Search Results (5,528)

Field-Programmable Gate Arrays (FPGAs) have become an important platform for accelerating real-time communication systems, and System-on-Chip (SoC) devices provide the flexibility to design and optimize architectures that support high data rates, different modulation formats, and channel equalization schemes. Selecting the appropriate architecture can be guided through Design Space Exploration (DSE) using high-level synthesis tools, which enables the identification of numerical representations that balance performance with reduced hardware resource consumption. Despite their relevance, recent developments in communication systems often overlook the impact of numerical precision in Digital Signal Processing algorithms, particularly the trade-offs between floating- and fixed-point arithmetic when targeting hardware implementations. In this work, two widely used blind equalization algorithms, the Constant Modulus Algorithm (CMA) and the Multi-Modulus Algorithm (MMA), were implemented on a low-cost Ultra96 SoC-FPGA to analyze the effect of a fixed-point representation. A multi-objective Design Space Exploration methodology was applied to minimize hardware utilization while maintaining reliable transmission performance. Resource consumption, latency, and throughput were measured across different binary formats using the Minimum Mean Square Error (MMSE) criterion. Parallelization techniques were incorporated to improve throughput. The DSE generated comprehensive performance surfaces quantifying latency, MMSE convergence, and FPGA resource utilization (DSP48E/FF/LUT/BRAM) across fixed-point formats, achieving optimal 4 MS/s throughput configurations. Although this throughput is naturally lower than the Gigabit speeds required in backbone optical networks, the results demonstrate the effectiveness of numerical representation optimization in resource-constrained SoC-FPGA devices, offering a practical approach for real-time Edge and IoT implementations where cost and hardware limitations are critical. Full article

This study examines a comprehensive class of coupled nonlinear $\varrho$-Hilfer fractional neutral impulsive integro-differential systems with mixed delays and non-local initial conditions. The primary contribution of this study is the creation of a unified analytical framework that encompasses coupled interactions, neutral-type dependencies, and impulsive disturbances, which have been studied separately by researchers. We utilize the Banach contraction principle and Krasnoselskii’s fixed-point theorem to provide suitable conditions for the existence and uniqueness of solutions within the product space of piecewise continuous weighted functions. In addition to existence, we examine Ulam–Hyers–Rassias (UHR) stability using a generalized Gronwall inequality, which guarantees the system’s robustness against functional perturbations. We also develop a controllability framework and a feedback control law that steer the system towards the desired terminal states. The theoretical results are supported by a numerical simulation using a complex kernel, implemented via a modified predictor-corrector algorithm, which validates the practical effectiveness of the proposed control and stability outcomes. Full article

Background/Objectives: The achievement of stable and functional occlusal contacts represents a key objective of orthodontic treatment, particularly in growing patients. Evidence comparing the effectiveness of these two modalities in establishing adequate occlusal contacts in growing patients remains limited. This study aimed to evaluate and compare occlusal contact characteristics following clear aligner therapy (CAT) and fixed orthodontic therapy (FAT). Methods: Twenty-four growing patients (<18 years with permanent dentition) were included in the study and divided into two groups: 12 patients treated with fixed appliances and 12 treated with clear aligners. Post-treatment digital dental scans were analyzed to assess occlusal contacts. Contacts were calculated as the minimum distance between upper and lower arches using a color-map analysis. The following outcomes were evaluated: Maximum Contact Point (MCP), occlusal contact surface (OCS, ≤50 μm from MCP), near occlusal contact surface (NOCS, ≤350 μm), half mm (≤0.5 mm), and one mm (≤1 mm). Total occlusal contacts, antero-posterior distribution, left–right asymmetry, and single-tooth contacts were assessed. Results: The FAT group showed higher total occlusal contact values in OCS compared to the CAT group (p < 0.05). Statistical difference was also observed in the antero-posterior ratio, with FAT presenting fewer anterior contacts in OCS, NOCS, half-mm, and one-mm measurements (p < 0.05). No significant differences were found between groups in terms of left–right asymmetry or post-treatment single-tooth contacts, except for the second premolar, which exhibited higher contacts in the FAT group (p < 0.05). Conclusions: Fixed orthodontic treatment is more effective than aligners in achieving adequate occlusal contacts, with differences limited to tight contacts and antero-posterior occlusal distribution. Full article

This article aims to describe the solvability of certain functional equations related to dynamic programming by fixed-point theorems in relational-metric spaces. To achieve our goal, we exhibit a non-unique fixed-point finding for a map of the Ćirić type in a relational-metric space. In this way, we consolidate and amend innumerable celebrated results in fixed-point theory. A couple of instances are supplied to emphasize the practical value of our findings. Full article

