Machine Translation
Why 85% of AI projects fail
Despite increased interest in and adoption of artificial intelligence (AI) in the enterprise, 85% of AI projects ultimately fail to deliver on their intended promises to business, according to a Thursday report from Pactera Technologies. A major source of AI challenges is found in senior leadership, the report, titled Artificial Intelligence Localization, Winners, Losers, Heroes, Spectators, and You, found. Some 77% of those surveyed said they face barriers to entry from senior management not seeing value or wanting to make the investment in the emerging technology. These findings are in line with those from a recent Dimensional Research report, which found that eight out of 10 organizations engaged with AI and machine learning said those projects had stalled, and 96% said they have run into problems with data quality, data labelling, and building model confidence. Pactera presented the report to a group of tech industry leaders including those from Facebook, Adobe, Amazon, and Microsoft at a recent private event in Seattle.
MLPerf Training Benchmark
Mattson, Peter, Cheng, Christine, Coleman, Cody, Diamos, Greg, Micikevicius, Paulius, Patterson, David, Tang, Hanlin, Wei, Gu-Yeon, Bailis, Peter, Bittorf, Victor, Brooks, David, Chen, Dehao, Dutta, Debojyoti, Gupta, Udit, Hazelwood, Kim, Hock, Andrew, Huang, Xinyuan, Jia, Bill, Kang, Daniel, Kanter, David, Kumar, Naveen, Liao, Jeffery, Narayanan, Deepak, Oguntebi, Tayo, Pekhimenko, Gennady, Pentecost, Lillian, Reddi, Vijay Janapa, Robie, Taylor, John, Tom St., Wu, Carole-Jean, Xu, Lingjie, Young, Cliff, Zaharia, Matei
Machine learning is experiencing an explosion of software and hardware solutions, and needs industry-standard performance benchmarks to drive design and enable competitive evaluation. However, machine learning training presents a number of unique challenges to benchmarking that do not exist in other domains: (1) some optimizations that improve training throughput actually increase time to solution, (2) training is stochastic and time to solution has high variance, and (3) the software and hardware systems are so diverse that they cannot be fairly benchmarked with the same binary, code, or even hyperparameters. We present MLPerf, a machine learning benchmark that overcomes these challenges. We quantitatively evaluate the efficacy of MLPerf in driving community progress on performance and scalability across two rounds of results from multiple vendors.
Auto-Sizing the Transformer Network: Improving Speed, Efficiency, and Performance for Low-Resource Machine Translation
Murray, Kenton, Kinnison, Jeffery, Nguyen, Toan Q., Scheirer, Walter, Chiang, David
Neural sequence-to-sequence models, particularly the Transformer, are the state of the art in machine translation. Y et these neural networks are very sensitive to architecture and hyper-parameter settings. Optimizing these settings by grid or random search is computationally expensive because it requires many training runs. In this paper, we incorporate architecture search into a single training run through auto-sizing, which uses regularization to delete neurons in a network over the course of training. On very low-resource language pairs, we show that auto-sizing can improve BLEU scores by up to 3.9 points while removing one-third of the parameters from the model.
SlowMo: Improving Communication-Efficient Distributed SGD with Slow Momentum
Wang, Jianyu, Tantia, Vinayak, Ballas, Nicolas, Rabbat, Michael
A BSTRACT Distributed optimization is essential for training large models on large datasets. Multiple approaches have been proposed to reduce the communication overhead in distributed training, such as synchronizing only after performing multiple local SGD steps, and decentralized methods ( e.g., using gossip algorithms) to decouple communications among workers. Although these methods run faster than A LLR EDUCEbased methods, which use blocking communication before every update, the resulting models may be less accurate after the same number of updates. Inspired by the BMUF method of Chen & Huo (2016), we propose a slow momentum (S LOWM O) framework, where workers periodically synchronize and perform a momentum update, after multiple iterations of a base optimization algorithm. Experiments on image classification and machine translation tasks demonstrate that S LOWM O consistently yields improvements in optimization and generalization performance relative to the base optimizer, even when the additional overhead is amortized over many updates so that the S LOWM O runtime is on par with that of the base optimizer. We provide theoretical convergence guarantees showing that S LOWM O converges to a stationary point of smooth non-convex losses. Since BMUF is a particular instance of the S LOWM O framework, our results also correspond to the first theoretical convergence guarantees for BMUF. 1 I NTRODUCTION Distributed optimization (Chen et al., 2016; Goyal et al., 2017) is essential for training large models on large datasets (Radford et al., 2019; Liu et al., 2019; Mahajan et al., 2018b). Currently, the most widely-used approaches have workers compute small mini-batch gradients locally, in parallel, and then aggregate these using a blocking communication primitive, A LLR EDUCE, before taking an optimizer step. Communication overhead is a major issue limiting the scaling of this approach, since A LLR EDUCE must complete before every step and blocking communications are sensitive to stragglers (Dutta et al., 2018; Ferdinand et al., 2019). Multiple complementary approaches have recently been investigated to reduce or hide communication overhead. Decentralized training (Jiang et al., 2017; Lian et al., 2017; 2018; Assran et al., 2019) reduces idling due to blocking and stragglers by employing approximate gradient aggregation ( e.g., via gossip or distributed averaging). Approaches such as Local SGD reduce the frequency of communication by having workers perform multiple updates between each round of communication (McDonald et al., 2010; McMahan et al., 2017; Zhou & Cong, 2018; Stich, 2019; Y u et al., 2019b). It is also possible to combine decentralized algorithms with Local SGD (Wang & Joshi, Work performed while doing an internship at Facebook AI Research. 1 arXiv:1910.00643v1
Revisiting Self-Training for Neural Sequence Generation
He, Junxian, Gu, Jiatao, Shen, Jiajun, Ranzato, Marc'Aurelio
Self-training is one of the earliest and simplest semi-supervised methods. The key idea is to augment the original labeled dataset with unlabeled data paired with the model's prediction (i.e. pseudo-parallel data). While self-training has been extensively studied on classification problems, in complex sequence generation tasks (e.g. machine translation) it is still unclear how self-training works due to the compositionality of the target space. In this work, we first empirically show that self-training is able to decently improve the supervised baseline on neural sequence generation tasks. Through careful examination of the performance gains, we find that the perturbation on the hidden states (i.e. dropout) is critical for self-training to benefit from the pseudo-parallel data, which acts as a regularizer and forces the model to yield close predictions for similar unlabeled inputs. Such effect helps the model correct some incorrect predictions on unlabeled data. To further encourage this mechanism, we propose to inject noise to the input space, resulting in a "noisy" version of self-training. Empirical study on standard machine translation and text summarization benchmarks shows that noisy self-training is able to effectively utilize unlabeled data and improve the performance of the supervised baseline by a large margin.
