4,024 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

    Proceedings of the NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications

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    The proceedings of the National Space Science Data Center Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications held July 23 through 25, 1991 at the NASA/Goddard Space Flight Center are presented. The program includes a keynote address, invited technical papers, and selected technical presentations to provide a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disk and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

    Sophisticated Batteryless Sensing

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    Wireless embedded sensing systems have revolutionized scientific, industrial, and consumer applications. Sensors have become a fixture in our daily lives, as well as the scientific and industrial communities by allowing continuous monitoring of people, wildlife, plants, buildings, roads and highways, pipelines, and countless other objects. Recently a new vision for sensing has emerged---known as the Internet-of-Things (IoT)---where trillions of devices invisibly sense, coordinate, and communicate to support our life and well being. However, the sheer scale of the IoT has presented serious problems for current sensing technologies---mainly, the unsustainable maintenance, ecological, and economic costs of recycling or disposing of trillions of batteries. This energy storage bottleneck has prevented massive deployments of tiny sensing devices at the edge of the IoT. This dissertation explores an alternative---leave the batteries behind, and harvest the energy required for sensing tasks from the environment the device is embedded in. These sensors can be made cheaper, smaller, and will last decades longer than their battery powered counterparts, making them a perfect fit for the requirements of the IoT. These sensors can be deployed where battery powered sensors cannot---embedded in concrete, shot into space, or even implanted in animals and people. However, these batteryless sensors may lose power at any point, with no warning, for unpredictable lengths of time. Programming, profiling, debugging, and building applications with these devices pose significant challenges. First, batteryless devices operate in unpredictable environments, where voltages vary and power failures can occur at any time---often devices are in failure for hours. Second, a device\u27s behavior effects the amount of energy they can harvest---meaning small changes in tasks can drastically change harvester efficiency. Third, the programming interfaces of batteryless devices are ill-defined and non- intuitive; most developers have trouble anticipating the problems inherent with an intermittent power supply. Finally, the lack of community, and a standard usable hardware platform have reduced the resources and prototyping ability of the developer. In this dissertation we present solutions to these challenges in the form of a tool for repeatable and realistic experimentation called Ekho, a reconfigurable hardware platform named Flicker, and a language and runtime for timely execution of intermittent programs called Mayfly

    Enabling Micro-level Demand-Side Grid Flexiblity in Resource Constrained Environments

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    The increased penetration of uncertain and variable renewable energy presents various resource and operational electric grid challenges. Micro-level (household and small commercial) demand-side grid flexibility could be a cost-effective strategy to integrate high penetrations of wind and solar energy, but literature and field deployments exploring the necessary information and communication technologies (ICTs) are scant. This paper presents an exploratory framework for enabling information driven grid flexibility through the Internet of Things (IoT), and a proof-of-concept wireless sensor gateway (FlexBox) to collect the necessary parameters for adequately monitoring and actuating the micro-level demand-side. In the summer of 2015, thirty sensor gateways were deployed in the city of Managua (Nicaragua) to develop a baseline for a near future small-scale demand response pilot implementation. FlexBox field data has begun shedding light on relationships between ambient temperature and load energy consumption, load and building envelope energy efficiency challenges, latency communication network challenges, and opportunities to engage existing demand-side user behavioral patterns. Information driven grid flexibility strategies present great opportunity to develop new technologies, system architectures, and implementation approaches that can easily scale across regions, incomes, and levels of development

    Index to 1981 NASA Tech Briefs, volume 6, numbers 1-4

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    Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1981 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

    TelosRFID an ad-hoc wireless networking capable multi-protocol RFID reader system

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    Radio Frequency IDentification (RFID) is rapidly being adopted as a powerful tool used in object tracking access control, telemedicine and inventory management. Its basic architecture endows reader devices with the capability to wirelessly read stored data off of RFID tags. Because of competing standards, there is no unified air protocol for RFID communication. The proliferation of competing standards, paired with the proprietary nature of commercial readers, can make maintaining and upgrading an RFID infrastructure expensive and time-consuming. Part of the solution that this thesis proposes is an RFID reader which supports custom air protocol implementations. To further reduce the costs associated with the adoption of a new infrastructure, RFID readers would benefit from supporting ad-hoc wireless networking. This feature mitigates the need for an installed infrastructure and facilitates immediate deployment of RFID systems. The development of a multi-protocol RFID reader with ad-hoc wireless capabilities will be a boon for both the commercial and academic sectors. This thesis outlines the design of an ad-hoc wireless networking capable multi-protocol RFID reader system called TelosRFID. The name TelosRFID stems from the system\u27s combination of Crossbow Telos rev. B (TelosB) ZigBee motes with a custom 13.56MHz RFID reader board. The TelosRFID reader board is a custom hardware device that can communicate with 13.56MHz RFID tags. It runs custom firmware in order to control tag communications, manage tag presence monitoring, and relay tag information through the ZigBee network (via its attached TelosB mote.) The system is designed to be demonstratably useful. Its functionality can be visibly confirmed, and configuration errors are easily detected at every component in the system. This framework provides a reliable and established baseline for future enhancements to the system\u27s feature set

    Factors shaping the evolution of electronic documentation systems

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    The main goal is to prepare the space station technical and managerial structure for likely changes in the creation, capture, transfer, and utilization of knowledge. By anticipating advances, the design of Space Station Project (SSP) information systems can be tailored to facilitate a progression of increasingly sophisticated strategies as the space station evolves. Future generations of advanced information systems will use increases in power to deliver environmentally meaningful, contextually targeted, interconnected data (knowledge). The concept of a Knowledge Base Management System is emerging when the problem is focused on how information systems can perform such a conversion of raw data. Such a system would include traditional management functions for large space databases. Added artificial intelligence features might encompass co-existing knowledge representation schemes; effective control structures for deductive, plausible, and inductive reasoning; means for knowledge acquisition, refinement, and validation; explanation facilities; and dynamic human intervention. The major areas covered include: alternative knowledge representation approaches; advanced user interface capabilities; computer-supported cooperative work; the evolution of information system hardware; standardization, compatibility, and connectivity; and organizational impacts of information intensive environments

    An IoT-oriented fast prototyping platform for BLE-based star topology networks

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    The Internet of Things (IoT) is characterized by many technologies, standards, tools and devices for a wide range of application fields and often, for the end-users (makers and developers), is hard to orientate in an equally wide range of offers from various manufacturers. In recent years, the Bluetooth Low Energy (BLE) communication protocol is achieving a large portion of the market, thanks to its low-power and low-cost orientation and its pervasiveness in mobile devices, like smartphones. For these reasons, BLE is increasingly used in IoT-oriented Wireless Personal Area Networks (WPAN), where a small set of devices arranged in star topology network and connected to a smartphone and a Wi-Fi gateway, can cover a large number of monitoring and controlling use case scenarios. This work presents the ST’s STM32 Open Development Environment (ODE), a complete suite of hardware and software tools representing a reference point for end-users willing to create BLE-based star topology networks for a wide range of applications. Through a simple use case in a smart home context, it is shown how all provided tools can be used to fast prototype applications addressing all user requirements
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