3,492 research outputs found

    The Design of a System Architecture for Mobile Multimedia Computers

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    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

    Distributed control of reconfigurable mobile network agents for resource coordination

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    Includes abstract.Includes bibliographical references.Considering the tremendous growth of internet applications and network resource federation proposed towards future open access network (FOAN), the need to analyze the robustness of the classical signalling mechanisms across multiple network operators cannot be over-emphasized. It is envisaged, there will be additional challenges in meeting the bandwidth requirements and network management...The first objective of this project is to describe the networking environment based on the support for heterogeneity of network components..

    Wireless Broadband Access: Policy Implications of Heterogeneous Networks

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    A wireless heterogeneous network can help increase the access transmission speed and contribute thereby to the broadband deployment policies of administrations and telecommunications operators. Given the technical particularities of wireless heterogeneous networks, the deployment of wireless heterogeneous networks raises a number of challenges that need to be addressed by regulatory authorities. This article analyses the following regulatory implications: standardisation and technology neutrality, spectrum management, market analysis, open access and infrastructure sharing, interconnection pricing and charging, broadband deployment policies, and privacy and security issues. --4G,heterogeneous networks,cooperative networks,spectrum management,regulation,wireless networks

    Development of a Hybrid Control and Monitoring System within a Reconfigurable Assembly System

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    Published ThesisExpanding global markets are constantly changing and unstable. South African manufacturing companies need to develop similar levels of sophistication and expertise in the automation industry as its international rivals, to compete for these markets and meet rising consumer expectations. To remain competitive, these manufacturing companies must manage their plants extremely efficiently to ensure the quality of assembled products; allow for rapid product introduction and product changes; achieve shortened throughput cycles; ensure more reliable delivery dates; and effectively coordinate product demand while contending with decreased product lifespans. To accomplish this, manufacturing companies in SA are progressively engaging in the current trend in automation known as reconfigurable manufacturing. Due to the extreme flexibility of these reconfigurable systems, the monitor and control systems for these require the same levels of flexibility. The purpose of the study is to develop a hybrid control and monitoring system, to supervise and control reconfigurable assembly systems (RAS), and adapt to the flexibility of these systems. To achieve this, a literature study was done in the research area to reveal the prerequisites for such systems; the physical assembly devices were designed and built; the separate software modules developed and ultimately integrated into the intended system. The tests to validate the system were developed in such a way that each subsection of the system is validated by using a different system software function. This inevitably confirms the functionality of the fundamental components and the system in entirety. The results indicated that devices are easily added to the system; devices are successfully detected and identified; how the system plans production, and how the system automatically configures itself. Further results showed the capability of the system to generate and virtually wire system runtime code; store and retrieve production data; as well as warn and alarm on unwanted conditions. By obtaining these results, companies can configure their systems with ease, in a shorter amount of time, and without any human error. Moreover, their systems will be more flexible, allow easy addition of new products and assembly devices, and with minimal downtime. This will enable SA manufacturing companies to be more competitive, ensure increased productivity, achieve extreme system flexibility, and decrease lead times – thus ensuring them an advantage over their international competitors

    ARTIST - a reAl-time low-effoRt mulTi-entity Interaction System for creaTing reusable and optimized MR experiences

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    ARTIST is a research approach introducing novel methods for real-time multi-entity interaction between human and non-human entities, to create reusable and optimized Mixed Reality (MR) experiences with low-effort, towards a Shared MR Experiences Ecosystem (SMRE2). As a result, ARTIST delivers high quality MR experiences, facilitating the interaction between a variety of entities which interact in a virtual and symbiotic way within a mega, virtual and fully-experiential world. Specifically, ARTIST aims to develop novel methods for low-effort (code-free) implementation and deployment of open and reusable MR content, applications and tools, introducing the novel concept of an Experience as a Trajectory (EaaT). In addition, ARTIST will provide tools for the tracking, monitoring and analysis of user behaviour and their interaction with the environment and with other users, towards optimizing MR experiences by recommending their reconfiguration, dynamically (at run-time) or statically (at development time). Finally, it will provide tools for synthesizing experiences into new mega and still reconfigurable EaaTs, enhancing them at the same time using semantically integrated related data/information available in disparate and heterogeneous resources

    Special Session on Industry 4.0

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    No abstract available

    Simulation of ultrasonic lamb wave generation, propagation and detection for an air coupled robotic scanner

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    A computer simulator, to facilitate the design and assessment of a reconfigurable, air-coupled ultrasonic scanner is described and evaluated. The specific scanning system comprises a team of remote sensing agents, in the form of miniature robotic platforms that can reposition non-contact Lamb wave transducers over a plate type of structure, for the purpose of non-destructive evaluation (NDE). The overall objective is to implement reconfigurable array scanning, where transmission and reception are facilitated by different sensing agents which can be organised in a variety of pulse-echo and pitch-catch configurations, with guided waves used to generate data in the form of 2-D and 3-D images. The ability to reconfigure the scanner adaptively requires an understanding of the ultrasonic wave generation, its propagation and interaction with potential defects and boundaries. Transducer behaviour has been simulated using a linear systems approximation, with wave propagation in the structure modelled using the local interaction simulation approach (LISA). Integration of the linear systems and LISA approaches are validated for use in Lamb wave scanning by comparison with both analytic techniques and more computationally intensive commercial finite element/difference codes. Starting with fundamental dispersion data, the paper goes on to describe the simulation of wave propagation and the subsequent interaction with artificial defects and plate boundaries, before presenting a theoretical image obtained from a team of sensing agents based on the current generation of sensors and instrumentation
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