Variable Path Research Articles

Evaluation of Structural Equation Model Forests Performance to Identify Omitted Influential Covariates

Model misspecification is typical in applied structural equation modeling (SEM). Traditional specification search methods, such as modification indices, search for misspecifications within the model’s variables but overlook influential variables not initially included and fail to detect interactions. This study evaluates SEM forests as a complementary method to conduct SEM specification search related to omitted influential covariates. The omitted influential paths include unique, mixed, and interaction paths. SEM forests’ performance is evaluated under different factor loading magnitudes, covariate path magnitudes, and sample sizes. Results show SEM forests accurately identify omitted influential covariates without falsely identifying non-influential covariates in large samples (1,000) with strong covariate-latent variable paths ( β = .5).

Unlocking employee potential through motivation workplace dynamics and incentives a holistic approach to driving productivity

Modern workplaces have evolved so much that it requires a change in how companies think of employee motivation and productivity. The study aimed to finding out the association between employee motivation and incentive systems to formulate a model that will guide on how best overall organizational productivity could be boosted. It also offers insights based on research proven strategies for building the type of workplace that will motivate employees. The research used a quantitative approach with cross-sectional survey design. Three hundred and fifty individuals were surveyed from 10 organizations across a range of industries, organizational levels. Stratified random sampling approach was used to ensure that all age groups as well as different generational and working models were represented in sample across cultures. Structural equation modelling (SEM) by means of AMOS 26 was applied and an analysis of the results revealed some important paths for critical organisational variables. The findings found was motivation, with high relationships to the workplace environment (β = 0.42), communication (β = 0.55) and incentives (p < Workplace environment was empirically shown to have a positive but weak effect on productivity (β =0.13), and the strong relationship with communication (β = 0.80). The proposed model shows a good fit in multiple indices: GFI (0.852), CFI (0.913), TLI (0.900) and RMSEA 90(74)], thereby validating the structure of the framework along with all its measured variables. These results suggest that organizations need to take a comprehensive view when looking at ways to motive and increase productivity of employees by being able understand the complex interrelations among work behaviors. This has operational implications for leaders and human resource professionals who seek a combined impact by aligning work designing, communication systems, incentive design structures and cultural integration strategies.

Selection Strategy for Yield Improvement of Chickpea Genotypes (Cicer arietinum L.)

An investigation was undertaken to assess the genetic variability parameters, correlation and path analysis in 25 chickpea genotypes for 12 quantitative traits during the Rabi season of 2022-23 in a Randomized Block Design with three replications. Analysis of variance indicated high significant differences among the genotypes for all the traits. Considerable variability existed in the genotypes for all the characters studied. The study found that CG23, CG159, and CG199 were the most superior genotypes for grain yield per plant among 25 chickpea genotypes. High PCV, GCV, heritability and genetic advance as percent of mean were recorded for test weight and biological yield. Grain yield per plant showed positive significant association with number of pods, days to maturity, days to 50% pod initiation and number of primary branches. High and positive direct effect of grain yield per plant at both phenotypic and genotypic levels were depicted by harvest index. These characters may be taken into consideration for selection of quantitative characters for crop improvement.

A review of research on the development of low-orbit Internet constellations

In recent years, with the surge in Internet users, innovative companies such as SpaceX and OneWeb have planned to build low-orbit Internet constellations, triggering a global boom in the development of low-orbit satellite Internet constellations. Therefore, it is of great significance to study the development of low-orbit Internet constellations at home and abroad and the technical difficulties currently faced by low-orbit Internet constellations in their development. This paper first introduces three representative low-orbit Internet constellation plans abroad (Starlink, OneWeb, Lightspeed) and the latest development of domestic constellations. Then, based on the characteristics of low-orbit Internet constellations, the five major technical challenges faced by low-orbit Internet constellations are analyzed in detail: constellation relative motion evolution prediction, constellation autonomous navigation and orbit determination, constellation variable path planning, constellation self-organization collaborative control, constellation communication and network services. Finally, based on the current development trend of low-orbit Internet constellations, suggestions are given for the development of low-orbit Internet constellations in my country based on my country's national conditions.

