期刊文献+
共找到14,229篇文章
< 1 2 250 >
每页显示 20 50 100
Big Data Testing Techniques:Taxonomy,Challenges and Future Trends
1
作者 Iram Arshad Saeed Hamood Alsamhi Wasif Afzal 《Computers, Materials & Continua》 SCIE EI 2023年第2期2739-2770,共32页
Big Data is reforming many industrial domains by providing decision support through analyzing large data volumes.Big Data testing aims to ensure that Big Data systems run smoothly and error-free while maintaining the ... Big Data is reforming many industrial domains by providing decision support through analyzing large data volumes.Big Data testing aims to ensure that Big Data systems run smoothly and error-free while maintaining the performance and quality of data.However,because of the diversity and complexity of data,testing Big Data is challenging.Though numerous research efforts deal with Big Data testing,a comprehensive review to address testing techniques and challenges of BigData is not available as yet.Therefore,we have systematically reviewed the Big Data testing techniques’evidence occurring in the period 2010–2021.This paper discusses testing data processing by highlighting the techniques used in every processing phase.Furthermore,we discuss the challenges and future directions.Our findings show that diverse functional,non-functional and combined(functional and non-functional)testing techniques have been used to solve specific problems related to Big Data.At the same time,most of the testing challenges have been faced during the MapReduce validation phase.In addition,the combinatorial testing technique is one of the most applied techniques in combination with other techniques(i.e.,random testing,mutation testing,input space partitioning and equivalence testing)to find various functional faults through Big Data testing. 展开更多
关键词 Big data testing techniques testing process
下载PDF
Analysis of TOPSIS techniques based on bipolar complex fuzzy N-soft setting and their applications in decision-making problems
2
作者 Tahir Mahmood Ubaid ur Rehman +1 位作者 Zeeshan Ali Izatmand Haleemzai 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第2期478-499,共22页
A novel model termed a bipolar complex fuzzy N-soft set(BCFN-SS)is initiated for tackling information that involves positive and negative aspects,the second dimension,and parameterised grading simultaneously.The theor... A novel model termed a bipolar complex fuzzy N-soft set(BCFN-SS)is initiated for tackling information that involves positive and negative aspects,the second dimension,and parameterised grading simultaneously.The theory of BCFN-SS is the generalisation of two various theories,that is,bipolar complex fuzzy(BCF)and N-SS.The invented model of BCFN-SS helps decision-makers to cope with the genuine-life dilemmas containing BCF information along with parameterised grading at the same time.Further,various algebraic operations,including the usual type of union,intersection,complements,and a few others types,are invented.Certain primary operational laws for BCFNSS are also invented.Moreover,a technique for order preference by similarity to the ideal solution(TOPSIS)approach is devised in the setting of BCFN-SS for managing strategic decision-making(DM)dilemmas containing BCFN-SS information.Keeping in mind the usefulness and benefits of the TOPSIS approach,two various types of TOPSIS approaches in the environment of BCFN-SS are devised and then a numerical example for exposing the usefulness of the devised TOPSIS approach is interpreted.To disclose the prominence and benefits of the devised work,the devised approaches with numerous prevailing work are compared. 展开更多
关键词 aggregation operators bipolar complex fuzzy N-soft sets decision-making similarity measures TOPSIS techniques
下载PDF
A novel method for geometric quality assurance of rock joint replicas in direct shear testing-Part 2:Validation and mechanical replicability
3
作者 J.Larsson F.Johansson +3 位作者 D.Mas Ivars E.Johnson M.Flansbjer N.W.Portal 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第9期2209-2223,共15页
Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter studies.However,a method to acquire knowledge about the ability of the replicas ... Each rock joint is unique by nature which means that utilization of replicas in direct shear tests is required in experimental parameter studies.However,a method to acquire knowledge about the ability of the replicas to imitate the shear mechanical behavior of the rock joint and their dispersion in direct shear testing is lacking.In this study,a novel method is presented for geometric quality assurance of replicas.The aim is to facilitate generation of high-quality direct shear testing data as a prerequisite for reliable subsequent analyses of the results.In Part 1 of this study,two quality assurance parameters,smf and V_(Hp100),are derived and their usefulness for evaluation of geometric deviations,i.e.geometric reproducibility,is shown.In Part 2,the parameters are validated by showing a correlation between the parameters and the shear mechanical behavior,which qualifies the parameters for usage in the quality assurance method.Unique results from direct shear tests presenting comparisons