bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discussion: “Selective-Compliance-Based Lagrange Model and Multilevel Noncollocated Feedback Control of a Humanoid Robot” (Spyrakos-Papastavridis, E., Dai, J. S., Childs, P. R. N., and Tsagarakis, N. G., 2018, ASME J. Mech. Rob., 10(3), p. 031009)
Authors: Medrano-Cerda Gustavo A. 
Published: November 2020

Abstract
The present comment concerns the above paper. [DOI: 10.1115/1.4039394]
A Piezocomposite Actuated Propeller With an Onboard Power Generator
Authors: Shah Bharg , Bilgen Onur 
Published: November 2020

Abstract
This paper presents an application of a novel piezocomposite rotor system on a model-scale helicopter. The piezocomposite rotor concept can be implemented on various rotary systems, including small unmanned aerial vehicles, and tandem rotor, multi-rotor, single-rotor and other rotary systems. Based on authors’ previous research, a new design of the so-called solid-state rotor concept is implemented on a single degree of the freedom apparatus that the derived from the model-scale helicopter. An electromagnetic power generator is used to convert the mechanical energy due to the rotation of the generator into electrical energy, and this is used to actuate the piezocomposite blades. The actuation by the piezocomposite actuators on the rotor blade results in a change of the camber of the rotor blade. The change in camber generates an increase of thrust.
Harnessing Kinetic Energy From Human Motions With a High-Efficiency Wearable Electromagnetic Energy Harvester
Authors: Peng Yan , Zhang Dong , Luo Jun , Xie Shaorong , Pu Huayan , Li Zhongjie 
Published: November 2020

Abstract
Recent years have witnessed explosive increase in the number of wearable devices in the market and industry. However, hardly have these devices gained the ability to capture energy from hosts and then get self-charged. In this paper, we design and build a novel wearable electromagnetic energy harvester to scavenge the kinetic energy of human ankle during walking or running. The design is composed of mainly three parts: a spring-mass system, rolling ball pair and the electromagnetic transduction mechanism. The harvester adopts an array of alternating south- and north-pole magnets. This arrangement allows the array exhibits a unique phenomenon, i.e. abrupt magnetic flux density changes within the array. Because of this phenomenon, the harvester displays excellent performance such as relatively high voltage and high power output. We then conducted FEM analysis to validate the hypothetical abrupt flux density changes. A prototype was fabricated for experimental studies. We investigated open-circuit voltage output, current output, and power as well as charging performance into energy storage components. The result shows that harvester possesses excellent performance with the maximum output voltage of 8.64V, peak-peak power of 700mW and the highest volume power density of 24.9mW/cm3. The energy harvester, as a renewable portable power source, can be of great significance for powering smart wearable electronic devices and health care monitoring sensors.
Spatial Statistical Methods for Complexity-Based Point Cloud Analysis
Authors: Dargahi Mozhgan Momtaz , Lattanzi David 
Published: November 2020

