Studying Interaction Methodologies in Video Retrieval

So far, several approaches have been studied to bridge the problem of the Semantic Gap, the bottleneck in image and video retrieval. However, no approach is successful enough to increase retrieval performances significantly. One reason is the lack of understanding the user's interest, a major condition towards adapting results to a user. This is partly due to the lack of appropriate interfaces and the missing knowledge of how to interpret user's actions with these interfaces. In this paper, we propose to study the importance of various implicit indicators of relevance. Furthermore, we propose to investigate how this implicit feedback can be combined with static user profiles towards an adaptive video retrieval model

Beyond multimedia adaptation: Quality of experience-aware multi-sensorial media delivery

Multiple sensorial media (mulsemedia) combines multiple media elements which engage three or more of human senses, and as most other media content, requires support for delivery over the existing networks. This paper proposes an adaptive mulsemedia framework (ADAMS) for delivering scalable video and sensorial data to users. Unlike existing two-dimensional joint source-channel adaptation solutions for video streaming, the ADAMS framework includes three joint adaptation dimensions: video source, sensorial source, and network optimization. Using an MPEG-7 description scheme, ADAMS recommends the integration of multiple sensorial effects (i.e., haptic, olfaction, air motion, etc.) as metadata into multimedia streams. ADAMS design includes both coarse- and fine-grained adaptation modules on the server side: mulsemedia flow adaptation and packet priority scheduling. Feedback from subjective quality evaluation and network conditions is used to develop the two modules. Subjective evaluation investigated users' enjoyment levels when exposed to mulsemedia and multimedia sequences, respectively and to study users' preference levels of some sensorial effects in the context of mulsemedia sequences with video components at different quality levels. Results of the subjective study inform guidelines for an adaptive strategy that selects the optimal combination for video segments and sensorial data for a given bandwidth constraint and user requirement. User perceptual tests show how ADAMS outperforms existing multimedia delivery solutions in terms of both user perceived quality and user enjoyment during adaptive streaming of various mulsemedia content. In doing so, it highlights the case for tailored, adaptive mulsemedia delivery over traditional multimedia adaptive transport mechanisms

On the impact of video stalling and video quality in the case of camera switching during adaptive streaming of sports content

The widespread usage of second screens, in combination with mobile video streaming technologies like HTTP Adaptive Streaming (HAS), enable new means for taking end-users' Quality of Experience (QoE) to the next level. For sports events, these technological evolutions can, for example, enhance the overall engagement of remote fans or give them more control over the content. In this paper, we consider the case of adaptively streaming multi-camera sports content to tablet devices, enabling the end-user to dynamically switch cameras. Our goal is to subjectively evaluate the trade-off between video stalling duration (as a result of requesting another camera feed) and initial video quality of the new feed. Our results show that short video stallings do not significantly influence overall quality ratings, that quality perception is highly influenced by the video quality at the moment of camera switching and that large quality fluctuations should be avoided

Evaluation of the interactive multimedia business simulation SPACE (Simulating Project Auditing and Controlling Excellence)

