Departamento de Algebrahttps://hdl.handle.net/10481/430882024-03-28T12:46:25Z2024-03-28T12:46:25ZMathematical Foundation of a Functional Implementation of the CNF AlgorithmGarcía Olmedo, Francisco MiguelGarcía Miranda, JesúsGonzález Rodelas, Pedrohttps://hdl.handle.net/10481/856372023-11-13T13:40:42ZMathematical Foundation of a Functional Implementation of the CNF Algorithm
García Olmedo, Francisco Miguel; García Miranda, Jesús; González Rodelas, Pedro
The conjunctive normal form (CNF) algorithm is one of the best known and most widely used algorithms in classical logic and its applications. In its algebraic approach, it makes use in a loop of a certain well-defined operation related to the “distributivity” of logical disjunction versus conjunction. For those types of implementations, the loop iteration runs a comparison between formulas to decide when to stop. In this article, we explain how to pre-calculate the exact number of loop iterations, thus avoiding the work involved in the above-mentioned comparison. After that, it is possible to concatenate another loop focused now on the “associativity” of conjunction and disjunction. Also for that loop, we explain how to calculate the optimal number of rounds, so that the decisional comparison phase for stopping can be also avoided.
Cenozoic tectono-sedimentary evolution of the onshore-offshore Tunisian Tell: Implications for oil-gas researchBelayouni, HabibBullejos Lorenzo, Manuelhttps://hdl.handle.net/10481/849622023-10-13T07:57:00ZCenozoic tectono-sedimentary evolution of the onshore-offshore Tunisian Tell: Implications for oil-gas research
Belayouni, Habib; Bullejos Lorenzo, Manuel
A review of the paleogeographic and tectonic reconstruction of the onshore and offshore Tunisian margin during
the Cenozoic is discussed. Five unconformities (A to E) and associated stratigraphic gaps of various vertical
extents allow subdivision of the stratigraphic record into depositional units in the following time intervals: (i)
Paleocene-Oligocene, (ii) Oligocene-early Aquitanian, (iii) early Aquitanian-Burdigalian, (iv) late Burdigalian-
Langhian and (v) Langhian-late Miocene. These intervals can in turn be grouped into four main sedimentary
cycles (SC1–SC4) dated to the (1) Paleocene-Oligocene, (2) Oligocene–Burdigalian, (3) Burdigalian-Langhian and
(4) Langhian-late Miocene. The oldest depositional unit reflects Eo-Alpine tectonics in the Maghrebian Flysch
Basin (MFB); the others are related to the Neo-Alpine syn- and late orogenic tectonic deformation affecting the
MFB. The uppermost unit represents post-orogenic deposition. Early Miocene synsedimentary tectonism led to
(1) deposition of thick successions owing to a large sediment supply and (2) the occurrence of various tectofacies
(unconformities, slumps, mega-turbidites, olistostromes, growth folds, chaotic intervals and heterogenous lithofacies),
that all, together with the occurrence of lateral change of facies, clearly indicate non-cyclical sedimentation.
During the middle Miocene the Tunisian Tell underwent polyphase thrust tectonism, followed by late
Miocene strike-slip deformation with contemporaneous rejuvenation of halokinetics and magmatism (the La
Galite Archipelago) that may be traced as far as the Algerian Tell. The margin experienced deep-seated
compressional tectonism during the Paleogene, a foreland basin during the early Miocene, and nappe stacking
during the middle Miocene, with the occurrence of wedge-top sub-basins. The evolution of the region makes the
existence of petroleum resources within either the thrust belt, the foredeep and/or the foreland systems plausible.
Oil and/or gas may have been trapped in either i) deep buried allochthonous thrust wedges that are located
below the Numidian Nappes, and/or in ii) the imbricate Medjerda Valley domain of the Tell foredeep. The
offshore area between northern Tunisia and the La Galite Archipelago may also hold potential for large oil/gas
fields, as has been confirmed by exploration of the same overthrust belt in other areas such as in Sicily and the
Southern Apennines.
Skew differential Goppa codes and their application to Mceliece cryptosystemGómez Torrecillas, JoséLobillo Borrero, Francisco JavierNavarro Garulo, Gabrielhttps://hdl.handle.net/10481/846482023-09-25T12:33:30ZSkew differential Goppa codes and their application to Mceliece cryptosystem
Gómez Torrecillas, José; Lobillo Borrero, Francisco Javier; Navarro Garulo, Gabriel
A class of linear codes that extends classical Goppa codes to a non-commutative context is defined. An efficient decoding algorithm, based on the solution of a non-commutative key equation, is designed. We show how the parameters of these codes, when the alphabet is a finite field, may be adjusted to propose a McEliece-type cryptosystem.