Soil moisture prediction is essential for precision irrigation in water-limited agricultural systems. This study presents a deep learning-driven irrigation framework for winter wheat, integrating a novel Informer–UNet model with a Comprehensive Irrigation Index for adaptive water management. The Informer–UNet combines ProbSparse self-attention mechanisms with UNet’s multi-scale feature fusion, enabling simultaneous prediction of soil moisture at 27 monitoring points across three depths, 10, 30, and 50 cm, while quantifying prediction uncertainty through Monte Carlo Dropout. A Comprehensive Irrigation Index incorporating moisture deviation, spatial variance, and confidence interval width was developed, with weights optimized via genetic algorithm. Field experiments were conducted in Chengdu, China, over two winter wheat growing seasons. The Informer–UNet achieved superior prediction accuracy, R² greater than 0.98, RMSE less than 0.65, compared to LSTM, Transformer, and standard Informer models, with the fastest convergence and lowest validation loss. The proposed DeepIndexIrr strategy maintained soil moisture within the target range, 55% to 75%, for over 81% of the irrigation period, reducing water consumption by 38.2% compared to fixed-threshold control and 19.2% compared to expert manual scheduling. These results demonstrate that integrating spatially distributed deep learning predictions with uncertainty-informed decision rules offers a promising approach for sustainable precision irrigation. Full article

Insulation deterioration is the leading cause of premature failures in high-voltage (HV) power equipment, with partial discharge (PD) serving as a key indicator of insulation health. This study introduces a novel compact PD sensor assembly that integrates fiber Bragg grating (FBG) with an exponential acoustic horn to enhance the sensitivity of PD detection. The horn’s geometry effectively collects ultrasonic emissions from the PD, concentrating the acoustic energy to amplify the force on the FBG located at its focal point. To further enhance signal transduction, the FBG is mounted on a fixed solid structure engineered to resonate at higher ultrasonic frequencies that closely align with the dominant acoustic components generated by PD activity, ensuring improved strain amplification and optimal sensitivity. This results in measurable wavelength shifts, which are used for PD detection. A fiber Bragg grating analyzer interrogates the reflected spectra, providing real-time PD detection during HV operations. The effectiveness of the system was validated against the IEC 60270 standard method using laboratory models that emulated corona and surface discharge. The laboratory experiments demonstrated a significant sensitivity of 2.2 pm/Pa and a favorable signal-to-noise ratio of ~21 dB for the proposed sensor module. The dielectric construction of the sensor module, lightweight design, and resistance to electromagnetic interference make it suitable for harsh HV environments and the long-term condition monitoring of HV power equipment. Full article

We present here a novel approach to the analysis of common knowledge based on Category Theory. We formalize knowledge hierarchies as presheaves over a category of agent sequences. The category of these presheaves constitutes a topos. We define an unfolding monad on the resulting topos, and use a Knaster–Tarski theorem to obtain common knowledge as a greatest fixed point under natural uniformity and exchangeability conditions on agent sequences. Full article

Background: Floating barbed threads are commonly used for minimally invasive midface lifting and rely on mobile subcutaneous tissue for support, which may limit stability. Fixation is primarily achieved by barb engagement within the subcutaneous fat and fibrous septa of the retinacula cutis. Objectives: To describe an anatomically guided modification of the APTOS Excellence Visage Soft (PLLA/PCL) thread technique, positioning the terminal segment posterior to the zygomatic retaining ligament line with the aim to enhancing mechanical stability. This technical report presents the anatomical rationale, procedural steps, and illustrative clinical cases demonstrating feasibility. Methods: The modified technique uses a single-entry point at the superior zygomatic margin, with five threads per hemiface. After linear insertion, the cannula is rotated laterally and inferiorly to position the terminal barbs posterior to the zygomatic retaining ligament line, thereby transferring tensile load toward a more fixed anatomical structure. Representative cases were documented and are presented. Results: Illustrative cases showed immediate midface elevation with improved malar projection and softening of the nasolabial and mentolabial folds. Standardized 3D imaging and vector analysis demonstrated a superolateral pattern of soft tissue displacement along the intended vectors, consistent with the proposed fixed-anchorage concept. The procedure was well tolerated, with only mild and transient local effects observed. One illustrative case included photographic follow-up at 12 months, in which preservation of midface contour and malar projection was visually appreciable. Conclusions: Redirecting the terminal thread segment posterior to the zygomatic retaining ligament line is a feasible modification that may contribute to improved vector stability by engaging a fixed fascial structure. Observations—including one case with 12-month follow-up—support the anatomical plausibility of the approach, although controlled studies with objective endpoints are necessary to confirm long-term efficacy and reproducibility. Full article

