期刊文献+
共找到397,517篇文章
< 1 2 250 >
每页显示 20 50 100
A new technical approach for real-time tensile strength testing of high-temperature granite based on micro-tensile testing technology
1
作者 Xianzhong Li Yinnan Tian +3 位作者 Zhenhua Li Shuai Heng Xiaodong Zhang Bing Liu 《International Journal of Mining Science and Technology》 2025年第8期1323-1339,共17页
The tensile strength of rocks under real-time high-temperatures is essential for enhanced geothermal system development.However,the complex occurrence and deep burial of hot dry rocks limit the quantity and quality of... The tensile strength of rocks under real-time high-temperatures is essential for enhanced geothermal system development.However,the complex occurrence and deep burial of hot dry rocks limit the quantity and quality of standard samples for mechanical testing.This paper compared the tensile strengths obtained from Brazilian splitting tests on standard samples(with a diameter of 50 mm and a thickness of 25 mm)and micro-tensile samples(with a diameter of 50 mm and a thickness of 25 mm)of two types of granites.A power-law size effect model was established between the two sets of data,validating the reliability of the testing method.Then,miniature Brazilian splitting under real-time high-temperature,combined with X-ray diffraction(XRD)revealed temperature-dependent strength variations and microstructural damage mechanisms.The results show that:(1)The comparison error between the tensile strength obtained by the fitting model and that of the measured standard samples was less than 6%.(2)In real-time high-temperature conditions,tensile strength of granite exhibited non-monotonic behavior,increasing below 300°C before decreasing,with sharp declines at 400–500°C and 600–700°C.(3)Thermal damage stems from the differences in the high-temperature behavior of minerals,including dehydration,phase transformation,and differential expansion. 展开更多
关键词 Dry hot rock development real-time high-temperature tensile strength Micro-tensile testing High-temperature microscopic mechanism Size effect
在线阅读 下载PDF
A model reference adaptive control based method for actuator delay estimation in real-time testing
2
作者 Cheng CHEN James M.RICLES 《Frontiers of Structural and Civil Engineering》 SCIE EI 2010年第3期277-286,共10页
Real-time testing provides a viable experimental technique to evaluate the performance of structural systems subjected to dynamic loading.Servo-hydraulic actuators are often utilized to apply calculated displacements ... Real-time testing provides a viable experimental technique to evaluate the performance of structural systems subjected to dynamic loading.Servo-hydraulic actuators are often utilized to apply calculated displacements from an integration algorithm to the experimental structures in a real-time manner.The compensation of actuator delay is therefore critical to achieve stable and reliable experimental results.The advances in compensation methods based on adaptive control theory enable researchers to accommodate variable actuator delay and achieve good actuator control for real-time tests.However,these adaptive methods all require time duration for actuator delay adaptation.Experiments show that a good actuator delay estimate can help optimize the performance of the adaptive compensation methods.The rate of adaptation also requires that a good actuator delay estimate be acquired especially for the tests where the peak structural response might occur at the beginning of the tests.This paper presents a model reference adaptive control based method to identify the parameter of a simplified discrete model for servo-hydraulic dynamics and the resulting compensation method.Simulations are conducted using both numerical analysis and experimental results to evaluate the effectiveness of the proposed estimation method. 展开更多
关键词 real-time testing actuator delay COMPENSATION adaptive control MIT rule discrete transfer function
原文传递
A Hybrid Approach to Software Testing Efficiency:Stacked Ensembles and Deep Q-Learning for Test Case Prioritization and Ranking
3
作者 Anis Zarrad Thomas Armstrong Jaber Jemai 《Computers, Materials & Continua》 2026年第3期1726-1746,共21页
