Cardiovascular Biomarkers' Inherent Timescales in Mental Workload Assessment During Simulated Air Traffic Control Tasks.

One central topic in ergonomics and human-factors research is the assessment of mental workload. Heart rate and heart rate variability are common for registering mental workload. However, a major problem of workload assessment is the dissociation among different workload measures. One potential reason could be the disregard of their inherent timescales and the interrelation between participants' individual differences and timescales. The aim of our study was to determine if different cardiovascular biomarkers exhibit different timescales. We focused on air traffic controller and investigated biomarkers' ability to distinguish between conditions with different load levels connected to prior work experience and different time slots. During an interactive real-time simulation, we varied the load situations with two independent variables: the traffic volume and the occurrence of a priority-flight request. Dependent variables for registering mental workload were the heart rate and heart rate variability from two time slots. Our results show that all cardiovascular biomarkers were sensitive to workload differences with different inherent timescales. The heart rate responded sooner than the heart rate variability features from the frequency domain and it was most indicative during the time slot immediately after the priority-flight request. The heart rate variability parameters from the frequency domain responded with latency and were most indicative during the subsequent time slot. Furthermore, by consideration of biomarkers' inherent timescales, we were able to assess a significant effect of work experience on heart rate and mid/high frequency-band ratio of the heart rate variability. Results indicated that different cardiovascular biomarkers reveal different inherent timescales.

A portable primary radar for general aviation.

A detailed situation awareness of the local environment is essential for safe flight in General Aviation. When operating under Visual Flight Rules, eyesight is crucial for maintaining situation awareness and objects may be overlooked. Technical solutions such as Flarm have been sought, but they only work on a basis of co-operation: obstacles without the proper equipment are invisible. Recent developments in the field of radar technology, partly empowered by the demand for sensors for autonomous cars, have improved the size and power consumption of available hardware. Today, the hardware exists to build a portable primary radar system for situation awareness. In this paper the results are presented of efforts to build the first portable primary radar for general, which has to be lightweight, cheap and have a low power consumption. The focus in this paper is on the software design of such a radar system. The physical principles of radar sensing are described, as well as the scientific steps needed to provide situation awareness. The hardware and software for the radar are both built and tested, and the results of these tests are presented. A flight experiment is performed with a small aircraft flying past a stationary radar on a small hill. It is found that the radar is capable of detecting the aircraft up to a distance of at least 3 kilometers. 3D localization is performed and the location determined by the radar was on average 46 meters away from the aircraft position as measured by satellite navigation, relative to a total distance of about 1000 meters from the radar. A low-pass filter can be applied on the raw results in order to improve the location estimation further. Future research will focus on bringing the portable radar in motion while operating.

An Innovative Technique for Identification of Missing Persons in Natural Disaster Based on Drone-Femtocell Systems.

The recent development of the IoT (Internet of Things), which has enabled new types of sensors that can be easily interconnected to the Internet, will also have a significant impact in the near future on the management of natural disasters (mainly earthquakes and floods) with the aim of improving effectiveness in research, identification, and recovery of missing persons, and therefore increasing the possibility of saving lives. In this paper, more specifically, an innovative technique is proposed for the search and identification of missing persons in natural disaster scenarios by employing a drone-femtocell system and devising an algorithm capable of locating any mobile terminal in a given monitoring area. In particular, through a series of power measurements based on the reference signal received power (RSRP), the algorithm allows for the classification of the terminal inside or outside the monitoring area and subsequently identify the position with an accuracy of about 1 m, even in the presence of obstacles that act in such a way as to make the propagation of the radio signal non-isotropic.

Line-of-sight in operating a small unmanned aerial vehicle: How far can a quadcopter fly in line-of-sight?

