Mathematical principle and engineering application of end-mining technology with non-pillar

The optimal control theory in mathematics aims to study the finding of control for a dynamic system over time, where an objective function is optimized. It has a broad range of applications in engineering, operations research, and science. The main purpose of this study is to provide numerical algorithms for two cases of optimal control problems of fractional order that involve fractional order derivatives with free and non-free terminal time. In addition to comparing the numerical results for three test problems with exact solutions of these problems, various computer simulations are also introduced.

The purpose of the study was to develop an MST Integrated Program for making a Maglev hands-on activity for higher elementary school students in Korea. In this MST Integrated Program, students will apply Mathematics, Science, and Technology principles and concepts to the design, construction, and evaluation of a magnetically levitated vehicle. The focus of this program was to help students to understand and solve integrative problems in relation to Mathematics, Science, and Technology Education in the real world.

Several theorems about the equivalence of familiar theories of reverse mathematics with certain well-ordering principles have been proved by recursion-theoretic and combinatorial methods (Friedman, Marcone, Montalbán et al.) and with far-reaching results by proof-theoretic technology (Afshari, Freund, Girard, Rathjen, Thomson, Valencia Vizcaíno, Weiermann et al.), employing deduction search trees and cut elimination theorems in infinitary logics with ordinal bounds in the latter case. At type level 1, the well-ordering principles are of the form $$ \text { (*) } ``\text {if}\,X \text { is well-ordered then } \, f(X) \, \text { is well-ordered''} $$where f is a standard proof-theoretic function from ordinals to ordinals (such f’s are always dilators). One aim of the paper is to present a general methodology underlying these results that enables one to construct omega-models of particular theories from \((*)\) and even \(\beta \)-models from the type 2 version of \((*)\). As \((*)\) is of complexity \(\Pi ^1_2\) such a principle cannot characterize stronger comprehensions at the level of \(\Pi ^1_1\)-comprehension. This requires a higher order version of \((*)\) that employs ideas from ordinal representation systems with collapsing functions used in impredicative proof theory. The simplest one is the Bachmann construction. Relativizing the latter construction to any dilator f and asserting that this always yields a well-ordering turns out to be equivalent to \(\Pi ^1_1\)-comprehension. This result has been conjectured and a proof strategy adumbrated roughly 10 years ago, but a detailed proof has only been worked out in recent years.KeywordsInfinite proof theoryReverse mathematicsOrdinal analysisOrdinal representation systemsCut eliminationDilators\(\omega \)-models\(\beta \)-models

BackgroundSchool education should improve science, technology, engineering, and mathematics (STEM) ability not only in science and mathematics but also in technology and engineering. However, practice and research are being conducted without clear definitions and methods for STEM education. Moreover, the positioning and characteristics of the technology included in each STEM field are unclear. Therefore, it is necessary to propose an appropriate framework for practice of STEM from the viewpoint of technology education. In response to this need, this commentary proposes a conceptual framework for the appropriate practice of STEM education.ResultsFirst, we referred to the perspectives and thinking styles of the fields of science, technology, and mathematics in the Japanese curriculum to specify the approach of the education system to each subject included in STEM. Next, to determine the concept of engineering in STEM education, we referred to the definition of engineering presented in Japan, the USA, and the UK. We positioned engineering, which means creating structures, processes, systems, etc., as a practical STEM activity and attempted to relate it to the unique perspectives and thinking styles of mathematics, science, and technology.ConclusionWe proposed a conceptual framework for the appropriate practice of STEM education based on the principles of subjects in the Japanese curriculum. The conceptual framework suggests that a means to improve the practice of STEM education is to retain the principles of science, technology, and mathematics in the activity of engineering. It can be inferred that the key point for practicing STEM education is to examine and design the appropriate order and combination of the learning process and activities based on the proposed conceptual framework. Although this framework is theoretical, it can be useful in determining an adequate practice of STEM education and clarifying the relationship between STEM education and technology education.

