This paper introduces the experience and practice in constructing the practical teaching system for the course“Electric Machine and Drive.”In response to the current status of cultivating innovative practical abilit...This paper introduces the experience and practice in constructing the practical teaching system for the course“Electric Machine and Drive.”In response to the current status of cultivating innovative practical abilities among electrical engineering majors,based on the independently developed virtual simulation experimental teaching platform for Electric Machine and Drive,a stepped practical teaching process consisting of“classroom teaching-experimental teaching-comprehensive training-scientific inquiry”has been elaborately designed.A hierarchical practical teaching model for the second classroom has also been established.With teaching objectives as the optimization index,the teaching content,methods and means have been optimized;the teaching process has been organized and implemented in the form of team collaboration,thus constructing a comprehensive,stepped,hierarchical,and closed-loop innovative practical teaching system.This achievement provides references and assistance for the practical teaching of the same or similar majors in other colleges and universities.展开更多
<strong>Background:</strong><span style="font-family:Verdana;"> The current competitive banking environment in Ghana demands that banks identify the factors key to their survival and work o...<strong>Background:</strong><span style="font-family:Verdana;"> The current competitive banking environment in Ghana demands that banks identify the factors key to their survival and work on these factors to ensure they remain in business. This in</span><span style="font-family:Verdana;">volves</span><span style="font-family:""><span style="font-family:Verdana;"> the banks knowing what influences customers to choose to do business with one bank over the other. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> The study aimed at determining the factors the influence Technical University student’s selection of banks. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Data from a cross-sectional survey of 545 student respondents of Takoradi Technical University was analysed using the statistical technique of factor analysis. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> Four factors were adduced to be influencing bank selection amongst Takoradi Technical University students: namely, Robust E-banking, Custom</span><span><span style="font-family:Verdana;">er Experience, Access to ATMs and Third Party Influence. </span><b><span style="font-family:Verdana;">Conclusion</span></b></span><b><span style="font-family:Verdana;">:</span></b><span style="font-family:Verdana;"> While some of the factors are universal in nature others present with subtle nuances dependent on the milieu in which a bank finds itself, making it imperative that banks study the market in which they are operating and implement strategies deemed most suitable for attracting and retaining customers.</span></span>展开更多
Background: This paper is a follow up to an earlier one on a study that sought to determine the factors that, in general, influence Takoradi Technical University students’ selection of banks, given the keen competiti...Background: This paper is a follow up to an earlier one on a study that sought to determine the factors that, in general, influence Takoradi Technical University students’ selection of banks, given the keen competition in the banking sector in Ghana. Having found the said factors in the first study, and in the face of evidence of a difference in the factors that influence bank choice elsewhere with respect to sex, the study whose findings is the subject of this paper sought to establish whether there is any such dichotomy amongst Takoradi Technical University students. Objectives: The study sought to 1) determine the factors that influence the selection of banks by males, 2) determine the factors that influence the selection of banks by females, and 3) determine whether there are any differences and similarities between male and female students with respect to the factors that influence bank selection. Methods: Data was obtained from 545 students, comprising 364 male students and 181 female students through a cross-sectional survey and was analysed using the statistical method of factor analysis, having initially established through the chi-square test of independence that bank choice and sex are not independent. Results: Four (4) factors were identified as influencing bank selection amongst the female students as against six (6) in the case of the male students. The factors identified for the female students are Customer Experience, Third Party Influence, E-banking, and Access to ATMs and that for the male students are Secure E-banking, Customer Experience, Promotion Strategy, Intelligent Responsiveness, Access to ATMs and Third Party Influence. Conclusion: Male and female students of Takoradi Technical University differ with respect to some of factors that influence bank choice. Even for the factors that are common, the importance female students attach to them is not the same as that of male students. The factors male students consider when making bank choices appear to be more strategic and wide-ranging than the females, with the latter tending to place premium on customer experience more than the former.展开更多
Appetizing peculiarities are formed from childhood and can vary throughout life. Although they are conditioned by genetic factors, over time, the internal regulation of eating behaviors is reduced, being influenced by...Appetizing peculiarities are formed from childhood and can vary throughout life. Although they are conditioned by genetic factors, over time, the internal regulation of eating behaviors is reduced, being influenced by a complex interaction of various external factors. According to the Behavioral Susceptibility (BST) Theory of Obesity, Food Sensitivity in Response to Food Stimuli (such as Food Sight and Smell) and Satiety Responsiveness (i.e. the ability to adjust diet in response to internal feelings of satiety) contribute to individual differences in terms of energy intake and weight status. The present research intended to assess the eating patterns and behavior of Moldovan students, especially those from Technical University of Moldova during the social isolation imposed by the COVID-19 pandemic. The study was conducted, based on the questionnaires (AEBQ—Adult Eating Behavior Questionnaire), on a group of 602 students from Technical University of Moldova. Participation in the survey was entirely voluntary, did not involve any invasive procedure, nor did it induce changes in participants’ food patterns. The obtained results could contribute to the formation of the database for the study of the behavioral phenotype associated with the risk of obesity, but also for the study of eating behavior in crises. The questionnaire was distributed, in the form of a link, on the corporate emails of all TUM students. Respondents completed the questionnaire on the Google platform between 13.10.2021 - 25.11.2021, and the final database has been downloaded as a Microsoft Excel file. It was established a positive correlation between, Emotional Over-Eating and Emotional Under-Eating. Nervousness and anger were the most incriminating emotions of students that would cause both overeating and under eating. The results of the AEBQ questionnaire appear to be largely in line with previous studies, and the collected data present interest, in particular to prevent the risk of obesity.展开更多
