我们在理论和实践之间的差距中介绍了我们的发现,即使用条件能量的模型(EBM)作为行为联系政策的隐式表示。我们还阐明了以前的工作中的几个微妙的,可能令人困惑的细节,以帮助未来的研究。我们指出无条件和有条件的EBM之间的关键差异,并警告说,盲目地将培训方法应用于另一个,可能会导致不良结果,这些结果并不能很好地概括。最后,我们强调了最大相互信息原理作为在条件EBM中获得良好概括作为回归任务模型的必要条件的重要性。
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在各种设备上部署深度学习模型已成为一个重要的话题。硬件专业化的浪潮为多维张量计算带来了一套多样化的加速度原始图。这些新的加速原始基原料以及新兴的机器学习模型带来了巨大的工程挑战。在本文中,我们提出了Tensorir,这是一种编译器抽象,用于通过这些张量计算原始素优化程序。Tensorir概括了现有机器学习编译器中使用的循环巢表示,以将张量计算作为一流的公民。最后,我们在抽象之上构建了一个端到端框架,以自动优化给定的张量计算原始图的深度学习模型。实验结果表明,Tensorir编译会自动使用给定硬件后端的张量计算原始图,并提供与跨平台的最新手工精制系统竞争性能的性能。
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数据不足问题(即数据缺失和标签稀缺问题)是由服务和基础架构不足或城市不平衡的发展水平引起的,在实际情况下严重影响了城市计算任务。先前的转移学习方法激发了对数据不足的优雅解决方案,但仅关注一种不足问题,并且未能考虑双方。此外,大多数以前的跨城市转移方法忽略了城市间数据隐私,这在实际应用中是公众关注的。为了解决上述具有挑战性的问题,我们提出了一个新颖的跨城市联合转移学习框架(CCFTL),以应对数据不足和隐私问题。具体而言,CCFTL将关系知识从多个Rich-Data源城市转移到目标城市。此外,针对目标任务的模型参数首先在源数据上进行训练,然后通过参数传输对目标城市进行微调。通过适应联合培训和同型加密设置,CCFTL可以有效地解决城市之间的数据隐私问题。我们将城市地区的分析作为智能城市的应用,并通过一项现实世界的研究评估拟议的方法。这些实验证明了我们框架比几种竞争性最新模型的显着优势。
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在本文中,我们研究了一些现有的和新的最先进的生成的对抗网络(GAN)语音转换方法,用于增强暂存语音,以改善发育性语音识别。我们将现有方法的关键组成部分进行比较,作为严格的消融研究的一部分,以找到提高发狂语音识别的最有效的解决方案。我们发现,直接的信号处理方法,例如静止噪声消除和基于声码的时间拉伸导致达到疑声语音识别结果,其与使用最先进的GaN的语音转换方法使用的那些使用音素识别任务测量而获得的结果相当。此外,我们提出的蒙面克萨根-VC和时间拉伸增强的组合解决方案能够改善与我们的时间拉伸基线相比的某些发育扬声器的音素识别结果。
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学习模当融合的表示和处理未对准的多模式序列在多式联情绪识别中是有意义的,具有挑战性。现有方法使用定向成对注意力或消息中心到熔丝语言,视觉和音频模态。然而,这些方法在融合特征时介绍信息冗余,并且在不考虑方式的互补性的情况下效率低效。在本文中,我们提出了一种高效的神经网络,以学习与CB变压器(LMR-CBT)的模型融合表示,用于从未对准的多模式序列进行多峰情绪识别。具体地,我们首先为三种方式执行特征提取,以获得序列的局部结构。然后,我们设计具有跨模块块(CB变压器)的新型变压器,其能够实现不同模式的互补学习,主要分为局部时间学习,跨模型特征融合和全球自我关注表示。此外,我们将融合功能与原始特征拼接以对序列的情绪进行分类。最后,我们在三个具有挑战性的数据集,IEMocap,CMU-MOSI和CMU-MOSEI进行词语对齐和未对准的实验。实验结果表明我们在两个设置中提出的方法的优势和效率。与主流方法相比,我们的方法以最小数量的参数达到最先进的。
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Increasing research interests focus on sequential recommender systems, aiming to model dynamic sequence representation precisely. However, the most commonly used loss function in state-of-the-art sequential recommendation models has essential limitations. To name a few, Bayesian Personalized Ranking (BPR) loss suffers the vanishing gradient problem from numerous negative sampling and predictionbiases; Binary Cross-Entropy (BCE) loss subjects to negative sampling numbers, thereby it is likely to ignore valuable negative examples and reduce the training efficiency; Cross-Entropy (CE) loss only focuses on the last timestamp of the training sequence, which causes low utilization of sequence information and results in inferior user sequence representation. To avoid these limitations, in this paper, we propose to calculate Cumulative Cross-Entropy (CCE) loss over the sequence. CCE is simple and direct, which enjoys the virtues of painless deployment, no negative sampling, and effective and efficient training. We conduct extensive experiments on five benchmark datasets to demonstrate the effectiveness and efficiency of CCE. The results show that employing CCE loss on three state-of-the-art models GRU4Rec, SASRec, and S3-Rec can reach 125.63%, 69.90%, and 33.24% average improvement of full ranking NDCG@5, respectively. Using CCE, the performance curve of the models on the test data increases rapidly with the wall clock time, and is superior to that of other loss functions in almost the whole process of model training.
