bluuebunny/crossref_metadata_2025 huggingface dataset:
Prinsepiae Nux Extract Activates NRF2 Activity and Protects UVB-Induced Damage in Keratinocyte
Authors: Wang Shih-Han , Chen Yi-Siao , Lai Kuei-Hung , Lu Chung-Kuang , Chang Hsun-Shuo , Wu Ho-Cheng , Yen Feng-Lin , Chen Lo-Yun , Lee Jin-Ching , Yen Chia-Hung
Published: September 2022

Ultraviolet B (UVB) is one of the most important environmental factors that cause extrinsic aging through increasing intracellular reactive oxygen species (ROS) production in the skin. Due to its protective roles against oxidative stress, nuclear factor erythroid-2-related factor (NRF2) has been traditionally considered as a target for skin aging prevention. Here, we identified the extract of Prinsepiae Nux, a top-grade drug listed in Shen Nong Ben Cao Jing, as a potent NRF2 activator by high-throughput screening. A bioassay-guided fractionation experiment revealed that NRF2-activating components were concentrated in the 90% methanol (MP) fraction. MP fraction significantly increased the expression of NRF2 and HO-1 protein and upregulated HO-1 and NQO1 mRNA expression in HaCaT cells. Moreover, MP fraction pre-treatment dramatically reversed UVB-induced depletion of NRF2 and HO-1, accumulation of intracellular ROS, NF-κB activation, and the upregulation of pro-inflammatory genes. Finally, the qualitative analysis using UPLC-tandem mass spectroscopy revealed the most abundant ion peak in MP fraction was identified as α-linolenic acid, which was further proved to activate NRF2 signaling. Altogether, the molecular evidence suggested that MP fraction has the potential to be an excellent source for the discovery of natural medicine to treat/prevent UVB-induced skin damage.
Dietary Antimicrobial Peptides Improve Intestinal Function, Microbial Composition and Oxidative Stress Induced by Aeromonas hydrophila in Pengze Crucian Carp (Carassius auratus var. Pengze)
Authors: Wang Shaodan , Liu Shulin , Wang Chong , Ye Bin , Lv Liqun , Ye Qiao , Xie Shaolin , Hu Guocheng , Zou Jixing
Published: September 2022

There is increasing evidence for the potential use of antimicrobial peptides as dietary supplements and antibiotic substitutes. In this study, we analyzed the differential effects of varying levels of antimicrobial peptides on the intestinal function and intestinal microbial and disease resistance of Pengze crucian carp. Approximately 630 experimental fishes were randomized in the control group (G0: 0 mg/kg) and in five groups supplemented with different doses of AMPs (G1: 100 mg/kg, G2: 200 mg/kg, G3: 400 mg/kg, G4: 800 mg/kg, and G5: 1600 mg/kg) and were fed for ten weeks. Three replicates per group of 35 fish were performed. The results showed that AMPs promoted intestinal villus development and increased intestinal muscular thickness (p < 0.05) and goblet cell abundance. The enzymatic activities of all groups supplemented with AMPs were effectively improved. AMP supplementation significantly enhanced the activities of antioxidant enzymes and digestive enzymes in the intestines of G3 animals (p < 0.05). Compared with G0 animals, AMP-supplemented animals regulated the expression of intestinal immune-related genes and exhibited significant differences in the G3 animal group (p < 0.05). The abundance of intestinal Firmicutes and Bacteroidetes increased in the AMP-supplemented groups, but the Firmicutes/Bacteroidetes ratio was lower than that in the G0 group. AMP supplementation also decreased the abundance of Fusobacterium while increasing the proportion of Actinobacteria (p < 0.05). After Aeromonas hydrophila infection, the expression levels of anti-inflammatory factors in the intestinal tract of G3 animals were significantly upregulated, and the level of the proinflammatory factor was decreased (p < 0.05). The intestinal Cetobacterium levels of G3 animals were significantly increased (p < 0.01), while the Proteobacteria levels were decreased, and the intestinal goblet cell proliferation was significantly lower than that of G0 animals (p < 0.05). This indicates that groups supplemented with AMPs have better disease resistance than the G0 group and can rapidly reduce the adverse effects caused by inflammatory response. Taken together, the present results suggest that AMP supplementation can improve intestinal function and intestinal microbial and pathogen resistance in Pengze crucian carp.
ContextKT: A Context-Based Method for Knowledge Tracing
Authors: Yu Minghe , Li Fan , Liu Hengyu , Zhang Tiancheng , Yu Ge
Published: September 2022

