Search Results (35,238)

A low-carbon society aims to achieve sustainable social development through innovative technologies and mechanisms, promoting low-carbon economic models and lifestyles. In light of China’s commitment to achieving carbon neutrality and transitioning to a low-carbon society, it is crucial to control waste generation at its source, as the waste management sector is highly polluting and contributes substantially to carbon emissions. Adopting the 3R (reduce, reuse, and recycle) approach, reducing the quantity of waste is the priority in waste management. Therefore, exploring rural residents’ willingness to adopt the “pay as you throw” (PAYT) policy in underdeveloped mountainous areas and the factors influencing this willingness is highly valuable. This paper adopts the Contingent Valuation Method (CVM) with a face-to-face questionnaire survey, involving 1429 farmers from six cities around the underdeveloped mountainous area in Northwestern China. It measures their willingness to pay (WTP) and preferred payment levels for the PAYT policy. Based on the theory of planned behavior, the paper finds that farmers’ environmental knowledge, environmental awareness and social trust positively influence their WTP, while farmers’ perception of pollution and daily waste disposal do not significantly impact their WTP. Additionally, social trust negatively moderates the relationship between environmental knowledge and WTP. This paper provides empirical results that can support the implementation of a nationwide waste fee management system and the promotion of volume-based waste fee management. It also offers targeted suggestions for the government to establish PAYT and improve the efficiency of rural household waste management in rural China. Full article

Background and Objective: In the context of the rapidly aging global population, the older adult vulnerability poses a significant challenge for public health systems. Frailty, cognitive and nutritional status, depression, and grip strength are essential parameters for staging the vulnerability of older adults. The objective of this study is to identify a rapid but multidimensional geriatric assessment tool that can enhance the rehabilitation process for older adults, tailored to their specific needs. Materials and Methods: This pilot study examines the relationships between grip strength, nutritional status, frailty, depression, and cognition in a group of 80 older adults with a mean age of 69.6 years, 49 male and 31 female, using standardized geriatric scales and digital grip strength measurements. The study employed a digital dynamometer, a portable and reliable tool that facilitated quick and accurate grip strength measurements. Results: The analysis revealed significant correlations among the parameters. Greater grip strength was associated with better cognitive performance (r = 0.237, p = 0.034) and improved nutritional status (r = 0.267, p = 0.016), while it was inversely related to frailty (r = −0.313, p = 0.005). Nutritional status also played a key role, showing an inverse relationship with frailty (r = −0.333, p = 0.003) and depression levels (r = −0.248, p = 0.027). Furthermore, frailty and depression were strongly interconnected, with those experiencing higher frailty levels also displaying more severe depressive symptoms (r = 0.545, p < 0.001). Marital status was also relevant: married participants exhibited higher grip strength, lower frailty, and fewer depressive symptoms, suggesting that social support positively influences both physical and mental health in older adults. Conclusions: These findings not only emphasize the need for integrated care approaches that simultaneously address physical health, nutrition, and cognitive function, but also provide a foundation for the development of a rapid and multidimensional assessment protocol, which consists of using a digital dynamometer and four geriatric scales. Such a tool could play a crucial role in the early detection of frailty syndrome and guide the implementation of multidisciplinary, tailored therapeutic strategies aimed at preserving the autonomy and improving the quality of life of older adults. Full article

As digital transformation deepens, digital agriculture plays a crucial role in advancing the Coordinated Development Level of Ecosystem Services and Human Well-Being (CD-ESWB). However, aligning ecosystem service capacities with human development needs remains a challenge. This study investigates how digital agriculture influences CD-ESWB, using panel data collected from 30 provinces in China between 2014 and 2022. First, an index system, the Level of Digital Agriculture Development (LDAD), is discussed, followed by a quantitative analysis using the entropy-weight TOPSIS method. The CD-ESWB is then evaluated through the “Ecosystem Services–Human Well-Being” coupling coordination model. Empirical analysis, incorporating fixed effects, mediation, and moderation models, demonstrates that digital agriculture significantly enhances CD-ESWB, though its impact varies across regions. Robustness checks, including instrumental variable methods, sample interval adjustment, and variable substitution, confirm the reliability of the findings. Notably, the Technological Innovation Effect (TIE) mediates digital agriculture’s impact, while Industrial Structure Upgrade (ISU) acts as a positive moderator. This study emphasizes the importance of regional policies in promoting technological innovation and optimizing industrial structures, providing both theoretical and empirical insights into how digital agriculture shapes CD-ESWB. Full article

