Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (10,387)

Search Parameters:
Keywords = measurable space

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
24 pages, 9483 KiB  
Article
Development of Methodology for Estimation of Energy-Efficient Building Renovation Using Application of MINLP-Optimized Timber–Glass Upgrade Modules
by Maja Lešnik Nedelko, Stojan Kravanja, Miroslav Premrov and Vesna Žegarac Leskovar
Sustainability 2025, 17(1), 319; https://doi.org/10.3390/su17010319 - 3 Jan 2025
Abstract
Vertical addition to already-existing structures is an approach to energy-efficient building renovation. It presents an opportunity for the densification of built-up areas and the construction of new usable spaces. While many studies have dealt with the subject of renovating buildings with a focus [...] Read more.
Vertical addition to already-existing structures is an approach to energy-efficient building renovation. It presents an opportunity for the densification of built-up areas and the construction of new usable spaces. While many studies have dealt with the subject of renovating buildings with a focus on energy efficiency, far fewer studies have specifically examined the potential of vertically extending existing buildings, an approach which could be introduced in new sustainable building policies. The objective of this study is to redevelop optimal timber–glass upgrade modules, considering the ideal proportions of glazing for all cardinal directions, by using discrete Mixed-Integer Non-Linear Programming optimization. The novelty of the suggested method resides in the synchronous optimization of the upgrade modules’ daylighting and energy-efficiency performance, resulting in the creation of optimization methods that can determine the optimal glazing proportions for all cardinal directions and incorporate rational design and window measurement. The impact of the developed Mixed-Integer Non-Linear Programming-optimized upgrade modules is compared to previously designed optimized upgrade modules. Finally, a methodology for estimating the energy efficiency of building renovations incorporating vertical additions using the timber–glass upgrade modules was developed, supporting the quick assessment of the reduction in hybrid buildings’ energy consumption for heating and cooling according to boundary conditions, presuming that they undergo the suggested renovations. The findings are applicable (not exclusively) to Slovenia’s residential building stock, which makes up around 20% of the country’s current housing stock and was mainly constructed between 1946 and 1970. This offers a substantial opportunity to improve the overall sustainability and energy efficiency of the country’s housing stock. The proposed approach offers a holistic solution to drive sustainable development in the built environment by incorporating all three pillars of sustainability (environmental, social, and economic). Full article
(This article belongs to the Section Energy Sustainability)
Show Figures

Figure 1

25 pages, 13675 KiB  
Article
KANDiff: Kolmogorov–Arnold Network and Diffusion Model-Based Network for Hyperspectral and Multispectral Image Fusion
by Wei Li, Lu Li, Man Peng and Ran Tao
Remote Sens. 2025, 17(1), 145; https://doi.org/10.3390/rs17010145 - 3 Jan 2025
Abstract
In recent years, the fusion of hyperspectral and multispectral images in remote sensing image processing still faces challenges, primarily due to their complexity and multimodal characteristics. Diffusion models, known for their stable training process and exceptional image generation capabilities, have shown good application [...] Read more.
In recent years, the fusion of hyperspectral and multispectral images in remote sensing image processing still faces challenges, primarily due to their complexity and multimodal characteristics. Diffusion models, known for their stable training process and exceptional image generation capabilities, have shown good application potential in this field. However, when dealing with multimodal data, it may prove challenging for the models to fully capture the intricate relationships between the modalities, which may result in incomplete information integration and a small amount of remaining noise in the generated images. To address these problems, we propose a new model, KanDiff, for hyperspectral and multispectral image fusion. To address the differences in modal information between multispectral and hyperspectral images, KANDiff incorporates Kolmogorov–Arnold Networks (KAN) to guide the inputs. It helps the model understand the complex relationships between the modalities by replacing the fixed activation function in the traditional MLP with a learnable activation function. Furthermore, the image generated by the diffusion model may exhibit a small amount of the remaining noise. Convolutional Neural Networks (CNNs) effectively extract local features through their convolutional layers and achieve noise suppression via layer-by-layer feature representation. Therefore, the MergeCNN module is further introduced to enhance the fusion effect, resulting in smoother and more accurate outcomes. Experimental results on the public CAVE and Harvard datasets indicate that KanDiff has achieved improvements over current high-performance methods across several metrics, particularly showing significant enhancements in the peak signal-to-noise ratio (PSNR) and the structural similarity index measure (SSIM), thus demonstrating superior performance. Additionally, we have created an image fusion dataset of the lunar surface, and KANDiff exhibits robust performance on this dataset as well. This work introduces an effective solution for addressing the challenges posed by missing high-resolution hyperspectral images (HRHS) data, which is essential for tasks including landing site selection and resource exploration within the realm of deep space exploration. Full article
(This article belongs to the Section Remote Sensing Image Processing)
Show Figures

