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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Topics in sequence analysis

Ma, Jinyong 12 November 2012 (has links)
This thesis studies two topics in sequence analysis. In the first part, we investigate the large deviations of the shape of the random RSK Young diagrams, associated with a random word of size n whose letters are independently drawn from an alphabet of size m=m(n). When the letters are drawn uniformly and when both n and m converge together to infinity, m not growing too fast with respect to n, the large deviations of the shape of the Young diagrams are shown to be the same as that of the spectrum of the traceless GUE. Since the length of the top row of the Young diagrams is the length of the longest (weakly) increasing subsequence of the random word, the corresponding large deviations follow. When the letters are drawn with non-uniform probability, a control of both highest probabilities will ensure that the length of the top row of the diagrams satisfies a large deviation principle. In either case, both speeds and rate functions are identified. To complete our study, non-asymptotic concentration bounds for the length of the top row of the diagrams, are obtained for both models. In the second part, we investigate the order of the r-th, 1<= r < +∞, central moment of the length of the longest common subsequence of two independent random words of size n whose letters are identically distributed and independently drawn from a finite alphabet. When all but one of the letters are drawn with small probabilities, which depend on the size of the alphabet, the r-th central moment is shown to be of order n^{r/2}. In particular, when r=2, we get the order of the variance of the longest common subsequence.
52

Ramadaneffekten? : En systematisk prisavvikelse på muslimska marknader / The Ramadan Effect? : A systematic price deviation on Muslim markets

Lindström, Mattias, Mattsson, Jessica, Strandberg, Johanna January 2011 (has links)
Bakgrund: Den heliga fastemånaden Ramadan innebär stora omställningar i cirka en och en halv miljard muslimers liv. Detta har, med bakgrund i den effektiva marknadshypotesen, föranlett flera olika undersökningar av eventuellt återkommande prisavvikelser i samband med Ramadan, en så kallad Ramadaneffekt. Tidigare studier visar dock på något motstridiga resultat vilket gör att vidare forskning inom området är motiverad. De till viss del förändrade livsvillkor som Ramadan innebär har i tidigare studier använts som förklaringsvariabler, något som dock kan ifrågasättas och undersökas vidare med utgångspunkt i Behavioral finance. Syfte: Denna studie ämnar undersöka om det existerar någon Ramadaneffekt på 17 olika muslimska aktiemarknader samt att kritiskt granska tidigare studier inom området och förklaringsvärdet i fastans fysiska och psykiska påverkan vid en eventuell Ramadaneffekt. Genomförande: Studien är av både kvalitativ och kvantitativ karaktär med huvudsaklig tyngdpunkt i statistiska analyser av studiens datamaterial. Regressionsanalys med dummyvariabler utgör den statistiska metoden och resultatet analyseras genom att applicera Behavioral finance till dokumentstudien för att försöka förklara de statistiska resultaten. Slutsats: Studien finner att endast den pakistanska aktiemarknaden uppvisar en signifikant prisavvikelse under Ramadan. Detta ligger inte i linje med tidigare forskning. Tidigare använda förklaringsvariabler tycks inte heller de ha något stort förklaringsvärde då fastans fysiska och psykiska påverkan torde yttra sig likadant i samtliga länder men effekterna på aktiemarknaderna skiljer sig åt. / Background: Ramadan, the holy month of fasting, means many changes in the lives of approximately one and a half billion Muslims. This, with background in the efficient market hypothesis, has resulted in several studies on potentially reoccurring price deviations in connection with Ramadan, a so-called Ramadan effect. Previous studies show somewhat conflicting results, which motivates further research within the subject. The changed routines of daily life during Ramadan have previously been used as the explanatory variable for the Ramadan effect. The authors question the validity of this relationship and therefore further examine it with an argumentative base in Behavioral finance. Aim: This study aims to investigate whether a Ramadan effect exists on any of 17 Muslim stock markets. Furthermore, it aims to critically analyze previous research within the area and examine whether the physical and psychological effects of fasting have any explanatory value in an eventual existence of a Ramadan effect. Completion: The study uses both a qualitative and quantitative approach with a focus on statistical analysis of the study’s numerical data. Regression analysis with dummy variables represents the statistical method and the results are analyzed by applying Behavioral finance to the literature study in order to explain the results. Conclusion: The only market that shows a systematic price deviation during Ramadan is Pakistan. This is not coherent with previous research. Furthermore, the previously used explanatory variables do not seem to have any great explanatory value since the variables are coherent across the markets whereas the effects on the stock markets are not.
53

Sexuell perversion eller moralisk progresion? : En idéhistorisk studie i hur 1960-talets sexualpolitiska debatt manifesterade de sexuella avvikarnas beskaffenheter, och hur dessa perspektiv sedan avspeglade sig i SOU 1976:9.

