Yanan Zheng, L. Wen, Jianmin Wang, Jun Yan, Lei Ji
Deep Generative Models (DGMs) are able to extract high-level representations from massive unlabeled data and are explainable from a probabilistic perspective. Such characteristics favor sequence modeling tasks. However, it still remains a huge challenge to model sequences with DGMs. Unlike real-valued data that can be directly fed into models, sequence data consist of discrete elements and require being transformed into certain representations first. This leads to the following two challenges. First, high-level features are sensitive to small variations of inputs as well as the way of representing data. Second, the models are more likely to lose long-term information during multiple transformations. In this paper, we propose a Hierarchical Deep Generative Model With Dual Memory to address the two challenges. Furthermore, we provide a method to efficiently perform inference and learning on the model. The proposed model extends basic DGMs with an improved hierarchically organized multi-layer architecture. Besides, our model incorporates memories along dual directions, respectively denoted as broad memory and deep memory. The model is trained end-to-end by optimizing a variational lower bound on data log-likelihood using the improved stochastic variational method. We perform experiments on several tasks with various datasets and obtain excellent results. The results of language modeling show our method significantly outperforms state-of-the-art results in terms of generative performance. Extended experiments including document modeling and sentiment analysis, prove the high-effectiveness of dual memory mechanism and latent representations. Text random generation provides a straightforward perception for advantages of our model.
{"title":"Sequence Modeling with Hierarchical Deep Generative Models with Dual Memory","authors":"Yanan Zheng, L. Wen, Jianmin Wang, Jun Yan, Lei Ji","doi":"10.1145/3132847.3132952","DOIUrl":"https://doi.org/10.1145/3132847.3132952","url":null,"abstract":"Deep Generative Models (DGMs) are able to extract high-level representations from massive unlabeled data and are explainable from a probabilistic perspective. Such characteristics favor sequence modeling tasks. However, it still remains a huge challenge to model sequences with DGMs. Unlike real-valued data that can be directly fed into models, sequence data consist of discrete elements and require being transformed into certain representations first. This leads to the following two challenges. First, high-level features are sensitive to small variations of inputs as well as the way of representing data. Second, the models are more likely to lose long-term information during multiple transformations. In this paper, we propose a Hierarchical Deep Generative Model With Dual Memory to address the two challenges. Furthermore, we provide a method to efficiently perform inference and learning on the model. The proposed model extends basic DGMs with an improved hierarchically organized multi-layer architecture. Besides, our model incorporates memories along dual directions, respectively denoted as broad memory and deep memory. The model is trained end-to-end by optimizing a variational lower bound on data log-likelihood using the improved stochastic variational method. We perform experiments on several tasks with various datasets and obtain excellent results. The results of language modeling show our method significantly outperforms state-of-the-art results in terms of generative performance. Extended experiments including document modeling and sentiment analysis, prove the high-effectiveness of dual memory mechanism and latent representations. Text random generation provides a straightforward perception for advantages of our model.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80398839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongwei Wang, Jia Wang, Miao Zhao, Jiannong Cao, M. Guo
Online voting is an emerging feature in social networks, in which users can express their attitudes toward various issues and show their unique interest. Online voting imposes new challenges on recommendation, because the propagation of votings heavily depends on the structure of social networks as well as the content of votings. In this paper, we investigate how to utilize these two factors in a comprehensive manner when doing voting recommendation. First, due to the fact that existing text mining methods such as topic model and semantic model cannot well process the content of votings that is typically short and ambiguous, we propose a novel Topic-Enhanced Word Embedding (TEWE) method to learn word and document representation by jointly considering their topics and semantics. Then we propose our Joint Topic-Semantic-aware social Matrix Factorization (JTS-MF) model for voting recommendation. JTS-MF model calculates similarity among users and votings by combining their TEWE representation and structural information of social networks, and preserves this topic-semantic-social similarity during matrix factorization. To evaluate the performance of TEWE representation and JTS-MF model, we conduct extensive experiments on real online voting dataset. The results prove the efficacy of our approach against several state-of-the-art baselines.
