Abstract:
The WSAN simultaneous failures recovery method ranks each node based on the number of hops to a pre-designated root node in the network. The method identifies some nodes as cluster heads based on the number of their children in the recovery tree. The method assigns a recovery weight and a nearby cluster node to each node. Nearby cluster nodes serve as gateways to other nodes that belong to that cluster. The recovery weight is used to decide which node is better to move in order to achieve lower recovery cost. The recovery method uses the same on-going set of actors to restore connectivity. Simulation results have demonstrated that the recovery method can achieve low recovery cost per failed node in small and large networks. The results have also shown that clustering leads to lower recovery cost if the sub-network needs to re-establish links with the rest of the network.
Abstract:
The method of routing for wireless ad hoc and sensor networks is a routing protocol that uses a greedy approach, selecting the best route having the maximum remaining energy above a pre-defined threshold limit. The method of routing for wireless ad hoc and sensor networks is an energy efficient routing protocol, in that the routing path is selected to maximize the lifetime of an individual source-destination pair by selecting a route between them that is based on the energy levels of neighboring nodes, without requiring an energy-intensive network flooding approach. The routing path between a source node and a destination node is selected by choosing, at each node, a neighboring node that has the greatest remaining energy level.
Abstract:
The synchronization-free pipeline leak detection system includes a plurality of acoustic sensor nodes positioned equidistantly and linearly against an external surface of a wall of a pipeline. Each of the acoustic sensor nodes receives an acoustic signal generated by a leak in the wall of the pipeline, which is transmitted through fluid flowing through the pipeline. Each of the acoustic sensor nodes measures an acoustic received signal strength associated with the acoustic signal and transmits a signal representative of the respective acoustic received signal strength to the immediately adjacent acoustic sensor nodes if the respective acoustic received signal strength is greater than a threshold signal strength value. From the transmitted acoustic received signal strengths between sensor nodes, the sensor node closest to the leak can be determined. From known values stored in each sensor node, the position of the leak can be calculated and transmitted in an alert signal.
Abstract:
Aspects of the disclosure provide a method for restoring connectivity among partitioned segments in a partitioned wireless sensor and actor network (WSAN). The method includes placing batches of mobile nodes at locations surrounding mobile nodes previously placed within a damaged area of the partitioned WSAN, spreading the batches of mobile nodes, determining whether connectivity among the partitioned segments has been restored, and repeating placing batches of mobile nodes, spreading the patches of mobile nodes, and determining whether connectivity among the partitioned segments has been restored when connectivity among the partitioned segments is not restored.The method is based on a distributed dropping approach which introduces minimal disruption to previously deployed mobile nodes, and decreases total travelled distance a mobile node might move compared with a traditional central dropping approach. Thus, the distributed dropping approach can expedite the restoration process, reduce power consumption, and expand survival time of a WSAN.
Abstract:
Systems and methods include a WSN having sensor nodes that are configured with electronic circuitry for interfacing with one or more associated sensors. The WSN also includes a gateway sensor node configured to receive sensor data from and forward instructions to the one or more sensor nodes, and a server configured to control the WSN in combination with the gateway sensor node. The WSN also includes circuitry configured to recognize a link break within a data communication route of the WSN via a routing protocol, and buffer incoming packets from a source node. The circuitry is also configured to propagate a RERR message of the link break to the plurality of sensor nodes, and build a bypass route around the link break of the data communication route towards a destination node. The circuitry is also configured to send the buffered incoming packets to the destination node through the bypass route.
Abstract:
The fastener tension monitoring system provides for automatic notification when a structural tensile fastener, such as a bolt, is loosened. The system incorporates piezoelectric material in the core of the fastener shank or deposited around the shank. The piezoelectric material communicates electrically with an electrical storage device, a microprocessor, and a transmitter installed on the fastener head. Vibration or other changes in the tensile force developed by the fastener result in electrical impulses being generated by the piezoelectric material, generating electrical energy that is stored in the storage device and used to operate the microprocessor. In the event that an out of tolerance condition is sensed by the microprocessor, the transmitter is activated to send a signal to that effect. A receiver and computer are provided to monitor any such signals. The piezoelectric material may include pyroelectric material as well for the generation of electrical energy due to temperature changes.