In this paper we propose a multiple feature approach for the normalization task which can map each disorder mention in the text to a unique unified medical language system（UMLS）concept unique identifier（CUI）. We d...In this paper we propose a multiple feature approach for the normalization task which can map each disorder mention in the text to a unique unified medical language system（UMLS）concept unique identifier（CUI）. We develop a two-step method to acquire a list of candidate CUIs and their associated preferred names using UMLS API and to choose the closest CUI by calculating the similarity between the input disorder mention and each candidate. The similarity calculation step is formulated as a classification problem and multiple features（string features,ranking features,similarity features,and contextual features） are used to normalize the disorder mentions. The results show that the multiple feature approach improves the accuracy of the normalization task from 32.99% to 67.08% compared with the Meta Map baseline.展开更多
TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures ...TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures were equiaxed γ phases,and the FG microstructures presented three types:near gamma,duplex,and nearly lamellar.However,the rule for controlling FG microstructures has not been found.Hence,a method needs to be built to find the rule for controlling FG microstructures.Here,we established a normalized process diagram by combining Al-equivalent and dimensionless process parameters.Based on the normalized process diagram,we successfully control the FG microstructures and customize three FG microstructures of the Ti-48Al-2Cr-2Nb alloy.Meanwhile,the average tensile yield strength reaches 756 MPa when the FG microstructure is near gamma.The yield strength is higher than the previous data for the Ti-48Al-2Cr-2Nb alloy.This is attributed to the strong interface-strengthening effect between FG near γ microstructures and CG γ bands.These findings can help shorten the research time of the other TiAl alloys fabricated by EB-PBF,improving the mechanical properties of the other EBPBF-built TiAl alloys in the future.展开更多
Microstructure, precipitate and magnetic characteristic of fmal products with different normalizing cooling processes for Fe-3.2%Si low-temperature hot-rolled grain-oriented silicon steel were analyzed and compared wi...Microstructure, precipitate and magnetic characteristic of fmal products with different normalizing cooling processes for Fe-3.2%Si low-temperature hot-rolled grain-oriented silicon steel were analyzed and compared with the hot-rolled plate by optical microscopy （OM）, transmission electron microscopy （TEM）, and energy dispersive spectrometry （EDS）. The results show that, the surface microstructure is uniform, the proportion of recrystallization in matrix increases, and the banding textures are narrowed; the precipitates, whose quantity in normalized plate is more than that in hot-rolled plate greatly, are mainly A1N, MnS, composite precipitates （Cu,Mn）S and so on. Normalizing technology with a temperature of 1120 ℃, holding for 3 min, and a two-stage cooling is a most advantaged method to obtain oriented silicon steel with sharper Goss texture and higher magnetic properties, owing to the uniform surface microstructures and the obvious inhomogeneity of microstructures along the thickness. The normalizing technology with the two-stage cooling is the optimum process, which can generate more fine precipitates dispersed over the matrix, and be beneficial for finished products to get higher magnetic properties.展开更多
We consider the periodic generalized autoregressive conditional heteroskedasticity(P-GARCH) process and propose a robust estimator by composite quantile regression. We study some useful properties about the P-GARCH mo...We consider the periodic generalized autoregressive conditional heteroskedasticity(P-GARCH) process and propose a robust estimator by composite quantile regression. We study some useful properties about the P-GARCH model. Under some mild conditions, we establish the asymptotic results of proposed estimator.The Monte Carlo simulation is presented to assess the performance of proposed estimator. Numerical study results show that our proposed estimation outperforms other existing methods for heavy tailed distributions.The proposed methodology is also illustrated by Va R on stock price data.展开更多
基金Supported by the National Natural Science Foundation of China(61133012,61202193,61373108)the Major Projects of the National Social Science Foundation of China(11&ZD189)+1 种基金the Chinese Postdoctoral Science Foundation(2013M540593,2014T70722)the Open Foundation of Shandong Key Laboratory of Language Resource Development and Application
文摘In this paper we propose a multiple feature approach for the normalization task which can map each disorder mention in the text to a unique unified medical language system（UMLS）concept unique identifier（CUI）. We develop a two-step method to acquire a list of candidate CUIs and their associated preferred names using UMLS API and to choose the closest CUI by calculating the similarity between the input disorder mention and each candidate. The similarity calculation step is formulated as a classification problem and multiple features（string features,ranking features,similarity features,and contextual features） are used to normalize the disorder mentions. The results show that the multiple feature approach improves the accuracy of the normalization task from 32.99% to 67.08% compared with the Meta Map baseline.
