• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 205
  • 100
  • 35
  • 32
  • 31
  • 7
  • 6
  • 6
  • 5
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 524
  • 524
  • 84
  • 81
  • 66
  • 60
  • 46
  • 46
  • 39
  • 38
  • 37
  • 36
  • 35
  • 31
  • 31
  • 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.
171

Applications en bioinformatique avec des modèles de Markov / Applications in Bioinformatics with Markov Models

Robinson, Sean 01 June 2018 (has links)
Dans cette thèse nous présentons quatre applications en bioinformatique avec des modèles de Markov. Ces modèles sont particulièrement répandus car la structure Markov permet de modéliser des indépendances conditionnelles complexes tout en permettant une inférence efficace. Nous atteignons une variété d’objectifs tels que l'alignement, la classification, la segmentation et la quantification, par inférence dans différents types de modèles de Markov. De cette manière nous montrons que les modèles de Markov peuvent être utilisés pour générer de nouvelles connaissances dans diverses applications liées à une variété de champs de recherche en biologie. / In this thesis we present four applications in bioinformatics with Markov models. Such models are especially popular since the Markov structure allows for complex conditional independences to be modelled while still allowing for efficient inference. We achieve a variety of aims, ranging from alignment, classification, segmentation and quantification, through inference in different types of Markov models. In this way we show that Markov models can be used to generate new knowledge in diverse applications relating to multiple domains of biological research.
172

Investigation of wind potential variation at three measurement sites based on atmospheric stability and power production

Eppanapelli, Lavan Kumar January 2013 (has links)
As tapping energy from wind expands rapidly worldwide, it is a common procedure to locate a practicable site to extract energy from abundant wind flow by building wind farms. Comprehensive understanding of wind resource at a site   is important to perform the main activities say, wind flow modeling, wind   turbines micro siting, annual energy yield calculation and cost of energy   estimation. Wind measuring campaigns involve using of measuring instruments   such as meteorological tower instrumented with anemometers, wind vanes and   temperature sensors; remote sensing devices such as SoDAR, LiDAR. These   meteorological devices provide detailed information on wind behavior with   respect to the height, time and temperature. These systems were proven in   providing promising wind measurements even though they are susceptible to   certain weather conditions. The   study progressed by focusing on the wind behavior at three locations to   investigate the possible factors that varies the wind character. A location   with one met mast and two AQ500 SoDAR systems was considered for this project   where one AQ500 is 800m away and other AQ500 is 5515m away from the point of   Met mast. The location is contemplated as a decent approach to the spatial   analysis of the wind resource as there is a large scope to analyze the wind   character between two nearby sites and two faraway sites. Monostatic 3-beam   SoDAR systems from AQ System, Sweden and 100m meteorological tower with   instruments are used in this project work for collecting the wind data.   One-year worth of wind data at standard 10min intervals has been collected   from the three systems. This report outlines the theoretical description of project location, AQ500 SoDAR and Met mast. A detailed explanation of the data quality control and filtering methods are discussed along with respective reasons. The conclusion is drawn after performing the statistical analysis between wind speed and other parameters such as turbulent intensity, wind direction, thermal stability and temperature. Mat lab is used for computing and analyzing the wind data from three systems.
173

Statistical Analysis of Conductor-Musician Interaction : With a Focus on Musical Expression / Statistisk analys av interaktion mellan dirigent och musiker