This paper deals with the post-occupancy performance evaluation of the SFL （School of Foreign Languages） that was designed by the authors and is located within the YTU （Yildiz Technical University） Davutpaa campus...This paper deals with the post-occupancy performance evaluation of the SFL （School of Foreign Languages） that was designed by the authors and is located within the YTU （Yildiz Technical University） Davutpaa campus in Istanbul. After the completion and occupation of the building, project review came into question and a POE was performed. Post-occupancy performance evaluation tries to answer the questions of space provision for social interaction： ＂How is this building working？＂ ＂Is it intended？＂ ＂How can it be improved？＂ and ＂How can future buildings be improved？＂ Answers to these vital questions are searched under four main sections. In the first section, the study discusses the physical location and functional properties of the building, in the second, the design decisions of the building are discussed in the context of and design principles, in the third, the method of performance evaluation is explained, and in the final section, the results are analyzed and discussed. These results will lead to a path to improve the quality of the building.展开更多
Based on the demand for complex English talents for the high-quality construction of“Belt and Road,”the study proposes a curriculum restructuring program oriented on“serving professional teaching,career development...Based on the demand for complex English talents for the high-quality construction of“Belt and Road,”the study proposes a curriculum restructuring program oriented on“serving professional teaching,career development,and quality development”in response to the real problems of the current university English curriculum,such as focusing on language but not on application,insufficient vocational relevance,and low degree of integration with the professional field.We propose a curriculum reconstruction plan oriented to“serve professional teaching,career development,and quality development.”We have constructed a three-in-one curriculum goal of“laying a foundation for professionalism,infiltrating humanity,and empowering development,”systematically designed a curriculum content system of“language foundation,industry knowledge,and quality development,”and established an AI-enabled multi-intelligence evaluation system.This will promote the transformation of university English from single-language teaching to a service-oriented curriculum that supports professional development,and cultivate internationalized talents with both workplace language application skills and cross-cultural communication literacy.The study highlights the“vocational”characteristics and“service”functions of college English,and provides an actionable,practical path for the reform of college English curriculum in vocational undergraduate colleges.展开更多
In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.T...In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.The amount of hydrogen produced was considered as a technical parameter,cost of hydrogen production was considered as an economic index,and the amount of carbon(IV)oxide saved from the use of diesel fuel was considered as an environmental index.The results reveal that ENERCON E-40 turbine yields the highest capacity factor in Lagos,Jos,Sokoto,Bauchi and Enugu sites while FUHRLAENDER,GMBH yields the highest capacity factor in Delta.The mean annual hydrogen production from wind ranged from 2.05 tons/annum at site S6(Delta)to 17.33 tons/annum at site S3(Sokoto),and the mean annual hydrogen production from SPV ranged from 64.33 tons/annum at sites S1(Lagos)to 140.28 tons/annum at site S6(Delta).The cost of hydrogen production from wind was 6.3679 and 25.9007$/kg for sites S3 and S6,respectively,and the cost of hydrogen production from SPV was 5.6659 and 6.1206$/kg for sites S3 and S1,respectively.The amount of CO_(2) saved annually from wind-based hydrogen generation was 137,267 kg/year in site S6 and 504,180 kg/year in site S3,and was used to produce electricity via fuel cells.The amount of CO_(2) saved using hydrogen produced from SPV was 615,400 kg/year and 1,341,899 kg/year in sites S1 and S6,respectively.The results also revealed that 75.55%,88.93%,80.28%,80.54%,85.65%,98.53%more hydrogen could be produced from SPV for sites S1–S6,respectively,compared to the wind resources.This study serves as a source of reliable technical information to relevant government agencies,policy makers and investors in making informed decisions on optimal investment in the hydrogen economy of Nigeria.展开更多
To address the key scientific challenge of monitoring the dynamic fracturing of surrounding rock in deep roadways,this study systematically investigates the quantitative relationship between stress and charge signals ...To address the key scientific challenge of monitoring the dynamic fracturing of surrounding rock in deep roadways,this study systematically investigates the quantitative relationship between stress and charge signals during coal mass loading.By integrating innovative analytical approaches,introducing quantitative evaluation indices,and developing a charge–stress inversion model,and incorporating underground monitoring practices,significant progress has been achieved in elucidating the correlation between stress variations and charge signals throughout the entire coal mass fracturing process.First,in the field of stress–charge correlation analysis,empirical mode decomposition(EMD)was combined with wavelet coherence analysis for the first time,enabling the removal of slow-varying stress trends while retaining high-frequency fluctuations.This approach allowed for the quantitative characterization of the evolution of coherence between stress variations and charge fluctuations across multiple time scales.Second,coherence skewness and the proportion of high-coherence intervals were innovatively introduced to examine the influence of time scale selection on correlation results.On this basis,a criterion for determining the near-optimal observation scale of charge signals was proposed,providing a quantitative reference for time scale selection in similar signal analyses.Finally,by correlating charge signals with coal damage factors and stress states,a charge-based damage evolution equation was established to achieve effective stress inversion.Combined with in situ monitoring of stress and charge in roadway surrounding rock,this approach revealed the correlation characteristics of stress and charge intensity responses during the dynamic fracturing process.The results indicate,first,that charge signals are not significantly correlated with the absolute stress level of coal but are directly associated with stress variations following coal damage and failure,with the amplitude of charge fluctuations increasing alongside stress fluctuations.Second,coherence between stress and charge signals varies markedly across time scales,with excessively small or large scales leading to distortion,and the scale corresponding to the peak proportion of intervals with coherence>0.8 was identified as the near-optimal observation scale.Third,charge signals can effectively characterize coal damage factors,and the established damage evolution equation can effectively invert stress variation trends.Fourth,in underground roadways,zones of dynamic fracturing in surrounding rock are commonly located in areas where stress concentration overlaps with regions of high charge intensity,further confirming the strong consistency between charge and stress variations.These findings improve the theoretical framework of charge signal responses in loaded coal and provide a scientific basis for precise“stress-charge”monitoring of dynamic disasters,offering practical potential for engineering applications.展开更多
