bluuebunny/crossref_metadata_2025 huggingface dataset:
Interventional Radiological Management and Prevention of Complications after Pancreatic Surgery: Drainage, Embolization and Islet Auto-Transplantation
Authors: Mosconi Cristina , Cocozza Maria Adriana , Piacentino Filippo , Fontana Federico , Cappelli Alberta , Modestino Francesco , Coppola Andrea , Palumbo Diego , Marra Paolo , Maffi Paola , Piemonti Lorenzo , Secchi Antonio , Ricci Claudio , Casadei Riccardo , Balzano Gianpaolo , Falconi Massimo , Carcano Giulio , Basile Antonio , Ierardi Anna Maria , Carrafiello Gianpaolo , De Cobelli Francesco , Golfieri Rita , Venturini Massimo
Published: October 2022

Pancreatic surgery still remains burdened by high levels of morbidity and mortality with a relevant incidence of complications, even in high volume centers. This review highlights the interventional radiological management of complications after pancreatic surgery. The current literature regarding the percutaneous drainage of fluid collections due to pancreatic fistulas, percutaneous transhepatic biliary drainage due to biliary leaks and transcatheter embolization (or stent–graft) due to arterial bleeding is analyzed. Moreover, also, percutaneous intra-portal islet auto-transplantation for the prevention of pancreatogenic diabetes in case of extended pancreatic resection is also examined. Moreover, a topic not usually treated in other similar reviewsas percutaneous intra-portal islet auto-transplantation for the prevention of pancreatogenic diabetes in case of extended pancreatic resection is also one of our areas of focus. In islet auto-transplantation, the patient is simultaneously donor and recipient. Differently from islet allo-transplantation, it does not require immunosuppression, has no risk of rejection and is usually efficient with a small number of transplanted islets.
Dynamic Changes in Port Logistics Caused by the COVID-19 Pandemic
Authors: Beškovnik Bojan , Zanne Marina , Golnar Marko
Published: October 2022

This study addresses the highly topical issue of the impact of the COVID-19 pandemic on port logistics. The impacts are reflected in all three pillars of sustainable operations and development that port logistics should pursue. The economic impact is strong and is reflected in the extremely high transport prices, the accessibility of transport, the lengthening of the supply chain, and the reduced liquidity of companies. The social aspect is very important regarding working conditions and workers’ roles in ports and logistics service providers (LSPs). The dynamic changes caused by the COVID-19 pandemic also have an impact on the environmental aspect. As supply chains are vulnerable, more attention is paid to the components of time, price, and reliability than greener transportation. This study highlights changes in port logistics due to the COVID-19 pandemic in logistics companies in the northern Adriatic region and covers a specific gap in the understanding of the sustainable adaptations of LSPs in their operations within port logistics. The results enrich the scientific field regarding LSPs to work processes, the digitalization of business processes, and the organization of logistics chains. The results can be used to develop new sustainable business models for port logistics and port governance, as some researchers have already called for because port logistics too often pursue the economic goals of the fastest and cheapest logistics process. At the same time, social and environmental aspects are somewhat neglected. The changes are particularly pronounced in critical situations, such as those typical of the COVID-19 pandemic. The study was conducted as part of the project about green port development with external research funding.
Capacity Analysis of Incentive Schemes in Opportunistic Networks
Authors: Feng Ruoyu , Jiang Shengming , Zheng Zhichao
Published: October 2022

Many incentive schemes address the selfishness issue in opportunistic networks and show performance improvement by simulations. However, the insights of incentive schemes that affect network performance are not clear. Network capacity analysis can reveal how factors affect performance, which is a guideline for new designs. To analyze incentive schemes, a well-defined mathematical model is necessary, which cannot be achieved by existing analytical models based on empirical formulas or types of incentive schemes. First, this paper proposes such a model to show the incentive degree with the incentive scheme, cooperation degree, energy usage, buffer usage, and security based on a quantum game model. Verification compares the model with delivery ratios that show impacts on selfish nodes in simulations under two typical incentive schemes. Then, network capacity is analyzed with this model and a sparse clustering regime that has similar mobility to opportunistic networks in order to show factors for future designs.
Spatial Evolution of Skewness and Kurtosis of Unidirectional Extreme Waves Propagating over a Sloping Beach
Authors: Abroug Iskander , Matar Reine , Abcha Nizar
Published: October 2022

The understanding of the occurrence of extreme waves is crucial to simulate the growth of waves in coastal regions. Laboratory experiments were performed to study the spatial evolution of the statistics of group-focused waves that have a relatively broad-banded spectra propagating from intermediate water depth to shallow regions. Breaking waves with different spectral types, i.e., spectral bandwidths and wave nonlinearities, were generated in a wave flume using the dispersive focusing technique. The non-Gaussian behavior of the considered wave trains was demonstrated by the means of the skewness and kurtosis parameters estimated from a time series and was compared with the second-order theory. The skewness and kurtosis parameters were found to have an increasing trend during the focusing process. During both the downstream wave breaking and defocusing process, the wave train dispersed again and became less steep. As a result, both skewness and kurtosis almost returned to their initial values. This behavior is clearer for narrower wave train spectra. Additionally, the learning algorithm multilayer perceptron (MLP) was used to predict the spatial evolution of kurtosis. The predicted results are in satisfactory agreement with experimental findings.
Evaluation of Port–Hinterland Synergy Level Considering Fixed Asset Allocation and Social Commodity Circulation under the “Dual Circulation” Development Pattern
Authors: Li Zhaohui , Huang Yujin , Yang Fan , Li Yi , Fang Yan , Fu Rui
Published: October 2022

