Cette thèse s'articule autour de l'étude de la cohérence de la lumière produite à partir de sources de paires de photons intriqués et de micro-lasers. Nous avons produit et manipulé des états photoniques intriqués, et conduit des investigations à la fois fondamentales et appliquées. Les deux études menées sur les aspects fondamentaux de la non localité avaient pour but de relaxer partiellement deux contraintes sur lesquelles s'appuie l'inégalité de Bell standard en vue d'applications à la cryptographie quantique. Ainsi, en collaboration avec l'Université de Genève, nous avons redéfini la notion de localité en prenant en compte les influences sur les mesures de corrélations des choix des configurations expérimentales et d'une efficacité globale de détection limitée. Cela a permis de définir des inégalités de Bell généralisées et les violations expérimentales qui en découlent permettent d'attester de la non localité des états quantiques observés. Nous avons aussi étudié et mis en place une solution expérimentale autorisant l'émission de photons intriqués dans des pairs de canaux télécoms pour la cryptographie quantique. Nous avons montré la préservation de l'intrication sur 150 km et obtenu des débits records en comparaison avec les réalisations similaires. Enfin, nous avons étudié les propriétés de l’émission de lasers à semi-conducteurs aux dimensions réduites. L’émission de ces composants microscopiques s'accompagne de grandes fluctuations en intensité lorsque ceux-ci sont pompés en-dessous du seuil laser. Cette étude a permis de mieux comprendre comment se construit la cohérence laser dans ces systèmes. / In this thesis we study the coherence of light emitted by entangled photon-pair sources and micro-lasers. We have generated an manipulated entangled photonic states and investigated both fundamental (non locality) and applied (quantum cryptography) research directions. The objective of two fundamental studies on non locality was to partially relax the strong assumptions on which standard Bell tests rely. To this end, we redefined, in collaboration with the University of Geneva, the formalism of locality taking into account the influence, on correlation measurements, of the freedom of choice (in the basis settings) and of the limitation of the overall detection efficiency. Both assumptions allow devising generalized Bell inequalities whose experimental violations indicate that we can still attest for non locality for the observed states. In addition, we have studied and realized an experimental setup allowing to distribute entangled photon pairs in paired telecom channels for high bit rate quantum cryptography. We have shown that entanglement is preserved over a distance of 150 km with record rates for similar realizations, by mimicking classical network solutions exploiting, in an optimal fashion, the capacity of an optical fiber link via dense spectral multiplexing. Finally, we have studied the properties of light emitted by semiconductor lasers showing reduced dimensionality. This micro-lasers actually provide output light under high intensity fluctuations when they are pumped below the threshold. Their study allowed to refine our understanding on how the coherence builds up in these systems as the cavity is filled with photons.

Title: Estimation of the algebraic error and stopping criteria in numerical solution of partial differential equations Author: Jan Papež Department: Department of Numerical Mathematics Supervisor of the master thesis: Zdeněk Strakoš Abstract: After introduction of the model problem and its properties we describe the Conjugate Gradient Method (CG). We present the estimates of the energy norm of the error and a heuristic for the adaptive refinement of the estimate. The difference in the local behaviour of the discretization and the algebraic error is illustrated by numerical experiments using the given model problem. A posteriori estimates for the discretization and the total error that take into account the inexact solution of the algebraic system are then discussed. In order to get a useful perspective, we briefly recall the multigrid method. Then the Cascadic Conjugate Gradient Method of Deuflhard (CCG) is presented. Using the estimates for the error presented in the preceding parts of the thesis, the new stopping criteria for CCG are proposed. The CCG method with the new stopping criteria is then tested. Keywords: numerical PDE, discretization error, algebraic error, error es- timates, locality of the error, adaptivity

Diploma thesis deals with the participation and representation of Roma in the Czech Republic mainly in social inclusion. Generally in the Czech Republic the principles of the participation are underused during the development and implementation of public policies. A certain change occurs at the local level. In some towns there are gradually promoted models of the participation and representation of the population of excluded localities. This thesis deals by the methods of case study, summative evaluation and observation with implementation of certain local good practice: the system of the caretaking in the town Kadaň - Prunéřov, which primarily addresses the issue of housing in the socially excluded locality, but with the full participation of its people, including the creation of a natural representation, leading to the improvement of social skills of people, their self-confidence and willingness to engage in solving their unsatisfactory situation. The thesis also summarizes the development in the formation of Roma representation at the highest level since the 90s of the last century and its adverse impact on the development of real participation of Roma in social inclusion at all levels of administration. Therefore there is a contrast between the situation in the participation and representation...

