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Automatsko određivanje i analitička provera parametara uzajamne entropije kardiovaskularnih vremenskih nizova / Automatic determination and analytical verification of cross entropyparameters of cardiovascular time seriesŠkorić Tamara 05 October 2017 (has links)
<p>Unakrsna aproksimativna entropija kvantifikuje međusobnu uređenost<br />dva istomvremeno snimljena vremenska niza. Iako je izvedena iz<br />veoma zastupljene entropije za procenu uređenosti jednog vremenskog<br />niza, još uvek nije dostigla njenu reputaciju. Cilj ove disertacije je<br />da identifikuje probleme koji otežavaju širu primenu unakrsne<br />entropije i da predloži skup rešenja. Validacija rezultata je rađena<br />na kardiovaskularnim signalima, sistolnog krvnog pritiska i palsnog<br />inetervala snimljenim na laboratorijskim pacovima i na signalima<br />zdravih volontera.</p> / <p>Cross-approximate entropy (XApEn) quantifies a mutual orderliness of two<br />simultaneously recorded time series. Although derived from the firmly<br />establishe solitary entropies, it has never reached their reputation and<br />deployment. The aim of this thesis is to identify the problems that preclude<br />wider XApEn implementation and to develop a set of solutions. Results were<br />validated using the cardiovascular time series, systolic blood pressure and<br />pulse interval, recorded from laboratories animals and also signals recorded<br />from healthy human volunteers.</p>
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Communication abstraction for data synchronization in distributed virtual environments : application to multiplayer games on mobile phones / Abstraction de communication pour la synchronisation de données dans les systèmes virtuels et répartis : application aux jeux multijoueurs sur téléphone portableKhan, Abdul Malik 17 June 2010 (has links)
Dans les jeux multijoueurs, où plusieurs joueurs participent à une même partie et communiquent entre eux à travers un réseau, les joueurs peuvent avoir des visions différentes du jeu en raison des délais de communication. Ceci engendre des incohérences encore plus importantes sur les réseaux mobiles tels que les réseaux 3G où les délais de communication peuvent atteindre plusieurs secondes. Des algorithmes doivent donc être mis en place pour maintenir la cohérence entre les joueurs. Ces algorithmes sont assez complexes et difficiles à programmer et mettre au point. Le but de cette thèse est de proposer une architecture logicielle qui découple la conception du jeu, de ses besoins de communication en proposant une infrastructure de communication qui pourra être interchangeable en fonction des technologies ; cette infrastructure prend la forme originale d'un composant de synchronisation. Ainsi, les conséquences des propriétés physiques du transport des informations pourront être plus ou moins masquées en intégrant dans cette infrastructure les algorithmes adéquats. / Multiplayer games users' have increased since the widespread use of the internet. Withthe arrival of rich portable devices and faster cellular wireless networks, multiplayer games on mobile phones and PDAs are becoming a reality. For multiplayer games to be playable, they should be highly interactive, fair and should have a consistent state for all the players. Because of the high wireless network latency and jitters, the issue of providing interactive games with consistent state across the network is non-trivial. In this thesis, we propose different approaches for achieving consistency in mobile multiplayer games in the face of high latency and large and variable jitters. Although absolute consistency is impossible to achieve because information takes time to travel from one place to another, we exploit the fact that strong consistency is not always required in the virtual world and can be relaxed in many cases. Our proposed approach uses the underlying network latency and the position of different objects in the virtual world to decide when to relax consistency and when to apply strong consistency mechanisms. We evaluate our approach by implementing these algorithms in J2ME based games played on mobile phones. The algorithms for consistency mechanism are very complex and are often intermixed with the game core logic's code, which makes it hard to program a game and to change its code in the future. We propose to separate the consistency mechanisms from the game logic and put them in a distributed component responsible for both consistency maintenance and communication over the network. We call this reusable component a Synchronization Medium.
