Model Test Results Research Articles

Uncertainty analysis method of high-speed wind tunnel standard model test results based on GUM and MCM

Abstract The standard model is a standard calibration model that has a well-known geometric shape and can represent the aerodynamic layout characteristics of a certain type of aircraft. It has many functions, including evaluating the accuracy of wind tunnel test data, verifying the integrity of the wind tunnel flow field and measurement system, and developing and verifying wind tunnel test technology. Conducting wind tunnel tests using standard models is a key step in realizing the functions of standard models. However, all existing literature on standard model tests has not effectively evaluated the uncertainty of the test results, which makes it impossible to evaluate the reliability of the test results. Based on the GUM and MCM uncertainty analysis methods, this paper establishes a method for quantitatively evaluating the uncertainty of the test results of high-speed wind tunnel standard model tests through rigorous mathematical derivation, providing technical support for precisely quantifying the uncertainty of standard model test results.

Study on Ground Motion Amplification in Upper Arch Bridge Due to “W”-Type Deep Canyon Using Boundary-Integral and Peak Frequency Shift Methods

The study of the dynamic response characteristics of “W”-type deep canyon terrain to double-span concrete arch bridges under earthquake action holds great practical significance. In this research, a bridge in Sichuan Province is taken as the object of study. The boundary-integral equation method and peak frequency shift method are combined to apply an embedded linear time–history analysis algorithm to the finite element spatial dynamic calculation model of the entire bridge, resulting in an improved model. By comparing these two methods with model test results, the seismic response characteristics of the middle part of a “W” concrete arch bridge under different foundation depths and seismic intensities are examined. The boundary integral equation method was utilized to calculate ground motion response at any point on site, revealing a significant amplifying effect of increased seismic wave intensity on acceleration response at the top of the arch bridge. When input seismic wave intensity increased from 0.1 g to 0.3 g, maximum acceleration at buried depths of 3 m and 8 m in the middle of the arch bridge foundation increased by 102.63% and 79.16%, respectively, indicating that shallow buried depth structures are more sensitive to seismic wave intensity. Furthermore, using peak frequency shift rules for analyzing seismic wave propagation characteristics in “W”-type deep canyon topography confirms the sensitivity of shallow buried depth structures to seismic wave intensity and reveals the mechanism through which topography influences seismic wave propagation. This study provides a helpful method for understanding the propagation law and energy distribution characteristics of seismic waves in complex terrain. It was observed that the displacement at the top of the arch bridge increased significantly with an increase in seismic intensity. When subjected to 0.1 g, 0.2 g, and 0.3 g EI-Centro seismic waves, the maximum displacement at the top of the arch bridge model with a foundation buried depth of 3 m was 8 mm, 32 mm, and 142 mm, respectively. For arch bridge models with an 8-m foundation buried depth, these displacements were measured at 6.2 mm, 21 mm, and 68 mm, respectively. The results from model tests verified that increasing the depth of foundation burial effectively reduces the displacement at the top of the structure. Furthermore, by combining a boundary-integral equation method and peak-frequency shift method, this study accurately predicted significant influences on W-shaped double deep canyon topography from seismic response, and successfully captured stress concentration and seismic wave amplification/focusing effects on arch foot structures. The calculated results from both methods align well with model test data which confirm their effectiveness and complementarity when analyzing seismic responses under complex terrain conditions for bridge structures.

Experimental Flow Performance Investigation of Francis Turbines from Model to Prototype

Investigating the flow performance of Francis turbines from model to prototype is a complex but essential process for ensuring reliable and efficient turbine operation in hydropower plants. It ensures that Francis turbine designs operate efficiently under various operating conditions, extending from laboratory reduced-scale models to full-scale prototype installations. In this investigation, a Francis turbine model was tested under different operating conditions, and its properties were measured, including torque, hydraulic efficiency, power output, cavitation coefficient, rotational speed, flow rate, and pressure pulsations. The results of the Francis turbine model test indicate that it achieved the maximum torque with the designed discharge and designed head. The cavitation coefficient consistently remained higher than the critical cavitation coefficient. The initial cavitation bubbles were observed at 50% partial load but disappeared at full load. Pressure pulsations under different operating conditions showed the maximum peak-to-peak amplitude appearing at the turbine inlet domain and the minimum amplitude occurring at the draft tube elbow. A hill chart shows that the model’s best efficiency was 93.66%, and the estimated best efficiency of the prototype was 95.03% at the design head. The conclusions and methodology of this study can be generalized to other similar hydraulic turbines, especially prototype Francis turbines that lack experimental results.

