Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Being able to accurately detect and classify fruits on trees would be important for smart farming in terms of the efficiency of yield management and labour cost savings. Conventional methods are prone to inconsistency in environmental conditions, resulting in lower precision in detection accuracy. This paper proposes a state-of-the-art fruit detection technique through an approach to image augmentation enhanced by a genetic algorithm and advanced deep learning models. The proposed approach works for the detection of chickoo, mango, sweet lime and tomato fruit. This approach employs a genetic algorithm to optimize image augmentation, which enhances the diversification of training data and also increases the adaptability of the model towards various conditions. Fruit detection will be performed using the newest You Only Look Once (YoLoV9s) framework, which provides the possibility of real-time detection of objects. Classification of the fruits will be done with the help of a transfer learning-based VGGNet16 model. A colour thresholding step is applied for further confirmation of fruit types; it gives the least number of wrong classifications. It can be shown from the experimental results that the model that I have proposed accords a very good level of accuracy (97.9%), precision (97.0%), recall (97.5%), and an F1-score of 97.3%, which is much beyond the different methodologies produced in the literature up till now. The model's real capability, that is, its ability to accurately predict fruits under various environmental conditions reflects its potential to increase productivity in the precision agriculture process.

The segmentation task for brain tumors from Magnetic Resonance Imaging (MRI) has been challenging and crucial to radiologists in their decision-making process. The recent developments in the attention mechanism in Natural Language Processing tasks have gained wide popularity and potential applications in Computer Vision and related problems. This article proposes a Generative ensembled Vision Transformer that achieves a State-of-the-Art (SOTA) performance in segmenting Brain tumors from multiple modalities of MRI scans. The proposed method includes an encoder and decoder block with CNN and Transformer, which forms the Generative architecture. The discriminator distinguishes the predictions of the Generator from the ground truth and consists of convolution layers along with a softmax for the classification tasks. The model was trained using the BraTS 2021 Task 1 dataset for the segmentation, and the Task 2 dataset was applied to evaluate the classification task. The proposed model scores a DICE average of 91% with a phenomenal score in tumor-core (TC), enhancing-tumor (ET), and whole-tumor (WT) categories. The model scores 99% ROC AUC score in the methylguanine‐methyltransferase (MGMT) classification task.

The use of alternative materials in construction is a growing trend aimed at reducing the environmental impact of cement production. This study evaluated the effect of cardboard ash as a partial cement substitute on the properties of concrete. An experimental methodology was used with 2.5%, 5% and 7.5% additions of cardboard ash. The results indicated that concrete with 5% cardboard ash reduced the absorption speed to 0.229 mm at 831.38 s^½ compared to the reference concrete. In addition, an improvement in mechanical strength was observed, with increases of 15.10%, 16.99% and  18.41% in compressive strength, and 13.76%, 19.63% and 27.33% in flexural strength, highlighting the potential of cardboard ash to optimize concrete properties. These results were evaluated according to ASTM standards. In conclusion, the use of cardboard ash in concrete production contributes significantly to sustainability by reducing CO(2) emissions, making this material a greener and more environmentally efficient option.

This paper details the development of PID controller tuning, based on the implementation of advanced optimization techniques in  MATLAB to find the optimal gains for control actions. The methodology used to create the solutions was that of genetic algorithms, an artificial intelligence technique developed in the 1970s and inspired by Darwin's natural selection, within the field of evolutionary computing. Its implementation is based on selection, crossover, and mutation processes, which allow the solutions to iteratively converge towards increasingly optimal results. Two different genetic algorithms were programmed and designed. The first focused exclusively on a single objective, which was the settling time; while the second was based on a multi-objective technique that additionally considered the maximum overshoot, rise time, and delay time. Different fitness functions were developed to create these neural models; subsequently, the gain results obtained from these genetic methods were compared with those proposed by analytical and experimental methods, both in the field of simulation and in physical implementation. The analysis of the responses validated theefficiency and effectiveness of the proposed algorithms for controller tuning, showing better performance with the gains obtained through genetic algorithms.