Abstract
Modern remote sensing technologies now provide the basis for flexible and highly accurate three-dimensional geometric modeling of structures in the form of point clouds. To date, most efforts are focused on how to use these point clouds to form a digital twin of an asset, but these models can also be used to augment and improve condition assessment and structural health monitoring (SHM). However, point cloud analytics require unique approaches given the complexity and scale of the data. To illustrate these capabilities, we propose a new SHM method that leverages 3D point cloud data and the evolution of this data over time. Taking inspiration from recent work on the use of complexity measures for sensor driven SHM, here we adapt the concept for spatial analysis of 3D digital twins. The fundamental assumption that underpins the approach presented here is that, as a structure degrades in integrity, the randomness of the data increases when compared against the null model of the homogeneous Poisson process, otherwise described as ‘complete spatial randomness’ (CSR). In spatial point analysis, points from a baseline model are generated and placed within a normalized Cartesian reference frame. The spatial randomness of this baseline is considered the null model of the homogeneous Poisson process. In subsequent 3D models of an asset, spatial complexity metrics are recomputed on a local neighborhood level, with increased complexity corresponding to potential damage or degradation of the asset. Another question of interest is to provide a suitable mathematical model for this underlying temporal evolution. Compared to more conventional analytical approaches that can only detect data anomalies via a single computation, this complexity-based approach enables us to further integrate multi-level information, in the form of first and second order moment metrics, to evaluate data anomalies in more depth. In this method we use the variation of the first and second moments of the average intensity of the points in space. A first order metric of a point pattern represents the density change across the study region such as Quadrat density or Kernel density. The second-order metric of the point pattern considers the distance between points, effectively quantifying how points are distributed relative to one another. Examples include Ripley’s K-function, the L-function or Baddeley’s J-function. This analytical approach was tested on a variety of laboratory scale specimens with varying levels of damage and degradation. The results show that this new technique provides rapid analytical capabilities for finding damage and quantifying both damage and evolution in point clouds. Ongoing work seeks to scale up these measures to full-scale specimens, and to explore methods of using the results for damage prognosis through statistical time-series modeling of the evolution of the complexity metrics.
Design Optimization of Shape Memory Alloy-Based Adaptive Building Skins for Thermal Regulation
Authors: Fang Yudong , Peraza Hernandez Edwin A. 
Published: November 2020

Abstract
This paper presents a design study of adaptive skins that enable thermal regulation for buildings. The skins consist of rectangular panels that adaptively open and close driven by shape memory alloy (SMA) wires in response to the variation of the environment temperature. The SMA wires are used as both thermal sensors and actuators that inspect the environmental temperature and provide a corresponding actuation response. When temperature is low, the SMA wires are stable in their elongated martensitic configuration, keeping the panels closed to maintain the building interior warm by reducing incoming airflow from the exterior. When temperature reaches the SMA austenite transformation values, the SMA wires transform into their contracted austenitic configuration and open the panels. This permits cooling of the building interior by allowing circulation of incoming airflow from the exterior. This repeatable response allows the skins to adaptively regulate the indoor temperature. The performance of the adaptive skins is evaluated using finite element analysis. Metallic and laminated fiber-reinforced composite plates are explored as material options for the panels. The adaptive skins are parameterized using design variables including the dimensions of the panels, the ply thickness and orientation angles in the case of fiber-reinforced panels, and the radii of the SMA wires. By employing genetic algorithms, these design variables are optimized to maximize the achievable opening area of the panels while satisfying material failure constraints.
Optimization of Rapid State Estimation in Structures Subjected to High-Rate Boundary Change
Authors: Scheppegrell James , Moura Adriane G. , Dodson Jacob , Downey Austin 
Published: November 2020

Abstract
Many structures are subjected to varying forces, moving boundaries, and other dynamic conditions. Whether part of a vehicle, building, or active energy mitigation device, data on such changes can represent useful knowledge, but also presents challenges in its collection and analysis. In systems where changes occur rapidly, assessment of the system’s state within a useful time span is required to enable an appropriate response before the system’s state changes further. Rapid state estimation is especially important but poses unique difficulties.
In determining the state of a structural system subjected to high-rate dynamic changes, measuring the frequency response is one method that can be used to draw inferences, provided the system is adequately understood and defined. The work presented here is the result of an investigation into methods to determine the frequency response, and thus state, of a structure subjected to high-rate boundary changes in real-time.
In order to facilitate development, the Air Force Research Laboratory created the DROPBEAR, a testbed with an oscillating beam subjected to a continuously variable boundary condition. One end of the beam is held by a stationary fixed support, while a pinned support is able to move along the beam’s length. The free end of the beam structure is instrumented with acceleration, velocity, and position sensors measuring the beam’s vertical axis. Direct position measurement of the pin location is also taken to provide a reference for comparison with numerical models.
This work presents a numerical investigation into methods for extracting the frequency response of a structure in real-time. An FFT based method with a rolling window is used to track the frequency of a data set generated to represent the range of the DROPBEAR, and is run with multiple window lengths. The frequency precision and latency of the FFT method is analyzed in each configuration. A specialized frequency extraction technique, Delayed Comparison Error Minimization, is implemented with parameters optimized for the frequency range of interest. The performance metrics of latency and precision are analyzed and compared to the baseline rolling FFT method results, and applicability is discussed.
Experimental Study of Flexible Skin Designs Between a Moving Wing Segment and a Fixed Wing Part on a Full Scale Demonstrator
Authors: Radestock Martin , Riemenschneider Johannes , Falken Alexander , Achleitner Johannes 
Published: November 2020