Knowledge tracing, which is used to predict students’ performance based on their previous practices, has attracted many researchers’ attention. Especially in this rising period of intelligent education, many knowledge tracing methods have been developed. However, most of the existing knowledge tracing methods focus on the personality of practices and knowledge concepts but ignore the contexts related to the studying process. In this paper, we propose a context-based knowledge tracing model, which combines students’ historical performance and their studying contexts during knowledge mastery. To be specific, we first define five studying contexts for performance prediction. The basic context is the current knowledge state of a student, which is described by their practice sequences. Then, a QR-matrix is defined to represent the relationship among questions, knowledge concepts, and responses, which describes the contexts of questions and knowledge. Furthermore, an improved LSTM model is proposed to capture the context of students’ memory and forgetness, and a multi-head attention mechanism is designed to capture the context of students’ behaviors. Finally, based on the captured contexts, the prediction model ContextKT is established. Our prediction model is evaluated on two real educational datasets. The experimental results show our model is effective and efficient in student performance prediction, and it outperforms the other existing methods.
SmartTips: Online Products Recommendations System Based on Analyzing Customers Reviews
Authors: Ali Noaman M. , Alshahrani Abdullah , Alghamdi Ahmed M. , Novikov Boris
Published: September 2022

Online customers’ opinions represent a significant resource for both customers and enterprises to extract much information that helps them make the right decision. Finding relevant data while searching the internet is a big challenge for web users, known as the “Problem of Information Overload”. Recommender systems have been recognized as a promising way of solving such problems. In this paper, a product recommendation system called “SmartTips” is introduced. The proposed model is built based on aspect-based sentiment analysis, which exploits customers’ feedback and applies the aspect term extraction model to rate various products and extract user preferences as well. Several factors were considered, including readers’ votes, aspect term frequency, opinion words’ frequencies, etc. We tested our model on benchmark datasets that are widely used, and the results show that it outperforms the baseline methods regarding the mean squared errors of generated predictions.
Spatial Distribution Pattern and Influencing Factors of Homestays in Chongqing, China
Authors: Wang Wenxin , Yang Qingyuan , Gan Xia , Zhao Xing , Zhang Junfan , Yang Han
Published: September 2022

As an emerging business form of tourism development, homestays also play an important role in China’s rural revitalization and tourism transformation and upgrading, and has attracted increasing social attention. At present, Chongqing is the city with the largest number of homestays in China. Taking Chongqing as a case-study area, based on the homestay data of the Baidu map, this paper comprehensively uses the methods of spatial analysis, multiple regression and geographical weighted regression to thoroughly analyze the regional characteristics and influencing factors of homestay distribution in Chongqing. The results show that: (1) the nearest-neighbor index R of homestay distributions in Chongqing and all regions is one, which shows an obvious agglomeration type. (2) In addition to being highly concentrated in the central urban area, three secondary high-density areas are also formed in the surrounding areas of the central urban area, and there is a trend of concentration and contiguity. The spatial distribution densities of the two urban agglomerations in Southeast and Northeast Chongqing are very low, and the overall distributions are extremely uneven. (3) The factors, such as tourism resource endowment, economic development, service industry development, traffic location, consumption demand and social development conditions, have significant impacts on the distribution pattern of homestays, and the impacts of each factor on the layout of homestays has obvious spatial heterogeneity. Analyzing and revealing the temporal and spatial characteristics and dynamic mechanism of homestays has an important theoretical value and practical significance for better serving the new urbanization plan and implementing the strategy of urban–rural integration and rural revitalization.
Synthesis of an Aluminum Alloy Metal Matrix Composite Using Powder Metallurgy: Role of Sintering Parameters
Authors: Nayak Kanhu C. , Rane Kedarnath K. , Date Prashant P. , Srivatsan T. S.
Published: September 2022

Powder metallurgy-based metal matrix composites (MMCs) are widely chosen and used for the development of components in the fields spanning aerospace, automotive and even electronic components. Engineered MMCs are known to offer a high strength-to-weight (σ/ρ) ratio. In this research study, we synthesized cylindrical sintered samples of a ceramic particle-reinforced aluminum metal matrix using the technique of powder metallurgy. The samples for the purpose of testing, examination and analysis were made by mixing aluminum powder with powders of silicon carbide and aluminum oxide or alumina. Four varieties of aluminum composite were synthesized for a different volume percent of the ceramic particle reinforcement. The hybrid composite contained 2 vol.% and 7 vol.% of silicon carbide and 3 vol.% and 8 vol.% of alumina with aluminum as the chosen metal matrix. Homogeneous mixtures of the chosen powders were prepared using conventional ball milling. The homogeneous powder mixture was then cold compacted and subsequently sintered in a tubular furnace in an atmosphere of argon gas. Five different sintering conditions (combinations of temperature and sintering time) were chosen for the purpose of this study. The density and hardness of each sintered specimen were carefully evaluated. Cold compression tests were carried out for the purpose of determining the compressive strength of the engineered MMC. The sintered density and hardness of the aluminum MMCs varied with the addition of ceramic particle reinforcements. An increase in the volume fraction of the alumina particles to the Al/SiC mixture reduced the density, hardness and compressive strength. The sintering condition was optimized for the aluminum MMCs based on the hardness, densification parameter and cold compressive strength. The proposed powder metallurgy-based route for the fabrication of the aluminum matrix composite revealed a noticeable improvement in the physical and mechanical properties when compared one-on-one with commercially pure aluminum.
Enhancement of In-Plane Seismic Full Waveform Inversion with CPU and GPU Parallelization
Authors: Basnet Min Bahadur , Anas Mohammad , Rizvi Zarghaam Haider , Ali Asmer Hamid , Zain Mohammad , Cascante Giovanni , Wuttke Frank
Published: September 2022