Ahnlund, Josefin January 2016 (has links)
The kind of interaction occurring between a conductor and musicians while performing a musical piece together is an unique instance of human non-verbal communication. This Musical Production Process (MPP) thus provides an interesting area of research, both from a communication perspective and by its own right. The long term goal of this project is to model the MPP with machine learning methods, for which large amounts of data are required. Since the amount of data available to this master thesis stems from a single recording session (collected at KTH May 2014) a direct modeling of the MPP is unfeasible. As such the thesis can instead be considered as a pilot project which examines pre-requisites for modeling of the MPP. The main aim of the thesis is to investigate how musical expression can be captured in the modeling of the MPP. Two experiments, as well as a theoretical investigation of the MPP, are performed to this end. The first experiment consists of a HMM classification of sound represented by expressive tone parameters extracted by the CUEX algorithm, and labeled by four emotions. This experiment complements the previous classification of conducting gesture in GP-LVM representation performed by Kelly Karipidou on the same data set. The result of the classification implicitly proves that expression has been transferred from conductor to musicians. As the first experiment considers expression over the musical piece as a whole, the second experiment investigates the transfer of expression from conductor to musician on a local level. To this end local representations of the sound and conducting gesture are extracted, the separability of the four emotions are calculated for both representations by use of the Bhattacharyya distance and the results are compared in search for correlation. Some indications of correlation between the representations of sound and gesture are found. The conclusion is nevertheless that the utilized representations of conducting gesture do not capture musical expression to a sufficient extent. / Interaktionen mellan en dirigent och musiker under ett musikframförande är en unik instans av mänsklig icke-verbal kommunikation. Denna “musikproduktionsprocess” (MPP) utgör därför ett intressant forskningsområde, både ur ett kommunikationsperspektiv såväl som i sin egen rätt. Det långsiktiga målet med detta projekt är att modellera MPP:n med maskininlärningsmetoder, vilket skulle kräva stora mängder data. Då den tillgängliga datamängden härstammar från ett enstaka inspelningstillfälle (KTH, maj 2014) är en direkt modellering av MPP:n inom detta examensarbete ej möjlig. Arbetet bör istället betraktas som ett pilotprojekt som undersöker förutsättningar för att modellera MPP:n. Huvudfokuset för detta examensarbete är att undersöka hur musikaliskt uttryck kan fångas i modelleringen av MPP:n. Två experiment och en teoretisk utredning av MPP:n utförs i detta syfte. Det första experimentet utgörs av HMM-klassificering av ljud, representerat av expressiva tonparametrar framtagna genom CUEX-algoritmen och uppmärkt med fyra olika känslor. Detta experiment kompletterar den tidigare genomförda klassificeringen av dirigentrörelse i en GP-LVM representation av Kelly Karipidou på samma datamängd. Resultatet av klassificeringen bevisar implicit att musikaliskt uttryck överförts från dirigent till musiker. Då det första experimentet undersöker musikaliskt uttrycköver musikstycket i sin helhet är målet för det andra experimentet att undersöka överföringen av musikaliskt uttryck från dirigent till musiker på en lokal nivå. För detta syfte tas lokala representationer för ljud och dirigentrörelse fram, separabiliteten mellan de fyra känslorna kalkyleras via Bhattacharyya-avståndet och resultaten jämförs på jakt efter korrelation. Vissa indikationer på korrelation mellan representationerna för ljud och dirigentrörelse kan iakttas. Slutsatsen är dock att de tillämpade representationerna för dirigentrörelse inte fångar musikaliskt uttryck i tillräckligt hög grad.
174

Accurately measuring content consumption on a modern Play service : Noggrann mätning av konsumtion på en modern Play-tjänst