“Port–hinterland synergy” means the development of port and hinterland should promote each other. The “dual circulation” development pattern indicates the requirement of exploring the domestic transportation demand and promoting the integration between ports and hinterlands. However, the current research on the synergy level between ports and hinterlands is not enough to meet the needs of constructing a “dual circulation” development pattern, and few studies have explored the influencing factors of port–hinterland synergy level directly, especially in the context of the new development pattern of “dual circulation”. After investigating the synergetic mechanism between ports and hinterlands, this study proposes to further consider the influence of fixed assets allocation and social commodity circulation on the synergy level under the “dual circulation” pattern. So, fixed asset investment and three different forms of commodity circulation activities are selected to represent the corresponding hinterland’s economic activities and added into the evaluation indices. To assess ports’ responsiveness to different kinds of transport demand, throughputs of each port are divided into those of domestic and foreign countries. Then this paper evaluates the level of port–hinterland synergy by the coupling synergy model, and the influence degree of these activities on the synergy level was studied with the partial least squares regression (PLS). The results show that there is heterogeneity in regional and port positioning in the port–hinterland synergy level, and that four selected economic activities’ improvement can enhance the port–hinterland synergy level. Among them, retail industry has the strongest positive effect, followed by tertiary industry, import and export trade, and fixed asset investment.
Distributed Path Tracking for Autonomous Underwater Vehicles Based on Pseudo Position Feedback
Authors: Gao Huanli , Li Wei , Cai He , Gu Zekai
Published: October 2022

In this paper, we consider the distributed polynomial path tracking problem for a swarm of autonomous underwater vehicles (AUVs) modeled by second-order uncertain multi-agent systems. The application scenario of this paper has three distinguished characteristics. First, the communication network for the multi-agent system is unreliable and switching. Under the jointly connected condition, the communication network can be disconnected the entire time. Second, it is supposed that only the relative position between AUVs can be obtained for trajectory tracking control. Third, the AUV dynamics are subject to uncertain system parameters. By applying the cooperative output regulation control framework, a novel distributed robust control scheme is proposed to solve the distributed path tracking problem, which consists of three parts. First, to cope with communication network uncertainty, the distributed observer was invoked to recover the polynomial path for each AUV. Second, based on the relative position measurement between AUVs, a pseudo position estimator was adopted to generate the pseudo position for each AUV. Finally, based on the estimated polynomial path and the pseudo position, a certainty equivalent robust internal model control law was synthesized to achieve asymptotic reference trajectory tracking, where the internal model compensator aims to tackle uncertain system parameters. Numerical simulations are provided to validate the effectiveness of the proposed control scheme.
Impact of SOFC Power Generation Plant on Carbon Intensity Index (CII) Calculation for Cruise Ships
Authors: Gianni Marco , Pietra Andrea , Coraddu Andrea , Taccani Rodolfo
Published: October 2022

The International Maritime Organization (IMO) has recently discussed the introduction of a new design index called the Carbon Intensity Indicator (CII), which is a measure of the total carbon dioxide emissions divided by the amount of cargo carried and by the distance travelled on a one-year basis. In this study, authors have analysed a cruise ship assuming its size, the electrical and thermal power required, and its operative profile. CII is calculated with reference to a 180,000 GRT cruise ship equipped with different possible power plant configurations. Emissions in these scenarios are abated by employing alternative fuels like Liquefied Natural Gas (LNG), a shore connection, or innovative technologies like Solid Oxide Fuel Cells (SOFC). The analysis affirms that a cruise ship powered only by MGO from 2024 will not comply with the CII regulation. Results highlight the potential of LNG in reducing carbon dioxide emissions and, for the reference vessel, the use of LNG alone can guarantee a maximum CII rating up to 2026. The benefits of the installation of 10 MW of SOFC are relevant and similar to the one archived with a power plant composed of dual-fuel internal combustion engines and a shore connection.
Experimental Modelling of an Isolated WECfarm Real-Time Controllable Heaving Point Absorber Wave Energy Converter
Authors: Vervaet Timothy , Stratigaki Vasiliki , Ferri Francesco , De Beule Louis , Claerbout Hendrik , De Witte Bono , Vantorre Marc , Troch Peter
Published: October 2022

