Search Results (415)

We develop a topological-combinatorial framework applying classical Ramsey theory to systems of arcs connecting points on Jordan curves and their higher-dimensional analogues. A Jordan curve Λ partitions the plane into interior and exterior regions, enabling a canonical two-coloring of every arc connecting points on Λ according to whether its interior lies in Int(Λ) or Ext(Λ). Using this intrinsic coloring, we prove that any configuration of six points on Λ necessarily contains a monochromatic triangle, and that this property is invariant under all homeomorphisms of the plane. Extending the construction by including arcs lying on Λ itself yields a natural three-coloring, from which the classical value $R\left(3,3.3\right)=17$ guarantees the appearance of monochromatic triangles for sufficiently large point sets. For infinite point sets on Λ, the infinite Ramsey theorem ensures the existence of infinite monochromatic cliques, which we likewise show to be preserved under arbitrary topological deformations. The framework extends to Jordan surfaces and Jordan–Brouwer hypersurfaces in higher dimensions, where interior, exterior, and boundary regions again generate canonical colorings and Ramsey-type constraints. These results reveal a general principle: the separation properties of codimension-one topological boundaries induce universal combinatorial structures—such as monochromatic triangles and infinite monochromatic subsets—that are stable under continuous deformations. The approach offers new links between geometric topology, extremal combinatorics, and the analysis of constrained networks and interfaces. Full article

High-quality development of agricultural enterprises is essential for China’s rural revitalization, yet the institutional conditions that support it remain poorly understood. Drawing on institutional logics and configuration theory, this study adopts a holistic systems perspective to examine how government, market, and social institutions interact to shape enterprise performance. Using provincial data (2013–2023) matched with firm-level data for 119 listed agricultural enterprises, we estimate total factor productivity as the core outcome and apply dynamic fuzzy-set Qualitative Comparative Analysis (dynamic fsQCA) to identify equifinal institutional pathways. The results reveal that high-quality development is an emergent property of complex institutional systems; instead, high-quality development emerges from several distinct configurations combining policy support, marketization, financial development, Agricultural Infrastructure Index, market stability, and urban–rural integration. Two contrasting configurations are associated with non-high-quality development, characterized by financial scarcity and infrastructure deficits or by fragmented policy support under weak regulation. Dynamic analysis further reveals clear temporal and spatial heterogeneity: some market–finance driven paths lose robustness over time, while policy–urbanization and regulation–infrastructure based configurations become increasingly stable. These findings extend institutional configuration research to the agricultural sector, demonstrate the value of dynamic fsQCA for capturing temporal effects, and offer differentiated policy implications for optimizing institutional environments to foster the high-quality development of agricultural enterprises. Full article

This study examines decision-making in intelligent virtual agents (IVAs) and formalizes the distinction between tactical decisions (individual actions) and strategic decisions (composed of sequences of tactical actions) using a mathematical model based on set theory and the Bellman equation. Although the equation itself is not modified, the analysis reveals that the discount factor (γ) influences the type of decision: low values favor tactical decisions, while high values favor strategic ones. The model was implemented and validated in a proof-of-concept simulated environment, namely the Snake Coin Change Problem (SCCP), using a Deep Q-Network (DQN) architecture, showing significant differences between agents with different decision profiles. These findings suggest that adjusting γ can serve as a useful mechanism to regulate both tactical and strategic decision-making processes in IVAs, thus offering a conceptual basis that could facilitate the design of more intelligent and adaptive agents in domains such as video games, and potentially in robotics and artificial intelligence as future research directions. Full article

In today’s rapidly evolving business environment, digitalization has emerged not only as a technological trend but also as a strategic imperative. This paper develops a conceptual framework that examines how Industry 4.0 (I4.0) technologies and tools drive strategic innovation and enable the transformation of business models. Based on a systematic literature review, the framework identifies a set of organizational and contextual preconditions (strategic vision, organizational culture, digital skills, infrastructure, financial resources, and regulatory conditions) that can act as either enablers or barriers to innovation. The analysis reveals that these preconditions give rise to two contrasting innovation cycles: a virtuous cycle, where favourable conditions amplify the adoption of digital technologies and foster business model transformation, and a vicious cycle, where unfavourable conditions reinforce technological inertia and hinder strategic development. By integrating insights from innovation management, digital transformation, and business model theory, the framework offers a nuanced understanding of how technology and strategy intersect and provides actionable guidance for managers seeking to move beyond operational improvements toward reimagining value creation, delivery, and capture in the digital age. Full article

