Complex Theory Research Articles

Thermal analysis of a perforated laminated plate with multiple random elliptical holes by specially formulated finite elements

The high-efficient and accurate analysis of anisotropic composite media weakened by a large amount of holes or cuts is still a great challenge in practical composite engineering. In this work, specially-proposed polygonal finite element enclosing an arbitrarily oriented elliptical hole in general anisotropic composite media is formulated for thermal analysis in the framework of hybrid finite element theory. Two independent temperature field approximations are defined for the present special element: Intra-element temperature field and element frame temperature field. The former defined inside the element is written in the form of truncated summation of the weighted special fundamental solutions, which are derived using the Stroh complex theory and conformal mapping whilst the latter is implemented by the conventional shape function interpolation. Then the hybrid variational functional is employed to combine them together to generate an element stiffness equation with respect to nodal temperature and an optional relationship between the interpolation coefficients. The element stiffness matrix is symmetric and involves element boundary integrals only. Compared to the traditional finite element, the distinctive element-boundary-integral and enclosed-elliptical-hole features make the present element significantly improve the meshing effort around an elliptical hole by reducing the number of elements and decreasing the meshing difficulty, and more importantly, effectively capture the critical variation of physical fields around the elliptical hole without locally-refined meshes. Moreover, the present special element can be incorporated directly into the conventional finite element system without any difficulty for extensive analysis. Finally, several typical examples are simulated by the present special elements to demonstrate their effectiveness.

A total rip-off—crack propagation in paper

The explanation of material properties starts at a young age identifying materials using words such as strong or brittle, but it is not until higher education that we teach how and why materials break along with what brittle really means. It is an important concept to understand, as a material that could be thought strong can be made to appear weak with the addition of a very small crack. As force is applied, these cracks, introduced through dents, scratches or even from the manufacturing process, can rapidly grow, leading to catastrophic failure. To help educators explain this concept in class without the need for specialised equipment or teaching complex theory, we present a set of accessible experiments on the fracture strength of paper strips. We show how the complexity of the experiment can be modified for various age groups, ranging from an engaging session for younger students pulling paper strips to a more involved extended practical using analytical solutions and fitting to determine the fracture strength of paper. These experiments have been delivered successfully to students of various ages and have led to stimulating discussions on the subject of materials science and engineering.

The Euler’s harmonic holomorphic regenerative universe

The Cartesian dualism is a precursor to Euler’s complex theory, that completes the Descartes-Leibnitz monadic conception using the natural quanta (non-splitting e, π) along with their topological torsion in the form of dual isomorphism. The complete Euler’s identity controls a bounded regenerative/ recurrent multiverse (a kind of multigraph) by two regenerative exponential functions, one quantic, e = exp (1) and another gravitational, g0 ≡ 10 = exp (1) with the fixed points, g0 = π2 and (g0g0) respectively. Physically, the fixed points give the well-defined the unit gravity (g0 m/s2) and light self-ignition velocity of a stable recurrent self-sustained process, provided the rate of mass production just equals the rate removal. This is the Euler’s fictitious regenerative universe - like our world, a quantum autocatalytic reaction system. The present paper describes such a system controlled by thermal gravitational waves, in the case the critical solar system.

Uncovering the endogenous features of potassium salts' global transfer: A complex network perspective.

Potassium is a decisive strategic resource to ensure food safety production and supply, which many nations define as a critical metal. Due to the unbalanced distribution of resources and production capacity and the separation of the primary potassium-consuming and supplying countries, international trade is the main supply channel for potassium-consuming countries to acquire enough resources. Understanding the characteristics of potassium trade networks and the evolution of trade patterns is essential for supply security. To explore this issue, this paper employs the complex network theory to quantitatively analyze the evolution characteristics of the global potassium trade network (PTN) from 2000 to 2021. The results show (1) Overall, the potassium trade shows a trend of gradual prosperity, efficiency, and concentration; (2) During the two decades, the main exporting countries of potassium remained stable, while imports changed significantly; (3) The evolution of the potassium trade community has characterized the fragmentation-regionalization-high concentration over time; (4) The trade flow of PTN is unbalanced, and few countries show outstanding capabilities but a single function. These findings would help trade policymakers manage the supply of strategic raw materials more effectively.

