自由图页中的手写文本识别(HTR)是一项艰巨的图像理解任务,可以为手写文档的数字化和重复使用其内容提供相关的增强。由于写作风格的变化和页面质量降解的变化,该任务在处理历史文档时变得更加具有挑战性。最先进的HTR方法通常将序列建模的复发结构与卷积神经网络进行视觉特征提取。由于卷积内核是在固定网格上定义的,并专注于所有输入像素时在输入映像时独立地独立于所有输入像素,因此该策略无视手写字符在形状,比例和规模和方向上,即使在同一文档中,并且墨水像素为比背景更相关。为了应对这些特定的HTR困难,我们建议采用可变形的卷积,这可能会根据手头的输入而变形,并更好地适应文本的几何变化。我们设计了两个可变形的架构,并在现代和历史数据集上进行了广泛的实验。实验结果证实了可变形卷积对HTR任务的适用性。
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手写文本识别(HTR)是计算机视觉和自然语言处理的交集的一个开放问题。当处理历史手稿时,主要挑战是由于保存纸张支撑,手写的可变性 - 甚至在广泛的时间内的同一作者的变异性 - 以及来自古代,代表不良的数据稀缺语言。为了促进有关该主题的研究,在本文中,我们介绍了Ludovico Antonio Muratori(LAM)数据集,这是一家大型线条级的HTR HTR数据集,该数据集是由单个作者编辑的60年来编辑的意大利古代手稿。该数据集有两种配置:基本分裂和基于日期的分裂,该分裂考虑了作者的年龄。第一个设置旨在研究意大利语的古代文档中的HTR,而第二个设置则侧重于HTR系统在无法获得培训数据的时期内识别同一作者编写的文本的能力。对于这两种配置,我们都在其他线路级别的HTR基准方面分析了定量和定性特征,并介绍了最先进的HTR架构的识别性能。该数据集可在\ url {https://aimagelab.ing.unimore.it/go/lam}下载。
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连接视觉和语言在生成智能中起着重要作用。因此,已经致力于图像标题的大型研究工作,即用句法和语义有意义的句子描述图像。从2015年开始,该任务通常通过由Visual Encoder组成的管道和文本生成的语言模型来解决任务。在这些年来,两种组件通过对象区域,属性,介绍多模态连接,完全关注方法和伯特早期融合策略的利用而显着发展。但是,无论令人印象深刻的结果,图像标题的研究还没有达到结论性答案。这项工作旨在提供图像标题方法的全面概述,从视觉编码和文本生成到培训策略,数据集和评估度量。在这方面,我们量化地比较了许多相关的最先进的方法来确定架构和培训策略中最有影响力的技术创新。此外,讨论了问题的许多变体及其开放挑战。这项工作的最终目标是作为理解现有文献的工具,并突出显示计算机视觉和自然语言处理的研究领域的未来方向可以找到最佳的协同作用。
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Computational units in artificial neural networks follow a simplified model of biological neurons. In the biological model, the output signal of a neuron runs down the axon, splits following the many branches at its end, and passes identically to all the downward neurons of the network. Each of the downward neurons will use their copy of this signal as one of many inputs dendrites, integrate them all and fire an output, if above some threshold. In the artificial neural network, this translates to the fact that the nonlinear filtering of the signal is performed in the upward neuron, meaning that in practice the same activation is shared between all the downward neurons that use that signal as their input. Dendrites thus play a passive role. We propose a slightly more complex model for the biological neuron, where dendrites play an active role: the activation in the output of the upward neuron becomes optional, and instead the signals going through each dendrite undergo independent nonlinear filterings, before the linear combination. We implement this new model into a ReLU computational unit and discuss its biological plausibility. We compare this new computational unit with the standard one and describe it from a geometrical point of view. We provide a Keras implementation of this unit into fully connected and convolutional layers and estimate their FLOPs and weights change. We then use these layers in ResNet architectures on CIFAR-10, CIFAR-100, Imagenette, and Imagewoof, obtaining performance improvements over standard ResNets up to 1.73%. Finally, we prove a universal representation theorem for continuous functions on compact sets and show that this new unit has more representational power than its standard counterpart.
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Iterative regularization is a classic idea in regularization theory, that has recently become popular in machine learning. On the one hand, it allows to design efficient algorithms controlling at the same time numerical and statistical accuracy. On the other hand it allows to shed light on the learning curves observed while training neural networks. In this paper, we focus on iterative regularization in the context of classification. After contrasting this setting with that of regression and inverse problems, we develop an iterative regularization approach based on the use of the hinge loss function. More precisely we consider a diagonal approach for a family of algorithms for which we prove convergence as well as rates of convergence. Our approach compares favorably with other alternatives, as confirmed also in numerical simulations.