Stability Analysis and Optimal Control for Spreading Typhoid Fever Model with Direct and Indirect Transmissions

This article discusses a model of spreading typhoid fever with direct and indirect transmissions. There are five compartments included in the model, namely susceptible individuals, infected individuals, chronic carrier individuals, recovered individuals, and salmonella typhi bacteria in the environment. As an effort to control and minimize the numbers of infected individuals and chronic carrier individuals, we introduce simultaneously campaign for the susceptible individuals and treatment for the infected individuals and for chronic carrier individuals. The resulting model is a system of non-linear differential equations and quite challenging to analysis globally. Existence of both disease-free equilibrium point and endemic equilibrium point are analysed analytically. Stability of the equilibrium point is analysed locally by determining the eigenvalues of the associated Jacobian matrix, Routh-Hurwitz stability criteria, and basic reproduction number () via next generation matrix. The minimum Pontryagin principle and Hamiltonian equation are referred to minimize the numbers of infected and chronic carrier individuals. Simulation is carried out using suitable values of parameters. We found that the eigenvalues for endemic equilibrium point are all negative real numbers and . Optimal paths for state and constate variables are plotted using fourth order forward-backward Runge-Kutta method. In case there are no campaign and treatments, we found and endemic occurs. When campaign and treatments are included together in the model, we found optimal paths for all compartments that minimize the number of infected and chronic carrier individuals. Giving campaign and treatments increase significantly the susceptible and recovered individuals. At the same time, it reduces significantly the infected, chronic carrier individuals, and salmonella typhi bacteria in the environment. Involving campaign and treatment in the model of spreading typhoid fever can be considered as an effective strategy to minimize the numbers of infected and chronic carrier individuals.

The Shield of Self-Esteem: Buffering against the Impact of Traumatic Experiences, Fear, Anxiety, and Depression.

Adverse life occurrences (e.g., severe accidents, violence/abuse, organic disorders such as COVID-19) can elicit traumatic responses that heighten fear, anxiety, and depression. However, scientific research has shown that certain variables, such as self-esteem, based on theories like terror management theory (TMT) and the anxiety-buffering hypothesis (ABH), can mitigate the negative effects of trauma. This study aimed to test the ABH by assessing the buffering role of self-esteem in the relationships among the impact of traumatic experiences, fear, anxiety, and depression. An observational research design was used. This study involved 321 participants who experienced COVID-19 as a traumatic experience. A sequential multiple-mediation model with observed variables (path analysis) was used to test the impact of the traumatic experience on fear, anxiety, and depression, examining the protective role of self-esteem. A path analysis revealed that fear and anxiety mediated the relationship between the impact of the traumatic experience of COVID-19 and depression. Additionally, in line with the ABH, self-esteem was found to mediate the relationship between the predictors and their adverse psychological consequences. This suggests that self-esteem played a buffering role, mitigating the negative impact of traumatic experiences on mental health outcomes. These findings underscore the central mediating role of self-esteem, as well as fear and anxiety, in the pathway from trauma-related factors to depression. These insights advocate for evidence-based interventions aimed at alleviating the psychological suffering associated with traumatic experiences, fostering adaptation, and supporting psychological health.

A variable diameter spiral path planning strategy for large eccentricity variable curvature rotating parts with focus on thickness and performance control in cladding

When laser cladding rotating parts that have large eccentricity and variable curvature, first-order discontinuities in the cladding path and fluctuations in the real-time scanning speed are common problems. These issues cause significant inhomogeneities in the cladding thickness and localized excessive material accumulation. This not only leads to unstable mechanical properties of the cladding layer but also results in a significant waste of cladding materials during subsequent precision machining. In response, this paper introduces a cladding method that employs a variable diameter constant linear velocity spiral path and establishes models for dynamic vector and angle conversion, constant linear velocity optimization, and cladding path data conversion. This approach enables consistent control over the real-time scanning speed and defocus distance during laser cladding of parts with large eccentricity and variable curvature. A comparison of the experimental results from spiral path cladding, variable linear velocity and variable diameter spiral cladding, and constant linear velocity variable diameter spiral cladding revealed that the latter method achieves a more uniform cladding layer thickness, with a maximum deviation of only 0.036 mm. The microstructure primarily consists of cellular structures, demonstrating improved consistency. Samples were taken from three different cladding methods, and hardness tests were performed on the cross-sections of the cladding layers.

