German Díaz-Flórez

Prof. Dr. German Díaz-Flórez

Academic Unit of Electrical Engineering, Autonomous University of Zacatecas, Zacatecas City, Mexico
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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 July 2023 in Applied Sciences
Verified
Journal Article
Open access
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Fabián García-VázquezFabián García-Vázquez
Fabián García-Vázquez
JPJesús R. Ponce-González
Jesús R. Ponce-González
Héctor Alonso Guerrero OsunaHéctor Alonso Guerrero Osuna
Héctor Alonso Guerrero Osuna
RCRocío Carrasco-Navarro
Rocío Carrasco-Navarro
Luis F. Luque-VegaLuis F. Luque-Vega
Luis F. Luque-Vega
German Díaz-FlórezGerman Díaz-Flórez
German Díaz-Flórez
Agricultural greenhouses must accurately predict environmental factors to ensure optimal crop growth and energy management efficiency. However, the existing predictors have limitations when dealing with dynamic, non-linear, and massive temporal data. This study proposes four supervised learning techniques focused on linear regression (LR) and Support Vector Regression (SVR) to predict the internal temperature of a greenhouse. A meteorological station is installed in the greenhouse to collect internal data (temperature, humidity, and dew point) and external data (temperature, humidity, and solar radiation). The data comprises a one year, and is divided into seasons for better analysis and modeling of the internal temperature. The study involves sixteen experiments corresponding to the four models and the four seasons and evaluating the models’ performance using R2, RMSE, MAE, and MAPE metrics, considering an acceptability interval of ±2 °C. The results show that LR models had difficulty maintaining the acceptability interval, while the SVR models adapted to temperature outliers, presenting the highest forecast accuracy among the proposed algorithms.

2 December 2021 in Applied Sciences
Verified
Journal Article
Open access
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Salvador Castro-TapiaSalvador Castro-Tapia
Salvador Castro-Tapia
CCCelina L. Castañeda-Miranda
Celina L. Castañeda-Miranda
Carlos A. Olvera-OlveraCarlos A. Olvera-Olvera
Carlos A. Olvera-Olvera
Héctor Alonso Guerrero OsunaHéctor Alonso Guerrero Osuna
Héctor Alonso Guerrero Osuna
JOJosé Manuel Ortiz-Rodriguez
José Manuel Ortiz-Rodriguez
LSLuis Octavio Solís-Sánchez
Luis Octavio Solís-Sánchez
Breast cancer is one of the diseases of most profound concern, with the most prevalence worldwide, where early detections and diagnoses play the leading role against this disease achieved through imaging techniques such as mammography. Radiologists tend to have a high false positive rate for mammography diagnoses and an accuracy of around 82%. Currently, deep learning (DL) techniques have shown promising results in the early detection of breast cancer by generating computer-aided diagnosis (CAD) systems implementing convolutional neural networks (CNNs). This work focuses on applying, evaluating, and comparing the architectures: AlexNet, GoogLeNet, Resnet50, and Vgg19 to classify breast lesions after using transfer learning with fine-tuning and training the CNN with regions extracted from the MIAS and INbreast databases. We analyzed 14 classifiers, involving 4 classes as several researches have done it before, corresponding to benign and malignant microcalcifications and masses, and as our main contribution, we also added a 5th class for the normal tissue of the mammary parenchyma increasing the correct detection; in order to evaluate the architectures with a statistical analysis based on the received operational characteristics (ROC), the area under the curve (AUC), F1 Score, accuracy, precision, sensitivity, and specificity. We generate the best results with the CNN GoogLeNet trained with five classes on a balanced database with an AUC of 99.29%, F1 Score of 91.92%, the accuracy of 91.92%, precision of 92.15%, sensitivity of 91.70%, and specificity of 97.66%, concluding that GoogLeNet is optimal as a classifier in a CAD system to deal with breast cancer.

11 February 2022 in Sensors
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Journal Article
Open access
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carlos Alberto paredes ortacarlos Alberto paredes orta
carlos Alberto paredes orta
Jorge Domingo Mendiola-SantibañezJorge Domingo Mendiola-Santibañez
Jorge Domingo Mendiola-Santibañez
DIDanjela Ibrahimi
Danjela Ibrahimi
Juvenal RodriguezJuvenal Rodriguez
Juvenal Rodriguez
German Díaz-FlórezGerman Díaz-Flórez
German Díaz-Flórez
Carlos A. Olvera-OlveraCarlos A. Olvera-Olvera
Carlos A. Olvera-Olvera
This article presents two procedures involving a maximal hyperconnected function and a hyperconnected lower leveling to segment the brain in a magnetic resonance imaging T1 weighted using new openings on a max-tree structure. The openings are hyperconnected and are viscous transformations. The first procedure considers finding the higher hyperconnected maximum by using an increasing criterion that plays a central role during segmentation. The second procedure utilizes hyperconnected lower leveling, which acts as a marker, controlling the reconstruction process into the mask. As a result, the proposal allows an efficient segmentation of the brain to be obtained. In total, 38 magnetic resonance T1-weighted images obtained from the Internet Brain Segmentation Repository are segmented. The Jaccard and Dice indices are computed, compared, and validated with the efficiency of the Brain Extraction Tool software and other algorithms provided in the literature.