This paper aims to explore and quantify the nonlinear vibration response of tri-directional functionally graded sandwich(3D-FGSW)plates partially supported by a Pasternak foundation(PF)subjected to blast loading(BL).A...This paper aims to explore and quantify the nonlinear vibration response of tri-directional functionally graded sandwich(3D-FGSW)plates partially supported by a Pasternak foundation(PF)subjected to blast loading(BL).A key objective is to develop a computationally efficient finite element framework capable of accurately capturing the complex behavior of 3D-FGSW plates.The studied configuration features a two-dimensional functionally graded material(2D-FGM)core between two threedimensional functionally graded material(3D-FGM)face layers.Nonlinear geometric effects,including mid-plane stretching,are modeled using von K arm an-type assumptions,and the governing equations are formulated via Hamilton's principle within an improved first-order shear deformation theory(iFSDT).The accuracy and computational efficiency of the proposed method are validated through comparison with existing benchmark solutions.Subsequently,a comprehensive parametric study is carried out to examine the effects of geometric dimensions,material properties,foundation sizes,and boundary conditions(BCs)on the nonlinear vibration of 3D-FGSW plates.The findings of this work are expected to provide valuable insights for the design and manufacturing of advanced sandwich structures subjected to BL.展开更多
This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens ...This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens manufactured using extrusion-based 3D printing.Through comprehensive testing,including cyclic compression at strain rates ranging from 0.12 to 120 mm/min(0%-15%strain)and creep/relaxation experiments(10%-30%strain),the lumped parameters were independently determined using both analytical and numerical solutions of the models’differential equations,followed by cross-verification in additional experiments.Numerical solutions for creep and relaxation problems were obtained using finite element analysis,with the three-parameter Mooney-Rivlin model and Prony series employed to simulate elastic and viscous stress components,respectively.Energy dissipation per cycle was quantified during cyclic compression tests.The results demonstrate that all three models adequately describe material behavior within the 0%-15%strain range across various strain rates.Comparative analysis revealed the Burgers model’s superior performance in characterizing creep and stress relaxation at low strain levels.While Zener and Burgers model parameters from uniaxial compression showed limited applicability for energy dissipation calculations,the generalized Maxwell model effectively captured viscoelastic properties across different strain rates.Notably,parameters derived from creep tests provided a more universal assessment of dissipative properties due to optimization based on characteristic curve regions.Both parameter sets described polyurethane’s elastic-hysteretic behavior with approximately 20%error,proving significantly more accurate than the linear strain-time dependence hypothesis.Finite element analysis(FEA)complemented numerical modeling by demonstrating that while the generalized Maxwell model effectively describes initial rapid stress-strain changes,FEA provides superior characterization of steady-state processes.This computational approach yields more physically representative results compared to simplified analytical solutions,despite certain limitations in transient analysis.展开更多
Missing data presents a crucial challenge in data analysis,especially in high-dimensional datasets,where missing data often leads to biased conclusions and degraded model performance.In this study,we present a novel a...Missing data presents a crucial challenge in data analysis,especially in high-dimensional datasets,where missing data often leads to biased conclusions and degraded model performance.In this study,we present a novel autoencoder-based imputation framework that integrates a composite loss function to enhance robustness and precision.The proposed loss combines(i)a guided,masked mean squared error focusing on missing entries;(ii)a noise-aware regularization term to improve resilience against data corruption;and(iii)a variance penalty to encourage expressive yet stable reconstructions.We evaluate the proposed model across four missingness mechanisms,such as Missing Completely at Random,Missing at Random,Missing Not at Random,and Missing Not at Random with quantile censorship,under systematically varied feature counts,sample sizes,and missingness ratios ranging from 5%to 60%.Four publicly available real-world datasets(Stroke Prediction,Pima Indians Diabetes,Cardiovascular Disease,and Framingham Heart Study)were used,and the obtained results show that our proposed model consistently outperforms baseline methods,including traditional and deep learning-based techniques.An ablation study reveals the additive value of each component in the loss function.Additionally,we assessed the downstream utility of imputed data through classification tasks,where datasets imputed by the proposed method yielded the highest receiver operating characteristic area under the curve scores across all scenarios.The model demonstrates strong scalability and robustness,improving performance with larger datasets and higher feature counts.These results underscore the capacity of the proposed method to produce not only numerically accurate but also semantically useful imputations,making it a promising solution for robust data recovery in clinical applications.展开更多
To address the issue of scarce labeled samples and operational condition variations that degrade the accuracy of fault diagnosis models in variable-condition gearbox fault diagnosis,this paper proposes a semi-supervis...To address the issue of scarce labeled samples and operational condition variations that degrade the accuracy of fault diagnosis models in variable-condition gearbox fault diagnosis,this paper proposes a semi-supervised masked contrastive learning and domain adaptation(SSMCL-DA)method for gearbox fault diagnosis under variable conditions.Initially,during the unsupervised pre-training phase,a dual signal augmentation strategy is devised,which simultaneously applies random masking in the time domain and random scaling in the frequency domain to unlabeled samples,thereby constructing more challenging positive sample pairs to guide the encoder in learning intrinsic features robust to condition variations.Subsequently,a ConvNeXt-Transformer hybrid architecture is employed,integrating the superior local detail modeling capacity of ConvNeXt with the robust global perception capability of Transformer to enhance