This paper develops a robust portfolio optimization framework that integrates Weighted Shannon Entropy (WSE) into the classical mean–variance paradigm, offering a distribution-free approach to diversification suited for volatile and heavy-tailed markets. While traditional variance-based models are highly sensitive to estimation errors and instability in covariance structures—issues that are particularly acute in cryptocurrency markets—entropy provides a structural mechanism for mitigating concentration risk and enhancing resilience under uncertainty. By incorporating informational weights that reflect asset-specific characteristics such as volatility, market capitalization, and liquidity, the WSE model generalizes classical Shannon entropy and allows for more realistic, data-driven diversification profiles. Analytical solutions derived from the maximum entropy principle and Lagrange multipliers yield exponential-form portfolio weights that balance expected return, variance, and diversification. The empirical analysis examines two case studies: a four-asset cryptocurrency portfolio (BTC, ETH, SOL, and BNB) over January–March 2025, and an extended twelve-asset portfolio over April 2024–March 2025 with rolling rebalancing and proportional transaction costs. The results show that WSE portfolios achieve systematically higher entropy scores, more balanced allocations, and improved downside protection relative to both equal-weight and classical mean–variance portfolios. Risk-adjusted metrics confirm these improvements: WSE delivers higher Sharpe ratios and less negative Conditional Value-at-Risk (CVaR), together with reduced overexposure to highly volatile assets. Overall, the findings demonstrate that Weighted Shannon Entropy offers a transparent, flexible, and robust framework for portfolio construction in environments characterized by nonlinear dependencies, structural breaks, and parameter uncertainty. Beyond its empirical performance, the WSE model provides a theoretically grounded bridge between information theory and risk management, with strong potential for applications in algorithmic allocation, index construction, and regulatory settings where diversification and stability are essential. Moreover, the integration of informational weighting schemes highlights the capacity of WSE to incorporate both statistical properties and market microstructure signals, thereby enhancing its practical relevance for real-world investment decision-making. Full article

In the context of growing environmental consciousness, the contemporary construction industry is placing significant emphasis on prolonging the functional lifespan of existing infrastructure. In the event of a modification in the utilisation of a building, an augmentation in the loads transferred to individual elements, or a deterioration in the condition of the structure due to wear and tear, it is often necessary to implement measures for structural reinforcement. The present paper sets out an analysis of the effectiveness of strengthening a steel column manufactured from SHS120×120×5. It was posited that four distinct reinforcement variants could be achieved by the implementation of additional stiffening elements through the process of welding. The efficiency analysis was conducted employing two distinct methodologies. The geometrical imperfection method is employed using the IDEAStatiCa Member 25.0.4 software, whilst the analytical method is implemented through the use of guidelines presented in the literature. It was demonstrated that all of the proposed solutions were capable of meeting the required column capacity when the loads were increased. A comparison was made between the values of the critical forces and the members’ stresses, determined by the selected methods. A substantial discrepancy was identified between the critical force values derived from linear buckling analysis and those calculated using elastic Euler theory. The following discourse herein delineates the primary advantages and limitations of the two aforementioned methods. Full article

As destinations featured in films and television programs attract growing numbers of tourists, exploring the factors that sustain film tourists’ loyalty and advocacy has become increasingly important. This study explores the determinants of post-visit behaviors through the lens of cognitive appraisal theory (CAT), investigating how perceived authenticity, perceived value, and satisfaction shape revisit and word-of-mouth (WOM) intentions among 436 Chinese film tourists visiting Thailand. Data were analyzed using structural equation modeling (SEM) and fuzzy-set qualitative comparative analysis (fsQCA) to capture both symmetrical and configurational effects. The SEM results reveal that perceived authenticity, perceived value, and satisfaction significantly enhance WOM intentions. The complementary fsQCA findings reveal multiple causal pathways leading to high revisit and WOM intentions. The study advances theoretical understanding by demonstrating the applicability of CAT to film tourism and showing how tourists’ cognitive evaluations and emotional appraisals jointly shape their post-visit behavioral intentions. The findings also offer practical guidance for developing authenticity-based strategies to foster loyalty and positive destination advocacy. Full article

Background: The management of inventory under realistic supply chain disruptions, which are often non-exponential, challenges classical control theory. This study addresses the critical question of whether the optimality of simple base-stock policies holds under the combined influence of non-exponential disruptions and random yield. Methods: We model the system as a Piecewise Deterministic Markov Process (PDMP) with impulse control, using Phase-Type (PH) distributions to capture non-memoryless event timings. The analysis involves proving the existence of a solution to the Average Cost Optimality Equation (ACOE) via a vanishing discount approach, and the framework is validated with a numerical experiment. Results: Our primary finding is a rigorous proof that a state-dependent base-stock policy is optimal, a significant generalisation of classical theory. We establish this by demonstrating the value function’s convexity. The numerical experiment quantifies the significant cost penalties (over 12%) incurred by using simpler, memoryless models for supply disruptions. Conclusions: The study provides a crucial theoretical justification for the robustness of simple threshold-based control policies in complex, realistic settings. It highlights for managers the importance of modelling the variability of disruptions, not just their average duration, to avoid costly strategic errors. Full article