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Due to their ability to offer more comprehensive information than data from a single view, multi-view (multi-source, multi-modal, multi-perspective, etc.) data are being used more frequently in remote sensing tasks. However, as the number of views grows, the issue of data quality becomes more apparent, limiting the potential benefits of multi-view data. Although recent deep neural network (DNN) based models can learn the weight of data adaptively, a lack of research on explicitly quantifying the data quality of each view when fusing them renders these models inexplicable, performing unsatisfactorily and inflexible in downstream remote sensing tasks. To fill this gap, in this paper, evidential deep learning is introduced to the task of aerial-ground dual-view remote sensing scene classification to model the credibility of each view. Specifically, the theory of evidence is used to calculate an uncertainty value which describes the decision-making risk of each view. Based on this uncertainty, a novel decision-level fusion strategy is proposed to ensure that the view with lower risk obtains more weight, making the classification more credible. On two well-known, publicly available datasets of aerial-ground dual-view remote sensing images, the proposed approach achieves state-of-the-art results, demonstrating its effectiveness. The code and datasets of this article are available at the following address: https://github.com/gaopiaoliang/Evidential.
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In the scenario of black-box adversarial attack, the target model's parameters are unknown, and the attacker aims to find a successful adversarial perturbation based on query feedback under a query budget. Due to the limited feedback information, existing query-based black-box attack methods often require many queries for attacking each benign example. To reduce query cost, we propose to utilize the feedback information across historical attacks, dubbed example-level adversarial transferability. Specifically, by treating the attack on each benign example as one task, we develop a meta-learning framework by training a meta-generator to produce perturbations conditioned on benign examples. When attacking a new benign example, the meta generator can be quickly fine-tuned based on the feedback information of the new task as well as a few historical attacks to produce effective perturbations. Moreover, since the meta-train procedure consumes many queries to learn a generalizable generator, we utilize model-level adversarial transferability to train the meta-generator on a white-box surrogate model, then transfer it to help the attack against the target model. The proposed framework with the two types of adversarial transferability can be naturally combined with any off-the-shelf query-based attack methods to boost their performance, which is verified by extensive experiments.
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Supervised Deep-Learning (DL)-based reconstruction algorithms have shown state-of-the-art results for highly-undersampled dynamic Magnetic Resonance Imaging (MRI) reconstruction. However, the requirement of excessive high-quality ground-truth data hinders their applications due to the generalization problem. Recently, Implicit Neural Representation (INR) has appeared as a powerful DL-based tool for solving the inverse problem by characterizing the attributes of a signal as a continuous function of corresponding coordinates in an unsupervised manner. In this work, we proposed an INR-based method to improve dynamic MRI reconstruction from highly undersampled k-space data, which only takes spatiotemporal coordinates as inputs. Specifically, the proposed INR represents the dynamic MRI images as an implicit function and encodes them into neural networks. The weights of the network are learned from sparsely-acquired (k, t)-space data itself only, without external training datasets or prior images. Benefiting from the strong implicit continuity regularization of INR together with explicit regularization for low-rankness and sparsity, our proposed method outperforms the compared scan-specific methods at various acceleration factors. E.g., experiments on retrospective cardiac cine datasets show an improvement of 5.5 ~ 7.1 dB in PSNR for extremely high accelerations (up to 41.6-fold). The high-quality and inner continuity of the images provided by INR has great potential to further improve the spatiotemporal resolution of dynamic MRI, without the need of any training data.
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Recent studies have shown that using an external Language Model (LM) benefits the end-to-end Automatic Speech Recognition (ASR). However, predicting tokens that appear less frequently in the training set is still quite challenging. The long-tail prediction problems have been widely studied in many applications, but only been addressed by a few studies for ASR and LMs. In this paper, we propose a new memory augmented lookup dictionary based Transformer architecture for LM. The newly introduced lookup dictionary incorporates rich contextual information in training set, which is vital to correctly predict long-tail tokens. With intensive experiments on Chinese and English data sets, our proposed method is proved to outperform the baseline Transformer LM by a great margin on both word/character error rate and tail tokens error rate. This is achieved without impact on the decoding efficiency. Overall, we demonstrate the effectiveness of our proposed method in boosting the ASR decoding performance, especially for long-tail tokens.
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