Experimental investigation and computational modelling of 304LN stainless steel under constant and variable strain path multiaxial loading conditions

This study investigates the fatigue behavior of 304LN stainless steel under constant and variable strain path multiaxial loading conditions. Experimental methods and computational modelling were used to analyze the response of the material to different loading scenarios. Experimental investigations were conducted to gather empirical data, which were subsequently validated using a modified Ohno-Wang and Tanaka cyclic plasticity framework. Two models were used for the analysis: the MOT model and a modified model that incorporated a weighted function and fractional functions for hardening and softening. In contrast, the modified model offers significant improvements, accurately capturing primary hardening and secondary softening across all loading scenarios. Furthermore, the modified model effectively simulates transient behavior, including load alteration and recovery effects, due to the integration of load history memory regulating functions. Overall, this study emphasizes the importance of considering the complexities of cyclic loading and the sensitivity of the material behavior to the loading history.

Does shrinkage have an impact on urban livability? An empirical analysis from Northeast China

Urban shrinkage has emerged as a global socioeconomic development issue, presenting new challenges for countries in advancing the construction of livable cities. To investigate whether urban shrinkage has an impact on urban livability (UL), along with its underlying mechanisms and transmission paths, this study employed comparative inductive analysis and took Northeast China as a case for theoretical discussion and empirical validation. The results indicated that: (1) Shrinkage did have an impact on UL, which was dominated by negative effects and supplemented by positive effects. Furthermore, it exhibited characteristics of phased and dimensional heterogeneity, with significant spatial differentiation. (2) The impact of shrinkage on UL was essentially a comprehensive result of the interplay between the positive and negative effects arising from changes in urban development capacity and per capita occupancy caused by shrinkage. This process involved both variable transmission paths and stock transmission paths, jointly explaining the positive and negative shrinkage effects. This study provides a new perspective on rational cognition for coping with shrinkage effects and their generative logic, as well as theoretical insights for other countries around the world to optimize UL in shrinkage scenarios.

Mechanisms of the influence of proactive personality on nurses' sense of social responsibility: A structural equation modelling study.

To explore the mechanism of proactive personality influence on nurses' sense of social responsibility through a serial multiple mediation model of volunteering motivation and self-efficacy. Further analysis of a cross-sectional and survey-based study. In June 2023, a study was conducted with 722 Chinese nurses from four hospitals. Data were collected using the Proactive Personality Scale, the Self-Efficacy Scale, the Motivation to Volunteer Scale and the Nurses' Sense of Social Responsibility Scale. Structural equation modelling was used to analyse the relationship between nurses' sense of social responsibility and its correlative factors. Structural equation modelling showed a good model fit. Proactive personality, self-efficacy and motivation to volunteer can directly influence nurses' sense of social responsibility (β = .12, β = .04, β = .50, p < .05). According to the test of chained mediation effects, proactive personality was significant through a single mediation path of self-efficacy (Z = 2.33, p < .05) and motivation to volunteer (Z = 7.32, p < .05) and through successive mediation paths of both variables (Z = 3.33, p < .05). A proactive personality can motivate nurses' social responsibility. Therefore, prompting nurses to be more proactive can effectively enhance nurses' sense of social responsibility. This study was reported following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for cross-sectional studies. This study explored the mechanisms influencing nurses' sense of social responsibility at the end of the epidemic. The results may inform the maintenance of high levels of long-term effects of nurses' social responsibility and shed light on building a standing workforce for public health emergencies.

