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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.
101

Extracting Topography from Historic Topographic Maps Using GIS-Based Deep Learning

Pierce, Briar Z, Ernenwein, Eileen G 25 April 2023 (has links)
Historical topographic maps are valuable resources for studying past landscapes, but two-dimensional cartographic features are unsuitable for geospatial analysis. They must be extracted and converted into digital formats. This has been accomplished by researchers using sophisticated image processing and pattern recognition techniques, and more recently, artificial intelligence. While these methods are sometimes successful, they require a high level of technical expertise, limiting their accessibility. This research presents a straightforward method practitioners can use to create digital representations of historical topographic data within commercially available Geographic Information Systems (GIS) software. This study uses convolutional neural networks to extract elevation contour lines from a 1940 United States Geological Survey (USGS) topographic map in Sevier County, TN, ultimately producing a Digital Elevation Model (DEM). The topographically derived DEM (TOPO-DEM) is compared to a modern LiDAR-derived DEM to analyze its quality and utility. GIS-capable historians, archaeologists, geographers, and others can use this method in their research and land management practices.
102

Gestaltning av Afrika i läroböcker för grundskolans senare år

Blessenius, Stefan, Larsson, Staffan January 2008 (has links)
Syftet med denna uppsats är att belysa hur Afrika gestaltas genom bilder i läroböcker i samhällskunskap för grundskolans senare år. För att kunna urskilja den övergripande framställningen av Afrika har en kvantitativ bildanalys använts. Dessutom har en kvali-tativ bildanalys enligt semiotisk modell gett oss redskap för ett förtydligande av våra iakttagelser.Som stöd för vår analys och slutsats av de framkomna resultaten har vi hämtat stöd från tidigare forskning och teorier inom den postkoloniala diskursen. Vår undersökning har resulterat i olika slutsatser. Vi kan konstatera att det finns fördomar och rester från den koloniala tiden som skildras i ett skapande av vi och dem. Vi ser också en framställ-ning av afrikaner och Afrika där anonymitet och generaliseringar förekommer men alla bilder förmedlar inte alltid negativt budskap utan tvärtom oftast positivt. Framför allt när det handlar om bilder som skildrar vardagshändelser. Läromedelsförlagen har i de flesta fall lyckats att förmedla samma budskap i bild och kontext vilket är viktigt för en god inlärningsprocess. Vi har i vår semiotiska bildanalys gett exempel på både när läro-medelsförlagen har lyckats och misslyckats med att förmedla samma budskap i både bild och kontext.
103

Dry Deshaling of Thermal Coals in India

Gupta, Nikhil 14 November 2011 (has links)
Beneficiation of thermal coal in India is a relatively new development. For the year 2006, India produced 380 million metric tons of thermal coal, of which only 17 million metric tons were beneficiated coals. One potentially attractive method for upgrading India's coal feed stocks is the air table dry deshaling technology. Dry deshaling offers significant advantages over wet cleaning operations, including reduced surface moisture, enhanced heating value, elimination of processing water and waste slurries, and reduced transportation of large amounts of ash-forming minerals. To evaluate this potential, a pilot-scale air table deshaling unit was tested at three locations in India for the specific purpose of upgrading thermal coals. The field testing confirmed that the separation performance for Indian coals is similar to that which has been achieved at sites in the United States for material in the 50 x 6 mm size range. The data indicate that material with 80% ash and higher can be rejected by the dry deshaler unit with a combustible recovery of more than 90%. Furthermore, a discreet elemental model was developed using PFC3D to understand the process of segregation on a dry density based vibratory table. Analysis was done to show the effect of different forces on the process efficiency. Also, operating parameters and particle properties such as frequency of vibrations, amplitude of velocity, bed depth, particle size and specific gravity were analyzed in the model. The model results were compared with field testing results of dry deshaling air table and All-Air Jig separator. / Master of Science
104

