Conversational recommender systems (CRSs) often utilize external knowledge graphs (KGs) to introduce rich semantic information and recommend relevant items through natural language dialogues. However, original KGs employed in existing CRSs are often incomplete and sparse, which limits the reasoning capability in recommendation. Moreover, only few of existing studies exploit the dialogue context to dynamically refine knowledge from KGs for better recommendation. To address the above issues, we propose the Variational Reasoning over Incomplete KGs Conversational Recommender (VRICR). Our key idea is to incorporate the large dialogue corpus naturally accompanied with CRSs to enhance the incomplete KGs; and perform dynamic knowledge reasoning conditioned on the dialogue context. Specifically, we denote the dialogue-specific subgraphs of KGs as latent variables with categorical priors for adaptive knowledge graphs refactor. We propose a variational Bayesian method to approximate posterior distributions over dialogue-specific subgraphs, which not only leverages the dialogue corpus for restructuring missing entity relations but also dynamically selects knowledge based on the dialogue context. Finally, we infuse the dialogue-specific subgraphs to decode the recommendation and responses. We conduct experiments on two benchmark CRSs datasets. Experimental results confirm the effectiveness of our proposed method.
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The number of international benchmarking competitions is steadily increasing in various fields of machine learning (ML) research and practice. So far, however, little is known about the common practice as well as bottlenecks faced by the community in tackling the research questions posed. To shed light on the status quo of algorithm development in the specific field of biomedical imaging analysis, we designed an international survey that was issued to all participants of challenges conducted in conjunction with the IEEE ISBI 2021 and MICCAI 2021 conferences (80 competitions in total). The survey covered participants' expertise and working environments, their chosen strategies, as well as algorithm characteristics. A median of 72% challenge participants took part in the survey. According to our results, knowledge exchange was the primary incentive (70%) for participation, while the reception of prize money played only a minor role (16%). While a median of 80 working hours was spent on method development, a large portion of participants stated that they did not have enough time for method development (32%). 25% perceived the infrastructure to be a bottleneck. Overall, 94% of all solutions were deep learning-based. Of these, 84% were based on standard architectures. 43% of the respondents reported that the data samples (e.g., images) were too large to be processed at once. This was most commonly addressed by patch-based training (69%), downsampling (37%), and solving 3D analysis tasks as a series of 2D tasks. K-fold cross-validation on the training set was performed by only 37% of the participants and only 50% of the participants performed ensembling based on multiple identical models (61%) or heterogeneous models (39%). 48% of the respondents applied postprocessing steps.
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The main challenge for fine-grained few-shot image classification is to learn feature representations with higher inter-class and lower intra-class variations, with a mere few labelled samples. Conventional few-shot learning methods however cannot be naively adopted for this fine-grained setting -- a quick pilot study reveals that they in fact push for the opposite (i.e., lower inter-class variations and higher intra-class variations). To alleviate this problem, prior works predominately use a support set to reconstruct the query image and then utilize metric learning to determine its category. Upon careful inspection, we further reveal that such unidirectional reconstruction methods only help to increase inter-class variations and are not effective in tackling intra-class variations. In this paper, we for the first time introduce a bi-reconstruction mechanism that can simultaneously accommodate for inter-class and intra-class variations. In addition to using the support set to reconstruct the query set for increasing inter-class variations, we further use the query set to reconstruct the support set for reducing intra-class variations. This design effectively helps the model to explore more subtle and discriminative features which is key for the fine-grained problem in hand. Furthermore, we also construct a self-reconstruction module to work alongside the bi-directional module to make the features even more discriminative. Experimental results on three widely used fine-grained image classification datasets consistently show considerable improvements compared with other methods. Codes are available at: https://github.com/PRIS-CV/Bi-FRN.
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In frequency-division duplexing (FDD) massive multiple-input multiple-output (MIMO) systems, downlink channel state information (CSI) needs to be sent from users back to the base station (BS), which causes prohibitive feedback overhead. In this paper, we propose a lightweight and adaptive deep learning-based CSI feedback scheme by capitalizing on deep equilibrium models. Different from existing deep learning-based approaches that stack multiple explicit layers, we propose an implicit equilibrium block to mimic the process of an infinite-depth neural network. In particular, the implicit equilibrium block is defined by a fixed-point iteration and the trainable parameters in each iteration are shared, which results in a lightweight model. Furthermore, the number of forward iterations can be adjusted according to the users' computational capability, achieving an online accuracy-efficiency trade-off. Simulation results will show that the proposed method obtains a comparable performance as the existing benchmarks but with much-reduced complexity and permits an accuracy-efficiency trade-off at runtime.
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One of the important topics in the research field of Chinese classical poetry is to analyze the poetic style. By examining the relevant works of previous dynasties, researchers judge a poetic style mostly by their subjective feelings, and refer to the previous evaluations that have become a certain conclusion. Although this judgment method is often effective, there may be some errors. This paper builds the most perfect data set of Chinese classical poetry at present, trains a BART-poem pre -trained model on this data set, and puts forward a generally applicable poetry style judgment method based on this BART-poem model, innovatively introduces in-depth learning into the field of computational stylistics, and provides a new research method for the study of classical poetry. This paper attempts to use this method to solve the problem of poetry style identification in the Tang and Song Dynasties, and takes the poetry schools that are considered to have a relatively clear and consistent poetic style, such as the Hongzheng Qizi and Jiajing Qizi, Jiangxi poetic school and Tongguang poetic school, as the research object, and takes the poems of their representative poets for testing. Experiments show that the judgment results of the tested poetry work made by the model are basically consistent with the conclusions given by critics of previous dynasties, verify some avant-garde judgments of Mr. Qian Zhongshu, and better solve the task of poetry style recognition in the Tang and Song dynasties.
