The Virtual Object as a Major Element of the Internet of Things: a Survey

The Internet of Things (IoT) paradigm has been evolving toward the creation of a cyber-physical world where everything can be found, activated, probed, interconnected, and updated, so that any possible interaction, both virtual and/or physical, can take place. A Crucial concept of this paradigm is that of the virtual object, which is the digital counterpart of any real (human or lifeless, static or mobile, solid or intangible) entity in the IoT. It has now become a major component of the current IoT platforms, supporting the discovery and mash up of services, fostering the creation of complex applications, improving the objects energy management efficiency, as well as addressing heterogeneity and scalability issues. This paper aims at providing the reader with a survey of the virtual object in the IoT world. Virtualness is addressed from several perspectives: historical evolution of its definitions, current functionalities assigned to the virtual object and how they tackle the main IoT challenges, and major IoT platforms, which implement these functionalities. Finally, we illustrate the lessons learned after having acquired a comprehensive view of the topic

Dynamic carpooling in urban areas: design and experimentation with a multi-objective route matching algorithm

This paper focuses on dynamic carpooling services in urban areas to address the needs of mobility in real-time by proposing a two-fold contribution: a solution with novel features with respect to the current state-of-the-art, which is named CLACSOON and is available on the market; the analysis of the carpooling services performance in the urban area of the city of Cagliari through emulations. Two new features characterize the proposed solution: partial ridesharing, according to which the riders can walk to reach the driver along his/her route when driving to the destination; the possibility to share the ride when the driver has already started the ride by modeling the mobility to reach the driver destination. To analyze which features of the population bring better performance to changing the characteristics of the users, we also conducted emulations. When compared with current solutions, CLACSOON allows for achieving a decrease in the waiting time of around 55% and an increase in the driver and passenger success rates of around 4% and 10%, respectively. Additionally, the proposed features allowed for having an increase in the reduction of the CO2 emission by more than 10% with respect to the traditional carpooling service

Estimation of Physical Layer Performance in WSNs Exploiting the Method of Indirect Observations

Wireless Sensor Networks (WSNs) are used in many industrial and consumer applications that are increasingly gaining impact in our day to day lives. Still great efforts are needed towards the definition of methodologies for their effective management. One big issue is themonitoring of the network status, which requires the definition of the performance indicators and methodologies and should be accurate and not intrusive at the same time. In this paper, we present a new process for the monitoring of the physical layer in WSNs making use of a completely passive methodology. From data sniffed by external nodes, we first estimate the position of the nodes by applying the Weighted Least Squares (WLS) to the method of indirect observations. The resulting node positions are then used to estimate the status of the communication links using the most appropriate propagation model. We performed a significant number of measurements on the field in both indoor and outdoor environments. From the experiments, we were able to achieve an accurate estimation of the channel links status with an average error lower than 1 dB, which is around 5 dB lower than the error introduced without the application of the proposed method

The problem of task allocation in the Internet of Things and the consensus-based approach

The realization of the Internet of Things (IoT) paradigm relies on the implementation of systems of cooperative intelligent objects with key interoperability capabilities. One of these interoperability features concerns the cooperation among nodes towards a collaborative deployment of applications taking into account the available resources, such as electrical energy, memory, processing, and object capability to perform a given task, which are often limited. In this paper, firstly, we define the issue related to resource allocation for the deployment of distributed applications in the IoT, and we describe the architecture and functionalities of a relevant middleware that represents a possible solution to this issue. Secondly, we propose a consensus protocol for the cooperation among network objects in performing the target application, which aims to distribute the burden of the application execution, so that resources are adequately shared. We demonstrate that, using the proposed protocol, the network converges to a solution where resources are homogeneously allocated among nodes. Performance evaluation of experiments in simulation mode and in real scenarios show that the algorithm converges with a percentage error of about 5% with respect to the optimal allocation obtainable with a centralized approach. © 2014 Elsevier B.V. All rights reserved

A persuasive real-time carpooling service in a smart city: A case-study to measure the advantages in urban area

Sustainable transport services are key for a smart city, especially when considering the increasing size of the population in major cities. In this context, carpooling solutions have gained more and more popularity in the last years. However, current implementations of carpooling services mostly rely on a 'static' approach where users, which have planned future mid or long distance trips, post a message for sharing future planned rides. This approach is not suitable in urban areas where the users arrange with short notice a relatively short trip. This work addresses the relevant challenge and propose a novel service to assist the users to find the companion of the trip in a semi-automatic way. The CLACSOON platform is proposed and tested in simulated smart urban real-time scenario. An emulation system has been used to evaluate the performance of the resulting system. From extensive trials we have analyzed the quality of experience provided to the users varying the characteristics of the population. The result allowed for extracting important information about the challenges to be addressed for successful deployments of a real-time carpooling service