On-street parking, just as any publicly owned utility, is used inefficiently if access is free or priced very far from market rates. This paper introduces a novel demand management solution: using data from dedicated occupancy sensors an iteration scheme updates parking rates to better match demand. The new rates encourage parkers to avoid peak hours and peak locations and reduce congestion and underuse. The solution is deliberately simple so that it is easy to understand, easily seen to be fair and leads to parking policies that are easy to remember and act upon. We study the convergence properties of the iteration scheme and prove that it converges to a reasonable distribution for a very large class of models. The algorithm is in use to change parking rates in over 6000 spaces in downtown Los Angeles since June 2012 as part of the LA Express Park project. Initial results are encouraging with a reduction of congestion and underuse, while in more locations rates were decreased than increased.
{"title":"New algorithms for parking demand management and a city-scale deployment","authors":"O. Zoeter, C. Dance, S. Clinchant, J. Andreoli","doi":"10.1145/2623330.2623359","DOIUrl":"https://doi.org/10.1145/2623330.2623359","url":null,"abstract":"On-street parking, just as any publicly owned utility, is used inefficiently if access is free or priced very far from market rates. This paper introduces a novel demand management solution: using data from dedicated occupancy sensors an iteration scheme updates parking rates to better match demand. The new rates encourage parkers to avoid peak hours and peak locations and reduce congestion and underuse. The solution is deliberately simple so that it is easy to understand, easily seen to be fair and leads to parking policies that are easy to remember and act upon. We study the convergence properties of the iteration scheme and prove that it converges to a reasonable distribution for a very large class of models. The algorithm is in use to change parking rates in over 6000 spaces in downtown Los Angeles since June 2012 as part of the LA Express Park project. Initial results are encouraging with a reduction of congestion and underuse, while in more locations rates were decreased than increased.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91400876","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}
In this talk, Drew will examine data science through the lens of the social scientist. He will discuss how the various skills and disciplines combine into data science. Drew will also present a motivating example directly from his work as a senior advisor to NYC's Mayor's Office of Analytics.
{"title":"Data science through the lens of social science","authors":"D. Conway","doi":"10.1145/2623330.2630824","DOIUrl":"https://doi.org/10.1145/2623330.2630824","url":null,"abstract":"In this talk, Drew will examine data science through the lens of the social scientist. He will discuss how the various skills and disciplines combine into data science. Drew will also present a motivating example directly from his work as a senior advisor to NYC's Mayor's Office of Analytics.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91519769","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 is concerned with the problem of personalized diversification of search results, with the goal of enhancing the performance of both plain diversification and plain personalization algorithms. In previous work, the problem has mainly been tackled by means of unsupervised learning. To further enhance the performance, we propose a supervised learning strategy. Specifically, we set up a structured learning framework for conducting supervised personalized diversification, in which we add features extracted directly from the tokens of documents and those utilized by unsupervised personalized diversification algorithms, and, importantly, those generated from our proposed user-interest latent Dirichlet topic model. Based on our proposed topic model whether a document can cater to a user's interest can be estimated in our learning strategy. We also define two constraints in our structured learning framework to ensure that search results are both diversified and consistent with a user's interest. We conduct experiments on an open personalized diversification dataset and find that our supervised learning strategy outperforms unsupervised personalized diversification methods as well as other plain personalization and plain diversification methods.
{"title":"Personalized search result diversification via structured learning","authors":"Shangsong Liang, Z. Ren, M. de Rijke","doi":"10.1145/2623330.2623650","DOIUrl":"https://doi.org/10.1145/2623330.2623650","url":null,"abstract":"This paper is concerned with the problem of personalized diversification of search results, with the goal of enhancing the performance of both plain diversification and plain personalization algorithms. In previous work, the problem has mainly been tackled by means of unsupervised learning. To further enhance the performance, we propose a supervised learning strategy. Specifically, we set up a structured learning framework for conducting supervised personalized diversification, in which we add features extracted directly from the tokens of documents and those utilized by unsupervised personalized diversification algorithms, and, importantly, those generated from our proposed user-interest latent Dirichlet topic model. Based on our proposed topic model whether a document can cater to a user's interest can be estimated in our learning strategy. We also define two constraints in our structured learning framework to ensure that search results are both diversified and consistent with a user's interest. We conduct experiments on an open personalized diversification dataset and find that our supervised learning strategy outperforms unsupervised personalized diversification methods as well as other plain personalization and plain diversification methods.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87670534","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}
A feature selection algorithm should ideally satisfy four conditions: reliably extract relevant features; be able to identify non-linear feature interactions; scale linearly with the number of features and dimensions; allow the incorporation of known sparsity structure. In this work we propose a novel feature selection algorithm, Gradient Boosted Feature Selection (GBFS), which satisfies all four of these requirements. The algorithm is flexible, scalable, and surprisingly straight-forward to implement as it is based on a modification of Gradient Boosted Trees. We evaluate GBFS on several real world data sets and show that it matches or outperforms other state of the art feature selection algorithms. Yet it scales to larger data set sizes and naturally allows for domain-specific side information.
