Group Analysis Method Research Articles

On thermoelastic deformation of a transversally isotropic medium in 3D construction printing

A three-dimensional dynamic model of a thermoelastic transversely isotropic medium is used to describe the thermoelastic deformation of materials with anisotropy of elastic properties with a selected direction of anisotropy. Such materials are layered and composite materials used in construction, mechanical engineering, aircraft and shipbuilding, soils in permafrost conditions, glaciers, as well as rocks (basalt, sandstone, marble, limestone, shale, and others). The study of this model, in particular, is relevant in connection with the use of 3D printers in construction. This is due to the fact that it is necessary to select the heating mode of the 3D printer head, in which cracks will not form during the cooling of the polystyrene concrete layers.We study this model using the group analysis methods, which is one of the most powerful and effective tools for obtaining exact solutions. The group stratification of the system of second-order differential equations defining this model is carried out. A system of first-order differential equations is obtained, which is equivalent to the equations of the original model. The solution describing a traveling wave for this system is obtained, that depends on arbitrary elements: parameters and function. For the specific sets of these elements, we study a deformation of a sphere and cube located inside a thermoelastic transversely isotropic medium with increasing time is found. The corresponding graphs are given.

Calculation of the temperature fields spread at subzero temperature in a monolithic beam

Monolithic construction in winter is faced with problems of concrete strength gain at subzero ambient temperatures. In order to ensure the necessary temperature conditions for hardening and hardening of concrete, various methods of heating structures are used. The relevance of this article is due to the climatic conditions of construction in most of the Russian territory and lack of a unified calculation method. The existing calculation methods are either easy to use, but give approximate answers, or exact solutions, but cumbersome and inconvenient in daily use. This paper presents group analysis method of differential equations used to predict temperature regimes for concreted structures. Solving the nonlinear differential equation of thermal conductivity by group analysis made it possible to derive, using nonlinear submodels, simple and convenient for practical application calculation formulas for modeling the temperature fields of heated structures. Experimental verification of the two proposed solutions of the nonlinear equation was carried out on the basis of the monolithic girder model, subjected to heat treatment at different powers.

THE DEVELOPMENT OF STRATEGIC MANAGEMENT PLANS FOR CONSTRUCTION EQUIPMENT, VEHICLES, AND TOOLS UNDER THE TRANSPORTATION POLICY TRANSFORMATIONS IN THAILAND

This article aims to propose the equipment, vehicle, and tool (EVT) management plans appropriate to the department of rural roads (DRR) in the current situation. This situation is influenced by the government policies that constrain human resources, with budget limitations and new forms of funding procedures. These factors along with technology advancement have challenged the DRR to establish an EVT management plan. To create the plan, the effective inquiry as part of design thinking is used to assess influences through the focus group and content analysis method. The results indicate that the DRR project development role is changed. This change results in four strategic management plans in the EVT. These strategic plans are concerning the EVT management system, EVT procurement and accessibility, unburden and support DRR staff, and finally EVT maintenance and disposal. Besides, the process of EVT strategic management plan development is described and more concerned with the engagement of the policymakers. Therefore, this report facilitates the other public agencies, particularly in the developing countries, in their plan development, based on multifactor real-world settings.

A generalized ([formula omitted])-dimensional Bogoyavlenskii–Kadomtsev–Petviashvili (BKP) equation: Multiple exp-function algorithm; conservation laws; similarity solutions

A generalized (1+2)-dimensional Bogoyavlenskii–Kadomtsev–Petviashvili (BKP) equation which is an augmentation of the Bogoyavlenskii–Schiff equation and Kadomtsev–Petviashvili equation is probed. This equation is hired as a prototype for evolutionary shallow-water waves. The Bogoyavlenskii–Kadomtsev–Petviashvili equation is ambassador of the higher dimensional Kadomtsev–Petviashvili hierarchy. This equation was acquired by a diminution for the well-known three-dimensional Kadomtsev–Petviashvili equation which illustrates the dissemination of nonlinear waves in plasmas and fluid dynamics. We determine novel exact solutions by utilizing the multiple exp-function algorithm and the modern group analysis method. Finally, we compute conserved currents courtesy using the invariance and multiplier technique. The findings can well mimic complex waves and their dealing dynamics in fluids.

