IEEE Latin America Transactions最新文献_第7页

COVID-19 impact in the Brazilian Multiplex Air Transportation Network 2019冠状病毒病对巴西多元航空运输网络的影响

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-03-17 DOI: 10.1109/TLA.2025.10930377

Fernanda Silva Toledo;Nelson Francisco Favilla Ebecken

{"title":"COVID-19 impact in the Brazilian Multiplex Air Transportation Network","authors":"Fernanda Silva Toledo;Nelson Francisco Favilla Ebecken","doi":"10.1109/TLA.2025.10930377","DOIUrl":"https://doi.org/10.1109/TLA.2025.10930377","url":null,"abstract":"The Brazilian Air Transportation Network has been changing in the last years, due to an economic recession since 2016, the concession of the main airports and the impact of the COVID-19 pandemic. Air transportation is a complex infrastructure system, in which each airline represents a different layer. Adding the weight of interactions combined with a multilayer approach can make the network description even more detailed than a single-layer analysis, because important network features emerge from the multilayer character. The multilayer approach for complex networks is yet new in the literature. As far as the authors know, there are no studies yet applying multiplex network to analyze domestic and international Brazilian air network to improve the understanding of complex systems and investigate macroeconomic effects of the economic recession and COVID-19 pandemic in the air network. The objective of this paper is to evaluate changes in the Brazilian Air Transportation network from 2019 to 2020, before and during the COVID-19 pandemic, using topology measures for network characterization. We compared the network topology and evaluated COVID-19 impact on airports under concession and on regional aviation, also comparing with the aggregated approach. Results show a network concentration during this period in hub airports, reduced connectivity and reduced density resulting in a sparser network. The airlines strategies were different over this period and the multilayer approach changed the importance ranking of airports compared with the aggregated approach. These analyses indicate an opportunity to improve regional air transportation and the need to enhance regional airports versatility.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 4","pages":"294-300"},"PeriodicalIF":1.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10930377","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dense-PMSFNet: DenseNet Pyramidal Multi-Scale Fusion Network for Retinal Vasculature and FAZ Segmentation in OCTA Images Dense-PMSFNet：用于oct图像中视网膜血管和FAZ分割的DenseNet金字塔多尺度融合网络

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-03-17 DOI: 10.1109/TLA.2025.10930374

Nisan Pranavah Raja;Srivatsan Sarvesan;Anju Thomas;Varun P Gopi

{"title":"Dense-PMSFNet: DenseNet Pyramidal Multi-Scale Fusion Network for Retinal Vasculature and FAZ Segmentation in OCTA Images","authors":"Nisan Pranavah Raja;Srivatsan Sarvesan;Anju Thomas;Varun P Gopi","doi":"10.1109/TLA.2025.10930374","DOIUrl":"https://doi.org/10.1109/TLA.2025.10930374","url":null,"abstract":"Diabetic retinopathy (DR) is a condition that leads to damage to the retina due to high blood sugar levels in the eyes caused by prolonged diabetes. People of working age in developing countries are particularly at risk of developing diabetic retinopathy, which causes permanent vision loss in diabetic patients. Diagnosis involves maintaining the current level of vision of the patient, as the disease can cause blindness. Optical Coherence Tomography Angiography (OCTA) is an advanced eye imaging technique that offers a detailed view of the structures of retinal blood vessels and effectively treats various eye conditions. Therefore, it is crucial to accurately identify and separate the capillary, artery, vein, and Foveal Avascular Zone (FAZ) from OCTA images. The DenseNet Pyramidal MultiScale Fusion Network (Dense-PMSFNet) is introduced in this article as a new segmentation network based on deep learning. It utilizes the DenseNet Encoder to integrate local semantic contextual information, the Multi-Scale Pyramidal Fusion Module (MSPFM) to effectively merge local features at different scales, and Deep Fusion to enhance the representation of multiscale decoder outputs. Through extensive experimentation on four distinct segmentation tasks involving capillary, artery, vein, and FAZ from OCTA images, it has demonstrated superior performance for the quantitative metrics such as Dice coefficient (DSC), Accuracy (ACC), Intersection Over Union (IoU), Specificity (SP) and Sensitivity (SE) in comparison to state-of-the-art methods.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 4","pages":"312-322"},"PeriodicalIF":1.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10930374","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design and Analysis of an Improved Gain Single Inductor Dual Switch DC-DC Converter with Reduced Duty Ratio and Minimal Voltage Stress 减小占空比和最小电压应力的改进增益单电感双开关DC-DC变换器的设计与分析

