In this paper, we propose a novel method to estimate the initial reputation values of newcomer web services. In fact, the reputation of web services is one of the criteria used for recommending services in service-oriented computing environments. The lack of evaluating the initial reputation values can subvert the performance of a service recommendation system making it vulnerable to different threats like whitewashing and Sybil attacks, which negatively affect its quality of recommendation. The proposed method uses Quality of Service (QoS) attributes from a side, and reputation values of similar services from the second side, to estimate the reputation values of newcomer services. Basically, it employs regression models, including Support Vector Regression, in the estimation process of the unknown reputation values of newcomers from their known QoS values. We demonstrate the efficiency of the method in estimating the reputation of newcomer services through statistical evidences gathered from experimentations conducted on a set of real-world web services.

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ABSTRACT

In a post-disaster situation, the construction of replacement communication infrastructure is crucial for the success of rescue operations. LTE Device-to-Device Proximity Services and IoT are considered as key enabling technologies for the construction of such replacement networks. Existing techniques rely on smartphones as relay stations to build a replacement broadcast-based network that connects available devices. In many cases, the using of such networks require querying a given type of IoT devices (e.g. surveillance cameras, heart-rate monitors, temperature sensors) depending on network users and service requirements. In such scenarios, incorporating all relays in the broadcast is inefficient and may lead to poor network performance. In this paper, we propose constructing for each service type a sub-network of relay stations that ensure connectivity among IoT devices providing the same service type. The resulting sub-networks ensure an efficient and robust message dissemination, avoiding transmission redundancy, and resulting in higher energy savings as well as high coverage. These properties have been validated by implementing our solution in NS-3 by extending the LTE D2D ProSe module provided by NIST. Obtained results show significant improvements in terms of energy consumption, and packet delivery ratio.

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