Lie Group Analysis of a Nonlinear Coupled System of Korteweg-de Vries Equations

In this paper, we consider coupled Korteweg-de Vries equations that model the propagation of shallow water waves, ion-acoustic waves in plasmas, solitons, and nonlinear perturbations along internal surfaces between layers of different densities in stratified fluids, for example propagation of solitons of long internal waves in oceans. The method of Lie group analysis is used to on the system to obtain symmetry reductions. Soliton solutions are constructed by use of a linear combination of time and space translation symmetries. Furthermore, we compute conservation laws in two ways that is by multiplier method and by an application of new conservation theorem developed by Nail Ibragimov.

CONCEPTUAL PRINCIPLES OF HOTEL AND RESTAURANT BUSINESS DEVELOPMENT

BACKGROUND AND OBJECTIVES. In Ukraine, not all issues relating to modern theoretical, methodological and applied foundations of enhancing the development of hotel and restaurant business are covered. There is a need for in-depth scientific research of theoretical aspects of the formation of methods of organizational and financial resource provision of tourism development at the national and regional levels, the definition of priorities and determination of ways to improve the efficiency of management of the complex use of the rich recreational and tourist potential of Ukraine.METHODS. Methodology of scientific research are general scientific and special research methods: dialectical method of research of processes and phenomena in their interrelation and development, system-structural analysis (when studying the conceptual foundations and systematization of methodical approaches to management of development of hotel-restaurant business); methods of group analysis and statistical approaches, economic-statistical methods, comparison (when analyzing social and economic preconditions, opportunities and motives of development of hotel-restaurant business), methods of analysis of the economic and social situation (when analyzing social and economic preconditions, opportunities and motives of development of hotel-restaurant business).FINDINGS. The elements of functional support for the development of domestic hotel and restaurant business are substantiated.CONCLUSION. The study of domestic hotel and restaurant business, in particular the regional market of tourist services, is based on the assessment of the environment of market activity. It involves the use of a comprehensive approach to the application of theoretical and applied foundations of sectoral and territorial analysis and aims to form the leading levers of development of hotel and restaurant business.

“Squeezed like a lemon”: A participatory approach on the effects of innovation on the well‐being of homecare workers in Belgium

Innovative programs that emerge in response to the rapidly changing care needs of older adults provide an opportunity to study the transformations in working and employment conditions within the homecare sector. This study seeks to understand how innovations introduced in the homecare sector have affected the well-being of homecare workers providing non-medical domestic support to older adults who wish to age in place. Our study is based on a participatory approach involving homecare workers exposed to two innovations in Wallonia (Belgium) that relate to flexible working hours, worker training, and technological equipment. We conducted a literature review, six semi-structured individual interviews with managers, and eight workshops based on the 'Group Analysis Method' involving 9 to 12 homecare workers. The results revealed that the innovations deteriorated working conditions, intensified occupational psychosocial risk factors, and impacted work-life balance. This gave rise to tensions that ultimately had a negative impact on the well-being of workers and on the quality of their care relationship with older adults/caregivers, while also weakening the viability of the services. The workers proposed some avenues to improve and regulate these tensions.

Stakeholders’ perceptions of family-centred care in the intensive care unit: An associative group analysis

AimTo explore different stakeholders’ including nurses, health care professionals and family member’s perceptions of ideal family-centred care in an intensive care unit. Research design and methodsWe used a mixed method approach to identify perceptions of family-centred care with 60 stakeholders of equal numbers who voluntarily participated in the study. Data were collected over one month using an associative group analysis method. The responses were ranked, scored, thematically themed and weighted. SettingA 23 bed adult intensive care unit in an urban private hospital in South Africa. FindingsAccording to the stakeholders’ responses, ideal family-centred care should be built around communication based on expectations and engagement. In addition, the physical environment should allow for overall comfort and spiritual care must be incorporated. ConclusionStakeholders had similar perceptions on the main themes however; nuances of different perspectives were identified showing some of the complexities related to family-centred care. Spiritual care was highlighted by the family members, revealing the need to broaden the care perspectives of healthcare providers.

