bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Denial of Service Attack in Cloud Based Kubernetes Using eBPF
Authors: Sadiq Amin , Syed Hassan Jamil , Ansari Asad Ahmed , Ibrahim Ashraf Osman , Alohaly Manar , Elsadig Muna
Published: April 2023

Kubernetes is an orchestration tool that runs and manages container-based workloads. It works as a collection of different virtual or physical servers that support multiple storage capacities, provide network functionalities, and keep all containerized applications active in a desired state. It also provides an increasing fleet of different facilities, known as microservices. However, Kubernetes’ scalability has led to a complex network structure with an increased attack vector. Attackers can launch a Denial of service (DoS) attack against servers/machines in Kubernetes by producing fake traffic load, for instance. DoS or Distributed Denial of service (DDoS) attacks are malicious attempts to disrupt a targeted service by flooding the target’s service with network packets. Constant observation of the network traffic is extremely important for the early detection of such attacks. Extended Berkeley Packet Filter (eBPF) and eXpress Datapath (XDP) are advanced technologies in the Linux kernel that perform high-speed packet processing. In the case of Kubernetes, eBPF and XDP can be used to protect against DDoS attacks by enabling fast and efficient network security policies. For example, XDP can be used to filter out traffic that is not authorized to access the Kubernetes cluster, while eBPF can be used to monitor network traffic for signs of DDoS attacks, such as excessive traffic from a single source. In this research, we utilize eBPF and XDP to build a detection and observation mechanism to filter out malicious content and mitigate a Denial of Service attack on Kubernetes.
Results of Indoor Radon Measurements in Campania Schools Carried Out by Students of an Italian Outreach Project
Authors: La Verde Giuseppe , Ambrosino Fabrizio , Ragosta Maria , Pugliese Mariagabriella
Published: April 2023

Outreach projects are often used to a limited extent for dissemination purposes and rarely have a significant impact on the student’s teaching and technical skills. The RadioLab project requires a proactive interaction between researchers and students by experimental activities for measuring environmental radioactivity, in particular radon gas. Buildings considered to be of radiological interest, such as schools, have been selected to carry out radon gas activity concentration measurements using solid-state nuclear track passive detectors LR-115. The results of annual measurements, made over 6 years and involving a total of 952 rooms, distributed in 67 schools throughout the Campania region, were collected. These data, deemed scientifically reliable (i) can be overlapped over geological characterization data enhancing the relationship between lithology and radon, (ii) confirmed data from the radon potential map of the Campania region about the distribution of indoor radon, and finally (iii) contributed to the collection of radon indoor data of the Campania region. The results obtained highlighted the need and effectiveness of increasing the network of schools involved in the outreach activity and in the implementation of experimental activities with applicative effects in the scientific and research sectors.
Multi-Class Phased Prediction of Academic Performance and Dropout in Higher Education
Authors: Martins Mónica V. , Baptista Luís , Machado Jorge , Realinho Valentim
Published: April 2023

The application of intelligent systems in the higher education sector is an active field of research, powered by the abundance of available data and by the urgency to define effective, data-driven strategies to overcome students’ dropout and improve students’ academic performance. This work applies machine learning techniques to develop prediction models that can contribute to the early detection of students at risk of dropping out or not finishing their degree in due time. It also evaluates the best moment for performing the prediction along the student’s enrollment year. The models are built on data of undergraduate students from a Polytechnic University in Portugal, enrolled between 2009 and 2017, comprising academic, social–demographic, and macroeconomic information at three different phases during the first academic year of the students. Five machine learning algorithms are used to train prediction models at each phase, and the most relevant features for the top performing models are identified. Results show that the best models use Random Forest, either incorporating strategies to deal with the imbalanced nature of the data or using such strategies at the data level. The best results are obtained at the end of the first semester, when some information about the academic performance after enrollment is already available. The overall results compare fairly with some similar works that address the early prediction of students’ dropout or academic performance.
A Multi-Objective Hybrid BESSA Optimization Scheme for Parameter Extraction from PV Modules
Authors: Saha Nutan , Mishra Prakash Chandra
Published: April 2023