This article frames the virtual museum as a meaning-modeling system within digital heritage and proposes an operational semiotic method for analysis. Grounded in Modeling Systems Theory and informed by Adorno’s non-identity, we construct a twelve-category coding matrix that combines three modeling levels with four organizational forms. Applying this matrix to five heterogeneous cases (web, VR, and 3D environments), we derive three quantitative ratios that summarize each system’s profile: the Abstraction Ratio (degree of conceptual mediation), the Connectivity Ratio (degree of interlinking and systematic organization), and the Object Primacy Score (degree of object-centered representation). Exploratory clustering on these ratios reveals three recurrent patterns of virtual-heritage mediation: Network-Symbolic, Concept-Dominant, and Object-Preserving. The results articulate how different curatorial and technical choices redistribute attention between objects, contexts, and concepts, and how these redistributions affect the subject–object balance in digital settings. The contribution is twofold: a transparent, reproducible coding protocol that enables cross-case comparison, and an interpretive lens that relates quantitative patterns to critical concerns in heritage, including authenticity, legibility, and over-standardization. We conclude with implications for curators and designers seeking to align immersive interfaces with heritage values while preserving the irreducible remainder of the object. Full article

Place attachment, or the emotional bond between people and physical settings, is a central concept in urban design and environmental psychology. Although biophilic and restorative environmental frameworks have stressed the value of natural environments, empirical research investigating nature and place attachment often reduces naturalness to simple greenness metrics, leaving the role of aesthetic and visual structural qualities underexplored. This study addresses this gap by drawing on empirical aesthetics and Christopher Alexander’s theory of living structures, which frames aesthetics as an underlying order that gives rise to the experience of visual coherence and beauty. We conducted a multi-method quantitative case study on ten campus open spaces, combining a student survey (n = 447), timed-interval behavioural observations, independent aesthetic ratings, and computational image analysis. The data analysis relied on correlation and regression, as well as data triangulation from multiple sources that encompassed both subjective and objective measurements. Regression and mediation models showed that perceived restorativeness was the strongest predictor of place attachment, complemented by sense of community, perceived wholeness, and naturalness. Indirect pathways revealed that passive interaction enhanced attachment through restorativeness, while active interaction did so through a sense of community. Image-based metrics, particularly fractal dimension and entropy, were closely aligned with perceptions of naturalness and restoration, while behavioural observations confirmed the distinct roles of social hubs, solitary natural retreats, and transitional spaces. The findings demonstrate that both naturalistic structure and social affordances are essential to attachment, and that living structure qualities offer a valuable framework for linking aesthetic order to restorative and emotional bonds. These insights provide both theoretical enrichment and practical guidance for designing restorative and life-enhancing public environments. Full article

Perceived value is a key factor shaping consumer purchase decisions. In the field of functional snack consumption, generational differences in value perception dimensions significantly influence decision-making processes, creating both challenges and opportunities for targeted marketing. Drawing on perceived value theory, this study develops a model examining the impact of perceived value on consumption intention for functional snacks. A questionnaire survey was conducted among Chinese Generation Y and Generation Z consumers, and the data were analyzed using PLS-SEM and fuzzy-set Qualitative Comparative Analysis (fsQCA). The results indicate that self-oriented values (functional and hedonic) exert a significant positive effect on other-oriented values (symbolic and social), and both categories of values positively affect consumption intention. Regarding generational moderation, the effects of functional and hedonic values on purchase intention do not differ significantly across generations; however, symbolic value has a stronger influence on Generation Z, while social value plays a more prominent role for Generation Y. Importance–Performance Map Analysis (IPMA) results further reveal differences in the relative importance and performance of value perception between the two groups. Configuration analysis shows that compared with Generation Y, Generation Z exhibits a higher threshold for strong consumption intention, a lower threshold for weak consumption intention, and greater sensitivity to value deficiency. These findings provide practical insights for functional snack companies to address generational differences and optimize marketing strategies. Full article