Regional differences in the impact paths of climate on aboveground biomass in alpine grasslands across the Qinghai-Tibet Plateau

Alpine grasslands on the Qinghai-Tibet Plateau (QTP) play an essential role in water conservation, biodiversity protection and climate feedback, with aboveground biomass (AGB) serving as a crucial indicator of grassland health and functionality. While previous studies have independently explored the phenological differences, cumulative effects, and spatial variability of climatic impacts on biomass/productivity in alpine grasslands, the cascading effects regarding climate and phenology on AGB still present knowledge gaps. Here, using peak AGB measurements, remote sensing and gridded climate data in the QTP alpine grasslands during 2002–2018, we systematically analyzed the impact paths of climatic variables (i.e., cumulative precipitation, CP; growing degree-days, GDD) and phenology-mediated paths (start and peak date of the growing season, SOS and POS) on AGB and their regional differences. During the preseason (pre60) or the growing season (sos-pos), climate primarily directly impacted variations in AGB across different climatic regions, although a phenology-mediated path by which climate indirectly affected AGB existed (i.e., GDDsos-pos → POS → AGB). Three general patterns were revealed: In the plateau temperate arid regions, an increase in CPpre60 significantly promoted AGB (path coefficients w = 0.61–0.71), whereas an increase in GDDpre60 inhibited AGB (w = −0.42 ~ −0.49); In the plateau sub-cold regions, increases in both CPsos-pos and GDDsos-pos significantly promoted AGB, respectively (w = 0.46–0.81 and w = 0.37–0.70); Similarly, in the plateau temperate arid or semi-arid regions, increases in CPsos-pos also significantly promoted the AGB (w = 0.56–0.73). This study highlights that the water and heat accumulation mainly exert direct impacts on alpine grassland AGB across various climatic regions and phenological stages, providing insights into the mechanism driving AGB by climate and phenology during spring and summer.

ASSESS THE ROLE OF MARKETING INTELLIGENCE AND NETWORK CAPABILITIES IN PRODUCT INNOVATION

This study aims to analyze and discuss the effect of network capability and marketing intelligence on product innovation through marketing misx. The population in this study were SMEs in West Bandung district. Researchers used 211 samples. The data collection technique used a questionnaire. Data were analyzed using path analysis. In the test results, the variable path analysis measure is the variable network capability and marketing intelligence that has an effect on product innovation through the marketing mix. This research emphasizes to SMEs the importance of network influence and market-related understanding in providing innovative products. The limitation in this study is that the sample obtained in Bandung Regency is 211. Further research can be carried out in different cities with more samples from this study.

노인여가복지시설 종사자의 슈퍼비전과 조직몰입의 관계

This study analyzed the relationship between supervision, professionalism awareness, and self-leadership, which are various variablesrelated to organizational commitment that can raise the level of leisure welfare facilities for older adults. Questionnaires were distributedto 375 workers in 19 facilities in Daejeon and Chungcheongnam-do through SPSS and Amos 18.0 program. Confirmatory factor and structuralequation model analysis were used as important analysis methods. The analysis results are as follows: Firstly, the supervision of workershas a significant effect on organizational commitment. Secondly, the paths of major variables were all significant. Thirdly, the dual mediatingeffect of professionalism awareness and self-leadership was confirmed. The measures to improve workers’ organizational commitment andto provide high quality leisure services are as follows. Firstly, for enhancing the supervision for the workers, it is necessary to educatethe supervisor to balance the detailed supervision, to develop the operating system and manual of the specific supervision, and to includethe supervision in the facility evaluation. Secondly, in order to improve workers’ professionalism perception, it is necessary to provideprofessional deepening education, to examine the type of social worker qualification examination, and to create an environment to improvethe professionalism voluntarily. Thirdly, for developing their self-leadership, it is desirable to include various supports of managers,self-leadership in job training and appropriate compensation for work performance caused by self-leadership.

