South America
DCV-ROOD Evaluation Framework: Dual Cross-Validation for Robust Out-of-Distribution Detection
Urrea-Castaño, Arantxa, Segura-Kunsagi, Nicolás, Suárez-Díaz, Juan Luis, Montes, Rosana, Herrera, Francisco
Out-of-distribution (OOD) detection plays a key role in enhancing the robustness of artificial intelligence systems by identifying inputs that differ significantly from the training distribution, thereby preventing unreliable predictions and enabling appropriate fallback mechanisms. Developing reliable OOD detection methods is a significant challenge, and rigorous evaluation of these techniques is essential for ensuring their effectiveness, as it allows researchers to assess their performance under diverse conditions and to identify potential limitations or failure modes. Cross-validation (CV) has proven to be a highly effective tool for providing a reasonable estimate of the performance of a learning algorithm. Although OOD scenarios exhibit particular characteristics, an appropriate adaptation of CV can lead to a suitable evaluation framework for this setting. This work proposes a dual CV framework for robust evaluation of OOD detection models, aimed at improving the reliability of their assessment. The proposed evaluation framework aims to effectively integrate in-distribution (ID) and OOD data while accounting for their differing characteristics. To achieve this, ID data are partitioned using a conventional approach, whereas OOD data are divided by grouping samples based on their classes. Furthermore, we analyze the context of data with class hierarchy to propose a data splitting that considers the entire class hierarchy to obtain fair ID-OOD partitions to apply the proposed evaluation framework. This framework is called Dual Cross-Validation for Robust Out-of-Distribution Detection (DCV-ROOD). To test the validity of the evaluation framework, we selected a set of state-of-the-art OOD detection methods, both with and without outlier exposure. The results show that the method achieves very fast convergence to the true performance.
Approximating Condorcet Ordering for Vector-valued Mathematical Morphology
Valle, Marcos Eduardo, Velasco-Forero, Santiago, Florindo, Joao Batista, Angulo, Gustavo Jesus
Mathematical morphology provides a nonlinear framework for image and spatial data processing and analysis. Although there have been many successful applications of mathematical morphology to vector-valued images, such as color and hyperspectral images, there is still no consensus on the most suitable vector ordering for constructing morphological operators. This paper addresses this issue by examining a reduced ordering approximating the Condorcet ranking derived from a set of vector orderings. Inspired by voting problems, the Condorcet ordering ranks elements from most to least voted, with voters representing different orderings. In this paper, we develop a machine learning approach that learns a reduced ordering that approximates the Condorcet ordering. Preliminary computational experiments confirm the effectiveness of learning the reduced mapping to define vector-valued morphological operators for color images.
HECATE: An ECS-based Framework for Teaching and Developing Multi-Agent Systems
Casals, Arthur, Brandão, Anarosa A. F.
This paper introduces HECATE, a novel framework based on the Entity-Component-System (ECS) architectural pattern that bridges the gap between distributed systems engineering and MAS development. HECATE is built using the Entity-Component-System architectural pattern, leveraging data-oriented design to implement multiagent systems. This approach involves engineering multiagent systems (MAS) from a distributed systems (DS) perspective, integrating agent concepts directly into the DS domain. This approach simplifies MAS development by (i) reducing the need for specialized agent knowledge and (ii) leveraging familiar DS patterns and standards to minimize the agent-specific knowledge required for engineering MAS. We present the framework's architecture, core components, and implementation approach, demonstrating how it supports different agent models.
Morphological Perceptron with Competitive Layer: Training Using Convex-Concave Procedure
Cunha, Iara, Valle, Marcos Eduardo
A morphological perceptron is a multilayer feedforward neural network in which neurons perform elementary operations from mathematical morphology. For multiclass classification tasks, a morphological perceptron with a competitive layer (MPCL) is obtained by integrating a winner-take-all output layer into the standard morphological architecture. The non-differentiability of morphological operators renders gradient-based optimization methods unsuitable for training such networks. Consequently, alternative strategies that do not depend on gradient information are commonly adopted. This paper proposes the use of the convex-concave procedure (CCP) for training MPCL networks. The training problem is formulated as a difference of convex (DC) functions and solved iteratively using CCP, resulting in a sequence of linear programming subproblems. Computational experiments demonstrate the effectiveness of the proposed training method in addressing classification tasks with MPCL networks.