Abstract
Commercial aircraft today require efficient high-lift and control systems on the wings to reduce the drag in flight or decrease the take-off and landing speeds. Morphing mechanisms are one approach for improved high-lift systems. In most cases the objective function is an increased lift to drag ratio or the noise reduction. On closer examination control systems as well as morphing mechanisms are located in a certain wing segment. The transition between a moving wing part and the fixed wing is a step, which creates additional vortices. This segments the wing in span-wise direction and reduces the efficiency. A flexible skin between a moving and a fixed wing parts smooths the contour and minimize the efficiency reduction of the wing. A full scale demonstrator of a wing segment was manufactured with two flexible skin designs.
The first subcomponent connects a morphing leading edge with a rib of the wing over a span of one meter. The skin is a material mix of ethylene-propylene-diene monomer (EPDM) rubber and fiberglass-reinforced plastic. The rubber is the basis of the skin and the glass-fiber is added as local skin stiffeners in the form of strips in chord-wise direction. The second subcomponent blends the aileron with a rib of the wing in a triangular design. The connection of three different hinges realizes a morphing triangle, which is loaded in an in-plane shear only state of stress in each aileron position. The core of the triangle is a 3D printed structure, which is free in shear. The covering skin is a combination of EPDM with carbon fibers oriented in +/−30° direction to obtain shear compliance and to resist the loads on the triangle.
The deformation of each concept is identified at the demonstrator. Therefore, an optical measurement system scans the surface in the initial and deflected state. The required deformation precision of the concepts differs due to their design. The contour at the leading edge requires a certain shape over the span. The analysis of the skin buckling is one requirement at the transition triangle during the aileron motion.
The experimental results show a smooth transition contour at the leading edge and no buckling effects at the triangle. The results can be used for the validation of simulation models. Furthermore, both skin concepts cover the gap between a moving wing segment and a fixed wing part. The elimination of steps in span-wise direction can improve the aero-acoustic behavior along the wing for future aircraft.
Sensor-Data Reconstruction for Helicopter Structural-Health Monitoring Using Deep Learning
Authors: Harper Andrew D. , Breen Nick , Alvord David , Pendleton David , Hresko Teresa 
Published: November 2020

Abstract
Predictive Maintenance (PMx) methods leverage available heritage data, maintenance records, and vehicle information to forecast rotorcraft failure modes before they become a problem. The goal of PMx is to decrease cost and vehicle downtime while increasing availability. When the required data are incomplete or corrupted, the worst case (grossly conservative) scenario must be assumed and unnecessary costs are incurred. In this manuscript we propose data-science methods to identify and characterize regions of data corruption, and machine-learning (ML) techniques to address the problem of missing and corrupted tri-axial H-60 4G accelerometer data for PMx for a H-60 rotorcraft. Accurate 4G sensor readings are a critical component of helicopter flight regime recognition and flight damage assessment. In contrast to the traditional time-series prediction approach, which commonly use recurrent or long short-term memory (LSTM) networks, our proposed methods use a simpler deep neural network (DNN) to reconstruct the 4G accelerometer signal independently at every time instant. We demonstrate that the DNN approach is a viable option for sensor reconstruction independent of the length of period the sensor malfunctions.
Design of Morphing Strips Using SMA Actuators Under Partial Phase Transformation Operation
Authors: Karakalas Anargyros A. , Machairas Theodoros T. , Lagoudas Dimitris C. , Saravanos Dimitris A. 
Published: November 2020