Figure 1

21 pages, 353 KiB  
Article
On Value Distribution for the Mellin Transform of the Fourth Power of the Riemann Zeta Function
by Virginija Garbaliauskienė, Audronė Rimkevičienė, Mindaugas Stoncelis and Darius Šiaučiūnas
Axioms 2025, 14(1), 34; https://doi.org/10.3390/axioms14010034 - 3 Jan 2025
Viewed by 12
Abstract
In this paper, the asymptotic behavior of the modified Mellin transform Z2(s), s=σ+it, of the fourth power of the Riemann zeta function is characterized by weak convergence of probability measures in the [...] Read more.
In this paper, the asymptotic behavior of the modified Mellin transform Z2(s), s=σ+it, of the fourth power of the Riemann zeta function is characterized by weak convergence of probability measures in the space of analytic functions. The main results are devoted to probability measures defined by generalized shifts Z2(s+iφ(τ)) with a real increasing to + differentiable functions connected to the growth of the second moment of Z2(s). It is proven that the mass of the limit measure is concentrated at the point expressed as h(s)0. This is used for approximation of h(s) by Z2(s+iφ(τ)). Full article
21 pages, 5653 KiB  
Article
Hierarchical Clustering and Small Baseline Subset Differential Interferometric Synthetic Aperture Radar (SBAS-DInSAR) for Remotely Sensed Building Identification and Risk Prioritisation
by Yassir Hamzaoui, Marco Civera, Andrea Miano, Manuela Bonano, Francesco Fabbrocino, Andrea Prota and Bernardino Chiaia
Remote Sens. 2025, 17(1), 128; https://doi.org/10.3390/rs17010128 - 2 Jan 2025
Viewed by 217
Abstract
The conventional Structural Health Monitoring (SHM) framework focuses on individual structures. However, preliminary studies are required at a large territorial scale to effectively identify the most vulnerable elements. This becomes particularly challenging in urban settings, where numerous buildings of varied shapes, ages, and [...] Read more.
The conventional Structural Health Monitoring (SHM) framework focuses on individual structures. However, preliminary studies are required at a large territorial scale to effectively identify the most vulnerable elements. This becomes particularly challenging in urban settings, where numerous buildings of varied shapes, ages, and structural conditions are closely spaced from one another. A twofold task is therefore required: the automated identification and differentiation of various structures, coupled with a ranking system based on perceived structural risk, here assumed to be linked to their deformation patterns. It integrates displacement measurements acquired through the Differential Synthetic Aperture Radar Interferometry (DInSAR) technique, specifically employing the full-resolution Small Baseline Subset (SBAS) approach coupled with Hierarchical Clustering. The effectiveness of this method is successfully demonstrated and validated in two selected areas of Rome, Italy, serving as case studies. The results of this vast-area scale monitoring can be used to select the constructions that need a more in-depth assessment. Full article
Show Figures