A field study was conducted to investigate the probabilities of human participants to detect a small unmanned aerial vehicle (UAV) at a certain distance. A Phantom 4 quadcopter was remotely controlled to hover at one of the 32 pre-determined locations in the air. Thirty-two participants on the ground were requested to judge if they could see the quadcopter on a four-point scale: 1. definitely yes, 2. probably yes, 3. probably no, and 4. definitely no. The participants also responded whether they could hear the quadcopter on the same four-point scale. Logistic regression models were established to estimate the probability of detecting the quadcopter in the air, both visually and auditory. When navigating a quadcopter flying away from the operator, the sound stimulus diminished and then disappeared earlier than that of the sight of the quadcopter. The results of the study indicated that the probability of visual detection of the quadcopter at a distance of 300 m was approximately 0.3. When adopting a 50% probability of visual detection and the "definitely or probably yes" criterion, the estimated distance of line-of-sight was 245 m. The corresponding visual angle was 0.065°. The information in this study is valuable for drone operators, operator training institutes, and drone designers. The aviation authorities may also consider revising the codes or regulations for small UAV operation based on our findings.

U.S. Army Parachute Mishap Fatalities: 2010-2015.

INTRODUCTION: Despite the large number of U.S. military members who conduct parachuting operations, its inherent safety risks, and the introduction of a new military parachute in 2010, little has been published in the last decade on U.S. military parachute fatalities.METHODS: Parachute fatality investigative records maintained by the U.S. Army Combat Readiness Center were reviewed for U.S. Army fatalities resulting from military parachuting operations from January 1, 2010, through December 31, 2015. De-identified data on cases were collected, including causes, lethal injuries, and demographic, environmental, and missional factors. A descriptive analysis was performed.RESULTS: There were 13 cases which met study inclusion criteria. Most occurred during static-line operations and were jumps from a C-17 aircraft using a T-11 parachute. The two most common assigned accident codes were "improper or abnormal exit" and "unstable or improper body position," which combined accounted for 33% of cases. Also noteworthy at 11% each were "entanglement," "parachute malfunction," and "dragged on the drop zone," and at 6% each were "static line injury," "lost or stolen air," and "drop zone hazard." In 69% of cases blunt force trauma was the cause of death.DISCUSSION: Incident factors included human actions, equipment failure, and the environment. Death from blunt force trauma upon impact with the ground as the most frequent lethal injury was expected for parachute operations. This descriptive study provides awareness to military leaders of circumstances in which fatalities occur. Future investigations should include data on the total number of jumps to provide a more comprehensive analysis of risk.Johnson ES, Gaydos SJ, Pavelites JJ, Kotwal RS, Houk JE. U.S. Army parachute mishap fatalities: 2010-2015. Aerosp Med Hum Perform. 2019; 90(7):637-642.

Reflecting upon the humanitarian use of unmanned aerial vehicles (drones).

Nine years after the earthquake in Haiti and the appearance of the concept of “humanitarian drones”, it remains a poorly discussed yet highly controversial issue. Emergency mapping and light cargo deliveries to inaccessible areas are only some of the most popular ways in which drones are currently used for post-disaster relief and health crisis management by first responders around the world. On the other hand, every single successful use for drones is always followed by controversy about the problems caused by that very same, initially successful, use. However, examples of good practices will contribute to the investigation, study and analysis of the ways in which new, cutting-edge technologies such as drones can be implemented and adapted to meet the needs and requirements of humanitarian organisations and local communities affected by disasters. The issue is how and under what circumstances drone use can potentially fulfil humanitarian functions, particularly in the aftermath of a disaster, and how this type of technology could be deployed in non-violent, ethically desirable ways as part of the humanitarian response. In conclusion, it is questionable whether the benefits of using drones outnumber the moral obstacles they raise, and whether they will eventually be considered an inseparable part of humanitarian aid as well as a cutting-edge technological toy.

Use of Highways in the Sky and a virtual pad for landing Head Up Display symbology to enable improved helicopter pilots situation awareness and workload in degraded visual conditions.