Numerical Investigation of the Effects of Aspect Ratio on the Hydrodynamic Performance of a Semi-Planing Catamaran

Abstract A semi-planing catamaran is a type of marine craft that benefits from high speed, in conjunction with the its inherent characteristics such as a large deck and high transverse stability. The aspect ratio, length over the beam of a demi-hull, significantly affects the hydrodynamic performance of this vessel. In this study, the effects of the aspect ratio on the hydrodynamic performance of a semi-planing catamaran in calm water and waves are investigated using numerical simulations. The numerical simulation of the AUT-SEM00 model itself is validated by its model test results. The results show that increasing the aspect ratio significantly increases the wetted surface, and that the increase in resistance in calm water is negligible. In addition, increasing the aspect ratio radically reduces the amplitude of vertical acceleration in waves at the center of gravity by up to 85%. Consequently, the seakeeping performance is considerably improved, and the risk to crew and equipment is reduced.

Improving the Managerial Ability of Dental and Oral Therapists in Adolescent Health Services through the Posyandu Management Information System (SIMYANDU)

Dental and oral therapists provide health services to adolescents in the Soppeng Regency area in the implementation of planning management, especially in posyandu, which is still manual and has not been implemented properly. The Posyandu Management Information System (SIMYANDU) is an information system that can overcome problems and improve the managerial skills of dental and oral therapists. This study uses the Research and Development (R&D) method, model testing using the pre-experimental design method. The data from the model test results were tested using Aiken's V and Intraclass Correlation Coefficient (ICC). The results of the expert validation test on SIMYANDU obtained an average feasibility score of 100% which means it is feasible as a posyandu management information system based on expert validation (v=0.68), ICC value (p=0.940). Assessment of the managerial ability of dental and oral therapists after treatment is meaningful. The results of the effect size test on the aspects of problem identification (p=0.001), problem priority (p=0.001), cause of problem (p=0.003), alternative solution to the problem (p=0.001), planning (p=0.001) means that the web-based SIMYANDU model to improve the managerial ability of dental and oral therapists is very effective in adolescent health services in the Soppeng Regency area. This study shows that the application of the web-based SIMYANDU model is feasible and its application is effective in improving the managerial ability of dental and oral therapists in health services for adolescents in the Soppeng Regency area.

Social License to Operate for NIMBY Infrastructures: The Mechanism of the Four Components of Procedural Justice

The key to obtaining the Social License to Operate (SLO) for businesses in the not-in-my-backyard (NIMBY) infrastructure projects is the justice of the process. The study constructs a model to analyze the effect of the four components of procedural justice (procedural regulations and the behavior and attitudes of the government and construction enterprises) on the SLO. A large-scale questionnaire survey is conducted to assess the role and the extent of the influence of these four components in obtaining the SLO for NIMBY infrastructures. The results of Structural Equation Modeling (SEM) and mediation effects tests show that procedural justice significantly influences the SLO for NIMBY infrastructure projects. All four components significantly improve community trust and social acceptance of the project. The construction enterprise’s informal treatment of the public’s behavior and attitudes has the largest influence, whereas the government’s formal treatment of the public’s behavior and attitudes has the least influence. The findings provide theoretical and practical guidance for improving the SLO for NIMBY infrastructure projects and promoting the sustainable development of these projects.