Figure 1

14 pages, 6956 KiB  
Article
Enhanced Inversion of Sound Speed Profile Based on a Physics-Inspired Self-Organizing Map
by Guojun Xu, Ke Qu, Zhanglong Li, Zixuan Zhang, Pan Xu, Dongbao Gao and Xudong Dai
Remote Sens. 2025, 17(1), 132; https://doi.org/10.3390/rs17010132 - 2 Jan 2025
Viewed by 231
Abstract
The remote sensing-based inversion of sound speed profile (SSP) enables the acquisition of high-spatial-resolution SSP without in situ measurements. The spatial division of the inversion grid is crucial for the accuracy of results, determining both the number of samples and the consistency of [...] Read more.
The remote sensing-based inversion of sound speed profile (SSP) enables the acquisition of high-spatial-resolution SSP without in situ measurements. The spatial division of the inversion grid is crucial for the accuracy of results, determining both the number of samples and the consistency of inversion relationships. The result of our research is the introduction of a physics-inspired self-organizing map (PISOM) that facilitates SSP inversion by clustering samples according to the physical perturbation law. The linear physical relationship between sea surface parameters and the SSP drives dimensionality reduction for the SOM, resulting in the clustering of samples exhibiting similar disturbance laws. Subsequently, samples within each cluster are generalized to construct the topology of the solution space for SSP reconstruction. The PISOM method significantly improves accuracy compared with the SOM method without clustering. The PISOM has an SSP reconstruction error of less than 2 m/s in 25% of cases, while the SOM method has none. The transmission loss calculation also shows promising results, with an error of only 0.5 dB at 30 km, 5.5 dB smaller than that of the SOM method. A physical interpretation of the neural network processing confirms that physics-inspired clustering can bring better precision gains than the previous spatial grid. Full article
(This article belongs to the Special Issue Artificial Intelligence for Ocean Remote Sensing)
Show Figures

Figure 1

16 pages, 304 KiB  
Article
A Study of p-Laplacian Nonlocal Boundary Value Problem Involving Generalized Fractional Derivatives in Banach Spaces
by Madeaha Alghanmi
Mathematics 2025, 13(1), 138; https://doi.org/10.3390/math13010138 - 1 Jan 2025
Viewed by 244
Abstract
The aim of this article is to introduce and study a new class of fractional integro nonlocal boundary value problems involving the p-Laplacian operator and generalized fractional derivatives. The existence of solutions in Banach spaces is investigated with the aid of the [...] Read more.
The aim of this article is to introduce and study a new class of fractional integro nonlocal boundary value problems involving the p-Laplacian operator and generalized fractional derivatives. The existence of solutions in Banach spaces is investigated with the aid of the properties of Kuratowski’s noncompactness measure and Sadovskii’s fixed-point theorem. Two illustrative examples are constructed to guarantee the applicability of our results. Full article
(This article belongs to the Section Difference and Differential Equations)
21 pages, 2777 KiB  
Article
Numerical Study on the Risk of Infection in Adjacent Residential Spaces: Door Operation and the Impact of Outdoor Wind Speeds
by Xunmei Wu, Mengtao Han and Hong Chen
Buildings 2025, 15(1), 116; https://doi.org/10.3390/buildings15010116 - 31 Dec 2024
Viewed by 353
Abstract
Infectious diseases have profoundly impacted global health and daily life. To control virus transmission, countries worldwide have implemented various preventive measures. A critical pathway for infection spread is cross-infection within households, especially among family members in the same or adjacent rooms. This study [...] Read more.
Infectious diseases have profoundly impacted global health and daily life. To control virus transmission, countries worldwide have implemented various preventive measures. A critical pathway for infection spread is cross-infection within households, especially among family members in the same or adjacent rooms. This study uses numerical simulations to examine aerosol transmission characteristics in adjacent spaces in home settings and assess associated infection risks. The study evaluated the effects of factors such as outdoor wind speed, door gap leakage, and door opening actions on aerosol concentration and infection risk across various areas. Key conclusions include the following: Under prolonged lack of ventilation, aerosol leakage through the door gap is minimal, with the average aerosol concentration outside the bedroom remaining low (<0.04). In the absence of ventilation, aerosol accumulation primarily occurs within the bedroom. Under ventilated conditions, door gap leakage may increase infection risk in adjacent areas, suggesting a stay duration of no more than 75 min to keep infection risk below 30%. The findings provide practical recommendations for airtight design and activity area selection within residential spaces, offering valuable guidance for effective infection control measures. Full article
21 pages, 7742 KiB  
Article
The Impact of Building and Green Space Combination on Urban Thermal Environment Based on Three-Dimensional Landscape Index
by Ying Wang, Yin Ren, Xiaoman Zheng and Zhifeng Wu
Sustainability 2025, 17(1), 241; https://doi.org/10.3390/su17010241 - 31 Dec 2024
Viewed by 323
Abstract
Urbanization transforms landscapes from natural ecosystems to configurations of impervious surfaces and green spaces, leading to urban heat island effects that impact health and ecosystem sustainability. This study in Xiamen City, China, categorizes urban areas into functional zones, employs Random Forest and Stepwise [...] Read more.
Urbanization transforms landscapes from natural ecosystems to configurations of impervious surfaces and green spaces, leading to urban heat island effects that impact health and ecosystem sustainability. This study in Xiamen City, China, categorizes urban areas into functional zones, employs Random Forest and Stepwise Regression models to assess thermal differences, and proposes optimization measures for the building–green space landscape. The optimization involves altering the characterization of the building–green space landscape pattern. Results indicate: (1) due to the spatial heterogeneity of the building–green space landscape pattern in different functional zones, the surface temperature also shows strong spatial heterogeneity in different functional zones; (2) different optimization measures for the building–green space pattern are needed for different functional zones; taking the urban residential zone as an example, the Normalized Difference Vegetation Index (NDVI) in the hot spot area can be adjusted according to the value range of the cold spot area; (3) considering the solar radiation process, Sun View Factor (SunVF) plays an important role in indicating the change in surface temperature in the commercial service area, and as SunVF increases, the surface temperature of the functional zone tends to rise. This research offers insights into urban thermal environment improvement and landscape pattern optimization. Full article
(This article belongs to the Special Issue Sustainability in Urban Climate Change and Ecosystem Services)
Show Figures