Test case prioritization and ranking play a crucial role in software testing by improving fault detection efficiency and ensuring software reliability.While prioritization selects the most relevant test cases for opti... Test case prioritization and ranking play a crucial role in software testing by improving fault detection efficiency and ensuring software reliability.While prioritization selects the most relevant test cases for optimal coverage,ranking further refines their execution order to detect critical faults earlier.This study investigates machine learning techniques to enhance both prioritization and ranking,contributing to more effective and efficient testing processes.We first employ advanced feature engineering alongside ensemble models,including Gradient Boosted,Support Vector Machines,Random Forests,and Naive Bayes classifiers to optimize test case prioritization,achieving an accuracy score of 0.98847 and significantly improving the Average Percentage of Fault Detection(APFD).Subsequently,we introduce a deep Q-learning framework combined with a Genetic Algorithm(GA)to refine test case ranking within priority levels.This approach achieves a rank accuracy of 0.9172,demonstrating robust performance despite the increasing computational demands of specialized variation operators.Our findings highlight the effectiveness of stacked ensemble learning and reinforcement learning in optimizing test case prioritization and ranking.This integrated approach improves testing efficiency,reduces late-stage defects,and improves overall software stability.The study provides valuable information for AI-driven testing frameworks,paving the way for more intelligent and adaptive software quality assurance methodologies. 展开更多
关键词 Software testing test case prioritization test case ranking machine learning reinforcement learning deep Q-learning
在线阅读 下载PDF
Electroacoustic tomography with dual-frequency array for real-time monitoring of electroporation
4
作者 Luke Xu Yifei Xu Liangzhong Xiang 《Journal of Innovative Optical Health Sciences》 2026年第1期45-55,共11页
Electroacoustic Tomography(EAT)is an imaging technique that detects ultrasound waves induced by electrical pulses,offering a solution for real-time electroporation monitoring.This study presents EAT system using a dua... Electroacoustic Tomography(EAT)is an imaging technique that detects ultrasound waves induced by electrical pulses,offering a solution for real-time electroporation monitoring.This study presents EAT system using a dual-frequency ultrasound array.The broadband nature of electroacoustic signals requires ultrasound detector to cover both the high-frequency range(around 6MHz)signals generated by small targets and the low-frequency range(around 1MHz)signals generated by large targets.In our EAT system,we use the 6 MHz array to detect high-frequency signals from the electrodes,and the 1 MHz array for the electrical field.To test this,we conducted simulations using COMSOL Multiphysics^(®) and MATLAB's k-Wave toolbox,followed by experiments using a custom-built setup with a dual-frequency transducer and real-time data acquisition.The results demonstrated that the dual-frequency EAT system could accurately and simultaneously monitor the electroporation process,effectively showing both the treatment area and electrode placement with the application of 1 kV electric pulses with 100 ns duration.The axial resolution of the 6MHz array for EAT was 0.45 mm,significantly better than the 2mm resolution achieved with the 1MHz array.These findings validate the potential of dual-frequency EAT as a superior method for real-time electroporation monitoring. 展开更多
关键词 DUAL-FREQUENCY electroacoustic imaging real-time ELECTROPORATION
原文传递
Design and Exploration of Intelligent Software Testing Course
5
作者 Depeng Gao Rui Wu +1 位作者 Shihan Xiao Shuxi Chen 《计算机教育》 2026年第3期47-53,共7页
With the rapid development of artificial intelligence,the intelligence level of software is increasingly improving.Intelligent software,which is widely applied in crucial fields such as autonomous driving,intelligent ... With the rapid development of artificial intelligence,the intelligence level of software is increasingly improving.Intelligent software,which is widely applied in crucial fields such as autonomous driving,intelligent customer service,and medical diagnosis,is constructed based on complex technologies like machine learning and deep learning.Its uncertain behavior and data dependence pose unprecedented challenges to software testing.However,existing software testing courses mainly focus on conventional contents and are unable to meet the requirements of intelligent software testing.Therefore,this work deeply analyzed the relevant technologies of intelligent software testing,including reliability evaluation indicator system,neuron coverage,and test case generation.It also systematically designed an intelligent software testing course,covering teaching objectives,teaching content,teaching methods,and a teaching case.Verified by the practical teaching in four classes,this course has achieved remarkable results,providing practical experience for the reform of software testing courses. 展开更多
关键词 Intelligent software testing Intelligent software Software testing Course design
在线阅读 下载PDF
PIDINet-MC:Real-Time Multi-Class Edge Detection with PiDiNet
