Search results

The safety and reliability of high-speed trains rely on the structural integrity of their components and the dynamic performance of the entire vehicle system. This paper aims to define and substantiate the assessment of the structural integrity and dynamical integrity of high-speed trains in both theory and practice. The key principles and approaches will be proposed, and their applications to high-speed trains in China will be presented.

First, the structural integrity and dynamical integrity of high-speed trains are defined, and their relationship is introduced. Then, the principles for assessing the structural integrity of structural and dynamical components are presented and practical examples of gearboxes and dampers are provided. Finally, the principles and approaches for assessing the dynamical integrity of high-speed trains are presented and a novel operational assessment method is further presented.

Vehicle system dynamics is the core of the proposed framework that provides the loads and vibrations on train components and the dynamic performance of the entire vehicle system. For assessing the structural integrity of structural components, an open-loop analysis considering both normal and abnormal vehicle conditions is needed. For assessing the structural integrity of dynamical components, a closed-loop analysis involving the influence of wear and degradation on vehicle system dynamics is needed. The analysis of vehicle system dynamics should follow the principles of complete objects, conditions and indices. Numerical, experimental and operational approaches should be combined to achieve effective assessments.

The practical applications demonstrate that assessing the structural integrity and dynamical integrity of high-speed trains can support better control of critical defects, better lifespan management of train components and better maintenance decision-making for high-speed trains.

This research studies the development of the evolving dynamic system model and explores the important elements or factors and what detailed attributes are the main influences model in achieving the success of a business, industry and management. It also identifies the real and major differences between static and dynamic business management models and the detailed factors that influence them. Later, this research investigates the benefits/advantages and limitations/disadvantages of some research studies. The studies conducted in this research put more emphasis on the capabilities of system dynamics (SD) in modeling and the ability to measure, analyse and capture problems in business, industry, manufacturing etc.

The research presented in this work is a qualitative research based on a literature review. Publicly available research publications and reports have been used to create a research foundation, identify the research gaps and develop new analyses from the comparative studies. As the literature review progressed, the scope of the literature search was further narrowed down to the development of SD models. Often, references to certain selected literature have been examined to find other relevant literature. To do so, a supporting tool (that connects related articles) provided by Google Scholar, Scopus, and particular journals has been used.

The dynamic business and management model is very different from the static business model in complexity, formality, flexibility, capturing, relationships, advantages, innovation model, new goals, updated information, perspective and problem-solving abilities. The initial approach of a static system was applied in the canvas business model, but further developments can be continued with a dynamic system approach.

Based on this study, which shows that businesses are developing more towards digitalisation, wanting the ability to keep up with the era that is moving so fast and the desire to increase profits, an instrument is needed that can help describe the difficulties of the needs and developments of the future world. This instrument, or tool of SD, is also expected to assist in drawing future models and in building a business with complex variables that can be predicted from the beginning.

This study will contribute to the SD study for many business incubator research studies. Many practical in business incubator management to have a benefit how to achieve the business performance management (BPM) in SD review.

The significant differences between static and dynamics to be used for business research and strategic performance management. This comparative study analyses some SD models from many authors worldwide. Their goals behind their strategic business models and encounter for their respective progress.

This study illustrates the economic and financial dynamics of the sector, analysing the evolution of the main ratios of profitability and financial structure of 1,559 Italian real estate companies divided into the three macro-regions: North, Centre and South, in the period 2011–2020. In this way, it is also possible to verify the responsiveness to the 2020 pandemic crisis.

The analysis uses descriptive statistics tools and the ANOVA method of analysis of variance, supplemented by the Tukey–Kramer test, to identify significant differences between the three Italian macro-regions.

The study shows the increase in profitability after the 2008 crisis, despite its reverberation in the years 2012–2013. The financial structure of companies improved almost everywhere. The pandemic had modest effects on performance.

In the future, other indices should be considered to gain a more comprehensive view. This is a quantitative study based on financial statements data that neglects other important economic and social factors.

Public policies could use this study for better interventions to support the sector. In addition, internal management can compare their company's performance with the industry average to identify possible improvements.

The research analyses an economic field that employs a large number of people, especially when considering the construction and real estate services covered by this analysis.

The study contributes to the literature by providing a quantitative analysis of industry dynamics, with comparative information that can be deduced from financial statements over the years.

This paper aims to investigate sustainability-led innovation, focusing on the interplay between product and process innovation for sustainability goals and the underlying supplier–customer relationships. Thus, the paper delves into sustainability-led innovation and how it affects supplier–customer relationships, and vice versa, thus providing a twofold perspective.

The textile industry is the empirical context of this study, which is exploratory research based on in-depth, semi-structured interviews with entrepreneurs, managers and experts in the textile industry.

