Cette thèse porte sur l'étude de la concentration autour de la moyenne de fonctions de variables aléatoires indépendantes à l'aide de techniques de martingales et d'inégalités de comparaison.Dans une première partie, nous prouvons des inégalités de comparaison pour des fonctions générales séparément convexes de variables aléatoires indépendantes non nécessairement bornées. Ces résultats sont établis à partir de nouvelles inégalités de comparaison dans des classes de fonctions convexes (contenant, en particulier, les fonctions exponentielles croissantes) pour des variables aléatoires réelles uniquement dominées stochastiquement.Dans la seconde partie, nous nous intéressons aux suprema de processus empiriques associés à des observations i.i.d. Le point clé de cette partie est un résultat d'échangeabilité des variables. Nous montrons d'abord des inégalités de type Fuk-Nagaev avec constantes explicites lorsque les fonctions de la classe ne sont pas bornées. Ensuite, nous prouvons de nouvelles inégalités de déviation avec une meilleure fonction de taux dans les bandes de grandes déviations dans le cas des classes de fonctions uniformément bornées. Nous donnons également des inégalités de comparaison de moments généralisés dans les cas uniformément borné et uniformément majoré. Enfin, les résultats de la première partie nous permettent d'obtenir une inégalité de concentration lorsque les fonctions de la classe ont une variance infinie. / This thesis deals with concentration properties around the mean of functions of independent random variables using martingale techniques and comparison inequalities.In the first part, we prove comparison inequalities for general separately convex functions of independent and non necessarily bounded random variables. These results are based on new comparison inequalities in convex classes of functions (including, in particular, the increasing exponential functions) for real-valued random variables which are only stochastically dominated.In the second part, we are interested in suprema of empirical processes associated to i.i.d. random variables. The key point of this part is a result of exchangeability of variables. We first give Fuk-Nagaev type inequalities with explicit constants when the functions of the considered class are unbounded. Next, we provide new deviation inequalities with an improved rate function in the large deviations bandwidth in the case of classes of uniformly bounded functions. We also provide generalized moment comparison inequalities in uniformly bounded and uniformly bounded from above cases. Finally, results from the first part allow us to prove a concentration inequality when the functions of the class have an infinite variance.

abstract: Despite high levels of academic achievement as a group (Ryan & Bauman, 2016), Asian American students face many challenges, including academic stress (Flatt, 2013; Liu, 2002) and depression (Aczon-Armstrong, Inouye, & Reyes-Salvail, 2013; Wang & Sheikh-Khalil, 2014). The purpose of this study was to examine self-beliefs (academic self-efficacy and independent self-construal) and family and cultural variables (perceived parental expectations for academic achievement and internalization of the model minority myth) that may affect the academic stress and depression experienced by Asian American undergraduates. A national sample of 314 participants (221 female, 89 male, 4 nonbinary) who self-identified as Asian American undergraduates were recruited online and through word of mouth. They completed assessments of six constructs: Academic self-efficacy, independent self-construal, perceived parental expectations for academic achievement, internalization of the model minority myth, academic stress, and depression. Hierarchical multiple regression analyses revealed that of the two self-beliefs, only academic self-efficacy was a predictor of academic stress and depression. The greater the students’ academic self-efficacy, the less academic stress and depression they reported. Independent self-construal was not a significant predictor. Additionally, perceived parental expectations for academic achievement also predicted academic stress and depression. The more students perceived that their parents had high expectations for their academic achievement, the more they experienced academic stress and depression. The cultural variable, internalization of the model minority myth, was not a predictor of academic stress or depression. A moderated hierarchical regression examining whether academic self-efficacy and independent self-construal moderated the relation between perceived parental expectations for academic achievement and academic stress and depression revealed no moderation effects. The importance of academic self-efficacy is discussed in the context of cognitive theory that posits that thoughts and beliefs affect behaviors and emotions. In addition, cognitive theory is used to explain perceived parental expectations for academic achievement, as these are perceptions and beliefs about others, as related to one’s self. That the internalization of the model minority myth was not related to depression and academic stress is discussed. Limitations and clinical implications for working with Asian Americans with academic stress and depression are also discussed. / Dissertation/Thesis / Doctoral Dissertation Counseling Psychology 2019

