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Various forms of presenting content via computer differ in the number and quality of visual and verbal cues. Many of these cues such as eye contact, tone of voice, appearance, facial expressions, proximity, and gestures have been found to be beneficial to the learning process. This study seeks to uncover what effects multimedia instruction, which contain a high degree of visual and verbal cues, compared to multimedia instruction, which contains a low degree of visual and verbal cues, may have on college students perception of social presence, satisfaction with their instruction, motivation, and achievement. The relationships among these dependent variables were also investigated. One hundred and fifty students were randomly assigned to five treatment groups. The treatment groups received three computer based multimedia lessons that included either full visual and verbal cues (video), limited visual and full verbal cues (still picture with audio), limited visual cues and no verbal cues (still picture and text), no visual cues and full verbal cues (audio only), or no visual or verbal cues (text only). Results show no significant differences among treatment groups regarding social presence, motivation, satisfaction, and achievement. Significant correlations were found between social presence and satisfaction; social presence and motivation; satisfaction and motivation; and motivation and achievement. Correlations for social presence and achievement, and satisfaction and achievement were not significant. This study suggests that visual and verbal cues in multimedia may not be important for student learning. Further research using different lesson content and a revised social presence scale is encouraged. / Ph. D.

This study explores the use of a multimedia survey instrument which includes an integrated treatment in the context of a one semester human sexuality course. The instrument was created to assess and affect student attitudes and to improve data collection and analysis options. A literature review on attitudes, attitude assessment, and applications of technology to the affective domain introduces the discussion. Developed by a team of three university researchers, the survey instrument was created as a stand-alone application using Macromedia Authorware® multimedia authoring system. The instrument was administered to 210 students in a university education technology laboratory via CD-ROM with data collected across the campus network to two remote servers. Due to problems within specific response sets, 21 users' responses were removed from the data set, leaving an N of 189 respondents in the analyzed data. The application was administered to the students twice, once early and once late in the semester. Each use included demographic data acquisition and two iterations of a 24-item survey instrument with audiovisual and reflective response treatment between them. There were also repines sections on truth of responses and evaluations of the multimedia instrument. The final interactions were opportunities for free text responses with no prompting on content. The four sets of responses to the 24-item survey comprised pretest/posttest data for six pairings of scores across time. The 24-item survey was explored for the effects of both the multimedia/reflective response treatment and of the human sexuality course on student attitudes. Statistical analysis showed no significant differences in scores among the four iterations of the survey. Further exploration indicated that there were some significant changes for specific survey items. This document examines the relationship among the elements of the survey and the free responses from the users for further illumination of the quantitative results. Five possible elements that may have affected the survey's outcome are considered in light of the respondents' text input. Themes that emerged from the free responses were identified and explored for possible improvements of multimedia applications for integrated information delivery and data gathering. Conclusions are discussed and suggestions are made for further study regarding the template on which the application under study was built and regarding other similar multimedia instruments. These include extensions into other disciplines and other types of delivery media. Because of the exploratory nature of this study, very little can be stated conclusively. The users' reactions to and engagement with the multimedia instrument in this context do suggest broader avenues for such applications. For the moment, this medium seems to present a useful range of options to designers and researchers. / Ph. D.

Multimedia content, e.g., sound files, interactive demos, and video files, has been widely used in digital courses to provide an easy to use format and to emphasize the ideas. In this work, we address aspects of generating multimedia contents automatically in digital courses. In particular, we focus on two types of automatically generated multimedia: interactive glossaries and sound files. Glossaries play a major role in enhancing students' comprehension of the course core concepts. Glossary terms have complex interrelationship that cannot be fully illustrated by standard approaches, e.g., including all the terms as a linear, alphabetized list. To overcome this limitation, we introduce an interactive design for the glossary terms using concept maps. Glossary terms are visualized as nodes in graphs and their relationships are included on the edges. We implement these concept maps within the OpenDSA e-textbook system. A concept map associated with the selected term is generated on demand. We evaluate the effectiveness of our design by comparing student use of our concept-map based glossary to the traditional alphabetized list. We have designed new exercises that target the comprehension of the glossary terms to make students familiar with the concept maps. Our other work generates sound files automatically to supplement text narration in slide shows. This is made feasible by the widespread availability of text-to-speech generators in web browsers. To this end, we designed an interactive narration tool and integrated it into the OpenDSA library. In this way, all slide shows automatically have their text augmented with narration. / Master of Science / Recently, there has been an increase in the use of multimedia contents in digital courses. Multimedia files, e.g., sound files, interactive demos, and video files, are used in digital courses to provide an easy to use format and to emphasize the ideas. In this work, we address aspects of generating multimedia contents in digital courses. In particular, we focus on two types of automatically generated multimedia: interactive glossaries and sound files. Glossaries play a major role in enhancing students’ comprehension of the core concepts in the courses. In general, glossary terms have complex interrelationship that cannot be fully illustrated by standard approaches, such as the alphabetized list. To overcome this limitation, we introduce an interactive design for the glossary terms using concept maps. In this design, glossary terms are visualized as nodes in graphs and their relationships are included on the edges. We implement these concept maps within the OpenDSA e-textbook system to be generated on demand. We evaluate the effectiveness of our design by comparing student use of our concept-map based glossary to the traditional alphabetized list. We have designed new exercises to make students familiar with the concept maps. Our other work generates sound files automatically to supplement text narration in slide shows. This was motivated by the widespread use of text-to-speech generators in web browsers. To this end, we designed an interactive narration tool and integrated it into the OpenDSA library so that all OpenDSA slide shows can benefit from the narration tool.

