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268 Uppsatser om Compression algorithm - Sida 15 av 18

Spela för nöje eller spela för kunskap? : Lärares uppfattningar av IT-baserade matematikspel och dess konsekvenser på elevers kunskapsutveckling

Sveriges Radio stores their data in large archives which makes it hard to retrieve specific information. The sheer size of the archives makes retrieving information about a specific event difficult and causes a big problem. To solve this problem a more consistent use of metadata is needed. This resulted in an investigation about metadata and keyword genera-tion.The appointed task was to automatically generate keywords from transcribed radio shows. This included an investigation of which systems and algorithms that can be used to generate keywords, based on previous works.

Blodtrycksmanschett eller manuell handkompression vid bedömning av venös insufficiens i Vena saphena magna

Bakgrund: Venduplex har på senare år vuxit fram som den mest använda metoden vid diagnostik av venös insufficiens eftersom det är en ofarlig, kostnadseffektiv, non-invasiv metod med hög sensitivitet och specificitet där både den anatomiska placeringen av insufficiensen samt den funktionella förändringen av venen kan påvisas direkt vid undersökningen. Olika manövrar kan genomföras för att påfresta venklaffarna och därmed framkalla en eventuell reflux, men det är oklart om de olika manövrerna kan påverka den reflux som provoceras fram och därmed också påverkar bedömningen av insufficiensgraden.Syfte: Syftet med studien var att undersöka om det förelåg skillnad i graderingen av insufficiensen samt om den maximala refluxhastigheten påverkades beroende på vilken manöver som användes för att framkalla en reflux.Metod: 20 v. saphena magna mitt på låret med påvisad reflux deltog i studien. Två upprepade mätningar genomfördes där venklaffarna provocerades med hjälp av en blodtrycksmanschett över vaden, med en manuell kompression över låret samt med en manuell kompression över vaden.Resultat: Den maximala refluxhastigheten blev 0,33±0,20m/s när en blodtrycksmanschett över vaden användes, 0,31±0,22m/s när en manuell handkompression över vaden användes samt 0,17±0,16m/s när en manuell lårkompression genomfördes.Slutsats: Ingen signifikant skillnad på maximal refluxhastighet kunde konstateras när en automatisk uppblåsbar blodtrycksmanschett över vaden jämfördes med en manuell handkompression över vaden. En signifikant högre maximal refluxhastighet konstaterades när en manuell vadkompression jämfördes med en manuell lårkompression..

En retrospektiv studie av hovbensfrakturer på svenska varmblodiga travhästar :

Records of P III fractures from 235 horses, 71 of them were standardbreds, treated at 3 major Swedish equine hospitals (Strömsholm, SLU and Mälaren hästklinik) between 1994 and 2004 were evaluated for information such as the patients age, sex, breed, type of fracture, affected leg, time and place of the injury, treatment and, if possible, result of treatment. For the standardbreds, result of treatment was also followed up through written correspondence with owners and by screening AB Trav och Galopp racing-results. Moreover, results of horses with type II and III-fractures treated with rest and therapeutic shooing only were compared to horses in which lag screw fixation were added to achieve interfragmental compression. Compared to the rest of the Swedish horse population, P III fractures were slightly more common among standardbred horses. The mean age of the affected standardbred was 5,8 years, compared to 7,9 years in the rest of the horse-population. Most horses injured themselves in the paddock.

Design av försöksanläggning för trycksatt rökgasrening vid oxy-fuelförbränning

Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.

CAD-visualisering av användarinstruktioner för en balpress

I detta kandidatarbete skapas en animation för att visualisera användarinstruktioner för en balpress. Förberedelser utförs i 3D-CADprogramvaran Geomagic Design 2014 innan arbetet med animeringen påbörjas i programmet SimLab Composer Animation. I förberedelserna rensas modellerna och modifieras. Modeller som saknas skapas. I detta förslag på visualisering av ett moment i användning av balpressen är i syfte att underlätta för brukaren hur den snabbt kan använda maskinen.

En livsviktig utveckling : en reviewstudie om hjärt- lungräddning (HLR)

AimThe aim of this study was to find out how the research that has changed CPR training developed from a historical perspective. The question at issue was: When the recommendations for chest compressions/ventilation, defibrillator and education have been changed, what kind of research led to the development?MethodTo fulfill the aim of this study we chose a review process. First we read the international guidelines for cardiopulmonary resuscitation (CPR) published by the American Heart Association (AHA), from year 1980 until year 2010. Secondly we chose the most important changes that had been made within the issues we had selected, then we examined the research that had supported these issues.

Direktsamplande digital transciever

Master thesis work at ITN (Department of Science and Technology) in the areas of A/D-construction and RF-circuit design. Major goal of project were to research suitable possibilities for implementations of direct conversion in transceivers operating in the 160MHz band, theoretic study followed by development of components in the construction environment Cadence. Suitable A/D- converter and other important parts were selected at the end of the theoretic study. Subsampling technique was applied to make A/D sample requirements more realistic to achieve. Besides lowering requirements on A/D-converter it allows a more simple construction, which saves more components than subsampling adds.