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Application du codage réseau aux plate-formes des jeux en ligne / Network coding application for online games platformesDammak, Marwa 20 November 2018 (has links)
L’application de jeu en ligne massivement multijoueurs fournit une grandepartie du trafic Internet global. Le trafic est généralement composé d’unepetite partie de données utiles encapsulé dans des segments TCP, entrainantun volume élevé d’entêtes transmis via le réseau. Cela implique: 1) la tailledes paquets est trop petite pour un routage efficace et; 2) la bande passanterequise par le serveur augmente. Par conséquent, il est nécessaire de trouverdes techniques de transmission et de routage plus efficaces afin de réduire levolume de trafic et augmenter l’efficacité du réseau permettant de prendre encharge le nombre croissant des joueurs. D’autre part, la qualité d’expérience(QoE) dans le contexte des jeux en ligne est fortement liée à la consistance.Cette consistance est influencée par la qualité de service (QoS) offerte parle réseau, principalement en termes de délai, de gigue et d’ordre de paquets.Par conséquent, une solution qui améliore ces paramètres aidera à satisfairedavantage de joueurs et à améliorer la qualité de service.L’objectif de cette thèse est de proposer des solutions pour améliorerla qualité d’expérience des jeux en ligne en augmentant la consistance devue, en réduisant les délais et en augmentant l’efficacité du réseau. Pour leproblème de consistance, nous proposons une topologie de réseau cyclique.Cette topologie ordonnée facilite la mise en place des procédures de gestionet de contrôle de la transmission pour imposer un ordre causal entre tousles joueurs. Concernant le délai et l’efficacité du réseau, certains ont proposé l’application de la technique du tunnel, compression et multiplexage(TCM). Cependant, les paquets transmis avec TCM sont plus grands queceux d’origine, ce qui nécessite plus de temps pour les transmettre et augmente le risque de saturation au niveau des fils d’attente. Nous proposonsl’utilisation de la technique de codage réseau (NC) qui permet d’augmenterle débit dans certaines conditions de topologies et de routage. Cette technique permet aux nœuds intermédiaires d’encoder les paquets qu’ils reçoivent plutôt que d’effectuer une simple fonction de stockage et de transfert. Celapeut réduire la charge de trafic, réduire les délais et augmenter l’efficacité duréseau.Dans cette thèse, nous proposons des modifications pour améliorer latechnique TCM et nous évaluons ses performances. De plus, nous proposonsd’ajouter le concept de partition des joueurs et de changer la topologie d’unarbre à une forêt. Nous étudions ensuite la topologie cyclique. Nous concevons un protocole de routage optimisé sur une topologie en cycle baséesur la technique de codage réseau. Puis, nous évaluons ses performances entermes de délai, de charge et d’ordre. Les résultats montrent que l’utilisationdu codage NC permet de réduire la charge et le nombre de paquets transmis, garantir un ordre de paquet par période et de réduire le délai. Eneffet, on peut gagner jusqu’à 14% de latence avec notre protocole par rapport à un protocole de routage optimisé sans codage réseau. Par la suite,nous proposons un scénario de mise en pratique de cette solution sur une infrastructure Device-to-Device. Nous validons les limites théoriques du délaien utilisant des simulations réseau et nous discutons ensuite des contraintespratiques qui s’imposent lors de l’implémentation dans un réseau réel. Finalement, nous proposons des solutions pour ces contraintes. / The application of massively multiplayer online games provides a large partof the global internet traffic. The traffic is typically encapsulated in TCPsegments of small size information (the so called payload) resulting in a highvolume of headers transmitted through the network. This implies the following: 1) the packets’ size is too small for efficient routing and; 2) thebandwidth required by the server seems to be increasing. Therefore, it isnecessary to find more efficient transmission and routing techniques to reduce the traffic’s volume and to increase the network’s efficiency in orderto support the growing number of players. On the other hand, Quality ofExperience (QoE) in the context of online games is strongly influenced byconsistency. This consistency is influenced by the quality of service (QoS) offered by the network, mainly in terms of delay, jitter and order of the packets.As a result, a solution that enhances these parameters will help in satisfyingmore players and subsequently improving QoE.The goal of this thesis is to propose solutions to enhance the QoE of onlinegames by increasing the consistency of view, reducing the delay and increasing the efficiency of the network. For consistency, we propose a cyclic networktopology. This ordered topology facilitates the implementation of transmission management and control procedures to impose a causal order betweenall players. As for the delay and the efficiency problem, some have proposed the application of Tunneling, Compression and Multiplexing (TCM)technique. However, the transmitted packets with TCM are larger than theoriginal ones, which requires more delay to transmit them and increases therisk of congestion. We propose the use of the Network Coding technique(NC) which makes it possible to increase the bit rate of the network undercertain topological and routing conditions. This technique allows intermediate nodes to encode the data they receive rather than perform a simple”store and forward” function. It can reduce the traffic load, reduce the delay and increase the network’s efficiency.In this thesis, we propose some modifications to enhance the TCM technique and evaluate its performance. Besides, we propose to add the playerspartition approach and change the topology from a tree to a forest. Afterwards, we investigate the cyclic topology. We design an optimized routingprotocol over a cycle topology based on the network coding technique andevaluate its performance in terms of delay and order. The results show thatby using NC coding, one can gain up to 14% of latency over an optimizedrouting protocol for the cycle topology without the use of network coding.Afterwards, we propose a practical implementation scenario of this solutionover a device-to-device (D2D) infrastructure. We finally validate the theoretical limits of delay using network simulations and discuss a number ofpractical constraints.