Anisotropic mechanism of cold-rolled pure titanium plate during the two-step tensile process of the variable path

The effects of pre-deformation on the macro-mesoscopic deformation characteristics of the titanium plate during variable path tensile were studied by a two-step tensile test and electron backscatter diffraction (EBSD). The Schmid law, Kernel Average Misorientation (KAM), Taylor axis, and In-Grain Misorientation Axis (IGMA) were used to forecast and identify the types and change laws of the activated deformation modes under different loading conditions. The results demonstrated that dislocation slip is the primary cause of the evolution of the basal split texture components. The nucleation and de-twinning of {10–12}ET resulted in the sudden appearance and disappearance of the <0001>//RD texture. The pre-tensile causes a texture redirection that reduces the activability of both prismatic <a> slip and pyramidal <a> slip in the following variable path tensile. Among them, prismatic <a> slip is the dominant deformation mechanism that causes yield and hardening behavior during RD tensile and TD-RD tensile (rolling direction-RD, transeverse direction-TD). A portion of the prismatic <a> slip is preferentially activated in TD tensile and RD-TD tensile deformation, and the deformation is subsequently jointly controlled by the prismatic <a> slip and the pyramidal <a> slip. The pre-tensile along RD promotes nucleation of {10–12} extension twin (ET) during subsequent RD-TD variable path tensile, while tensile along TD-RD coordinates plastic deformation by consuming a significant quantity of {10–12}ET generated during pre-tensile along TD. The formation of slip-assisted twins in neighboring grains is facilitated by the dislocation pile-up at grain boundaries, and the de-twinning phenomenon also cause the local dislocation pile-up to weaken.

Determining the optimal dome shape using a novel variable slippage coefficient non‐geodesic

AbstractThe research of high‐performance composite pressure vessels in practical application has become the focus of attention, and fiber paths play an important role in the structural performance of composite pressure vessels. Therefore, a method is proposed for determining the optimal geometric parameters of the pressure vessel head shape under a novel variable slippage coefficient non‐geodesic(NVSCNG). First, NVSCNG is used as the dome fiber path design mode, and the classical lamination theory is used to construct a dome stress field model. In addition, on the basis of the Tsai‐Wu failure criterion, the minimum laminate thickness is determined to satisfy the strength constraints. Second, the performance factor (pressure*volume/weight) is used to calculate the structural performance of the dome with variable geometric parameters under the novel variable slippage coefficient fiber path. Moreover, the stability constraints are considered to determine the optimal geometric parameter values of the dome. Finally, the structural properties, stress response and thickness were analyzed under two types of fiber paths based on the optimal dome profile. Results show that compared to the conventional variable slippage coefficient, the performance factor can be maximally improved by nearly 60.94% using the novel variable slippage coefficient, and the thickness of the composite layer at the equator of the dome can be maximally reduced by nearly 34.88%. In addition, the research shows that NVSCNG can improve the structural performance of the dome and realize the lightweight of dome components, which are greatly important in guiding the design of fiber paths for pressure vessels.Highlights No unconstrained linear problem between NVSCNG and initial winding angle. Optimal dome profile geometry parameters are m = 0.8, rc = 0.5. The dome structural failure is controlled by the longitudinal stresses. Winding angle distribution has a strong influence on dome stress distribution. Higher dimensionless performance factor and lighter mass for NVSCNG.

Source Scaling, Spatially Variable Path Attenuation, and Site-Effect Parameters via a Generalized Inversion Technique for Strong-Motion Data from Sichuan, China

