Scene-based recommendation has proven its usefulness in E-commerce,by recommending commodities based on a given scene.However,scenes are typically unknown in advance,which necessitates scene discovery for E-commerce.I...Scene-based recommendation has proven its usefulness in E-commerce,by recommending commodities based on a given scene.However,scenes are typically unknown in advance,which necessitates scene discovery for E-commerce.In this article,we study scene discovery for E-commerce systems.We first formalize a scene as a set of commodity cate-gories that occur simultaneously and frequently in real-world situations,and model an E-commerce platform as a heteroge-neous information network(HIN),whose nodes and links represent different types of objects and different types of rela-tionships between objects,respectively.We then formulate the scene mining problem for E-commerce as an unsupervised learning problem that finds the overlapping clusters of commodity categories in the HIN.To solve the problem,we pro-pose a non-negative matrix factorization based method SMEC(Scene Mining for E-Commerce),and theoretically prove its convergence.Using six real-world E-commerce datasets,we finally conduct an extensive experimental study to evaluate SMEC against 13 other methods,and show that SMEC consistently outperforms its competitors with regard to various evaluation measures.展开更多
Aspirin has been widely used in primary prevention of atherosclerotic cardiovascular disease(ASCVD)J141 Aspirin for primary prevention of ASCVD does not significantly reduce all-cause mortality or cardiovascular morta...Aspirin has been widely used in primary prevention of atherosclerotic cardiovascular disease(ASCVD)J141 Aspirin for primary prevention of ASCVD does not significantly reduce all-cause mortality or cardiovascular mortality,and the main benefit of aspirin for primary prevention of ASCVD is a significant reduction in non-fatal ischemic events including myocardial infarction,transient ischemic attack,ischemic stroke,and major cardiovascular events(cardiovascular death,non-fatal myocardial infarction,and non-fatal stroke),whereas the main risk is a significant increase in non-fatal major bleeding events including gastrointestinal bleeding and intracranial hemorrhage.1 Obviously,it makes sense to prescribe aspirin for primary prevention only if the benefits clearly outweigh the risks.In Europe and the United States,the benefit-risk ratio of aspirin for primary prevention has gradually decreased compared to the past due to the wide application of other primary prevention measures such as blood pressure reduction,smoking cessation,and the use of statins.Three recent large-scale clinical trials have shown that aspirin has no net clinical benefit when used in low-risk populations.19'1^Therefore,aspirin must be used with caution in the primary prevention of ASCVD.展开更多
基金The work was supported by the National Key Research and Development Program of China under Grant No.2018AAA0102301the National Natural Science Foundation of China under Grant No.61925203.
文摘Scene-based recommendation has proven its usefulness in E-commerce,by recommending commodities based on a given scene.However,scenes are typically unknown in advance,which necessitates scene discovery for E-commerce.In this article,we study scene discovery for E-commerce systems.We first formalize a scene as a set of commodity cate-gories that occur simultaneously and frequently in real-world situations,and model an E-commerce platform as a heteroge-neous information network(HIN),whose nodes and links represent different types of objects and different types of rela-tionships between objects,respectively.We then formulate the scene mining problem for E-commerce as an unsupervised learning problem that finds the overlapping clusters of commodity categories in the HIN.To solve the problem,we pro-pose a non-negative matrix factorization based method SMEC(Scene Mining for E-Commerce),and theoretically prove its convergence.Using six real-world E-commerce datasets,we finally conduct an extensive experimental study to evaluate SMEC against 13 other methods,and show that SMEC consistently outperforms its competitors with regard to various evaluation measures.
文摘Aspirin has been widely used in primary prevention of atherosclerotic cardiovascular disease(ASCVD)J141 Aspirin for primary prevention of ASCVD does not significantly reduce all-cause mortality or cardiovascular mortality,and the main benefit of aspirin for primary prevention of ASCVD is a significant reduction in non-fatal ischemic events including myocardial infarction,transient ischemic attack,ischemic stroke,and major cardiovascular events(cardiovascular death,non-fatal myocardial infarction,and non-fatal stroke),whereas the main risk is a significant increase in non-fatal major bleeding events including gastrointestinal bleeding and intracranial hemorrhage.1 Obviously,it makes sense to prescribe aspirin for primary prevention only if the benefits clearly outweigh the risks.In Europe and the United States,the benefit-risk ratio of aspirin for primary prevention has gradually decreased compared to the past due to the wide application of other primary prevention measures such as blood pressure reduction,smoking cessation,and the use of statins.Three recent large-scale clinical trials have shown that aspirin has no net clinical benefit when used in low-risk populations.19'1^Therefore,aspirin must be used with caution in the primary prevention of ASCVD.