Full waveform inversion is a widely used technique to estimate the subsurface parameters with the help of seismic measurements on the surface. Due to the amount of data, model size and non-linear iterative procedures, the numerical computation of Full Waveform Inversion are computationally intensive and time-consuming. This paper addresses the parallel computation of seismic full waveform inversion with Graphical Processing Units. Seismic full-waveform inversion of in-plane wave propagation in the finite difference method is presented here. The stress velocity formulation of the wave equation in the time domain is used. A four nodded staggered grid finite-difference method is applied to solve the equation, and the perfectly matched layers are considered to satisfy Sommerfeld’s radiation condition at infinity. The gradient descent method with conjugate gradient method is used for adjoined modelling in full-waveform inversion. The host code is written in C++, and parallel computation codes are written in CUDA C. The computational time and performance gained from CUDA C and OpenMP parallel computation in different hardware are compared to the serial code. The performance improvement is enhanced with increased model dimensions and remains almost constant after a certain threshold. A GPU performance gain of up to 90 times is obtained compared to the serial code.
Towards Federated Learning with Byzantine-Robust Client Weighting
Authors: Portnoy Amit , Tirosh Yoav , Hendler Danny
Published: September 2022

Federated learning (FL) is a distributed machine learning paradigm where data are distributed among clients who collaboratively train a model in a computation process coordinated by a central server. By assigning a weight to each client based on the proportion of data instances it possesses, the rate of convergence to an accurate joint model can be greatly accelerated. Some previous works studied FL in a Byzantine setting, in which a fraction of the clients may send arbitrary or even malicious information regarding their model. However, these works either ignore the issue of data unbalancedness altogether or assume that client weights are a priori known to the server, whereas, in practice, it is likely that weights will be reported to the server by the clients themselves and therefore cannot be relied upon. We address this issue for the first time by proposing a practical weight-truncation-based preprocessing method and demonstrating empirically that it is able to strike a good balance between model quality and Byzantine robustness. We also establish analytically that our method can be applied to a randomly selected sample of client weights.
Benincasa hispida Extract Promotes Proliferation, Differentiation, and Mineralization of MC3T3-E1 Preosteoblasts and Inhibits the Differentiation of RAW 246.7 Osteoclast Precursors
Authors: Choi Ye-Eun , Yang Jung-Mo , Cho Ju-Hyun
Published: September 2022

Owing to global population aging, instances of bone metabolic diseases have increased. Consequently, interest in natural and functional plant food products for the prevention and treatment of osteoporosis is also increasing. In this study, we determine the potential therapeutic effects of Benincasa hispida extract (HR1901-W) on osteoblast and osteoclast differentiation. The potential preventive effects of Benincasa hispida in osteoporosis have not previously been reported. We identified and analyzed 2-furoic acid, a chemical component of HR1901-W. We evaluated whether HR1901-W promoted osteogenesis in the MC3T3-E1 cell line and whether it inhibited the differentiation of RAW 264.7 macrophage cells (osteoblast precursors). We observed that HR1901-W promoted significantly high dose-dependent proliferation and extracellular matrix mineralization in MC3T3-E1 cells. In fact, increased cell proliferation was found to be associated with increased protein expression of factors related to osteoblast differentiation, including alkaline phosphatase, osteocalcin, and runt-related transcription factor 2. On the other hand, macrophage colony-stimulating factor (10 ng/mL) and nuclear factor-κB ligand (100 ng/mL) treated differentiated RAW264.7 macrophages exhibited a significant reduction in tartrate-resistant acid phosphatase activity. Taken together, our results indicate that HR1901-W is a promising candidate of functional materials that regulate the balance between bone-forming osteoblasts and bone-resorbing osteoclasts to prevent osteoporosis.
Uncertainty Quantification for Infrasound Propagation in the Atmospheric Environment
Authors: Yu Liang , Yi Xiaoquan , Wang Ran , Zhang Chenyu , Wang Tongdong , Zhang Xiaopeng
Published: September 2022

The propagation of infrasound in the atmosphere is influenced by atmospheric environmental parameters, which affect the precise localization of the infrasound source. Therefore, it has become crucial to quantify the influence of atmospheric environmental parameters on infrasound propagation. First, in this paper, the tau-p model is chosen as the physical model of infrasound propagation in a non-uniform moving medium. The atmospheric environmental parameters affecting infrasound propagation are determined. Secondly, the atmospheric environmental parameter distribution data are generated using the Sobol sampling method. Third, the generated atmospheric data are incorporated into the physical model of infrasound propagation to solve the output. Finally, Sobol sensitivity analysis is performed for each parameter, and the atmospheric parameter with the largest Sobol index is identified as the one with the most significant influence on infrasound propagation.
On the Efficacy of Turbulence Modelling for Sloshing
Authors: Mahfoze Omar Ahmed , Liu Wendi , Longshaw Stephen M. , Skillen Alex , Emerson David R.
Published: September 2022

