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Publications

Publications by HASLab

2023

A Year Embedded in the Crypto-NFT Space

Authors
Baquero, C;

Publication
COMMUNICATIONS OF THE ACM

Abstract

2023

Consistent comparison of symptom-based methods for COVID-19 infection detection

Authors
Rufino, J; Ramirez, JM; Aguilar, J; Baquero, C; Champati, J; Frey, D; Lillo, RE; Fernandez Anta, A;

Publication
INTERNATIONAL JOURNAL OF MEDICAL INFORMATICS

Abstract
Background: During the global pandemic crisis, various detection methods of COVID-19-positive cases based on self-reported information were introduced to provide quick diagnosis tools for effectively planning and managing healthcare resources. These methods typically identify positive cases based on a particular combination of symptoms, and they have been evaluated using different datasets.Purpose: This paper presents a comprehensive comparison of various COVID-19 detection methods based on self-reported information using the University of Maryland Global COVID-19 Trends and Impact Survey (UMD-CTIS), a large health surveillance platform, which was launched in partnership with Facebook.Methods: Detection methods were implemented to identify COVID-19-positive cases among UMD-CTIS participants reporting at least one symptom and a recent antigen test result (positive or negative) for six countries and two periods. Multiple detection methods were implemented for three different categories: rule-based approaches, logistic regression techniques, and tree-based machine-learning models. These methods were evaluated using different metrics including F1-score, sensitivity, specificity, and precision. An explainability analysis has also been conducted to compare methods.Results: Fifteen methods were evaluated for six countries and two periods. We identify the best method for each category: rule-based methods (F1-score: 51.48% -71.11%), logistic regression techniques (F1-score: 39.91% -71.13%), and tree-based machine learning models (F1-score: 45.07% -73.72%). According to the explainability analysis, the relevance of the reported symptoms in COVID-19 detection varies between countries and years. However, there are two variables consistently relevant across approaches: stuffy or runny nose, and aches or muscle pain.Conclusions: Regarding the categories of detection methods, evaluating detection methods using homogeneous data across countries and years provides a solid and consistent comparison. An explainability analysis of a tree-based machine-learning model can assist in identifying infected individuals specifically based on their relevant symptoms. This study is limited by the self-report nature of data, which cannot replace clinical diagnosis.

2023

Efficient Embedding of Strategic Attribute Grammars via Memoization

Authors
Macedo, JN; Rodrigues, E; Viera, M; Saraiva, J;

Publication
Proceedings of the 2023 ACM SIGPLAN International Workshop on Partial Evaluation and Program Manipulation, PEPM 2023, Boston, MA, USA, January 16-17, 2023

Abstract
Strategic term re-writing and attribute grammars are two powerful programming techniques widely used in language engineering. The former relies on strategies to apply term re-write rules in defining large-scale language transformations, while the latter is suitable to express context-dependent language processing algorithms. These two techniques can be expressed and combined via a powerful navigation abstraction: generic zippers. This results in a concise zipper-based embedding offering the expressiveness of both techniques. Such elegant embedding has a severe limitation since it recomputes attribute values. This paper presents a proper and efficient embedding of both techniques. First, attribute values are memoized in the zipper data structure, thus avoiding their re-computation. Moreover, strategic zipper based functions are adapted to access such memoized values. We have implemented our memoized embedding as the Ztrategic library and we benchmarked it against the state-of-the-art Strafunski and Kiama libraries. Our first results show that we are competitive against those two well established libraries. © 2023 ACM.

