Abstract Oversampling data converters based on Delta-Sigma modulation are a popular solution for modern high-resolution applications. In the design of digital-to-analog or analog-to-digital Delta-sigma converters there are common obstacles due to the difficulties on predicting and verifying their performance. Being a highly nonlinear system, a Delta-Sigma modulator’s (DSM) quantization noise and therefore the spurious tones are difficult to analyze and predict. Multi-bit DACs can be used to improve the performance and linearize the behavior of DSMs. However, this will give rise to the need for linearizing the multi-bit DAC. A popular DAC linearization method, data weighted averaging (DWA) shapes the DAC mismatch noise spectrum. There are many variants of DWA, for low-pass and band-pass DSMs. This thesis proposes a generalization which integrates a few published variants into one, broader DWA scheme. The generalization enables expanding the tone-suppression studies into a larger concept. The performance of one- or multibit DSMs is usually verified by simulations. This thesis proposes a simulation-based qualification (characterization) method that can be used to repeatedly verify and compare the performance of multibit DSM with a DAC mismatch shaping or scrambling scheme. The last contribution of this thesis is a very simple model for tonal behavior. The model enables accurate prediction of spurious tones from both DSMs and DWA-DACs. The model emulates the tone behavior by its true birth-mechanism: frequency modulation. The proposed prediction model for tone-behavior can be used for developing new tone-cancelation methods. Based on the model, a DWA linearization method is also proposed. / Tiivistelmä Delta-Sigma modulaatio on suosituin tekniikka ylinäytteistävissä datan muuntimissa. Riippumatta toteutustarkoituksesta (analogia-digitaali- tai digitaali-analogia-muunnos), Delta-Sigma (DS) modulaatiossa on yleisesti tunnettuja käyttäytymisen ennustamiseen liittyviä ongelmia. Nämä ongelmat ovat peräisin modulaattorin luontaisesta epälineaarisuudesta: DS-muunnin on nimittäin vahvasti epälineaarinen takaisinkytketty systeemi, jonka harhatoistojen ennustaminen ja analysointi on erittäin hankalaa. Yksibittisestä monibittiseen DS-muuntimeen siirryttäessä muuntimen suorituskyky paranee, ja muuntimen kohinakäyttäytyminen on lineaarisempaa. Tämä kuitenkin kostautuu tarpeena linearisoida DS-muuntimen digitaali-analogia (D/A) muunnin. Tällä hetkellä tunnetuin linearisointimenetelmä on nimeltään DWA (data weighted averaging) algoritmi. Tässä työssä DWA:lle ja sen lukuisille varianteille esitellään eräänlainen yleistys, jonka avulla algoritmia voidaan soveltaa sekä alipäästö- että kaistanpäästö-DS-muuntimelle. Kuten tunnettua, DS-modulaattorin analyyttinen tarkastelu on raskasta. Yksi- ja monibittisten DS-muuntimien suunnitellun käyttäytymisen varmistaminen tapahtuukin yleensä simulointien avulla. Työssä esitetään simulointiperiaate, jolla voidaan kvalifioida (karakterisoida) monibittinen DS-muunnin. Tarkemmin, kvalifioinnin kohteena on DWA:n kaltaiset D/A -muuntimien linearisointimentelmät. Kyseessä on pyrkimys ennen kaikkea toistettavaan menetelmään, jolla eri menetelmiä voidaan verrata nopeasti ja luotettavasti. Tämän väitöstyön viimeinen kontribuutio on matemaattinen malli harhatoistojen syntymekanismille. Mallilla sekä DS-muunnoksen että DWA-D/A -muunnokseen liittyvät harhatoistot voidaan ennustaa tarkasti. Harhatoistot mallinnetaan yksinkertaisella havaintoihin perustuvalla FM-modulaatiokaavalla. Syntymekanismin mallinnus mahdollistaa DS-muuntimien ennustettavuuden ja täten auttaa harhatoiston kumoamismenetelmien kehittämistä. Työssä esitetään yksi matemaattisen mallin avulla kehitetty DWA-D/A -muunnoksen linearisointimenetelmä.

The study examines how print media in Sweden portray Putin, Russia and Russians and what makes an impact on Swedish journalists when they write on that subject. The first part presents a content analysis of articles published in the two main Swedish newspapers Dagens Nyheter and Svenska Dagbladet (DN and SvD). The two most significant years of coverage of Russia in Sweden (2014-2015) were chosen as a time frame for the analysis. It examines the predominant tones that were used in the articles towards three keywords “Putin”, “Russia” and “Russians”, as well as the sources that were chosen by the journalists. In line with previous researchers, the author of this study observed a certain tendency shared in two Swedish printed media to report negatively about the Russian president. At the same time tones towards the country in general and its citizens were more neutral than negative. The second part of the research focuses on qualitative interviews with journalists representing different media in Sweden (radio, TV channels and newspapers). During the interviews, journalists were invited to reflect how they see Russian society, what connection they have with Russian culture and what impacts their choice of topics. According to the findings, a journalist’s work is affected by their individual background, economical situation in media organisations and expectations from the audience.

