122 research outputs found
Information retrieval and machine learning methods for academic expert finding
In the context of academic expert finding, this paper investigates and compares the performance of information retrieval (IR) and machine learning (ML) methods, including deep learning, to approach the problem of identifying academic figures who are experts in different domains when a potential user requests their expertise. IR-based methods construct multifaceted textual profiles for each expert by clustering information from their scientific publications. Several methods fully tailored for this problem are presented in this paper. In contrast, ML-based methods treat expert finding as a classification task, training automatic text classifiers using publications authored by experts. By comparing these approaches, we contribute to a deeper understanding of academic-expert-finding techniques and their applicability in knowledge discovery. These methods are tested with two large datasets from the biomedical field: PMSC-UGR and CORD-19. The results show how IR techniques were, in general, more robust with both datasets and more suitable than the ML-based ones, with some exceptions showing good performance.Agencia Estatal de InvestigaciĂłn | Ref. PID2019-106758GB-C31Agencia Estatal de InvestigaciĂłn | Ref. PID2020-113230RB-C22FEDER/Junta de AndalucĂa | Ref. A-TIC-146-UGR2
Combating Misinformation in the Age of LLMs: Opportunities and Challenges
Misinformation such as fake news and rumors is a serious threat on
information ecosystems and public trust. The emergence of Large Language Models
(LLMs) has great potential to reshape the landscape of combating
misinformation. Generally, LLMs can be a double-edged sword in the fight. On
the one hand, LLMs bring promising opportunities for combating misinformation
due to their profound world knowledge and strong reasoning abilities. Thus, one
emergent question is: how to utilize LLMs to combat misinformation? On the
other hand, the critical challenge is that LLMs can be easily leveraged to
generate deceptive misinformation at scale. Then, another important question
is: how to combat LLM-generated misinformation? In this paper, we first
systematically review the history of combating misinformation before the advent
of LLMs. Then we illustrate the current efforts and present an outlook for
these two fundamental questions respectively. The goal of this survey paper is
to facilitate the progress of utilizing LLMs for fighting misinformation and
call for interdisciplinary efforts from different stakeholders for combating
LLM-generated misinformation.Comment: 9 pages for the main paper, 35 pages including 656 references, more
resources on "LLMs Meet Misinformation" are on the website:
https://llm-misinformation.github.io
Explainable Artificial Intelligence (XAI) 2.0: A Manifesto of Open Challenges and Interdisciplinary Research Directions
As systems based on opaque Artificial Intelligence (AI) continue to flourish
in diverse real-world applications, understanding these black box models has
become paramount. In response, Explainable AI (XAI) has emerged as a field of
research with practical and ethical benefits across various domains. This paper
not only highlights the advancements in XAI and its application in real-world
scenarios but also addresses the ongoing challenges within XAI, emphasizing the
need for broader perspectives and collaborative efforts. We bring together
experts from diverse fields to identify open problems, striving to synchronize
research agendas and accelerate XAI in practical applications. By fostering
collaborative discussion and interdisciplinary cooperation, we aim to propel
XAI forward, contributing to its continued success. Our goal is to put forward
a comprehensive proposal for advancing XAI. To achieve this goal, we present a
manifesto of 27 open problems categorized into nine categories. These
challenges encapsulate the complexities and nuances of XAI and offer a road map
for future research. For each problem, we provide promising research directions
in the hope of harnessing the collective intelligence of interested
stakeholders
ClusterLLM: Large Language Models as a Guide for Text Clustering
We introduce ClusterLLM, a novel text clustering framework that leverages
feedback from an instruction-tuned large language model, such as ChatGPT.
