Both unit and integration testing are incredibly crucial for almost any software application because each of them operates a distinct process to examine the product.Due to resource constraints,when software is subject...Both unit and integration testing are incredibly crucial for almost any software application because each of them operates a distinct process to examine the product.Due to resource constraints,when software is subjected to modifications,the drastic increase in the count of test cases forces the testers to opt for a test optimization strategy.One such strategy is test case prioritization(TCP).Existing works have propounded various methodologies that re-order the system-level test cases intending to boost either the fault detection capabilities or the coverage efficacy at the earliest.Nonetheless,singularity in objective functions and the lack of dissimilitude among the re-ordered test sequences have degraded the cogency of their approaches.Considering such gaps and scenarios when the meteoric and continuous updations in the software make the intensive unit and integration testing process more fragile,this study has introduced a memetics-inspired methodology for TCP.The proposed structure is first embedded with diverse parameters,and then traditional steps of the shuffled-frog-leaping approach(SFLA)are followed to prioritize the test cases at unit and integration levels.On 5 standard test functions,a comparative analysis is conducted between the established algorithms and the proposed approach,where the latter enhances the coverage rate and fault detection of re-ordered test sets.Investigation results related to the mean average percentage of fault detection(APFD)confirmed that the proposed approach exceeds the memetic,basic multi-walk,PSO,and optimized multi-walk by 21.7%,13.99%,12.24%,and 11.51%,respectively.展开更多
The water Cherenkov detector array(WCDA) is an important part of the large high-altitude air shower observatory(LHAASO),which is in a research and development phase.The central scientific goal of LHAASO is to explore ...The water Cherenkov detector array(WCDA) is an important part of the large high-altitude air shower observatory(LHAASO),which is in a research and development phase.The central scientific goal of LHAASO is to explore the origin of high-energy cosmic rays of the universe and to push forward the frontier of new physics.To simplify the WCDA's readout electronics,a prototype of a front-end readout for an application-specific integrated circuit(ASIC) is designed based on the timeover-threshold method to achieve charge-to-time conversion.High-precision time measurement and charge measurement are necessary over a full dynamic range[1-4000photoelectrons(P.E.)].To evaluate the performance of this ASIC,a test system is designed that includes the front-end ASIC test module,digitization module,and test software.The first module needs to be customized for different ASIC versions,whereas the digitization module and test software are tested for general-purpose use.In the digitization module,a field programmable gate array-based time-todigital converter is designed with a bin size of 333 ps,which also integrates an inter-integrated circuit to configure the ASIC test module,and a universal serial bus interface is designed to transfer data to the remote computer.Test results indicate that the time resolution is better than 0.5 ns,and the charge resolution is better than 30%root mean square(RMS) at 1 P.E.and 3%RMS at 4000 P.E.,which are beyond the application requirements.展开更多
In many application scenarios,silicon(Si)photonics favors the integration of Ⅲ-Ⅴ gain material onto Si substrate to real-ize the on-chip light source.In addition to the current popular integration approaches of Ⅲ-...In many application scenarios,silicon(Si)photonics favors the integration of Ⅲ-Ⅴ gain material onto Si substrate to real-ize the on-chip light source.In addition to the current popular integration approaches of Ⅲ-Ⅴ-on-Si wafer bonding or dir-ect heteroepitaxial growth,a newly emerged promising solution of epitaxial regrowth on bonded substrate has attracted a lot of interests.High-quality Ⅲ-Ⅴ material realization and successful laser demonstrations show its great potential to be a promising integration platform for low-cost,high-integration density and highly scalable active-passive photonic integra-tion on Si.This paper reviews recent research work on this regrowth on bonded template platform including template de-velopments,regrown material characterizations and laser demonstrations.The potential advantages,opportunities and challenges of this approach are discussed.展开更多
Introduction: the problem of Severe Acute Malnutrition (SAM) and its consequences concern and challenge all social actors worldwide. The objective of the study was to identify the real obstacles that actors face in th...Introduction: the problem of Severe Acute Malnutrition (SAM) and its consequences concern and challenge all social actors worldwide. The objective of the study was to identify the real obstacles that actors face in the integrated management of children aged 6 - 59 months suffering from SAM at the University Hospital of Mother and Child (CHUME) and the Chad-China Friendship Hospital (HATC) of N’Djamena. Methodology: this is a cross-sectional descriptive and interpretative study conducted from January to October 2023 at the CHUME and HATC of N’Djamena. It is based on questionnaires and direct observation of two hundred and thirty-six (236) parents or guardians of malnourished children admitted to these health facilities. All 236 agreed to participate freely in this study. Results: it appears from this study that the obstacles to the integrated management of malnourished children were: poor care-care relationship (26.7%) permanent product breaks (22.9%), the direct costs of services ranged from 30,000 to 60,000 FCFA (41.53%), drugs used for the treatment of patients came from the street (66.10%), malaria and anemia occupy an important place (27.5%), 57.2% respondents had monthly income below 60,000 CFAF. Conclusion: the present study carried out has identified the real bottlenecks to the integrated management of children suffering from SAM in the therapeutic nutritional units of the city of N’Djamena. .展开更多
