bluuebunny/crossref_metadata_2025 huggingface dataset:
Some New Contributions on the Marshall–Olkin Length Biased Lomax Distribution: Theory, Modelling and Data Analysis
Authors: Mathew Jismi , Chesneau Christophe
Published: December 2020

The Lomax distribution is arguably one of the most useful lifetime distributions, explaining the developments of its extensions or generalizations through various schemes. The Marshall–Olkin length-biased Lomax distribution is one of these extensions. The associated model has been used in the frameworks of data fitting and reliability tests with success. However, the theory behind this distribution is non-existent and the results obtained on the fit of data were sufficiently encouraging to warrant further exploration, with broader comparisons with existing models. This study contributes in these directions. Our theoretical contributions on the the Marshall–Olkin length-biased Lomax distribution include an original compounding property, various stochastic ordering results, equivalences of the main functions at the boundaries, a new quantile analysis, the expressions of the incomplete moments under the form of a series expansion and the determination of the stress–strength parameter in a particular case. Subsequently, we contribute to the applicability of the Marshall–Olkin length-biased Lomax model. When combined with the maximum likelihood approach, the model is very effective. We confirm this claim through a complete simulation study. Then, four selected real life data sets were analyzed to illustrate the importance and flexibility of the model. Especially, based on well-established standard statistical criteria, we show that it outperforms six strong competitors, including some extended Lomax models, when applied to these data sets. To our knowledge, such comprehensive applied work has never been carried out for this model.
Antimicrobial Peptide Arenicin-1 Derivative Ar-1-(C/A) as Complement System Modulator
Authors: Krenev Ilia A. , Umnyakova Ekaterina S. , Eliseev Igor E. , Dubrovskii Yaroslav A. , Gorbunov Nikolay P. , Pozolotin Vladislav A. , Komlev Alexei S. , Panteleev Pavel V. , Balandin Sergey V. , Ovchinnikova Tatiana V. , Shamova Olga V. , Berlov Mikhail N.
Published: December 2020

Antimicrobial peptides (AMPs) are not only cytotoxic towards host pathogens or cancer cells but also are able to act as immunomodulators. It was shown that some human and non-human AMPs can interact with complement proteins and thereby modulate complement activity. Thus, AMPs could be considered as the base for complement-targeted therapeutics development. Arenicins from the sea polychaete Arenicola marina, the classical example of peptides with a β-hairpin structure stabilized by a disulfide bond, were shown earlier to be among the most prospective regulators. Here, we investigate the link between arenicins’ structure and their antimicrobial, hemolytic and complement-modulating activities using the derivative Ar-1-(C/A) without a disulfide bond. Despite the absence of this bond, the peptide retains all important functional activities and also appears less hemolytic in comparison with the natural forms. These findings could help to investigate new complement drugs for regulation using arenicin derivatives.
The Acid–Base Flow Battery: Sustainable Energy Storage via Reversible Water Dissociation with Bipolar Membranes
Authors: Pärnamäe Ragne , Gurreri Luigi , Post Jan , van Egmond Willem Johannes , Culcasi Andrea , Saakes Michel , Cen Jiajun , Goosen Emil , Tamburini Alessandro , Vermaas David A. , Tedesco Michele
Published: December 2020

The increasing share of renewables in electric grids nowadays causes a growing daily and seasonal mismatch between electricity generation and demand. In this regard, novel energy storage systems need to be developed, to allow large-scale storage of the excess electricity during low-demand time, and its distribution during peak demand time. Acid–base flow battery (ABFB) is a novel and environmentally friendly technology based on the reversible water dissociation by bipolar membranes, and it stores electricity in the form of chemical energy in acid and base solutions. The technology has already been demonstrated at the laboratory scale, and the experimental testing of the first 1 kW pilot plant is currently ongoing. This work aims to describe the current development and the perspectives of the ABFB technology. In particular, we discuss the main technical challenges related to the development of battery components (membranes, electrolyte solutions, and stack design), as well as simulated scenarios, to demonstrate the technology at the kW–MW scale. Finally, we present an economic analysis for a first 100 kW commercial unit and suggest future directions for further technology scale-up and commercial deployment.
General Research on the Process of the Indirect Hot Stamping Ultra-High-Strength Steel
Authors: Tang Ziming , Gu Zhengwei , Li Xin , Zhu Lijuan , Xu Hong , Yu Ge
Published: December 2020

Aiming at the need for lightweight requirements of the components in the bus, combined with the advantages of the hot stamping ultra-high-strength steel, a new television (TV) bracket was proposed. The finite element (FE) simulation of the beam part in the TV bracket during the indirect hot stamping process was discussed. After two-stages of pre-forming, the blank was in good formability and without visible cracks. According to the FE simulation results, the punch speed, quenching force, and quenching time significantly affected the temperature, microstructure, hardness, and mechanical properties of the beam part during hot stamping. With the increase of the quenching force and quenching time, the martensite fraction of the beam part was increased. For the beam part, the punch speed should be at least 80 mm/s during the forming stage. For complete quenching, the quenching force should be above 1000 kN and quenching time should be up to 10 s. Based on the parameters from the FE simulation, the forming experiment of the beam part was discussed. Microstructure analyses and microhardness tests as well as tensile tests of the hot stamping beam part were performed. The results confirmed that the FE simulation of the beam part was reliable.
Antibacterial Multi-Layered Nanocellulose-Based Patches Loaded with Dexpanthenol for Wound Healing Applications
Authors: Fonseca Daniela F. S. , Carvalho João P. F. , Bastos Verónica , Oliveira Helena , Moreirinha Catarina , Almeida Adelaide , Silvestre Armando J. D. , Vilela Carla , Freire Carmen S. R.
Published: December 2020

