开放意图分类是构建智能对话系统的重要任务之一,其目标是在识别已知意图的同时准确检测未知意图.然而,现有方法在建模复杂语义结构方面存在局限,难以刻画类别内部的多样性分布,容易导致类间混淆.为此,文中提出基于自适应粒球与纯净簇...开放意图分类是构建智能对话系统的重要任务之一,其目标是在识别已知意图的同时准确检测未知意图.然而,现有方法在建模复杂语义结构方面存在局限,难以刻画类别内部的多样性分布,容易导致类间混淆.为此,文中提出基于自适应粒球与纯净簇拆分的开放意图分类方法(Adaptive Granular-Ball and Pure Cluster Splitting for Open Intent Classification,AGPCS-OIC).首先,通过自适应粒球聚类构建反映数据真实分布的多中心子类结构,刻画类内异质性.然后,引入结构稀疏性驱动的纯净簇拆分策略,进一步划分边界松散但纯度较高的粒球,提升决策边界的表达能力和对未知类别的排斥能力.同时,结合粒球感知对比学习机制,以粒球中心为锚点构建结构级语义对,引导模型在特征空间中增强类内聚合性与类间可分性.实验表明,AGPCS-OIC在多个开放意图分类数据集上性能较优.展开更多
Gold nanoclusters exhibit extraordinary catalytic activities,but the dominating factor is still unclear due to the complexity of the structures.In this review,we briefly summarized the recent theoretical progress on t...Gold nanoclusters exhibit extraordinary catalytic activities,but the dominating factor is still unclear due to the complexity of the structures.In this review,we briefly summarized the recent theoretical progress on their structures and catalytic activities.Combining the experimental and theoretical efforts,the structures of small-sized gold clusters have been explored systematically.Based on the determined structures,factors that influence the catalytic capabilities of small-sized gold clusters(Au_(16)-Au_(35))are studied using CO oxidation asa probe.The preadsorption energies of CO and O_2are found strongly correlated with catalytic activities,which could be affected by the clusters'geometries,sizes,and charge distributions.In addition,the presence of water could significantly lower the activation energy barrier of O_2 dissociation to enhance the clusters'catalytic activities.展开更多
文摘开放意图分类是构建智能对话系统的重要任务之一,其目标是在识别已知意图的同时准确检测未知意图.然而,现有方法在建模复杂语义结构方面存在局限,难以刻画类别内部的多样性分布,容易导致类间混淆.为此,文中提出基于自适应粒球与纯净簇拆分的开放意图分类方法(Adaptive Granular-Ball and Pure Cluster Splitting for Open Intent Classification,AGPCS-OIC).首先,通过自适应粒球聚类构建反映数据真实分布的多中心子类结构,刻画类内异质性.然后,引入结构稀疏性驱动的纯净簇拆分策略,进一步划分边界松散但纯度较高的粒球,提升决策边界的表达能力和对未知类别的排斥能力.同时,结合粒球感知对比学习机制,以粒球中心为锚点构建结构级语义对,引导模型在特征空间中增强类内聚合性与类间可分性.实验表明,AGPCS-OIC在多个开放意图分类数据集上性能较优.
基金supported by the Startup Funding from the Shanghai Institute of Applied Physics,Chinese Academyof Sciences(Y290011011)the National Natural Science Foundationof China(21273268)+1 种基金the"Pujiang Rencai Project"from Science and Technology Commission of Shanghai Municipality(13PJ1410400)the"Hundred People Project"from the Chinese Academy of Sciences
文摘Gold nanoclusters exhibit extraordinary catalytic activities,but the dominating factor is still unclear due to the complexity of the structures.In this review,we briefly summarized the recent theoretical progress on their structures and catalytic activities.Combining the experimental and theoretical efforts,the structures of small-sized gold clusters have been explored systematically.Based on the determined structures,factors that influence the catalytic capabilities of small-sized gold clusters(Au_(16)-Au_(35))are studied using CO oxidation asa probe.The preadsorption energies of CO and O_2are found strongly correlated with catalytic activities,which could be affected by the clusters'geometries,sizes,and charge distributions.In addition,the presence of water could significantly lower the activation energy barrier of O_2 dissociation to enhance the clusters'catalytic activities.