To offer point absorber wave energy converters (WECs) as a bankable product on the marine renewable energy market, multiple WECs will be installed together in an array configuration. The wave energy community (research and industrial) has identified the urgent need for available realistic and reliable data on WEC array tests in order to perform a better WEC array optimization approach and in order to validate recently developed (non-linear) numerical models. The ‘WECfarm’ project is initiated to cover this scientific gap on necessary experimental data. The ‘WECfarm’ experimental setup consists of an array of five generic heaving point-absorber WECs. The WECs are equipped with a permanent magnet synchronous motor (PMSM), addressing the need for WEC array tests with an accurate and actively controllable power take-off (PTO). The WEC array control and data acquisition are realized with a Speedgoat Performance real-time target machine, offering the possibility to implement advanced WEC array control strategies in the MATLAB-Simulink environment. The presented article describes the experimental setup, the performed tests and the results of the test campaign using a single, isolated ‘WECfarm’ WEC in April 2021 at the wave basin of Aalborg University (AAU), Denmark. A Coulomb and viscous friction model is determined to partly compensate for the drivetrain (motor, gearbox, rack and pinion) friction. A system identification (SID) approach is adopted considering the WEC system to be composed of two single input single output (SISO) models, the radiation and the excitation model. Radiation tests yield the intrinsic impedance. Excitation tests yield the excitation frequency response function. Adopting an impedance matching approach, the control parameters for the resistive and reactive controller are determined from the complex conjugate of the intrinsic impedance. Both controllers are tested for a selection of regular wave conditions. The performed experimental test campaign using an isolated ‘WECfarm’ WEC allows a full evaluation of the WEC design prior to extending the setup to five WECs. Within the ‘WECfarm’ project, an experimental campaign with a five-WEC array in the Coastal and Ocean Basin (COB) in Ostend, Belgium, is under preparation.
Advances in Autonomous Underwater Robotics Based on Machine Learning
Authors: Burguera Antoni , Bonin-Font Francisco
Published: October 2022

Autonomous or semi-autonomous robots are nowadays used in a wide variety of scenarios, including marine and underwater environments [...]
Rural Land Transfer in the Information Age: Can Internet Use Affect Farmers’ Land Transfer-In?
Authors: Zhang Fengwan , Bao Xueling , Deng Xin , Xu Dingde
Published: October 2022

Land transfer is an essential prerequisite for moderate-scale operation. Using the internet realizes the rational allocation of resources and promotes the development of agriculture and rural areas. Based on the data of 8198 farmers surveyed in the 2016 China Labor Dynamics Survey, the conditional mixed estimation method (CMP) was used to analyze how the internet use of rural households affects their land transfer-in. The results showed that: (1) There was a significant negative correlation between internet use and land transfer-in, and the marginal effect was 0.206. (2) Internet use can affect land transfer-in through social networks and the stability of off-farm employment. Among them, social networks have a positive mediating effect, which is 0.026%. The non-agricultural employment stability of the labor force has a negative mediating effect, which is 0.51%. (3) Internet use has no significant heterogeneity in land management scale, income, or suburb status, but there is heterogeneity in the way of surfing the internet. This research can deepen our understanding of the relationship between internet use and land transfer-in, and provide a reference for rural digital construction and land transfer-related policy formulation.
The Spatial-Temporal Evolution of Population in the Yangtze River Delta, China: An Urban Hierarchy Perspective
Authors: Tang Yanting , Gao Jinlong , Chen Wen
Published: October 2022

The reason for changes in ranking within urban systems is the subject of much debate. Employing the census data from 1990 to 2020, this paper investigates population dynamics across urban hierarchies and its influencing factors in the Yangtze River Delta. The results reveal an upward pattern of population dynamics and show that the advantages of high-ranking cities in population gathering are obvious, though they have declined recently. Based on a framework of urban amenity and the ridge regression model, the authors argue that concerns of residents in choosing cities in which to settle are gradually changing from economic opportunities to multidimensional amenities, finding that the influencing mechanisms vary across time. This is slightly different from Glaeser’s consumer cities; economic gains, as physiological needs, are always important for population growth. As higher-level needs, social and natural amenities, including Internet accessibility and urban green space, did not affect growth until the turn of the new millennium. In terms of negative factors, the ‘crowding-out effect’ of living costs and environmental pollution are not significant, as theoretically expected, suggesting that residents tend to care more about development opportunities than the negative impacts of living in high-ranking cities. Finally, policies are proposed to promote population growth and the coordinated development of large, medium, and small cities in the Yangtze River Delta.
Legal Analogy in the Cases of Overcoming a Contract’s Verbal and Numerical Ambiguity
Authors: Mikryukov Viktor A.
Published: October 2022

The relevance of the research stems from the wider spread of contract conflicts and legal disputes caused by verbal and numerical ambiguity of certain contract terms, given the absence of a special legislative rule to overcome such ambiguities. The work aims to identify and evaluate the most effective law enforcement methods of overcoming the discrepancy of the notations of quantitative values in a contract that is expressed with words and numbers. Research methods included a special technical–legal toolkit, including methods of analogy and legal modeling, civil doctrine means of analysis and synthesis, induction, and deduction, as well as comparison and generalization. As a result, the paper refutes the universal character of the analogy of law as a method of overcoming legal gaps in the area under study. At the same time, the active and positive role of analogy as a part of other methods of interpretation of ambiguous contractual provisions, such as literal interpretation, combination of textual and contextual interpretations, and its appeal to tradition, isshown. The significance of the work lies not only in its ability to orient lawyers and practitioners in a set of different options to overcome the verbal and numerical ambiguity of the contracts but also to indicate ways to solve common problems associated with the ambiguities and incompleteness that come with the contractual terms.
Mechanisms of Action of the Antimicrobial Peptide Cecropin in the Killing of Candida albicans
Authors: Peng Cui , Liu Yang , Shui Liangyong , Zhao Zhongyi , Mao Xinfang , Liu Zhongyuan
Published: October 2022