Don’t Call It a Failure: Systemic Risk Governance for Complex Financial Systems

The probability that an event will avalanche into an impairment of essential services constitutes a “systemic risk.” Owing to the inherent complexities of modern societies, the outbreak of a novel disease or the failure of a financial institution can rapidly escalate into an impact significantly larger than the initial event. Through the lens of complex system theory, this article draws a parallel between financial crises and disasters to contend that the regulatory framework for financial systemic risk is unequipped to address its fundamental dynamics. Epitomized by the market failure rationale, financial regulation is premised on a reductionist view that purports both systemic risk and law as external to the actions of market participants. Conversely, this article advances a twofold conceptual framework. First, it shows that systemic risk emerges from the same complex dynamics that generate the financial system. Second, it understands law as an agent of complexity, thus contributing to the emergence of finance and its inherent instability. Normatively, this conceptual framework reveals the limits of current regulatory approaches and constructs a holistic risk governance framework that is akin to the one adopted to govern disaster risks.

Kein Sündenfall der Frau, sondern ein Fanal der Erziehung zur Freiheit in der Urgeschichte der Bibel

Abstract Not a Fall of Woman, but a Fanal for Education for Freedom in the Bible’s Creation Story The article aims at a re-evaluation of the so-called Fall of Man narrative in Genesis 2:4–3:24, which since the early church interpretation has been linked to the loss of the image of God, which man had lost because he had partaken of the tree of knowledge in a forbidden way, whereby the woman is assigned a special guilt because she had seduced the man. This, however, was in no way the intention of the authors of this story in the 4th century BCE. Rather, the story is in dialogue with late-wisdom texts that, on the one hand, deny man the knowledge of good and evil, such as Qohelet and Job 28, or consider this knowledge to be a creative endowment of man, so Ben Sira. According to Gen 2–3, God has granted man the freedom of choice, which man can and does fail at, which is to be countered in the book of Deuteronomy by a complex theory of education.

PeerG: A P2P botnet detection method based on representation learning and graph contrastive learning

P2P botnets are distributed with complex topology and communication behavior, making them harder to detect and remove. Individuals or organizations can effectively detect P2P botnets by analyzing abnormal behaviors in network traffic. Existing works focus on extracting deterministic traffic interaction features, which are highly dependent on statistical features. Moreover, these methods are mainly aimed at generalized botnet detection and lack specificity for detecting P2P botnets. They ignore the topological information of P2P botnets, resulting in unsatisfactory detection accuracy. Among the few existing methods targeting P2P botnets, they consider the topological information but mainly rely on classical graph theory statistical features, such as degree, feature vector centrality, etc. This limits the generalization ability of the detection model. In this paper, we delve into the topological features of P2P botnets from the perspective of complex graph theory. We propose a P2P botnet detection method that combines representation learning and graph contrastive learning, dubbed PeerG. Specifically, we construct the communication graphs based on the flow interaction behavior between components of the P2P botnets. The Line algorithm is employed to embed the nodes of the communication graph into a low-dimensional representation vector space. Subsequently, the graph contrastive learning approach is utilized to optimize the feature extractor, enabling it to capture more representative node features. PeerG serves as a benchmark detection model for identifying P2P botnet nodes. Additionally, we devise two optimized contrastive detection strategies (PeerG-PreG and PeerG-PreF) based on graph-level and feature-level to boost the performance of PeerG. Extensive experiments demonstrate that PeerG brings significant improvements in detection accuracy over state-of-art detection methods. Furthermore, compared with PeerG, the detection strategies PeerG-PreG and PeerG-PreF have further improved detection performance, and achieve the best detection accuracy among multiple filtered P2P botnet types.

Interplay of network topologies in aviation delay propagation: A complex network and machine learning analysis

In this study, the fundamental characteristics of flight delay propagation and the key factors influencing such propagation are investigated. Three distinct types of networks were constructed: an aviation network, a traffic flow network, and a delay propagation network. Employing complex network theory, an analysis of the fundamental topological attributes of each network was conducted, exploring the interrelations among these attributes. Findings reveal a notable resemblance between the network topology attributes of the delay propagation network and the traffic flow network. The delay propagation network overall adheres to scale-free network attributes, with a few dominant major airports playing a pivotal role in the delay propagation process. Furthermore, it was uncovered that smaller airports are more susceptible to the influence of delay propagation than their larger counterparts. Delays, in a general sense, exhibit a pronounced tendency to aggregate and spread extensively within the realm of smaller airports. Regarding delay propagation, airport traffic emerges as the primary factor precipitating this phenomenon, with a feature importance score reaching 0.889. An escalation in airport traffic significantly amplifies the extent of delay propagation, yet concurrently, this escalation is not incessant but stabilizes beyond a certain threshold.