Decomposing Textual Information For Style Transfer
Yamshchikov, Ivan P., Shibaev, Viacheslav, Nagaev, Aleksander, Jost, Jürgen, Tikhonov, Alexey
However, natural language generation with encoder-decoder based methods but depends is still a challenging task due to a number on the used architecture. Moreover, architectures of factors that include the absence of local information with higher quality of information decomposition continuity and non-smooth disentangled perform better in terms of the style transfer task.
Attention Forcing for Sequence-to-sequence Model Training
Dou, Qingyun, Lu, Yiting, Efiong, Joshua, Gales, Mark J. F.
Auto-regressive sequence-to-sequence models with attention mechanism have achieved state-of-the-art performance in many tasks such as machine translation and speech synthesis. These models can be difficult to train. The standard approach, teacher forcing, guides a model with reference output history during training. The problem is that the model is unlikely to recover from its mistakes during inference, where the reference output is replaced by generated output. Several approaches deal with this problem, largely by guiding the model with generated output history. To make training stable, these approaches often require a heuristic schedule or an auxiliary classifier. This paper introduces attention forcing, which guides the model with generated output history and reference attention. This approach can train the model to recover from its mistakes, in a stable fashion, without the need for a schedule or a classifier. In addition, it allows the model to generate output sequences aligned with the references, which can be important for cascaded systems like many speech synthesis systems. Experiments on speech synthesis show that attention forcing yields significant performance gain. Experiments on machine translation show that for tasks where various re-orderings of the output are valid, guiding the model with generated output history is challenging, while guiding the model with reference attention is beneficial.
Reducing Transformer Depth on Demand with Structured Dropout
Fan, Angela, Grave, Edouard, Joulin, Armand
Overparameterized transformer networks have obtained state of the art results in various natural language processing tasks, such as machine translation, language modeling, and question answering. These models contain hundreds of millions of parameters, necessitating a large amount of computation and making them prone to overfitting. In this work, we explore LayerDrop, a form of structured dropout, which has a regularization effect during training and allows for efficient pruning at inference time. In particular, we show that it is possible to select sub-networks of any depth from one large network without having to finetune them and with limited impact on performance. We demonstrate the effectiveness of our approach by improving the state of the art on machine translation, language modeling, summarization, question answering, and language understanding benchmarks. Moreover, we show that our approach leads to small BERT-like models of higher quality compared to training from scratch or using distillation.
Annotated Guidelines and Building Reference Corpus for Myanmar-English Word Alignment
Reference corpus for word alignment is an important resource for developing and evaluating word alignment methods. For Myanmar - English language pairs, there is no reference corpus to evaluate the word alignment tasks. Therefore, we created the guidelines f or Myanmar - English word alignment annotation between two languages over contrastive learning and built the Myanmar - English reference corpus consisting of verified alignments from Myanmar ALT of the Asian Language Treebank (ALT). This reference corpus conta ins confident labels sure (S) and possible (P) for word alignments which are used to test for the purpose of evaluation of the word alignments tasks. We discuss the most linking ambiguities to define consistent and systematic instructions to align manual w ords. We evaluated the results of annotators agreement using our reference corpus in terms of alignment error rate (AER) in word alignment tasks and discuss the words relationships in terms of BLEU scores. A bilingual corpus aligned at the level of sentences or words is a precious resource for developing machine translation systems. Word alignment is a fundamental step in extracting translation information from bilingual corpus and determines which words and phrases are translations of each other in the original and translated sentence. In most translation systems, translational correspondences are rather complex; for a language pair such as Myanmar and Eng lish that belong to the different word order languages.
Scale MLPerf-0.6 models on Google TPU-v3 Pods
Kumar, Sameer, Bitorff, Victor, Chen, Dehao, Chou, Chiachen, Hechtman, Blake, Lee, HyoukJoong, Kumar, Naveen, Mattson, Peter, Wang, Shibo, Wang, Tao, Xu, Yuanzhong, Zhou, Zongwei
The recent submission of Google TPU-v3 Pods to the industry wide MLPerf v0.6 training benchmark demonstrates the scalability of a suite of industry relevant ML models. MLPerf defines a suite of models, datasets and rules to follow when benchmarking to ensure results are comparable across hardware, frameworks and companies. Using this suite of models, we discuss the optimizations and techniques including choice of optimizer, spatial partitioning and weight update sharding necessary to scale to 1024 TPU chips. Furthermore, we identify properties of models that make scaling them challenging, such as limited data parallelism and unscaled weights. These optimizations contribute to record performance in transformer, Resnet-50 and SSD in the Google MLPerf-0.6 submission.