Visual comparisons are pervasive in science, technology, engineering, and mathematics (STEM) instruction and practice. In previous work, adults' visual comparisons of simple stimuli were faster and more accurate when the layout of a display facilitated alignment of corresponding elements-the spatial alignment principle (Matlen et al., 2020). Here, we asked whether the spatial alignment principle extends to rich, educationally relevant stimuli, and how prior experience and spatial skill relate to spatial alignment effects. Participants were asked to find an incorrect bone within a skeleton, presented individually or paired with a correct skeleton in a layout that did (direct placement) or did not (impeded placement) support alignment (Kurtz & Gentner, 2013). Consistent with the spatial alignment principle, undergraduates (Study 1) showed an advantage of direct over impeded placement. Middle schoolers (Study 2) showed a direct advantage on items presented in atypical orientations. That atypical items showed the strongest effects suggests that direct placement may help most when materials are less familiar. However, neither individual differences in undergraduates' STEM course history, nor undergraduates' or middle schoolers' spatial skills moderated spatial alignment effects. Thus, applying the spatial alignment principle in science, technology, engineering, and mathematics has potential to improve visual comparisons, especially those that are challenging, for students of all spatial skill levels. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

STEM Education is an area of study that intergrates the four principles of science, technology, engineering, and mathematics through coherent and active teaching and learning approaches which base on problem-based learning in the real-world. Thus, the purpose of this study is to synthesize the research on STEM Education Approach effected on students’ learning achievement in Thailand. There are two sets of variables. The first set is the description of research and the second set is the effect size of research. Data collection and analysis tools are the recording data form for research synthesis, frequency, percentage and meta-analysis. The results showed that (1) description of researches dated by 2009-2019, STEM Education research was mostly published in 2017 (68.18%), Rajabhat Mahasarakham University often produced STEM Education research (59.09%), Sciences Education major usually produced the STEM Education research (68.18%), researchers from the Office of the Basic Education Commission commonly produced the research (72.72%), most of the researchers were female (72.72%), common research objectives found was to compare (35.19%), research design most found was One group pretest-posttest design (77.27%), frequent sampling method found was purposive sampling (59.09%), sampling level of research was upper secondary school (68.18%) and analyzing method largely found was descriptive analysis (48.89%). (2) the effect size (d) from STEM Education on Learning Achievement = 0.445 which means STEM Education can affect the scores of the experimental group more than the control group.

Vibration analysis and control have always been regarded as crucial in engineering practice, as they directly affect the safety of structures, the efficiency of systems, and the stability of operations. This article provides an overall review of three aspects, namely the theoretical basis of vibration analysis, the development of control methods, and its application in engineering. Through the research and analysis of the research progress in recent years, this study highlights the role of vibration technology in various aspects of society, including civil infrastructure, aerospace systems, and mechanical manufacturing, among others. In addition, this paper also analyzes the main challenges currently faced in this field, including the complexity of the modeling process, the uncertainty of the research environment, and the need for real-time adaptability. The method adopted in this article is based on comparative and analytical literature, drawing on both classic research and emerging trend studies. Finally, the research results show that combining advanced sensing technology with intelligent control technology can, to a certain extent, improve the accuracy and reliability of vibration management in complex environments. This review paper is expected to provide guidance for future research directions and practical engineering applications.

In deep underground engineering environments, the strong interaction between pore water and the rock skeleton constitutes the fundamental mechanical mechanism behind dynamic disasters such as rockbursts and water inrush. This study systematically develops a dynamic similarity criterion system applicable to saturated porous media under combined static and dynamic loading. Through rigorous dimensional analysis, four key dimensionless parameters are proposed: Cauchy number (CA), Euler number (EU), Darcy number (DA), and Biot number (BI), each characterizing solid inertia, fluid impact, nonlinear seepage, and coupling diffusivity, respectively. These parameters form a coupled system of similarity equations, revealing the paradox of similarity constraints in physical model design. The framework is further validated by applying it to experimental data, enabling analysis of how geometric scaling and loading intensity influence coupling responses. Specifically, results show that under dynamic loading, the CA value increased by over four orders of magnitude while the EU value dropped by seven orders, signifying a critical shift from a pressure-driven to an inertia-dominated regime. Furthermore, the analysis reveals that both the DA and BI values increase linearly with the geometric similarity ratio, fundamentally altering the hydraulic response and suppressing pore pressure build-up in downscaled models. This work provides critical theoretical guidance and a quantitative basis for improving hazard simulation and experimental model design in deep engineering applications.