The religious landscape in Sweden has changed in recent years as a result of secularization processes, individualization, and migration. This has led to religion occupying new places in society and one such place is media. The visibility of religion in the media creates space for debate about what role religion should play in different context, which in this thesis applies to school. Since 2018, there has been a debate in the media regarding the being or non-being of independent confessional schools. This bachelor thesis aims to examine the arguments that appear in the criticism versus the defense of independent confessional schools in debate articles in Sweden. Debate articles from the Swedish newspapers Svenska Dagbladet, Dagens Nyheter, Aftonbladet and Expressen are examined with qualitative text analysis. The result shows that the most common arguments among those who want to ban independent confessional schools are: religious indoctrination, segregation, and extremism. From the other side of the debate are the ones who defend independent confessional schools and the most common arguments from this side are: freedom of religion, corresponds to the Swedish curriculum, and integration. Further, an additional aim is to analyze how the debate can be understood using the theoretical concepts of narrative, institutional and cultural transformation processes in mediatization theory. The analysis shows that there are signs of these transformation processes in the debate articles. Many of the debate articles on the ban side are structured according to media logics where one perspective is set against another to provoke reactions from the readers, which expresses the narrative transformation process. The institutional transformation process is reflected in how actors from different institutions communicate in the debate, where political actors control the debate and religious actors adapt accordingly. The cultural transformation process is made visible by seeing how the debate relates to the surrounding society which is characterized by secular norms on one hand and increased religious diversity on the other.

Purpose: The purpose of this study is to explain how the share of independent boardmembers, controlling for different forms of independence, and agency costs correlate within Swedish firms listed on the Nasdaq OMX Stockholm list for large firms. The goal is to extend the understanding of board independence in relation to agency costs while adding empirical insight into the Swedish Code requirements on the board of directors. Theoretical Perspective: With a theoretical anchor in agent theory, this study presents the two conflicts assumed to exist between the agent and the principals within the firms. The first conflict is between agent and principal, and the second is between principal and principal. The agency perspective is used to explain how agency costs arise, within which conflict they arise, and how board members' independence should mitigate these. Method: This study applied a positivistic, deductive research approach using a quantitative strategy. Data was collected from annual reports and the databases Orbis, Holdings, and Retriever Business. Proxies were used for measuring agency costs. The statistical analysis ofthe data consisted of Pearson correlation, linear regressions, and binary logistic regressions. Conclusion: No unambiguous negative correlation could be confirmed between independent board members and agency costs when examined separately. A tradeoff in board members'independence and total agency costs can be confirmed. This implies that when coexisting board members’ different independence works in opposing directions for reducing the residual loss tied both to the agent-principal conflict and the principal-principal conflict

För att ge alla elever möjlighet att läsa enskilt är det av stor vikt att den enskilda läsningen är ett inplanerat moment i undervisningen. Genom enskild läsning får eleverna möjlighet att utveckla sin läsförmåga, vilket bland annat innebär utveckling av avkodning, läsförståelse och läsflyt. Det är lärarna som ansvarar för den enskilda läsningen som sker i undervisningen och därför avser studien att bidra med kunskap om hur enskild läsning planeras, tillämpas och följs upp i undervisningen. Studien tar utgångspunkt i ett sociokulturellt perspektiv eftersom läsning sker i ett sammanhang och eleverna utvecklas efter sin förmåga. Det sociokulturella perspektivet beskriver även vikten av att använda språket som ett redskap och att utveckling sker ständigt. Syftet med studien är att bidra med kunskap om hur legitimerade lärare i årskurs 2 planerar och tillämpar enskild läsning i undervisningen för att utveckla elevers läsförmåga. En kvalitativ undersökningsmetod har använts i form av semistrukturerade intervjuer med fem lärare i årskurs 2. Intervjuerna som har genomförts transkriberades och sedan analyserades transkriberingarna utifrån en tematisk analysmetod. Resultatet visade att lärarna tillämpar enskild läsning i undervisningen, men att den inte får så mycket tid. Det framkom även att lärarnas betydelse är av stor vikt på olika sätt. Den enskilda läsningen följs upp i undervisningen med olika tester och mätmaterial samt att eleverna blir lyssnade till när de läser. Resultatet visade även att den enskilda läsningen planeras in i undervisningen men på olika sätt, det varierar i hur länge och hur många gånger i veckan eleverna får läsa. / In order to give all students the opportunity to read individually, it is of great importance that individual reading is a planned part in the classroom. Through individual reading, the students have the opportunity to develop their reading ability, which, among other things, means the development of decoding, reading comprehension and reading fluency. It is the teachers who are responsible for the individual reading that takes place in the classroom and therefore the study intends to contribute with knowledge about how individual reading is planned, applied and followed up in the classroom. The study is based on a socio-cultural perspective because reading takes place in a context and students develops according to one's ability. The socio-cultural perspective also describes the importance of using language as a tool and that development takes place constantly. The aim of the study is to contribute knowledge about how certified teachers in grade 2 plan and apply individual reading in teaching to develop students' reading ability. A qualitative research method has been used in the form of semi-structured interviews with five teachers in grade 2. The interviews that have been conducted were transcribed and then the transcriptions were analyzed based on a thematic analysis method. The result showed that the teachers apply individual reading in the classroom, but that it does not get much time. It also emerged that the importance of teachers is of great importance in different ways. The individual reading is followed up in the classroom with various tests and measuring materials and that the students are listened to when they read. The result also showed that the individual reading is planned into the teaching, but in different ways, it varies in how long and how many times a week the students are allowed to read.