Background: A previous experiment with 70 interrupted monosyllabic words demonstrated that recognition performance was influenced by the location of an interruption pattern (Wilson, 2014). The interruption paradigm (10 interruptions/sec, 50% duty cycle periodic interruption) was referenced to word onset. The words were interrupted such that alternate 50-msec segments were parsed to separate files. In the 0-msec condition the first on-segment coincided with the word onset, whereas in the 50-msec condition the first on-segment occurred 50 msec after word onset. The 0- and 50-msec conditions were complementary halves. Recognition performance by young listeners was 19% better on the 0-msec condition (86%) than on the 50-msec condition (68%); there were a minority number of words on which the results were just the opposite. A second study using the same interruption paradigm but 300 different words reported similar relations, with 63% correct recognition on the 0-msec condition and 48% on the 50-msec condition (Wilson and Irish, 2015). Both studies suggest the importance that the first 50 msec of the target word has on intelligibility. Purpose: To define in detail the effects that interruption patterns have on word recognition as the interruption pattern was incremented with reference to word onset from 0 to 90 msec in 10-msec steps. Research Design: A repeated-measures design with ten interruption patterns (onset conditions). Study Sample: Twenty-four young listeners (19-29 yr) with normal hearing for pure tones participated in this study. Data Collection and Analyses: Seventy consonant-nucleus-consonant words formed the corpus of materials with 25 additional words used for practice. For each participant, the 700 stimuli (70 words by ten onset conditions) were interrupted (10 interruptions/sec; 50% duty cycle), randomized, and recorded on compact disc in 28, 25-word tracks. Results: The overall mean recognition performance was 80.4% with mean performances for the ten conditions ranging from 73.0% (50-msec condition) to 87.7% (90-msec condition). The mean recognition performances changed systematically, decreasing from the 0-msec condition to the 50-msec condition and then increasing to the 90-msec condition, which formed a U-shaped function of the means. Of the 45 mean paired comparisons (post hoc t-tests with Bonferroni corrections), there were 17 significant differences at the p ≤ 0.001 level, increasing to 31 significant differences when the significance level was increased to the p ≤ 0.01 level. Visual inspection of the 70-word performance functions revealed that 32 words had flat functions, 34 words had U-shaped functions, two functions were rising, one was an inverted V-shape, and one was irregular. Conclusions: First, some words (utterances of those words) were immune to any differential effects of the ten interruption patterns. These words with flat performance functions constituted 46% of the word corpus. Second, 49% of the words exhibited U-shaped performance functions that were always systematic, going from maximum to minimum and back to maximum. These words were thought to be more dependent on the initial consonant to attain maximum performance. The conclusion is that some words are not affected by the location of the interruption pattern (those with flat functions) whereas other words are substantially affected (those with U-shaped functions).

Background: Two previous experiments from our laboratory with 70 interrupted monosyllabic words demonstrated that recognition performance was influenced by the temporal location of the interruption pattern. The interruption pattern (10 interruptions/sec, 50% duty cycle) was always the same and referenced word onset; the only difference between the patterns was the temporal location of the onand off-segments of the interruption cycle. In the first study, both young and older listeners obtained better recognition performances when the initial on-segment coincided with word onset than when the initial on-segment was delayed by 50 msec. The second experiment with 24 young listeners detailed recognition performance as the interruption pattern was incremented in 10-msec steps through the 0-To 90-msec onset range. Across the onset conditions, 95% of the functions were either flat or U-shaped. Purpose: To define the effects that interruption pattern locations had on word recognition by older listeners with sensorineural hearing loss as the interruption pattern incremented, re: Word onset, from 0 to 90 msec in 10-msec steps. Research Design: A repeated-measures design with ten interruption patterns (onset conditions) and one uninterruption condition. Study Sample: Twenty-four older males (mean = 69.6 yr) with sensorineural hearing loss participated in two 1-hour sessions. The three-frequency pure-Tone average was 24.0 dB HL and word recognition was $80% correct. Data Collection and Analyses: Seventy consonant-vowel nucleus-consonant words formed the corpus of materials with 25 additional words used for practice. For each participant, the 700 interrupted stimuli (70 words by 10 onset conditions), the 70 words uninterrupted, and two practice lists each were randomized and recorded on compact disc in 33 tracks of 25 words each. Results: The data were analyzed at the participant and word levels and compared to the results obtained earlier on 24 young listeners with normal hearing. The mean recognition performance on the 70 words uninterrupted was 91.0% with an overallmean performance on the ten interruption conditions of 63.2% (range: 57.9-69.3%), compared to 80.4% (range: 73.0-87.7%) obtained earlier on the young adults. The best performances were at the extremes of the onset conditions. Standard deviations ranged from 22.1% to 28.1% (24 participants) and from 9.2% to 12.8% (70 words). An arithmetic algorithm categorized the shapes of the psychometric functions across the ten onset conditions.With the older participants in the current study, 40% of the functions were flat, 41.4% were U-shaped, and 18.6% were inverted U-shaped, which compared favorably to the function shapes by the young listeners in the earlier study of 50.0%, 41.4%, and 8.6%, respectively. There were two words on which the older listeners had 40% better performances. Conclusion: Collectively, the data are orderly, but at the individual word or participant level, the data are somewhat volatile, which may reflect auditory processing differences between the participant groups. The diversity of recognition performances by the older listeners on the ten interruption conditions with each of the 70 words supports the notion that the term hearing loss is inclusive of processes well beyond the filtering produced by end-organ sensitivity deficits.