Compared with traditional unsupervised methods that builds upon "small"
embedders, ClusterLLM exhibits two intriguing advantages: (1) it enjoys the
emergent capability of LLM even if its embeddings are inaccessible; and (2) it
understands the user's preference on clustering through textual instruction
and/or a few annotated data. First, we prompt ChatGPT for insights on
clustering perspective by constructing hard triplet questions <does A better
correspond to B than C>, where A, B and C are similar data points that belong
to different clusters according to small embedder. We empirically show that
this strategy is both effective for fine-tuning small embedder and
cost-efficient to query ChatGPT. Second, we prompt ChatGPT for helps on
clustering granularity by carefully designed pairwise questions <do A and B
belong to the same category>, and tune the granularity from cluster hierarchies
that is the most consistent with the ChatGPT answers. Extensive experiments on
14 datasets show that ClusterLLM consistently improves clustering quality, at
an average cost of ~$0.6 per dataset
A review on deep-learning-based cyberbullying detection
Bullying is described as an undesirable behavior by others that harms an individual physically, mentally, or socially. Cyberbullying is a virtual form (e.g., textual or image) of bullying or harassment, also known as online bullying. Cyberbullying detection is a pressing need in today’s world, as the prevalence of cyberbullying is continually growing, resulting in mental health issues. Conventional machine learning models were previously used to identify cyberbullying. However, current research demonstrates that deep learning surpasses traditional machine learning algorithms in identifying cyberbullying for several reasons, including handling extensive data, efficiently classifying text and images, extracting features automatically through hidden layers, and many others. This paper reviews the existing surveys and identifies the gaps in those studies. We also present a deep-learning-based defense ecosystem for cyberbullying detection, including data representation techniques and different deep-learning-based models and frameworks. We have critically analyzed the existing DL-based cyberbullying detection techniques and identified their significant contributions and the future research directions they have presented. We have also summarized the datasets being used, including the DL architecture being used and the tasks that are accomplished for each dataset. Finally, several challenges faced by the existing researchers and the open issues to be addressed in the future have been presented
Accountability in Offline Reinforcement Learning: Explaining Decisions with a Corpus of Examples
Learning controllers with offline data in decision-making systems is an
essential area of research due to its potential to reduce the risk of
applications in real-world systems. However, in responsibility-sensitive
settings such as healthcare, decision accountability is of paramount
importance, yet has not been adequately addressed by the literature. This paper
introduces the Accountable Offline Controller (AOC) that employs the offline
dataset as the Decision Corpus and performs accountable control based on a
tailored selection of examples, referred to as the Corpus Subset. AOC operates
effectively in low-data scenarios, can be extended to the strictly offline
imitation setting, and displays qualities of both conservation and
adaptability. We assess AOC's performance in both simulated and real-world
healthcare scenarios, emphasizing its capability to manage offline control
tasks with high levels of performance while maintaining accountability
Towards Poisoning Fair Representations
Fair machine learning seeks to mitigate model prediction bias against certain
demographic subgroups such as elder and female. Recently, fair representation
learning (FRL) trained by deep neural networks has demonstrated superior
performance, whereby representations containing no demographic information are
inferred from the data and then used as the input to classification or other
downstream tasks. Despite the development of FRL methods, their vulnerability
under data poisoning attack, a popular protocol to benchmark model robustness
under adversarial scenarios, is under-explored. Data poisoning attacks have
been developed for classical fair machine learning methods which incorporate
fairness constraints into shallow-model classifiers. Nonetheless, these attacks
fall short in FRL due to notably different fairness goals and model
architectures. This work proposes the first data poisoning framework attacking
FRL. We induce the model to output unfair representations that contain as much
demographic information as possible by injecting carefully crafted poisoning
samples into the training data. This attack entails a prohibitive bilevel
optimization, wherefore an effective approximated solution is proposed. A
theoretical analysis on the needed number of poisoning samples is derived and
sheds light on defending against the attack. Experiments on benchmark fairness
datasets and state-of-the-art fair representation learning models demonstrate
the superiority of our attack
Improving Demand Forecasting: The Challenge of Forecasting Studies Comparability and a Novel Approach to Hierarchical Time Series Forecasting
Bedarfsprognosen sind in der Wirtschaft unerlässlich. Anhand des erwarteten Kundenbe-darfs bestimmen Firmen beispielsweise welche Produkte sie entwickeln, wie viele Fabri-ken sie bauen, wie viel Personal eingestellt wird oder wie viel Rohmaterial geordert wer-den muss. Fehleinschätzungen bei Bedarfsprognosen können schwerwiegende Auswir-kungen haben, zu Fehlentscheidungen führen, und im schlimmsten Fall den Bankrott einer Firma herbeiführen.
Doch in vielen Fällen ist es komplex, den tatsächlichen Bedarf in der Zukunft zu antizipie-ren. Die Einflussfaktoren können vielfältig sein, beispielsweise makroökonomische Ent-wicklung, das Verhalten von Wettbewerbern oder technologische Entwicklungen. Selbst wenn alle Einflussfaktoren bekannt sind, sind die Zusammenhänge und Wechselwirkun-gen häufig nur schwer zu quantifizieren.
Diese Dissertation trägt dazu bei, die Genauigkeit von Bedarfsprognosen zu verbessern.
Im ersten Teil der Arbeit wird im Rahmen einer überfassenden Übersicht über das gesamte Spektrum der Anwendungsfelder von Bedarfsprognosen ein neuartiger Ansatz eingeführt, wie Studien zu Bedarfsprognosen systematisch verglichen werden können und am Bei-spiel von 116 aktuellen Studien angewandt. Die Vergleichbarkeit von Studien zu verbes-sern ist ein wesentlicher Beitrag zur aktuellen Forschung. Denn anders als bspw. in der Medizinforschung, gibt es für Bedarfsprognosen keine wesentlichen vergleichenden quan-titativen Meta-Studien. Der Grund dafür ist, dass empirische Studien für Bedarfsprognosen keine vereinheitlichte Beschreibung nutzen, um ihre Daten, Verfahren und Ergebnisse zu beschreiben. Wenn Studien hingegen durch systematische Beschreibung direkt miteinan-der verglichen werden können, ermöglicht das anderen Forschern besser zu analysieren, wie sich Variationen in Ansätzen auf die Prognosegüte auswirken – ohne die aufwändige Notwendigkeit, empirische Experimente erneut durchzuführen, die bereits in Studien beschrieben wurden. Diese Arbeit führt erstmals eine solche Systematik zur Beschreibung ein.
