OpenRaiser/Intern-Atlas huggingface dataset:
Tracking and recognizing rigid and non-rigid facial motions using local parametric models of image motion
Authors: Michael J. Black, Yaser Yacoob
Venue: Conference ICCV 1995
Year: 1995

This paper explores the use of local parametrized models of image motion for recovering and recognizing the non-rigid and articulated motion of human faces. Parametric flow models (for example affine) are popular for estimating motion in rigid scenes. We observe that within local regions in space and time, such models not only accurately model non-rigid facial motions but also provide a concise description of the motion in terms of a small number of parameters. These parameters are intuitively related to the motion of facial features during facial expressions and we show how expressions such as anger, happiness, surprise, fear, disgust and sadness can be recognized from the local parametric motions in the presence of significant head motion. The motion tracking and expression recognition approach performs with high accuracy in extensive laboratory experiments involving 40 subjects as well as in television and movie sequences.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Graph topic scan statistic for spatial event detection
Authors: Yu Liu, Baojian Zhou, Feng Chen, David W. Cheung
Venue: Conference CIKM 2016
Year: 2016

Spatial event detection is an important and challenging problem. Unlike traditional event detection that focuses on the timing of global urgent event, the task of spatial event detection is to detect the spatial regions (e.g. clusters of neighboring cities) where urgent events occur. In this paper, we focus on the problem of spatial event detection using textual information in social media. We observe that, when a spatial event occurs, the topics relevant to the event are often discussed more coherently in cities near the event location than those far away. In order to capture this pattern, we propose a new method called Graph Topic Scan Statistic (Graph-TSS) that corresponds to a generalized log-likelihood ratio test based on topic modeling. We first demonstrate that the detection of spatial event regions under Graph-TSS is NP-hard due to a reduction from classical node-weighted prize-collecting Steiner tree problem (NW-PCST). We then design an efficient algorithm that approximately maximizes the graph topic scan statistic over spatial regions of arbitrary form. As a case study, we consider three applications using Twitter data, including Argentina civil unrest event detection, Chile earthquake detection, and United States influenza disease outbreak detection. Empirical evidence demonstrates that the proposed Graph-TSS performs superior over state-of-the-art methods on both running time and accuracy.
Text embedding for sub-entity ranking from user reviews
Authors: Chih-Yu Chao, Yi-Fan Chu, Hsiu-Wei Yang, Chuan-Ju Wang, Ming-Feng Tsai
Venue: Conference CIKM 2017
Year: 2017

This paper attempts to conduct analysis for one certain type of user reviews; that is, the reviews on a super-entity (e.g., restaurant) involve descriptions for many sub-entities (e.g., dishes). To deal with such analysis, we propose a text embedding framework for ranking sub-entities from user reviews of a given super-entity. Experiments on two real-world datasets show that our method outperforms three baselines by a statistically significant amount. Intriguing cases from the experiments are discussed in the paper.
Automatic construction of a context-aware sentiment lexicon: an optimization approach
Authors: Yue Lu, Malú Castellanos, Umeshwar Dayal, ChengXiang Zhai
Venue: Conference WWW 2011
Year: 2011

The explosion of Web opinion data has made essential the need for automatic tools to analyze and understand people's sentiments toward different topics. In most sentiment analysis applications, the sentiment lexicon plays a central role. However, it is well known that there is no universally optimal sentiment lexicon since the polarity of words is sensitive to the topic domain. Even worse, in the same domain the same word may indicate different polarities with respect to different aspects. For example, in a laptop review, "large" is negative for the battery aspect while being positive for the screen aspect. In this paper, we focus on the problem of learning a sentiment lexicon that is not only domain specific but also dependent on the aspect in context given an unlabeled opinionated text collection. We propose a novel optimization framework that provides a unified and principled way to combine different sources of information for learning such a context-dependent sentiment lexicon. Experiments on two data sets (hotel reviews and customer feedback surveys on printers) show that our approach can not only identify new sentiment words specific to the given domain but also determine the different polarities of a word depending on the aspect in context. In further quantitative evaluation, our method is proved to be effective in constructing a high quality lexicon by comparing with a human annotated gold standard. In addition, using the learned context-dependent sentiment lexicon improved the accuracy in an aspect-level sentiment classification task.
Ice: Item concept embedding via textual information
Authors: Chuan-Ju Wang, Ting-Hsiang Wang, Hsiu-Wei Yang, Bo-Sin Chang, Ming-Feng Tsai
Venue: Conference SIGIR 2017
Year: 2017

