92 research outputs found

    Reconciling Repeatable Timing with Pipelining and Memory Hierarchy

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    This paper argues that repeatable timing is more important and more achievable than predictable timing. It describes microarchitecture approaches to pipelining and memory hierarchy that deliver repeatable timing and promise comparable or better performance compared to established techniques. Specifically, threads are interleaved in a pipeline to eliminate pipeline hazards, and a hierarchical memory architecture is outlined that hides memory latencies

    Spatial and Temporal Analysis on the Distribution of Active Radio-Frequency Identification (RFID) Tracking Accuracy with the Kriging Method

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    Radio frequency identification (RFID) technology has already been applied in a number of areas to facilitate the tracking process. However, the insufficient tracking accuracy of RFID is one of the problems that impedes its wider application. Previous studies focus on examining the accuracy of discrete points RFID, thereby leaving the tracking accuracy of the areas between the observed points unpredictable. In this study, spatial and temporal analysis is applied to interpolate the continuous distribution of RFID tracking accuracy based on the Kriging method. An implementation trial has been conducted in the loading and docking area in front of a warehouse to validate this approach. The results show that the weak signal area can be easily identified by the approach developed in the study. The optimum distance between two RFID readers and the effect of the sudden removal of readers are also presented by analysing the spatial and temporal variation of RFID tracking accuracy. This study reveals the correlation between the testing time and the stability of RFID tracking accuracy. Experimental results show that the proposed approach can be used to assist the RFID system setup process to increase tracking accuracy

    Desafíos en el diseño de sistemas Ciber-Físicos

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    Los sistemas cyber-físicos ─Cyber-Physical Systems CPS─ es un proceso que integra la computación con los procesos físicos. Los computadores embebidos, el monitoreo de redes y el control de procesos físicos, usualmente tienen ciclos de retroalimentación en los que los procesos físicos afectan los cálculos, y viceversa. En este artículo se examinan los desafíos en el diseño de estos sistemas, y se plantea la cuestión de si la informática y las tecnologías de redes actuales proporcionan una base adecuada para ellos. La conclusión es que para mejorar los procesos de diseño de estos sistemas no será suficiente con elevar el nivel de abstracción o verificar, formalmente o no, los diseños en los que se basan las abstracciones de hoy. El potencial social y económico de los CPS es mucho mayor de lo que hasta el momento se ha pensado; en todo el mundo se están realizando grandes inversiones para desarrollar esta tecnología, pero los retos son considerables. Para aprovechar todo el potencial de los CPS se tendrán que reconstruir los procesos de las abstracciones informáticas y de las redes, y los procesos se deberán acoger en pleno a los principios de las dinámicas físicas y de la computación

    A framework for analyzing RFID distance bounding protocols

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    Many distance bounding protocols appropriate for the RFID technology have been proposed recently. Unfortunately, they are commonly designed without any formal approach, which leads to inaccurate analyzes and unfair comparisons. Motivated by this need, we introduce a unied framework that aims to improve analysis and design of distance bounding protocols. Our framework includes a thorough terminology about the frauds, adversary, and prover, thus disambiguating many misleading terms. It also explores the adversary's capabilities and strategies, and addresses the impact of the prover's ability to tamper with his device. It thus introduces some new concepts in the distance bounding domain as the black-box and white-box models, and the relation between the frauds with respect to these models. The relevancy and impact of the framework is nally demonstrated on a study case: Munilla-Peinado distance bounding protocol

    Context Aware Middleware Architectures: Survey and Challenges

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    Abstract: Context aware applications, which can adapt their behaviors to changing environments, are attracting more and more attention. To simplify the complexity of developing applications, context aware middleware, which introduces context awareness into the traditional middleware, is highlighted to provide a homogeneous interface involving generic context management solutions. This paper provides a survey of state-of-the-art context aware middleware architectures proposed during the period from 2009 through 2015. First, a preliminary background, such as the principles of context, context awareness, context modelling, and context reasoning, is provided for a comprehensive understanding of context aware middleware. On this basis, an overview of eleven carefully selected middleware architectures is presented and their main features explained. Then, thorough comparisons and analysis of the presented middleware architectures are performed based on technical parameters including architectural style, context abstraction, context reasoning, scalability, fault tolerance, interoperability, service discovery, storage, security & privacy, context awareness level, and cloud-based big data analytics. The analysis shows that there is actually no context aware middleware architecture that complies with all requirements. Finally, challenges are pointed out as open issues for future work