In this work, a multi-objective Hybrid Bald Eagle Search Simulated Annealing (Hybrid BESSA) parameter extraction technique for photovoltaic (PV) modules is discussed. First, the efficacy of the Hybrid BESSA was proved via testing on unimodal functions, multimodal functions, and fixed dimensional multimodal functions and the results were compared with the Bald Eagle Search (BES) and other recently proposed optimization techniques. Then, a multi-objective Hybrid Bald Eagle Search Simulated Annealing (Hybrid BESSA) parameter extraction technique was devised for photovoltaic (PV) module parameter extraction. The Hybrid BESSA parameter extraction technique was simulated and analyzed in the MATLAB/SIMULINK environment and in a practical experimental setup for the PV Module AS-M3607-S (G1 CELLS). It was found that the Hybrid BESSA possessed better exploration and exploitation capabilities as compared to the BES and other state-of-the-art techniques. It was found that the fitness function value derived by the Hybrid BESSA technique was less than that of the BES technique when tested under various weather conditions. The percentage error for open circuit voltage, output power, and short circuit current was lower when derived by the Hybrid BESSA in comparison with the BES technique. From the results obtained from modeling the PV Module AS-M3607-S (G1 CELLS) based on Hybrid BESSA-based extracted parameters and BES-based extracted parameters, it was seen that percentage improvement in the combined objective function for the condition of keeping irradiance fixed at 1000 W/m2 at a temperature varying from −30 °C, 0 °C, 25 °C, 30 °C, 50 °C, and 70 °C were 0.9%, 8.5%, 29.2%, 0.03%, 5.7%, and 0.5%, respectively. When the temperature was kept fixed at 250 °C and irradiance varied from 1000 W/m2, 800 W/m2, 600 W/m2, and 400 W/m2, the percentage improvement in combined objective function was found to be 0.5%, 8.1%, 0.5%, and 0.8%, respectively. By analyzing the simulation as well as the experimental results, it was established that the PV model parameter extraction method based on the Hybrid BESSA is more accurate than the BES technique. This analysis is based on a single-diode PV module. A double-diode PV module analysis still needs to be explored.
Analysis of the Influence of Silty Sands Moisture Content and Impact Velocity in SHPB Testing on Their Compactability and Change in Granulometric Composition
Authors: Sobczyk Kamil , Chmielewski Ryszard , Kruszka Leopold , Rekucki Ryszard
Published: April 2023

This paper presents the results of a test cycle of two types of silty sand (siSa) with different contents of fine fractions. Fine fractions are understood as soil grains with a grain diameter of less than 63 µm (as the sum of silt and clay fractions). The soils tested had a content of fine fractions of fSi+Cl,1 = 15.14% and fSi+Cl,2 = 20.48%, respectively, before the study. Changes in the content of these fractions after the experiments were analyzed. These experiments consisted of dynamic bar projectile impact loading, and a split Hopkinson pressure bar (SHPB) test stand was used in the study. Changes in the granulometric composition of the silty sands studied were carried out in a laser particle size analyzer, allowing measurement of fractional content in the grain size range from 0.01 µm to 3500 µm. As a result, a summary of changes in soil grain size curves in the range of fine fractions was compiled. Repeated trends were observed in the changes in the granulometric composition of the soil samples as a function of the moisture content of the soil sample (w1 = 0%, w2 = 5%, w3 = 10%, and w4 = 15%) and the impact velocity of the loading bar projectile for SHPB pneumatic launcher pressures (p1 = 1.2 bar → v1 = 12.76 m/s, p2 = 1.8 bar → v2 = 17.69 m/s and p3 = 2.4 bar → v3 = 21.32 m/s). The influence of the initial moisture content of the investigated soil on the value of the optimum moisture content obtained during its dynamic compaction was discussed. The trend in the behavior of the change in the granulometric composition of the tested samples was determined, taking the value of the initial moisture content of the soil in relation to the optimum moisture content of the reference sample as a reference. The largest percentage change in granulometric composition through an increase in the value of the silt and clay fraction relative to the reference sample fSi+Cl for both types of silty sand tested occurs for the same moisture content variant w2 = 5%–for soil fSi+Cl,1 = 15.14% there is an increase in the fine fraction of 11.08% and for soil fSi+Cl,2 = 20.48% there is an increase in the fine fraction of 15.17%. In general, it can be seen that more silty soil is more strongly susceptible to the phenomenon of grain crushing for moisture content w1 = 0% and w2 = 5% less than its optimum moisture content wopt,1 = 8.70%. In contrast, less silty soil is more susceptible to the phenomenon of grain crushing for moisture contents w3 = 10% and w4 = 15% greater than its optimum moisture content wopt,2 = 9.20%. The presented dynamic physical phenomenon of soil behavior is crucial during explosive and impact impacts on structures made of soil, e.g., as ground protection layers.
Research on Coordinated Control Strategy of Thermal Heating and Melting Depth of Steam Heating and Melting Salt Reservoir
Authors: Li Le , Li Wenyi , Ma Jianlong
Published: April 2023

The implementation of the upgrading of the national coal electric power unit has provided a clear proposal to promote the clean and low-carbon transformation of the power industry. With the power of large-scale intermittent renewable energy and power generation, the electric crew should be flexible enough to adjust resources to achieve a depth of 35% THA. This article aims to propose a heat extracting and heat storage system for fire power plants, to realize the coordinated control strategy of the deep peak, and to explore the coordinated control strategy of the steam–molten salt heat exchanger, molten salt and water exchanger, and the turbine’s main control. The simulation results reveal that the coordinated control of the steam–molten salt heat exchanger, molten salt and water heat exchanger, and steam turbine control could reduce the depth of the fire power unit by 10% THA. The output power response speed of the thermal power unit is enhanced by utilizing the heat turbine, which could effectively enhance the output power response speed of the thermal power unit and increase the output power response speed pertinent to 302.55 s by 75.60%.
Influences of Microwave Irradiation on Rock-Breaking Efficiency of a Reduced-Scale TBM Cutter
Authors: Lu Gaoming , Ding Cong , Zhou Jianjun , Liu Haining , Liu Chaoyin
Published: April 2023