feature extraction in complex scenarios.Thereafter,a contrastive learning model is constructed with the optimization objective of maximizing feature similarity across different masked instances of the same sample,enabling the extraction of consistent features from multiple masked perspectives and reducing reliance on labeled data.In the final supervised fine-tuning phase,a multi-scale attention mechanism is incorporated for feature rectification,and a domain adaptation module combining Local Maximum Mean Discrepancy(LMMD)with adversarial learning is proposed.This module embodies a dual mechanism:LMMD facilitates fine-grained class-conditional alignment,compelling features of identical fault classes to converge across varying conditions,while the domain discriminator utilizes adversarial training to guide the feature extractor toward learning domain-invariant features.Working in concert,they markedly diminish feature distribution discrepancies induced by changes in load,rotational speed,and other factors,thereby boosting the model’s adaptability to cross-condition scenarios.Experimental evaluations on the WT planetary gearbox dataset and the Case Western Reserve University(CWRU)bearing dataset demonstrate that the SSMCL-DA model effectively identifies multiple fault classes in gearboxes,with diagnostic performance substantially surpassing that of conventional methods.Under cross-condition scenarios,the model attains fault diagnosis accuracies of 99.21%for the WT planetary gearbox and 99.86%for the bearings,respectively.Furthermore,the model exhibits stable generalization capability in cross-device settings.展开更多
This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,Calcu...This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.展开更多
Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typical...Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typically evaluated by a dimensionless figure of merit (ZT = S2σT/(κe+ κl)), which depends on the delicate interplay among the electrical conductivity (σ), Seebeck coefficient (S), lattice thermal conductivity (κl), and electronic thermal conductivity (κe) [4].展开更多
This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for ...This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.展开更多
Although the combination of chemotherapy and immunotherapy can improve the treatment of breast cancer,traditional drugs are highly toxic because they do not specifically target tumors.In this study,we developed a self...Although the combination of chemotherapy and immunotherapy can improve the treatment of breast cancer,traditional drugs are highly toxic because they do not specifically target tumors.In this study,we developed a self-driving bacteria/nanoparticle biohybrid called Bif@PDA-aPD1/DOX-Lip by attaching polydopamine(PDA)coated doxorubicin(DOX)liposomes and the immune checkpoint inhibitor anti-programmed cell death protein 1 antibody(aPD-1)to Bifidobacterium infantis(B.infantis,Bif).Using the homing abilities of bacteria,Bif@PDA-aPD1/DOX-Lip could actively accumulate in tumor tissue,releasing DOX and aPD-1 in the acidic environment to have a synergistic anti-tumor effect.Results show that the concentration of DOX in tumors of the Bif@PDA-aPD1/DOX-Lip group was 6.31 times higher than in the free DOX group.The combination of DOX and aPD-1 not only killed tumor cells but also promoted immune normalization by maturing dendritic cells(DCs),increasing M1 macrophage ratio,and enhancing infiltration of CD8+and CD4+T cells in tumors and spleen.Therefore,Bif@PDA-aPD1/DOX-Lip therapy significantly inhibited tumor growth and increased the average survival time of mice to over 80 days.The Bif@PDA-aPD1/DOX-Lip biomotors offer a highly effective method for enhancing chemo-immunotherapy in solid tumors.展开更多
Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrain...Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrained onboard devices to nearby Roadside Unit(RSU),thereby achieving lower delay and energy consumption.However,due to the limited storage capacity and energy budget of RSUs,it is challenging to meet the demands of the highly dynamic Internet of Vehicles(IoV)environment.Therefore,determining reasonable service caching and computation offloading strategies is crucial.To address this,this paper proposes a joint service caching scheme for cloud-edge collaborative IoV computation offloading.By modeling the dynamic optimization problem using Markov Decision Processes(MDP),the scheme jointly optimizes task delay,energy consumption,load balancing,and privacy entropy to achieve better quality of service.Additionally,a dynamic adaptive multi-objective deep reinforcement learning algorithm is proposed.Each Double Deep Q-Network(DDQN)agent obtains rewards for different objectives based on distinct reward functions and dynamically updates the objective weights by learning the value changes between objectives using Radial Basis Function Networks(RBFN),thereby efficiently approximating the Pareto-optimal decisions for multiple objectives.Extensive experiments demonstrate that the proposed algorithm can better coordinate the three-tier computing resources of cloud,edge,and vehicles.Compared to existing algorithms,the proposed method reduces task delay and energy consumption by 10.64%and 5.1%,respectively.展开更多
In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-pin...In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise.This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference.By decomposing A-scan signals into Intrinsic Mode Functions(IMFs),the framework employs energy contribution thresholds(>85%)and kurtosis indices(>3)to autonomously select IMFs containing valid specimen echoes.Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing.Experimental results demonstrate the framework’s robustness,achieving 92.3%thickness accuracy for 5 mm steel specimens with 5 mm rubber coupling,outperforming conventional methods by up to 18.7%.The dual-criterion approach reduces operator dependency by 37%and maintainsΔT<0.03 mm under surface roughness up to 6.3μm,offering a practical solution for industrial nondestructive testing with thick dry-coupled interfaces.展开更多
基金Project of the 14th Five-Year Plan for Educational Science in Liaoning Province(JG24DB234)Project of Graduate Education and Teaching Reform Research in Liaoning Province(LNYJG2023115)。
文摘This paper introduces the experience and practice in constructing the practical teaching system for the course“Electric Machine and Drive.”In response to the current status of cultivating innovative practical abilities among electrical engineering majors,based on the independently developed virtual simulation experimental teaching platform for Electric Machine and Drive,a stepped practical teaching process consisting of“classroom teaching-experimental teaching-comprehensive training-scientific inquiry”has been elaborately designed.A hierarchical practical teaching model for the second classroom has also been established.With teaching objectives as the optimization index,the teaching content,methods and means have been optimized;the teaching process has been organized and implemented in the form of team collaboration,thus constructing a comprehensive,stepped,hierarchical,and closed-loop innovative practical teaching system.This achievement provides references and assistance for the practical teaching of the same or similar majors in other colleges and universities.
