Text clustering and topic extraction are two important tasks in text mining. Usually, these two tasks are performed separately. For topic extraction to facilitate clustering, we can first project texts into a topic space and then perform a clustering algorithm to obtain clusters. To promote topic extraction by clustering, we can first obtain clusters with a clustering algorithm and then extract cluster-specific topics. However, this naive strategy ignores the fact that text clustering and topic extraction are strongly correlated and follow a chicken-and-egg relationship. Performing them separately fails to make them mutually benefit each other to achieve the best overall performance. In this paper, we propose an unsupervised text clustering and topic extraction framework (ClusTop) which integrates text clustering and topic extraction into a unified framework and can achieve high-quality clustering result and extract topics from each cluster simultaneously. Our framework includes four components: enhanced language model training, dimensionality reduction, clustering and topic extraction, where the enhanced language model can be viewed as a bridge between clustering and topic extraction. On one hand, it provides text embeddings with a strong cluster structure which facilitates effective text clustering; on the other hand, it pays high attention on the topic related words for topic extraction because of its self-attention architecture. Moreover, the training of enhanced language model is unsupervised. Experiments on two datasets demonstrate the effectiveness of our framework and provide benchmarks for different model combinations in this framework.
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了解出版物思想的起源和影响对于进行科学研究至关重要。但是,科学出版物的扩散使研究人员难以弄清所有相关文献的演变。为此,我们介绍了Ideareader,这是一种机器阅读系统,发现哪些论文最有可能激发或受到目标出版物的影响,并以自然语言总结了这些论文的想法。具体而言,Ideareader首先将目标出版物的参考和引用(一阶或高阶)和所获得的集群视为激发或受到目标出版物影响的主题。然后,它从每个集群中挑选出重要的论文来提取想法流的骨骼。最后,Ideareader会自动生成对每个主题中重要论文的文献综述。我们的系统可以帮助研究人员深入了解科学思想如何通过自动生成的调查和想法流的可视化来从目标出版物的引用引用。
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多变量时间序列(MTS)预测在智能应用的自动化和优化中起着重要作用。这是一个具有挑战性的任务,因为我们需要考虑复杂的变量依赖关系和可变间依赖关系。现有的作品仅在单个可变依赖项的帮助下学习时间模式。然而,许多真实世界MTS中有多种时间模式。单个可变间依赖项使模型更倾向于学习一种类型的突出和共享的时间模式。在本文中,我们提出了一个多尺度自适应图形神经网络(MOLDN)来解决上述问题。 MOLDN利用多尺度金字塔网络,以在不同的时间尺度上保留潜在的时间依赖关系。由于可变间依赖关系可以在不同的时间尺度下不同,所以自适应图学习模块被设计为在没有预先定义的前沿的情况下推断规模特定的可变依赖关系。鉴于多尺度特征表示和规模特定的可变间依赖关系,引入了一个多尺度的时间图神经网络,以共同模拟帧内依赖性和可变间依赖性。之后,我们开发一个尺度明智的融合模块,以在不同时间尺度上有效地促进协作,并自动捕获贡献的时间模式的重要性。四个真实数据集的实验表明,Magnn在各种设置上表明了最先进的方法。
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多变量时间序列(MTS)预测在许多智能应用中引起了很多关注。它不是一个琐碎的任务,因为我们需要考虑一个可变的依赖关系和可变间依赖关系。但是,现有的作品是针对特定场景设计的,需要很多域知识和专家努力,这难以在不同的场景之间传输。在本文中,我们提出了一种尺度意识的神经结构,用于MTS预测(SNAS4MTF)的搜索框架。多尺度分解模块将原始时间序列转换为多尺度子系列,可以保留多尺度的时间模式。自适应图形学习模块在没有任何先前知识的情况下,在不同的时间尺度下递送不同的变量间依赖关系。对于MTS预测,搜索空间旨在在每次尺度上捕获可变的可变依赖性和可变间依赖关系。在端到端框架中共同学习多尺度分解,自适应图学习和神经架构搜索模块。两个现实世界数据集的大量实验表明,与最先进的方法相比,SNAS4MTF实现了有希望的性能。
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时间序列预测是许多应用中的重大问题,例如,金融预测和业务优化。现代数据集可以具有多个相关时间序列,这些时间往往是通过全局(共享)规律和本地(特定)动态生成的。在本文中,我们寻求与DeepdGL的这种预测问题进行解决,这是一种深入预测模型,将动态与全球和局部时间模式脱颖而出。 DeepdGL采用编码器解码器架构,包括两个编码器,分别学习全局和本地时间模式,以及解码器以进行多步预测。具体地,为了模拟复杂的全局模式,引入了矢量量化(VQ)模块,允许全局特征编码器在所有时间序列中学习共享码本。为了模型多样化和异质局部模式,提出了一种由对比多地位编码(CMC)增强的自适应参数生成模块,以为每个单独的时间序列产生本地特征编码器的参数,这使得串联之间的相互信息最大化 - 具体的上下文变量和相应时间序列的长/短期表示。我们对几个现实世界数据集的实验表明DeepdGL优于现有的最先进的模型。
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This paper concerns realizing highly efficient information-theoretic robot exploration with desired performance in complex scenes. We build a continuous lightweight inference model to predict the mutual information (MI) and the associated prediction confidence of the robot's candidate actions which have not been evaluated explicitly. This allows the decision-making stage in robot exploration to run with a logarithmic complexity approximately, this will also benefit online exploration in large unstructured, and cluttered places that need more spatial samples to assess and decide. We also develop an objective function to balance the local optimal action with the highest MI value and the global choice with high prediction variance. Extensive numerical and dataset simulations show the desired efficiency of our proposed method without losing exploration performance in different environments. We also provide our open-source implementation codes released on GitHub for the robot community.