基金financially supported by the National Science Foundation of China(Nos.92163215,52305379,52322101,52174364,52101143,51771093,and 12202201)the Fundamental Research Funds for the Central Universities(Nos.30922010202,and 30922010711)+4 种基金the Key Laboratory Funds for the Science and Technology of National Defense(No.6142212210103)the Natural Science Foundation of Jiangsu Province Major Project(No.BK20212009)the Xi’an Qinchuangyuan Construction of Two-Chain Integration Major Special Projects(No.23LLRHZDZX0015)the Aviation Science Foundation of AVIC(No.2024M0530S8002)the Natural Science Basic Research Program of Shaanxi Province(No.2024JC-YBQN-0579).
文摘TiAl alloys fabricated by electron beam powder bed fusion(EB-PBF)usually exhibit special microstructures with alternating fine-grained(FG)regions and coarse-grained(CG)bands.In previous studies,the CG microstructures were equiaxed γ phases,and the FG microstructures presented three types:near gamma,duplex,and nearly lamellar.However,the rule for controlling FG microstructures has not been found.Hence,a method needs to be built to find the rule for controlling FG microstructures.Here,we established a normalized process diagram by combining Al-equivalent and dimensionless process parameters.Based on the normalized process diagram,we successfully control the FG microstructures and customize three FG microstructures of the Ti-48Al-2Cr-2Nb alloy.Meanwhile,the average tensile yield strength reaches 756 MPa when the FG microstructure is near gamma.The yield strength is higher than the previous data for the Ti-48Al-2Cr-2Nb alloy.This is attributed to the strong interface-strengthening effect between FG near γ microstructures and CG γ bands.These findings can help shorten the research time of the other TiAl alloys fabricated by EB-PBF,improving the mechanical properties of the other EBPBF-built TiAl alloys in the future.
基金Projects(51274083,51074062)supported by the National Natural Science Foundation of China
文摘Microstructure, precipitate and magnetic characteristic of fmal products with different normalizing cooling processes for Fe-3.2%Si low-temperature hot-rolled grain-oriented silicon steel were analyzed and compared with the hot-rolled plate by optical microscopy （OM）, transmission electron microscopy （TEM）, and energy dispersive spectrometry （EDS）. The results show that, the surface microstructure is uniform, the proportion of recrystallization in matrix increases, and the banding textures are narrowed; the precipitates, whose quantity in normalized plate is more than that in hot-rolled plate greatly, are mainly A1N, MnS, composite precipitates （Cu,Mn）S and so on. Normalizing technology with a temperature of 1120 ℃, holding for 3 min, and a two-stage cooling is a most advantaged method to obtain oriented silicon steel with sharper Goss texture and higher magnetic properties, owing to the uniform surface microstructures and the obvious inhomogeneity of microstructures along the thickness. The normalizing technology with the two-stage cooling is the optimum process, which can generate more fine precipitates dispersed over the matrix, and be beneficial for finished products to get higher magnetic properties.
基金supported by National Natural Science Foundation of China(Grant No.11371354)Key Laboratory of Random Complex Structures and Data Science+2 种基金Chinese Academy of Sciences(Grant No.2008DP173182)National Center for Mathematics and Interdisciplinary SciencesChinese Academy of Sciences
文摘We consider the periodic generalized autoregressive conditional heteroskedasticity(P-GARCH) process and propose a robust estimator by composite quantile regression. We study some useful properties about the P-GARCH model. Under some mild conditions, we establish the asymptotic results of proposed estimator.The Monte Carlo simulation is presented to assess the performance of proposed estimator. Numerical study results show that our proposed estimation outperforms other existing methods for heavy tailed distributions.The proposed methodology is also illustrated by Va R on stock price data.