In this paper, the design and verification process of an automobile-engine-fan control system on chip (SoC) are introduced. The SoC system, SHU-MV08, reuses four new intellectual property (IP) cores and the design...In this paper, the design and verification process of an automobile-engine-fan control system on chip (SoC) are introduced. The SoC system, SHU-MV08, reuses four new intellectual property (IP) cores and the design flow is accomplished with 0.35 btm chartered CMOS technology. Some special functions of IP cores, the detailed integration scheme of four IP cores, and the verification method of the entire SoC are presented. To settle the verification problems brought by analog IP cores, NanoSim based chip-level mixed-signal verification method is introduced. The verification time is greatly reduced and the first tape-out achieves success which proves the validity of our design.展开更多
The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure sh...The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure should be tested first to guarantee the validation of the results of the rest functional test and diagnosis. This paper describes the fault models and test principles of the BS test access port (TAP) lines on PCBs. A test algorithm with high fault coverage and short time is then presented for the PCB on which all ICs are BS ones.展开更多
Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazar...Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazards following the rapid discharge of gas and rocks, requires solutions which would enable quick and unambiguous detection of the hazard, immediate power supply cut-off and evacuation of personnel from potentially hazardous areas. For this purpose, an integrated outburst detector was developed. Assumed functions of the sensor which was equipped with three measuring and detection elements: a chamber for constant measurement of methane concentration, pressure sensor and microphone. Tests of the sensor model were carried out to estimate the parameters which characterize the dynamic properties of the sensor. Given the impossibility of carrying out the full scale experimental outburst, the sensor was tested during the methane and coal dust explosions in the testing gallery at KD Barbara. The obtained results proved that the applied solutions have been appropriate.展开更多
The thesis selects freight volume and passenger capacity from 1978 to 2008 in Zhejiang Province and the total output value of the primary industry as the object of research, uses quantitative method of co-integration ...The thesis selects freight volume and passenger capacity from 1978 to 2008 in Zhejiang Province and the total output value of the primary industry as the object of research, uses quantitative method of co-integration analysis to analyze the freight volume and passenger capacity, and the total output value of the primary industry in Zhejiang Province. After the stationary test of the time sequence, I conduct the regression analysis of the relationship between freight volume and the total output value of agriculture, and the relationship between passenger capacity and the total output value of agriculture. In addition, I conduct Granger causality test of the relationship between freight volume and passenger capacity, and the total output value of agriculture. The results show that the transportation of Zhejiang Province has promoted the development of agricultural economy prominently, and the development of agricultural economy plays indistinctive role in promoting the transportation volume in Zhejiang Province.展开更多
An algorithm for integrating the constitutive equations in thermal framework is presented, in which the plastic deformation gradient is chosen as the integration variable. Compared with the classic algorithm, a key fe...An algorithm for integrating the constitutive equations in thermal framework is presented, in which the plastic deformation gradient is chosen as the integration variable. Compared with the classic algorithm, a key feature of this new approach is that it can describe the finite deformation of crystals under thermal conditions. The obtained plastic deformation gradient contains not only plastic defor- mation but also thermal effects. The governing equation for the plastic deformation gradient is obtained based on ther- mal multiplicative decomposition of the total deformation gradient. An implicit method is used to integrate this evo- lution equation to ensure stability. Single crystal 1 100 aluminum is investigated to demonstrate practical applications of the model. The effects of anisotropic properties, time step, strain rate and temperature are calculated using this integration model.展开更多
In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, increme...In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.展开更多