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A "heart attack" or myocardial infarction (MI), occurs when an artery supplying blood to the heart is abruptly occluded. The "gold standard" method for imaging MI is Cardiovascular Magnetic Resonance Imaging (MRI), with intravenously administered gadolinium-based contrast (late gadolinium enhancement). However, no "gold standard" fully automated method for the quantification of MI exists. In this work, we propose an end-to-end fully automatic system (MyI-Net) for the detection and quantification of MI in MRI images. This has the potential to reduce the uncertainty due to the technical variability across labs and inherent problems of the data and labels. Our system consists of four processing stages designed to maintain the flow of information across scales. First, features from raw MRI images are generated using feature extractors built on ResNet and MoblieNet architectures. This is followed by the Atrous Spatial Pyramid Pooling (ASPP) to produce spatial information at different scales to preserve more image context. High-level features from ASPP and initial low-level features are concatenated at the third stage and then passed to the fourth stage where spatial information is recovered via up-sampling to produce final image segmentation output into: i) background, ii) heart muscle, iii) blood and iv) scar areas. New models were compared with state-of-art models and manual quantification. Our models showed favorable performance in global segmentation and scar tissue detection relative to state-of-the-art work, including a four-fold better performance in matching scar pixels to contours produced by clinicians.
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Reduced system dependability and higher maintenance costs may be the consequence of poor electric power quality, which can disturb normal equipment performance, speed up aging, and even cause outright failures. This study implements and tests a prototype of an Online Sequential Extreme Learning Machine (OS-ELM) classifier based on wavelets for detecting power quality problems under transient conditions. In order to create the classifier, the OSELM-network model and the discrete wavelet transform (DWT) method are combined. First, discrete wavelet transform (DWT) multi-resolution analysis (MRA) was used to extract characteristics of the distorted signal at various resolutions. The OSELM then sorts the retrieved data by transient duration and energy features to determine the kind of disturbance. The suggested approach requires less memory space and processing time since it can minimize a large quantity of the distorted signal's characteristics without changing the signal's original quality. Several types of transient events were used to demonstrate the classifier's ability to detect and categorize various types of power disturbances, including sags, swells, momentary interruptions, oscillatory transients, harmonics, notches, spikes, flickers, sag swell, sag mi, sag harm, swell trans, sag spike, and swell spike.
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Morality in dialogue systems has raised great attention in research recently. A moral dialogue system could better connect users and enhance conversation engagement by gaining users' trust. In this paper, we propose a framework, MoralDial to train and evaluate moral dialogue systems. In our framework, we first explore the communication mechanisms of morality and resolve expressed morality into four sub-modules. The sub-modules indicate the roadmap for building a moral dialogue system. Based on that, we design a simple yet effective method: constructing moral discussions from Rules of Thumb (RoTs) between simulated specific users and the dialogue system. The constructed discussion consists of expressing, explaining, and revising the moral views in dialogue exchanges, which makes conversational models learn morality well in a natural manner. Furthermore, we propose a novel evaluation method in the framework. We evaluate the multiple aspects of morality by judging the relation between dialogue responses and RoTs in discussions, where the multifaceted nature of morality is particularly considered. Automatic and manual experiments demonstrate that our framework is promising to train and evaluate moral dialogue systems.
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This thesis introduces quantum natural language processing (QNLP) models based on a simple yet powerful analogy between computational linguistics and quantum mechanics: grammar as entanglement. The grammatical structure of text and sentences connects the meaning of words in the same way that entanglement structure connects the states of quantum systems. Category theory allows to make this language-to-qubit analogy formal: it is a monoidal functor from grammar to vector spaces. We turn this abstract analogy into a concrete algorithm that translates the grammatical structure onto the architecture of parameterised quantum circuits. We then use a hybrid classical-quantum algorithm to train the model so that evaluating the circuits computes the meaning of sentences in data-driven tasks. The implementation of QNLP models motivated the development of DisCoPy (Distributional Compositional Python), the toolkit for applied category theory of which the first chapter gives a comprehensive overview. String diagrams are the core data structure of DisCoPy, they allow to reason about computation at a high level of abstraction. We show how they can encode both grammatical structures and quantum circuits, but also logical formulae, neural networks or arbitrary Python code. Monoidal functors allow to translate these abstract diagrams into concrete computation, interfacing with optimised task-specific libraries. The second chapter uses DisCopy to implement QNLP models as parameterised functors from grammar to quantum circuits. It gives a first proof-of-concept for the more general concept of functorial learning: generalising machine learning from functions to functors by learning from diagram-like data. In order to learn optimal functor parameters via gradient descent, we introduce the notion of diagrammatic differentiation: a graphical calculus for computing the gradients of parameterised diagrams.
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