Flight within degraded visual conditions is a great challenge to pilots of rotary-wing craft. Environmental cues typically used to guide interpretation of speed, location and approach can become obscured, forcing the pilots to rely on data available from in-cockpit instrumentation. To ease the task of flight during degraded visual conditions, pilots require easy access to flight critical information. The current study examined the effect of 'Highways in the Sky' symbology and a conformal virtual pad for landing presented using a Head Up Display (HUD) on pilots' workload and situation awareness for both clear and degraded conditions across a series of simulated rotary-wing approach and landings. Results suggest that access to the HUD lead to significant improvements to pilots' situation awareness, especially within degraded visual conditions. Importantly, access to the HUD facilitated pilot awareness in all conditions. Results are discussed in terms of future HUD development. Practitioner Summary: This paper explores the use of a novel Heads Up Display, to facilitate rotary-wing pilots' situation awareness and workload for simulated flights in both clear and degraded visual conditions. Results suggest that access to HUD facilitated pilots' situation awareness, especially when flying in degraded conditions.

Tactile Display Design for Flight Envelope Protection and Situational Awareness.

Spatial disorientation and visual channel saturation are defined as critical situations encountered by military pilots. Such subjects are interesting research areas likely to create innovative systems able to surmount obstacles of this kind. The integration of new stimulation techniques (sensory substitute, adjunct for visual and audio feedback) may be considered to make the visual channel better. This contribution may help in integrating tactile stimulation to improve or substitute the visual channel. It may also help to better interpret the spatial disorientation awareness signals and the vestibulo-ocular response limitations. The innovation of the proposed approach translates in: (i) the development of the PI-Inverse dynamics controller to provide a time delay reduction of the low cost tactile actuator, and thus, high-performance tactile system; (ii) an approach based on fuzzy logic controller (FLC) is being used in order to translate the turn rate angle, the flight path climb angle and the warning messages into tactile signal features instead of a conventional approach based on direct coding of the pitch and bank angles; and (iii) the consideration of the flight envelope. The fuzzy set translation of flight parameters into tactile signals is also a pragmatic and useful way to design the system.

Future technology on the flight deck: assessing the use of touchscreens in vibration environments.

Use of touchscreens in the flight deck has been steadily increasing, however, their usability may be severely impacted when turbulent conditions arise. Most previous research focusses on using touchscreens in static conditions; therefore, this study assessed touchscreen use whilst undergoing turbulent representative motion, generated using a 6-axis motion simulator. Touchscreens were tested in centre, side and overhead positions, to investigate how turbulence affected: (1) error rate, movement times and accuracy, (2) arm fatigue and discomfort. Two touchscreen technologies were compared: a 15" infra-red and a 17.3" projected capacitive touchscreen with force sensing capability. The potential of the force sensing capability to minimise unintentional interactions was also investigated. Twenty-six participants undertook multi-direction tapping (ISO 9241; ISO 2010 ) and gesture tasks, under four vibration conditions (control, light chop, light turbulence and moderate turbulence). Error rate, movement time and workload increased and usability decreased significantly, with screen position and increasing turbulence level. Practitioner Summary: This study evaluated the use of infra-red and projected capacitive touchscreen technologies using multi-directional tapping and gesture tasks, whilst being subjected to different levels of turbulence representative motion. Performance degraded significantly with increasing turbulence level and touchscreen location. This has implications for future flight deck design.

Medical Applications of Drones for Disaster Relief: A Review of the Literature.

INTRODUCTION: Rapid progress has been made with unmanned aerial systems (UAS), which are now used in a wide variety of different fields, including media, agriculture, wildlife, and infrastructure. However, the application of UAS for medical purposes, and in particular disaster relief efforts, has been slower to develop. This paper will review and present pertinent studies in the literature. METHODOLOGY: Studies related to drones and medical applications for disaster relief were identified as part of a larger search regarding the civilian application of drones. A search for civilian drone applications was performed in the EBSCO (Elton B. Stephens Company) database. Non-civilian applications as well as redundant sources were excluded. RESULTS: The search identified 711 sources pertaining to civilian drone applications. Of these, 117 involved drone applications in disaster relief, and 28 articles specifically addressed medical uses. CONCLUSION: Drones can be useful during immediate and non-immediate medical disaster relief efforts. They can provide an instant telecommunications infrastructure, assist in telemedicine-enabled clinical services, perform equipment/drug/patient delivery, enhance search and rescue efforts, assess damage and map disaster zones. Rapid processing of permission for emergency operations, promotion of industry expansion, public awareness, and public participation must be emphasized for these to become routine applications. There is a major concern about the organizational umbrella that would promote this initiative. Creation of an organization such as a Drone Civil Air Patrol Wing (DCAPW) could improve our ability to provide post-disaster healthcare delivery services.

