期刊文献+
共找到374,737篇文章
< 1 2 250 >
每页显示 20 50 100
A new interpretation and quantitative method for diplopia test: 304 cases of ocular motor nerve palsy for clinical test and verify 被引量:3
1
作者 Ling-Yun Zhou Tie-Juan Liu +3 位作者 Xue-Mei Li Chang Su Xiao-Jie Ji Ming Zhao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第11期1768-1770,共3页
We introduce a new interpretation and quantitative method for computerized diplopia test. By comparing this new method to the Hess screen test, we validate its applicability among 304 patients with ocular motor nerve ... We introduce a new interpretation and quantitative method for computerized diplopia test. By comparing this new method to the Hess screen test, we validate its applicability among 304 patients with ocular motor nerve palsy. This new method shows great assistant value as the Hess screen test in making accurate diagnosis and quantitative evaluation the severity of diplopia. Furthermore, it is more convenient and suitable for daily clinical use. 展开更多
关键词 diplopia test interpreting and scoring method Hess charts ocular motor nerve palsy max angle of diplopia
下载PDF
Unbound^(28)O,the heaviest oxygen isotope observed:a cutting-edge probe for testing nuclear models 被引量:1
2
作者 Jian-Guo Li Bai-Shan Hu +1 位作者 Shuang Zhang Fu-Rong Xu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期1-2,共2页
The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an ... The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N. 展开更多
关键词 testING QUANTUM system
下载PDF
Electrochemical biosensors for point-of-care testing 被引量:1
3
作者 Jinsol Kim Juho Jeong Seung Hwan Ko 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第4期548-565,共18页
Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT... Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings. 展开更多
关键词 Point-of-care testing(POCT) Electrochemical sensor ENZYME ANTIBODY Health care
下载PDF
结合GUM和MCM的R-Test在机标定不确定度评定方法
4
作者 周永兵 赖旭伟 +1 位作者 江磊 丁国富 《机械设计与制造》 北大核心 2024年第3期62-66,共5页
R-Test因其高精度、操作便捷等的优点而被广泛应用于五轴数控机床转动轴误差测量,但其测量精度受其标定不确定度的影响。针对原有通用的评定方法不能对接触式R-Test标定不确定度进行准确评定,基于接触式R-Test标定原理,提出一种结合GUM... R-Test因其高精度、操作便捷等的优点而被广泛应用于五轴数控机床转动轴误差测量,但其测量精度受其标定不确定度的影响。针对原有通用的评定方法不能对接触式R-Test标定不确定度进行准确评定,基于接触式R-Test标定原理,提出一种结合GUM和MCM的在机标定不确定度评定方法,首先分析了不确定度的影响因素并采用变参数方法确定了其灵敏度系数,然后根据测量不确定度导则(GUM)计算传感器位置的标准不确定度分量,最后采用蒙特卡洛方法(MCM)实现对标定方法最终的不确定度评定。通过具体的评定实例,与独立使用GUM的评定结果进行对比,验证了该方法具有更高的评定精度。 展开更多
关键词 接触式R-test 在机标定 不确定度 不确定度导则 蒙特卡洛
下载PDF
Aquifer Test求群孔抽水试验水文地质参数
5
作者 李红伟 《中国高新科技》 2024年第5期56-57,129,共3页
在水文地质条件复杂的地区,往往采用大型的群孔抽水试验充分揭露含水层特征,获取水文地质参数。用Aquifer Test软件求解水文地质参数,则方便实用、简捷高效,可快速输出拟合图形和求参结果。Aquifer Test提供了丰富的求参方案,求参必须... 在水文地质条件复杂的地区,往往采用大型的群孔抽水试验充分揭露含水层特征,获取水文地质参数。用Aquifer Test软件求解水文地质参数,则方便实用、简捷高效,可快速输出拟合图形和求参结果。Aquifer Test提供了丰富的求参方案,求参必须结合当地当时的水文地质条件实际情况考虑,选择适合的方案和时空数据求取水文地质参数。 展开更多
关键词 群孔抽水试验 水文地质参数 Aquifer test
下载PDF
Failure characterization of fully grouted rock bolts under triaxial testing
6
作者 Hadi Nourizadeh Ali Mirzaghorbanali +3 位作者 Mehdi Serati Elamin Mutaz Kevin McDougall Naj Aziz 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期778-789,共12页
Confining stresses serve as a pivotal determinant in shaping the behavior of grouted rock bolts.Nonetheless,prior investigations have oversimplified the three-dimensional stress state,primarily assuming hydrostatic st... Confining stresses serve as a pivotal determinant in shaping the behavior of grouted rock bolts.Nonetheless,prior investigations have oversimplified the three-dimensional stress state,primarily assuming hydrostatic stress conditions.Under these conditions,it is assumed that the intermediate principal stress(σ_(2))equals the minimum principal stress(σ_(3)).This assumption overlooks the potential variations in magnitudes of in situ stress conditions along all three directions near an underground opening where a rock bolt is installed.In this study,a series of push tests was meticulously conducted under triaxial conditions.These tests involved applying non-uniform confining stresses(σ_(2)≠σ_(3))to cubic specimens,aiming to unveil the previously overlooked influence of intermediate principal stresses on the strength properties of rock bolts.The results show that as the confining stresses increase from zero to higher levels,the pre-failure behavior changes from linear to nonlinear forms,resulting in an increase in initial stiffness from 2.08 kN/mm to 32.51 kN/mm.The load-displacement curves further illuminate distinct post-failure behavior at elevated levels of confining stresses,characterized by enhanced stiffness.Notably,the peak load capacity ranged from 27.9 kN to 46.5 kN as confining stresses advanced from σ_(2)=σ_(3)=0 to σ_(2)=20 MPa and σ_(3)=10 MPa.Additionally,the outcomes highlight an influence of confining stress on the lateral deformation of samples.Lower levels of confinement prompt overall dilation in lateral deformation,while higher confinements maintain a state of shrinkage.Furthermore,diverse failure modes have been identified,intricately tied to the arrangement of confining stresses.Lower confinements tend to induce a splitting mode of failure,whereas higher loads bring about a shift towards a pure interfacial shear-off and shear-crushed failure mechanism. 展开更多
