The rapid development of drones (or Unmanned Aerial Systems) and their potential deployment in urban areas poses a number of safety issues. Some degree of automation is most probably necessary to ensure that the UAS missions are safely and efficiently performed in urban environments. In a context where a large number of non-cooperative, noncommunicative UAS would fly in dense urban areas, decentralized and autonomous approaches naturally come to mind. In such approaches, each agent would navigate among the buildings while avoiding the other traffic. ORCA (Optimal Reciprocal Collision Avoidance) is a state-of-the art geometric method for robot collision avoidance that...

<div><p>We propose a mixed-integer linear programming model to design optimal trajectories of unmanned aerial vehicles in urban airspaces. The model integrates multiple decision levers, and takes account of the drone dynamics as well as of operational constraints characterizing the addressed problem. Two variants of the model are also presented, to the aim of assessing the impact of the optimization levers and their effect on the overall efficiency. Computational experiments demonstrate the scalability and effectiveness of the proposed approach even for high-density urban air traffic.</p></div>

Several factors need to be taken into account when generating a feasible optimized trajectory. The optimization process heavily relies on the dynamic model of the system. Currently, there are various drone designs available, categorized based on their actuation status. In this study, we apply a trajectory optimization technique to a fully actuated hexacopter (FA-Hex), which is a new application to the best of our knowledge. This type of vehicle has been successfully integrated into several practical applications. Unlike the under-actuated hexacopter (UA-Hex), the FA-Hex can perform maneuvers with minimal banking angles, significantly enhancing the drone's maneuverability...

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This work investigates the time-domain propagation of waves in rigid frame porous media, that can be modelled as an equivalent fluid. Using a multipole approximation, frequency-domain representations of single and double porosity media are translated into the time domain while ensuring system passivity through a constrained nonlinear least squares approach. The proposed method is validated with time domain simulations using an example of double porosity media in an impedance tube.

This paper presents a comprehensive analysis of system complexity in the context of Model-Based Systems Engineering (MBSE) using the System Modeling Language (SysML). The study evaluates the complexity of four key SysML diagrams: Requirements, Use Case, Block, and State Machine Diagrams and looks at the scale, interconnectivity, and various hierarchical order features of the system. There are a number of complexity issues, such as systematic complications captured by met- rics and quantitative measures. The paper outlines the manual and automated computation processes, eventually automating the proposed approach that streamlines complexity analysis, thereby improving...

A Huygens source dielectric resonator antenna (DRA) with unidirectional radiation pattern is presented. It consists of a coaxial probe exciting a rectangular, homogeneous and uniaxial anisotropic dielectric resonator (DR). To obtain a Huygens source radiation pattern, a pair of quasi-TM and TE modes are combined by controlling the permittivity tensor of the DR. A prototype operating at 2.5 GHz has been designed. The DR is made up of periodic anisotropic unit cells on a subwavelength scale and fabricated using a three-dimensional (3-D) printer. The simulated and measured results are in reasonable agreement. A relative impedance bandwidth of 12.5% and a front-to-back ratio...

Uncrewed Aerial Systems (UAS) are common in many industries and an important pillar ofmany modern militaries. While technology advances rapidly, military long-endurance UASstill suffer from high rates of human error-related mishaps, especially when operators experience mental fatigue.In particular, the frequent switching between tasks required by operators presents an opportunity for improvement. Cognitive flexibility, the mental ability to switch between tasks or responses, is an important executive function. However, little research has investigated cognitive flexibility during complex tasks such as UAS control. In this thesis we address this lack, and the possibility...

The concept of Corporate Social Responsibility (CSR) has evolved since Milton Friedman’s 1970 assertion that a business’s sole responsibility is profit. Today, global frameworks like the UN Global Compact and EU regulations emphasize corporate accountability, particularly regarding social and environmental impacts. Corporate Social Responsibility (CSR) has become central in discussions of firm behavior, governance, and public goods provision. CSR however varies across firms. Some adopt basic strategic CSR (b-CSR), considering social and environmental issues only to the extent that they affect consumer demand and profitability. Others practice environmentally committed CSR...