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Several available free software audio solutions were analyzed, and Jackdmp—a C++ reimplementation of the renowned JACK Audio Connection Kit—was selected as the most appropriate solution for a real-time audio architecture on DROPS. The JACK sound architecture provides the lowest processing latency possible on a desktop computer for a given set of sound card parameters. It reduces the latency jitter caused by software to zero and synchronizes streams at sample accuracy. A real-time admission scheme for JACK clients is proposed. The execution time of different typical JACK clients was analyzed with measurements to validate the assumptions the proposal is based on, but also to gain further knowledge about their timing behavior. The measurements showed that the condition set by Paul Davis—the time to process a client must be a linear function of the buffer size—holds for all tested clients. Jackdmp was ported to DROPS. The developed design of the port and its implementation is documented here. Measurements showed that—although the real-time performance of the Linux kernel is continuously being improved in the mainline and on special external branches—DROPS can provide a signaling latency that is two times lower on average than the values that can be achieved on the same machine running with a low latency patched Linux kernel. Thus, it can be stated that DROPS is well-suited for real-time audio processing and that the pursued path to use it as the foundation of a truly real-time capable audio workstation should be followed. / Wenn man heute digitale Audiotechnik zum Aufnehmen oder Abmischen von Musik oder anderen Audiodaten verwenden möchte, steht man vor der Wahl, entweder auf eine sehr spezialisierte Hardwarelösung zurückzugreifen oder aber sich eines gewöhnlichen Desktopsystems mit entsprechender Audiosoftware zu bedienen. Der Vorteil eines Desktopsystems ist neben seinem deutlich niedrigeren Preis vor allem die Flexibilität. Bezüglich seines Echtzeitverhaltens bietet ein Computer mit einem Standard-Desktop-Betriebssystem aber bei weitem nicht dieselbe Verlässlichkeit einer spezialisierten Hardwarelösung oder analoger Technik. Die Architektur von DROPS --- mit dem echtzeitfähigen Fiasco- Mikrokern auf der einen Seite sowie der Unterstützung von Legacy-Anwendungen durch L4Linux auf der anderen Seite --- birgt die Hoffnung, die Vorteile von den beiden eben beschriebenen Welten auf einem System mit DROPS kombinieren zu können. Die Motivation meiner Arbeit war es, für dieses langfristige Ziel einen ersten Grundstein zu legen. Dazu war es meine Aufgabe, verschiedene Open-Source- Lösungen hinsichtlich ihrer Eignung als Echtzeit-Audioarchitektur für DROPS zu analysieren und die am besten geeignete auf L4Env zu portieren. Meine Wahl fiel dabei auf das in der Linux-Audio-Szene wohlbekannte Jack Audio Connection Kit (JACK). Desweiteren konnte ich in der Arbeit untersuchen, wie sich die JACK Audioarchitektur in ein globales Echtzeit-Scheduling --- z.B. eines von DROPS --- einbetten ließe, und schlage eine generische Methode dafür vor.

Several available free software audio solutions were analyzed, and Jackdmp—a C++ reimplementation of the renowned JACK Audio Connection Kit—was selected as the most appropriate solution for a real-time audio architecture on DROPS. The JACK sound architecture provides the lowest processing latency possible on a desktop computer for a given set of sound card parameters. It reduces the latency jitter caused by software to zero and synchronizes streams at sample accuracy. A real-time admission scheme for JACK clients is proposed. The execution time of different typical JACK clients was analyzed with measurements to validate the assumptions the proposal is based on, but also to gain further knowledge about their timing behavior. The measurements showed that the condition set by Paul Davis—the time to process a client must be a linear function of the buffer size—holds for all tested clients. Jackdmp was ported to DROPS. The developed design of the port and its implementation is documented here. Measurements showed that—although the real-time performance of the Linux kernel is continuously being improved in the mainline and on special external branches—DROPS can provide a signaling latency that is two times lower on average than the values that can be achieved on the same machine running with a low latency patched Linux kernel. Thus, it can be stated that DROPS is well-suited for real-time audio processing and that the pursued path to use it as the foundation of a truly real-time capable audio workstation should be followed. / Wenn man heute digitale Audiotechnik zum Aufnehmen oder Abmischen von Musik oder anderen Audiodaten verwenden möchte, steht man vor der Wahl, entweder auf eine sehr spezialisierte Hardwarelösung zurückzugreifen oder aber sich eines gewöhnlichen Desktopsystems mit entsprechender Audiosoftware zu bedienen. Der Vorteil eines Desktopsystems ist neben seinem deutlich niedrigeren Preis vor allem die Flexibilität. Bezüglich seines Echtzeitverhaltens bietet ein Computer mit einem Standard-Desktop-Betriebssystem aber bei weitem nicht dieselbe Verlässlichkeit einer spezialisierten Hardwarelösung oder analoger Technik. Die Architektur von DROPS --- mit dem echtzeitfähigen Fiasco- Mikrokern auf der einen Seite sowie der Unterstützung von Legacy-Anwendungen durch L4Linux auf der anderen Seite --- birgt die Hoffnung, die Vorteile von den beiden eben beschriebenen Welten auf einem System mit DROPS kombinieren zu können. Die Motivation meiner Arbeit war es, für dieses langfristige Ziel einen ersten Grundstein zu legen. Dazu war es meine Aufgabe, verschiedene Open-Source- Lösungen hinsichtlich ihrer Eignung als Echtzeit-Audioarchitektur für DROPS zu analysieren und die am besten geeignete auf L4Env zu portieren. Meine Wahl fiel dabei auf das in der Linux-Audio-Szene wohlbekannte Jack Audio Connection Kit (JACK). Desweiteren konnte ich in der Arbeit untersuchen, wie sich die JACK Audioarchitektur in ein globales Echtzeit-Scheduling --- z.B. eines von DROPS --- einbetten ließe, und schlage eine generische Methode dafür vor.