Rydström, Fredrik January 2008 (has links)
The main purpose with this essay is to evaluate how the characters of the sexually deviated was discussed during the sexual political debate in the 1960s, and if those apprehensions were reflected in SOU 1976:9 concerning sexual abuse. Furthermore, my prime intention will be to compare the reconstructed historical context, alias the sexual political debate, with the analyzed document, with the purpose to explicate why the anticipated political action weren’t sanctioned and implemented by the parliament. The analysis is carried out through a methodology that retrieves its primal premises from Quentin Skinners theories regarding the history of ideas. My most essential conclusions would be that there in fact existed an equivalence regarding the ideological framework between the radical axioms that was conceived during the sexual political debate and the stipulations that was formulated in the document. Thus, the comparison indicate that SOU 1976:9 was published in a ideological milieu that were in fact contrasting with the ontological premises that supposedly guided the committees intentions.
54

Kalkylavvikelser : Aktiv påverkan i det dagliga arbetet i tillverkande företag / Calculated deviations : Active impact in the daily work in manufacturing companies

Filipsson, Amanda, Andersson, Elin January 2015 (has links)
Dagens samhälle präglas av ständiga förändringar i omvärlden. Internationalisering, globalisering och teknikutveckling är faktorer som leder till en ökad global konkurrens för företagen, vilket gjort att företag måste förbättra sina processer för att vara fortsatt konkurrenskraftiga och lönsamma. Det ständigt förändrade samhället kräver en väl genomförd ekonomistyrning för att företag ska kunna följa med i utvecklingen. Tillverkande företag är en stor del av det svenska näringslivet och måste därmed anpassa sig i den takt som globaliseringen sker. Många forskare har identifierat en kunskapslucka mellan ekonomistyrning i teori och praktik, då mycket forskning och utveckling av metoder inom ekonomistyrningen äger rum utan att man ser till hur detta uppfattas i praktiken.   Syftet med denna studie är att se vilka orsaker som kan förklara varför eventuella kalkylavvikelser uppstår i ett tillverkande företag inom fordonsindustrin i Sverige, samt hur dessa avvikelser kan påverkas och reduceras genom aktiv påverkan i det dagliga arbetet. Med intern benchmarking och Kaizen som verktyg vill vi öka kunskapen om dessa avvikelser och hur de kan påverkas, för att sedan reduceras och ge en bättre precision i förkalkylerna. Studien har genomförts med intervjuer, möten och observationer på två fallavdelningar i ett större tillverkande företag, för att skapa en djupare förståelse. Vidare har studien genomförts med ett kvalitativt tillvägagångssätt.   Resultaten vi funnit genom studien visar att möjligheten till att påverka de kalkylavvikelser som uppstår är stor. Möjligheten till aktiv påverkan skiljer sig beroende på vilken position i företaget respondenterna har. Studien visar att de flesta respondenter anser att tidsbrist är den största anledningen till att de inte använder sig mer av verktyg för påverkan såsom Kaizen och intern benchmarking. Vidare har vi funnit att medarbetare motiveras av mer än enbart monetär ersättning, såsom att få gehör och muntlig uppmuntran. Av studien kan konstateras att olika verktyg för effektiviseringar i teorin ofta framställs som oproblematiska och enkla att implementera, men i verkligheten och praktiken är det mer komplicerat. / Today´s society is characterized by constant changes in the business environment. Internationalization, globalization and development in technology are factors that lead to increased global competition between companies, why companies must improve their processes to remain competitive and profitable. The constantly changing society requires a well-implemented management control to keep up with the development, Manufacturing companies represents a big part of the Swedish industry. The companies must therefore adapt to the pace of globalization. Researchers have identified a gap in knowledge between management control in theory and practice. Research and development of methods for management control take place without ensuring how it is perceived in practice.   The purpose of this study is to define the reasons that explain why calculated deviations occur in the automobile industry in Sweden and how these deviations can be affected and reduced by active impact in the daily work. Our hope is to increase the knowledge about the deviations; how they can be affected, reduced and give a better precision in the calculations, with internal benchmarking and Kaizen as tools. The study was accomplished by interviews, meetings and observations of two departments in a large manufacturing company in order to create a deeper understanding. The study carried out with a qualitative approach.   The results we have found show that there is a great ability to affect the deviations. The opportunity for active impact differs depending on the respondent´s position in the company. The study shows that most respondents consider the lack of time as the main reason why they don´t use instruments for active impact, such as Kaizen and internal benchmarking. Furthermore we have found that employees are motivated by more than just monetary compensations, such as verbal encouragement and being noticed. The study concludes that different instruments for increasing efficiency in theory often is presented as unproblematic and easy to implement, but in reality and practice it is more complicated.
55

