-up of the Soviet Union is that the DOD has been forced to reevaluate the roles of each of the Armed Services based on the declining resource pool. From the Marine Corps' evaluation of itself came the Combined Arms Regiment (CAR) concept. The objective of this study was to develop an estimate of the Life Cycle Cost (LCC) of the two possible vehicles used with the CAR and the CAR's components. Standard cost factors are used to cost out the various organizations involved. Two supporting analyses done in this study are: an evaluation of the Marine Corps' role in national security and how the CAR could be used to support that security role, and a comparison of the vehicle option operating characteristics which was done to enrich the dimensions under which the CAR could be evaluated. The results of the study are a tool which can help Marine Corps planners make more informed decisions in regards to the CAR concept. The final conclusion, based on the assumption that any CAR would act as a follow-on element of the MAGTF, was that although the CAR(LAV) was a workable option, the CAR using upgraded AAVs was the better, more cost effective option.

Veteran trees such as large Quercus robur L. function as biodiversity hotspots and provide a number of valuable ecological functions. This study aimed to increase knowledge about the mechanisms that influence the longevity of Q. robur by: (i) describing the status of veteran Q. robur in Linköping municipality, (ii) describing findings of valuable lichens among these trees, (iii) examine whether land use, nature type, crown layer closure, land management, or overgrowth of brushwood or forest in 2018 or an earlier year could explain girdle growth or crown vitality in Q. robur, and (iv) predict the future population of veteran Q. robur. Data was collected from 51 Q. robur with a circumference larger than 450 cm in April 2018 in Linköping municipality, Sweden. Out of these, 28 individuals could be compared to data from a previous inventory. These were the basis for statistical analyses of correlations between environmental factors, growth and crown vitality. Generally, most Q. robur individuals were standing in pastures, had high crown vitality, had a low amount of overgrowth of brushwood or forest around them, and many of them hosted indicator lichens. The main correlation found was between crown vitality and overgrowth of brushwood. The girdle growth was 1.81 cm year-1 and the mortality was 0.18 % year-1 on average. Based on these growth and mortality numbers, and data from other studies, the future population of veteran Q. robur was predicted to increase from 471 to 2996 individuals in the area in the next 100 years (1615-3433 pcs). / Grova, gamla träd som Quercus robur L. (skogsek) kan fungera som s.k. hotspots för biologisk mångfald och tillhandahåller en mängd värdefulla ekologiska funktioner. Denna studie syftade till att öka förståelsen kring de mekanismer som påverkar livslängden för Q. robur genom fyra syften: (i) att beskriva status för grova Q. robur i området, (ii) att beskriva förekomster av värdefulla lavar hos dessa träd, (iii) att undersöka om någon av omgivningsfaktorerna markanvändning, naturtyp, slutenhet i kronskikt, markskötsel, eller igenväxning av sly eller skog vid 2018 års inventering eller tidigare inventering kan förklara tillväxt eller kronvitalitet hos Q. robur, och (iv) förutsäga framtidens tillgång av grova Q. robur. Data samlades in genom fältinventering av 51 Q. robur större än 450 cm i omkrets i april 2018 i Linköpings kommun. Av dessa kunde 28 jämföras med data från en tidigare inventering. Dessa 28 individer låg till grund för statistiska analyser av samband mellan omgivningsfaktorer och tillväxt och kronvitalitet. De flesta individer av Q. robur stod i betesmark, hade hög kronvitalitet, hade låg grad av igenväxning av sly eller skog runt sig, och på många av individerna förekom signalartslavar. Det huvudsakliga sambandet som konstaterades var att igenväxning av sly var negativt för kronvitalitet. Hos grova ekar var omkretstillväxten 1,81 cm år-1 och mortaliteten 0,18 % år-1. Baserat på dessa tillväxt- och mortalitetsdata samt data från andra studier beräknades populationen av grova Q. robur öka från 471 till 2996 (1615-3433 st) individer de kommande 100 åren.

The boreal forest in Fennoscandia has been subjected to major loss and fragmentation of natural forests due to intensive forestry. This has resulted in that forest edges are now abundant and important landscape features. Edges have documented effects on the structure, function and biodiversity in forests. Edge influence on biodiversity is complex and depends on interactions between many local and regional factors. This thesis focuses on sharp forest edges and their potential to influence biodiversity at the landscape-level. I have developed a method for quantification and characterization of sharp forest edges by interpretation of colour infrared (CIR) aerial photographs in combination with line intersect sampling (LIS) and sample plots. The method was used to estimate density of forest edge in 28 landscapes (each 1600 ha) in northern Sweden, differing in management intensity, landscape composition and geographical location. Forest edges were described in detail using edge, canopy and neighbourhood attributes. By combining these attributes it was possible to classify edges with respect to levels of exposure. A field experiment was conducted to examine the effect of edge contrast on growth of the old forest lichen Usnea longissima. The edge quantification method is accurate and efficient for estimating the length of sharp forest edges on an area basis (edge density, m ha-1) and for collecting detailed attributes of edges and their surroundings. In northern Sweden, the forest edge density is high (54 m ha-1) but varies extensively (12-102 m ha-1) between landscapes. Edge density is strongly correlated with the level of human disturbance and increases towards the southern part of the study area, at lower altitudes were management intensity is highest. Edge orientation, contrast and neighbourhood size shows an immense variation between edges and also varies between edge types. Regenerating edges are generally of higher contrast and face larger neighbourhoods than natural edges. Maintained edges had high contrast but small neighbourhoods. A larger proportion of edges in mature forests are highly exposed to microclimatic edge influence than edges in general. The field experiment revealed that growth of U. longissima was highest near edges where the vegetation on the adjacent area was sheltering, but not shading, the lichen. In the present thesis, I have provided a valuable tool for estimating density of forest edges with potential to yield information on important factors determining edge influence at landscape-level. The large variability in edge density, edge and neighbourhood attributes imply large differences in microclimate anf thus in the potential for ede influence. Management and conservation strategies must incorporate these factors to realistically address edge influence on biota at the landscape-level.

