1,418 research outputs found
AoI-optimal Joint Sampling and Updating for Wireless Powered Communication Systems
This paper characterizes the structure of the Age of Information
(AoI)-optimal policy in wireless powered communication systems while accounting
for the time and energy costs of generating status updates at the source nodes.
In particular, for a single source-destination pair in which a radio frequency
(RF)-powered source sends status updates about some physical process to a
destination node, we minimize the long-term average AoI at the destination
node. The problem is modeled as an average cost Markov Decision Process (MDP)
in which, the generation times of status updates at the source, the
transmissions of status updates from the source to the destination, and the
wireless energy transfer (WET) are jointly optimized. After proving the
monotonicity property of the value function associated with the MDP, we
analytically demonstrate that the AoI-optimal policy has a threshold-based
structure w.r.t. the state variables. Our numerical results verify the
analytical findings and reveal the impact of state variables on the structure
of the AoI-optimal policy. Our results also demonstrate the impact of system
design parameters on the optimal achievable average AoI as well as the
superiority of our proposed joint sampling and updating policy w.r.t. the
generate-at-will policy
On the Age-Optimality of Relax-then-Truncate Approach under Partial Battery Knowledge in Energy Harvesting IoT Networks
We consider an energy harvesting (EH) IoT network, where users make on-demand
requests to a cache-enabled edge node to send status updates about various
random processes, each monitored by an EH sensor. The edge node serves users'
requests by either commanding the corresponding sensor to send a fresh status
update or retrieving the most recently received measurement from the cache. We
aim to find a control policy at the edge node that minimizes the average
on-demand AoI over all sensors subject to per-slot transmission and energy
constraints under partial battery knowledge at the edge node. Namely, the
limited radio resources (e.g., bandwidth) causes that only a limited number of
sensors can send status updates at each time slot (i.e., per-slot transmission
constraint) and the scarcity of energy for the EH sensors imposes an energy
constraint. Besides, the edge node is informed of the sensors' battery levels
only via received status update packets, leading to uncertainty about the
battery levels for the decision-making.We develop a low-complexity algorithm --
termed relax-then-truncate -- and prove that it is asymptotically optimal as
the number of sensors goes to infinity. Numerical results illustrate that the
proposed method achieves significant gains over a request-aware greedy policy
and show that it has near-optimal performance even for moderate numbers of
sensors.Comment: 7 pages. arXiv admin note: substantial text overlap with
arXiv:2201.1227
Sensor Systems for Prognostics and Health Management
Prognostics and health management (PHM) is an enabling discipline consisting of technologies and methods to assess the reliability of a product in its actual life cycle conditions to determine the advent of failure and mitigate system risk. Sensor systems are needed for PHM to monitor environmental, operational, and performance-related characteristics. The gathered data can be analyzed to assess product health and predict remaining life. In this paper, the considerations for sensor system selection for PHM applications, including the parameters to be measured, the performance needs, the electrical and physical attributes, reliability, and cost of the sensor system, are discussed. The state-of-the-art sensor systems for PHM and the emerging trends in technologies of sensor systems for PHM are presented
BHiveSense: An integrated information system architecture for sustainable remote monitoring and management of apiaries based on IoT and microservices
Precision Beekeeping, a field of Precision Agriculture, is an apiary management strategy based on monitoring
honeybee colonies to promote more sustainable resource usage and maximise productivity. The approach related
to Precision Beekeeping is based on methodologies to mitigate the stress associated with human intervention in
the colonies and the waste of resources. These goals are achieved by supporting the intervention and managing
the beekeeper’s timely and appropriate action at the colony’s level. In recent years, the growth of IoT (Internetof-Things) in Precision Agriculture has spurred several proposals to contribute to the paradigm of Precision
Beekeeping, built on different technical concepts and with different production costs. This work proposes and
describes an information systems architecture concept named BHiveSense, based on IoT and microservices, and
different artefacts to demonstrate its concept: (1) a low-cost COTS (Commercial Off-The-Shelf) hive sensing
prototype, (2) a REST backend API, (3) a Web application, and (4) a Mobile application. This project delivers a
solution for a more integrated and sustainable beekeeping activity. Our approach stresses that by adopting
microservices and a REST architecture, it is possible to deal with long-standing problems concerning interoperability, scalability, agility, and maintenance issues, delivering an efficient beehive monitoring system.info:eu-repo/semantics/publishedVersio
Development of solar powered irrigation system
Development of a solar powered irrigation system has been discussed in this paper. This
system would be SCADA-based and quite useful in areas where there is plenty of sunshine but
insufficient water to carry out farming activities, such as rubber plantation, strawberry plantation,
or any plantation, that requires frequent watering. The system is powered by solar system as a
renewable energy which uses solar panel module to convert Sunlight into electricity. The
development and implementation of an automated SCADA controlled system that uses PLC as a
controller is significant to agricultural, oil and gas monitoring and control purpose purposes. In
addition, the system is powered by an intelligent solar system in which solar panel targets the
radiation from the Sun. Other than that, the solar system has reduced energy cost as well as
pollution. The system is equipped with four input sensors; two soil moisture sensors, two level
detection sensors. Soil moisture sensor measures the humidity of the soil, whereas the level
detection sensors detect the level of water in the tank. The output sides consist of two solenoid
valves, which are controlled respectively by two moistures sensors
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