{"title":"Gradient boosted feature selection","authors":"Z. Xu, Gao Huang, Kilian Q. Weinberger, A. Zheng","doi":"10.1145/2623330.2623635","DOIUrl":"https://doi.org/10.1145/2623330.2623635","url":null,"abstract":"A feature selection algorithm should ideally satisfy four conditions: reliably extract relevant features; be able to identify non-linear feature interactions; scale linearly with the number of features and dimensions; allow the incorporation of known sparsity structure. In this work we propose a novel feature selection algorithm, Gradient Boosted Feature Selection (GBFS), which satisfies all four of these requirements. The algorithm is flexible, scalable, and surprisingly straight-forward to implement as it is based on a modification of Gradient Boosted Trees. We evaluate GBFS on several real world data sets and show that it matches or outperforms other state of the art feature selection algorithms. Yet it scales to larger data set sizes and naturally allows for domain-specific side information.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90167325","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}
Stochastic gradient descent (SGD) is a popular technique for large-scale optimization problems in machine learning. In order to parallelize SGD, minibatch training needs to be employed to reduce the communication cost. However, an increase in minibatch size typically decreases the rate of convergence. This paper introduces a technique based on approximate optimization of a conservatively regularized objective function within each minibatch. We prove that the convergence rate does not decrease with increasing minibatch size. Experiments demonstrate that with suitable implementations of approximate optimization, the resulting algorithm can outperform standard SGD in many scenarios.
{"title":"Efficient mini-batch training for stochastic optimization","authors":"Mu Li, T. Zhang, Yuqiang Chen, Alex Smola","doi":"10.1145/2623330.2623612","DOIUrl":"https://doi.org/10.1145/2623330.2623612","url":null,"abstract":"Stochastic gradient descent (SGD) is a popular technique for large-scale optimization problems in machine learning. In order to parallelize SGD, minibatch training needs to be employed to reduce the communication cost. However, an increase in minibatch size typically decreases the rate of convergence. This paper introduces a technique based on approximate optimization of a conservatively regularized objective function within each minibatch. We prove that the convergence rate does not decrease with increasing minibatch size. Experiments demonstrate that with suitable implementations of approximate optimization, the resulting algorithm can outperform standard SGD in many scenarios.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90595013","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}
Solving the missing-value (MV) problem with small estimation errors in big data environments is a notoriously resource-demanding task. As datasets and their user community continuously grow, the problem can only be exacerbated. Assume that it is possible to have a single machine (`Godzilla'), which can store the massive dataset and support an ever-growing community submitting MV imputation requests. Is it possible to replace Godzilla by employing a large number of cohort machines so that imputations can be performed much faster, engaging cohorts in parallel, each of which accesses much smaller partitions of the original dataset? If so, it would be preferable for obvious performance reasons to access only a subset of all cohorts per imputation. In this case, can we decide swiftly which is the desired subset of cohorts to engage per imputation? But efficiency and scalability is just one key concern! Is it possible to do the above while ensuring comparable or even better than Godzilla's imputation estimation errors? In this paper we derive answers to these fundamentals questions and develop principled methods and a framework which offer large performance speed-ups and better, or comparable, errors to that of Godzilla, independently of which missing-value imputation algorithm is used. Our contributions involve Pythia, a framework and algorithms for providing the answers to the above questions and for engaging the appropriate subset of cohorts per MV imputation request. Pythia functionality rests on two pillars: (i) dataset (partition) signatures, one per cohort, and (ii) similarity notions and algorithms, which can identify the appropriate subset of cohorts to engage. Comprehensive experimentation with real and synthetic datasets showcase our efficiency, scalability, and accuracy claims.