Social Cluster and Heritage Memory: A Study on the Space Perception of Zhaozhou Basin Horse Caravan Vernacular Architecture

Located in Dali, Yunnan, the Zhaozhou basin is home to many precious architectural heritages, particularly the historical horse caravan architecture. These buildings face the challenge of renewal and transformation. It is of great significance to explore the local population’s awareness of the architectural heritage of the horse caravan in order to protect the architectural heritage and facilitate rural revitalization. This study reviews the related research on “space perception”, establishes a theoretical framework of space perception under the architectural dimension, and develops hypotheses. The social cluster of typical settlements in the Zhaozhou basin is selected as the research object, and empirical analyses are carried out using SPSS and AMOS software. An analytical framework model of empirical research is constructed to evaluate the space perception of the current social population. The results of the reliability and validity tests of the questionnaire show that the CR is greater than 0.7 and that the AVE is greater than 0.5. The value of the structural equation model fitting index χ2/df is 1.863, which is less than 3. The model test results show that research hypotheses H1–H5 are supported; that is, space perception has a significant positive impact on cognition and local identity, cognition has a significant positive impact on local identity and space function, and place identity has a significant positive impact on space appeal. This study demonstrates the relationship between space perception and the architectural remains of the horse caravan, and it analyzes the human psychological perception behind the material space. The findings support the need for further conservation of the horse caravan architecture. This study further deepens the theory of space perception and its application in the study of vernacular architecture, which can provide a research path for the protection and development of vernacular architectural heritage.

Experimental research on PPF anti-cracking effect in scale model of hollow rigid frame bridge

The hollow rigid frame bridge has many advantages, such as being lightweight, having strong spanning ability, and having slight deflection in span. This type of bridge has a broad potential for application in regions of many canyons and hills. While there has been less research into the application of this type of bridge, some of the bridges in early service have cracking problems. To satisfy the demand for cracking resistance of the Yunnanzhuang large-span hollow rigid frame bridge, our group proposed using Polypropylene Fibers (PPF) to enhance the strength of concrete against cracking. After analyzing the structure of the whole bridge, we gave the critical sections of the bridge and carried out a series of tests to give the PPF dosage that applies to the project. This paper focuses on the use of reduced-size bridge model tests to investigate the effect of PPF on the cracking resistance of hollow rigid frame bridges under bending.In this paper, the similarity criterion between the actual bridge and the model was calculated by the method of magnitude analysis, according to which scale-down model beams of the upper chord S4 segment and mid-span jointing segment of Yunnanzhuang Bridge were designed under the geometry of 1:5. We respectively made these models using the same C55 concrete as the actual bridge and Polypropylene Fibre Reinforced Concrete (PPFRC) with 0.3 % volumetric admixture of PPF in the same mix ratio, and three-point bending static load tests were performed on these models. To make up for the insufficiency of test groups, we performed a finite element analysis using ABAQUS and the CDP constitution, which led us to some reliable conclusions.Considering that concrete materials have size effect, directly using the results of model tests to predict the cracking stresses of the actual bridge is not accurate. In this paper, some theories on size effects were examined. Finally, the Size Effect Model (SEM), Boundary Effects Model (BEM), and Weibull's brittle strength theory were selected to correct the test results.The results show that PPF can increase the cracking load of the test beams, ranging from 11.22 % to 13.49 %. After using selected size effect theories to predict the cracking stresses in actual bridges, the results show that PPF can enhance the cracking strength of C55 concrete, with an increase ranging from 9.15 % to 18.75 %. Combined with the results of the structural analysis of the whole bridge, the critical section has a cracking stress between 2.6 MPa and 3.5 MPa when using C55 concrete, which has a certain risk of cracking. However, when using PPFRC, the cracking stress ranges from 3.1 MPa to 4.2 MPa, with no risk of cracking in most unfavorable cases, which can satisfy the demand for concrete cracking resistance of Yunnanzhuang Bridge.

Study on the Shear Strength and Erosion Resistance of Sand Solidified by Enzyme-Induced Calcium Carbonate Precipitation (EICP).

