7,039 research outputs found

    Knowing with Experts: Contextual Knowledge in and Around Science

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    The original concept of epistemic dependence suggests uncritical deference to expert opinions for non-experts. In the light of recent work in science studies, however, the actual situation of epistemic dependence is seen to involve the necessary and ubiquitous need for lay evaluations of scientific experts. As expert knowledge means restricted cognitive access to some epistemic domain, lay evaluations of expert knowledge are rational and informed only when the criteria used by non-experts when judging experts are different from the criteria used by experts when making their claims. The distinction between ‘substantial knowledge’ and ‘contextual knowledge’ allows for the laypeople to know with experts without having to know precisely what experts know. Such meta-expert evaluations are not specific to the public sphere outside science, nor are they limited internally to science, but they are present in a wide range of contexts in and around science. The paper legitimizes the concept of contextual knowledge by relating it to the relevant literature, and expounds the idea by identifying some elements of such a knowledge

    Computational Argumentation for the Automatic Analysis of Argumentative Discourse and Human Persuasion

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    Tesis por compendio[ES] La argumentación computacional es el área de investigación que estudia y analiza el uso de distintas técnicas y algoritmos que aproximan el razonamiento argumentativo humano desde un punto de vista computacional. En esta tesis doctoral se estudia el uso de distintas técnicas propuestas bajo el marco de la argumentación computacional para realizar un análisis automático del discurso argumentativo, y para desarrollar técnicas de persuasión computacional basadas en argumentos. Con estos objetivos, en primer lugar se presenta una completa revisión del estado del arte y se propone una clasificación de los trabajos existentes en el área de la argumentación computacional. Esta revisión nos permite contextualizar y entender la investigación previa de forma más clara desde la perspectiva humana del razonamiento argumentativo, así como identificar las principales limitaciones y futuras tendencias de la investigación realizada en argumentación computacional. En segundo lugar, con el objetivo de solucionar algunas de estas limitaciones, se ha creado y descrito un nuevo conjunto de datos que permite abordar nuevos retos y investigar problemas previamente inabordables (e.g., evaluación automática de debates orales). Conjuntamente con estos datos, se propone un nuevo sistema para la extracción automática de argumentos y se realiza el análisis comparativo de distintas técnicas para esta misma tarea. Además, se propone un nuevo algoritmo para la evaluación automática de debates argumentativos y se prueba con debates humanos reales. Finalmente, en tercer lugar se presentan una serie de estudios y propuestas para mejorar la capacidad persuasiva de sistemas de argumentación computacionales en la interacción con usuarios humanos. De esta forma, en esta tesis se presentan avances en cada una de las partes principales del proceso de argumentación computacional (i.e., extracción automática de argumentos, representación del conocimiento y razonamiento basados en argumentos, e interacción humano-computador basada en argumentos), así como se proponen algunos de los cimientos esenciales para el análisis automático completo de discursos argumentativos en lenguaje natural.[CA] L'argumentació computacional és l'àrea de recerca que estudia i analitza l'ús de distintes tècniques i algoritmes que aproximen el raonament argumentatiu humà des d'un punt de vista computacional. En aquesta tesi doctoral s'estudia l'ús de distintes tècniques proposades sota el marc de l'argumentació computacional per a realitzar una anàlisi automàtic del discurs argumentatiu, i per a desenvolupar tècniques de persuasió computacional basades en arguments. Amb aquestos objectius, en primer lloc es presenta una completa revisió de l'estat de l'art i es proposa una classificació dels treballs existents en l'àrea de l'argumentació computacional. Aquesta revisió permet contextualitzar i entendre la investigació previa de forma més clara des de la perspectiva humana del raonament argumentatiu, així com identificar les principals limitacions i futures tendències de la investigació realitzada en argumentació computacional. En segon lloc, amb l'objectiu de sol⋅\cdotlucionar algunes d'aquestes limitacions, hem creat i descrit un nou conjunt de dades que ens permet abordar nous reptes i investigar problemes prèviament inabordables (e.g., avaluació automàtica de debats orals). Conjuntament amb aquestes dades, es proposa un nou sistema per a l'extracció d'arguments i es realitza l'anàlisi comparativa de distintes tècniques per a aquesta mateixa tasca. A més a més, es proposa un nou algoritme per a l'avaluació automàtica de debats argumentatius i es prova amb debats humans reals. Finalment, en tercer lloc es presenten una sèrie d'estudis i propostes per a millorar la capacitat persuasiva de sistemes d'argumentació computacionals en la interacció amb usuaris humans. D'aquesta forma, en aquesta tesi es presenten avanços en cada una de les parts principals del procés d'argumentació computacional (i.e., l'extracció automàtica d'arguments, la representació del coneixement i raonament basats en arguments, i la interacció humà-computador basada en arguments), així com es proposen alguns dels fonaments essencials per a l'anàlisi automàtica completa de discursos argumentatius en llenguatge natural.[EN] Computational argumentation is the area of research that studies and analyses the use of different techniques and algorithms that approximate human argumentative reasoning from a computational viewpoint. In this doctoral thesis we study the use of different techniques proposed under the framework of computational argumentation to perform an automatic analysis of argumentative discourse, and to develop argument-based computational persuasion techniques. With these objectives in mind, we first present a complete review of the state of the art and propose a classification of existing works in the area of computational argumentation. This review allows us to contextualise and understand the previous research more clearly from the human perspective of argumentative reasoning, and to identify the main limitations and future trends of the research done in computational argumentation. Secondly, to overcome some of these limitations, we create and describe a new corpus that allows us to address new challenges and investigate on previously unexplored problems (e.g., automatic evaluation of spoken debates). In conjunction with this data, a new system for argument mining is proposed and a comparative analysis of different techniques for this same task is carried out. In addition, we propose a new algorithm for the automatic evaluation of argumentative debates and we evaluate it with real human debates. Thirdly, a series of studies and proposals are presented to improve the persuasiveness of computational argumentation systems in the interaction with human users. In this way, this thesis presents advances in each of the main parts of the computational argumentation process (i.e., argument mining, argument-based knowledge representation and reasoning, and argument-based human-computer interaction), and proposes some of the essential foundations for the complete automatic analysis of natural language argumentative discourses.This thesis has been partially supported by the Generalitat Valenciana project PROME- TEO/2018/002 and by the Spanish Government projects TIN2017-89156-R and PID2020- 113416RB-I00.Ruiz Dolz, R. (2023). Computational Argumentation for the Automatic Analysis of Argumentative Discourse and Human Persuasion [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/194806Compendi

