bluuebunny/crossref_metadata_2025 huggingface dataset:
Jute Fiber-Reinforced Polymer Tube-Confined Sisal Fiber-Reinforced Recycled Aggregate Concrete Waste
Authors: Gao Chang , Fu Qiuni , Huang Liang , Yan Libo , Gu Guangming
Published: March 2022

In this study, the compressive performance of sisal fiber-reinforced recycled aggregate concrete (SFRAC) composite, confined with jute fiber-reinforced polymer (JFRP) tube (the structure was termed as JFRP–SFRAC) was assessed. A total of 36 cylindrical specimens were tested under uniaxial compression. Three major experimental variables were investigated: (1) the compressive strength of concrete core (i.e., 25.0 MPa and 32.5 MPa), (2) jute fiber orientation angle with respect to the hoop direction of a JFRP tube (i.e., β = 0°, 30° and 45°), and (3) the reinforcement of sisal fiber (i.e., 0% and 0.3% by mass of cement). This study revealed that the prefabricated JFRP tube resulted in a significant enhancement of the compressive strength and deformation ability of RAC and SFRAC. The enhancements in strength and ultimate strain of the composite columns were more pronounced for concrete with a higher strength. The strength and ultimate strain of JFRP-confined specimens decreased with an increase in fiber orientation angle β from 0° to 45°. The sisal fiber reinforcement effectively improved the integrity of the RAC and reduced the propagation of cracks in RAC. The stress–strain behaviors of JFRP–RAC and JFRP–SFRAC were predicted by the Lam and Teng’s model with the revised ultimate condition equations.
The Role of Structure in Polymer Rheology: Review
Authors: Kulichikhin Valery G. , Malkin Alexander Ya.
Published: March 2022

The review is devoted to the analysis of the current state of understanding relationships among the deformation-induced structure transformations, observed rheological properties, and the occurrence of non-linear effects for polymer liquids (melts, solutions, and composites). Three levels of non-linearity are the base for consideration. The first one concerns changes in the relaxation spectra of viscoelastic liquids, which are responsible for weak non-linear phenomena. The second one refers to the strong non-linearity corresponding to such changes in the structure of a medium that leads to the emergence of a new relaxation state of a matter. Finally, the third one describes the deformation-induced changes in the phase state and/or the occurring of bifurcations and instability in flow and reflects the thermodynamic non-linear behavior. From a structure point of view, a common cause of the non-linear effects is the orientation of macromolecules and changes in intermolecular interaction, while a dominant factor in describing fluid dynamics of polymer liquids is their elasticity. The modern understanding of thixotropic effects, yielding viscoplastic materials, deformation-induced phase transition, and the experimental observations, demonstrating direct correlations between the structure and rheology of polymer liquids, are the main objects for discussion. All these topics are reviewed and discussed mainly on the basis of the latest five-year publications.
In Vivo Evaluation of Gamma-Irradiated and Heparin-Immobilized Small-Diameter Polycaprolactone Vascular Grafts with VEGF in Aged Rats
Authors: Kim Se-Eun , Jeong Sung-In , Shim Kyung-Mi , Jang Kwangsik , Park Jong-Seok , Lim Youn-Mook , Kang Seong-Soo
Published: March 2022

The effectiveness of small-diameter vascular grafts depends on their antithrombogenic properties and ability to undergo accelerated endothelialization. The extreme hydrophobic nature of poly(ε-caprolactone) (PCL) hinders vascular tissue integration, limiting its use in medical implants. To enhance the antithrombogenicity of PCL as a biomaterial, we grafted 2-aminoethyl methacrylate (AEMA) hydrochloride onto the PCL surface using gamma irradiation; developed a biodegradable heparin-immobilized PCL nanofibrous scaffold using gamma irradiation and N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide reaction chemistry; and incorporated vascular endothelial growth factor (VEGF) into the scaffold to promote vascular endothelial cell proliferation and prevent thrombosis on the vascular grafts. We assessed the physicochemical properties of PCL, heparin-AEMA-PCL (H-PCL), and VEGF-loaded heparin-AEMA-PCL (VH-PCL) vascular grafts using scanning electron microscopy, attenuated total reflection–Fourier transform infrared spectroscopy, toluidine blue O staining, and fibrinogen adsorption and surface wettability measurement. In addition, we implanted the vascular grafts into 24-month-old Sprague Dawley rats and evaluated them for 3 months. The H-PCL and VH-PCL vascular grafts improved the recovery of blood vessel function by promoting the proliferation of endothelial cells and preventing thrombosis in clinical and histological evaluation, indicating their potential to serve as functional vascular grafts in vascular tissue engineering.
Special Issue on “Synthesis and Application of Nano- and Microdispersed Systems”
Authors: Kuznetsov Denis , Karunakaran Gopalu
Published: March 2022

With numerous advancements, nano- and microdispersed systems are rapidly increasing worldwide [...]
Catalytic Properties of Free-Base Porphyrin Modified Graphite Electrodes for Electrochemical Water Splitting in Alkaline Medium
Authors: Taranu Bogdan-Ovidiu , Fagadar-Cosma Eugenia
Published: March 2022