Effects of Stream Order and Data Resolution on Sinuosity Using GIS

Lohani, Meena 03 July 2008 (has links)
This research focuses on estimation and analysis of stream sinuosity using GIS. Fifty-five streams including 13 streams of order 0, 17 streams of order 1, 15 streams of order 2 and 10 streams of order 3 in Virginia were considered. Several GIS datasets from various sources, including the Virginia Base Mapping Program (VBMP) and United States Geological Survey (USGS), were used to generate stream networks using GIS. Sinuosity was computed using GIS based on a technique comparable to the approach used in an Environmental Monitoring and Assessment Program's (EMAP's) field survey report. Field sinuosity data from EMAP report were used as reference data for analyzing the accuracy of sinuosity values from different GIS data sources and resolutions. The GIS technique was implemented for computing sinuosity for 55 streams in Virginia using vector data including the VBMP Hydro44 and National Hydrography Data (NHD). Insufficient statistical evidence was found to support the hypothesis that the computed sinuosity values using Hydro44 and NHD data are different from EMAP field data for all 55 streams. Sinuosity values computed using Hydro44 and NHD were found to increase with the increase in EMAP sinuosity (positive correlation) for all 55 streams. EMAP data on sinuosity, however, did not predict sinuosity values computed using Hydro44 (R² = 27%) and NHD (R² = 10%) sources well. It was found that the GIS technique of computing sinuosity using digital data such as Hydro44 (VBMP source) and NHD (USGS source 1:24,000) is better suited for stream orders 2 and 3. Insufficient statistical evidence was found that computed sinuosity values for streams derived using various resolutions (i.e., DTM 3m, DTM 10m, DTM 30m, DEM 10m and DEM 30m) are different from EMAP field data. Positive correlation was observed between sinuosity values for streams derived in all resolutions with EMAP field data. DTM 10m resolution data yielded best correlation value (75%) with EMAP field data. / Master of Science
105

Distinktion utan skillnad : En kvalitativ studie om hur socialarbetare upplever mångfald inom en arbetsgrupp / Distinction without difference : An empirical study of how social workers experience diversity within a working group

Huaiquimil, Paulina January 2022 (has links)
This study aims to increase the understanding of how social workers experience “Diversity”- within their working group. The study focuses on the significance of ethnic origin and gender when differences meet, taking into consideration the interaction between categories of ethnicity and gender. Considering the imbalances of power and cultural differences when social workers stereotype “the other/ the others”.This study is based on a qualitative hermeneutic scientific tradition. The research method used consisted of semi-structured interviews with six social workers’. The respondents of this study were between 35 and 65 years old, two men and four women, some born in Sweden and some abroad. There was a wide variety of professional backgrounds within the study group. The empirical material was analysed by using two interrelated theoretical approaches: diversity in relation to intersectionality analysis and gender theory. And even including the “insiders” and “outsider” - theory, as previous research often connects the “insiders” and “outsiders”- theory to diversity and the beforementioned theories this study is based on. This study describes distinctions with different intersections between a number of factors regarding the individual’s cultural background; national, racial, ethnic, age, gender, and educational background. It aims to reflect how individual ideas about cultural differences are related to prejudicial values and judgmental norms. These values then give rise to conflicting thinking patterns between the “insider and outsiders”. In particular there was a significant divide between the respondents with Swedish background and with a foreignbackground; and division based on gender. Both cultural background and gender turned out to be the most challenging for this study.This study shows how the respondents identified the importance of the workplace reflecting a diverse cross-section of the community. They argued, among other things, that if there were greater tolerance for and experiences of different views and values, it would encourage cooperation in the workplace as well as a healthier “working climate”. Conclusively, this study shows that a heterogeneous group can increase the idea of “insiders and outsiders”, resulting in obstacles and barriers within the working group, which could cause complications and impacts on the construction and maintenance of positive working relationships. / Syftet med denna studie är att öka förståelsen för hur socialarbetare upplever mångfaldi arbetsgruppen d.v.s. olikheterna inom arbetsgruppen som finns socialarbetarna emellan, med fokus på betydelsen av etnicitet och könstillhörighet, som utgörande grund för maktrelationer - och med hänsyn till kulturella skillnader och social arbetarnas föreställning om ”den andre”/ ”de andraDenna undersökning utgår ifrån en kvalitativ hermeneutisk vetenskaplig tradition. Den kvalitativa forskningsmetoden består av semistrukturerade intervjuer som omfattar sex socialarbetare. Respondenterna är mellan 35 och 65 år gamla. Socialarbetarna har olika yrkesbakgrunder och inkluderar både inrikes- och utrikesfödda; med och utan utländskbakgrund. De intervjuade är två män och fyra kvinnor. Analysen av det empiriska materialet utgår från begreppet mångfald i anslutning till intersektionellanalys och genusteori.Mångfaldsbegreppet skildrades som distinktioner mellan människor, där det uppstodintersektioner mellan skillnader. Olikheterna ansågs framför allt vara kulturella med hänsyn till etnicitet och könstillhörighet, och därmed kollektivt förankrade. Med kulturavsåg informanterna essentiella skillnader som ofta var nationella och etniskt kulturella men även ålders- och utbildningsmässiga.Det uppmärksammades även hur individuella föreställningar om kulturella skillnader varkopplade till fördomsfullhet, värderingar och normer, som kunde ge upphov till ett vi-och detänk mellan respondenterna med svensk - och utländsk bakgrund - och mellan och kvinnor och män. Detta ansågs vara den största utmaningen med mångfald med hänsyn till etnicitets och könstillhörighet. Social arbetarna ansåg att det fanns ett behov att arbeta för en ökad mångfald på arbetsplatsen. De menade att om det rådde större tolerans och acceptans för olika synsätt och värderingar, så skulle det främja samarbetet och arbetsklimatet.
106