To explore the influences of microwave irradiation on the rock-breaking efficiency of tunnel boring machine (TBM) cutters, a multimode cavity with a microwave power of 2100 W was used to conduct microwave irradiation tests on Chifeng basalt for different durations. A combined abrasion test device for the reduced-scale SP3-I TBM cutter was adopted to conduct cutter wear and rock-breaking tests on basalt samples before and after microwave irradiation. Influences of microwave irradiation on the wear loss of the reduced-scale TBM cutter, rock removal, cutting force, and specific energy were investigated. The results show that the wear loss of the reduced-scale TBM cutter linearly reduces while the rock removal linearly increases with increasing exposure to microwave irradiation. When the penetration depth and the cutter spacing are fixed, the cutting force and the work done by the cutting force exerted by the reduced-scale TBM cutter decrease linearly with increasing exposure to microwave irradiation. The rock-breaking specific energy decreases with increasing exposure to microwave irradiation in an exponential manner. These results indicate that microwave irradiation can prolong the service life of the TBM cutter in the rock-breaking process, reduce the required thrust and torque of the cutter, and improve the rock-breaking efficiency of the TBM.
Two-Way Shape Memory Effect of a Shape Memory Composite Strip
Authors: Du Haiyang , Yao Yongtao , Liu Yang , Zhao Wei
Published: April 2023

In this work, a NiTi shape memory alloy (SMA) wire was embedded into a rubber/shape memory polymer (SMP) soft matrix to form a composite strip with a two-way reversible bending behavior. First, the elastic moduli of SMA wire were characterized as increasing about 3 times (18.6 GPa at martensite phase and 50.1 GPa at austenite phase) from 25 °C to 90 °C. Then, an SMA composite strip using SMP to replace the rubber matrix was fabricated to significantly improve the load-bearing ability (16-fold) at 28 °C. After that, the good two-way bending behaviors of the rubber/SMP-based SMA strip with high shape deploying ratio above 80% were demonstrated. Finally, the application of rubber/SMP-based composite strips in a space-deployable antenna model with two-way reversible bending behavior was developed and demonstrated through a heating and cooling temperature cycle.
A Small-Sample Text Classification Model Based on Pseudo-Label Fusion Clustering Algorithm
Authors: Yang Linda , Huang Baohua , Guo Shiqian , Lin Yunjie , Zhao Tong
Published: April 2023

The problem of text classification has been a mainstream research branch in natural language processing, and how to improve the effect of classification under the scarcity of labeled samples is one of the hot issues in this direction. The current models supporting small-sample classification can learn knowledge and train models with a small number of labels, but the classification results are not satisfactory enough. In order to improve the classification accuracy, we propose a Small-sample Text Classification model based on the Pseudo-label fusion Clustering algorithm (STCPC). The algorithm includes two cores: (1) Mining the potential features of unlabeled data by using the training strategy of clustering assuming pseudo-labeling and then reducing the noise of the pseudo-labeled dataset by consistent training with its enhanced samples to improve the quality of the pseudo-labeled dataset. (2) The labeled data is augmented, and then the Easy Plug-in Data Augmentation (EPiDA) framework is used to balance the diversity and quality of the augmented samples to improve the richness of the labeled data reasonably. The results of comparison tests with other classical algorithms show that the STCPC model can effectively improve classification accuracy.
Three-Dimensional Point Cloud Data Pre-Processing for the Multi-Source Information Fusion in Aircraft Assembly
Authors: Li Rupeng , He Weiping , Liu Siren
Published: April 2023

Wing-body assembly is a key part of aircraft manufacturing, and during the process of wing assembly, the 3D point cloud data of the components are an important basis for attitude adjustment. The large amount of measured point cloud data and the obvious noise affect the quality and efficiency of the final assembly. To address this problem, research on the pre-processing method of the component point cloud data is carried out. Firstly, a feature-enhanced point cloud resampling method is proposed to preserve key features such as part contours in the resampling process. Then, a multi-scale point cloud data noise filtering method is proposed, which can effectively filter out the outliers. The experimental results show that the proposed method improves the speed and accuracy of the subsequent point cloud analysis effectively and is successfully applied to the assembly process of a large passenger aircraft, laying the foundation for high-quality assembly.
Zebrafish Larval Melanophores Respond to Electromagnetic Fields Exposure
Authors: Nassisi Vincenzo , Mazzei Aurora , Del Vecchio Gianmarco , Calisi Antonio , Velardi Luciano , Alifano Pietro , Verri Tiziano
Published: April 2023

Groups of zebrafish (Danio rerio) embryos receive radiations of different frequencies and intensities by means of new prototype devices. They are exposed to static (B0, 0 Hz), extremely low-frequency (ELF, 0.2 Hz), low-frequency (LF, 270 kHz), very-high-frequency (VHF, 100 MHz), and ultra-high-frequency (UHF, 900 MHz) field irradiations. The applied magnetic field intensities are 40 mT at 0 Hz, 40 mT at 0.2 Hz, 470 μT at 270 kHz, 240 nT at 100 MHz, and 240 nT at 900 MHz. Such combinations are meant to cover environmental radiations from geomagnetic fields and cosmic magnetism to electromagnetic radiation of electronic instruments such as GSM and UMTS transmission-mode mobile systems. For each frequency, fish are monitored for up to 5 days. Unexposed embryos are used as controls. Notably, exposure to the different radiations brings alterations of body pigmentation in zebrafish embryos and larvae in terms of total number, area, and morphology of (black) melanophores. This research may contribute to evaluating the roles and effects of magnetic radiation on living matter.
UAV Cluster-Assisted Task Offloading for Emergent Disaster Scenarios
Authors: Shi Minglin , Zhang Xiaoqi , Chen Jia , Cheng Hongju
Published: April 2023

