47,197 research outputs found

    Context constraint integration and validation in dynamic web service compositions

    Get PDF
    System architectures that cross organisational boundaries are usually implemented based on Web service technologies due to their inherent interoperability benets. With increasing exibility requirements, such as on-demand service provision, a dynamic approach to service architecture focussing on composition at runtime is needed. The possibility of technical faults, but also violations of functional and semantic constraints require a comprehensive notion of context that captures composition-relevant aspects. Context-aware techniques are consequently required to support constraint validation for dynamic service composition. We present techniques to respond to problems occurring during the execution of dynamically composed Web services implemented in WS-BPEL. A notion of context { covering physical and contractual faults and violations { is used to safeguard composed service executions dynamically. Our aim is to present an architectural framework from an application-oriented perspective, addressing practical considerations of a technical framework

    In-Vivo Bytecode Instrumentation for Improving Privacy on Android Smartphones in Uncertain Environments

    Get PDF
    In this paper we claim that an efficient and readily applicable means to improve privacy of Android applications is: 1) to perform runtime monitoring by instrumenting the application bytecode and 2) in-vivo, i.e. directly on the smartphone. We present a tool chain to do this and present experimental results showing that this tool chain can run on smartphones in a reasonable amount of time and with a realistic effort. Our findings also identify challenges to be addressed before running powerful runtime monitoring and instrumentations directly on smartphones. We implemented two use-cases leveraging the tool chain: BetterPermissions, a fine-grained user centric permission policy system and AdRemover an advertisement remover. Both prototypes improve the privacy of Android systems thanks to in-vivo bytecode instrumentation.Comment: ISBN: 978-2-87971-111-

    Device-Centric Monitoring for Mobile Device Management

    Full text link
    The ubiquity of computing devices has led to an increased need to ensure not only that the applications deployed on them are correct with respect to their specifications, but also that the devices are used in an appropriate manner, especially in situations where the device is provided by a party other than the actual user. Much work which has been done on runtime verification for mobile devices and operating systems is mostly application-centric, resulting in global, device-centric properties (e.g. the user may not send more than 100 messages per day across all applications) being difficult or impossible to verify. In this paper we present a device-centric approach to runtime verify the device behaviour against a device policy with the different applications acting as independent components contributing to the overall behaviour of the device. We also present an implementation for Android devices, and evaluate it on a number of device-centric policies, reporting the empirical results obtained.Comment: In Proceedings FESCA 2016, arXiv:1603.0837

    Bridges Structural Health Monitoring and Deterioration Detection Synthesis of Knowledge and Technology

    Get PDF
    INE/AUTC 10.0

    Context-aware adaptation in DySCAS

    Get PDF
    DySCAS is a dynamically self-configuring middleware for automotive control systems. The addition of autonomic, context-aware dynamic configuration to automotive control systems brings a potential for a wide range of benefits in terms of robustness, flexibility, upgrading etc. However, the automotive systems represent a particularly challenging domain for the deployment of autonomics concepts, having a combination of real-time performance constraints, severe resource limitations, safety-critical aspects and cost pressures. For these reasons current systems are statically configured. This paper describes the dynamic run-time configuration aspects of DySCAS and focuses on the extent to which context-aware adaptation has been achieved in DySCAS, and the ways in which the various design and implementation challenges are met

    Nypa Frutican Rachis as building envelope heat insulator

    Get PDF
    This research is conducted to investigate the possibility of cellulose in Nypa Frutican Rachis to achieve thermal comfort. As Malaysia was known as tropical country which has hot and humid climate, this research focus on to study the transfer of heat through Nypa Frutican Rachis as a roof. Since only Nypa leaves have been used as a roof and have been applied until now in East Malaysia, this project uses an innovation of Nypa palm by using its rachis that contain chemical material that have lower thermal conductivity value such as cellulose and lignin as a roof or building envelope heat insulator. This paper described the experimental study method by measuring the temperature of outer and inner surface of Nypa Frutican Rachis on small physical model study. The temperature was measured by using Digital Infrared Thermometer. The average outer and inner tempe rature for five consecutive days was obtained from the experiment is highlighted. Results show that the average of heat loss and heat transfer conduction for five consecutive days are 9.63 W/h and 9.86 W. This experiment shows a good result and proved that Nypa Frutican Rachis is suitable and effective to be a building envelope heat insulator

    High-speed, in-band performance measurement instrumentation for next generation IP networks

    Get PDF
    Facilitating always-on instrumentation of Internet traffic for the purposes of performance measurement is crucial in order to enable accountability of resource usage and automated network control, management and optimisation. This has proven infeasible to date due to the lack of native measurement mechanisms that can form an integral part of the network‟s main forwarding operation. However, Internet Protocol version 6 (IPv6) specification enables the efficient encoding and processing of optional per-packet information as a native part of the network layer, and this constitutes a strong reason for IPv6 to be adopted as the ubiquitous next generation Internet transport. In this paper we present a very high-speed hardware implementation of in-line measurement, a truly native traffic instrumentation mechanism for the next generation Internet, which facilitates performance measurement of the actual data-carrying traffic at small timescales between two points in the network. This system is designed to operate as part of the routers' fast path and to incur an absolutely minimal impact on the network operation even while instrumenting traffic between the edges of very high capacity links. Our results show that the implementation can be easily accommodated by current FPGA technology, and real Internet traffic traces verify that the overhead incurred by instrumenting every packet over a 10 Gb/s operational backbone link carrying a typical workload is indeed negligible
    corecore