在线投票是社交网络的新兴功能，用户可以在其中表达对各种问题的态度，并显示自己独特的兴趣。在线投票给推荐带来了新的挑战，因为投票的传播严重依赖于社交网络的结构以及投票的内容。本文主要研究在进行投票推荐时，如何综合利用这两个因素。首先，由于现有的文本挖掘方法如主题模型和语义模型不能很好地处理典型的简短和模糊的投票内容，我们提出了一种新的主题增强词嵌入(topic - enhanced Word Embedding, TEWE)方法，通过联合考虑词和文档的主题和语义来学习词和文档的表示。然后，我们提出了联合主题语义感知社会矩阵分解(JTS-MF)投票推荐模型。JTS-MF模型通过结合用户和投票的TEWE表示和社会网络的结构信息来计算用户和投票之间的相似度，并在矩阵分解过程中保持这种主题-语义-社会相似度。为了评估TEWE表示和JTS-MF模型的性能，我们在真实的在线投票数据集上进行了大量的实验。结果证明了我们的方法对几种最先进的基线的有效性。
{"title":"Joint Topic-Semantic-aware Social Recommendation for Online Voting","authors":"Hongwei Wang, Jia Wang, Miao Zhao, Jiannong Cao, M. Guo","doi":"10.1145/3132847.3132889","DOIUrl":"https://doi.org/10.1145/3132847.3132889","url":null,"abstract":"Online voting is an emerging feature in social networks, in which users can express their attitudes toward various issues and show their unique interest. Online voting imposes new challenges on recommendation, because the propagation of votings heavily depends on the structure of social networks as well as the content of votings. In this paper, we investigate how to utilize these two factors in a comprehensive manner when doing voting recommendation. First, due to the fact that existing text mining methods such as topic model and semantic model cannot well process the content of votings that is typically short and ambiguous, we propose a novel Topic-Enhanced Word Embedding (TEWE) method to learn word and document representation by jointly considering their topics and semantics. Then we propose our Joint Topic-Semantic-aware social Matrix Factorization (JTS-MF) model for voting recommendation. JTS-MF model calculates similarity among users and votings by combining their TEWE representation and structural information of social networks, and preserves this topic-semantic-social similarity during matrix factorization. To evaluate the performance of TEWE representation and JTS-MF model, we conduct extensive experiments on real online voting dataset. The results prove the efficacy of our approach against several state-of-the-art baselines.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80489631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yujie Fan, Yiming Zhang, Yanfang Ye, Xin Li, W. Zheng
Opioid (e.g., heroin and morphine) addiction has become one of the largest and deadliest epidemics in the United States. To combat such deadly epidemic, there is an urgent need for novel tools and methodologies to gain new insights into the behavioral processes of opioid abuse and addiction. The role of social media in biomedical knowledge mining has turned into increasingly significant in recent years. In this paper, we propose a novel framework named AutoDOA to automatically detect the opioid addicts from Twitter, which can potentially assist in sharpening our understanding toward the behavioral process of opioid abuse and addiction. In AutoDOA, to model the users and posted tweets as well as their rich relationships, a structured heterogeneous information network (HIN) is first constructed. Then meta-path based approach is used to formulate similarity measures over users and different similarities are aggregated using Laplacian scores. Based on HIN and the combined meta-path, to reduce the cost of acquiring labeled examples for supervised learning, a transductive classification model is built for automatic opioid addict detection. To the best of our knowledge, this is the first work to apply transductive classification in HIN into drug-addiction domain. Comprehensive experiments on real sample collections from Twitter are conducted to validate the effectiveness of our developed system AutoDOA in opioid addict detection by comparisons with other alternate methods. The results and case studies also demonstrate that knowledge from daily-life social media data mining could support a better practice of opioid addiction prevention and treatment.