As part of a wider project to understand the applicability of utilising slosh-based damping for wing-like structures, simulations of partially filled tanks subjected to harmonically oscillating and vertical motion are presented. The Volume of Fluid modelling approach is used to capture the air–water interface and different turbulence models based on the Reynolds Averaged Navier–Stokes equations employed. No-model simulations are also conducted to demonstrate the efficacy of using turbulence models in the simulation of sloshing flows. Accuracy of the models is assessed by comparing with recent well-validated experimental data in terms of the damping effect of the sloshing. A wide range of excitation amplitudes are considered in the study to demonstrate the effectiveness of different turbulence models in representing the flow feature of weak and very violent sloshing. The results show that standard turbulence models can produce an excessive dissipation, especially at the interface, leading to inaccuracies in the estimation of sloshing dynamics of the violent sloshing. This issue is absent in the no-model simulations, and better results are obtained for all tested sloshing conditions, suggesting approaches to mitigate this interfacial dissipation within RANS-based modelling is an important consideration for future direction.
Experimental Study on Lateral and Vertical Capacity of Piled Raft and Pile Group System in Sandy Soil
Authors: Jamil Irfan , Ahmad Irshad , Ullah Wali , Ahmad Mahmood , Sabri Mohanad Muayad Sabri , Majdi Ali
Published: September 2022

In deep foundations, the pile group and the pile raft are generally used. To date, the contribution of the raft is not taken into account in the design, even when the raft is in contact with the soil and the whole system is therefore considered to work as a pile group foundation. In a combined pile raft system, the raft takes a considerable portion of the applied load, depending upon the number of piles, the spacing to diameter ratio of the piles, and the length to diameter ratio. In this paper, an experimental investigation is carried out to study the response of small-scale pile group and piled raft models with a varying number of piles subjected to both vertical and lateral loads. Additionally, the response mechanism of these models to both types of loads is also studied. A comparison was made between these models. It was found that, unlike the pile group, the piled raft provides considerably high stiffness to both types of loads, and the difference between the stiffness of both systems decreases as the number of piles increases. By comparing the response of the piled raft and the pile group with the same number of piles under the same vertical and lateral load, it was concluded that the piled raft response to the lateral and vertical loads was much stiffer than the pile group response. The lateral deflection and the vertical settlement of the piled raft were less than those of the pile group with the same pile configuration. This effective response of the piled raft to the vertical and lateral loads was due to the raft contribution in resisting the vertical and lateral loads. Moreover, with the increase in the number of piles, the vertical and lateral contribution of the raft decreases.
Geometry-Based Radiation Prediction of Laser Exposure Area for Laser Powder Bed Fusion Using Deep Learning
Authors: Zhang Song , Jahn Anne , Jauer Lucas , Schleifenbaum Johannes Henrich
Published: September 2022

Laser powder bed fusion (LPBF) is a promising technique used to manufacture complex geometries in a layer-wised manner. Radiation during the LPBF process is influenced by the part geometry, e.g., the overhang angle and the wall thickness. Locally varying radiation can cause deformation of the product after manufacturing. Thus, the prediction of the geometry-caused radiation before the manufacturing can support the evaluation of the design printability to achieve first-time-right printing. In this paper, we present a framework to predict the geometry-based radiation information using a deep learning (DL) algorithm based on the part geometry from computer-aided design (CAD). The algorithm was trained using data from an LPBF-print job consisting of parts with varying overhang angles. Image data, which include the information of radiation, were captured with an optical tomography (OT) camera system that was installed on a LPBF machine used in a laboratory environment. For the DL algorithm, a U-Net based network with mean absolute error (MAE) loss was applied. The training input was binarized OT data representing the contour of the designed geometry. Complementary, the OT data were used as ground truth for the model training. For the application, the design contours of multiple layers were extracted from the CAD file. The result shows the applicability to predict the OT-like radiation by its contour, which has the possibility to show the anomaly due to the part geometry.
Special Issue “Physics and Mechanics of New Materials and Their Applications 2020”
Authors: Parinov Ivan A. , Kim Yun-Hae , Chang Shun-Hsyung , Wang Hung-Yu
Published: September 2022

Material science, including design, manufacture, research, development and application of new materials and composites, is the one of the most quickly developing and important scientific directions of science, techniques and technologies [...]
Non-Waste Technology for Utilization of Tree Branches
Authors: Lyashenko Serhii , Gorbenko Oleksandr , Kelemesh Anton , Kalinichenko Antonina , Stebila Jan , Patyka Volodymyr
Published: September 2022

The trees (e.g., fruit or decorative) growing on the homestead plots of private households provide opportunities for sustainable biomass obtained from pruned branches every year. Profitable production of fuel material requires high-performance equipment and methods by which wood chips can be produced at low cost. The practice of chopping tree branches shows that not all chopping machines are suitable for use on homestead plots. This research gives the five-year test results of a developed and patented tree branch chopping machine under special operating conditions. The machine was tested under the conditions of the homestead plot of a private household in the Poltava region, and the engineering parameters to set up the chopper were determined. It is recommended to set a 0.3404 radian (19 degrees 50 min) angle on the chopper to cut tree branches as well as to set the size of the cutting knives’ protrusion above the disc plane within 0.0120 m. As a result of the correct settings, the power consumption of the chopper motor will be W = 1.3549 kW, which is an optimal value for the studied chopper. The research results made it possible to provide instructions for the tree branch chopper’s operation and to adapt it to the conditions of homestead plots.
The Transition to Chaos of Pendulum Systems
Authors: Litak Grzegorz , Borowiec Marek , Da̧bek Krzysztof
Published: September 2022

