基于草图的图像检索(SBIR)是检索与语义和手绘草图查询的空间配置相匹配的自然图像(照片)的任务。草图的普遍性扩大了可能的应用程序的范围,并增加了对有效SBIR解决方案的需求。在本文中,我们研究了经典的基于三胞胎的SBIR解决方案,并表明对水平翻转(即使在模型登录之后)的持续不变性也损害了性能。为了克服这一限制,我们提出了几种方法,并深入评估它们每个方法以检查其有效性。我们的主要贡献是双重的:我们提出并评估几种直观的修改,以构建具有更好的翻转均衡性的SBIR解决方案。我们表明,视觉变压器更适合SBIR任务,并且它们的优于CNN的优于较大的CNN。我们进行了许多实验,并引入了第一个模型,以优于大规模SBIR基准(粗略)的人类表现。与以前的最新方法相比,我们的最佳模型在粗略的基准测试中达到了62.25%(在k = 1)的召回率为46.2%。
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Pronoun resolution is a challenging subset of an essential field in natural language processing called coreference resolution. Coreference resolution is about finding all entities in the text that refers to the same real-world entity. This paper presents a hybrid model combining multiple rulebased sieves with a machine-learning sieve for pronouns. For this purpose, seven high-precision rule-based sieves are designed for the Persian language. Then, a random forest classifier links pronouns to the previous partial clusters. The presented method demonstrates exemplary performance using pipeline design and combining the advantages of machine learning and rulebased methods. This method has solved some challenges in end-to-end models. In this paper, the authors develop a Persian coreference corpus called Mehr in the form of 400 documents. This corpus fixes some weaknesses of the previous corpora in the Persian language. Finally, the efficiency of the presented system compared to the earlier model in Persian is reported by evaluating the proposed method on the Mehr and Uppsala test sets.
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Coreference resolution (CR) is one of the most challenging areas of natural language processing. This task seeks to identify all textual references to the same real-world entity. Research in this field is divided into coreference resolution and anaphora resolution. Due to its application in textual comprehension and its utility in other tasks such as information extraction systems, document summarization, and machine translation, this field has attracted considerable interest. Consequently, it has a significant effect on the quality of these systems. This article reviews the existing corpora and evaluation metrics in this field. Then, an overview of the coreference algorithms, from rule-based methods to the latest deep learning techniques, is provided. Finally, coreference resolution and pronoun resolution systems in Persian are investigated.
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Mixture of factor analyzer (MFA) model is an efficient model for the analysis of high dimensional data through which the factor-analyzer technique based on the covariance matrices reducing the number of free parameters. The model also provides an important methodology to determine latent groups in data. There are several pieces of research to extend the model based on the asymmetrical and/or with outlier datasets with some known computational limitations that have been examined in frequentist cases. In this paper, an MFA model with a rich and flexible class of skew normal (unrestricted) generalized hyperbolic (called SUNGH) distributions along with a Bayesian structure with several computational benefits have been introduced. The SUNGH family provides considerable flexibility to model skewness in different directions as well as allowing for heavy tailed data. There are several desirable properties in the structure of the SUNGH family, including, an analytically flexible density which leads to easing up the computation applied for the estimation of parameters. Considering factor analysis models, the SUNGH family also allows for skewness and heavy tails for both the error component and factor scores. In the present study, the advantages of using this family of distributions have been discussed and the suitable efficiency of the introduced MFA model using real data examples and simulation has been demonstrated.
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在环境和水文研究中检测两个时间序列之间的关系非常重要。可以应用几种参数和非参数方法来检测关系。这些技术通常对平稳性假设敏感。在这项研究中,引入了一种新的基于COPULA的方法,以检测两个胞体时间序列与分数布朗运动(FBM)误差之间的关系。数值研究验证了引入方法的性能。
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仅使用图像级注释的弱监督对象检测(WSOD)在过去几年中引起了不断增长的关注。然而,此类任务通常以专注于自然图像的特定于域的解决方案,而我们表明应用于预先训练的深度特征的简单多实例方法会产生优异的非摄影数据集的性能,可能包括新类。该方法不包括任何微调或跨域学习,因此有效且可能适用于任意数据集和类。我们调查了拟议方法的几种口味,一些包括多层的Perceptron和多层分类器。尽管其简单性,我们的方法在一系列公开的数据集中展示了竞争结果,包括绘画(人民艺术,象征),水彩画,剪贴画和漫画,并允许快速学习未经看的视觉类别。
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