{"title":"Scaling out big data missing value imputations: pythia vs. godzilla","authors":"C. Anagnostopoulos, P. Triantafillou","doi":"10.1145/2623330.2623615","DOIUrl":"https://doi.org/10.1145/2623330.2623615","url":null,"abstract":"Solving the missing-value (MV) problem with small estimation errors in big data environments is a notoriously resource-demanding task. As datasets and their user community continuously grow, the problem can only be exacerbated. Assume that it is possible to have a single machine (`Godzilla'), which can store the massive dataset and support an ever-growing community submitting MV imputation requests. Is it possible to replace Godzilla by employing a large number of cohort machines so that imputations can be performed much faster, engaging cohorts in parallel, each of which accesses much smaller partitions of the original dataset? If so, it would be preferable for obvious performance reasons to access only a subset of all cohorts per imputation. In this case, can we decide swiftly which is the desired subset of cohorts to engage per imputation? But efficiency and scalability is just one key concern! Is it possible to do the above while ensuring comparable or even better than Godzilla's imputation estimation errors? In this paper we derive answers to these fundamentals questions and develop principled methods and a framework which offer large performance speed-ups and better, or comparable, errors to that of Godzilla, independently of which missing-value imputation algorithm is used. Our contributions involve Pythia, a framework and algorithms for providing the answers to the above questions and for engaging the appropriate subset of cohorts per MV imputation request. Pythia functionality rests on two pillars: (i) dataset (partition) signatures, one per cohort, and (ii) similarity notions and algorithms, which can identify the appropriate subset of cohorts to engage. Comprehensive experimentation with real and synthetic datasets showcase our efficiency, scalability, and accuracy claims.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85916114","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}
Tourism industry has become a key economic driver for Singapore. Understanding the behaviors of tourists is very important for the government and private sectors, e.g., restaurants, hotels and advertising companies, to improve their existing services or create new business opportunities. In this joint work with Singapore's Land Transport Authority (LTA), we innovatively apply machine learning techniques to identity the tourists among public commuters using the public transportation data provided by LTA. On successful identification, the travelling patterns of tourists are then revealed and thus allow further analyses to be carried out such as on their favorite destinations, region of stay, etc. Technically, we model the tourists identification as a classification problem, and design an iterative learning algorithm to perform inference with limited prior knowledge and labeled data. We show the superiority of our algorithm with performance evaluation and comparison with other state-of-the-art learning algorithms. Further, we build an interactive web-based system for answering queries regarding the moving patterns of the tourists, which can be used by stakeholders to gain insight into tourists' travelling behaviors in Singapore.
{"title":"Identifying tourists from public transport commuters","authors":"Mingqiang Xue, Huayu Wu, Wei Chen, W. Ng, Gin Howe Goh","doi":"10.1145/2623330.2623352","DOIUrl":"https://doi.org/10.1145/2623330.2623352","url":null,"abstract":"Tourism industry has become a key economic driver for Singapore. Understanding the behaviors of tourists is very important for the government and private sectors, e.g., restaurants, hotels and advertising companies, to improve their existing services or create new business opportunities. In this joint work with Singapore's Land Transport Authority (LTA), we innovatively apply machine learning techniques to identity the tourists among public commuters using the public transportation data provided by LTA. On successful identification, the travelling patterns of tourists are then revealed and thus allow further analyses to be carried out such as on their favorite destinations, region of stay, etc. Technically, we model the tourists identification as a classification problem, and design an iterative learning algorithm to perform inference with limited prior knowledge and labeled data. We show the superiority of our algorithm with performance evaluation and comparison with other state-of-the-art learning algorithms. Further, we build an interactive web-based system for answering queries regarding the moving patterns of the tourists, which can be used by stakeholders to gain insight into tourists' travelling behaviors in Singapore.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86021061","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}
E-commerce has largely been a 'Pull' model to date. Offline retailers have nailed discovery, delight, serendipity, and impulse purchases in person with greater success than online commerce sites. However, in an always-on, mobile-first world, companies like Groupon have the opportunity to push the frontier even further than offline retailers or comprehensive sites due to the fact that our smartphones are always with us. The challenge is to provide the right deals to the right user at the right time. That involves learning about the users and their locations, their personal preferences, and predicting which deals are likely to delight them, presenting diversity, discovery and engaging UX to gather user preferences and semantic graph approaches for user-deal matching. This presentation will give insight into how Groupon manages to grapple with these challenges via a data-driven system in order to delight and surprise customers.