关键词 Rock bolts Bolt-grout interface Bond strength Push test Triaxial tests
下载PDF
Development of multi-functional anchorage support dynamic-static coupling performance test system and its application
7
作者 Qi Wang Shuo Xu +4 位作者 Bei Jiang Chong Zhang Zhe Sun Jingxuan Liu Cailin Jiao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期339-349,共11页
In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses... In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high prestress.It is essential to study the support components performance under dynamic-static coupling conditions.Based on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so on.The bolt and cable mechanical tests are conducted by MAC system under different prestress levels.The results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly reduced.In the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress condition.In the prestress range of 150–300 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress condition.The MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system. 展开更多
关键词 Anchorage support system Development of test system Dynamic-static coupling test Combined stress
下载PDF
Inflow and outflow permeability tests in a very soft clay under low stresses
8
作者 J.W.S.Vargas F.A.B.Danziger +1 位作者 F.R.Lopes T.Lunne 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3270-3283,共14页
In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,es... In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low stresses.Pore pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the filter.The role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe installation.Results show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early measurements.Both inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading condition.Various sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests performed.Data are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases. 展开更多
关键词 Permeability test Soft clay BAT probe Inflow and outflow tests
下载PDF
Real-world utility of serological tests in patients with suspected scrub typhus in the Republic of Korea:A single-center,retrospective,observational study
9
作者 Seulki Kim A Reum Kim +2 位作者 Seungjin Lim Su Jin Lee Moonsuk Bae 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第6期273-280,I0004,I0005,共10页
Objective:Serological tests are widely used for scrub typhus diagnosis;however,their limitations are evident.This study aims to assess their practical value in clinical settings.Methods:We analyzed the data of adult p... Objective:Serological tests are widely used for scrub typhus diagnosis;however,their limitations are evident.This study aims to assess their practical value in clinical settings.Methods:We analyzed the data of adult patients with suspected scrub typhus who visited a tertiary care hospital in the Republic of Korea from September to December from 2019 to 2021.The included patients had an acute fever and at least one of the following ten secondary findings:myalgia,skin rash,eschar,headache,thrombocytopenia,increased liver enzyme levels,lymphadenopathy,hepatomegaly,splenomegaly,and pleural effusion.The diagnoses were grouped as scrub typhus or other diseases by two infectious disease physicians.Results:Among 136 patients who met the eligibility criteria,109 had scrub typhus and 27 had different diseases.Single and paired total antibodies using immunofluorescence assay(IFA),and total antibodies using immunochromatography-based rapid diagnostic testing(ICT)were measured in 98%,22%,and 75%of all patients,respectively.Confirmation using paired samples for scrub typhus was established at a median of 11[interquartile range(IQR)10-16]days following the first visit.Among the 82 admitted patients,the median admission time was 9(IQR 7-13)days.According to IFA,58(55%)patients with scrub typhus had total immunoglobulin titers≥1:320,while 23(85%)patients with other disease had titers<1:320.Positive ICT results were observed in 64(74%)patients with scrub typhus and 10(67%)patients with other diseases showed negative ICT results.Conclusions:Serological testing for scrub typhus is currently insufficient for decision-making in clinical practice. 展开更多
关键词 Scrub typhus Serological test Immunofluorescence assay IMMUNOCHROMATOGRAPHY Rapid detecting test
下载PDF
Efficient Penetration Testing Path Planning Based on Reinforcement Learning with Episodic Memory
10
作者 Ziqiao Zhou Tianyang Zhou +1 位作者 Jinghao Xu Junhu Zhu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第9期2613-2634,共22页