The development of drug resistance has caused fungal infections to become a global health concern. Antimicrobial peptides (AMPs) offer a viable solution to these pathogens due to their resistance to drug resistance and their diverse mechanisms of actions, which include direct killing and immunomodulatory properties. The peptide Cecropin, which is expressed by genetically engineered bacteria, has antifungal effects on Candida albicans. The minimal inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) of Candida albicans were 0.9 μg/mL and 1.8 μg/mL, respectively, detected by the micro-broth dilution method. According to the killing kinetics, the MFC of Cecropin could kill Candida albicans in 40 min. The electron microscope indicated that Cecropin could cause the cell wall to become rough and nicked, eventually killing Candida albicans. The effects of Cecropin on the cell membrane of treated C. albicans, using the 1,6-diphenyl-1,3,5-hexatriene and propidium iodide protocol, showed that they could change the permeability and fluidity, destroy it, and lead to cell necrosis. In addition, Cecropin can also induce cells to produce excessive reactive oxygen species, causing changes in the mitochondrial membrane potential. Therefore, this study provides a certain theoretical basis for the antifungal infection of new antifungal agents.
Correlation between the Mechanical and Tribological Properties of Rutile Reinforced LM27 Alloy Composite
Authors: Nagpal Pardeep Kumar , Kumar Suresh , Sharma Jagmohan Datt , Mahla Sunil Kumar , Salunkhe Sachin , Hussein Hussein Mohamed Abdelmoneam
Published: October 2022

To meet the global requirements of the industry, there is a need for innovative light weight, low cost, eco-friendly, high quality engineering materials with superior performance at a wide range of temperatures. Aluminum Matrix Composites (AMCs) are lightweight materials with isotropic properties, a suitable choice for modern industry. Low-cost aluminum alloys reinforced with minerals have found a special place in the automotive industry for the manufacture of automobile parts. Rutile particles improve the mechanical properties of the aluminum matrix, making it attractive for structural applications as well as providing greater wear resistance to the composite during sliding. In the present studies, a rutile mineral reinforced LM27 aluminum alloy composite was developed through a stir casting route with 6, 9 and 12 wt.% reinforcements. To study the effect of particle size on the mechanical and tribological properties of composite samples reinforced with fine-sized (50–75 μm) and coarse-sized (106–125 μm) rutile particles were prepared From the results of the experiment, it was found that the hardness, compressive strength and wear resistance increase with increasing rutile wt.% addition. The worn surface and re-groove of the new surface are restored during sliding with the help of oxide films. The analysis of the fractured surface clearly indicates with the help of energy dispersive X-ray spectroscopy (EDS) that with the increase in the volume fraction of the reinforced particles, the porosity increases, which could be the main reason for the compression failure of the composite material.
Ascorbyl Palmitate-Vitamin C Effective Friction Modifier and Wear Inhibitor for Steel in a PAO Base Oil
Authors: Long Yun , Martin Jean Michel , Dubreuil Frederic , Thiebaut Benoit , Loehle Sophie , Lacassagne Corinne , De Barros Bouchet Maria-Isabel
Published: October 2022

Ascorbyl palmitate (AP), known as a nutrition pill, and an antioxidant agent in food, has demonstrated excellent lubricity as an additive in PAO4. Adding one wt% AP in PAO4 drastically decreases friction Coefficient (CoF) up to 66% and protects the steel surface from wear. Meanwhile, it shows a more vital friction reduction ability than conventional Mo-based additives and fatty acids, especially palmitic acid. Ascorbic acid core on AP optimises palmitic acid lubricity by forming robust chemical C-O-Fe bond on steel, increasing surface coverage rate. Masked by AP self-assembled layers, steel surfaces can also handle extreme pressure (up to 2.34 GPa) and temperature (150 °C) with unmeasurable wear. This work broadens human-friendly AP vitamin C application for industrial use and introduces a new pathway for optimizing fatty acids lubricity.
Zero Shear Viscosity of Hybrid Modified Asphalts and Its Gray Correlation with Other Properties
Authors: Wang Wei , Chen Baomin , Shen Junan
Published: October 2022