We examine the nonlinear response of two planar pendula under external and kinematic excitations, which are very relevant as paradigmatic models in nonlinear dynamics. These pendula act under the action of an additional constant torque, and are subjected to one of the following excitations: a further external periodic torque, and a vertically periodic forcing of the point of suspension. Here, we show the influence of the constant torque strength on the transition to chaotic motions of the pendulum using both Melnikov analysis and the computation of the basins of attraction. The global bifurcations are illustrated by the erosion of the corresponding basins of attraction.
Carrier-Based Obturation: Effect of Sonication Technique on Sealer Penetration in Dentinal Tubules: A Confocal Laser Scanning Microscope Study
Authors: Tonini Riccardo , Salvadori Matteo , Bartoli Marco , Francinelli Jacopo , Bertoletti Paolo , Garo Maria Luisa , Salgarello Stefano
Published: September 2022

(1) Background: In endodontics, anatomical complexities and irregularities in the root canal system may interfere with sealer penetration, increasing the risk of treatment failure. This work aimed to investigate the effects of sonicated Thermafil (Dentsply, Tulsa Dental Specialties, Johnson City, TN, USA) on sealer penetration into the dentinal tubules. (2) Methods: Thirty teeth with single round-shaped root canals were used to compare Sonicated Thermafil with sonication (ST—10 teeth), System B (EIE Analytical Technology, Orange, CE, USA) (SB—10 teeth), and Thermafil without sonication (T—10 teeth). A confocal laser scanning microscope (CLSM) was used to determine the depth, area, and percentage of sealer penetration into the dentinal tubules. (3) Results: ST showed the deepest average penetration at 6 mm from the apex compared to SB (p < 0.01) and T (p < 0.01) and at 3 mm compared to SB (p < 0.01). In addition, it had the highest penetration values at both levels compared to SB (p < 0.01) and T (p < 0.05) and a higher penetration area at 6 mm compared to T (p < 0.05) and SB (p < 0.05). (4) Conclusion: Sonic activation can improve the carrier-based obturation technique thanks to deeper sealer penetration and thus better retention of materials.
Influence of the Urban Intersection Reconstruction on the Reduction of Road Traffic Noise Pollution
Authors: Jandacka Dusan , Decky Martin , Hodasova Katarina , Pisca Peter , Briliak Dusan
Published: September 2022

The authors present the unsolved issue of the contextual design of urban intersections (UI) from the point of view of traffic noise emissions around residential buildings in the Slovak context. Noise barriers are very rarely used in urban areas, due to such reasons as lack of space for their installation, traffic safety (view at intersections), architectural factors, as well as the fact that they represent a barrier for pedestrians and cyclists. The use of low-noise asphalt pavements is limited in urban areas primarily due to the high cost of production and maintenance of these covers, their limited durability in a colder climate, and lower efficiency compared to the roads outside urban areas. From this aspect of urban intersection design, the authors focused on the identification of individual factors associated with the significant reduction (2–8 dB) of traffic noise induced by the reconstruction of non-signalized urban intersections into roundabouts. The authors draw attention to the fact that both new surfaces of intersection branches and the change in traffic processes contribute to the aforementioned reduction. This finding was obtained by comparing direct measurements of noise levels and the results of their predicted values using validated 3D models in the CadnaA program. Noise emissions were measured by a noise analyzer (NOR-1210), and traffic noise emissions were predicted by the “Nouvelle Méthode de Prévision du Bruit” methodology (NMPB-1996). Based on the analysis of the measured and predicted traffic noise levels, the authors objectivized the share of reduction in traffic processes in the 2–3 dB range. The authors objectified the share of traffic noise reduction due to the change in traffic processes as being in the 2.2–3.3 dB range. The presented research results could contribute to a quantifiable reduction in the noise load in the external environment of residential buildings using the contextual design of intersections.
Towards a Counting Point Detector for Nanosecond Coherent X-ray Science
Authors: Lee Sooheyong , Kwon Hyusang , Cho Byeong-Gwan , Landahl Eric C.
Published: September 2022

We present the technical realization of a high-speed hard X-ray single-photon counting-detection scheme based on a commercial avalanche silicon photodiode and high-speed oscilloscope. The development is motivated by the need to perform pulse-resolved photon-correlation and pump-probe studies at synchrotron sources with densely packed pulse patterns that result in high repetition rate pulses on the order of hundreds of MHz. Commissioning experiments are performed at the 1C PAL-KRISS beamline at PLS-II of South Korea operating at a burst mode maximum repetition rate of 500 MHz. In such a high count-rate measurement, detector dead-time can lead to a distortion of counting statistics. We are able to model the counting behavior of our detector under these conditions with a detector dead-time comparable to time between X-ray pulses, implying that nanosecond X-ray photon correlation spectroscopy should be possible at diffraction-limited light sources.
A Robust H∞ Application for Motor-Link Control Systems of Industrial Manipulators
Authors: Indri Marina , Bellissimo Martina , Pesce Stefano , Perna Valerio
Published: September 2022