Antibacterial multi-layered patches composed of an oxidized bacterial cellulose (OBC) membrane loaded with dexpanthenol (DEX) and coated with several chitosan (CH) and alginate (ALG) layers were fabricated by spin-assisted layer-by-layer (LbL) assembly. Four patches with a distinct number of layers (5, 11, 17, and 21) were prepared. These nanostructured multi-layered patches reveal a thermal stability up to 200 °C, high mechanical performance (Young’s modulus ≥ 4 GPa), and good moisture-uptake capacity (240–250%). Moreover, they inhibited the growth of the skin pathogen Staphylococcus aureus (3.2–log CFU mL−1 reduction) and were non-cytotoxic to human keratinocytes (HaCaT cells). The in vitro release profile of DEX was prolonged with the increasing number of layers, and the time-dependent data imply a diffusion/swelling-controlled drug release mechanism. In addition, the in vitro wound healing assay demonstrated a good cell migration capacity, headed to a complete gap closure after 24 h. These results certify the potential of these multi-layered polysaccharides-based patches toward their application in wound healing.
Incorporation of NiO into SiO2, TiO2, Al2O3, and Na4.2Ca2.8(Si6O18) Matrices: Medium Effect on the Optical Properties and Catalytic Degradation of Methylene Blue
Authors: Diaz Carlos , Valenzuela María L. , Cifuentes-Vaca Olga , Segovia Marjorie , Laguna-Bercero Miguel A.
Published: December 2020

The medium effect of the optical and catalytic degradation of methylene blue was studied in the NiO/SiO2, NiO/TiO2, NiO/Al2O3, and NiO/Na4.2Ca2.8(Si6O18) composites, which were prepared by a solid-state method. The new composites were characterized by XRD (X-ray diffraction of powder), SEM/EDS, TEM, and HR-TEM. The size of the NiO nanoparticles obtained from the PSP-4-PVP (polyvinylpyrrolidone) precursors inside the different matrices follow the order of SiO2 > TiO2 > Al2O3. However, NiO nanoparticles obtained from the chitosan precursor does not present an effect on the particle size. It was found that the medium effect of the matrices (SiO2, TiO2, Al2O3, and Na4.2Ca2.8(Si6O18)) on the photocatalytic methylene blue degradation, can be described as a specific interaction of the NiO material acting as a semiconductor with the MxOy materials through a possible p-n junction. The highest catalytic activity was found for the TiO2 and glass composites where a favorable p-n junction was formed. The isolating character of Al2O3 and SiO2 and their non-semiconductor behavior preclude this interaction to form a p-n junction, and thus a lower catalytic activity. NiO/SiO2 and NiO/Na4.2Ca2.8(Si6O18) showed a similar photocatalytic behavior. On the other hand, the effect of the matrix on the optical properties for the NiO/SiO2, NiO/TiO2, NiO/Al2O3, and NiO/Na4.2Ca2.8(Si6O18) composites can be described by the different dielectric constants of the SiO2, TiO2, Al2O3, Na4.2Ca2.8(Si6O18) matrices. The maxima absorption of the composites (λmax) exhibit a direct relationship with the dielectric constants, while their semiconductor bandgap (Eg) present an inverse relationship with the dielectric constants. A direct relationship between λmax and Eg was found from these correlations. The effect of the polymer precursor on the particle size can explain some deviations from this relationship, as the correlation between the particle size and absorption is well known. Finally, the NiO/Na4.2Ca2.8(Si6O18) composite was reported in this work for the first time.
Selenium and Coenzyme Q10 Supplementation Improves Renal Function in Elderly Deficient in Selenium: Observational Results and Results from a Subgroup Analysis of a Prospective Randomised Double-Blind Placebo-Controlled Trial
Authors: Alehagen Urban , Aaseth Jan , Alexander Jan , Brismar Kerstin , Larsson Anders
Published: December 2020

