theory and praxis

This paper offers a review of technological developments regarding massive storage devices and the emergence of new streaming services for audio and video on-demand. While the capacity of storage devices has been increasing exponentially, the price of a stored bit has been falling at an even faster rate. Audio and video files can be stored on-line in personal computers and computer networks. Accessing this information requires new type of databases capable of handling special types of queries: access through annotations and metadata, access by similarity, and access by feature search. Databases with in-built streaming capabilities would be extremely useful for transmitting the information to the end user, while providing at the same time consistency checks, indexing, reporting, and querying features. They should also be fast and scalable. This paper reviews recent academic and industrial projects, and describes an implementation of a streaming video servlet based on the Oracle SQL database, its Binary Large Object storage data type, and the Java Database Connectivity interface

Trends in hardware architecture for mobile devices

In the last ten years, two main factors have fueled the steady growth in sales of mobile computing and communication devices: a) the reduction of the footprint of the devices themselves, such as cellular handsets and small computers; and b) the success in developing low-power hardware which allows the devices to operate autonomously for hours or even days. In this review, I show that the first generation of mobile devices was DSP centric – that is, its architecture was based in fast processing of digitized signals using low- power, yet numerically powerful DSPs. However, the next generation of mobile devices will be built around DSPs and low power microprocessor cores for general processing applications. Mobile devices will become data-centric. The main challenge for designers of such hybrid architectures is to increase the computational performance of the computing unit, while keeping power constant, or even reducing it. This report shows that low-power mobile hardware architectures design goes hand in hand with advances in compiling techniques. We look at the synergy between hardware and software, and show that a good balance between both can lead to innovative lowpower processor architectures

Streaming Databases for Audio and Video Theory and Praxis

This paper offers a review of technological developments regarding massive storage devices and the emergence of new streaming services for audio and video on-demand. While the capacity of storage devices has been increasing exponentially, the price of a stored bit has been falling at an even faster rate. Audio and video files can be stored on-line in personal computers and computer networks. Accessing this information requires new type of databases capable of handling special types of queries: access through annotations and metadata, access by similarity, and access by feature search. Databases with in-built streaming capabilities would be extremely useful for transmitting the information to the end user, while providing at the same time consistency checks, indexing, reporting, and querying features. They should also be fast and scalable. This paper reviews recent academic and industrial projects, and describes an implementation of a streaming video servlet based on the Oracle SQL database, its Binary Large Object storage data type, and the Java Database Connectivity interface. 1 Motivation: Th

An Algorithmic Animation Platform for the Web

This paper describes a system for generating animations of algorithms for use in the classroom. The animations emulate the individual steps of an algorithm in graphical form and can be posted to the Web. The system is based in Flash. In order to generate an animation the code of an algorithm is extended with annotations which generate the script code. We call our scripting language â??Flashdanc