{"title":"Social Media for Opioid Addiction Epidemiology: Automatic Detection of Opioid Addicts from Twitter and Case Studies","authors":"Yujie Fan, Yiming Zhang, Yanfang Ye, Xin Li, W. Zheng","doi":"10.1145/3132847.3132857","DOIUrl":"https://doi.org/10.1145/3132847.3132857","url":null,"abstract":"Opioid (e.g., heroin and morphine) addiction has become one of the largest and deadliest epidemics in the United States. To combat such deadly epidemic, there is an urgent need for novel tools and methodologies to gain new insights into the behavioral processes of opioid abuse and addiction. The role of social media in biomedical knowledge mining has turned into increasingly significant in recent years. In this paper, we propose a novel framework named AutoDOA to automatically detect the opioid addicts from Twitter, which can potentially assist in sharpening our understanding toward the behavioral process of opioid abuse and addiction. In AutoDOA, to model the users and posted tweets as well as their rich relationships, a structured heterogeneous information network (HIN) is first constructed. Then meta-path based approach is used to formulate similarity measures over users and different similarities are aggregated using Laplacian scores. Based on HIN and the combined meta-path, to reduce the cost of acquiring labeled examples for supervised learning, a transductive classification model is built for automatic opioid addict detection. To the best of our knowledge, this is the first work to apply transductive classification in HIN into drug-addiction domain. Comprehensive experiments on real sample collections from Twitter are conducted to validate the effectiveness of our developed system AutoDOA in opioid addict detection by comparisons with other alternate methods. The results and case studies also demonstrate that knowledge from daily-life social media data mining could support a better practice of opioid addiction prevention and treatment.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84438896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Numerical data clustering is a tractable task since well-defined numerical measures like traditional Euclidean distance can be directly used for it, but nominal data clustering is a very difficult problem because there exists no natural relative ordering between nominal attribute values. This paper mainly aims to make the Euclidean distance measure appropriate to nominal data clustering, and the core idea is to transform each nominal attribute value into numerical. This transformation method consists of three steps. In the first step, the weighted self-information, which can quantify the amount of information in attribute values, is calculated for each value in each nominal attribute. In the second step, we find k nearest neighbors for each object because k nearest neighbors of one object have close similarities with it. In the last step, the weighted self-information of each attribute value in each nominal object is modified according to the object's k nearest neighbors. To evaluate the effectiveness of our proposed method, experiments are done on 10 data sets. Experimental results demonstrate that our method not only enables the Euclidean distance to be used for nominal data clustering, but also can acquire the better clustering performance than several existing state-of-the-art approaches.
{"title":"An Euclidean Distance based on the Weighted Self-information Related Data Transformation for Nominal Data Clustering","authors":"Lei Gu, Liying Zhang, Yang Zhao","doi":"10.1145/3132847.3133062","DOIUrl":"https://doi.org/10.1145/3132847.3133062","url":null,"abstract":"Numerical data clustering is a tractable task since well-defined numerical measures like traditional Euclidean distance can be directly used for it, but nominal data clustering is a very difficult problem because there exists no natural relative ordering between nominal attribute values. This paper mainly aims to make the Euclidean distance measure appropriate to nominal data clustering, and the core idea is to transform each nominal attribute value into numerical. This transformation method consists of three steps. In the first step, the weighted self-information, which can quantify the amount of information in attribute values, is calculated for each value in each nominal attribute. In the second step, we find k nearest neighbors for each object because k nearest neighbors of one object have close similarities with it. In the last step, the weighted self-information of each attribute value in each nominal object is modified according to the object's k nearest neighbors. To evaluate the effectiveness of our proposed method, experiments are done on 10 data sets. Experimental results demonstrate that our method not only enables the Euclidean distance to be used for nominal data clustering, but also can acquire the better clustering performance than several existing state-of-the-art approaches.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85385065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Automatic tagging techniques are important for many applications such as searching and recommendation, which has attracted many researchers' attention in recent years. Existing methods mainly rely on users' tagging behavior or items' content information for tagging, yet users' consuming behavior is ignored. In this paper, we propose to leverage such information and introduce a probabilistic model called joint-tagging LDA to improve tagging accuracy. An effective algorithm based on Zero-Order Collapsed Variational Bayes is developed. Experiments conducted on a real dataset demonstrate that joint-tagging LDA outperforms existing competing methods.
