Fatigue fracture is one of the most common failure modes of engineering compo-nents,and the combined action of geometrie discontinuity and multiaxial loading is more likely to cause severe fatigue damage of components...Fatigue fracture is one of the most common failure modes of engineering compo-nents,and the combined action of geometrie discontinuity and multiaxial loading is more likely to cause severe fatigue damage of components.This work focuses on the fatigue behavior of U-notched Q345 steel specimens with differen t notch sizes under proportional cyclic tension-torsion.Firstly,based on the concept of strain energy,the calculation method of critical plane is given and the equivalent stress of the specified path on the critical plane is extracted to char-acterize the equivalent stress distribution state and the stress gradient effect.Then,based on the high stress volume method and theory of critical distance,a simple method for determining the critical distance is given considering the contribution of stress at the dangerous point and the critical point.In addition,based on the idea of stress-distance normalization,a new stress gradient impact factor is defined and a new method for predicting the multiaxial fatigue life of notched specimens is given.The prediction results of the proposed model,the local stress-strain method and the point method of theory of critical distance are compared with the experimental results.The comparisons show that the prediction results of the proposed model are closer to experimentai life,and the calculation accuracy is higher.展开更多
Predicting protein functions is an important issue in the post-genomic era. This paper studies several network-based kernels including local linear embedding （LLE） kernel method, diffusion kernel and laplacian kerne...Predicting protein functions is an important issue in the post-genomic era. This paper studies several network-based kernels including local linear embedding （LLE） kernel method, diffusion kernel and laplacian kernel to uncover the relationship between proteins functions and protein-protein interactions （PPI）. The author first construct kernels based on PPI networks, then apply support vector machine （SVM） techniques to classify proteins into different functional groups. The 5-fold cross validation is then applied to the selected 359 GO terms to compare the performance of different kernels and guilt-by-association methods including neighbor counting methods and Chi-square methods. Finally, the authors conduct predictions of functions of some unknown genes and verify the preciseness of our prediction in part by the information of other data source.展开更多
In the present paper, we propose an approach of combination prediction of chaotic time series. The method is based on the adding-weight one-rank local-region method of chaotic time series. The method allows us to defi...In the present paper, we propose an approach of combination prediction of chaotic time series. The method is based on the adding-weight one-rank local-region method of chaotic time series. The method allows us to define an interval containing a future value with a given probability, which is obtained by studying the prediction error distribution. Its effectiveness is shown with data generated by Logistic map.展开更多
基金This research was supported by the National Natural Science Foundation of China(Grant No.51605212)the Natural Science Foundation of Gansu Province(Grant No.20JR10RA161)the Project of Hongliu Excellent Youth Program of Lanzhou University of Technology(Grant No.2020062001).
文摘Fatigue fracture is one of the most common failure modes of engineering compo-nents,and the combined action of geometrie discontinuity and multiaxial loading is more likely to cause severe fatigue damage of components.This work focuses on the fatigue behavior of U-notched Q345 steel specimens with differen t notch sizes under proportional cyclic tension-torsion.Firstly,based on the concept of strain energy,the calculation method of critical plane is given and the equivalent stress of the specified path on the critical plane is extracted to char-acterize the equivalent stress distribution state and the stress gradient effect.Then,based on the high stress volume method and theory of critical distance,a simple method for determining the critical distance is given considering the contribution of stress at the dangerous point and the critical point.In addition,based on the idea of stress-distance normalization,a new stress gradient impact factor is defined and a new method for predicting the multiaxial fatigue life of notched specimens is given.The prediction results of the proposed model,the local stress-strain method and the point method of theory of critical distance are compared with the experimental results.The comparisons show that the prediction results of the proposed model are closer to experimentai life,and the calculation accuracy is higher.
基金This research is supported in part by HKRGC Grant 7017/07P, HKU CRCG Grants, HKU strategic theme grant on computational sciences, HKU Hung Hing Ying Physical Science Research Grant, National Natural Science Foundation of China Grant No. 10971075 and Guangdong Provincial Natural Science Grant No. 9151063101000021. The preliminary version of this paper has been presented in the OSB2009 conference and published in the corresponding conference proceedings[25]. The authors would like to thank the anonymous referees for their helpful comments and suggestions.
文摘Predicting protein functions is an important issue in the post-genomic era. This paper studies several network-based kernels including local linear embedding （LLE） kernel method, diffusion kernel and laplacian kernel to uncover the relationship between proteins functions and protein-protein interactions （PPI）. The author first construct kernels based on PPI networks, then apply support vector machine （SVM） techniques to classify proteins into different functional groups. The 5-fold cross validation is then applied to the selected 359 GO terms to compare the performance of different kernels and guilt-by-association methods including neighbor counting methods and Chi-square methods. Finally, the authors conduct predictions of functions of some unknown genes and verify the preciseness of our prediction in part by the information of other data source.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 70271065 and 10201008)
文摘In the present paper, we propose an approach of combination prediction of chaotic time series. The method is based on the adding-weight one-rank local-region method of chaotic time series. The method allows us to define an interval containing a future value with a given probability, which is obtained by studying the prediction error distribution. Its effectiveness is shown with data generated by Logistic map.
基金教育部留学回国人员科研启动基金(The Project-sponsored by SRF for ROCS SEM No.2004.176.4)+1 种基金山东省自然科学基金( the Natural Science Foundation of Shandong Province of China under Grant No.2004G01 No.2004ZRC03016)