Key Features of the Performance of Chinese Musicians (Sample Case: Playing on the Saxophone)

The article is devoted to the methods of teaching saxophone playing within the framework of two classical approaches to teaching, developed by two famous teachers: the French teacher and saxophonist Marcel Moulet and his American colleague Larry Teale. The purpose of the article is to identify the features of two classical approaches to teaching the saxophone within the French and American traditions from the point of view of the peculiarities of the perception of these two techniques by Chinese students. The objectives of the research are to reveal the basic principles of the pedagogical system of Marcel Moulet; identifying the features of the Larry Teale method; conducting comparative classes in two groups of Chinese students based on the criteria for mastering the performance skills of playing the saxophone. The research methodology is based on a systematic approach and includes the methods of the general scientific group (analysis, synthesis, induction, deduction), as well as a group of special methods: content analysis of scientific literature on the research topic; method of sociological survey and method of statistical analysis. To process the results of the empirical research, special software Neural Designer, a tool for advanced analytics, was used.The study revealed the preferences of Chinese saxophonists regarding two classical saxophone playing techniques. The survey was conducted among three groups of 25 people, two of them were involved in experimental classes and the third group was a control. The general sample consisted of 75 respondents.Based on the study, the author of the article came to the conclusion that Chinese performers are more committed to the French method of playing the saxophone, since the European musical tradition is easier for Chinese students to perceive in the context of the musical traditions and philosophy of China.

Impact and features of Chinese realism in painting with focus on tradition and modernity

The relevance of the research topic lies in the fact that Western trends dominate in contemporary the Chinese realistic art, while interest in traditional painting techniques in a realistic direction has practically disappeared. To preserve the national cultural heritage, it is necessary to study more carefully the possibilities of applying traditional ideas in modern realistic painting. The purpose of the study is to identify the features of the traditional foundations of Chinese painting and their applied value for teaching students of modern painting. The objectives of the research are to analyze the scientific literature on the topic, conduct a survey among students to assess the traditions of Chinese re-artistic painting, as well as summarize the results of empirical research. The research methodology includes the methods of the general scientific group (analysis, synthesis, induction, deduction), as well as methods of art history analysis: historical and logical; analogy method; method of formal comparison. In an empirical study, the method of statistical analysis was used, applied using the program Neural Designer, a tool for advanced statistical analysis. The research materials were the results of a survey of 3rd year students (bachelor’s degree). Three groups of students were interviewed, each of which included 25 people: two experimental groups and one control group. The author of the study came to the conclusion that the combination of traditional and modern techniques in realistic painting in the classroom can increase the motivation for learning, develop new technical skills among students studying in the specialty «painting and graphics».

Electronic commerce and its regulation in the European Union and China

The article provides a statistical analysis of the trends in the development of e-commerce in the world in general and in China in particular, a comparative legal analysis of the system of legal regulation of key aspects affecting the functioning of e-commerce in the European Union and in the People’s Republic of China (further PRC). The research methodology is based on a systematic approach and includes the methods of the general scientific group (analysis, synthesis, induction, deduction), as well as special methods: statistical analysis, content analysis of scientific literature on the research topic, the method of comparative legal analysis. As a result of the study, the author came to the conclusion that the legislation of China and the European Union regarding the regulation of e-commerce is aimed at fundamentally different goals: in the EU, legislation is aimed at protecting private transactions and trade, and for China, the priority is the development of legal norms that allow the state as much as possible control electronic commercial flows and procuring a cybersecurity in e-commerce sector.