6
作者 Mingming Huang Yunfan Ye Zhiping Cai 《Computers, Materials & Continua》 2026年第2期1983-1999,共17页
As a fundamental component in computer vision,edges can be categorized into four types based on discontinuities in reflectance,illumination,surface normal,or depth.While deep CNNs have significantly advanced generic e... As a fundamental component in computer vision,edges can be categorized into four types based on discontinuities in reflectance,illumination,surface normal,or depth.While deep CNNs have significantly advanced generic edge detection,real-time multi-class semantic edge detection under resource constraints remains challenging.To address this,we propose a lightweight framework based on PiDiNet that enables fine-grained semantic edge detection.Our model simultaneously predicts background and four edge categories from full-resolution inputs,balancing accuracy and efficiency.Key contributions include:a multi-channel output structure expanding binary edge prediction to five classes,supported by a deep supervision mechanism;a dynamic class-balancing strategy combining adaptive weighting with physical priors to handle extreme class imbalance;and maintained architectural efficiency enabling real-time inference.Extensive evaluations on BSDS-RIND show our approach achieves accuracy competitive with state-of-the-art methods while operating in real time. 展开更多
关键词 Multi-class edge detection real-time LIGHTWEIGHT deep supervision
在线阅读 下载PDF
Block-Wise Sliding Recursive Wavelet Transform and Its Application in Real-Time Vehicle-Induced Signal Separation
7
作者 Jie Li Nan An Youliang Ding 《Structural Durability & Health Monitoring》 2026年第1期1-22,共22页
Vehicle-induced response separation is a crucial issue in structural health monitoring(SHM).This paper proposes a block-wise sliding recursive wavelet transform algorithm to meet the real-time processing requirements ... Vehicle-induced response separation is a crucial issue in structural health monitoring(SHM).This paper proposes a block-wise sliding recursive wavelet transform algorithm to meet the real-time processing requirements of monitoring data.To extend the separation target from a fixed dataset to a continuously updating data stream,a block-wise sliding framework is first developed.This framework is further optimized considering the characteristics of real-time data streams,and its advantage in computational efficiency is theoretically demonstrated.During the decomposition and reconstruction processes,information from neighboring data blocks is fully utilized to reduce algorithmic complexity.In addition,a delay-setting strategy is introduced for each processing window to mitigate boundary effects,thereby balancing accuracy and efficiency.Simulated signal experiments are conducted to determine the optimal delay configuration and to verify the algorithm’s superior performance,achieving a lower Root Mean Square Error(RMSE)and only 0.0249 times the average computational time compared with the original algorithm.Furthermore,strain signals from the Lieshi River Bridge are employed to validate the method.The proposed algorithm successfully separates the static trend from vehicle-induced responses in real time across different sampling frequencies,demonstrating its effectiveness and applicability in real-time bridge monitoring. 展开更多
关键词 Wavelet transform vehicle-induced signal separation real-time structure monitoring
在线阅读 下载PDF
A REST API Fuzz Testing Framework Based on GUI Interaction and Specification Completion
8
作者 Zonglin Li Xu Zhao +2 位作者 Yan Cao Yazhe Li Yihong Zhang 《Computers, Materials & Continua》 2026年第3期2201-2222,共22页
With the rapid development of Internet technology,REST APIs(Representational State Transfer Application Programming Interfaces)have become the primary communication standard in modern microservice architectures,raisin... With the rapid development of Internet technology,REST APIs(Representational State Transfer Application Programming Interfaces)have become the primary communication standard in modern microservice architectures,raising increasing concerns about their security.Existing fuzz testing methods include random or dictionary-based input generation,which often fail to ensure both syntactic and semantic correctness,and OpenAPIbased approaches,which offer better accuracy but typically lack detailed descriptions of endpoints,parameters,or data formats.To address these issues,this paper proposes the APIDocX fuzz testing framework.It introduces a crawler tailored for dynamic web pages that automatically simulates user interactions to trigger APIs,capturing and extracting parameter information from communication packets.A multi-endpoint parameter adaptation method based on improved Jaccard similarity is then used to generalize these parameters to other potential API endpoints,filling in gaps in OpenAPI specifications.Experimental results demonstrate that the extracted parameters can be generalized with 79.61%accuracy.Fuzz testing using the enriched OpenAPI documents leads to improvements in test coverage,the number of valid test cases generated,and fault detection capabilities.This approach offers an effective enhancement to automated REST API security testing. 展开更多
