The water drop penetration time(WDPT)test consists of placing water drops on a material's surface in order to evaluate how long it takes to penetrate the pores.It is used to evaluate the hydrophobicity of material...The water drop penetration time(WDPT)test consists of placing water drops on a material's surface in order to evaluate how long it takes to penetrate the pores.It is used to evaluate the hydrophobicity of materials.This study aims at investigating in more detail the soil-water interaction during the test,exposing its mechanism.For that,a model soil named Hamburg Sand was coated with a hydrophobic fluoropolymer and then a WDPT test was performed while computed tomography(CT)images were taken.Tomography experiments were performed at the P07 high-energy materials science(HEMS)beamline,operated by Helmholtz–Zentrum Hereon,at the storage ring PETRA III at the Deutsches Elektronen-Synchrotron(DESY)in Hamburg.Using synchrotron radiation,a tomogram can be obtained in about 10 min,way less time than regular laboratory X-ray sources usually owned by universities.The faster imaging enables the observation of the drop penetration during time and thus provides insight into the dynamics of the process.After that,digital discrete image correlation is performed to track the displacement of the grains throughout time.From the results one can observe that,as the drop is absorbed at the material's surface,the grains directly around the droplet base are dragged to the liquid-air interface around the drop,revealing grain kinematics during capillary interactions of the penetrating liquid and sand grains.展开更多
In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh enviro...In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh environment leads to significant variations in the shape and size of the defects.To address this challenge,we propose the multivariate time series segmentation network(MSSN),which adopts a multiscale convolutional network with multi-stage and depth-separable convolutions for efficient feature extraction through variable-length templates.To tackle the classification difficulty caused by structural signal variance,MSSN employs logarithmic normalization to adjust instance distributions.Furthermore,it integrates classification with smoothing loss functions to accurately identify defect segments amid similar structural and defect signal subsequences.Our algorithm evaluated on both the Mackey-Glass dataset and industrial dataset achieves over 95%localization and demonstrates the capture capability on the synthetic dataset.In a nuclear plant's heat transfer tube dataset,it captures 90%of defect instances with75%middle localization F1 score.展开更多
Skin cancer is the abnormal development of cells on the surface of the skin and is one of the most fatal diseases in humans.It usually appears in locations that are exposed to the sun,but can also appear in areas that...Skin cancer is the abnormal development of cells on the surface of the skin and is one of the most fatal diseases in humans.It usually appears in locations that are exposed to the sun,but can also appear in areas that are not regularly exposed to the sun.Due to the striking similarities between benign and malignant lesions,skin cancer detection remains a problem,even for expert dermatologists.Considering the inability of dermatologists to di-agnose skin cancer accurately,a convolutional neural network(CNN)approach was used for skin cancer diag-nosis.However,the CNN model requires a significant number of image datasets for better performance;thus,image augmentation and transfer learning techniques have been used in this study to boost the number of images and the performance of the model,because there are a limited number of medical images.This study proposes an ensemble transfer-learning-based model that can efficiently classify skin lesions into one of seven categories to aid dermatologists in skin cancer detection:(i)actinic keratoses,(ii)basal cell carcinoma,(iii)benign keratosis,(iv)dermatofibroma,(v)melanocytic nevi,(vi)melanoma,and(vii)vascular skin lesions.Five transfer learning models were used as the basis of the ensemble:MobileNet,EfficientNetV2B2,Xception,ResNeXt101,and Den-seNet201.In addition to the stratified 10-fold cross-validation,the results of each individual model were fused to achieve greater classification accuracy.An annealing learning rate scheduler and test time augmentation(TTA)were also used to increase the performance of the model during the training and testing stages.A total of 10,015 publicly available dermoscopy images from the HAM10000(Human Against Machine)dataset,which contained samples from the seven common skin lesion categories,were used to train and evaluate the models.The proposed technique attained 94.49%accuracy on the dataset.These results suggest that this strategy can be useful for improving the accuracy of skin cancer classification.However,the weighted average of F1-score,recall,and precision were obtained to be 94.68%,94.49%,and 95.07%,respectively.展开更多
In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata...In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata model is established based on function analysis of the zone controller, and the correctness of the model is verified by UPPAAL. Then by parsing the timed automata model files, state information and transition conditions can be extracted to generate test case sets. Finally, according to the serialization conditions of test cases, the test cases are serialized into test sequences by using the improved depth first search algorithm. A case, the ZC controls the train running within its jurisdiction, shows that the method is correct and can effectively improve the efficiency of test sequence generation.展开更多
