Search results for "Algoritmer"
showing 10 items of 33 documents
Mechanisms for OAM on MPLS in large IP backbone networks
2002
Masteroppgave i informasjons- og kommunikasjonsteknologi 2002 - Høgskolen i Agder, Grimstad The telecom industry has an ongoing work on the Operation and Maintenance (OAM) mechanisms for the MultiProtocol Label Switching (MPLS) technology. We are expecting that this technology will be the future platform for sending Internet Protocol (IP) packets through the backbone networks. OAM functionalities that exist or are proposed for MPLS are: Reachability and failure detection, avoidance of congested routers, Simple Network Management Protocol (SNMP) features, fast rerouting functions, traffic engineering and ad-hoc mechanisms like Ping. Our work shows that through a comparison of OAM mechanisms …
Wavelet-based video compression: A glimpse of the future?
2004
Masteroppgave i informasjons- og kommunikasjonsteknologi 2004 - Høgskolen i Agder, Grimstad Even though wavelet-based video compression has been an area of research for more than a decade, motion estimation and compensation has been considered complex and inefficient until recently. We have carried out a thorough investigation of existing research work in this field, and found that fundamental problem with wavelet-based temporal removal while obtaining highly scalability (the wavelet-properties of multiresolution structure in combination with embedded coding), has been solved by performing motion compensated temporal filtering within the wavelet domain of a overcomplete three-dimensional li…
Interconnected learning automata playing Iterated Prisoner's Dilemma
2004
Masteroppgave i informasjons- og kommunikasjonsteknologi 2004 - Høgskolen i Agder, Grimstad There exist several examples of situations where interaction between entities is essential in order to reach a common goal, for instance negotiations. Problems arise when the parties of a case are in disagreement with each other and they all want the best for themselves. Our thesis focuses around one such case. Analyzing the results of its own actions, an entity can learn what kind of adversaries it faces. For instance they may be cooperative, hostile, ignorant or irrational. The situation becomes even more complex when the opposing parties change its behaviour while trying to reach a goal. In this c…
Analysis of audio coding algorithms for networked embedded systems
2004
Masteroppgave i informasjons- og kommunikasjonsteknologi 2004 - Høgskolen i Agder, Grimstad Today there are many different audio coding algorithms, some of them standardized by the ITU, like G.711, G.726 and G.728, and several other codecs by other organizations like Fraunhofer (mp3) and Microsoft (WMA). All these algorithms differ in several important features, like speech quality, bit or compression rate, robustness, delay, sampling frequency, complexity and range of use. The past decade we have witnessed a great progress towards application of low-rate speech/music coders as well as computer related voice/music applications. Central to this progress has been the development of speech cod…
Predicting Electrical Power Consumption on Yearly Events for Substations: Algorithm Design and Performance Evaluations
2020
Master's thesis in Information- and communication technology (IKT590) Accurate prediction of electricity usage is critical for grid companies in or-der to ensure reliable power supply for their customers. Many factors in-fluence usage patterns, but generally they consist of yearly-, weekly- and daily trends in addition to stochastic noise due to random user behaviour. Besides the above-mentioned cyclic trends, certain yearly events, i.e. events that take place once per year, can affect usage patterns significantly and thus may cause abnormally high or -low power consumption. Therefore, it is in the interest of grid companies to predict the consumption on such events so they can take measure…
Selvorganiserende læring av trafikkategorier i Bayesianskpakkebasert IDS
2005
Masteroppgave i informasjons- og kommunikasjonsteknologi 2005 - Høgskolen i Agder, Grimstad Detektering av uønsket trafikk i et datanettverk utføres i dag av systemer med mer eller mindre grad av manuelt vedlikehold. Slikt vedlikehold består typisk av nedlasting av oppdateringer som bidrar til deteksjon av de nyeste typene angrep. For å unngå dette manuelle vedlikeholdet forskes det rundt systemer som skal være i stand til å lære seg hva som er normal og hva som er unormal nettverkstrafikk i et datanettverk. Slike systemer er gjerne basert på en læringsalgoritme, som basert på et sett med treningsdata, kan ta beslutninger om hva som er normalt og ikke. Denne masteroppgaven ser på hvordan en…
Semi-automatic web resource discovery using ontology-focused crawling
2005
Masteroppgave i informasjons- og kommunikasjonsteknologi 2005 - Høgskolen i Agder, Grimstad The enormous amount of information available on the Internet makes it difficult to find resources with relevant information using regular breadth-first crawlers. Focused crawlers seek to exclusively find web pages that are relevant for the user, and avoid downloading irrelevant web pages. Ontologies have recently been proposed as a tool for defining the target domain for focused crawlers. In this project we have developed a prototype of an ontology-focused crawler. We have accomplished this by developing extra modules to the Java open source crawler Heritrix. In one of the modules we have developed, …
Semi-automated web resource discovery and analysis : an approach based on interactive machine learning principles
2001
Masteroppgave i informasjons- og kommunikasjonsteknologi 2001 - Høgskolen i Agder, Grimstad This report presents a semi-automated approach to web Resource Discovery based on an architecture in which both human learning and machine learning is integrated in the same model. The fundamental idea of the semi-automated approach is to let the machine automatically identify semantic ambiguities and ask a human analyst to resolve them. An application prototype is developed that demonstrates an experimental Focused Crawler algorithm and the use of the ISO 13250 Topic Map standard for the purpose of knowledge representation. The main area of deployment is for use in Competitive Intelligence activitie…
Ontology guided financial knowledge extraction from semistructured information sources
2003
Masteroppgave i informasjons- og kommunikasjonsteknologi 2003 - Høgskolen i Agder, Grimstad Intermedium has an agent searching the Web for financial articles defined by certain criteria, for instance an industrial domain of interest. A portal service for reading and searching these articles, are available for the customers. The sources searched among are secondary sources, like online newspapers. Secondary sources publish information more frequently, and other information than can be found in annual reports etc, like predictions. Finding and comparing financial figures in the articles are often time consuming and hard to compare with each other. Having the financial figures, and what these …
Noen aspekter ved implementasjon og ytelse for kryptosystemer basert på elliptiske kurver
2003
Masteroppgave i informasjons- og kommunikasjonsteknologi 2003 - Høgskolen i Agder, Grimstad I den senere tid har kryptografi basert på elliptiske kurver blitt tatt i bruk i økende grad. De fleste av dagens implementasjoner baserer seg på kurver på Weierstrassform, y2z + a1xyz + a3yz2 = x3 + a2x2z + a4xz2 + a6z3. Hesseform av elliptiske kurver, x3 +y3 +z3 = Dxyz, har en del egenskaper som gjør den velegnet til bruk i kryptografi. Basert på antall grunnoperasjoner som utføres i algoritmene, bør Hesseform være bedre enn Weierstrassform ytelsesmessig. I dette arbeidet utfører vi en del hastighetstester av punktoperasjoner på kurver på kort Weierstrass- og Hesseform. Vi har implementert algoritm…