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-03-17 DOI: 10.1109/TLA.2025.10930372

Srimaheswaran V;Niveditha N;Rajan Singaravel M M

{"title":"Design and Analysis of an Improved Gain Single Inductor Dual Switch DC-DC Converter with Reduced Duty Ratio and Minimal Voltage Stress","authors":"Srimaheswaran V;Niveditha N;Rajan Singaravel M M","doi":"10.1109/TLA.2025.10930372","DOIUrl":"https://doi.org/10.1109/TLA.2025.10930372","url":null,"abstract":"This paper proposes an Improved Gain Single Inductor Dual Switch Converter (IGSIDSC) for the grid integration of solar and fuel cells, which achieves high voltage gain at reduced duty ratio and with less component count. The proposed converter is designed to operate with a duty ratio less than 50% to ensures reduced losses and less component stress This salient feature makes the proposed converter unique among the other converters reported so far. By reducing voltage stress on switches and diodes, the design permits the use of lower-rated components and reduces the cost. The common ground configuration helps to reduce dv/dt issue. The IGSIDSC is analyzed in steady state with consideration of parasitic resistance for all components of the converter. Further, the simulation results are validated through experimental investigation using the prototype developed in laboratory for the power rating of 200 W. Also, the investigations on steady-state performance and dynamic behavior of the experimental prototype effectively demonstrate the successful operation of the IGSIDSC.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 4","pages":"339-352"},"PeriodicalIF":1.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10930372","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Table of Contents April 2025 目录2025年4月

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-03-17 DOI: 10.1109/TLA.2025.10930371

引用次数: 0

Dynamic Phasor Modeling of the Single-Phase MMC under Modulation PSC-PWM PSC-PWM调制下单相MMC的动态相量建模

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-03-17 DOI: 10.1109/TLA.2025.10930370

Glendy A. Catzin-Contreras;Gerado Escobar;Andres Alejandro Valdez-Fernandez;Manuel J. Lopez-Sanchez

{"title":"Dynamic Phasor Modeling of the Single-Phase MMC under Modulation PSC-PWM","authors":"Glendy A. Catzin-Contreras;Gerado Escobar;Andres Alejandro Valdez-Fernandez;Manuel J. Lopez-Sanchez","doi":"10.1109/TLA.2025.10930370","DOIUrl":"https://doi.org/10.1109/TLA.2025.10930370","url":null,"abstract":"This paper develops a model, based on the dynamic phasor approach, for the single-phase modular multilevel converter (MMC), where the switching sequences are generated by the phase-shifted carrier-based pulse-width modulation (PSC-PWM) scheme. The modeling process begins with the MMC state space model, from which the DC and the fundamental complex Fourier coefficients, called dynamic phasors, are extracted for both the original state variables and the switching functions. It is worth noting that, in the developed dynamic phasor-based model (DPhM) of the MMC, all capacitor voltages per phase are considered separately in the modeling process, which contrast with the usual definition of variables based on the sum and difference of the capacitor voltages on the arms. Experimental results are presented to demonstrate the validity of the MMC DPhM as compared to the response of the switched MMC under the PSC-PWM scheme. In particular, it is observed that the developed MMC DPhM is able to reproduce the steady-state waveforms of all original state variables, including the ripple amplitude, as compared to the results obtained with the switched MMC. Furthermore, it is shown that, both in the switched MMC under the PSC-PWM and in the derived DPhM MMC, all capacitors converge to the same steady-state average value without adding an external balance controller, but only due to the natural balancing action of the PSC-PWM scheme, despite arbitrary initial conditions of capacitor voltages.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 4","pages":"353-361"},"PeriodicalIF":1.3,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10930370","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Memetic Genetic Particle Swarm Optimization for Druglike Molecule Discovery 类药物分子发现的模因遗传粒子群优化

