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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Topics in Localization and Mapping

Callmer, Jonas January 2011 (has links)
The need to determine ones position is common and emerges in many different situations. Tracking soldiers or a robot moving in a building or aiding a tourist exploring a new city, all share the questions ”where is the unit?“ and ”where is the unit going?“. This is known as the localization problem.Particularly, the problem of determining ones position in a map while building the map at the same time, commonly known as the simultaneous localization and mapping problem (slam), has been widely studied. It has been performed in cities using different land bound vehicles, in rural environments using au- tonomous aerial vehicles and underwater for coral reef exploration. In this thesis it is studied how radar signals can be used to both position a naval surface ves- sel but also to simultaneously construct a map of the surrounding archipelago. The experimental data used was collected using a high speed naval patrol boat and covers roughly 32 km. A very accurate map was created using nothing but consecutive radar images.A second contribution covers an entirely different problem but it has a solution that is very similar to the first one. Underwater sensors sensitive to magnetic field disturbances can be used to track ships. In this thesis, the sensor positions them- selves are considered unknown and are estimated by tracking a friendly surface vessel with a known magnetic signature. Since each sensor can track the vessel, the sensor positions can be determined by relating them to the vessel trajectory. Simulations show that if the vessel is equipped with a global navigation satellite system, the sensor positions can be determined accurately.There is a desire to localize firefighters while they are searching through a burn- ing building. Knowing where they are would make their work more efficient and significantly safer. In this thesis a positioning system based on foot mounted in- ertial measurement units has been studied. When such a sensor is foot mounted, the available information increases dramatically since the foot stances can be de- tected and incorporated in the position estimate. The focus in this work has therefore been on the problem of stand still detection and a probabilistic frame- work for this has been developed. This system has been extensively investigated to determine its applicability during different movements and boot types. All in all, the stand still detection system works well but problems emerge when a very rigid boot is used or when the subject is crawling. The stand still detection frame- work was then included in a positioning framework that uses the detected stand stills to introduce zero velocity updates. The system was evaluated using local- ization experiments for which there was very accurate ground truth. It showed that the system provides good position estimates but that the estimated heading can be wrong, especially after quick sharp turns.
32

Improved Material Models for High Strength Steel

Larsson, Rikard January 2011 (has links)
The mechanical behaviour of the three advanced high strength steel grades, Docol 600DP, Docol 1200M and HyTens 1000, has been experimentally investigated under various types of deformation, and material models have been developed, which account for the experimentally observed behaviour. Two extensive experimental programmes have been conducted in this work. In the first, the dual phase Docol 600DP steel and martensitic Docol 1200M steel were subjected to deformations both under linear and non-linear strain paths. Regular test specimens were made both from virgin materials, i.e. as received, and from materials pre-strained in various directions. The plastic strain hardening, as well as plastic anisotropy and its evolution during deformation of the two materials, were evaluated and modelled with a phenomenological model. In the second experimental program, the austenitic stainless HyTens 1000 steel was subjected to deformations under various proportional strain paths and strain rates. It was shown experimentally that the material is sensitive both to dynamic and static strain ageing. A phenomenological model accounting for these effects was developed, calibrated, implemented in a Finite Element software and, finally,validated. Both direct methods and inverse analyses were used in order to calibrate the parameters in the material models. The agreement between the  numerical and experimental results are in general very good. This thesis is divided into two main parts. The background, theoretical framework and mechanical experiments are presented in the rst part. In the second part, two papers are appended.
33

A Mobile-based Navigation Web Application: Finding the Shortest-time Path based on Factor Analysis

