Search

The search for efficient higher order methods is a constant goal in numerical analysis. In this paper, a higher order two-step hybrid block method is presented to directly solve second-order initial value problems in ordinary differential equations. In addition to the higher order, the proposed method has been formulated in variable step-size mode to extract its best performance. Comparisons with other methods in the literature show the good accuracy it can provide. Theoretical aspects such as linear stability and convergence analysis are also discussed. [ABSTRACT FROM AUTHOR]

The development of geographically indicative (GI) agricultural products can effectively promote the development of local rural residents' per capita net income (PCNI) and the gross output value of agriculture, forestry, animal husbandry, and fishery (GOV-AFAHF). This paper takes agricultural products with geographical indications in Anhui Province as the object of study and uses numerical analysis to analyze their application, geographical distribution, and various distribution in detail. By comparing it with the central region, this paper conducts an empirical study on its impact on agricultural economic development, analyzes its related variables and data, draws its effect on farmers' PCNI, and on this basis puts forward some countermeasures. In order to make the agricultural products with GI in Anhui Province develop better, according to the results of comparative analysis and empirical analysis, it puts forward suggestions for regulating the development of management industry associations, implementing the regional branding strategy of GI agricultural products, and increasing the construction of rural infrastructure. In addition, the experiment shows that under the condition of controlling other influencing factors unchanged, for every 1% increase in GI agricultural products, the average increase of PCNI of rural residents is 0.08%, which further confirms the conclusion that GI agricultural products can promote the development of GOV-AFAHF. [ABSTRACT FROM AUTHOR]

In Dempster–Shafer evidence theory (DST), some classical evidence combination rules can be used to fuse the multiple pieces of evidence, respectively abstracted from different attributes (features) so as to increase the accuracy of multiattribute classification decision making. However, most of them have not yet considered the interdependence among multiple pieces of evidence. The newly proposed maximum likelihood evidential reasoning (MAKER) rule measures such ubiquitous interdependence by introducing correlation factors into evidence combination. Hence, this paper designs a MAKER-based classifier to mine more correlation information for data classification. Finally, some numerical analysis (classification) experiments are carried out using five popular benchmark databases from the University of California, Irvine (UCI) to illustrate that the refined measure for evidence interdependence can aggregate the fused probability (belief degree) into real class label of a sample and further improve classification accuracy. [ABSTRACT FROM AUTHOR]

The development of underground space is fast because of the lack of space. To build shafts in underwater tunnels, the vertical tunneling method (VTM) was invented in 1974 in China, which can act as a freshwater intake or sewage outlet. During the operation of the VTM, the jacking force is one of the essential factors that draw attention. This paper conducts a numerical study of the jacking force and its influencing factors during the vertical tunneling process. First, based on the finite element software ABAQUS, a numerical model of the vertical tunneling process is established according to the VTM project in Beihai, China. Second, in accordance with the Latin hypercube sampling method and the multivariate significance analysis, the mechanical parameters are determined or back-analyzed. Then, the calculated jacking force of the numerical model is compared with the measured jacking force. It turns out that the changing trend of the jacking force in the numerical model and the measured jacking force is relatively consistent. Finally, the influencing factors of the jacking force, such as elastic modulus and the angle of internal friction, are analyzed based on the numerical model. The results show that the elastic modulus and the angle of internal friction of soil are the main influencing factors of the jacking force. The secondary factors are Poisson's ratio, static earth pressure coefficient, unit weight, and cohesion. [ABSTRACT FROM AUTHOR]