Fatigue is a common sense caused by crushing labor, stressful social events and various illnesses. It is usually judged by their subjective symptoms, but it should be evaluated in an objective perspective. Here we sho...Fatigue is a common sense caused by crushing labor, stressful social events and various illnesses. It is usually judged by their subjective symptoms, but it should be evaluated in an objective perspective. Here we show that the decrease of working efficiency and sympathetic hyperactivity are associated with mental fatigue state caused by prolonged mental workload. Recently we made a new mental fatigue model of healthy volunteers caused by long-term computerized Kraepelin test (CKT) workload. CKT is our new software for automatically checking the calculation capability, with which it is easy to determine the reaction time (RT), coefficient of variance of reaction time (CV), and accuracy of the answers (AC) during tasks. We put 24 healthy volunteers into the fatigue state by subjecting them to 120 minutes’ CKT workload, and then studied the changes in fatigue sensation, RT, CV, and AC before and after the CKT workload. The fatigue sensation, RT, and CV were clearly increased by the fatigue-inducing task and recovered during the resting period. We also studied the changes in autonomic nerve activity by using heart rate variability analysis. The low/high frequency component ratio (LF/HF) was signifi-cantly increased by the fatigue-inducing task and decreased by resting, suggesting that mental stress causes a relatively sympathetic nerve activity-dominant state. Therefore, our new fatigue model involving a long-term CKT workload is a good mental fatigue model to provide much information about the fatigue state simultane-ously, and the increase of RT, CV, and proportion of sympathetic activity (LF/HF) are associated with mental fatigue state. These might be useful objective biomarkers or evaluating a mental fatigue state.展开更多
AIM:To evaluate the quantitative and qualitative results of the noninvasive tear film break-up time(NI-BUT)test and investigate the predictive ability of the new NIBUT parameter in discriminating between normal Ocular...AIM:To evaluate the quantitative and qualitative results of the noninvasive tear film break-up time(NI-BUT)test and investigate the predictive ability of the new NIBUT parameter in discriminating between normal Ocular Surface Disease Index(OSDI;scores≤12)and abnormal OSDI(scores≥13).METHODS:A total of 341 eyes of 341 volunteers who applied for routine eye outpatient control were included in the prospective study.All participants'noninvasive first tear film break-up time(NIF-BUT),noninvasive average tear film break-up time(NIAvg-BUT)and average value of the first three break-up time(A3F-BUT)were analyzed.A3F-BUT,the new NI-BUT parameter,is calculated by adding the NIF-BUT value to the 2^(nd )break-up time value that has a difference of at most 1 second from the NIF-BUT value and to the 3^(rd) break-up time and then dividing the respective sum by 3.Receiver operating characteristic(ROC)curve and forward logistic regression analyses were performed to determine the parameter that had the best predictive ability between the OSDI groups.RESULTS:The NI-BUT values of 255 eyes of 255 volunteers included in the study were analyzed statistically.The mean NIF-BUT,NIAvg-BUT,and A3F-BUT values were calculated as 5.3±3.0,8±3.1,and 5.8±3.0 seconds,respectively.All three parameters were found to be significantly lower in the abnormal OSDI group(P=0.014,0.034,and 0.011,respectively).The area under the curve(AUC)of the A3F-BUT to predict abnormal OSDI was AUC=0.625(0.529-0.720),P=0.011 and NIF-BUT was AUC=0.599(0.502-0.696),P=0.043.The A3F-BUT parameter and NIF-BUT parameters were found to be significantly efficient in discriminating abnormal OSDI.CONCLUSION:The new parameter for the NI-BUT test has more predictive ability in the discrimination of OSDI groups.展开更多
To solve the problem of time-awarc test case prioritization,a hybrid algorithm composed of integer linear programming and the genetic algorithm(ILP-GA)is proposed.First,the test case suite which cm maximize the number...To solve the problem of time-awarc test case prioritization,a hybrid algorithm composed of integer linear programming and the genetic algorithm(ILP-GA)is proposed.First,the test case suite which cm maximize the number of covered program entities a d satisfy time constraints is selected by integer linea progamming.Secondly,the individual is encoded according to the cover matrices of entities,and the coverage rate of program entities is used as the fitness function and the genetic algorithm is used to prioritize the selected test cases.Five typical open source projects are selected as benchmark programs.Branch and method are selected as program entities,and time constraint percentages a e 25%and 75%.The experimental results show that the ILP-GA convergence has faster speed and better stability than ILP-additional and IP-total in most cases,which contributes to the detection of software defects as early as possible and reduces the software testing costs.展开更多
The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by apply...The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by applying the concept of the double sampling plan and existing multiple dependent state sampling plans.A warning sign for acceptance number was proposed to increase the probability of current lot acceptance.The optimal plan parameters were determined simultaneously with nonlinear optimization problems under the producer’s risk and consumer’s risk.A simulation study was presented to support the proposed sampling plan.A comparison between the proposed and existing sampling plans,namely multiple dependent state(MDS)sampling plans and a modified multiple dependent state(MMDS)sampling plan,was considered under the average sampling number and operating characteristic curve values.In addition,the use of two real datasets demonstrated the practicality and usefulness of the proposed sampling plan.The results indicated that the proposed plan is more flexible and efficient in terms of the average sample number compared to the existing MDS and MMDS sampling plans.展开更多
