Formal analysis of a calculus for WSNs from quality perspective

In viewing the common unreliability problem in wireless communications, the CWQ calculus (a Calculus for Wireless sensor networks from Quality perspective) was recently proposed for modeling and reasoning about WSNs (Wireless Sensor Networks) and their applications from a quality perspective. The CWQ calculus ensures that sensor nodes, even though in an unreliable communication network, can still behave in a reasonable manner using default values. Nevertheless, the topological structure in CWQ calculus is considered at the network level and it is tightly coupled with the processes and other configurations; this may limit its flexibility. In this paper, we extend our previous CWQ calculus to be a parametric framework to make it more flexible to be able to model and reason about networks of different topological structures. In the parametric framework, we extract the topological structure of a network and make it to be a configuration so that all topological structure changes can be captured by this framework

A Survey on IT-Techniques for a Dynamic Emergency Management in Large Infrastructures

This deliverable is a survey on the IT techniques that are relevant to the three use cases of the project EMILI. It describes the state-of-the-art in four complementary IT areas: Data cleansing, supervisory control and data acquisition, wireless sensor networks and complex event processing. Even though the deliverable’s authors have tried to avoid a too technical language and have tried to explain every concept referred to, the deliverable might seem rather technical to readers so far little familiar with the techniques it describes

The heuristic strategies for assessing wireless sensor network: an event-based formal approach

Wireless Sensor Networks (WSNs) are increasingly being adopted in critical applications. In these networks undesired events may undermine the reliability level; thus their effects need to be properly assessed from the early stages of the development process onwards to minimize the chances of unexpected problems during use. In this paper we propose two heuristic strategies: what-if analysis and robustness checking. They allow to drive designers towards optimal WSN deployment solutions, from the point of view of the connection and data delivery resiliency, exploiting a formal approach based on the event calculus formal language. The heuristics are backed up by a support tool aimed to simplify their adoption by system designers. The tool allows to specify the target WSN in a user-friendly way and it is able to elaborate the two heuristic strategies by means of the event calculus specifications automatically generated. The WSN reliability is assessed computing a set of specific metrics. The effectiveness of the strategies is shown in the context of three case studies

The heuristic strategies for assessing wireless sensor network: an event-based formal approach

Wireless Sensor Networks (WSNs) are increasingly being adopted in critical applications. In these networks undesired events may undermine the reliability level; thus their effects need to be properly assessed from the early stages of the development process onwards to minimize the chances of unexpected problems during use. In this paper we propose two heuristic strategies: what-if analysis and robustness checking. They allow to drive designers towards optimal WSN deployment solutions, from the point of view of the connection and data delivery resiliency, exploiting a formal approach based on the event calculus formal language. The heuristics are backed up by a support tool aimed to simplify their adoption by system designers. The tool allows to specify the target WSN in a user-friendly way and it is able to elaborate the two heuristic strategies by means of the event calculus specifications automatically generated. The WSN reliability is assessed computing a set of specific metrics. The effectiveness of the strategies is shown in the context of three case studies

A formal methodology to design and deploy dependable wireless sensor networks

Wireless Sensor Networks (WSNs) are being increasingly adopted in critical applications, where verifying the correct operation of sensor nodes is a major concern. Undesired events may undermine the mission of the WSNs. Hence their effects need to be properly assessed before deployment to obtain a good level of expected performance and during the operation in order to avoid dangerous unexpected results. In this paper we propose amethodology that aims at assessing and improving the dependability level of WSNs by means of an event-based formal verification technique. The methodology includes a process to guide designers towards the realization of dependable WSN and a tool ("ADVISES") to simplify its adoption. The tool is applicable to homogeneous WSNs with static routing topologies. It allows to generate automatically formal specifications used to check correctness properties and evaluate dependability metrics at design time and at runtime for WSNs where an acceptable percentage of faults can be defined. During the runtime we can check the behavior of the WSN accordingly to the results obtained at design time and we can detect sudden and unexpected failures, in order to trigger recovery procedures. The effectiveness of the methodology is shown in the context of two case studies, as proof-of-concept, aiming to illustrate how the tool is helpful to drive design choices and to check the correctness properties of the WSN at runtime. Although the method scales up to very large WSNs, the applicability of the methodology maybe compromised by the state space explosion of the reasoning model, which must be faced partitioning large topologies into sub-topologies