文摘<strong>Background:</strong><span style="font-family:Verdana;"> The current competitive banking environment in Ghana demands that banks identify the factors key to their survival and work on these factors to ensure they remain in business. This in</span><span style="font-family:Verdana;">volves</span><span style="font-family:""><span style="font-family:Verdana;"> the banks knowing what influences customers to choose to do business with one bank over the other. </span><b><span style="font-family:Verdana;">Objective:</span></b><span style="font-family:Verdana;"> The study aimed at determining the factors the influence Technical University student’s selection of banks. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> Data from a cross-sectional survey of 545 student respondents of Takoradi Technical University was analysed using the statistical technique of factor analysis. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> Four factors were adduced to be influencing bank selection amongst Takoradi Technical University students: namely, Robust E-banking, Custom</span><span><span style="font-family:Verdana;">er Experience, Access to ATMs and Third Party Influence. </span><b><span style="font-family:Verdana;">Conclusion</span></b></span><b><span style="font-family:Verdana;">:</span></b><span style="font-family:Verdana;"> While some of the factors are universal in nature others present with subtle nuances dependent on the milieu in which a bank finds itself, making it imperative that banks study the market in which they are operating and implement strategies deemed most suitable for attracting and retaining customers.</span></span>
文摘Background: This paper is a follow up to an earlier one on a study that sought to determine the factors that, in general, influence Takoradi Technical University students’ selection of banks, given the keen competition in the banking sector in Ghana. Having found the said factors in the first study, and in the face of evidence of a difference in the factors that influence bank choice elsewhere with respect to sex, the study whose findings is the subject of this paper sought to establish whether there is any such dichotomy amongst Takoradi Technical University students. Objectives: The study sought to 1) determine the factors that influence the selection of banks by males, 2) determine the factors that influence the selection of banks by females, and 3) determine whether there are any differences and similarities between male and female students with respect to the factors that influence bank selection. Methods: Data was obtained from 545 students, comprising 364 male students and 181 female students through a cross-sectional survey and was analysed using the statistical method of factor analysis, having initially established through the chi-square test of independence that bank choice and sex are not independent. Results: Four (4) factors were identified as influencing bank selection amongst the female students as against six (6) in the case of the male students. The factors identified for the female students are Customer Experience, Third Party Influence, E-banking, and Access to ATMs and that for the male students are Secure E-banking, Customer Experience, Promotion Strategy, Intelligent Responsiveness, Access to ATMs and Third Party Influence. Conclusion: Male and female students of Takoradi Technical University differ with respect to some of factors that influence bank choice. Even for the factors that are common, the importance female students attach to them is not the same as that of male students. The factors male students consider when making bank choices appear to be more strategic and wide-ranging than the females, with the latter tending to place premium on customer experience more than the former.
文摘Appetizing peculiarities are formed from childhood and can vary throughout life. Although they are conditioned by genetic factors, over time, the internal regulation of eating behaviors is reduced, being influenced by a complex interaction of various external factors. According to the Behavioral Susceptibility (BST) Theory of Obesity, Food Sensitivity in Response to Food Stimuli (such as Food Sight and Smell) and Satiety Responsiveness (i.e. the ability to adjust diet in response to internal feelings of satiety) contribute to individual differences in terms of energy intake and weight status. The present research intended to assess the eating patterns and behavior of Moldovan students, especially those from Technical University of Moldova during the social isolation imposed by the COVID-19 pandemic. The study was conducted, based on the questionnaires (AEBQ—Adult Eating Behavior Questionnaire), on a group of 602 students from Technical University of Moldova. Participation in the survey was entirely voluntary, did not involve any invasive procedure, nor did it induce changes in participants’ food patterns. The obtained results could contribute to the formation of the database for the study of the behavioral phenotype associated with the risk of obesity, but also for the study of eating behavior in crises. The questionnaire was distributed, in the form of a link, on the corporate emails of all TUM students. Respondents completed the questionnaire on the Google platform between 13.10.2021 - 25.11.2021, and the final database has been downloaded as a Microsoft Excel file. It was established a positive correlation between, Emotional Over-Eating and Emotional Under-Eating. Nervousness and anger were the most incriminating emotions of students that would cause both overeating and under eating. The results of the AEBQ questionnaire appear to be largely in line with previous studies, and the collected data present interest, in particular to prevent the risk of obesity.
文摘This paper deals with the post-occupancy performance evaluation of the SFL （School of Foreign Languages） that was designed by the authors and is located within the YTU （Yildiz Technical University） Davutpaa campus in Istanbul. After the completion and occupation of the building, project review came into question and a POE was performed. Post-occupancy performance evaluation tries to answer the questions of space provision for social interaction： ＂How is this building working？＂ ＂Is it intended？＂ ＂How can it be improved？＂ and ＂How can future buildings be improved？＂ Answers to these vital questions are searched under four main sections. In the first section, the study discusses the physical location and functional properties of the building, in the second, the design decisions of the building are discussed in the context of and design principles, in the third, the method of performance evaluation is explained, and in the final section, the results are analyzed and discussed. These results will lead to a path to improve the quality of the building.
基金Special Project of Foreign Language Education Reform in Vocational Colleges and Universities in 2023 by the Foreign Language Education Working Committee of China Society for Vocational and Technical Education(WYW2023A05)Teaching Reform Project of Shandong Vocational and Technical University of International Studies(JG202314).