2023

Exploring Data Analysis and Visualization Techniques for Project Tracking: Insights from the ITC

Authors
Barrocas, A; da Silva, AR; Saraiva, J;

Publication
QUALITY OF INFORMATION AND COMMUNICATIONS TECHNOLOGY, QUATIC 2023

Abstract
Data analysis has emerged as a cornerstone in facilitating informed decision-making across myriad fields, in particular in software development and project management. This integrative practice proves instrumental in enhancing operational efficiency, cutting expenditures, mitigating potential risks, and delivering superior results, all while sustaining structured organization and robust control. This paper presents ITC, a synergistic platform architected to streamline multi-organizational and multi-workspace collaboration for project management and technical documentation. ITC serves as a powerful tool, equipping users with the capability to swiftly establish and manage workspaces and documentation, thereby fostering the derivation of invaluable insights pivotal to both technical and business-oriented decisions. ITC boasts a plethora of features, from support for a diverse range of technologies and languages, synchronization of data, and customizable templates to reusable libraries and task automation, including data extraction, validation, and document automation. This paper also delves into the predictive analytics aspect of the ITC platform. It demonstrates how ITC harnesses predictive data models, such as Random Forest Regression, to anticipate project outcomes and risks, enhancing decision-making in project management. This feature plays a critical role in the strategic allocation of resources, optimizing project timelines, and promoting overall project success. In an effort to substantiate the efficacy and usability of ITC, we have also incorporated the results and feedback garnered from a comprehensive user assessment conducted in 2022. The feedback suggests promising potential for the platform's application, setting the stage for further development and refinement. The insights provided in this paper not only underline the successful implementation of the ITC platform but also shed light on the transformative impact of predictive analytics in information systems.

2023

Paint Your Programs Green: On the Energy Efficiency of Data Structures

Authors
Pereira, R; Couto, M; Cunha, J; Melfe, G; Saraiva, J; Fernandes, JP;

Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Abstract
This tutorial aims to provide knowledge on a different facet of efficiency in data structures: energy efficiency. As many recent studies have shown, the main roadblock in regards to energy efficient software development are the misconceptions and heavy lack of support and knowledge, for energy-aware development, that programmers have. Thus, this tutorial aims at helping provide programmers more knowledge pertaining to the energy efficiency of data structures. We conducted two in-depth studies to analyze the performance and energy efficiency of various data structures from popular programming languages: Haskell and Java. The results show that within the Haskell programming language, the correlation between performance and energy consumption is statistically almost identical, while there are cases with more variation within the Java language. We have presented which data structures are more efficient for common operations, such as inserting and removing elements or iterating over the data structure. The results from our studies can help support developers in better understanding such differences within data structures, allowing them to carefully choose the most adequate implementation based on their requirements and goals. We believe that such results will help further close the gap when discussing the lack of knowledge in energy efficient software development. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

2023

GPT-3-Powered Type Error Debugging: Investigating the Use of Large Language Models for Code Repair

Authors
Ribeiro, F; de Macedo, JNC; Tsushima, K; Abreu, R; Saraiva, J;

Publication
PROCEEDINGS OF THE 16TH ACM SIGPLAN INTERNATIONAL CONFERENCE ON SOFTWARE LANGUAGE ENGINEERING, SLE 2023

Abstract
Type systems are responsible for assigning types to terms in programs. That way, they enforce the actions that can be taken and can, consequently, detect type errors during compilation. However, while they are able to flag the existence of an error, they often fail to pinpoint its cause or provide a helpful error message. Thus, without adequate support, debugging this kind of errors can take a considerable amount of effort. Recently, neural network models have been developed that are able to understand programming languages and perform several downstream tasks. We argue that type error debugging can be enhanced by taking advantage of this deeper understanding of the language's structure. In this paper, we present a technique that leverages GPT-3's capabilities to automatically fix type errors in OCaml programs. We perform multiple source code analysis tasks to produce useful prompts that are then provided to GPT-3 to generate potential patches. Our publicly available tool, Mentat, supports multiple modes and was validated on an existing public dataset with thousands of OCaml programs. We automatically validate successful repairs by using Quickcheck to verify which generated patches produce the same output as the user-intended fixed version, achieving a 39% repair rate. In a comparative study, Mentat outperformed two other techniques in automatically fixing ill-typed OCaml programs.

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