Search Results (20)

Background/Objectives: Parental involvement is essential in managing type 1 diabetes mellitus (T1DM) in children, particularly with the growing use of continuous glucose monitoring (CGM). Validated tools assessing parental self-efficacy in this context remain limited. This study aimed to validate the Parental Self-Efficacy Scale for Diabetes Management (PSESDM) among parents of children using a CGM sensor and to examine its associations with diabetes outcomes and parental characteristics. Methods: A cross-sectional study was conducted involving 106 parent–child dyads at a university pediatric diabetes center. Parents completed the Hungarian PSESDM. Data regarding children’s HbA1c level were recorded, along with standard measures of their general and diabetes-specific quality of life (EQ-5D-Y-3L, PedsQL Diab); data regarding parents’ health literacy (Chew), fear of hypoglycemia (HFS), health-related quality of life (EQ-5D-5L), and capability well-being (ICECAP-A) were also collected. The PSESDM’s reliability, internal consistency, and discriminant and criterion validity were assessed using standard statistical methods. Results: The PSESDM demonstrated good internal consistency (Cronbach’s α = 0.857) and strong item–total correlations (range: 0.678–0.791). Higher parental self-efficacy was significantly associated with better glucose control (lower HbA1c, r_s = −0.50) and weakly correlated with the child’s diabetes-specific quality of life (r_s = 0.20). Among parental characteristics, self-efficacy correlated strongly with capability well-being (r_s = 0.52), moderately with health literacy (r_s = −0.30), and showed no difference between socio-demographic subgroups, except for the subgroup related to income. Conclusions: The PSESDM is a valid and reliable tool for measuring self-efficacy in parents of children with T1DM using CGM sensors. Its associations with children’s HbA1c levels, diabetes-specific quality of life, and parental characteristics support its clinical relevance and potential use in identifying families at risk for poorer diabetes outcomes. Full article

The time-dependent deformation control of weakly cemented soft rock in deep underground engineering is a critical scientific issue that directly affects the long-term stability of roadways. Traditional Nishihsara models encounter limitations in accurately capturing the weakening effects of material parameters during rock creep failure and in describing the accelerated creep stage, making them insufficient for analyzing the creep failure mechanisms of weakly cemented surrounding rock. To address these limitations, this study integrates SEM and X-ray scanning results to reveal the microscopic degradation process during creep: under external forces, clay minerals, primarily bonded face-to-face or through cementation, gradually fracture, leading to continuous microcrack propagation and progressive parameter degradation. Based on damage theory, an enhanced Nishihara creep model is proposed, incorporating a time-dependent damage factor to characterize the attenuation of the elastic modulus and a nonlinear winding element connected in series to represent the accelerated creep stage. The corresponding three-dimensional constitutive equations are derived. Using the Levenberg–Marquardt (L-M) algorithm for parameter inversion, the model achieves over 98% fitting accuracy across the full creep stages of weakly cemented soft rock, validating its applicability to other rock types such as salt rock and anthracite. The damage creep model is numerically implemented through secondary development in FLAC3D 6.0, with simulation results showing less than 5% deviation from experimental data and the failure mode is similar. These findings provide a solid theoretical foundation for further understanding the creep behavior of weakly cemented soft rocks. Full article

This paper presents a preliminary proof-of-concept study of a novel approach to 3D millimeter-wave (MMW) imaging, demonstrating the first implementation of Glow Discharge Detectors (GDDs) in this domain. GDDs offer significant advantages over conventional MMW detectors like Schottky diodes or bolometers due to their cost-effectiveness, robustness to high-power MMW signals, and reliable operation under diverse environmental conditions. Based on weakly ionized plasma (WIP) technology, GDDs detect changes in discharge current upon MMW exposure, providing an affordable and durable alternative to traditional MMW imaging systems. The system operates within a subset of the W-band (101–109 GHz), utilizing a customized transmitter (Tx 272 from VDI Technologies), which operates at a frequency range proportional to the VCO supply voltage level. The Frequency-Modulated Continuous Wave (FMCW) signal source is split into target and reference paths via a compact waveguide splitter, improving stability and reducing the complexity of the optical setup. Reflected signals are processed by the GDD, which functions as a heterodyne receiver, and Fast Fourier Transform (FFT) is used to extract range data. A 2D grid scanning mechanism, controlled by step motors, maps the surface of the object, while depth information is derived from FMCW frequency differentials to construct a complete 3D profile. This work demonstrates the potential of GDD-based 3D MMW imaging as a low-cost, efficient solution for security screening and industrial inspection. By addressing challenges in cost, scalability, and performance under high-power MMW signals, this approach represents a significant step forward in making MMW imaging technology more accessible, while highlighting the need for further development to achieve practical implementation. Full article