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-02-10 DOI: 10.1109/TLA.2025.10879174

Matías Gabriel Rojas;Ana Carolina Olivera;Pablo Javier Vidal

{"title":"Memetic Genetic Particle Swarm Optimization for Druglike Molecule Discovery","authors":"Matías Gabriel Rojas;Ana Carolina Olivera;Pablo Javier Vidal","doi":"10.1109/TLA.2025.10879174","DOIUrl":"https://doi.org/10.1109/TLA.2025.10879174","url":null,"abstract":"Given the vast and complex chemical search space, developing new techniques for identifying promising ligands that satisfy multiple objectives is highly desirable to reduce the costs and times required for effective drug discovery. Neural networks are frequently employed for this task, but they tend to generate molecules that are invalid both chemically and syntactically. As an alternative, metaheuristics have emerged as promising approaches, delivering notable results with reasonable computational costs. However, they often suffer from information loss during the process, leading to poor quality generations. In this work, we introduce a novel memetic algorithm that hybridizes Particle Swarm Optimization with Simulated Annealing. This approach aims to improve the balance between exploration and exploitation in the de-novo drug discovery process, ensuring that promising molecules are not overlooked during generation steps. We compare our approach against six state-of-the-art algorithms, and the results demonstrate that our algorithm enhances molecule generation quality, showing an increased diversity and improved chemical properties of the resulting ligands.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 3","pages":"216-222"},"PeriodicalIF":1.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879174","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Table of Contents March 2025 目录2025年3月

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-02-10 DOI: 10.1109/TLA.2025.10879179

引用次数: 0

Agreement analysis of heart rate variability indices at two different sampling rates for monitoring applications. 心率变异性指标在两种不同采样率下的一致性分析。

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-02-10 DOI: 10.1109/TLA.2025.10879195

Eduardo San Roman;Javier Zelechower;Jose Manuel Gallardo;Marcelo Risk

{"title":"Agreement analysis of heart rate variability indices at two different sampling rates for monitoring applications.","authors":"Eduardo San Roman;Javier Zelechower;Jose Manuel Gallardo;Marcelo Risk","doi":"10.1109/TLA.2025.10879195","DOIUrl":"https://doi.org/10.1109/TLA.2025.10879195","url":null,"abstract":"Beat-to-beat variations in heart rate lead to heart rate variability (HRV), analysed from electrocardiogram or photoplethysmography signals, forming a non-equispaced time series of beats, which requires a resampling of 3 Hz or 4 Hz, for analysis in the frequency domain. HRV is considered a biomarker, predictor of the evolution of diseases in intensive care units (ICU). To enhance these HRV studies, it is necessary to monitor the patients health using portable devices, from admission to the ICU until discharge from it and subsequently at home. This requires monitoring devices that can minimise energy consumption and data storage. Reducing the sampling frequency in HRV can reduce energy consumption, computing power and to limite data storage. Therefore, the objective of this work is to prove that a series resampled at 1 Hz allows obtaining HRV indices, equivalent to a 3 Hz. Through concordance analysis, using a database of subjects with pharmacological autonomic blockade and postural changes. The results show equivalences between the indices, standard deviation (SDNN), total spectral power (PT), low frequency (LF) and long-term variability (SD2) and agree with those reported as predictors. This study has limitations, since only a small number of young men participated. Future studies should consider this. The reduction of SDNN, PT, LF values would be predictors of mortality in hospitals, so the equivalence found from series with 1Hz resampling, would allow the use of portable devices with optimized performance, to monitor the evolution of the disease in patients in ICUs.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 3","pages":"258-264"},"PeriodicalIF":1.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