This report presents the evaluation of the computer-based simulation SPACE – Simulating Project Auditing & Controlling Excellence – which is an interactive multiedia business simulation developed in partnership by Andersen Consulting and Siemens AG. The aims of SPACE are fostering self-directed learning and the acquisition of applicable knowledge in the economic domain regarding construction and solution projects of US GAAP. The evaluation was conducted in cooperation with the Institute of Educational Psychology at the Ludwig-Maximilians-University in Munich. The aim of the evaluation was to compare the effectiveness of SPACE with a traditional classroom instruction. Therefore, a problem-based transfer task was designed which assessed learning gains with respect to applicable knowledge in the following areas: (1) strategic knowledge and problem-solving skills, that means selection of appropriate information and strategies to solve a realistic business problem, (2) basic skills to calculate POC and (3) conceptual knowledge, i.e. an understanding of principles and interconnections of concepts in the domain. 38 students of business administration participated in the evaluation. 19 students learned eight hours with SPACE, the other 19 students received a traditional classroom instruction lasting also eight hours in the same subject area of US GAAP. Results show that SPACE was significantly better with regard to strategic knowledge and applying problem solving skills. In other words, the study showed that SPACE is superior to classroom instruction in this area of knowledge acquisition and application. In the other areas of basic skills to calculate POC and conceptional knowledge, differences were not significant between the classroom instruction and SPACE. When SPACE is employed under realistic conditions, i.e. in business, it can be assumed that SPACE is even more superior to classroom instruction.Das computerbasierte Lernprogramm SPACE (Simulating Project Auditing & Controlling Excellence), eine interaktive, multimediale Simulationssoftware, wurde von Anderson Consulting und der Siemens AG entwickelt. SPACE zielt auf die Förderung selbstgesteuerten Lernens und die Vermittlung anwendbaren Wissens. Das Simulationsprogramm behandelt inhaltlich die Kalkulation von Projektdaten auf Basis von US GAAP. Die hier berichtete Evaluationsstudie hatte zum Ziel, die Effektivität von SPACE im Vergleich zu einem traditionellen Klassenzimmerunterricht festzustellen. Mit einer problemorientierten Transferaufgabe wurden folgende Dimensionen erfasst: (1) Strategisches Wissen und Problemlösefertigkeiten (hierbei ging es um die Selektion relevanter Informationen und Strategien in Bezug auf eine realistische Problemstellung), (2) Basisfertigkeiten zur Berechnung von POC und (3) konzeptionelles Wissen im Sinne eines Verständnisses von Prinzipien und Zusammenhängen innerhalb des behandelten Inhaltsgebietes. An der Studie nahmen 38 Studenten der Betriebswirtschaftslehre teil. 19 Studenten lernten in einem Zeitraum von acht Stunden mit SPACE, die anderen 19 Teilnehmer nahmen an einem achtstündigen Klassenzimmerunterricht zum selben Inhaltsbereich teil. Hinsichtlich der Dimension "Strategiewissen und Problemlösefertigkeiten" schnitten diejenigen Studenten signifikant besser ab, die mit SPACE lernten. Das Simulationsprogramm zeigte sich somit in Bezug auf diese Dimension der Wissensanwendung dem traditionellen Klassenzimmerunterricht überlegen. In den Dimensionen "Berechnung von POC" und "Konzeptionelles Wissen" ergaben sich keine signifikanten Unterschiede zwischen den beiden Untersuchungsgruppen. Es ist anzunehmen, dass SPACE dem traditionellem Unterricht deutlicher überlegen ist, wenn das Lernprogramm unter realistischeren Bedingungen, d.h. in Betrieben, eingesetzt wird

Congestion Control using FEC for Conversational Multimedia Communication

In this paper, we propose a new rate control algorithm for conversational multimedia flows. In our approach, along with Real-time Transport Protocol (RTP) media packets, we propose sending redundant packets to probe for available bandwidth. These redundant packets are Forward Error Correction (FEC) encoded RTP packets. A straightforward interpretation is that if no losses occur, the sender can increase the sending rate to include the FEC bit rate, and in the case of losses due to congestion the redundant packets help in recovering the lost packets. We also show that by varying the FEC bit rate, the sender is able to conservatively or aggressively probe for available bandwidth. We evaluate our FEC-based Rate Adaptation (FBRA) algorithm in a network simulator and in the real-world and compare it to other congestion control algorithms

User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience

A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitors’ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further step towards an iterative design that considers the user interaction a central point. The paper discusses how such an environment allows designers and developers to experiment with different system’s behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the developments that followed that first experience: our findings seem still valid despite the passed time

A directionally based bandwidth reservation scheme for call admission control

This paper proposes a new advanced Call Admission Control(CAC) strategy involving for the first time, a bandwidth reservation scheme that is influenced by the direction attribute of a mobile terminal (MT). Aside from the Quality-of-Service (QoS) parameters, the direction attribute plays a key role in efficiently reserving resources for MTs supporting multimedia communications for different QoS classes. The framework for a direction-based CAC system is entirely distributed and may be viewed as a message passing system, where MTs inform their neighbouring base stations (BS) not only of their QoS requirements, but also of their mobility parameters. The base stations then predict future demand and reserve resources accordingly, only admitting those terminals that can be adequately supported. The bandwidth reservation scheme proposed in this paper, integrates the direction attribute into the conventional Guard Channel (GC) scheme. Simulation results prove that this new scheme offers significant improvements in both Call Blocking Probability (CBP) and bandwidth utilization, under a variety of differing traffic conditions