Deep-sea mining pipes are different from traditional ocean risers articulated at both ends: they are free-suspended, weakly constrained at the bottom, and have an intermediate silo at the end, compared to which relatively little research has been carried out on vortex-induced vibration in mining pipes. In this study, a sophisticated quasi-3D numerical model with two degrees of freedom for the flow field domain and structural dynamics of a deep-sea mining pipe is developed through a novel slicing method. The investigation explores how the vortex-induced vibrations of the mining pipe behave in various scenarios, including uniform and oscillating flows, as well as changes in the mass of the relay bin. The findings indicate that the displacement of the deep-sea mining pipe increases continuously as it moves from top to bottom along its axial direction. The upper motion track appears chaotic, while the middle and lower tracks exhibit a stable “8” shape capture, with the tail capturing a “C” shape track. Furthermore, with an increase in flow velocity, both transverse vibration frequency and vibration modes of the mining pipe progressively rise. Under oscillating flow conditions, there exists a “delay effect” between vibration amplitude and velocity. Additionally, an increase in oscillation frequency leads to gradual sparsity in the vibration envelope of the mining pipe in transverse flow direction without affecting its overall vibration frequency. Under the same flow velocity and different bottom effects, the main control frequency of the deep-sea mining pipe is basically unchanged, but the vibration mode of the mining pipe is changed. Full article

The paper presents the results of developing Er-doped optical fibers for creating random single-frequency lasers in the wavelength range of 1570–1610 nm. The possibility of broadening the luminescence band of Er³⁺ ions in silicate glasses in the long-wavelength region of the spectrum by introducing a high concentration of P₂O₅, as well as by additional doping with Sb₂O₃, is investigated. It is found that both approaches do not improve the dynamics of luminescence decay in the L-band. In addition, Er₂O₃-GeO₂-Al₂O₃-SiO₂ and Er₂O₃-GeO₂-Al₂O₃-P₂O₅-SiO₂ glasses were studied as the core material for L-band optical fibers. The developed fibers exhibited high photosensitivity and a high gain of 5 and 7.2 dB/m, respectively. In these fibers, homogeneous arrays of extended weakly reflecting Bragg gratings were recorded directly during the fiber drawing process. Samples of arrays 5 m long and with a narrow reflection maximum at ~1590 nm were used as the base for laser resonators. Narrow-band random laser generation in the wavelength region of 1590 nm was recorded for the first time. At a temperature of 295 K, the laser mode was strictly continuous wave and stable in terms of output power. The maximal power exceeded 16 mW with an efficiency of 16%. Full article

This is a comprehensive overview on our research work to link interdisciplinary modeling and simulation techniques to improve the predictability and reliability simulations (PARs) of compressible turbulence with shock waves for general audiences who are not familiar with our nonlinear approach. This focused nonlinear approach is to integrate our “nonlinear dynamical approach” with our “newly developed high order entropy-conserving, momentum-conserving and kinetic energy-preserving methods” in the quantification of numerical uncertainty in highly nonlinear flow simulations. The central issue is that the solution space of discrete genuinely nonlinear systems is much larger than that of the corresponding genuinely nonlinear continuous systems, thus obtaining numerical solutions that might not be solutions of the continuous systems. Traditional uncertainty quantification (UQ) approaches in numerical simulations commonly employ linearized analysis that might not provide the true behavior of genuinely nonlinear physical fluid flows. Due to the rapid development of high-performance computing, the last two decades have been an era when computation is ahead of analysis and when very large-scale practical computations are increasingly used in poorly understood multiscale data-limited complex nonlinear physical problems and non-traditional fields. This is compounded by the fact that the numerical schemes used in production computational fluid dynamics (CFD) computer codes often do not take into consideration the genuinely nonlinear behavior of numerical methods for more realistic modeling and simulations. Often, the numerical methods used might have been developed for weakly nonlinear flow or different flow types other than the flow being investigated. In addition, some of these methods are not discretely physics-preserving (structure-preserving); this includes but is not limited to entropy-conserving, momentum-conserving and kinetic energy-preserving methods. Employing theories of nonlinear dynamics to guide the construction of more appropriate, stable and accurate numerical methods could help, e.g., (a) delineate solutions of the discretized counterparts but not solutions of the governing equations; (b) prevent numerical chaos or numerical “turbulence” leading to FALSE predication of transition to turbulence; (c) provide more reliable numerical simulations of nonlinear fluid dynamical systems, especially by direct numerical simulations (DNS), large eddy simulations (LES) and implicit large eddy simulations (ILES) simulations; and (d) prevent incorrect computed shock speeds for problems containing stiff nonlinear source terms, if present. For computation intensive turbulent flows, the desirable methods should also be efficient and exhibit scalable parallelism for current high-performance computing. Selected numerical examples to illustrate the genuinely nonlinear behavior of numerical methods and our integrated approach to improve PARs are included. Full article