Combining TSL and LLM to Automate REST API Testing: A Comparative Study
Barradas, Thiago, Paes, Aline, Neves, Vânia de Oliveira
The effective execution of tests for REST APIs remains a considerable challenge for development teams, driven by the inherent complexity of distributed systems, the multitude of possible scenarios, and the limited time available for test design. Exhaustive testing of all input combinations is impractical, often resulting in undetected failures, high manual effort, and limited test coverage. To address these issues, we introduce RestTSLLM, an approach that uses Test Specification Language (TSL) in conjunction with Large Language Models (LLMs) to automate the generation of test cases for REST APIs. The approach targets two core challenges: the creation of test scenarios and the definition of appropriate input data. The proposed solution integrates prompt engineering techniques with an automated pipeline to evaluate various LLMs on their ability to generate tests from OpenAPI specifications. The evaluation focused on metrics such as success rate, test coverage, and mutation score, enabling a systematic comparison of model performance. The results indicate that the best-performing LLMs - Claude 3.5 Sonnet (Anthropic), Deepseek R1 (Deepseek), Qwen 2.5 32b (Alibaba), and Sabia 3 (Maritaca) - consistently produced robust and contextually coherent REST API tests. Among them, Claude 3.5 Sonnet outperformed all other models across every metric, emerging in this study as the most suitable model for this task. These findings highlight the potential of LLMs to automate the generation of tests based on API specifications.
Distributed Link Sparsification for Scalable Scheduling Using Graph Neural Networks (Journal Version)
Zhao, Zhongyuan, Verma, Gunjan, Swami, Ananthram, Segarra, Santiago
--In wireless networks characterized by dense connectivity, the significant signaling overhead generated by distributed link scheduling algorithms can exacerbate issues like congestion, energy consumption, and radio footprint expansion. T o mitigate these challenges, we propose a distributed link sparsification scheme employing graph neural networks (GNNs) to reduce scheduling overhead for delay-tolerant traffic while maintaining network capacity. A GNN module is trained to adjust contention thresholds for individual links based on traffic statistics and network topology, enabling links to withdraw from scheduling contention when they are unlikely to succeed. Our approach is facilitated by a novel offline constrained unsupervised learning algorithm capable of balancing two competing objectives: minimizing scheduling overhead while ensuring that total utility meets the required level. In simulated wireless multi-hop networks with up to 500 links, our link sparsification technique effectively alleviates network congestion and reduces radio footprints across four distinct distributed link scheduling protocols. Index T erms --Threshold, massive access, scalable scheduling, graph neural networks, constrained unsupervised learning. The proliferation of wireless devices and emerging machine-type communications (MTC) [2] has led to new requirements for next-generation wireless networks, including massive access in ultra-dense networks, spectrum and energy efficiencies, multi-hop connectivity, and scalability [3]-[6]. A promising solution to these challenges is self-organizing wireless multi-hop networks, which have been applied to scenarios where infrastructure is infeasible or overloaded, such as military communications, satellite communications, vehicular/drone networks, Internet of Things (IoT), and 5G/6G (device-to-device (D2D), wireless backhaul, integrated access and backhaul (IAB)) [3]-[10]. Received 27 February 2024; revised 20 January 2025, 17 June 2025, and 13 August 2025; accepted 1 September 2025. Research was sponsored by the DEVCOM ARL Army Research Office and was accomplished under Cooperative Agreement Number W911NF-19-2-0269. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Office or the U.S. Government. Zhongyuan Zhao and Santiago Segarra are with the Department of Electrical and Computer Engineering, Rice University, USA.
Turkish police clash with opposition members in Istanbul
Turkish police stormed the Istanbul offices of the main opposition Republican People's Party's (CHP), using shields and pepper spray to enforce a court ruling ousting provincial head Ozgur Celik. Party members barricaded themselves inside with furniture to block police. Nepal'Gen Z' protest death toll climbs, parliament stormed Israel wants to'destroy Gaza City, not occupy it'
Nepal 'Gen Z' protest death toll climbs, parliament stormed
Nepal'Gen Z' protest death toll climbs, parliament stormed NewsFeed Nepal'Gen Z' protest death toll climbs, parliament stormed At least 19 people have been killed in clashes between security forces and protesters in Nepal. Mostly young'Gen Z' demonstrators took to the streets and stormed parliament amid anger over a social media ban and corruption. Israel wants to'destroy Gaza City, not occupy it'
Aid group delivers food, medicine to flooding victims in Pakistan
Al Jazeera's Kamal Hyder joined aid workers on a boat as they delivered food and important medical supplies to people who have lost everything as Pakistan's flood-ravaged Punjab province braces for even more heavy rain over the next two days. Nepal'Gen Z' protest death toll climbs, parliament stormed Israel wants to'destroy Gaza City, not occupy it'
Suspected Palestinian gunmen kill six people in East Jerusalem
Six people were killed in a shooting attack by suspected Palestinian gunmen at a bus stop in occupied East Jerusalem. Israeli Prime Minister Benjamin Netanyahu visited the site, as Palestinian groups praised the attack without claiming responsibility. Israel wants to'destroy Gaza City, not occupy it'