On the basis of strict mathematical description about Failure_Free Period Life Test (FFPLT), the statistical properties of the tests and optimal confidence limit of the parameter are discussed in detail and correspond...On the basis of strict mathematical description about Failure_Free Period Life Test (FFPLT), the statistical properties of the tests and optimal confidence limit of the parameter are discussed in detail and corresponding calculating formulae are found out.展开更多
The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliab...The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.展开更多
The results of visual event-related potential(ERP)examinations and reactiontime(RT)tests were reported in 30 elders and compared with their performanceintellegence quotient(PIQ)scores.The subjects consisted of 18 male...The results of visual event-related potential(ERP)examinations and reactiontime(RT)tests were reported in 30 elders and compared with their performanceintellegence quotient(PIQ)scores.The subjects consisted of 18 males and 12 femalesaged 50-71(mean 61.4)years old.No history of central nervous system disease wasfound.The visual stimuli were randomly presented to the subject,including three sym-bols:E as target stimulus with 0.15 probability,and H and E as nontarget stimuliwith 0.15 and 0.70 probability respectively.The recording electrodes were placed on Fzand Pz.The duration from the subject seeing the target to touching a button immediatelywas considered as reaction time(RT).It was shown that the P3 latency at Pz was longer than that at Fz and the P3amplitude at Pz was larger than that at Fz,and that the RT was longer than P3 latencywith obvious effect of distribution(P【0.05 at Fz and P】0.05 at Pz)as well .The higherthe PIQ scores,the longer the RT and the P3 latency.It is suggested that the ERPmight reflect the differences of PIQ scores,and the P3 is an objective index.We considerthat the research of ERP is of great interest in the neuropsychological and neurological sci-ences.展开更多
This paper proposes a formal model of the automatic testing system for scheduling strategies in real-time UNIX and describes the algorithm of the key part of the system. The model of the system is an important technol...This paper proposes a formal model of the automatic testing system for scheduling strategies in real-time UNIX and describes the algorithm of the key part of the system. The model of the system is an important technology of the automatization of software development. According to the model presented in the paper, many different kinds of automatic testing systems can be designed and developed easily. At the end of the paper, the prototype proves the feasibility of the model and design.展开更多
A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test an...A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip （SoC） test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC02 test benchmark.展开更多
The wireline formation tester （WFT） is an important tool for formation evaluation, such as calculating the formation pressure and permeability, identifying the fluid type, and determining the interface between oil a...The wireline formation tester （WFT） is an important tool for formation evaluation, such as calculating the formation pressure and permeability, identifying the fluid type, and determining the interface between oil and water. However, in a low porosity and low permeability formation, the supercharge pressure effect exists, since the mudcake has a poor sealing ability. The mudcake cannot isolate the hydrostatic pressure of the formation around the borehole and the mud seeps into the formations, leading to inaccurate formation pressure measurement. At the same time, the tool can be easily stuck in the low porosity/low permeability formation due to the long waiting and testing time. We present a method for determining the minimum testing time for the wireline formation tester. The pressure distribution of the mudcake and the formation were respectively calculated with the finite element method （FEM）. The radius of the influence of mud pressure was also computed, and the minimum testing time in low porosity/low permeability formations was determined within a range of values for different formation permeabilities. The determination of the minimum testing time ensures an accurate formation pressure measurement and minimizes possible accidents due to long waiting and testing time.展开更多
It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing （RTDHT）. This paper focuses on the delay-dependent stability and adde...It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing （RTDHT）. This paper focuses on the delay-dependent stability and added damping of SDOF systems in RTDHT. The exponential delay term is transferred into a rational fraction by the Pad6 approximation, and the delay-dependent stability conditions and instability mechanism of SDOF RTDHT systems are investigated by the root locus technique. First, the stability conditions are discussed separately for the cases of stiffness, mass, and damping experimental substructure. The use of root locus plots shows that the added damping effect and instability mechanism for mass are different from those for stiffness. For the stiffness experimental substructure case, the instability results from the inherent mode because of an obvious negative damping effect of the delay. For the mass case, the delay introduces an equivalent positive damping into the inherent mode, and instability occurs at an added high frequency mode. Then, the compound stability condition is investigated for a general case and the results show that the mass ratio may have both upper and lower limits to remain stable. Finally, a high-emulational virtual shaking table model is built to validate the stability conclusions.展开更多