between replicas and the rock joint show that replicas fulfilling proposed threshold values of σ_(mf)<0.06 mm and|V_(Hp100)|<0.2 mm have a narrow dispersion and imitate the shear mechanical behavior of the rock joint in all aspects apart from having a slightly lower peak shear strength.The wear in these replicas,which have similar morphology as the rock joint,is in the same areas as in the rock joint.The wear is slightly larger in the rock joint and therefore the discrepancy in peak shear strength derives from differences in material properties,possibly from differences in toughness.It is shown by application of the suggested method that the quality assured replicas manufactured following the process employed in this study phenomenologically capture the shear strength characteristics,which makes them useful in parameter studies. 展开更多
关键词 Three-dimensional(3D)scanning Contact area measurements Direct shear testing Geometric quality assurance Mechanical replicability Replicas Rock joint
下载PDF
Study on the Safety and Prevention Technology of Coal Mining under the River in Xingyuan Coal Mine
4
作者 Abdoulaye Sylla Wenbing Guo 《Open Journal of Geology》 CAS 2024年第3期339-402,共64页
Coal mining-induced surface subsidence poses significant ecological and infrastructural challenges, necessitating a comprehensive study to ensure safe mining practices, particularly in underwater conditions. This proj... Coal mining-induced surface subsidence poses significant ecological and infrastructural challenges, necessitating a comprehensive study to ensure safe mining practices, particularly in underwater conditions. This project aims to address the extensive impact of coal mining on the environment, infrastructure, and overall safety, focusing on the Shigong River area above the working face. The study employs qualitative and quantitative analyses, along with on-site engineering measurements, to gather data on crucial parameters such as coal seam characteristics, roof rock lithology, thickness, water resistance, and structural damage degree. The research encompasses a multidisciplinary approach, involving mining, geology, hydrogeology, geophysical exploration, rock mechanics, mine surveying, and computational mathematics. The importance of effective safety measures and prevention techniques is emphasized, laying the foundation for research focused on the Xingyun coal mine. The brief concludes by highlighting the potential economic and social benefits of this project and its contribution to valuable experience for future subsea coal mining. 展开更多
关键词 Coal Mining-Induced Surface Subsidence Ecological and Infrastructural Challenges Safe Mining Practices Underwater Conditions Multidisciplinary Approach Safety Measures Prevention techniques
下载PDF
Peritoneal fluid indocyanine green test for diagnosis of gut leakage in anastomotic leakage rats and colorectal surgery patients
5
作者 Yu Huang Tian-Yang Li +4 位作者 Jie-Feng Weng Hui Liu Yu-Jie Xu Shuai Zhang Wei-Li Gu 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第6期1825-1834,共10页
BACKGROUND Application of indocyanine green(ICG)fluorescence has led to new developments in gastrointestinal surgery.However,little is known about the use of ICG for the diagnosis of postoperative gut leakage(GL).In a... BACKGROUND Application of indocyanine green(ICG)fluorescence has led to new developments in gastrointestinal surgery.However,little is known about the use of ICG for the diagnosis of postoperative gut leakage(GL).In addition,there is a lack of rapid and intuitive methods to definitively diagnose postoperative GL.AIM To investigate the effect of ICG in the diagnosis of anastomotic leakage in a surgical rat GL model and evaluate its diagnostic value in colorectal surgery patients.METHODS Sixteen rats were divided into two groups:GL group(n=8)and sham group(n=8).Approximately 0.5 mL of ICG(2.5 mg/mL)was intravenously injected postoperatively.The peritoneal fluid was collected for the fluorescence test at 24 and 48 h.Six patients with rectal cancer who had undergone laparoscopic rectal cancer resection plus enterostomies were injected with 10 mL of ICG(2.5 mg/mL)on postoperative day 1.Their ostomy fluids were collected 24 h after ICG injection to identify the possibility of the ICG excreting from the peripheral veins to the enterostomy stoma.Participants who had undergone colectomy or rectal cancer resection were enrolled in the diagnostic test.The peritoneal fluids from drainage were collected 24 h after ICG injection.The ICG fluorescence test was conducted using OptoMedic endoscopy along with a near-infrared fluorescent imaging system.RESULTS The peritoneal fluids from the GL group showed ICG-dependent green fluorescence in contrast to the sham group.Six samples of ostomy fluids showed green fluorescence,indicating the possibility of ICG excreting from the peripheral veins to the enterostomy stoma in patients.The peritoneal fluid ICG test exhibited a sensitivity of 100%and a specificity of 83.3%for the diagnosis of GL.The positive predictive value was 71.4%,while the negative predictive value was 100%.The likelihood ratios were 6.0 for a positive test result and 0 for a negative result.CONCLUSION The postoperative ICG test in a drainage tube is a valuable and simple technique for the diagnosis of GL.Hence,it should be employed in clinical settings in patients with suspected GL. 展开更多
