Enhancing safety feedback to the design of small, unmanned aircraft by joint assessment of impact area and human fatality.

Advantages of commercial UAS-based services come with the disadvantage of posing third party risk (TPR) to overflown population on the ground. Especially challenging is that the imposed level of ground TPR tends to increase linearly with the density of potential customers of UAS services. This challenge asks for the development of complementary directions in reducing ground TPR. The first direction is to reduce the rate of a UAS crash to the ground. The second direction is to reduce overflying in more densely populated areas by developing risk-aware UAS path planning strategies. The third direction is to develop UAS designs that reduce the product A impact · P { F | impact } ${{A}_{{\mathrm{impact}}}} \cdot \mathbb{P}\{ F| {{\mathrm{impact}}\} } $ in case of a crashing UAS, where A impact ${{A}_{{\mathrm{impact}}}}$ is the size of the crash impact area on the ground, and P { F | impact } $\mathbb{P}\{ F| {{\mathrm{impact}}\} } $ is the probability of fatality for a person in the crash impact area. Because small UAS accident and incident data are scarce, each of these three developments is in need of predictive models regarding their contribution to ground TPR. Such models have been well developed for UAS crash event rate and risk-aware UAS path planning. The objective of this article is to develop an improved model and assessment method for the product A impact · P { F | impact } . ${{A}_{{\mathrm{impact}}}} \cdot \mathbb{P}\{ F| {{\mathrm{impact}}\} } .$ In literature, the model development and assessment of the latter two terms is accomplished along separate routes. The objective of this article is to develop an integrated approach. The first step is the development of an integrated model for the product A impact · P { F | impact } ${{A}_{{\mathrm{impact}}}} \cdot \mathbb{P}\{ F| {{\mathrm{impact}}\} } $ . The second step is to show that this integrated model can be assessed by conducting dynamical simulations of Finite Element (FE) or Multi-Body System (MBS) models of collision between a UAS and a human body. Application of this novel method is illustrated and compared to existing methods for a DJI Phantom III UAS crashing to the ground.

Global optimization for accurate determination of EBSD pattern centers.

Accurate pattern center determination has long been a challenge for the electron backscatter diffraction (EBSD) community and is becoming critically accuracy-limiting for more recent advanced EBSD techniques. Here, we study the parameter landscape over which a pattern center must be fitted in quantitative detail and reveal that it is both "sloppy" and noisy, which limits the accuracy to which pattern centers can be determined. To locate the global optimum in this challenging landscape, we propose a combination of two approaches: the use of a global search algorithm and averaging the results from multiple patterns. We demonstrate the ability to accurately determine pattern centers of simulated patterns, inclusive of effects of binning and noise on the error of the fitted pattern center. We also demonstrate the ability of this method to accurately detect changes in pattern center in an experimental dataset with noisy and highly binned patterns. Source code for our pattern center fitting algorithm is available online.

Mechanical power output in rowing should not be determined from oar forces and oar motion alone.

Mechanical power output is a key performance-determining variable in many cyclic sports. In rowing, instantaneous power output is commonly determined as the dot product of handle force moment and oar angular velocity. The aim of this study was to show that this commonly used proxy is theoretically flawed and to provide an indication of the magnitude of the error. To obtain a consistent dataset, simulations were performed using a previously proposed forward dynamical model. Inputs were previously recorded rower kinematics and horizontal oar angle, at 20 and 32 strokes∙min-1. From simulation outputs, true power output and power output according to the common proxy were calculated. The error when using the common proxy was quantified as the difference between the average power output according to the proxy and the true average power output (P̅residual), and as the ratio of this difference to the true average power output (ratiores./rower). At stroke rate 20, P̅residual was 27.4 W and ratiores./rower was 0.143; at stroke rate 32, P̅residual was 44.3 W and ratiores./rower was 0.142. Power output in rowing appears to be underestimated when calculated according to the common proxy. Simulations suggest this error to be at least 10% of the true power output.

Mechanism and structure studies of cinnamaldehyde/cyclodextrins inclusions by computer simulation and NMR technology.

This work aims to explore the inclusion mechanism and structure of cinnamaldehyde (CNMA) and cyclodextrins (CDs), and to provide some theoretical information for the application of CNMA and its inclusion. In this study, we prepared three kinds of inclusion and investigated the mechanism and structure by theory and experiment. Molecular docking and dynamical simulations presented a stable 1:1 inclusion complex and the visual structure model. The structural features indicated that the benzene ring of CNMA was enclosed in the hydrophobic cavity of CDs, which were consistent with the results of 1H NMR, 2D-ROESY, Fourier transform infrared spectroscopy. The inclusion mechanism studies showed that the inclusion process was driven mainly by enthalpy with the binding constant following the order of DM (dimethyl) > HP (hydroxypropyl) > ß-CD. Moreover, the inclusion complex showed an advantageous water solubility and dissolution rate compared with CNMA.

Application of the pattern matching approach for EBSD calibration and orientation mapping, utilising dynamical EBSP simulations.

In this paper an alternative method of off-line Kikuchi pattern centre calibration and orientation mapping, utilising the cross-correlation between entire experimental patterns and dynamical simulated patterns is applied and evaluated. To demonstrate the improvement in angular resolution compared to Hough transform based methods, EBSD datasets of a silicon monocrystal were analysed using both, classical and the presented cross-correlation based method, which revealed significant enhancement of angular resolution for the refined method. The mean misorientation over the monocrystalline sample was found to be up to one order of magnitude lower compared to common methods, with an angular resolution of up to 0.06° indicating a substantial gain in orientation precision. The pattern centres were determined for a number of patterns on the map, using pattern matching refinement as well. Subsequently, a multiple linear regression model was computed to correlate pattern centre positions (XPC, YPC) and detector distances (ZSSD) to x- and y-coordinates on the map by means of plane equations. Employing this method, a reduction of orientation noise was achieved in highly deformed Silicon crystals with large intragranular orientation ranges. Furthermore, it was shown that the cross correlation coefficient CC can be used as a parameter indicating the pattern quality and hence can be utilised to create a pseudo greyscale image of the surface, showing grain boundaries and also depicting lattice distortions.