关键词 REST APIs fuzz testing OpenAPI specifications
在线阅读 下载PDF
Energy relief effect of real-time drilling to prevent rockburst in high-stress rock
9
作者 Zhichao He Fengqiang Gong +2 位作者 Li Ren Weimin Yang Xuezhen Wu 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1460-1475,共16页
To investigate the energy relief effect of real-time drilling in preventing rockburst in high-stress rock,a series of high-stress real-time drilling uniaxial compression tests were conducted on red sandstone specimens... To investigate the energy relief effect of real-time drilling in preventing rockburst in high-stress rock,a series of high-stress real-time drilling uniaxial compression tests were conducted on red sandstone specimens using the SG4500 drilling rig.Results showed that the mechanical behavior(i.e.peak strength and rockburst intensity)of the rock was weakened under high-stress real-time drilling and exhibited a downward trend as the drilling diameter increased.The real-time drilling energy dissipation index(ERD)was proposed to characterize the energy relief during high-stress real-time drilling.The ERD exhibited a linear increase with the real-time drilling diameter.Furthermore,the elastic strain energy of post-drilling rock showed a linear relationship with the square of stress across different stress levels,which also applied to the peak elastic strain energy and the square of peak stress.This findingreveals the intrinsic link between the weakening effect of peak elastic strain energy and peak strength due to high-stress real-time drilling,confirmingthe consistency between energy relief and pressure relief effects.By establishing relationships among rockburst proneness,peak elastic strain energy,and peak strength,it was demonstrated that high-stress real-time drilling reduces rockburst proneness through energy dissipation.Specifically,both peak elastic strain energy and rockburst proneness decreased with larger drill bit diameters,consistent with reductions in peak strength,rockburst intensity,and fractal dimensions of high-stress real-time drilled rock.These results validate the energy relief mechanism of real-time drilling in mitigating rockburst risks. 展开更多
关键词 Rock mechanics ROCKBURST real-time drilling Drilling energy relief Energy storage capacity Rockburst proneness
在线阅读 下载PDF
Experimental study on real-time monitoring of surrounding rock 3D wave velocity structure and failure zone in deep tunnels
10
作者 Hongyun Yang Chuandong Jiang +4 位作者 Yong Li Zhi Lin Xiang Wang Yifei Wu Wanlin Feng 《International Journal of Mining Science and Technology》 2026年第2期423-437,共15页
An innovative real-time monitoring method for surrounding rock damage based on microseismic time-lapse double-difference tomography is proposed for delayed dynamic damage identification and insufficient detection of a... An innovative real-time monitoring method for surrounding rock damage based on microseismic time-lapse double-difference tomography is proposed for delayed dynamic damage identification and insufficient detection of adverse geological conditions in deep-buried tunnel construction.The installation techniques for microseismic sensors were optimized by mounting sensors at bolt ends which significantly improves signal-to-noise ratio(SNR)and anti-interference capability compared to conventional borehole placement.Subsequently,a 3D wave velocity evolution model that incorporates construction-induced disturbances was established,enabling the first visualization of spatiotemporal variations in surrounding rock wave velocity.It finds significant wave velocity reduction near the tunnel face,with roof and floor damage zones extending 40–50 m;wave velocities approaching undisturbed levels at 15 m ahead of the working face and on the laterally undisturbed side;pronounced spatial asymmetry in wave velocity distribution—values on the left side exceed those on the right,with a clear stress concentration or transition zone located 10–15 m;and systematically lower velocities behind the face than in front,indicating asymmetric rock damage development.These results provide essential theoretical support and practical guidance for optimizing dynamic construction strategies,enabling real-time adjustment of support parameters,and establishing safety early warning systems in deep-buried tunnel engineering. 展开更多