关键词 Gut leakage Indocyanine green Anastomotic leakage model Diagnostic test Diagnostic technique
下载PDF
Techniques and Apparatus for Measuring Rotational Core Losses of Soft Magnetic Materials
6
作者 Jin-Jiang Zhong You-Guang Guo +2 位作者 Jian-Guo Zhu Hai-Yan Lu Jian-Xun Jin 《Journal of Electronic Science and Technology of China》 2007年第3期218-225,共8页
In many situations such as the cores of a rotating electrical machine and the T joints of a multiphase transformer, the local flux density varies with time in terms of both magnitude and direction, i.e. the flux densi... In many situations such as the cores of a rotating electrical machine and the T joints of a multiphase transformer, the local flux density varies with time in terms of both magnitude and direction, i.e. the flux density vector is rotating. Therefore, the magnetic properties of the core materials under the rotating flux density vector excitation should be properly measured, modeled and applied in the design and analysis of these electromagnetic devices. This paper presents an extensive review on the development of techniques and apparatus for measuring the rotational core losses of soft magnetic materials based on the experiences of various researchers in the last hundred years. 展开更多
关键词 Magnetic property measurement measuring apparatus measuring technique rotational core loss soft magnetic material.
下载PDF
SPECTRAL TECHNIQUES FOR OFF-LINE TESTING AND DIAGNOSIS OF COMPUTER SYSTEMS
7
作者 Mark G.Karpovsky 《Analysis in Theory and Applications》 1998年第3期55-72,共18页
In this paper we present some of our recent results on applications of spectral techniques over finite fields to the problems of testing and diagnosis of computer systems.
关键词 SPECTRAL techniques FOR OFF-LINE testing and DIAGNOSIS OF COMPUTER SYSTEMS LFSR 几几 FFT LENGTH
全文增补中
Applications of Ultrasonic Techniques in Oil and Gas Pipeline Industries: A Review 被引量:5
8
作者 Wissam M. Alobaidi Entidhar A. Alkuam +1 位作者 Hussain M. Al-Rizzo Eric Sandgren 《American Journal of Operations Research》 2015年第4期274-287,共14页
The diversity of ultrasound techniques used in oil and gas pipeline plants provides us with a wealth of information on how to exploit this technology when combined with other techniques, in order to improve the qualit... The diversity of ultrasound techniques used in oil and gas pipeline plants provides us with a wealth of information on how to exploit this technology when combined with other techniques, in order to improve the quality of analysis. The fundamental theory of ultrasonic nondestructive evaluation (NDE) technology is offered, along with practical limitations as related to two factors (wave types and transducers). The focus is limited to the two main techniques used in pipe plants: First, straight beam evaluation and second, angle beam evaluation. The depth of defect (DD) is calculated using straight beam ultrasonic in six different materials according to their relative longitudinal wave (LW) velocities. The materials and respective velocities of LW are: rolled aluminum (6420 m/s), mild steel (5960 m/s), stainless steel-347 (5790 m/s), rolled copper (5010 m/s), annealed copper (4760 m/s), and brass (4700 m/s). In each material eight defects are modeled;the first represents l00% of the material thickness (D), 50.8 mm. The other seven cases represent the DD, as 87.5% of the material thickness, 75%, 62.5%, 50%, 37.5%, 25%, and 12.5%, respectively. Using angle beam evaluation, several parameters are calculated for six different reflection angles (βR) (45°, 50°, 55°, 60°, 65° and 70°). The surface distance (SD), &frac12;skip distance (SKD), full SKD, and 1&frac12;SKD,&frac12;sound path (SP) length, full SP, and 1&frac12;SP are calculated for each βR. The relationship of SKD and SP to the βR is graphed. A chief limitation is noted that ultrasound testing is heavily dependent on the expertise of the operator, and because the reading of the outcome is subjective, precision may be hard to achieve. This review also clarifies and discusses the options used in solving the industrial engineering problem, with a comprehensive historical summary of the information available in the literature. Merging various NDE inspection techniques into the testing of objects is discussed. Eventually, it is hoped to find a suitable technique combined with ultrasonic inspection to deliver highly effective remote testing. 展开更多
关键词 Ultrasonic testing Guided WAVES NONDESTRUCTIVE testing (NDT) PIPE Inspection PIPE Thickness Measurement
下载PDF
Analysis and Applications of the Measurement Uncertainty in Electrical Testing 被引量:2
9
作者 Hung-Lu Wang 《Journal of Power and Energy Engineering》 2015年第4期297-305,共9页