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Statistical inference in high dimensional linear and AFT modelsChai, Hao 01 July 2014 (has links)
Variable selection procedures for high dimensional data have been proposed and studied by a large amount of literature in the last few years. Most of the previous research focuses on the selection properties as well as the point estimation properties. In this paper, our goal is to construct the confidence intervals for some low-dimensional parameters in the high-dimensional setting. The models we study are the partially penalized linear and accelerated failure time models in the high-dimensional setting. In our model setup, all variables are split into two groups. The first group consists of a relatively small number of variables that are more interesting. The second group consists of a large amount of variables that can be potentially correlated with the response variable. We propose an approach that selects the variables from the second group and produces confidence intervals for the parameters in the first group. We show the sign consistency of the selection procedure and give a bound on the estimation error. Based on this result, we provide the sufficient conditions for the asymptotic normality of the low-dimensional parameters. The high-dimensional selection consistency and the low-dimensional asymptotic normality are developed for both linear and AFT models with high-dimensional data.
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Data-centric solution methodologies for vehicle routing problemsCakir, Fahrettin 01 August 2016 (has links)
Data-driven decision making has become more popular in today’s businesses including logistics and vehicle routing. Leveraging historical data, companies can achieve goals such as customer satisfaction management, scalable and efficient operation, and higher overall revenue.
In the management of customer satisfaction, logistics companies use consistent assignment of their drivers to customers over time. Creating this consistency takes time and depends on the history experienced between the company and the customer. While pursuing this goal, companies trade off the cost of capacity with consistency because demand is unknown on a daily basis. We propose concepts and methods that enable a parcel delivery company to balance the trade-off between cost and customer satisfaction. We use clustering methods that use cumulative historical service data to generate better consistency using the information entropy measure.
Parcel delivery companies route many vehicles to serve customer requests on a daily basis. While clustering was important to the development of early routing algorithms, modern solution methods rely on metaheuristics, which are not easily deployable and often do not have open source code bases. We propose a two-stage, shape-based clustering approach that efficiently obtains a clustering of delivery request locations. Our solution technique is based on creating clusters that form certain shapes with respect to the depot. We obtain a routing solution by ordering all locations in every cluster separately. Our results are competitive with a state-of-the-art vehicle routing solver in terms of quality. Moreover, the results show that the algorithm is more scalable and is robust to problem parameters in terms of runtime.
Fish trawling can be considered as a vehicle routing problem where the main objective is to maximize the amount of fish (revenue) facing uncertainty on catch. This uncertainty creates an embedded prediction problem before deciding where to harvest. Using previous catch data to train prediction models, we solve the routing problem a fish trawler faces using dynamically updated routing decisions allowing for spatiotemporal correlation in the random catch. We investigate the relationship between the quality of predictions and the quality of revenue generated as a result.
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Individual Endorsement of Remarriage beliefs, Consistency of Cognitions between Spouses, and Outcomes in RemarriageAgee, Lyndy Sue 01 May 2009 (has links)
ABSTRACT Despite the increasing prevalence of remarriages over the last several decades, little work has been done in establishing theories and models specific to remarried couples and stepfamilies. To address this gap, the multidimensional cognitive development model for individuals in stepfamilies was utilized. To evaluate the model, this study tested the consistency tenet, which is central to the model. Consistency of cognitions is assumed to be of primary importance in stepfamily relationships and a balanced system is one that is defined by consistency of cognitions. Data were analyzed from the "Relationship Quality and Stability in Utah Newlywed Remarriages" study. With a sample of 447 husband and wife couples, paired sample t tests and hierarchical regression were completed. The results indicate that individual endorsements of remarriage beliefs are more predictive of remarital outcomes than is consistency of cognitions between husband and wife. A critique of the multidimensional cognitive development model is discussed. Limitations of the current study are addressed and recommendations for future research are given.
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Improving Spectrophotometric Carbon System MeasurementsPatsavas, Mark 03 April 2014 (has links)
This work provides improved procedures for spectrophotometric carbon system measurements. Indicator dyes used for routine spectrophotometric pH measurements in seawater suffer from impurity issues, which introduce vendor-specific systematic errors in pH determinations. The magnitude of these errors for several vendors was investigated for meta Cresol Purple (mCP) and Cresol Red (CR). Flash chromatography procedures were developed to obtain purified mCP and CR on a bulk scale in order to supply the oceanographic research community with the indicators. Easy access to the purified indicators ensures global intercomparability of spectrophotometric pH determinations.