The robust stability test of time-delay systems with interval parameters can be concluded into the robust stability of the interval quasipolynomials. It has been revealed that the robust stability of the quasipolynomi...The robust stability test of time-delay systems with interval parameters can be concluded into the robust stability of the interval quasipolynomials. It has been revealed that the robust stability of the quasipolynomials depends on that of their edge polynomials. This paper transforms the interval quasipolynomials into two-dimensional （2-D） interval polynomials （2-D s-z hybrid polynomials）, proves that the robust stability of interval 2-D polynomials are sufficient for the stability of given quasipolynomials. Thus, the stability test of interval quasipolynomials can be completed in 2-D s-z domain instead of classical 1-D s domain. The 2-D s-z hybrid polynomials should have different forms under the time delay properties of given quasipolynomials. The stability test proposed by the paper constructs an edge test set from Kharitonov vertex polynomials to reduce the number of testing edge polynomials. The 2-D algebraic tests are provided for the stability test of vertex 2-D polynomials and edge 2-D polynomials family. To verify the results of the paper to be correct and valid, the simulations based on proposed results and comparison with other presented results are given.展开更多
A solution scheme is proposed in this paper for an existing RTDHT system to simulate large-scale finite element （FE） numerical substructures. The analysis of the FE numerical substructure is split into response anal...A solution scheme is proposed in this paper for an existing RTDHT system to simulate large-scale finite element （FE） numerical substructures. The analysis of the FE numerical substructure is split into response analysis and signal generation tasks, and executed in two different target computers in real-time. One target computer implements the response analysis task, wherein a large time-step is used to solve the FE substructure, and another target computer implements the signal generation task, wherein an interpolation program is used to generate control signals in a small time-step to meet the input demand of the controller. By using this strategy, the scale of the FE numerical substructure simulation may be increased significantly. The proposed scheme is initially verified by two FE numerical substructure models with 98 and 1240 degrees of freedom （DOFs）. Thereafter, RTDHTs of a single frame-foundation structure are implemented where the foundation, considered as the numerical substructure, is simulated by the FE model with 1240 DOFs. Good agreements between the results of the RTDHT and those from the FE analysis in ABAQUS are obtained.展开更多
Conventional test of the peak wavelength of a laser used to be applied immediately after a device is injected current. However, the results can not be considered as an accurate description to temperature characteristi...Conventional test of the peak wavelength of a laser used to be applied immediately after a device is injected current. However, the results can not be considered as an accurate description to temperature characteristic. This passage puts forward a concept of relaxation time in wavelength texts, mainly based on the experiment of 940 nm strain quantum well laser, confirming that under constant current, wavelength will get through a process of rising, and then, reach the limit. This process brings the effect on spectral characteristics of a device which cannot be ignored and the accumulated heat in relaxation time will gradually impact the emission wavelength of the laser, even crest split to form bimodal phenomenon.展开更多
Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic ...Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic field's peak both in the time domain and in the frequency domain.With regard to this problem,after analyzing the time-domain and the frequency-domain characteristics of radar pulsed signals,we propose a new time-frequency combination test method based on the correction of the test parameters,as well as its correction method at different bandwidths.The test method is applied in a quick test of a high-power pulsed radar signal,and the corrected results have error less than 1 dB in both the time domain and the frequency domain,which indicates that the proposed time-frequency combined method is effective in testing strong and pulsed electromagnetic fields.展开更多
Flowering time is critically important for crop yield, and detection of its genetic factors with strongly associated DNA markers is necessary in breeding programs. This study was undertaken to validate the quantitativ...Flowering time is critically important for crop yield, and detection of its genetic factors with strongly associated DNA markers is necessary in breeding programs. This study was undertaken to validate the quantitative trait loci （QTLs） underlying flowering time of sorghum based on the association between genotypes at SSR marker loci and flowering time in F3 family lines from self-pollinated heterozygous F2 plants developed by crossing between ＂SC112＂---an early flowering variety from Ethiopia and ＂Kikuchi Zairai＂--a late flowering variety from Japan. The results showed that the SSR markers linked to the QTLs on sorghum chromosomes 1, 2, 3, 5b, 7 and 8b were significantly （P 〈 0.05） associated with flowering time, and these markers and the QTLs reported previously are valid. On the other hand, the genotypes at the marker locus SB596 of qFT1-2 on chromosome 1 was not significantly associated with flowering time. The valid DNA markers, SB258 in qFTI-1, SB 1512 in qFT2, SB 1839 in qFT3, SB3369 in qFT5b, SB4096 in qFT7 and SB4540 and SB4660 in qFT8b, might be useful for DNA-marker assisted breeding.展开更多
基金funding of this research by the German Research Foundation(Deutsche Forschungsgemeinschaft,DFG)in the framework of Research Training Group GRK 2462:Processes in natural and technical Particle-Fluid-Systems at Hamburg University of Technology(TUHH).