Cederman, Mårten January 2015 (has links)
This research represents an attempt to define and accurately measure user consumption of content on a modern, advertised VOD service (AVOD), more specifically known in Sweden as a Play service. With a foundation of previous research in the area of VOD and AVOD services, the characteristics and flaws of these types of platforms are discussed to shine light on factors that might concern Play services. Optimizing the vast content inventory offered on these services is crucial for long term profitability, and to achieve this, content providers need to understanding how to measure the consumption properly. A content­centric approach was used to focus on individual formats (e.g. TV shows) and the factors that can describe its consumption. A macro perspective was initially applied to investigate global factors that dictates consumption. Analysis on a micro level was carried out by analyzing tracking data collected for a full year from one of the biggest Play services in Sweden, TV3play.se. Ultimately, the development of a new method to measure consumption called Consumption Volume Score (CVS) is proposed. It is introduced as an alternative to the traditional unit which has been to measure the amount of video starts (VS). The validity was evaluated using comparison of rank difference for individual formats, using both methods and different criterias. The results shows that the method of using CVS to measure consumption yields little to no difference in ranking of highly popular formats, while less consumed formats had a more varied change in rank. Further analysis on some of these formats indicated that they might have a dedicated niche audience, where content editors might see potential gains from handpicking them to optimize the consumption further. The findings gives support to believe that CVS as a unit of measuring consumption can help to further understand how individual formats perform, especially less consumed and potentially niched ones. Future research on CVS is recommended to discern its feasibility in a live context. / Denna forskning ämnar att finna metoder för att definiera samt noggrant kunna mäta konsumtionen av streamad media på en modern, reklamfinansierad VOD­tjänst (AVOD), i Sverige är dessa mer kända som Play­tjänster. Med utgångspunkt från tidigare forskning inom på streaming­tjänster, belyses de egenskaper och brister dessa typer av plattformar kan påverkas av, i synnerhet de faktorer som kan vara relevanta för Play­tjänster. Att kunna organisera och underhålla de stora mängder media som erbjuds på dessa tjänster är avgörande för långsiktig lönsamhet, och för att uppnå detta måste redaktörerna förstå hur man mäter konsumtionen med hög tillförlitlighet i sin uppgift att ta väl grundade beslut. En innehållscentrerat (content­centric) tillvägagångssätt användes för att kunna fokusera på enskilda format (t.ex. TV­program) och de inbördes faktorer som kan beskriva dess konsumtion. Ett makroperspektiv applicerades initialt för att undersöka de globala faktorer som styr konsumtion. Vidare tillämpades en analys på mikronivå genom att undersöka spårningsdata kopplat till det innehåll som finns tillgängligt på plattformen. Underlaget för spårningsdatan bestod av ett helt års konsumtion (2014) från en av de största Play­tjänsterna i Sverige, TV3play.se. Framtagning av en ny metod för att mäta konsumtionen kallad Consumption Volume Score (CVS) föreslås och införs som ett alternativ till den traditionella metod som har varit att mäta den totala mängden av Videostarter (VS). Signifikansen av den nya metoden utvärderades genom jämförelse av rangordning av enskilda format baserat på CVS och VS samt olika kriterier. Resultaten visar att CVS för att mäta konsumtion ger ytterst liten eller ingen skillnad i ranking av mycket populära format, medan mindre konsumerade format hade en mer varierad förändring i rang. Vidare analys av en del av dessa format indikerade att de skulle kunna ha en nischad publik som uppskattar innehållet, trots relativt låg konsumption. För dessa format anser jag att det finns möjlighet för redaktörer att manuellt handplocka dem för att optimera konsumtionen ytterligare. Resultaten ger underlag för godta CVS som en signifikant mätenhet för konsumtion och kan bidra till att förstå hur enskilda format presterar, särskilt mindre konsumerade och potentiellt nischade sådana. Framtida forskning om CVS som metod för att mäta konsumtion rekommenderas, i synnerhet för att avgöra hur väl det lämpas att applicera i en skarp miljö.
175

Increased Salinity of Drilled Wells in Stockholm County – analysis of natural factors.

Bleppony, Rueben Arnoldz January 2013 (has links)
Almost 50 % of drinking water in Sweden comes from aquifers. The sustainability of groundwater resources in Stockholm County is threatened by increased salinity although most of the drinking water comes from Lake Mälaren. For a region known to be located within the areas covered by seawater after the last glaciation, the health and socio-economic development of the county is in a balance as development plans are challenged by high risk of salt groundwater. It is therefore important to know the extent and spread of salinity within the areas and the factors that correlate well with the salinity in the first attempt to study the risk of the areas to high salt content of groundwater. This paper looks at the distribution of salinity within the county and analyses the correlation between salinity and several natural factors. Using well co-ordinates and chemical data (compiled by Stockholm County Administration), and digital topographical, geological and land use data (from SGU and Swedish Land Survey), it is possible to project and visualize wells and salinity over the area, spatially develop and extract natural factor values to respective wells based on their co-ordinates, and finally perform statistical analyses on a resultant well attributes table, with the aid of Surfer, ArcGIS and Statistica Software. Results showing the spatial distribution of wells’ salinity and graphs of variance between the salinity of wells and respective natural factors of topography, depth, predominant soil cover, land use and distance from the sea, are further discussed.
176