Figure 1

11 pages, 1690 KiB  
Article
Effects of Doping on Elastic Strain in Crystalline Ge-Sb-Te
by Ju-Young Cho and So-Yeon Lee
Materials 2025, 18(1), 132; https://doi.org/10.3390/ma18010132 - 31 Dec 2024
Viewed by 234
Abstract
Phase-change random access memory (PcRAM) faces significant challenges due to the inherent instability of amorphous Ge2Sb2Te5 (GST). While doping has emerged as an effective method for amorphous stabilization, understanding the precise mechanisms of structural modification and their impact [...] Read more.
Phase-change random access memory (PcRAM) faces significant challenges due to the inherent instability of amorphous Ge2Sb2Te5 (GST). While doping has emerged as an effective method for amorphous stabilization, understanding the precise mechanisms of structural modification and their impact on material stability remains a critical challenge. This study provides a comprehensive investigation of elastic strain and stress in crystalline lattices induced by various dopants (C, N, and Al) through systematic measurements of film thickness changes during crystallization. Through detailed analysis of cross-sectional electron microscopy data and theoretical calculations, we reveal distinct behavior patterns between interstitial and substitutional dopants. Interstitial dopants (C and N) generate substantial elastic strain energy (~9 J/g) due to their smaller atomic radii (0.07–0.08 nm) and ability to occupy spaces between lattice sites. In contrast, substitutional dopants (Al) produce lower strain energy (~5 J/g) due to their similar atomic radius (0.14 nm) to host atoms. We demonstrate that N doping achieves higher elastic strain energy compared to C doping, attributed to its preferential formation of Ge-N bonds and resulting lattice distortions. The correlation between dopant properties, structural features, and induced strain energy provides quantitative insights for optimizing dopant selection. These findings establish a fundamental framework for understanding dopant-induced thermodynamic stabilization in GST materials, offering practical guidelines for enhancing the reliability and performance of next-generation PcRAM devices. Full article
(This article belongs to the Special Issue Advanced Semiconductor/Memory Materials and Devices)
Show Figures

Figure 1

22 pages, 3114 KiB  
Article
Comparative Analysis of Restorative Interior Design Elements: Screen-Based Versus Virtual Reality Evaluations for Future Medical Treatment Prospects
by Alp Tural and Elif Tural
Int. J. Environ. Res. Public Health 2025, 22(1), 44; https://doi.org/10.3390/ijerph22010044 - 31 Dec 2024
Viewed by 303
Abstract
Given the increasing prevalence of anxiety and depression, this research aims to identify design features that enhance the sense of restoration, with the goal of supporting mental and behavioral healthcare facility design. This study employed both screen-based and virtual reality (VR) stimuli to [...] Read more.
Given the increasing prevalence of anxiety and depression, this research aims to identify design features that enhance the sense of restoration, with the goal of supporting mental and behavioral healthcare facility design. This study employed both screen-based and virtual reality (VR) stimuli to evaluate the perceived restorativeness of different interior settings. The key variables analyzed included window view access, view content, materiality, and room geometry. Thirty-five undergraduate and graduate students assessed 16 distinct interior environments. Findings indicate that the VR presentations generally produced higher restorativeness scores compared with screen-based presentations, though this effect varied across stimuli. Repeated-measures ANOVA revealed that larger windows consistently correlated with higher restorativeness scores in both presentation modes. Views of water were rated as most restorative, followed by wooded areas. Natural materials were perceived as significantly more restorative than other materials, particularly in VR presentations. Varied ceiling designs, especially vaulted ceilings, were associated with evaluations of higher restorativeness compared with flat ceiling designs, with this effect more pronounced in VR. This research underscores the potential of VR technology to simulate and assess interior design interventions, offering insights into creating more effective and personalized restorative environments in mental health treatment facilities. The findings can inform evidence-based design strategies for healthcare spaces, supporting treatment processes and patient well-being. Full article
Show Figures

