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Development and Validation of a Laboratory Aging Method for the Accelerated Simulation of Reclaimed Asphalt 被引量:4
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作者 MOLLENHAUER K PIERARD N +2 位作者 TUSAR M MOUILLET V GABET T 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第4期631-636,共6页
The paper presented first results elaborated during the European Research Project Re-road which aims at the development of techniques for increasing the recycling rates of reclaimed asphalt. During service life surfac... The paper presented first results elaborated during the European Research Project Re-road which aims at the development of techniques for increasing the recycling rates of reclaimed asphalt. During service life surface asphalt courses are subjected to aging due to oxidation effects which causes the hardening of the binder and thereby a change in the chemical, physical and mechanical properties of the material. Surface courses often contain highly modified binders as well as special additives for improving the performance characteristics. As these layers inhibit the shortest service lives compared to other road construction layers every year high amounts of reclaimed surface asphalt are available for recycling. The question is raised how the reclaimed asphalt consisting of high quality and costly material components can be recycled for optimal added value. To analyze the asphalt mix service life performance and its recyclability during mix design a laboratory method was developed to simulate the real in-situ aging. First the effects of site aging on the binder and asphalt characteristics were presented. Three laboratory aging methods were discussed which aimed the accelerated aging which meets similar property changes as site aging. At last the effects of two different laboratory aging methods on the same SMA mixture were compared. 展开更多
关键词 asphalt recycling laboratory aging site aging long-term aging validation tests chemical characteristics cracking resistance
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Artificial intelligence model validation before its application in clinical diagnosis assistance
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作者 Gustavo Jesus Vazquez-Zapien Monica Maribel Mata-Miranda +1 位作者 Francisco Garibay-Gonzalez Miguel Sanchez-Brito 《World Journal of Gastroenterology》 SCIE CAS 2022年第5期602-604,共3页
The process of selecting an artificial intelligence(AI)model to assist clinical diagnosis of a particular pathology and its validation tests is relevant since the values of accuracy,sensitivity and specificity may not... The process of selecting an artificial intelligence(AI)model to assist clinical diagnosis of a particular pathology and its validation tests is relevant since the values of accuracy,sensitivity and specificity may not reflect the behavior of the method in a real environment.Here,we provide helpful considerations to increase the success of using an AI model in clinical practice. 展开更多
关键词 Artificial intelligence Diagnostic assistance validation tests Leave-one-out cross-validation K-fold validation Hold-out validation
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Reliability and Validity Test of Questionnaire on the Adaptation Strategy of Cryosphere Changes in Arid Inland River Basin
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作者 WANG Ying-wei1, LIU Shou-dong1, DENG Mao-zhi2,3 1. School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China 2. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China 3. State Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences, Lanzhou 730000, China 《Meteorological and Environmental Research》 CAS 2011年第4期1-4,8,共5页
[Objective] The aim was to test the reliability and validity of questionnaire on the adaptation strategy of cryosphere changes in arid inland river basin. [Method] A questionnaire on 'the adaptation strategy of cr... [Objective] The aim was to test the reliability and validity of questionnaire on the adaptation strategy of cryosphere changes in arid inland river basin. [Method] A questionnaire on 'the adaptation strategy of cryosphere changes in arid inland river basin' was carried out in Urumchi River basin and Aksu River basin, and its reliability and validity were tested by means of statistical method, so as to investigate the stability and accuracy of questionnaire. [Result] Reliability analysis of questionnaire showed that the split-half reliability coefficient of questionnaire in Urumchi River basin and Aksu River basin was 0.729 and 0.750, respectively, and Cronbach’s α reliability coefficient was 0.613 and 0.616, respectively, which revealed that the questionnaire had good equivalence and internal consistency which reflected good reliability and stability. According to validity analysis on questionnaire, there was significant correlation between the score of most questions and questionnaire, and it indicated that questionnaire had high content validity. There were 8 common factors collected from 26 questions, which were summarized as agricultural planting, agricultural water conservation, life satisfaction, cultivated land variation, social integration sense, climate and cryosphere changes, capital input improved by environment and family economic condition, respectively. Meanwhile, the contribution rate of various questions in corresponding indexes was higher, and reflected structure was in full accord with questionnaire content, which revealed that questionnaire owned good construct validity. [Conclusion] With higher stability and accuracy, the questionnaire could determine the desired topic and content and was suitable for the study on the perception of common people and choices of adaptive strategy under cryosphere changes in arid inland river basin in northwestern China. 展开更多
