Recent years have witnessed the rapid progress of image captioning. However, the demands for large memory storage and heavy computational burden prevent these captioning models from being deployed on mobile devices. The main obstacles lie in the heavyweight visual feature extractors (i.e., object detectors) and complicated cross-modal fusion networks. To this end, we propose LightCap, a lightweight image captioner for resource-limited devices. The core design is built on the recent CLIP model for efficient image captioning. To be specific, on the one hand, we leverage the CLIP model to extract the compact grid features without relying on the time-consuming object detectors. On the other hand, we transfer the image-text retrieval design of CLIP to image captioning scenarios by devising a novel visual concept extractor and a cross-modal modulator. We further optimize the cross-modal fusion model and parallel prediction heads via sequential and ensemble distillations. With the carefully designed architecture, our model merely contains 40M parameters, saving the model size by more than 75% and the FLOPs by more than 98% in comparison with the current state-of-the-art methods. In spite of the low capacity, our model still exhibits state-of-the-art performance on prevalent datasets, e.g., 136.6 CIDEr on COCO Karpathy test split. Testing on the smartphone with only a single CPU, the proposed LightCap exhibits a fast inference speed of 188ms per image, which is ready for practical applications.
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强化学习(RL)通过与环境相互作用的试验过程解决顺序决策问题。尽管RL在玩复杂的视频游戏方面取得了巨大的成功,但在现实世界中,犯错误总是不希望的。为了提高样本效率并从而降低错误,据信基于模型的增强学习(MBRL)是一个有前途的方向,它建立了环境模型,在该模型中可以进行反复试验,而无需实际成本。在这项调查中,我们对MBRL进行了审查,重点是Deep RL的最新进展。对于非壮观环境,学到的环境模型与真实环境之间始终存在概括性错误。因此,非常重要的是分析环境模型中的政策培训与实际环境中的差异,这反过来又指导了更好的模型学习,模型使用和政策培训的算法设计。此外,我们还讨论了其他形式的RL,包括离线RL,目标条件RL,多代理RL和Meta-RL的最新进展。此外,我们讨论了MBRL在现实世界任务中的适用性和优势。最后,我们通过讨论MBRL未来发展的前景来结束这项调查。我们认为,MBRL在被忽略的现实应用程序中具有巨大的潜力和优势,我们希望这项调查能够吸引更多关于MBRL的研究。
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大规模预训练的语言模型的出现为自然语言处理的最新进展做出了巨大贡献。许多最先进的语言模型首先在大型文本语料库上进行培训,然后在下游任务上进行微调。尽管它最近获得了成功和广泛的采用,但对预训练的语言模型的微调通常会遭受过度拟合,这会导致由于模型的复杂性极高的复杂性和下游任务的有限培训样本而导致的普遍性差。为了解决这个问题,我们提出了一个新颖有效的微调框架,称为Layerwise噪声稳定性正则化(LNSR)。具体而言,我们建议注入标准的高斯噪声或势内噪声,并将微调模型的隐藏表示形式定向。我们首先提供理论分析以支持我们方法的功效。然后,我们证明了所提出的方法的优势,而不是其他最先进的算法,包括L2-SP,MixOut和Smart。尽管这些先前的作品仅验证其方法对相对简单的文本分类任务的有效性,但我们还验证了方法对问题答案任务的有效性,而目标问题更加困难,并且可以使用更多的培训示例。此外,广泛的实验结果表明,所提出的算法不仅可以提高语言模型的内域性能,而且还可以改善域外数据的域概括性能。
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室内场景云的无监督对比学习取得了巨大的成功。但是,室外场景中无监督的学习点云仍然充满挑战,因为以前的方法需要重建整个场景并捕获对比度目标的部分视图。这在带有移动物体,障碍物和传感器的室外场景中是不可行的。在本文中,我们提出了CO^3,即合作对比度学习和上下文形状的预测,以无监督的方式学习3D表示室外景点云。与现有方法相比,Co^3具有几种优点。 (1)它利用了从车辆侧和基础架构侧来的激光点云来构建差异,但同时维护对比度学习的通用语义信息,这比以前的方法构建的视图更合适。 (2)在对比度目标的同时,提出了形状上下文预测作为预训练目标,并为无监督的3D点云表示学习带来了更多与任务相关的信息,这在将学习的表示形式转移到下游检测任务时是有益的。 (3)与以前的方法相比,CO^3学到的表示形式可以通过不同类型的LIDAR传感器收集到不同的室外场景数据集。 (4)CO^3将一次和Kitti数据集的当前最新方法提高到2.58地图。代码和模型将发布。我们认为Co^3将有助于了解室外场景中的LiDar Point云。
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优化问题的全局最小点对工程领域感兴趣,难以解决,特别是对于非凸大的大规模优化问题。在本文中,我们考虑了一种新的迭代算法。也就是说,我们使用所确定的点(函数的静止点)作为进化算法的初始种子,除了已知的进化算法的随机初始种子之外。首先,我们修改了延续的牛顿方法与放气技术,以便尽可能多地找到来自几个确定的初始点的静止点。然后,我们使用那些找到的静止点作为准遗传算法的初始进化种子。在它进化为几代之后,我们获得了优化问题的次优点。最后,我们使用这个次优点点作为初始点来获得静止点的延续牛顿方法,并在这一最终静止点与发现的次遗传算法之间的最小值输出最小值。最后,我们将其与之比较多启动方法(Matlab R2020A环境的内置子程序Gloadlearch.m),差分演进算法(DE方法,MATLAB中央文件Exchange 2021的子程序DE.M)和分支和绑定方法(用于混合整数非线性编程问题的最先进的开源求解器的COONNE)。数值结果表明,该方法对于大规模的全局优化问题表现良好,特别是通过已知的全局优化方法难以解决的问题。
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We present DetCo, a simple yet effective self-supervised approach for object detection. Unsupervised pre-training methods have been recently designed for object detection, but they are usually deficient in image classification, or the opposite. Unlike them, DetCo transfers well on downstream instance-level dense prediction tasks, while maintaining competitive image-level classification accuracy. The advantages are derived from (1) multi-level supervision to intermediate representations, (2) contrastive learning between global image and local patches. These two designs facilitate discriminative and consistent global and local representation at each level of feature pyramid, improving detection and classification, simultaneously.Extensive experiments on VOC, COCO, Cityscapes, and ImageNet demonstrate that DetCo not only outperforms recent methods on a series of 2D and 3D instance-level detection tasks, but also competitive on image classification. For example, on ImageNet classification, DetCo is 6.9% and 5.0% top-1 accuracy better than InsLoc and DenseCL, which are two contemporary works designed for object detection. Moreover, on COCO detection, DetCo is 6.9 AP better than SwAV with Mask R-CNN C4. Notably, DetCo largely boosts up Sparse R-CNN, a recent strong detector, from 45.0 AP to 46.5 AP (+1.5 AP), establishing a new SOTA on COCO. Code is available.