In this paper a novel miniaturized frequency reconfigurable microstrip patch antenna for wireless communication is presented. The antenna consists of a square patch and for achieving miniaturization the ground plane of the antenna is modified. The antenna incorporates two switches for achieving frequency reconfigurability. By controlling the states of the switches, the antenna exhibits three distinct operating modes, two single band (i.e. 2.42 GHz and 5.55 GHz) and a dual band (i.e. 3.77 GHz, 6.21 GHz). For the proposed antenna the reflection coefficient (S11) is well below -10 dB. The proposed antenna having geometric configuration of 16 × 17 × 0.8 mm3 is designed and simulated using CST Microwave studio. A prototype of the antenna is fabricated using low cost FR-4 glass epoxy  substrate and the reflection coefficient is measured using Vector Network Analyzer. The simulated reflection coefficient for all the modes are presented and compared with the experimental data validating its usefulness for modern wireless system applications.

Stroke is a major cause of disability and death worldwide, and it constitutes a considerable burden on global health. Thus, prompt detection of strokes reduces the possible risk of death. In this work, an antenna in the form of a Moroccan decoration was proposed for early detection of hemorrhagic stroke. This includes testing the five main types of hemorrhagic stroke, which are subdural, epidural, subarachnoid, intracerebral, and intraventricular, and this method provides the possibility of distinguishing between them, thus reducing the rate of death and disability by a large percentage. The proposed antenna is characterized by its small size with dimensions of 30×35×0.62 mm3, a resonance frequency of 2.806 GHz, a 3.196 GHz bandwidth, and a 2.8 dB gain. The simulation results of the proposed antenna show high efficiency in detecting and distinguishing hemorrhagic strokes, as indicated by clear changes in resonance frequency and return losses S11 caused by brain percentage change due to hemorrhagic stroke.

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This article analyzes the production of a concept of Latin America in the ambit of the central government of the Roman Catholic Church. The Catholic/Roman concept of Latin America that was disseminated at the end of the nineteenth century closely synthesizes the region’s colonial and later republican experience and deeply involves tensions associated with the rise of unprecedented divisions between politics and religion in the Catholic world at the time, thus expressing a series of expectations that were a product of secularization processes. This article thus centers on the way in which the pontifical discourse appropriated an expression created and disseminated elsewhere and gave it a content that provided a particular reading of the region’s history, as well as a specific horizon of expectations. Its reflection is based on the exploration of widely-disseminated pontifical documents, published between 1816 and 1892, in which the concept of America plays a central role. This exploration is accompanied by a contextualization of the political problems of the Atlantic world over the course of the century. The production of a concept with its own nuances speaks to the dispute over naming regions of the world in the context of an intense geopolitical readjustment and struggles over political and economic dominance, which also had a religious aspect.

Perhaps due to their affected nature, political histories have tended to express disdain for the extravagant expressions found in the political language of the nineteenth century. The spectacular collapse of the monarchical universe at the beginning of the century involved the emergence of dizzying experiences regarding the foundation, forms and subjects of the political community and so forms, practices and languages emerged to imagine it and define it, but also contain it. Passions –exacerbated, pursued, liberated– appear stubbornly, repeatedly, obsessively in the political universe of the epoch: “the meekness of the American heart,” “the toxic vapors produced by rancor and spite,” “the unhealed wounds” that “lead men to commit ferocious, remorseless excesses” are common expressions in the political language of the time. The place granted by historical understanding to such an uncomfortable understanding of the human is less clear, however. This article shows that passions –and their particular way of conceiving the human– became an object of calculation and political action, as well as an essential mechanism for understanding the duties and concerns implied by the emergence of unprecedented political orders. In this effort to channel passions as the very possibility of order, complaints about the clergy exacerbated passions regarding the image of a Catholic and republican political community that served as a barrier against a universe that was increasingly ominous and difficult to control.

This article explores the relationship established by nineteenth century men of letters between the study of rhetoric, the notion of neoclassical good taste and the normative guidelines that should guide eloquence in the new public space of the Chilean press and parliament, up through the middle of the nineteenth century. It argues that, during this period, these aesthetic norms also possessed an ethical and political character, connected to the civilizational standards put forward by liberal and Enlightenment men of letters. This paradigm was in tension with the guidelines of ecclesiastical oratory. Though the political sphere adopted the rules of political eloquence, priests still turned to images and messages that appealed to the spiritual fears of their parishioners, violating the principles of good taste, which earned them criticism from liberal men of letters.