A low selenium intake is found in European countries, and is associated with increased cardiovascular mortality. There is an association between selenium level and the severity of kidney disease. An association between inflammation and selenium intake is also reported. The coenzyme Q10 level is decreased in kidney disease. The aim of this study was to examine a possible association between selenium and renal function in an elderly population low in selenium and coenzyme Q10, and the impact of intervention with selenium and coenzyme Q10 on the renal function. The association between selenium status and creatinine was studied in 589 elderly persons. In 215 of these (mean age 71 years) a randomised double-blind placebo-controlled prospective trial with selenium yeast (200 µg/day) and coenzyme Q10 (200 mg/day) (n = 117) or placebo (n = 98) was conducted. Renal function was determined using measures of glomerular function at the start and after 48 months. The follow-up time was 5.1 years. All individuals were low on selenium (mean 67 μg/L (SD 16.8)). The changes in renal function were evaluated by measurement of creatinine, cystatin-C, and the use of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) algorithm, and by the use of T-tests, repeated measures of variance and ANCOVA analyses. An association between low selenium status and impaired renal function was observed. Intervention causes a significantly lower serum creatinine, and cystatin-C concentration in the active treatment group compared with those on placebo (p = 0.0002 and p = 0.001 resp.). The evaluation with CKD-EPI based on both creatinine and cystatin-C showed a corresponding significant difference (p < 0.0001). All validations showed corresponding significant differences. In individuals with a deficiency of selenium and coenzyme Q10, low selenium status is related to impaired renal function, and thus supplementation with selenium and coenzyme Q10 results in significantly improved renal function as seen from creatinine and cystatin-C and through the CKD-EPI algorithm. The explanation could be related to positive effects on inflammation and oxidative stress as a result of the supplementation.
Courses Preferences and Occupational Aspirations of Students in Australian Islamic Schools
Authors: Nathie Mahmood , Abdalla Mohamad
Published: December 2020

Course selection by year 11 and 12 students exert a significant influence on occupational outcomes of young people. While many studies have been conducted by the Australian Council for Educational Research (ACER) across a broad spectrum of schools, not much is known about this aspect in relation to Islamic School students. In this research, data was collected on student course choice from nine randomly selected Islamic schools across Australia. For the first time, the results reveal the most prevalent course clusters studied by students are Science, Technology, Engineering and Mathematics (STEM) aligned courses. Mathematics and sciences followed by legal and business studies sit at the peak of the course hierarchy. Long-held views and anecdotal evidence that suggest Arabic and Islamic Studies feature prominently in course selection proved to be unfounded. Preference for these courses are shown to be very low. Vocational Education & Training (VET) courses do not feature prominently in Islamic school curriculums to the disadvantage of students who may wish to pursue non-academic careers instead of opting for university inspired career paths. Professionally, medicine, engineering, law and business (in that order) are the most preferred occupations. We also find a conspicuous gender-based difference regarding course selection and occupational aspirations.
Snow and Ice Thickness Retrievals Using GNSS-R: Preliminary Results of the MOSAiC Experiment
Authors: Munoz-Martin Joan Francesc , Perez Adrian , Camps Adriano , Ribó Serni , Cardellach Estel , Stroeve Julienne , Nandan Vishnu , Itkin Polona , Tonboe Rasmus , Hendricks Stefan , Huntemann Marcus , Spreen Gunnar , Pastena Massimiliano
Published: December 2020

The FSSCat mission was the 2017 ESA Sentinel Small Satellite (S⌃3) Challenge winner and the Copernicus Masters competition overall winner. It was successfully launched on 3 September 2020 onboard the VEGA SSMS PoC (VV16). FSSCat aims to provide coarse and downscaled soil moisture data and over polar regions, sea ice cover, and coarse resolution ice thickness using a combined L-band microwave radiometer and GNSS-Reflectometry payload. As part of the calibration and validation activities of FSSCat, a GNSS-R instrument was deployed as part of the MOSAiC polar expedition. The Multidisciplinary drifting Observatory for the Study of Arctic Climate expedition was an international one-year-long field experiment led by the Alfred Wegener Institute to study the climate system and the impact of climate change in the Arctic Ocean. This paper presents the first results of the PYCARO-2 instrument, focused on the GNSS-R techniques used to measure snow and ice thickness of an ice floe. The Interference Pattern produced by the combination of the GNSS direct and reflected signals over the sea-ice has been modeled using a four-layer model. The different thicknesses of the substrate layers (i.e., snow and ice) are linked to the position of the fringes of the interference pattern. Data collected by MOSAiC GNSS-R instrument between December 2019 and January 2020 for different GNSS constellations and frequencies are presented and analyzed, showing that under general conditions, sea ice and snow thickness can be retrieved using multiangular and multifrequency data.
An Assessment of High-Density UAV Point Clouds for the Measurement of Young Forestry Trials
Authors: Hartley Robin J. L. , Leonardo Ellen Mae , Massam Peter , Watt Michael S. , Estarija Honey Jane , Wright Liam , Melia Nathanael , Pearse Grant D.
Published: December 2020