Nowadays, we are witnessing a transition from physical togetherness towards networked togetherness around media content. Novel forms of shared media experiences are gaining momentum, allowing geographically distributed users to concurrently consume the same media content while socially interacting (e.g., via text, audio or video chat). Relevant use cases are, for example, Social TV, networked games and multi-party conferencing. However, realizing enjoyable shared media services faces many challenges. In particular, a key technological enabler is the concurrent synchronization of the media playout across multiple locations, which is known as Inter-Destination Multimedia Synchronization (IDMS). This PhD thesis presents an inter-operable, adaptive and accurate IDMS solution, based on extending the capabilities of RTP/RTCP standard protocols (RFC 3550). Concretely, two new RTCP messages for IDMS have been defined to carry out the necessary information to achieve IDMS. Such RTCP extensions have been standardized within the IETF, in RFC 7272. In addition, novel standard-compliant Early Event-Driven (EED) RTCP feedback reporting mechanisms have been also designed to enhance the performance in terms of interactivity, flexibility, dynamism and accuracy when performing IDMS. The designed IDMS solution makes use of globally synchronized clocks (e.g., using NTP) and can adopt different (centralized and distributed) architectural schemes to exchange the RTCP messages for IDMS. This allows efficiently providing IDMS in a variety of networked scenarios and applications, with different requirements (e.g., interactivity, scalability, robustness…) and available resources (e.g., bandwidth, latency, multicast support…). Likewise, various monitoring and control algorithms, such as dynamic strategies for selecting the reference timing to synchronize with, and fault tolerance mechanisms, have been added. Moreover, the proposed IDMS solution includes a novel Adaptive Media Playout (AMP) technique, which aims to smoothly adjust the media playout rate, within perceptually tolerable ranges, every time an asynchrony threshold is exceeded. Prototypes of the IDMS solution have been implemented in both a simulation and in real media framework. The evaluation tests prove the consistent behavior and the satisfactory performance of each one of the designed components (e.g.,protocols, architectural schemes, master selection policies, adjustment techniques…). Likewise, comparison results between the different developed alternatives for such components are also provided. In general, the obtained results demonstrate the ability of this RTP/RTCP-based IDMS solution to concurrently and independently maintain an overall synchronization status (within allowable limits) in different logical groups of users, while avoiding annoying playout discontinuities and hardly increasing the computation and traffic load. / Montagut Climent, MA. (2015). DESIGN, DEVELOPMENT AND EVALUATION OF AN ADAPTIVE AND STANDARDIZED RTP/RTCP-BASED IDMS SOLUTION [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48549 / Premios Extraordinarios de tesis doctorales

In response to the recent intensive needs for civilian security surveillance, both full and compact versions of a Multimedia Security Surveillance (MSS) system have been built up. The new Microsoft DirectShow technology was applied in implementing the multimedia stream-processing module. Through Microsoft Windows Driver Model interface, the chosen IEEE1394 enabled Fire-i cameras as external sensors are integrated with PC based continuous storage unit. The MSS application also allows multimedia broadcasting and remote controls. Cost analysis is included.

This study investigates the impact of multimedia on the effectiveness of information scanning. Information scanning is the act of seeking and receiving a wide variety of special information to develop a thorough understanding of the organization and the environment. The application domain of this study is Executive Support Systems. The experimental task is to identify potential threats and opportunities, a strategic information-scanning activity, based on the information stored in three ESS prototypes. Forty subjects from four organizations participated in the experiment. A random assignment process allocated them into three groups. The control group used the text-based ESS. The first experimental group used the visual multimedia ESS. The second experimental group used the audiovisual multimedia ESS. The experiment was carried out on the sites of the participating organizations. The investigator measured the effectiveness of information scanning based on the number of threats and opportunities each subject identifies. A close-ended questionnaire measured subjects' retention of information. The results of this study support the cognitive-fit theory. The findings indicate that multimedia is not an appropriate presentation format for analytical tasks. Subjects who use text-based ESS identify significantly more threats and opportunities than subjects who use audiovisual multimedia ESS. The cognitive style of subjects does not moderate the impact of multimedia. The results show that the use of multimedia does not necessarily improve retention of information. Further research is needed to determine the most effective combination of text, graphics, animation, video, and sound.

