基于transformer架构,提出一种面向学习轨迹的知识追踪预测模型(knowledge tracing prediction model for learning trajectories,LTKT),解决知识追踪领域使用transformer架构所存在的问题:网络中缺乏知识点信息、注意力被分散到众多关...基于transformer架构,提出一种面向学习轨迹的知识追踪预测模型(knowledge tracing prediction model for learning trajectories,LTKT),解决知识追踪领域使用transformer架构所存在的问题:网络中缺乏知识点信息、注意力被分散到众多关联较小的试题及忽略了学习能力在答题决策中的影响。LTKT在数据预处理阶段,采用教育领域的知识融通机制整合题目涉及的多个知识点,作为模型学习的一个信息维度。在编码器与解码器结构中,根据注意力呈现长尾分布的特点引入稀疏自注意力机制,并在其中嵌入包含绝对距离和相对距离的位置编码,使注意力集中在少数高度相似的试题上,同时加强模型对位置信息的感知。在预测策略上,使用双线性层融合学习能力特征与学生的知识状态,综合预测学生下一时刻的作答表现。在两个真实的大型公开数据集上进行实验,与其他优秀模型进行对比,结果显示LTKT的AUC有了明显提升。展开更多
The drumstick tree(Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we repo...The drumstick tree(Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.展开更多
In this article,we study certain quadratic Diophantine equations in Picard lattices of blow-ups of the complex projective plane,and describe their relations with root systems and Weyl group orbits of quasiminuscule fu...In this article,we study certain quadratic Diophantine equations in Picard lattices of blow-ups of the complex projective plane,and describe their relations with root systems and Weyl group orbits of quasiminuscule fundamental weights.We apply these to study the geometry of certain rational surfaces.展开更多
文摘基于transformer架构,提出一种面向学习轨迹的知识追踪预测模型(knowledge tracing prediction model for learning trajectories,LTKT),解决知识追踪领域使用transformer架构所存在的问题:网络中缺乏知识点信息、注意力被分散到众多关联较小的试题及忽略了学习能力在答题决策中的影响。LTKT在数据预处理阶段,采用教育领域的知识融通机制整合题目涉及的多个知识点,作为模型学习的一个信息维度。在编码器与解码器结构中,根据注意力呈现长尾分布的特点引入稀疏自注意力机制,并在其中嵌入包含绝对距离和相对距离的位置编码,使注意力集中在少数高度相似的试题上,同时加强模型对位置信息的感知。在预测策略上,使用双线性层融合学习能力特征与学生的知识状态,综合预测学生下一时刻的作答表现。在两个真实的大型公开数据集上进行实验,与其他优秀模型进行对比,结果显示LTKT的AUC有了明显提升。
文摘The drumstick tree(Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.
基金supported by National Natural Science Foundation of China (Grant No.11126264)Doctoral Fund of Ministry of Education of China (Grant No. 20110181120091)
文摘In this article,we study certain quadratic Diophantine equations in Picard lattices of blow-ups of the complex projective plane,and describe their relations with root systems and Weyl group orbits of quasiminuscule fundamental weights.We apply these to study the geometry of certain rational surfaces.