Near Real-Time Flood Forecasts from Global Hydrologic Forecasting Models

Krewson, Corey Nicholas 01 April 2019 (has links)
This research assesses possible methods for extending the Streamflow Prediction Tool from a streamflow forecasting model to a flood extent forecasting model. This new flood extent forecasting model would allow valuable and easy to understand information be disseminated in a timely manner for flood preparation and flood response. The Height Above Nearest Drainage (HAND) method and AutoRoute method were considered for flood extent models but the HAND was the better option for its simple and quick computation as well as its viability on a global scale. Due to the importance of Digital Elevation Models (DEMs) in these flood extent models, an analysis was performed on the sensitivity and response of different DEMs with the HAND method. The HAND method with the differing DEMs was also analyzed using the Streamflow Prediction Tool for model boundary conditions against Sentinel-1 SAR generated flood extent images from August 24, 2017. The MERIT DEM performed the best in this analysis and is recommended for future research in creating a global forecasting flood extent model. The HAND method covered about 25% of the generated flood extent images and more complex flood extent models may need to be considered in areas where HAND underperforms. Finally, a proof of concept flood extent model was created and deployed as a web application for easy accessibility and distribution of flood information. Additional research to consider is flood impact based on affected population or an economic analysis, as well as optimizing model parameters for increased accuracy and performance. Additional research is also needed for HAND DEM analysis in other parts of the world.
107

Vem definerar feminism? : En kritisk diskursanalys om den politiska diskursen kring feminism

Eriksson, Tuva January 2023 (has links)
Denna studie har haft till syfte att undersöka den politiska diskursen om feminism i artiklar från fyra olika tidskrifter med sympatiserande åsikter i linje med vänstersidan och högersidan i politiken. Samt att se hur dessa diskurser om feminism kan synliggöra sociala grupper och deras relationer till varandra. Metoden som har använts är Faircloughs kritiska diskursanalys. Den kritiska diskursanalysen hjälper oss att undersöka hur saker sägs, vilka underliggande åsikter och idéer som kan finnas. Materialet för studien består av sex politiska artiklar från vänstersidan i politiken och sex från högersidan. Den främsta teorin som har använts som verktyg är Henri Tajfel och John C. Turners ”sociala identitetsteori”. Teorin fokuserar på sociala grupper och dess relationer till andra grupper. Individer identifierar sig med sin grupptillhörighet och känner en inkludering med sin grupp, in-gruppen och därmed också en exkludering från en annan grupp, ut-gruppen. Det bildas ett tydligt ”vi och dem” tänk där ”vi” är den bättre gruppen och ”de”, ”de andra” är den sämre gruppen. Den kritiska diskursanalysen användes även som teoretiskt ramverk och kompletterade den sociala identitetsteorin. De båda användes som hjälpmedel för att få fram och tolka innehållet i denna studie, något som resulterade i fyra olika teman; Tema 1: Generella diskurser kring feminism, Tema 2: Attityder mot ”andra sidans” feminism, Tema 3: Grammatiska maktutövningar och Tema 4: Grupperingar (vi och dem). En kortfattad beskrivning av resultatet är att vänstersidan har en mer positiv diskurs om feminism medan högern har en negativ diskurs. Däremot verkar det vara tydligt att det framförallt handlar om en begreppslig nivå av feminism där det finns olika varianter, då många av artiklarna är negativa mot andra sidans feminism. Det allra främsta resultatet grundar sig i gruppindelningar där ett tydligt ”vi och dem” kan utläsas. Detta är något som både vänstersidan och högersidan använder sig av i stor utsträckning.
108