H∞ control approaches are widely investigated in various application fields and in the robotics area, too, for their robustness properties. However, they are still rarely adopted in the industrial context for the control of robot manipulators, mainly due to the lack of predefined procedures to build weighting functions able to automatically guarantee the fulfillment of the control objectives. This paper reports the first results of an academic–industrial research activity aimed at investigating the adoption of an H∞ approach in the control software architecture of industrial manipulators, equipped with standard sensors on the motor side only. The design of the control system for a single-axis of an industrial manipulator is developed, showing that the construction of the weighting functions according to standard procedures can provide a satisfying behavior only on the motor side, leaving unacceptable oscillations of the link. A different procedure is then developed for the definition of the weighting functions with the specific aim of eliminating the possible vibrations of the mechanical structure. The proposed new form of such functions, including the main dynamic characteristics of the plant, ensures a robust, satisfying behavior on both the motor and the link side, as proven by simulation and experimental results.
Special Issue on Applied Engineering to Lean Manufacturing and Production Systems 2020
Authors: García-Alcaraz Jorge Luis , Sánchez Ramírez Cuauhtémoc
Published: September 2022

At the end of 2018, a call for papers was made for the Special Issue called “Applied Engineering to Lean Manufacturing Production Systems”, whose objective was to bring together different articles with industrial applications of the different lean manufacturing (LM) tool theories for problem-solving and case studies that improve the indices of the production systems [...]
Arabic Automatic Speech Recognition: A Systematic Literature Review
Authors: Dhouib Amira , Othman Achraf , El Ghoul Oussama , Khribi Mohamed Koutheair , Al Sinani Aisha
Published: September 2022

Automatic Speech Recognition (ASR), also known as Speech-To-Text (STT) or computer speech recognition, has been an active field of research recently. This study aims to chart this field by performing a Systematic Literature Review (SLR) to give insight into the ASR studies proposed, especially for the Arabic language. The purpose is to highlight the trends of research about Arabic ASR and guide researchers with the most significant studies published over ten years from 2011 to 2021. This SLR attempts to tackle seven specific research questions related to the toolkits used for developing and evaluating Arabic ASR, the supported type of the Arabic language, the used feature extraction/classification techniques, the type of speech recognition, the performance of Arabic ASR, the existing gaps facing researchers, along with some future research. Across five databases, 38 studies met our defined inclusion criteria. Our results showed different open-source toolkits to support Arabic speech recognition. The most prominent ones were KALDI, HTK, then CMU Sphinx toolkits. A total of 89.47% of the retained studies cover modern standard Arabic, whereas 26.32% of them were dedicated to different dialects of Arabic. MFCC and HMM were presented as the most used feature extraction and classification techniques, respectively: 63% of the papers were based on MFCC and 21% were based on HMM. The review also shows that the performance of Arabic ASR systems depends mainly on different criteria related to the availability of resources, the techniques used for acoustic modeling, and the used datasets.
Superconducting Sub-Terahertz Oscillator with Continuous Frequency Tuning
Authors: Paramonov Maxim E. , Filippenko Lyudmila V. , Khan Fedor V. , Kiselev Oleg S. , Koshelets Valery P.
Published: September 2022

The development and approbation of a superconducting local oscillator based on a long Josephson junction made it possible to create a fully superconducting integrated receiver in sub-terahertz frequency range, which was successfully tested both on board a high-altitude balloon and in the laboratory. In order to expand the frequency range of a superconducting integrated local oscillator, it is necessary to ensure the continuous tuning of its frequency at an arbitrary bias current, including a so-called resonant mode regime. The resonant mode regime takes place for high-quality tunnel junctions with low leakage; in this regime, stable generation is possible only at Fiske steps, the distance in frequency between which is tens of GHz. A method for suppressing resonances has been proposed and implemented; this method is based on the introduction of normal metal layers into the region near the long Josephson junction. Modeling of the propagation of electromagnetic waves in the proposed integrated structure was carried out; experimental samples were fabricated, and their comprehensive study was performed. The complete suppression of resonances and the possibility of the continuous tuning of the frequency of a superconducting local oscillator in the range of 200–700 GHz have been demonstrated. The linewidth of the FFO radiation does not exceed 15 MHz over the entire frequency range, which makes it possible to implement the phase locked loop mode in an integrated receiver intended for spectral studies.
Surface Defect Detection of Rolled Steel Based on Lightweight Model
Authors: Zhou Shunyong , Zeng Yalan , Li Sicheng , Zhu Hao , Liu Xue , Zhang Xin
Published: September 2022