Sand solidification of earth-rock dams is the key to flood discharge capacity and collapse prevention of earth-rock dams. It is urgent to find an economical, environmentally friendly, and durable sand solidification technology. However, the traditional grouting reinforcement method has some problems, such as high costs, complex operations, and environmental pollution. Enzyme-induced calcium carbonate precipitation (EICP) is an anti-seepage reinforcement technology emerging in recent years with the characteristics of economy, environmental protection, and durability. The erosion resistance and shear strength of earth-rock dams solidified by EICP need further verification. In this paper, EICP-solidified standard sand is taken as the research object, and EICP-cemented standard sand is carried out by a consolidated undrained triaxial test. A two-stage pouring method is adopted to pour samples, and the effects of dry density, cementation times, standing time, and confining pressure on the shear strength of cemented standard sand are emphatically analyzed. The relationship between cohesion, internal friction angle, and CaCO3 formation was analyzed. After the optimal curing conditions are obtained through the triaxial shear strength test, the erosion resistance model test is carried out. The effects of erosion angle, erosion flow rate, and erosion time on the erosion resistance of EICP-solidified sand were analyzed through an erosion model test. The results of triaxial tests show that the standard sand solidified by EICP exhibits strain softening, and the peak strength increases with the increase in initial dry density, cementation times, standing time, and confining pressure. When the content of CaCO3 increases from 2.84 g to 12.61 g, the cohesive force and internal friction angle change to 23.13 times and 1.18 times, and the determination coefficients reach 0.93 and 0.94, respectively. Erosion model test results indicate that the EICP-solidified sand dam has good erosion resistance. As the increase in erosion angle, erosion flow rate, and erosion time, the breach of solidified samples gradually becomes larger. Due to the deep solidification of sand by EICP, the development of breaches is relatively slow. Under different erosion conditions, the solidified samples did not collapse and the dam broke. The research results have important reference value and scientific significance for the practice of sand consolidation engineering in earth-rock dams.

Analytical modeling and experiments on soft soil consolidation with vacuum preloading‐airbag pressurization

AbstractThis study aims to provide substantial theoretical support for employing vacuum preloading‐airbag pressurization (VP‐AP) to enhance soft soil foundations. By integrating the airbags and prefabricated vertical drains (PVDs) within the analytical framework, the consolidation models are developed to accommodate double smear zones and well resistance. Analytical solutions for various airbag pressurization scenarios are derived under the equal‐strain assumption. A model test is subsequently conducted to investigate the settlement process of soft soil using the VP‐AP method. The validity of the proposed theoretical model is corroborated through comparison with existing analytical solutions and experimental data. The accuracy of the predictive model is further substantiated by the model test results. Lastly, this research offers an in‐depth analysis of soil consolidation behavior under diverse influencing factors. The findings indicate that the VP‐AP method demonstrates superior efficacy over conventional vacuum‐surcharge preloading when the airbag pressure matches the external load pressure. Additionally, an increase in the radius of airbags enhances the soil consolidation efficiency. The analytical model presented in this study elucidates the consolidation mechanisms of the VP‐AP method, with experimental research confirming the efficacy of this approach and the predictive model established herein.

Exploring The Relationship Between Responsiveness And Usability And Its Impact On Customer Satisfaction In E-Commerce

This research explores the use of chatbots in e-commerce from a customer perspective, with the aim of determining how responsiveness affects usability, as well as how this usability affects customer satisfaction. The data collection method used was a questionnaire distributed to 195 respondents. For model and hypothesis testing, SPSS and AMOS software were used. The results of the validity and reliability tests show that the respondent data is valid and reliable for use in hypothesis testing. The normality test shows that the questionnaire data is normally distributed. The multicollinearity test shows that multicollinearity has occurred. The results of the fit model test are that most of the criteria can be met or are fit, so the statistical interpretation results can not only be used on the sample but on the population as a whole. And the hypothesis test shows that there is a significant positive relationship between responsiveness (X) and usability (Y) of the chatbot. These findings indicate that the more responsive a chatbot is, the higher its level of usefulness in the eyes of customers. When a chatbot is able to provide relevant answers, customers tend to feel that the chatbot is effective and practical to use in meeting customer needs. Furthermore, this research also found that usability (Y) significantly influences customer satisfaction (Z). In other words, easy-to-use and effective chatbots can increase customer satisfaction in an e-commerce context. When a chatbot is designed with a simple interface, customers can easily ask questions and receive the answers or help they need. In addition, if the chatbot is able to provide accurate and relevant answers, customers feel that their needs can be met.