This work is focusing on exploration of multimedia collections. It describes the problematic of exploration and proposes new approaches to it, two based on the data structure M-Index and two utilizing multiple similarity models at once. Those approaches were compared using an extensive user study. Part of this work is also devoted to analysis of a new exploration system, design of its architecture, system implementation and its deployment. This exploration system was used in several applications, which are also shown and described in this thesis.

A experiência com autoria de material didático multimídia para propósitos educacionais mostra um grande problema: como prover uma maneira de tratar objetos multimídia de modo que usuários inexperientes (como professores) possam estar aptos a projetar e construir suas próprias apresentações? A criação de tais apresentações envolve fatores como armazenamento, entrega, busca e apresentação de material multimídia (vídeo em especial). Uma infra-estrutura básica que armazene e entregue eficientemente os dados de vídeo é necessária, porém, outro ponto importante é organizar esses dados armazenados no servidor de forma a facilitar seu acesso por parte dos usuários. Neste trabalho, isto é alcançado através do uso de um sistema interativo de recuperação e gerenciamento de informações projetado para facilitar o acesso a itens (ou parte deles) armazenados no servidor. A principal característica de tal sistema é o uso de uma base de metadados contendo os atributos dos vídeos armazenados no servidor. Buscas podem ser feitas por título, assunto, tamanho, autor, conteúdo ou, mais importante no caso de material didático, por cenas ou frames específicos. O sistema foi implementado segundo uma abordagem cliente/servidor utilizando a linguagem de programação JAVA. A comunicação entre clientes e servidores é realizada através do uso do Visibroker 3.0, que é uma ferramenta de programação para Objetos Distribuídos segundo o padrão CORBA. O acesso aos dados a partir da base de metadados é realizado através do uso de um driver PostgreSQL que segue a API JDBC. Para propósitos de avaliação do sistema um player foi construído utilizando a ferramenta Java Media Framework (JMF). Foi realizada uma análise para a verificação do impacto da utilização das tecnologias CORBA e JDBC no sistema. Foi detectado que a utilização da tecnologia JDBC impõe um atraso muito mais significante que a utilização da tecnologia CORBA. Outra conclusão é que a utilização de metadados provê uma melhor interatividade em buscas, permite economia de tempo durante o processo de edição e provê economia de espaço de armazenamento através do compartilhamento de objetos como vídeos, cenas e frames. / The experience with authoring multimedia material for educational purposes shows a major problem: how to provide an easy and efficient way to handle multimedia objects in a manner that non-expert users (namely school teachers) can be able to design and build their own presentations? The creation of this presentations involves factors like storage, delivery, search and presentation of multimedia material (video in special). A basic infra-structure that stores and efficiently deliver the video data is needed. However, another important point is the organization of these data stored into the server in a way to facilitate the access to them from the users. In the system wich is the subject of this work, this is achived through the use of an interactive information management and retrieval system designed to facilitate the access to items (or parts of the items) stored in the server. The main characteristic of the system is the use of a metadata base which contains attributes of the videos stored in the server. Searches can be made by title, subject, length, author, content or, most important in the didatic multimedia material case, by a specific scene or frame. The system was built with JAVA programming language in a client/server way. The communication between clients and servers is realized through the use of the Visibroker 3.0, which is a Distributed Objects programming tool according to the CORBA standard. The data access from the metadata base use a PostgreSQL driver which follows the JDBC API. For evaluation purposes a playback tool was built using Java Media Framework (JMF). An analisys was carried out to verify the impact of the utilization of CORBA and JDBC technologies in the system. It was detected that JDBC technology utilization imposes a much more significate delay than the CORBA technology utilization. Another conclusion is that metadata utilization provide better interactivity searches, making the editing process faster and save storage space through the sharing of objects like videos, scenes and frames.

"As streaming techniques and wireless access networks become more widely deployed, a streaming multimedia connection with the "last mile" being a wireless network is becoming increasingly common. However, since current streaming techniques are primarily designed for wired networks, streaming multimedia applications can perform poorly in wireless networks. Recent research has shown that the wireless network conditions, such as the wireless link layer rate adaptation, contending traffic, and interference can significantly degrade the performance of streaming media applications. This performance degradation includes increased multimedia frame losses and lower image quality caused by packet loss, and multiple rebuffering events that stop the media playout. This dissertation presents the model, design, implementation and evaluation of an application layer solution for improving streaming multimedia application performance in IEEE 802.11 wireless networks by using enhanced bandwidth estimation techniques. The solution includes two parts: 1) a new Wireless Bandwidth estimation tool (WBest) designed for fast, non-intrusive, accurate estimation of available bandwidth in IEEE 802.11 networks, which can be used by streaming multimedia applications to improve the performance in wireless networks; 2) a Buffer and Rate Optimization for Streaming (BROS) algorithm using WBest to guide the streaming rate selection and initial buffer optimization. WBest and BROS are implemented and incorporated into an emulated streaming client-server system, Emulated Streaming (EmuS), in Linux and evaluated under a variety of wireless conditions. The evaluations show that with WBest and BROS, the performance of streaming multimedia applications in wireless networks can be significantly improved in terms of multimedia frame loss, rebuffer events and buffer delay."