Free Flow Research Articles

Physics-informed neural networks for fully non-linear free surface wave propagation

This study proposed fully nonlinear free surface physics-informed neural networks (FNFS-PINNs), an advancement within the framework of PINNs, to tackle wave propagation in fully nonlinear potential flows with the free surface. Utilizing the nonlinear fitting capabilities of neural networks, FNFS-PINNs offer an approach to addressing the complexities of modeling nonlinear free surface flows, broadening the scope for applying PINNs to various wave propagation scenarios. The improved quasi-σ coordinate transformation and dimensionless formulation of the basic equations are adopted to transform the time-dependent computational domain into the stationary one and align variable scale changes across different dimensions, respectively. These innovations, alongside a specialized network structure and a two-stage optimization process, enhance the mathematical formulation of nonlinear water waves and solvability of the model. FNFS-PINNs are evaluated through three scenarios: solitary wave propagation featuring nonlinearity, regular wave propagation under high dispersion, and an inverse problem of nonlinear free surface flow focusing on the back-calculation of an initial state from its later state. These tests demonstrate the capability of FNFS-PINNs to compute the propagation of solitary and regular waves in the vertical two-dimensional scenarios. While focusing on two-dimensional wave propagation, this study lays the groundwork for extending FNFS-PINNs to other free surface flows and highlights their potential in solving inverse problems.

A review of the experimental techniques research progress of the Pelton turbine

Abstract The Pelton turbine internal flow is by far the most complex of all hydraulic turbo-machinery, which consists of confined flow, free jet flow, free-surface water sheet flow and dispersed flow. The efficiency of Pelton turbine is closely related to these flow phenomena, thus knowing the dynamic behaviour of these flow patterns is of high interest to the optimization of Pelton turbine hydraulic flow parts. The experimental techniques were used to analyse the relationship between the connect of the turbine performance and flow patterns for the earlier researches. The present paper reviewed the development of experimental techniques of Pelton turbines, summarized the emerging test means and discussed the internal flow mechanism.

Earnings management and dividend policy of listed firms in the Ho Chi Minh City stock exchange

Prior studies show that paying dividends limits private control benefits available to managers, which may restrict agency problems and the pos sibilities of managers manipulating earnings. This paper examines whether dividend policy has an impact on earnings management on a sample of listed firms on the Ho Chi Minh Stock Exchange in the period from 2012 to 2022. We use different proxies of earnings management, including accrual based and real earnings management. The results show that dividend pay ing firms have a lower level of earnings management than non-dividend paying firms. Besides, book-to-market equity ratio, firm size, leverage, re turn on assets, number of years listed and free cash flow also have impacts on earnings management. Our results are consistent when using different estimation methods, including OLS, fixed effects, random effects, GLS and GMM regressions with STATA 14. We offer some solutions for the govern ment, the firms and investors to better ensure and understand the quality of firms’ financial reporting.

Global board reforms and corporate acquisition performance

This paper examines the effect of board reforms on corporate acquisition performance using data from 31 countries. Using a difference-in-differences design, we find that the implementation of board reforms in the acquirer's country significantly increases acquirer returns. The increase is driven by reforms involving board independence, but not reforms involving audit committee independence nor the separation of CEO and board chair roles. Further analysis shows that the uplift in acquisition performance following improvements in board independence is strongest in acquirers with more agency problems. The ‘Board reform strengthening’ effect is concentrated in larger acquirers, with more free cash flows, executing large and public-target deals and operating in countries with ex-ante poor investor protection. The empirical evidence indicates that reforming board independence effectively alleviates agency problems between managers and shareholders and improves corporate acquisition performance.