Research funded by grant (PID2019-110525GB-I00 / AEI / 10.13039/501100011033) and by the IMAG-Maria de Maeztu grant (CEX2020-001105-M / AEI / 10.13039/501100011033).
A Python Application for Visualizing an Imbricate Thrust System: Palomeque Duplex (SE, Spain)Bullejos Lorenzo, ManuelMartín Martín, Manuelhttps://hdl.handle.net/10481/846192023-10-09T22:21:28ZA Python Application for Visualizing an Imbricate Thrust System: Palomeque Duplex (SE, Spain)
Bullejos Lorenzo, Manuel; Martín Martín, Manuel
This paper introduces a Python application for visualizing an imbricate thrust system.
The application uses the traditional geologic information to create an HTML geological map with
real topography and a set of geological cross-sections with the essential structural and stratigraphic
elements. On the basis of the high geological knowledge gained during the last three decades, the
Palomeque sheets affecting the Cenozoic Malaguide succession in the Internal Betic Zone (SE Spain)
were selected to show the application. In this area, a Malaguide Cretaceous to Lower Miocene
succession is deformed as an imbricate thrust system, with two thrusts forming a duplex, affected
later by a set of faults with a main strike-slip kinematic. The modeled elements match well with
the design of the stratigraphic intervals and the structures reported in recent scientific publications.
This proves the good performance of this Python application for visualizing the structural and
stratigraphic architecture. This kind of application could be a crucial stage for future groundwater,
mining, and civil engineering management.
Using python libraries and k-Nearest neighbors algorithms to delineate syn-sedimentary faults in sedimentary porous mediaMartín Martín, ManuelBullejos Lorenzo, ManuelCabezas Berrido, DavidAlcalá, Francisco Javierhttps://hdl.handle.net/10481/824272023-06-14T07:31:59ZUsing python libraries and k-Nearest neighbors algorithms to delineate syn-sedimentary faults in sedimentary porous media
Martín Martín, Manuel; Bullejos Lorenzo, Manuel; Cabezas Berrido, David; Alcalá, Francisco Javier
This paper introduces a methodology based on Python libraries and machine learning k-Nearest Neighbors (KNN) algorithms to create an interactive 3D HTML model (3D_Vertical_Sections_Faults_LRD.html) that combines 2D grain-size KNN-prediction vertical maps (vertical sections) from which syn-sedimentary faults and other features in sedimentary porous media can be delineated. The model can be visualized and handled with conventional web browsers. The grain-size physical parameter is measurable, constant over instrumental time, handleable math-ematically, and its range can be associated to lithological classes. Grain-size input data comes from a public database of 433 boreholes in the Llobregat River Delta (LRD) in NE Spain. Four lithological classes were defined: Pre-Quaternary basement, and Quaternary gravel, sand, and clay-silt. Using a new KNN-prediction algorithm, seven NW-SE (transversal) and three SW-NE (longitudinal) vertical sections were created following the orien-tation of faults identified in surface and detected in reflection seismic geophysical surveys. For exploratory K values in the 1-75 range were used. K around 25 provides the general and smoothy shape of the basement top surface, whereas K =1 is a optimal value to represent the heterogeneity of the LRD at short distance. Using a new KNN-prediction confidence algorithm inspired in the Similarity Ratio algorithm for machine-learning KNN, the vertical sections overall confidence was evaluated as satisfactory. A general decreasing confidence trend ac-cording to the decreasing data density with depth and from inland to seaward was found. The vertical sections created with K = 1 show horizontal interruptions (displacements or vertical steps) in the basement continuity and in the Quaternary coarse bodies (gravel and sand) attributable to the action of Quaternary active faults. These faults have been linked or correlated with well-known active faults in the area related in much cases with the Valencia Trough opening. Moreover, several faults detected in surface and other identified in this paper by the first time have been revealed as fault zones made of fault branches with different steps in an echelon-like arrangement. Faulting seems to be more evident in the Pleistocene Lower Detrital Complex and much less active or inactive in the Holocene Upper Detrital Complex. Syn-tectonic gravel channels faulty controlled, progradation of gravel lobes, and lateral migration of channel bars were also observed. At its current develop-ment stage, this methodology could also be applied to other geological environments, making the due minor modifications of the code, and is especially suitable to reduce the high (usually unmeasurable) uncertainty associated to the qualitative geological data used in more complex numerical tools aimed at modelling a lot of geological resources (groundwater, minerals, geothermal, petroleum) or different Earth phenomena.
Supplementary data to this article can be found online at https://doi.
org/10.1016/j.marpetgeo.2023.106283