Background: Lung cancer, also known as lung carcinoma, has a high mortality rate; however, an early prediction helps to reduce the risk. In the current literature, various approaches have been developed for the prediction of lung carcinoma (at an early stage), but these still have various issues, such as low accuracy, high noise, low contrast, poor recognition rates, and a high false-positive rate, etc. Thus, in this research effort, we have proposed an advanced algorithm and combined two different types of deep neural networks to make it easier to spot lung melanoma in the early phases. Methods: We have used WDSI (weakly supervised dense instance-level lung segmentation) for laborious pixel-level annotations. In addition, we suggested an SS-CL (deep continuous learning-based deep neural network) that can be applied to the labeled and unlabeled data to improve efficiency. This work intends to evaluate potential lightweight, low-memory deep neural net (DNN) designs for image processing. Results: Our experimental results show that, by combining WDSI and LSO segmentation, we can achieve super-sensitive, specific, and accurate early detection of lung cancer. For experiments, we used the lung nodule (LUNA16) dataset, which consists of the patients’ 3D CT scan images. We confirmed that our proposed model is lightweight because it uses less memory. We have compared them with state-of-the-art models named PSNR and SSIM. The efficiency is 32.8% and 0.97, respectively. The proposed lightweight deep neural network (DNN) model archives a high accuracy of 98.2% and also removes noise more effectively. Conclusions: Our proposed approach has a lot of potential to help medical image analysis to help improve the accuracy of test results, and it may also prove helpful in saving patients’ lives. Full article

Background: Obesity and type 2 diabetes (T2D) pose global health problems that continue to rise. A chronic low-grade inflammation and activation of the immune system are well established in both conditions. The presence of these factors can predict disease development and progression. Emerging evidence suggests that platelet–high density lipoprotein ratio (PHR) is a potential inflammatory marker. The purpose of this study was to investigate the relationship between PHR and T2D among obese patients. Methods: 203 patients with BMI ≥ 30 kg/m² participated in the study. Patients were categorized into two groups: non-diabetic obese and diabetic obese. Comorbidities, baseline characteristics, laboratory data, as well as PHR levels of the study groups were analyzed. Medians, risk assessment, and the diagnostic performance of PHR values were examined in both groups. Results: In obese patients, the median PHR were significantly increased in obese patients with T2D compared to non-diabetic obese (p < 0.0001). Furthermore, T2D obese with high PHR had a significantly higher FBG and HbA1c (p < 0.05). Although PHR was weakly yet significantly correlated with glycemic markers, ROC curve analysis of the PHR indicated an AUC of 0.700 (p < 0.0001) in predicting T2D in obese patients, and the cutoff value was 6.96, with a sensitivity and specificity of 53.4% and 76.1%, respectively. Moreover, increased PHR (OR = 4.77, p < 0.0001) carried a significantly higher risk for developing T2D in obese individuals. Conclusions: The PHR is a convenient and cost-effective marker that can reliably predict the presence of T2D in high-risk obese population. Full article

This paper works with functions defined in metric spaces and takes values in complete paranormed vector spaces or in Banach spaces, and proves some necessary and sufficient conditions for weak convergence of probability measures. Our main result is as follows: Let X be a complete paranormed vector space and $\Omega$ an arbitrary metric space, then a sequence $\left\{{\mu }_n\right\}$ of probability measures is weakly convergent to a probability measure $\mu$ if and only if $\underset{n\to \infty }{\lim }{\displaystyle {\int }_{\Omega }}g(s)d{\mu }_n={\displaystyle {\int }_{\Omega }}g(s)d\mu$ for every bounded continuous function g: Ω → X. A special case is as the following: if X is a Banach space, $\Omega$ an arbitrary metric space, then $\left\{{\mu }_n\right\}$ is weakly convergent to $\mu$ if and only if $\underset{n\to \infty }{\lim }{\displaystyle {\int }_{\Omega }}g(s)d{\mu }_n={\displaystyle {\int }_{\Omega }}g(s)d\mu$ for every bounded continuous function g: Ω → X. Our theorems and corollaries in the article modified or generalized some recent results regarding the convergence of sequences of measures. Full article

