328 research outputs found
What you say and how you say it : joint modeling of topics and discourse in microblog conversations
This paper presents an unsupervised framework for jointly modeling topic content and discourse behavior in microblog conversations. Concretely, we propose a neural model to discover word clusters indicating what a conversation concerns (i.e., topics) and those reflecting how participants voice their opinions (i.e., discourse).1 Extensive experiments show that our model can yield both coherent topics and meaningful discourse behavior. Further study shows that our topic and discourse representations can benefit the classification of microblog messages, especially when they are jointly trained with the classifier
Temporal Information Models for Real-Time Microblog Search
Real-time search in Twitter and other social media services is often biased
towards the most recent results due to the “in the moment” nature of topic
trends and their ephemeral relevance to users and media in general. However,
“in the moment”, it is often difficult to look at all emerging topics and single-out
the important ones from the rest of the social media chatter. This thesis proposes
to leverage on external sources to estimate the duration and burstiness of live
Twitter topics. It extends preliminary research where itwas shown that temporal
re-ranking using external sources could indeed improve the accuracy of results.
To further explore this topic we pursued three significant novel approaches: (1)
multi-source information analysis that explores behavioral dynamics of users,
such as Wikipedia live edits and page view streams, to detect topic trends
and estimate the topic interest over time; (2) efficient methods for federated
query expansion towards the improvement of query meaning; and (3) exploiting
multiple sources towards the detection of temporal query intent. It differs from
past approaches in the sense that it will work over real-time queries, leveraging
on live user-generated content. This approach contrasts with previous methods
that require an offline preprocessing step
iAggregator: Multidimensional Relevance Aggregation Based on a Fuzzy Operator
International audienceRecently, an increasing number of information retrieval studies have triggered a resurgence of interest in redefining the algorithmic estimation of relevance, which implies a shift from topical to multidimensional relevance assessment. A key underlying aspect that emerged when addressing this concept is the aggregation of the relevance assessments related to each of the considered dimensions. The most commonly adopted forms of aggregation are based on classical weighted means and linear combination schemes to address this issue. Although some initiatives were recently proposed, none was concerned with considering the inherent dependencies and interactions existing among the relevance criteria, as is the case in many real-life applications. In this article, we present a new fuzzy-based operator, called iAggregator, for multidimensional relevance aggregation. Its main originality, beyond its ability to model interactions between different relevance criteria, lies in its generalization of many classical aggregation functions. To validate our proposal, we apply our operator within a tweet search task. Experiments using a standard benchmark, namely, Text REtrieval Conference Microblog,1 emphasize the relevance of our contribution when compared with traditional aggregation schemes. In addition, it outperforms state-of-the-art aggregation operators such as the Scoring and the And prioritized operators as well as some representative learning-to-rank algorithms
Social Media Text Processing and Semantic Analysis for Smart Cities
With the rise of Social Media, people obtain and share information almost
instantly on a 24/7 basis. Many research areas have tried to gain valuable
insights from these large volumes of freely available user generated content.
With the goal of extracting knowledge from social media streams that might be
useful in the context of intelligent transportation systems and smart cities,
we designed and developed a framework that provides functionalities for
parallel collection of geo-located tweets from multiple pre-defined bounding
boxes (cities or regions), including filtering of non-complying tweets, text
pre-processing for Portuguese and English language, topic modeling, and
transportation-specific text classifiers, as well as, aggregation and data
visualization.
We performed an exploratory data analysis of geo-located tweets in 5
different cities: Rio de Janeiro, S\~ao Paulo, New York City, London and
Melbourne, comprising a total of more than 43 million tweets in a period of 3
months. Furthermore, we performed a large scale topic modelling comparison
between Rio de Janeiro and S\~ao Paulo. Interestingly, most of the topics are
shared between both cities which despite being in the same country are
considered very different regarding population, economy and lifestyle.
We take advantage of recent developments in word embeddings and train such
representations from the collections of geo-located tweets. We then use a
combination of bag-of-embeddings and traditional bag-of-words to train
travel-related classifiers in both Portuguese and English to filter
travel-related content from non-related. We created specific gold-standard data
to perform empirical evaluation of the resulting classifiers. Results are in
line with research work in other application areas by showing the robustness of
using word embeddings to learn word similarities that bag-of-words is not able
to capture
A Fair and Comprehensive Comparison of Multimodal Tweet Sentiment Analysis Methods
Opinion and sentiment analysis is a vital task to characterize subjective
information in social media posts. In this paper, we present a comprehensive
experimental evaluation and comparison with six state-of-the-art methods, from
which we have re-implemented one of them. In addition, we investigate different
textual and visual feature embeddings that cover different aspects of the
content, as well as the recently introduced multimodal CLIP embeddings.
Experimental results are presented for two different publicly available
benchmark datasets of tweets and corresponding images. In contrast to the
evaluation methodology of previous work, we introduce a reproducible and fair
evaluation scheme to make results comparable. Finally, we conduct an error
analysis to outline the limitations of the methods and possibilities for the
future work.Comment: Accepted in Workshop on Multi-ModalPre-Training for Multimedia
Understanding (MMPT 2021), co-located with ICMR 202
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