The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

Mobile-Based Interactive Music for Public Spaces

With the emergence of modern mobile devices equipped with various types of built-in sensors, interactive art has become easily accessible to everyone, musicians and non-musicians alike. These efficient computers are able to analyze human activity, location, gesture, etc., and based on this information dynamically change, or create an artwork in realtime. This thesis presents an interactive mobile system that solely uses the standard embedded sensors available in current typical smart devices such as phones, and tablets to create an audio-only augmented reality for a singled out public space in order to explore the potential for social-musical interaction, without the need for any significant external infrastructure

Physical heart in a digital instrument

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 113-119).Today's tools and instruments, whether musical or graphical, fall into two very distinct classes, each with its own benefits and drawbacks. Traditional physical instruments offer a richness and uniqueness of qualities that result from the unique properties of the physical materials used to make them. The hand-crafted qualities are also very important for these tools. In contrast, electronic and computer-based instruments lack this richness and uniqueness; they produce very predictable and generic results, but offer the advantage of flexibility, as they can be many instruments in one. I propose a new approach to designing and building instruments which attempts to combine the best of both, and I call this approach "hybrid instruments", since the resulting instruments exist simultaneously in both the physical and digital environments. The approach is characterized by a sampling of the instrument's physical matter and its properties and is complemented by a physically simulated, virtual shape or other digital signal manipulations. This thesis describes the key concepts of the approach and presents an actual example of such a hybrid instrument: the Chameleon Guitar. The guitar project contains several aspects: separation of the guitar interface from its acoustic content; division of the acoustic content into a physical part and a digital processing part; and maximization of the user's freedom in each of the domains. I provide a historical and technical overview; discuss related works, motivation and concepts, and present the design of the Chameleon Guitar.(cont.) In addition the project evaluation by musicians and instrument-makers is described, together with future work and conclusions. I hope to demonstrate that this approach to building digital instruments maintains some of the rich qualities and variation found in real instruments (the result of natural materials combined with craft) with the flexibility and open-endedness of virtual instruments.by Amit Zoran.S.M

High definition systems in Japan

The successful implementation of a strategy to produce high-definition systems within the Japanese economy will favorably affect the fundamental competitiveness of Japan relative to the rest of the world. The development of an infrastructure necessary to support high-definition products and systems in that country involves major commitments of engineering resources, plants and equipment, educational programs and funding. The results of these efforts appear to affect virtually every aspect of the Japanese industrial complex. The results of assessments of the current progress of Japan toward the development of high-definition products and systems are presented. The assessments are based on the findings of a panel of U.S. experts made up of individuals from U.S. academia and industry, and derived from a study of the Japanese literature combined with visits to the primary relevant industrial laboratories and development agencies in Japan. Specific coverage includes an evaluation of progress in R&D for high-definition television (HDTV) displays that are evolving in Japan; high-definition standards and equipment development; Japanese intentions for the use of HDTV; economic evaluation of Japan's public policy initiatives in support of high-definition systems; management analysis of Japan's strategy of leverage with respect to high-definition products and systems

A platform for low-latency continuous keyboard sensing and sound generation

On several acoustic and electromechanical keyboard instruments, the produced sound is not always strictly dependent exclusively on a discrete key velocity parameter, and minute gesture details can affect the final sonic result. By contrast, subtle variations in articulation have a relatively limited effect on the sound generation when the keyboard controller uses the MIDI standard, used in the vast majority of digital keyboards. In this paper we present an embedded platform that can generate sound in response to a controller capable of sensing the continuous position of keys on a keyboard. This platform enables the creation of keyboard-based DMIs which allow for a richer set of interaction gestures than would be possible through a MIDI keyboard, which we demonstrate through two example instruments. First, in a Hammond organ emulator, the sensing device allows to recreate the nuances of the interaction with the original instrument in a way a velocity-based MIDI controller could not. Second, a nonlinear waveguide flute synthesizer is shown as an example of the expressive capabilities that a continuous-keyboard controller opens up in the creation of new keyboard-based DMIs

Artificial Reality Enhanced Learning

This disclosure describes techniques for performing a medical operation in an artificial reality environment. The described techniques include providing, via a user device configured to render the artificial reality environment, first artificial reality content that simulates performance of the medical operation. Anatomical features of a subject being treated by the medical operation are labeled. An audio signal corresponding to a video frame of the first artificial reality content is determined and the video frame is annotated based on the audio signal. The techniques further include reproducing the audio signal based on determining second artificial reality content corresponding to the performance of the medical operation. A portion of the first artificial reality content matching a portion of the second artificial reality content based on the anatomical features is provided in the artificial reality environment

Some Application of Switched Current Circuits.