Hydrogen generation via electrochemical water splitting is considered an eco-friendly pathway for obtaining this desired alternative energy source, and it has triggered an intensive search for low cost and efficient catalysts. Within this context, four free-base porphyrins were studied as heterogeneous catalysts for the oxygen and hydrogen evolution reactions (OER and HER) in alkaline aqueous solutions. TEM and STEM analyses of samples obtained by drop-casting the porphyrins from different organic solvents on TEM grids revealed a rich variety of aggregates due to the self-assembling property of the porphyrin molecules. Modified electrodes were manufactured by applying the four tetrapyrrolic macrocycles from various solvents on the surface of graphite supports, in one or more layers. Experiments performed in 0.1 M and 1 M KOH electrolyte solutions allowed the identification of the most electrocatalytically active electrodes for the OER and HER, respectively. In the first case, the electrode was manufactured by applying three layers of 5-(4-pyridyl)-10,15,20-tris(4-phenoxyphenyl)porphyrin on the graphite substrate from N,N-dimethylformamide solution was identified as overall catalytically superior. In the second case, the electrode obtained by applying one layer of 5,10,15,20-tetrakis(4-allyloxyphenyl)-porphyrin from benzonitrile solution displayed an HER overpotential value of 500 mV at i = −10 mA/cm2 and a Tafel slope of 190 mV/dec.
Effects of the Balance Hole Diameter on the Flow Characteristics of the Rear Chamber and the Disk Friction Loss in the Centrifugal Pump
Authors: Dong Wei , Liu Ze , Zhang Haichen , Zhang Guang , Jiang Haoqing , Li Peixuan
Published: March 2022

This paper studies the flow characteristics and disk friction loss of the rear chamber in a centrifugal pump at a design flow condition with six values of the balance holes at diameters from 0 to 12 mm. The results show that the turbulent boundary layer in the rear chamber is greatly affected by the leakage flow. When the balance hole diameter increases, the flow characteristics of the rear chamber is mainly restricted by the mainstream flow field of the volute. However, when the balance hole diameter is larger than the design value, the disk friction loss of the rear chamber remains basically unchanged. On the contrary, when the balance hole diameter is smaller than the design value, the larger the balance hole diameter the smaller the friction loss of the disk in the rear chamber area. The results of this paper provide a reference for reducing axial force and stable operation of a centrifugal pump.
Modeling and Experimental Studies on Carbon Dioxide Absorption with Sodium Hydroxide Solution in a Rotating Zigzag Bed
Authors: Liu Zhibang , Esmaeili Arash , Zhang Hanxiao , Wang Dan , Lu Yuan , Shao Lei
Published: March 2022

The enhancement of mass transfer is very important in CO2 absorption, and a rotating zigzag bed (RZB) is a promising device to intensify the gas–liquid mass transfer efficiency. In this study, the mass transfer characteristics in an RZB in relation to the overall gas-phase volumetric mass-transfer coefficient (KGa) were investigated with a CO2–NaOH system. A mathematical model was established to illustrate the mechanism of the gas–liquid mass transfer with irreversible pseudo-first-order reaction in the RZB. The effects of various operating conditions on KGa were examined. Experimental results show that a rise in the liquid flow rate, inlet gas flow rate, rotational speed, absorbent temperature, and absorbent concentration was conducive to the mass transfer between gas and liquid in the RZB. It was found that the rotational speed had the largest impact on KGa in the RZB. The KGa predicted by the model agreed well with that by the experiments, with deviations generally within 10%. Therefore, this model can be employed to depict the mass transfer process between gas and liquid in an RZB and provide guidance for the application of RZBs in CO2 absorption.
High-Performance Extraction Process of Anthocyanins from Jussara (Euterpe edulis) Using Deep Eutectic Solvents
Authors: Vannuchi Nicholas , Braga Anna Rafaela Cavalcate , De Rosso Veridiana Vera
Published: March 2022

New strategies for obtaining target bioactive compounds and natural pigments with the use of “green solvents” are consistently being developed, and deep eutectic solvents are (DES) a great alternative. This work established the significant variables and models for anthocyanin extraction, using DES and experimental design, of Euterpe edulis Mart. (jussara) fruit pulp, an endangered palm tree from the Brazilian Atlantic Forest. From a screening of seven initially tested DES, choline chloride/xylitol-based solvents had the best results with up to 42% increase in the total anthocyanin yield compared to methanolic extraction. Antioxidant assays also revealed a maximum antioxidant capacity of 198.93 mmol Trolox/100 g dry weight basis. The DES extract showed slower degradation to heat at 60° and 90 °C (2.5 times) and indoor constant light source (1.9 times) than methanolic extracts. The optimal extract also revealed slight inhibition of S. enterica and S. aureus growth in the agar plate.
The ‘Great Whore’ of Babylon (Rev 17) as a Non-Survivor of Sexual Abuse
Authors: König Judith
Published: March 2022

The article aims to re-read Rev 17:16 amid the catastrophic patterns of sexual abuse in the Catholic Church. Employing narratological methods as well as a close reading of the text, it is argued that Rev 17:16 can be coherently read as the violent sexual punishment of an anthropomorphic female character. Signals in the text point to God’s involvement in this punishment and to its overall positive evaluation. Considering reader’s realities in the context of sexual abuse and its cover-up, the article argues for the necessity of taking a positional stance while reading biblical ‘texts of sexual terror’. Such a positional stance must have visible effects on a responsible reading and interpretation of the ‘great whore’s’ story.
The Impact of Eatmarna Application Usability on Improving Performance Expectancy, Facilitating the Practice of Rituals and Improving Spirituality Feelings during Umrah Amid the COVID-19 Outbreak
Authors: Hassan Thowayeb H. , Salem Amany E. , Refaat Sameh A.
Published: March 2022