Der weitere Teil dieser Arbeit behandelt Prognoseverfahren für intermittierende Zeitreihen, also Zeitreihen mit wesentlichem Anteil von Bedarfen gleich Null. Diese Art der Zeitreihen erfüllen die Anforderungen an Stetigkeit der meisten Prognoseverfahren nicht, weshalb gängige Verfahren häufig ungenügende Prognosegüte erreichen. Gleichwohl ist die Rele-vanz intermittierender Zeitreihen hoch – insbesondere Ersatzteile weisen dieses Bedarfs-muster typischerweise auf. Zunächst zeigt diese Arbeit in drei Studien auf, dass auch die getesteten Stand-der-Technik Machine Learning Ansätze bei einigen bekannten Datensät-zen keine generelle Verbesserung herbeiführen. Als wesentlichen Beitrag zur Forschung zeigt diese Arbeit im Weiteren ein neuartiges Verfahren auf: Der Similarity-based Time Series Forecasting (STSF) Ansatz nutzt ein Aggregation-Disaggregationsverfahren basie-rend auf einer selbst erzeugten Hierarchie statistischer Eigenschaften der Zeitreihen. In Zusammenhang mit dem STSF Ansatz können alle verfügbaren Prognosealgorithmen eingesetzt werden – durch die Aggregation wird die Stetigkeitsbedingung erfüllt. In Expe-rimenten an insgesamt sieben öffentlich bekannten Datensätzen und einem proprietären Datensatz zeigt die Arbeit auf, dass die Prognosegüte (gemessen anhand des Root Mean Square Error RMSE) statistisch signifikant um 1-5% im Schnitt gegenüber dem gleichen Verfahren ohne Einsatz von STSF verbessert werden kann. Somit führt das Verfahren eine wesentliche Verbesserung der Prognosegüte herbei.
Zusammengefasst trägt diese Dissertation zum aktuellen Stand der Forschung durch die zuvor genannten Verfahren wesentlich bei. Das vorgeschlagene Verfahren zur Standardi-sierung empirischer Studien beschleunigt den Fortschritt der Forschung, da sie verglei-chende Studien ermöglicht. Und mit dem STSF Verfahren steht ein Ansatz bereit, der zuverlässig die Prognosegüte verbessert, und dabei flexibel mit verschiedenen Arten von Prognosealgorithmen einsetzbar ist. Nach dem Erkenntnisstand der umfassenden Literatur-recherche sind keine vergleichbaren Ansätze bislang beschrieben worden
Exploration and adaptation of large language models for specialized domains
Large language models have transformed the field of natural language processing (NLP). Their improved performance on various NLP benchmarks makes them a promising tool—also for the application in specialized domains. Such domains are characterized by highly trained professionals with particular domain expertise. Since these experts are rare, improving the efficiency of their work with automated systems is especially desirable. However, domain-specific text resources hold various challenges for NLP systems. These challenges include distinct language, noisy and scarce data, and a high level of variation. Further, specialized domains present an increased need for transparent systems since they are often applied in high stakes settings. In this dissertation, we examine whether large language models (LLMs) can overcome some of these challenges and propose methods to effectively adapt them to domain-specific requirements.
We first investigate the inner workings and abilities of LLMs and show how they can fill the gaps that are present in previous NLP algorithms for specialized domains. To this end, we explore the sources of errors produced by earlier systems to identify which of them can be addressed by using LLMs. Following this, we take a closer look at how information is processed within Transformer-based LLMs to better understand their capabilities. We find that their layers encode different dimensions of the input text. Here, the contextual vector representation, and the general language knowledge learned during pre-training are especially beneficial for solving complex and multi-step tasks common in specialized domains.
Following this exploration, we propose solutions for further adapting LLMs to the requirements of domain-specific tasks. We focus on the clinical domain, which incorporates many typical challenges found in specialized domains. We show how to improve generalization by integrating different domain-specific resources into our models. We further analyze the behavior of the produced models and propose a behavioral testing framework that can serve as a tool for communication with domain experts. Finally, we present an approach for incorporating the benefits of LLMs while fulfilling requirements such as interpretability and modularity. The presented solutions show improvements in performance on benchmark datasets and in manually conducted analyses with medical professionals.
Our work provides both new insights into the inner workings of pre-trained language models as well as multiple adaptation methods showing that LLMs can be an effective tool for NLP in specialized domains
Geographic information extraction from texts
A large volume of unstructured texts, containing valuable geographic information, is available online. This information – provided implicitly or explicitly – is useful not only for scientific studies (e.g., spatial humanities) but also for many practical applications (e.g., geographic information retrieval). Although large progress has been achieved in geographic information extraction from texts, there are still unsolved challenges and issues, ranging from methods, systems, and data, to applications and privacy. Therefore, this workshop will provide a timely opportunity to discuss the recent advances, new ideas, and concepts but also identify research gaps in geographic information extraction
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