Pengaruh Kebijakan Hutang, Keputusan Investasi dan Free Cash Flow Terhadap Nilai Perusahaan

This research aims to analyze the influence of debt policy, investment decisions and free cash flow on company value. This research was conducted by analyzing the financial reports of companies in the transportation and logistics sector listed on the Indonesia Stock Exchange (BEI) during the 2018-2022 period. The sample used in the research was 11 companies or 55 observation data from the transportation and logistics sector listed on the Indonesia Stock Exchange (BEI) during 2018-2022 using quantitative methods with a sampling technique using purposive sampling. The data used in this research is secondary data in the form of financial reports from each company that has been used as a research sample. The variables used in this research are Debt Policy (X1) as the first independent variable, Investment Decision (X2) as the second independent variable, and Free Cash Flow (X3) as the third independent variable and Company Value (Y) as the dependent variable. The panel data regression method was used as the research methodology in this study. Analysis of research results using the EViews 11 Student Version Lite device. The results of this research show that the best model is the Fixed Effect Model (FEM). The results of this research t test (partial) show that Debt Policy partially has no effect on Company Value, Investment Decisions partially have an effect on Company Value

Investigation of hydraulic characteristics of Pelton turbine with casing structure using a moving particle simulation method

Abstract This paper reports the initial results of three dimensional simulation of the jet/bucket interactions in the vertical Pelton turbine with different casing structures. The casing is an important part of the Pelton turbine, and a reasonable casing structure can reduce the interaction between the jet and bucket, so as to improve the hydraulic efficiency of the turbine. Previous research has little numerical simulation analysis on the casing. In this paper, a Moving Particle Simulation(MPS) method without grid generation is adopted to compare and analyze the hydraulic characteristics of the runner under the regular hexagonal and circular casing structures. The simulation results show that the hydraulic efficiency of the runner under the hexagonal casing structure is better, and the runner time average torque is improved by 3.09%, which compared with the circular casing. The distribution of free surface flows in the hexagonal casing is analysis, and the obvious interference phenomenon between jets can be observed, which has an important guiding role in the design of the casing structure of Pelton turbine in the future.

A Neural Particle Method with Interface Tracking and Adaptive Particle Refinement for Free Surface Flows

A Neural Particle Method with Interface Tracking and Adaptive Particle Refinement for Free Surface Flows

PROJECT ARCHETYPES OF THE EUROPEAN RESEARCH AREA: EXPLORING THE OCCASIONAL ENGAGEMENT PATTERNS OF THE EUROPEAN SOUTHERN NEIGHBOURHOOD

This paper examines the project-based pattern of European Southern Neighbourhood engagement in the European Research Area. Thereby, this study informs about the role of the European Research Area in advancing EU objectives and ambitions in the enduringly salient European Neighbourhood Policy context. The research question that drives this study is: What project archetypes’ pattern denotes the European Southern Neighbourhood’s participation in the pan-European space intended to facilitate the free flow of talent and ideas? The guiding hypothesis anticipates that the prevailing archetype corresponds to an encounter lasting for one project, and prolonged engagement throughout several consecutive projects is a rarity. This enquiry into the relationality weaved by research collaboration formulates four archetypes. The main empirical material employed to model and study the four archetypes is semi-structured interviews with Europe-based project managers. Insights offered by the leading figures of projects funded by Framework Programme 7 and Horizon 2020 reveal how multilateral research-driven ties contribute to post-Westphalian external action aspirations. Devised analytic narratives attest to the performances of the EU science diplomacy, for example, in the form of technoscientific gifts as well as sharing and jointly developing kn/own/ables. Expert experiences of co-developing research-intensive solutions with Morocco- and Tunisia-based colleagues to address the most pressing challenges faced by the EU and its Southern neighbours are resourceful. They offer new insights into the patterned routines that support the implementation of such supranationally steered governance frameworks as the European Research Area, including its external action and science diplomacy dimensions. Almost half of the studied projects correspond to the archetype with one EU-funded project interaction. This confirms the rather sporadic or ad hoc relational ties of the European Southern Neighbourhood to the European Research Area, facilitated by various Europe-based competence centres.