关键词 Deep-buried tunnel Microseismic monitoring Wave velocity tomography Surrounding rock damage zone real-time monitoring
在线阅读 下载PDF
Beads-on-a-Tip testing for ultrasensitive antigen detection across a large dynamic range
11
作者 Ziwei Wu Yangjian Cai +4 位作者 Yitong Zhao Mahnaz Maddahfar Mohammad Sadraeian Dayong Jin Jiajia Zhou 《Smart Molecules》 2026年第1期165-176,共12页
Lateral flow immunoassays(LFIAs)are low-cost,rapid,and easy to use for pointof-care testing(POCT),but the majority of the available LFIA tests are indicative,rather than quantitative,and their sensitivity in antigen t... Lateral flow immunoassays(LFIAs)are low-cost,rapid,and easy to use for pointof-care testing(POCT),but the majority of the available LFIA tests are indicative,rather than quantitative,and their sensitivity in antigen tests are usually limited at the nanogram range,which is primarily due to the passive capillary fluidics through nitrocellulose membranes,often associated with non-specific bindings and high background noise.To overcome this challenge,we report a Beads-on-a-Tip design by replacing nitrocellulose membranes with a pipette tip loaded with magnetic beads.The beads are pre-conjugated with capture antibodies that support a typical sandwich immunoassay.This design enriches the low-abundant antigen proteins and allows an active washing process to significantly reduce non-specific bindings.To further improve the detection sensitivity,we employed upconversion nanoparticles(UCNPs)as luminescent reporters and SARS-CoV-2 spike(S)antigen as a model analyte to benchmark the performance of this design against our previously reported methods.We found that the key to enhance the immunocomplex formation and signal-to-noise ratio lay in optimizing incubation time and the UCNP-to-bead ratio.We therefore successfully demonstrated that the new method can achieve a very large dynamic range from 500 fg/mL to 10μg/mL,across over 7 digits,and a limit of detection of 706 fg/mL,nearly another order of magnitude lower than the best reported LFIA using UCNPs in COVID-19 spike antigen detection.Our system offers a promising solution for ultra-sensitive and quantitative POCT diagnostics. 展开更多
关键词 Beads-on-a-Tip COVID-19 rapid testing ultrasenstive assay upconversion nanoparticles
暂未订购
A Hybrid Deep Learning Approach for Real-Time Cheating Behaviour Detection in Online Exams Using Video Captured Analysis
12
作者 Dao Phuc Minh Huy Gia Nhu Nguyen Dac-Nhuong Le 《Computers, Materials & Continua》 2026年第3期1179-1198,共20页
Online examinations have become a dominant assessment mode,increasing concerns over academic integrity.To address the critical challenge of detecting cheating behaviours,this study proposes a hybrid deep learning appr... Online examinations have become a dominant assessment mode,increasing concerns over academic integrity.To address the critical challenge of detecting cheating behaviours,this study proposes a hybrid deep learning approach that combines visual detection and temporal behaviour classification.The methodology utilises object detection models—You Only Look Once(YOLOv12),Faster Region-based Convolutional Neural Network(RCNN),and Single Shot Detector(SSD)MobileNet—integrated with classification models such as Convolutional Neural Networks(CNN),Bidirectional Gated Recurrent Unit(Bi-GRU),and CNN-LSTM(Long Short-Term Memory).Two distinct datasets were used:the Online Exam Proctoring(EOP)dataset from Michigan State University and the School of Computer Science,Duy Tan Unievrsity(SCS-DTU)dataset collected in a controlled classroom setting.A diverse set of cheating behaviours,including book usage,unauthorised interaction,internet access,and mobile phone use,was categorised.Comprehensive experiments evaluated the models based on accuracy,precision,recall,training time,inference speed,and memory usage.We evaluate nine detector-classifier pairings under a unified budget and score them via a calibrated harmonic mean of detection and classification accuracies,enabling deployment-oriented selection under latency and memory constraints.Macro-Precision/Recall/F1 and Receiver Operating Characteristic-Area Under the Curve(ROC-AUC)are reported for the top configurations,revealing consistent advantages of object-centric pipelines for fine-grained cheating cues.The highest overall score is achieved by YOLOv12+CNN(97.15%accuracy),while SSD-MobileNet+CNN provides the best speed-efficiency trade-off for edge devices.This research provides valuable insights into selecting and deploying appropriate deep learning models for maintaining exam integrity under varying resource constraints. 展开更多