No description available.

This thesis study investigates gains in the speaking of China study abroad (SA) students from Brigham Young University. Pre-and post-program Simulated Oral Proficiency Interview (SOPI) tasks were used to generate multiple fluency measures, such as native judges' subjective fluency ratings, word count, number of unique words, number of filler words, mean pause length, tonal accuracy, etc. The study results display significant differences between pre- and post-tests for all fluency measures. In other words, China SA students were perceived to be more fluent in their speech by native judges after SA; their speech samples show more word (token and type) production, and shorter pauses in post-SOPI tasks than in pre-SOPI tasks. Participants used more filler words and had more unfilled pauses in post-measures than in pre-measures and they enhanced their tonal accuracy during the SA. Native judges' perception of task completion was also measured and the students were more capable of completing speech tasks in the post-program measures than in the pre-program measures. The OPI ratings indicate that some students made as much as two sub levels' improvement on the American Council on the Teaching of Foreign Languages (ACTFL) scale.

No description available.

A presente dissertação pretende mostrar marcas de uma possível criação de um \"espaço ficcional\" no contato do aluno de espanhol como língua estrangeira (LE) e a língua que estuda. Para chegar a estas marcas postulamos uma metáfora que pode comparar o \"espaço ficcional\" com as representações sobre a língua espanhola no Brasil. Como amostra de pesquisa coletamos redações de alunos de espanhol como LE de níveis intermediário e avançado. Foram obtidas cinco amostras com diferentes gêneros e temáticas. Analisando as redações encontramos regularidades que nos levam a perceber a criação de um \"espaço ficcional\", cuja descrição crítica pode ser outro modo de ver o que acontece com a subjetividade na aprendizagem de uma LE. No caminho que nos leva em direção ao espaço ficcional, encontramos uma série de tons e vozes. E também enunciados sobre um encantamento com a língua espanhola que parece promover a possibilidade de entrar em espaços novos e transformar estes espaços alheios em próprios por uma apropriação ou absorção do estranho. / The present dissertation intends to show marks of a possible creation of a \'fictional space\' in the contact of a student of Spanish as a foreign language and with the language he studies. In order to get these marks a metaphor that can compare the \'fictional space\' to the representations on the Spanish language in Brazil was postulated. As research sample, compositions of intermediate and advanced-level students of Spanish were collected. Five samples with different genres and themes were made. Analyzing the compositions we have found regularities that lead us to notice the creation of a \'fictional space\', whose critical description can be another way of seeing what happens with the subjectivity in the learning of one foreign language. On the road that takes us towards the fictional space, we have found a series of tones and voices. It is also enunciated an enchantment with the Spanish language that seems to promote the possibility to enter in new spaces and to transform these strange spaces in their own for a stranger\'s appropriation or absorption.

No description available.

This thesis develops the phonological model for the Stockholm Swedish intonation system. Though previous research provides a general model of this system, many phonological aspects of it have remained understudied. The intonational options that are available to speakers of Stockholm Swedish are discussed, and it is argued that Stockholm Swedish provides evidence for complex branching of phonological domains. Specifically, it is argued that so called focal accents, which are referred to as (H)LH-accents in the present work, have essentially two different functions. First, they signal information structural categories such as focus. Second, they signal left edges of Intonation Phrases (IP). It is also argued that a wide range of options exist in the post-nuclear area. Six types of contours for such areas are distinguished, plus one additional rising contour when there are no post-nuclear accents. Based on these findings, I present an account of the branching options for the phonological categories in the Stockholm Swedish prosodic hierarchy. I argue that there is evidence for recursive phonological structures in Stockholm Swedish, i.e. that a mother node and a daughter node can belong to the same phonological category. Also, Stockholm Swedish provides evidence for a distinction between prosodic coordination (equal sister nodes) and prosodic adjunction (unequal sister nodes). Prosodic structure is mapped onto syntactic structure via a set of variably ranked Optimality Theoretic constraints. The relation between phonological and syntactic structure shows that the phonology prefers prosodic coordination (equal sisters) over adjunction (unequal sisters). The material for the study comprises a corpus of approximately 420 read sentences, which were specifically designed to test various phonological hypotheses, and approximately 17 minutes of uncontrolled speech.