文摘The water drop penetration time(WDPT)test consists of placing water drops on a material's surface in order to evaluate how long it takes to penetrate the pores.It is used to evaluate the hydrophobicity of materials.This study aims at investigating in more detail the soil-water interaction during the test,exposing its mechanism.For that,a model soil named Hamburg Sand was coated with a hydrophobic fluoropolymer and then a WDPT test was performed while computed tomography(CT)images were taken.Tomography experiments were performed at the P07 high-energy materials science(HEMS)beamline,operated by Helmholtz–Zentrum Hereon,at the storage ring PETRA III at the Deutsches Elektronen-Synchrotron(DESY)in Hamburg.Using synchrotron radiation,a tomogram can be obtained in about 10 min,way less time than regular laboratory X-ray sources usually owned by universities.The faster imaging enables the observation of the drop penetration during time and thus provides insight into the dynamics of the process.After that,digital discrete image correlation is performed to track the displacement of the grains throughout time.From the results one can observe that,as the drop is absorbed at the material's surface,the grains directly around the droplet base are dragged to the liquid-air interface around the drop,revealing grain kinematics during capillary interactions of the penetrating liquid and sand grains.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2024ZD0608100)the National Natural Science Foundation of China(62332017,U22A2022)
文摘In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh environment leads to significant variations in the shape and size of the defects.To address this challenge,we propose the multivariate time series segmentation network(MSSN),which adopts a multiscale convolutional network with multi-stage and depth-separable convolutions for efficient feature extraction through variable-length templates.To tackle the classification difficulty caused by structural signal variance,MSSN employs logarithmic normalization to adjust instance distributions.Furthermore,it integrates classification with smoothing loss functions to accurately identify defect segments amid similar structural and defect signal subsequences.Our algorithm evaluated on both the Mackey-Glass dataset and industrial dataset achieves over 95%localization and demonstrates the capture capability on the synthetic dataset.In a nuclear plant's heat transfer tube dataset,it captures 90%of defect instances with75%middle localization F1 score.
文摘Skin cancer is the abnormal development of cells on the surface of the skin and is one of the most fatal diseases in humans.It usually appears in locations that are exposed to the sun,but can also appear in areas that are not regularly exposed to the sun.Due to the striking similarities between benign and malignant lesions,skin cancer detection remains a problem,even for expert dermatologists.Considering the inability of dermatologists to di-agnose skin cancer accurately,a convolutional neural network(CNN)approach was used for skin cancer diag-nosis.However,the CNN model requires a significant number of image datasets for better performance;thus,image augmentation and transfer learning techniques have been used in this study to boost the number of images and the performance of the model,because there are a limited number of medical images.This study proposes an ensemble transfer-learning-based model that can efficiently classify skin lesions into one of seven categories to aid dermatologists in skin cancer detection:(i)actinic keratoses,(ii)basal cell carcinoma,(iii)benign keratosis,(iv)dermatofibroma,(v)melanocytic nevi,(vi)melanoma,and(vii)vascular skin lesions.Five transfer learning models were used as the basis of the ensemble:MobileNet,EfficientNetV2B2,Xception,ResNeXt101,and Den-seNet201.In addition to the stratified 10-fold cross-validation,the results of each individual model were fused to achieve greater classification accuracy.An annealing learning rate scheduler and test time augmentation(TTA)were also used to increase the performance of the model during the training and testing stages.A total of 10,015 publicly available dermoscopy images from the HAM10000(Human Against Machine)dataset,which contained samples from the seven common skin lesion categories,were used to train and evaluate the models.The proposed technique attained 94.49%accuracy on the dataset.These results suggest that this strategy can be useful for improving the accuracy of skin cancer classification.However,the weighted average of F1-score,recall,and precision were obtained to be 94.68%,94.49%,and 95.07%,respectively.
文摘In order to solve the problem of artificial generation and low efficiency of test sequences for zone controller (ZC), a model-based automatic generation method of test sequence is proposed. Firstly, the timed automata model is established based on function analysis of the zone controller, and the correctness of the model is verified by UPPAAL. Then by parsing the timed automata model files, state information and transition conditions can be extracted to generate test case sets. Finally, according to the serialization conditions of test cases, the test cases are serialized into test sequences by using the improved depth first search algorithm. A case, the ZC controls the train running within its jurisdiction, shows that the method is correct and can effectively improve the efficiency of test sequence generation.