关键词 Online exam proctoring cheating behavior detection deep learning real-time monitoring object detection human behavior recognition
在线阅读 下载PDF
Real-time decision support for bolter recovery safety:Long short-term memory network-driven aircraft sequencing
13
作者 Wei Han Changjiu Li +4 位作者 Xichao Su Yong Zhang Fang Guo Tongtong Yu Xuan Li 《Defence Technology(防务技术)》 2026年第2期184-205,共22页
The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,th... The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,this study proposes an intelligent decision-making framework based on a deep long short-term memory Q-network.This framework transforms the real-time sequencing for bolter recovery problem into a partially observable Markov decision process.It employs a stacked long shortterm memory network to accurately capture the long-range temporal dependencies of bolter event chains and fuel consumption.Furthermore,it integrates a prioritized experience replay training mechanism to construct a safe and adaptive scheduling system capable of millisecond-level real-time decision-making.Experimental demonstrates that,within large-scale mass recovery scenarios,the framework achieves zero safety violations in static environments and maintains a fuel safety violation rate below 10%in dynamic scenarios,with single-step decision times at the millisecond level.The model exhibits strong generalization capability,effectively responding to unforeseen emergent situations—such as multiple bolters and fuel emergencies—without requiring retraining.This provides robust support for efficient carrier-based aircraft recovery operations. 展开更多
关键词 Carrier-based aircraft Recovery scheduling Deep reinforcement learning Long short-term memory networks Dynamic real-time decision-making
在线阅读 下载PDF
Monotonic triaxial testing and hypoplastic modelling of calcareous sand:A focus on particle breakage and initial relative density
14
作者 Jiarui Chen Yaolan Tang +4 位作者 Shun Wang Chunshun Zhang Wei Wei Jie Dong Congying Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1504-1525,共22页
The stress-strain behavior of calcareous sand is significantly influencedby particle breakage(B)and initial relative density(Dri),but few constitutive models consider their combined effects.To bridge this gap,we condu... The stress-strain behavior of calcareous sand is significantly influencedby particle breakage(B)and initial relative density(Dri),but few constitutive models consider their combined effects.To bridge this gap,we conducted a series of triaxial tests on calcareous sand with varying Dri and stress paths,examining particle breakage and critical state behavior.Key findingsinclude:(1)At a constant stress ratio(η),B follows a hyperbolic relationship with mean effective stress(p'),and for a given p',B increases proportionally withη;(2)The critical state line(CSL)moves downward with increasing Dri,whereas the critical state friction angle(φcs)decreases with increasing B.Based on these findings,we propose a unifiedbreakage evolution model to quantify particle breakage in calcareous sand under various loading conditions.Integrating this model with the Normal Consolidation Line(NCL)and CSL equations,we successfully simulate the steepening of NCL and CSL slopes as B increases with the onset of particle breakage.Furthermore,we quantitatively evaluate the effect of B onφcs.Finally,within the framework of Critical State Soil Mechanics and Hypoplasticity theory,we develop a hypoplastic model incorporating B and Dri.The model is validated through strong agreement with experimental results across various initial relative densities,stress paths and drainage conditions. 展开更多
关键词 Calcareous sand Constitutive model HYPOPLASTICITY Particle breakage Initial relative density Triaxial test
在线阅读 下载PDF
Design and optimization of a compact high-energy electron source applied to on-site non-destructive testing for electrical equipment
15
作者 Hai-Meng Wang Yi-Feng Zeng +2 位作者 Hao Hu Jun-Yang Li Tong-Ning Hu 《Nuclear Science and Techniques》 2026年第4期28-40,共13页
X-rays are widely used in the non-destructive testing(NDT)of electrical equipment.Radio frequency(RF)electron linear accelerators can generate MeV high-energy X-rays with strong penetrating ability;however,the system ... X-rays are widely used in the non-destructive testing(NDT)of electrical equipment.Radio frequency(RF)electron linear accelerators can generate MeV high-energy X-rays with strong penetrating ability;however,the system generally has a large scale,which is not suitable for on-site testing.Compared with the S-band(S-linac)at the same stage of beam energy,the accelerator working in the X-band(X-linac)can compress the facility scale by over 2/3 in the longitudinal direction,which is convenient for the on-site NDT of electrical