The electronic tourism era has rapidly emerged during the explosive spread of the COVID-19 pandemic worldwide. The role of information technology was also evident in the religious tourism sector, and this facilitated the organization of religious events for Muslims, such as Hajj and Umrah. In the present study, we assessed the usability of a mobile application (Eatmarna) which provides permits to perform Umrah and other religious practices in Makkah and Madina in Saudi Arabia. We sought also to assess the impact of usability on the app effectiveness in improving Umrah experience. Pilgrims were asked to fill out an electronic survey distributed by the coordinators of Umrah service providers. Results showed that the perceived effectiveness was predicted by two domains of usability, namely system information arrangement (β = 0.27, 95% CI, 0.09 to 0.46, p = 0.004) and app usefulness (β = 0.52, 95% CI, 0.34 to 0.69, p < 0.0001). Both the usability domains were independently associated with all the subdomains of app effectiveness, including performance expectancy, facilitating the practice of rituals, and feelings of spirituality. The Eatmarna application was effective in providing a safe environment for pilgrims, which was accounted for by the app usability, and this facilitated the improvement of Umrah experience. National authorities can further integrate additional services in the app to improve pilgrims’ perceptions.
Calibration and Validation of SWAT Model by Using Hydrological Remote Sensing Observables in the Lake Chad Basin
Authors: Bennour Ali , Jia Li , Menenti Massimo , Zheng Chaolei , Zeng Yelong , Asenso Barnieh Beatrice , Jiang Min
Published: March 2022

Model calibration and validation are challenging in poorly gauged basins. We developed and applied a new approach to calibrate hydrological models using distributed geospatial remote sensing data. The Soil and Water Assessment Tool (SWAT) model was calibrated using only twelve months of remote sensing data on actual evapotranspiration (ETa) geospatially distributed in the 37 sub-basins of the Lake Chad Basin in Africa. Global sensitivity analysis was conducted to identify influential model parameters by applying the Sequential Uncertainty Fitting Algorithm–version 2 (SUFI-2), included in the SWAT-Calibration and Uncertainty Program (SWAT-CUP). This procedure is designed to deal with spatially variable parameters and estimates either multiplicative or additive corrections applicable to the entire model domain, which limits the number of unknowns while preserving spatial variability. The sensitivity analysis led us to identify fifteen influential parameters, which were selected for calibration. The optimized parameters gave the best model performance on the basis of the high Nash–Sutcliffe Efficiency (NSE), Kling–Gupta Efficiency (KGE), and determination coefficient (R2). Four sets of remote sensing ETa data products were applied in model calibration, i.e., ETMonitor, GLEAM, SSEBop, and WaPOR. Overall, the new approach of using remote sensing ETa for a limited period of time was robust and gave a very good performance, with R2 > 0.9, NSE > 0.8, and KGE > 0.75 applying to the SWAT ETa vs. the ETMonitor ETa and GLEAM ETa. The ETMonitor ETa was finally adopted for further model applications. The calibrated SWAT model was then validated during 2010–2015 against remote sensing data on total water storage change (TWSC) with acceptable performance, i.e., R2 = 0.57 and NSE = 0.55, and remote sensing soil moisture data with R2 and NSE greater than 0.85.
Ground Maneuvering Target Focusing via High-Order Phase Correction in High-Squint Synthetic Aperture Radar
Authors: Ran Lei , Liu Zheng , Xie Rong
Published: March 2022

Moving target imaging in high-squint synthetic aperture radar (SAR) shows great potential for reconnaissance and surveillance tasks. For the desired resolution, high-squint SAR has a long-time coherent processing interval (CPI). In this case, the maneuvering motion of the moving target usually causes high-order phase terms in the echoed data, which cannot be neglected for precise focusing. Many ground moving target imaging (GMTIm) algorithms have been proposed in the literature, but some high-order phase terms remain uncompensated in high-squint SAR. For this problem, a high-order phase correction-based GMTIm (HPC-GMTIm) method is proposed in this paper. We assumed that the target of interest has a constant velocity in the subaperture CPI, but maneuvering motion parameters for the whole CPI. Within the short subaperture CPI, the target signal can be simplified as a three-order phase expression, and the instantaneous Doppler frequency (DF) was estimated by some time–frequency analysis tools, including the Hough transform and the fractional Fourier transform. For the whole CPI, the subaperture, the instantaneous DF was combined to form a total least-squares problem, outputting the undetermined phase coefficients. Using the proposed local-to-global processing chain, all high-order phase terms can be estimated and corrected, which outperforms existing methods. The effectiveness of the HPC-GMTIm method is demonstrated by real measured high-squint SAR data.
Estimating High-Resolution PM2.5 Concentrations by Fusing Satellite AOD and Smartphone Photographs Using a Convolutional Neural Network and Ensemble Learning
Authors: Wang Fei , Yao Shiqi , Luo Haowen , Huang Bo
Published: March 2022