文摘Fatigue is a common sense caused by crushing labor, stressful social events and various illnesses. It is usually judged by their subjective symptoms, but it should be evaluated in an objective perspective. Here we show that the decrease of working efficiency and sympathetic hyperactivity are associated with mental fatigue state caused by prolonged mental workload. Recently we made a new mental fatigue model of healthy volunteers caused by long-term computerized Kraepelin test (CKT) workload. CKT is our new software for automatically checking the calculation capability, with which it is easy to determine the reaction time (RT), coefficient of variance of reaction time (CV), and accuracy of the answers (AC) during tasks. We put 24 healthy volunteers into the fatigue state by subjecting them to 120 minutes’ CKT workload, and then studied the changes in fatigue sensation, RT, CV, and AC before and after the CKT workload. The fatigue sensation, RT, and CV were clearly increased by the fatigue-inducing task and recovered during the resting period. We also studied the changes in autonomic nerve activity by using heart rate variability analysis. The low/high frequency component ratio (LF/HF) was signifi-cantly increased by the fatigue-inducing task and decreased by resting, suggesting that mental stress causes a relatively sympathetic nerve activity-dominant state. Therefore, our new fatigue model involving a long-term CKT workload is a good mental fatigue model to provide much information about the fatigue state simultane-ously, and the increase of RT, CV, and proportion of sympathetic activity (LF/HF) are associated with mental fatigue state. These might be useful objective biomarkers or evaluating a mental fatigue state.
文摘AIM:To evaluate the quantitative and qualitative results of the noninvasive tear film break-up time(NI-BUT)test and investigate the predictive ability of the new NIBUT parameter in discriminating between normal Ocular Surface Disease Index(OSDI;scores≤12)and abnormal OSDI(scores≥13).METHODS:A total of 341 eyes of 341 volunteers who applied for routine eye outpatient control were included in the prospective study.All participants'noninvasive first tear film break-up time(NIF-BUT),noninvasive average tear film break-up time(NIAvg-BUT)and average value of the first three break-up time(A3F-BUT)were analyzed.A3F-BUT,the new NI-BUT parameter,is calculated by adding the NIF-BUT value to the 2^(nd )break-up time value that has a difference of at most 1 second from the NIF-BUT value and to the 3^(rd) break-up time and then dividing the respective sum by 3.Receiver operating characteristic(ROC)curve and forward logistic regression analyses were performed to determine the parameter that had the best predictive ability between the OSDI groups.RESULTS:The NI-BUT values of 255 eyes of 255 volunteers included in the study were analyzed statistically.The mean NIF-BUT,NIAvg-BUT,and A3F-BUT values were calculated as 5.3±3.0,8±3.1,and 5.8±3.0 seconds,respectively.All three parameters were found to be significantly lower in the abnormal OSDI group(P=0.014,0.034,and 0.011,respectively).The area under the curve(AUC)of the A3F-BUT to predict abnormal OSDI was AUC=0.625(0.529-0.720),P=0.011 and NIF-BUT was AUC=0.599(0.502-0.696),P=0.043.The A3F-BUT parameter and NIF-BUT parameters were found to be significantly efficient in discriminating abnormal OSDI.CONCLUSION:The new parameter for the NI-BUT test has more predictive ability in the discrimination of OSDI groups.
基金The Natural Science Foundation of Education Ministry of Shaanxi Province(No.15JK1672)the Industrial Research Project of Shaanxi Province(No.2017GY-092)Special Fund for Key Discipline Construction of General Institutions of Higher Education in Shaanxi Province
文摘To solve the problem of time-awarc test case prioritization,a hybrid algorithm composed of integer linear programming and the genetic algorithm(ILP-GA)is proposed.First,the test case suite which cm maximize the number of covered program entities a d satisfy time constraints is selected by integer linea progamming.Secondly,the individual is encoded according to the cover matrices of entities,and the coverage rate of program entities is used as the fitness function and the genetic algorithm is used to prioritize the selected test cases.Five typical open source projects are selected as benchmark programs.Branch and method are selected as program entities,and time constraint percentages a e 25%and 75%.The experimental results show that the ILP-GA convergence has faster speed and better stability than ILP-additional and IP-total in most cases,which contributes to the detection of software defects as early as possible and reduces the software testing costs.
基金This research was supported by Thailand ScienceResearch and Innovation(TSRI)and Rajamangala University of Technology Thanyaburi(RMUTT)under National Science,Research and Innovation Fund(NSRF)BasicResearch Fund:Fiscal year 2022(ContractNo.FRB650070/0168 and under Project number FRB65E0634 M.3).
文摘The design of a new adaptive version of the multiple dependent state(AMDS)sampling plan is presented based on the time truncated life test under the Weibull distribution.We achieved the proposed sampling plan by applying the concept of the double sampling plan and existing multiple dependent state sampling plans.A warning sign for acceptance number was proposed to increase the probability of current lot acceptance.The optimal plan parameters were determined simultaneously with nonlinear optimization problems under the producer’s risk and consumer’s risk.A simulation study was presented to support the proposed sampling plan.A comparison between the proposed and existing sampling plans,namely multiple dependent state(MDS)sampling plans and a modified multiple dependent state(MMDS)sampling plan,was considered under the average sampling number and operating characteristic curve values.In addition,the use of two real datasets demonstrated the practicality and usefulness of the proposed sampling plan.The results indicated that the proposed plan is more flexible and efficient in terms of the average sample number compared to the existing MDS and MMDS sampling plans.