Recently, uncertainty measurement is more and more recognizable in modern data management, conformity assessment, and laboratory accreditation system because of its importance. In this paper, a set of reasonable proba... Recently, uncertainty measurement is more and more recognizable in modern data management, conformity assessment, and laboratory accreditation system because of its importance. In this paper, a set of reasonable probability explanations are introduced and an effective method is pro- posed to quantify the assessment indices for the uncertainty measurement of electrical testing laboratory. First of all, the influence from uncertainty factors during the test process is taken into account. With the use of ISO/IEC Guide 98-3 standard and probability theory, the index and model for the measurement uncertainty assessment of a laboratory is then derived. From the simulation results of safety testing, laboratory uncertainty measurement assessment activity for actual electrical appliances, and the confirmation of Monte Carlo simulation method, the appropriateness and correctness of proposed method are verified. 展开更多
关键词 ELECTRICAL testing MEASUREMENT UNCERTAINTY testing LABORATORY
下载PDF
Measuring the velocity of sand particles in an air/particle two-phase flow:A comparison of several commonly used methods 被引量:2
10
作者 Zhibao Dong GuangQiang Qian WanYin Luo HongTaoWang 《Research in Cold and Arid Regions》 2010年第3期185-197,共13页
The velocity of blown sand particles is an important parameter in aeolian movement (a special case of gas particle two-phase flow) and has ever been a topic of interest. At present, several techniques have been appl... The velocity of blown sand particles is an important parameter in aeolian movement (a special case of gas particle two-phase flow) and has ever been a topic of interest. At present, several techniques have been applied in measuring velocity of the blown sand particles. This paper reviews the measurement results of several commonly used methods: photoelectric cell method, high-speed photographic method, Particle Dynamics Analyzer (PDA) method and Particle Image Velocimetry (PIV) method. Photoelectric cell method, high-speed photograph method and PDA method are useful in studying the velocity distribution of particles. PIV is a whole-flow-field technique and a useful tool to study the average velocity field in a target area. These methods got some similar results but considerable differences also exist. They have come to similar conclusions on the velocity distributions at a single height but direct measurement results with respect to the velocity distribution very close to the surface are still scarce except some PDA results. The magnitude of measured mean particle velocity differs greatly. The relationship obtained by different methods between mean particle velocity and wind velocity, particle size and possibly other influencing factors also differs considerably. Although several authors have proposed similar power functions to describe the variation with height of the mean particle velocity, the predicted results have wide differences. Each technique is based on some unique principles, and has its advantages and disad- vantages. To make full use of different techniques, a lot of work needs be done to validate them. Developing a reliable technique to measure the velocity of blown particles is still a necessary task in aeolian research. 展开更多
关键词 aeolian transport velocity of particles measurement techniques
下载PDF
Development and Electrochemical Testing of Novel Bipolar Nickel Metal Hydride Batteries
11
作者 邓超 史鹏飞 《Journal of Beijing Institute of Technology》 EI CAS 2006年第4期492-495,共4页
Some aspects in the designt and development of bipolar Ni/MH battery are presented. After optimizing sealing technique and modifying capacity ratio of two adjacent electrodes in one sub-cell, some bipolar Ni/MH stacks... Some aspects in the designt and development of bipolar Ni/MH battery are presented. After optimizing sealing technique and modifying capacity ratio of two adjacent electrodes in one sub-cell, some bipolar Ni/MH stacks with 6 sub-cells have been assembled and investigated. Electrochemical testing results show the bipolar battery has excellent high rate discharge capability and fast recharge ability, artd satisfactory charging efficiency in different states of charge. Moreover, the hattery also displays good stability under pulse cycles in simulating hybrid vehicle working oonditions. 展开更多
关键词 bipolar battery electrochemical testing sealing technique
下载PDF
Software Development for Digital Control of WDW Series Testing Machine and Measurement of K_(IC)
12
作者 黄兴 马杭 程昌钧 《Journal of Shanghai University(English Edition)》 CAS 2005年第1期58-61,共4页
Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communica... Software has been developed for digital control of WDW series testing machine and the measurement of fracture toughness by modularized design. Development of the software makes use of multi-thread and serial communication techniques, which can accurately control the testing machine and measure the fracture toughness in real-time. Three-point bending specimens were used in the measurement. The software operates stably and reliably, expanding the function of WDW series testing machine. 展开更多
关键词 testing machine digital control measurement of fracture toughness software development.