High-performance scheduling algorithms for wireless networks

Bodas, Shreeshankar Ravishankar 02 February 2011 (has links)
The problem of designing scheduling algorithm for multi-channel (e.g., OFDM-based) wireless downlink networks is considered, where the system has a large bandwidth and proportionally large number of users to serve. For this system, while the classical MaxWeight algorithm is known to be throughput-optimal, its buffer-overflow performance is very poor (formally, it is shown that it has zero rate function in our setting). To address this, a class of algorithms called iHLQF (iterated Heaviest matching with Longest Queues First) is proposed. The algorithms in this class are shown to be throughput-optimal for a general class of arrival/channel processes, and also rate-function optimal (i.e., exponentially small buffer overflow probability) for certain arrival/channel processes, where the channel-rates are 0 or 1 packets per timeslot. iHLQF however has higher computational complexity than MaxWeight (n⁴ vs. n² computations per timeslot respectively). To overcome this issue, a new algorithm called SSG (Server-Side Greedy) is proposed. It is shown that SSG is throughput-optimal, results in a much better per-user buffer overflow performance than the MaxWeight algorithm (positive rate function for certain arrival/channel processes), and has a computational complexity (n²) that is comparable to the MaxWeight algorithm. Thus, it provides a nice trade-off between buffer-overflow performance and computational complexity. For multi-rate channel processes, where the channels can serve multiple packets per timeslot, new Markov chain-based coupling arguments are used to derive rate-function positivity results for the SSG algorithm. Finally, an algorithm called DMEQ is proposed and shown to be rate-function optimal for certain multi-rate channel scenarios, whose definition characterizes the sufficient conditions for rate-function optimality in this regime. These results are validated by both analysis and simulations. / text
56

Das Nicht war zu leise! / The don't was spoken too softly

Goes, Stefan 18 December 1997 (has links)
No description available.
57

Pirmaklasių laikysenos priklausomybė nuo mokyklinės kuprinės svorio / The first year schoolchildren‘s posture and it‘s dependence of backpack‘s weight

Vosyliūtė, Agnė 16 August 2007 (has links)
Tyrimo objektas: pirmaklasių laikysena, jos sąsajos su kuprinės svoriu. Tyrimo problema: kiekvienais metais blogėja į mokyklą ateinančių pirmokų ir ypač vyresnių klasių mokinių sveikata. Sveikatos statistikoje nurodoma, kad vienas dažniausių sveikatos sutrikimų, pasitaikančių mokyklinio amžiaus vaikams – laikysenos sutrikimai. Šio darbo tikslas - nustatyti pirmaklasių laikysenos priklausomybę nuo mokyklinės kuprinės svorio. Tyrimo tikslui pasiekti buvo iškelti tokie tyrimo uždaviniai: 1) Nustatyti pirmaklasių laikyseną be kuprinės; 2) Nustatyti kaip pakinta moksleivio laikysena užsidėjus kuprinę; 3) Nustatyti pirmaklasių laikyseną, priklausomai nuo kuprinės svorio. Keltos dvi hipotez���s. Pirma teigė, kad „pirmaklasių, užsidėjusių kuprinę, laikysena, lyginant su jų pačių laikysena be kuprinės, pablogėja“. Antroji – kad „pirmaklasių, nešiojančių rekomenduojamą svorį atitinkančias kuprines, laikysena, lyginant jų laikysena be kuprinės, nepablogėja“. Pirmą hipotezę tyrimas patvirtino, antros – ne. Tiriamieji: 43 neatsitiktine tvarka iš Kazlų Rūdos pradinės mokyklos parinkti pirmos klasės mokiniai. Buvo atliekami mokinių matavimai (ūgio, svorio, kuprinės svorio, kojų ilgio) ir fotografavimas (frontaliniu, sagitaliniu ir dorsaliniu planu laikysenos be kuprinės įvertinimui bei sagitaliniu planu laikysenos su kuprine įvertinimui. Išanalizavus 258 nuotraukas, padarytos šios išvados: 1. Pirmaklasių laikysena, net esant be kuprinės, turi įvairių nukrypimų nuo normos, nei vieno tirto... [toliau žr. visą tekstą] / Object of research: the first year schoolchildren‘s posture and it‘s dependence of backpack‘s weight Problem of research: Children’s, who first comes to school and especially children’s in higher forms health becomes more bad every year. Health statistics notes, that one of most common health disturbancies in school age children is postoral deviations. The intention of this research is to find out the first year schoolchildren‘s posture and it‘s dependence of backpack‘s weight. To reach the intention of research we raise these tasks of research: 1) To establish the first year schoolchildren‘s posture without backpack; 2) To establish how changes the first year schoolchildren‘s posture after he/she puts the backpack on; 3) To find how changes the first year schoolchildren‘s posture, depending of backpack weight. We raised two hypothesis. The first said, that “first year schoolchildren‘s posture, when they has their backpack on, comparing with their posture without backpack, becomes worst”. The second – that “first year schoolchildren‘s, who carry the backpack which mach for his/her weight, posture, if compare with their posture without backpack, is changeless”. Research have proved the first hypothesis, the second was wrong. Exploratories: 43 first year school childrens of Kazlu Ruda primary school. To reach our intention of research we made childrens measuremensts (height, weight, packpack weight and legs height) and tooked photos of each child from frontal, sagital and... [to full text]
58