Near-wake measurements and simulations of a floating wind turbine using a four-beam nacelle-based lidar

Recent advances in lidar technology have expanded the possibilities for measuring full-scale wind turbine wakes within the atmospheric boundary layer. This study utilizes a four-beam pulsed lidar installed on the nacelle of a floating turbine to measure the near-wake. The wake measurement campaign was conducted on the Floatgen, with lidar measurements reaching up to 2.5 times the rotor diameter distance. These measurements are presented as 10-minute average radial wind speeds. The focus of this study is on the below rated wind speed of 7 m/s. Free flow conditions were assumed at the farthest measurement points, which are located ±0.9 times the rotor diameter from to the rotor center. The sensitivity of lidar measurements to turbulence intensity, vertical wind shear, and significant wave height was investigated. The environmental conditions were categorized into five cases, considering turbulence, vertical shear, and yaw misalignment as well as waves. Two simulation models with different fidelity levels are used to simulate these cases, and the beam-wise radial wind speed predictions are compared with the measurements. A maximum mean absolute error of 11.3% between the measurements and simulations is observed.

The data quality problem (in the European Financial Data Space)

Abstract By creating the European Financial Data Space (EFDS), the European Commission aims to foster the development of data-driven innovation in the financial sector. Artificial intelligence (AI) is the most notable innovation that could benefit from enhanced access to data through the EFDS. However, the current policy framework establishing the EFDS suffers from a major limitation—it neglects the question of data quality or whether the data shared in the EFDS will be fit for the purpose of the development of AI applications. The AI Act and General Data Protection Regulation could play a role in fostering data quality in this area, but the two frameworks are also unlikely to do that to a satisfactory extent. To address the data quality problem, this article proposes policymakers should develop a framework for data quality that encompasses both a conceptual and an organizational dimension aimed at promoting the free flow of high-quality data in the EFDS.

Key Financial Ratios Drive Earnings Management in Indonesian Firms

This study investigates the impact of leverage, profitability, liquidity, total asset turnover, and free cash flow on earnings management in LQ45 index companies from 2019 to 2021. Using a sample of 23 companies selected through purposive sampling and analyzed with multiple linear regression via SPSS version 26, the results show that leverage, total asset turnover, and free cash flow significantly influence earnings management, while profitability and liquidity do not. These findings highlight key financial indicators that can signal earnings management practices, providing useful insights for investors, regulators, and auditors. Highlights: 1. Influential Factors: Leverage, asset turnover, and free cash flow affect earnings management.2. Non-influential Factors: Profitability and liquidity don't affect earnings management.3. Practical Use: Insights help investors, regulators, auditors detect earnings management. Keywords: Leverage, Profitability, Liquidity, Total Asset Turnover, Free Cash Flow

Enhancing fuel distribution of downward steps in supersonic combustion chambers using shock generators

This study investigates the impact of a shock generator on the fuel distribution of downward step fuel injection in a scramjet engine’s combustor. Computational simulations of CFD are employed to analyze the three-dimensional structure of multi-jets released in a downward-step configuration. The inlet is subjected to a free stream supersonic flow with [Formula: see text], while hydrogen gas is injected at [Formula: see text] through injectors situated on the vertical planes of the downward step. A shock generator with a [Formula: see text] angle is positioned at the top of the domain to induce a bow shock, which significantly affects fuel distribution. The research assesses the influence of free stream and jet pressure on the fuel distribution behind the jets. The results indicate that increasing the free stream flow strengthens the induced bow shock, leading to enhanced fuel jet interactions and improved fuel mixing behind the jets.

Modeling of transient free convection flow in terms of permeability and thermal radiation

Modeling of transient free convection flow in terms of permeability and thermal radiation

Computational study of the aligned magnetic field in a plume generated by the energy line source

This present research concerns with the study of two-dimensional, steady, magnetohydrodynamic free convection flow in a plume generated due to horizontal line heat source. The aligned magnetic field is applied at the vertical component of plume. The mathematical model of the governing flow problem is based on coupled nonlinear partial differential equations. Later, the system of partial differential equations is transformed into system of ordinary differential equations by using appropriate form of stream function formulation. For computational results, a Shooting technique along with bvp4c algorithm for MATLAB is employed to estimate the missing conditions in flow model. The effects of variation in Prandtl number., magnetic force parameter S , and magnetic Prandtl number γ on the velocity, current density, and temperature profile are illustrated in graphical manner along with their physical impacts. The novelty of current work is that the magnetic field has its strong impact on the vertical component of plume generated due to heat source. It is observed that, with the increase in the parameter S , the missing conditions, the velocity, current density, and temperature decreased. Whereas, the specified conditions, the skin friction f ″ and magnetic flux ϕ ′ drop while heat transfer rate θ ′ enhanced with increment in parameter S .

