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Vehicular Ad-hoc Networks (VANETs) are a crucial component of Cooperative Intelligent Transportation Systems (C-ITS), enabling vehicles to communicate and share vital information to enhance road safety and efficiency. Basic Safety Messages (BSMs), periodically broadcast by vehicles to provide real-time kinematic data, form the foundation of numerous safety applications within VANETs. Ensuring the security of BSMs is paramount, as malicious entities can exploit vulnerabilities to launch attacks that could have catastrophic consequences. In this study, we provide a comprehensive analysis of BSM attacks and detection mechanisms in VANETs. We begin by outlining the system model, security requirements, and attacker models relevant to BSMs. Then, we categorize and describe a range of attacks, from simple position falsification to more sophisticated and evasive techniques, such as the SixPack attack. We also classify existing attack detection methods into machine learning-based, deep learning-based, plausibility and consistency-based, and software-defined networking (SDN)-based mechanisms, analyzing their effectiveness and limitations. Additionally, we highlight the challenges in securing BSMs, such as the trade-off between model accuracy and real-time performance. Future research directions are also discussed. This survey paper serves as a foundational step towards building safe, secure, and reliable cooperative intelligent transportation systems and their associated applications. 

We study systems of two and three electrons confined to circular rings. The electrons are considered spinless, and we assume that one electron occupies a single ring. We use the framework of such a model to calculate the linear entropy and, thus, the spatial entanglement between the confined electrons. The geometry of the problem for the case of two electrons incorporates situations in which the planes of the two rings form an arbitrary angle with each other. The resulting Schrödinger’s equation is solved numerically with very high accuracy by means of the exact diagonalization method. We compute the ground state energy and entanglement for all configurations under consideration. We also study the case of three electrons confined to identical, parallel and concentric rings which are located in three different equidistant planes. The vertically separated system of rings is allowed to gradually merge into a single ring geometry, which would represent the equivalent system of a ring with three electrons. It is observed that the system of three electrons gives rise to a richer structure, as the three rings merge into a single one. 

Systems composed of several multi-layer compounds have been extremely useful in tailoring different quantum physical properties of nanomaterials. This is very much true when it comes to semiconductor materials and, in particular, to heterostructures and heterojunctions. The formalism of a position-dependent effective mass has proved to be a very efficient tool in those cases where quantum wells emerge either in one or two dimensions. In this work, we use a variety of mathematical theorems, as well as numerical computations, to study different scenarios pertaining to choices of a specific piecewise constant effective mass for a particle that causes its energy eigenvalues to reach an extremum. These results are relevant when it comes to practical technological applications such as modifying the optical energy gap between the first excited state and the ground state energy of the system. At the end of our contribution, we also question the physical validity of some approximations for systems with particles that possess a position-dependent mass especially for those cases in which the mass distribution is divergent. 

This article investigates the feasibility of using regenerative energy from braking trains to charge electric buses in the context of New York City’s (NYC) subway and electric bus networks. A case study centered around NYC’s system has been performed to evaluate the benefits and challenges pertaining to the use of the preexisting subway network as a power supply for its new all-electric buses. The analysis shows that charging electric buses via the subway system during subway off-peak periods does not hinder regular train operation. In addition, having the charging electric buses connected to the third rail allows for more regenerative braking energy (RBE) to be recuperated, decreasing the energy wasted throughout the system. It was also found that including a wayside energy storage system (WESS) reduces the overall substation peak power consumption. 

Abstract This paper investigates the deployment of solar technology throughout an electric railway system to accommodate tractive power needs. The approach is evaluated from both a technical and financial standpoint to better understand its overall feasibility. A case study is presented using New York City's subway system as the centre of deployment. As a means to both prevent excess voltages, as well as contribute to the city's shift to zero emission, parallel electric bus charging is also studied. It has been demonstrated that the proposed integration allows the subway system to still function without any hindrance to rail operation. The system is able to provide charging power for three to six electric buses per passenger station. In addition, the approach shows long‐term financial growth with average annual electric bill savings of approximately $50,000 per passenger station, each with a relatively short payback period of approximately 4 years.