Comparison of methods of functional group analysis using results from laboratory and field aerosol measurements

A study was conducted to compare two methods for analysis of functional groups in secondary organic aerosol (SOA) generated in the laboratory and organic aerosol collected in the Southeastern Oxidants and Aerosol Study (SOAS). Although not as widely used as molecular and elemental analysis, functional group analysis of filter samples provides chemically specific information that can be used to characterize organic aerosol sources, mechanisms of formation, and physical-chemical properties. Here, we compared measurements made using Fourier Transform Infrared (FTIR) spectroscopy, the most widely used method of functional group analysis, with those made using derivatization-spectrophotometric methods. When used to analyze SOA generated from a series of environmental chamber reactions, the methods agreed quite well when results were assigned to four groups: (1) functional groups that contain an O–H bond; (2) non-acid functional groups containing a C = O moiety; (3) organonitrate groups; and (4) alkane groups. Overall, the agreement between the two methods indicates that either is adequate for measuring the functional group composition of SOA. While the derivitization-spectrophotometric methods offer more specificity, they also require more time and aerosol mass for sample analysis than the FTIR methods. It was also shown that functional group signatures obtained from SOA generated in environmental chambers can potentially be used to gain insight into oxidation and particle-phase reactions responsible for SOA formation in field samples.Copyright © 2021 American Association for Aerosol Research

A self-similar solution for unsteady adiabatic and isothermal flows behind the shock wave in a non-ideal gas using Lie group analysis method with azimuthal or axial magnetic field in rotating medium

The similarity solutions using Lie group analysis for shock wave propagation in a rotational axisymmetric non-ideal gas with azimuthal or axial magnetic field in the case of isothermal and adiabatic flows are obtained. All possible cases of similarity solutions are discussed using the Lie group analysis for the isothermal and adiabatic flows. The arbitrary constants involved in the generators of local Lie groups bring various possible cases of solutions with exponential law and power law shock paths. Similarity solution for isothermal and adiabatic flows with power law shock path is discussed in detail. The density of ambient medium is taken to be constant. The axial and azimuthal fluid velocities and magnetic field in the ambient medium are assumed to be varying according to power law. The effect on shock wave strength and that on the flow variables due to variation of the Alfven Mach number, adiabatic index of the gas, non-idealness parameter, rotational parameter and initial magnetic field variation exponent are investigated. It is found that these parameters have decaying effects on shock wave. The obtained results in the case of isothermal and adiabatic flows are also compared with each other.

Studies on population balance equation involving aggregation and growth terms via symmetries

Abstract The population balance equation (PBE) is one of the most popular integro-differential equations modeled for several industrial processes. The solution to this equation is usually solved using a numerical approach as the analytical solutions of such equations are not obtained easily. Typically, the available analytical solutions are limited and are based on momentous Laplace transform. In this study, the reduced equations of the PBE are obtained via the group analysis method. Two particulate cases involving aggregation, growth and nucleation are selected, the determining equations are solved and the reduced equations are solved via approximate methods. The approximate method involves the target solution of the nonlinear evolution equation, here the PBE, to be expressed as a polynomial in an elementary function which satisfies a particular ordinary differential equation termed as an auxiliary equation.

Painlevé analysis, group invariant analysis, similarity reduction, exact solutions, and conservation laws of Mikhailov–Novikov–Wang equation

In this paper, for the study of integrability, symmetry analysis, group invariant solutions and conservation laws, the Mikhailov–Novikov–Wang equation is considered. Firstly, Painlevé analysis is being employed to study the integrability properties for the considered equation so as to check the possibility that this equation passes the Painlevé test. Secondly, Lie group analysis is studied for finding the symmetries by using Lie classical group analysis method and to obtain its symmetry group, infinitesimal generator, Lie algebra commutation table, and similarity reductions. The vector fields and the symmetry reduction of this equation are calculated with the aid of Lie symmetry analysis. From the similarity reduction equation, some explicit exact solutions are derived. Finally, using the new conservation theorem proposed by Ibragimov [N. H. Ibragimov, A new conservation theorem, J. Math. Anal. Appl. 333 (2007) 311–328], the conservation laws of the aforesaid equation have been constructed.

Lie Symmetry Analysis and Explicit Solutions for the Time-Fractional Regularized Long-Wave Equation

This paper systematically investigates the Lie group analysis method of the time-fractional regularized long-wave (RLW) equation with Riemann–Liouville fractional derivative. The vector fields and similarity reductions of the time-fractional (RLW) equation are obtained. It is shown that the governing equation can be transformed into a fractional ordinary differential equation with a new independent variable, where the fractional derivatives are in Erdèlyi–Kober sense. Furthermore, the explicit analytic solutions of the time-fractional (RLW) equation are obtained using the power series expansion method. Finally, some graphical features were presented to give a visual interpretation of the solutions.