equipment.To address the beam quality and design complexity simultaneously,the non-dominated sorting genetic algorithmⅡ(NSGA-Ⅱ),which is a multi-objective genetic algorithm(MOGA),was developed to optimize the cavity chain design of the X-linac.Additionally,the designs of the focusing coils,electron gun,and RF couplers,which are other key components of the X-linac,were introduced in this context.In particular,the focusing coil distributions were optimized using a genetic algorithm.Furthermore,after designing such key components,PARMELA software was adopted to perform beam dynamics calculations with the optimized accelerating fields and magnetic fields.The results show that the beam performance was obtained with a capture ratio of more than 90%,an energy spread of less than 10%,and an average energy of approximately 3 MeV.The design and simulation results indicate that the proposed NSGAⅡ-based approach is feasible for X-linac accelerator design.Furthermore,it can be generalized as a universal technique for industrial electron linear accelerators provided that specific optimization objectives and constraints are set according to different application scenarios and requirements. 展开更多
关键词 Non-destructive testing X-band linac accelerator Focusing coils Electron gun Radio frequency couplers
在线阅读 下载PDF
Delay-dependent stability and added damping of SDOF real-time dynamic hybrid testing 被引量:14
16
作者 Chi Fudong Wang Jinting Jin Feng 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第3期425-438,共14页
It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing (RTDHT). This paper focuses on the delay-dependent stability and adde... It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing (RTDHT). This paper focuses on the delay-dependent stability and added damping of SDOF systems in RTDHT. The exponential delay term is transferred into a rational fraction by the Pad6 approximation, and the delay-dependent stability conditions and instability mechanism of SDOF RTDHT systems are investigated by the root locus technique. First, the stability conditions are discussed separately for the cases of stiffness, mass, and damping experimental substructure. The use of root locus plots shows that the added damping effect and instability mechanism for mass are different from those for stiffness. For the stiffness experimental substructure case, the instability results from the inherent mode because of an obvious negative damping effect of the delay. For the mass case, the delay introduces an equivalent positive damping into the inherent mode, and instability occurs at an added high frequency mode. Then, the compound stability condition is investigated for a general case and the results show that the mass ratio may have both upper and lower limits to remain stable. Finally, a high-emulational virtual shaking table model is built to validate the stability conclusions. 展开更多
关键词 real-time dynamic hybrid testing root locus analysis delay-dependent stability Pade approximation added damping
在线阅读 下载PDF
Simulation of large-scale numerical substructure in real-time dynamic hybrid testing 被引量:9
17
作者 Zhu Fei Wang Jinting +2 位作者 Jin Feng Zhou Mengxia Gui Yao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第4期599-609,共11页
A solution scheme is proposed in this paper for an existing RTDHT system to simulate large-scale finite element (FE) numerical substructures. The analysis of the FE numerical substructure is split into response anal... A solution scheme is proposed in this paper for an existing RTDHT system to simulate large-scale finite element (FE) numerical substructures. The analysis of the FE numerical substructure is split into response analysis and signal generation tasks, and executed in two different target computers in real-time. One target computer implements the response analysis task, wherein a large time-step is used to solve the FE substructure, and another target computer implements the signal generation task, wherein an interpolation program is used to generate control signals in a small time-step to meet the input demand of the controller. By using this strategy, the scale of the FE numerical substructure simulation may be increased significantly. The proposed scheme is initially verified by two FE numerical substructure models with 98 and 1240 degrees of freedom (DOFs). Thereafter, RTDHTs of a single frame-foundation structure are implemented where the foundation, considered as the numerical substructure, is simulated by the FE model with 1240 DOFs. Good agreements between the results of the RTDHT and those from the FE analysis in ABAQUS are obtained. 展开更多
关键词 real-time dynamic hybrid testing large-scale numerical substructure control signal generation finite element simulation