Natural disasters often have an unpredictable impact on human society and can even cause significant problems, such as damage to communication equipment in disaster areas. In such post-disaster emergency rescue situations, unmanned aerial vehicles (UAVs) are considered an effective tool by virtue of high mobility, easy deployment, and flexible communication. However, the limited size of UAVs leads to bottlenecks in battery capacity and computational power, making it challenging to perform overly complex computational tasks. In this paper, we propose a UAV cluster-assisted task-offloading model for disaster areas, by adopting UAV clusters as aerial mobile edge servers to provide task-offloading services for ground users. In addition, we also propose a deep reinforcement learning-based UAV cluster-assisted task-offloading algorithm (DRL-UCTO). By modeling the energy efficiency optimization problem of the system model as a Markov decision process and jointly optimizing the UAV flight trajectory and task-offloading policy to maximize the reward value, DRL-UCTO can effectively improve the energy use efficiency of UAVs under limited-resource conditions. The simulation results show that the DRL-UCTO algorithm improves the UAV energy efficiency by about 79.6% and 301.1% compared with the DQN and Greedy algorithms, respectively.
Machines Perceive Emotions: Identifying Affective States from Human Gait Using On-Body Smart Devices
Authors: Imran Hamza Ali , Riaz Qaiser , Zeeshan Muhammad , Hussain Mehdi , Arshad Razi
Published: April 2023

Emotions are a crucial part of our daily lives, and they are defined as an organism’s complex reaction to significant objects or events, which include subjective and physiological components. Human emotion recognition has a variety of commercial applications, including intelligent automobile systems, affect-sensitive systems for customer service and contact centres, and the entertainment sector. In this work, we present a novel deep neural network of the Convolutional Neural Network - Bidirectional Gated Recurrent Unit (CNN-RNN) that can classify six basic emotions with an accuracy of above 95%. The deep model was trained on human gait data captured with body-mounted inertial sensors. We also proposed a reduction in the input space by utilizing 1D magnitudes of 3D accelerations and 3D angular velocities (maga^, magω^), which not only minimizes the computational complexity but also yields better classification accuracies. We compared the performance of the proposed model with existing methodologies and observed that the model outperforms the state-of-the-art.
Experimental Study on Maximum Dynamic Shear Modulus of Yangtze River Overconsolidated Floodplain Soft Soils
Authors: Zhou Yifeng , Xiao Xing , Zhou Zhenglong , Wu Qi
Published: April 2023

This study conducted experimental tests on the undisturbed Nanjing Yangtze River floodplain soft soil using the bender element instrument to determine the maximum dynamic shear modulus of the Yangtze River floodplain overconsolidated soft soil. The Gmax of floodplain soft soil with different overconsolidated ratio OCR, initial effective confining pressure σ3c′, and void ratio e are discussed. The results indicated that Gmax reduced as e rose for given σ3c′ and OCR. In addition, an increase in OCR contributed to a gradual decrease in the decay rate of Gmax, while the Gmax decay rate is insensitive to the change of σ3c′. The void ratio-normalized maximum shear modulus Gmax/F(e) improved with the increase in the stress-normalized initial effective confining pressure σ3c′/Pa, whereas the growth rate gradually drops, and a power relationship is then obtained between Gmax/F(e) and σ3c′/Pa. Based on the regression analysis, a Gmax prediction method is established for reasonably characterizing Yangtze River floodplain soft soils with various over-consolidation states, initial stress conditions, and compactness levels, with a prediction error of less than 10%.
On the Performance of LDPC-Coded Large Intelligent Antenna System
Authors: Gashtasbi Ali , da Silva Mário Marques , Dinis Rui , Guerreiro João
Published: April 2023

This article studies Large Intelligent Systems (LIS) along with Single Carrier with Frequency Domain Equalization (SC-FDE), utilizing Low-Density Parity-Check (LDPC). Four different receivers are studied in the scenarios described above, namely Equal Gain Combining (EGC), Maximum Ratio Combining (MRC), Zero Forcing (ZF), and Minimum Mean Squared Error (MMSE). The results of this article show that the use of LDPC codes leads to an improvement of performance by about 2 dB for a 4X25 LIS system and by 3 dB for a 4X225 LIS system, as compared to similar systems without LDPC codes. Moreover, for all simulations, the MMSE receiver achieves the best overall performance, while EGC performs the worst.
The Changes in Nickel and Chromium Ion Levels in Saliva with Fixed Orthodontic Appliances: A Systematic Review
Authors: Urbutytė Klaudija , Barčiūtė Andrė , Lopatienė Kristina
Published: April 2023