Statistical-Based Suspect RetrievalUsing Modus Operandi

Tran, Bao Khang January 2020 (has links)
Introduction. The police and the investigation team has been manually doing behavioural analysis and connecting different crimes to an offender. With the help of computers technologies, databases, and automated system, the statistical analysis of the offender’s behaviour significantly improved. There we can transfer from a manual process to an automated one, and the investigator can allocate time and resources better by prioritising the offenders to investigate. In this study, we create and experiment with a proof of concept system that ranks and prioritise different offenders using the Random Choice method in combination with the state of the art Spatial-Temporal method. Objectives. In experimenting with the proof of concept system, we are aiming to understand the effect of different offender’s behaviour having on the offenders ranking and the effect of having multiple different numbers of reference crimes in the database. The objective is also to understand the role of consistency and distinctiveness in offenders ranking. Moreover, understanding the performances of our proof of concept system comparing to already existing methods such as Random Choice, Spatial-Temporal and a baseline method that based on pure randomness. Method. The method we chose for this study was an experimental study. With an experimental environment with independent and dependent variables, we presented and evaluated the system. We were using the experimenting approach because it has a stable presence and widely used in similar studies in this field. Results. After the experiments, we found that different Modus Operandi (MO)categories have a different effect on the ranking results and different distinctive combinations of MO categories also has different accuracy when ranking the offenders. Offenders that were consistent with more references crime in the database were often higher ranked and were linked more correctly. Our proof of concept system shows significant improvement over Random Choice method and the Spatial-Temporalmethod. Conclusion. From the results, we concluded that the proof of concept system displays a significant accuracy in ranking and prioritising offenders, there different MO categories and combinations of them has a different effect on the accuracy of the ranking. The ranking system was also affected by the number of reference cases that exist in the database. Future works can extend the study by trying to improve different aspects of the proof of concept systems, such as the Random Choice aspect or the Spatial-Temporal aspect.
177

The identification of batting trends through a comparative analysis in Twenty20 cricket between Varsity Cup winning teams and the University of the Western Cape Cricket Club from its origin in 2015 – 2017

Ramoo, Romano Jude January 2020 (has links)
Magister Artium (Sport, Recreation and Exercise Science) - MA(SRES) / Over the years cricket has developed from a traditional and conservative game into an extremely lucrative sport, which requires a great deal of professionalism in all surrounding areas. In recent years cricket has evolved and resulted in the emergence of Twenty20 cricket. The aim of this study focused on identifying batting trends through a comparative analysis between Varisty Cup winning teams and the University of the Western Cape Cricket Club between the age group of 18 – 25. The study used a quantitative research approach with a content analysis methodology research design. Nine key batting variables were analysed in three phases of a cricket match (Powerplay, Middle overs and Death overs) between winning teams and the University of the Western Cape Cricket Club to establish the magnitude of differences (Cohen’s effect size). The top indicators for success in the tournament were averaging a higher number of boundary fours, accumulating a higher number of single runs throughout the match, averaging a high number of sixes during the Middle and Death Overs of a batting innings and accumulating two’s throughout all three phases of a match. The overall summary of this study’s results navigates to a batting strategy that should focus on batting trends by maintaining a higher batting run rate, target to scoring more boundary fours and sixes, good running between the wickets to accumulate two’s, select batsmen with a low dismissal rate and select batsmen with a high single scoring rate [equates to better strike rotation].
178

On the representation of precipitation in high-resolution regional climate models