The measurement of forestry trials is a costly and time-consuming process. Over the past few years, unmanned aerial vehicles (UAVs) have provided some significant developments that could improve cost and time efficiencies. However, little research has examined the accuracies of these technologies for measuring young trees. This study compared the data captured by a UAV laser scanning system (ULS), and UAV structure from motion photogrammetry (SfM), with traditional field-measured heights in a series of forestry trials in the central North Island of New Zealand. Data were captured from UAVs, and then processed into point clouds, from which heights were derived and compared to field measurements. The results show that predictions from both ULS and SfM were very strongly correlated to tree heights (R2 = 0.99, RMSE = 5.91%, and R2 = 0.94, RMSE = 18.5%, respectively) but that the height underprediction was markedly lower for ULS than SfM (Mean Bias Error = 0.05 vs. 0.38 m). Integration of a ULS DTM to the SfM made a minor improvement in precision (R2 = 0.95, RMSE = 16.5%). Through plotting error against tree height, we identified a minimum threshold of 1 m, under which the accuracy of height measurements using ULS and SfM significantly declines. Our results show that SfM and ULS data collected from UAV remote sensing can be used to accurately measure height in young forestry trials. It is hoped that this study will give foresters and tree breeders the confidence to start to operationalise this technology for monitoring trials.
Device for Contact Measurement of Turbine Blade Geometry in Robotic Grinding Process
Authors: Szybicki Dariusz , Burghardt Andrzej , Kurc Krzysztof , Gierlak Piotr
Published: December 2020

The article discusses the design, implementation, and testing of the accuracy of a measuring device used to measure the thickness of aircraft engine blades subjected to a robotic grinding process. The assumptions that the measuring device should meet were presented. The manufactured device was subjected to accuracy and repeatability tests using a standard workpiece. The analysis of research results proved that the measuring device exhibits an accuracy of one order of magnitude better than the accuracy required for blades. For control of the grinding process, the results should be perceived as appropriate. Then, the device was subjected to verification consisting in using it to measure the thickness of aircraft engine blades. The constructed device can be used, not only for inspection of final products, but also for control of the robotic grinding process because thanks to the output interface it can be used in the robotic station’s feedback loop.
Quality Assessment of a Manufactured Bell Using a 3D Scanning Process
Authors: Cekus Dawid , Kwiatoń Paweł , Nadolski Maciej , Sokół Krzysztof
Published: December 2020

Bells as percussion instruments have been known to humanity for ages. The casting process, the shape and the materials have changed over the years. The functional properties of bells depend on the casting quality and the generated sound. The casting quality is related to the shape, material and technology. The acoustic quality must fulfill specific parameters. This work concerns the assessment of the quality of the manufactured bells and the possibility of replacing tin bronze with a material with similar mechanical properties. Therefore, bell bronze—which is dedicated to this type of work—and aluminum bronze—which is characterized by high strength and hardness, have been applied to casting. The laser scanning technique was used to assess the quality of castings. Based on a point cloud, an optimized mesh was generated from which the 3D model was finally created. On the basis of the CAD model, the defects resulting from the casting process were determined in the form of graphical comparison. The correctness of the selected foundry shrinkage of the selected material was also determined. The manufactured bells were also assessed for sound quality. Vibration frequencies were determined using a vibration analyzer and free software Wavanal. The experimental results were compared with the ones obtained from the numerical frequency analysis. With the help of tests, the quality of the bells was assessed, and it was determined whether aluminum bronze meets the acoustic criteria. The presented method can be used in the development of bell templates. These templates will allow the bell to obtain the correct shape and acoustic quality without the need for a tuning process.
Self-Abrading Servo Electrode Helmet for Electrical Impedance Tomography
Authors: Avery James , Packham Brett , Koo Hwan , Hanson Ben , Holder David
Published: December 2020

Electrical Impedance Tomography (EIT) is a medical imaging technique which has the potential to reduce time to treatment in acute stroke by rapidly differentiating between ischaemic and haemorrhagic stroke. The potential of these methods has been demonstrated in simulation and phantoms, it has not yet successfully translated to clinical studies, due to high sensitivity to errors in scalp electrode mislocation and poor electrode-skin contact. To overcome these limitations, a novel electrode helmet was designed, bearing 32 independently controlled self-abrading electrodes. The contact impedance was reduced through rotation on an abrasive electrode on the scalp using a combined impedance, rotation and position feedback loop. Potentiometers within each unit measure the electrode tip displacement within 0.1 mm from the rigid helmet body. Characterisation experiments on a large-scale test rig demonstrated that approximately 20 kPa applied pressure and 5 rotations was necessary to achieve the target 5 kΩ contact impedance at 20 Hz. This performance was then replicated in a simplified self-contained unit where spring loaded electrodes are rotated by servo motors. Finally, a 32-channel helmet and controller which sequentially minimised contact impedance and simultaneously located each electrode was built which reduced the electrode application and localisation time to less than five minutes. The results demonstrated the potential of this approach to rapidly apply electrodes in an acute setting, removing a significant barrier for imaging acute stroke with EIT.
Semantic Segmentation of Intralobular and Extralobular Tissue from Liver Scaffold H&E Images
Authors: Jirik Miroslav , Gruber Ivan , Moulisova Vladimira , Schindler Claudia , Cervenkova Lenka , Palek Richard , Rosendorf Jachym , Arlt Janine , Bolek Lukas , Dejmek Jiri , Dahmen Uta , Zelezny Milos , Liska Vaclav
Published: December 2020

