Search Results (158)

This study explores the relationship between institutional shareholders and climate-related disclosure (CRD) and how sustainability committees influence this relationship among publicly listed Malaysian firms. For the analysis, 990 firm-year observations were studied from 198 highly polluting firms from 2021 to 2024. A strong CRD index was designed using the recognized climate reporting frameworks and well-grounded literature to assess the level of climate-related disclosure. Fixed-effects and hierarchical panel regression models show that CRD increases when institutional investor ownership increases, meaning firms with more institutional investors disclose more information on climate-related topics. In addition, a sustainability committee at the board level greatly improves this relationship by highlighting the positive impact of strong internal governance. As a result, such committees establish climate management and improve communication with investors, making the firm’s actions more transparent. The findings of this study are consistent with agency and legitimacy theories because institutional investors assist in monitoring firms’ environmental performance, and sustainability committees help the company maintain these standards internally. Further, this study helps grow the understanding of corporate governance (CG) and sustainability by pointing out that the presence of institutional owners and sustainability committees can promote openness about climate matters. Accordingly, these findings can guide policymakers, investors, and business leaders in boosting responsible environmental reporting and sustainable business practices in developing countries. Full article

Objective: The present review aims to compare the oral microbial profile (OMP) of patients undergoing fixed orthodontic therapy (OT) versus clear aligner therapy (CAT) for the treatment of malocclusions. Methods: Clinical studies were included. Case-reports/-series, letters to the editor, reviews, perspectives, and expert opinions were excluded. Indexed databases (MEDLINE/PubMed, Embase, Scopus, and Web of Science) were searched up to the end point of May 2025, without time and language barriers. The study was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The risk of bias (RoB) and quality of evidence were assessed. Results: Three randomized clinical trials (RCTs) and seven non-RCTs were included. In all RCTs and five non-RCTs, OMP was assessed using subgingival plaque samples. Periodontopathogenic bacteria and Gram-negative anaerobic microbes were more often identified in patients undergoing fixed OT than CAT. The biofilm mass was higher in patients undergoing fixed OT than CAT. In two RCTs, periodontopathogenic bacteria were dominant among patients undergoing fixed OT than CAT. All RCTs and two non-RCTs had a high RoB. The certainty of evidence was “moderate” in 70% of the studies. Conclusions: Due to a high RoB, variability in study designs, and lack of power analysis, direct comparisons remain limited. Full article

In recent years, the number of vehicles in cities has visibly increased, leading to continuous modifications in general mobility. Pollution levels and congestion cases are reaching higher numbers as well, pointing to a need for better optimization solutions. Several existing control systems still rely on fixed timings for traffic lights, lacking an adaptive approach that can adjust the timers depending on real-time conditions. This study aims to provide a design for such a tool, by implementing two different approaches: Fuzzy Logic Optimization and an Adaptive Traffic Management strategy. The first controller involves Fuzzy Logic based on rule-based that adjust green and red-light timings depending on the number of vehicles at an intersection. The second model provides traffic adjustments based on external equipment such as road sensors and cameras, offering dynamic solutions tailored to current traffic conditions. Both methods are tested in a simulated environment using SUMO (Simulation of Urban Mobility). They were evaluated according to key efficiency indicators, namely average waiting time, lost time per cycle, number of stops per intersection, and overall traffic fluidity. Results demonstrate that Q-learning maintains consistent waiting times between 2.57 and 3.71 s across all traffic densities while achieving Traffic Flow Index values above 85%, significantly outperforming Fuzzy Logic, which shows greater variability and lower efficiency under high-density conditions. Full article

Background: The femoral artery is a continuation of the external iliac artery. Knowledge of the topography and morphological variability of the thigh vessels informs various fields of medicine, such as hip replacement, hip fracture and femoral trochanter fracture, embolectomy, and angiography. The main aim of this study was to calculate the δ index from morphological measurements. We introduce the δ index to quantify the relative dominance of the DFA in supplying the thigh, aiming to improve clinical assessment and procedural planning. Methods: The study comprised two parts: anatomical dissection and radiological examination. During the anatomical study, 80 lower limbs (34 female and 46 male) fixed in 10% formalin were dissected. For the radiological study, angio-CT scans of the lower limbs of 100 patients (200 lower limbs) were analyzed. In both studies, the δ index was determined. This is the ratio of the diameter of the deep femoral artery at its point of origin to the diameter of the femoral artery after that origin. The morphometric measurements were analyzed statistically using Statistica 12.0 software. Results: The average values of the δ index for the right side were 0.95 (±0.23) and 0.89 (±0.21), respectively, in the anatomical and radiological studies, while for the left side they were 0.94 (±0.23) and 0.89 (±0.27), respectively. The average values for males were 0.88 (±0.18) and 0.80 (±0.17), respectively, while for females they were 1.04 (±0.26) and 1.12 (±0.23), respectively. Conclusions: The δ index, elaborated and calculated in anatomical and radiological studies, showed no statistically significant body side difference. However, it showed a statistically significant sex difference; there was a greater distribution of blood through the deep femoral artery in women than in men. Full article