This study investigates hybridization of a solid oxide fuel cell with a gas turbine (SOFC–GT) for application in an ATR 72 regional aircraft. Several challenges hinder its viability, including the low gravimetric power density of SOFC stacks and stringent heat integration constraints. A steady-state model sweeps the cell voltage, overall pressure ratio (OPR), and a bounded turbine inlet temperature (TIT). This study introduces a new corrected power-share metric. This metric accounts for operating-point-dependent SOFC power density. It also enables weight-relevant comparisons. We analyze two types of coupling: direct and indirect. In the direct coupling, SOFC cooling fixes the core airflow and a TIT ceiling imposes a minimum power share. In the indirect coupling, a bypass decouples SOFC and gas turbine operation, incurring an efficiency penalty. We compare two heat-integration architectures: preheating with SOFC cathode exhaust versus low-pressure turbine (LPT) exhaust. Results show that direct coupling achieves efficiencies above 65% at high-corrected power shares, whereas indirect coupling offers greater operational flexibility but lower efficiency. Cathode exhaust preheating improves feasibility and outperforms LPT recuperation by more than 15% efficiency at low-to-mid-corrected power shares. However, LPT recuperation attains higher peak efficiency only at high-corrected power shares and within a narrow OPR window, which is limited by recuperator pinch. Full article

Fractional-order models are widely recognized for their ability to capture memory and hereditary effects in biological and physiological systems. In this paper, we develop and analyze a Caputo fractional-order dynamical model for the regulation of blood oxygen saturation (SpO₂) under bounded control inputs. The model incorporates nonlinear saturation mechanisms and auxiliary state variables to represent delayed oxygen transport and adaptation effects. By reformulating the system as an operator equation in a suitable Banach space, sufficient conditions for existence and uniqueness of solutions are established using fixed-point theory. An optimal control problem is then formulated to steer oxygen saturation toward a prescribed safe target level, and the existence of an optimal control is proved via compactness arguments and the direct method of the calculus of variations. Numerical simulations are provided to illustrate the theoretical findings and to demonstrate the impact of the fractional order on transient oxygen saturation dynamics, including comparison with the classical integer-order case. The results show that fractional modeling offers a mathematically rigorous and physiologically interpretable framework for describing delayed oxygenation responses and achieving stable regulation under bounded control constraints. Full article

This paper develops a functional operator-theoretic framework for nonlinear Erdelyi–Kober (EK) fractional dynamical systems formulated in Banach spaces endowed with the compact-open topology. Within this setting, sufficient conditions for existence, uniqueness, and Ulam–Hyers stability of solutions are established using the Banach and Schaefer fixed-point theorems. The continuity, boundedness, and Lipschitz properties of the associated nonlinear operators are analyzed to ensure well-posedness of the fractional system. As a constructive complement to the theoretical results, a power series iterative method (PSIM) is employed to obtain an explicit fractional series representation of the solution in the case $0<\alpha <1$. The applicability of the theoretical framework is illustrated through a nonlinear fractional dynamical Belousov–Zhabotinsky system (DBZS), where the assumptions of the main theorems are verified and the solution is constructed via the proposed series scheme. The results provide a coherent link between abstract fixed-point analysis and a constructive semi-analytical representation of solutions for EK fractional systems. Full article

Background: The BEST study investigated the effectiveness of a 12-week digital treatment program for male LUTS. Here, we report on the long-term outcomes of the patients involved in this trial. Methods: The randomized controlled BEST trial enrolled 237 patients (intervention group, IG: n = 112, hereafter referred to as the direct intervention group [DIG]; control group, CG: n = 125, hereafter referred to as the postponed intervention group [PIG]). The intervention consisted of pelvic floor muscle training, behavioral training, completion of a micturition diary, bladder training, urge suppression techniques, fluid and dietary management, and structured educational content. Patients in the DIG received the intervention immediately, Patients in the PIG after a 12-week waiting period. Patients in both groups were offered the option to complete additional treatment cycles at their discretion. The primary endpoint was change from baseline in the International Prostate Symptom Score (IPSS). Secondary endpoints included the symptom severity (OAB-q SF1) and quality-of-life (OAB-q SF2) subscales of the Overactive Bladder Questionnaire, among others. Long-term follow-up assessments at 24, 36, and 48 weeks for participants in both study arms were prospectively specified in the study protocol. Results: Baseline data from 236 patients were available for the follow-up analyses. In a linear mixed-effects model, the fixed effect of time on IPSS was found to be statistically significant (F(4, 515.245) = 89.77, p < 0.001), indicating differences across measurement time points. Compared with the baseline, IPSS scores were lower at all subsequent follow-up assessments. The mean difference between the baseline and 12 weeks after was −6.32 points (95% CI: −7.60 to −5.04; p < 0.001). Differences between the baseline and 24 weeks (−7.81 points; 95% CI: −9.37 to −6.25; p < 0.001), baseline and 36 weeks (−8.62 points; 95% CI: −10.46 to −6.79; p < 0.001), and baseline and 48 weeks (−9.56 points; 95% CI: −12.66 to −6.46; p < 0.001) were also statistically significant. Comparable patterns of improvement were observed for both subscales of the OAB-q Short Form questionnaire. In a separate linear mixed-effects model, the fixed effect of time on IPSS after the discontinuation of app usage was not statistically significant (F(2, 19.750) = 0.01, p = 0.992), suggesting stable effects after discontinuation. Conclusions: Long-term outcomes of the structured app-based therapeutic program demonstrated that a multimodal digital intervention for male LUTS induces a rapid and clinically meaningful symptom reduction within the first 12 weeks, with consolidating and sustaining benefits over up to 48 weeks. Full article