{"title":"Exploiting User Consuming Behavior for Effective Item Tagging","authors":"Shen Liu, Hongyan Liu","doi":"10.1145/3132847.3133071","DOIUrl":"https://doi.org/10.1145/3132847.3133071","url":null,"abstract":"Automatic tagging techniques are important for many applications such as searching and recommendation, which has attracted many researchers' attention in recent years. Existing methods mainly rely on users' tagging behavior or items' content information for tagging, yet users' consuming behavior is ignored. In this paper, we propose to leverage such information and introduce a probabilistic model called joint-tagging LDA to improve tagging accuracy. An effective algorithm based on Zero-Order Collapsed Variational Bayes is developed. Experiments conducted on a real dataset demonstrate that joint-tagging LDA outperforms existing competing methods.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84039474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Azarbonyad, Mostafa Dehghani, K. Beelen, Alexandra Arkut, maarten marx, J. Kamps
Recently, researchers started to pay attention to the detection of temporal shifts in the meaning of words. However, most (if not all) of these approaches restricted their efforts to uncovering change over time, thus neglecting other valuable dimensions such as social or political variability. We propose an approach for detecting semantic shifts between different viewpoints---broadly defined as a set of texts that share a specific metadata feature, which can be a time-period, but also a social entity such as a political party. For each viewpoint, we learn a semantic space in which each word is represented as a low dimensional neural embedded vector. The challenge is to compare the meaning of a word in one space to its meaning in another space and measure the size of the semantic shifts. We compare the effectiveness of a measure based on optimal transformations between the two spaces with a measure based on the similarity of the neighbors of the word in the respective spaces. Our experiments demonstrate that the combination of these two performs best. We show that the semantic shifts not only occur over time but also along different viewpoints in a short period of time. For evaluation, we demonstrate how this approach captures meaningful semantic shifts and can help improve other tasks such as the contrastive viewpoint summarization and ideology detection (measured as classification accuracy) in political texts. We also show that the two laws of semantic change which were empirically shown to hold for temporal shifts also hold for shifts across viewpoints. These laws state that frequent words are less likely to shift meaning while words with many senses are more likely to do so.
{"title":"Words are Malleable: Computing Semantic Shifts in Political and Media Discourse","authors":"H. Azarbonyad, Mostafa Dehghani, K. Beelen, Alexandra Arkut, maarten marx, J. Kamps","doi":"10.1145/3132847.3132878","DOIUrl":"https://doi.org/10.1145/3132847.3132878","url":null,"abstract":"Recently, researchers started to pay attention to the detection of temporal shifts in the meaning of words. However, most (if not all) of these approaches restricted their efforts to uncovering change over time, thus neglecting other valuable dimensions such as social or political variability. We propose an approach for detecting semantic shifts between different viewpoints---broadly defined as a set of texts that share a specific metadata feature, which can be a time-period, but also a social entity such as a political party. For each viewpoint, we learn a semantic space in which each word is represented as a low dimensional neural embedded vector. The challenge is to compare the meaning of a word in one space to its meaning in another space and measure the size of the semantic shifts. We compare the effectiveness of a measure based on optimal transformations between the two spaces with a measure based on the similarity of the neighbors of the word in the respective spaces. Our experiments demonstrate that the combination of these two performs best. We show that the semantic shifts not only occur over time but also along different viewpoints in a short period of time. For evaluation, we demonstrate how this approach captures meaningful semantic shifts and can help improve other tasks such as the contrastive viewpoint summarization and ideology detection (measured as classification accuracy) in political texts. We also show that the two laws of semantic change which were empirically shown to hold for temporal shifts also hold for shifts across viewpoints. These laws state that frequent words are less likely to shift meaning while words with many senses are more likely to do so.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78525181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Imrul Chowdhury Anindya, Harichandan Roy, Murat Kantarcioglu, B. Malin
A wide variety of personal data is routinely collected by numerous organizations that, in turn, share and sell their collections for analytic investigations (e.g., market research). To preserve privacy, certain identifiers are often redacted, perturbed or even removed. A substantial number of attacks have shown that, if care is not taken, such data can be linked to external resources to determine the explicit identifiers (e.g., personal names) or infer sensitive attributes (e.g., income) for the individuals from whom the data was collected. As such, organizations increasingly rely upon record linkage methods to assess the risk such attacks pose and adopt countermeasures accordingly. Traditional linkage methods assume only two datasets would be linked (e.g., linking de-identified hospital discharge to identified voter registration lists), but with the advent of a multi-billion dollar data broker industry, modern adversaries have access to a massive data stash of multiple datasets that can be leveraged. Still, realistic adversaries have budget constraints that prevent them from obtaining and integrating all relevant datasets. Thus, in this work, we investigate a novel privacy risk assessment framework, based on adversaries who plan an integration of datasets for the most accurate estimate of targeted sensitive attributes under a certain budget. To solve this problem, we introduce a graph-based formulation of the problem and predictive modeling methods to prioritize data resources for linkage. We perform an empirical analysis using real world voter registration data from two different U.S. states and show that the methods can be used efficiently to accurately estimate potentially sensitive information disclosure risks even under a non-trivial amount of noise.
