In this paper, a tactical Production-Distribution Planning (PDP) has been handled in a fuzzy and stochastic environment for supply chain systems (SCS) which has four echelons (suppliers, plants, warehouses, retailers) with multi-products, multi-transport paths, and multi-time periods. The mathematical model of fuzzy stochastic PDP is a NP-hard problem for large SCS because of the binary variables which determine the transportation paths between echelons of the SCS and cannot be solved by optimization packages. In this study, therefore, two new meta-heuristic algorithms have been developed for solving fuzzy stochastic PDP: Ant Colony Optimization (ACO) and Genetic Algorithm (GA). The proposed meta-heuristic algorithms are designed for route optimization in PDP and integrated with the GAMS optimization package in order to solve the remaining mathematical model which determines the other decisions in SCS, such as procurement decisions, production decisions, etc. The solution procedure in the literature has been extended by aggregating proposed meta-heuristic algorithms. The ACO and GA algorithms have been performed for test problems which are randomly generated. The results of the test problem showed that the both ACO and GA are capable to solve the NP-hard PDP for a big size SCS. However, GA produce better solutions than the ACO.

This study investigated twin-propeller-induced scour on sandy seabeds with varying grain sizes (d₅₀ = 0.11, 0.5, and 0.95 mm) through a series of laboratory experiments. The effects of propeller rotation speed (rpm), offset height (y₀), propeller diameter (D_p), and sediment grain size (d₅₀) on scour development were examined. Results indicated that sediment grain size significantly influences scour patterns. A key objective was to develop predictive expressions for primary scour characteristics at equilibrium: maximum scour depth (S_max), scour hole length (L_max), and maximum scour width (B_max). Using a nonlinear regression approach, the proposed expressions demonstrated strong predictive performance. Findings show that equilibrium scour depth increases with higher Froude numbers (F₀) but decreases with larger sediment size (d₅₀) and higher propeller offset (y₀). Additionally, empirical equations were formulated to predict the temporal evolution of scour depth, achieving high correlations with experimental data (R² > 0.97). These results enhance understanding of scour induced by unconfined twin-propeller jets in harbors or navigation channels and provide valuable data for the design and protection of harbor basins.

Digital technologies have transformed educational paradigms, particularly in language learning through mobile-assisted language learning (MALL) and gamification strategies. Digital natives expect interactive learning experiences integrating with their technology-rich environments. Game-based learning (GBL) combines entertainment with educational objectives, demonstrating potential for improving learner motivation and knowledge retention in second language acquisition. This study evaluates the effectiveness and user experience of a proprietary gamified mobile application for English language learning, focusing on practical skill development and cross-cultural applicability. A comprehensive evaluation was conducted using a 38question, 5-point Likert-scale questionnaire administered to 516 participants aged 14-25 from Türkiye, Hungary, and Germany following two months of application usage. The questionnaire encompassed five dimensions: User Experience and Interface, Content Quality and Effectiveness, Motivation and Tracking Mechanisms, Interaction and Personalization, and Overall Satisfaction. Data analysis employed descriptive statistics, correlation analysis, and thematic evaluation. The application achieved consistently high satisfaction scores across all dimensions, with mean values ranging from 3.79 to 4.18. The highest-rated aspect was overall effectiveness as a language learning tool $(\bar{x}=4.18, \sigma=0.94)$, while practical language skill applicability received strong endorsement ($\bar{x}=4.14, \sigma=1.00$). Correlation analysis revealed strong positive relationships between user experience factors, particularly between User Experience and Interface and Content Quality and Effectiveness ($r=0.839$). The study demonstrates successful integration of gamification and mobile learning technologies for language education, with users perceiving significant educational value and practical applicability across different cultural contexts.