This paper proposes an item concept embedding (ICE) framework to model item concepts via textual information. Specifically, in the proposed framework there are two stages: graph construction and embedding learning. In the first stage, we propose a generalized network construction method to build a network involving heterogeneous nodes and a mixture of both homogeneous and heterogeneous relations. The second stage leverages the concept of neighborhood proximity to learn the embeddings of both items and words. With the proposed carefully designed ICE networks, the resulting embedding facilitates both homogeneous and heterogeneous retrieval, including item-to-item and word-to-item retrieval. Moreover, as a distributed embedding approach, the proposed ICE approach not only generates related retrieval results but also delivers more diverse results than traditional keyword-matching-based approaches. As our experiments on two real-world datasets show, ICE encodes useful textual information and thus outperforms traditional methods in various item classification and retrieval tasks.
L2knng: Fast exact k-nearest neighbor graph construction with l2-norm pruning
Authors: David C. Anastasiu, George Karypis
Venue: Conference CIKM 2015
Year: 2015

The k-nearest neighbor graph is often used as a building block in information retrieval, clustering, online advertising, and recommender systems algorithms. The complexity of constructing the exact k-nearest neighbor graph is quadratic on the number of objects that are compared, and most existing methods solve the problem approximately. We present L2Knng, an efficient algorithm that finds the exact cosine similarity k-nearest neighbor graph for a set of sparse high-dimensional objects. Our algorithm quickly builds an approximate solution to the problem, identifying many of the most similar neighbors, and then uses theoretic bounds on the similarity of two vectors, based on the L2-norm of part of the vectors, to find each object's exact k-neighborhood. We perform an extensive evaluation of our algorithm, comparing against both exact and approximate baselines, and demonstrate the efficiency of our method across a variety of real-world datasets and neighborhood sizes. Our approximate and exact L2Knng variants compute the k-nearest neighbor graph up to an order of magnitude faster than their respective baselines.
Optimizing budget allocation among channels and influencers
Authors: Noga Alon, Iftah Gamzu, Moshe Tennenholtz
Venue: Conference WWW 2012
Year: 2012

Brands and agencies use marketing as a tool to influence customers. One of the major decisions in a marketing plan deals with the allocation of a given budget among media channels in order to maximize the impact on a set of potential customers. A similar situation occurs in a social network, where a marketing budget needs to be distributed among a set of potential influencers in a way that provides high-impact.
Fast and accurate anomaly detection in dynamic graphs with a two-pronged approach
Authors: Minji Yoon, Bryan Hooi, Kijung Shin, Christos Faloutsos
Venue: Conference KDD 2019
Year: 2019

Given a dynamic graph stream, how can we detect the sudden appearance of anomalous patterns, such as link spam, follower boosting, or denial of service attacks? Additionally, can we categorize the types of anomalies that occur in practice, and theoretically analyze the anomalous signs arising from each type? In this work, we propose AnomRank, an online algorithm for anomaly detection in dynamic graphs. AnomRank uses a two-pronged approach defining two novel metrics for anomalousness. Each metric tracks the derivatives of its own version of a 'node score' (or node importance) function. This allows us to detect sudden changes in the importance of any node. We show theoretically and experimentally that the two-pronged approach successfully detects two common types of anomalies: sudden weight changes along an edge, and sudden structural changes to the graph. AnomRank is (a) Fast and Accurate: up to 49.5x faster or 35% more accurate than state-of-the-art methods, (b) Scalable: linear in the number of edges in the input graph, processing millions of edges within 2 seconds on a stock laptop/desktop, and (c) Theoretically Sound: providing theoretical guarantees of the two-pronged approach.
Cross domain regularization for neural ranking models using adversarial learning
Authors: Daniel Cohen, Bhaskar Mitra, Katja Hofmann, W. Bruce Croft
Venue: Conference SIGIR 2018
Year: 2018