ABSTRACT Quantifying the source, propagation path, and site characteristics accurately is pivotal for evaluating regional earthquake hazards. The nonparametric generalized inversion technique of strong-motion records offers an effective approach for analyzing these three fundamental elements. However, this technique might overlook the spatial variation of regional attenuation and the inherent uncertainty of reference stations. To enhance the understanding of strong ground motion characteristics in the Sichuan area, this study employs an improved nonparametric inversion scheme to analyze 3338 sets of strong-motion data from 397 earthquakes (Ms 3–6.5) that occurred in the Sichuan region between 2007 and 2020. In terms of regional source characteristics, the setting of low-frequency cutoffs in strong-motion records may lead to the overestimation of corner frequency and stress drop for earthquakes with higher magnitudes. Conversely, for events with moment magnitudes less than 5, the regional stress drop levels tend to stabilize as the magnitude increases. Furthermore, stress drop is independent of depth and fault type. Regarding path attenuation, considering the influence of Moho reflection, the geometric attenuation is limited to R−1 within a hypocentral distance of 75 km. The nonparametric results from 75 to 300 km show that as the hypocentral distance increases, the geometric attenuation in this region first decreases and then stabilizes. Furthermore, the mean level of the inelastic attenuation factor Qs is 199.5f0.98. Pertaining to site effects, we observe that at the edge of the Sichuan basin, the amplification of sites in the long-period part is clearly characterized and tends to stabilize with increasing frequency. In addition, the site amplification factor of 33 logarithmically spaced frequency points between 0.5 and 20 Hz has a linear relationship with the soil layer parameter VS30 or VS20. The correlation coefficients of both show moderate correlation, among which VS30 is slightly better than VS20.

Path-Following Control of Unmanned Vehicles Based on Optimal Preview Time Model Predictive Control

In order to reduce the lateral error of path-following control of unmanned vehicles under variable curvature paths, we propose a path-following control strategy for unmanned vehicles based on optimal preview time model predictive control (OP-MPC). The strategy includes the longitudinal speed limit, the optimal preview time surface, and the model predictive control (MPC)controller. The longitudinal speed limit controls speed to prevent vehicle rollover and sideslip. The optimal preview time surface adjusts the preview time according to the vehicle speed and path curvature. The preview point determined by the preview time is used as the reference waypoint of OP-MPC controller. Finally, the effectiveness of the strategy was verified through simulation and with the real unmanned vehicle. The maximum lateral deviation obtained by the OP-MPC controller was reduced from 0.522 m to 0.145 m under the simulation compared with an MPC controller. The maximum lateral deviation obtained by the OP-MPC controller was reduced from 0.5185 m to 0.2298 m under the real unmanned vehicle compared with the MPC controller.

Self-rated professional competence and well-being at work after obtaining a Swedish nursing license: A longitudinal mixed-methods study of internationally and domestically educated nurses

BackgroundAn inclusive workplace is where everyone is supported to thrive and succeed regardless of their background. Supportive working conditions and general self-efficacy have been found to be important for nurses' perceived competence and well-being at work, however, in the context of being a nurse in a new country, research is limited. Moreover, knowledge is lacking about whether different paths to a nursing license are related to nurses' perceived competence and well-being when working. ObjectiveTo examine determinants and experiences of nursing competence and well-being at work (thriving and stress) among internationally and domestically educated nurses. DesignA longitudinal descriptive and correlational design with a mixed-methods convergent approach was used. MethodsA longitudinal study was conducted between January 2019 and June 2022 with two groups of internationally educated nurses who had completed a bridging program or validation to obtain a Swedish nursing license and one group of domestically newly educated nurses. Data were collected on three occasions: Time1 at the end of the nursing licensure process (n = 402), Time2 after three months (n = 188), and Time3 after 12 months (n = 195). At Time3, 14 internationally educated nurses were also interviewed. Data were analyzed separately and then interpreted together. ResultsMultiple regression models showed that greater access to structural empowerment (B = 0.70, 95 % CI [0.31; 1.08]), better cooperation (B = 3.76, 95 % CI [1.44; 6.08]), and less criticism (B = 3.63, 95 % CI [1.29; 5.96]) were associated with higher self-rated competence at Time3, whereas the variable path to a nursing license was non-significant (R2 = 49.2 %). For well-being, greater access to structural empowerment (B = 0.07, 95 % CI [0.02; 0.12]), better cooperation (B = 0.36, 95 % CI [0.07; 0.66]) and being domestically educated (B = 0.53, 95 % CI [0.14; 0.92]) were associated with higher thriving at work (R2 = 25.8 %). For stress, greater access to structural empowerment (B = −0.06, 95 % CI [−0.09; −0.02]), better cooperation (B = −0.30, 95 % CI [−0.51; −0.10]), and less criticism (B = −0.28, 95 % CI [−0.46; −0.05]) were associated with having symptoms less frequently while being domestically educated was associated with having stress symptoms more often (B = 0.44, 95 % CI [0.07; 0.81]) (R2 = 43.3 %). Higher general self-efficacy at Time1 was associated with higher self-rated competence at Time2 (B = 4.76, 95 % CI [1.94; 7.59]). Quantitative findings concurred with findings from interviews with internationally educated nurses. However, qualitative findings also highlighted the importance of previous education, working experience, the new context, and communication abilities. ConclusionsBoth quantitative and qualitative data showed that working conditions were important for nurses' self-rated competence and well-being at work. Although communication difficulties, previous education, and working experience were not statistically significant in the multiple regression models, in the interviews these factors emerged as important for internationally educated nurses' competence and well-being.