UAV Flight Comparison Using Backstepping: On-board Data and Observers 无人机飞行对比反演：机载数据和观测者

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-02-10 DOI: 10.1109/TLA.2025.10879177

Jesus Santiaguillo-Salinas;Eduardo Aranda-Bricaire;Hiram N. Garcia-Lozano

{"title":"UAV Flight Comparison Using Backstepping: On-board Data and Observers","authors":"Jesus Santiaguillo-Salinas;Eduardo Aranda-Bricaire;Hiram N. Garcia-Lozano","doi":"10.1109/TLA.2025.10879177","DOIUrl":"https://doi.org/10.1109/TLA.2025.10879177","url":null,"abstract":"This paper presents the comparison of performance in flight trajectory tracking for a commercial UAV AR.Drone 2.0, using state observers and on board data. This work seeks to establish that state observers are an alternative to close the control loop in this type of applications. The control strategy proposed for the flight is designed using the Backstepping technique. For the implementation of the control law, knowledge of the position and orientation of the UAV is assumed, therefore, its longitudinal and rotational velocities are estimated either by using observers or data from the combination of inertial and visual measurement of the on-board sensors. In both cases, the designed control strategy makes the UAV converge to the pre-established flight trajectory. However, an analysis of the mean square error between the UAV trajectory with respect to the desired trajectory, gives as a result that, in three of the four compared states, the error obtained with the observer is lower. The theoretical results presented are validated experimentally.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 3","pages":"182-190"},"PeriodicalIF":1.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879177","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Convolutional Neural Networks using the SMOTE Algorithm and Features Fusion for Wind Turbine Fault Prediction 基于SMOTE算法和特征融合的卷积神经网络风电机组故障预测

IF 1.3 4区工程技术

IEEE Latin America Transactions Pub Date : 2025-02-10 DOI: 10.1109/TLA.2025.10879178

Lucas França Aires;Júlio Oliveira Schmidt;Guilherme Ricardo Hübner;Frederico Menine Schaf;Claiton Moro Franchi;Humberto Pinheiro;Daniel Fernando Tello Gamarra

{"title":"Convolutional Neural Networks using the SMOTE Algorithm and Features Fusion for Wind Turbine Fault Prediction","authors":"Lucas França Aires;Júlio Oliveira Schmidt;Guilherme Ricardo Hübner;Frederico Menine Schaf;Claiton Moro Franchi;Humberto Pinheiro;Daniel Fernando Tello Gamarra","doi":"10.1109/TLA.2025.10879178","DOIUrl":"https://doi.org/10.1109/TLA.2025.10879178","url":null,"abstract":"This research introduces an innovative method using Convolutional Neural Networks (CNNs) to identify mass imbalances in wind turbine rotors through a feature fusion strategy. To address the issue of class imbalance, the Synthetic Minority Oversampling Technique (SMOTE) is applied. A detailed simulation was carried out using a 1.5 MW three-bladed Wind Turbine model, employing tools such as Turbsim, FAST, and Matlab Simulink, to collect rotor speed data under different wind conditions. Mass imbalances were simulated by modifying blade density in the software. The fusion architecture combines feature extraction with Power Spectral Density analysis, improving the CNNs ability to work across both frequency and time domains. The effectiveness of this approach was confirmed through a comparative analysis with 9 classifiers and 4 different dataset combinations, demonstrating its capability in detecting mass imbalances.","PeriodicalId":55024,"journal":{"name":"IEEE Latin America Transactions","volume":"23 3","pages":"191-197"},"PeriodicalIF":1.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10879178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0