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When neural networks are employed for high-stakes decision-making, it is desirable that they provide explanations for their prediction in order for us to understand the features that have contributed to the decision. At the same time, it is…

Machine Learning · Computer Science 2022-05-10 Penny Chong , Ngai-Man Cheung , Yuval Elovici , Alexander Binder

Outlier detection can serve as an extremely important tool for researchers from a wide range of fields. From the sectors of banking and marketing to the social sciences and healthcare sectors, outlier detection techniques are very useful…

Methodology · Statistics 2023-12-12 Efthymios Costa , Ioanna Papatsouma

Feature selection places an important role in improving the performance of outlier detection, especially for noisy data. Existing methods usually perform feature selection and outlier scoring separately, which would select feature subsets…

Machine Learning · Computer Science 2020-01-17 Li Cheng , Yijie Wang , Xinwang Liu , Bin Li

Continuous-time event sequences represent discrete events occurring in continuous time. Such sequences arise frequently in real-life. Usually we expect the sequences to follow some regular pattern over time. However, sometimes these…

Machine Learning · Computer Science 2021-06-15 Siqi Liu , Milos Hauskrecht

Disinformation and fake news have posed detrimental effects on individuals and society in recent years, attracting broad attention to fake news detection. The majority of existing fake news detection algorithms focus on mining news content…

Social and Information Networks · Computer Science 2021-04-27 Yingtong Dou , Kai Shu , Congying Xia , Philip S. Yu , Lichao Sun

Analyzing sequence data usually leads to the discovery of interesting patterns and then anomaly detection. In recent years, numerous frameworks and methods have been proposed to discover interesting patterns in sequence data as well as…

Databases · Computer Science 2021-12-01 Wensheng Gan , Lili Chen , Shicheng Wan , Jiahui Chen , Chien-Ming Chen

Out-of-scope intent detection is of practical importance in task-oriented dialogue systems. Since the distribution of outlier utterances is arbitrary and unknown in the training stage, existing methods commonly rely on strong assumptions on…

Computation and Language · Computer Science 2021-06-18 Li-Ming Zhan , Haowen Liang , Bo Liu , Lu Fan , Xiao-Ming Wu , Albert Y. S. Lam

We propose a novel unsupervised keyphrase extraction approach that filters candidate keywords using outlier detection. It starts by training word embeddings on the target document to capture semantic regularities among the words. It then…

Computation and Language · Computer Science 2020-07-14 Eirini Papagiannopoulou , Grigorios Tsoumakas

Despite tremendous progress in outlier detection research in recent years, the majority of existing methods are designed only to detect unconditional outliers that correspond to unusual data patterns expressed in the joint space of all data…

Machine Learning · Computer Science 2016-12-23 Charmgil Hong , Milos Hauskrecht

Ensemble methods for classification and clustering have been effectively used for decades, while ensemble learning for outlier detection has only been studied recently. In this work, we design a new ensemble approach for outlier detection…

Machine Learning · Computer Science 2016-09-20 Shebuti Rayana , Wen Zhong , Leman Akoglu

Outlier detection is one of the most important processes taken to create good, reliable data in machine learning. The most methods of outlier detection leverage an auxiliary reconstruction task by assuming that outliers are more difficult…

Computer Vision and Pattern Recognition · Computer Science 2022-11-23 Ning Huyan , Dou Quan , Xiangrong Zhang , Xuefeng Liang , Jocelyn Chanussot , Licheng Jiao

Outliers arise in networks due to different reasons such as fraudulent behavior of malicious users or default in measurement instruments and can significantly impair network analyses. In addition, real-life networks are likely to be…

Machine Learning · Statistics 2020-12-02 Solenne Gaucher , Olga Klopp , Geneviève Robin

Anomalies in economic and financial data -- often linked to rare yet impactful events -- are of theoretical interest, but can also severely distort inference. Although outlier-robust methodologies can be used, many researchers prefer…

Methodology · Statistics 2025-09-01 Monica Billio , Roberto Casarin , Fausto Corradin , Antonio Peruzzi

A method for unsupervised contextual anomaly detection is proposed using a cross-linked pair of Variational Auto-Encoders for assigning a normality score to an observation. The method enables a distinct separation of contextual from…

Machine Learning · Statistics 2019-04-02 Yaniv Shulman

The problem of estimating subjective visual properties from image and video has attracted increasing interest. A subjective visual property is useful either on its own (e.g. image and video interestingness) or as an intermediate…

Computer Vision and Pattern Recognition · Computer Science 2015-07-28 Yanwei Fu , Timothy M. Hospedales , Tao Xiang , Jiechao Xiong , Shaogang Gong , Yizhou Wang , Yuan Yao

In a corpus of data, outliers are either errors: mistakes in the data that are counterproductive, or are unique: informative samples that improve model robustness. Identifying outliers can lead to better datasets by (1) removing noise in…

Unsupervised learning poses one of the most difficult challenges in computer vision today. The task has an immense practical value with many applications in artificial intelligence and emerging technologies, as large quantities of unlabeled…

Computer Vision and Pattern Recognition · Computer Science 2019-05-28 Ioana Croitoru , Simion-Vlad Bogolin , Marius Leordeanu

Sequential recommendation models are primarily optimized to distinguish positive samples from negative ones during training in which negative sampling serves as an essential component in learning the evolving user preferences through…

Information Retrieval · Computer Science 2022-08-09 Xiaoyang Liu , Chong Liu , Pinzheng Wang , Rongqin Zheng , Lixin Zhang , Leyu Lin , Zhijun Chen , Liangliang Fu

Outlier detection and cleaning are essential steps in data preprocessing to ensure the integrity and validity of data analyses. This paper focuses on outlier points within individual trajectories, i.e., points that deviate significantly…

Databases · Computer Science 2025-11-26 Mariana M Garcez Duarte , Mahmoud Sakr

Anomaly detection or outlier is one of the challenging subjects in unsupervised learning . This paper is introduced a student-teacher framework for anomaly detection that its teacher network is enhanced for achieving high-performance…

Computer Vision and Pattern Recognition · Computer Science 2025-12-23 Mohammad Zolfaghari , Hedieh Sajedi