REGULATION OF CROSS-BORDER DATA FLOW AND ITS PRIVACY IN THE DIGITAL ERA

We are living in a world where information systems are becoming a new weapon to control the future. When the data flows across national borders, it becomes an invaluable resource for economic and informational development in any nation. Today, cross-border data flows are an important component of international trade because companies are frequently transfer customer’s and employee’s data across different countries. This paper will examine the importance of the free flow of cross-border data and its privacy concerns. It also examines the failure of the Information Technology Act, 2000, and the Digital Personal Data Protection Act, 2023, to provide protection from cross-border data transfer; specifically, the Digital Personal Data Protection Act, 2023, is silent on the criteria of listing countries for data transfer and the processing of personal data of those data principals who are living outside India. Some countries have implemented laws pertaining to “data localization” as a means to restrict the movement of data outside their respective borders, but it affects international trade and development. So, it raises a question: What kind of and how much data do nations have to restrict for cross-border data transfer internationally? This paper analyse the General Data Protection Regulation of the European Union, the Cross-Border Privacy Rules of the Asia-Pacific Economic Cooperation of the United States, and the Privacy Shield Framework between the EU and the US. In the end this paper concludes with suggestions for the privacy of cross-border data and the need of uniform law for its worldwide applicability.

Let’s love boredom! Boredom as an alternative to the overstimulated world oftoday’s youth in the context of capacity development

This article addresses the topic of boredom in the context of skill development, presentingan analysis of the subject literature that presents boredom ambiguously. On one hand, itis depicted as an inhibitor of abilities and a threat to well-being and mental health, and onthe other, as a potentially positive element in the education and development of the gifted.The analysis focuses on various definitions and classifications of boredom, presenting it asa multidimensional phenomenon that can have both negative and positive impacts on thecondition of the gifted student. Modern youth live in conditions of stimulus overload, mainlydue to the digital world, which affects their social, psychological, and physical well-being.The intensity of emotions and fears amongst the young related to living on social media hasnever been so intense. The results of the discussed studies indicate that boredom can serve asa free space for deeper self-knowledge, a space for the free flow of thoughts, self-reflection,and creative thinking, contrasting with the negative aspects of continuous stimulation. Thearticle concludes that there may be a third way beyond killing or dying of boredom. A newperspective on the use of boredom in the educational context suggests that boredom can beappreciated and utilised as a catalyst for the development of the gifted student instead ofeliminating it. The article encourages breaking away from conventional approaches to giftededucation, exploring and accepting boredom as an integral part of the learning and developmentprocess, and offering an alternative to the stimulus-saturated world.

Pengaruh Arus Kas Bebas dan Efektivitas Komite Audit Terhadap Kualitas Audit

Good audit quality is an important factor in ensuring the integrity and reliability of an entity's financial reports. This research aims to examine the influence of free cash flow and audit committee effectiveness on audit quality. Free cash flow reflects the availability of financial resources for a company to finance operational and audit activities. Meanwhile, an effective audit committee can ensure adequate oversight of the financial reporting and audit processes. This research uses panel data which includes companies listed on the Indonesia Stock Exchange during the 2018-2022 period. Free cash flow is measured using the ratio of operating cash flow to total assets, while audit committee effectiveness is measured using a composite score that includes the audit committee's independence, expertise and activities. Audit quality is assessed based on proxies such as the size of the public accounting firm, auditor industry specialization, and audit fees. The research results show that free cash flow and audit committee effectiveness have a significant positive influence on audit quality. Companies with high free cash flow tend to have adequate resources to pay higher audit fees, thereby encouraging auditors to carry out a more in-depth and quality audit process. In addition, an effective audit committee can ensure good oversight of the financial reporting and audit process, thereby improving audit quality. These findings provide important implications for companies and regulators in improving audit quality through managing free cash flow and establishing effective audit committees. Future research can explore other factors that influence audit quality and include relevant control variables.