In this paper, we introduce the notion of $\left(p,q\right)$-fuzzy local function and DF-ideal topological space. Also, we introduce the concepts DFU-ð-continuous and DFL-ð-continuous, almost ð-continuous, weakly ð-continuous and almost weakly ð-continuous multifunctions. Several properties and characterizations of the introduced multifunctions and types of continuity are established. Some examples are given to explain the correct implications between these notions. Full article

We consider the large class $\mathfrak{G}$ of locally convex spaces that includes, among others, the classes of $\left(DF\right)$-spaces and $\left(LF\right)$-spaces. For a space E in class $\mathfrak{G}$ we have characterized that a subspace Y of $(E,\sigma (E,E^{\prime }))$, endowed with the induced topology, is analytic if and only if Y has a $\sigma (E,E^{\prime })$-compact resolution and is contained in a $\sigma (E,E^{\prime })$-separable subset of E. This result is applied to reprove a known important result (due to Cascales and Orihuela) about weak metrizability of weakly compact sets in spaces of class $\mathfrak{G}$. The mentioned characterization follows from the following analogous result: The space $C\left(X\right)$ of continuous real-valued functions on a completely regular Hausdorff space X endowed with a topology $\xi$ stronger or equal than the pointwise topology ${\tau }_p$ of $C\left(X\right)$ is analytic iff $\left(C\right(X),\xi )$ is separable and is covered by a compact resolution. Full article

In this paper, we study the long-time behavior of a weakly dissipative viscoelastic equation with variable exponent nonlinearity of the form ${\displaystyle u_{tt}+{\Delta }^{2}u-{\int }_0^{t}g(t-s)\Delta u\left(s\right)ds+a{|u_t|}^{n(·)-2}{u}_t-\Delta u_t=0,}$ where $n(.)$ is a continuous function satisfying some assumptions and g is a general relaxation function such that $g^{\prime }\left(t\right)\le -\xi \left(t\right)\mathbb{G}\left(g\left(t\right)\right),$ where $\xi$ and $\mathbb{G}$ are functions satisfying some specific properties that will be mentioned in the paper. Depending on the nature of the decay rate of g and the variable exponent $n(.)$, we establish explicit and general decay results of the energy functional. We give some numerical illustrations to support our theoretical results. Our results improve some earlier works in the literature. Full article

Unmanned underwater vehicles (UUV) face maneuverability and rapidity challenges when they are applied for detecting and repairing submarine oil and gas pipelines, and fiber cables near the seabed. This research establishes numerical models of the bare UUV and self-propelled UUV near the seabed using the computational fluid dynamics (CFD) method. The effect of dimensionless distance Hd and $R{e}_L$ on the hydrodynamic performance of the vehicle and the interaction between the hull and the propeller is investigated. The range of Hd is 1.5D–10D, and the $R{e}_L$ is 9.97 × 10⁵~7.98 × 10⁶. Findings indicate that: (1) There is an obvious strong coupling between the hydrodynamic performance of the bare UUV and Hd. With the increase of Hd, the hydrodynamic performance such as $C_d$, the absolute value of $C_l$ and $m_y$ decreases continuously and finally tends to be stable. The absolute values of $C_d$ and $C_l$ increase with the increase of $R{e}_L$. The change trend of $m_y$ is opposite to that of $C_l$. (2) The variation trend of hydrodynamic performance of the self-propelled UUV with Hd is consistent with those of the bare UUV. Additionally, it increases to some extent, respectively, compared with the bare UUV. (3) The self-propelled characteristics such as $t$, ${\eta }_H$, $w$ and ${\eta }_i$ are weakly related to Hd. The $t$ and ${\eta }_i$ increase with the increasing of $R{e}_L$, while ${\eta }_H$ and $w$ decrease with the increasing of $R{e}_L$. Full article