Remembering to execute deferred tasks in simulated air traffic control: The impact of interruptions.

Air traffic controllers can sometimes forget to complete deferred tasks, with safety implications. In two experiments, we examined how the presence and type of interruptions influenced the probability and speed at which individuals remembered to perform deferred tasks in simulated air traffic control (ATC). Participants were required to accept/handoff aircraft, detect aircraft conflicts, and perform two deferred tasks: a deferred conflict task that required remembering to resolve a conflict in the future and a deferred handoff task that required substituting an alternative aircraft handoff action in place of routine handoff action. Relative to no interruption, a blank display interruption slowed deferred conflict resumption, but this effect was not augmented by a cognitively demanding n-back task or a secondary ATC task interruption. However, the ATC task interruption increased the probability of failing to resume the deferred conflict relative to the blank interruption. An ex-Gaussian model of resumption times revealed that these resumption failures likely reflected true forgetting of the deferred task. Deferred handoff task performance was unaffected by interruptions. These findings suggest that remembering to resume a deferred task in simulated ATC depended on frequent interaction with situational cues on the display and that individuals were particularly susceptible to interference-based forgetting. (PsycINFO Database Record

Use of unmanned aerial vehicles for efficient beach litter monitoring.

A global beach litter assessment is challenged by use of low-efficiency methodologies and incomparable protocols that impede data integration and acquisition at a national scale. The implementation of an objective, reproducible and efficient approach is therefore required. Here we show the application of a remote sensing based methodology using a test beach located on the Saudi Arabian Red Sea coastline. Litter was recorded via image acquisition from an Unmanned Aerial Vehicle, while an automatic processing of the high volume of imagery was developed through machine learning, employed for debris detection and classification in three categories. Application of the method resulted in an almost 40 times faster beach coverage when compared to a standard visual-census approach. While the machine learning tool faced some challenges in correctly detecting objects of interest, first classification results are promising and motivate efforts to further develop the technique and implement it at much larger scales.

UAS stealth: target pursuit at constant distance using a bio-inspired motion camouflage guidance law.

The aim of this study is to derive a guidance law by which an unmanned aerial system(s) (UAS) can pursue a moving target at a constant distance, while concealing its own motion. We derive a closed-form solution for the trajectory of the UAS by imposing two key constraints: (1) the shadower moves in such a way as to be perceived as a stationary object by the shadowee, and (2) the distance between the shadower and shadowee is kept constant. Additionally, the theory presented in this paper considers constraints on the maximum achievable speed and acceleration of the shadower. Our theory is tested through Matlab simulations, which validate the camouflage strategy for both 2D and 3D conditions. Furthermore, experiments using a realistic vision-based implementation are conducted in a virtual environment, where the results demonstrate that even with noisy state information it is possible to remain well camouflaged using the constant distance motion camouflage technique.

Evaluation of the Intel Xeon Phi 7120 and NVIDIA K80 as accelerators for two-dimensional panel codes.

To optimize the geometry of airfoils for a specific application is an important engineering problem. In this context genetic algorithms have enjoyed some success as they are able to explore the search space without getting stuck in local optima. However, these algorithms require the computation of aerodynamic properties for a significant number of airfoil geometries. Consequently, for low-speed aerodynamics, panel methods are most often used as the inner solver. In this paper we evaluate the performance of such an optimization algorithm on modern accelerators (more specifically, the Intel Xeon Phi 7120 and the NVIDIA K80). For that purpose, we have implemented an optimized version of the algorithm on the CPU and Xeon Phi (based on OpenMP, vectorization, and the Intel MKL library) and on the GPU (based on CUDA and the MAGMA library). We present timing results for all codes and discuss the similarities and differences between the three implementations. Overall, we observe a speedup of approximately 2.5 for adding an Intel Xeon Phi 7120 to a dual socket workstation and a speedup between 3.4 and 3.8 for adding a NVIDIA K80 to a dual socket workstation.