Pulsed eddy current (PEC) non-destructive test- ing and evaluation (NDT&E) has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed th...Pulsed eddy current (PEC) non-destructive test- ing and evaluation (NDT&E) has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed through the reports reviewed in this paper. Thanks to its richness of spectral components, various applications of this technique have been proposed and reported in the lit- erature covering both structural integrity inspection and material characterization in various industrial sectors. To support its development and for better understanding of the phenomena around the transient induced eddy currents, attempts for its modelling both analytically and numeri- cally have been made by researchers around the world. This review is an attempt to capture the state-of-the-art development and applications of PEC, especially in the last 15 years and it is not intended to be exhaustive. Future challenges and opportunities for PEC NDT&E are also presented.展开更多
Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformat...Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformation and marine renewable energy development. By analyzing three core indicators, including the power output characteristics of the tidal current device, the generating capacity, energy conversion efficiency, proposed the test contents and evaluation methods of indicators are proposed in this paper; and based on the research of wind farms, power quality testing and assessment methods of offshore tidal energy device are proposed; given the security access to the test contents of tidal current energy device, tidal current energy device running conditions in the testing ground are comprehensively assessed.展开更多
In detecting system fault algorithms,the false alarm rate and undectect rate generated by residual Chi-square test can affect the stability of filters.The paper proposes a fault detection algorithm based on sequential...In detecting system fault algorithms,the false alarm rate and undectect rate generated by residual Chi-square test can affect the stability of filters.The paper proposes a fault detection algorithm based on sequential residual Chi-square test and applies to fault detection of an integrated navigation system.The simulation result shows that the algorithm can accurately detect the fault information of global positioning system(GPS),eliminate the influence of false alarm and missed detection on filter,and enhance fault tolerance of integrated navigation systems.展开更多
The principle and process of parallel seismic (PS) testing for the integrity testing of cemented soil columns are in- troduced in this paper. A three-dimensional (3D) finite element model (FEM) for the pile-soil syste...The principle and process of parallel seismic (PS) testing for the integrity testing of cemented soil columns are in- troduced in this paper. A three-dimensional (3D) finite element model (FEM) for the pile-soil system is established for impulse responses. Under saturated soil or unsaturated soil condition, several vibrating velocity-time histories at different depths in parallel hole are obtained based on the numerical simulation. It shows that the length of the pile and the one-dimensional (1D) P-wave velocity in the pile can be determined easily from the features of the mentioned velocity-time histories. By examining the slopes of the first arrival time plotted versus depth or the depth where the amplitude of the first arrival significantly decreases, the length of the pile can be determined. The effects of the 3D P-wave propagation through the saturated soil and the defect of the cemented soil column on the velocity-time histories are also investigated.展开更多
Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system s...Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.展开更多
To determine whether a given deterministic nonlinear dynamic system is chaotic or periodic, a novel test approach named zero-one (0-1) test has been proposed recently. In this approach, the regular and chaotic motio...To determine whether a given deterministic nonlinear dynamic system is chaotic or periodic, a novel test approach named zero-one (0-1) test has been proposed recently. In this approach, the regular and chaotic motions can be decided by calculating the parameter K approaching asymptotically to zero or one. In this study, we focus on the 0-1 test algorithm and illustrate the selection of parameters of this algorithm by numerical experiments. To validate the reliability and the universality of this algorithm, it is applied to typical nonlinear dynamic systems, including fractional-order dynamic system.展开更多
Selecting Chaoying small watershed with representative karst rocky desertification in the Bijie test area of Guizhou Province as an example, according to karst rocky desertiflcation degree and the existing eco-environ...Selecting Chaoying small watershed with representative karst rocky desertification in the Bijie test area of Guizhou Province as an example, according to karst rocky desertiflcation degree and the existing eco-environmental problems in the small watershed, we study developmental model and technique support system for integrated rehabilitation of rocky desertification in the small watershed, and bring forward the development model and technique integration for integrated rehabilitation of rocky desertification, which adapt to the karst areas of Bijie test area, Guizhou Province and even South China.展开更多