In order to solve the hysteresis nonlinearity and resonance problems of piezoelectric stages, this paper takes a three-degree-of-freedom tip-tilt-piston piezoelectric stage as the object, compensates for the hysteresis nonlinearity through inverse hysteresis model feedforward control, and then combines the composite control method of positive acceleration velocity position feedback damping control and high-gain integral feedback controller to suppress the resonance of the system and improve the tracking speed and positioning accuracy. Firstly, the three-degree-of-freedom motion of the end-pose is converted into the output of three sets of piezoelectric actuators and single-axis control is performed. Then, the rate-dependent Prandtl–Ishlinskii model is established and the parameters of the inverse model are identified. The accuracy and effectiveness of parameter identification are verified through open-loop and closed-loop compensation experiments. After that, for the third-order system, the parameters of positive acceleration velocity position feedback damping control and high-gain integral feedback controller are designed as a whole based on the pattern of the Butterworth filter. The effectiveness of the design method is proved by step signal and triangle wave signal trajectory tracking experiments, which suppresses the resonance of the system and improves the bandwidth of the system and the tracking speed of the stage. Full article

The study of energy savings in ventilation systems within buildings is crucial. Impinging jet ventilation (IJV) systems have garnered significant interest from researchers. The identification of the appropriate location for the IJV reveals a gap in the existing literature. This research was conducted to address the existing gap by examining the impact of IJV location on energy savings and thermal comfort. A comprehensive three-dimensional CFD model is examined to accurately simulate the real environment of an office room (3 × 3 × 2.9 m³) during cooling mode, without the application of symmetrical plans. Four locations have been selected: two at the corners and two along the midwalls, designated for fixed-person positions. The return vent height is analyzed utilizing seven measurements: 2.9, 2.6, 2.3, 1.7, 1.1, 0.8, and 0.5 m. The RNG k–ε turbulence model is implemented alongside enhanced wall treatment. The findings indicated that the optimal range for the return vent height is between 1.7 and 0.8 m. It is advisable to utilize the IJV midwall 1 location, positioned behind the seated individual and away from the exterior hot wall. It is characterized by low vortex formation in the local working zone that contributes to a more comfortable sensation while providing recognized energy-saving potential. Full article

The mathematical theories and methods of fractional calculus are relatively mature, which have been widely used in signal processing, control systems, nonlinear dynamics, financial models, etc. The studies of some basic theories of fractional differential equations can provide more understanding of mechanisms for the applications. In this paper, the expression of the Green function as well as its special properties are acquired and presented through theoretical analyses. Subsequently, on the basis of these properties of the Green function, the existence and uniqueness of positive solutions are achieved for a singular p-Laplacian fractional-order differential equation with nonlocal integral and infinite-point boundary value systems by using the method of a nonlinear alternative of Leray–Schauder-type Guo–Krasnoselskii’s fixed point theorem in cone, and the Banach fixed point theorem, respectively. Some existence results are obtained for the case in which the nonlinearity is allowed to be singular with regard to the time variable. Several examples are correspondingly provided to show the correctness and applicability of the obtained results, where nonlinear terms are controlled by the integrable functions $\frac{1}{\pi {(lnt)}^{\frac{1}{2}}{(1-lnt)}^{\frac{1}{2}}}$ and $\frac{1}{\pi {(lnt)}^{\frac{3}{4}}{(1-lnt)}^{\frac{3}{4}}}$ in Example 1, and by the integrable functions $\theta ,\overline{\theta }$ and $\phi \left(v\right),\psi \left(u\right)$ in Example 2, respectively. The present work may contribute to the improvement and application of the coupled p-Laplacian Hadamard fractional differential model and further promote the development of fractional differential equations and fractional differential calculus. Full article

Humic acid, as a novel organic fertilizer, has the potential to improve soil fertility and the agronomic performance of crops. However, the efficacy of humic acid varied in previous studies and the mechanisms by which climatic conditions, soil properties, and fertilization regimes regulate it remain unclear. To test this, a comprehensive meta-analysis was conducted to evaluate the effects of humic acid across various environmental and agricultural conditions. The results showed that the humic acid amendment significantly increased the crop yield by 12%, nitrogen use efficiency by 27%, and nitrogen uptake by 17%, on average. Optimal effects were observed in regions with an annual precipitation > 300 mm and mean annual temperatures > 10 °C, and in soils with a moderate pH (6 < pH ≤ 8) or low total nitrogen. Its efficacy was attenuated in alkaline soils and high total nitrogen (≤1.5 g kg⁻¹) or low soil organic carbon (<10 g kg⁻¹) conditions. Cash crops and upland cereals showed a superior response compared to paddy rice, with optimal nitrogen application rates of 100–200 kg ha⁻¹. This study quantifies humic acid’s positive impacts on crop productivity and nitrogen utilization across various conditions, providing empirical evidence for optimizing its application in sustainable agricultural systems, potentially reducing excessive fertilizer use and its associated environmental pollution. Full article