{"title":"Building a Dossier on the Cheap: Integrating Distributed Personal Data Resources Under Cost Constraints","authors":"Imrul Chowdhury Anindya, Harichandan Roy, Murat Kantarcioglu, B. Malin","doi":"10.1145/3132847.3132951","DOIUrl":"https://doi.org/10.1145/3132847.3132951","url":null,"abstract":"A wide variety of personal data is routinely collected by numerous organizations that, in turn, share and sell their collections for analytic investigations (e.g., market research). To preserve privacy, certain identifiers are often redacted, perturbed or even removed. A substantial number of attacks have shown that, if care is not taken, such data can be linked to external resources to determine the explicit identifiers (e.g., personal names) or infer sensitive attributes (e.g., income) for the individuals from whom the data was collected. As such, organizations increasingly rely upon record linkage methods to assess the risk such attacks pose and adopt countermeasures accordingly. Traditional linkage methods assume only two datasets would be linked (e.g., linking de-identified hospital discharge to identified voter registration lists), but with the advent of a multi-billion dollar data broker industry, modern adversaries have access to a massive data stash of multiple datasets that can be leveraged. Still, realistic adversaries have budget constraints that prevent them from obtaining and integrating all relevant datasets. Thus, in this work, we investigate a novel privacy risk assessment framework, based on adversaries who plan an integration of datasets for the most accurate estimate of targeted sensitive attributes under a certain budget. To solve this problem, we introduce a graph-based formulation of the problem and predictive modeling methods to prioritize data resources for linkage. We perform an empirical analysis using real world voter registration data from two different U.S. states and show that the methods can be used efficiently to accurately estimate potentially sensitive information disclosure risks even under a non-trivial amount of noise.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77830377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qizhen Zhang, Tengyuan Ye, Meryem Essaidi, S. Agarwal, Vincent Liu, B. T. Loo
A key ingredient to a startup's success is its ability to raise funding at an early stage. Crowdfunding has emerged as an exciting new mechanism for connecting startups with potentially thousands of investors. Nonetheless, little is known about its effectiveness, nor the strategies that entrepreneurs should adopt in order to maximize their rate of success. In this paper, we perform a longitudinal data collection and analysis of AngelList - a popular crowdfunding social platform for connecting investors and entrepreneurs. Over a 7-10 month period, we track companies that are actively fund-raising on AngelList, and record their level of social engagement on AngelList, Twitter, and Facebook. Through a series of measures on social en- gagement (e.g. number of tweets, posts, new followers), our analysis shows that active engagement on social media is highly correlated to crowdfunding success. In some cases, the engagement level is an order of magnitude higher for successful companies. We further apply a range of machine learning techniques (e.g. decision tree, SVM, KNN, etc) to predict the ability of a company to success- fully raise funding based on its social engagement and other metrics. Since fund-raising is a rare event, we explore various techniques to deal with class imbalance issues. We observe that some metrics (e.g. AngelList followers and Facebook posts) are more signi cant than other metrics in predicting fund-raising success. Furthermore, despite the class imbalance, we are able to predict crowdfunding success with 84% accuracy.
{"title":"Predicting Startup Crowdfunding Success through Longitudinal Social Engagement Analysis","authors":"Qizhen Zhang, Tengyuan Ye, Meryem Essaidi, S. Agarwal, Vincent Liu, B. T. Loo","doi":"10.1145/3132847.3132908","DOIUrl":"https://doi.org/10.1145/3132847.3132908","url":null,"abstract":"A key ingredient to a startup's success is its ability to raise funding at an early stage. Crowdfunding has emerged as an exciting new mechanism for connecting startups with potentially thousands of investors. Nonetheless, little is known about its effectiveness, nor the strategies that entrepreneurs should adopt in order to maximize their rate of success. In this paper, we perform a longitudinal data collection and analysis of AngelList - a popular crowdfunding social platform for connecting investors and entrepreneurs. Over a 7-10 month period, we track companies that are actively fund-raising on AngelList, and record their level of social engagement on AngelList, Twitter, and Facebook. Through a series of measures on social en- gagement (e.g. number of tweets, posts, new followers), our analysis shows that active engagement on social media is highly correlated to crowdfunding success. In some cases, the engagement level is an order of magnitude higher for successful companies. We further apply a range of machine learning techniques (e.g. decision tree, SVM, KNN, etc) to predict the ability of a company to success- fully raise funding based on its social engagement and other metrics. Since fund-raising is a rare event, we explore various techniques to deal with class imbalance issues. We observe that some metrics (e.g. AngelList followers and Facebook posts) are more signi cant than other metrics in predicting fund-raising success. Furthermore, despite the class imbalance, we are able to predict crowdfunding success with 84% accuracy.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82561170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fault-tolerant group recommendation systems based on subspace clustering successfully alleviate high-dimensionality and sparsity problems. However, the cost of recommendation grows exponentially with the size of dataset. To address this issue, we model the fault-tolerant subspace clustering problem as a search problem on graphs and present an algorithm, GraphRec, based on the concept of α-ß-core. Moreover, we propose two variants of our approach that use indexes to improve query latency. Our experiments on different datasets demonstrate that our methods are extremely fast compared to the state-of-the-art.