The diploma thesis deals with the use of the localities Houšťka Forest Park and Hluchov Floodplain Forest in the teaching of natural history at the 2nd level of primary schools, biology at the lower levels of grammar schools and at vocational secondary schools. Part of the theoretical part is a description of natural conditions and history of the site, the division into habitats and their characteristics. Furthermore, an inventory and description of plant species, including a list of zoological taxa, was performed for the needs of teachers. The questionnaire survey among teachers was focused on the use of localities during regular lessons, or compulsory optional subjects focused on natural history. The time required for the worksheets was based on the results of this survey. The didactic part includes the issue of interdisciplinary relationships, enumeration and description of forms and methods used in the teaching of science and biology. The main part of this part of the thesis are worksheets, which are in addition to consolidating knowledge of natural sciences and biology focused on the application of knowledge from other subjects such as mathematics, physics. After completing the worksheet, the individual exercises were corrected. In the qualitative research, on the basis of a questionnaire...

The rapid growth of Internet Traffic has emerged as a major issue due to the rapid development of various network applications and Internet services. One of the challenges facing Internet Service Providers (ISPs) is to optimize the performance of their networks in the face of continuously increasing amounts of IP traffic while guaranteeing some specific Quality of Services (QoS). Therefore it is necessary for ISPs to study the traffic patterns and user behaviors in different localities, to estimate the application usage trends, and thereby to come up with solutions that can effectively, efficiently, and economically support their users’ traffic. The main objective of this thesis is to analyze and characterize traffic in a local multi-service residential IP network in Sweden (referred to in this report as “Network North”). The data about the amount of traffic was measured using a real-time traffic-monitoring tool from PacketLogic. Traffic from the monitored network to various destinations was captured and classified into 5 ring-wise locality levels in accordance with the traffic’s geographic destinations: traffic within Network North and traffic to the remainder of the North of Sweden, Sweden, Europe, and World. Parameters such as traffic patterns (e.g., traffic volume distribution, application usage, and application popularity) and user behavior (e.g., usage habits, user interests, etc.) at different geographic localities were studied in this project. As a result of a systematic and in-depth measurement and the fact that the number of content servers at the World, Europe, and Sweden levels are quite large, we recommend that an intelligent content distribution system be positioned at Level 1 localities in order to reduce the amount of duplicate traffic in the network and thereby removing this traffic load from the core network. The results of these measurements provide a temporal reference for ISPs of their present traffic and should allow them to better manage their network. However, due to certain circumstances the analysis was limited due to the set of available daily traffic traces. To provide a more trustworthy solution, a relatively longer-term, periodic, and seasonal traffic analysis could be done in the future based on the established measurement framework. / Den ökande tillväxten av Internet Trafik har blivit en viktig fråga med anledning av den snabba utvecklingen av olika internetbaserade applikationer och tjänster. En av utmaningarna för Internet leverantörerna är att optimera prestandan i sina nät inför de ständigt ökande datamängderna och samtidigt garantera kvalitet på tjänsterna (QoS). Därför är det nödvändigt för Internetleverantörer att studera trafikmönster och lokala differentierade användarbeteenden, för att uppskatta trender av nyttjande av internettjänster, och därmed komma med lösningar som effektivt och ekonomiskt stödja deras kunders trafik. Det främsta syftet med denna avhandling är att analysera och karaktärisera internettrafiken i ett lokalt IP baserat multiservicenätverk i Sverige (i denna rapport avseende "Network North"). Uppgifterna om trafikmängden mättes i realtid med ett övervakningsverktyg från PacketLogic. Trafik till och från det övervakade nätverkets olika destinationer fångades upp och delades in i 5 cirkelliknande lokaliseringsnivåer i enlighet med geografiska trafikdestinationer: trafik inom nätverket North och till resten av norra Sverige, Sverige, Europa och världen. Parametrar som trafikmönster (t.ex. distribuerad internettrafik mängd, användning av olika tjänster och applikationer med dess popularitet) och användarbeteenden (t.ex. användar-vanor och intressen, etc.) på olika geografiska lokaliseringsnivåer har studerades i inom projekt. Som ett resultat av de systematiska och djupgående internetmätningar med det faktum av det stora antalet existerande tjänsteinnehållsservrar som ofta finns placerad långt ifrån slutanvändaren, ute i världen eller i Europa som är ganska så många till antalet. Rekommenderar vi att ett intelligent tjänstedistributionssystem appliceras närmre slutanvändaren på en regional nivå, för att minska på dagens onödiga omfattande duplicerande internettrafik i nom stamnäteten. Resultaten av dessa trafikmätningar av internettrafik ger en tidsmässig referens för Internetleverantörerna av deras nuvarande trafik och bör göra det möjligt för dem att bättre hantera sin nätverksinfrastruktur. Men på grund av vissa omständigheter begränsades mätanalysen på grund av möjliga och tillgängliga tidrammar att utföra dagliga trafikmätningsuppsättningen. För att ge en mer tillförlitlig lösning kan en på en längre sikt, periodisk och säsongsbunden trafikanalys göras i framtiden, baserat på den etablerade mätinfrastrukturen.