In the textile industry, sustainability-led product innovation concerns mainly product durability and performance, product recyclability and the use of waste for new product development. Process innovation deals with circular economy, traceability and water and chemical use minimization. The paper also shows how sustainability-led innovation is implemented in more technical terms and regarding supplier–customer relationships.

The paper adopts an original perspective on how processes take place in the relationships between suppliers and customers, where there is no dominance of one actor, but innovation emerges from interdependence and interaction. Such perspective allows to provide an in-depth analysis of the supplier–customer relationships and underlying dynamics that affect sustainability-led innovation; moreover, the authors study how such innovation impacts supplier–customer relationships and the underlying relational dynamics. The value of the paper also stands in delivering a real representation of the innovation processes grounded in the textile industry.

The susceptible-infectious-susceptible (SIS) infectious disease models without spatial heterogeneity have limited applications, and the numerical simulation without considering models’ global existence and uniqueness of classical solutions might converge to an impractical solution. This paper aims to develop a robust and reliable numerical approach to the SIS epidemic model with spatial heterogeneity, which characterizes the horizontal and vertical transmission of the disease.

This study used stability analysis methods from nonlinear dynamics to evaluate the stability of SIS epidemic models. Additionally, the authors applied numerical solution methods from diffusion equations and heat conduction equations in fluid mechanics to infectious disease transmission models with spatial heterogeneity, which can guarantee a robustly stable and highly reliable numerical process. The findings revealed that this interdisciplinary approach not only provides a more comprehensive understanding of the propagation patterns of infectious diseases across various spatial environments but also offers new application directions in the fields of fluid mechanics and heat flow. The results of this study are highly significant for developing effective control strategies against infectious diseases while offering new ideas and methods for related fields of research.

Through theoretical analysis and numerical simulation, the distribution of infected persons in heterogeneous environments is closely related to the location parameters. The finding is suitable for clinical use.

The theoretical analysis of the stability theorem and the threshold dynamics guarantee robust stability and fast convergence of the numerical solution. It opens up a new window for a robust and reliable numerical study.

The purpose of this paper is to improve autonomous flight performance of a fixed-wing unmanned aerial vehicle (UAV) via simultaneous morphing wingtip and control system design conducted with optimization, computational fluid dynamics (CFD) and machine learning approaches.

The main wing of the UAV is redesigned with morphing wingtips capable of dihedral angle alteration by means of folding. Aircraft dynamic model is derived as equations depending only on wingtip dihedral angle via Nonlinear Least Squares regression machine learning algorithm. Data for the regression analyses are obtained by numerical (i.e. CFD) and analytical approaches. Simultaneous perturbation stochastic approximation (SPSA) is incorporated into the design process to determine the optimal wingtip dihedral angle and proportional-integral-derivative (PID) coefficients of the control system that maximizes autonomous flight performance. The performance is defined in terms of trajectory tracking quality parameters of rise time, settling time and overshoot. Obtained optimal design parameters are applied in flight simulations to test both longitudinal and lateral reference trajectory tracking.

Longitudinal and lateral autonomous flight performances of the UAV are improved by redesigning the main wing with morphing wingtips and simultaneous estimation of PID coefficients and wingtip dihedral angle with SPSA optimization.

This paper originally discusses the simultaneous design of innovative morphing wingtip and UAV flight control system for autonomous flight performance improvement. The proposed simultaneous design idea is conducted with the SPSA optimization and a machine learning algorithm as a novel approach.

The purpose of this article is to make a contribution to the existing knowledge by using the unique cross-jurisdiction data drawn from the FCA’s REP-CRIM submissions to explore dynamics behind firms’ perceptions on financial crime. Capturing firm’s sentiment is notoriously challenging, and any relevant regulatory data is usually not available in the public domain. A recent exception is the UK Financial Conduct Authority’s (FCA’s) financial crime data return (REP-CRIM) submissions which include the cross-country regulatory data on the UK financial institutions’ perceptions of jurisdiction risk. Despite a broad literature with respect to financial crime, there exists an important gap in the existing knowledge with respect to factors that are associated with the perceptions of firms with respect to jurisdiction risk, which this article aims to close.

Using cross-country regulatory data on the UK financial institutions’ perceptions of jurisdiction risk, this study empirically determines that perceptions of jurisdiction risk is significantly and positively associated with anti-money laundering and countering the financing of terrorism (AML/CFT) framework, as well as with tax burden on business and institutional and legal risk in the case of 165 jurisdictions.

The findings lend support to the proposition that unsystematic efforts and too much publicity may ascertain the high-risk image of a jurisdiction, deterring cross-border business. Policy implications that emerge from the study also add to the case for strengthening institutional and legal frameworks, as well as relieving the tax burden on doing business.