Decellularized tissue is an important source for biological tissue engineering. Evaluation of the quality of decellularized tissue is performed using scanned images of hematoxylin-eosin stained (H&E) tissue sections and is usually dependent on the observer. The first step in creating a tool for the assessment of the quality of the liver scaffold without observer bias is the automatic segmentation of the whole slide image into three classes: the background, intralobular area, and extralobular area. Such segmentation enables to perform the texture analysis in the intralobular area of the liver scaffold, which is crucial part in the recellularization procedure. Existing semi-automatic methods for general segmentation (i.e., thresholding, watershed, etc.) do not meet the quality requirements. Moreover, there are no methods available to solve this task automatically. Given the low amount of training data, we proposed a two-stage method. The first stage is based on classification of simple hand-crafted descriptors of the pixels and their neighborhoods. This method is trained on partially annotated data. Its outputs are used for training of the second-stage approach, which is based on a convolutional neural network (CNN). Our architecture inspired by U-Net reaches very promising results, despite a very low amount of the training data. We provide qualitative and quantitative data for both stages. With the best training setup, we reach 90.70% recognition accuracy.
Design of a High-Sensitivity Microstrip Patch Sensor Antenna Loaded with a Defected Ground Structure Based on a Complementary Split Ring Resonator
Authors: Yeo Junho , Lee Jong-Ig
Published: December 2020

A comparative study to determine the most highly sensitive resonant frequency among the first four resonant frequencies of a conventional patch antenna and defected ground structure (DGS)-loaded patch antennas using commonly used DGS geometries in the literature, such as a rectangular slit, single-ring complementary split ring resonators (CSRRs) with different split positions, and double-ring CSRRs (DR-CSRRs) with different locations below the patch, for relative permittivity measurement of planar materials was conducted. The sensitivity performance for placing the DGS on two different locations, a center and a radiating edge of the patch, was also compared. Finally, the effect of scaling down the patch size of the DGS-loaded patch antenna was investigated in order to enhance the sensitivities of the higher order resonant frequencies. It was found that the second resonant frequency of the DR-CSRR DGS-loaded patch antenna aligned on a radiating edge with a half scaled-down patch size shows the highest sensitivity when varying the relative permittivity of the material under test from 1 to 10. In order to validate the simulated performance of the proposed antenna, the conventional and the proposed patch antennas were fabricated on 0.76-mm-thick RF-35 substrate, and they were used to measure their sensitivity when several standard dielectric substrate samples with dielectric constants ranging from 2.17 to 10.2 were loaded. The measured sensitivity of the second resonant frequency for the proposed DGS-loaded patch antenna was 4.91 to 7.72 times higher than the first resonant frequency of the conventional patch antenna, and the measured performance is also slightly better compared to the patch antenna loaded with a meander-line slot on the patch.
Damage Identification in Plate Structures Using Sparse Regularization Based Electromechanical Impedance Technique
Authors: Fan Xingyu , Li Jun
Published: December 2020

This paper proposes a novel structural damage quantification approach using a sparse regularization based electromechanical impedance (EMI) technique. Minor structural damage in plate structures by using the measurement of only a single surface bonded lead zirconate titanate piezoelectric (PZT) transducer was quantified. To overcome the limitations of using model-based EMI based methods in damage detection of complex or relatively large-scale structures, a three-dimensional finite element model for simulating the PZT–structure interaction is developed and calibrated with experimental results. Based on the sensitivities of the resonance frequency shifts of the impedance responses with respect to the physical parameters of plate structures, sparse regularization was applied to conduct the undetermined inverse identification of structural damage. The difference between the measured and analytically obtained impedance responses was calculated and used for identification. In this study, only a limited number of the resonance frequency shifts were obtained from the selected frequency range for damage identification of plate structures with numerous elements. The results demonstrate a better performance than those from the conventional Tikhonov regularization based methods in conducting inverse identification for damage quantification. Experimental studies on an aluminum plate were conducted to investigate the effectiveness and accuracy of the proposed approach. To test the robustness of the proposed approach, the identification results of a plate structure under varying temperature conditions are also presented.
Sky Monitoring System for Flying Object Detection Using 4K Resolution Camera
Authors: Kashiyama Takehiro , Sobue Hideaki , Sekimoto Yoshihide
Published: December 2020

The use of drones and other unmanned aerial vehicles has expanded rapidly in recent years. These devices are expected to enter practical use in various fields, such as taking measurements through aerial photography and transporting small and lightweight objects. Simultaneously, concerns over these devices being misused for terrorism or other criminal activities have increased. In response, several sensor systems have been developed to monitor drone flights. In particular, with the recent progress of deep neural network technology, the monitoring of systems using image processing has been proposed. This study developed a monitoring system for flying objects using a 4K camera and a state-of-the-art convolutional neural network model to achieve real-time processing. We installed a monitoring system in a high-rise building in an urban area during this study and evaluated the precision with which it could detect flying objects at different distances under different weather conditions. The results obtained provide important information for determining the accuracy of monitoring systems with image processing in practice.
Assessing the Performance of RGB-D Sensors for 3D Fruit Crop Canopy Characterization under Different Operating and Lighting Conditions
Authors: Gené-Mola Jordi , Llorens Jordi , Rosell-Polo Joan R. , Gregorio Eduard , Arnó Jaume , Solanelles Francesc , Martínez-Casasnovas José A. , Escolà Alexandre
Published: December 2020