In this thesis, we study the notion of graph summarization, which is a fundamental task of finding a compact representation of the original graph called the summary. Graph summarization can be used for reducing the footprint of the input graph, better visualization, anonymizing the identity of users, and query answering. There are two different frameworks of graph summarization we consider in this thesis, the utility-based framework and the correction set-based framework. In the utility-based framework, the input graph is summarized until a utility threshold is not violated. In the correction set-based framework a set of correction edges is produced along with the summary graph. In this thesis we propose two algorithms for the utility-based framework and one for the correction set-based framework. All these three algorithms are for static graphs (i.e. graphs that do not change over time). Then, we propose two more utility-based algorithms for fully dynamic graphs (i.e. graphs with edge insertions and deletions). Algorithms for graph summarization can be lossless (summarizing the input graph without losing any information) or lossy (losing some information about the input graph in order to summarize it more). Some of our algorithms are lossless and some lossy, but with controlled utility loss. Our first utility-driven graph summarization algorithm, G-SCIS, is based on a clique and independent set decomposition, that produces optimal compression with zero loss of utility. The compression provided is significantly better than state-of-the-art in lossless graph summarization, while the runtime is two orders of magnitude lower. Our second algorithm is T-BUDS, a highly scalable, utility-driven algorithm for fully controlled lossy summarization. It achieves high scalability by combining memory reduction using Maximum Spanning Tree with a novel binary search procedure. T-BUDS outperforms state-of-the-art drastically in terms of the quality of summarization and is about two orders of magnitude better in terms of speed. In contrast to the competition, we are able to handle web-scale graphs in a single machine without performance impediment as the utility threshold (and size of summary) decreases. Also, we show that our graph summaries can be used as-is to answer several important classes of queries, such as triangle enumeration, Pagerank and shortest paths. We then propose algorithm LDME, a correction set-based graph summarization algorithm that produces compact output representations in a fast and scalable manner. To achieve this, we introduce (1) weighted locality sensitive hashing to drastically reduce the number of comparisons required to find good node merges, (2) an efficient way to compute the best quality merges that produces more compact outputs, and (3) a new sort-based encoding algorithm that is faster and more robust. More interestingly, our algorithm provides performance tuning settings to allow the option of trading compression for running time. On high compression settings, LDME achieves compression equal to or better than the state of the art with up to 53x speedup in running time. On high speed settings, LDME achieves up to two orders of magnitude speedup with only slightly lower compression. We also present two lossless summarization algorithms, Optimal and Scalable, for summarizing fully dynamic graphs. More concretely, we follow the framework of G-SCIS, which produces summaries that can be used as-is in several graph analytics tasks. Different from G-SCIS, which is a batch algorithm, Optimal and Scalable are fully dynamic and can respond rapidly to each change in the graph. Not only are Optimal and Scalable able to outperform G-SCIS and other batch algorithms by several orders of magnitude, but they also significantly outperform MoSSo, the state-of-the-art in lossless dynamic graph summarization. While Optimal produces always the most optimal summary, Scalable is able to trade the amount of node reduction for extra scalability. For reasonable values of the parameter $K$, Scalable is able to outperform Optimal by an order of magnitude in speed, while keeping the rate of node reduction close to that of Optimal. An interesting fact that we observed experimentally is that even if we were to run a batch algorithm, such as G-SCIS, once for every big batch of changes, still they would be much slower than Scalable. For instance, if 1 million changes occur in a graph, Scalable is two orders of magnitude faster than running G-SCIS just once at the end of the 1 million-edge sequence. / Graduate

