Search Results (155)

A basic duality arises throughout the mathematical and natural sciences. Traditionally, logic is thought to be based on the Boolean logic of subsets, but the development of category theory in the mid-twentieth century shows the duality between subsets and partitions (or equivalence relations). Hence, there is an equally fundamental dual logic of partitions. At a more basic or granular level, the elements of a subset are dual to the distinctions (pairs of elements in different blocks) of a partition. The quantitative version of subset logic is probability theory (as developed by Boole), and the quantitative version of the logic of partitions is information theory re-founded on the notion of logical entropy. The subset side of the duality uses a one-sample (or one-element) approach, e.g., the mean of a random variable; the partition side uses a two-sample (or pair-of-elements) approach. This paper gives a new derivation of the variance (and covariance) based on the two-sample approach, which positions the variance on the partition and information theory side of the duality and thus dual to the mean. Full article

In this study, we define the $k$-Cullen, $k$-Cullen–Lucas, and Modified $k$-Cullen sequences, and certain terms in these sequences are given. Then, we obtain the Binet formulas, generating functions, summation formulas, etc. In addition, we examine the relations among the terms of the $k$-Cullen, $k$-Cullen–Lucas, Modified $k$-Cullen, Cullen, Cullen–Lucas, Modified Cullen, $k$-Woodall, $k$-Woodall–Lucas, Modified $k$-Woodall, Woodall, Woodall–Lucas, and Modified Woodall sequences. The generating functions were derived and analyzed, especially for cases where Fibonacci numbers were assigned to parameter $k.$ Graphical representations of the generating functions and their logarithmic transformations revealed interesting growth trends and convergence behavior. Further, by multiplying the generating functions with exponential expressions such as $e^k$, we explored the self-similar nature and mirrored dynamics among the sequences. Specifically, it was observed that the Modified Cullen sequence exhibited a symmetric and inverse-like resemblance to the Cullen and Cullen–Lucas sequences, suggesting the presence of deeper structural dualities. Additionally, indefinite integrals of the generating functions were computed and visualized over a range of Fibonacci-indexed k values. These integral-based graphs further reinforced the phenomenon of symmetry and self-similarity, particularly in the Modified Cullen sequence. A key insight of this study is the discovery of a structural duality between the Modified Cullen and standard Cullen-type sequences, supported both algebraically and graphically. This duality suggests new avenues for analyzing generalized recursive sequences through generating function transformations. This observation provides new insight into the structural behavior of generalized Cullen-type sequences. Full article

In recent years, businesses have faced increasing pressure from consumers, investors, and regulators to prioritize sustainability, ethics, and transparency. Consequently, Corporate Social Responsibility (CSR) is growing and companies are integrating CSR into their core strategies to enhance long-term value and align with societal expectations. Board characteristics significantly influence CSR outcomes. With boards that actively support and oversee CSR initiatives, sustainable practices would be supported. Hence, studying the relationship between board composition and CSR is very useful. The purpose of this paper is to check whether board characteristics affect CSR for European firms. To achieve this goal, we used a large sample of 1376 listed companies located in 23 European countries from 2014 to 2023. The System Generalized Method of Moment (SGMM) was performed as an econometric approach. Overall, the empirical results show that board-related variables, such as board size, duality, independent investors, gender diversity, culture diversity, and board-specific skills significantly influence ESG performance. In contrast, variables that reflect firm specifics such as firm size and profitability do not have a significant impact on CSR performance. Full article

The purpose of this article is to extend agency theory (AT) by applying it to social enterprises (SEs), which exhibit a dual focus on both corporate social responsibility (CSR) and profit-driven operations. This duality, often referred to as the double-bottom-line attribute, complicates the agency relationship within SEs and has led to conceptual unclear in previous studies. This study also explains why traditional AT and reciprocal theory are not applicable to the analysis of complex agency relationships in SEs. In response, this article builds upon traditional AT to propose a developmental framework that redefines the roles of principal and agent in SE contexts. This research proposes a new theory, Sustainability Agency Theory (SAT), which aims to more clearly define the dynamic agency relationships within SEs. The article further distinguishes SAT from other AT-based extensions, such as the reciprocal theory. By offering a theoretical extension to SEs, this study contributes a novel perspective to the literature on agency relationships in hybrid organizations. Furthermore, this article expands SAT through seven distinct dimensions, laying a strong foundation for future theoretical developments related to SAT. Full article