Integrating new visualization methods based on virtual reality (VR) in the design evaluation process remains a challenge despite its expanding use in architectural design in recent years. This article proposes a VR-based evaluation model to improve the efficiency and quality of the overall architectural design process. By adopting a structural equation model in conjunction with the Technology Acceptance Model (TAM), the study examines users’ intention and perceived ease of use of VR in the design evaluation process based on a questionnaire survey using the proposed VR model of architectural and non-architectural professionals and students. The findings of the study show that the output quality plays a significant role in increasing behavioral intention to use the system, and perceived ease of use has a positive effect on perceived immersion and perceived usefulness of VR in the evaluation process. The study illustrates the importance of understanding “user perspective” and “willingness to use” in the development of VR-based systems to increase their practical use in architecture and design fields. Full article

Nowadays, driving accidents are considered one of the most crucial challenges for governments and communities that affect transportation systems and peoples lives. Unfortunately, there are many causes behind the accidents; however, drowsiness is one of the main factors that leads to a significant number of injuries and deaths. In order to reduce its effect, researchers and communities have proposed many techniques for detecting drowsiness situations and alerting the driver before an accident occurs. Mostly, the proposed solutions are visually-based, where a camera is positioned in front of the driver to detect their facial behavior and then determine their situation, e.g., drowsy or awake. However, most of the proposed solutions make a trade-off between detection accuracy and speed. In this paper, we propose a novel Visual-based Alerting System for Detecting Drowsy Drivers (VAS-3D) that ensures an optimal trade-off between the accuracy and speed metrics. Mainly, VAS-3D consists of two stages: detection and classification. In the detection stage, we use pre-trained Haar cascade models to detect the face and eyes of the driver. Once the driver’s eyes are detected, the classification stage uses several pre-trained Convolutional Neural Network (CNN) models to classify the driver’s eyes as either open or closed, and consequently their corresponding situation, either awake or drowsy. Subsequently, we tested and compared the performance of several CNN models, such as InceptionV3, MobileNetV2, NASNetMobile, and ResNet50V2. We demonstrated the performance of VAS-3D through simulations on real drowsiness datasets and experiments on real world scenarios based on real video streaming. The obtained results show that VAS-3D can enhance the accuracy detection of drowsy drivers by at least $7.5\%$ (the best accuracy reached was $95.5\%$) and the detection speed by up to $57\%$ (average of $0.25$ ms per frame) compared to other existing models. Full article

The Internet of Things (IoT) has emerged as a popular topic in both industrial and academic research. IoT devices are often equipped with rapid response capabilities to ensure seamless communication and interoperability, showing significant potential for IoT-based maritime traffic monitoring and navigation safety tasks. However, this also presents major challenges for maritime surveillance systems. The diversity of IoT devices and variability in collected data are substantial. Visual image ship detection is crucial for maritime tasks, yet it must contend with environmental challenges such as haze and waves that can obscure ship details. To address these challenges, we propose an adaptive query selection transformer (AQSFormer) that utilizes two-dimensional rotational position encoding for absolute positioning and integrates relative positions into the self-attention mechanism to overcome insensitivity to the position. Additionally, the introduced deformable attention module focuses on ship edges, enhancing the feature space resolution. The adaptive query selection module ensures a high recall rate and a high end-to-end processing efficiency. Our method improves the mean average precision to 0.779 and achieves a processing speed of 31.3 frames per second, significantly enhancing both the real-time capabilities and accuracy, proving its effectiveness in ship detection. Full article

The conventional hydraulic system of excavators suffers from significant valve throttling losses and inadequate matching between the hydraulic power source and the load, which substantially impact the system’s overall energy consumption and severely impede the trend toward electrification and energy efficiency in construction machinery. To address this issue, a pump-controlled hydraulic cylinder system has been implemented to replace the original valve-controlled hydraulic system that utilizes a single pump with multiple actuators. The influence of energy conversion efficiency and the speed between the motor and the hydraulic pump under varying load-power conditions has been determined through experimental investigations. Based on these findings, a compound-control strategy is proposed that adjusts the displacement of the hydraulic pump to achieve precise control over the position of the hydraulic cylinder and facilitates both the speed and displacement coordination while ensuring optimal motor speed matching with the load power. This strategy is implemented in the boom pump’s hydraulic cylinder control system. The research findings indicate that this combined-control approach enhances efficiency by approximately 18.9% compared with traditional variable-speed pump-controlled hydraulic cylinder systems. Furthermore, energy consumption is reduced by about 39% compared with the conventional valve-controlled hydraulic system. Full article