Fixed orthodontic appliances (braces systems) contain variable amounts of nickel and chromium, which can lead to immune responses and allergic reactions. The objective of the present review was to evaluate the changes in the quantity of nickel and chromium in saliva among patients wearing braces systems. The electronic databases used to perform the search were Pubmed, ReasearchGate, and Google scholar. After an initial search of these electronic databases, 12 studies were included in the systematic literature review. Overall, 554 patients wearing non-removable orthodontic appliances participated in the research that we reviewed. The age of the subjects ranged from 11 to 35 years. The quantity of chromium and nickel ions in saliva was measured before the braces systems were placed and after some period of having them. After evaluating the changes in nickel and chromium levels in saliva during orthodontic treatment with fixed brackets, it can be concluded that there is an increase in the levels of nickel and chromium ions in saliva. There is a significant increase in these ions after placement of the orthodontic appliances, peaking from three to six months, but not reaching toxic levels. The levels then gradually decrease. A full and detailed examination of the patient before starting orthodontic treatment is important, and alternative orthodontic appliances for patients who are allergic to nickel and/or chromium should be recommended.
Shock Wave Formation and Cloaking in Hyperelastic Rods
Authors: Kuznetsov Sergey V.
Published: April 2023

The analysis of propagating an initially harmonic acoustic pulse in a semi-infinite hyperelastic rod obeying the Yeoh strain energy potential reveals attenuation with distance of the wave amplitudes caused by the elastic energy dissipation due to forming and propagation of the shock wave fronts and heat production. The observed attenuation of harmonic waves results in a broadband cloaking of fairly remote regions. The analysis is based on solving a nonlinear equation of motion by an explicit Lax–Wendroff time-difference scheme combined with the finite element discretization in the spatial domain. The revealing phenomena are applicable to studies of acoustic wave propagation in various elastomeric rubberlike materials modeled by the Yeoh hyperelastic potentials.
Implant Model Generation Method for Mandibular Defect Based on Improved 3D Unet
Authors: Fang Zitao , Liu Dan , Wu Yangdong
Published: April 2023

The accurate reconstruction of a defective part of the mandible is a time-consuming task in maxillofacial surgery. In order to design accurate 3D implants quickly, a method for generating a mandibular defect implant model based on deep learning was proposed. First, an algorithm for generating a defective mandible 3D model randomly from a complete mandible 3D model was proposed due to the insufficiency of 3D models. Then a mandible 3D model dataset that consists of defective mandible 3D models and a complete mandible 3D model was constructed. An improved 3D Unet network that combines residual structure and dilated convolution was designed to generate a repaired mandibular model automatically. Finally, a mandibular defect implant model was generated using the reconstruction–subtraction strategy and was validated on the constructed dataset. Compared with the other three networks (3D Unet, 3D RUnet, and 3D DUnet), the proposed method obtained the best results. The Dice, IoU, PPV, and Recall for mandible repair reached 0.9873, 0.9750, 0.9850, and 0.9897, respectively, while those for implants reached 0.8018, 0.6731, 0.7782, and 0.8330. Statistical analysis was carried out on the experimental results. Compared with other methods, the P value of the method proposed in this paper was less than 0.05 for most indicators, which is a significant improvement.
The Assimilation Effect of Multi-New Types Observation Data in the Forecasts of Meiyu-Front Rainstorm
Authors: Zhao Hong , Shu Yu , Mao Yuqing , Liu Yin , Yu Kun
Published: April 2023

Meiyu-front rainstorm is one of the main disastrous weather events in summer in East China. In this study, seven assimilation experiments of multi-type observation data such as wind profile data, microwave radiometer data and radiosonde sounding data are designed to forecast the Meiyu-front rainstorm on 15 June 2020. The results show that the seven experiments can basically simulate the orientation of rain belt. The comprehensive experiment which assimilates all types of observations performs the best in simulating the location of heavy rainstorm and shows good performance in simulating the precipitation above moderate rain. For the comprehensive experiment, the forecast deviation of rainstorm and heavy rainstorm is small, and the equitable threat score has also been greatly improved compared with other experiments. It is found that the convective available potential energy is enhanced after the assimilation of surface observation data. In addition, the wind convergence and water vapor transportation are modified after assimilating wind profile data. Accordingly, the precipitation efficiency is improved in the comprehensive experiment. The profiles of pseudo-equivalent potential temperature, vorticity and divergence show that, the assimilation of new-types observation data from wind profiler radar and microwave radiometer increases the instability of atmospheric stratification and enhances the ascending motion in the heavy precipitation center. The above results show that the introduction of various some new-type data before the numerical simulation can reduce the forecast deviation. In addition, the combined assimilation of microwave radiometer and sounding data presents better performance than single data assimilation, which indicates that data mutual complementation is essential to improving forecast accuracy.
Semiempirical Models of Speedup Effect for Downburst Wind Field over 3-D Hills
Authors: Yan Bowen , He Yini , Ma Chenyan , Cheng Xu
Published: April 2023