With the development of intelligent grid systems, smart circuit breakers are widely used. The control circuit is the core component of the smart circuit breaker, making its performance degradation characteristics highly significant. This paper focuses on the control circuit’s accelerated degradation test and performance degradation characteristics. First, an accelerated degradation test is designed, and a test platform is established. By analyzing the degradation mechanism of the intelligent circuit breaker control loop, the key weak links in the control loop are determined, and then the monitoring quantity is determined. Then, degradation data are preprocessed to extract features from the time, frequency, and wavelet domains. The multidimensional evaluation index model is applied to select the optimal features, fit the degradation trend, and use the fixed segmentation algorithm to divide the degradation stages and analyze the performance degradation characteristics of the control circuit. The experimental results show that the turning points of the two-stage degradation process at 85 °C, 95 °C, and 105 °C are 78.8%, 77.6%, and 77.0%, respectively. The position of the turning point is relatively fixed. The key circuit’s PSpice simulation model is built to verify the two-stage nonlinear characteristics observed in the experimental results. Finally, the results are verified by the Pearson correlation coefficient. The results show that the Pearson correlation coefficient between the simulation and accelerated life test results is above 0.9158, and the consistency between the two is high. Full article

In this article, we study singular fractional-order differential equations with a variable coefficient, namely the linear operator of the differential equation containing a linear term with a variable coefficient. The coefficient $a\left(s\right)$ permits singularity at $s=0, 1$, and the nonlinearity $\mathfrak{f}(s,\chi )$ may be singular at $s=0, 1$ and $\chi =0$. By utilizing the fixed-point index theory, the existence of positive solutions are derived under sharp conditions concerning spectral radius. Full article

In this paper, we discuss the positive solutions to a class of semipositone boundary value problems of fractional differential equations. The nonlinearity $f(t,\mathfrak{x})$ may be singular at $t=0,1$ and satisfies $f(t,\mathfrak{x})\ge -\mathfrak{a}\left(t\right)\mathfrak{x}-\mathfrak{R}\left(t\right)$. We derive some new properties of the Green’s function of the auxiliary problems, and discover the multiplicity and existence of the positive solutions by utilizing the fixed point index theory. Two examples are illustrated to validate the main results. Full article

We present a new word embedding technique in a (non-linear) metric space based on the shared membership of terms in a corpus of textual documents, where the metric is naturally defined by the Boolean algebra of all subsets of the corpus and a measure $\mu$ defined on it. Once the metric space is constructed, a new term (a noun, an adjective, a classification term) can be introduced into the model and analyzed by means of semantic projections, which in turn are defined as indexes using the measure $\mu$ and the word embedding tools. We formally define all necessary elements and prove the main results about the model, including a compatibility theorem for estimating the representability of semantically meaningful external terms in the model (which are written as real Lipschitz functions in the metric space), proving the relation between the semantic index and the metric of the space (Theorem 1). Our main result proves the universality of our word-set embedding, proving mathematically that every word embedding based on linear space can be written as a word-set embedding (Theorem 2). Since we adopt an empirical point of view for the semantic issues, we also provide the keys for the interpretation of the results using probabilistic arguments (to facilitate the subsequent integration of the model into Bayesian frameworks for the construction of inductive tools), as well as in fuzzy set-theoretic terms. We also show some illustrative examples, including a complete computational case using big-data-based computations. Thus, the main advantages of the proposed model are that the results on distances between terms are interpretable in semantic terms once the semantic index used is fixed and, although the calculations could be costly, it is possible to calculate the value of the distance between two terms without the need to calculate the whole distance matrix. “Wovon man nicht sprechen kann, darüber muss man schweigen”. Tractatus Logico-Philosophicus. L. Wittgenstein. Full article