Universalism, as defined in Schwartz’s theory of basic human values, reflects a motivational orientation toward understanding, appreciation, and protection of all people and nature. This study examines the psychological foundations of ethical concern and ecological sensitivity among university students, focusing on the role of transcendence strengths. A cross-sectional correlational design was employed and a total of 1240 students from five Spanish universities participated in the study, completing validated instruments designed to assess both transcendence strengths—spirituality, gratitude, hope/optimism, humor, and appreciation of beauty—and universalism. Stepwise regression analysis identified four strengths—gratitude, appreciation of beauty, hope/optimism, and spirituality—as significant predictors of ethical concern for others and nature, explaining 20.1% of the variance. These findings contribute to the growing body of research linking positive psychological traits with ethical engagement and environmental responsibility. They also suggest that fostering transcendence-related strengths in educational settings may enhance students’ capacity for global empathy and moral development. Moreover, rather than functioning in isolation, spirituality interacts dynamically with other transcendence strengths. The study highlights the importance of integrating transcendental dimensions into sustainability discourse. Future research should explore these relationships across cultures and developmental stages to inform policy and educational practice. Full article

We suggest a novel strategy in the theory of elastic plane composites. The macroscopic properties are quantified, and an analytical–numerical algorithm to derive expressions for the effective constants is designed. The effective elastic constants of dispersed random composites are given by new analytical and approximate formulas where the dependence on the location of inclusions is explicitly shown in symbolic form. This essentially extends the results of previous numerical simulations for a fixed set of material constants and fixed locations of inclusions. This paper extends the analysis from Part I, which addressed dispersed random conducting composites, to the two-dimensional elastic composites. Hill’s concept of Representative Volume Element (RVE), traditionally used in elastic composites, is revised. It is rigorously demonstrated that the RVE must be a fundamental domain of the plane torus, for instance, a periodicity parallelogram, since other shapes of RVE may lead to incorrect values of the effective constants. The effective tensors of the elasticity theory are decomposed into geometrical and physical parts, represented by structural sums and material constants of the components. Novel computational methodology based on such decomposition is applied to a two-phase isotropic composite with non-overlapping circular inclusions embedded in an elastic matrix. For the first time, it is demonstrated explicitly how the effective tensors depend on the geometric probabilistic distributions of inclusions and the computational protocols involved. Analytical polynomial formulas for the effective shear modulus for the moderate concentration of inclusions are transformed using the resummation methods into practical expressions valid for all concentrations of inclusions. The critical index for the effective shear modulus is calculated from the polynomials derived for the modulus. Full article

This systematic search with narrative synthesis examines metaverse business models and their shift toward immersive virtual ecosystems. Following the PRISMA flow for identification and screening to structure transparency, we review 91 publications to map the shift from classical and digital models to metaverse models, highlighting new value propositions, revenue mechanisms, and the integration of VR, AR, and blockchain across the value chain. Our contributions are threefold: we articulate the transition patterns from classical and digital to metaverse business models; we propose a structured metaverse business framework with evaluation dimensions; and we compile a candidate metric set to support comparative analysis. Interpreting the evidence through a socio-technical systems lens, the synthesis indicates an emergent shift in how value is created, delivered, and captured. We identify five core dimensions for assessing metaverse business models: scalability, technological adaptability, user engagement and retention, ethical and sustainability practices, and economic viability as critical dimensions for future comparative analysis of metaverse business models. Building on these findings, we propose a metaverse business framework and a set of candidate KPIs to enable comparative evaluation and guide investment, design, and governance. The paper advances digital transformation theory and outlines a research agenda on dynamic capabilities and the long-term sustainability of metaverse business models. Full article

Inatlar limestone, which is dated to the Middle Jurassic–Lower Cretaceous, is exposed between the villages of Kabulbaba and Söğütalan in the Mustafakemalpaşa district of Bursa, Turkey. This study investigates its mineralogical, petrographic, and geochemical characteristics, focusing on major, trace, and rare earth element (REEs) compositions to interpret the depositional environment, paleoenvironmental conditions, and diagenetic processes. Petrographic analysis identified four main limestone types: siliceous, micritic, fossiliferous, and dolomitic. REEs geochemistry indicates enrichment in heavy REEs (HREEs), depletion in light REEs (LREEs), and characteristic anomalies with negative Ce and Eu and positive La, suggesting an open marine depositional environment and early diagenesis. Trace element data point to deposition in settings ranging from continental margins to open marine environments. Ni and V concentrations reflect a spectrum of depositional conditions, including terrestrial, transitional (oxic–dysoxic), and marine anoxic settings. Z values support the theory that the limestones have a marine origin. δ¹³C and δ¹⁸O isotope values indicate deposition in both hydrothermal and typical marine carbonate environments. Y/Ho and Er/Nd ratios reveal the influence of terrestrial input, as well as diagenetic and detrital material. Furthermore, V/(V + Ni) ratios reflect fluctuating oxic to suboxic/anoxic conditions, while Ni/Co ratios indicate predominantly euxinic and, to a lesser extent, anoxic conditions. Altogether, these geochemical signatures suggest that the Inatlar limestone was deposited in a dynamic marine system characterized by variable redox states and salinity fluctuations. Full article