    Probing the Low-Energy Electronic Structure of Complex Systems by ARPES

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    Angle-resolved photoemission spectroscopy (ARPES) is one of the most direct methods of studying the electronic structure of solids. By measuring the kinetic energy and angular distribution of the electrons photoemitted from a sample illuminated with sufficiently high-energy radiation, one can gain information on both the energy and momentum of the electrons propagating inside a material. This is of vital importance in elucidating the connection between electronic, magnetic, and chemical structure of solids, in particular for those complex systems which cannot be appropriately described within the independent-particle picture. The last decade witnessed significant progress in this technique and its applications, thus ushering in a new era in photoelectron spectroscopy; today, ARPES experiments with 2 meV energy resolution and 0.2 degree angular resolution are a reality even for photoemission on solids. In this paper we will review the fundamentals of the technique and present some illustrative experimental results; we will show how ARPES can probe the momentum-dependent electronic structure of solids providing detailed information on band dispersion and Fermi surface, as well as on the strength and nature of those many-body correlations which may profoundly affect the one-electron excitation spectrum and, in turn, determine the macroscopic physical properties.Comment: Lecture notes for the 2003 Exciting Summer School (http://www.fysik4.fysik.uu.se/~thor/school.html). A HIGH-RESOLUTION pdf file is available at http://www.physics.ubc.ca/~damascel/ARPES_Intro.pdf, and related viewgraphs at http://www.physics.ubc.ca/~damascel/Exciting2003.pd

