Wireless sensor networks (WSNs) have the potential to assist advanced target tracking applications. The major challenge related to the design of such networks is to cope with the energy and computational limitations that characterize sensor nodes. To address this problem, we propose a hybrid architecture that integrates two sensor categories. The first performs basic detection and tracking functions while the second supports complex tasks such as imaging and broadband communication via a satellite network. Moreover, we develop a technique that allows vision sensors adapting the rate of the exchanged data according to the target activity in the monitored zone. Finally, a tracking approach taking into consideration the error on local sensor position measurements is presented.

As a result of the shift to low-carbon sustainable energy systems, hydrogen is now a major energy carrier. With an emphasis on hydrogen generation, storage, applications, infrastructure development and policy landscape, this review examines the "power-to-hydrogen" pathway. While hydrogen constitutes 75% of the universe's mass, scalable terrestrial production remains challenging, with electrolysis efficiencies currently at 60–80% and costs at ＄3–8/kg for green hydrogen. Key applications span steelmaking (reducing 7% of global CO₂ emissions) and fuel cells (reaching 60% energy efficiency). Storage solutions, including 700-bar compressed tanks and metal hydrides, face density and safety hurdles. Infrastructure demands ＄15 trillion in investment by 2050 for pipelines and refueling stations. Policy levers like carbon pricing (<＄100/ton CO₂) and research and development (R & D) subsidies are critical to accelerate deployment. The carbon price, subsidies, and further research will all influence the direction of hydrogen in the future. Notwithstanding the obstacles, policy, technological, and infrastructure advancements can fully realize hydrogen's potential to revolutionize the world's energy system. From both global and universal perspectives, this review seeks to raise public understanding of hydrogen's critical role in a sustainable energy future.

Vehicular Networks must be sufficiently secured against the wide variety of security challenges to which they are exposed. Cryptography provides tools to solve many of these security problems. In this paper, we address the secure group communications problem in VANETs. By generating a secret group key that can be used to encrypt or authenticate, the members of a VANET platoon can thus guarantee secure communication between them. To address this need, we propose a new secure variant of the Diffie-Hellman algorithm for groups that we fortified by a pre-shared secret to withstand the famous Man in the Middle attack. As necessary, our proposal can be used by several types of authentication and encryption VANET applications. We demonstrate the unforgeability and the privacy of our scheme and we study its secure-efficiency.

This paper aims to quantify sensitivities of energy and exergy performances of Flat Plate Solar Water Heaters (FPSWHs) with respect to measurement parameters. For that purpose, a computational tool is developed and validated by using outdoor conditions according to the test standard EN 12975. First of all, numerical simulations are compared with experimental results and available data in the literature, and the comparison shows a good agreement. Then, we apply the proposed model to the quantification of uncertainties associated with transient simulation. Results show that ambient temperature is the main relevant factor in operating conditions, and its effect reaches 13.7% and 3.89% on energy and exergy efficiencies, respectively, when the deviation in the sensor measurement is about ±1°C. When 0.15 v% multiwall carbon nanotubes (MWCNT)-Ethylene-Glycol (E-G) (30 : 70) nanofluid is used as working fluid, results show that a suitable choice of nanofluid properties achieves 84.7% of the thermal efficiency during the zero reduced temperature conditions compared to 75.4% when the collector works with E-G. Using common empirical correlations affects substantially the accuracy of the fitting parameters, and the deviation in exergy efficiency reaches 1.18%.