文摘Based on the demand for complex English talents for the high-quality construction of“Belt and Road,”the study proposes a curriculum restructuring program oriented on“serving professional teaching,career development,and quality development”in response to the real problems of the current university English curriculum,such as focusing on language but not on application,insufficient vocational relevance,and low degree of integration with the professional field.We propose a curriculum reconstruction plan oriented to“serve professional teaching,career development,and quality development.”We have constructed a three-in-one curriculum goal of“laying a foundation for professionalism,infiltrating humanity,and empowering development,”systematically designed a curriculum content system of“language foundation,industry knowledge,and quality development,”and established an AI-enabled multi-intelligence evaluation system.This will promote the transformation of university English from single-language teaching to a service-oriented curriculum that supports professional development,and cultivate internationalized talents with both workplace language application skills and cross-cultural communication literacy.The study highlights the“vocational”characteristics and“service”functions of college English,and provides an actionable,practical path for the reform of college English curriculum in vocational undergraduate colleges.
基金supported by Abiola Ajimobi Technical UniversityUniversity of Ibadan
文摘In this study,ten wind turbines and fourteen solar photovoltaic(SPV)modules were employed to compare the potential of hydrogen production from wind and solar energy resources in the six geopolitical zones of Nigeria.The amount of hydrogen produced was considered as a technical parameter,cost of hydrogen production was considered as an economic index,and the amount of carbon(IV)oxide saved from the use of diesel fuel was considered as an environmental index.The results reveal that ENERCON E-40 turbine yields the highest capacity factor in Lagos,Jos,Sokoto,Bauchi and Enugu sites while FUHRLAENDER,GMBH yields the highest capacity factor in Delta.The mean annual hydrogen production from wind ranged from 2.05 tons/annum at site S6(Delta)to 17.33 tons/annum at site S3(Sokoto),and the mean annual hydrogen production from SPV ranged from 64.33 tons/annum at sites S1(Lagos)to 140.28 tons/annum at site S6(Delta).The cost of hydrogen production from wind was 6.3679 and 25.9007$/kg for sites S3 and S6,respectively,and the cost of hydrogen production from SPV was 5.6659 and 6.1206$/kg for sites S3 and S1,respectively.The amount of CO_(2) saved annually from wind-based hydrogen generation was 137,267 kg/year in site S6 and 504,180 kg/year in site S3,and was used to produce electricity via fuel cells.The amount of CO_(2) saved using hydrogen produced from SPV was 615,400 kg/year and 1,341,899 kg/year in sites S1 and S6,respectively.The results also revealed that 75.55%,88.93%,80.28%,80.54%,85.65%,98.53%more hydrogen could be produced from SPV for sites S1–S6,respectively,compared to the wind resources.This study serves as a source of reliable technical information to relevant government agencies,policy makers and investors in making informed decisions on optimal investment in the hydrogen economy of Nigeria.
基金supported by the Research Fund of the National Natural Science Foundation of China(No.52374205)the Fundamental Research Project of the Educational Department of Liaoning Province(No.JYTMS20230793)the Research Fund of the State Key Laboratory of Coal Resources and Safe Mining,CUMT(No.YJY-XD-2024-A-016).
文摘To address the key scientific challenge of monitoring the dynamic fracturing of surrounding rock in deep roadways,this study systematically investigates the quantitative relationship between stress and charge signals during coal mass loading.By integrating innovative analytical approaches,introducing quantitative evaluation indices,and developing a charge–stress inversion model,and incorporating underground monitoring practices,significant progress has been achieved in elucidating the correlation between stress variations and charge signals throughout the entire coal mass fracturing process.First,in the field of stress–charge correlation analysis,empirical mode decomposition(EMD)was combined with wavelet coherence analysis for the first time,enabling the removal of slow-varying stress trends while retaining high-frequency fluctuations.This approach allowed for the quantitative characterization of the evolution of coherence between stress variations and charge fluctuations across multiple time scales.Second,coherence skewness and the proportion of high-coherence intervals were innovatively introduced to examine the influence of time scale selection on correlation results.On this basis,a criterion for determining the near-optimal observation scale of charge signals was proposed,providing a quantitative reference for time scale selection in similar signal analyses.Finally,by correlating charge signals with coal damage factors and stress states,a charge-based damage evolution equation was established to achieve effective stress inversion.Combined with in situ monitoring of stress and charge in roadway surrounding rock,this approach revealed the correlation characteristics of stress and charge intensity responses during the dynamic fracturing process.The results indicate,first,that charge signals are not significantly correlated with the absolute stress level of coal but are directly associated with stress variations following coal damage and failure,with the amplitude of charge fluctuations increasing alongside stress fluctuations.Second,coherence between stress and charge signals varies markedly across time scales,with excessively small or large scales leading to distortion,and the scale corresponding to the peak proportion of intervals with coherence>0.8 was identified as the near-optimal observation scale.Third,charge signals can effectively characterize coal damage factors,and the established damage evolution equation can effectively invert stress variation trends.Fourth,in underground roadways,zones of dynamic fracturing in surrounding rock are commonly located in areas where stress concentration overlaps with regions of high charge intensity,further confirming the strong consistency between charge and stress variations.These findings improve the theoretical framework of charge signal responses in loaded coal and provide a scientific basis for precise“stress-charge”monitoring of dynamic disasters,offering practical potential for engineering applications.
文摘This paper aims to explore and quantify the nonlinear vibration response of tri-directional functionally graded sandwich(3D-FGSW)plates partially supported by a Pasternak foundation(PF)subjected to blast loading(BL).A key objective is to develop a computationally efficient finite element framework capable of accurately capturing the complex behavior of 3D-FGSW plates.The studied configuration features a two-dimensional functionally graded material(2D-FGM)core between two threedimensional functionally graded material(3D-FGM)face layers.Nonlinear geometric effects,including mid-plane stretching,are modeled using von K arm an-type assumptions,and the governing equations are formulated via Hamilton's principle within an improved first-order shear deformation theory(iFSDT).The accuracy and computational efficiency of the proposed method are validated through comparison with existing benchmark solutions.Subsequently,a comprehensive parametric study is carried out to examine the effects of geometric dimensions,material properties,foundation sizes,and boundary conditions(BCs)on the nonlinear vibration of 3D-FGSW plates.The findings of this work are expected to provide valuable insights for the design and manufacturing of advanced sandwich structures subjected to BL.
