77 research outputs found
Sometimes less is more : Romanian word sense disambiguation revisited
Recent approaches to Word Sense Disambiguation (WSD) generally fall into two classes: (1) information-intensive approaches and (2) information-poor approaches. Our hypothesis is that for memory-based learning (MBL), a reduced amount of data is more beneficial than the full range of features used in the past. Our experiments show that MBL combined with a restricted set of features and a feature selection method that minimizes the feature set leads to competitive results, outperforming all systems that participated in the SENSEVAL-3 competition on the Romanian data. Thus, with this specific method, a tightly controlled feature set improves the accuracy of the classifier, reaching 74.0% in the fine-grained and 78.7% in the coarse-grained evaluation
Weakly Supervised Cross-Lingual Named Entity Recognition via Effective Annotation and Representation Projection
The state-of-the-art named entity recognition (NER) systems are supervised
machine learning models that require large amounts of manually annotated data
to achieve high accuracy. However, annotating NER data by human is expensive
and time-consuming, and can be quite difficult for a new language. In this
paper, we present two weakly supervised approaches for cross-lingual NER with
no human annotation in a target language. The first approach is to create
automatically labeled NER data for a target language via annotation projection
on comparable corpora, where we develop a heuristic scheme that effectively
selects good-quality projection-labeled data from noisy data. The second
approach is to project distributed representations of words (word embeddings)
from a target language to a source language, so that the source-language NER
system can be applied to the target language without re-training. We also
design two co-decoding schemes that effectively combine the outputs of the two
projection-based approaches. We evaluate the performance of the proposed
approaches on both in-house and open NER data for several target languages. The
results show that the combined systems outperform three other weakly supervised
approaches on the CoNLL data.Comment: 11 pages, The 55th Annual Meeting of the Association for
Computational Linguistics (ACL), 201
Learning morphology with Morfette
Morfette is a modular, data-driven, probabilistic system which learns to perform joint morphological tagging and lemmatization from morphologically annotated corpora. The system is composed of two learning modules which are trained to predict morphological tags and lemmas using the Maximum Entropy classifier. The third module dynamically combines the predictions of the Maximum-Entropy models and outputs a probability distribution over tag-lemma pair sequences. The lemmatization module exploits the idea of recasting lemmatization as a classification task by using class labels which encode mappings from wordforms to lemmas. Experimental evaluation results and error analysis on three morphologically rich languages show that the system achieves high accuracy with no language-specific
feature engineering or additional resources
Leveraging Intellectual Capital Management in Virtual Teams: What the Covid-19 Pandemic Taught Us
This study undertakes a review of the scientific literature on the role and impact of Intellectual Capital (IC) with all its components (human, structural and relational capital) on Virtual Team (VT) work. As already proven in the discipline research, IC as a summum of organizational knowledge resources plays a fundamental role in the knowledge economy in sustaining competitive advantage, innovation and performance. Despite an abundance of papers investigating VTs from both a theoretical and empirical perspective, a surprising discovery has been made during this research. The extent of work dedicated to analysing the relationships between IC and VTs is minimal, notwithstanding the unprecedented expansion of the use of VTs since the beginning of the Covid-19 pandemic. Following a first review of the extant literature regarding IC and VTs, a second literature review has been conducted for the benefit of revealing crucial aspects and the newest best practices in what concerns work in VTs. In doing so, the authors attempt to draw attention to the need for in-depth researches in the IC field, to catch up with the business, economic and societal most recent developments. Furthermore, this study aims to provide the practitioners with up-to-date, concise knowledge on the practical aspects relevant for the work in VTs
Better training for function labeling
Function labels enrich constituency parse tree nodes with information about their abstract syntactic and semantic roles. A common way to obtain function-labeled trees is to use a two-stage architecture where first a statistical parser produces the constituent structure and then a second
component such as a classifier adds the missing function tags. In order to achieve optimal results, training
examples for machine-learning-based classifiers should be as similar as possible to the instances seen during prediction. However, the method which has been used so far to obtain training examples for the function labeling classifier suffers from a serious drawback: the training examples come from perfect treebank trees, whereas test
examples are derived from parser-produced, imperfect trees.
We show that extracting training instances from the reparsed training part of the treebank results in better training material as measured by similarity to test instances. We show that our training method achieves statistically significantly higher f-scores on the function labeling task for the English Penn Treebank. Currently our method achieves 91.47% f-score on the section 23 of WSJ, the highest score reported in the literature so far
Word meaning in context : a probabilistic model and its application to question answering
The need for assessing similarity in meaning is central to most language technology applications. Distributional methods are robust, unsupervised methods which achieve high performance on this task. These methods measure similarity of word types solely based on patterns of word occurrences in large corpora, following the intuition that similar words occur in similar contexts. As most Natural Language Processing (NLP) applications deal with disambiguated words, words occurring in context, rather than word types, the question of adapting distributional methods to compute sense-specific or context-sensitive similarities has gained increasing attention in recent work. This thesis focuses on the development and applications of distributional methods for context-sensitive similarity. The contribution made is twofold: the main part of the thesis proposes and tests a new framework for computing similarity in context, while the second part investigates the application of distributional paraphrasing to the task of question answering.Die Notwendigkeit der Beurteilung von Bedeutungsähnlichkeit spielt für die meisten sprachtechnologische Anwendungen eine wesentliche Rolle. Distributionelle Verfahren sind solide, unbeaufsichtigte Verfahren, die für diese Aufgabe sehr effektiv sind. Diese Verfahren messen die Ähnlichkeit von Wortarten lediglich auf Basis von Mustern, nach denen die Wörter in großen Korpora vorkommen, indem sie der Erkenntnis folgen, dass ähnliche Wörter in ähnlichen Kontexten auftreten. Da die meisten Anwendungen im Natural Language Processing (NLP) mit eindeutigen Wörtern arbeiten, also eher Wörtern, die im Kontext vorkommen, als Wortarten, hat die Frage, ob distributionelle Verfahren angepasst werden sollten, um bedeutungsspezifische oder kontextabhängige Ähnlichkeiten zu berechnen, in neueren Arbeiten zunehmend an Bedeutung gewonnen. Diese Dissertation konzentriert sich auf die Entwicklung und Anwendungen von distributionellen Verfahren für kontextabhängige Ähnlichkeit und liefert einen doppelten Beitrag: Den Hauptteil der Arbeit bildet die Präsentation und Erprobung eines neuen framework für die Berechnung von Ähnlichkeit im Kontext. Im zweiten Teil der Arbeit wird die Anwendung des distributional paraphrasing auf die Aufgabe der Fragenbeantwortung untersucht
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