文摘On the basis of strict mathematical description about Failure_Free Period Life Test (FFPLT), the statistical properties of the tests and optimal confidence limit of the parameter are discussed in detail and corresponding calculating formulae are found out.
基金supported by the Aviation Science Foundation of China
文摘The reliability of real-time embedded software directly determines the reliability of the whole real-time embedded sys- tem, and the effective software testing is an important way to ensure software quality and reliability. Based on the analysis of the characteristics of real-time embedded software, the formal method is introduced into the real-time embedded software testing field and the real-time extended finite state machine （RT-EFSM） model is studied firstly. Then, the time zone division method of real-time embedded system is presented and the definition and description methods of time-constrained transition equivalence class （timeCTEC） are presented. Furthermore, the approaches of the testing sequence and test case generation are put forward. Finally, the proposed method is applied to a typical avionics real- time embedded software testing practice and the examples of the timeCTEC, testing sequences and test cases are given. With the analysis of the testing result, the application verification shows that the proposed method can effectively describe the real-time embedded software state transition characteristics and real-time requirements and play the advantages of the formal methods in accuracy, effectiveness and the automation supporting. Combined with the testing platform, the real-time, closed loop and automated simulation testing for real-time embedded software can be realized effectively.
文摘The results of visual event-related potential(ERP)examinations and reactiontime(RT)tests were reported in 30 elders and compared with their performanceintellegence quotient(PIQ)scores.The subjects consisted of 18 males and 12 femalesaged 50-71(mean 61.4)years old.No history of central nervous system disease wasfound.The visual stimuli were randomly presented to the subject,including three sym-bols:E as target stimulus with 0.15 probability,and H and E as nontarget stimuliwith 0.15 and 0.70 probability respectively.The recording electrodes were placed on Fzand Pz.The duration from the subject seeing the target to touching a button immediatelywas considered as reaction time(RT).It was shown that the P3 latency at Pz was longer than that at Fz and the P3amplitude at Pz was larger than that at Fz,and that the RT was longer than P3 latencywith obvious effect of distribution(P【0.05 at Fz and P】0.05 at Pz)as well .The higherthe PIQ scores,the longer the RT and the P3 latency.It is suggested that the ERPmight reflect the differences of PIQ scores,and the P3 is an objective index.We considerthat the research of ERP is of great interest in the neuropsychological and neurological sci-ences.
基金the Defense Advanced research Projects Agency of the Department of Defense (No.15.3.2).
文摘This paper proposes a formal model of the automatic testing system for scheduling strategies in real-time UNIX and describes the algorithm of the key part of the system. The model of the system is an important technology of the automatization of software development. According to the model presented in the paper, many different kinds of automatic testing systems can be designed and developed easily. At the end of the paper, the prototype proves the feasibility of the model and design.
基金Project supported by the SDC Project of Science and Technology Commission of Shanghai Municipality (Grant No.08706201000)the AM Foundation Project of Science and Technology Commission of Shanghai Municipality (Grant No.08700741000)+1 种基金the Leading Academic Discipline Project of Shanghai Education Commission (Grant No.J50104)the Innovation Foundation Project of Shanghai University
文摘A novel test access mechanism （TAM） architecture with multi test-channel （TC） based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip （SoC） test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC02 test benchmark.
文摘The wireline formation tester （WFT） is an important tool for formation evaluation, such as calculating the formation pressure and permeability, identifying the fluid type, and determining the interface between oil and water. However, in a low porosity and low permeability formation, the supercharge pressure effect exists, since the mudcake has a poor sealing ability. The mudcake cannot isolate the hydrostatic pressure of the formation around the borehole and the mud seeps into the formations, leading to inaccurate formation pressure measurement. At the same time, the tool can be easily stuck in the low porosity/low permeability formation due to the long waiting and testing time. We present a method for determining the minimum testing time for the wireline formation tester. The pressure distribution of the mudcake and the formation were respectively calculated with the finite element method （FEM）. The radius of the influence of mud pressure was also computed, and the minimum testing time in low porosity/low permeability formations was determined within a range of values for different formation permeabilities. The determination of the minimum testing time ensures an accurate formation pressure measurement and minimizes possible accidents due to long waiting and testing time.
基金State Key Laboratory of Hydroscience and Engineering Under Grant No.2008-TC-2National Natural Science Foundation of China Under Grant No.90510018,50779021 and 90715041
文摘It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing （RTDHT）. This paper focuses on the delay-dependent stability and added damping of SDOF systems in RTDHT. The exponential delay term is transferred into a rational fraction by the Pad6 approximation, and the delay-dependent stability conditions and instability mechanism of SDOF RTDHT systems are investigated by the root locus technique. First, the stability conditions are discussed separately for the cases of stiffness, mass, and damping experimental substructure. The use of root locus plots shows that the added damping effect and instability mechanism for mass are different from those for stiffness. For the stiffness experimental substructure case, the instability results from the inherent mode because of an obvious negative damping effect of the delay. For the mass case, the delay introduces an equivalent positive damping into the inherent mode, and instability occurs at an added high frequency mode. Then, the compound stability condition is investigated for a general case and the results show that the mass ratio may have both upper and lower limits to remain stable. Finally, a high-emulational virtual shaking table model is built to validate the stability conclusions.