Aerosol optical depth (AOD) data derived from satellite products have been widely used to estimate fine particulate matter (PM2.5) concentrations. However, existing approaches to estimate PM2.5 concentrations are invariably limited by the availability of AOD data, which can be missing over large areas due to satellite measurements being obstructed by, for example, clouds, snow cover or high concentrations of air pollution. In this study, we addressed this shortcoming by developing a novel method for determining PM2.5 concentrations with high spatial coverage by integrating AOD-based estimations and smartphone photograph-based estimations. We first developed a multiple-input fuzzy neural network (MIFNN) model to measure PM2.5 concentrations from smartphone photographs. We then designed an ensemble learning model (AutoELM) to determine PM2.5 concentrations based on the Collection-6 Multi-Angle Implementation of Atmospheric Correction AOD product. The R2 values of the MIFNN model and AutoELM model are 0.85 and 0.80, respectively, which are superior to those of other state-of-the-art models. Subsequently, we used crowdsourced smartphone photographs obtained from social media to validate the transferability of the MIFNN model, which we then applied to generate smartphone photograph-based estimates of PM2.5 concentrations. These estimates were fused with AOD-based estimates to generate a new PM2.5 distribution product with broader coverage than existing products, equating to an average increase of 12% in map coverage of PM2.5 concentrations, which grows to an impressive 25% increase in map coverage in densely populated areas. Our findings indicate that the robust estimation accuracy of the ensemble learning model is due to its detection of nonlinear correlations and high-order interactions. Furthermore, our findings demonstrate that the synergy of smartphone photograph-based estimations and AOD-based estimations generates significantly greater spatial coverage of PM2.5 distribution than AOD-based estimations alone, especially in densely populated areas where more smartphone photographs are available.
A GNSS/5G Integrated Three-Dimensional Positioning Scheme Based on D2D Communication
Authors: Zhang Wei , Yang Yuanxi , Zeng Anmin , Xu Yangyin
Published: March 2022

The fifth generation (5G) communication has the potential to achieve ubiquitous positioning when integrated with a global navigation satellite system (GNSS). The device-to-device (D2D) communication, serving as a key technology in the 5G network, provides the possibility of cooperative positioning with high-density property. The mobile users (MUs) collaborate to jointly share the position and measurement information, which can make use of more references for positioning. In this paper, a GNSS/5G integrated three-dimensional positioning scheme based on D2D communication is proposed, where the time of arrival (TOA) and received signal strength (RSS) measurements are jointly utilized in the 5G network. The density spatial clustering of application with noise (DBSCAN) is exploited to reduce the position uncertainty of the cooperative nodes, and the positions of the requesting nodes are obtained simultaneously. The particle filter (PF) algorithm is further conducted to improve the position accuracy of the requesting nodes. Numerical results show that the position deviation of the cooperative nodes can be significantly decreased and that the proposed algorithm performs better than the nonintegrated one. The DBSCAN brings an increase of about 50% in terms of the positioning accuracy compared with GNSS results, and the PF further increases the accuracy about 8%. It is also verified that the algorithm suits the fixed and dynamic condition well.
Projections of Climate Change Impacts on Flowering-Veraison Water Deficits for Riesling and Müller-Thurgau in Germany
Authors: Yang Chenyao , Menz Christoph , De Abreu Jaffe Maxim Simões , Costafreda-Aumedes Sergi , Moriondo Marco , Leolini Luisa , Torres-Matallana Arturo , Molitor Daniel , Junk Jürgen , Fraga Helder , van Leeuwen Cornelis , Santos João A.
Published: March 2022

With global warming, grapevine is expected to be increasingly exposed to water deficits occurring at various development stages. In this study, we aimed to investigate the potential impacts of projected climate change on water deficits from the flowering to veraison period for two main white wine cultivars (Riesling and Müller-Thurgau) in Germany. A process-based soil-crop model adapted for grapevine was utilized to simulate the flowering-veraison crop water stress indicator (CWSI) of these two varieties between 1976–2005 (baseline) and 2041–2070 (future period) based on a suite of bias-adjusted regional climate model (RCM) simulations under RCP4.5 and RCP8.5. Our evaluation indicates that the model can capture the early-ripening (Müller-Thurgau) and late-ripening (Riesling) traits, with a mean bias of prediction of ≤2 days and a well-reproduced inter-annual variability for more than 60 years. Under climate projections, the flowering stage is advanced by 10–20 days (higher in RCP8.5) between the two varieties, whereas a slightly stronger advancement is found for Müller-Thurgau than for Riesling for the veraison stage. As a result, the flowering-veraison phenophase is mostly shortened for Müller-Thurgau, whereas it is extended by up to two weeks for Riesling in cool and high-elevation areas. The length of phenophase plays an important role in projected changes of flowering-veraison mean temperature and precipitation. The late-ripening trait of Riesling makes it more exposed to increased summer temperature (mainly in August), resulting in a higher mean temperature increase for Riesling (1.5–2.5 °C) than for Müller-Thurgau (1–2 °C). As a result, an overall increased CWSI by up to 15% (ensemble median) is obtained for both varieties, whereas the upper (95th) percentile of simulations shows a strong signal of increased water deficit by up to 30%, mostly in the current winegrowing regions. Intensified water deficit stress can represent a major threat for high-quality white wine production, as only mild water deficits are acceptable. Nevertheless, considerable variabilities of CWSI were discovered among RCMs, highlighting the importance of efforts towards reducing uncertainties in climate change impact assessment.
Classification of Tree Species in Different Seasons and Regions Based on Leaf Hyperspectral Images
Authors: Yang Rongchao , Kan Jiangming
Published: March 2022