Peng, Tao, Wang, Xiaowen January 2012 (has links)
With the economic growth, the number of motor vehicles has increased rapidly for the last decades, especially in developing countries like China and India. Availability of more vehicles makes it more convenient for people to travel and merchandise transport. The increase of the number of vehicles also brings stresses to public traffic and pollution to the environment. When the number of vehicles on the road is over the available space, it results in traffic congestion. The problem is being studied and there are several solutions to it, like building more roads, rebuilding the existing streets and enlarging the cities. Based on the traffic reason and the environment reason, the government and the institute of environmental protection appeal to the public to take public transport means instead of private cars. But the measure affects the utilization ofmotor vehicles. Global Positioning System (GPS) provides autonomous geo-spatial positioningand navigation service. Once the user enters the destination, the navigation service will show the shortest path from the location of the user to the destination. Following the guide makes the vehicles running purposively, and it is also favorable for traffic control and management. Theoretically, if the diver keeps the same driving mode, the shortest path will cost the shortest time, but in reality, the traffic environment is complex and the driving speed is variable thus the shortest path is probably not the fastest path. In this study, the hinder factors of the speed and traffic are fixed constructions on the road, like: turnings, hospitals, schools, residential areas, traffic lights and the user-controlled factor (sites of traffic jams, accidents, and temporary construction on the road). We take the hinderfactors of traffic and driving speed into consideration while providing the route plan, finding the shortest-time path, and showing the result as an online map via the web Geographic Information System (GIS) application. We show that reducing the travelling time of motor vehicles, makes the traffic flow more rapid and efficient. Alsoreducing the emission time of motor vehicles, diminishes the greenhouse effect. Beside these, the achievement of our study also shows that the public can take advantage of open source tools and data to build their GIS application to do spatial and data analysis.
34

Den orena revisionsberättelsen / The qualified opinion

Kesen, Ulas, Koc, Serdar January 2011 (has links)
Bakgrund: Revisionsberättelsen är den rapport som intressenter kan ta del av. Det är revisorns uttalande som har högt värde då det är revisorn som är informationsmedlare mellan parterna. Tolkningar som revisorn gör, är grund för andras beslut. Tidigare forskning visar att en revisionsberättelse inte signalerar tillräckligt om företagets fortsatta drift, samt att det var endast 20-27% som erhållit orena revisionsberättelser innan företagen inlett konkurs. De olika anmärkningarna i orena revisionsberättelsen har olika allvarlighetsgrader enligt andra studier. Syfte: Vi vill med denna studie undersöka om aktiebolagens sist erhållna orena revisionsberättelser, har ett statistiskt signifikant samband med aktiebolagens inledda konkurs under året 2010. Teori: De teorier som har använts i denna studie är agentteorin och intressentmodellen. I kapitlet definieras även begrepp som används inom revision. Metod: En kvantitativ metod med en deduktiv ansats har gjorts i form av dokumentstudie. Urvalet har utgått från svenska aktiebolag som inlett konkurs under 2010. Kontrollgruppen bestod av svenska aktiebolag som inte hade inlett konkurs under samma år. Resultat och slutsats: De mest uppkomna anmärkningarna är förbrukat mer än det registrerade egna aktiekapitalet samt skatte- och avgiftsanmärkning. Anmärkningar som är av den allvarligaste graden förekommer inte ofta. Däremot vid de uppkomna tillfällena med dessa anmärkningar har företagen i de flesta fallen gått i konkurs. Vidare visar resultatet att det finns ett samband mellan företagens orena revisionsberättelse och konkurs.
35

En studie om demokratiförutsättningarna i Bosnien-Hercegovina, Makedonien och Serbien/Montenegro

Hajo, Medya, Bunjaku, Besnik January 2005 (has links)
Demokrati ses som den idealiska styrelseformen. Många länder i världen har börjat etablera demokrati eller i varje fall håller på att demokratiseras. Bosnien-Hercegovina, Serbien/Montenegro och Makedonien är några av dem. Men för att demokratin ska kunna etableras i dessa länder är bestående demokrati och långvarig fred och stabilitet grundläggande förutsättningar. Syftet med denna uppsats är att undersöka demokratiförutsättningar i dessa tre länder. Följande frågeställning ska besvaras: Vilka förutsättningar har Bosnien-Hercegovina, Makedonien och Serbien/Montenegro för demokrati? Vi har använt oss av Axel Hadenius teori om förutsättningar för demokrati som vi sedan har operationaliserat för att kunna besvara frågeställningen. Vi har undersökt den socioekonomiska utvecklingen, det civila samhället, etniska klyftor i befolkningen och institutionella förutsättningar. Vår studie uppvisade liknande resultat i alla tre länderna med vissa variationer. Vi kom fram till att alla tre länderna har dåliga förutsättningar för demokrati. Den socioekonomiska utvecklingen var låg, det civila samhället var svagt och de etniska klyftorna i befolkningen varierade. I Makedonien var de allra störst, medan Serbien/Montenegro och Bosnien-Hercegovina hade märkbart mindre etniska konflikter. De institutionella faktorerna visade olika resultat men alla tre hade i överlag bra förutsättningar för demokrati.
36