Sinceits introduction in the 19th century to address geometric problems, topology as a methodology has undergone a series of evolutions, encompassing branches of geometric topology, point-set topology (analytic topology), algebraic topology, and differential topology, gradually permeating into various interdisciplinary applied fields. Starting from disciplines with typical geometric characteristics such as geography, physics, biology, and computer science, topology has found its way to economic fields in the 20th century. Given that the introduction of topology to economics is relatively new and presents features of being fragmented and non-systematic, this review aimed to provide scholars with a systematic evolution map to refine the characteristics of topology as a methodology applied in economics and finance, thereby aiding future potential interdisciplinary developments in these fields. By collecting abundant literature indexed in SCOPUS/WoS and other famous databases, with a qualitative analysis to classify and summarize it, we found that topological methods were introduced to modern economics when dealing with dynamic optimization, functional analysis, and convex programming problems, including famous applications such as uncovering equilibrium with fixed-point theorems in Walrasian economics. Topology can help uncover and refine the topological properties of these function space transformations, thus finding unchangeable features. Meanwhile, in contemporary economics, topology is being used for high-dimension reduction, complex network construction, and structural data mining, combined with techniques of machine learning, and applied to high-dimensional time series and structure analysis in financial markets. The most famous practical applications include the use of topological data analysis (TDA) and topological machine learning (TML) for different applied problems. Full article

Control charts are frequently used instruments for process quality monitoring. Another name for the NEEWMA control chart is the new extended exponentially weighted moving average (new extended EWMA) control chart. The lower control limit (LCL) and upper control limit (UCL) are equally spaced from the center line, giving it a symmetrical design. Because of its symmetry, the NEEWMA chart is very good at identifying even the tiniest changes in operation by detecting deviations from the target in both upward and downward directions. This study derives an explicit formula for the average run length (ARL) of the NEEWMA control chart based on the autoregressive (AR) model with exponential white noise. The focus is on the zero-state performance of the NEEWMA control chart, which is derived using explicit formulas. Banach’s fixed-point theorem was used to prove existence and uniqueness of this formula. The accuracy of this formula is validated by comparing it to the numerical integral equation (NIE) method using percentage accuracy (%Acc). The results show that the NEEWMA control chart is more efficient than the ARL evaluated by the NIE method, particularly regarding computation time. The performance of the NEEWMA control chart is compared with the EWMA and extended EWMA control charts by evaluating both the ARL and standard deviation run length (SDRL). The NEEWMA control chart outperforms the others in detection performance, followed by the extended EWMA and EWMA control charts. Further verification of its superior performance is provided through comparisons using the average extra quadratic loss (AEQL) and the performance comparison index (PCI), which confirm that it outperforms both the EWMA and extended EWMA control charts across various parameters and shift sizes. Finally, an illustrative example using real-life economic data demonstrates its efficiency. Full article

A bolt loosening detection method based on the summation coefficient of the absolute spectrum ratio technique is proposed to address the prevalent issue of bolt loosening in mechanical connections. This proposed method involves initially collecting vibration and rotation speed signals of the motor bolt connection structure, acquiring the baseline spectrum curve of a healthy structure and the spectrum curves of non-healthy structures under different degrees of bolt looseness through chirp Fourier transform (CFT). Subsequently, the spectrum ratio curves between healthy and non-healthy structures are calculated for different degrees of bolt loosening, and then the Summation Coefficient of Absolute Spectrum Ratio (SCASR) is defined to indicate the looseness. In the mathematical model, a linear relationship is observed between the SCASR and the frequency shift of the resonance peak. To standardize the results of bolt loosening detection, the SCASR could be divided by the number of points in the fixed frequency band to obtain the average of SCASR as the detection index for bolt loosening. Finally, a linear fitting equation is established between the bolt torque and the average of SCASR, so that the change in the average value can be used to determine whether the bolt is loose and evaluate the severity of bolt looseness. The detection performance of this proposed method has been effectively validated through both simulation and experiments. Experimental results indicate that the proposed method can effectively detect bolt loosening, particularly in its early stages, using low-frequency band data in three axes. Full article

Urban parks are important components of the urban green space system, providing residents with a variety of leisure options. The design’s focal point is the spatial layout of the different use scenarios within these parks. Previous studies have largely concentrated on the scene and macro layout of urban public spaces but have not thoroughly investigated the digital characteristics and corresponding parametric methods for the layout of different internal use scenes in urban green spaces. This research selected 18 urban parks from various global regions as case samples and categorized eight typical park scene space types based on common activity scene requirements in park design using AutoCAD to identify vector boundaries in each sample. To examine the digital characteristics of these scene space types, a quantitative index system was established, including spatial density and scale indicators, spatial connection relationship indicators, and spatial unit morphology indicators. The analysis of these indicators across the samples shows that the number of scene spaces is positively correlated with the total park area, while natural experience scenes constitute the largest proportion of urban parks. Different scene types exhibit distinct spatial layouts; for example, circulation spaces demonstrate high connectivity due to their role in directing visitor flow. Some spaces exhibit a more fixed scale and size, while others vary considerably. Finally, this research develops a parametric design framework using the Grasshopper platform. By taking a park in Nanjing as a case study, this paper illustrates how to utilize digital layout features to generate scene space layouts, offering insights into intelligent generative design. This approach provides a structured method to enhance urban park design through the application of digital and parametric tools, contributing to the broader field of urban park design. Full article