A lightweight rolled steel strip surface defect detection model, YOLOv5s-GCE, is proposed to improve the efficiency and accuracy of industrialized rolled steel strip defect detection. The Ghost module is used to replace the CBS structure in a part of the original YOLOv5s model, and the Ghost bottleneck is employed to replace the bottleneck structure in C3 to minimize the model’s size and make the network lightweight. The EIoU function is added to improve the accuracy of the regression of the prediction frame and accelerate its convergence. The CA (Coordinate Attention) attention method is implemented to reinforce critical feature channels and their position information, enabling the model to identify and find targets correctly. The experimental results demonstrate that the accuracy of YOLOv5s-GCE is 85.7%, which is 3.5% higher than that of the original network; the model size is 7.6 MB, which is 44.9% smaller than that of the original network; the number of model parameters and calculations are reduced by 47.1% and 48.8%, respectively; and the detection speed reached 58.8 fps. YOLOv5s-GCE meets the necessity for real-time identification of rolled steel flaws in industrial production compared to other common algorithms.
A Fuzzy-Based Method for Objects Selection in Blockchain-Enabled Edge-IoT Platforms Using a Hybrid Multi-Criteria Decision-Making Model
Authors: Gardas Bhaskar B. , Heidari Arash , Navimipour Nima Jafari , Unal Mehmet
Published: September 2022

The broad availability of connected and intelligent devices has increased the demand for Internet of Things (IoT) applications that require more intense data storage and processing. However, cloud-based IoT systems are typically located far from end-users and face several issues, including high cloud server load, slow response times, and a lack of global mobility. Some of these flaws can be addressed with edge computing. In addition, node selection helps avoid common difficulties related to IoT, including network lifespan, allocation of resources, and trust in the acquired data by selecting the correct nodes at a suitable period. On the other hand, the IoT’s interconnection of edge and blockchain technologies gives a fresh perspective on access control framework design. This article provides a novel node selection approach for blockchain-enabled edge IoT that provides a quick and dependable node selection. Moreover, fuzzy logic to approximation logic was used to manage numerical and linguistic data simultaneously. In addition, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), a powerful tool for examining Multi-Criteria Decision-Making (MCDM) problems, is used. The suggested fuzzy-based technique employs three input criteria to select the correct IoT node for a given mission in IoT-edge situations. The outcomes of the experiments indicate that the proposed framework enhances the parameters under consideration.
Mechanical and Thermal Properties of Aluminum Matrix Composites Reinforced by In Situ Al2O3 Nanoparticles Fabricated via Direct Chemical Reaction in Molten Salts
Authors: Yolshina Liudmila A. , Kvashnichev Aleksander G. , Vichuzhanin Dmitrii I. , Smirnova Evgeniya O.
Published: September 2022

The development of novel methods for industrial production of metal-matrix composites with improved properties is extremely important. An aluminum matrix reinforced by “in situ” α-Al2O3 nanoparticles was fabricated via direct chemical reaction between molten aluminum and rutile TiO2 nanopowder under the layer of molten salts at 700–800 °C in air atmosphere. Morphology, size, and distribution of the in situ particles, as well as the microstructure and mechanical properties of the composites were investigated by XRD, SEM, Raman spectra, and hardness and tensile tests. Synthesized aluminum–alumina composites with Al2O3 concentration up to 19 wt.% had a characteristic metallic luster, their surfaces were smooth without any cracks and porosity. The obtained results indicate that the “in situ” particles were mainly cube-shaped on the nanometer scale and uniform matrix distribution. The concentration of Al2O3 nanoparticles depended on the exposure time and initial precursor concentration, rather than on the synthesis temperature. The influence of the structure of the studied materials on their ultimate strength, yield strength, and plasticity under static loads was established. It is shown that under static uniaxial tension, the cast aluminum composites containing aluminum oxide nanoparticles demonstrated significantly increased tensile strength, yield strength, and ductility. The microhardness and tensile strength of the composite material were by 20–30% higher than those of the metallic aluminum. The related elongation increased three times after the addition of nano-α Al2O3 into the aluminum matrix. Composite materials of the Al-Al2O3 system could be easily rolled into thin and ductile foils and wires. They could be re-melted for the repeated application.
Implementation of Autonomous Mobile Robot in SmartFactory
Authors: Hercik Radim , Byrtus Radek , Jaros Rene , Koziorek Jiri
Published: September 2022

This study deals with the technology of autonomous mobile robots (AMR) and their implementation on the SmartFactory production line at the Technical University of Ostrava. The task of the mobile robot is to cooperate with the production line, take over the manufactured products, and then deliver them. The content also includes a description of the individual steps that were necessary to make the mobile robot operational, such as loading a virtual map of the space, creating a network for communication with the mobile robot, and programming it. The main part of the experiment deals with testing the accuracy of moving the mobile robot to each position and establishing communication between the production line and the mobile robot. A high accuracy is a necessity in this process. The result of the study is the configuration of the autonomous mobile robot. The repetitive precision of the approach of the autonomous mobile robot to a position is ±3 mm.
Roll Eccentricity Signal Detection and Its Engineering Application Based on SFFT-IAA
Authors: Yang Zhe , Liu Ding , Zheng Gang
Published: September 2022

