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Identifikace počítače na základě časových značek paketů / Computer Identification Based on Packet's TimestampsKrba, Martin January 2012 (has links)
Basic way how to identify a device in computer network is by MAC address and IP address. Main goal of this work is to create an application capable of clear identification of devices in computer network regardless change of their MAC address or IP address. This is done by exploiting tiny deviations in hardware clock known as clock skew. They appear in every clock based on quartz oscillator. Using clock skew is beneficial, because there is no need of any changes in fingerprinted device nor their cooperation. Accessing these values is done by capturing packets with timestamps included. Application of this method is very wide, for example computer forensics, tracking the device using different access points or counting devices behind router with NAT.
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Tvorba a aplikace algoritmů pro odhad modálních parametrů v časové oblasti a studie jejich citlivosti na okrajové podmínky / Creation and Application of Algorithms for Estimating Modal Parameters in Time Domain and Sensitivity to the Boundary Condition StudyJakuš, Matúš January 2016 (has links)
Cieľom tejto diplomovej práce je predstavenie Experimentálnej modálnej analýzy a štúdium a použitie algoritmov pre výpočet modálnych parametrov z odmeraných vibrácií pri Experimentálnej modálnej analýze. Bodom záujmu sú predovšetkým algoritmy, pracujúce s odmeranými dátami v časovej oblasti. Diplomová práca sa zaoberá programovaním algoritmu ITD a jeho implementáciou pre Experimentálnu modálnu analýzu. Ďaľšou časťou práce je štúdium citlivosti algoritmu na okrajové podmienky meranej sústavy pri výpočte modálnych parametrov a štúdium možnosti využitia algoritmu pri Operačnej modálnej analýze.
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Direct Mass Measurements and Global Evaluation of Atomic Masses / Mesures directes de masses et évaluation globale des masses atomiquesHuang, Wenjia 06 June 2018 (has links)
L’évaluation des masses atomiques (Ame), commencée dans les années 1960, est la source la plus fiable d’informations complètes sur les masses atomiques. Elle fournit les meilleures valeurs pour les masses atomiques et les incertitudes associées en évaluant les données expérimentales de désintégration, de réactions et de la spectrométrie de masse. Dans cette thèse, la philosophie et les caractéristiques les plus importantes de l’Ame seront discutées en détail. Les développements les plus récents de l’évaluation, AME2016, tels que l’énergie de liaison moléculaire, la correction d’énergie des mesures par implantation, et la formule relativiste pour le processus de décroissance alpha, seront présentés. Une autre partie de cette thèse concerne l’analyse des données du spectromètre à piège de Penning ISOLTRAP au ISOLDE/CERN. Les nouveaux résultats sont inclus dans l’ajustement global et leurs influences sur les masses existantes sont discutées. La dernière partie de cette thèse porte sur les études des erreurs systématiques du spectromètre de masse à multi-réflexion à temps de vol d’ISOLTRAP, utilisant une source d’ions hors ligne et le faisceau de protons en ligne. A partir de l’analyse des mesures sélectionnées, j’ai trouvé que l’erreur systématique est beaucoup plus faible que les incertitudes statistiques obtenues jusqu’à présent. / The Atomic Mass Evaluation (AME), started in the 1960s, is the most reliable source for comprehensive information related to atomic masses. It provides the best values for the atomic masses and their associated uncertainties by evaluating experimental data from decay, reactions, and mass spectrometry. In this thesis, the philosophy and the most important features of the Ame will be discussed in detail. The most recent developments of the latest mass table (AME2016), such as molecular binding energy, energy correction of the implantation measurements, and the relativistic formula for the alpha-decay process, will be presented. Another part of this thesis concerns the data analysis from the Penning-trap spectrometer ISOLTRAP at ISOLDE/CERN. The new results are included in the global adjustment and their influences on the existing masses are discussed. The last part of this thesis is related to the systematic error studies of the ISOLTRAP multi-reflection time-of-flight mass spectrometer, using an off-line ion source and the on-line proton beam. From the analysis of the selected measurements, I found that the systematic error is much smaller than the statistical uncertainties obtained up to now.
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On the Autoconvolution Equation and Total Variation ConstraintsFleischer, G., Gorenflo, R., Hofmann, B. 30 October 1998 (has links)
This paper is concerned with the numerical analysis of the autoconvolution equation
$x*x=y$ restricted to the interval [0,1]. We present a discrete constrained least
squares approach and prove its convergence in $L^p(0,1),1<p<\infinite$ , where
the regularization is based on a prescribed bound for the total variation of admissible
solutions. This approach includes the case of non-smooth solutions possessing jumps.
Moreover, an adaption to the Sobolev space $H^1(0,1)$ and some remarks on monotone
functions are added. The paper is completed by a numerical case study concerning
the determination of non-monotone smooth and non-smooth functions x from the autoconvolution
equation with noisy data y.
