Search Results (9)

With the rapid growth of urban populations and the expansion of metro networks, accurate energy consumption prediction has become a critical task for optimizing metro operations and supporting low-carbon city development. Traditional statistical and machine learning methods often struggle to model the complex, nonlinear, and time-varying nature of metro energy data. To address these challenges, this paper proposes MTMM, a novel hybrid model that integrates the multi-head attention mechanism of the Transformer with the efficient, state-space-based Mamba architecture. The Transformer effectively captures long-range temporal dependencies, while Mamba enhances inference speed and reduces complexity. Additionally, the model incorporates multivariate energy features, leveraging the correlations among different energy consumption types to improve predictive performance. Experimental results on real-world data from the Guangzhou Metro demonstrate that MTMM significantly outperforms existing methods in terms of both MAE and MSE. The model also shows strong generalization ability across different prediction lengths and time step configurations, offering a promising solution for intelligent energy management in metro systems. Full article

The present work aims to investigate the newly modified transfer matrix method (MTMM) to predict an automotive exhaust muffler’s transmission loss (AEMTL). The MTMM is a mixed method between a 3D-CFD (Computation Fluid Dynamics in 3D), namely AVL FIRE^TM M Engine (process-safe 3D-CFD Simulations of Internal Combustions Engines), and the classic TMM for the exhaust muffler. For all the continuous and discontinuous sections of the exhaust muffler, the Mach number of the cross-section, the temperature, and the type of discontinuity of the exhaust gas flow were taken into consideration to evaluate the specific elements of the acoustic quadrupole that define the MTMM coupled with AVL FIRE^TM M Engine for one given muffler exhaust. Also, the perforations of intermediary ducts were considered in the new MTMM (AVL FIRE^TM M Engine linked with TMM) to predict the TL (transmission loss) of an automotive exhaust muffler with three expansion chambers. The results obtained for the TL in the frequency range 0.1-4 kHz agree with the experimental results published in the literature. The TMM was improved by adding the AVL FIRE^TM M Engine as a valuable tool in designing the automotive exhaust muffler (AEM). Full article

Porous materials have emerged as one of the most widely employed sound-absorbing materials in practical applications, owing to their excellent sound absorption properties and lightweight nature. Unsaturated porous materials have the potential to achieve superior sound absorption effects and significantly reduce mass. However, current research on the sound absorption performance of unsaturated porous materials is limited. This paper used a modified transfer matrix method (MTMM), which relies on matrix dimensionality reduction, to analyze the sound absorption characteristics of unsaturated porous materials under various boundary conditions. The study also examines the impact of different parameters, such as material thickness and saturation, on sound absorption performance and compares the results. The findings indicate that when a solid elastic plate is attached to an unsaturated porous elastic plate, the absorption coefficient decreases while the transmission loss increases. Additionally, reducing the thickness of the plate and increasing its porosity and saturation levels lead to an increase in the absorption coefficient and a decrease in the transmission loss. Full article

This study aims to theoretically address the design and analysis of an efficient pressure sensor designed using a polymer-based defective 1D annular photonic crystal (APC). The 1D APC comprises an alternate arrangement of Si and SiO₂ in a cylindrical fashion, incorporating a central defect layer. The investigation of the reflectance characteristics of the proposed structure is conducted by separately considering the polystyrene (PS) and the polymethyl methacrylate (PMMA) polymer materials as the defect layer. The pressure-sensitive refractive index of the polymers and the constituent materials of the APC play a vital role in envisaging the pressure-sensing application. The cornerstone of this study is represented by the shift analysis regarding the wavelength of the defect mode inside the band gap using different applied pressures, employing the modified transfer matrix method (MTMM). Various geometrical parameters like the defect polymer layer’s thickness and the APC period were carefully optimized to achieve an improved sensing performance. The proposed design demonstrated a remarkable pressure sensitivity and FoM of 51.29 nm/GPa and 301.7 GPa⁻¹, respectively, which is considerably high in the current research scenario. It is believed that the proposed structure can be an apt candidate for an innovative high-performance pressure sensor, and could play a key role in photonic integrated circuits. Full article

A focus on implementing social and emotional (SE) learning into curricula continues to gain popularity in K-12 educational contexts at the policy and practitioner levels. As it continues to be elevated in educational discourse, it becomes increasingly clear that it is important to have reliable, validated measures of students’ SE skills. Here we argue that framework and design are additional important considerations for the development and selection of SE skill assessments. We report the reliability and validity evidence for The Mosaic™ by ACT^® Social Emotional Learning Assessment, an assessment designed to measure SE skills in middle and high school students that makes use of a research-based framework (the Big Five) and a multi-method approach (three item types including Likert, forced choice, and situational judgment tests). Here, we provide the results from data collected from more than 33,000 students who completed the assessment and for whom we have data on various outcome measures. We examined the validity evidence for the individual item types and the aggregate scores based on those three. Our findings support the contribution of multi-method assessment and an aggregate score. We discuss the ways the field can benefit from this or similarly designed assessments and discuss how the assessment results can be used by practitioners to promote programs aimed at stimulating students’ personal growth. Full article