The viscosity of modified asphalt binders is the most important property to ensure the durability of open-graded friction course (OGFC). Zero shear viscosity (ZSV) is considered to be the optimum result to reflect the rutting characterization of high viscosity modified asphalt binders, compared with conventional vacuum capillary viscosity. However, there are few reports on using ZSV to evaluate the material characteristics of hybrid modified asphalt binders and to establish the relationship between ZSV and other properties. In this paper, a high viscosity hybrid modified asphalt binder was prepared with Sty-rene-butadiene-styrene (SBS) and Crumb rubber modifier (CRM). ZSV, three major indicators, 60 °C dynamic viscosity, 135 °C Brookfield viscosity, and a dynamic rheological test were used to determine the properties of the hybrid modified asphalt binders. The relationship between ZSV and other properties was studied by the gray correlation analysis method. Results indicated that: (1) The viscosity of hybrid modified asphalt binders increases with the decreasing frequency. When the frequency tends to 0, the viscosity of asphalt at this time is zero shear viscosity; (2) The values of the ZSV of hybrid modified asphalt binders have a large increase as the dose of both CRM and SBS modifiers were increased; and (3) The ZSV at 60 °C correlated well with the performance properties of rutting factor (G*/sin(θ)), indicating that the ZSV of hybrid modified asphalt binders could be a good indicator of performance.
Al0.25CoCrFeNiV High Entropy Alloy Coating Deposited by Laser Cladding on Stainless Steel
Authors: Samoilova Olga , Shaburova Nataliya , Pashkeev Kirill , Samodurova Marina , Trofimov Evgeny
Published: October 2022

This paper studies the microstructure, composition and properties of a Al0.25CoCrFeNiV high entropy alloy coating (HEAC) deposited by laser cladding on austenitic-grade stainless steel. Laser cladding was carried out in an argon atmosphere on a FL-Clad-R-4 laser metal deposition complex with the following parameters: the laser power was 1400 W, the spot diameter was 3 mm, the track displacement was 1.2 mm, and the scanning speed was set to 10 mm/s. A change in the microstructure of the coating after laser cladding was revealed in comparison with as-cast high entropy alloy (HEA) Al0.25CoCrFeNiV. A significant decrease was found in the size of vanadium precipitates, from 20–40 µm in the as-cast state to 1–3 µm after laser cladding. A change in microhardness over the thickness of the coating from 370 HV0.3 at the outer surface to 270 HV0.3 at the boundary with the substrate was established, which may be due to the diffusion of Fe from the stainless steel into the coating material during laser cladding. Despite these features, the resulting coating adheres tightly to the substrate, and has no cracks or other defects, which indicates the possibility of using laser cladding to create coatings from high entropy alloys.
Reveal the Viscoplastic Behaviour and Microstructure Evolution of Stainless Steel 316L
Authors: Lu Qiong , Zhang Chi , Wang Wei , Jiang Shuai , Aucott Lee , Yasmeen Tabassam , Jiang Jun
Published: October 2022

Stainless steel 316L is a widely used structural material in the nuclear industry because of its excellent corrosion resistance and mechanical properties. However, very little research can be found on its viscoplastic behaviour and microstructure evolution at warm and hot deformation conditions, which hinder the possible application of advanced manufacturing technologies for producing complex parts, such as superplastic forming or hydroforming. The aims of this study are to explore stainless steel 316L’s viscoplastic behaviour, to determine its strain rate sensitivities, and to reveal its underlying microstructure evolution; this will allow appropriate manufacturing (forming) technologies and the optimal forming condition to be determined. Hence, isothermal tensile tests at 700 °C, 800 °C, 900 °C, and 1000 °C at strain rates of 0.01 s−1 and 0.001 s−1 have been conducted. Moreover, the corresponding microstructure evolution, including the grain orientation and geometrically necessary dislocation density, has been revealed by the electron backscatter diffraction method. The data show the viscoplastic behaviour of stainless steel 316L under various thermomechanical deformation conditions and how microstructure evolution influences the viscoplastic flow stress.
Exceptional Strengthening Efficiency and Hardness of Ti/Mg-9Al-Zn-0.3Mn Matrix Composite
Authors: Wang Rongrong , Han Yejin , Yu Huan , Su Qian , Li Hang , Cheng Kaiming , Zhou Jixue , Tang Shouqiu , Ju Wei
Published: October 2022

The involvement of magnesium matrix composite enhanced by metal particles, the development of low lattice mismatch interface, and the refining of particle size are all of great significance in improving strengthening efficiency. In this work, nano-crystalline Ti/Mg-9Al-Zn-0.3Mn composites were prepared by mechanical milling. The microstructure was characterized and the mechanical property was measured. After mechanical milling, the grain of the Mg matrix was refined to ~72 nm. Ti particles were smashed to submicron scale, and dispersed in the Mg matrix. In total, 68% of Ti particles were nano-scale and the average particle size was 133 nm. A nano-scale Mg17Al12 precipitate was found and the average particle size was approximately 44 nm. Meanwhile, coherent interfaces of Ti/Mg and Mg17Al12/Mg were observed, and it was found that the (101)Mg plane and (100)Ti plane inclined 12° and [044]Mg17Al12 was parallel to [010]Mg. The hardness of the milled Ti/Mg-9Al-Zn-0.3Mn composite was 1.98 GPa, 247% higher than the initial alloy. Milled Mg-9Al-Zn-0.3Mn alloy under the same preparation processing was used as a comparison, and the value of hardness was 1.53 GPa. Tiny Ti particles displayed excellent strengthening efficiency. Strengthening mechanisms of the milled Ti/Mg-9Al-Zn-0.3Mn composite were analyzed and the main strengthening mechanisms included the strengthening of grain boundary strengthening, Orowan strengthening, dislocation strengthening, solid solution strengthening and load-bearing strengthening, which accounted for 56.3%, 18.2%, 17.4%, 4.7% and 3.5%, respectively.
Shear Strength Prediction Model for RC Exterior Joints Using Gene Expression Programming
Authors: Tariq Moiz , Khan Azam , Ullah Asad
Published: October 2022