The diploma thesis titled "Social exclusion of Roma at the local level and strategy of overcoming" is divided into two parts - theoretical and practical. The goal of the thesis is to answer two main research questions: "What are the specific characteristics of life of the Roma in socially excluded locality Smíchov?" and "How do the Roma living in Smíchov perceive possibilities of the overcoming social exclusion of the Roma?". The theoretical part is insight into the problems of social exclusion of the Roma in the Czech Republic. It outlines the history of the Roma and the general concepts of coexistence of majority and minority. It also contains a description of the specific features of the social exclusion of the Roma in the Czech Republic and opportunities of social work in the Roma community. The theoretical part is followed by empirical part, which is based on a framework analysis of ten interviews with Roma respondents from Smíchov. The research examined the economic situation, social contacts, education level, life satisfaction and difficulties experience of discrimination and attitudes towards media image of Roma, politics and the police.

<p>    </p> <p>Programs that use loops to operate over arrays and matrices are generally known as <em>regular programs</em>. These programs appear in critical applications such as image processing, differential equation solvers, and machine learning. Over the past few decades, extensive research has been done on composing, verifying, and applying scheduling transformations like loop interchange and loop tiling for regular programs. As a result, we have general frameworks such as the polyhedral model to handle transformations for loop-based programs. Similarly, programs that use recursion and loops to manipulate pointer-based data structures are known as <em>irregular programs</em>. Irregular programs also appear in essential applications such as scientific simulations, data mining, and graphics rendering. However, there is no analogous framework for recursive programs. In the last decade, although many scheduling transformations have been developed for irregular programs, they are ad-hoc in various aspects, such as being developed for a specific application and lacking portability. This dissertation examines principled ways to handle scheduling transformations for recursive programs through a unified framework resulting in performance enhancement. </p> <p>Finding principled approaches to optimize irregular programs at compile-time is a long-standing problem. We specifically focus on scheduling transformations that reorder a program’s operations to improve performance by enhancing locality and exploiting parallelism. In the first part of this dissertation, we present PolyRec, a unified general framework that can compose and apply scheduling transformations to nested recursive programs and reason about the correctness of composed transformations. PolyRec is a first-of-its-kind unified general transformation framework for irregular programs consisting of nested recursion and loops. It is built on solid theoretical foundations from the world of automata and transducers and provides a fundamentally novel way to think about recursive programs and scheduling transformations for them. The core idea is designing mechanisms to strike a balance between the expressivity in representing the set of dynamic instances of computations, transformations, and dependences and the decidability of checking the correctness of composed transformations. We use <em>multi-tape </em>automata and transducers to represent the set of dynamic instances of computations and transformations, respectively. These machines are similar yet more expressive than their classical single-tape counterparts. While in general decidable properties of classical machines are undecidable for multi-tape machines, we have proven that those properties are decidable for the class of machines we consider, and we present algorithms to verify these properties. Therefore these machines provide the building blocks to compose and verify scheduling transformations for nested recursion and loops. The crux of the PolyRec framework is its regular string-based representation of dynamic instances that allows to lexicographically order instances identically to their execution order. All the transformations considered in PolyRec require different ordering of these strings representable only with <em>additive </em>changes to the strings. </p> <p>Loop transformations such as <em>skewing </em>require performing arithmetic on the representation of dynamic instances. In the second part of this dissertation, we explore this space of transformations by introducing skewing to nested recursion. Skewing plays an essential role in producing easily parallelizable loop nests from seemingly difficult ones due to dependences carried across loops. The inclusion of skewing for nested recursion to PolyRec requires significant extensions to representing dynamic instances and transformations that facilitate <em>performing arithmetic using strings</em>. First, we prove that the machines that represent the transformations are still composable. Then we prove that the representation of dependences and the algorithm that checks the correctness of composed transformations hold with minimal changes. Our new extended framework is known as UniRec, since it resembles the unimodular transformations for perfectly nested loop nests, which consider any combination of the primary transformations interchange, reversal, and skewing. UniRec opens possibilities of producing newly composed transformations for nested recursion and loops and verifying their correctness. We claim that UniRec completely subsumes the unimodular framework for loop transformations since nested recursion is more general than loop nests. </p>

No description available.

No description available.