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As more data is being gathered in industrial production facilities, the interest in applying machine learning models to the data is growing. This includes the iron ore mining industry, and in particular the build-up of slag in grate-kiln furnaces. Slag is a byproduct in the pelletizing process within these furnaces, that can cause production stops, quality issues, and unplanned maintenance. Previous studies on slag build-up have been done mainly by chemists and process engineers. Whilst previous research has hypothesized contributing factors to slag build-up, the studies have mostly been conducted in simulation environments and thus have not used real sensor data utilizing machine learning models. Luossavaara-Kiirunavaara Aktiebolag (LKAB) has provided data from one of their grate-kiln furnaces, a time-series data of sensor readings, that compressed before storage.  A Scala package was built to ingest and interpolate the LKAB data and make it ready for machine learning experiments. The estimation of slag within the kiln was found too arbitrary to make accurate predictions. Therefore, three quality metrics, tightly connected to the build-up of slag, were selected as target variables instead. Independent and identically distributed (IID) units of data were created by isolating fuel usage, product type produced and production rate. Further, another IID criterion was created, adjusting the time for each feature in order to be able to compare feature values for a single pellet in production. Specifically, the time it takes for a pellet to go from the feature sensor to the quality test was added to the original timestamp. This resulted in a table where each row represents multiple features and quality measures for the same small batch of pellets. An IID unit of interest was then used to find the most contributing features by using principal component analysis (PCA) and lasso regression. It was found that using the two mentioned methods, the number of features could be reduced to a smaller set of important features. Further, using decision tree regression with the subset of features, selected from the most important features, it was found that decision tree regression had a similar performance with the subset of features as the lasso regression. Decision tree and lasso regression were chosen for interpretability, which was important in order to be able to discuss the contributing factors with LKAB process engineers. / Idag genereras allt mer data från industriella produktionsanläggningar och intresset att applicera maskininlärningsmodeller på denna data växer. Detta inkluderar även industrin för utvining av järnmalm, i synnerhet uppbyggnaden av slagg i grate-kiln ugnar. Slagg är en biprodukt från pelletsproduktionen som kan orsaka produktionsstopp, kvalitetsbrister och oplanerat underhåll av ugnarna. Tidigare forskning kring slagguppbyggnad har i huvudsak gjorts av kemister och processingenjörer och ett antal bidragande faktorer till slagguppbyggnad ha antagits. Däremot har dessa studier främst utförts i simulerad experimentmiljö och därför inte applicerat maskininlärningsmodeler på sensordata från produktion. Luossavaara-Kiirunavaara Aktiebolag (LKAB) har till denna studie framställt och försett data från en av deras grate-kiln ugnar, specifikt tidsseriedata från sensorer som har komprimerats innan lagring. Ett Scala-paket byggdes för att ladda in och interpolera LKAB:s data, för att sedan göra den redo och applicerbar för experiment med maskininlärningsmodeller. Direkta mätningar för slagguppbyggnad och slaggnivå upptäcktes vara för slumpartade och bristfälliga för prediktion, därför användas istället tre kvalitetsmätningar, med tydligt samband till påföljderna från slagguppbyggnad, som målvariabler. Independent and identically distributed (IID) enheter skapades för all data genom att isolera bränsleanvändning, produkttyp och produktionstakt. Vidare, skapades ytterligare ett kriterie för IID:er, en tidsjustering av varje variabel för att göra det möjligt att kunna jämföra variabler inbördes för en enskild pellet i produktion. Specifikt, användes tiden det tar för en pellet från att den mäts av en enskild sensor till att kvalitetstestet tas. Tidsskillnaden adderas sedan till sensormätningens tidsstämpel. Detta resulterade i en tabell där varje rad representerade samma lilla mängd av pellets. En IID enhet av intresse analyserades sedan för att undersöka vilka variabler som har störst varians och påverkan genom en principal komponentsanalys (PCA) och lassoregression. Genom att använda dessa metoder konstaterades det att antalet variabler kunde reduceras till ett mindre antal variabler och ett nytt, mindre, dataset av de viktigaste variablerna skapades. Vidare, genom regression av beslutsträd med de viktigaste variablerna, konstaterades att beslutträdsregression och lassoregression hade liknande prestanda när data med de viktigaste variablerna användes. Beslutträdsregression och lassoregression användes för att experimentens resultat skulle ha en hög förklaringsgrad, vilket är viktigt för att kunna diskutera variabler med högst påverkan på slagguppbyggnaden och ge resultat som är tolkbara och användbara för LKAB:s processingenjörer.