This paper introduces ACCORD, a support platform designed to digitalize and automate the coordination processes required by the current drone regulatory framework. Drone operators must complete several coordination actions with both aeronautical and non-aeronautical entities. Traditional aeronautical coordination actions relate to the need to access protected airspace volumes around airports. Additional coordination should be established with smaller aeronautical infrastructures, like small aerodromes and heliports, which are not surrounded by any type of pre-defined airspace. Therefore, drone-specific protection volumes have been created. ACCORD enables a single entry point for all the necessary coordination processes for drone operators and infrastructure managers. The objective is to minimize the number of required actions, guarantee full traceability of the process, maximize access to the relevant information, automate the processes as much as possible, and maintain a high level of flexibility to support all coordination processes. After coordination is established, it moves from the strategic/planning phase to the actual execution phase. ACCORD also enables a communication mechanism between the drone operators and the aeronautical infrastructures to extend the coordination to the actual mission execution. ACCORD is currently being tested by some of the most relevant actors in the Catalan drone ecosystem. The current version of the system provides support for all types of aeronautical infrastructures (heliports, aerodromes, and airports) and management duality for situations in which the infrastructure manager and the aeronautical service provider coexist. Full article

The hospitality industry’s global reach and resource-intensive operations have placed it under growing scrutiny for environmental impact. This empirical study examines how corporate governance influences corporate environmental citizenship (CEC) among eight major hotel companies across North America, Europe, and Asia from 2020 to 2023. Drawing on agency, stakeholder, institutional, and legitimacy theories, the study hypothesizes that stronger governance—measured by board independence, separation of CEO and Chair roles (non-duality), and ownership concentration—positively relates to environmental performance. A panel dataset of 32 firm-year observations is analyzed using regression models. The results show that higher board independence and greater ownership concentration are associated with significantly improved CEC index scores, while CEO duality corresponds with weaker environmental performance. The findings represent one of the first cross-national empirical demonstrations of governance–CEC links in hospitality, offering theoretical insights and practical guidance. Overall, the evidence suggests that robust governance mechanisms can serve as catalysts for environmental stewardship in the hotel sector. Full article

Normal pregnancy is associated with multiple changes in the coagulation and the fibrinolytic system. In contrast to a non-pregnant state, pregnancy is a hypercoagulable state where the level of VWF increases by 200–375%, affecting coagulation activity. Moreover, in this hypercoagulable state of pregnancy, preeclampsia is exacerbated. ADAMTS13 cleaves the bond between Tyr1605 and Met1606 in the A2 domain of VWF, thereby reducing its molecular weight. A deficiency of ADAMTS13 originates from mutations in gene or autoantibodies formed against the protease, leading to defective enzyme production. Von Willebrand protein is critical for hemostasis and thrombosis, promoting thrombus formation by mediating the adhesion of platelets and aggregation at high shear stress conditions within the vessel wall. Mutations in VWF disrupts multimer assembly, secretion and/or catabolism, thereby influencing bleeding. VWF is the primary regulator of plasma ADAMTS13 levels since even minute amounts of active ADAMTS13 protease have a significant inhibitory effect on inflammation and thrombosis. VWF is released as a result of endothelial activation brought on by HIV infection. The SARS-CoV-2 infection promotes circulating proinflammatory cytokines, increasing endothelial secretion of ultra large VWF that causes an imbalance in VWF/ADAMTS13. Raised VWF levels corresponds with greater platelet adhesiveness, promoting a thrombotic tendency in stenotic vessels, leading to increased shear stress conditions. Full article

