12,240 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

    PenDraw - A Language for Improving Take-Up of SVG

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    The case is presented for preferring a dedicated Computer Graphics (CG) language to the traditional conventional language plus add-on. PenDraw is presented as an existing language that overcomes many problems of CG add-ons, providing compile-time checking and reduced need for run-time debugging. PenDraw produces well-formed SVG. Evidence is given that PenDraw decreases development costs. Evidence is presented that PenDraw has brought CG programming to a wider ability range of potential users than professional programmers. It is argued that, given its qualities, PenDraw should be able to improve the take-up of CG programming. Such take-up is expected to be slow at first, given the market-place focus on interactivity and 3D. But it is believed that PenDraw's expressive power and cost benefits should lead to growth in its use, and in use of SVG

    Low Power system Design techniques for mobile computers

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    Portable products are being used increasingly. Because these systems are battery powered, reducing power consumption is vital. In this report we give the properties of low power design and techniques to exploit them on the architecture of the system. We focus on: min imizing capacitance, avoiding unnecessary and wasteful activity, and reducing voltage and frequency. We review energy reduction techniques in the architecture and design of a hand-held computer and the wireless communication system, including error control, sys tem decomposition, communication and MAC protocols, and low power short range net works

    A survey on short-range WBAN communication; technical overview of several standard wireless technologies

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    In a healthy environment, a WBAN system is the key component or aspect of the patient monitoring system. WBAN systems allow for easy networking with other devices and networks so that healthcare professionals can easily access critical and non-critical patient data. One of the main advantages of WBAN is the remote monitoring of patients using an Intranet or the Internet. There are two main components to the type of communication technology used in WBAN. This page shows an insight of a variety of short-range standardized wireless devices, as well as a taxonomy of short-range technologies. These are proposed as intra-BAN communication candidates for communication within and between body area network (BAN) entities. This paper also highlights the advantages and disadvantages of the WBAN perspective. Finally, a side-by-side comparison of the basic principles of using MICS frequency bands and preparatory technologies

    Acceleration-as-a-Service: Exploiting Virtualised GPUs for a Financial Application

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    'How can GPU acceleration be obtained as a service in a cluster?' This question has become increasingly significant due to the inefficiency of installing GPUs on all nodes of a cluster. The research reported in this paper is motivated to address the above question by employing rCUDA (remote CUDA), a framework that facilitates Acceleration-as-a-Service (AaaS), such that the nodes of a cluster can request the acceleration of a set of remote GPUs on demand. The rCUDA framework exploits virtualisation and ensures that multiple nodes can share the same GPU. In this paper we test the feasibility of the rCUDA framework on a real-world application employed in the financial risk industry that can benefit from AaaS in the production setting. The results confirm the feasibility of rCUDA and highlight that rCUDA achieves similar performance compared to CUDA, provides consistent results, and more importantly, allows for a single application to benefit from all the GPUs available in the cluster without loosing efficiency.Comment: 11th IEEE International Conference on eScience (IEEE eScience) - Munich, Germany, 201

    A Physical Layer Model for G3-PLC Networks Simulation

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    This work presents a model of the G3-PLC physical (PHY) layer tailored for network simulations. It allows simulating frequency selective channels with non-stationary colored noise. Collisions with other frames are modeled taking into account the length and the power of the interfering frames. Frame errors are estimated using the effective signal-to-interference-and-noise ratio mapping (ESM) function. The proposed PHY layer has been integrated into a distributed event-based simulator developed by Microchip. The layer 2+ stack of the simulator uses the same code that actual Microchip G3-PLC devices. Validation has been accomplished by comparing its results to a test network deployed in the laboratory. The latter consists of a coordinator and one hundred meters distributed in 5 levels. Faster-than-real-time simulations and an excellent agreement between the simulated and the measured performance indicators at the application layer have been obtained.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    A Review of the Energy Efficient and Secure Multicast Routing Protocols for Mobile Ad hoc Networks

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    This paper presents a thorough survey of recent work addressing energy efficient multicast routing protocols and secure multicast routing protocols in Mobile Ad hoc Networks (MANETs). There are so many issues and solutions which witness the need of energy management and security in ad hoc wireless networks. The objective of a multicast routing protocol for MANETs is to support the propagation of data from a sender to all the receivers of a multicast group while trying to use the available bandwidth efficiently in the presence of frequent topology changes. Multicasting can improve the efficiency of the wireless link when sending multiple copies of messages by exploiting the inherent broadcast property of wireless transmission. Secure multicast routing plays a significant role in MANETs. However, offering energy efficient and secure multicast routing is a difficult and challenging task. In recent years, various multicast routing protocols have been proposed for MANETs. These protocols have distinguishing features and use different mechanismsComment: 15 page

    An Experimental Test of Criminal Behavior Among Juveniles and Young Adults

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    We report results from economic experiments that provide a direct test of the hypothesis that criminal behavior responds rationally to changes in the possible rewards and in the probability and severity of punishment. The experiments involve decisions that are best described as petty larceny, and are done using high school and college students who can anonymously take real money from each other. We find that decisions about whether and how much to steal are, in general, rational and responsive to the variations in tradeoffs, and sometimes, though not always, to the overall availability of criminal opportunities.

    ZigBee-Based wireless sensor network topologies using one and multiple coordinators

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    Wireless Sensor Networks (WSN) have been a cost-effective and feasible solution for a wide range of applications, such as communications infrastructure, traffic networks, telecommunications systems, military operations and so forth. IEEE804.15.4 ZigBee network model is ideally suited to the constraints of WSN in terms of bandwidth, processing power and battery capacity. This paper investigated tree and mesh routing in WSN with multiple coordinators and the failure of single coordinator using OPNET Modeler v14 which is an efficient computational platform for data networks simulation. Throughput, delay, traffic received, MAC Load are studied in this system and the results showed that tree routing was better suited for WSN than mesh routing and mobility of end node in multiple coordinator network was the best
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