Downbursts occur frequently in mountainous regions, such as the southwest of China, and causing extensive damage to engineering structures. While some researchers have developed semiempirical models for the speedup effect, most are based on the wind field in the boundary layer over the hill, and there is a lack of semiempirical models for the downburst wind field over the hill. This study employs three RANS (Reynolds Average Navier-Stokes) turbulence models to numerically simulate the downburst wind field over a quadratic curved hill. The realizable k-ε model is selected as the optimal model for the subsequent numerical simulations based on comparison with wind tunnel test results. Then, a semiempirical model of the speedup effect of the downburst wind field over the hill is constructed by numerically simulating the downburst wind field over the hill with different radial locations and different slopes. Finally, the constructed semiempirical model is validated and demonstrates good accuracy.
Variation Characteristics of Temperature and Rainfall and Their Relationship with Geographical Factors in the Qinling Mountains
Authors: Lei Yangna , Liao Rongwei , Su Yumeng , Zhang Xia , Liu Duanyang , Zhang Lei
Published: April 2023

The Qinling Mountains (QMs) are considered to be the division in geology, geochemistry, and physical geography between northern China and southern China. They have crucial effects on regional climate, especially on rainfall and temperature, and have shown great scientific relevance to climate change research in China. Using the observational daily and monthly rainfall and temperature data derived from meteorological and regional automatic stations—as well as the methods of correlation analysis, climate trend analysis, and Mann–Kendal and t tests—we revealed the spatiotemporal change characteristics of temperature and rainfall and their correlation with elevation, longitude, and latitude. The results show that the annual mean temperature (AMT) underwent a significant increasing trend in the QMs. The maximum AMT increase occurred in spring, and the minimum occurred in summer. Positive anomalies of annual mean rainfall amount (AMRA) occurred in the 1960s, 1980s, and 2010s, and negative anomalies occurred in the 1970s, 1990s, and 2000s. In the QMs, the amount of moderate rainfall (MR) occupied the maximum proportion and accounted for 27.9% of the AMRA, whereas the torrential rainfall (TR) occupied the minimum proportion and accounted for 12.8%. The AMRA amount significantly decreased by 130.1 mm from the 1980s to the 1990s and accounted for 13.5% of the measure in the 1980s. The AMT and AMRA showed consistent change trends with increases in elevation and latitude and showed the opposite trend as the longitude increased. The results offer a further understanding of the meteorological background of the QMs, helping us in further investigating the potential physical mechanisms that influence the spatiotemporal distribution characteristics of temperature and rainfall in the QMs. This study will provide a scientific basis for rainfall and temperature forecasts, with relevance to local ecosystems, agriculture, soil erosion, and the prevention and mitigation of floods in the future.
Assessment of Mobile Air Cleaners to Reduce the Concentration of Infectious Aerosol Particles Indoors
Authors: Kähler Christian J. , Hain Rainer , Fuchs Thomas
Published: April 2023

Airborne transmission via aerosol particles without close human contact is a possible source of infection with airborne viruses such as SARS-CoV-2 or influenza. Reducing this indirect infection risk, which is mostly present indoors, requires wearing adequate respiratory masks, the inactivation of the viruses with radiation or electric charges, filtering of the room air, or supplying ambient air by means of ventilation systems or open windows. For rooms without heating, ventilation, and air conditioning (HVAC) systems, mobile air cleaners are a possibility for filtering out aerosol particles and therefore lowering the probability of indirect infections. The main questions are as follows: (1) How effectively do mobile air cleaners filter the air in a room? (2) What are the parameters that influence this efficiency? (3) Are there room situations that completely prevent the air cleaner from filtering the air? (4) Does the air cleaner flow make the stay in the room uncomfortable? To answer these questions, particle imaging methods were employed. Particle image velocimetry (PIV) was used to determine the flow field in the proximity of the air cleaner inlet and outlet to assess regions of unpleasant air movements. The filtering efficiency was quantified by means of particle image counting as a measure for the particle concentration at multiple locations in the room simultaneously. Moreover, different room occupancies and room geometries were investigated. Our results confirm that mobile air cleaners are suitable devices for reducing the viral load indoors. Elongated room geometries, e.g., hallways, lead to a reduced filtering efficiency, which needs to be compensated by increasing the volume flow rate of the device or by deploying multiple smaller devices. As compared to an empty room, a room occupied with desks, desk separation walls, and people does not change the filtering efficiency significantly, i.e., the change was less than 10%. Finally, the flow induced by the investigated mobile air cleaner does not reach uncomfortable levels, as by defined room comfort standards under these conditions, while at the same time reaching air exchange rates above 6, a value which is recommended for potentially infectious environments.
Resonance States of Negative Hydrogen-like Ions in Quantum Plasmas
Authors: Yao Suya , Jiang Zishi , Kar Sabyasachi
Published: April 2023

We studied the 1Se and 1,3Po resonance states of negative hydrogen-like ions immersed in quantum plasmas. The exponential cosine screened Coulomb potential was considered to model the quantum plasma environment. The correlated exponential wave functions in which the exponents were generated by a pseudo-random technique were applied to represent the correlation effects between the charged particles. The stabilization method was used to calculate the resonance parameters (position and width). The resonance parameters (position and width) for Ps−, Mμ−, π−, 1H−, D−, T− and ∞H− embedded in quantum plasmas are reported for various screening parameters. The 1Se resonance parameters for Mμ−, π−, 1H−, D−, T− ions and 1,3 Po states for Ps−, Mμ−, π−, 1H−, D−, T− and ∞H− of the proposed systems are reported for the first time in the literature.
Fine-Tuning of Atomic Energies in Relativistic Multiconfiguration Calculations
Authors: Li Yanting , Gaigalas Gediminas , Li Wenxian , Chen Chongyang , Jönsson Per
Published: April 2023

