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 Statistical Learning


Machine Learning for Utility Prediction in Argument-Based Computational Persuasion

arXiv.org Artificial Intelligence

Automated persuasion systems (APS) aim to persuade a user to believe something by entering into a dialogue in which arguments and counterarguments are exchanged. To maximize the probability that an APS is successful in persuading a user, it can identify a global policy that will allow it to select the best arguments it presents at each stage of the dialogue whatever arguments the user presents. However, in real applications, such as for healthcare, it is unlikely the utility of the outcome of the dialogue will be the same, or the exact opposite, for the APS and user. In order to deal with this situation, games in extended form have been harnessed for argumentation in Bi-party Decision Theory. This opens new problems that we address in this paper: (1) How can we use Machine Learning (ML) methods to predict utility functions for different subpopulations of users? and (2) How can we identify for a new user the best utility function from amongst those that we have learned? To this extent, we develop two ML methods, EAI and EDS, that leverage information coming from the users to predict their utilities. EAI is restricted to a fixed amount of information, whereas EDS can choose the information that best detects the subpopulations of a user. We evaluate EAI and EDS in a simulation setting and in a realistic case study concerning healthy eating habits. Results are promising in both cases, but EDS is more effective at predicting useful utility functions.


Measuring a Texts Fairness Dimensions Using Machine Learning Based on Social Psychological Factors

arXiv.org Artificial Intelligence

Fairness is a principal social value that can be observed in civilisations around the world. A manifestation of this is in social agreements, often described in texts, such as contracts. Yet, despite the prevalence of such, a fairness metric for texts describing a social act remains wanting. To address this, we take a step back to consider the problem based on first principals. Instead of using rules or templates, we utilise social psychology literature to determine the principal factors that humans use when making a fairness assessment. We then attempt to digitise these using word embeddings into a multi-dimensioned sentence level fairness perceptions vector to serve as an approximation for these fairness perceptions. The method leverages a pro-social bias within word embeddings, for which we obtain an F1= 81.0. A second approach, using PCA and ML based on the said fairness approximation vector produces an F1 score of 86.2. We detail improvements that can be made in the methodology to incorporate the projection of sentence embedding on to a subspace representation of fairness.


Consumer adoption of telemedicine in 2021

#artificialintelligence

Thank you to the Stanford Center of Digital Health for their continued collaboration on this work, with special gratitude to Natasha Din, MD, Clark Seninger, MBA, Sravya Rallapalli, Ashish Sarraju, MD, James Tooley, MD, Krishna Pundi, MD, Mario Funes-Hernandez, MD, and Mintu Turakhia, MD. Nearly two years into the COVID-19 pandemic, more consumers have used telemedicine than ever before. Venture investment in telemedicine is up, and big and small players are making land grabs for their share of the market, with many rolling out virtual–first care offerings. So with these accelerants--balanced with the full return of in-person care--what's the state of telemedicine? To answer this question and many more, we have surveyed U.S. adults every year since 2015 to check in with consumers and their relationship to digital health.


8 Best Machine Learning Courses for Finance

#artificialintelligence

Tell me in the comment section, which course you like. Some most popular use cases of machine learning in finance are Process Automation, Security, Algorithmic Trading, Robo-advisory, and Underwriting & Credit Scoring. Python is broadly used in finance, especially in quantitative finance. Python is one of the most famous programming languages for Fintech Companies. The HackerRank 2018 Developer Skills Report said that Python was among the top three most popular languages in financial services. On the report of HackerRank, Python, Java, C, C#, C, and Ruby are the six best programming languages for FinTech and finance.


Cluster Analysis and Unsupervised Machine Learning in Python

#artificialintelligence

Cluster analysis is a staple of unsupervised machine learning and data science. It is very useful for data mining and big data because it automatically finds patterns in the data, without the need for labels, unlike supervised machine learning. In a real-world environment, you can imagine that a robot or an artificial intelligence won't always have access to the optimal answer, or maybe there isn't an optimal correct answer. You'd want that robot to be able to explore the world on its own, and learn things just by looking for patterns. Do you ever wonder how we get the data that we use in our supervised machine learning algorithms?


Identification of Twitter Bots Based on an Explainable Machine Learning Framework: The US 2020 Elections Case Study

arXiv.org Artificial Intelligence

Twitter is one of the most popular social networks attracting millions of users, while a considerable proportion of online discourse is captured. It provides a simple usage framework with short messages and an efficient application programming interface (API) enabling the research community to study and analyze several aspects of this social network. However, the Twitter usage simplicity can lead to malicious handling by various bots. The malicious handling phenomenon expands in online discourse, especially during the electoral periods, where except the legitimate bots used for dissemination and communication purposes, the goal is to manipulate the public opinion and the electorate towards a certain direction, specific ideology, or political party. This paper focuses on the design of a novel system for identifying Twitter bots based on labeled Twitter data. To this end, a supervised machine learning (ML) framework is adopted using an Extreme Gradient Boosting (XGBoost) algorithm, where the hyper-parameters are tuned via cross-validation. Our study also deploys Shapley Additive Explanations (SHAP) for explaining the ML model predictions by calculating feature importance, using the game theoretic-based Shapley values. Experimental evaluation on distinct Twitter datasets demonstrate the superiority of our approach, in terms of bot detection accuracy, when compared against a recent state-of-the-art Twitter bot detection method.