This paper aims to establish a tree species identification model suitable for different seasons and regions based on leaf hyperspectral images, and to mine a more effective hyperspectral identification algorithm. Firstly, the reflectance spectra of leaves in different seasons and regions were analyzed. Then, to solve the problem that 0-element in sparse random (SR) coding matrices affects the classification performance of error-correcting output codes (ECOC), two versions of supervision-mechanism-based ECOC algorithms, namely SM-ECOC-V1 and SM-ECOC-V2, were proposed in this paper. In addition, the performance of the proposed algorithms was compared with that of six traditional algorithms based on all bands and feature bands. The experiment results show that seasonal and regional changes have an effect on the reflectance spectra of leaves, especially in the near-infrared region of 760–1000 nm. When the spectral information of different seasons and different regions is added into the identification model, tree species can be effectively classified. SM-ECOC-V2 achieves the best classification performance based on both all bands and feature bands. Furthermore, both SM-ECOC-V1 and SM-ECOC-V2 outperform the ECOC method under SR coding strategy, indicating the proposed methods can effectively avoid the influence of 0-element in SR coding matrix on classification performance.
Recursive Enhancement of Weak Subsurface Boundaries and Its Application to SHARAD Data
Authors: Fang Peng , Zhang Jinhai
Published: March 2022

Sedimentary layers are composed of alternately deposited compositions in different periods, reflecting the geological evolution history of a planet. Orbital radar can detect sedimentary layers, but the radargram is contaminated by varying background noise levels. Traditional denoising methods, such as median filter, have difficulty dealing with such kinds of noise. We propose a recursive signal enhancement scheme to identify weak reflections from intense background noise. Numerical experiments with synthetic data and SHARAD radargrams illustrate that the proposed method can enhance the clarity of the radar echoes and reveal delicate sedimentary structures previously buried in the background noise. The denoising result presents better horizontal continuity and higher vertical resolution compared with those of the traditional methods.
Joint Resource Allocation in Secure OFDM Two-Way Untrusted Relay System
Authors: Jin Yifeng , Li Xunan , Lv Guocheng , Zhao Meihui , Jin Ye
Published: March 2022

The security issue of wireless communication is a common concern because of its broadcast nature, especially when the relay becomes an eavesdropper. In the orthogonal frequency division multiplexing (OFDM) relay system, when the relay is untrusted, the security of the system faces serious threats. Although there exist some resource allocation schemes in a single-carrier system with untrusted relaying, it is difficult to apply them to the multi-carrier system. Hence, a resource allocation scheme for the multi-carrier system is needed. Compared to the one-way relay system, a two-way relay system can improve the data transmission efficiency. In this paper, we consider joint secure resource allocation for a two-way cooperative OFDM system with an untrusted relay. The joint resource allocation problem of power allocation and subcarrier pairing is formulated to maximize the sum secrecy rate of the system under individual power constraints. To solve the non-convex problem efficiently, we propose an algorithm based on the alternative optimization method. The proposed algorithm is evaluated by simulation results and compared with the benchmarks in the literature. According to the numerical results, in a high signal-to-noise ratio (SNR) scenario, the proposed algorithm improves the achievable sum secrecy rate of the system by more than 15% over conventional algorithms.
An Integrated Millimeter-Wave Satellite Radiometer Working at Room-Temperature with High Photon Conversion Efficiency
Authors: Abdalmalak Kerlos Atia , Botello Gabriel Santamaria , Suresh Mallika Irene , Falcón-Gómez Enderson , Lavado Alejandro Rivera , García-Muñoz Luis Enrique
Published: March 2022

In this work, the design of an integrated 183GHz radiometer frontend for earth observation applications on satellites is presented. By means of the efficient electro-optic modulation of a laser pump with the observed millimeter-wave signal followed by the detection of the generated optical sideband, a room-temperature low-noise receiver frontend alternative to conventional Low Noise Amplifiers (LNAs) or Schottky mixers is proposed. Efficient millimeter-wave to 1550 nm upconversion is realized via a nonlinear optical process in a triply resonant high-Q Lithium Niobate (LN) Whispering Gallery Mode (WGM) resonator. By engineering a micromachined millimeter-wave cavity that maximizes the overlap with the optical modes while guaranteeing phase matching, the system has a predicted normalized photon-conversion efficiency ≈10−1 per mW pump power, surpassing the state-of-the-art by around three orders of magnitude at millimeter-wave frequencies. A piezo-driven millimeter-wave tuning mechanism is designed to compensate for the fabrication and assembly tolerances and reduces the complexity of the manufacturing process.
Distorted Acquisition of Dynamic Events Sensed by Frequency-Scanning Fiber-Optic Interrogators and a Mitigation Strategy
Authors: Bhatta Hari Datta , Davidi Roy , Yeredor Arie , Tur Moshe
Published: March 2022