在线阅读 下载PDF
Magnetic pulse welding of Al-5754 with Al-7075 and MARS 380:Weldability windows and ballistic testing
18
作者 Benoit Lagain Thomas Heuzé +1 位作者 Guillaume Racineux Michel Arrigoni 《Defence Technology(防务技术)》 2026年第1期64-79,共16页
Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining... Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining technique that overcomes these issues by using impact to create strong bonds without melting the substrate materials.This study investigates the weldability of aluminum alloy Al-5754 with Al-7075 and MARS 380 steel,used in armouring solutions of defense systems,by the use of MPW.In this work,weldability windows are investigated by varying standoff distances between the coating material and its substrate(0.25-4.5 mm)and discharge energies(5-13 kJ)with both O-shape and U-shape inductors.Mechanical strength of the welded joints were assessed through single lap shear tests,identifying optimal welding parameters.Then,the velocity profiles of the flyer plates were measured using heterodyne velocimetry to understand the dynamics of the impact.Then,substructures assembled with the optimal welding conditions were subjected to ballistic testing using 7.62 mm×51 mm NATO and 9 mm×19 mm Parabellum munitions to evaluate the resilience of the welds under ballistic impact.The outcomes demonstrate that MPW effectively joins Al-5754 with both Al-7075 and MARS 380,producing robust welds capable of withstanding ballistic impacts under certain conditions.This research advances the application of MPW in lightweight ballistic protection of defense systems,contributing to the development of more resilient and lighter protective structures. 展开更多
关键词 Magnetic pulse welding(MPW) Dissimilar material joining Weldability windows Impact welding Ballistic testing
在线阅读 下载PDF
Factors affecting the utilization of HIV counseling and testing services:A case-control study in Indonesia
19
作者 Ricka Putri Hardianti Arlinda Sari Wahyuni +2 位作者 Delfitri Munir Restuti Hidayani Saragih Juliandi Harahap 《Asian Pacific Journal of Tropical Medicine》 2026年第2期82-90,共9页
Objective:To analyze factors affecting the utilization of human immunodeficiency virus counseling and testing(HCT)service among human immunodeficiency virus risk groups at Hessa Air Genting Health Center,Asahan Regenc... Objective:To analyze factors affecting the utilization of human immunodeficiency virus counseling and testing(HCT)service among human immunodeficiency virus risk groups at Hessa Air Genting Health Center,Asahan Regency,North Sumatera,Indonesia.Methods:This quantitative unmatched case-control study was conducted from April 2024 to April 2025 at Hessa Air Genting Health Center,Asahan Regency,North Sumatra Province,Indonesia.Female sex workers and men who have sex with men were selected using purposive sampling based on predefined inclusion and exclusion criteria.Data were collected via questionnaires and analyzed using SPSS version 18.0,with univariate analysis,bivariate analysis(Chi-square test),and multivariate analysis(logistic regression analysis).Results:Comprehensive analysis of 75 cases and 75 controls was conducted to identify factors affecting the utilization of HCT services.Specifically,this study identified significant effects of knowledge(OR 3.2,95%CI 1.5-7.0,P=0.003),perception(OR 5.6,95%CI 2.5-12.5,P<0.001),information media(OR 3.1,95%CI 1.4-6.8,P=0.005),and health workers encouragement(OR 4.0,95%CI 1.5-10.4,P=0.005).In contrast,access to health services did not have a significant effect.Conclusions:Knowledge,perception,information media,and health worker encouragement had significant effects on HCT service utilization,with perception identified as the dominant factor.To improve utilization,strengthening positive perceptions,targeted training for healthcare workers,strengthened partnerships with local non-governmental organizations,and the use of social media for health promotion are recommended. 展开更多
关键词 Human immunodeficiency virus counseling and testing Human immunodeficiency virus risk group Case-control study Indonesia
暂未订购
Real-time embedded software testing method based on extended finite state machine 被引量:6
20
作者 Yongfeng Yin Bin Liu Hongying Ni 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第2期276-285,共10页
The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliab... The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine (RT-EFSM) model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class (timeCTEC) are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively. 展开更多
关键词 real-time system real-time embedded software for- mal method extended finite state machine (EFSM) testing se- quence test case.
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部