Experimental analysis on the progressive failure mechanism of soft rock subjected to tunnel excavation

The failure of the soft rock can seriously threaten the construction and operation of tunnels, which may suffer from larger deformation and instability. The knowledge of the failure process and mechanism of soft rock can help to optimize the tunnel design and construction. In the present paper, a large-scale physical model test with the use of both contact and non-contact measurement methods was conducted to investigate the progressive failure mechanism of soft rock. The results show that a notable pattern of progressive failure was observed in the soft rock, whereby failure initiates in the proximal regions and propagates to the distal regions within the surrounding rock. The occurrence of the failure intensifies the deformation of the soft rock, and the tunnel suffers from the cross-section flattening finally. The effectiveness of the non-contact measurement method was accessed by the comparison of the strain measurements between embedded sensors and digital photogrammetry analysis. Subsequently, the radius of the failure zone determined by the stress distribution and mechanical analysis is between two and three times the radius of the tunnel. The results of model tests were then verified by numerical analysis. Eventually, the failure modes were evaluated by local relative deformation. The shear failure takes place in the tunnel inverted arch which suffers from large shear stress, while compression failure appears on the tunnel sidewall, and the tension failure occurs at the top of the tunnel arch.

Testing Of Deep Learning-Based LSTM Model For Number Of Road Accidents Predicting

Many have used the prediction of the number of road accidents, but it is still rare to find those who use and test prediction models that are not suitable. Predictive models that have been used to predict road accidents have proven successful, but have not provided model testing with data that is different from the deep learning approach. The LSTM model test is proposed to be tested with 5 different datasets from Kaggle and 3 hidden layer variations. The test results of the LSTM model are that with variations of 4 hidden layers it can achieve higher accuracy results than those without hidden layers and 2 hidden layers. The results are obtained from stability with the lowest average MSLE value and relatively balanced average time. Deep learning-based LSTM model testing was carried out to ensure and prove the stability of the model for predicting the number of road accidents in the future. Stakeholders can predict the number of road accidents using the resulting prediction model.

Application of an offline grey box method for predicting the manoeuvring performance

The prediction of manoeuvring performance for safe navigation and effective design of ships increasingly depends on artificial intelligence (AI), mainly digital twin technology. This technology requires a digital model of the physical ship. The hydrodynamic coefficients and parameters of these models are commonly obtained through two experimental methods: the planar motion mechanism (PMM) and the circular motion test (CMT). These methods are time-consuming and expensive, which may not be feasible during the early stages of the design process. This study investigates a cost-effective alternative approach to these methods by implementing a grey box method on ships. For the first of these implementations, a full-scale tanker ship was applied with artificial training data of zigzag manoeuvres. A validation study was carried out by comparing the simulation and free-running model test results of the tanker. For the second of these implementations, a scale model of a car carrier was selected, and several numerical search methods were combined to obtain a more accurate digital model. The 3-degree-of-freedom (DOF) Manoeuvring Modelling Group (MMG) models identified through this combination were validated with simulations and compared with the free-running model test results for various manoeuvres. The contribution of this study lies in the accurate capture of the manoeuvring characteristics of the physical model, which is achieved through the use of the adjustment interval and the combination of various numerical search method of the grey box method. Consequently, the developed model can be used in future studies as a faster decision-making tool for determining the straight-line stability or instability of a ship in the ship design and in predicting the manoeuvring performance of the ship.

