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22 Uppsatser om Imprecise Computation - Sida 1 av 2
Hantering av QoS i Distribuerade MPEG-videosystem
With the advance in computer and network technologies, multimedia systems and Internet applications are becoming more popular. As broadband network is prevailing, more clients are able to watch streaming videos or to play multimedia data over the Internet in real-time. Consequently, there is an increasing demand in the Internet for streaming video systems. As the run-time environment of such applications tends to be dynamic, it is imperative to handle transient overloads effectively. The goal of this work is to develop an algorithm that would provide a robust and controlled behavior of the video system so that important data is delivered on time to the video clients.
Parallell beräkning av omslutande volymer
This paper presents techniques for speeding up commonly used algorithms forbounding volume (BV) computation, such as the AABB, sphere and k-DOP. Byexploiting the possibilities of parallelismin modern processors, the result exceedsthe expected theoretical result. The methods focus on data-level-parallelism(DLP) using Intel?s SSE instructions, for operations on 4 parallel independentsingle precision floating point values, with a theoretical speed-up factor of 4 ondata throughput. Still, a speed-up between 7?9 are shown in the computation ofAABBs and k-DOPs.
GPGPU : Bildbehandling på grafikkort
GPGPU is a collective term for research involving general computation on graphics cards. A modern graphics card typically provides more than ten times the computational power of an ordinary PC processor. This is a result of the high demands for speed and image quality in computer games.This thesis investigates the possibility of exploiting this computational power for image processing purposes. Three well known methods where implemented on a graphics card: FFT (Fast Fourier Transform), KLT (Kanade Lucas Tomasi point tracking) and the generation of scale pyramids. All algorithms where successfully implemented and they are tree to ten times faster than correspondning optimized CPU implementation..
Kosten ombord : Hur vill sjömannen att kostregleringen ska se ut?
Diet is mentioned by many seamen as a subject of joy and aims to give nutritional value and sufficient energy to manage a long working day at sea. The purpose with this investigation is to examine if there is a need among seamen to receive more information about diet regulations onboard and if they wish that it was shaped differently to meet their demands. The study is based on a literature part where diet regulations are examined and an interview part with semi structured qualitative interviews with five seamen. The conclusion of the study indicates that seamen have limited knowledge about the enunciation of the regulation, where it is to be found and consider it to be imprecise. Interviews showed that seamen believe that variety is the most important factor in diet intake and it was this expression that they primarily wanted stated in the regulations.
Diskontinuerliga Galerkinmetoder för initialvärdesproblem och prissättning av optioner
Efficient numerical methods for option pricing is an active field of research. This project has the goal to examine possible ways to improve an established method of numerical pricing. The method is based on an adaptive finite difference method in price and uses the backwards differentiation formula of order 2, BDF2, in time. The project will focus on improvements to the time integration through implementation of discontinuous Galerkin methods, dG. Empirical convergence and accuracy results are obtained for equidistant dG-methods up to order 3 and performance is compared to BDF2.
Adaptiv temperaturreglering av bostadshus
The control of indoor temperature must be able to handle large time constants and both measureable disturbances like outdoor temperature, and non-measurable disturbances, like waste heat from appliances. Due to cheaper microcontrollers (small computers with designated tasks) with better performance, more advanced and computation-demanding methods for control can be used.In this thesis, Generalized Predictive Control (GPC) has been implemented and tested on a theoretically derived model of a house. GPC states that a model of the system is estimated in every sample, and the control is carried out simultaneously, based on predictions of the model. Disturbances like solar radiation can be estimated and used in the control as well. The control signals are determined by quadratic programming, which makes it possible to consider conditions, for example limitations on the control signals.GPC requires a number of parameters to be defined, like model order and control signal penalty, but is relatively robust for variations in them.
Maktavstånd och kommunikation - en studie av upplevda och verkliga kulturella skillnader och deras följder
Hofstede constructed a culture dimension called Power Distance, measuring the inequality of Power. Germany and Sweden have relatively similar values according to his world-renowned research. But a series of interviews of Swedish entrepreneurs in Germany shows that these perceive a large difference in inequality of power in the two countries. This essay seeks to explain the difference between these subjective-qualitative experiences and the objective-quantitative data of Hofstedes Power Distance Index. We propose that a combination of differences in communication, exercise and visibility of power and formality influence the way Power Distance is perceived.