A complete digital signal processing system requires analog circuits acting as an interface between the digital system and the outside analog world. Various techniques have been proposed to implement these circuits, but the one compatible with digital technology is switched capacitor (SC) technique. However, there are still some problems with SC circuits which are as follows: (i) The process technology used for these circuits is not compatible with the standard digital process technology due to extra poly-silicon layer, (ii) the performance of these circuits worsens for low voltage operations, because lower supply voltage will tend to increase power consumption for the same dynamic range, and in order to maintain the same dynamic range on a low supply voltage requires a quadratic increase in sampling capacitance to reduce thermal noise. The required increase in bias current to maintain circuit bandwidth results in a net increase in the overall power consumption. To overcome these problems, a new technique called the switched current (SI) technique has been proposed. The technique utilizes the ability of an MOS transistor to maintain its drain current, when its gate is open circuited, through the charge stored on its gate oxide capacitance. In this technique signals are represented by currents instead of voltages and, therefore, the signal swing is only indirectly limited by a reduction of the available voltage range. In a traditional voltage mode circuit, the supply voltage imposes a direct limitation on signal swing. Switched current circuits could therefore be a better for low voltage operation. 5 The application of switched current systems is much same as for switched capacitor systems viz. filters, A/D and D/A converters, general signal processing etc. but the prime aim is that switched current circuits should be implemented using a standard VLSI. In this work, the SI technique has been studied and several reported SI circuits have been simulated for their performance. Specifically, the work was aimed at the study of developing SI technique for the design of high performance circuits such as Integrators, Differentiators, Programmable filters, A/D and D/A converters, Sigma Delta Modulators, Multipliers, Delays etc. All the investigations are based on the PSPICE simulations using model parameters of the BISIM335 MOS transistors. The investigations match the theoretical interpretations and predictions. The entire gamut of this dissertation has been to study the already reported SI circuits and to investigate them for improved accuracy, dynamic range, bandwidth, linearity and low voltage operation

Real-time sound synthesis on a multi-processor platform

Real-time sound synthesis means that the calculation and output of each sound sample for a channel of audio information must be completed within a sample period. At a broadcasting standard, a sampling rate of 32,000 Hz, the maximum period available is 31.25 μsec. Such requirements demand a large amount of data processing power. An effective solution for this problem is a multi-processor platform; a parallel and distributed processing system. The suitability of the MIDI [Music Instrument Digital Interface] standard, published in 1983, as a controller for real-time applications is examined. Many musicians have expressed doubts on the decade old standard's ability for real-time performance. These have been investigated by measuring timing in various musical gestures, and by comparing these with the subjective characteristics of human perception. An implementation and its optimisation of real-time additive synthesis programs on a multi-transputer network are described. A prototype 81-polyphonic-note- organ configuration was implemented. By devising and deploying monitoring processes, the network's performance was measured and enhanced, leading to an efficient usage; the 88-note configuration. Since 88 simultaneous notes are rarely necessary in most performances, a scheduling program for dynamic note allocation was then introduced to achieve further efficiency gains. Considering calculation redundancies still further, a multi-sampling rate approach was applied as a further step to achieve an optimal performance. The theories underlining sound granulation, as a means of constructing complex sounds from grains, and the real-time implementation of this technique are outlined. The idea of sound granulation is quite similar to the quantum-wave theory, "acoustic quanta". Despite the conceptual simplicity, the signal processing requirements set tough demands, providing a challenge for this audio synthesis engine. Three issues arising from the results of the implementations above are discussed; the efficiency of the applications implemented, provisions for new processors and an optimal network architecture for sound synthesis

Flexi-WVSNP-DASH: A Wireless Video Sensor Network Platform for the Internet of Things

abstract: Video capture, storage, and distribution in wireless video sensor networks (WVSNs) critically depends on the resources of the nodes forming the sensor networks. In the era of big data, Internet of Things (IoT), and distributed demand and solutions, there is a need for multi-dimensional data to be part of the Sensor Network data that is easily accessible and consumable by humanity as well as machinery. Images and video are expected to become as ubiquitous as is the scalar data in traditional sensor networks. The inception of video-streaming over the Internet, heralded a relentless research for effective ways of distributing video in a scalable and cost effective way. There has been novel implementation attempts across several network layers. Due to the inherent complications of backward compatibility and need for standardization across network layers, there has been a refocused attention to address most of the video distribution over the application layer. As a result, a few video streaming solutions over the Hypertext Transfer Protocol (HTTP) have been proposed. Most notable are Apple’s HTTP Live Streaming (HLS) and the Motion Picture Experts Groups Dynamic Adaptive Streaming over HTTP (MPEG-DASH). These frameworks, do not address the typical and future WVSN use cases. A highly flexible Wireless Video Sensor Network Platform and compatible DASH (WVSNP-DASH) are introduced. The platform's goal is to usher video as a data element that can be integrated into traditional and non-Internet networks. A low cost, scalable node is built from the ground up to be fully compatible with the Internet of Things Machine to Machine (M2M) concept, as well as the ability to be easily re-targeted to new applications in a short time. Flexi-WVSNP design includes a multi-radio node, a middle-ware for sensor operation and communication, a cross platform client facing data retriever/player framework, scalable security as well as a cohesive but decoupled hardware and software design.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201