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已经进行了一项详尽的研究,以研究基于跨度的联合实体和关系提取任务的模型。但是,这些模型在模型训练过程中采样了大量的负实体和负关系,这是必不可少的,但导致数据分布严重不平衡,进而导致次优模型性能。为了解决上述问题,我们为基于跨度的联合实体和关系提取提出了两个阶段范式,其中涉及在第一阶段对实体和关系进行分类,并预测第二阶段的这些实体和关系的类型阶段。两阶段范式使我们的模型能够显着缩小数据分布差距,包括负实体与其他实体之间的差距,以及负面关系与其他关系之间的差距。此外,我们首次尝试将实体类型和实体距离与全球特征相结合,这已被证明有效,尤其是对于关系提取而言。几个数据集的实验结果表明,基于两阶段范式的基于跨度的联合提取模型增强,全局功能始终优于先前用于联合提取任务的基于最新的跨度模型,并建立了新的标准基准。定性和定量分析进一步验证了提出的范式和全球特征的有效性。
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文本对抗攻击暴露了文本分类器的漏洞,可用于改善其稳健性。现有的上下文感知方法仅考虑黄金标签的概率,并在搜索攻击路径时使用贪婪的搜索,通常会限制攻击效率。为了解决这些问题,我们提出了PDB,这是一种使用概率差的引导光束搜索的上下文感知的文本对抗攻击模型。概率差异是所有类标签概率的总体考虑,PDB使用它来指导攻击路径的选择。此外,PDBS使用Beam搜索找到成功的攻击路径,从而避免搜索空间有限。广泛的实验和人类评估表明,PDB在一系列评估指标中的表现优于以前的最佳模型,尤其是提高 +19.5%的攻击成功率。消融研究和定性分析进一步证实了PDB的效率。
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几个名称的实体识别(NER)使我们能够使用很少的标记示例为新域构建一个NER系统。但是,该任务的现有原型网络具有大致估计的标签依赖性和紧密分布的原型,因此经常导致错误分类。为了解决上述问题,我们提出了EP-NET,这是一个实体级原型网络,通过分散分布的原型增强。EP-NET构建实体级原型,并认为文本跨度为候选实体,因此它不再需要标签依赖性。此外,EP-NET从头开始训练原型,以分散分配它们,并使用空间投影将跨度与嵌入空间中的原型对齐。两项评估任务和少量网络设置的实验结果表明,EP-NET在整体性能方面始终优于先前的强大模型。广泛的分析进一步验证了EP-NET的有效性。
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基于图像的3D检测是自主驾驶感知系统的必不可少的组成部分。但是,它仍然受到不满意的表现,这是有限的培训数据的主要原因之一。不幸的是,在3D空间中注释对象是极度时间/资源消耗的,这使得很难任意扩展训练集。在这项工作中,我们专注于半监督的方式,并探索更便宜的替代方案(即伪标记)的可行性,以利用未标记的数据。为此,我们进行了广泛的实验,以研究伪标签是否可以在不同环境下为基线模型提供有效的监督。实验结果不仅证明了基于图像的3D检测的伪标记机制的有效性(例如,在单眼设置下,我们在没有铃铛和哨声的Kitti-3D测试集上实现了20.23 AP,用于中等水平,从6.03 AP),但还显示了几个有趣且值得注意的发现(例如,经过伪标签训练的模型的性能要比基于相同培训数据的地面真相注释训练的表现更好)。我们希望这项工作可以在半监督环境下为基于图像的3D检测社区提供见解。代码,伪标签和预培训模型将公开可用。
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高速,高分辨率的立体视频(H2-STEREO)视频使我们能够在细粒度上感知动态3D内容。然而,对商品摄像机的收购H2-STEREO视频仍然具有挑战性。现有的空间超分辨率或时间框架插值方法分别提供了缺乏时间或空间细节的折衷解决方案。为了减轻这个问题,我们提出了一个双摄像头系统,其中一台相机捕获具有丰富空间细节的高空间分辨率低框架速率(HSR-LFR)视频,而另一个摄像头则捕获了低空间分辨率的高架框架-Rate(LSR-HFR)视频带有光滑的时间细节。然后,我们设计了一个学习的信息融合网络(LIFNET),该网络利用跨摄像机冗余,以增强两种相机视图,从而有效地重建H2-STEREO视频。即使在大型差异场景中,我们也利用一个差异网络将时空信息传输到视图上,基于该视图,我们建议使用差异引导的LSR-HFR视图基于差异引导的流量扭曲,并针对HSR-LFR视图进行互补的扭曲。提出了特征域中的多尺度融合方法,以最大程度地减少HSR-LFR视图中闭塞引起的翘曲幽灵和孔。 LIFNET使用YouTube收集的高质量立体视频数据集以端到端的方式进行训练。广泛的实验表明,对于合成数据和摄像头捕获的真实数据,我们的模型均优于现有的最新方法。消融研究探讨了各个方面,包括时空分辨率,摄像头基线,摄像头解理,长/短曝光和应用程序,以充分了解其对潜在应用的能力。
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