Business communities in the construction market are becoming increasingly diverse, with a deepening impact on industrial development and enterprise competition. Despite many existing empirical studies on communities, they weaken competitive interactions and have limited applicability to the dynamic issues of community formation and evolution. To address the gaps identified in the literature on bidding competition dynamics, this study constructs a multi-agent system (MAS) model. This model is designed to simulate the formation of community-type rivalry in the construction market by incorporating key variables identified from empirical observations of bidding behavior. It also designs and runs two experiments focusing on the impact of overall market factors and enterprises’ own factors on the formation of an equilibrium state of community-type rivalry to explore the mechanism behind its formation. We find that the density of community networks and the process of community formation are significantly affected by the number of enterprises, the scope of competition among enterprises, and the lifespan of the link, while they are not significantly affected by the size of the market or the exit thresholds of enterprises. In addition, this study finds that, under the bidding competition rule, the number of times that an enterprise bids is closely related to its network location advantage. However, larger and more mature enterprises have difficulty in maintaining a central position in a competitive network. This study provides different perspectives for an understanding of corporate community formation and offers valuable insights into the governance of community phenomena in the construction market. Full article

The rapid evolution of smart cities relies heavily on advancements in wireless communication systems and extensive IoT networks. This paper offers a comprehensive review of the critical role and future potential of integrating unmanned aerial vehicles (UAVs) and reconfigurable intelligent surfaces (RISs) to enhance Internet of Vehicles (IoV) systems within beyond-fifth-generation (B5G) and sixth-generation (6G) networks. We explore the combination of quasi-optical millimeter-wave (mmWave) signals with UAV-enabled, RIS-assisted networks and their applications in urban environments. This review covers essential areas such as channel modeling and position-aware beamforming in dynamic networks, including UAVs and IoVs. Moreover, we investigate UAV navigation and control, emphasizing the development of obstacle-free trajectory designs in dense urban areas while meeting kinodynamic and motion constraints. The emerging potential of RIS-equipped UAVs (RISeUAVs) is highlighted, along with their role in supporting IoVs and in mobile edge computing. Optimization techniques, including convex programming methods and machine learning, are explored to tackle complex challenges, with an emphasis on studying computational complexity and feasibility for real-time operations. Additionally, this review highlights the integrated localization and communication strategies to enhance UAV and autonomous ground vehicle operations. This tutorial-style overview offers insights into the technical challenges and innovative solutions of the next-generation wireless networks in smart cities, with a focus on vehicular communications. Finally, future research directions are outlined. Full article

Background/objectives: The growing use of mobile health (mHealth) applications needs reliable tools to assess their usability and user experience in clinical practice to improve the digital health (eHealth) interventions and ensure engagement, as higher engagement is often linked to increased efficacy of healthcare interventions. This study aimed to validate the patient Satisfaction and Usability with APPs questionnaire (pSUAPP), a multidimensional tool designed for the comprehensive assessment of mHealth applications, particularly for the integrated follow-up of patients with chronic diseases. Methods: A validation study was conducted between August and December 2022 with 85 participants from two hospitals in Spain, who completed the pSUAPP questionnaire, comprising 27 Likert-like items across four dimensions: first contact, registration, features and overall experience, and 1 open question. The questionnaire was validated by a panel of 11 experts and further assessed for psychometric properties. Results: The mean pSUAPP score was 79.0 (SD = 12.0), indicating high usability and positive user experience, with the highest scores in the ‘features’ dimension. The pSUAPP demonstrated moderate correlation with the System Usability Scale (SUS) and high reliability (Cronbach’s alpha and omega t > 0.9). A reproducibility analysis showed negligible changes between repeated measures. Conclusions: The pSUAPP questionnaire was found to be a robust tool for evaluating mHealth app usability and user experience, with potential application across various clinical settings. Full article

Land management is critical for the conservation of natural resources, particularly in agroforestry systems which rely heavily on land productivity and availability. Optimizing land utilization is critical for sustainable biomass production and is a key component of achieving effective, long-term sustainable land management. This study assesses the resource efficiency of agroforestry production systems with a novel exergy-based indicator (ΔEF). The indicator was used in the Biobío and Ñuble regions to assess the resource balance between six agricultural and two forestry production systems. The ΔEF values ranged from positive to negative, with positive values indicating better resource usage and negative values suggesting the opposite. Eucalyptus globulus had higher ΔEF values (18.06–19.5 MJex/m².yr) than Pinus radiata (−2.71 to −1.47 MJex/m².yr), indicating better sustainability due to its high biomass yields and lower harvesting period and resource consumption. Sugar beet, wheat, and potatoes were the most sustainable (8.57–154.6 MJex/m².yr) because of their high yields and less intensive harvesting methods. Disparities in biomass yield, potential net primary production (NPP_pot), and land management intensity drive differences in ΔEF across regions. Our findings enhance the understanding of local and non-local resource efficiency in agroforestry systems, revealing significant drivers to encourage more sustainable land management practices. Full article