Ein neues Algorithmenanimations-Rahmenwerk für den Klassenraum und das Internet

Title and Table of Contents Preface and Acknowledgements Introduction 1 Algorithmic Animation in Education 2 Survey of Algorithmic Animation Platforms 3 Principles of Algorithmic Animation 4 Chalk Animator - Algorithmic Animation for an Electronic Chalkboard 5 Interactive Computer Driven Animation of Sketches 6 Flashdance - An Algorithmic Animation Platform for the Web 7 Conclusions and Future Work 8 Summary of Contributions ReferencesThis thesis describes a new approach to the generation of algorithmic animations for computer science education. Two different rendering platforms are used for the animations: the first is an electronic chalkboard in which the user enters data and starts computations by using handwritten symbols and letters; the second is a de-facto standard high quality animation engine for the Web, i.e. Macromedia's Flash. The animations described in this thesis are produced by generating commands in a special new script language which I have called Flashdance. The commands are interpreted by one of my animation engines: Chalk Animator is the animation interpreter I wrote for the electronic chalk system (E-Chalk); Flashdance is the name of the animation interpreter I wrote for Macromedia Flash (the interpreter and the script language share the same name). Animation files can be played on any of these two platforms. E-Chalk Animator is the first algorithmic animation system able to process handwritten and sketched input. An instructor can explain an algorithm using an electronic blackboard, sketch a graph or write numbers, which are then consumed as input for the algorithm. The algorithm is animated on the E-Chalk board. In this thesis, I explain how to adapt a handwriting recognizer to the recognition of computer code, so that an instructor can execute the code he or she just wrote in the electronic blackboard. In the future, pseudocode will be also recognizable and will be executed on the fly. Flashdance is the first algorithmic animation system based on a standard animation engine. By adopting Flash, the interpreter of the script language can be reduced to its essential algorithmic features, the animations are portable, and they can be viewed on the Web. The graphic rendering is of high quality. This thesis introduces also the concept of overlays in algorithmic animations, providing additional information layers for the viewer.Diese Dissertation beschreibt einen neuen Ansatz für die Erzeugung von Algorithmenanimationen für die Lehre. Zwei verschiedene Plattformen werden für die Wiedergabe der Animationen verwendet. Die erste ist eine elektronische Kreide, bei der die Dateneingabe und der Animationsbeginn mit Hilfe von handgeschriebenen Symbolen erfolgt. Die zweite Plattform ist der stark verbreitete Flashplayer von Macromedia. Die Animationen, die in dieser Arbeit beschrieben werden, werden durch das Generieren von Animationsbefehlen in einer speziell für diese Arbeit entwickelten Animationsskriptsprache produziert. In Anlehnung an die Flash-Plattform habe ich diese Animationssprache Flashdance genannt. Die Befehle der Animationssprache werden von einem der zwei Interpreter ausgearbeitet: Chalk-Animator ist der Animationsinterpreter für die elektronische Kreide; Flashdance ist der Name des Interpreters für Macromedia-Flash (der Interpreter und die Skriptsprache tragen den gleichen Namen). Das E-Chalk Animationssystem ist das erste System, das in der Lage ist, handgeschriebene Symbole direkt zu verarbeiten und für die Animation zu verwenden. Ein Dozent kann einen Algorithmus an einer elektronischen Tafel erklären, Graphiken zeichnen oder Zahlen mit der Hand schreiben; diese Daten werden dann als Eingabe für den Algorithmus verarbeitet. In dieser Dissertation erkläre ich, wie Handschrifterkennung so angepasst werden kann, dass Programmcode erkannt wird, so dass der Dozent seinen gerade geschriebenen Programmcode an der elektronischen Tafel ausführen kann. In der Zukunft wird auch Pseudocode erkennbar sein und direkt ausgeführt werden können. Flashdance ist das erste Animationssystem, welches auf einer Standard-Animationsumgebung basiert ist. Durch die Verwendung von Flash kann der Interpreter der Skriptsprache auf seine essentiellen algorithmischen Funktionen reduziert werden, die Animationen sind portabel und können ins Internet gestellt werden. Die graphische Wiedergabe ist von hoher Qualität. Diese Dissertation stellt weiterhin auch das Konzept der "overlays" in Algorithmenanimationen vor, wodurch dem Betrachter zusätzliche Informationsschichten geboten werden

Social Editing of Video Recordings of Lectures

In this paper we show how video recordings of lectures can be enhanced through “social editing”, a special sort of “human computation”. We record lectures using six cameras arranged to produce a panoramic view (360 degrees) of the classroom. After recording, viewers can replay the lectures on a computer and can navigate through them tilting and zooming a virtual camera. All user interactions are recorded by the system, and are later used to decide which views should be stored and their zoom level. The result is an automatically edited video as a result of the social navigation of the first few initial viewers of the lecture

Learning Algorithms with an Electronic Chalkboard over the Web

Abstract. This paper describes a system for the animation of algorithms on an electronic chalkboard. The instructor teaching an algorithm can enter data directly through a drawing- the algorithm then makes use of this data, for exampIe numbers, or the image of a graph. The drawing becomes alive. The result is a more natural way of teaching and starting algorithmic animations. The paper also describeshow to couple a sign and handwritingrecognitionengine with the animation system. The lecturer can then write programs using her own handwriting, and the prograrnsruns. All animations can be enriched with sound and explanationsfrom the lecturer and can be posted to the Web.

PowerChalk: An adaptive E-Learning application

Abstract This paper present a new interactive e-learning application called PowerChalk. PowerChalk arises as the result from the analysis of the evolution of Information Systems Design Theory for E-Learning; it was designed to resolve an important limitation of current design methods and e-learning systems: adaptability. Modular programming is the design technique used in PowerChalk to improve human computer interaction with the management of different types of data in order to have positive effect on both learning score and learning satisfaction. PowerChalk works like a Transaction Processing System in order to support collaboration, communication, creativity and learning through a collection of organized modules. The characteristics of PowerChalk facilitate developing of competencies for using multimedia technologies in any learning session taking into account the teacher and student perspective. The goal of PowerChalk is to provide a robust, reliable, usable and sustainable multimedia technology for collaborative learning