Towards Discrete Element Modelling of Rock Drilling

Wessling, Albin January 2021 (has links)
The method of percussive rotary drilling is recognized as the most efficient method for hard rock drilling. Despite the clear advantages over conventional rotary meth-ods, there are still uncertainties associated with percussive rotary drilling. For geothermal applications, it is estimated that 50 % of the total cost per installed megawatt of energy is associated with drilling and well construction, with drill bit wear being a predominant cost factor. Numerical modelling and simulation of rock drilling, calibrated and validated towards rigorous experiments, can give insight into the rock drilling process. This thesis is focused on the prerequisites of numer-ical simulations of rock drilling, i.e. the development of a numerical model and experimental characterization of rock materials. A new approach for modelling brittle heterogeneous materials was developed in this work. The model is based on the Bonded Particle Method (BPM) for the Discrete Element Method (DEM), where heterogeneity is introduced in two ways. Firstly, the material grains are rep-resented by random, irregular ellipsoids that are distributed throughout the body. Secondly, these grains are constructed using the BPM-DEM approach with mi-cromechanical parameters governed by the Weibull distribution. The model was applied to the Brazilian Disc Test (BDT), where crack initiation, propagation, coalescence and branching could be investigated for different levels of heterogene-ity and intergranular cement strengths. The initiation and propagation of the cracks were found to be highly dependent on the level of heterogeneity and cement strengths. In the experimental study, the static and dynamic properties of two rock materials - Kuru grey granite and Kuru black diorite - were obtained from uniaxial compression and indirect tension tests. A Split-Hopkinson Pressure Bar was used to obtain the dynamic properties. Using high-speed photography with frame rate 663,000 fps, the crack initiation and propagation could be studied in de-tail, and the full-field exterior deformation fields of the samples were evaluated by using digital image correlation. From the high-speed images, the onset of unstable crack growth was detected. The crack-damage stresses, associated with unstable crack growth, was approx. 90 % of the peak strength in the dynamic compression tests, whereas the tensile crack-damage stress was approx 70 % of the tensile peak strength.
109

Discrete Representation of Urban Areas through Simplification of Digital Elevation Data

Chittineni, Ruparani 10 May 2003 (has links)
In recent years there has been large increase in the amount of digital mapping data of landscapes and urban environments available through satellite imaging. This digital information can be used to develop wind flow simulators over large cities or regions for various purposes such as pollutant transport control, weather forecasts, cartography and other topographical analysis. It can also be used by architects for city planning or by game programmers for virtual reality and similar applications. But this data is massive and contains a lot of redundant information such as trees, cars, bushes, etc. For many applications, it is beneficial to reduce these huge amounts of data through elimination of unwanted information and provide a good approximate model of the original dataset. The resultant dataset can then be utilized to generate surface grids suitable for CFD purposes or can be used directly for real-time rendering or other graphics applications. Digital Elevation Model, DEM, is the most basic data type in which this digital data is available. It consists of a sampled array of elevations for ground positions that are regularly spaced in a Cartesian coordinate system. The purpose of this research is to construct and test a simple and economical prototype which caters to image procesing and data reduction of DEM images through noise elimination and compact representations of complex objects in the dataset. The model is aimed at providing a synergy between resultant image quality and its size through the generation of various levels of detail. An alternate approach using the concepts of standard deviation helps in achieving the desired goal and the results obtained by testing the model on Salt Lake City dataset verify the claims. Thus, this thesis is aimed at DEM image processing to provide a simple and compact representation of complex objects encountered in large scale urban environment datasets and reduce the size of the dataset to accommodate efficient storage, computation, fast transmission across networks and interactive visualization.
110

UNDERSTANDING AGGLOMERATE DISPERSION: EXPERIMENTS AND SIMULATIONS

Fanelli, Maddalena 27 June 2005 (has links)
No description available.

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