文摘Both unit and integration testing are incredibly crucial for almost any software application because each of them operates a distinct process to examine the product.Due to resource constraints,when software is subjected to modifications,the drastic increase in the count of test cases forces the testers to opt for a test optimization strategy.One such strategy is test case prioritization(TCP).Existing works have propounded various methodologies that re-order the system-level test cases intending to boost either the fault detection capabilities or the coverage efficacy at the earliest.Nonetheless,singularity in objective functions and the lack of dissimilitude among the re-ordered test sequences have degraded the cogency of their approaches.Considering such gaps and scenarios when the meteoric and continuous updations in the software make the intensive unit and integration testing process more fragile,this study has introduced a memetics-inspired methodology for TCP.The proposed structure is first embedded with diverse parameters,and then traditional steps of the shuffled-frog-leaping approach(SFLA)are followed to prioritize the test cases at unit and integration levels.On 5 standard test functions,a comparative analysis is conducted between the established algorithms and the proposed approach,where the latter enhances the coverage rate and fault detection of re-ordered test sets.Investigation results related to the mean average percentage of fault detection(APFD)confirmed that the proposed approach exceeds the memetic,basic multi-walk,PSO,and optimized multi-walk by 21.7%,13.99%,12.24%,and 11.51%,respectively.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KJCX2-YW-N27)the CAS Center for Excellence in Particle Physics(CCEPP)
文摘The water Cherenkov detector array(WCDA) is an important part of the large high-altitude air shower observatory(LHAASO),which is in a research and development phase.The central scientific goal of LHAASO is to explore the origin of high-energy cosmic rays of the universe and to push forward the frontier of new physics.To simplify the WCDA's readout electronics,a prototype of a front-end readout for an application-specific integrated circuit(ASIC) is designed based on the timeover-threshold method to achieve charge-to-time conversion.High-precision time measurement and charge measurement are necessary over a full dynamic range[1-4000photoelectrons(P.E.)].To evaluate the performance of this ASIC,a test system is designed that includes the front-end ASIC test module,digitization module,and test software.The first module needs to be customized for different ASIC versions,whereas the digitization module and test software are tested for general-purpose use.In the digitization module,a field programmable gate array-based time-todigital converter is designed with a bin size of 333 ps,which also integrates an inter-integrated circuit to configure the ASIC test module,and a universal serial bus interface is designed to transfer data to the remote computer.Test results indicate that the time resolution is better than 0.5 ns,and the charge resolution is better than 30%root mean square(RMS) at 1 P.E.and 3%RMS at 4000 P.E.,which are beyond the application requirements.
文摘In many application scenarios,silicon(Si)photonics favors the integration of Ⅲ-Ⅴ gain material onto Si substrate to real-ize the on-chip light source.In addition to the current popular integration approaches of Ⅲ-Ⅴ-on-Si wafer bonding or dir-ect heteroepitaxial growth,a newly emerged promising solution of epitaxial regrowth on bonded substrate has attracted a lot of interests.High-quality Ⅲ-Ⅴ material realization and successful laser demonstrations show its great potential to be a promising integration platform for low-cost,high-integration density and highly scalable active-passive photonic integra-tion on Si.This paper reviews recent research work on this regrowth on bonded template platform including template de-velopments,regrown material characterizations and laser demonstrations.The potential advantages,opportunities and challenges of this approach are discussed.
文摘Introduction: the problem of Severe Acute Malnutrition (SAM) and its consequences concern and challenge all social actors worldwide. The objective of the study was to identify the real obstacles that actors face in the integrated management of children aged 6 - 59 months suffering from SAM at the University Hospital of Mother and Child (CHUME) and the Chad-China Friendship Hospital (HATC) of N’Djamena. Methodology: this is a cross-sectional descriptive and interpretative study conducted from January to October 2023 at the CHUME and HATC of N’Djamena. It is based on questionnaires and direct observation of two hundred and thirty-six (236) parents or guardians of malnourished children admitted to these health facilities. All 236 agreed to participate freely in this study. Results: it appears from this study that the obstacles to the integrated management of malnourished children were: poor care-care relationship (26.7%) permanent product breaks (22.9%), the direct costs of services ranged from 30,000 to 60,000 FCFA (41.53%), drugs used for the treatment of patients came from the street (66.10%), malaria and anemia occupy an important place (27.5%), 57.2% respondents had monthly income below 60,000 CFAF. Conclusion: the present study carried out has identified the real bottlenecks to the integrated management of children suffering from SAM in the therapeutic nutritional units of the city of N’Djamena. .
