This study addresses the problem of Chinese microblog opinion retrieval, which aims to retrieve opinionated Chinese microblog posts relevant to a target specified by a user query. Existing studies have shown that lexi...This study addresses the problem of Chinese microblog opinion retrieval, which aims to retrieve opinionated Chinese microblog posts relevant to a target specified by a user query. Existing studies have shown that lexicon-based approaches employed online public sentiment resources to rank sentiment words relying on the document features. However, this approach could not be effectively applied to mi- croblogs that have typical user-generated content with valu- able contextual information: "user-user" interpersonal interactions and "user-post/comment" intrapersonal interactions. This contextual information is very helpful in estimating the strength of sentiment words more accurately. In this study, we integrate the social contextual relationships among users, posts/comments, and sentiment words into a mutual reinforcement model and propose a unified three-layer heterogeneous graph, on which a random walk sentiment word weighting algorithm is presented to measure the strength of opinion of the sentiment words. Furthermore, the weights of sentiment words are incorporated into a lexicon-based model for Chinese microblog opinion retrieval. Comparative experiments are conducted on a Chinese microblog corpus, and the results show that our proposed mutual reinforcement model achieves significant improvement over previous methods.展开更多
Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological functions.This understanding was fueled by the recent development of genome editing tools and our im...Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological functions.This understanding was fueled by the recent development of genome editing tools and our improved capacity for analyzing the global DNA methylome in mammalian cells.This review focuses on the maintenance of DNA methylation patterns during mitotic cell division.We discuss the latest discoveries of the mechanisms for the inheritance of DNA methylation as a stable epigenetic memory.We also highlight recent evidence showing the rapid turnover of DNA methylation as a dynamic gene regulatory mechanism.A body of work has shown that altered DNA methylomes are common features in aging and disease.We discuss the potential links between methylation maintenance mechanisms and diseaseassociated methylation changes.展开更多
Based on the traditional Nielsen model,a unified failure model on the uniformly reinforced concrete box section members under combined forces was introduced by Luo and Liu.One of their contributions is adjustment of t...Based on the traditional Nielsen model,a unified failure model on the uniformly reinforced concrete box section members under combined forces was introduced by Luo and Liu.One of their contributions is adjustment of the shear carrying capacity of concrete at the member failure surface.In the unified failure model,the comparison with the experimental results verified this adjustment.Nevertheless,it should be pointed out that the adjustment factor of shear carrying capacity at member failure surface for the reinforced concrete members in the unified failure model is a fixed adjustment constant for all experiment data,which is basically determined by curve fitting.However,the adjustment factor should vary with the normal stress at the member failure surface.In this paper,an advanced theoretical model is introduced,in which the adjustment factor of shear carrying capacity at failure surface is a variable related to the normal stress at failure surface.Furthermore,the advanced unified failure model on the uniformly reinforced concrete box section member can still be expressed in a simple form.Finally,the comparison with several groups of test data has verified that this advanced model is more accurate and feasible to be used in design.展开更多
文摘This study addresses the problem of Chinese microblog opinion retrieval, which aims to retrieve opinionated Chinese microblog posts relevant to a target specified by a user query. Existing studies have shown that lexicon-based approaches employed online public sentiment resources to rank sentiment words relying on the document features. However, this approach could not be effectively applied to mi- croblogs that have typical user-generated content with valu- able contextual information: "user-user" interpersonal interactions and "user-post/comment" intrapersonal interactions. This contextual information is very helpful in estimating the strength of sentiment words more accurately. In this study, we integrate the social contextual relationships among users, posts/comments, and sentiment words into a mutual reinforcement model and propose a unified three-layer heterogeneous graph, on which a random walk sentiment word weighting algorithm is presented to measure the strength of opinion of the sentiment words. Furthermore, the weights of sentiment words are incorporated into a lexicon-based model for Chinese microblog opinion retrieval. Comparative experiments are conducted on a Chinese microblog corpus, and the results show that our proposed mutual reinforcement model achieves significant improvement over previous methods.
基金supported by the Chinese Ministry of Science and Technology (2019YFA0801401 to B.Z.)the Chinese Academy of Sciences (XDB39000000 and QYZDY-SSW-SMC031 to B.Z.+1 种基金2019 Special Research Assistant Funding to Y.L.)the National Natural Science Foundation of China (32000559 to Y.L.)。
文摘Decades of investigation on DNA methylation have led to deeper insights into its metabolic mechanisms and biological functions.This understanding was fueled by the recent development of genome editing tools and our improved capacity for analyzing the global DNA methylome in mammalian cells.This review focuses on the maintenance of DNA methylation patterns during mitotic cell division.We discuss the latest discoveries of the mechanisms for the inheritance of DNA methylation as a stable epigenetic memory.We also highlight recent evidence showing the rapid turnover of DNA methylation as a dynamic gene regulatory mechanism.A body of work has shown that altered DNA methylomes are common features in aging and disease.We discuss the potential links between methylation maintenance mechanisms and diseaseassociated methylation changes.
基金the National Natural Science Foundation of China(No.50378054)the National Basic Research Program(973)of China(No.2002CB412709)
文摘Based on the traditional Nielsen model,a unified failure model on the uniformly reinforced concrete box section members under combined forces was introduced by Luo and Liu.One of their contributions is adjustment of the shear carrying capacity of concrete at the member failure surface.In the unified failure model,the comparison with the experimental results verified this adjustment.Nevertheless,it should be pointed out that the adjustment factor of shear carrying capacity at member failure surface for the reinforced concrete members in the unified failure model is a fixed adjustment constant for all experiment data,which is basically determined by curve fitting.However,the adjustment factor should vary with the normal stress at the member failure surface.In this paper,an advanced theoretical model is introduced,in which the adjustment factor of shear carrying capacity at failure surface is a variable related to the normal stress at failure surface.Furthermore,the advanced unified failure model on the uniformly reinforced concrete box section member can still be expressed in a simple form.Finally,the comparison with several groups of test data has verified that this advanced model is more accurate and feasible to be used in design.