The role of BRICS countries in the optimal low-carbon transition path for sustainable development

With the development of industrialization, greenhouse gas emissions caused by human activities, especially carbon dioxide emissions, continue to increase. The BRICS countries (Brazil, Russia, India, China, and South Africa) account for a significant share of global carbon emissions. This study focuses on the BRICS countries as the subject of inquiry, employing carbon emission-related data spanning the temporal range from 2000 to 2020. This study systematically assesses the interrelationships among variables using the Pearson correlation analysis and Granger causality test. Variables exhibiting pronounced correlation and causality, as discerned from the analytical outcomes, are subsequently identified and selected for further examination. Use the GCAM (Global Change Assessment Model) to simulate the Rcp-ref scenario (baseline scenario) and the Rcp2.6 scenario (assuming that the temperature will not rise by 2 °C), and compare the optimal paths of key variables in the two scenarios, and draw the following conclusions. (1) By the end of this century, the total carbon emissions of the BRICS countries under Rcp2.6 scenario will be 6139MTC less than those under Rcp-ref scenario. (2) Compared with the Rcp-ref scenario, in the Rcp2.6 scenario, the proportion of fossil fuels such as oil, natural gas, and coal in the main energy consumption significantly reduces, while the proportion of renewable energy sources such as wind, solar, and biomass increases. It is worth noting that the proportion of nuclear is significantly rising. (3) The demand for electricity increases significantly in the Rcp2.6 scenario. This study reveals the specific directions for improving the energy structure of BRICS countries to achieve the global average temperature rise of no more than 2 °C. It provides suggestions for the future policies of these countries' governments. In addition, BRICS countries should focus on observing changes in some factors, such as the increase in nuclear energy consumption and the increase in electricity demand. The reasons behind the changes in these factors are the direction of future research.

Investigating wave solutions and impact of nonlinearity: Comprehensive study of the KP-BBM model with bifurcation analysis.

In this paper, we investigate the (2+1)-dimensional Kadomtsev-Petviashvili-Benjamin-Bona Mahony equation using two effective methods: the unified scheme and the advanced auxiliary equation scheme, aiming to derive precise wave solutions. These solutions are expressed as combinations of trigonometric, rational, hyperbolic, and exponential functions. Visual representations, including three-dimensional (3D) and two-dimensional (2D) combined charts, are provided for some of these solutions. The influence of the nonlinear parameter p on the wave type is thoroughly examined through diverse figures, illustrating the profound impact of nonlinearity. Additionally, we briefly investigate the Hamiltonian function and the stability of the model using a planar dynamical system approach. This involves examining trajectories, isoclines, and nullclines to illustrate stable solution paths for the wave variables. Numerical results demonstrate that these methods are reliable, straightforward, and potent tools for analyzing various nonlinear evolution equations found in physics, applied mathematics, and engineering.