Large Deviations for Brownian Intersection Measures

Mukherjee, Chiranjib 18 October 2011 (has links) (PDF)
We consider p independent Brownian motions in ℝd. We assume that p ≥ 2 and p(d- 2) < d. Let ℓt denote the intersection measure of the p paths by time t, i.e., the random measure on ℝd that assigns to any measurable set A ⊂ ℝd the amount of intersection local time of the motions spent in A by time t. Earlier results of Chen derived the logarithmic asymptotics of the upper tails of the total mass ℓt(ℝd) as t →∞. In this paper, we derive a large-deviation principle for the normalised intersection measure t-pℓt on the set of positive measures on some open bounded set B ⊂ ℝd as t →∞ before exiting B. The rate function is explicit and gives some rigorous meaning, in this asymptotic regime, to the understanding that the intersection measure is the pointwise product of the densities of the normalised occupation times measures of the p motions. Our proof makes the classical Donsker-Varadhan principle for the latter applicable to the intersection measure. A second version of our principle is proved for the motions observed until the individual exit times from B, conditional on a large total mass in some compact set U ⊂ B. This extends earlier studies on the intersection measure by König and Mörters.
59

The impact of intellectual functioning and adverse life events on the psychosocial development of maltreated children /

Romney, Stephanie C. January 2005 (has links)
Thesis (Ph. D.)--University of California, San Diego, 2005. / Vita. Includes bibliographical references (leaves 68-78).
60

Principes de grandes déviations pour des modèles de matrices aléatoires / Large deviations problems for random matrices

Augeri, Fanny 27 June 2017 (has links)
Cette thèse s'inscrit dans le domaine des matrices aléatoires et des techniques de grandes déviations. On s'attachera dans un premier temps à donner des inégalités de déviations pour différentes fonctionnelles du spectre qui reflètent leurs comportement de grandes déviations, pour des matrices de Wigner vérifiant une propriété de concentration indexée par un paramètre alpha ∈ (0,2]. Nous présenterons ensuite le principe de grandes déviations obtenu pour la plus grande valeur propre des matrices de Wigner sans queues Gaussiennes, dans la lignée du travail de Bordenave et Caputo, puis l'étude des grandes déviations des traces de matrices aléatoires que l'on aborde dans trois cas : le cas des beta-ensembles, celui des matrices de Wigner Gaussiennes, et enfin des matrices de Wigner sans queues Gaussiennes. Le cas Gaussien a été l'occasion de revisiter la preuve de Borell et Ledoux des grandes déviations des chaos de Wiener, que l'on prolonge en proposant un énoncé général de grandes déviations qui nous permet donner une autre preuve des principes de grandes déviations des matrices de Wigner sans queues Gaussiennes. Enfin, nous donnons une nouvelle preuve des grandes déviations de la mesure spectrale empirique des beta-ensembles associés à un potentiel quadratique, qui ne repose que sur leur représentation tridiagonale. / This thesis falls within the theory of random matrices and large deviations techniques. We mainly consider large deviations problems which involve a heavy-tail phenomenon. In a first phase, we will focus on finding concentration inequalities for different spectral functionals which reflect their large deviations behavior, for random Hermitian matrices satisfying a concentration property indexed by some alpha ∈ (0,2]. Then we will present the large deviations principle we obtained for the largest eigenvalue of Wigner matrices without Gaussian tails, in line with the work of Bordenave and Caputo. Another example of heavy-tail phenomenon is given by the large deviations of traces of random matrices which we investigate in three cases: the case of beta-ensembles, of Gaussian Wigner matrices, and the case of Wigner matrices without Gaussian tails. The Gaussian case was the opportunity to revisit Borell and Ledoux's proof of the large deviations of Wiener chaoses, which we investigate further by proposing a general large deviations statement, allowing us to give another proof of the large deviations principles known for the Wigner matrices without Gaussian tail. Finally, we give a new proof of the large deviations principles for the beta-ensembles with a quadratic potential, which relies only on the tridiagonal representation of these models. In particular, this result gives a proof of the large deviations of the GUE and GOE which does not rely on the knowledge of the law of the spectrum.

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