Power system state estimation (PSSE) is an energy management system function responsible for the computation of the most likely values of state variables viz., bus voltage magnitudes and angles. The state estimation is obtained within a network at a given instant by solving a system of mostly non-linear equations whose parameters are the redundant measurements, both static such as transformer/line parameters and dynamic such as, status of circuit breakers/isolators, transformer tap positions, active/reactive power flows, generator active/reactive power outputs etc. PSSE involves solving an over determined set of nonlinear equations by minimizing a weighted norm of the measurement residuals. Typically, the L1 and L2 norms are employed. The use of L2 norm leads to state estimation based on the weighted least squares (WLS) criterion. This method is known to exhibit efficient filtering capability when the errors are Gaussian but fails in the case of presence of bad data. The method of hypothesis testing identification can be incorporated into the WLS estimator to detect and identify bad data. Nevertheless, it is prone to failure when the measurement is a leverage point. On the other hand state estimation based on the weighted least absolute value (WLAV) criterion using L1 norm, has superior bad data suppression capability. But it also fails in rejecting bad data measurements associated with leverage points. Leverage points are highly influential measurements that attract the state estimator solution towards them. Consequently, much research effort has focused recently, on producing a LAV estimator that remains robust in the presence of bad leverage measurements. This problem has been addressed in the thesis work. Two methods, which aims development of robust estimator that are insensitive to bad leverage points, have been proposed viz., (i) The objective function used here is obtained by linearizing L2 norm of the error function. In addition to the constraints corresponding to measurement set, constraints corresponding to bounds of state variables are also involved. Linear programming (LP) optimization is carried out using upper bound optimization technique. (ii) A hybrid optimization algorithm which is combination of”upper bound optimization technique” and ”an improved algorithm for discrete l1 linear approximation”, to restrict the state variables not to leave the basis during optimization process. Linear programming optimization, with bounds of state variables as additional constraints is carried out using the proposed hybrid optimization algorithm. The proposed state estimator algorithms are tested on 24-bus EHV equivalent of southern power network, 36-bus EHV equivalent of western grid, 205-bus interconnected grid system of southern region and IEEE-39 bus New England system. Performances of the proposed two methods are compared with the WLAV estimator in the presence of bad data associated with leverage points. Also, the effect of bad leverage measurements on the interacting bad data, which are non-leverage, has been compared. Results show that proposed state estimator algorithms rejects bad data associated with leverage points efficiently.

The exploitation of land in Northern Sweden has caused a significant depletion of grazing grounds for semi-domesticated reindeer. This is a threat to the indigenous Sami reindeer herders of Sweden, who rely on the grazing ground in order to sustainably feed their herds. In the last decade, a significant amount of grazing land has been lost due to the construction of wind power parks (WPP) in important grazing regions. This thesis examines the discourse surrounding a WPP built in Härjedalen for IKEA. The WPP was built on Glötesvålen, a unique highland used for grazing by Mittådalen, a local herding community. Through a dissection of electronic sources and semi-structured interviews, the author conducts a discourse analysis to identify the most prevalent narratives surrounding the construction of IKEA’s WPP on Glötesvålen. An inductive approach is used to identify underlying ideologies present in the discourse through a relevant theoretical framework. The results show a pervasive enthusiasm for the WPP as a pivot towards renewable energy which mirrors the ideology of ecological modernization. The results also find a critical narrative which lifts the uneven power dynamic experienced by reindeer herders. This narrative is understood through the lens of Spivak’s (2010) “Can the Subaltern Speak?”. An additional discourse found is the symbolic issue between industrial ecological transitioning and the right to reindeer husbandry as a cultural heritage. / Exploateringen av mark i norra Sverige har orsakat en betydande förlust av betesmarker för renskötare. Detta hotar den svensk-samiska rennäringen, som förlitar sig på betesmarken för att hållbart mata sina hjordar. Under det senaste decenniet har en betydande mängd betesmark gått förlorad på grund av den ökande mängden vindkraftsparker (WPP) på, eller intillrenbetesmarker. Denna avhandling undersöker diskursen kring en WPP byggd i Härjedalen för IKEA. WPP byggdes på Glötesvålen, ett låg-fjäll som tidigare haft strategiskt viktiga betesmarker för samebyn Mittådalen. Genom en dissektion av elektroniska källor och halvstrukturerade intervjuer genomför författaren en diskursanalys för att identifiera de vanligaste narrativen om IKEAs vindkraftpark på Glötesvålen. En induktiv metod används för att identifiera underliggande ideologier som finns i diskursen genom ett relevant teoretisk ramverk. Resultaten visar en genomgripande entusiasm för vindkraft som ett steg mot förnybar energi. Detta narrativ speglar ideologin för ekologisk modernisering. Resultaten hittar också ett kritisk narrativ som lyfter den ojämna maktdynamiken som renskötarna upplever. Detta förstås genom Spivaks (2010) "Kan den underordnade tala?". Ytterligare en diskurs som upptäcks är symbolfrågan mellan industriell ekologisk omställning och bevarandet av renskötseln som kulturarv.