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Recent advances in language modeling have enabled new conversational systems. In particular, it is often desirable for people to make choices among specified options when using such systems. We address the problem of reference resolution, when people use natural expressions to choose between real world entities. For example, given the choice `Should we make a Simnel cake or a Pandan cake?' a natural response from a non-expert may be indirect: `let's make the green one'. Reference resolution has been little studied with natural expressions, thus robustly understanding such language has large potential for improving naturalness in dialog, recommendation, and search systems. We create AltEntities (Alternative Entities), a new public dataset of entity pairs and utterances, and develop models for the disambiguation problem. Consisting of 42K indirect referring expressions across three domains, it enables for the first time the study of how large language models can be adapted to this task. We find they achieve 82%-87% accuracy in realistic settings, which while reasonable also invites further advances.
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In this work, we apply a kinetic version of a bounded confidence consensus model to biomedical segmentation problems. In the presented approach, time-dependent information on the microscopic state of each particle/pixel includes its space position and a feature representing a static characteristic of the system, i.e. the gray level of each pixel. From the introduced microscopic model we derive a kinetic formulation of the model. The large time behavior of the system is then computed with the aid of a surrogate Fokker-Planck approach that can be obtained in the quasi-invariant scaling. We exploit the computational efficiency of direct simulation Monte Carlo methods for the obtained Boltzmann-type description of the problem for parameter identification tasks. Based on a suitable loss function measuring the distance between the ground truth segmentation mask and the evaluated mask, we minimize the introduced segmentation metric for a relevant set of 2D gray-scale images. Applications to biomedical segmentation concentrate on different imaging research contexts.
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Chain event graphs are a family of probabilistic graphical models that generalise Bayesian networks and have been successfully applied to a wide range of domains. Unlike Bayesian networks, these models can encode context-specific conditional independencies as well as asymmetric developments within the evolution of a process. More recently, new model classes belonging to the chain event graph family have been developed for modelling time-to-event data to study the temporal dynamics of a process. However, existing model selection algorithms for chain event graphs and its variants rely on all parameters having conjugate priors. This is unrealistic for many real-world applications. In this paper, we propose a mixture modelling approach to model selection in chain event graphs that does not rely on conjugacy. Moreover, we also show that this methodology is more amenable to being robustly scaled than the existing model selection algorithms used for this family. We demonstrate our techniques on simulated datasets.
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The detection of state-sponsored trolls acting in information operations is an unsolved and critical challenge for the research community, with repercussions that go beyond the online realm. In this paper, we propose a novel AI-based solution for the detection of state-sponsored troll accounts, which consists of two steps. The first step aims at classifying trajectories of accounts' online activities as belonging to either a state-sponsored troll or to an organic user account. In the second step, we exploit the classified trajectories to compute a metric, namely "troll score", which allows us to quantify the extent to which an account behaves like a state-sponsored troll. As a study case, we consider the troll accounts involved in the Russian interference campaign during the 2016 US Presidential election, identified as Russian trolls by the US Congress. Experimental results show that our approach identifies accounts' trajectories with an AUC close to 99\% and, accordingly, classify Russian trolls and organic users with an AUC of 97\%. Finally, we evaluate whether the proposed solution can be generalized to different contexts (e.g., discussions about Covid-19) and generic misbehaving users, showing promising results that will be further expanded in our future endeavors.
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我们介绍并讨论了一个运行时体系结构,该架构将感官数据和分类器与基于逻辑的决策系统集成在一起,并在电子健康系统的背景下,用于康复神经运动障碍儿童。在此应用程序中,儿童以游戏的形式执行康复任务。该系统的主要目的是从可用的传感器和分类器(例如,眼镜跟踪器,运动传感器,情感识别技术)中得出一组儿童当前的认知和行为表现(例如参与,注意力,任务准确性)的参数。 )并做出相应的决定。这些决策通常旨在通过在注意力较低时触发适当的重新参与刺激,改变游戏或使孩子对任务失去兴趣时的困难来改善孩子的表现,因为它太容易了。除了对情绪识别和头部姿势估计的最新技术外,我们还使用了事件计算的概率和认知逻辑编程方言的运行时变体,称为认识论概率概率事件。特别是,该符号框架的概率组成部分允许与机器学习技术的自然接口。我们概述了体系结构及其组件,并通过讨论运行的示例和实验来展示其一些特征。正在考虑逻辑编程理论和实践(TPLP)的出版物。
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