Fiber-optic dynamic interrogators, which use periodic frequency scanning, actually sample a time-varying measurand on a non-uniform time grid. Commonly, however, the sampled values are reported on a uniform time grid, synchronized with the periodic scanning. It is the novel and noteworthy message of this paper that this artificial assignment may give rise to significant distortions in the recovered signal. These distortions increase with both the signal frequency and measurand dynamic range for a given sampling rate and frequency scanning span of the interrogator. They may reach disturbing values in dynamic interrogators, which trade-off scanning speed with scanning span. The paper also calls for manufacturers of such interrogators to report the sampled values along with their instants of acquisition, allowing interpolation algorithms to substantially reduce the distortion. Experimental verification of a simulative analysis includes: (i) a commercial dynamic interrogator of ‘continuous’ FBG fibers that attributes the measurand values to a uniform time grid; as well as (ii) a dynamic Brillouin Optical time Domain (BOTDA) laboratory setup, which provides the sampled measurand values together with the sampling instants. Here, using the available measurand-dependent sampling instants, we demonstrate a significantly cleaner signal recovery using spline interpolation.
Performance Degradation Prediction Using LSTM with Optimized Parameters
Authors: Hu Yawei , Wei Ran , Yang Yang , Li Xuanlin , Huang Zhifu , Liu Yongbin , He Changbo , Lu Huitian
Published: March 2022

Predicting the degradation of mechanical components, such as rolling bearings is critical to the proper monitoring of the condition of mechanical equipment. A new method, based on a long short-term memory network (LSTM) algorithm, has been developed to improve the accuracy of degradation prediction. The model parameters are optimized via improved particle swarm optimization (IPSO). Regarding how this applies to the rolling bearings, firstly, multi-dimension feature parameters are extracted from the bearing’s vibration signals and fused into responsive features by using the kernel joint approximate diagonalization of eigen-matrices (KJADE) method. Then, the between-class and within-class scatter (SS) are calculated to develop performance degradation indicators. Since network model parameters influence the predictive accuracy of the LSTM model, an IPSO algorithm is used to obtain the optimal prediction model via the LSTM model parameters’ optimization. Finally, the LSTM model, with said optimal parameters, was used to predict the degradation trend of the bearing’s performance. The experiment’s results show that the proposed method can effectively identify the trends of degradation and performance. Moreover, the predictive accuracy of this proposed method is greater than that of the extreme learning machine (ELM) and support vector regression (SVR), which are the algorithms conventionally used in degradation modeling.
Heuristic Greedy Scheduling of Electric Vehicles in Vehicle-to-Grid Microgrid Owned Aggregators
Authors: Abdel-Hakim Alaa , Abo-Elyousr Farag
Published: March 2022

In on-grid microgrids, electric vehicles (EVs) have to be efficiently scheduled for cost-effective electricity consumption and network operation. The stochastic nature of the involved parameters along with their large number and correlations make such scheduling a challenging task. This paper aims at identifying pertinent innovative solutions for reducing the relevant total costs of the on-grid EVs within hybrid microgrids. To optimally scale the EVs, a heuristic greedy approach is considered. Unlike most existing scheduling methodologies in the literature, the proposed greedy scheduler is model-free, training-free, and yet efficient. The proposed approach considers different factors such as the electricity price, on-grid EVs state of arrival and departure, and the total revenue to meet the load demands. The greedy-based approach behaves satisfactorily in terms of fulfilling its objective for the hybrid microgrid system, which is established of photovoltaic, wind turbine, and a local utility grid. Meanwhile, the on-grid EVs are being utilized as an energy storage exchange location. A real time hardware-in-the-loop experimentation is comprehensively conducted to maximize the earned profit. Through different uncertainty scenarios, the ability of the proposed greedy approach to obtain a global optimal solution is assessed. A data simulator was developed for the purposes of generating evaluation datasets, which captures uncertainties in the behaviors of the system’s parameters. The greedy-based strategy is considered applicable, scalable, and efficient in terms of total operating expenditures. Furthermore, as EVs penetration became more versatile, total expenses decreased significantly. Using simulated data of an effective operational duration of 500 years, the proposed approach succeeded in cutting down the energy consumption costs by about 50–85%, beating existing state-of-the-arts results. The proposed approach is proved to be tolerant to the large amounts of uncertainties that are involved in the system’s operational data.
EggBlock: Design and Implementation of Solar Energy Generation and Trading Platform in Edge-Based IoT Systems with Blockchain
Authors: Kwak Subin , Lee Joohyung , Kim Jangkyum , Oh Hyeontaek
Published: March 2022

In this paper, to balance power supplement from the solar energy’s intermittent and unpredictable generation, we design a solar energy generation and trading platform (EggBlock) using Internet of Things (IoT) systems and blockchain technique. Without a centralized broker, the proposed EggBlock platform can promote energy trading between users equipped with solar panels, and balance demand and generation. By applying the second price sealed-bid auction, which is one of the suitable pricing mechanisms in the blockchain technique, it is possible to derive truthful bidding of market participants according to their utility function and induce the proceed transaction. Furthermore, for efficient generation of solar energy, EggBlock proposes a Q-learning-based dynamic panel control mechanism. Specifically, we set the instantaneous direction of the solar panel and the amount of power generation as the state and reward, respectively. The angle of the panel to be moved becomes an action at the next time step. Then, we continuously update the Q-table using transfer learning, which can cope with recent changes in the surrounding environment or weather. We implement the proposed EggBlock platform using Ethereum’s smart contract for reliable transactions. At the end of the paper, measurement-based experiments show that the proposed EggBlock achieves reliable and transparent energy trading on the blockchain and converges to the optimal direction with short iterations. Finally, the results of the study show that an average energy generation gain of 35% is obtained.
Development of a 3D Relative Motion Method for Human–Robot Interaction Assessment
Authors: Ballen-Moreno Felipe , Bautista Margarita , Provot Thomas , Bourgain Maxime , Cifuentes Carlos A. , Múnera Marcela
Published: March 2022