The aim of this research was to make recommendations how parents and educators can select and use audio-visual media for supporting learners with behavioural problems (LBP). A literature study was conducted on behavioural problems and on the use of audio-visual media to address these. Thereafter an empirical investigation was done by means of a case study design. A purposive sample was chosen from Grades 10 and 12 learners in Pietermaritzburg. Websites were also selected for addressing a variety of topics. The most important findings were that audio-visual media can be selected by means of five criteria related to content accuracy and appropriateness, diversity and quality. The findings indicate that visual media can stimulate cognitive skills (including problem solving and critical thinking) and reflection about the acceptance of responsibility, positive attitudes and respect for authority, among others. It is concluded that audio-visual media can be used by educators to support LBP. / Educational Studies / M.Ed. (Specialisation in Psychology of Education)

published_or_final_version / Education / Master / Master of Education

Nous abordons dans cette thèse le problème de la séparation de sources selon un angle novateur à de nombreux niveaux. Ces travaux associent deux domaines du traitement du signal jusqu'alors traités de manière disjointe, la séparation de source et le tatouage numérique. Le procédé mis en place au cours de ces travaux a pour but de permettre à un utilisateur "client" de séparer les différents signaux numériques sources composant un mélange audio à partir de ce seul mélange tatoué. Pour ce faire un marquage du signal est effectué par un utilisateur "fournisseur" avant la fixation du mélange sur son support numérique. Ce marquage consiste en l'insertion sur le signal lui-même d'informations utiles à la séparation, et ceci de façon imperceptible. Le tatouage peut, en principe, être inséré soit sur le mélange, soit sur les signaux sources, qui sont disponibles à l'utilisateur fournisseur. Deux systèmes composent donc ce procédé, un encodeur qui permet à l'utilisateur fournisseur de réaliser la phase de mélange et de marquage, et un décodeur qui permet à l'utilisateur client de contrôler la séparation à partir du mélange. Au cours de cette thèse, il est choisi de tatouer le signal de mélange. Une application cible particulièrement visée est le cas d'un mélange polyphonique (signal de musique) fixé sur un support CD audio. La séparation doit permettre à l'utilisateur client d'effectuer un certain nombre de contrôles (par exemple le volume sonore) sur les différentes composantes de la scène sonore (les différents instruments et voix).

