In this paper we review basic and emerging models and associated algorithms
for large-scale tensor networks, especially Tensor Train (TT) decompositions
using novel mathematical and graphical representations. We discus the concept
of tensorization (i.e., creating very high-order tensors from lower-order
original data) and super compression of data achieved via quantized tensor
train (QTT) networks. The purpose of a tensorization and quantization is to
achieve, via low-rank tensor approximations "super" compression, and
meaningful, compact representation of structured data. The main objective of
this paper is to show how tensor networks can be used to solve a wide class of
big data optimization problems (that are far from tractable by classical
numerical methods) by applying tensorization and performing all operations
using relatively small size matrices and tensors and applying iteratively
optimized and approximative tensor contractions.
Keywords: Tensor networks, tensor train (TT) decompositions, matrix product
states (MPS), matrix product operators (MPO), basic tensor operations,
tensorization, distributed representation od data optimization problems for
very large-scale problems: generalized eigenvalue decomposition (GEVD),
PCA/SVD, canonical correlation analysis (CCA).

本文探讨了基本的张量网络模型和相关算法，尤其是使用新的数学和图形表示的张量列车（TT）分解。通过张量化和使用量子化张量列车网络实现数据的超级压缩，对大规模数据优化问题进行了分布式表示，并通过优化迭代和近似张量缩并的方式，应用小型矩阵和张量运算来解决一系列难以用经典数值方法解决的问题，例如广义特征值分解，主成分分析 / 奇异值分解和规范相关分析。