The use of 3D sensors combined with appropriate data processing and analysis has provided tools to optimise agricultural management through the application of precision agriculture. The recent development of low-cost RGB-Depth cameras has presented an opportunity to introduce 3D sensors into the agricultural community. However, due to the sensitivity of these sensors to highly illuminated environments, it is necessary to know under which conditions RGB-D sensors are capable of operating. This work presents a methodology to evaluate the performance of RGB-D sensors under different lighting and distance conditions, considering both geometrical and spectral (colour and NIR) features. The methodology was applied to evaluate the performance of the Microsoft Kinect v2 sensor in an apple orchard. The results show that sensor resolution and precision decreased significantly under middle to high ambient illuminance (>2000 lx). However, this effect was minimised when measurements were conducted closer to the target. In contrast, illuminance levels below 50 lx affected the quality of colour data and may require the use of artificial lighting. The methodology was useful for characterizing sensor performance throughout the full range of ambient conditions in commercial orchards. Although Kinect v2 was originally developed for indoor conditions, it performed well under a range of outdoor conditions.
Autodyne Sensor Signals with Amplitude-Frequency Modulation of Radiation
Authors: Noskov Vladislav , Galeev Rinat , Bogatyrev Evgeniy , Ignatkov Kirill , Shaidurov Kirill
Published: December 2020

A mathematical model of an autodyne oscillator with a combined amplitude-frequency modulation, which is under the influence of its own radiation reflected from the target, is developed. The main relations are obtained for analyzing the autodyne response of a single-circuit oscillator depending on the delay time of the radiation reflected from the target with an arbitrary law of simultaneous amplitude and frequency modulation. The characteristics of the amplitude selection of signals, as well as their temporal and spectral characteristics, are calculated for harmonic amplitude-frequency modulation. The features of signal formation are established for various values of the amplitude and frequency modulation parameters and the feedback parameter of the “oscillator—target” autoparametric system. The results of experimental studies, performed on a Tigel-0.8M hybrid-integrated Ka-band oscillator module with a Gann mesa-planar diode, confirmed the findings of the theoretical analysis.
Position Estimator Design for a MEMS Top-Drive Electrostatic Rotary Actuator
Authors: Woo Jemin , Hahn Bongsu , Ahn Changsun
Published: December 2020

The capacitance and rotor angle of a MEMS top-drive electrostatic rotary actuator do not have a linear relationship due to the non-ignorable fringe effect and low aspect ratio of the electrodes. Therefore, the position estimation is not as straightforward as that for a comb-drive linear actuator or a side-drive rotary actuator. The reason is that the capacitance is a nonlinear and periodic function of the rotor angle and is affected by the three-phase input voltages. Therefore, it cannot be approximated as a simple two-plate capacitor. Sensing the capacitance between a rotor and a stator is another challenge. The capacitance can be measured in the electrodes (stators), but the electrodes also have to perform actuation, so a method is needed to combine actuation and sensing. In this study, a nonlinear capacitance model was derived as a data-driven model that effectively represents the nonlinear capacitance with sufficient accuracy. To measure the capacitance accurately, the stator parts for actuation and those for sensing are separated. Using the nonlinear model and the capacitance measurement, an unscented Kalman filter was designed to mitigate the large estimation error due to the periodic nonlinearity. The proposed method shows stable and accurate estimation that cannot be achieved with a simple two-plate capacitor model. The proposed approach can be applied to a similar system with highly nonlinear capacitance.
IceSense Proof of Concept: Calibrating an Instrumented Figure Skating Blade to Measure On-Ice Forces
Authors: Ridge Sarah , Bruening Dustin , Charles Steven , Stahl Cody , Smith Daniel , Reynolds Riley , Adamo Brandon , Harper Blake , Adair Chris , Manwaring Preston , King Deborah
Published: December 2020

Competitive figure skaters often suffer from overuse injuries, which may be due to the high impact forces endured during jump repetitions performed in practice and competition. However, to date, forces during on-ice figure skating have not been quantified due to technological limitations. The purpose of this study was to determine the optimal calibration procedure for a previously developed instrumented figure skating blade (IceSense). Initial calibration was performed by collecting data from the blade while 11 skaters performed off-ice jumps, landing on a force plate in the lab. However, mean peak force measurements from the blade were greater than the desired error threshold of ±10%. Therefore, we designed a series of controlled experiments which included measuring forces from a load cell rigidly attached to the top of the blade concurrently with strain data from the strain gauges on the blade. Forces were applied to the blade by adding weight to a drop tower or by manually applying force in a quasi-static manner. Both methods showed similar accuracy, though using the drop tower allowed precise standardization. Therefore, calibration was performed using the weighted drop method. This calibration was applied to strain gauge data from out-of-sample drop trials, resulting in acceptable estimates of peak force (less than 10% error). Using this calibration, we collected data on one figure skater and present results from an exemplar on-ice double flip jump. Using the IceSense device to quantify on-ice forces in a research setting may help inform training, technique, and equipment design.
Hybrid Method of Automated EEG Signals’ Selection Using Reversed Correlation Algorithm for Improved Classification of Emotions
Authors: Wosiak Agnieszka , Dura Aleksandra
Published: December 2020