NÄR FÖRÖVAREN ÄR EN KVINNA : Våld i nära relationer

Hellberg, Emma January 2012 (has links)
Denna uppsats är en litteraturstudie och diskursanalys kring våld i nära relationer där kvinnanär förövaren och mannen offret. Frågor som uppsatsen behandlar är huruvida kvinnor ochmän är lika benägna att begå partnerrelaterat våld eller inte, samt varför mäns våld motkvinnor är mer uppmärksammat än kvinnors våld mot män. Syftet med uppsatsen är att belysakvinnors våld mot män och inte att ta bort fokus från mäns våld mot kvinnor.Uppsatsen går igenom såväl litteratur och rapporter som hur olika organisationer ochmyndigheter ställer sig till våld i nära relationer. Resultatet analyseras och diskuteras ur ettsocialkonstruktivistiskt perspektiv, med teorier och begrepp som det ideala offret och denideala förövaren, genus och makt.Det jag har kunnat påvisa med studien är att våld i nära relationer är någonting både kvinnoroch män faller offer för i ett heterosexuellt förhållande. Män och kvinnor är således likabenägna att begå partnerrelaterat våld. Kvinnors våld mot män uppmärksammas dock inte allsi lika stor utsträckning som mäns våld mot kvinnor, vilket bland annat har att göra med attanmälningsbenägenheten bland utsatta män i princip är obefintlig. Män anmäler sällan pågrund av skamkänslor och rädslan över att förlora sin maskulinitet. Vidare förekommer enavsaknad av forskning, insatser och stöd för män som blivit utsatta för partnerrelaterat våld.
37

Germanic Women: Mundium and Property, 400-1000

Dunn, Kimberlee Harper 08 1900 (has links)
Abstract Many historians would like to discover a time of relative freedom, security and independence for women of the past. The Germanic era, from 400-1000 AD, was a time of stability, and security due to limitations the law placed upon the mundwald and the legal ability of women to possess property. The system of compensations that the Germans initiated in an effort to stop the blood feuds between Germanic families, served as a deterrent to men that might physically or sexually abuse women. The majority of the sources used in this work were the Germanic Codes generally dated from 498-1024 AD. Ancient Roman and Germanic sources provide background information about the individual tribes. Secondary sources provide a contrast to the ideas of this thesis, and information.
38

Charcoal Kiln Detection from LiDAR-derived Digital Elevation Models Combining Morphometric Classification and Image Processing Techniques

Zutautas, Vaidutis January 2017 (has links)
This paper describes a unique method for the semi-automatic detection of historic charcoal production sites in LiDAR-derived digital elevation models. Intensified iron production in the early 17th century has remarkably influenced ways of how the land in Sweden was managed. Today, the abundance of charcoal kilns embedded in the landscape survives as cultural heritage monuments that testify about the scale forest management for charcoal production has contributed to the uprising iron manufacturing industry. An arbitrary selected study area (54 km2) south west of Gävle city served as an ideal testing ground, which is known to consist of already registered as well as unsurveyed charcoal kiln sites. The proposed approach encompasses combined morphometric classification methods being subjected to analytical image processing, where an image that represents refined terrain morphology was segmented and further followed by Hough Circle transfer function applied in seeking to detect circular shapes that represent charcoal kilns. Sites that have been identified manually and using the proposed method were only verified within an additionally established smaller validation area (6 km2). The resulting outcome accuracy was measured by calculating harmonic mean of precision and recall (F1-Score). Along with indication of previously undiscovered site locations, the proposed method showed relatively high score in recognising already registered sites after post-processing filtering. In spite of required continual fine-tuning, the described method can considerably facilitate mapping and overall management of cultural resources.
39

Automatic information extraction and prediction of karst rocky desertification in Puding using remote sensing data

