The advent of Internet of Things has propelled the agricultural domain through the integration of sensory devices, capable of monitoring and wirelessly propagating information to producers; thus, they employ Wireless Sensor Networks (WSNs). These WSNs allow real time monitoring, enabling intelligent decision-making to maximize yields and minimize cost. Designing and deploying a WSN is a challenging and multivariate task, dependent on the considered environment. For example, a need for network synchronization arises in such networks to correlate acquired measurements. This work focuses on the design and installation of a WSN that is capable of facilitating the sensing aspects of smart and precision agriculture applications. A system is designed and implemented to address specific design requirements that are brought about by the considered environment. A simple synchronization scheme is described to provide time-correlated measurements using the sink node’s clock as reference. The proposed system was installed on an olive grove to assess its effectiveness in providing a low-cost system, capable of acquiring synchronized measurements. The obtained results indicate the system’s overall effectiveness, revealing a small but expected difference in the acquired measurements’ time correlation, caused mostly by serial transmission delays, while yielding a plethora of relevant environmental conditions.

Structural health monitoring (SHM) in historical buildings can be achieved through systems that rely on Wireless Sensor Networks (WSNs). Such systems have the ability to acquire information fast and reliably, making them ideal for SHM applications. Historical buildings, having been exposed to the wear of time, are especially sensitive to any kind of intervention. As a result, keeping them as intact as possible is a critical factor for their integrity. In the current work, a low-cost WSN system and a synchronization algorithm are developed in order to be employed for SHM of historical buildings. The synchronization of WSN-based SHM systems is critical for the collection of accurate information describing the building’s condition. The effectiveness of the assumed hardware and the synchronization algorithm were evaluated with two experiments. The first took place under laboratory conditions and its results showcase the algorithm’s accuracy of synchronization. The second experiment was conducted in a real-world environment. For that purpose, the Ionian Campus Testbed was chosen since it comprises buildings that are more than 200 years old. These buildings are appropriate since they were built with thick stone walls which help determine the system’s effectiveness under such conditions. The results derived from the second experiment showcase the effects of the packet transmission collision avoidance mechanism utilized by the assumed hardware. Finally, an estimation of the average clock skew required for accurate information gathering is derived, based on the materials comprising a historical building.

Unmanned Aerial Vehicles (UAVs) or drones presently are enhanced with miniature sensors that can provide information relative to their environment. As such, they can detect changes in temperature, orientation, altitude, geographical location, electromagnetic fluctuations, lighting conditions, and more. Combining this information properly can help produce advanced environmental awareness; thus, the drone can navigate its environment autonomously. Wireless communications can also aid in the creation of drone swarms that, combined with the proper algorithm, can be coordinated towards area coverage for various missions, such as search and rescue. Coverage Path Planning (CPP) is the field that studies how drones, independently or in swarms, can cover an area of interest efficiently. In the current work, a CPP algorithm is proposed for a swarm of drones to detect points of interest and collect information from them. The algorithm’s effectiveness is evaluated under simulation results. A set of characteristics is defined to describe the coverage radius of each drone, the speed of the swarm, and the coverage path followed by it. The results show that, for larger swarm sizes, the missions require less time while more points of interest can be detected within the area. Two coverage paths are examined here—parallel lines and spiral coverage. The results depict that the parallel lines coverage is more time-efficient since the spiral increases the required time by an average of 5% in all cases for the same number of detected points of interest.

A Security Information and Event Management system (SIEM) is a tool used to collect, analyze, normalize and correlate data from various devices to identify potential cyber threats almost in real-time. SIEM provides a unified approach to security issues through two zones: Security Information Management (SIM) and Security Event Management (SEM). SIM deals with managing logs and reporting, while SEM deals with event management and real-time monitoring. SIEM tools collect data events in a central unit from various devices, normalize their format, analyze them, and generate reports and alerts. SIEM combines the ability of log management to generate a compliance report with the ability to manage threats. However, the central approach may present significant disadvantages, such as slowing system performance and complicating the prioritization of queries.