Spectrum

Low-False-Alarm Evaluation Changes the Ranking of Multisensor Anomaly Detectors

Murilo Salem — 2026-10-09

This study investigated multisensor anomaly detection under low false-alarm constraints in safety-critical systems, examining whether conventional aggregate metrics provide a reliable basis for model selection under strict false-alarm budgets. A detection framework combining temporal modeling, anomaly scoring, calibration, and temporal persistence was evaluated across forecasting, autoencoding, and conformal multisensor approaches on four public multivariate sensor datasets. Low-false-alarm evaluation changed detector rankings in seven model-dataset pairs: on the Mars Science Laboratory dataset, the Temporal Autoencoder moved from third to first place under recall at false-alarm rate up to 0.05, reaching 0.1062; on the Secure Water Treatment dataset, the Gated Recurrent Unit Forecaster reached 0.6448; on the Water Distribution dataset, subsystem-aware grouping increased the same metric from 0.0241 to 0.1838, while correlation-based grouping degraded performance. Calibration improved false-alarm control but did not compensate for poor score separability, and cross-sensor modeling was beneficial only when groupings reflected the monitored system structure.

Quantum Communication: Global Landscape and Potential Applications for the Brazilian Air Force

Denys Derlian Carvalho Brito — 2026-08-03

Quantum communication exploits the principles of quantum superposition and entanglement to provide advantages over classical communication. It has emerged as one of the key branches of quantum technologies, offering significant disruptive potential compared with its classical counterparts. Among quantum technologies, quantum communication is one of the most mature, having already been successfully demonstrated through both optical fiber and free-space links, including satellite-based communication. This paper discusses the fundamental concepts of quantum communication, reviews the current global landscape with emphasis on European, American, and Chinese initiatives, and examines its potential applications in the context of air power.

Quantum Technologies: Current Outlook, Challenges and Opportunities

André J. Chaves — 2026-08-03

Quantum technologies result from the use of the laws of modern physics in increasingly sophisticated devices, promising enormous advances in computing, communication, and sensing, for both civilian and military use. As a consequence of technological progress that has miniaturized instrumentation down to atomic scales, we are witnessing the nanoscale manipulation of physical systems using intrinsic properties of quantum systems, such as entanglement. Quantum sensors are able to go beyond classical detection limits. Quantum communication offers a security advantage over classical communication. Quantum computing enables the solution of problems considered impossible to solve with classical computers. These technologies emerge as a result of advances in science and engineering, enabling the manipulation of systems at the atomic level. In this article we briefly present the fundamental concepts of quantum mechanics, the main examples of quantum technologies in sensing, communication, and computing. We show military applications and conclude by presenting the challenges and opportunities.

Prediction of High-Explosive Detonation Effects on Steel Sheets During Experimental Tests Using Finite Element Analysis

Anselmo Augusto — 2026-08-10

Investigating the effects of high explosives on metallic structures is important for the development of new protective systems and for assessing the load-bearing capacity of existing structures. To achieve these objectives, a series of detonation tests using TNT charges will be conducted to evaluate the resulting effects on 2 mm-thick A36 structural steel sheets. However, before performing the experimental tests, it is essential to accurately predict the effects of the detonations on the steel sheets in order to ensure test safety and verify that the selected explosive configurations produce the intended structural response. To accomplish this, a series of finite element method (FEM) simulations was carried out using Abaqus®, considering different expected standoff distances. The numerical results indicated that the steel sheets experienced permanent deformations exceeding the material's elastic limit without reaching failure. These findings satisfy the objectives of the study, since either negligible or catastrophic deformations would prevent the proper measurement and evaluation of blast effects on the structural elements during the experimental campaign.

Reference values for damage predictions of reinforced concrete slabs subjected to blast from field tests

Fausto Batista Mendonça — 2026-08-31

Destructive blast testing using explosives is one of the methods to verify the lethality of military weapons against potential military target structures. Adequate damage prediction on these structures allows for optimized planning of resources and materials for the field test. This work focuses on validating responses to recent experiments and proposing a mathematical expression to aid in predicting expected structural responses. Results from full-scale experiments were gathered to seek mathematical reference values for predicting damage in future experiments involving damage to reinforced concrete slabs. The observed damages were classified on a proposed scale with varying absolute values. A reference value equation was proposed as a prediction solution. It was concluded that variations in reinforcement ratio, scaled distance, concrete compressive strength (fck), and support conditions in the same experiment adhere to the proposed damage prediction equation.

Building an Integrated Simulation Model with Ontologies for Prescriptive Maintenance

Mariana Teixeira Rosalin da Silva — 2026-10-09

This article provides studies to support the creation of prescriptive maintenance frameworks, addressing the difficulty caused by the lack of formalized data that hinders the application of rule sets and the execution of data-driven maintenance measures. The absence of adequate data structuring makes it difficult to develop automated and efficient approaches to solve maintenance problems.

One adopted solution is the use of semantic approaches through ontologies. By modeling the domain at a conceptual level, ontologies make it possible to establish relationships and decision logic to drive prescriptive maintenance solutions in an automated way, providing a coherent and consistent structure for the data and facilitating its understanding and manipulation. The use of ontologies enables a formal representation of the data, allowing the creation of more efficient frameworks for prescriptive maintenance.

Using a solution that integrates a simulation model with an ontology simultaneously would bring significant gains to the academic community, since it is possible to obtain benefits in terms of in-depth data understanding, automation of prescriptive maintenance measures, and efficiency in creating frameworks to solve maintenance problems.

Benchmarking of Military Systems Applied to an Unmanned Aircraft Project

Douglas Estevam Casale — 2026-10-09

This paper presented a systematized method for benchmarking military systems and applied it to military attack Unmanned Aircraft Systems (UAS). The study sought to contribute to the development and acquisition of these systems by the Brazilian Armed Forces. The method comprised three stages: selecting the design characteristics for analysis, establishing criteria for system selection, and conducting the benchmarking study. The application compared systems similar to the system under development according to the defined characteristics and selection criteria. It identified the main characteristics of those systems and established a shared understanding among the participants involved in the project. The results showed that the proposed sequence organized the benchmarking process and supported the examination of comparable attack UAS. The study concluded that the method provided a structured basis for benchmarking military systems and supported activities related to the development and acquisition of attack UAS by the Brazilian Armed Forces.