Ab initio calculations sometimes do not reproduce the experimentally observed energy separations at a high enough accuracy. Fine-tuning of diagonal elements of the Hamiltonian matrix is a process which seeks to ensure that calculated energy separations of the states that mix are in agreement with experiment. The process gives more accurate measures of the mixing than can be obtained in ab initio calculations. Fine-tuning requires the Hamiltonian matrix to be diagonally dominant, which is generally not the case for calculations based on jj-coupled configuration state functions. We show that this problem can be circumvented by a method that transforms the Hamiltonian in jj-coupling to a Hamiltonian in LSJ-coupling for which fine-tuning applies. The fine-tuned matrix is then transformed back to a Hamiltonian in jj-coupling. The implementation of the method into the General Relativistic Atomic Structure Package is described and test runs to validate the program operations are reported. The new method is applied to the computation of the 2s21S0−2s2p1,3P1 transitions in C III and to the computation of Rydberg transitions in B I, for which the 2s2p22S1/2 perturber enters the 2s2ns2S1/2 series. Improved convergence patterns and results are found compared with ab initio calculations.
Customizing Random Replacement Model and Flexible Warranty Model from the Perspective of Screening Reliability
Authors: Shang Lijun , Liu Baoliang , Yang Li , Gao Kaiye
Published: April 2023

In the present academic and engineering fields, every measure function of product reliability is modeled and estimated from the statistical perspective. These indicate that there universally exist differences in the reliabilities of new identical products that survive the burn-in test. On the basis of the differences in the reliabilities of new identical products, designing through-life maintenance models for managing the different reliabilities is a very practical topic for engineering fields. In this study, a random warranty model and a random maintenance model are designed by screening product reliabilities to manage the through-life reliabilities of products. In the random warranty model, the coverage areas of the warranty are set as the different areas for applying flexibility to them to control the warranty costs of new identical products with different reliabilities, and thus this warranty is called a flexible random free repair warranty (FRFRW) model. In the random maintenance model, two random replacement actions are customized by setting different replacement ranges for controlling maintenance costs and lengthening service life. This random maintenance model is called a customized random replacement (CRR), which is used to manage product reliabilities after the FRFRW expiration. These two random models are characterized from the mathematical perspective, and some derivatives of both are provided to model other maintenance problems. The characteristics of every model and the performance of the CRR are explored and illustrated through numerical experiments. The results show that the CRR is superior to random age replacement.
Measure-Based Extension of Continuous Functions and p-Average-Slope-Minimizing Regression
Authors: Arnau Roger , Calabuig Jose M. , Sánchez Pérez Enrique A.
Published: April 2023

This work is inspired by some recent developments on the extension of Lipschitz real functions based on the minimization of the maximum value of the slopes of a reference set for this function. We propose a new method in which an integral p–average is optimized instead of its maximum value. We show that this is a particular case of a more general theoretical approach studied here, provided by measure-valued representations of the metric spaces involved, and a duality formula. For p=2, explicit formulas are proved, which are also shown to be a particular case of a more general class of measure-based extensions, which we call ellipsoidal measure extensions. The Lipschitz-type boundedness properties of such extensions are shown. Examples and concrete applications are also given.
Bell Distribution Series Defined on Subclasses of Bi-Univalent Functions That Are Subordinate to Horadam Polynomials
Authors: Aldawish Ibtisam , Frasin Basem , Amourah Ala
Published: April 2023

Several different subclasses of the bi-univalent function class Σ were introduced and studied by many authors using distribution series like Pascal distribution, Poisson distribution, Borel distribution, the Mittag-Leffler-type Borel distribution, Miller–Ross-Type Poisson Distribution. In the present paper, by making use of the Bell distribution, we introduce and investigate a new family GΣt(x,p,q,λ,β,γ) of normalized bi-univalent functions in the open unit disk U, which are associated with the Horadam polynomials and estimate the second and the third coefficients in the Taylor-Maclaurin expansions of functions belonging to this class. Furthermore, we establish the Fekete–Szegö inequality for functions in the family GΣt(x,p,q,λ,β,γ). After specializing the parameters used in our main results, a number of new results are demonstrated to follow.
Regulation of Cx43 Gap Junction Intercellular Communication by Bruton’s Tyrosine Kinase and Interleukin-2-Inducible T-Cell Kinase
Authors: Basu Ishika , Li Hanjun , Trease Andrew J. , Sorgen Paul L.
Published: April 2023