In wireless communications, frequency-selective fading is a major source of impairment for wireless communications. In this research, a novel Frequency-Domain Independent Component Analysis (ICA-F) approach is proposed to blindly separate and deconvolve signals traveling through frequency-selective, slow fading channels. Compared with existing time-domain approaches, the ICA-F is computationally efficient and possesses fast convergence properties. Simulation results confirm the effectiveness of the proposed ICA-F. Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in wireless communications nowadays. However, OFDM systems are very sensitive to Carrier Frequency Offset (CFO). Thus, an accurate CFO compensation technique is required in order to achieve acceptable performance. In this dissertation, two novel blind approaches are proposed to estimate and compensate for CFO within the range of half subcarrier spacing: a Maximum Likelihood CFO Correction approach (ML-CFOC), and a high-performance, low-computation Blind CFO Estimator (BCFOE). The Bit Error Rate (BER) improvement of the ML-CFOC is achieved at the expense of a modest increase in the computational requirements without sacrificing the system bandwidth or increasing the hardware complexity. The BCFOE outperforms the existing blind CFO estimator [25, 128], referred to as the YG-CFO estimator, in terms of BER and Mean Square Error (MSE), without increasing the computational complexity, sacrificing the system bandwidth, or increasing the hardware complexity. While both proposed techniques outperform the YG-CFO estimator, the BCFOE is better than the ML-CFOC technique. Extensive simulation results illustrate the performance of the ML-CFOC and BCFOE approaches.

In today’s society, it is increasingly important for retailers to have an online presence, yet the adoption rate of e-commerce by small retailers is still lagging behind the that of larger retailers. This is due to the difficulty small retailers have to overcome the barriers to develop their web-shops, such as cost and time. This thesis will examine the barriers of single-store independent retail businesses to sell and market their goods online. It will use the Technology Acceptance Model framework developed by Davis (1986) to help understand how the barriers affect the retailers attitude towards the process of developing their web-shops. Specifically, it will ask the retailers, through interviews, what barriers exist, what their perception of difficulty to overcome these barriers is, and what their perception of importance to overcome these barriers is. The major findings show that the barriers for retailers have not changed in the past decade, nor has the difficulty level of overcoming these barriers. The majority of small retailers who have not yet developed their web-shops don’t feel that the effort to do so is worth the potential gains, yet the small retailers who have already developed their web-shops did feel it was worth the effort. The retailers all felt that the process was more difficult than it should be, and insisted they would make the leap if the cost and effort required was reduced.