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Weakly-supervised object localization aims to indicate the category as well as the scope of an object in an image given only the image-level labels. Most of the existing works are based on Class Activation Mapping (CAM) and endeavor to enlarge the discriminative area inside the activation map to perceive the whole object, yet ignore the co-occurrence confounder of the object and context (e.g., fish and water), which makes the model inspection hard to distinguish object boundaries. Besides, the use of CAM also brings a dilemma problem that the classification and localization always suffer from a performance gap and can not reach their highest accuracy simultaneously. In this paper, we propose a casual knowledge distillation method, dubbed KD-CI-CAM, to address these two under-explored issues in one go. More specifically, we tackle the co-occurrence context confounder problem via causal intervention (CI), which explores the causalities among image features, contexts, and categories to eliminate the biased object-context entanglement in the class activation maps. Based on the de-biased object feature, we additionally propose a multi-teacher causal distillation framework to balance the absorption of classification knowledge and localization knowledge during model training. Extensive experiments on several benchmarks demonstrate the effectiveness of KD-CI-CAM in learning clear object boundaries from confounding contexts and addressing the dilemma problem between classification and localization performance.
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In this paper, a semantic communication framework for image transmission is developed. In the investigated framework, a set of servers cooperatively transmit images to a set of users utilizing semantic communication techniques. To evaluate the performance of studied semantic communication system, a multimodal metric is proposed to measure the correlation between the extracted semantic information and the original image. To meet the ISS requirement of each user, each server must jointly determine the semantic information to be transmitted and the resource blocks (RBs) used for semantic information transmission. We formulate this problem as an optimization problem aiming to minimize each server's transmission latency while reaching the ISS requirement. To solve this problem, a value decomposition based entropy-maximized multi-agent reinforcement learning (RL) is proposed, which enables servers to coordinate for training and execute RB allocation in a distributed manner to approach to a globally optimal performance with less training iterations. Compared to traditional multi-agent RL, the proposed RL improves the valuable action exploration of servers and the probability of finding a globally optimal RB allocation policy based on local observation. Simulation results show that the proposed algorithm can reduce the transmission delay by up to 16.1% compared to traditional multi-agent RL.
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Machine Reading Comprehension has become one of the most advanced and popular research topics in the fields of Natural Language Processing in recent years. The classification of answerability questions is a relatively significant sub-task in machine reading comprehension; however, there haven't been many studies. Retro-Reader is one of the studies that has solved this problem effectively. However, the encoders of most traditional machine reading comprehension models in general and Retro-Reader, in particular, have not been able to exploit the contextual semantic information of the context completely. Inspired by SemBERT, we use semantic role labels from the SRL task to add semantics to pre-trained language models such as mBERT, XLM-R, PhoBERT. This experiment was conducted to compare the influence of semantics on the classification of answerability for the Vietnamese machine reading comprehension. Additionally, we hope this experiment will enhance the encoder for the Retro-Reader model's Sketchy Reading Module. The improved Retro-Reader model's encoder with semantics was first applied to the Vietnamese Machine Reading Comprehension task and obtained positive results.
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New architecture GPUs like A100 are now equipped with multi-instance GPU (MIG) technology, which allows the GPU to be partitioned into multiple small, isolated instances. This technology provides more flexibility for users to support both deep learning training and inference workloads, but efficiently utilizing it can still be challenging. The vision of this paper is to provide a more comprehensive and practical benchmark study for MIG in order to eliminate the need for tedious manual benchmarking and tuning efforts. To achieve this vision, the paper presents MIGPerf, an open-source tool that streamlines the benchmark study for MIG. Using MIGPerf, the authors conduct a series of experiments, including deep learning training and inference characterization on MIG, GPU sharing characterization, and framework compatibility with MIG. The results of these experiments provide new insights and guidance for users to effectively employ MIG, and lay the foundation for further research on the orchestration of hybrid training and inference workloads on MIGs. The code and results are released on https://github.com/MLSysOps/MIGProfiler. This work is still in progress and more results will be published soon.
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