Solar-induced chlorophyll fluorescence (SIF) is closely related to the light-reaction process and has been recognized as a good indicator for tracking gross primary productivity (GPP). Nevertheless, it has not been widely examined how SIF and GPP respond to temperature. Here, we explored the linkage mechanisms between SIF and GPP in winter wheat based on continuous measurements of canopy SIF ($cSIF$), GPP, and meteorological data. To separately explore the structural and physiological mechanisms underlying the SIF–GPP relationship, we studied the temperature responses of the estimated light use efficiency ($LU{E}_p$), canopy-level chlorophyll fluorescence yield ($cSI{F}_{yield}$) and photosystem-level chlorophyll fluorescence yield (${\mathsf{\Phi }}_F$) estimated using canopy-scale remote sensing measurements. We found that GPP, red canopy SIF ($cSI{F}_{688}$) and far-red canopy SIF ($cSI{F}_{760}$) all exhibited a decreasing trend during overwintering periods. However, GPP and $cSI{F}_{688}$ showed relatively more obvious changes in response to air temperature ($T_a$) than $cSI{F}_{760}$ did. In addition, the $LU{E}_p$ responded sensitively to $T_a$ (the correlation coefficient, r = 0.83, p-value < 0.01). The $cSI{F}_{yield\_688}$ and ${\mathsf{\Phi }}_{F\_688}$ (${\mathsf{\Phi }}_F$ at 688 nm) also exhibited significantly positive correlations with $T_a$ (r > 0.7, p-value < 0.05), while $cSI{F}_{yield\_760}$ and ${\mathsf{\Phi }}_{F\_760}$ (${\mathsf{\Phi }}_F$ at 760 nm) were weakly correlated with $T_a$ (r < 0.3, p-value > 0.05) during overwintering periods. The results also show that $LU{E}_p$ was more sensitive to $T_a$ than ${\mathsf{\Phi }}_F$, which caused changes in the $LU{E}_p/{\mathsf{\Phi }}_F$ ratio in response to $T_a$. By considering the influence of $T_a$, the GPP estimation based on the total SIF emitted at the photosystem level ($tSIF$) was improved (with R² increased by more than 0.12 for $tSI{F}_{760}$ and more than 0.05 for $tSI{F}_{688}$). Therefore, our results indicate that the $LU{E}_p/{\mathsf{\Phi }}_F$ ratio is affected by temperature conditions and highlights that the SIF–GPP model should consider the influence of temperature. Full article

Let $A,X,Y$ be Banach spaces and $A\times X\to Y$, $(a,x)\mapsto ax$ be a continuous bilinear function, called a Banach action. We say that this action preserves unconditional convergence if for every bounded sequence ${\left(a_n\right)}_{n\in \omega }$ in A and unconditionally convergent series ${\sum }_{n\in \omega }{x}_n$ in X, the series ${\sum }_{n\in \omega }{a}_n{x}_n$ is unconditionally convergent in Y. We prove that a Banach action $A\times X\to Y$ preserves unconditional convergence if and only if for any linear functional $y^{*}\in Y^{*}$ the operator $D_{y^{*}}:X\to A^{*}$, $D_{y^{*}}\left(x\right)\left(a\right)=y^{*}\left(ax\right)$ is absolutely summing. Combining this characterization with the famous Grothendieck theorem on the absolute summability of operators from ${\ell }_1$ to ${\ell }_2$, we prove that a Banach action $A\times X\to Y$ preserves unconditional convergence if A is a Hilbert space possessing an orthonormal basis ${\left(e_n\right)}_{n\in \omega }$ such that for every $x\in X$, the series ${\sum }_{n\in \omega }{e}_{n}x$ is weakly absolutely convergent. Applying known results of Garling on the absolute summability of diagonal operators between sequence spaces, we prove that for (finite or infinite) numbers $p,q,r\in [1,\infty ]$ with $\frac{1}{r}\le \frac{1}{p}+\frac{1}{q}$, the coordinatewise multiplication ${\ell }_p\times {\ell }_q\to {\ell }_r$ preserves unconditional convergence if and only if one of the following conditions holds: (i) $p\le 2$ and $q\le r$, (ii) $2<p<q\le r$, (iii) $2<p=q<r$, (iv) $r=\infty$, (v) $2\le q<p\le r$, (vi) $q<2<p$ and $\frac{1}{p}+\frac{1}{q}\ge \frac{1}{r}+\frac{1}{2}$. Full article