34,793 research outputs found
A Novel Distributed Representation of News (DRNews) for Stock Market Predictions
In this study, a novel Distributed Representation of News (DRNews) model is
developed and applied in deep learning-based stock market predictions. With the
merit of integrating contextual information and cross-documental knowledge, the
DRNews model creates news vectors that describe both the semantic information
and potential linkages among news events through an attributed news network.
Two stock market prediction tasks, namely the short-term stock movement
prediction and stock crises early warning, are implemented in the framework of
the attention-based Long Short Term-Memory (LSTM) network. It is suggested that
DRNews substantially enhances the results of both tasks comparing with five
baselines of news embedding models. Further, the attention mechanism suggests
that short-term stock trend and stock market crises both receive influences
from daily news with the former demonstrates more critical responses on the
information related to the stock market {\em per se}, whilst the latter draws
more concerns on the banking sector and economic policies.Comment: 25 page
Improving the predictability of take-off times with Machine Learning : a case study for the Maastricht upper area control centre area of responsibility
The uncertainty of the take-off time is a major contribution to the loss of trajectory predictability. At present, the Estimated Take-Off Time (ETOT) for each individual flight is extracted from the Enhanced Traffic Flow Management System (ETFMS) messages, which are sent each time there is an event triggering a recalculation of the flight data by the Network Man- ager Operations Centre. However, aircraft do not always take- off at the ETOTs reported by the ETFMS due to several factors, including congestion and bad weather conditions at the departure airport, reactionary delays and air traffic flow management slot improvements. This paper presents two machine learning models that take into account several of these factors to improve the take- off time prediction of individual flights one hour before their estimated off-block time. Predictions performed by the model trained on three years of historical flight and weather data show a reduction on the take-off time prediction error of about 30% as compared to the ETOTs reported by the ETFMS.Peer ReviewedPostprint (published version
Measuring, Predicting and Visualizing Short-Term Change in Word Representation and Usage in VKontakte Social Network
Language in social media is extremely dynamic: new words emerge, trend and
disappear, while the meaning of existing words can fluctuate over time. Such
dynamics are especially notable during a period of crisis. This work addresses
several important tasks of measuring, visualizing and predicting short term
text representation shift, i.e. the change in a word's contextual semantics,
and contrasting such shift with surface level word dynamics, or concept drift,
observed in social media streams. Unlike previous approaches on learning word
representations from text, we study the relationship between short-term concept
drift and representation shift on a large social media corpus - VKontakte posts
in Russian collected during the Russia-Ukraine crisis in 2014-2015. Our novel
contributions include quantitative and qualitative approaches to (1) measure
short-term representation shift and contrast it with surface level concept
drift; (2) build predictive models to forecast short-term shifts in meaning
from previous meaning as well as from concept drift; and (3) visualize
short-term representation shift for example keywords to demonstrate the
practical use of our approach to discover and track meaning of newly emerging
terms in social media. We show that short-term representation shift can be
accurately predicted up to several weeks in advance. Our unique approach to
modeling and visualizing word representation shifts in social media can be used
to explore and characterize specific aspects of the streaming corpus during
crisis events and potentially improve other downstream classification tasks
including real-time event detection
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