Intelligent penetration testing is of great significance for the improvement of the security of information systems,and the critical issue is the planning of penetration test paths.In view of the difficulty for attack... Intelligent penetration testing is of great significance for the improvement of the security of information systems,and the critical issue is the planning of penetration test paths.In view of the difficulty for attackers to obtain complete network information in realistic network scenarios,Reinforcement Learning(RL)is a promising solution to discover the optimal penetration path under incomplete information about the target network.Existing RL-based methods are challenged by the sizeable discrete action space,which leads to difficulties in the convergence.Moreover,most methods still rely on experts’knowledge.To address these issues,this paper proposes a penetration path planning method based on reinforcement learning with episodic memory.First,the penetration testing problem is formally described in terms of reinforcement learning.To speed up the training process without specific prior knowledge,the proposed algorithm introduces episodic memory to store experienced advantageous strategies for the first time.Furthermore,the method offers an exploration strategy based on episodic memory to guide the agents in learning.The design makes full use of historical experience to achieve the purpose of reducing blind exploration and improving planning efficiency.Ultimately,comparison experiments are carried out with the existing RL-based methods.The results reveal that the proposed method has better convergence performance.The running time is reduced by more than 20%. 展开更多
关键词 Intelligent penetration testing penetration testing path planning reinforcement learning episodic memory exploration strategy
下载PDF
Evaluation of urea breath test as a diagnostic tool for Helicobacter pylori infection in adult dyspeptic patients
11
作者 Zeinab Nabil Ahmed Said Asmaa Mohamed El-Nasser 《World Journal of Gastroenterology》 SCIE CAS 2024年第17期2302-2307,共6页
In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helico... In this editorial,we discuss the article in the World Journal of Gastroenterology.The article conducts a meta-analysis of the diagnostic accuracy of the urea breath test(UBT),a non-invasive method for detecting Helicobacter pylori(H.pylori)infection in humans.It is based on radionuclide-labeled urea.Various methods,both invasive and non-invasive,are available for diagnosing H.pylori infection,inclu-ding endoscopy with biopsy,serology for immunoglobulin titers,stool antigen analysis,and UBT.Several guidelines recommend UBTs as the primary choice for diagnosing H.pylori infection and for reexamining after eradication therapy.It is used to be the first choice non-invasive test due to their high accuracy,specificity,rapid results,and simplicity.Moreover,its performance remains unaffected by the distribution of H.pylori in the stomach,allowing a high flow of patients to be tested.Despite its widespread use,the performance characteristics of UBT have been inconsistently described and remain incompletely defined.There are two UBTs available with Food and Drug Administration approval:The 13C and 14C tests.Both tests are affordable and can provide real-time results.Physicians may prefer the 13C test because it is non-radioactive,compared to 14C which uses a radioactive isotope,especially in young children and pregnant women.Although there was heterogeneity among the studies regarding the diagnostic accuracy of both UBTs,13C-UBT consistently outperforms the 14C-UBT.This makes the 13C-UBT the preferred diagnostic approach.Furthermore,the provided findings of the meta-analysis emphasize the significance of precise considerations when choosing urea dosage,assessment timing,and measurement techniques for both the 13C-UBT and 14C-UBT,to enhance diagnostic precision. 展开更多
关键词 Helicobacter pylori Urea breath test DIAGNOSIS Diagnostic test accuracy META-ANALYSIS
下载PDF
Urea breath test for Helicobacter pylori infection in adult dyspeptic patients: A meta-analysis of diagnostic test accuracy
12
作者 Fabian Fellipe Bueno Lemos Caroline Tianeze de Castro +9 位作者 Marcel Silva Luz Gabriel Reis Rocha Gabriel Lima Correa Santos Luís Guilherme de Oliveira Silva Mariana Santos Calmon Cláudio Lima Souza Ana Carla Zarpelon-Schutz Kádima Nayara Teixeira Dulciene Maria de Magalhães Queiroz Fabrício Freire de Melo 《World Journal of Gastroenterology》 SCIE CAS 2024年第6期579-598,共20页
BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for... BACKGROUND Helicobacter pylori(H.pylori)infection has been well-established as a significant risk factor for several gastrointestinal disorders.The urea breath test(UBT)has emerged as a leading non-invasive method for detecting H.pylori.Despite numerous studies confirming its substantial accuracy,the reliability of UBT results is often compromised by inherent limitations.These findings underscore the need for a rigorous statistical synthesis to clarify and reconcile the diagnostic accuracy of the UBT for the diagnosis of H.pylori infection.AIM To determine and compare the diagnostic accuracy of 13C-UBT and 14C-UBT for H.pylori infection in adult patients with dyspepsia.METHODS We conducted an independent search of the PubMed/MEDLINE,EMBASE,and Cochrane Central databases until April 2022.Our search included diagnostic accuracy studies that evaluated at least one of the index tests(^(13)C-UBT or ^(14)C-UBT)against a reference standard.We used the QUADAS-2 tool to assess the methodo-logical quality of the studies.We utilized the bivariate random-effects model to calculate sensitivity,specificity,positive and negative test likelihood ratios(LR+and LR-),as well as the diagnostic odds ratio(DOR),and their 95%confidence intervals.We conducted subgroup analyses based on urea dosing,time after urea administration,and assessment technique.To investigate a possible threshold effect,we conducted Spearman correlation analysis,and we generated summary receiver operating characteristic(SROC)curves to assess heterogeneity.Finally,we visually inspected a funnel plot and used Egger’s test to evaluate publication bias.endorsing both as reliable diagnostic tools in clinical practice.CONCLUSION In summary,our study has demonstrated that ^(13)C-UBT has been found to outperform the ^(14)C-UBT,making it the preferred diagnostic approach.Additionally,our results emphasize the significance of carefully considering urea dosage,assessment timing,and measurement techniques for both tests to enhance diagnostic precision.Nevertheless,it is crucial for researchers and clinicians to evaluate the strengths and limitations of our findings before implementing them in practice. 展开更多
关键词 Helicobacter pylori Urea breath test DIAGNOSIS Diagnostic test accuracy META-ANALYSIS
下载PDF
Research on aiming methods for small sample size shooting tests of two-dimensional trajectory correction fuse
13
作者 Chen Liang Qiang Shen +4 位作者 Zilong Deng Hongyun Li Wenyang Pu Lingyun Tian Ziyang Lin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期506-517,共12页
The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction ... The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future. 展开更多
关键词 Two-dimensional trajectory correction fuse Small sample size test Compatibility test KL divergence Fusion bayesian estimation
下载PDF
C-CORE:Clustering by Code Representation to Prioritize Test Cases in Compiler Testing
14
作者 Wei Zhou Xincong Jiang Chuan Qin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期2069-2093,共25页
Edge devices,due to their limited computational and storage resources,often require the use of compilers for program optimization.Therefore,ensuring the security and reliability of these compilers is of paramount impo... Edge devices,due to their limited computational and storage resources,often require the use of compilers for program optimization.Therefore,ensuring the security and reliability of these compilers is of paramount importance in the emerging field of edge AI.One widely used testing method for this purpose is fuzz testing,which detects bugs by inputting random test cases into the target program.However,this process consumes significant time and resources.To improve the efficiency of compiler fuzz testing,it is common practice to utilize test case prioritization techniques.Some researchers use machine learning to predict the code coverage of test cases,aiming to maximize the test capability for the target compiler by increasing the overall predicted coverage of the test cases.Nevertheless,these methods can only forecast the code coverage of the compiler at a specific optimization level,potentially missing many optimization-related bugs.In this paper,we introduce C-CORE(short for Clustering by Code Representation),the first framework to prioritize test cases according to their code representations,which are derived directly from the source codes.This approach avoids being limited to specific compiler states and extends to a broader range of compiler bugs.Specifically,we first train a scaled pre-trained programming language model to capture as many common features as possible from the test cases generated by a fuzzer.Using this pre-trained model,we then train two downstream models:one for predicting the likelihood of triggering a bug and another for identifying code representations associated with bugs.Subsequently,we cluster the test cases according to their code representations and select the highest-scoring test case from each cluster as the high-quality test case.This reduction in redundant testing cases leads to time savings.Comprehensive evaluation results reveal that code representations are better at distinguishing test capabilities,and C-CORE significantly enhances testing efficiency.Across four datasets,C-CORE increases the average of the percentage of faults detected(APFD)value by 0.16 to 0.31 and reduces test time by over 50% in 46% of cases.When compared to the best results from approaches using predicted code coverage,C-CORE improves the APFD value by 1.1% to 12.3% and achieves an overall time-saving of 159.1%. 展开更多
关键词 Compiler testing test case prioritization code representation
下载PDF