In recent years, there are many problems in the construction of street landscape spatial pattern, such as emphasizing the surface, ignoring the substance, focusing on construction, and ignoring protection. The reason is closely related to the lack of visual evaluation of streetscape for guidance. This research mainly discusses the numerical analysis and calculation for the spatial pattern of urban streetscape. This study clarifies the related concepts of visual evaluation of urban streetscape and discusses the formation process, overall characteristics, and constituent elements of streetscape. It emphasizes the importance of two subjective and objective factors of "landscape" and "vision" for evaluation. This paper studies this spatial composition relationship from the perspective of street space and the building itself. In the research process, it selects the pedestrian street in the northwest of the city as the object and uses the questionnaire survey method and the multifactor evaluation method to carry out the visual evaluation of the streetscape. It deeply discusses the application of evaluation methods in practice and counts the relevant evaluation results. In the urban street space proportion curve and the corresponding comparative analysis, it is found that most of the street space proportion is between 0.6 and 3.0. This kind of space composition has mutual inclusive symmetry, which enhances the order and communication of urban architecture. This somewhat improves this alienated spatial morphological pattern. This research is helpful to promote the development of streetscape visual evaluation. [ABSTRACT FROM AUTHOR]

English is a universal language in the world. It has become the consensus of society as a subject of education in primary and secondary schools and even universities. Therefore, how to improve English reading ability has also become a focus area of school education and students. The current research on English reading is mainly based on the sense of reading questions, reading patterns, answering skills, etc. and lacks the analysis of English reading corpus. In view of this, this paper used a self-built English reading corpus, adopts the feature extraction method, and combines the convolutional neural network (CNN) to build a model to carry out numerical analysis on the self-built English reading corpus, optimized the model, and compared and analyzed the results obtained. The optimal dropout rate and iteration times were obtained by updating experimental parameters. In order to make the experimental results more convincing, the W2V-SVM and W2V-CNN models that combine different feature extraction and classification methods are designed. Compared with the optimized CNN model, the accuracy rate, recall rate, and F1 value of the optimized CNN model were 89.81%, 92.39%, and 92.8%, respectively. The accuracy, recall, and F1 value of the W2V-SVM model are 81.31%, 82.09%, and 81.25%, respectively. The accuracy, recall, and F1 value of the W2V-CNN model are 85.24%, 84.98%, and 85.12%, respectively. It shows that the optimized CNN feature classification model has better feature classification effect on the self-built English reading corpus. The experimental results meet the expected value. [ABSTRACT FROM AUTHOR]

Precast technology is increasingly favoured by bridge engineers, and the seismic performance of precast bridge piers urgently needs to be addressed. Precast piers have a complex load-bearing mechanism, and their design method has not been clearly determined. Fibre plastic hinge theory can satisfactorily analyse the seismic performance of precast piers. In this study, the seismic performance of precast piers is analysed through numerical simulation of pier columns based on the pseudostatic testing of a set of existing precast piers and combined with fibre plastic hinge theory. The results show the following: With reasonable constructional measures, precast piers connected by grouted sleeves indeed have seismic performance similar to that of cast-in-place components. Finite-element programs can be employed to simulate the mechanical properties of steel rebars before yielding well but not those after yielding or under fatigue. When fibre plastic hinges are used for finite-element analysis, if the fibre cross-section is reasonably divided, the length of the plastic hinge has little influence on the results; otherwise, too densely distributed plastic hinges may lead to nonconvergence of the results in a later working condition. The plastic hinge method recommended in this paper, especially the sectional fibre-cross-section division method, can obtain the plastic hinge performance state, it can help save the test cost and make up for the shortage of test data. [ABSTRACT FROM AUTHOR]

The positioning accuracy is a key index to measure the performance of the robot. This paper studies the positioning accuracy of the main pouring mechanism of the hybrid truss pouring robot and analyzes that the main error sources affecting the positioning accuracy are machining error, assembly error, and thermal deformation error. Error transfer matrix is constructed to describe the influence of machining errors and assembly errors on the position and pose of the terminal, and the error parameters have physical significance. The probability distribution of sensitive errors is discussed. A joint regression prediction model based on sensitive error sets is established to determine the thermal deformation error on the basis of fully considering the contribution rate of component error. The results show that the position error has a wide range of influences on the end pose, but the angle error is more sensitive, and the probability distribution of the sensitive error is concentrated. The reliable data can be obtained without reorganizing the measurement in the calibration process. The joint regression model considering the contribution rate of component error can effectively eliminate the collinearity problem in the prediction of thermal deformation from a single heat source. Compared with the single regression model, it has better prediction accuracy and effect. [ABSTRACT FROM AUTHOR]