Multidiszciplináris Tudományok

Exploring stress-dependent acoustic velocity hysteresis in rocks

Edoson Manuel Ernesto, Mihály Dobróka — p, 13 febr 2026 00:00:00 +0100

Knowledge of acoustic wave velocity in rocks is essential for geophysical studies, as it helps identify geological structures that may contain hydrocarbon accumulations. Acoustic velocity is strongly influenced by pressure and the presence of pore volume. This paper integrates experimental data with theoretical modeling to investigate stress-dependent acoustic velocity hysteresis in rocks and to analyze how stress affects acoustic velocity during loading and unloading. The study focuses on quasi-static elastic properties and introduces a new petrophysical model that explains acoustic hysteresis through pore closure and opening, thereby affecting P-wave propagation. The model is consistent with the observed data and provides a coherent framework for understanding the interactions among stress, pressure, and acoustic behavior. To validate the model, a sandstone sample was tested under incremental pressures, and the model parameters were determined using a linearized inversion method. The calculated and measured velocities showed close agreement, confirming the model’s applicability.

The compliance assurance function in light of the recommendation for internal defense lines in Hungary

Klaudia Murányi — p, 13 febr 2026 00:00:00 +0100

The internal defense lines are closely intertwined with the overall operation and security of financial organizations. Their effective functioning is critically important not only for the organization itself but also for maintaining economic stability and societal trust. Consequently, their establishment and maintenance are indispensable for the sustainable and secure operation of the financial sector. In my study, I aim to provide a descriptive overview of the compliance assurance function, including a brief review of the literature, legal regulations, and the National Bank of Hungary Recommendation No. 12/2022 (VIII. 11.), which pertains to the establishment and operation of internal defense lines, as well as the governance and control functions of financial organizations. The purpose of the study is to present in detail the rules formulated by the recommendation regarding the compliance assurance function, emphasizing the importance of internal defense lines for the stability and integrity of the financial sector.

Real time formation prediction using machine learning models based on drilling parameters

József Pap, Norbert Péter Szabó, Mátyás Krisztián Baracza, Dr. Turzó Zoltán — p, 13 febr 2026 00:00:00 +0100

Accurate knowledge of formation characteristics is critical during well development, particularly in the drilling phase, as it guides trajectory planning, casing depth selection, and the design of bit, fluid, and cementing programs. Additionally, a precise lithological sequence is essential for determining optimal perforation depths and managing production. Real-time data interpretation is increasingly valuable for enabling faster decisions and reducing operational costs. Traditionally, formation interpretation relies on manual analysis of drilling logs and shaker samples by petrophysicists or geologists. This paper introduces a machine learning-based approach to predict formation types using real-time drilling and MWD parameters, demonstrating the potential to enhance accuracy and decision-making efficiency compared to conventional methods.

Audit requirements in Europe

Judit Füredi-Fülöp, Klaudia Murányi, Mária Várkonyiné Juhász — p, 13 febr 2026 00:00:00 +0100

Statutory audit is essential for ensuring transparency and reliability in ensuring the transparency and reliability of financial reporting. In Hungary, the Accounting Act defines the mandatory cases of audit, primarily based on sales revenue and number of employees. In recent years, however, these thresholds have been significantly increased have recently been increased, significantly reshaping the audit landscape. This paper aims to provide a comprehensive overview of the statutory audit requirements in Hungary, by placing the Hungarian case in a broader European context. Given the diversity of national audit regimes within the EU, the paper explores how recent threshold changes align with or diverge from trends observed across Member States. Special attention is paid to the underlying motivations of the EU and individual countries to adjust audit obligations. The goal is to assess the potential implications of higher thresholds on audit quality, financial transparency, and the role of auditors in corporate governance.