LEADERSHIP PRACTICES AND RISK MANAGEMENT AND ITS RELATIONSHIP WITH SCHOOL PERFORMANCE: EVIDENCE THROUGH PLS-SEM AND IPMA ANALYSIS

A key component of running a tahfiz school is the system of educational governance. A school's reputation can be destroyed and community trust can be lost if it is unable to manage academics, stakeholder satisfaction, internal processes, as well as learning and growth in school. The school's progress towards reaching the Malaysia Education Development Plan 2015-2025, which focuses on producing holistic human capital, will be hampered by ineffective educational governance. Tahfiz school's performance can be enhanced by implementing leadership practices and risk management to address the problem. The purpose of this study was to identify the level of leadership practices and risk management, as well as the level of performance in tahfiz schools. Furthermore, an investigation was conducted into the correlation between leadership practices and risk management with the performance of tahfiz school. This research examines 190 school administrators from Negeri Sembilan, Kedah, Kelantan, Terengganu, Pahang, Perak, Selangor, and Johor through a quantitative survey approach. A series of questionnaires were used as instruments for data collection, and the statistical packages Partial Least Squares Structural Equation Modeling (PLS-SEM) and Statistical Package for Social Science (SPSS) were used for analysis. A descriptive analysis reveals that tahfiz schools perform exceptionally well and have moderate and very high standards for leadership practices and risk management. The results of the structural model test indicate a moderate positive influence of leadership practices (β=0.308, t=4.276, p<0.01, f2=0.132) and a strong positive influence of risk management (β=0.618, t=5.225, p<0.01, f2=0.531) on the performance of tahfiz schools. This study also used IPMA analysis to identify the overall effect, indicating the significance of the risk management dimension in predicting tahfiz school performance. The findings of the study can help the Malaysian Ministry of Education develop a number of efforts to assist the administration of tahfiz school in reaching their goal of 125,000 professional huffaz by the year 2050.

Soil Fungal Community Differences in Manual Plantation Larch Forest and Natural Larch Forest in Northeast China.

Soil fungal communities are pivotal components in ecosystems and play an essential role in global biogeochemical cycles. In this study, we determined the fungal communities of a natural larch forest and a manual plantation larch forest in Heilongjiang Zhongyangzhan Black-billed Capercaillie Nature Reserve and Gala Mountain Forest using high-throughput sequencing. The interactions between soil fungal communities were analysed utilising a co-occurrence network. The relationship between soil nutrients and soil fungal communities was determined with the help of Mantel analysis and a correlation heatmap. The Kruskal-Wallis test indicated that different genera of fungi differed in the two forest types. The results show that there was a significant change in the alpha diversity of soil fungal communities in both forests. In contrast, nonmetric multidimensional scaling (NMDS) analysis showed significant differences in the soil fungal community structures between the manual plantation larch forest and the natural larch forest. The soil fungal co-occurrence network showed that the complexity of the soil fungal communities in the manual plantation larch forest decreased significantly compared to those in the natural larch forest. A Mantel analysis revealed a correlation between the soil fungal co-occurrence network, the composition of soil fungi, and soil nutrients. The RDA analysis also showed that AN, TK, and pH mainly influenced the soil fungal community. The null model test results showed the importance of stochastic processes in soil fungal community assembly in manual plantation larch forests. Overall, this study enhances our understanding of the differences in soil fungal communities in manual plantation larch forests and natural larch forests, providing insights into their sustainable management. It also serves as a reminder that the ecological balance of natural ecosystems is difficult to restore through human intervention, so we need to protect natural ecosystems.

Large-scale model test and numerical analysis of load-bearing arch characteristics of large cross-section tunnel under high geostress

Understanding the failure process and the load-bearing arch effect of the surrounding rock is crucial for the stability control and support design of tunnels under high geostresses. In this study, the progressive collapse behavior and the formation mechanism of the load-bearing arch of a soft rock tunnel under high geostress were investigated by a model test and numerical simulations. First, a large-scale model test was conducted to study the stress redistribution rules and the failure process of the soft rock under different overloads. According to the model test results, the formation of the final load-bearing arch was divided into four stages including initial local load-bearing arch formation, rock failure inside the local arch, overall load-bearing arch formation and load-bearing arch outward transition. Both the progressive failure and arch mechanism were related to the stress transfer effect. Then, numerical simulations were carried out to verify the stress response results from the model test. The determination method for the inner and outer boundaries of the load-bearing arch was put forward based on the circumferential stress distribution, which was validated by the model test results. Furthermore, the relationship between the radial displacement of the tunnel boundary and the arch position was illustrated. It was found that the load-bearing arch showed an oval shape with a big top and a small bottom. The arch position was linearly correlated with the radial displacement at the tunnel wall. This study provides a comprehensive understanding of the load-bearing arch characteristics of large cross-section tunnels in soft rocks under high geostress conditions, which can be referred to in construction control and support design during tunnel construction.