Understanding the evolution of China’s approach to digital trade: interests, ideas, and institutions

Amid economic globalisation and the rapid development of advanced technologies in recent years, the world economy has shown an increasing trend of digitalisation, whilst digital trade has become the primary pattern of international trade. Based on differences rooted in socio-political systems, as well as the current precarious geopolitical realities, governments adopt different ideas in accordance with their respective interests in the institutionalisation of digital trade. As the world’s second-largest economy and a major digital power, China’s behaviours and ideological stances attract scholarly attention and states’ concern. Whilst Western countries and scholars have criticised China’s ideas of “government intervention in data regulation” and “cyber sovereignty” applied in its existing approach to digital trade, warning that China’s approach poses a threat to Western powers’ adherence to liberalism in the international digital trade system and the idea of “free data flow” in their approaches to digital trade, there has been insufficient research into how China’s approach to digital trade has evolved over time and which ideas and interests have influenced it. To bridge this gap in the literature, this paper divides the evolution of China’s approach to digital trade over the past three decades (1993–2023) into three phases using a longitudinal approach. This research conducts qualitative content analysis using official documents, white papers, and declarations from official Chinese websites, then adopts the 3I analytical framework to analyse which ideas and interests have influenced China’s approach in each phase and how its approach to digital trade has evolved over time.

Between Freedom and Order: Evolution logic of urban-rural population mobility Policy from the perspective of historical institutionalism

Urban-rural population flow is the key element and important driving force for urban-rural integration development and rural revitalization. The pattern of urban-rural population flow in China is restricted and guided by policies. From the perspective of historical institutionalism, this paper analyzes the evolution context, structural logic and dynamic mechanism of the change of urban and rural population mobility policy. The urban and rural population mobility policy has gone through five historical stages: the order reconstruction period at the beginning of the founding of New China, the political call period after the Great Leap Forward Movement, the free flow period after the reform and opening up, the period of making the best use of the situation under the economic system reform and the accelerated integration period under the background of the new era. The institutional choice under different paths, the institutional evolution under the key nodes and the institutional continuation under the path dependence constitute the structural logic of the policy change of urban-rural population mobility. The situation coupling under the action of exogenous variables, the value coupling promoted by the change of ideas, and the subject coupling under the interaction of actors’ game constitute the dynamic mechanism of policy change, which promotes the historical change and realistic development of policy.

Does Debt Structure Explain the Relationship between Agency Cost of Free Cash Flow and Dividend Payment? Evidence from Saudi Arabia

This paper investigates the impact of debt financing on dividend payments when they face the agency costs of free cash flow. It focuses on a sample of 120 firms listed on the Saudi Stock Exchange during the period of 2011–2021. The findings from the Generalized Least Squares regression model revealed that the presence of agency costs of free cash flows may limit the funds available for dividend payments. Regarding the moderating effect of debt structure, the research highlights the significant role of long-term debt in making more prudent use of free cash flow. The use of long-term debt becomes more effective and can enhance shareholder wealth when a firm is facing agency costs of free cash flow. More specifically, bondholders primarily focus on affirmative covenants which require the firm to undertake specified actions such as maintaining assets and financial ratios, or paying taxes, but they do not restrict financing activities such as dividend payments. Since interest and debt repayments are fixed obligations, using free cash flow for dividend disbursement is considered a more profitable and beneficial approach for shareholders in the context of Saudi Arabia. This study contributes to our understanding of financial management under different debt structures and improves our scientific knowledge of the culture of Saudi firms regarding the dividend distribution policy.