基金This project was supported by the National Science Foundation of China (60572093).
文摘The robust stability test of time-delay systems with interval parameters can be concluded into the robust stability of the interval quasipolynomials. It has been revealed that the robust stability of the quasipolynomials depends on that of their edge polynomials. This paper transforms the interval quasipolynomials into two-dimensional （2-D） interval polynomials （2-D s-z hybrid polynomials）, proves that the robust stability of interval 2-D polynomials are sufficient for the stability of given quasipolynomials. Thus, the stability test of interval quasipolynomials can be completed in 2-D s-z domain instead of classical 1-D s domain. The 2-D s-z hybrid polynomials should have different forms under the time delay properties of given quasipolynomials. The stability test proposed by the paper constructs an edge test set from Kharitonov vertex polynomials to reduce the number of testing edge polynomials. The 2-D algebraic tests are provided for the stability test of vertex 2-D polynomials and edge 2-D polynomials family. To verify the results of the paper to be correct and valid, the simulations based on proposed results and comparison with other presented results are given.
基金National Natural Science Foundation under Grant Nos.51179093,91215301 and 41274106the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20130002110032Tsinghua University Initiative Scientific Research Program under Grant No.20131089285
文摘A solution scheme is proposed in this paper for an existing RTDHT system to simulate large-scale finite element （FE） numerical substructures. The analysis of the FE numerical substructure is split into response analysis and signal generation tasks, and executed in two different target computers in real-time. One target computer implements the response analysis task, wherein a large time-step is used to solve the FE substructure, and another target computer implements the signal generation task, wherein an interpolation program is used to generate control signals in a small time-step to meet the input demand of the controller. By using this strategy, the scale of the FE numerical substructure simulation may be increased significantly. The proposed scheme is initially verified by two FE numerical substructure models with 98 and 1240 degrees of freedom （DOFs）. Thereafter, RTDHTs of a single frame-foundation structure are implemented where the foundation, considered as the numerical substructure, is simulated by the FE model with 1240 DOFs. Good agreements between the results of the RTDHT and those from the FE analysis in ABAQUS are obtained.
文摘Conventional test of the peak wavelength of a laser used to be applied immediately after a device is injected current. However, the results can not be considered as an accurate description to temperature characteristic. This passage puts forward a concept of relaxation time in wavelength texts, mainly based on the experiment of 940 nm strain quantum well laser, confirming that under constant current, wavelength will get through a process of rising, and then, reach the limit. This process brings the effect on spectral characteristics of a device which cannot be ignored and the accumulated heat in relaxation time will gradually impact the emission wavelength of the laser, even crest split to form bimodal phenomenon.
文摘Many conventional methods of testing strong and pulsed electromagnetic fields,the ones used in radars for example,had deficiencies due to the difficulty in obtaining simultaneous information about the electromagnetic field's peak both in the time domain and in the frequency domain.With regard to this problem,after analyzing the time-domain and the frequency-domain characteristics of radar pulsed signals,we propose a new time-frequency combination test method based on the correction of the test parameters,as well as its correction method at different bandwidths.The test method is applied in a quick test of a high-power pulsed radar signal,and the corrected results have error less than 1 dB in both the time domain and the frequency domain,which indicates that the proposed time-frequency combined method is effective in testing strong and pulsed electromagnetic fields.
文摘Flowering time is critically important for crop yield, and detection of its genetic factors with strongly associated DNA markers is necessary in breeding programs. This study was undertaken to validate the quantitative trait loci （QTLs） underlying flowering time of sorghum based on the association between genotypes at SSR marker loci and flowering time in F3 family lines from self-pollinated heterozygous F2 plants developed by crossing between ＂SC112＂---an early flowering variety from Ethiopia and ＂Kikuchi Zairai＂--a late flowering variety from Japan. The results showed that the SSR markers linked to the QTLs on sorghum chromosomes 1, 2, 3, 5b, 7 and 8b were significantly （P 〈 0.05） associated with flowering time, and these markers and the QTLs reported previously are valid. On the other hand, the genotypes at the marker locus SB596 of qFT1-2 on chromosome 1 was not significantly associated with flowering time. The valid DNA markers, SB258 in qFTI-1, SB 1512 in qFT2, SB 1839 in qFT3, SB3369 in qFT5b, SB4096 in qFT7 and SB4540 and SB4660 in qFT8b, might be useful for DNA-marker assisted breeding.