The effect of incentive policies on the diffusion of construction and demolition waste recycling: A government perspective.

Construction and demolition (C&D) waste recycling plays a significant role in waste reduction and carbon reduction, which is critical for sustainable development. However, due to various limitations such as financial problems, C&D waste recycling industry is not well developed in developing countries. To address this problem, this study combines complex network theory and evolutionary game theory to analyse the diffusion of C&D waste recycling behaviour among enterprises under governmental incentive policies within a complex network context. The results demonstrate that the size of the network has limited effects on behaviour diffusion in Watts-Strogatz small-world network. Additionally, the study highlights the clear impact of governmental incentive probability, initial rate and connection degree on the diffusion path. By quantitatively investigating the effects of incentive tools, this study contributes to the knowledge of C&D waste management and provides valuable implications for stakeholders seeking to promote the diffusion of C&D waste recycling.

Financial risk contagion based on dynamic multi-layer network between banks and firms

Banks and firms play pivotal roles within the financial system and serve as primary channels for systemic risk contagion. While progress has been made in understanding risk contagion within financial network systems, many studies tend to overlook the intricate interplay of multi-channel risk transmission and the dynamic evolution of network structures. Leveraging complex network theory, we have developed a dynamic multi-layer financial network risk transmission model that encompasses traditional bank–firm lending relationships and incorporates dynamic short-term loans. Through our analysis of various parameters such as loan recovery ratios, cross-shareholding ratios, network structures, short-term loan ratios, and attack strategies, we have made significant observations: In scenarios where both the interbank lending network and cross-shareholding network among firms exhibit random network structure, the financial network presents the highest level of risk. Excessive deviations in network average degrees, either too high or too low, can also heighten network vulnerability. An increase in the recovery ratio of interbank loans and the cross-shareholding ratio among firms corresponds to an escalation in systemic risk. Nodes with higher lending assets, more liquid assets, greater total assets, or higher out-degrees within the network become significant contributors to an elevated network bankruptcy rate when subjected to targeted attacks. Notably, the dynamic short-term loan network significantly amplifies systemic risks, with this amplification effect intensifying as the scale of short-term loans increases. From both macro and micro perspectives, our findings furnish regulatory authorities with novel analytical tools and insights to effectively mitigate and manage systemic risks in the financial sector.

Local, colocal, and antilocal properties of modules and complexes over commutative rings

This paper is a commutative algebra introduction to the homological theory of quasi-coherent sheaves and contraherent cosheaves over quasi-compact semi-separated schemes. Antilocality is an alternative way in which global properties are locally controlled in a finite affine open covering. For example, injectivity of modules over non-Noetherian commutative rings is not preserved by localizations, while homotopy injectivity of complexes of modules is not preserved by localizations even for Noetherian rings. The latter also applies to the contraadjustedness and cotorsion properties. All the mentioned properties of modules or complexes over commutative rings are actually antilocal. They are also colocal, if one presumes contraadjustedness. Generally, if the left class in a (hereditary complete) cotorsion theory for modules or complexes of modules over commutative rings is local and preserved by direct images with respect to affine open immersions, then the right class is antilocal. If the right class in a cotorsion theory for contraadjusted modules or complexes of contraadjusted modules is colocal and preserved by such direct images, then the left class is antilocal. As further examples, the class of flat contraadjusted modules is antilocal, and so are the classes of acyclic, Becker-coacyclic, or Becker-contraacyclic complexes of contraadjusted modules. The same applies to the classes of homotopy flat complexes of flat contraadjusted modules and acyclic complexes of flat contraadjusted modules with flat modules of cocycles.

Disentangling the complexity of human–nature interactions

Abstract Human–nature interactions have been identified as an important leverage point for achieving sustainability. Processes to recognize, protect, improve and reimagine human–nature interactions will be central to shift the world to more sustainable and equitable pathways and futures. In the context of the interconnected and rapidly changing Anthropocene, work on human–nature interactions must move beyond dominant linear assumptions of a relatively simple and easily and predictably manipulated world to acknowledge and engage with the complex, dynamic, asymmetrical and unequal nature of the interactions connecting people and nature. Based on three key features highlighted by the study of complex social–ecological systems (SES)—that these systems are relational, open and dynamic—we propose three new directions for the study and management of human–nature interactions that can help to acknowledge and disentangle the globally intertwined and dynamic nature of these interactions. These features suggest new directions and foci for sustainability science: the inseparable and relational qualities of the interactions between people and nature; the cross‐scale nature of these relationships; and the continuously evolving and changing form of these relationships. To bridge the gap between the theory of complex, inseparable and unequal human–nature interactions and the reductionist tendencies in research and practice, SES research raises opportunities to connect local action and global learning; to mobilize and develop new cross‐scale and relational capacities to encourage synergies and avoid trade‐offs; and to explore, experiment and learn our way forward onto more sustainable and equitable pathways. Read the free Plain Language Summary for this article on the Journal blog.