The roll eccentricity signal is a weak and complex periodic signal that is difficult to be identified. To improve the detection accuracy of the roll eccentricity signal and to compensate effectively, this study proposed a roll eccentricity signal detection method by combining the sparse fast Fourier transform (SFFT) and the iterative adaptive approach (IAA). The proposed method can rapidly determine the frequency range of the roll eccentricity signal by using the SFFT. Then, it divides the frequency range into several small frequency bands. In each small frequency band, the frequency, amplitude, and phase angle of each harmonic component of the roll eccentricity signal were estimated by using IAA. The simulation results show that the proposed method can find all frequency components, and the frequency estimation accuracy is higher than 99.88%. Finally, the engineering application of this method and the eccentricity compensation control were investigated. In engineering applications, the proposed method can reduce the thickness fluctuation of the finished strip by 89.2%, and the product quality is improved significantly. The simulation results and engineering experiments show that the proposed method has an excellent effect on detecting and compensating roll eccentricity signals.
An Insight into the Integration of Distributed Energy Resources and Energy Storage Systems with Smart Distribution Networks Using Demand-Side Management
Authors: Panda Subhasis , Mohanty Sarthak , Rout Pravat Kumar , Sahu Binod Kumar , Parida Shubhranshu Mohan , Kotb Hossam , Flah Aymen , Tostado-Véliz Marcos , Abdul Samad Bdereddin , Shouran Mokhtar
Published: September 2022

Demand-side management (DSM) is a significant component of the smart grid. DSM without sufficient generation capabilities cannot be realized; taking that concern into account, the integration of distributed energy resources (solar, wind, waste-to-energy, EV, or storage systems) has brought effective transformation and challenges to the smart grid. In this review article, it is noted that to overcome these issues, it is crucial to analyze demand-side management from the generation point of view in considering various operational constraints and objectives and identifying multiple factors that affect better planning, scheduling, and management. In this paper, gaps in the research and possible prospects are discussed briefly to provide a proper insight into the current implementation of DSM using distributed energy resources and storage. With the expectation of an increase in the adoption of various types of distributed generation, it is estimated that DSM operations can offer a valuable opportunity for customers and utility aggregators to become active participants in the scheduling, dispatch, and market-oriented trading of energy. This review of DSM will help develop better energy management strategies and reduce system uncertainties, variations, and constraints.
Bacterial Profile and Changes in the Protein–Peptide Fraction in Spontaneously Fermented Lens culinaris Medik.
Authors: Skrzypczak Katarzyna , Michalak Katarzyna , Wyrostek Jakub , Jabłońska-Ryś Ewa , Sławińska Aneta , Radzki Wojciech , Gustaw Waldemar
Published: September 2022

Pulses have desirable nutritional properties and a wide range of applications in the food industry as meat-free, casein-free, gluten-free, and functional food products. Unfortunately, the legume raw material contains some anti-nutrients and allergenic agents; nonetheless, fermentation processes may reduce some of these undesirable compounds. Therefore, the objective of the preliminary investigation was to determine the profile of bacteria occurring after spontaneous fermentation of Lens culinaris Medik. and detect changes in the protein–peptide pattern, including potential modifications of Len c3, i.e., a non-specific lipid-transfer protein (nsLTP) recognized as an important allergen. This study involved MALDI TOF/TOF, Illumina next-generation sequencing, and FT-IR spectroscopy analyses. Sixteen different species were identified in the plant-based material after 48-h spontaneous fermentation. The most abundant species were Lactococcus taiwanensis and Pediococcus pentosaceus (54.95% and 25.34%, respectively). The performed initial analysis revealed that after spontaneous fermentation had occurred the degradation of proteins (~10 kDa) and peptides (6–8 kDa), as well as the decomposition of proteins in the mass range that might be attributed to allergenic nsLTP. The preliminary findings encourage further research into the functional and technological properties of the isolated bacteria and in-depth analyses of the possibility of the removal of allergenic compounds from red lentils through fermentation carried out by the isolates.
Potential Use of Fusarium Isolates as Biological Control Agents: Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) Case Study
Authors: Mantzoukas Spiridon , Kitsiou Foteini , Lagogiannis Ioannis , Eliopoulos Panagiotis A.
Published: September 2022

The cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) is a notorious agricultural pest with world-wide distribution, extreme polyphagy, high mobility and fecundity, facultative diapause, and significant resistance to chemical insecticides. Isolates from various Fusarium species were collected from soil, identified, and tested for their entomopathogenicity against H. armigera larvae in field experiments. Fungi of the genus Fusarium are ubiquitous and include phytopathogenic as well as entomopathogenic strains. Seven Fusarium species were identified and tested, including: F. algeriense, F. chlamydosporum var. chlamydosporum, F. fujikuroi, F. longifundum, F. pseudoanthophilum, F.solani, and F. tonkinense. All the collected fungi demonstrated a notable insecticidal effect on H. armigera larvae in field conditions, while some proved to be significantly lethal. The larval mortality of H. armigera ranged from 10 (103 conidia/mL) to 91% (108 conidia/mL) after 9 days (216 h). Larval survival time in treated plants ranged from 95 h (108 conidia/mL) to 208 h (103 conidia/mL). According to our results, F. solani isolate displayed the highest toxicity against H. armigera larvae and could be considered as a promising biocontrol agent of this serious pest.