关键词 Cryosphere changes Adaptive strategy QUESTIONNAIRE Reliability and validity test China
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Factors to Give Full Play to the Positive Backwash Effect in the Language Testing
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作者 Guanyu Chen 《Sino-US English Teaching》 2004年第6期50-53,共4页
"Backwash" has usually been described in terms of the effect of testing on language teaching and learning. "Backwash can be harmful or beneficial", as Arthur Hughes states. (Hughes: 1989) This paper set out to ... "Backwash" has usually been described in terms of the effect of testing on language teaching and learning. "Backwash can be harmful or beneficial", as Arthur Hughes states. (Hughes: 1989) This paper set out to see how far this term can be applied to the ways in which both the students and teachers can benefit from language testing. 展开更多
关键词 positive backwash beneficial testing motivation validity and reliability
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Software Package Evaluation for Lyapunov Exponent and Others Features of Signals Evaluating Condition Monitoring Performance of Nonlinear Dynamic Systems
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作者 Julio Cesar Gomez-Mancilla Luis Manuel Palacios-Pineda Valeriy Nosov 《Journal of Energy and Power Engineering》 2015年第5期443-451,共9页
Efficient use of industrial equipment, increase its availability, safety and economic issues spur strong research on maintenance programs based on their operating conditions. Machines normally operate in a linear rang... Efficient use of industrial equipment, increase its availability, safety and economic issues spur strong research on maintenance programs based on their operating conditions. Machines normally operate in a linear range, but when malfunctions occur, nonlinear behavior might set in. By studying and comparing five nonlinear features, which listed in decreasing order by their damage detection capability are: LLE (largest Lyapunov exponent), embedded dimension, Kappa determinism, time delay and cross error values; i.e., LLE performs best. Using somewhat similar ideas from Chaos control, i.e., vary the "mass imbalance" forcing parameters, we aim to stabilize the Lorenz equation. Quite interestingly, for certain imbalance excitation values, the system is stabilized. The previous even when paradigmatically chaotic parameters for Lorenz system are used (plus our forcing terms). This quasi-control approach is validated studying signals obtained from the previously mentioned lab test. Finally, it is concluded that analyzing and comparing nonlinear features extracted from baseline vs. malfunction condition (test acquired), one might increase the efficiency and the performance of machine condition monitoring. 展开更多
关键词 Modified Lorenz equation largest Lyapunov exponent nonlinear features chaos control test validation.
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Method study and uncertainty analysis of calibration coefficients validation based on the Inner Mongolia test site 被引量:1
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作者 GAO HaiLiang GU XingFa +3 位作者 YU Tao GONG Hui LI JiaGuo LI XiaoYing 《Science China Earth Sciences》 SCIE EI CAS 2013年第9期1540-1547,共8页
Calibration coefficients validation is the foundation for ascertaining the sensor performance and carrying out the quantitative application.Based on the analysis of the differences between the calibration and validati... Calibration coefficients validation is the foundation for ascertaining the sensor performance and carrying out the quantitative application.Based on the analysis of the differences between the calibration and validation,two calibration coefficients validation methods were introduced in this paper.Taking the HJ-1A satellite CCD1 camera as an example,the uncertainties of calibration coefficients validation were analyzed.The calibration coefficients validation errors were simulated based on the measured data at an Inner Mongolia test site.The result showed that in the large view angle,the ground directional reflectance variation and the atmospheric path variation were the main error sources in calibration coefficients validation.The ground directional reflectance correction and atmospheric observation angle normalization should be carried out to improve the validation accuracy of calibration coefficients. 展开更多
关键词 Method study and uncertainty analysis of calibration coefficients validation based on the Inner Mongolia test site
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Quantitative Stock Selection Model Based on Long-Short Term Memory(LSTM)Neural Network
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作者 Xiao Wu Yanqiu Tang 《Proceedings of Business and Economic Studies》 2021年第3期19-24,共6页