Abstract
Novel morphing structures show high potential in various engineering applications where shape adaptivity is deemed essential to achieve the optimum functionality under a wide range of operational conditions. Shape memory alloys have been selected as the main actuation elements in a large number of research projects. However, the successful design and realization of a morphing concept is highly dependent on the accuracy of the available modeling tools that provide essential information on the response of both the actuator itself and the whole structure. To this end, a three dimensional, thermodynamically consistent constitutive model that has been recently extended with a modified hardening function to account for partial transformation behavior is adopted to simulate SMA response. The design of a morphing strip system with a SMA ribbon actuator is presented and discussed, while its response is predicted when the effect of partial transformation is taken into account or omitted.
Design and Analysis of a Modular VTOL Drone With Bat-Inspired Wings
Authors: Anachkova Maja , Stankoski Marko , Berberu Mihael , Atanasov Aleksandar , Janevski Jane , Jovanova Jovana 
Published: November 2020

Abstract
The future of technology lies in the diverse characteristics and capabilities of autonomous machines and devices and their application in many technical challenge. Rapid technology development, market globalization and availability of affordable electronics and controllers, have recently resulted in increased scientific and technical interest in drones as autonomous solutions for professional, as well as, amateur applications. On the other hand, researchers have been improving how manmade machines move through air by attempting to replicate animals motion by mimicking their aerial abilities.
In this paper, we propose a development of a bio-inspired modular drone concept motivated by the bats agility, wingspan and wings folding into various shapes. The drone can be tailored for different applications, from sea port mapping, surveying, tank inspection and port traffic control to pollution monitoring and detection of illegal activities. The aerial performances of the drone allow it to be able to conduct windmills monitoring by connecting to their local monitoring units and send alerts to officials in real-time. This small bat-inspired drone is proposed to have an ability of performing flights with precisely defined trajectories. The accent will be put on the interchangeable wings, analysis of their dynamic attributes and transformation possibilities as a crucial segment of the overall drone performance. The design and fabrication process and the flight characteristics of the various wing configurations of the drone are discussed in details. Limitations of the drone, proposed solutions for further development and recommendations are also presented.
System Design and Implementation of a Transient-Motion-Powered IoT Sensor Node
Authors: Li Xin , Tang Hong , Liang Junrui 
Published: November 2020

Abstract
In this paper, we introduce ViPSN-E: a transient-motion-powered IoT sensor node. It carries out motion detection and wireless communication by making good use of the energy harvested from an instantaneous motion. In our design, a piezo-magneto-elastic structure, which is composed of a low-cost piezoelectric cantilever and a pair of magnets, is used to induce a plucking excitation and power generation under a transient and one-way movement. An energy management circuit, which is composed of a self-powered synchronized switch harvesting on inductor (SP-SSHI) interface circuit and a voltage regulator is utilized for efficient energy conversion. Through the sophisticated collaboration between mechatronic design and computer program, the motion information can also be identified and sent out by a wireless communication module. The cyber-electromechanical synergy among mechanical dynamics, power conditioning circuit, and the low-power embedded system is emphasized towards the successful implementation of such a motion-powered IoT device. The prototyped ViPSN-E has done a good job by making good use of the energy associated with each transient plucking motion. With only one plucking excitation, the system can realize motion detection and several rounds of wire-less transmission. The study on ViPSN-E provides valuable guidance towards the self-powered ubiquitous motion-sensing systems.
Sleep Hygiene and Light Exposure Can Improve Performance Following Long-Haul Air Travel
Authors: Fowler Peter M. , Knez Wade , Thornton Heidi R. , Sargent Charli , Mendham Amy E. , Crowcroft Stephen , Miller Joanna , Halson Shona , Duffield Rob 
Published: November 2020