文摘This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens manufactured using extrusion-based 3D printing.Through comprehensive testing,including cyclic compression at strain rates ranging from 0.12 to 120 mm/min(0%-15%strain)and creep/relaxation experiments(10%-30%strain),the lumped parameters were independently determined using both analytical and numerical solutions of the models’differential equations,followed by cross-verification in additional experiments.Numerical solutions for creep and relaxation problems were obtained using finite element analysis,with the three-parameter Mooney-Rivlin model and Prony series employed to simulate elastic and viscous stress components,respectively.Energy dissipation per cycle was quantified during cyclic compression tests.The results demonstrate that all three models adequately describe material behavior within the 0%-15%strain range across various strain rates.Comparative analysis revealed the Burgers model’s superior performance in characterizing creep and stress relaxation at low strain levels.While Zener and Burgers model parameters from uniaxial compression showed limited applicability for energy dissipation calculations,the generalized Maxwell model effectively captured viscoelastic properties across different strain rates.Notably,parameters derived from creep tests provided a more universal assessment of dissipative properties due to optimization based on characteristic curve regions.Both parameter sets described polyurethane’s elastic-hysteretic behavior with approximately 20%error,proving significantly more accurate than the linear strain-time dependence hypothesis.Finite element analysis(FEA)complemented numerical modeling by demonstrating that while the generalized Maxwell model effectively describes initial rapid stress-strain changes,FEA provides superior characterization of steady-state processes.This computational approach yields more physically representative results compared to simplified analytical solutions,despite certain limitations in transient analysis.
文摘Missing data presents a crucial challenge in data analysis,especially in high-dimensional datasets,where missing data often leads to biased conclusions and degraded model performance.In this study,we present a novel autoencoder-based imputation framework that integrates a composite loss function to enhance robustness and precision.The proposed loss combines(i)a guided,masked mean squared error focusing on missing entries;(ii)a noise-aware regularization term to improve resilience against data corruption;and(iii)a variance penalty to encourage expressive yet stable reconstructions.We evaluate the proposed model across four missingness mechanisms,such as Missing Completely at Random,Missing at Random,Missing Not at Random,and Missing Not at Random with quantile censorship,under systematically varied feature counts,sample sizes,and missingness ratios ranging from 5%to 60%.Four publicly available real-world datasets(Stroke Prediction,Pima Indians Diabetes,Cardiovascular Disease,and Framingham Heart Study)were used,and the obtained results show that our proposed model consistently outperforms baseline methods,including traditional and deep learning-based techniques.An ablation study reveals the additive value of each component in the loss function.Additionally,we assessed the downstream utility of imputed data through classification tasks,where datasets imputed by the proposed method yielded the highest receiver operating characteristic area under the curve scores across all scenarios.The model demonstrates strong scalability and robustness,improving performance with larger datasets and higher feature counts.These results underscore the capacity of the proposed method to produce not only numerically accurate but also semantically useful imputations,making it a promising solution for robust data recovery in clinical applications.
基金supported by the National Natural Science Foundation of China Funded Project(Project Name:Research on Robust Adaptive Allocation Mechanism of Human Machine Co-Driving System Based on NMS Features,Project Approval Number:52172381).
文摘To address the issue of scarce labeled samples and operational condition variations that degrade the accuracy of fault diagnosis models in variable-condition gearbox fault diagnosis,this paper proposes a semi-supervised masked contrastive learning and domain adaptation(SSMCL-DA)method for gearbox fault diagnosis under variable conditions.Initially,during the unsupervised pre-training phase,a dual signal augmentation strategy is devised,which simultaneously applies random masking in the time domain and random scaling in the frequency domain to unlabeled samples,thereby constructing more challenging positive sample pairs to guide the encoder in learning intrinsic features robust to condition variations.Subsequently,a ConvNeXt-Transformer hybrid architecture is employed,integrating the superior local detail modeling capacity of ConvNeXt with the robust global perception capability of Transformer to enhance feature extraction in complex scenarios.Thereafter,a contrastive learning model is constructed with the optimization objective of maximizing feature similarity across different masked instances of the same sample,enabling the extraction of consistent features from multiple masked perspectives and reducing reliance on labeled data.In the final supervised fine-tuning phase,a multi-scale attention mechanism is incorporated for feature rectification,and a domain adaptation module combining Local Maximum Mean Discrepancy(LMMD)with adversarial learning is proposed.This module embodies a dual mechanism:LMMD facilitates fine-grained class-conditional alignment,compelling features of identical fault classes to converge across varying conditions,while the domain discriminator utilizes adversarial training to guide the feature extractor toward learning domain-invariant features.Working in concert,they markedly diminish feature distribution discrepancies induced by changes in load,rotational speed,and other factors,thereby boosting the model’s adaptability to cross-condition scenarios.Experimental evaluations on the WT planetary gearbox dataset and the Case Western Reserve University(CWRU)bearing dataset demonstrate that the SSMCL-DA model effectively identifies multiple fault classes in gearboxes,with diagnostic performance substantially surpassing that of conventional methods.Under cross-condition scenarios,the model attains fault diagnosis accuracies of 99.21%for the WT planetary gearbox and 99.86%for the bearings,respectively.Furthermore,the model exhibits stable generalization capability in cross-device settings.
基金supported in part by the Mining Hydraulic Technology and Equipment Engineering Research Center,Liaoning Technical University,Fuxin,China(Grant No.MHTE23-R04)the Fundamental Research Funds for the Central Universities(ID N25BSS068).
文摘This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems.