This article initiates the semantic study of distribution-free normal modal logic systems, laying the semantic foundations and anticipating further research in the area. The article explores roughly the same area, though taking a different approach, as a recent article by Bezhanishvili, de Groot, Dmitrieva and Morachini, who studied a distribution-free version of Dunn’s positive modal logic (PML). Unlike PML, we consider logics that may drop distribution and that are equipped with both an implication connective and modal operators. We adopt a uniform relational semantics approach, relying on recent results on representation and duality for normal lattice expansions. We prove canonicity and completeness in the relational semantics of the minimal distribution-free normal modal logic, assuming just the K-axiom, as well as those of its axiomatic extensions obtained by adding any of the D, T, B, S4 or S5 axioms. Adding distribution can be easily accommodated and, as a side result, we also obtain a new semantic treatment of intuitionistic modal logic. Full article

This paper presents a new model-independent constraint on the Hubble constant ($H_0$) by anchoring relative distances from Type Ia supernovae (SNe Ia) observations to absolute distance measurements from time-delay strong Gravitational Lensing (SGL) systems. The approach only uses the validity of the cosmic distance duality relation (CDDR) to derive constraints on $H_0$. By using Gaussian Process (GP) regression to reconstruct the unanchored luminosity distance from the Pantheon+ compilation to match the time-delay angular diameter distance at the redshift of the lenses, one yields a value of $H_0=75.57\pm 4.415$ km/s/Mpc at a 68% confidence level. The result aligns well with the local estimate from Cepheid variables within the $1\sigma$ confidence region, indicating consistency with late-universe probes. Full article

The rapidly growing proliferation of digital technology presents unprecedented opportunities to address sustainability challenges in today’s manufacturing sector. This research examines the effects of digital transformation on sustainable corporate performance, focusing on the mediating roles of green knowledge acquisition and innovative performance. Grounded in new institutional theory, this research targets the Turkish manufacturing industry, employing a quantitative methodology. Data were collected via structured surveys from 332 middle and senior managers, representing diverse sectors, using purposive sampling. Statistical analyses, including regression and moderated multiple regression, were executed using AMOS and Hayes’ PROCESS macro. Findings demonstrate that digital transformation positively influences sustainable corporate performance. Green knowledge acquisition and innovation performance serve as significant mediators. Moreover, digital transformational leadership was found to enhance the relations between digital transformation and its mediators. However, limited leadership capabilities weakened these connections. This result highlights the significance of digital tactics with sustainable goals to achieve competitiveness with eco-friendly corporate practices. These findings significantly enhance sustainable performance by facilitating the acquisition of green knowledge and fostering innovation performance. The implications emphasize the necessity for policymakers and business leaders to foster digital leadership, enhance innovation capabilities, and promote green knowledge management as part of their organizational strategies. The research study investigating organizations can leverage digital technologies to achieve sustainable performance by actively acquiring green knowledge and driving innovation. This research introduces a novel distinction into the mechanism through digital transformation that can drive sustainability, thus contributing to a duality of academic literature and practical implementation in a period of rising ecological and economic difficulties. Full article

Fundamentally, duality gives two different points of view of looking at the same object. It appears in many subjects in mathematics (geometry, algebra, analysis, PDEs, Geometric Measure Theory, etc.) and in physics. For example, Connections on Fiber Bundles in mathematics, and Gauge Fields in physics are exactly the same. In n-dimensional geometry, a fundamental notion is the “duality” between chains and cochains, or domains of integration and the integrands. In this paper, we extend ideas given in our earlier articles and connect seemingly unrelated areas of F-harmonic maps, f-harmonic maps, and cohomology classes via duality. By studying cohomology classes that are related with p-harmonic morphisms, F-harmonic maps, and f-harmonic maps, we extend several of our previous results on Riemannian submersions and p-harmonic morphisms to F-harmonic maps and f-harmonic maps, which are Riemannian submersions. Full article

“Cause analysis” constitutes an indispensable component in quality management systems, serving to systematically identify the causes of quality defects, thereby enabling the development of targeted improvement strategies that concurrently address surface-level manifestations and fundamental drivers. However, relying solely on personal experience makes it challenging to conduct a comprehensive and in-depth analysis of quality problems. The reason is that, when analyzing the causes of quality problems, it is essential not only to consider the specific context in which the problems occur. This enables “specific problems” to be “specifically analyzed” for the formulation of temporary containment measures. Additionally, the context of the problem needs to be stripped. This allows for a general and in-depth analysis of the “class problem” or the causal linkages underlying the problem, thereby determining the root cause of the problem and formulating a corresponding long-term program. The analysis of the causes of quality problems exhibits “duality” characteristics. Based on this, this study proposes and constructs a two-layer causal knowledge network by leveraging the causal knowledge generated and applied in the process of quality problem solving to address the “duality” characteristic of the cause analysis of quality problems. The proposed network can assist front-line employees in analyzing the quality problems of products from diverse perspectives and overcome the challenge of relying solely on personal experience to comprehensively and profoundly analyze the causal relationships of quality problems. Our method not only contributes to enhancing the efficiency of quality problem solving but also makes a valuable contribution to the advancement of theories and methods related to quality management and knowledge management. Full article