Predictive models were developed to effectively estimate the RC exterior joint’s shear strength using gene expression programming (GEP). Two separate models are proposed for the exterior joints: the first with shear reinforcement and the second without shear reinforcement. Experimental results of the relevant input parameters using 253 tests were extracted from the literature to carry out a knowledge analysis of GEP. The database was further divided into two portions: 152 exterior joint experiments with joint transverse reinforcements and 101 unreinforced joint specimens. Moreover, the effects of different material and geometric factors (usually ignored in the available models) were incorporated into the proposed models. These factors are beam and column geometries, concrete and steel material properties, longitudinal and shear reinforcements, and column axial loads. Statistical analysis and comparisons with previously proposed analytical and empirical models indicate a high degree of accuracy of the proposed models, rendering them ideal for practical application.
Effect of Residual Stresses on Wheel Fatigue Life and Experimental Validation
Authors: Jiang Qingshan , Zhao Zhiwen , Xu Zhilong , Sun Jie , Chen Xiuyu , Su Bosheng , Zhao Zhenye , Jiang Wanbiao
Published: October 2022

Steel wheels, consisting of rims and spokes, are important load-bearing parts of vehicles, and the fatigue fractures’ life estimation accuracy directly determines the stability and safety when applied in the transportation industry. The most common form of failure is fatigue fracture. The strong elastic–plastic deformation during the rim roll-forming process generates a residual stress field in its surface layer, which changes the actual stress distribution in the rim when it is loaded and thus affects the fatigue life of the steel wheel. In this paper, ABAQUS software was used to establish a rim-rolling simulation model to obtain the residual stress field distribution after forming and compare it with the actual residual stress on the formed surface of the rim to verify the reliability of the model. On the basis of this model establishment, the service hazard areas and maximum stresses of steel wheels with or without superimposed residual stress fields were calculated separately, and their fatigue lives were predicted separately using the local stress-strain method. The simulation results show that the maximum stress of the rim before and after the superimposed residual stress occurs in the area of the bottom of the groove, which is consistent with the actual failure location. However, the maximum stress after superposition increased from 120.7 MPa to 332.9 MPa, and the corresponding calculated life decreased from 158,340,000 to 459,500 cycles, which is closer to the actual test results. The results of the study can provide a theoretical basis for the lightweight design and process improvement of automotive steel wheels.
Discriminant Analysis of the Vibrational Behavior of a Gas Micro-Turbine as a Function of Fuel
Authors: Niola Vincenzo , Savino Sergio , Quaremba Giuseppe , Cosenza Chiara , Nicolella Armando , Spirto Mario
Published: October 2022

Several studies were conducted previously on fuel and biofuel performance of micro-turbines. The present paper combines experimental and statistical approaches to study the vibrational behavior of a gas micro-turbine supplied with different pure fuels and admixed with rapeseed oils. Experimental tests carried out at different operating conditions have allowed us to build a classification model through using discriminant analysis. The classification model can distinguish the vibrational behavior occurring when the turbine is fueled with kerosene, or pure and admixed diesel with rapeseed oil. Moreover, the methodology has even allowed us to highlight differences in vibrational behavior caused by small amounts of rapeseed oil admixed in the fuel. The model reliability, in terms of Cohen’s kappa, results in optimal data classification.
Cognitive Implementation of Metaverse Embedded Learning and Training Framework for Drivers in Rolling Stock
Authors: Danylec Andrew , Shahabadkar Krutika , Dia Hussein , Kulkarni Ambarish
Published: October 2022

Public safety is prime concern in rail industry and driver training on hazard perception is crucial. Additionally, a new driver’s skill set determines the productivity and quality of existing driver training methods. Apprentice train drivers are required to complete massive hours under supervision of experienced drivers to attain the required skill sets causing productivity issues. Traditional driver training is paper based, and assessments are individually evaluated without any scientific rigor, resulting in quality challenges. This paper proposes a Metaverse embedded learning and training framework for drivers in rolling stock. The framework includes driver vision analysis by eye tracking and pupil dilation focusing on enhancing the productivity and quality of driver training and hazard detection for drivers in rolling stock. Metaverse embedded training and learning enhances experiential learning with unique benefits. In this paper, a metaverse-based training framework is proposed for train drivers to enhance productivity, quality, and safety aspects through case studies including: (i) driver sightline studies and (ii) vision analysis. The studies developed quantifying driver hazard perceptions and related comprehension rates based on eye tracking and vision studies. In conclusion, the overall savings on cost and time are 95% effective using Metaverse-based training method compared to traditional methods. Stakeholders need to supervise on driver tasks, knowledge retention, damage control due to the occurrence of hazards. The framework substantially reduced hazards to 50% with saving up to 3696 man-hours. The assessment was completely automated to provide real time assessment thus providing 93% more positive results compared to traditional methods.
On the Physical Layer Security Peculiarities of Wireless Communications in the Presence of the Beaulieu-Xie Shadowed Fading
Authors: Gvozdarev Aleksey S. , Artemova Tatiana K.
Published: October 2022