    Survey on Lightweight Primitives and Protocols for RFID in Wireless Sensor Networks

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    The use of radio frequency identification (RFID) technologies is becoming widespread in all kind of wireless network-based applications. As expected, applications based on sensor networks, ad-hoc or mobile ad hoc networks (MANETs) can be highly benefited from the adoption of RFID solutions. There is a strong need to employ lightweight cryptographic primitives for many security applications because of the tight cost and constrained resource requirement of sensor based networks. This paper mainly focuses on the security analysis of lightweight protocols and algorithms proposed for the security of RFID systems. A large number of research solutions have been proposed to implement lightweight cryptographic primitives and protocols in sensor and RFID integration based resource constraint networks. In this work, an overview of the currently discussed lightweight primitives and their attributes has been done. These primitives and protocols have been compared based on gate equivalents (GEs), power, technology, strengths, weaknesses and attacks. Further, an integration of primitives and protocols is compared with the possibilities of their applications in practical scenarios

    Design of Authentication Model Preserving Intimacy and Trust in Intelligent Environments

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    With the recent advances in communication technologies for low-power devices, pervasive computing environments (PCE) spread as new domains beyond legacy enterprise and personal computing. The intelligent home network environment is thing which invisible device that is not shown linked mutually through network so that user may use device always is been pervasive. Smart devices are interconnected and collaborate as a global distributed system to infuse intelligence into systems and processes. This kind of environment provides various smart services and makes consequently an offer of convenient, pleasant, and blessed lives to people. However, the risk is high as long as the offer is pleasant and convenient. In such context, security is stil very fragile and there is often a violation of user privacy and service interference. For this, a special interest in ubiquitous network security is going up. Safety lies primarily in the authentication of users accessing the network. It guarantees that only legitimate users can login and access to services indoor the network. In this paper, we propose an anonymous authentication and access control scheme to secure the interaction between mobile users handling smart devices and smart services in PCEs. In an environment based on public key infrastructure (PKI) and Authentication, Authorization, and Accounting (AAA), the proposed authentication protocol combines both network authentication technique based on symmetric keys and single sign-on mechanisms. The authentication protocol is simple and secure, protects the privacy of user and aims to satisfy the security requirements

    Performance Evaluation of On Demand Routing Protocols AODV and Modified AODV (R-AODV) in MANETS

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    A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations

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    This paper presents a novel radio-frequency identification (RFID) sensing system using enhanced surface wave technology for battery exchange stations (BESs) of electric motorcycles. Ultrahigh-frequency (UHF) RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs), coupling cable lines (CCLs), and small radiation patches (SRPs). The RFID sensing system overcomes the electromagnetic interference in the metallic environment of a BES cabinet. The developed RFID sensing system can effectively increase the efficiency of BES operation and promote the development of electric vehicles which solve the problem of air pollution as well as protect the environment of the Earth

    A System-Level Dynamic Binary Translator using Automatically-Learned Translation Rules

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    System-level emulators have been used extensively for system design, debugging and evaluation. They work by providing a system-level virtual machine to support a guest operating system (OS) running on a platform with the same or different native OS that uses the same or different instruction-set architecture. For such system-level emulation, dynamic binary translation (DBT) is one of the core technologies. A recently proposed learning-based DBT approach has shown a significantly improved performance with a higher quality of translated code using automatically learned translation rules. However, it has only been applied to user-level emulation, and not yet to system-level emulation. In this paper, we explore the feasibility of applying this approach to improve system-level emulation, and use QEMU to build a prototype. ... To achieve better performance, we leverage several optimizations that include coordination overhead reduction to reduce the overhead of each coordination, and coordination elimination and code scheduling to reduce the coordination frequency. Experimental results show that it can achieve an average of 1.36X speedup over QEMU 6.1 with negligible coordination overhead in the system emulation mode using SPEC CINT2006 as application benchmarks and 1.15X on real-world applications.Comment: 10 pages, 19 figures, to be published in International Symposium on Code Generation and Optimization (CGO) 202
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