基金Project supported by the IC Special Foundation of Shanghai Municipal Commission of Science and Technology (Grant No.09706201300)the Shanghai Municipal Commission of Economic and Information (Grant No.090344)the Shanghai High-Tech Industrialization of New Energy Vehicles (Grant No.09625029),and the Graduate Innovation Foundation of Shanghai University
文摘In this paper, the design and verification process of an automobile-engine-fan control system on chip (SoC) are introduced. The SoC system, SHU-MV08, reuses four new intellectual property (IP) cores and the design flow is accomplished with 0.35 btm chartered CMOS technology. Some special functions of IP cores, the detailed integration scheme of four IP cores, and the verification method of the entire SoC are presented. To settle the verification problems brought by analog IP cores, NanoSim based chip-level mixed-signal verification method is introduced. The verification time is greatly reduced and the first tape-out achieves success which proves the validity of our design.
文摘The IEEE Standard 1149.1 boundary scan (BS) implementation provides the internal access required for testing the digital printed circuit board (PCB). However, the integrity of the boundary scan test infrastructure should be tested first to guarantee the validation of the results of the rest functional test and diagnosis. This paper describes the fault models and test principles of the BS test access port (TAP) lines on PCBs. A test algorithm with high fault coverage and short time is then presented for the PCB on which all ICs are BS ones.
文摘Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazards following the rapid discharge of gas and rocks, requires solutions which would enable quick and unambiguous detection of the hazard, immediate power supply cut-off and evacuation of personnel from potentially hazardous areas. For this purpose, an integrated outburst detector was developed. Assumed functions of the sensor which was equipped with three measuring and detection elements: a chamber for constant measurement of methane concentration, pressure sensor and microphone. Tests of the sensor model were carried out to estimate the parameters which characterize the dynamic properties of the sensor. Given the impossibility of carrying out the full scale experimental outburst, the sensor was tested during the methane and coal dust explosions in the testing gallery at KD Barbara. The obtained results proved that the applied solutions have been appropriate.
基金Supported by the Program of Characteristic Major (International Economy and Trade) of Zhejiang Province in the Year 2009(TZZ09084)
文摘The thesis selects freight volume and passenger capacity from 1978 to 2008 in Zhejiang Province and the total output value of the primary industry as the object of research, uses quantitative method of co-integration analysis to analyze the freight volume and passenger capacity, and the total output value of the primary industry in Zhejiang Province. After the stationary test of the time sequence, I conduct the regression analysis of the relationship between freight volume and the total output value of agriculture, and the relationship between passenger capacity and the total output value of agriculture. In addition, I conduct Granger causality test of the relationship between freight volume and passenger capacity, and the total output value of agriculture. The results show that the transportation of Zhejiang Province has promoted the development of agricultural economy prominently, and the development of agricultural economy plays indistinctive role in promoting the transportation volume in Zhejiang Province.
基金supported by the Key Project of the National Natural Science Foundation of China(10932003)Project of Chinese National Programs for Fundamental Research and Development(2012CB619603 and 2010CB832700)"04" Great Project of Ministry of Industrialization and Information of China (2011ZX04001-21)
文摘An algorithm for integrating the constitutive equations in thermal framework is presented, in which the plastic deformation gradient is chosen as the integration variable. Compared with the classic algorithm, a key feature of this new approach is that it can describe the finite deformation of crystals under thermal conditions. The obtained plastic deformation gradient contains not only plastic defor- mation but also thermal effects. The governing equation for the plastic deformation gradient is obtained based on ther- mal multiplicative decomposition of the total deformation gradient. An implicit method is used to integrate this evo- lution equation to ensure stability. Single crystal 1 100 aluminum is investigated to demonstrate practical applications of the model. The effects of anisotropic properties, time step, strain rate and temperature are calculated using this integration model.
文摘In this paper, by means of effective testing practices, main strategies of integration testing for GUI software, including differentiating strategy for distinguished system, strategy of personnel organization, incremental testing strategy based on baseline version, testing strategy of circulating loop through the whole life, and the strategy of test suite construction, were briefly investigated. Moreover, for the code analysis, the FTA (Fault Tree analysis) is proposed to deal with the software change in regression testing. For test suite constructing, the constructing methods for baseline version and the incremental change are deeply discussed, in which main points focus on the testing strategy based on “Sheet/Form”, the “Grey-box approach” for integration testing process, and the application of the improved STD (State Transform Diagram) in state testing. At the same time, the suite construction of integration testing for two types, including small scale program and large scale software, is analyzed and discussed in detail. For testing execution, the specific method based on “Cross-testing” is investigated. Concurrently, by a lot of examples, all results of testing activity indicate that these strategies and methods are useful and fitted to integration testing for GUI software.