A formal methodology to design and deploy dependable wireless sensor networks

Wireless Sensor Networks (WSNs) are being increasingly adopted in critical applications, where verifying the correct operation of sensor nodes is a major concern. Undesired events may undermine the mission of the WSNs. Hence their effects need to be properly assessed before deployment to obtain a good level of expected performance and during the operation in order to avoid dangerous unexpected results. In this paper we propose amethodology that aims at assessing and improving the dependability level of WSNs by means of an event-based formal verification technique. The methodology includes a process to guide designers towards the realization of dependable WSN and a tool ("ADVISES") to simplify its adoption. The tool is applicable to homogeneous WSNs with static routing topologies. It allows to generate automatically formal specifications used to check correctness properties and evaluate dependability metrics at design time and at runtime for WSNs where an acceptable percentage of faults can be defined. During the runtime we can check the behavior of the WSN accordingly to the results obtained at design time and we can detect sudden and unexpected failures, in order to trigger recovery procedures. The effectiveness of the methodology is shown in the context of two case studies, as proof-of-concept, aiming to illustrate how the tool is helpful to drive design choices and to check the correctness properties of the WSN at runtime. Although the method scales up to very large WSNs, the applicability of the methodology maybe compromised by the state space explosion of the reasoning model, which must be faced partitioning large topologies into sub-topologies

Exploring conflicts in rule-based Sensor Networks

This paper addresses rule conflicts within wireless sensor networks. The work is situatedwithin psychiatric ambulatory assessment settings where patients are monitored in andaround their homes. Detecting behaviours within these settings favours sensor networks,while scalability and resource concerns favour processing data on smart nodes incorporatingrule engines. Such monitoring involves personalisation, thereby becoming important toprogram node rules on the fly. Since rules may originate from distinct sources and changeover time, methods are required to maintain rule consistency. Drawing on lessons fromFeature Interaction, the paper contributes novel approaches for detecting and resolving rule-conflict across sensor networks

Handling Emergent Conflicts in Adaptable Rule-based Sensor Networks

This thesis presents a study into conflicts that emerge amongst sensor device rules when such devices are formed into networks. It describes conflicting patterns of communication and computation that can disturb the monitoring of subjects, and lower the quality of service. Such conflicts can negatively affect the lifetimes of the devices and cause incorrect information to be reported. A novel approach to detecting and resolving conflicts is presented. The approach is considered within the context of home-based psychiatric Ambulatory Assessment (AA). Rules are considered that can be used to control the behaviours of devices in a sensor network for AA. The research provides examples of rule conflict that can be found for AA sensor networks. Sensor networks and AA are active areas of research and many questions remain open regarding collaboration amongst collections of heterogeneous devices to collect data, process information in-network, and report personalised findings. This thesis presents an investigation into reliable rule-based service provisioning for a variety of stakeholders, including care providers, patients and technicians. It contributes a collection of rules for controlling AA sensor networks. This research makes a number of contributions to the field of rule-based sensor networks, including areas of knowledge representation, heterogeneous device support, system personalisation, and in particular, system reliability. This thesis provides evidence to support the conclusion that conflicts can be detected and resolved in adaptable rule-based sensor networks

Dependability Assessment of Wireless Sensor Networks with Formal Methods

Wireless Sensor Networks (WSNs) are increasingly being adopted in critical applications, where verifying the correct operation of sensor nodes is a major concern. Undesired events, such as node crash and packet loss, may undermine the dependability of the WSN. Hence their effects need to be properly assessed from the early stages of the development process onwards to minimize the chances of unexpected problems during use. It is also necessary to monitor the system during operation in order to avoid unexpected results or dangerous effects. In this thesis we propose a framework to investigate the correctness of the design of a WSN from the point of view of its dependability, i.e., resilience to undesired events. The framework is based on the Event Calculus formalism and it is backed-up by a support tool aimed to simplify its adoption by system designers. The tool allows to specify the target WSN in a user-friendly way and it is able to generate automatically the Event Calculus specifications used to check correctness properties and evaluate dependability metrics, such as connection resiliency, coverage and lifetime. It is able to work at design time and runtime. In particular at runtime the tool works a server that is in waiting for new events coming from the WSN and, performed the reasoning using the same specifications, is able to do prediction about future criticalities of the WSN. The effectiveness of the approach is shown in the context of five case studies, aiming to illustrate how the framework is helpful to drive design choices by means of what-if scenario analysis and robustness checking, and to check the correctness properties of the WSN at runtime

Sistema de valoración funcional para sistemas de aeronavegación no tripulados a partir de la calidad de la información

Unmanned aerial navigation systems are not used in many military and non-military applications. However, these systems are susceptible be operated by hackers partially or completely. Therefore, in this article based on the JDL model for safety assessment of the drone’s framework it is proposed. Metrics for each level of the merger in conjunction with a mapping system in order to determine the dependence of data between different levels are proposed, considering the contextual user ratings.Los sistemas de aeronavegación no tripulados son utilizados en múltiples aplicaciones militares y no militares. Sin embargo, estos sistemas son susceptibles de ser intervenidos por delincuentes informáticos parcial o totalmente. En este artículo se propone un framework basado en el modelo JDL para la evaluación de la seguridad de los drones y se establecen criterios de evaluación de desempeño y de calidad de la información para cada nivel de la fusión, en conjunto con un sistema de mapeo de estas métricas, con el fin de determinar la dependencia de los datos entre diferentes niveles, contemplando la valoración contextual del usuario