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Speeding up a mixed reality application: A study of two encoding algorithms / Att snabba upp en applikation med blandad verklighet: En undersökning av två kodekalgoritmerElgh, Jesper, Thor, Ludvig January 2020 (has links)
Mixed reality (MR) or augmented reality (AR) is a way of combining the digital world with the real world. It is utilized in a number of different applications. The mobile devices of today may not always provide sufficient processing power to handle these kind of applications. One way of increasing the amount of available processing power is to offload the processing to a computer that sits on the edge of the network, for example residing in part of an access network (5G or dedicated unit connected to a router today). The upside of doing this is that it allows you to have a lot more processing power using a more powerful computer instead of the mobile device itself. The downside is that it increases latency which can deteriorate the user experience. To be able to send video to and from the edge computer, the video frames have to be encoded using an encoding algorithm. In this study we implemented two different encoding algorithms, VP8 and H.265, into an existing open source mixed reality application and studied how they affect the responsiveness of the application compared to the already implemented encoders, as well as how they perform when encoding at different bitrates. It is shown that the encoding algorithm affects the responsiveness to a certain degree, where the VP8 codec was the overall best performer in terms of responsiveness combined with visual quality. One major reason is that the VP8 codec had much faster decoding compared to the other codecs. The bitrate affects the encoding and decoding speed where higher bitrates resulted in higher encoding times. Higher bitrates also led to the application becoming less responsive which show a correlation between the bitrate magnitude and the responsiveness.
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Opartiska spel : I teori och praktikKraft, Gustav January 2022 (has links)
I det här arbetet ger vi en introduktion till opartiska kombinatoriska spel, där optimala strategier lyfts fram. Hur kan vi med matematiska metoder bevisa att en spelare kan tvinga fram en vinst, och hur räknar vi ut det optimala draget? För alla spel som beskrivs kan en vinst tvingas fram om spelet är i en så kallad P-position. Grundy-värdet kan användas för bestämning av utfallet på ett spel, där ett Grundy-värde på noll motsvarar P-position. Grundy-värdet definieras rekursivt och tester har implementerats där en rekursiv och en iterativ implementering jämförs. Resultatet visar att den iterativa metoden är mycket mer effektiv. Vi kan lägga ihop flera spel för att skapa ett summa-spel, där flera spel spelas samtidigt. Grundy-värdet för ett summa-spel beräknas av Nimsumman mellan de separata spelens Grundy-värden. Nim-summan mellan två heltal är en binär xor-operation mellan heltalen. En applikation har utvecklats för tester på teorin där spelen Nim, Silver-Dollar, ett subtraktions-spel och Wythoffs spel är implementerade. Applikationen ger möjlighet att tillämpa de optimala strategierna på de separata spelen eller på ett eget kombinerat summa-spel.
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Algorithmic composition from text : How well can a computer generated song express emotion?Sievers, Jacob, Wagenius, Rex January 2014 (has links)
Algorithmic composition has long been a subject of research in computer science. In this report we investigate how well this knowledge can be applied to generating an emotional song from a piece of text, such as a text message, a tweet or a poem. The algorithm described in this paper uses Markov chains to generate a melody from just a sentence and a mood (happy or sad). It can then be output from some voice software such as Vocaloid, which is used here. The results show that a simple algorithm can be used to generate songs that communicate the wanted emotion. / Algoritmisk komposition har länge varit ett forskningsämne inom datavetenskapen. I den här rapporten undersöker vi hur denna kunskap kan appliceras för att generera en sång ifrån ett stycke text såsom ett textmeddelande, en tweet eller en dikt. Algoritmen som beskrivs använder Markovkedjor för att generera melodier från bara en mening och en känsla (glad eller ledsen). Sången kan sedan spelas från röstmjukvara, såsom Vocaloid, vilket används här. Resultaten visar att en simpel algoritm kan användas för att generera sånger som kommunicerar den önskade känslan.