Unlike traditional learning to rank models that depend on hand-crafted features, neural representation learning models learn higher level features for the ranking task by training on large datasets. Their ability to learn new features directly from the data, however, may come at a price. Without any special supervision, these models learn relationships that may hold only in the domain from which the training data is sampled, and generalize poorly to domains not observed during training. We study the effectiveness of adversarial learning as a cross domain regularizer in the context of the ranking task. We use an adversarial discriminator and train our neural ranking model on a small set of domains. The discriminator provides a negative feedback signal to discourage the model from learning domain specific representations. Our experiments show consistently better performance on held out domains in the presence of the adversarial discriminator---sometimes up to 30% on precision$@1$.
Online adaptive topic focused tweet acquisition
Authors: Mehdi Sadri, Sharad Mehrotra, Yaming Yu
Venue: Conference CIKM 2016
Year: 2016

Twitter provides a public streaming API that is strictly limited, making it difficult to simultaneously achieve good coverage and relevance when monitoring tweets for a specific topic of interest. In this paper, we address the tweet acquisition challenge to enhance monitoring of tweets based on the client/application needs in an online adaptive manner such that the quality and quantity of the results improves over time. We propose a Tweet Acquisition System (TAS), that iteratively selects phrases to track based on an explore-exploit strategy. Our experimental studies show that TAS significantly improves recall of relevant tweets and the performance improves when the topics are more specific.
Scalpel-cd: leveraging crowdsourcing and deep probabilistic modeling for debugging noisy training data
Authors: Jie Yang, Alisa Smirnova, Dingqi Yang, Gianluca Demartini, Yuan Lu, Philippe Cudré-Mauroux
Venue: Conference WWW 2019
Year: 2019

This paper presents Scalpel-CD, a first-of-its-kind system that leverages both human and machine intelligence to debug noisy labels from the training data of machine learning systems. Our system identifies potentially wrong labels using a deep probabilistic model, which is able to infer the latent class of a high-dimensional data instance by exploiting data distributions in the underlying latent feature space. To minimize crowd efforts, it employs a data sampler which selects data instances that would benefit the most from being inspected by the crowd. The manually verified labels are then propagated to similar data instances in the original training data by exploiting the underlying data structure, thus scaling out the contribution from the crowd. Scalpel-CD is designed with a set of algorithmic solutions to automatically search for the optimal configurations for different types of training data, in terms of the underlying data structure, noise ratio, and noise types (random vs. structural). In a real deployment on multiple machine learning tasks, we demonstrate that Scalpel-CD is able to improve label quality by 12.9% with only 2.8% instances inspected by the crowd.
Multi-layer representation learning for medical concepts
Authors: Edward Choi, Mohammad Taha Bahadori, Elizabeth Searles, Catherine Coffey, Michael Thompson, James Bost, Javier Tejedor-Sojo, Jimeng Sun
Venue: Conference KDD 2016
Year: 2016