The article presents an analysis of the physical layer security of a wireless communication system functioning in the presence of multipath fading and a wiretap. Under the assumption of the equal propagation conditions (both for the legitimate receiver and the eavesdropper) described by the shadowed Beaulieu–Xie model, a closed-form expression for the secrecy outage probability was derived. The correctness of the obtained expression was numerically verified via comparison with the direct numerical integration. The truncated version of the obtained expression was analyzed for various channel parameters to establish the requirements for numerically efficient implementation (in terms of the number of summands delivering the desired precision). An in-depth study of the secrecy outage probability dependence from all the possible channel parameters for different fading scenarios was performed, including heavy fading and light fading, with and without strong dominant and multipath components. The performed research demonstrated the existence of the secrecy outage probability non-uniqueness with the respect to the average signal-to-noise ratio in the main channel and the relative distance between the legitimate and wiretap receivers.
Forecasting a New Type of Virus Spread: A Case Study of COVID-19 with Stochastic Parameters
Authors: Zakharov Victor , Balykina Yulia , Ilin Igor , Tick Andrea
Published: October 2022

The consideration of infectious diseases from a mathematical point of view can reveal possible options for epidemic control and fighting the spread of infection. However, predicting and modeling the spread of a new, previously unexplored virus is still difficult. The present paper examines the possibility of using a new approach to predicting the statistical indicators of the epidemic of a new type of virus based on the example of COVID-19. The important result of the study is the description of the principle of dynamic balance of epidemiological processes, which has not been previously used by other researchers for epidemic modeling. The new approach is also based on solving the problem of predicting the future dynamics of precisely random values of model parameters, which is used for defining the future values of the total number of: cases (C); recovered and dead (R); and active cases (I). Intelligent heuristic algorithms are proposed for calculating the future trajectories of stochastic parameters, which are called the percentage increase in the total number of confirmed cases of the disease and the dynamic characteristics of epidemiological processes. Examples are given of the application of the proposed approach for making forecasts of the considered indicators of the COVID-19 epidemic, in Russia and European countries, during the first wave of the epidemic.
A Note on a Class of Generalized Parabolic Marcinkiewicz Integrals along Surfaces of Revolution
Authors: Ali Mohammed , Al-Qassem Hussain
Published: October 2022

In this article, certain sharp Lp estimates for a specific class of generalized Marcinkiewicz operators with mixed homogeneity associated to surfaces of revolution are established. By virtue of Yano’s extrapolation argument, beside these estimates, the Lp boundedness of the aforementioned operators under weaker assumptions on the kernels is confirmed. The obtained results in this article are fundamental extensions and improvements of numerous previously known results on parabolic generalized Marcinkiewicz integrals.
Variational Estimation Methods for Sturm–Liouville Problems
Authors: Cipu Elena Corina , Barbu Cosmin Dănuţ
Published: October 2022

In this paper, we are concerned with approach solutions for Sturm–Liouville problems (SLP) using variational problem (VP) formulation of regular SLP. The minimization problem (MP) is also set forth, and the connection between the solution of each formulation is then proved. Variational estimations (the variational equation associated through the Euler–Lagrange variational principle and Nehari’s method, shooting method and bisection method) and iterative variational methods (He’s method and HPM) for regular RSL are unitary presented in final part of the paper, which ends with applications.
Minimum Randić Index of Trees with Fixed Total Domination Number
Authors: Ahmad Jamri Ayu Ameliatul Shahilah , Movahedi Fateme , Hasni Roslan , Gobithaasan Rudrusamy , Akhbari Mohammad Hadi
Published: October 2022

The Randić index is among the most famous degree-based topological indices in chemical graph theory. It was introduced due to its application in modeling the properties of certain molecular structures and has been extensively studied. In this paper, we study the lower bound of the Randić index of trees in terms of the order and the total domination number. Finally, trees with the minimal Randić index are characterized.
Some Families of Generating Functions Associated with Orthogonal Polynomials and Other Higher Transcendental Functions
Authors: Srivastava Hari Mohan
Published: October 2022

In this invited survey-cum-expository review article, we present a brief and comprehensive account of some general families of linear and bilinear generating functions which are associated with orthogonal polynomials and such other higher transcendental functions as (for example) hypergeometric functions and hypergeometric polynomials in one, two and more variables. Many of the results as well as the methods and techniques used for their derivations, which are presented here, are intended to provide incentive and motivation for further research on the subject investigated in this article.
An Intersection-Based Routing Scheme Using Q-Learning in Vehicular Ad Hoc Networks for Traffic Management in the Intelligent Transportation System
Authors: Khan Muhammad Umair , Hosseinzadeh Mehdi , Mosavi Amir
Published: October 2022