A method to predict rockburst using temporal trend test and its application
15
作者 Yarong Xue Zhenlei Li +5 位作者 Dazhao Song Xueqiu He Honglei Wang Chao Zhou Jianqiang Chen Aleksei Sobolev 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期909-923,共15页
Rockbursts have become a significant hazard in underground mining,underscoring the need for a robust early warning model to ensure safety management.This study presents a novel approach for rockburst prediction,integr... Rockbursts have become a significant hazard in underground mining,underscoring the need for a robust early warning model to ensure safety management.This study presents a novel approach for rockburst prediction,integrating the Mann-Kendall trend test(MKT)and multi-indices fusion to enable real-time and quantitative assessment of rockburst hazards.The methodology employed in this study involves the development of a comprehensive precursory index library for rockbursts.The MKT is then applied to analyze the real-time trend of each index,with adherence to rockburst characterization laws serving as the warning criterion.By employing a confusion matrix,the warning effectiveness of each index is assessed,enabling index preference determination.Ultimately,the integrated rockburst hazard index Q is derived through data fusion.The results demonstrate that the proposed model achieves a warning effectiveness of 0.563 for Q,surpassing the performance of any individual index.Moreover,the model’s adaptability and scalability are enhanced through periodic updates driven by actual field monitoring data,making it suitable for complex underground working environments.By providing an efficient and accurate basis for decision-making,the proposed model holds great potential for the prevention and control of rockbursts.It offers a valuable tool for enhancing safety measures in underground mining operations. 展开更多
关键词 ROCKBURST MICROSEISMICITY Early warning Mann-Kendall trend test Confusion matrix Multi-indices fusion
下载PDF
A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability
16
作者 Jingyu Wang Ping Jiang Jianjun Qi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1889-1918,共30页
The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the... The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV swarm.Due to the high cost and long duration of operational tests,it is essential to plan the test in advance.To solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission reliability.Therefore,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test plans.This study first constructs a mission reliability model for the UAV swarm in the combat stage.Then,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability model.Finally,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the model.The optimal plans considering both reliability and cost are obtained.The proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning. 展开更多
关键词 UAV swarm PMS MOQPSO BDD mission reliability operational test planning
下载PDF
Analytical evaluation of steady-state solute distribution in through- diffusion and membrane behavior test under non-perfectly flushing boundary conditions
17
作者 Guannian Chen Yuchao Li +1 位作者 Kristin MSample-Lord Shan Tong 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期258-267,共10页
The through-diffusion and membrane behavior testing procedure using a closed-system apparatus has been widely used for concurrent measurement of diffusion and membrane efficiency coefficients of low-permeability clay-... The through-diffusion and membrane behavior testing procedure using a closed-system apparatus has been widely used for concurrent measurement of diffusion and membrane efficiency coefficients of low-permeability clay-based barrier materials.However,the common assumption of perfectly flushing conditions at the specimen boundaries could induce errors in analyses of the diffusion coefficients and membrane efficiencies.In this study,an innovative pseudo three-dimensional(3D)analytical method was proposed to evaluate solute distribution along the boundary surfaces of the soil-porous disks system,considering the non-perfectly flushing conditions.The results were consistent with numerical models under two scenarios considering different inflow/outflow positions.The proposed model has been demonstrated to be an accurate and reliable method to estimate solute distributions along the bound-aries.The calculated membrane efficiency coefficient and diffusion coefficient based on the proposed analytical method are more accurate,resulting in up to 50%less relative error than the traditional approach that adopts the arithmetic mean value of the influent and effluent concentrations.The retar-dation factor of the clay specimen also can be calculated with a revised cumulative mass approach.Finally,the simulated transient solute transport matched with experimental data from a multi-stage through-diffusion and membrane behavior test,validating the accuracy of the proposed method. 展开更多