T and B cell receptor signaling involves the activation of Akt, MAPKs, and PKC as well as an increase in intracellular Ca2+ and calmodulin activation. While these coordinate the rapid turnover of gap junctions, also implicated in this process is Src, which is not activated as part of T and B cell receptor signaling. An in vitro kinase screen identified that Bruton’s tyrosine kinase (BTK) and interleukin-2-inducible T-cell kinase (ITK) phosphorylate Cx43. Mass spectroscopy revealed that BTK and ITK phosphorylate Cx43 residues Y247, Y265, and Y313, which are identical to the residues phosphorylated by Src. Overexpression of BTK or ITK in the HEK-293T cells led to increased Cx43 tyrosine phosphorylation as well as decreased gap junction intercellular communication (GJIC) and Cx43 membrane localization. In the lymphocytes, activation of the B cell receptor (Daudi cells) or T cell receptor (Jurkat cells) increased the BTK and ITK activity, respectively. While this led to increased tyrosine phosphorylation of Cx43 and decreased GJIC, the cellular localization of Cx43 changed little. We have previously identified that Pyk2 and Tyk2 also phosphorylate Cx43 at residues Y247, Y265, and Y313 with a similar cellular fate to that of Src. With phosphorylation critical to Cx43 assembly and turnover, and kinase expression varying between different cell types, there would be a need for different kinases to achieve the same regulation of Cx43. The work presented herein suggests that in the immune system, ITK and BTK have the capacity for the tyrosine phosphorylation of Cx43 to alter the gap junction function in a similar manner as Pyk2, Tyk2, and Src.
Senescence-Related lncRNA Signature Predicts Prognosis, Response to Immunotherapy and Chemotherapy in Skin Cutaneous Melanoma
Authors: Lin Kefan , Zhou Yingtong , Lin Yanling , Feng Yuanyuan , Chen Yuting , Cai Longmei
Published: April 2023

Skin cutaneous melanoma (SKCM) is a highly malignant and aggressive cancer. Previous studies have shown that cellular senescence is a promising therapeutic strategy to limit melanoma cell progression. However, models to predict the prognosis of melanoma based on senescence-related lncRNAs and the efficacy of immune checkpoint therapy remain undefined. In this study, we developed a predictive signature consisting of four senescence-related lncRNAs (AC009495.2, U62317.1, AATBC, MIR205HG), and we then classified patients into high- and low-risk groups. GSEA (Gene set enrichment analysis) showed different activation of immune-related pathways in two groups. In addition, there were significant differences between the scores of tumor immune microenvironment, tumor burden mutation, immune checkpoint expression, and chemotherapeutic drug sensitivity between the two groups of patients. It provides new insights to guide more personalized treatment for patients with SKCM.
Characterization of Inflammatory Signals in BV-2 Microglia in Response to Wnt3a
Authors: Li Cheng , Wu Ying , Huang Ming-Yue , Song Xue-Jun
Published: April 2023

Activation of microglia is one of the pathological bases of neuroinflammation, which involves various diseases of the central nervous system. Inhibiting the inflammatory activation of microglia is a therapeutic approach to neuroinflammation. In this study, we report that activation of the Wnt/β-catenin signaling pathway in a model of neuroinflammation in Lipopolysaccharide (LPS)/IFN-γ-stimulated BV-2 cells can result in inhibition of production of nitric oxide (NO), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Activation of the Wnt/β-catenin signaling pathway also results in inhibition of the phosphorylation of nuclear factor-κB (NF-κB) and extracellular signal-regulated kinase (ERK) in the LPS/IFN-γ-stimulated BV-2 cells. These findings indicate that activation of the Wnt/β-catenin signaling pathway can inhibit neuroinflammation through downregulating the pro-inflammatory cytokines including iNOS, TNF-α, and IL-6, and suppress NF-κB/ERK-related signaling pathways. In conclusion, this study indicates that the Wnt/β-catenin signaling activation may play an important role in neuroprotection in certain neuroinflammatory diseases.
Marginal Bone Loss Compared in Internal and External Implant Connections: Retrospective Clinical Study at 6-Years Follow-Up
Authors: D’Orto Bianca , Chiavenna Carlo , Leone Renato , Longoni Martina , Nagni Matteo , Capparè Paolo
Published: April 2023

The aim of this study was to assess and compare the marginal bone loss between two different categories of implants (Winsix, Biosafin, Ancona, Italy) having the same diameter and belonging to the Torque Type® (TT®) line, in the internal hexagon version (TTi, Group A) and in the external hexagon configuration (TTx, Group B). Patients with one or more straight implants (insertion parallel to the occlusal plane) in the molar and premolar regions in association with tooth extraction at least 4 months prior to implant insertion, who have a fixture diameter of 3.8 mm, who followed up for at least 6 years, and whose radiographic records were available were enrolled in this study. Depending on implant connections (externally or internally), the sample was divided into groups A and B. For externally connected implants (66), the marginal resorption was 1.1 ± 0.17 mm. The subgroup of single and bridge implants showed no statistically significant differences with a marginal bone resorption of 1.07 ± 0.15 mm and 1.1 ± 0.17 mm, respectively. Internally connected implants (69) showed an overall marginal resorption of 0.91 ± 0.17 mm, while the subgroup of single and bridge implants showed resorption of 0.90 ± 0.19 mm and 0.90 ± 0.17 mm, respectively, with no statistically significant differences. According to the obtained results, internally connected implants showed less marginal bone resorption than externally connected implants.