13 May 2023 in Applied Sciences
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Journal Article
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Manuel de Jesús López-MartínezManuel de Jesús López-Martínez
Manuel de Jesús López-Martínez
German Díaz-FlórezGerman Díaz-Flórez
German Díaz-Flórez
SVSantiago Villagrana-Barraza
Santiago Villagrana-Barraza
LSLuis Octavio Solís-Sánchez
Luis Octavio Solís-Sánchez
Héctor Alonso Guerrero OsunaHéctor Alonso Guerrero Osuna
Héctor Alonso Guerrero Osuna
Carlos A. Olvera-OlveraCarlos A. Olvera-Olvera
Carlos A. Olvera-Olvera
One of the main concerns in precision agriculture (PA) is the growth of weeds within a crop field. Currently, to prevent the spread of weeds, automatic techniques and computational tools are used to help to identify, classify, and detect the different types of weeds found in agricultural fields. One of the technologies that can help us to process digital information gathered from the agricultural fields is high-performance computing (HPC); this technology has been adopted to carry out projects requiring extra processing and storage in order to execute tasks with a large computational cost. This paper shows the implementation of an HPC cluster (HPCC), in which image processing (IP) and analysis are executed using deep learning (DL) techniques, specifically, convolutional neural networks (CNNs) with the VGG16 and InceptionV3 models, to classify different weed species. The results show the great benefits of using high-performance computing clusters in PA, specifically for classifying images. To apply distributed computing within the HPCC, the Keras and Horovod frameworks were used to train the CNN models, obtaining the best time with the InceptionV3 model with a value of 37 min 55.193 s using six HPCC cores, obtaining an accuracy of 0.65 as a result.

23 August 2024 in Applied Sciences
Verified
Journal Article
Open access
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MEMartha Isabel Escalona-Llaguno
Martha Isabel Escalona-Llaguno
LSLuis Octavio Solís-Sánchez
Luis Octavio Solís-Sánchez
CCCelina L. Castañeda-Miranda
Celina L. Castañeda-Miranda
Carlos A. Olvera-OlveraCarlos A. Olvera-Olvera
Carlos A. Olvera-Olvera
MMMa. del Rosario Martínez-Blanco
Ma. del Rosario Martínez-Blanco
GOGerardo Ornelas-Vargas
Gerardo Ornelas-Vargas
This work explores the prediction of daily Global Horizontal Irradiance (GHI) patterns in the region of Zacatecas, Mexico, using a diverse range of predictive models, encompassing traditional regressors and advanced neural networks like Evolutionary Neural Architecture Search (ENAS), Convolutional Neural Networks (CNN), Recurrent Neural Networks (RNN), and Meta’s Prophet. This work addressing a notable gap in regional research, and aims to democratize access to accurate solar radiation forecasting methodologies. The evaluations carried out using the time series data obtained by Comisión Nacional del Agua (Conagua) covering the period from 2015 to 2018 reveal different performances of the model in different sky conditions, showcasing strengths in forecasting clear and partially cloudy days while encountering challenges with cloudy conditions. Overall, correlation coefficients (r) ranged between 0.55 and 0.72, with Root Mean Square Error % (RMSE %) values spanning from 20.05% to 20.54%, indicating moderate to good predictive accuracy. This study underscores the need for longer datasets to bolster future predictive capabilities. By democratizing access to these predictive tools, this research facilitates informed decision-making in renewable energy planning and sustainable development strategies tailored to the unique environmental dynamics of the region of Zacatecas and comparable regions.

6 June 2025 in Agriengineering
Verified
Journal Article
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JSJacqueline Guerrero Sanchez
Jacqueline Guerrero Sanchez
Carlos A. Olvera-OlveraCarlos A. Olvera-Olvera
Carlos A. Olvera-Olvera
LSLuis Octavio Solís-Sánchez
Luis Octavio Solís-Sánchez
MMMa. del Rosario Martínez-Blanco
Ma. del Rosario Martínez-Blanco
Manuel de Jesús López-MartínezManuel de Jesús López-Martínez
Manuel de Jesús López-Martínez
German Díaz-FlórezGerman Díaz-Flórez
German Díaz-Flórez
This Technical Note presents the design and implementation of a low-cost modular growth chamber developed to keep mother plants under controlled environmental conditions for vegetative propagation. The system was conceived as an accessible alternative to expensive commercial equipment, offering reproducibility and adaptability for small-scale and research-based cultivation. The proposed chamber integrates thermal insulation, LED lighting, forced ventilation through the implementation of extractors, a recirculating irrigation system with double filtration, and a sensor-based environmental monitoring platform operated via an Arduino UNO microcontroller. The design features a removable tray that serves as a support for the mother plant, an observation window covered by a movable dark acrylic that prevents the passage of external light, and a vertical structure that facilitates optimal space utilization and ergonomic access. Functionality was conducted using a Stevia rebaudiana Bertoni mother plant maintained for 30 days under monitored conditions. Environmental parameters—temperature, relative humidity, and illuminance—were recorded continuously. The plant showed vegetative development through new shoot emergence and the growth in height of the plant, and despite a loss in foliage expansion, it confirmed the chamber’s capacity to support sustained growth. Although no statistical replication or control group was included in this preliminary evaluation, the system demonstrates technical feasibility and practical utility. This chamber provides a replicable platform for future experimentation and propagation studies. Complete technical specifications, schematics, and component lists are provided to enable replication and further development by other researchers. The growth chamber design aligns with the goals of open-source agricultural innovation and supports knowledge transfer in controlled-environment plant propagation technologies.