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Quadrature and cubature formulae with high oscillation
Gregor, Luděk ; Najzar, Karel (referee) ; Kofroň, Josef (advisor)
In the present work we study aproximation methods for values of integrals with strongly oscillating integrand. It's typical that the integrand can be split into two factors such that one is a rapidly oscillating function and the other is a smooth function - typical examples are Fourier series and Fourier integral. A usual way is aproximation of a smooth function to get product, which is simply integrable. A common choice is to aproximate smooth function instead of the whole integrand by aid of polynomials. It is possible to apply Möbius inversion technique which is applied to the Poisson summation formula. We describe methods which use orthogonal polynoms. For computing of bivariate integrals with a nondegenerate stationary point we produce an asymptotic expansion.
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Software support of education in cryptography based on integer factorization
Vychodil, Petr ; Martinásek, Zdeněk (referee) ; Burda, Karel (advisor)
This thesis deals with new teaching software, which supports asymmetric encryption algorithms based on the issue of large numbers´ factorization. A model program was created. It allows to carry out operations related to encryption and decryption with an interactive control. There is a simple way to understand the principle of the RSA encryption method with its help. The encryption of algorithms is generally analysed in chapters 1,2. Chapters 3 and 4 deals with RSA encryption algorithm in much more details, and it also describes the principles of the acquisition, management and usage of encryption keys. Chapters 5 suggest choosing of appropriate technologies for the creation of the final software product, which allow an appropriate way to present the characteristics of the extended RSA encryption algorithm. The final software product is the java applet. Aplet is described in the chaprers 6 and 7. It is divided into a theoretical and practical part. The theoretical part presents general information about the RSA encryption algorithm. The practical part allows the users of the program to have a try at tasks connected with the RSA algorthm in their own computers. The last part of Java applet deals with the users´ work results. The information obtained by the user in the various sections of the program are satisfactory enough to understand the principle of this algorithm´s operations.
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Exploring Higher Order Dependency Parsers
Madhyastha, Pranava Swaroop ; Zeman, Daniel (advisor) ; Ramasamy, Loganathan (referee)
Most of the recent efficient algorithms for dependency parsing work by factoring the dependency trees. In most of these approaches, the parser loses much of the contextual information during the process of factorization. There have been approaches to build higher order dependency parsers - second order, [Carreras2007] and third order [Koo and Collins2010]. In the thesis, the approach by Koo and Collins should be further exploited in one or more ways. Possible directions of further exploitation include but are not limited to: investigating possibilities of extension of the approach to non-projective parsing; integrating labeled parsing; joining word-senses during the parsing phase [Eisner2000]
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Quasigroup based cryptography
Christov, Adam ; Drápal, Aleš (referee) ; Stanovský, David (advisor)
Public-key cryptographic schemes based on the complexity of solving multivariate quadratic equations over a finite field represent an alternative to widely used schemes relying on the complexity of factorization or on the discrete logarithm. Such a scheme was proposed by D. Gligoroski et al. [8]. Keys in this scheme are constructed using a special kind of quasigroups, the socalled quadratic quasigroups. In this paper we try and describe the quadratic quasigroups and classify them according to their properties. Finally, we present a theory which can be used to generate such quasigroups.