Displacement and pressure of surrounding rock during shield tunnelling and supporting in low water content loess

Using a self-developed micro shield machine, a laboratory-scale experimental scheme for shield tunnelling and supporting was designed, and the soil displacement law and earth pressure on the segments during tunnel construction were studied. Based on a nonlinear elastic constitutive model describing the characteristics of loess, the UMAT subroutine was redeveloped and verified by conventional triaxial tests. It was then applied to the numerical simulation of shield tunnelling and supporting. The following are the findings: 1) The disturbance modes of surrounding rock directly above the shield tunnel under different boundaries are similar. The main disturbances occur approximately 4 m above the shield tunnel, extending to a distance of one segment outer diameter on either side of the tunnel's central axis. 2) The pressures on the top and bottom of the segments can be divided into rapid increase, slow increase, and stable fluctuation. These stages correspond to the processes of the segments getting out of the shield shell and the soil collapsing. 3) The largest surrounding rock pressure is at the vault, followed by that at the arch bottom, and the smallest is at both sides of the arch waist, which is consistent with the law obtained based on laboratory-scale model tests. The surrounding rock pressure values of the vault in the numerical simulation are consistent with the laboratory-scale model test results. These verify the reliability of the laboratory-scale model test and the UMAT subroutine based on the nonlinear elastic constitutive model of loess in simulating the shield tunnel construction in loess strata.

The Effect of Religiosity on Customer Trust on Brand Loyalty to McDonalds in Generation Z After the Israeli-Palestinian Conflict

The purpose of this study is to examine the effect of religiosity and customer trust on brand loyalty among Generation Z (Muslim consumers in Indonesia), during a particular timeframe (post-Israeli-Palestinian conflict), thereby adding nuanced insights to consumer behavior research in a globalized context. The study is located in Cirebon, Indonesia, with research subjects namely consumers who buy products from McDonald's and people who follow the issue of boycotting Israeli products from the Palestinian conflict among FEB Management students of Universitas Swadaya Gunung Jati. The results of the fit model test show that religious values and consumer trust significantly impact McDonald''s brand loyalty in the Z generation. Consumer trust has a positive and significant effect on Brand loyalty (Z), with the remaining (1 - 0.505) = 0.495 (49.5%), which is influenced by other variables not determined by the model. This research contributes by bridging the gap between religious values, consumer trust, and brand loyalty, in the post-israeli conflict Z generation (Generation Z, Muslims in Indonesia). The study suggests strengthening the involvement of consumers through social media and promotional events, while also considering the importance of religious beliefs in decision-making.

Developing A Differentiated Learning Model Based on Artificial Intelligence : Implementation in The Mathematics Classroom

This study aims to produce a model that can meet the needs of Differentiated Learning based on AI. This method used research and development (R&D) with the Generic Desain Research Model (GDRM). The subject of this study was mathematics education experts and mathematics learning model experts. Instruments used in this study include quality validity assessment and feasibility assessment analysis. The data analysis techniques used were quantitative methods with learning model validity assessment criteria that use A Linkert Scale of 1-4. The test results of the AI-based Mathematics learning model show that (1) the Content Validity test resulted in an average of 3.47 which means the model is very valid, and (2) The average feasibility test is 3.43, which means it is also very valid. The results showed that the AI-based Mathematics learning model can be implemented in differentiated mathematics classes and train students to learn independently, think critically, provide solutions to problems, and have the courage to convey solutions.