Sökresultat:
45 Uppsatser om Filtering - Sida 2 av 3
Portning och utökning av processor för ASIC och FPGA
In this master thesis, the possibilities of customizing a low-cost microprocessor with the purpose of replacing an existing microprocessor solution are investigated. A brief survey of suitable processors is carried out wherein a replacement is chosen. The replacement processor is then analyzed and extended with accelerators in order to match set requirements.The result is a port of the processor Lattice Mico32 for the FPGA curcuit Xilinx Virtex-5 which replaces an earlier solution using Xilinx MicroBlaze. To reach the set requirements, accelerators for floating point arithmetics and FIR Filtering have been developed. The toolchain for the processor has been modified to support the addition of accelerated floating point arithmetics.A final evaluation of the presented solution shows that it fulfills the set requirements and constitutes a functional replacement for the previous solution..
Mätning av axiella magnetiska läckflöden i vattenkraftsgeneratorer
This thesis describes a method of measuring axial magnetic leakage flux in an operational hydropower generator. Axial magnetic leakage flux is the magnetic flux at the ends of a rotating generator, which goes through the stator parallel to the rotor axis. This flux can cause circulating currents in the stator iron, giving rise to losses, and can in the worst case overheat a generator, causing it to melt down. To measure the axial flux, and how it affects the generator temperature, a measurement system was constructed on behalf of Vattenfall. The system consists of search coil sensors and a signal-processing unit with amplifiers and active Filtering. To confirm the behaviour of the axial leakage flux and the functionality of the measurement system, a test installation was made.
En studie om studenters användning av vänlistor på Facebook
Friend lists allow Facebook users to group their friends and may be used to share certain information only with those in a specific list. This function has been around for several years, but has never gained any particular popularity among users, most of whom probably did not know it even existed a couple of years ago. In the fall of 2011, however, the function was updated and made more visible on the site.There are several possible uses of friend lists, such as privacy control, Filtering of the news feed, self-presentation and targeted information sharing. This paper aims to investigate the extent to which friend lists are used by students today, as well as why students actually use their lists, i.e. for what purposes.Judging from the results of this study in comparison with earlier research, there seems to have been a somewhat recent increase in the awareness of the fact that friend lists actually do exist, but still most users tend not to utilize them.
Optimering av informationsinsamlingvid prototyptillverkning
This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the Filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.
Långa skuggor med shadow maps
Skuggor i 3D-miljöer är ett mycket efterforskat område, och detta arbete koncentrerar sig på shadow map-algoritmen. Det finns ett problem med denna algoritm, för då en shadow map projiceras på en yta som är större än sig själv så bildas stora trappstegseffekter, vilket kallas aliasing. Problemet som har undersökts är hur olika shadow map-algoritmer i en miljö med långa skuggor beter sig, där ett minimerat antal artefakter så som brus och aliasing är synligt. För detta undersöktes Percentage-Closer Filtering (PCF), som är en variant av shadow map, med olika samplingstekniker ? och även en vidarebyggnad med Percentage-Closer Soft Shadow (PCSS) implementerades.
Passive acoustic diver detection
This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the Filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.
Platsbaserad sökning : En metod fo?r filtrering och sortering av so?kresultat
Informationsso?kningar av olika slag sker dagligen va?rlden o?ver och so?kresultatet kan ma?nga ga?nger vara sa? stort att anva?ndarna har sva?rt att veta vilka so?kresultat som a?r relevanta. I denna uppsats har syftet varit att underso?ka hur so?kresultat kan filtreras och sorteras med hja?lp av platsbaserad so?kning fo?r att det ska bli mer relevant fo?r anva?ndaren. Genom litteraturstudie och intervjuer har det blivit mo?jligt att ta reda pa? hur ett so?kresultat skulle kunna filtreras och sorteras fo?r att mo?ta anva?ndarnas fo?rva?ntningar.
Framkomlighetsanalys med hjälp av en digital terrängmodell och kartdata
Driveability analysis of terrain data offers an important technique for decision support for all kinds of movements in the terrain. The work described in this report uses a high resolution digital terrain model generated from the laser radar data and further processed by the Category Viewer program, and information from the Real Estate Map. Properties of features found in a Filtering process are calculated and compared with a set of rules in a knowledge base to get a driveability cost. This cost is then visualized in a graphical user interface. An evaluation of what driveability is and what it is affected by is performed, and a general cost function is developed, which can be used even if not all relevant information is available.
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.
Studie av integration mellan rategyron och magnetkompass
This master thesis is a study on how a rategyro triad, an accelerometer triad, and a magnetometer triad can be integrated into a navigation system, estimating a vehicle?s attitude, i.e. its roll, tipp, and heading angles. When only a rategyro triad is used to estimate a vehicle?s attitude, a drift in the attitude occurs due to sensor errors.
Tala är silver, skriva är guld (?) En studie om bloggars demokratiska potential
The number of blogs, from weblogs, are increasing every day. Blogs are also becoming more visible in the public debate as well as the awareness of their existance is rising among politicians and citizens. The aim of this thesis is to answer the question what democratic potential blogs can have. This question will be answered by initially studying the research that exists today about weblogs and democracy. The second part of the analysis consists of a selection of texts from weblogs that touches this subject.
Konstruktion av datainsamlingskort för mätsystemet COMET
During test flights SAAB uses the data acquisition system COMET 16. The part of the system that receives the signals from the sensors and converts them is called KSM 15. The purpose of this thesis is to develop a data acquisition module on stacked PC/104 modules with a lower production cost. Our work has been divided into one part about analog signal conditioning and a second part with digital Filtering and memory management of the sampled data. The analog part, designed of regular components like instrument amplifiers, voltage references, operational amplifiers and multiplexers, adjusts the sensors signal levels for the ADC?s that converts the signals.
Digitizing the Parthenon using 3D Scanning : Managing Huge Datasets
Digitizing objects and environments from real world has become an important part of creating realistic computer graphics. Through the use of structured lighting and laser time-of-flight measurements the capturing of geometric models is now a common process. The result are visualizations where viewers gain new possibilities for both visual and intellectual experiences. This thesis presents the reconstruction of the Parthenon temple and its environment in Athens, Greece by using a 3D laser-scanning technique. In order to reconstruct a realistic model using 3D scanning techniques there are various phases in which the acquired datasets have to be processed.
Filtrering av e-post ? Binär klassifikation med naiv Bayesiansk teknik
In this thesis we compare how different strategies in choosing attribute values affects junk mail Filtering. We used two different variants of a naïve Bayesian junk mail filter. The first variant classified an e-mail by comparing it to a feature vector containing all attribute values that were found in junk mails in the part of the e-mail collection we used for training the filter. The second variant compared an e-mail to a feature vector that consisted of the attributes that was found in ten or more junk mails in the part of the e-mail collection we used for training the filter. We used an e-mail collection that consisted of 300 e-mails, 210 of these were junk mails and 90 were legitimate e-mails.
1553-Simulator. In-/uppspelning av databusstrafik med hjälp av FPGA
At Saab Aerospace in Linköping, components for measurement systems to the fighter aircraft JAS 39 Gripen are developed. In this activity you sometimes want to record the traffic transmitted on the data busses that connects different sys-tems. This traffic on the data busses is using the military standard MIL-STD-1553. This project has aimed to create a system for recording and sending 1553-data. The system is used on an ordinary personal computer, equipped with a recon- figurable I/O card that among others has a programmable logic circuit (FPGA).