8,704 research outputs found

    Definition Research Study

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    Data were complied on the physical behavior and characteristics of plasma gas and/or dust in the context of how they relate to the self-contamination of manned orbiting vehicles. A definition is given of a systematic experimental program designed to yield the required empirical data on the plasma, neutral gas, and/or the particulate matter surrounding the orbiting vehicles associated with shuttle missions. Theoretical analyses were completed on the behavior of materials to be released from the orbiting or subsatellite shuttle vehicles. The results were used to define some general experimental design recommendations directly applicable to the space shuttle program requirement. An on-board laser probe technique is suggested for measuring the dynamic behavior, inventory, and physical characteristics of particulates in the vicinity of an orbiting spacecraft. Laser probing of cometary photodissociation is also assessed

    Influencing interaction: Development of the design with intent method

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    Persuasive Technology has the potential to influence user behavior for social benefit, e.g. to reduce environmental impact, but designers are lacking guidance choosing among design techniques for influencing interaction. The Design with Intent Method, a ‘suggestion tool’ addressing this problem, is introduced in this paper, and applied to the briefs of reducing unnecessary household lighting use, and improving the efficiency of printing, primarily to evaluate the method’s usability and guide the direction of its development. The trial demonstrates that the DwI Method is quick to apply and leads to a range of relevant design concepts. With development, the DwI Method could be a useful tool for designers working on influencing user behavior

    Nonbanks and risk in retail payments

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    This paper documents the importance of nonbanks in retail payments in the United States and in 15 European countries and analyzes the implications of the importance and multiple roles played by nonbanks on retail payment risks. This paper also reviews the main regulatory safeguards in place, and concludes that there may be a need to reconsider some of them in view of the growing role of nonbanks and of the global reach of risks in the electronic era.

    A new generation of real-time systems in the JET tokamak

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    Recently a new recipe for developing and deploying real-time systems has become increasingly adopted in the JET tokamak. Powered by the advent of x86 multi-core technology and the reliability of the JET’s well established Real-Time Data Network (RTDN) to handle all real-time I/O, an official Linux vanilla kernel has been demonstrated to be able to provide realtime performance to user-space applications that are required to meet stringent timing constraints. In particular, a careful rearrangement of the Interrupt ReQuests’ (IRQs) affinities together with the kernel’s CPU isolation mechanism allows to obtain either soft or hard real-time behavior depending on the synchronization mechanism adopted. Finally, the Multithreaded Application Real-Time executor (MARTe) framework is used for building applications particularly optimised for exploring multicore architectures. In the past year, four new systems based on this philosophy have been installed and are now part of the JET’s routine operation. The focus of the present work is on the configuration and interconnection of the ingredients that enable these new systems’ real-time capability and on the impact that JET’s distributed real-time architecture has on system engineering requirements, such as algorithm testing and plant commissioning. Details are given about the common real-time configuration and development path of these systems, followed by a brief description of each system together with results regarding their real-time performance. A cycle time jitter analysis of a user-space MARTe based application synchronising over a network is also presented. The goal is to compare its deterministic performance while running on a vanilla and on a Messaging Real time Grid (MRG) Linux kernel

    Photoheliograph study for the Apollo telescope mount

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    Photoheliograph study for Apollo telescope moun

    A programmable architecture for the provision of hybrid services

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    The success of new service provision platforms will largely depend on their ability to blend with existing technologies. The advent of Internet telephony, although impressive, is unlikely to make telephone customers suddenly turn in favor of computers. Rather, customers display increasing interest in services that span multiple networks (especially Internet Protocol-based networks and the telephone and cellular networks) and open new vistas. We refer to these services as hybrid services and propose an architecture for their provision. This architecture allows for programming the service platform elements (i.e., network nodes, gateways, control servers, and terminals) in order to include new service logics. We identify components that can be assembled to build these logics by considering a service as a composition of features such as address translation, security, call control, connectivity, charging and user interaction. Generic service components are derived from the modeling of these features. We assure that our proposal can be implemented even in existing systems in return for slight changes: These systems are required to generate an event when a special service is encountered. The treatment of this event is handled by an object at a Java Service Layer. Java has been chosen for its platform-neutrality feature and its embedded security mechanisms. Using our architecture, we design a hybrid closed user group service

    The Application of Model Predictive Control on Paralleled Converters for Zero Sequence Current Suppression and Active Thermal Management

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    In the field of power electronics, the control of rectifiers is a crucial area of study. Rectifiers are used to convert AC power into DC power, and are commonly used in a wide range of applications, including renewable energy systems, industrial automation, and consumer electronics. However, in medium and high-power systems when multiple rectifiers are connected in parallel to a DC bus, stability issues can arise, including voltage fluctuations, zero sequence circulating current, and thermal imbalance. Achieving stable DC bus voltage is essential for maintaining the proper functioning of electronic devices, while suppressing zero sequence current is necessary for protecting the power electronics equipment from damage and ensuring that a power system\u27s performance is not degraded. Active thermal management is important for ensuring the longevity and reliability of the power electronics equipment. To achieve these objectives, advanced control techniques must be developed and implemented. This research investigates the use model predictive control to achieve three objectives in two paralleled rectifier each control cycle: DC voltage stability, zero sequence suppression, and thermal balance. These objectives are critical for ensuring the reliable and efficient operation of power electronics systems. The findings of this research will contribute to the development of more reliable and efficient power electronics systems, with the Navy\u27s (power electronic building block) PEBB systems particularly in mind. However, this research can be extended to other medium and high-powered applications in modern technology too such as missile defense systems, data centers, and uninterruptible power supplies

    Network-based business process management: embedding business logic in communications networks

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    Advanced Business Process Management (BPM) tools enable the decomposition of previously integrated and often ill-defined processes into re-usable process modules. These process modules can subsequently be distributed on the Internet over a variety of many different actors, each with their own specialization and economies-of-scale. The economic benefits of process specialization can be huge. However, how should such actors in a business network find, select, and control, the best partner for what part of the business process, in such a way that the best result is achieved? This particular management challenge requires more advanced techniques and tools in the enabling communications networks. An approach has been developed to embed business logic into the communications networks in order to optimize the allocation of business resources from a network point of view. Initial experimental results have been encouraging while at the same time demonstrating the need for more robust techniques in a future of massively distributed business processes.active networks;business process management;business protocols;embedded business logic;genetic algorithms;internet distributed process management;payment systems;programmable networks;resource optimization
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