A film can attract all kinds of emotions and moods of the audience through its audiovisual communications and cinematic expression, in which music plays a significant role in both understanding and interpretation of film content. It is interesting to explore the musical significance and the emotional aspect of the film out of a media and communications perspective and visual communications perspective because it’s a subject that belongs to the communications of scientific discipline as film is a media text which is working both as communicative and as audio-visual medium with its expressive aspects. The purpose of this bachelor’s paper is to increase and deepen the understanding of music's function and significant role in context with its reinforcing sense of visual expression in film. More specifically, it aims to explore the musical value of the expressive aspect of the media text in form of film musical Les Misérables (2012), which has been transmedialised from the novel of the same name, referring to the sound, music and song in relation to the film's visual expression. The research questions are at the core of the essay study: "how is music used to reinforce the cinematic visual expression?" and "how can music signify the narrative and highlight the emotional aspect of the film?" The theoretical framework is based on some of the key scholars assumptions such as Michel Chion (1994) and Claudia Gorbman (1987), who share the same theoretical views that the soundtrack seems powerful when it expresses its participation in a scene’s emotional moods as the music follows the scene’s rhythm, the image’s flow and contributes emotional and musical codes of emotions and expressions. According to Chion sound and image interact together to tell a story where sound enrich the image with expressive and informative values. Other important researchers in the field and their theoretical frameworks are included in the theory chapter. As in whole, aspects of musical communication and sound emotionalisation are seen by the previous research as a form of expression, where visual communication in the film is considered as important as the aural and musical for the narrative storytelling, and where the musical aspect with the interaction of the cinematic visual expression highlights the characters emotions and moods. The results of the empirical work is presented in about twenty pages qualitative content analysis together with its analytical perspectives that focus on the close reading of the narrative, visual and musical elements and their abstract narratives (emotional moods) in the media text’s seven selected film–song sequences. In performing of the analysis and interpretation of the media text content, the regard was taken to these before mentioned elements to answer the research questions and emphasize the purpose of the study as relevant as possible. The conclusion is based on the empirical work analysis and results, and the scholars previous theoretical assumptions in connection with my observations. Keywords:  musical  film  les miserables  soundtrack  emotions  moods narrative audio           visual expression  communication musicology / En film kan locka fram alla slags känslor och stämningar hos publiken genom sin audiovisuella kommunikation och filmiska uttryck, där musiken har en betydande roll i både förståelsen och tolkningen av filmmediet.        Det är intressant att utforska den musikaliska gestaltningen och den känslomässiga aspekten i film utifrån ett medie- och kommunikationsperspektiv samt visuell kommunikationsperspektiv därför att det är ett ämne som hör till den kommunikationsvetenskapliga disciplinen eftersom film är en medietext, som fungerar både som ett kommunikativt och ett audiovisuellt medium med uttrycksmässiga aspekter. Syftet med den här uppsatsen är att är att öka och fördjupa förståelsen för musikens funktion och gestaltning i sammanhang med dess förstärkande känsla i visuell gestaltning i film. Mer konkret är syftet att utforska det musikaliska värdet i den uttrycksmässiga aspekten i medietexten i form av musikalfilmen Les Misérables (2012), som har transmedialiserats från roman med samma namn, berörande ljud, musik och sång i relation till filmens visuella uttryck. Dem frågeställningar som utgör kärnan för uppsatsens ämne är: ”hur används musik för att förstärka det filmiska visuella uttrycket?” samt ”hur kan musiken gestalta det narrativa och belysa den känslomässiga aspekten i film?”  Det teoretiska ramverket baseras på några av framstående forskares antaganden så som Michel Chion (1994), och Claudia Gorbman (1987) som delar likadana teoretiska uppfattningar och anser att filmmusiken verkar kraftfullt genom att den uttrycker sitt deltagande i en scens känslostämning eftersom musiken följer scenens rytm, bildernas flöde och bidrar med emotionella och musikaliska koder för känslor och uttryck. Enligt Chion verkar ljud och bild i samspel för att tillsammans berätta en historia där ljud berikar bilden med uttrycksfulla och informativa värden. Även andra viktiga forskare inom området och deras teoretiska ramverk tas upp i teori-kapitlet. I sin helhet ses aspekter av musikalisk kommunikation och ljudets emotionalisering av den tidigare forskningen som en form av uttryck, där den visuella kommunikationen i film anses lika viktig som den ljudmässiga och musikaliska för det narrativa historieberättandet och där den musikaliska aspekten i samspel med det filmiska visuella uttrycket belyser rollkaraktärers känslo- och sinnesstämningar. Resultatet av det empiriska arbetet presenterar cirka tjugo sidors kvalitativ innehållsanalys tillsammans med dess textanalytiska perspektiv som fokuserar på närläsningen av dem narrativa, visuella och musikaliska elementen samt dem abstrakta narrativerna (känslomässiga sinnesstämningar) i medietextens sju utvalda film-sångsekvenser. I utförandet av analysen och tolkningen av medietextens innehåll, togs hänsyn till dessa omnämnda element för att kunna besvara frågeställningarna och understryka syftet så relevant som möjligt. Slutsatsen baseras på det empiriska arbetets dataanalys och närläsning samt resultat och forskarnas tidigare teoretiska antaganden i koppling till mina observationer. Nyckelord:  musikalfilm  les miserables  filmmusik  ljudspår  känslor  stämningar  narrativ  audio visuell  uttryck  kommunikation  musikologi