Learning efficient representations for concepts has been proven to be an important basis for many applications such as machine translation or document classification. Proper representations of medical concepts such as diagnosis, medication, procedure codes and visits will have broad applications in healthcare analytics. However, in Electronic Health Records (EHR) the visit sequences of patients include multiple concepts (diagnosis, procedure, and medication codes) per visit. This structure provides two types of relational information, namely sequential order of visits and co-occurrence of the codes within each visit. In this work, we propose Med2Vec, which not only learns distributed representations for both medical codes and visits from a large EHR dataset with over 3 million visits, but also allows us to interpret the learned representations confirmed positively by clinical experts. In the experiments, Med2Vec displays significant improvement in key medical applications compared to popular baselines such as Skip-gram, GloVe and stacked autoencoder, while providing clinically meaningful interpretation.
Community detection based on distance dynamics
Authors: Junming Shao, Zhichao Han, Qinli Yang, Tao Zhou
Venue: Conference KDD 2015
Year: 2015

In this paper, we introduce a new community detection algorithm, called Attractor, which automatically spots communities in a network by examining the changes of "distances" among nodes (i.e. distance dynamics). The fundamental idea is to envision the target network as an adaptive dynamical system, where each node interacts with its neighbors. The interaction will change the distances among nodes, while the distances will affect the interactions. Such interplay eventually leads to a steady distribution of distances, where the nodes sharing the same community move together and the nodes in different communities keep far away from each other. Building upon the distance dynamics, Attractor has several remarkable advantages: (a) It provides an intuitive way to analyze the community structure of a network, and more importantly, faithfully captures the natural communities (with high quality). (b) Attractor allows detecting communities on large-scale networks due to its low time complexity (O(|E|)). (c) Attractor is capable of discovering communities of arbitrary size, and thus small-size communities or anomalies, usually existing in real-world networks, can be well pinpointed. Extensive experiments show that our algorithm allows the effective and efficient community detection and has good performance compared to state-of-the-art algorithms.
Which information sources are more effective and reliable in video search
Authors: Zhiyong Cheng, Xuanchong Li, Jialie Shen, Alexander G. Hauptmann
Venue: Conference SIGIR 2016
Year: 2016

It is common that users are interested in finding video segments, which contain further information about the video contents in a segment of interest. To facilitate users to find and browse related video contents, video hyperlinking aims at constructing links among video segments with relevant information in a large video collection. In this study, we explore the effectiveness of various video features on the performance of video hyperlinking, including subtitle, metadata, content features (i.e., audio and visual), surrounding context, as well as the combinations of those features. Besides, we also test different search strategies over different types of queries, which are categorized according to their video contents. Comprehensive experimental studies have been conducted on the dataset of TRECVID 2015 video hyperlinking task. Results show that (1) text features play a crucial role in search performance, and the combination of audio and visual features cannot provide improvements; (2) the consideration of contexts cannot obtain better results; and (3) due to the lack of training examples, machine learning techniques cannot improve the performance.
Graph summarization for entity relatedness visualization
Authors: Yukai Miao, Jianbin Qin, Wei Wang
Venue: Conference SIGIR 2017
Year: 2017

In modern search engines, Knowledge Graphs have become a key component for knowledge discovery. When a user searches for an entity, the existing systems usually provide a list of related entities, but they do not necessarily give explanations of how they are related. However, with the help of knowledge graphs, we can generate relatedness graphs between any pair of existing entities. Existing methods of this problem are either graph-based or list-based, but they all have some limitations when dealing with large complex relatedness graphs of two related entity. In this work, we investigate how to summarize the relatedness graphs and how to use the summarized graphs to assistant the users to retrieve target information. We also implemented our approach in an online query system and performed experiments and evaluations on it. The results show that our method produces much better result than previous work.
What is the added value of negative links in online social networks?
Authors: Jérôme Kunegis, Julia Preusse, Felix Schwagereit
Venue: Conference WWW 2013
Year: 2013