Exoskeletons have been assessed by qualitative and quantitative features known as performance indicators. Within these, the ergonomic indicators have been isolated, creating a lack of methodologies to analyze and assess physical interfaces. In this sense, this work presents a three-dimensional relative motion assessment method. This method quantifies the difference of orientation between the user’s limb and the exoskeleton link, providing a deeper understanding of the Human–Robot interaction. To this end, the AGoRA exoskeleton was configured in a resistive mode and assessed using an optoelectronic system. The interaction quantified a difference of orientation considerably at a maximum value of 41.1 degrees along the sagittal plane. It extended the understanding of the Human–Robot Interaction throughout the three principal human planes. Furthermore, the proposed method establishes a performance indicator of the physical interfaces of an exoskeleton.
One4all—A New SCADA Approach
Authors: Vaduva Bogdan , Pop Ionut-Flaviu , Valean Honoriu
Published: March 2022

The main purpose of this paper is to introduce a new concept, named “one4all” in the realm of SCADA (Supervisory Control and Data Acquisition) systems, used by a regional company (particularly a water supplying company) for managing the different views of its users. As a secondary purpose, the paper presents an integration of such an SCADA system with a GIS (Geographical Information System) system. All the regional water supply companies in Romania manage water and wastewater networks, many sensors and actuators, dozens of water pump plants, several water treatment and wastewater plants, tanks and many hydrophores in different parts of their operating range. Due to the wide geographical operating range, an SCADA system needs to be put in place, but the management of such a system in a traditional way is hard to implement, especially when the human resource is low. The methodology presented in this paper, involving adding helper tables and dynamic template windows within an SCADA tool (“one4all” tool), will show how efficiently the human resource can be used. Additionally, the paper shows that companies as described above, can use a single SCADA system that generates different views for all the managed sub regions instead of different systems for every sub region. Implementing only one SCADA system built with the concept “one4all” in mind, and integrating it with a GIS system that is built on the same principle, represents a new approach that will bring value to any organization willing to adopt it. The concept of “one4all”, implemented as a software tool for an SCADA system, is a new concept that will help any developer to easily build applications that generate different views for different users based on their permissions and their operating range. Finally, the paper presents some examples of the same concept, implemented in a different vertical (GIS) and programming language, thus presenting that a “one4all” concept is viable and helpful, bringing value to the information technology industry.
Motion Shield: An Automatic Notifications System for Vehicular Communications
Authors: Balios Petros , Kyriakidis Philotas , Zimeras Stelios , Bithas Petros S. , Sarakis Lambros
Published: March 2022

Motion Shield is an automatic crash notification system that uses a mobile phone to generate automatic alerts related to the safety of a user when the user is boarding a means of transportation. The objective of Motion Shield is to improve road safety by considering a moving vehicle’s risk, estimating the probability of an emergency, and assessing the likelihood of an accident. The system, using multiple sources of external information, the mobile phone sensors’ readings, geolocated information, weather data, and historical evidence of traffic accidents, processes a plethora of parameters in order to predict the onset of an accident and act preventively. All the collected data are forwarded into a decision support system which dynamically calculates the mobility risk and driving behavior aspects in order to proactively send personalized notifications and alerts to the user and a public safety answering point (PSAP) (112).
n-Player Stochastic Duel Game Model with Applied Deep Learning and Its Modern Implications
Authors: Gupta Manik , Sharma Bhisham , Tripathi Akarsh , Singh Shashank , Bhola Abhishek , Singh Rajani , Dwivedi Ashutosh Dhar
Published: March 2022

This paper provides a conceptual foundation for stochastic duels and contains a further study of the game models based on the theory of stochastic duels. Some other combat assessment techniques are looked upon briefly; a modern outlook on the applications of the theory through video games is provided; and the possibility of usage of data generated by popular shooter-type video games is discussed. Impactful works to date are carefully chosen; a timeline of the developments in the theory of stochastic duels is provided; and a brief literature review for the same is conducted, enabling readers to have a broad outlook at the theory of stochastic duels. A new evaluation model is introduced in order to match realistic scenarios. Improvements are suggested and, additionally, a trust mechanism is introduced to identify the intent of a player in order to make the model a better fit for realistic modern problems. The concept of teaming of players is also considered in the proposed mode. A deep-learning model is developed and trained on data generated by video games to support the results of the proposed model. The proposed model is compared to previously published models in a brief comparison study. Contrary to the conventional stochastic duel game combat model, this new proposed model deals with pair-wise duels throughout the game duration. This model is explained in detail, and practical applications of it in the context of the real world are also discussed. The approach toward solving modern-day problems through the use of game theory is presented in this paper, and hence, this paper acts as a foundation for researchers looking forward to an innovation with game theory.
The Cult of the Child: A Critical Examination of Its Consequences on Parents, Teachers and Children
Authors: Dupont Serge , Mikolajczak Moïra , Roskam Isabelle
Published: March 2022