Building upon classical fixed point theory, the concept of enriched contractions introduces a new class of mappings. For a normed linear space $(X,\parallel ·\parallel )$, a mapping $T:X\to X$ is called an enriched contraction if there exist $b\in [0,\infty )$ and $\theta \in [0,b+1)$ such that $\parallel b(x-y)+Tx-Ty\parallel \le \theta \parallel x-y\parallel ,\forall x,y\in X.$ This class of mappings includes both the well-known Picard–Banach contraction and certain nonexpansive mappings. In this paper, we extend the definition by allowing $b\in \mathbb{R}\backslash \{-1\}$ instead of $b\in [0,\infty )$. This extension enables the condition to cover both contraction and certain nonexpansive mappings. We establish results on the existence and uniqueness of fixed points and present the Krasnosel’skii iteration for approximating such points. An example is provided to demonstrate mapping that meets the extended condition but not the original. Full article

This paper provides a feasibility study of a non-invasive microwave-based glucose-sensing system based on a small printed slot antenna with etched step-impedance resonators (SIRs) on an FR4 substrate in the ground plane at approximately 5.7 GHz. The sensor proposed takes advantage of the effect of the antenna resonant frequency and reflection coefficient (S11) perturbation due to the dielectric loading of a human finger placed in the antenna near field. Instead of declaring direct glucose specificity, this paper is dedicated to understand whether the measures of RF can be translated to the invasive glucose values under the condition of controlled positioning. A vector network analyzer was used to measure the experimental values where resonant frequency and S11 magnitude were obtained at the point of peak sensitivity due to fixed finger placement at the point. These RF properties were associated with invasively measured glucose values using three modeling methods: a simple analytical linear formula, a second-degree Polynomial Ridge regression model, and a Random Forest machine learning model. The comparative analysis has established that nonlinear data-driven models outperform the analytical formulations significantly with the highest predictive accuracy being the Random Forest model (R² = 0.72, RMSE = 10.57 mg/dL, MAE = 5.16 mg/dL). The findings affirm that the impacts of antenna loading control the raw measurements, but the trend related to glucose can be extracted upon machine learning calibration under controlled conditions. The research provides a methodological framework of RF-based non-invasive glucose sensing and the need to employ various phantom-based validation, sub-subject-based modeling, or clinically based evaluation metrics in future studies. Full article

Accurate short-term electric load forecasting is essential for the operation and management of energy-intensive manufacturing processes such as quicklime production, for which power demand is driven by stage-based operation, fixed schedules, and abrupt load transitions. This study presents a data-driven forecasting framework based on a Temporal Fusion Transformer (TFT) model applied to real industrial measurements collected during 2024 from an operating quicklime production plant. The dataset comprises hourly average power demand records (kW) measured at a plant level, stage-dependent motor operation, and a fixed working schedule from 08:00 to 18:00 (Monday to Friday), with weekends and non-operational hours characterized by near-zero load. Coke consumption during the calcination stage is included as an additional contextual variable. The TFT model is trained for multi-horizon forecasting and provides probabilistic prediction intervals through quantile regression. Weekly evaluations demonstrate that the proposed approach accurately captures start–stop behavior, peak-load periods, and structured inactivity intervals. In addition to point-wise accuracy metrics, cumulative energy is evaluated by integrating hourly power over the forecasting horizon, allowing the assessment of energy preservation at the operational level. The resulting energy deviation reaches 4.78% for the full horizon and 5.25% when restricted to active production hours, confirming strong consistency between predicted and actual cumulative energy. A comparative analysis against LSTM, GRU, and N-BEATS models shows that recurrent architectures achieve lower MAE and RMSE values, while the TFT model delivers superior cumulative energy consistency, highlighting a trade-off between instantaneous accuracy and operational energy fidelity. Overall, the results demonstrate that the proposed TFT-based framework provides a robust and practically relevant solution for short-term industrial electric load forecasting and decision support in stage-driven manufacturing systems under real operating conditions. Full article