An empirical assessment of whether urban green ecological networks have the capacity to store higher levels of carbon

Carbon–neutral growth is a crucial long-term climatic aim in the context of global warming. This paper introduces complex network theory and explores its potential application to achieve this goal. Specifically, we investigate the spatial and temporal distribution of nodes and sources in the ecological network, and examine whether a relationship exists between the topological index of network nodes and the landscape pattern index of ecological source areas. We also determine the contribution of nodes to the carbon stock of the entire network by exploring the correlation between the carbon stock of nodes and sources to develop an optimization strategy based on the synergistic effect of node-source carbon enhancement. Finally, we test the effect of network optimization through robustness. Our results show that: (1) The correlation topological feature index analysis reveals that the degree distribution of the node network's topological characteristics becomes dispersed and modular, exhibiting the characteristics of small-world networks according to a large clustering coefficient. The heterogeneity and extent of ecological source landscapes have increased by modularity index but remain distributed and locally fragmented; (2) According to correlation analysis, by enhancing the eccentricity of the node topology, the patch cohesion index (COHESION) of the ecological source site can maximize the contribution of the node to the enhancement of the carbon stock benefits of the source site; (3) According to the tests on the robustness of nodes and edges and the robustness of network links, network stability is improved and carbon sink capacity is enhanced. Simultaneously, the restoration and rejuvenation of ecological space through national ecological construction projects can effectively improve the carbon sink within the organized region, contributing to the carbon neutrality aim. This research gives scientific and quantifiable references for potential ecological construction projects for sustainable cities and the optimization of urban ecological space structure.

Analysis for Digital Economy Ecosystem Based on Three-Dimensional Lotka-Volterra Model

Inspired by the complex system theory, we have expanded the two-dimensional Lotka- Volterra model to three- dimensional Lotka-Volterra model to obtain the stability conditions for all the equilibrium points, and to analyze the symbiotic evolution among the central enterprises and other two sorts of satellite digital enterprises in the ecosystem of digital economy.

An Improved CBBA Generation Method Based on Triangular Fuzzy Numbers

AbstractAcknowledged as a robust tool for managing uncertain information, Dempster–Shafer evidence theory has seen significant progress in recent years, especially in the refinement of mass functions, also known as basic belief assignments (BBAs). This progress is particularly noticeable in complex domains where the effective handling of uncertainty is considered of paramount importance. Despite these advancements, the generation of complex mass functions, referred to as complex basic belief assignments (CBBAs), continues to be viewed as an open and challenging aspect within the framework of complex evidence theory. A method for CBBA generation based on triangular fuzzy numbers was introduced by Xiao, specifically applied to target recognition. However, despite its application, there is notable room for improvement in the recognition rate achieved by this method. In response to this gap, an improved CBBA generation method based on triangular fuzzy numbers is proposed in this paper. Notably, the consideration of attribute weights is incorporated into the CBBA generation process by this approach. This refinement is rooted in the recognition that, in practical scenarios, different attributes carry distinct levels of importance. Hence, adopting a more rational approach by assigning higher weights to crucial attributes becomes imperative. The proposed method is subjected to rigorous testing in the paper of target recognition, with its performance systematically compared against Xiao’s method and the conventional Dempster–Shafer evidence theory. The ensuing simulation results unequivocally demonstrate the superior efficacy of the proposed method in achieving enhanced target recognition rates.