We investigate the "negative link" feature of social networks that allows users to tag other users as foes or as distrusted in addition to the usual friend and trusted links. To answer the question whether negative links have an added value for an online social network, we investigate the machine learning problem of predicting the negative links of such a network using only the positive links as a basis, with the idea that if this problem can be solved with high accuracy, then the "negative link" feature is redundant. In doing so, we also present a general methodology for assessing the added value of any new link type in online social networks. Our evaluation is performed on two social networks that allow negative links: The technology news website Slashdot and the product review site Epinions. In experiments with these two datasets, we come to the conclusion that a combination of centrality-based and proximity-based link prediction functions can be used to predict the negative edges in the networks we analyse. We explain this result by an application of the models of preferential attachment and balance theory to our learning problem, and show that the "negative link" feature has a small but measurable added value for these social networks.
Identify susceptible locations in medical records via adversarial attacks on deep predictive models
Authors: Mengying Sun, Fengyi Tang, Jinfeng Yi, Fei Wang, Jiayu Zhou
Venue: Conference KDD 2018
Year: 2018

The surging availability of electronic medical records (EHR) leads to increased research interests in medical predictive modeling. Recently many deep learning based predicted models are also developed for EHR data and demonstrated impressive performance. However, a series of recent studies showed that these deep models are not safe: they suffer from certain vulnerabilities. In short, a well-trained deep network can be extremely sensitive to inputs with negligible changes. These inputs are referred to as adversarial examples. In the context of medical informatics, such attacks could alter the result of a high performance deep predictive model by slightly perturbing a patient's medical records. Such instability not only reflects the weakness of deep architectures, more importantly, it offers guide on detecting susceptible parts on the inputs. In this paper, we propose an efficient and effective framework that learns a time-preferential minimum attack targeting the LSTM model with EHR inputs, and we leverage this attack strategy to screen medical records of patients and identify susceptible events and measurements. The efficient screening procedure can assist decision makers to pay extra attentions to the locations that can cause severe consequence if not measured correctly. We conduct extensive empirical studies on a real-world urgent care cohort and demonstrate the effectiveness of the proposed screening approach.
Experiments with query acquisition and use in document retrieval systems
Authors: W. Bruce Croft, Raj Das
Venue: Conference SIGIR 1990
Year: 1990

In some recent experimental document retrieval systems, emphasis has been placed on the acquisition of a detailed model of the information need through interaction with the user. It has been argued that these “enhanced” queries, in combination with relevance feedback, will improve retrieval performance. In this paper, we describe a study with the aim of evaluating how easily enhanced queries can be acquired from users and how effectively this additional knowledge can be used in retrieval. The results indicate that significant effectiveness benefits can be obtained through the acquisition of domain concepts related to query concepts, together with their level of importance to the information need.
Collaborative matrix factorization with multiple similarities for predicting drug-target interactions
Authors: Xiaodong Zheng, Hao Ding, Hiroshi Mamitsuka, Shanfeng Zhu
Venue: Conference KDD 2013
Year: 2013

We address the problem of predicting new drug-target interactions from three inputs: known interactions, similarities over drugs and those over targets. This setting has been considered by many methods, which however have a common problem of allowing to have only one similarity matrix over drugs and that over targets. The key idea of our approach is to use more than one similarity matrices over drugs as well as those over targets, where weights over the multiple similarity matrices are estimated from data to automatically select similarities, which are effective for improving the performance of predicting drug-target interactions. We propose a factor model, named Multiple Similarities Collaborative Matrix Factorization(MSCMF), which projects drugs and targets into a common low-rank feature space, which is further consistent with weighted similarity matrices over drugs and those over targets. These two low-rank matrices and weights over similarity matrices are estimated by an alternating least squares algorithm. Our approach allows to predict drug-target interactions by the two low-rank matrices collaboratively and to detect similarities which are important for predicting drug-target interactions. This approach is general and applicable to any binary relations with similarities over elements, being found in many applications, such as recommender systems. In fact, MSCMF is an extension of weighted low-rank approximation for one-class collaborative filtering. We extensively evaluated the performance of MSCMF by using both synthetic and real datasets. Experimental results showed nice properties of MSCMF on selecting similarities useful in improving the predictive performance and the performance advantage of MSCMF over six state-of-the-art methods for predicting drug-target interactions.