Based on the growing interest in encephalography to enhance human–computer interaction (HCI) and develop brain–computer interfaces (BCIs) for control and monitoring applications, efficient information retrieval from EEG sensors is of great importance. It is difficult due to noise from the internal and external artifacts and physiological interferences. The enhancement of the EEG-based emotion recognition processes can be achieved by selecting features that should be taken into account in further analysis. Therefore, the automatic feature selection of EEG signals is an important research area. We propose a multistep hybrid approach incorporating the Reversed Correlation Algorithm for automated frequency band—electrode combinations selection. Our method is simple to use and significantly reduces the number of sensors to only three channels. The proposed method has been verified by experiments performed on the DEAP dataset. The obtained effects have been evaluated regarding the accuracy of two emotions—valence and arousal. In comparison to other research studies, our method achieved classification results that were 4.20–8.44% greater. Moreover, it can be perceived as a universal EEG signal classification technique, as it belongs to unsupervised methods.
Modeling and Design of a Rear-Mounted Underwater Projector Using Equivalent Circuits
Authors: Kim Jinwook , Roh Yongrae
Published: December 2020

Tonpilz is a popular transducer for underwater projector arrays for sonar systems. For low-frequency transmission, a larger axial dimension of the conventional Tonpilz transducer is required. However, a bulky and heavy Tonpilz element is not suitable due to limitations in terms of the space and payload of the array platform. To address this problem, we developed a rear-mounted Tonpilz transducer to generate a sub-fundamental resonance in addition to the common longitudinal resonance. For this purpose, we developed a new equivalent circuit model that can reflect all the effects of the key design parameters of the transducer, such as suspension thickness (stiffness), tail mass thickness, and head mass thickness. The impedance and transmitting voltage response were evaluated as performance factors at both resonance frequencies. The validity of the circuit was verified by comparing the analysis results with those from the finite element analysis of the same transducer. Based on the results, the transducer structure was designed to have comparable transmitting performance at both resonance frequencies by employing relatively high suspension stiffness, light tail mass, and heavy head mass. The novel design can permit the dual-band operation of the transducer so that the transducer can operate as a wideband projector.
Comparing Equation-Based and Agent-Based Data Generation Methods for Early Warning Signal Analysis
Authors: Reisinger Daniel , Füllsack Manfred
Published: December 2020

Dynamical systems are known to exhibit sudden state transitions, with abrupt shifts from one stable state to another. Such transitions are widely observed, with examples ranging from abrupt extinctions of species in ecosystems to unexpected financial crises in the economy or sudden changes in medical conditions. Statistical methods known as early warning signals (EWSs) are used to predict these transitions. In most studies to date, EWSs have been tested on data generated using equation-based methods that represent a system’s aggregate state and thus show limitations in considering the interactions of a system at the component level. Agent-based models offer an alternative without these limitations. This study compares the performance of EWSs when applied to data from an equation-based and from an agent-based version of the Ising model. The results provide a reason to consider agent-based modelling a promising complementary method for investigating the predictability of state changes with EWSs.
An Evaluation of Programmatic Community-Based Chest X-ray Screening for Tuberculosis in Ho Chi Minh City, Vietnam
Authors: Nguyen Lan Huu , Codlin Andrew J. , Vo Luan Nguyen Quang , Dao Thang , Tran Duc , Forse Rachel J. , Vu Thanh Nguyen , Le Giang Truong , Luu Tuan , Do Giang Chau , Truong Vinh Van , Minh Ha Dang Thi , Nguyen Hung Huu , Creswell Jacob , Caws Maxine , Nguyen Hoa Binh , Nguyen Nhung Viet
Published: December 2020

Across Asia, a large proportion of people with tuberculosis (TB) do not report symptoms, have mild symptoms or only experience symptoms for a short duration. These individuals may not seek care at health facilities or may be missed by symptom screening, resulting in sustained TB transmission in the community. We evaluated the yields of TB from 114 days of community-based, mobile chest X-ray (CXR) screening. The yields at each step of the TB screening cascade were tabulated and we compared cohorts of participants who reported having a prolonged cough and those reporting no cough or one of short duration. We estimated the marginal yields of TB using different diagnostic algorithms and calculated the relative diagnostic costs and cost per case for each algorithm. A total of 34,529 participants were screened by CXR, detecting 256 people with Xpert-positive TB. Only 50% of those diagnosed with TB were detected among participants reporting a prolonged cough. The study’s screening algorithm detected almost 4 times as much TB as the National TB Program’s standard diagnostic algorithm. Community-based, mobile chest X-ray screening can be a high yielding strategy which is able to identify people with TB who would likely otherwise have been missed by existing health services.
Evaluating a Technology-Mediated HPV Vaccination Awareness Intervention: A Controlled, Quasi-Experimental, Mixed Methods Study
Authors: Brandt Heather M. , Sundstrom Beth , Monroe Courtney M. , Turner-McGrievy Gabrielle , Larsen Chelsea , Stansbury Melissa , Magradey Karen , Gibson Andrea , West Delia Smith
Published: December 2020