Findings of the present study should be interpreted with caution, as the dependent variable used in the present study reflects UK firms’ perceptions of jurisdiction risk, which may depend on various factors such as different risk appetites and the countries in which firms carry out business, and not necessarily the actual level of risks based on financial crime statistics. For example, a jurisdiction which may indeed be considered high risk, would not necessarily be ranking high on the FCA’s list of UK firms’ jurisdiction risk perceptions due to few firms operating in that particular country. As a result, the list could differ from the Financial Action Task Force’s black and grey lists. Findings based on the regulatory data on the UK financial institutions’ perceptions of jurisdiction risk should be considered preliminary in nature, given that they are based on a single year cross sectional data. As global and country-level AML/CFT efforts continue to intensify and as more regulatory data becomes publicly available, it would be imperative to bring further empirical evidence to bear on the question of whether financial crime perceptions are likely to be more pronounced for jurisdictions where AML/CFT efforts are more intensified. Likewise, from a policy standpoint, it would be equally important to explore further the role that institutional and legal risk, as well as tax burden on businesses, play in shaping firms’ perceptions of jurisdiction risk.

Findings lend support to the proposition that unsystematic efforts and too much publicity may ascertain the high-risk image of a jurisdiction, deterring cross-border business. Therefore, rather than waiting for more data to be made available by other financial regulators, which could lead to a more conclusive evidence in the future, on balance, the findings of this study add to the case for carefully designing and systematically implementing AML/CFT measures in a less publicized manner. Findings lend support to the theoretical postulation that disorderly efforts and undue publicity regarding AML/CFT efforts serve to ascertain the high-risk image of a jurisdiction, which could deter cross-border business and could be detrimental to how firms undertake due diligence. They also suggest that disorderly implementation of AML/CFT measures may hinder access to formal financial service and jeopardize authorities’ ability to trace the movement of funds, which may also add to negative perceptions of jurisdiction risk.

Findings are in line with the theoretical expectations that perceptions of jurisdiction risk would be expected to be higher in countries with inadequate disclosure rules, lax regulation and opacity jurisdiction. Likewise, results are aligned with the expectations that tax burden on business would be expected to be in a positive relationship with jurisdiction risk, as it would increase the likelihood of tax evasion, which incentivizes financial crime. Therefore, policy implications that emerge from the study also add to the case for strengthening institutional and legal frameworks and relieving the tax burden on doing business as part of efforts to improve the international image of jurisdictions with respect to financial crime risks.

Using the cross-country regulatory data on the UK financial institutions’ perceptions of jurisdiction risk, this study has empirically determined that perceptions of jurisdiction risk is significantly and positively associated with AML/CFT framework, as well as with tax burden on business and institutional and legal risk. These findings have implications from a policy standpoint.

The purpose of this paper is to investigate the impact of near-wall treatment approaches, which are crucial parameters in predicting the flow characteristics of open channels, and the influence of different vegetation covers in different layers.

Ansys Fluent, a computational fluid dynamics software, was used to calculate the flow and turbulence characteristics using a three-dimensional, turbulent (k-e realizable), incompressible and steady-flow assumption, along with various near-wall treatment approaches (standard, scalable, non-equilibrium and enhanced) in the vegetated channel. The numerical study was validated concerning an experimental study conducted in the existing literature.

The numerical model successfully predicted experimental results with relative error rates below 10%. It was determined that nonequilibrium wall functions exhibited the highest predictive success in experiment Run 1, standard wall functions in experiment Run 2 and enhanced wall treatments in experiment Run 3. This study has found that plant growth significantly alters open channel flow. In the contact zones, the velocities and the eddy viscosity are low, while in the free zones they are high. On the other hand, the turbulence kinetic energy and turbulence eddy dissipation are maximum at the solid–liquid interface, while they are minimum at free zones.

This is the first study, to the best of the author’s knowledge, concerning the performance of different near-wall treatment approaches on the prediction of vegetation-covered open channel flow characteristics. And this study provides valuable insights to improve the hydraulic performance of open-channel systems.

This study aims to investigate the influence of resource slack on the decline of Brazilian companies, with a particular focus on the moderating role of environmental dynamism. The authors specifically examine three types of resource slack: available, potential and recoverable. These represent surplus resources that exceed what is necessary for the organization’s basic operations. The role of environmental dynamism, characterized by rapid changes in customer preferences, technologies and competitive dynamics, is considered as a moderating factor in this relationship.

The authors used data from Brazilian companies spanning from 1997 to 2008. The research sample was composed using the matching-pairs method, which included a group of publicly traded companies that experienced decline (43 companies) and a group that did not (40 companies) within the specified timeframe.

Findings of this study indicate that the presence of available slack, being more liquid resources, decreases the likelihood of organizational decline. Furthermore, the moderation effect of potential resource slack can mitigate decline in companies operating in dynamic industries.