Effect of spudcan penetration on laterally loaded pile groups

Engineering cases, where jack-up rigs with large-diameter spudcan foundations operate near a jacket platform supported by pile groups, are increasing. Therefore, the group interaction of lateral-loaded pile groups should be re-evaluated. A pile group analysis method that is able to evaluate the effect of spudcan penetration on the pile group interaction is proposed in this study. This method is based on the modified Poulos method and is universally used in current ocean engineering practices. The pile group interaction-induced additional pile head deflection of a pile group, when subjected to both spudcan penetration and the influence of another pile group, is initially determined by elastic analysis. Next, the nonlinear foundation beam (NFB) method is adopted to calculate the head deflection of an isolated pile, which we utilise to calculate the head deflection of the pile group after considering the effects of spudcan penetration. Finally, the Y multiplier is obtained by several pilot modifications of p-y curves of the isolated pile in the NFB model, whose variation during spudcan penetration indicates the effect that such penetration has on the pile group interaction. Predicted results were compared with those of the centrifuge model test, and further with numerical simulation results, in order to prove the validity of the method in analysing a free-head and a fixed-head pile group.

Multiple Group Analysis in Multilevel Data Across Within-Level Groups: A Comparison of Multilevel Factor Mixture Modeling and Multilevel Multiple-Indicators Multiple-Causes Modeling.

The purpose of this two-part study is to evaluate methods for multiple group analysis when the comparison group is at the within level with multilevel data, using a multilevel factor mixture model (ML FMM) and a multilevel multiple-indicators multiple-causes (ML MIMIC) model. The performance of these methods was evaluated integrally by a series of procedures testing weak and strong invariance models and the latent group mean differences testing after holding for factorial invariance. Two Monte Carlo simulation studies were conducted under the following conditions: number of clusters, cluster size, and the design type in groups. A multilevel one-factor confirmatory factor analysis (CFA) model as a research model in Study 1 was investigated to compare the results under different conditions with those of previous studies. A multilevel two-factor CFA model as a research model in Study 2 was evaluated by fitting alternative models that can be applied when the model is complicated. The results indicated that the two methods were reasonable in multilevel multiple groups analysis across within-level groups. However, pros and cons were found between the two methods. In the multilevel one-factor CFA model, ML MIMIC model was slightly better when the sample size is small. In the multilevel complex model, two alternative models of ML FMM were recommended because the weak invariance testing of ML MIMIC was considerably time-consuming. Finally, it was shown that information criteria, which are criteria for determining whether factorial invariance is established, need to be applied differently according to the sample size conditions. Guidelines for this situation are provided.

Symmetries and exact solutions of the population balance equation with growth and breakage processes, using group analysis

Population balance equation which may be employed to handle a wide variety of particle processes has certainly received unprecedented attention, but the absence of explicit exact solutions necessitates the use of numerical approaches. The one‐dimensional population balance equation with time independent but size dependent growth and breakage rate is investigated. The corresponding system of equation is solved analytically by use of the Lie group analysis method. Symmetries, reduced equations, invariant solutions, explicit exact, and unphysical solutions are presented in this paper.

Group formalism of Lie transformations, exact solutions and conservation laws of nonlinear time-fractional Kramers equation

In this paper, we will concentrate on a systematic investigation of finding Lie point symmetries of the nonlinear [Formula: see text]-dimensional time-fractional Kramers equation via Riemann–Liouville and Caputo derivatives. By using the Lie group analysis method, the invariance properties and the symmetry reductions of the time-fractional Kramers equation are provided. It is shown that by using one of the symmetries of the underlying equation, it can be transformed into a nonlinear [Formula: see text]-dimensional fractional differential equation with a new dependent variable and the derivative in Erdélyi–Kober sense. Furthermore, we construct some exact solutions for the time-fractional Kramers equation using the invariant subspace method. In addition, adapting Ibragimov’s method, using Noether identity, Noether operators and formal Lagrangian, we construct conservation laws of this equation.