Internal consistency of marine inorganic carbon system measurements was studied using datasets obtained on two large coastal ocean acidification research cruises. In both cases, purified mCP was used to obtain the pH measurements, thereby improving accuracy relative to previous studies in which measurements were obtained with unrefined mCP. Based on this internal consistency study, recommendations are made for selecting the parameter pairs used for saturation state calculations.
Direct spectrophotometric methods for measuring carbonate ion concentrations in seawater were improved by (a) using a higher concentration of lead as the carbonate indicator and (b) altering the carbonate computational algorithm based on high quality field data. Measurements of DIC and pH (using purified mCP) were used to calculate carbonate ion concentrations for comparison with spectrophotometrically measured carbonate ion concentrations (i.e., via spectrophotometric measurements of Pb(II) spectra in the ultraviolet). Minor changes in the computational algorithm substantially improved agreement between measured and calculated carbonate ion concentrations.
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Varför gick jag på det där? : Konsumentens behov av att vara konsekventThomsen, Linda January 2009 (has links)
<p>Individer har olika grad av Preference for consistency (PFC) och är en bidragande orsak till hur man uppfattar och agerar i konsumentsammanhang. Studien undersökte om höga PFC- individer var mer positiva till ”ett erbjudande” med hög konsekvenskänsla. Tre betingelser med varierande manipulationsgrad användes och data samlades in från 74 studenter. Ett frågeformulär med tillhörande erbjudande presenterades för deltagarna som fyllde i ett antal frågor och en PFC-B skala. Studien lyckades inte ge stöd åt hypotesen. Däremot förekom en illusion av osårbarhet och en tredjepersoneffekt. Studien lyckades troligtvis inte konstruera ett tillräckligt bra instrument som skapade rätt konsekventkänsla vilket bidrog till att deltagarna inte blev påverkade av erbjudandet i den grad som var förväntat.</p>
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Mémoire partagée distribuée pour systèmes dynamiques à grande échelleGramoli, Vincent 22 November 2007 (has links) (PDF)
Cette thèse étudie les nouveaux défis du contexte du partage de donnée liés au récent changement d'échelle des systèmes répartis. De nos jours les systèmes répartis deviennent très grands. Cet accroissement concerne non seulement le nombre de personnes qui communiquent dans le monde via leur ordinateur mais aussi le nombre d'entités informatiques personnelles connectées. De tels grands systèmes sont sujets au dynamisme du fait du comportement imprévisible de leurs entités. Ce dynamisme empêche l'adoption de solutions classiques et plus simplement affecte la communication entre des entités distinctes. Cette thèse étudie les solutions existantes et propose des suggestions de recherche pour la résolution du problème fondamental de mémoire partagée distribuée dans un tel contexte dynamique et à grande échelle.
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Two Sides of the Same Coin : A study of EFL-teachers‟ knowledge regarding the divergences between British and American English; and the challenges which arise from having more than one accepted variety of English in EFL teaching.Jensen, Linda January 2010 (has links)
<p>Institution: Halmstad University/School of Teacher Education (LUT)</p><p>Course: C-level paper, 15 credits</p><p>Term: Spring 2010</p><p>Title: Two Sides of the Same Coin - A study of EFL-teachers knowledge regarding the divergences between British and American English; and the challenges which arise from having more than one accepted variety of English in EFL teaching.</p><p>Pages: 41</p><p>Writer: Linda Jensen</p><p>Purpose: The purpose of this essay is to ascertain if Swedish EFL teachers have sufficient knowledge regarding the differences between BrE and AmE, the two major varieties of English. Furthermore, I aim to examine what challenges are created when two models of English, BrE and AmE, are accepted in upper secondary schools in Sweden.</p><p>Method: A quantitative web-based survey.Material: Questionnaire filled in by 59 EFL teachers in upper secondary schools in Halland, Sweden.</p><p>Main results: Upper secondary EFL teachers in Halland, Sweden do appear to have a basic knowledge of the differences between BrE and AmE and as such a majority placed themselves in the correct category. However, there is a lack of consistency and all the teachers mixed the two varieties to some extent. The challenges that arise from having two accepted varieties in Swedish schools are amongst other things the question of the consistency rule, dealing with the value system associated with British and American English and the question of whether Mid-Atlantic English should be accepted as a third educational standard.</p><p>Keywords: British English, American English, Mid-Atlantic English, divergence, EFL, consistency, challenges, value system.</p>
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