This research provides valuable insights into the impact of slack resources on potential organizational turnarounds. Given the relative scarcity of resources in these companies compared to those in developed countries, whether they be financial, human or technological, the study highlights the unique influence of slack in a less explored institutional environment. This research underscores the importance of examining the decline of Brazilian companies from a broader perspective, emphasizing that decisions regarding resource use can have significant implications on a company’s trajectory, either amplifying or mitigating its decline.

¿Cuál es el impacto del slack de recursos en el declive de grandes empresas brasileñas? Para responder a esta pregunta, hemos probado hipótesis por separado para tres tipos de salck de recursos: disponible, potencial y recuperable. Estos excedentes consisten en recursos en exceso más allá de lo necesario para mantener la organización funcionando.

Desarrollamos un estudio empírico cuantitativo y longitudinal con datos de empresas brasileñas de 1997 a 2008. Adoptamos el método de pares emparejados, componiendo la muestra de investigación con un grupo de empresas cotizadas en bolsa que declinaron (43 empresas) y otro que no declinó (40 empresas) en el período de tiempo.

Encontramos que la disponibilidad de recursos más líquidos reduce la posibilidad de declive. El efecto de moderación en el slack de recursos potenciales para empresas en industrias dinámicas puede mitigar el declive.

Esta investigación contribuye a una mejor comprensión del efecto del excedente en posibles recuperaciones. Extender los estudios de recursos excedentes al contexto de empresas brasileñas mostró la influencia que el excedente ejerce en un ambiente institucional relativamente menos explorado. Ya sea financiero, humano o tecnológico, la escasez de recursos es más pronunciada que en empresas de países desarrollados. Esta investigación llama la atención sobre el hecho de que la declinación de empresas brasileñas se analiza desde una perspectiva más amplia. Las decisiones sobre cómo la empresa usa sus recursos pueden afectar positiva o negativamente la declinación de las empresas, reforzando la importancia de discutir esta relación.

A Qual é o impacto da folga de recursos no declínio de grandes empresas brasileiras? Para responder a essa pergunta, testamos hipóteses separadamente para três tipos de folga de recursos: disponível, potencial e recuperável. Essas folgas consistem em recursos além do necessário para manter a organização funcionando.

Desenvolvemos um estudo empírico quantitativo e longitudinal com dados de empresas brasileiras de 1997 a 2008. Adotamos o método de pares combinados, compondo a amostra de pesquisa com um grupo de empresas de capital aberto que declinaram (43 empresas) e outro que não declinou (40 empresas) no período.

Descobrimos que a disponibilidade de recursos mais líquidos reduz a possibilidade de declínio. O efeito moderador na folga de recursos potenciais para empresas em indústrias dinâmicas pode mitigar o declínio.

Esta pesquisa contribui para uma melhor compreensão do efeito da folga sobre possíveis recuperações. A extensão dos estudos de folgas de recursos para o contexto de empresas brasileiras mostrou a influência que a folga exerce em um ambiente institucional relativamente menos explorado. Seja financeiro, humano ou tecnológico, a escassez de recursos é mais pronunciada do que em empresas de países desenvolvidos. Esta pesquisa chama a atenção para o fato de que o declínio de empresas brasileiras é analisado sob uma perspectiva mais ampla. Decisões sobre como a empresa usa seus recursos podem afetar positiva ou negativamente o declínio das empresas, reforçando a importância de discutir essa relação.

The study's objective is to examine the relevance of globalization in affecting the size of the shadow economy in selected African nations.

To do this, the authors employ the KOF globalization index and implement both static and dynamic common correlated mean group estimators on a panel of 24 African nations from 1995–2017. This technique accommodates the issue of cross-sectional dependence, sample bias and endogenous regressors. Panel threshold analysis is also conducted to establish the nonlinearity between globalization and the shadow economy. To examine the causality between the variables, the study employs Dumitrescu and Hurlin's panel causality test.

The results show that globalization reduces the size of the shadow economy. The results of the nonlinear analysis suggest a U-shaped relationship. Overall globalization has a threshold impact of 48.837%, economic globalization has 45.615% and political globalization has 66.661% while social globalization has a threshold value of 35.744%. The results of the panel causality show that there is a bidirectional causality between the two variables.

The results suggest that the government and other relevant authorities need to introduce capital controls and other policy measures to moderate the degree of social, political and cultural diffusion. Appropriate policies should be formulated to monitor the extent of African economic openness to other continents to maximize the gains from globalization.

Apart from being the first study in the African region that evaluates the relevance of globalization in controlling the shadow economy, it also analyzes the dynamics and threshold analysis between the two variables using advanced panel econometrics which makes the study unique. The study suggests that globalization tools are useful for affecting the size of the shadow economy in Africa. This study provides fresh empirical evidence on the impact of globalization on the shadow economy in the case of Africa.