下载PDF
Nondestructive Testing Techniques for Quality Detection of Meats 被引量:1
13
作者 KONG Xianqin HUANG Suzhen 《肉类研究》 2009年第2期89-91,共3页
关键词 肉类 检测方法 食品工业 食品质量 产品质量
下载PDF
Determination of the Activation Energy for Migration the Dislocation in 7075 Aircraft Material by Positron Annihilation Lifetime and Electrical Techniques 被引量:1
14
作者 Nasser Abdel-Azeem Kamel Yahia A. Lotfy 《材料科学与工程(中英文A版)》 2011年第5X期711-716,共6页
关键词 正电子湮没寿命 电气技术 活化能 飞机材料 错位 移民 测定 电气测量
下载PDF
A Cross-cultural Examination of the Noise-sensitivity Scale-short Form:Measurement Invariance Testing between the US and Chinese Samples
15
作者 Zachary D Miller HUANG Jun Wu +12 位作者 Heather Costigan LUO Jing DENG Hui Juan XU Xiao Qing B Derrick Taff SUN Cheng YANG Xi WANG Zhong Lei LIN Dan QU Shu Wen PAN Bing LI Guang Ming Peter Newman 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2018年第11期851-854,共4页
Unwanted sound that is unpleasant or disruptive to hear, often interpreted as noise, is a widespread environmental pollutant. Similar to other environmental pollutants, this noise incurs a variety of costs to society.... Unwanted sound that is unpleasant or disruptive to hear, often interpreted as noise, is a widespread environmental pollutant. Similar to other environmental pollutants, this noise incurs a variety of costs to society. Numerous negative health impacts are linked to increases in noise exposure,such as increased cardiovascular risk;and sleep 展开更多
关键词 SF NSS A Cross-cultural Examination of the Noise-sensitivity Scale-short Form:Measurement Invariance testing between the US and Chinese Samples CFA TLI CFI US
下载PDF
The Relationship between Interchangeability Standards and Precision Design in Teaching a Course on Interchangeability and Measurement Techniques
16
作者 Ren Xiu 《China Standardization》 2007年第4期19-24,共6页
This article discusses some views on the relationship between carrying out and applying standards and precision design and the teaching of a course on interchangeability and measurement techniques. It points out that ... This article discusses some views on the relationship between carrying out and applying standards and precision design and the teaching of a course on interchangeability and measurement techniques. It points out that while emphasizing precision design, we should not underrate the significance of interchangeability and standardization. Although there are presently many teaching models available for such courses, each course should be designed separately to preserve its systematic character and integrality. As well, the development of students' abilities in precision design and the application of standards should be strengthened in experimental lessons within each course. 展开更多
关键词 INTERCHANGEABILITY STandARDIZATION precision design TEACHING mode'Interchangeability and measurement techniques WHICH are closely
下载PDF
A Parallel Hybrid Testing Technique for Tri-Programming Model-Based Software Systems
17
作者 Huda Basloom Mohamed Dahab +3 位作者 Abdullah Saad AL-Ghamdi Fathy Eassa Ahmed Mohammed Alghamdi Seif Haridi 《Computers, Materials & Continua》 SCIE EI 2023年第2期4501-4530,共30页
Recently,researchers have shown increasing interest in combining more than one programming model into systems running on high performance computing systems(HPCs)to achieve exascale by applying parallelism at multiple ... Recently,researchers have shown increasing interest in combining more than one programming model into systems running on high performance computing systems(HPCs)to achieve exascale by applying parallelism at multiple levels.Combining different programming paradigms,such as Message Passing Interface(MPI),Open Multiple Processing(OpenMP),and Open Accelerators(OpenACC),can increase computation speed and improve performance.During the integration of multiple models,the probability of runtime errors increases,making their detection difficult,especially in the absence of testing techniques that can detect these errors.Numerous studies have been conducted to identify these errors,but no technique exists for detecting errors in three-level programming models.Despite the increasing research that integrates the three programming models,MPI,OpenMP,and OpenACC,a testing technology to detect runtime errors,such as deadlocks and race conditions,which can arise from this integration has not been