中文口译
救护车
(1)[救护车]:医院或医疗单位专用于运送伤病员的车辆。
(2)[急救卡车]:一种装有特殊设备的汽车,用于营救飞机失事的幸存者。
救护车是英文,具体定义如下:
发音:英语[MBJLNS],美国[MBJLNS]
表情:救护车;战时流动医院
词性:通常在句子中用作名词。
固定:救护官救护官
救护人员正在照料到达的伤员。
救护车里的救护人员正在照顾伤者。一站式出国留学攻略 http://wwwoffercomingcom
SpaGCN首先构建一个图来表示 考虑空间位置和组织学信息的所有点的关系 。 接下来,SpaGCN 利用 图卷积层来聚合来自相邻点的基因表达信息 。 然后,SpaGCN 使用 聚合表达式矩阵使用无监督迭代聚类算法对点进行聚类 。 每个clusters被视为一个空间域,SpaGCN 然后从中检测通过 DE 分析在域中丰富的 SVG。 当单个基因不能标记一个域的表达模式时, SpaGCN 会构建一个meta基因,由多个基因组合形成,来代表该域的表达模式 。
The current version of SpaGCN requres three input data:
The gene expreesion data can be stored as an AnnData object AnnData stores a data matrix X together with annotations of observations obs, variables var and unstructured annotations uns
Set hyper-parameters
Run SpaGCN
Plot spatial domains
生活很好,有你更好
Single Cell Gene Co-Expression Network Reveals FECH / CROT Signature as a Prognostic Marker
AR(Androgen receptor,雄激素受体)活性的增加驱动晚期前列腺癌的治疗耐药,深入剖析AR调控网络的机制至关重要。GCN(co-expression network)有助于成功识别AR变量驱动的基因模块,但是由于GCN的高度稀疏性和维数高,为所有被检测基因构建的GCN太大而无法解释。而加权相关网络分析(WGCNA)利用层次聚类方法识别基因簇,并能提取潜在表型的有意义的生物信息。近期研究表明LNCaP细胞对雄激素剥夺治疗反应不一。现已发现雄激素剥夺治疗的耐药亚群,其特征是细胞周期活动增强。因此,本研究旨在从单细胞的角度找出AR调控的关键生物学过程及其雄激素调控基因。
==androgen(R1881)== ,也被称为甲基三烯醇,是一种合成的雄激素。它是AR激动剂。
biomodal:双峰性表达,描述如下图
BI value:BI index,用来代表 biomodal expression的extent,The bimodality index (BI) is used to distribution of marker genes (AR, KLK3, and TMPRSS2) in single cells; Genes with BI > 12 are regarded as bimodally expressed genes
数据:We downloaded the processed expression (RPKM) profiles of LNCaP cells generated by single cell RNA-seq from GEO (accession ID: GSE99795) The dataset contains 144 LNCaP cells from 0 h untreated, 12 h untreated and 12 h R1881 treated conditions There are 48 cells under each condition
Bimodality expression was performed using the ==R package, SIBER== First, a normal mixture model (‘NL’) was specified on the log2 transformed RPKM expression values to fit the gene expression distribution into a two component mixture model ( component 1 and 2) Next the average values ( mu1 and mu2 ) were calculated Other parameters were also obtained including variance values ( sigma1, sigma2 ) and corresponding proportion of the component 1 and 2 ( pi1 and pi2 )
==应用的包是RobustRankaAggreg==
GraphSage是在论文Inductive Representation Learning on Large Graphs
William中提出的一种归纳式的embedding表示训练方法。
在上一篇所讲的GCN是transductive learning(直推式学习),即通过一个固定的图,直接训练每个节点的embedding。但是在很多图场景下,图节点是实时更新的,所以本文提出了inductive learning(归纳式学习)。不是在一个静态图上训练每个节点的embedding,而是通过训练得到一个由neighbood到embedding的映射关系(aggregator),使得结果可以仅通过邻居关系得到新加入的节点的embedding。
针对无监督学习,训练loss用的是pair-wise,认为有联系的2个节点间embedding应该是接近的,而没有联系的2个节点间embedding应该是远离的。(用内积表达的是余弦距离)
在训练数据集中有每个节点的feature information,然后用feature information来训练得到用户的节点,那如果没有feature information怎么办呢?用index来表示吗?
这篇论文做融合的总体框架还是GraphSage:从neighbor中抽取一定数量进行融合。但是与Graph有所区别在于不是随机抽取而是importance pooling 以下说一下这篇论文的主要创新点:
这篇论文的总体框架其实很经典:
这篇文章是对上述NGCF所做的一个改进。文章发现NGCF中的feature transformation(W1, W2)和nonlinear activation( )操作不但使训练更困难,并且降低了准确度。这个的主要原因在于:GCN is originally proposed for node classification on attributed graph, where each node has rich attributes as input features; whereas in user-item interaction graph for CF, each node (user or item) is only described by a one-hot ID, which has no concrete semantics besides being an identifier In such a case, given the ID embedding as the input, performing multiple layers of nonlinear feature transformation —which is the key to the success of modern neural networks — will bring no benefits, but negatively increases the difficulty for model training
优化后的LightGCN的forward propagation layer:
注:在forward propagation中并没有加入self connection是因为layer embedding 的weighted sum操作其实包含了self connection。具体证明过程如下:
So inserting self-connection into A and propagating embeddings on it is essentially equivalent to a weighted sum of the embeddings propagated at each LGC layer
这篇论文旨在解决2个问题:
So MGNN-SPred jointly considers target behavior and auxiliary behavior sequences and explores global item-to-item relations for accurate prediction
本文算法框架:
构图算法:
Item Representation Learning:
for each node , one-hot representation ;
Sequence Representation Learning:
It was found that simple mean-pooling could already achieve comparable performance compared with attention mechanism while retaining low complexity
It is self-evident that the contributions of auxiliary behavior sequence for the next item prediction are different in different situationsSo a gated mechanism is designed to calculate the relative importance weight :
where denotes the one-hot representation of the ground truth
这篇论文是解决sequential recommendation主要贡献点在于:
首先在一个序列中用sliding window strategy取出子序列 ,然后对每个子序列如下图所示对item添加边
用external memory units去存储随时间变化的用户长期兴趣。用户随时间接触的序列为:
则首先用multi-dimensional attention model生成query embedding:
其中 是sinusoidal positional encoding function that maps the item positions into position embeddings
然后对memory unit作操作:
The superscript C denotes the fusion of long- and short-term interests
表示短期内接触的item与所要求的item的关系远近
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