{"title":"Efficient Fault-Tolerant Group Recommendation Using alpha-beta-core","authors":"Danhao Ding, Hui Li, Zhipeng Huang, N. Mamoulis","doi":"10.1145/3132847.3133130","DOIUrl":"https://doi.org/10.1145/3132847.3133130","url":null,"abstract":"Fault-tolerant group recommendation systems based on subspace clustering successfully alleviate high-dimensionality and sparsity problems. However, the cost of recommendation grows exponentially with the size of dataset. To address this issue, we model the fault-tolerant subspace clustering problem as a search problem on graphs and present an algorithm, GraphRec, based on the concept of α-ß-core. Moreover, we propose two variants of our approach that use indexes to improve query latency. Our experiments on different datasets demonstrate that our methods are extremely fast compared to the state-of-the-art.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76539937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces a novel framework, namely SelectVC and its instance POP, for learning selective value couplings (i.e., interactions between the full value set and a set of outlying values) to identify outliers in high-dimensional categorical data. Existing outlier detection methods work on a full data space or feature subspaces that are identified independently from subsequent outlier scoring. As a result, they are significantly challenged by overwhelming irrelevant features in high-dimensional data due to the noise brought by the irrelevant features and its huge search space. In contrast, SelectVC works on a clean and condensed data space spanned by selective value couplings by jointly optimizing outlying value selection and value outlierness scoring. Its instance POP defines a value outlierness scoring function by modeling a partial outlierness propagation process to capture the selective value couplings. POP further defines a top-k outlying value selection method to ensure its scalability to the huge search space. We show that POP (i) significantly outperforms five state-of-the-art full space- or subspace-based outlier detectors and their combinations with three feature selection methods on 12 real-world high-dimensional data sets with different levels of irrelevant features; and (ii) obtains good scalability, stable performance w.r.t. k, and fast convergence rate.
{"title":"Selective Value Coupling Learning for Detecting Outliers in High-Dimensional Categorical Data","authors":"Guansong Pang, Hongzuo Xu, Longbing Cao, Wentao Zhao","doi":"10.1145/3132847.3132994","DOIUrl":"https://doi.org/10.1145/3132847.3132994","url":null,"abstract":"This paper introduces a novel framework, namely SelectVC and its instance POP, for learning selective value couplings (i.e., interactions between the full value set and a set of outlying values) to identify outliers in high-dimensional categorical data. Existing outlier detection methods work on a full data space or feature subspaces that are identified independently from subsequent outlier scoring. As a result, they are significantly challenged by overwhelming irrelevant features in high-dimensional data due to the noise brought by the irrelevant features and its huge search space. In contrast, SelectVC works on a clean and condensed data space spanned by selective value couplings by jointly optimizing outlying value selection and value outlierness scoring. Its instance POP defines a value outlierness scoring function by modeling a partial outlierness propagation process to capture the selective value couplings. POP further defines a top-k outlying value selection method to ensure its scalability to the huge search space. We show that POP (i) significantly outperforms five state-of-the-art full space- or subspace-based outlier detectors and their combinations with three feature selection methods on 12 real-world high-dimensional data sets with different levels of irrelevant features; and (ii) obtains good scalability, stable performance w.r.t. k, and fast convergence rate.","PeriodicalId":20449,"journal":{"name":"Proceedings of the 2017 ACM on Conference on Information and Knowledge Management","volume":"17 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87087098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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