Vehicular ad hoc networks (VANETs) create an advanced framework to support the intelligent transportation system and increase road safety by managing traffic flow and avoiding accidents. These networks have specific characteristics, including the high mobility of vehicles, dynamic topology, and frequent link failures. For this reason, providing an efficient and stable routing approach for VANET is a challenging issue. Reinforcement learning (RL) can solve the various challenges and issues of vehicular ad hoc networks, including routing. Most of the existing reinforcement learning-based routing methods are incompatible with the dynamic network environment and cannot prevent congestion in the network. Network congestion can be controlled by managing traffic flow. For this purpose, roadside units (RSUs) must monitor the road status to be informed about traffic conditions. In this paper, an intersection-based routing method using Q-learning (IRQ) is presented for VANETs. IRQ uses both global and local views in the routing process. For this reason, a dissemination mechanism of traffic information is introduced to create these global and local views. According to the global view, a Q-learning-based routing technique is designed for discovering the best routes between intersections. The central server continuously evaluates the created paths between intersections to penalize road segments with high congestion and improve the packet delivery rate. Finally, IRQ uses a greedy strategy based on a local view to find the best next-hop node in each road segment. NS2 software is used for analyzing the performance of the proposed routing approach. Then, IRQ is compared with three methods, including IV2XQ, QGrid, and GPSR. The simulation results demonstrate that IRQ has an acceptable performance in terms of packet delivery rate and delay. However, its communication overhead is higher than IV2XQ.
Artificial Neural Network as a Tool for Estimation of the Higher Heating Value of Miscanthus Based on Ultimate Analysis
Authors: Brandić Ivan , Pezo Lato , Bilandžija Nikola , Peter Anamarija , Šurić Jona , Voća Neven
Published: October 2022

Miscanthus is a perennial energy crop that produces high yields and has the potential to be converted into energy. The ultimate analysis determines the composition of the biomass and the energy value in terms of the higher heating value (HHV), which is the most important parameter in determining the quality of the fuel. In this study, an artificial neural network (ANN) model based on the principle of supervised learning was developed to predict the HHV of miscanthus biomass. The developed ANN model was compared with the models of predictive regression models (suggested from the literature) and the accuracy of the developed model was determined by the coefficient of determination. The paper presents data from 192 miscanthus biomass samples based on ultimate analysis and HHV. The developed model showed good properties and the possibility of prediction with high accuracy (R2 = 0.77). The paper proves the possibility of using ANN models in practical application in determining fuel properties of biomass energy crops and greater accuracy in predicting HHV than the regression models offered in the literature.
A Combined Dynamic Programming and Simulation Approach to the Sizing of the Low-Level Order-Picking Area
Authors: Djurdjević Dragan , Bjelić Nenad , Popović Dražen , Andrejić Milan
Published: October 2022

In order to increase the efficiency of the order-picking process, warehouses are forced to find ways to adopt to constantly intensifying changes in the assortment and quantities of stored products. Accordingly, we present a methodology that deals with such a problem at a tactical level by defining the optimal size and an allocation of products within the order-picking area of the most typical order-picking setting. The methodology combined two methods, dynamic programming and simulation modelling, with the aim of taking advantages of their positive features. In that sense, the optimal allocation of products for different sizes of the order-picking zone were obtained by the dynamic programming approach. Afterwards, the influence of a demand’s seasonality and variations were treated by the simulation model, so that the more realistic performances of the system were captured for the optimal allocation of products. The methodology was tested on the retailer data with significant week seasonality. The obtained results confirmed the practical applicability of the methodology in real systems, while the sensitivity analysis of results showed that special attention and effort should be given to the determination of costs related to the engagement of order-pikers, storage equipment and unit replenishment during a planning period.
Resource- and Time-Efficient Computation Offloading in Vehicular Edge Computing: A Max-Min Fairness Oriented Approach
Authors: Wang Shujuan , Peng Hao , Guo Dongchao
Published: October 2022

Nowadays, computation offloading has become a research focus since it has the potential to solve the challenges faced when dealing with computation-intensive applications in the Internet of Vehicles (IoVs), especially in the 5G or future network environment. However, major issues still exist and the performance of main metrics can be improved to better adapt to the practical scenarios. This paper focuses on achieving resource- and time-efficient computation offloading in IoVs by boosting the cooperation efficiency of vehicles. Firstly, a fuzzy logic-based pricing strategy is designed to evaluate the cooperation tendency and capability of each vehicle from multiple aspects. Vehicles are encouraged to participate in the offloading process even if they are in a disadvantageous position compared to other vehicles. Secondly, a Max-Min fairness-oriented approach is proposed to find the most suitable offloading decision, and vehicles with poor cooperation capabilities are guaranteed to be treated equally in the offloading. Finally, two heuristic algorithms are presented to solve the problem with applicable complexity and to suit the practical IoV environment. Extensive simulation results prove that the proposed approach achieves remarkable performance improvements in terms of delay, service cost and the resource utilization ratios of vehicles.