The paper puts forth a methodology for the arrangement of calculation control at the outputs of combinational digital devices based on utilizing multiple diagnostic features. The first diagnostic feature is the belonging of the formed codewords to a pre-selected weight-based sum code. The second and third diagnostic features are the control of calculations by the belonging of calculated functions describing data and checking bits of sum codes to the class of self-dual and related functions. The arrangement of calculation control by multiple diagnostic features is founded upon the implementation of Boolean signal correction during the synthesis of the embedded control circuit. This is conducted in consideration of the established characteristics of weight-based sum codes, wherein the functions describing their checking bits exhibit identical values on pairs of data vectors inversed in all bits (these are the so-called self-quasidual functions). The utilization of Boolean signal correction on the orthogonal to all input variable combinations enables the additional determination of correction function values. This ensures the self-duality of functions describing data bits and, consequently, the self-quasiduality of functions describing checking bits. The paper proposes a structure for arranging the calculation control in accordance with the three specified diagnostic features. Furthermore, it develops the algorithm of correction function additional determination that underlies the synthesis of the embedded control circuit. It should be noted that the algorithm does not require the analysis of the values of functions calculated at the outputs of the object of diagnostics; instead, it automatically allows for the performance of additional determinations. This facilitates its utilization when integrated with computer-aided logic design systems. The paper presents a case study of the process of obtaining correction functions and simulates the operation of the synthesized self-checking device, thereby demonstrating the effectiveness of the proposed method. Full article

Background/Objectives: As cells divide, telomeres shorten through a phenomenon known as telomere attrition, which leads to unavoidable senescence of cells. Unprotected DNA exponentially increases the odds of mutations, which can evolve into premature aging disorders and tumorigenesis. There has been growing academic and clinical interest in exploring this duality and developing optimal therapeutic strategies to combat telomere attrition in aging and cellular immortality in cancer. The purpose of this review is to provide an updated overview of telomere biology and therapeutic tactics to address aging and cancer. Methods: We used the Rayyan platform to review the PubMed database and examined the ClinicalTrial.gov registry to gain insight into clinical trials and their results. Results: Cancer cells activate telomerase or utilize alternative lengthening of telomeres to escape telomere shortening, leading to near immortality. Contrarily, normal cells experience telomeric erosion, contributing to premature aging disorders, such as Werner syndrome and Hutchinson–Gilford Progeria, and (2) aging-related diseases, such as neurodegenerative and cardiovascular diseases. Conclusions: The literature presents several promising therapeutic approaches to potentially balance telomere maintenance in aging and shortening in cancer. This review highlights gaps in knowledge and points to the potential of these optimal interventions in preclinical and clinical studies to inform future research in cancer and aging. Full article

We compute the evolution of linear perturbations on top of a background solution of a general nonlinear electromagnetic theory. This evolution can be described in terms of two effective metrics, and we analyze under what conditions they are conformally related so that they can be regarded as analog models of non-trivial gravitational fields in the eikonal approximation. This is the case in Born–Infeld theory. For the background created by a static point electric charge in the Born–Infeld theory, the effective metric describes a wormhole geometry for light rays. Depending on the impact parameter, incoming light rays are either scattered to infinity or approach the wormhole slowing down their pace until they hit the charge at vanishing speed. The same effective wormhole geometry is obtained for a magnetic monopole and a dyon and we relate it to the duality invariance of Born–Infeld electromagnetism. Finally, we analyze the scalar Dirac–Born–Infeld theory and show that the effective wormhole geometry is not generated by a particle with scalar charge. Full article