Lind, Petter January 2016 (has links)
Weather and climate models applied with sufficiently fine mesh grids to enable a large part of atmospheric deep convection to be explicitly resolved have shown a significantly improved representation of local, short-duration and intense precipitation events compared to coarser scale models. In this thesis, two studies are presented aimed at exploring the dependence of horizontal resolution and of parameterization of convection on the simulation of precipitation. The first examined the ability of HARMONIE Climate (HCLIM) regional climate model to reproduce the recent climate in Europe with two different horizontal resolutions, 15 and 6.25 km. The latter is part of the ”grey-zone” resolution interval corresponding to approximately 3-10 km. Particular focus has been given to rainfall and its spatial and temporal variability and other characteristics, for example intensity distributions. The model configuration with the higher resolution is much better at simulating days of large accumulated precipitation amounts, most evident when the comparison is made against high-resolution observations. Otherwise, the two simulations show similar skill, including the representation of the spatial structure of individual rainfall areas of primarily convective origin. The results suggest a ”scale-awareness” in HCLIM, which supports a central feature of the model’s description of deep convection as it is designed to operate independently of the horizontal resolution. In the second study, summer season precipitation over the Alps region, as simulated by HCLIM at different resolutions, is investigated. Similar model configurations as in the previous study were used, but in addition a simulation at the ”convection-permitting” 2 km resolution has been made over Central Europe. The latter considerably increases the realism compared to the former regarding the distribution and intensities of precipitation, as well as other important characteristics including the duration of rain spells, particularly on sub-daily time scales and for extreme events. The simulations with cumulus parameterization active underestimate short-duration heavy rainfall, and rainspells with low peak intensities are too persistent. Furthermore, even though the 6.25 km simulation generally reduces the biases seen in the 15 km run, definitive conclusions of the benefit of ”grey-zone” resolution is difficult to establish in context of the increased requirement of computer resources for the higher-resolution simulation.
179

Establishing the minimal sufficient number of measurements to validate a 24h blood pressure recording

Agarwal, Rajiv 17 May 2018 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Background: Ambulatory blood pressure (BP) monitoring (ABPM) remains a reference standard but the number of readings required to make the measurement valid has not been empirically validated. Methods: Among 360 patients with chronic kidney disease and 38 healthy controls, BP was recorded 2 per hour during the night and 3 per hour during the day over 24h using a validated ABPM device; all had at least 90% of the expected readings. From this full set of ABPM recording, a variable number of BP measurements were selected and we compared the performance of the selected readings against that of the full sample using random or sequential selection schemes. To address the question whether random or sequential selection schemes affect the diagnostic performance in diagnosing hypertension control we compared the diagnostic decisions reached with the subsample and the full sample using area under the receiver operating-characteristic curves (AUC ROC). To answer the question regarding the number of readings needed to achieve over 90% coverage of the mean BP of the full ABPM sample we ascertained the point and confidence interval (CI) estimates based on the selected data. Results: To diagnose hypertension control, the number of readings randomly drawn to establish lower bound with 2.5% error of area under the receiver operating-characteristic curve (AUC ROC) of 0.9 was 3, 0.95 was 7, and 0.975 was 13 . In contrast, the corresponding number of readings with serial selections was 18, 30 and 39 respectively. With a random selection scheme, 18 readings provided 80% coverage of the 90th percentile of CI of the true systolic BP mean, for 90% coverage, 26 readings were needed, for 95% coverage 33. With serial selections, the number of readings increased to 42, 47, and 50 respectively. Similar results emerged for diastolic BP. Conclusions: For diagnosing hypertension control 3 random measurements or 18 serial measurements is sufficient. For quantitative analysis, the minimal sufficient number of 24h ambulatory BP is 26 random recordings or 42 serial recordings.
180

Civic Engagement and Political Trust of Young People in Sweden in Relation to Their Immigration Backgrounds

Unver, Ayse Naz January 2020 (has links)
Currently, nearly 25% of people living in Sweden have foreign background. With one in every four people having immigration background, the question “how does civic engagement and political trust of people differ depending on their immigration backgrounds?” becomes important. More to the point, how does civic participation and political trust differ amongst young people living in Sweden in relation to their immigration backgrounds?In order to answer these questions, this thesis uses data from the European Social Survey and looks into the political trust and civic engagement behaviors of young people living in Sweden who have different immigration backgrounds by forming three groups; native- Swedes, second-generation immigrant-origin individuals and first-generation immigrants.The analysis is done by using SPSS and performing statistical analysis. Chi-Square and Kruskal-Willis tests were used, as well as descriptive statistics and cross tables. The results show that there is a statistically significant difference for civic participation due to immigration background, but the same cannot be said for political trust.

Page generated in 0.086 seconds