developed.Therefore,this paper begins with a definition and explanation of runtime errors that result fromintegrating the three programming models that compilers cannot detect.For the first time,this paper presents a classification of operational errors that can result from the integration of the three models.This paper also proposes a parallel hybrid testing technique for detecting runtime errors in systems built in the C++programming language that uses the triple programming models MPI,OpenMP,and OpenACC.This hybrid technology combines static technology and dynamic technology,given that some errors can be detected using static techniques,whereas others can be detected using dynamic technology.The hybrid technique can detect more errors because it combines two distinct technologies.The proposed static technology detects a wide range of error types in less time,whereas a portion of the potential errors that may or may not occur depending on the 4502 CMC,2023,vol.74,no.2 operating environment are left to the dynamic technology,which completes the validation. 展开更多
关键词 Software testing hybrid testing technique OpenACC OPENMP MPI tri-programming model exascale computing
下载PDF
Teaching Test-Taking Strategies: Importance and Techniques
18
作者 Hamzeh Dodeen 《Psychology Research》 2015年第2期108-113,共6页
关键词 应试策略 教学方法 测试内容 多项选择题 教育工作者 认知能力 有效利用 测试条件
下载PDF
Results and Analysis on Proficiency Testing and Measurement Audit for Molds and Yeast in Cosmetics
19
作者 Ma Qunming Zhou Lei +4 位作者 Chen Rui Chen Jingjing Hua Xin Zhu Qingli Yang Jia 《China Detergent & Cosmetics》 2022年第2期49-53,共5页
In order to improve and evaluate the proficiency testing of cosmetic microorganism detection laboratory,strengthen the control of cosmetic microbial detection quality.In 2019 and 2020,the laboratory of the author’s u... In order to improve and evaluate the proficiency testing of cosmetic microorganism detection laboratory,strengthen the control of cosmetic microbial detection quality.In 2019 and 2020,the laboratory of the author’s unit participated in the proficiency testing(NIFDC-PT-242)and measurement audit(NIFDC-MA-2020-148)for molds and yeasts in cosmetics organized by the National Institutes for Food and Drug Control,respectively.According to the operation instruction for counting molds and yeasts in cosmetics and the Safety and Technical Standards for Cosmetics,the results of the sample for proficiency testing numbered NIFDC-PT-242 were unsatisfactory,and the results of the sample for measurement audit numbered NIFDC-MA-2020-148 were satisfactory.In view of the unsatisfactory results,the laboratory analyzed and summarized from the aspects of“human,machine,material,method and environment”,providing reference for the laboratories participating in proficiency testing and measurement audit.. 展开更多
关键词 proficiency testing measurement audit molds and yeasts COSMETICS
下载PDF
Speed Measurement Feasibility by Eddy Current Effect in the High-Speed MFL Testing
20
作者 Zhaoting Liu Jianbo Wu +4 位作者 Sha He Xin Rao Shiqiang Wang Shen Wang Wei Wei 《Structural Durability & Health Monitoring》 EI 2023年第4期299-314,共16页
It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate t... It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate testing signals.This speed measurement method is complicated,and inevitable abrasion and occasional slippage will reduce the measurement accuracy.In order to solve this problem,based on eddy current effect due to the relative movement,a speed measurement method is proposed,which is contactless and simple.In the high-speed MFL testing,eddy current induced in the specimen will cause an obvious modification to the applied field.This modified field,which is measured by Hall sensor,can be utilized to reflect the moving speed.Firstly,the measurement principle is illustrated based on Faraday’s law.Then,dynamic finite element simulations are conducted to investigate the modified magnetic field distribution.Finally,laboratory experiments are performed to validate the feasibility of the proposed method.The results show that Bmz(r1)and Bmx(r2)have a linear relation with moving speed,which could be used as an alternative measurement parameter. 展开更多
关键词 Magnetic flux leakage testing(MFL) speed measurement eddy current effect modified magnetic field
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部