The concept of the “cult of the child” highlights a radical change in child representation. Having been neglected and even disrespected for centuries, children are now valued, and their interests are placed above all others. This change in views of children, reflected in changes in laws, institutions and practices, has also spread to two pillars of our democratic societies, the family and the school, with a number of consequences for parents, teachers and children. The purpose of this article is to (1) describe the changes in thinking that have led to the cult of the child, (2) examine their consequences for children and parents, (3) examine their consequences for students and teachers, and (4) reflect on how to preserve the benefits of these changes while limiting the negative consequences.
Plank Times and Lower Extremity Overuse Injury in Collegiate Track-and-Field and Cross Country Athletes
Authors: Luedke Lace E. , Rauh Mitchell J.
Published: March 2022

Trunk muscle endurance has been theorized to play a role in running kinematics and lower extremity injury. However, the evidence examining the relationships between static trunk endurance tests, such as plank tests, and lower extremity injury in athletes is conflicting. The purpose of this study was to assess if collegiate cross country and track-and-field athletes with shorter pre-season prone and side plank hold times would have a higher incidence of lower extremity time-loss overuse injury during their competitive sport seasons. During the first week of their competitive season, 75 NCAA Division III uninjured collegiate cross country and track-and-field athletes (52% female; mean age 20.0 ± 1.3 years) performed three trunk endurance plank tests. Hold times for prone plank (PP), right-side plank (RSP) and left-side plank (LSP) were recorded in seconds. Athletes were followed prospectively during the season for lower extremity overuse injury that resulted in limited or missed practices or competitions. Among the athletes, 25 (33.3%) experienced a lower extremity overuse injury. There were no statistically significant mean differences or associations found between PP, RSP or LSP plank test hold times (seconds) and occurrence of lower extremity overuse injury. In isolation, plank hold times appear to have limited utility as a screening test in collegiate track-and-field and cross country athletes.
Effect of Fresh Dendrobe Juice Consumption on Senile Habitual Constipation for Older People: A Four-Week Randomized Controlled Trial
Authors: Le Yuchao , Cao Shihua , Wang Mengxin , He Danni , Chen Yanfei , Qian Beiying
Published: March 2022

Background: In Chinese medicine, it is believed that fresh dendrobe juice, which is mild in nature, can relieve the symptom of constipation. Methods: A pilot research design was conducted. Fifty-six older people with senile habitual constipation were recruited and randomly enrolled into control or experimental groups, each with 28 people. The control group was offered water routinely in a day. In addition, the experimental group received 125 mL of dendrobe juice twice a day for four weeks. Quality of life for the old people was evaluated by the Patient Assessment of Constipation Quality of Life (PAC-QOL) Score and the symptom of constipation was assessed by Wexner score. Results: The four-week intervention brought significant performance improvement in all the measured parameters in the experimental group in comparison with the control group. These included significantly more frequency and shorter durations of defecation (p < 0.01, respectively), improved quality of life based on constipation score (PAC-QOL) (experimental group: 50.41 ± 3.46 vs. control group: 70.25 ± 2.35; p < 0.05), and improved score on the Wexner constipation scale (experimental group: 6.56 ± 0.89 vs. control group: 15.50 ± 0.64; p < 0.05). Conclusions: Fresh dendrobe beverage therapy is effective in improving stool frequency, reducing duration of defecation, and enhancing quality of life.
Energy Balance, Productivity and Resource-Use Efficiency of Diverse Sustainable Intensification Options of Rainfed Lowland Rice Systems under Different Fertility Scenarios
Authors: Singh Teekam , Bana Ram , Satapathy Bhabani , Lal Banwari , Yogi Akshay , Singh Raj
Published: March 2022

Rice-based cropping systems (RBCS) are a kingpin of global food security and rice fallow is one of the largest (>14 m ha) RBCS. A three-year study was carried out to develop sustainable intensification options and efficient nutrient management protocols of RBCS with greater water and energy productivity and more profits. Rice-lentil, rice-linseed and rice-rapeseed systems were tested in a split-plot design with nutrient management practices involving fertilizer levels (50%, 75% and 100% recommended fertilizer dose; RDF), green manuring with Sesbania (SGM) and rice residue incorporation (RRI). The results indicated that SGM produced significantly better rice productivity, enhanced 6.4–22.7% yield of succeeding crops and increased profits by ~20%. Application of 75 or 100% of RDF produced 24.5–30.3% higher grain yield of rabi crops. System intensification resulted in an additional rice equivalent yield (REY) of ~1–1.6 t ha−1. SGM consumed relatively more energy (76,793 MJ ha−1) but at the same time, resulted in higher energy output (182,657 MJ ha−1), net energy (105,864 MJ ha−1), energy intensity (1.68 MJ INR−1) and human energy profitability (787) than the RRI. However, RRI recorded a higher energy ratio (2.42), energy productivity (0.082 kg MJ−1) and energy profitability (1.42 kg MJ−1). The rice-linseed cropping system resulted in greater system productivity, higher energy output (186,305 MJ ha−1) and net energy (112,029 MJ ha−1) than other systems. Overall, considering energy productivity, resource-use efficiency and profits, a rice-linseed system coupled with SGM and 75% RDF may be recommended as a sustainable intensification option in RBCS.