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Emotionally expressive song synthesis using formants and syllablesGramfors, Dexter, Johansson, Andreas January 2014 (has links)
Speech synthesis is an area of computer science with many practical uses, such as enabling people with visual impairments to take part of text and to provide more human-like feedback from information systems. A similar area of research is text-to-song, where systems comparable to those used in text-to-speech pro- vide mappings from text to melodic units of song. This paper discusses how a text-to-song algorithm can be developed and what parameters affect what emotion is communicated. Fifty participants listened to music generated with our algorithm. Results show that tempo and mode both heavily account for what emotion is communicated; a melody performed with a tempo of 250 bpm was perceived as significantly more happy than a performance with a tempo of 120 bpm, and a melody in major tonality was perceived as significantly more happy than a melody in minor tonality. Combined, these parameters gave even more significant results. A fast tempo combined with major tonality produced a performance that was perceived as even more happy. The opposite was observed when a slow tempo was combined with minor tonality. When a fast tempo was combined with a minor tonality the average answer was neu- tral with answers distributed over the whole spectrum from sad to happy. A slow tempo combined with a major tonality gave almost identical results. We concluded that generating emotionally expressive song with the use of an al- gorithm is definitely possible, but that the methodology can be improved in order to convey emotions even more clearly.
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Human Interaction in 3D Manipulations : Can sonification improve the performance of the interaction?Edström, Viking, Hallberg, Fredrik January 2014 (has links)
In this report the effects of using sonification when performing move- ments in 3D space are explored. User studies were performed where partic- ipants had to repeatedly move their hand toward a target. Three different sonification modes were tested where the fundamental frequency, sound level and sound rate were varied respectively depending on the distance to the target. The results show that there is no statistically significant performance increase for any sonification mode. There is however an in- dication that sonification increases the interaction speed for some users. The mode which provided the greatest average performance increase was when the sound level was varied. This mode gave a 7% average speed increase over the silent control mode. However, the sound level mode has some significant drawbacks, especially the very high base volume re- quirement, which might not make it the best suited sonification mode for all applications. In the general case we instead recommend using the sonification mode that varies the sound rate, which gave a slightly lower performance gain but can be played at a lower volume due to its binary nature.
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Basic simulation of natural selection : A study of the evolution of artificial life in varied environmentsEKSTAM LJUSEGREN, LOVE, FLORÉN, MIKAEL January 2014 (has links)
In this project one way of simulating natural selection and its most basic principles was examined. In order to show how simple and effective evolutionary systems really can be, a number of simulated lifeforms struggled for survival and evolved over generations. With this project we wanted both to showcase simple evolutionary principles for educational purposes and to highlight the potential of self improving al- gorithms. This has been done by posing two questions. Can this type of simple simulation suffice to produce stable popu- lation and gene pools, given time? And if so, can it evolve to different stable solutions given different problems, in this case environments, to tackle? The test setup was very simple; a set of simulated organisms were placed in different environ- ments, with the ability to produce offspring with random mutations. The results of the simulation show that the pop- ulation stabilizes in both numbers and gene configurations over time. It also shows that different environmental con- ditions lead to different gene configurations. From this we can conclude that a basic test environment such as the one described in this project can be used for producing both dif- ferent and stable species that are far better suited to survive than early generations. / I det här projektet undersöktes ett sätt att simulera natur- ligt urval med sina mest grundläggande principer. För att visa hur simpla och kraftfulla evolutionära system kan va- ra, kämpade ett antal simulerade livsformer för överlevnad och utvecklades över generationer. Med detta projekt ville vi både påvisa hur enkla evolutionära system kan vara för ut- bildningsändamål, och visa potentialen hos självförbättrande algoritmer. Detta gjordes genom att ställa två frågor. Kan ett enkelt system, så som det som beskrivs i denna rapport, räcka för att producera stabila populationer och genpooler, givet tid? Och om så är fallet, kan de utvecklas till olika stabila lösningar givet olika problem, i detta fall olika mil- jöer, att ta itu med? Testmiljön var väldigt enkel; ett antal simulerade livsformer, med förmågan att producera avkom- ma med slumpmässiga mutationer, placerades i olika miljöer. Resultaten från simulationen visar att vi efter en tid får po- pulationer som är stabila i både genuppsättning och antal. De visar också att olika miljöer leder till olika genuppsätt- ningar. Från detta kan vi dra slutsatsen att ett så simpelt test som detta, kan användas för att producera både olika och stabila arter som är bättre anpassade för att överleva än tidiga generationer.