The Stabilizing Role of Shanghai Cooperation Organization in Afghanistan

Terrorism is one of the main reasons contributing to Afghanistan's insecurity. The fragile peace in Afghanistan has given terrorist groups much freedom to manoeuvre and grow. These situations require the countries in the region to assume greater responsibility to stabilise the country. Shanghai Cooperation Organisation (SCO) member states and Afghanistan relations are based on historical friendship and shared interests. The SCO's involvement in Afghanistan is facilitated by the common interests of Pakistan, China, Russia, and other neighbouring countries. The withdrawal of the North Atlantic Treaty Organisation (NATO) from Afghanistan gave the SCO more room to advance in Afghanistan. This article highlights the concrete steps that the SCO has taken to stabilise Afghanistan, as well as the interests of member countries and their peace efforts. In this study, the theories of the Regional Security Complex Theory and Liberal Institutionalism were used. The current economic crisis and political disruption following NATO's withdrawal from Afghanistan highlight the role of the SCO in the situation. Collaboration to boost Afghanistan's economy and growth would be beneficial. Reconstruction, development, governance, and humanitarian assistance are not only the responsibility of the countries in the region but also of the international community and organizations. The economic crisis and the rapid international recognition of the Taliban pose great challenges to the SCO.

Abiy Ahmed's Domestic Policy in Ethiopia: Securitization and conflict resolution

The subject of this study is a set of political reforms carried out by Ethiopian Prime Minister Abiy Ahmed from 2018 to the present. The object of the study is the internal political contradictions accumulated in Ethiopia from 1974 to 2018. The purpose of the work is to test the hypothesis that the policy of A. Ahmed is subject to the provisions of the theory of securitization of B. Buzan and O. Weaver and is aimed at transforming the conflict education of Ethiopia into a security regime. The topic of the study is relevant, since Ethiopia is considered by a number of scientists as a potential regional heavyweight capable of stabilizing the Horn of Africa region and ultimately influencing the security of the whole of Africa. Therefore, it is important to study the dynamics of political processes in modern Ethiopia. The research is based on the theory of regional security complexes by B. Buzan and O. Weaver. The methods of work are qualitative content analysis of official documents and expert opinions, as well as event analysis, logical and philosophical assumptions are allowed. A realistic approach is used to analyze the internal political situation in Ethiopia. The scientific novelty of the work lies in the fact that the policy of Abiy Ahmed is analyzed not from the standpoint of historical approaches, but from the point of view of political science theory, which is applied to the political process taking place in our time. The author concludes that the political course of A. Ahmed is determined by the difficult situation in which Ethiopia found itself by 2018. The Prime Minister is trying to stabilize the situation in the country, using his rich experience and professional knowledge, trying to change Ethiopia's position as a conflict entity to a security regime, his internal policy traces approaches based on strengthening the central government, which, from the point of view of the theory of B. Buzan and O. Weaver, makes Ethiopia a functional entity capable of respond to existential threats and develop successfully.

The shorter a man is, the more he defends fairness: relative height disadvantage promoting third-party punishment-evidence from inter-brain synchronization.

Third-party punishment occurs in interpersonal interactions to sustain social norms, and is strongly influenced by the characteristics of the interacting individuals. During social interactions, height is the striking physical appearance features first observed, height disadvantage may critically influence men's behavior and mental health. Herein, we explored the influence of height disadvantage on third-party punishment through time-frequency analysis and electroencephalography hyperscanning. Two participants were randomly designated as the recipient and third party after height comparison and instructed to complete third-party punishment task. Compared with when the third party's height is higher than the recipient's height, when the third party's height is lower, the punishment rate and transfer amount were significantly higher. Only for highly unfair offers, the theta power was significantly greater when the third party's height was lower. The inter-brain synchronization between the recipient and the third party was significantly stronger when the third party's height was lower. Compared with the fair and medium unfair offers, the inter-brain synchronization was strongest for highly unfair offers. Our findings indicate that the height disadvantage-induced anger and reputation concern promote third-party punishment and inter-brain synchronization. This study enriches research perspective and expands the application of the theory of Napoleon complex.

Retracted: Collaborative Intelligent Environment Perception and Mission Control of Scientific Researchers in Semantic Knowledge Framework Based on Complex Theory

Retracted: Collaborative Intelligent Environment Perception and Mission Control of Scientific Researchers in Semantic Knowledge Framework Based on Complex Theory

Breakdown of the Meissner effect at the zero exceptional point in non-Hermitian two-band BCS model

The spontaneous symmetry breaking of a continuous symmetry in complex field theory at the exceptional point (EP) of the parameter space is known to exhibit interesting phenomena, such as the breakdown of a Higgs mechanism. In this work, we derive the complex Ginzburg–Landau model from a non-Hermitian two-band Bardeen–Cooper–Schrieffer model via path integral and investigate its spontaneous symmetry breaking. We find that analog to the Higgs mechanism, the Meissner effect of the complex Ginzburg–Landau model also breaks down at the EP while the gap parameters stay finite.