Flow separation on flapping and rotating profiles with spanwise gradients.

The growth of leading-edge vortices (LEV) on analogous flapping and rotating profiles has been investigated experimentally. Three time-varying cases were considered: a two-dimensional reference case with a spanwise-uniform angle-of-attack variation α; a case with increasing α towards the profile tip (similar to flapping flyers); and a case with increasing α towards the profile root (similar to rotor blades experiencing an axial gust). It has been shown that the time-varying spanwise angle-of-attack gradient produces a vorticity gradient, which, in combination with spanwise flow, results in a redistribution of circulation along the profile. Specifically, when replicating the angle-of-attack gradient characteristic of a rotor experiencing an axial gust, the spanwise-vorticity gradient is aligned such that circulation increases within the measurement domain. This in turn increases the local LEV growth rate, which is suggestive of force augmentation on the blade. Reversing the relative alignment of the spanwise-vorticity gradient and spanwise flow, thereby replicating that arrangement found in a flapping flyer, was found to reduce local circulation. From this, we can conclude that spanwise flow can be arranged to vary LEV growth to prolong lift augmentation and reduce the unsteadiness of cyclic loads.

Forensic Analysis of Parachute Deaths.

Deaths associated with parachuting are very uncommon. However, these deaths do tend to be "high profile" in the traditional and social media. When forensic pathologists examine the deceased after a fatal parachuting incident, the anatomical cause of death is usually not in question. For most forensic pathologists, it is usually the case that we will have very limited knowledge of parachuting equipment or the mechanics of a typical successful parachute jump. As such, the investigation of the death should involve a multidisciplinary approach with an appropriate expert providing the formal forensic examination of the parachuting equipment. We have endeavored to describe, in simple terms, the usual components of a typical parachute rig, a précis of the sequence of events in a routine skydive and BASE jump, and the various types of malfunctions that may occur. Last, we present a case report of a BASE jump fatality to illustrate how an expert examination of the BASE jumper's gear aided the medicolegal investigation of the death with some important aspects in the forensic examination of the jumper's equipment.

Designs and Algorithms to Map Eye Tracking Data with Dynamic Multielement Moving Objects.

Design concepts and algorithms were developed to address the eye tracking analysis issues that arise when (1) participants interrogate dynamic multielement objects that can overlap on the display and (2) visual angle error of the eye trackers is incapable of providing exact eye fixation coordinates. These issues were addressed by (1) developing dynamic areas of interests (AOIs) in the form of either convex or rectangular shapes to represent the moving and shape-changing multielement objects, (2) introducing the concept of AOI gap tolerance (AGT) that controls the size of the AOIs to address the overlapping and visual angle error issues, and (3) finding a near optimal AGT value. The approach was tested in the context of air traffic control (ATC) operations where air traffic controller specialists (ATCSs) interrogated multiple moving aircraft on a radar display to detect and control the aircraft for the purpose of maintaining safe and expeditious air transportation. In addition, we show how eye tracking analysis results can differ based on how we define dynamic AOIs to determine eye fixations on moving objects. The results serve as a framework to more accurately analyze eye tracking data and to better support the analysis of human performance.

Towards Microscale Flight: Fabrication, Stability Analysis, and Initial Flight Experiments for 300 µm × 300 µm × 1.5 µm Sized Untethered MEMS Microfliers.

This paper presents modeling, designs, and initial experimental results demonstrating successful untethered microscale flight of stress-engineered microscale structures propelled by thermal forces. These MEMS Microfliers are 300 µm×300 µm×1.5 µm in size and are fabricated out of polycrystalline silicon using a surface micromachining process. A concave chassis, created using a novel in-situ masked post-release stress-engineering process, promotes static in-flight stability. High-speed optical micrography was used to capture image sequences of their flight, and this imagery was subsequently used to analyze their mid-flight performance. Our analysis, combined with finite element modeling (FEM) confirms stable flight of the microfliers within the thermal gradient above the heaters. This novel microscale flying platform presented in this paper may pave the way for new types of aerial microrobots.