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The 3σ-rule for outlier detection from the viewpoint of geodetic adjustmentLehmann, Rüdiger January 2013 (has links)
The so-called 3σ-rule is a simple and widely used heuristic for outlier detection. This term is a generic term of some statistical hypothesis tests whose test statistics are known as normalized or studentized residuals. The conditions, under which this rule is statistically substantiated, were analyzed, and the extent it applies to geodetic least-squares adjustment was investigated. Then, the efficiency or non-efficiency of this method was analyzed and demonstrated on the example of repeated observations. / Die sogenannte 3σ-Regel ist eine einfache und weit verbreitete Heuristik für die Ausreißererkennung. Sie ist ein Oberbegriff für einige statistische Hypothesentests, deren Teststatistiken als normierte oder studentisierte Verbesserungen bezeichnet werden. Die Bedingungen, unter denen diese Regel statistisch begründet ist, werden analysiert. Es wird untersucht, inwieweit diese Regel auf geodätische Ausgleichungsprobleme anwendbar ist. Die Effizienz oder Nichteffizienz dieser Methode wird analysiert und demonstriert am Beispiel von Wiederholungsmessungen.
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Alternative Approaches for the Registration of Terrestrial Laser Scanners Data using Linear/Planar FeaturesDewen Shi (9731966) 15 December 2020 (has links)
<p>Static terrestrial laser scanners have been increasingly used in three-dimensional data acquisition since it can rapidly provide accurate measurements with high resolution. Several scans from multiple viewpoints are necessary to achieve complete coverage of the surveyed objects due to occlusion and large object size. Therefore, in order to reconstruct three-dimensional models of the objects, the task of registration is required to transform several individual scans into a common reference frame. This thesis introduces three alternative approaches for the coarse registration of two adjacent scans, namely, feature-based approach, pseudo-conjugate point-based method, and closed-form solution. In the feature-based approach, linear and planar features in the overlapping area of adjacent scans are selected as registration primitives. The pseudo-conjugate point-based method utilizes non-corresponding points along common linear and planar features to estimate transformation parameters. The pseudo-conjugate point-based method is simpler than the feature-based approach since the partial derivatives are easier to compute. In the closed-form solution, a rotation matrix is first estimated by using a unit quaternion, which is a concise description of the rotation. Afterward, the translation parameters are estimated with non-corresponding points along the linear or planar features by using the pseudo-conjugate point-based method. Alternative approaches for fitting a line or plane to data with errors in three-dimensional space are investigated.</p><p><br></p><p>Experiments are conducted using simulated and real datasets to verify the effectiveness of the introduced registration procedures and feature fitting approaches. The proposed two approaches of line fitting are tested with simulated datasets. The results suggest that these two approaches can produce identical line parameters and variance-covariance matrix. The three registration approaches are tested with both simulated and real datasets. In the simulated datasets, all three registration approaches produced equivalent transformation parameters using linear or planar features. The comparison between the simulated linear and planar features shows that both features can produce equivalent registration results. In the real datasets, the three registration approaches using the linear or planar features also produced equivalent results. In addition, the results using real data indicates that the registration approaches using planar features produced better results than the approaches using linear features. The experiments show that the pseudo-conjugate point-based approach is easier to implement than the feature-based approach. The pseudo-conjugate point-based method and feature-based approach are nonlinear, so an initial guess of transformation parameters is required in these two approaches. Compared to the nonlinear approaches, the closed-form solution is linear and hence it can achieve the registration of two adjacent scans without the requirement of any initial guess for transformation parameters. Therefore, the pseudo-conjugate point-based method and closed-form solution are the preferred approaches for coarse registration using linear or planar features. In real practice, the planar features would have a better preference when compared to linear features since the linear features are derived indirectly by the intersection of neighboring planar features. To get enough lines with different orientations, planes that are far apart from each other have to be extrapolated to derive lines.</p><div><br></div>
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Dating lake bottom sediment by searching for 210Pb using gamma-ray spectroscopyBäckström, William January 2020 (has links)
In a collaboration with limnologists at Uppsala University a planar HPGe detector has been used to find 210Pb in lake bottom sediment in hopes of getting an estimation for the sedimentation rate. Using a least squares fit to the data, the sedimentation rate was calculated to 0.08 ± 0.01 cm/year with background subtraction, and with it a timescale for the age of the sediment could be implemented. With this timescale the lake bottom sediment can be dated as far back as a century. Along with this, using 137Cs traces from the Chernobyl disaster of 1986 a consistency check can be made for our timescale. It is estimated that the Chernobyl disaster occurred at 1989 ± 7 years which is consistent with reality since 1986 is included in the interval 1982-1989. This helps us validate the determined sedimentation rates.