基金supports from the Department of Education of Liaoning Province (LJ242510147006)
文摘Thermoelectric (TE) materials enable precise, noiseless, and moving-part-free waste heat recovery and solid-state refrigeration through the Seebeck and Peltier effects [1–3]. The efficiency of TE materials is typically evaluated by a dimensionless figure of merit (ZT = S2σT/(κe+ κl)), which depends on the delicate interplay among the electrical conductivity (σ), Seebeck coefficient (S), lattice thermal conductivity (κl), and electronic thermal conductivity (κe) [4].
基金supported by Istanbul Technical University(Project No.45698)supported through the“Young Researchers’Career Development Project-training of doctoral students”of the Croatian Science Foundation.
文摘This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.
基金supported by the Science and Technology Strategic Cooperation Programs of Luzhou Municipal People's Government and Southwest Medical University(No.2024LZXNYDJ017)the Project Program of the Science and Technology Department of Sichuan Province(No.2025zNSFSC0679)the Project Program of Chongqing Science and Technology Bureau(No.cstc2020jcyjmsxmX1037).
文摘Although the combination of chemotherapy and immunotherapy can improve the treatment of breast cancer,traditional drugs are highly toxic because they do not specifically target tumors.In this study,we developed a self-driving bacteria/nanoparticle biohybrid called Bif@PDA-aPD1/DOX-Lip by attaching polydopamine(PDA)coated doxorubicin(DOX)liposomes and the immune checkpoint inhibitor anti-programmed cell death protein 1 antibody(aPD-1)to Bifidobacterium infantis(B.infantis,Bif).Using the homing abilities of bacteria,Bif@PDA-aPD1/DOX-Lip could actively accumulate in tumor tissue,releasing DOX and aPD-1 in the acidic environment to have a synergistic anti-tumor effect.Results show that the concentration of DOX in tumors of the Bif@PDA-aPD1/DOX-Lip group was 6.31 times higher than in the free DOX group.The combination of DOX and aPD-1 not only killed tumor cells but also promoted immune normalization by maturing dendritic cells(DCs),increasing M1 macrophage ratio,and enhancing infiltration of CD8+and CD4+T cells in tumors and spleen.Therefore,Bif@PDA-aPD1/DOX-Lip therapy significantly inhibited tumor growth and increased the average survival time of mice to over 80 days.The Bif@PDA-aPD1/DOX-Lip biomotors offer a highly effective method for enhancing chemo-immunotherapy in solid tumors.
基金supported by Key Science and Technology Program of Henan Province,China(Grant Nos.242102210147,242102210027)Fujian Province Young and Middle aged Teacher Education Research Project(Science and Technology Category)(No.JZ240101)(Corresponding author:Dong Yuan).
文摘Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrained onboard devices to nearby Roadside Unit(RSU),thereby achieving lower delay and energy consumption.However,due to the limited storage capacity and energy budget of RSUs,it is challenging to meet the demands of the highly dynamic Internet of Vehicles(IoV)environment.Therefore,determining reasonable service caching and computation offloading strategies is crucial.To address this,this paper proposes a joint service caching scheme for cloud-edge collaborative IoV computation offloading.By modeling the dynamic optimization problem using Markov Decision Processes(MDP),the scheme jointly optimizes task delay,energy consumption,load balancing,and privacy entropy to achieve better quality of service.Additionally,a dynamic adaptive multi-objective deep reinforcement learning algorithm is proposed.Each Double Deep Q-Network(DDQN)agent obtains rewards for different objectives based on distinct reward functions and dynamically updates the objective weights by learning the value changes between objectives using Radial Basis Function Networks(RBFN),thereby efficiently approximating the Pareto-optimal decisions for multiple objectives.Extensive experiments demonstrate that the proposed algorithm can better coordinate the three-tier computing resources of cloud,edge,and vehicles.Compared to existing algorithms,the proposed method reduces task delay and energy consumption by 10.64%and 5.1%,respectively.
基金funded by the National Natural Science Foundation of China,grant number U24A20135Inner Mongolia Natural Science Foundation major project,grant number 2023ZD12+7 种基金Inner Mongolia Autonomous Region key research and development and achievement transformation plan project,grant number 2023YFHH0090Natural Science Foundation of Inner Mongolia,grant number 2022MS05006Inner Mongolia Autonomous Region Talent Development FundUniversity basic research business expenses,grant number 2023RCTD012University basic research business expenses,grant number 2023QNJS075Postgraduate Research Innovation Program and of Inner Mongolia Autonomous Region,grant number KC2024053BUniversity basic research business expenses,grant number 2024YXXS012National Key Laboratory of Special Vehicle Design and Manufacturing Integration Technology,grant number GZ2023KF012.
文摘In dry-coupled ultrasonic thickness measurement,thick rubber layers introduce high-amplitude parasitic echoes that obscure defect signals and degrade thickness accuracy.Existing methods struggle to resolve overlap-ping echoes under variable coupling conditions and non-stationary noise.This study proposes a novel dual-criterion framework integrating energy contribution and statistical impulsivity metrics to isolate specimen re-flections from coupling-layer interference.By decomposing A-scan signals into Intrinsic Mode Functions(IMFs),the framework employs energy contribution thresholds(>85%)and kurtosis indices(>3)to autonomously select IMFs containing valid specimen echoes.Hybrid time-frequency thresholding further suppresses interference through amplitude filtering and spectral focusing.Experimental results demonstrate the framework’s robustness,achieving 92.3%thickness accuracy for 5 mm steel specimens with 5 mm rubber coupling,outperforming conventional methods by up to 18.7%.The dual-criterion approach reduces operator dependency by 37%and maintainsΔT<0.03 mm under surface roughness up to 6.3μm,offering a practical solution for industrial nondestructive testing with thick dry-coupled interfaces.