基金Ministry of Higher Education of Malaysia for funding the project on PEC NDT at IIUM through the research grant FRGS16-059-0558supported by the National Natural Science Foundation of China under research grants 51677187 and 51307172
文摘Pulsed eddy current (PEC) non-destructive test- ing and evaluation (NDT&E) has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed through the reports reviewed in this paper. Thanks to its richness of spectral components, various applications of this technique have been proposed and reported in the lit- erature covering both structural integrity inspection and material characterization in various industrial sectors. To support its development and for better understanding of the phenomena around the transient induced eddy currents, attempts for its modelling both analytically and numeri- cally have been made by researchers around the world. This review is an attempt to capture the state-of-the-art development and applications of PEC, especially in the last 15 years and it is not intended to be exhaustive. Future challenges and opportunities for PEC NDT&E are also presented.
基金supported by the Implementation Programs for Marine Renewable Energy Special Funds (GHME2012ZC02)
文摘Actual sea condition testing and inspection and evaluation method research are carried out for tidal energy devices to provide scientific and effective technical support for the ocean high-tech achievement transformation and marine renewable energy development. By analyzing three core indicators, including the power output characteristics of the tidal current device, the generating capacity, energy conversion efficiency, proposed the test contents and evaluation methods of indicators are proposed in this paper; and based on the research of wind farms, power quality testing and assessment methods of offshore tidal energy device are proposed; given the security access to the test contents of tidal current energy device, tidal current energy device running conditions in the testing ground are comprehensively assessed.
基金supported by the National Natural Science Foundation of China(6063403060702066)+1 种基金the Aerospace Science Foundation(20090853013)Fundmental Research Foundation of NWPU(JC201015),Soaring Star of NWPU
文摘In detecting system fault algorithms,the false alarm rate and undectect rate generated by residual Chi-square test can affect the stability of filters.The paper proposes a fault detection algorithm based on sequential residual Chi-square test and applies to fault detection of an integrated navigation system.The simulation result shows that the algorithm can accurately detect the fault information of global positioning system(GPS),eliminate the influence of false alarm and missed detection on filter,and enhance fault tolerance of integrated navigation systems.
基金Project (No. 50478022) supported by the National Natural Science Foundation of China
文摘The principle and process of parallel seismic (PS) testing for the integrity testing of cemented soil columns are in- troduced in this paper. A three-dimensional (3D) finite element model (FEM) for the pile-soil system is established for impulse responses. Under saturated soil or unsaturated soil condition, several vibrating velocity-time histories at different depths in parallel hole are obtained based on the numerical simulation. It shows that the length of the pile and the one-dimensional (1D) P-wave velocity in the pile can be determined easily from the features of the mentioned velocity-time histories. By examining the slopes of the first arrival time plotted versus depth or the depth where the amplitude of the first arrival significantly decreases, the length of the pile can be determined. The effects of the 3D P-wave propagation through the saturated soil and the defect of the cemented soil column on the velocity-time histories are also investigated.
基金Supported by National Natural Science Foundation of China(Grant No.51605417)Key Project of Hebei Provincial Natural Science Foundation,China(Grant No.E2016203264)State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)Open Fund Project(Grant No.GZKF-201502)
文摘Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.
基金Project supported by the National Natural Science Foundation of of China (Grant No. 60672041)
文摘To determine whether a given deterministic nonlinear dynamic system is chaotic or periodic, a novel test approach named zero-one (0-1) test has been proposed recently. In this approach, the regular and chaotic motions can be decided by calculating the parameter K approaching asymptotically to zero or one. In this study, we focus on the 0-1 test algorithm and illustrate the selection of parameters of this algorithm by numerical experiments. To validate the reliability and the universality of this algorithm, it is applied to typical nonlinear dynamic systems, including fractional-order dynamic system.
基金Supported by Major Issue of National "12~(th) Five-year Plan"Science and Technology Support Plan,China(2011BAC09B01)
文摘Selecting Chaoying small watershed with representative karst rocky desertification in the Bijie test area of Guizhou Province as an example, according to karst rocky desertiflcation degree and the existing eco-environmental problems in the small watershed, we study developmental model and technique support system for integrated rehabilitation of rocky desertification in the small watershed, and bring forward the development model and technique integration for integrated rehabilitation of rocky desertification, which adapt to the karst areas of Bijie test area, Guizhou Province and even South China.