Biogeography-based optimization (BBO) is an evolutionary algorithm which is inspired by the migration of species between habitats. Almost 10 years have passed since the first BBO paper was published in 2008. BBO has successfully solved optimization problems in many different domains and has reached a relatively mature state. Considering the significant and expanding research on BBO and its applications, we find that the time is right to provide a 10-year anniversary review of the published literature, and also to point out some important avenues of future research. The purpose of this paper is to summarize and organize the literature related to the past 10 years of BBO research. Beginning with a foundation of basic BBO, we review the family of BBO algorithms and discuss BBO modifications, hybridizations, applications in science and engineering, and mathematical theory. Finally, the paper presents some interesting open problems and future research directions for BBO.

Investigation on dynamic recrystallization using a modified cellular automaton

In the high-speed operation of SRM, the conventional pulse width modulation (PWM) drive method is not available because of the limitation of switching speed; therefore the single-pulse drive method is commonly employed. On the contrary, the use of the single-pulse drive method cannot avoid the overcurrent in the low-speed operation because of the insufficient back emf and the difficulty of duty control. With these reasons, the switching method is commonly changed from PWM at the low-speed operation to the single-pulse method at the high-speed operation. In the fan application, the required load torque increases as a square of the fan speed; it requires more current for the torque generation. Therefore at the mode transition between PWM and single-pulse drive, it is unavoidable that the phase current rapidly increases if the nonlinearity of inductance to the current is not considered. In this paper, by using finite element method (FEM) which is considered with the nonlinearity of the inductance with respect to the current, the speed of mode transition is calculated (18 000 rpm) and verified by the experiment.

Informatization and intelligence are the development trends of the future highway asphalt pavement construction quality process control. This paper starts with the principle of asphalt pavement management and control technology, and verifies the application effect of information technology in the early warning and disposal of asphalt pavement construction quality. At the same time, this paper realizes the online control and management of highway construction quality by collecting the raw material processing, mixing and transportation information of asphalt mixture, and monitoring the construction links such as pavement paving and compaction in real time. Finally, the analysis is carried out in combination with engineering examples. The research results can provide reference for other engineering practices.

As one of the representatives of precision agriculture, variable spray technology has made great progress in the development and application of technology in recent years. This paper describes the principle and characteristics of variable spray technology, and outlines the development results of variable spray technology in target detection, automatic control, and spray application. In terms of target detection technology, automatic target spray technology based on real-time sensors and automatic target spray technology based on geographic information technology are introduced; In control technology, pressure control flow regulation technology, PWM control flow regulation technology and liquid chemical concentration mixed regulation system are described. In the field of spray technology, it mainly describes the research and application of variable nozzles and forecasts the application prospect and development direction of variable spray technology.

From the 19th century, the theory of permutation polynomial over finite fields, that are arose in the work of Hermite and Dickson, has drawn general attention. Permutation polynomials over finite fields are an active area of research due to their rising applications in mathematics and engineering. The last three decades has seen rapid progress on the research on permutation polynomials due to their diverse applications in cryptography, coding theory, finite geometry, combinatorics and many more areas of mathematics and engineering. For this reason, the study of permutation polynomials is important nowadays. In this chapter, we propose some new problems in connection to permutation polynomials over finite fields by the help of prime numbers.

Biosystem engineering is a discipline resulting from the evolution of the traditional agricultural engineering to include new engineering challenges related with biological systems, from the cell to the environment. Modern buildings and infrastructures are needed to satisfy crop and animal production demands. In this paper a review on the status of numerical methods applied to solve engineering problems in the field of buildings and infrastructures in biosystem engineering is presented. The history and basic background of the finite element method is presented. This is the first numerical method implemented and also the more developed one. The history and background of other two more recent methods, with practical applications, the computer fluids dynamics and the discrete element method are also presented. Besides, a review on the scientific and professional applications on the field of buildings and infrastructures for biosystem engineering needs is presented. Today we can simulate engineering problems with solids, engineering problems with fluids and engineering problems with particles and get to practical solutions faster and cheaper than in the past. The paper encourages young engineers and researchers to make progress these tools and their engineering applications. The capacities of all numerical methods in their present development status go beyond the present practical applications. There is a broad field to work on it.