Implementation av webbsida för rekommendationssystem med användaruppbyggd databas
The goal of this project was to create a web-based, crowd-sourced, correlational database, that easily allowed users to submit objects and receive correlated objects as results. The webservice was created in the web development languages of HTML, CSS, PHP and Javscript, with MySQL to handle the database. Simultaneous development was kept in check with the aid of the source code management system GIT. Upon completion, the service contained several HTML-views, the ability to add and rate objects, a per-object dedicated page with information parsed from Wikipedia.org, and a view with objects ranked in accordance to the preferences specific to the current user. Roughly a month after the beginning of development, the website was publicly launched and promoted in order to collect data, and improvements were added to the website as needed.
Jämförelse mellan MultiScat och konventionell beräkning av intensiteter till koncentrationer vid analys med röntgenflourescensspektrometri
In this master thesis work, a new method called MultiScat, is compared with the conventional method with alfa-correction, for computing concentrations from intensities in X-ray spectrometric analysis. The conventional model is a linear model, which only takes the photoelectric effect into consideration. It doesn't consider Rayleigh and Compton scattering even though it has a great impact on the measured intensities. Here MultiScat differs a lot. MultiScat is based on a solution of the Boltzmann transport equation.
Undersökning av mätsystem och regulatorstrukturer för industriella tillämpningar
This thesis is divided in to two different parts. The first part includes examination of the measurementsystem of an industrial robot using a resolver sensor. The main focus is on methods for suppressing noise in the angularvelocity signal without increasing timedelay. Five different methods are investigated. Three of these are based on oversampling: burstsamplingmethod, meanvaluemethod and correlationmethod.
Rörelsens generativa kraft : Den kroppsliga rörelsen som varseblivningens möjlighetsbetingelse
The standard model concerning the relationship between perception and motility is linear and one-way. It depicts the flow between the two as moving from sensation to perception to representation to computation, and finally, to motility and action. According to this model, animal being is basically a bundle of reflexes. But what can correctly be considered a bundle of reflexes from a natural science point of view, doesn't necessarily have to be true. This conception does not take into consideration the more complex interactions between motility and perception that constitutes, or generates, animal and human beings.
Chalmers oanvända datorkraft - Distribuering av arbete och energihantering med HTCondor
Chalmers University of Technology today have numerous computers which are never powereddown, at the same time there is a need for more computation power for researchers.Hence, we have investigated the possibility to use the computers for computing power andsecondly, if there is no work to be done, to put them into power saving mode.We have made a thorough study where we compared different distributing systems andin the end HTCondor was chosen as the best to implement. HTCondor is an excellent systemfor opportunistic use of computing power, i.e. make use of computers that no one elseis currently using. The system is used at several universities around the world with goodresults and would be excellent at Chalmers, where there is a need for such a system.Our implementation shows that HTCondor is well capable of handling unused computingpower. HTCondor can handle most file types that may be run on the system.
Heuristisk profilbaserad optimering av instruktionscache i en online Just-In-Time kompilator
This master?s thesis examines the possibility to heuristically optimise instruction cache performance in a Just-In-Time (JIT) compiler. Programs that do not fit inside the cache all at once may suffer from cache misses as a result of frequently executed code segments competing for the same cache lines. A new heuristic algorithm LHCPA was created to place frequently executed code segments to avoid cache conflicts between them, reducing the overall cache misses and reducing the performance bottlenecks. Set-associative caches are taken into consideration and not only direct mapped caches.
Dairy fat biomarkers and cardiometabolic health
Commonly held dietary guidelines discourage full-fat dairy consumption due its to high levels of saturated fatty acids, which are believed to aversely influence cardiovascular disease risk. Cardiovascular diseases cause more than one third of deaths in the developed world. With dairy often providing a large part of energy and nutrients in Western diets, research into its effects on human health is warranted.
Several recent studies have suggested a protective role of dairy in the development of cardiometabolic disease. However, many of these have used imprecise methods of dietary assessment, based on questionnaires or interviews. Biomarkers are emerging as a means of evaluating diet in a more objective way.
Currently used dairy fat biomarkers are minor fatty acid constituents of dairy that preferably are unique to dairy and not influenced by endogenous metabolism.
Vad säger bilden?: En utvärdering av återvinningseffektiviteten i ImBrowse
The aim of this master thesis is to evaluate the performance of the content-based image retrieval system ImBrowse from a semantic point of view. Evaluation of retrieval performance is a problem in content-based image retrieval (CBIR). There are many different methods for measuring the performance of content-based image retrieval systems, but no common way for performing the evaluation. The main focus is on image retrieval regarding the extraction of the visual features in the image, from three semantic levels. The thesis tries to elucidate the semantic gap, which is the problem when the systems extraction of the visual features from the image and the user?s interpretation of that same information do not correspond.