We propose a novel inference technique based on a pretrained diffusion model
for text-conditional video generation. Our approach, called FIFO-Diffusion, is
conceptually capable of generating infinitely long videos without training.
This is achieved by iteratively performing diagonal denoising, which
concurrently processes a series of consecutive frames with increasing noise
levels in a queue; our method dequeues a fully denoised frame at the head while
enqueuing a new random noise frame at the tail. However, diagonal denoising is
a double-edged sword as the frames near the tail can take advantage of cleaner
ones by forward reference but such a strategy induces the discrepancy between
training and inference. Hence, we introduce latent partitioning to reduce the
training-inference gap and lookahead denoising to leverage the benefit of
forward referencing. We have demonstrated the promising results and
effectiveness of the proposed methods on existing text-to-video generation
baselines.

我们提出了一种基于预训练扩散模型的新推理技术，用于文本条件视频生成。我们的方法名为 FIFO-Diffusion，能够概念性地生成无需训练的无限长视频。通过迭代地进行对角去噪处理，我们同时处理一个队列中噪声逐渐增加的一系列连续帧；我们的方法在队列头部出队完全去噪的帧，并在队列尾部入队一个新的随机噪声帧。但是，对角去噪处理是一把双刃剑，因为靠近尾部的帧可以通过向前引用来利用更干净的帧，但这种策略会引起训练和推理之间的差异。因此，我们引入了潜在分区来减小训练和推理之间的差距，并引入了前瞻去噪来利用向前引用的好处。我们已经在现有的文本到视频生成基准上展示了该方法的有希望的结果和有效性。

FIFO-Diffusion: 从文本生成无需训练的无限视频

FIFO-Diffusion: Generating Infinite Videos from Text without Training

There have been several recent attempts to improve the accuracy of grammar
induction systems by bounding the recursive complexity of the induction model
(Ponvert et al., 2011; Noji and Johnson, 2016; Shain et al., 2016; Jin et al.,
2018). Modern depth-bounded grammar inducers have been shown to be more
accurate than early unbounded PCFG inducers, but this technique has never been
compared against unbounded induction within the same system, in part because
most previous depth-bounding models are built around sequence models, the
complexity of which grows exponentially with the maximum allowed depth. The
present work instead applies depth bounds within a chart-based Bayesian PCFG
inducer (Johnson et al., 2007b), where bounding can be switched on and off, and
then samples trees with and without bounding. Results show that depth-bounding
is indeed significantly effective in limiting the search space of the inducer
and thereby increasing the accuracy of the resulting parsing model. Moreover,
parsing results on English, Chinese and German show that this bounded model
with a new inference technique is able to produce parse trees more accurately
than or competitively with state-of-the-art constituency-based grammar
induction models.

本研究利用深度限制的贝叶斯 PCFG 自动词法分析器，通过截取词句间的递归结构复杂度，有效增强了模型准确性，在英语、中文和德语文本的句法分析实验中表现出与最先进的构成基础语法诱导模型同等甚至更高的准确性。

深度限制是有效的：无监督 PCFG 归纳的改进和评估

Depth-bounding is effective: Improvements and evaluation of unsupervised  PCFG induction

We are interested in learning customers' video preferences from their
historic viewing patterns and geographical location. We consider a Bayesian
latent factor modeling approach for this task. In order to tune the complexity
of the model to best represent the data, we make use of Bayesian nonparameteric
techniques. We describe an inference technique that can scale to large
real-world data sets. Finally we show results obtained by applying the model to
a large internal Netflix data set, that illustrates that the model was able to
capture interesting relationships between viewing patterns and geographical
location.

使用 Bayesian 潜在因子建模方法和 Bayesian 非参数技术来学习 Netflix 用户的视频偏好，并使用可扩展的推理技术应用于大型数据集，最终结果表明该模型能够捕捉到观看模式和地理位置之间的有趣关系。