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Observing coevolution in simulated bacteria : Using asexual reproduction and simple direct mapped functions for decision-makingBlanco Paananen, Adrian, Storby, Johan January 2014 (has links)
In this report we have presented the results of a program which performs simula- tions of artificial bacteria with the ability to evolve different characteristics and behaviours through genetic algorithms. Over time unfit bacteria will die out, and the more fit bacteria will produce offspring with slightly mutated variants of it’s genetic code resembling the evolutionary process. The simulation does not follow the traditional macro-scale hand-picked sexual reproduction often used in genetic algorithms to produce optimal results, but it instead uses individ- ual asexual reproduction which more closely resembles how bacteria reproduce in nature. Furthermore we do not use traditional neural networks for decision making, but simple functions which directly map the bacterias inputs to their decisions. The purpose of this study was to observe whether bacteria with different initial starting populations would coevolve, and specialize into heterogeneous populations. Furthermore we have tried to analyze how the populations inter- act with each other and how changing the different parameters of the simulation would affect the populations. We have performed three separate experiments that differ in their initial conditions, one with pre-created and heterogeneous herbivores and carnivores, one with homogeneous omnivores, and one with bac- teria whose genetic values have been decided at random. The result of our experiments was that we observed coevolution in the bacteria, and that they would despite very different initial starting conditions always grow towards sta- ble heterogeneous populations with very few exceptions.
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How auditory stimuli affects navigation in a user interface with mouse inputLambertsson, Christoffer, Skagerberg, Marcus January 2014 (has links)
In this study we investigated the influence of sound when interacting with a target button with constant size and distance on a 2-dimensional plane on a computer screen. In particular we wanted to verify if the use of auditory stimuli could improve the time it takes for a user to reach the target button with mouse as an interface. We conducted experiments in which participants had to click a button with the aid of visual stimuli only, audio stimuli only, or a combination of both visual and audio stimuli. Participants performed faster with audio-visual stimuli than with audio stimuli only. Because of inconclusive results we could not prove that audio- visual stimuli always yields a faster time average than visual stimuli only.
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Algorithmic trading using MACD signalsFalk, Andreas, Moberg, Johannes January 2014 (has links)
Todays stock market is dominated by algorithmic trading either as helpful tool for trading decisions or as a fully automatic trader. We test howa fully automated trading algorithm using MACD signals as indicatorsperform on historical stock data. The purpose of this essay is to seehow a simple algorithm performs and get a better understanding ofeconomical forecasting.
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A comparison of reductions from FACT to CNF-SATEriksson, John, Höglund, Jonas January 2014 (has links)
The integer factorisation problem (FACT) is a well-known number-theoreticproblem, with many applications in areas such as cryptography. An instanceof a FACT problem (a number n such that n = p × q) can be reduced to aninstance of the conjunctive normal form boolean satisfiability problem (CNF-SAT), a well-known NP-complete problem. Some applications of this is toutilize advances in SAT solving for solving FACT, and for creating difficultCNF-SAT instances.This report compares four different reductions from FACT to CNF-SAT,based on the full adder, array multiplier and Wallace tree multiplier circuits.The comparisons were done by reducing a set of FACT instances to CNF-SATinstances with the different reductions. The resulting CNF-SAT instanceswere then compared with respect to the number of clauses and variables, aswell as the time taken to solve the instances with the SAT solver MiniSat.
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