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Optimal strategy for factorizing smaller composite integers
Kadlček, Tomáš ; Kechlibar, Marian (referee) ; Drápal, Aleš (advisor)
Nazpv prace: Opt.inialni strategic faktorizaoe moiisicl) slozenych ciscl Autor: TomaM Kadlcok Katedra. (ust.av): Katcdra algebry Vedouci bakalafske prace: Doc. RNDr. Ales Drapal, CSc. (vnia.il vodouciho: Ales.DrapaH'iJmff.cuni.cz Abstrakt: Cilein prace bylo tostovat tfi algoritiny implementovane v kva.dratic.kom situ, ktereje vefojno k dispo/ici na wcbovych strankach katedry algobry MFF (/dc [3]). .Tojich ukolcm v ranici algorit.mu MPQS/SIQS jo rozkladat kladna cisla na cisla fadu nojvyse unsigned int (v C I I ). tj. do 32 l)itn delky vcctne. Tat.o chmost jo mitna pfi spnst.oni variant}- double large prime variation (DLPV), kdy rozkladainc oisla. ktora so tie zi'ela ro/lo/ila do faktori/arni Ita/e. AlgoriUny dostnpno pro tos- tovani byly: Pollard /), Pollard p - 1 a C'FHAC. Motoda oliptiokych kfivok neljyla dosud implemontovaiia. Porovna\;'nii inotod bylo provedeno na nekolika odli.snyeh pocitacich. Vysledkem i)lynonciin /, nioreni je lakt, '2v. ]>ro roxkladani ci.sel delsich no/ 70 cifor s pou/.itim varianty ULPV jo nojvhodnejsi nojdfivo spnstit /; - 1 algo- ritnms a pokud v ro/kladani nenspeje, pak joj dojilnit algoritnuun p nebo CFRAC. Zrychloni ooloho algoritniu x,|)nsobouo tiinto optiinalixovanym dilcini rozkladanini so pohybnje v facln 5-10%. Klic'ova slova: Pollard (>, Pollard p - \, CFH.AC!,...
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Parallelization of Integer Factorization from the View of RSA Breaking
Breitenbacher, Dominik ; Henzl, Martin (referee) ; Homoliak, Ivan (advisor)
This paper follows up the factorization of integers. Factorization is the most popular and used method for RSA cryptoanalysis. The SIQS was chosen as a factorization method that will be used in this paper. Although SIQS is the fastest method (up to 100 digits), it can't be effectively computed at polynomial time, so it's needed to look up for options, how to speed up the method as much as possible. One of the possible ways is paralelization. In this case OpenMP was used. Other possible way is optimalization. The goal of this paper is also to show, how easily is possible to use paralelizion and thanks to detailed analyzation the source codes one can reach relatively large speed up. Used method of iterative optimalization showed itself as a very effective tool. Using this method the implementation of SIQS achieved almost 100 multiplied speed up and at some parts of the code even more.
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Navigace mobilních robotů v neznámém prostředí s využitím měření vzdáleností
Jež, Ondřej ; Žalud, Luděk (advisor)
The ability of a robot to navigate itself in the environment is a crucial step towards its autonomy. Navigation as a subtask of the development of autonomous robots is the subject of this thesis, focusing on the development of a method for simultaneous localization an mapping (SLAM) of mobile robots in six degrees of freedom (DOF). As a part of this research, a platform for 3D range data acquisition based on a continuously inclined laser rangefinder was developed. This platform is presented, evaluating the measurements and also presenting the robotic equipment on which the platform can be fitted. The localization and mapping task is equal to the registration of multiple 3D images into a common frame of reference. For this purpose, a method based on the Iterative Closest Point (ICP) algorithm was developed. First, the originally implemented SLAM method is presented, focusing on the time-wise performance and the registration quality issues introduced by the implemented algorithms. In order to accelerate and improve the quality of the time-demanding 6DOF image registration, an extended method was developed. The major extension is the introduction of a factorized registration, extracting 2D representations of vertical objects called leveled maps from the 3D point sets, ensuring these representations are 3DOF invariant. The extracted representations are registered in 3DOF using ICP algorithm, allowing pre-alignment of the 3D data for the subsequent robust 6DOF ICP based registration. The extended method is presented, showing all important modifications to the original method. The developed registration method was evaluated using real 3D data acquired in different indoor environments, examining the benefits of the factorization and other extensions as well as the performance of the original ICP based method. The factorization gives promising results compared to a single phase 6DOF registration in vertically structured environments. Also, the disadvantages of the method are discussed, proposing possible solutions. Finally, the future prospects of the research are presented.
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