This study investigates the effects of frequency variance on duration perception, using musically trained subjects. In the experiment three silent duration intervals were examined (4.75, 5.00, and 5.25 seconds); each interval was preceded and followed by tone markers. The onset marker was preceded by seven discrete tones one second apart, on the frequency 174.968 Hertz. This established a pulse or an external standard time measure. The subjects made judgments as to whether the offset marker fell "before," "on," or "after," the pulse. The offset marker had a variable frequency. In the study, the direction of the frequency change, the distance of frequency change, and the mathematical intervallic relationships of the two frequencies show possible influence on duration perception.

TITLE: Podcast as a didactic aid of teacher AUTHOR: Bc. Miloslav Khas DEPARTMENT: Department of Information & Technical Education SUPERVISOR: Ing. Bořivoj Brdička, Ph.D. ABSTRACT: Use of podcast as an educational medium is the principal and crucial topic of this thesis. The diploma thesis is focused on history and development of this phenomenon and points to the possibilities of podcast use at primary schools. The goal of this thesis is to show not only the advantages and benefit of the podcast for pupils and the teacher, but also to highlight the possible problems during its use and introduction. The theoretical part is dealing with aspects and podcast use at schools and provides an overview of existing researches. The other part is giving us an overview of existing solutions and good examples of practice at Czech schools and schools in abroad. The main part represents an experiment description including own solution proposal used at the primary school in Staňkov. This thesis can serve as a podcast guide for other possible interested persons striving for similar activities. KEYWORDS: Podcast, iPod, information and communication technology, MP3, sound, video, audio records, education, competence, school radio.

L'évolution des systèmes de télécommunications conduit à la conception de codecs de la parole et du son de plus en plus sophistiqués, accroissant ainsi la concurrence de l'industrie de l'audio et accordant une importance grandissante à la qualité de service. Si l'évaluation de la qualité des codecs peut s'opérer suivant des mesures objectives ou subjectives, les secondes restent les plus fiables dans la mesure où la qualité perçue par les utilisateurs est intrinsèquement subjective. Toutefois, les tests subjectifs requièrent des signaux d'ancrage, i.e. des signaux artificiels visant la reproduction des défauts perceptifs des codecs de sorte que les dégradations provoquées soient aisément contrôlables. Le système de référence actuellement normalisé par l'Union Internationale des Télécommunications est le MNRU (Modulated Noise Reference Unit) qui simule le bruit de quantification introduit par les premiers codecs en forme d'onde. L'évolution de la technologie rend aujourd'hui ce système obsolète, et il s'agit donc de concevoir un nouveau système d'ancrage plus adapté aux codecs actuels. En considérant la qualité audio comme un objet multidimensionnel, nous avons mis en évidence un espace perceptif à quatre dimensions, et ce à partir de deux approches de réduction de dimensionnalité, l'AFM (Analyse Factorielle Multiple) et la MDS 3–voies (MultiDimensional Scaling). A partir des quatre dimensions identifiées – « Réduction de la largeur de bande », « Bruit de fond », « Écho/Réverbération » et « Distorsion de la parole » –, nous avons modélisé puis validé les signaux d'ancrage des trois premières dimensions et proposé deux modèles de signaux d'ancrage pour la quatrième. / The evolution of technology led to the design of very sophisticated speech and audio codecs. Accordingly, the competition in audio devices manufacturing has increased and today the quality of service becomes crucial for telecommunications operators. Quality of codecs is assessed through objective and subjective measures, the second ones being the most reliable since the quality perceived by users is inherently subjective. Nevertheless, subjective tests require anchor signals corresponding to artificial signals, which reproduce the perceptual impairments of codecs in such a manner that the amount of degradation can be easily controlled. The reference system currently standardized by the International Telecommunication Union is the Modulated Noise Reference Unit (MNRU), which simulates the quantization noise of the first generation of waveform codecs. Due to the evolution of codecs, the MNRU system became obsolete and researchers aim at designing a new reference system of anchor signals more suited to current codecs. Assuming that speech and audio quality is multidimensional, we first identified four perceptual dimensions using two dimensionality reduction techniques – the MFA (Multiple Factor Analysis) and the 3–way MDS (MultiDimensional Scaling). From the identified dimensions, namely “Bandwidth limitation”, “Background noise”, “Echo/Reverberation” and “Speech distortion”, we succeeded in modeling and validating anchor signals for three of them and we suggested two models of anchor signals for the last one.