Figure 1

28 pages, 7288 KiB  
Article
Geometric Feature Characterization of Apple Trees from 3D LiDAR Point Cloud Data
by Md Rejaul Karim, Shahriar Ahmed, Md Nasim Reza, Kyu-Ho Lee, Joonjea Sung and Sun-Ok Chung
J. Imaging 2025, 11(1), 5; https://doi.org/10.3390/jimaging11010005 - 31 Dec 2024
Viewed by 403
Abstract
The geometric feature characterization of fruit trees plays a role in effective management in orchards. LiDAR (light detection and ranging) technology for object detection enables the rapid and precise evaluation of geometric features. This study aimed to quantify the height, canopy volume, tree [...] Read more.
The geometric feature characterization of fruit trees plays a role in effective management in orchards. LiDAR (light detection and ranging) technology for object detection enables the rapid and precise evaluation of geometric features. This study aimed to quantify the height, canopy volume, tree spacing, and row spacing in an apple orchard using a three-dimensional (3D) LiDAR sensor. A LiDAR sensor was used to collect 3D point cloud data from the apple orchard. Six samples of apple trees, representing a variety of shapes and sizes, were selected for data collection and validation. Commercial software and the python programming language were utilized to process the collected data. The data processing steps involved data conversion, radius outlier removal, voxel grid downsampling, denoising through filtering and erroneous points, segmentation of the region of interest (ROI), clustering using the density-based spatial clustering (DBSCAN) algorithm, data transformation, and the removal of ground points. Accuracy was assessed by comparing the estimated outputs from the point cloud with the corresponding measured values. The sensor-estimated and measured tree heights were 3.05 ± 0.34 m and 3.13 ± 0.33 m, respectively, with a mean absolute error (MAE) of 0.08 m, a root mean squared error (RMSE) of 0.09 m, a linear coefficient of determination (r2) of 0.98, a confidence interval (CI) of −0.14 to −0.02 m, and a high concordance correlation coefficient (CCC) of 0.96, indicating strong agreement and high accuracy. The sensor-estimated and measured canopy volumes were 13.76 ± 2.46 m3 and 14.09 ± 2.10 m3, respectively, with an MAE of 0.57 m3, an RMSE of 0.61 m3, an r2 value of 0.97, and a CI of −0.92 to 0.26, demonstrating high precision. For tree and row spacing, the sensor-estimated distances and measured distances were 3.04 ± 0.17 and 3.18 ± 0.24 m, and 3.35 ± 0.08 and 3.40 ± 0.05 m, respectively, with RMSE and r2 values of 0.12 m and 0.92 for tree spacing, and 0.07 m and 0.94 for row spacing, respectively. The MAE and CI values were 0.09 m, 0.05 m, and −0.18 for tree spacing and 0.01, −0.1, and 0.002 for row spacing, respectively. Although minor differences were observed, the sensor estimates were efficient, though specific measurements require further refinement. The results are based on a limited dataset of six measured values, providing initial insights into geometric feature characterization performance. However, a larger dataset would offer a more reliable accuracy assessment. The small sample size (six apple trees) limits the generalizability of the findings and necessitates caution in interpreting the results. Future studies should incorporate a broader and more diverse dataset to validate and refine the characterization, enhancing management practices in apple orchards. Full article
(This article belongs to the Special Issue Exploring Challenges and Innovations in 3D Point Cloud Processing)
Show Figures