Nitrogen (N), while the most abundant element in the atmosphere, is an essential soil nutrient that limits plant growth. Leguminous plants naturally possess the ability to fix atmospheric nitrogen through symbiotic relationships with rhizobia in their root nodules. However, the widespread use of synthetic N fertilizers in modern agriculture has led to N enrichment in soils, causing complex and profound effects on legumes. Amid ongoing debates about how leguminous plants respond to N enrichment, the present study compiles 2174 data points from 162 peer-reviewed articles to analyze the impacts and underlying mechanisms of N enrichment on legumes. The findings reveal that N enrichment significantly increases total legume biomass by 30.9% and N content in plant tissues by 13.2% globally. However, N enrichment also leads to notable reductions, including a 5.8% decrease in root-to-shoot ratio, a 21.2% decline in nodule number, a 29.3% reduction in nodule weight, and a 27.1% decrease in the percentage of plant N derived from N₂ fixation (%Ndfa). Legume growth traits and N₂-fixing capability in response to N enrichment are primarily regulated by climatic factors, such as mean annual temperature (MAT) and mean annual precipitation (MAP), as well as the aridity index (AI) and N fertilizer application rates. Correlation analyses show that plant biomass is positively correlated with MAT, and tissue N content also exhibits a positive correlation with MAT. In contrast, nodule numbers and tissue N content are negatively correlated with N fertilizer application rates, whereas %Ndfa shows a positive correlation with AI and MAP. Under low N addition, the increase in total biomass in response to N enrichment is twice as large as that observed under high N addition. Furthermore, regions at lower elevations with abundant hydrothermal resources are especially favorable for total biomass accumulation, indicating that the responses of legumes to N enrichment are habitat-specific. These results provide scientific evidence for the mechanisms underlying legume responses to N enrichment and offer valuable insights and theoretical references for the conservation and management of legumes in the context of global climate change. Full article

In this paper, we present the existence of a mild solution for a class of a neutral stochastic integro-differential system over a Hilbert space. Such systems are influenced by both multiplicative and fractional noise, alongside non-instantaneous impulses, with a Hurst index H in the interval $({\displaystyle \frac{1}{2}},1)$. Additionally, the systems under consideration feature state-dependent delays (SDDs). To address this, we develop an approach to reformulate the neutral stochastic integro-differential system, incorporating SDDs and non-instantaneous impulses, into an equivalent fixed-point (FP) problem via an appropriate integral operator. By integrating stochastic analysis with the theory of resolvent operators, we employ Banach’s FP theorem to establish both the existence and uniqueness of the solution. Furthermore, we explore the Ulam–Hyers–Rassias stability of the system. Lastly, we provide illustrative examples to demonstrate the practical applicability of our results. Full article

The deployment of fixed-wing aircraft in fire-extinguishing operations represents a significant advancement in the domain of aviation emergency rescue. Addressing the challenge of enhancing firefighting efficacy, this study delves into the water-dropping strategies of fixed-wing extinguishers and provides a methodological framework for the strategic planning and assessment of water-dropping tactics, employing multi-resolution modeling. The formulation of the planning algorithm and the structure of the effectiveness evaluation index system are explained accordingly. The corresponding prototype system was designed, comprising four subsystems that utilized distinct resolution models: fire environment simulation, water-dropping point scheme planning, approaching path planning, and mission evaluation simulation. Case studies validate the system’s capability to forecast fire and smoke propagation, plan a water-dropping trajectory based on the fire line, optimize flight paths based on the trajectory, and simulate as well as evaluate the whole firefighting mission process. The above research comprehensively constructs the model, finishes the iterative optimization, and evaluates the water-dropping strategy by simulation. The technical path and methodological framework of studying water-dropping strategies are established. The outcomes of this study provide invaluable support for the parameter inversion design of the fixed-wing extinguisher, offering decision-making assistance to commanders and supplying training scenarios for new aviation crews. Full article