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Řešení problému nejmenších čtverců s maticemi o proměnlivé hustotě nenulových prvků / Least-squares problems with sparse-dense matricesRiegerová, Ilona January 2020 (has links)
Problém nejmenších čtverc· (dále jen LS problém) je aproximační úloha řešení soustav lineárních algebraických rovnic, které jsou z nějakého d·vodu za- tíženy chybami. Existence a jednoznačnost řešení a metody řešení jsou známé pro r·zné typy matic, kterými tyto soustavy reprezentujeme. Typicky jsou ma- tice řídké a obrovských dimenzí, ale velmi často dostáváme z praxe i úlohy s maticemi o proměnlivé hustotě nenulových prvk·. Těmi se myslí řídké matice s jedním nebo více hustými řádky. Zde rozebíráme metody řešení tohoto LS pro- blému. Obvykle jsou založeny na rozdělení úlohy na hustou a řídkou část, které řeší odděleně. Tak pro řídkou část m·že přestat platit předpoklad plné sloupcové hodnosti, který je potřebný pro většinu metod. Proto se zde speciálně zabýváme postupy, které tento problém řeší. 1
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Pop-up public spaces : Explore, experiment, expand / Temporära allmänna platser : utforska, undersök, utvecklaModén, Erick January 2015 (has links)
The 21st century presents the urban environments with challenges in the form of demo- graphic changes, new urban economies and international and culturally diverse cities. These challenges exist within a globalized context that together with digital technology has created rapidly shifting environments. As a result there is a need for constant innovation in a constantly shifting environment. There is a need for temporary exploratory solutions in the built environment in order to highlight tendencies, visualize unseen conflicts and explore new urban forms in order for cities to grow with their residents and users. By analyzing current local regulation in Stockholm regarding public space, temporary structures, usage as well as social factors and an in-depth analysis of three case studies, this project explores and outlines how temporary user projects can act as a compliment to traditional planning practices. The project also explores the role and the limitations of urban entrepreneurship and examines a clear set of values for urban entrepreneurship within temporary spaces. The final synthesis is a framework that seeks to ensure equal access and achieving solutions that are flexible and local. / Det 21:a århundradet presenterar en rad utmaningar för de urbana miljöerna i form av demografiska förändringar, nya urbana ekonomier samt internationella och mångkulturella städer. Dessa utmaningar sker ur ett globaliserat sammanhang som tillsammans med digitala teknologier har skapat snabbt skiftande urbana miljöer. Därmed finns det ett behov av en kontinuerlig innovationsprocess i kontinuerligt skiftande miljöer. Det finns ett behov av temporära, utforskande lösningar, i den byggda miljön för att kunna påvisa tendenser, åskådliggöra osedda konflikter samt utforska nya urbana former för att städer ska kunna växa med sina innevånare och användare. Genom att analysera rådande regelverk i Stockholm gällande offentliga utrymmen, temporära konstruktioner, användande samt sociala faktorer och ingående analyser av tre fallstudier, utforskar detta projekt temporära användarprojekt i den urbana miljön som ett komplement till traditionella planerings praxis. Projektet utforskar urbant entreprenörskaps roll samt begränsningar och undersöker en tydligen värdegrund för urbant entreprenörskap gällande temporära platser. Slutsyntesen är ett ramverk som ämnar till att säkerställa jämlik åtkomst samt skapa flexibla och lokalt relevanta lösningar.
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MSCI Climate Paris Aligned Indices : A quantitative study comparing the performance of SR indices and their conventional benchmark indicesCasselryd, Linnéa, Lantto, Agnes, Zanic, Alicia Julienne January 2021 (has links)
There is no clear consensus about whether green investments perform better, worse orequal to conventional brown investments. With the rising popularity of socialinvestments, it becomes increasingly important to understand these investments. Therecent launch of the MSCI Climate Paris Aligned Indices (CPAI) aim to illustrate thedevelopment of an economy that is in line with the requirements and goals of the ParisAgreement from 2015. In this research we aim to find out whether the MSCI Europe,USA and EM Climate Paris Aligned Indices outperform their parent indices. We do thisby comparing performance measures such as the net return, standard deviation of netreturns and Sharpe ratio. We further conduct an ordinary least squares regression to testwhether the betas and Jensen´s alphas of the CPAI differ significantly from their parentindices.The results show that only the USA CPAI clearly outperforms its parent index. This isdue to it having a higher Sharpe Ratio and Jensen’s alpha as well as higher monthly netreturns and a lower standard deviation compared to its parent index. The regressionshows that it does perform better than the parent index. The results for the EM CPAIshow that it performs in a similar way as its parent index. It has a higher monthly netreturn but also slightly higher standard deviation which leads to an equally large Sharperatio. Neither the estimated Jensen’s alpha nor the beta are significantly different fromthose of its parent index and thus the hypothesis of it performing equally as well as itsparent index cannot not be rejected. Lastly, the Europe CPAI has a higher Sharpe ratio,Jensen’s alpha and monthly net returns than its parent index, but it also exhibits a higherstandard deviation. The regression indicated that it performs in a similar way as itsparent index, no difference could be proven. In conclusion, this means that all CPAIperform at least equally as well as their parent indices, if not better.
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