Figure 1

21 pages, 857 KiB  
Review
Empowerment in Adolescent Patients with a Disability/Chronic Condition: A Scoping Review
by Kennedy Austin, Carly Pistawka, Colin J. D. Ross, Kathryn A. Selby, Alice Virani, Vanessa Kitchin and Alison M. Elliott
Children 2025, 12(1), 49; https://doi.org/10.3390/children12010049 - 31 Dec 2024
Viewed by 359
Abstract
Background/Objectives: Empowerment has been associated with several positive outcomes in healthcare; however, there is limited insight on empowerment levels within the adolescent population of those with a chronic condition/disability. The aim of this scoping review was to identify gaps in the existing literature [...] Read more.
Background/Objectives: Empowerment has been associated with several positive outcomes in healthcare; however, there is limited insight on empowerment levels within the adolescent population of those with a chronic condition/disability. The aim of this scoping review was to identify gaps in the existing literature on empowerment levels within this population. Methods: Five databases (MEDLINE [Ovid], EMBASE [Ovid], PsycINFO [Ebsco], CINHAL [Ebsco] and Web of Science [UBC]) and grey literature were searched. Results: A total of 67 studies were included and used for data extraction including descriptive numerical analysis followed by a narrative review. Extracted data were divided into demographic characteristics (e.g., ethnicity/ancestry), type of disability/condition (e.g., type 1 diabetes), interventions used to increase empowerment or empowerment-adjacent elements, quantitative and qualitative tools used to measure empowerment (e.g., questionnaires and/or interviews), domains/outcomes associated with empowerment (e.g., self-control), and review articles. Several interventions were shown to have positive effects on empowerment levels in adolescents with a chronic condition/disability. Conclusions: Gaps were identified in the consideration of ethnicity/ancestry and socioeconomic status, demonstrating a need for future research in this space to focus on the intersection of disability, ethnicity/ancestry, and socio-economic status and the implementation of interventions promoting empowerment. Full article
(This article belongs to the Section Global Pediatric Health)
Show Figures

Figure 1

18 pages, 9456 KiB  
Article
Enhanced Three-Phase Shunt Active Power Filter Utilizing an Adaptive Frequency Proportional-Integral–Resonant Controller and a Sensorless Voltage Method
by Haneen Ghanayem, Mohammad Alathamneh, Xingyu Yang, Sangwon Seo and R. M. Nelms
Energies 2025, 18(1), 116; https://doi.org/10.3390/en18010116 - 30 Dec 2024
Viewed by 416
Abstract
This article introduces a frequency-adaptive control strategy for a three-phase shunt active power filter, aimed at improving energy efficiency and ensuring high power quality in consumer-oriented power systems. The proposed control system utilizes real-time frequency estimation to dynamically adjust the gain of a [...] Read more.
This article introduces a frequency-adaptive control strategy for a three-phase shunt active power filter, aimed at improving energy efficiency and ensuring high power quality in consumer-oriented power systems. The proposed control system utilizes real-time frequency estimation to dynamically adjust the gain of a proportional-integral–resonant (PIR) controller, facilitating precise harmonic compensation under challenging unbalanced grid conditions, such as unbalanced three-phase loads, grid impedance variations, and diverse nonlinear loads like three-phase rectifiers and induction motors. These scenarios often increase total harmonic distortion (THD) at the point of common coupling (PCC), degrading the performance of connected loads and reducing the efficiency of induction motors. The PIR controller integrates both proportional-integral (PI) and proportional-resonant (PR) control features, achieving improved stability and reduced overshoot. A novel voltage sensorless control method is proposed, requiring only current measurements to determine reference currents for the inverter, thereby simplifying the implementation. Validation of the frequency adaptive control scheme through MATLAB/Simulink simulations and real-time experiments on a dSPACE (DS1202) platform demonstrates significant improvements in harmonic compensation, energy efficiency, and system stability across varying grid frequencies. This approach offers a robust consumer-oriented solution for managing power quality, positioning the SAPF as a key technology for advancing sustainable energy management in smart applications. Full article
(This article belongs to the Special Issue Power Electronics and Power Quality 2024)
12 pages, 5578 KiB  
Article
Transformation of Hydroacoustic Energy into Seismoacoustic Energy at 22 Hz in Medium Depth- and Deep-Sea Conditions
by Grigory Dolgikh, Mikhail Bolsunovskii, Sergey Budrin, Stanislav Dolgikh, Mikhail Ivanov, Vladimir Ovcharenko, Aleksandr Pivovarov, Aleksandr Samchenko, Vladimir Chupin and Igor Yaroshchuk
Appl. Sci. 2025, 15(1), 267; https://doi.org/10.3390/app15010267 - 30 Dec 2024
Viewed by 318
Abstract
This work is devoted to an experiment studying the regularities of the propagation of hydroacoustic low-frequency signals in the conditions of the sea at intermediate depth and deep in terms of their transformation into vibrations in the upper layer of the Earth’s crust. [...] Read more.
This work is devoted to an experiment studying the regularities of the propagation of hydroacoustic low-frequency signals in the conditions of the sea at intermediate depth and deep in terms of their transformation into vibrations in the upper layer of the Earth’s crust. This experiment belongs to the field of acoustic tomography and is aimed at solving the problems of non-contact methods for studying the geological structure of the shelf areas of the World Ocean. The novelty and uniqueness of the work lies in the use of a harmonic low-frequency hydroacoustic signal with a frequency of 22 Hz of high power, capable of creating Rayleigh surface waves at the “water–bottom” interface. The surface waves propagating at the bottom are registered by a coastal laser-interference measuring system capable of recording deformations in the upper crustal layer with an accuracy of 0.01 nm. The experimental results showed that the radiated hydroacoustic energy is not localized in the liquid half-space and propagates predominantly according to the law close to spherical divergence, even when the shelf depth is comparable to the wavelength of the radiated signal. Full article
(This article belongs to the Section Marine Science and Engineering)
Show Figures