This article attempted to construct a multi-factor quantitative stock selection model,analyze the financial indicators and transaction data of listed companies in detail via the big data statistical test method,and to... This article attempted to construct a multi-factor quantitative stock selection model,analyze the financial indicators and transaction data of listed companies in detail via the big data statistical test method,and to find out the alpha excess return relative to the market in the case of short stock index futures as a hedge in the Chinese market. 展开更多
关键词 Multi-factor Validity test Stock selection model Quantitative strategy
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Log-rank and stratified log-rank tests
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作者 Ting Ye Jun Shao Yanyao Yi 《Statistical Theory and Related Fields》 CSCD 2023年第4期309-317,共9页
In randomized clinical trials with right-censored time-to-event outcomes,the popular log-rank test without adjusting for baseline covariates is asymptotically valid for treatment effect under simple randomization of t... In randomized clinical trials with right-censored time-to-event outcomes,the popular log-rank test without adjusting for baseline covariates is asymptotically valid for treatment effect under simple randomization of treatments but is too conservative under covariate-adaptive random-ization.The stratified log-rank test,which adjusts baseline covariates in the test procedure by stratification,is asymptotically valid regardless of what treatment randomization is applied.In the literature,however,under simple randomization there is no affirmative conclusion about whether the stratified log-rank test is asymptotically more powerful than the unstratified log-rank test.In this article we show when the stratified and unstratified log-rank tests aim for the same null hypothesis and that,under simple randomization,the stratified log-rank test is asymp-totically more powerful than the unstratified log-rank test in the region of alternative hypothesis that is specified by a Cox proportional hazards model.We also provide some discussion about why we do not have an affirmative conclusion in general. 展开更多
关键词 Baseline covariates covariate-adaptive randomization null hypothesis of no treatment effect Pitman’s relative effciency TIME-TO-EVENT validity of tests
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Test verification of a seat-cabin system vertical dynamic model for high-grade fork lift trucks
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作者 Leilei Zhao Yuewei Yu +1 位作者 Changcheng Zhou Shaofang Mao 《International Journal of Modeling, Simulation, and Scientific Computing》 EI 2018年第1期125-134,共10页
The seat-cabin system of fork lift trucks has a great influence on ride comfort.On the basis of the structure and characteristics of the seat-cabin system for a high-grade fork lift truck,a seat-cabin system vertical ... The seat-cabin system of fork lift trucks has a great influence on ride comfort.On the basis of the structure and characteristics of the seat-cabin system for a high-grade fork lift truck,a seat-cabin system vertical dynamic model was created.The vertical dynamic responses of the model under the random irregularities excitation were calculated.The calculated responses including the seat dynamic response and the cabin dynamic responses at the four corners are very close to the field measurement data and the relative deviations of the(root mean square)RMS acceleration responses are all less than 6.0%.The results show that the vertical dynamic model is acceptable and can truly describe the basic mechanical behavior of the seat-cabin system.The model provides a good basis for investigating the relations between the dynamic parameters and the vibration attenuation characteristics of the seat-cabin system to further improve ride comfort. 展开更多
关键词 Vehicle engineering seat-cabin system vertical dynamic model test validation
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DETERMINING THE RELIABILITY AND VALIDITY OF A MODIFICATION OF THE CET 4 WRITING TEST
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作者 Qu Yunhua Zhejiang Agricultural University 《Chinese Journal of Applied Linguistics》 1997年第1期13-18,共6页
The CET 4 writing test is widely used in China,but whether it is a more reliable and valid test ofwriting for CET 4 than other methods of evaluation is still not clear.The purpose of this study was to examine the reli... The CET 4 writing test is widely used in China,but whether it is a more reliable and valid test ofwriting for CET 4 than other methods of evaluation is still not clear.The purpose of this study was to examine the reliability and the validity of a modification of this test.In carrying out the study,a total of 60 Band 4 students in Zhejiang University took the modified test,aCET 4 test and a First Certificate Practice Test.The results of this study demonstrate that themodified version is a significantly more reliable and valid writing test than the present CET 4 writingtest.These results suggest that the CET 4 writing test needs modification. 展开更多
关键词 CET TING DETERMINING THE RELIABILITY AND VALIDITY OF A MODIFICATION OF THE CET 4 WRITING test test
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