Radar-Only Off-Road Local Navigation

Off-road robotics have traditionally utilized lidar for local navigation due to its accuracy and high resolution. However, the limitations of lidar, such as reduced performance in harsh environmental conditions and limited range, have prompted the exploration of alternative sensing technologies. This paper investigates the potential of radar for off-road local navigation, as it offers the advantages of a longer range and the ability to penetrate dust and light vegetation. We adapt existing lidar-based methods for radar and evaluate the performance in comparison to lidar under various off-road conditions. We show that radar can provide a significant range advantage over lidar while maintaining accuracy for both ground plane estimation and obstacle detection. And finally, we demonstrate successful autonomous navigation at a speed of 2.5 m/s over a path length of 350 m using only radar for ground plane estimation and obstacle detection.Comment: 7 pages, 17 figures, ITSC 202

Planning Sensitivities for Building Contingency Robustness and Graph Properties into Large Synthetic Grids

Interest in promoting innovation for large, high-voltage power grids has driven recent efforts to reproduce actual system properties in synthetic electric grids, which are fictitious datasets designed to be large, complex, realistic, and totally public. This paper presents new techniques based on system planning sensitivities, integrated into a synthesis methodology to mimic the constraints used in designing actual grids. This approach improves on previous work by explicitly quantifying each candidate transmission line’s contribution to contingency robustness, balancing that with geographic and topological metrics. Example synthetic grids build with this method are compared to actual transmission grids, showing that the emulated careful design also achieves observed complex network properties. The results shed light on how the underlying graph structure of power grids reflects the engineering requirements of their design. Moreover, the datasets synthesized here provide researchers in many fields with public power system test cases that are detailed and realistic

Location-Dependent Impacts of Resource Inertia on Power System Oscillations

Inertial responses are seen by the system as the injection or withdrawal of electrical energy, corresponding to a change of frequency. The inertia of a machine primarily contributes to the power system transient stability. Oscillations are always present in the bulk power system due to the electromechanical nature of the grid. Poorly damped oscillations may cause system instability. Thus, this paper aims to study inertia\u27s impacts on system primary frequency response, in particular on system oscillation modes. Both transient stability simulations and modal analysis are performed to provide insights into the extent to which inertia and its location influence the system oscillation behavior. Simulation results using both a small-scale test system and a large-scale synthetic network dynamic model are presented to verify the locational impacts of resource inertia

Iterative Matrix Pencil Method for Power System Modal Analysis

This paper introduces a modal analysis approach termed as the Iterative Matrix Pencil method. It uses the Matrix Pencil Method as the primary tool for mode identification, and adds to it by utilizing the concept of a cost function in order to reduce the number of signals needed to identify the modes for a large system. The method is tested for a variety of large synthetic power grids in this paper, with the cost function being reported to measure accuracy. A sensitivity analysis is also considered, showing how this new method behaves when adjusting the two primary user-based inputs; the number of iterations, and the SVD threshold

Walking the line? An investigation into elite athletes' sport-related use of painkillers and their willingness to use analgesics to train or compete when injured

Pain and injuries are inevitable occupational hazards and health risks in athletes’ working lives. The sport-related use of analgesics with and without injury is widespread. Taking analgesics to compete while injured is conceptualised as a sickness-presenteeism problem. This study examines the complexity of the sport-related use of analgesics in elite sport. A mixed-method design was adopted consisting of a survey (n=775) and interviews (n=21) with elite athletes. Many athletes reported a sport-related use of analgesics. Analgesics had commonly been used to enable an injured athlete to: compete in an important match; train during an important period; qualify for an important match/final; and keep one’s position on the team or have one’s contract prolonged. Particularly team-sport athletes had experience of such use. Apart from the therapeutic use of analgesics, they were sometimes integrated into different routines, for example enhancing performance, avoid lowering performance, aiding recovery, training/competing injured, and prophylactic use. Simultaneously, many had refrained from using or sought to minimise their sport-related use of analgesics; reasons were related to: trust in/feeling the body, side-effects, knowledge and social norms. Social norms and interaction with support personnel played a key role. Physiotherapists and doctors often advised athletes on analgesics, but self-administered use was widespread. How risk cultures manifested themselves varied greatly between sports, and gender differences were scarce. Although, ‘absenteeism’ is also present a majority of athletes would be willing to ‘walk the line’, using analgesics to compete when injuries may threaten their career or sporting success

An (un)desirable trade of harms? How elite athletes might react to medically supervised 'doping' and their considerations of side-effects in this situation

Background The zero-tolerance approach to doping in sport has long been criticised. Legalising ‘doping’ under medical supervision has been proposed as a better way of protecting both athletes’ health and fair competition. This paper investigates how elite athletes might react if specific doping substances were permitted under medical supervision and explore athletes’ considerations about side-effects in this situation. The results are interpreted using a framework, which views elite sport as an exceptional and risky working environment.  Methods 775 elite athletes (mean age: 21.73, SD=5.52) representing forty sports completed a web-based questionnaire (response rate: 51%) presenting a scenario of legalised, medically supervised ‘doping’.  Results 58% of athletes reported an interest in one or more of the 13 proposed substances/methods. Athletes’ interest in a specific product was linked to its capacity to enhance performance levels in the athletes’ particular sport and depended on gender and age. 23% showed interest in either one or more of erythropoietin (EPO), anabolic-androgenic steroids (AAS), blood transfusions and/or Growth Hormone if permitted and provided under qualified medical supervision. Male speed and power sports athletes of increasing age had the highest likelihood of being interested in AAS (41%, age 36), female motor-skill sports athletes had the lowest (< 1%, age 16). 59% feared side-effects. This fear kept 39% of all athletes from being interested in specific substances/methods whereas 18% declared their interest despite fearing the side-effects. Conclusion Interpreting results with the understanding of sport as an exceptional and risky working environment suggests that legalising certain 'doping' substances under medical supervision would create other/new types of harms, and this 'trade-off of harms and benefits' would be undesirable considering the occupational health, working conditions and well-being of most athletes. Assessing the risks and harms produced/reduced by specific drugs when considering sport as a precarious occupation may prove useful in composing the Prohibited List and reducing drug-related harm in sport