{"title":"Frontiers in E-commerce personalization","authors":"S. Subramaniam","doi":"10.1145/2623330.2630820","DOIUrl":"https://doi.org/10.1145/2623330.2630820","url":null,"abstract":"E-commerce has largely been a 'Pull' model to date. Offline retailers have nailed discovery, delight, serendipity, and impulse purchases in person with greater success than online commerce sites. However, in an always-on, mobile-first world, companies like Groupon have the opportunity to push the frontier even further than offline retailers or comprehensive sites due to the fact that our smartphones are always with us. The challenge is to provide the right deals to the right user at the right time. That involves learning about the users and their locations, their personal preferences, and predicting which deals are likely to delight them, presenting diversity, discovery and engaging UX to gather user preferences and semantic graph approaches for user-deal matching. This presentation will give insight into how Groupon manages to grapple with these challenges via a data-driven system in order to delight and surprise customers.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87944007","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}
Clustering categorical data poses some unique challenges: Due to missing order and spacing among the categories, selecting a suitable similarity measure is a difficult task. Many existing techniques require the user to specify input parameters which are difficult to estimate. Moreover, many techniques are limited to detect clusters in the full-dimensional data space. Only few methods exist for subspace clustering and they produce highly redundant results. Therefore, we propose ROCAT (Relevant Overlapping Subspace Clusters on Categorical Data), a novel technique based on the idea of data compression. Following the Minimum Description Length principle, ROCAT automatically detects the most relevant subspace clusters without any input parameter. The relevance of each cluster is validated by its contribution to compress the data. Optimizing the trade-off between goodness-of-fit and model complexity, ROCAT automatically determines a meaningful number of clusters to represent the data. ROCAT is especially designed to detect subspace clusters on categorical data which may overlap in objects and/or attributes; i.e. objects can be assigned to different clusters in different subspaces and attributes may contribute to different subspaces containing clusters. ROCAT naturally avoids undesired redundancy in clusters and subspaces by allowing overlap only if it improves the compression rate. Extensive experiments demonstrate the effectiveness and efficiency of our approach.
{"title":"Relevant overlapping subspace clusters on categorical data","authors":"Xiao He, Jing Feng, B. Konte, S. T. Mai, C. Plant","doi":"10.1145/2623330.2623652","DOIUrl":"https://doi.org/10.1145/2623330.2623652","url":null,"abstract":"Clustering categorical data poses some unique challenges: Due to missing order and spacing among the categories, selecting a suitable similarity measure is a difficult task. Many existing techniques require the user to specify input parameters which are difficult to estimate. Moreover, many techniques are limited to detect clusters in the full-dimensional data space. Only few methods exist for subspace clustering and they produce highly redundant results. Therefore, we propose ROCAT (Relevant Overlapping Subspace Clusters on Categorical Data), a novel technique based on the idea of data compression. Following the Minimum Description Length principle, ROCAT automatically detects the most relevant subspace clusters without any input parameter. The relevance of each cluster is validated by its contribution to compress the data. Optimizing the trade-off between goodness-of-fit and model complexity, ROCAT automatically determines a meaningful number of clusters to represent the data. ROCAT is especially designed to detect subspace clusters on categorical data which may overlap in objects and/or attributes; i.e. objects can be assigned to different clusters in different subspaces and attributes may contribute to different subspaces containing clusters. ROCAT naturally avoids undesired redundancy in clusters and subspaces by allowing overlap only if it improves the compression rate. Extensive experiments demonstrate the effectiveness and efficiency of our approach.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85718260","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}
Short text clustering has become an increasingly important task with the popularity of social media like Twitter, Google+, and Facebook. It is a challenging problem due to its sparse, high-dimensional, and large-volume characteristics. In this paper, we proposed a collapsed Gibbs Sampling algorithm for the Dirichlet Multinomial Mixture model for short text clustering (abbr. to GSDMM). We found that GSDMM can infer the number of clusters automatically with a good balance between the completeness and homogeneity of the clustering results, and is fast to converge. GSDMM can also cope with the sparse and high-dimensional problem of short texts, and can obtain the representative words of each cluster. Our extensive experimental study shows that GSDMM can achieve significantly better performance than three other clustering models.
{"title":"A dirichlet multinomial mixture model-based approach for short text clustering","authors":"Jianhua Yin, Jianyong Wang","doi":"10.1145/2623330.2623715","DOIUrl":"https://doi.org/10.1145/2623330.2623715","url":null,"abstract":"Short text clustering has become an increasingly important task with the popularity of social media like Twitter, Google+, and Facebook. It is a challenging problem due to its sparse, high-dimensional, and large-volume characteristics. In this paper, we proposed a collapsed Gibbs Sampling algorithm for the Dirichlet Multinomial Mixture model for short text clustering (abbr. to GSDMM). We found that GSDMM can infer the number of clusters automatically with a good balance between the completeness and homogeneity of the clustering results, and is fast to converge. GSDMM can also cope with the sparse and high-dimensional problem of short texts, and can obtain the representative words of each cluster. Our extensive experimental study shows that GSDMM can achieve significantly better performance than three other clustering models.","PeriodicalId":20536,"journal":{"name":"Proceedings of the 20th ACM SIGKDD international conference on Knowledge discovery and data mining","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87623284","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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