Purpose: To assess the efficacy of a combined light exposure and sleep hygiene intervention to improve team-sport performance following eastward long-haul transmeridian travel. Methods: Twenty physically trained males underwent testing at 09:00 and 17:00 hours local time on 4 consecutive days at home (baseline) and the first 4 days following 21 hours of air travel east across 8 time zones. In a randomized, matched-pairs design, participants traveled with (INT; n = 10) or without (CON; n = 10) a light exposure and sleep hygiene intervention. Performance was assessed via countermovement jump, 20-m sprint, T test, and Yo-Yo Intermittent Recovery Level 1 tests, together with perceptual measures of jet lag, fatigue, mood, and motivation. Sleep was measured using wrist activity monitors in conjunction with self-report diaries. Results: Magnitude-based inference and standardized effect-size analysis indicated there was a very likely improvement in the mean change in countermovement jump peak power (effect size 1.10, ±0.55), and likely improvement in 5-m (0.54, ±0.67) and 20-m (0.74, ±0.71) sprint time in INT compared with CON across the 4 days posttravel. Sleep duration was most likely greater in INT both during travel (1.61, ±0.82) and across the 4 nights following travel (1.28, ±0.58) compared with CON. Finally, perceived mood and motivation were likely worse (0.73, ±0.88 and 0.63, ±0.87) across the 4 days posttravel in CON compared with INT. Conclusions: Combined light exposure and sleep hygiene improved speed and power but not intermittent-sprint performance up to 96 hours following long-haul transmeridian travel. The reduction of sleep disruption during and following travel is a likely contributor to improved performance.
Effect of a financial incentive (shopping point) on increasing the number of daily walking steps among community-dwelling adults in Japan: a randomised controlled trial
Authors: Tanji Fumiya , Tomata Yasutake , Abe Saho , Matsuyama Sanae , Kotaki Yumika , Nurrika Dieta , Matsumoto Koichi , Liu Yingxu , Zhang Shu , Lu Yukai , Sugawara Yumi , Bando Shino , Yamazaki Teiichiro , Otsuka Tatsui , Sone Toshimasa , Tsuji Ichiro 
Published: November 2020

ObjectiveThe aim of this study was to investigate the effect of a financial incentive on the number of daily walking steps among community-dwelling adults in Japan.Study designTwo-arm, parallel-group randomised controlled trial.Setting/participantsWe recruited physically inactive community-dwelling adults from Sendai city, Japan. Eligible participants were randomly allocated to an intervention or a wait list control group. Pedometers were used to assess the mean number of daily steps in three periods: baseline (weeks 1–3), intervention (weeks 4–6) and follow-up (weeks 7–9).InterventionThe intervention group was offered a financial incentive (shopping points) to meet the target number of increased daily steps in the intervention period.Main outcome measuresThe primary outcome was an increase in the mean number of daily steps in the intervention and follow-up periods compared with baseline.ResultsSeventy-two participants (69.4% women; mean age, 61.2±16.2 years; mean number of daily steps at baseline, 6364±2804) were randomised to the intervention (n=36) and control groups (n=36). During the intervention period, the increase in mean daily steps was significantly higher in the intervention group (1650, 95% CI=1182 to 2119) than in the control group (514, 95% CI=136 to 891; p<0.001). However, the difference between groups was not significant at follow-up after the incentives were removed (p=0.311). In addition, compared with controls, a significantly higher proportion of participants in the intervention group showed an increase in mean daily steps of ≥1000 (69.4% vs 30.6%, respectively; OR=5.17, 95% CI=1.89 to 14.08). There were no adverse effects from the intervention.ConclusionsThe present results suggest that financial incentives are effective in promoting short-term increases in physical activity.Trial registration numberUMIN000033276.