A real-time spatiotemporal AI model analyzes skill in open surgical videos

arXiv.org Artificial Intelligence

Surgery offers the potential to treat and cure many diseases, but complications from surgical procedures remain the third highest cause of death globally [1]. Recent studies have shown that surgeons rated as higher-skilled via peer grading have lower rates of complications and death [2, 3]. Systems to evaluate surgical skill and provide feedback to improve technique could have a dramatic effect on the variation that exists in the field. Unfortunately, current approaches for evaluating surgical procedures and technique are primarily qualitative and do not have the ability to scale or even identify the elements of surgeon judgment that drive patient outcomes [4]. Artificial intelligence (AI) in the form of computer vision algorithms could provide scalable, automated analysis of surgical behaviors from video streams. AI could serve as an additional coach for surgical trainees and as an expert colleague for experienced surgeons [5]. However, the development of computer vision for open surgery--the dominant form of surgery defined as traditional, non-camera-based surgical techniques [6]--has been limited by two factors: the complexity of the AI task, and a lack of diverse and sizable training datasets [7]. Our work shows that a multi-task, spatiotemporal AI model, trained on multi-institutional data from numerous surgeons, has the potential to provide consistent analysis and feedback without the bias of any particular surgeon's experience.


Data Valuation for Vertical Federated Learning: An Information-Theoretic Approach

arXiv.org Artificial Intelligence

Federated learning (FL) is a promising machine learning paradigm that enables cross-party data collaboration for real-world AI applications in a privacy-preserving and law-regulated way. How to valuate parties' data is a critical but challenging FL issue. In the literature, data valuation either relies on running specific models for a given task or is just task irrelevant; however, it is often requisite for party selection given a specific task when FL models have not been determined yet. This work thus fills the gap and proposes \emph{FedValue}, to our best knowledge, the first privacy-preserving, task-specific but model-free data valuation method for vertical FL tasks. Specifically, FedValue incorporates a novel information-theoretic metric termed Shapley-CMI to assess data values of multiple parties from a game-theoretic perspective. Moreover, a novel server-aided federated computation mechanism is designed to compute Shapley-CMI and meanwhile protects each party from data leakage. We also propose several techniques to accelerate Shapley-CMI computation in practice. Extensive experiments on six open datasets validate the effectiveness and efficiency of FedValue for data valuation of vertical FL tasks. In particular, Shapley-CMI as a model-free metric performs comparably with the measures that depend on running an ensemble of well-performing models.


CORE-Text: Improving Scene Text Detection with Contrastive Relational Reasoning

arXiv.org Artificial Intelligence

Localizing text instances in natural scenes is regarded as a fundamental challenge in computer vision. Nevertheless, owing to the extremely varied aspect ratios and scales of text instances in real scenes, most conventional text detectors suffer from the sub-text problem that only localizes the fragments of text instance (i.e., sub-texts). In this work, we quantitatively analyze the sub-text problem and present a simple yet effective design, COntrastive RElation (CORE) module, to mitigate that issue. CORE first leverages a vanilla relation block to model the relations among all text proposals (sub-texts of multiple text instances) and further enhances relational reasoning via instance-level sub-text discrimination in a contrastive manner. Such way naturally learns instance-aware representations of text proposals and thus facilitates scene text detection. We integrate the CORE module into a two-stage text detector of Mask R-CNN and devise our text detector CORE-Text. Extensive experiments on four benchmarks demonstrate the superiority of CORE-Text. Code is available: \url{https://github.com/jylins/CORE-Text}.


Artificial Intelligence Ethics and Safety: practical tools for creating "good" models

arXiv.org Artificial Intelligence

The AI Robotics Ethics Society (AIRES) is a non-profit organization founded in 2018 by Aaron Hui to promote awareness and the importance of ethical implementation and regulation of AI. AIRES is now an organization with chapters at universities such as UCLA (Los Angeles), USC (University of Southern California), Caltech (California Institute of Technology), Stanford University, Cornell University, Brown University, and the Pontifical Catholic University of Rio Grande do Sul (Brazil). AIRES at PUCRS is the first international chapter of AIRES, and as such, we are committed to promoting and enhancing the AIRES Mission. Our mission is to focus on educating the AI leaders of tomorrow in ethical principles to ensure that AI is created ethically and responsibly. As there are still few proposals for how we should implement ethical principles and normative guidelines in the practice of AI system development, the goal of this work is to try to bridge this gap between discourse and praxis. Between abstract principles and technical implementation. In this work, we seek to introduce the reader to the topic of AI Ethics and Safety. At the same time, we present several tools to help developers of intelligent systems develop "good" models. This work is a developing guide published in English and Portuguese. Contributions and suggestions are welcome.