College-aged women and men are an important catch-up population for human papillomavirus (HPV) vaccination interventions. Limited research has explored technology-mediated HPV vaccination awareness interventions aimed at college students. The purpose was to evaluate a novel, technology-mediated, social media-based intervention to promote HPV vaccination among college students. A controlled, quasi-experimental, mixed methods study examined the feasibility of a technology-based intervention among two undergraduate classes (n = 58) at a public university in the southeastern United States of America. Classes were randomized to receive one of two cancer prevention programs (i.e., HPV vaccination (intervention) or healthy weight (control)). Both programs contained eight technology-mediated sessions, including weekly emails and private Facebook group posts. Participants completed pre-/post-test surveys and submitted weekly qualitative reflections. Data were analyzed using descriptive statistics and thematic review for qualitative data. Knowledge improved among participants in the HPV vaccination intervention relative to those in the control condition. Participants (97%) interacted on Facebook by “liking” a post or comment or posting a comment. Participants demonstrated robust engagement and high treatment satisfaction. Results suggests that social media is an effective platform to reach college students with health promotion interventions and increase HPV vaccination awareness in this important catch-up population.
Prevalence of erectile dysfunction in male survivors of cancer: a systematic review and meta-analysis of cross-sectional studies
Authors: Pizzol Damiano , Xiao Tao , Smith Lee , Sánchez Guillermo F López , Garolla Andrea , Parris Christopher , Barnett Yvonne , Ilie Petre Cristian , Soysal Pinar , Shin Jae Il , Tully Mark A , Yang Lin , Veronese Nicola , Grabovac Igor
Published: December 2020

Background

Prevalence of erectile dysfunction (ED) in male survivors of cancer across cancer types has not been systematically analysed.

Aim

To estimate the prevalence of ED in all types of cancer and identify characteristics associated with ED in survivors of cancer.

Design and setting

Systematic review and meta-analysis (MA) of cross-sectional studies.

Method

MEDLINE, CINAHL, PsycINFO, and EMBASE were searched, targeting reports published from inception to 1 February 2020. All retrospective or prospective studies reporting prevalence of ED in male patients with cancer and using a validated tool for detection of ED were included. A random-effects MA model was used to pool prevalence of ED as absolute estimates at three different stages, that is, ‘healthy’, ‘at diagnosis’, and ‘after treatment’. A univariate MA regression including the three-level group variable as the only independent variable was used to assess the difference in ED prevalence across the three groups. Further MAs were conducted for studies involving patients at diagnosis and after treatment, and statistical inferences were made with setting for multiple testing controlling for a false discovery rate (FDR) <0.05.

Results

In total, 1301 studies were assessed for inclusion. Of these, 141 were potentially eligible and subsequently scrutinised in full text. Finally, 43 studies were included with a total of 13 148 participants. Overall, pooled data of the included studies showed an ED prevalence of 40.72% (95% confidence interval [CI] = 31.80 to 50.29) in patients with cancer, with prevalences of 28.60% (95% CI = 12.10 to 53.83) at time of diagnosis and 42.70% (95% CI = 32.97 to 53.03) after treatment, with significant difference between these two stages and across cancer locations, controlling for an FDR <0.05.

Conclusion

Erectile dysfunction was particularly high in male survivors of cancer and was associated with cancer treatment, cancer site, and age.
Implementing the UN Sustainable Development Goals: How Is Health Framed in the Norwegian and Swedish Voluntary National Review Reports?
Authors: Lillehagen Ida , Heggen Kristin M. , Tomson Göran , Engebretsen Eivind
Published: December 2020

Background: The United Nations (UN) Sustainable Development Goals (SDGs) are parts of an ambitious framework for global development, the 2030 Agenda. Voluntary national reviews (VNRs) are described as "cornerstones" in the followup system, which is premised on international sharing of knowledge and experience. Norway and Sweden are among the world’s most sustainable countries, aiming to be leaders in the implementation of the SDGs. The objective of this article is to investigate and compare how health is framed in the VNRs of these two high-income countries, and to discuss the implications of these framings for potential actions. Methods: Discourse analysis inspired by the concept of ‘framing,’ which refers to the discursive presentation of an issue where certain problem definitions and solutions are privileged over others. Frames are structures that organise and direct attention to particular aspects of reality, and define what is seen. Results: Our analysis demonstrates that in the Norwegian VNR (NVNR), the issue of health is simplistically framed, focusing on the favourable situation of the majority, thus providing weak grounds for transformative action. In the Swedish VNR (SVNR), health is framed to highlight health as inextricably tied to societal inequalities. This underscores the need for integrated political action and leadership to counteract structural differences with negative consequences for health. Conclusion: Analysis of the two VNRs studied found a difference in how health is framed in these documents and these frames point to differences in approach and capacity to address health inequities and realise the holistic and integrative concept of health promoted in the 2030 Agenda. To realize the Agenda’s vision of "leaving no one behind" discourses of implementation that support the Agenda’s inclusive and holistic ambition must be developed. Further development of the follow-up and review system should acknowledge and address how frames can limit or enable integrative actions and are therefore important drivers of change.