关键词 Diffusion testing Membrane behavior Coupled transport Clay barrier Transport modeling
下载PDF
Dynamic response of mountain tunnel,bridge,and embankment along the Sichuan-Tibet transportation corridor to active fault based on model tests
18
作者 HUANG Beixiu QIAO Sijia +2 位作者 CHEN Xulei LI Lihui QI Shengwen 《Journal of Mountain Science》 SCIE CSCD 2024年第1期182-199,共18页
The Sichuan-Tibet transportation corridor is prone to numerous active faults and frequent strong earthquakes.While extensive studies have individually explored the effect of active faults and strong earthquakes on dif... The Sichuan-Tibet transportation corridor is prone to numerous active faults and frequent strong earthquakes.While extensive studies have individually explored the effect of active faults and strong earthquakes on different engineering structures,their combined effect remains unclear.This research employed multiple physical model tests to investigate the dynamic response of various engineering structures,including tunnels,bridges,and embankments,under the simultaneous influence of cumulative earthquakes and stick-slip misalignment of an active fault.The prototype selected for this study was the Kanding No.2 tunnel,which crosses the Yunongxi fault zone within the Sichuan-Tibet transportation corridor.The results demonstrated that the tunnel,bridge,and embankment exhibited amplification in response to the input seismic wave,with the amplification effect gradually decreasing as the input peak ground acceleration(PGA)increased.The PGAs of different engineering structures were weakened by the fault rupture zone.Nevertheless,the misalignment of the active fault may decrease the overall stiffness of the engineering structure,leading to more severe damage,with a small contribution from seismic vibration.Additionally,the seismic vibration effect might be enlarged with the height of the engineering structure,and the tunnel is supposed to have a smaller PGA and lower dynamic earth pressure compared to bridges and embankments in strong earthquake zones crossing active faults.The findings contribute valuable insights for evaluating the dynamic response of various engineering structures crossing an active fault and provide an experimental reference for secure engineering design in the challenging conditions of the Sichuan-Tibet transportation corridor. 展开更多
关键词 Dynamic response Engineering structure Sichuan-Tibet transportation corridor Active fault EARTHQUAKE Model test
下载PDF
Optimality of Group Testing with Differential Misclassification
19
作者 LI Yiming ZHANG Hong LIU Aiyi 《应用概率统计》 CSCD 北大核心 2024年第4期644-662,共19页
Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature ... Group testing is a method that can be used to estimate the prevalence of rare infectious diseases,which can effectively save time and reduce costs compared to the method of random sampling.However,previous literature only demonstrated the optimality of group testing strategy while estimating prevalence under some strong assumptions.This article weakens the assumption of misclassification rate in the previous literature,considers the misclassification rate of the infected samples as a differentiable function of the pool size,and explores some optimal properties of group testing for estimating prevalence in the presence of differential misclassification conforming to this assumption.This article theoretically demonstrates that the group testing strategy performs better than the sample by sample procedure in estimating disease prevalence when the total number of sample pools is given or the size of the test population is determined.Numerical simulation experiments were conducted to evaluate the performance of group tests in estimating prevalence in the presence of dilution effect. 展开更多
关键词 group testing sensitivity SPECIFICITY dilution effect differential misclassification PREVALENCE
下载PDF
Explosion resistance performance of reinforced concrete box girder coated with polyurea:Model test and numerical simulation
20
作者 Guangpan Zhou Rong Wang +2 位作者 Mingyang Wang Jianguo Ding Yuye Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期1-18,共18页
To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyur... To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests.The reliability of the numerical simulation using LS-DYNA software was verified by the test results.The effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were studied.The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder.The top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local dent.The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen G.For the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of fracture.With the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more significant.The optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn. 展开更多
关键词 Explosive load Explosion resistance performance Model test POLYUREA Concrete box girder Numerical simulation
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部