    Transfomer Models: From Model Inspection to Applications in Patents

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    L'elaborazione del linguaggio naturale viene utilizzata per affrontare diversi compiti, sia di tipo linguistico, come ad esempio l'etichettatura della parte del discorso, il parsing delle dipendenze, sia più specifiche, come ad esempio la traduzione automatica e l'analisi del sentimento. Per affrontare questi compiti, nel tempo sono stati sviluppati approcci dedicati.Una metodologia che aumenta le prestazioni in tutti questi casi in modo unificato è la modellazione linguistica, che consiste nel preaddestrare un modello per sostituire i token mascherati in grandi quantità di testo, in modo casuale all'interno di pezzi di testo o in modo sequenziale uno dopo l'altro, per sviluppare rappresentazioni di uso generale che possono essere utilizzate per migliorare le prestazioni in molti compiti contemporaneamente.L'architettura di rete neurale che attualmente svolge al meglio questo compito è il transformer, inoltre, le dimensioni del modello e la quantità dei dati sono essenziali per lo sviluppo di rappresentazioni ricche di informazioni. La disponibilità di insiemi di dati su larga scala e l'uso di modelli con miliardi di parametri sono attualmente il percorso più efficace verso una migliore rappresentazione del testo.Tuttavia, i modelli di grandi dimensioni comportano una maggiore difficoltà nell'interpretazione dell'output che forniscono. Per questo motivo, sono stati condotti diversi studi per indagare le rappresentazioni fornite da modelli di transformers.In questa tesi indago questi modelli da diversi punti di vista, studiando le proprietà linguistiche delle rappresentazioni fornite da BERT, per capire se le informazioni che codifica sono localizzate all'interno di specifiche elementi della rappresentazione vettoriale. A tal fine, identifico pesi speciali che mostrano un'elevata rilevanza per diversi compiti di sondaggio linguistico. In seguito, analizzo la causa di questi particolari pesi e li collego alla distribuzione dei token e ai token speciali.Per completare questa analisi generale ed estenderla a casi d'uso più specifici, studio l'efficacia di questi modelli sui brevetti. Utilizzo modelli dedicati, per identificare entità specifiche del dominio, come le tecnologie o per segmentare il testo dei brevetti. Studio sempre l'analisi delle prestazioni integrandola con accurate misurazioni dei dati e delle proprietà del modello per capire se le conclusioni tratte per i modelli generici valgono anche in questo contesto.Natural Language Processing is used to address several tasks, linguistic related ones, e.g. part of speech tagging, dependency parsing, and downstream tasks, e.g. machine translation, sentiment analysis. To tackle these tasks, dedicated approaches have been developed over time.A methodology that increases performance on all tasks in a unified manner is language modeling, this is done by pre-training a model to replace masked tokens in large amounts of text, either randomly within chunks of text or sequentially one after the other, to develop general purpose representations that can be used to improve performance in many downstream tasks at once.The neural network architecture currently best performing this task is the transformer, moreover, model size and data scale are essential to the development of information-rich representations. The availability of large scale datasets and the use of models with billions of parameters is currently the most effective path towards better representations of text.However, with large models, comes the difficulty in interpreting the output they provide. Therefore, several studies have been carried out to investigate the representations provided by transformers models trained on large scale datasets.In this thesis I investigate these models from several perspectives, I study the linguistic properties of the representations provided by BERT, a language model mostly trained on the English Wikipedia, to understand if the information it codifies is localized within specific entries of the vector representation. Doing this I identify special weights that show high relevance to several distinct linguistic probing tasks. Subsequently, I investigate the cause of these special weights, and link them to token distribution and special tokens.To complement this general purpose analysis and extend it to more specific use cases, given the wide range of applications for language models, I study their effectiveness on technical documentation, specifically, patents. I use both general purpose and dedicated models, to identify domain-specific entities such as users of the inventions and technologies or to segment patents text. I always study performance analysis complementing it with careful measurements of data and model properties to understand if the conclusions drawn for general purpose models hold in this context as well

    Investigations into the value of labeled and unlabeled data in biomedical entity recognition and word sense disambiguation

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    Human annotations, especially in highly technical domains, are expensive and time consuming togather, and can also be erroneous. As a result, we never have sufficiently accurate data to train andevaluate supervised methods. In this thesis, we address this problem by taking a semi-supervised approach to biomedical namedentity recognition (NER), and by proposing an inventory-independent evaluation framework for supervised and unsupervised word sense disambiguation. Our contributions are as follows: We introduce a novel graph-based semi-supervised approach to named entity recognition(NER) and exploit pre-trained contextualized word embeddings in several biomedical NER tasks. We propose a new evaluation framework for word sense disambiguation that permits a fair comparison between supervised methods trained on different sense inventories as well as unsupervised methods without a fixed sense inventory

    Computational acquisition of knowledge in small-data environments: a case study in the field of energetics

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    The UK’s defence industry is accelerating its implementation of artificial intelligence, including expert systems and natural language processing (NLP) tools designed to supplement human analysis. This thesis examines the limitations of NLP tools in small-data environments (common in defence) in the defence-related energetic-materials domain. A literature review identifies the domain-specific challenges of developing an expert system (specifically an ontology). The absence of domain resources such as labelled datasets and, most significantly, the preprocessing of text resources are identified as challenges. To address the latter, a novel general-purpose preprocessing pipeline specifically tailored for the energetic-materials domain is developed. The effectiveness of the pipeline is evaluated. Examination of the interface between using NLP tools in data-limited environments to either supplement or replace human analysis completely is conducted in a study examining the subjective concept of importance. A methodology for directly comparing the ability of NLP tools and experts to identify important points in the text is presented. Results show the participants of the study exhibit little agreement, even on which points in the text are important. The NLP, expert (author of the text being examined) and participants only agree on general statements. However, as a group, the participants agreed with the expert. In data-limited environments, the extractive-summarisation tools examined cannot effectively identify the important points in a technical document akin to an expert. A methodology for the classification of journal articles by the technology readiness level (TRL) of the described technologies in a data-limited environment is proposed. Techniques to overcome challenges with using real-world data such as class imbalances are investigated. A methodology to evaluate the reliability of human annotations is presented. Analysis identifies a lack of agreement and consistency in the expert evaluation of document TRL.Open Acces
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