53 research outputs found
Deep Learning Relevance: Creating Relevant Information (as Opposed to Retrieving it)
What if Information Retrieval (IR) systems did not just retrieve relevant
information that is stored in their indices, but could also "understand" it and
synthesise it into a single document? We present a preliminary study that makes
a first step towards answering this question. Given a query, we train a
Recurrent Neural Network (RNN) on existing relevant information to that query.
We then use the RNN to "deep learn" a single, synthetic, and we assume,
relevant document for that query. We design a crowdsourcing experiment to
assess how relevant the "deep learned" document is, compared to existing
relevant documents. Users are shown a query and four wordclouds (of three
existing relevant documents and our deep learned synthetic document). The
synthetic document is ranked on average most relevant of all.Comment: Neu-IR '16 SIGIR Workshop on Neural Information Retrieval, July 21,
2016, Pisa, Ital
Entropy and Graph Based Modelling of Document Coherence using Discourse Entities: An Application
We present two novel models of document coherence and their application to
information retrieval (IR). Both models approximate document coherence using
discourse entities, e.g. the subject or object of a sentence. Our first model
views text as a Markov process generating sequences of discourse entities
(entity n-grams); we use the entropy of these entity n-grams to approximate the
rate at which new information appears in text, reasoning that as more new words
appear, the topic increasingly drifts and text coherence decreases. Our second
model extends the work of Guinaudeau & Strube [28] that represents text as a
graph of discourse entities, linked by different relations, such as their
distance or adjacency in text. We use several graph topology metrics to
approximate different aspects of the discourse flow that can indicate
coherence, such as the average clustering or betweenness of discourse entities
in text. Experiments with several instantiations of these models show that: (i)
our models perform on a par with two other well-known models of text coherence
even without any parameter tuning, and (ii) reranking retrieval results
according to their coherence scores gives notable performance gains, confirming
a relation between document coherence and relevance. This work contributes two
novel models of document coherence, the application of which to IR complements
recent work in the integration of document cohesiveness or comprehensibility to
ranking [5, 56]
Near-optimal adjacency labeling scheme for power-law graphs
An adjacency labeling scheme is a method that assigns labels to the vertices
of a graph such that adjacency between vertices can be inferred directly from
the assigned label, without using a centralized data structure. We devise
adjacency labeling schemes for the family of power-law graphs. This family that
has been used to model many types of networks, e.g. the Internet AS-level
graph. Furthermore, we prove an almost matching lower bound for this family. We
also provide an asymptotically near- optimal labeling scheme for sparse graphs.
Finally, we validate the efficiency of our labeling scheme by an experimental
evaluation using both synthetic data and real-world networks of up to hundreds
of thousands of vertices
Neural Speed Reading with Structural-Jump-LSTM
Recurrent neural networks (RNNs) can model natural language by sequentially
'reading' input tokens and outputting a distributed representation of each
token. Due to the sequential nature of RNNs, inference time is linearly
dependent on the input length, and all inputs are read regardless of their
importance. Efforts to speed up this inference, known as 'neural speed
reading', either ignore or skim over part of the input. We present
Structural-Jump-LSTM: the first neural speed reading model to both skip and
jump text during inference. The model consists of a standard LSTM and two
agents: one capable of skipping single words when reading, and one capable of
exploiting punctuation structure (sub-sentence separators (,:), sentence end
symbols (.!?), or end of text markers) to jump ahead after reading a word. A
comprehensive experimental evaluation of our model against all five
state-of-the-art neural reading models shows that Structural-Jump-LSTM achieves
the best overall floating point operations (FLOP) reduction (hence is faster),
while keeping the same accuracy or even improving it compared to a vanilla LSTM
that reads the whole text.Comment: 10 page
Modelling Sequential Music Track Skips using a Multi-RNN Approach
Modelling sequential music skips provides streaming companies the ability to
better understand the needs of the user base, resulting in a better user
experience by reducing the need to manually skip certain music tracks. This
paper describes the solution of the University of Copenhagen DIKU-IR team in
the 'Spotify Sequential Skip Prediction Challenge', where the task was to
predict the skip behaviour of the second half in a music listening session
conditioned on the first half. We model this task using a Multi-RNN approach
consisting of two distinct stacked recurrent neural networks, where one network
focuses on encoding the first half of the session and the other network focuses
on utilizing the encoding to make sequential skip predictions. The encoder
network is initialized by a learned session-wide music encoding, and both of
them utilize a learned track embedding. Our final model consists of a majority
voted ensemble of individually trained models, and ranked 2nd out of 45
participating teams in the competition with a mean average accuracy of 0.641
and an accuracy on the first skip prediction of 0.807. Our code is released at
https://github.com/Varyn/WSDM-challenge-2019-spotify.Comment: 4 page
The Copenhagen Team Participation in the Check-Worthiness Task of the Competition of Automatic Identification and Verification of Claims in Political Debates of the CLEF-2018 CheckThat! Lab
Near Optimal Adjacency Labeling Schemes for Power-Law Graphs
An adjacency labeling scheme labels the n nodes of a graph with bit strings in a way that allows, given the labels of two nodes, to determine adjacency based only on those bit strings. Though many graph families have been meticulously studied for this problem, a non-trivial labeling scheme for the important family of power-law graphs has yet to be obtained. This family is particularly useful for social and web networks as their underlying graphs are typically modelled as power-law graphs. Using simple strategies and a careful selection of a parameter, we show upper bounds for such labeling schemes of ~O(sqrt^{alpha}(n)) for power law graphs with coefficient alpha;, as well as nearly matching lower bounds. We also show two relaxations that allow for a label of logarithmic size, and extend the upper-bound technique to produce an improved distance labeling scheme for power-law graphs
Unsupervised Semantic Hashing with Pairwise Reconstruction
Semantic Hashing is a popular family of methods for efficient similarity
search in large-scale datasets. In Semantic Hashing, documents are encoded as
short binary vectors (i.e., hash codes), such that semantic similarity can be
efficiently computed using the Hamming distance. Recent state-of-the-art
approaches have utilized weak supervision to train better performing hashing
models. Inspired by this, we present Semantic Hashing with Pairwise
Reconstruction (PairRec), which is a discrete variational autoencoder based
hashing model. PairRec first encodes weakly supervised training pairs (a query
document and a semantically similar document) into two hash codes, and then
learns to reconstruct the same query document from both of these hash codes
(i.e., pairwise reconstruction). This pairwise reconstruction enables our model
to encode local neighbourhood structures within the hash code directly through
the decoder. We experimentally compare PairRec to traditional and
state-of-the-art approaches, and obtain significant performance improvements in
the task of document similarity search.Comment: Accepted at SIGIR'2
- …