The most popular instrument to measure burnout is the Maslach Burnout Inventory (MBI). Recently, to overcome some of the limitations of the MBI, a new instrument has been proposed, namely the Burnout Assessment Tool. The purpose of this study is to examine the psychometric properties of the Italian version of the BAT. This tool is comprised of a set of four core dimensions (BAT-C; i.e., exhaustion, mental distance, cognitive and emotional impairment) and two secondary symptom dimensions (BAT-S; i.e., psychological and psychosomatic complaints). Data were collected on a sample of 738 participants from heterogeneous sectors and professional roles. In the sample women were slightly overrepresented (52.9%), the participants had a mean age of 41.57 years (SD = 10.51) and a mean organizational tenure of 9.65 years (SD = 8.50). The reliability and factorial structure of the BAT-C and BAT-S, together with the convergent and discriminant validity of BAT-C and MBI were explored, as well as the incremental validity to the BAT-C, over and beyond the MBI. Our results confirmed the factorial validity of a two-factor second-order factor model (BAT-C and BAT-S) represented by 4 first-order factors in the case of BAT-C and 2 first-order factors for BAT-S. Results also attested that BAT-C explains additional variance of the BAT-S, above and beyond what is explained by the MBI-GS. All in all, this study provided evidence that the Italian version of BAT represents a reliable and valid tool for measuring burnout in the work context. Full article

The objectives of this study were to analyze the evolution of peer relationships and academic performance and the effect of the former on the latter in primary education, differentiating between positive and negative relationships. To this end, the likes and dislikes received by each student from his/her classmates were measured at four time points between first and sixth grades, as well as the marks given by their teachers in the subjects of mathematics and Spanish language. One-hundred-sixty-nine students (52.7% girls) from 10 classes of five public schools participated in this study. To verify the objectives, we used a complex structural equation model, obtained from a combination of two autoregressive models (AR, one for social preferences and another one for academic performance), two multi-trait multi-method models (MTMM, one for acceptances and rejections and another one for academic performance in mathematics and Spanish language), and an effects model of social preferences on academic performance. This study confirms: (a) The stability of both peer relationships and academic performance throughout childhood; (b) the stable influence of social relationships on academic performance; and (c) the importance of considering acceptance and rejection differentially. This work reveals the failure of the school to address initial disadvantages, and it provides guidelines for early and inclusive interventions. Full article

Phononic crystals can be used to control elastic waves due to their frequency bands. This paper analyzes the passive and active control as well as the dispersion properties of longitudinal waves in rod-type piezoelectric phononic crystals over large frequency ranges. Based on the Love rod theory for modeling the longitudinal wave motions in the constituent rods and the method of reverberation-ray matrix (MRRM) for deriving the member transfer matrices of the constituent rods, a modified transfer matrix method (MTMM) is proposed for the analysis of dispersion curves by combining with the Floquet–Bloch principle and for the calculation of transmission spectra. Numerical examples are provided to validate the proposed MTMM for analyzing the band structures in both low and high frequency ranges. The passive control of longitudinal-wave band structures is studied by discussing the influences of the electrode’s thickness, the Poisson’s effect and the elastic rod inserts in the unit cell. The influences of electrical boundaries (including electric-open, applied electric capacity, electric-short and applied feedback control conditions) on the band structures are investigated to illustrate the active control scheme. From the calculated comprehensive frequency spectra over a large frequency range, the dispersion properties of the characteristic longitudinal waves in rod-type piezoelectric phononic crystals are summarized. Full article

A new automated approach to the high-accuracy registration of airborne and terrestrial LiDAR data is proposed, which has three primary steps. Firstly, airborne and terrestrial LiDAR data are used to extract building corners, known as airborne corners and terrestrial corners, respectively. Secondly, an initial matching relationship between the terrestrial corners and airborne corners is automatically derived using a matching technique based on maximum matching corner pairs with minimum errors (MTMM). Finally, a set of leading points are generated from matched airborne corners, and a shiftable leading point method is proposed. The key feature of this approach is the implementation of the concept of shiftable leading points in the final step. Since the geometric accuracy of terrestrial LiDAR data is much better than that of airborne LiDAR data, leading points corresponding to anomalous airborne corners could be modified for the improvement of the geometric accuracy of registration. The experiment demonstrates that the proposed approach can advance the geometric accuracy of two-platform LiDAR data registration effectively. Full article