Wang, Guiwei January 2016 (has links)
Karst rocky desertification (KRD) is one kind of severe environmental problem existing in southwest of China. Reveal KRD condition is vital to solve the problem. A way to address the problem is by identifying KRD areas, so that policy-makers and researchers may get a better view of the issue and know where the areas affected by the problem are located. The study area is called Puding which is a county located in the central part of Guizhou province. Based on Landsat data, by using GIS and RS techniques, KRD information of Puding was extracted. Furthermore, the study monitored decades of change of the environmental problem in Puding and predicted possible condition in the future. Other researchers and decision makers may get a better view of the issue from the study results. In addition to Landsat data, other used data includes: ASTER Global digital elevation model data, Modis data, Google Earth data and other thematic maps. In the study, expert classification system and spectral features based model two methods were applied to extract KRD information and compare with each other. Their classified rules were taken from previous studies separately. Necessary preprocessing procedures such as atmospheric correction and geometrical correction were performed before extraction. After extraction relevant results were evaluated and analyzed. Predictions were made by cellular automata Markov module. Based on extracted KRD results, the distribution, percentage, change, and prediction of KRD conditions in Puding were presented. The results of the accuracy evaluation showed that the spectral features based model had acceptable performance. However, the KRD results extracted by expert classification system method were poor. The extracted KRD results, including KRD maps and the prediction map, both indicated that KRD areas in Puding were decreased from 1993 (spring) to 2016 (spring) and suggested to pay more attention to KRD areas changes with the seasons
40

Lokalisering av nya bostadsområden i översiktlig planering : En rumslig multikriterieanalys över Gävle

Andersson, Jacob, Norbäck, Markus January 2017 (has links)
Urbanisering i kombination med miljöfarliga utsläpp från fordonstrafiken ställer högre krav på bostadsplaneringen i städer. Studiens syfte är att öka förståelsen för hur multikriterieanalyser inom geografiska informationssystem kan tillämpas i den översiktliga planeringen för att bidra till ett hållbarare samhälle. En effektivare strategisk bostadsplanering med anslutning till befintliga samhällsfunktioner kan bidra till att miljövänligare transportalternativ prioriteras före bilen. Med hjälp av intervjuer från två tjänstemän inom offentlig och privat sektor har ett antal kriterier tagits fram till analysen. Utifrån befintliga samhällsfunktioner var målet med studien att lokalisera nya områden för bostadsutveckling med hjälp av en multikriterieanalys. Detta kan bidra till att miljövänligare transportmedel kan prioriteras före bilen eftersom avstånden till samhällsfunktionerna blir kortare. Utöver detta var även målet att undersöka hur politiska intressen skiljer sig åt med hjälp av en rangordning utifrån de framtagna kriterierna. Resultatet visar att representanterna från de två största politiska partierna i en svensk småstad rangordnar kriterierna olika gällande vilka samhällsfunktioner som bör finnas i närhet till nya bostadsområden. Däremot visar slutresultatet att de lokaliserade områdena för bostadsutveckling inte skiljer sig nämnvärt mycket ifrån varandra, trots politikernas varierande bostadspolitik. Studien kan bidra till en effektivare politisk hantering av ärenden eftersom politiska skiljaktigheter i slutändan inte alltid visar skillnader i vilka aktiviteter eller objekt som bör placeras var. / Urbanization combined with toxic emissions from motor traffic calls forhigher demands when house planning in cities. The purpose of this study is toincrease understanding about how to apply multi criteria analyses whenmaster planning to contribute to a more sustainable society. A more effectivehouse planning connected to existing societal functions might add to the usageof more sustainable transportation alternatives rather than that of cars. Using the input from interviews with representatives from both the privateand the public sector, a number of criterias have been developed for theanalysis. Considering existing societal functions, this study was intended toidentify new areas for housing development using a multi criterial analysis.This might contribute to more sustainable transportation because of thedistance to the societal functions. In addition to this, the intention extended tothe investigation of how political interests differs from one another, using aranking system based on the developed criterias. The results show that representatives from the two largest political parties in asmall town in Sweden rank the criterias different when it comes to whatsocietal functions a new housing area should have in close proximity. On theother hand, the end results show that the areas chosen for housingdevelopment have similar qualities, in spite of varying housing politics amongthe politicians. This study might contribute to a more effective politicalhandling of business, since political differences does not ultimately showdifferences in where activities or objects should be placed.

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