Shape from Silhouette Scanner

The availability of digital models of real 3D objects is becoming more and more important in many different applications (e-commerce, virtual visits etc). Very often the objects to be represented cannot be modeled by means of the classical 3D modeling tools because of the geometrical complexity or color texture. In these cases, devices for the automatic acquisition of the shape and the color of the objects (3D scanners or range scanners) have to be used. The scanner presented in this work, a Shape from silhouette scanner, is very cheap (it is based on the use of a simple digital camera and a turntable) and easy to use. While maintaining the camera on a tripod and the object on the turntable, the user acquires images with different rotation angles of the table.

Utveckling av kyl- och smörjsystem för ekobilen Agilis HCCI motor

Every year, KTH participates in the Shell Eco Marathon, a competition whose goal is to design a vehicle that can go as far as possible using only the equivalent energy of one liter of petrol fuel. This year, one of KTH?s contributions to this race is the Agilis prototype; a car powered by a uniquely configured HCCI-engine developed at the university. The engine is dependent of several subsystems in order to work properly, among other, systems for cooling and lubrication.Combustion engines are in need of a cooling system that reduces the heat developed during the combustion. In general, two main types of cooling systems are employed; either air cooling, where the outside of the cylinder is exposed to a flow of the surrounding air, ore water cooling, where water flows in tubes around the engine, and the heat are transferred by the water to the surrounding air through a heat exchanger.The purpose of the lubrication system is to prevent the friction that builds up in the interference between moving parts in the engine.

CAD-visualisering av användarinstruktioner för en balpress

I detta kandidatarbete skapas en animation för att visualisera användarinstruktioner för en balpress. Förberedelser utförs i 3D-CADprogramvaran Geomagic Design 2014 innan arbetet med animeringen påbörjas i programmet SimLab Composer Animation. I förberedelserna rensas modellerna och modifieras. Modeller som saknas skapas. I detta förslag på visualisering av ett moment i användning av balpressen är i syfte att underlätta för brukaren hur den snabbt kan använda maskinen. Användarens perspektiv sätts i fokus hur den kan tänkas betrakta och uppfatta maskinen genom instruktionerna i animeringen.

Servostyrning med binaural ljudlokalisering

People are usually directed towards each other in conversations, to make it easier to hear what is being said. Algorithms for voice and speech recognition works in a similar way, regarding the microphone direction towards the sound source. In this thesis in electronics has therefore a servo control with binaural sound localization been implemented on a microcontroller connected to two microphones.When people perceive sound, the brain can estimate the sound source direction by comparing the time taken by the sound reaching one ear to the other [1]. The difference in time is called the interaural time difference, and can be calculated using various techniques. An exploratory comparison between the techniques cross-correlation and cross-spectrum analysis was carried out before implementation.

Datorstödd implementering med hjälp av Xilinx System Generator

The development in electronics increases the demand for good design methods and design tools in the field of electrical engeneering. To improve their design methods Ericsson Microwave Systems AB is interested in using computer tools to create a link between the specification and the implementation of a digital system in a FPGA. Xilinx System Generator for DSP is a tool for implementing a model of a digital signalprocessing algorithm in a Xilinx FPGA. To evaluate Xilinx System Generator two testcases has been designed. The testcases are selected to represent the FPGA designs made at Ericsson Microwave Systems.

Radomoptimering för luftburna störsändarkapslar

These studies are done in behalf of Saab AB AVITRONICS in Järfälla in the form of a thesis atthe Royal Institute of Technology in Stockholm.The task was to examine the parameters that plays a role in the construction of modern radomesoperating in broadband applications.This was interesting for Saab to get an indication of which way they should go at the newdevelopment of radomes for the next generation of equipment for electronic warfare.After a thorough analysis of the influencing parameters, a optimization application was made toget a automated way to get a radome design by specifying data on the radome size, airloads,materials, etc.This is to minimise the time of the laborious work that radome development.inply.This was solved by letting ANSYS calculate the strength of the radome structure and MATLABcalculate electromagnetic data and cost models of different sizes and materials.All these parameters woven together with the optimization tool modeFrontier picks data from therespective program and perform an optimization algorithm and then iterate a step and sends thisdata to calculation programs for the new input data. In the end, we have received a convergedpoint with our optimal solution.For the presumptions and limitations for which applied for this thesis, the result was prettyintuitive. That is to say that the smaller radome - the less materal is needed and lowermanufacturing costs results in the cheapest solution possible. The reality is not so simple. Whereyou have to take more of the electrical details such as the effect on the transmitter as a majorfactor..

RCC-Jordfelsskydd, mätmodul för övertonsanalys

The majority of all power cuts that affects individuals and communities are caused by earth faults on the power transmission lines at 10kV and 20kV level [1]. If these power cuts could be eliminated, less disturbances and interrupts would lead to large amounts of money savings.Swedish Neutral has developed such a protection system. When an earth fault occurs power is injected into the neutral point of the transformer. The RCC (Residual Current Compensation) protection calculates a compensation current exactly 180 degrees out of phase to the fault current. Doing this, the voltage at the fault location becomes very close to zero, without affecting the power transmission.The protection system can only compensate automatically for the fundamental frequency (50Hz), and manually for the 3rd, 5th, 7th and 9th harmonics.

Optimering av sintrade kugghjul

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

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