Figure 1

20 pages, 2128 KiB  
Article
Optimizing Cardiovascular Health Monitoring with IoT-Enabled Sensors and AI: A Focus on Obesity-Induced Cardiovascular Risks in Young Adults
by Meiling Chan, Ying Yu, Pohan Chang, Tsung-Yi Chen, Hok-Long Wong, Jian-Hua Huang, Wiping Zhang and Shih-Lun Chen
Electronics 2025, 14(1), 121; https://doi.org/10.3390/electronics14010121 - 30 Dec 2024
Viewed by 312
Abstract
With shifts in lifestyle and dietary patterns, obesity has become an increasing health issue among younger demographics, particularly affecting young adults. This trend is strongly associated with a heightened risk of developing chronic diseases, especially cardiovascular conditions. However, conventional health monitoring systems are [...] Read more.
With shifts in lifestyle and dietary patterns, obesity has become an increasing health issue among younger demographics, particularly affecting young adults. This trend is strongly associated with a heightened risk of developing chronic diseases, especially cardiovascular conditions. However, conventional health monitoring systems are often limited to basic parameters such as heart rate, pulse pressure (PP), and systolic blood pressure (SBP), which may not provide a comprehensive assessment of cardiac health. This study introduces an intelligent heart health monitoring system that leverages the Internet of Things (IoT) and advanced sensor technologies. By incorporating IoT-based sensors, this system aims to improve the early detection and continuous monitoring of cardiac function in young obese women. The research employed a TERUMO ES-P2000 to measure blood pressure and a PhysioFlow device to assess noninvasive cardiac hemodynamic parameters. Through precise sensor data collection, the study identified key indicators for monitoring cardiovascular health. Machine learning models and big data analysis were utilized to predict cardiac index (CI) values based on the sensor-derived inputs. The findings indicated that young obese women showed significant deviations in blood pressure (SBP and PP) and cardiac hemodynamic metrics (SVI, EDV, and ESV) at an early stage. The implementation of signal processing techniques and IoT sensors enhanced the CI prediction accuracy from 33% (using basic parameters like heart rate, PP, and SBP) to 66%. Moreover, the integration of extra sensor-based parameters, such as Stroke Volume Index (SVI) and Cardiac Output (CO), along with the use of color space transformations, successfully improved the prediction accuracy of the original data by 36.68%, increasing from 53.33% to 90.01%. This represents a significant improvement of 30.01% compared to the existing technology’s accuracy of 60%. These results underscore the importance of utilizing sensor-derived parameters as critical early indicators of cardiac function in young obese women. This research advances smart healthcare through early cardiovascular risk assessment using AI and noninvasive sensors. Full article
(This article belongs to the Special Issue IoT-Enabled Smart Devices and Systems in Smart Environments)
Show Figures

Graphical abstract

Back to TopTop