This paper presents a comparative study between the absolute and relative methods for altimetric positional accuracy of Digital Elevation Models (DEM). For the theoretical basis of this research, the definitions of accuracy (exactness) and precision, as well the concepts related to absolute and relative positional accuracy were explored. In the case study, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and the Shuttle Radar Topography Mission (SRTM) DEM were used. In the analysis of the absolute accuracy, 6,568 ground control points from GNSS orbital survey were used, collected through relative-static method. In the relative accuracy, it was used as reference DEM with spatial resolution of 5 meters generated by stereophotogrammetrical process for the Mapping Project of Bahia (Brazil). It was concluded that, once the accuracy of the reference DEM is better than the other two evaluated DEM, the results of the classification for the PEC-PCD for the relative evaluation are equal to or better than the absolute evaluation results, with the advantage to being able to verify the pixel population of the evaluated models, which makes it possible to identify outliers, distortions and displacements, including delimiting regions, which is much less likely with a limited set of control points.

Military troops rely on maintenance management projects and operations to preserve the materials’ ordinary conditions or restore them to combat or military training. Maintenance management in the defense domain has its particularities, such as those related to the type of equipment operated, the environment and operating conditions, the need to maintain equipment readiness in cases of external aggression, and the security of the information. This study aims to understand the challenges, principles, scenarios, techniques, and open questions of predictive maintenance (PdM) in the military domain. We conducted a systematic literature review that resulted in the discussion of 43 articles, leading to the identification of 23 challenges and principles, 4 scenarios where predictive maintenance is crucial, besides discussing techniques used for PdM in the military domain. Our results contribute to understanding the perspective of PdM in the defense context.

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The heritage issue, after nearly two centuries of discussion, is still full of myths and inconsistencies in keeping with the theory and practice of safeguarding assets and thematic accessibility. It is also known that the patrimony demarcates the memorial foundations of the collectivity and should serve the population from its socio-educational capacity, but, in practice, this often does not occur, resulting in the destitution of the sociocultural function of the good. The question of modern heritage makes the discussion even more ambiguous, promoting polemical debates, detaching the object from its historical value or framing its aesthetic value as mistaken. In this perspective, the choice of the object of study was based on the analysis of the set of the Palácio da Abolição and the Castelo Branco Mausoleum in Fortaleza (CE), as it is a significant landmark for the city in both a functional and formal aspect, housing the headquarters of the state government and composing a daring architectural ensemble in an important neighborhood in Fortaleza. However, looking at it in the semiological perspective of its architecture, it appears that the Mausoleum pays homage to the first president of the Brazilian dictatorial period, making it necessary, therefore, to raise a problematization related to the modern heritage and its function, under the memory architecture perspective.

Triangular Irregular Networks (TINs) are one of the most used ways to represent surface topology when working with Digital Terrain Models (DTM) or Geographic Information Systems (GIS). Given this form of representation, this article investigates one probabilistic demonstration to quantify how each point's accuracy σ (sigma) can be considered to have ambiguity, from the topological point of view, in any new 2D Delaunay Triangulation. To achieve it, this research designed an initial demonstration that, there is a maximum precision for which the network topology remains constant in a new Delaunay Triangulation, at each point and in the TIN as a whole. The methodological approach was experimental, with various mathematical experiments carried out using the Monte Carlo Simulation method. First, for each point of the network, and then for all network points for varied σ. The experiments culminate in helping to solve the problem of the existence of maximum σ for which the probability of occurrence in constant TIN topology is 100%. The mathematical results originated the following statement: Considering a TIN generated by Delaunay Triangulation, if any point of coordinates (x i , y i ) in a Triangular Irregular Network is disrupted (i.e., has its place altered), according to a Normal distribution N(μ, σ 2 ), then, exists a value σ max (sigma maximum) for which the topology of the network remains constant. For example, it was found that σ max.1 of one point exists and is obtained by σ max.1 = 0.30866, and at another point, σ max.2 = 0.2. The results also indicate the following for TIN: Every two-dimensional Triangular Irregular Network generated by the Delaunay Triangulation has a value σ * (sigma asterisk) to which the network topology remains constant. In this work, simulating the worst case of a Triangular Irregular Network: σ * = 0.2. Finally, it is concluded that the σ maximum for each point exists, as well as for the network as a whole. However, the results need to be tested in more extensive networks to prove (or not) if it always