Relativistic models of an expanding universe followed by contraction, or a big bang followed by a big crunch, were first proposed by A. Friedmann in 1922 and nine years later by A. Einstein. In the period ca. 1922–1960, the more speculative idea of a large and possibly infinite number of cycles was discussed by R. Tolman in particular. To some cosmologists, the idea was philosophically appealing because it seemed to justify an eternal yet dynamic universe without an absolute beginning in (...) time. During the 1950s models of this kind, sometimes known as Phoenix models, were investigated by a few cosmologists of whom the most important were A. Dauvillier, W. Bonnor, and H. Zanstra. (shrink)

The Trek Separation Theorem states necessary and sufficient conditions for a linear directed acyclic graphical model to entail for all possible values of its linear coefficients that the rank of various sub-matrices of the covariance matrix is less than or equal to n, for any given n. In this paper, I extend the Trek Separation Theorem in two ways: I prove that the same necessary and sufficient conditions apply even when the generating model is partially non-linear and contains (...) some cycles. This justifies application of constraint-based causal search algorithms to data generated by a wider class of causal models that may contain non-linear and cyclic relations among the latent variables. (shrink)

We present an algorithm to infer causal relations between a set of measured variables on the basis of experiments on these variables. The algorithm assumes that the causal relations are linear, but is otherwise completely general: It provides consistent estimates when the true causal structure contains feedback loops and latent variables, while the experiments can involve surgical or ‘soft’ interventions on one or multiple variables at a time. The algorithm is ‘online’ in the sense that it combines the results from (...) any set of available experiments, can incorporate background knowledge and resolves con- flicts that arise from combining results from different experiments. In addition we provide a necessary and sufficient condition that (i) determines when the algorithm can uniquely return the true graph, and (ii) can be used to select the next best experiment until this condition is satisfied. We demonstrate the method by applying it to simulated data and the flow cytometry data of Sachs et al (2005). (shrink)

We present an algorithm to infer causal relations between a set of measured variables on the basis of experiments on these variables. The algorithm assumes that the causal relations are linear, but is otherwise completely general: It provides consistent estimates when the true causal structure contains feedback loops and latent variables, while the experiments can involve surgical or `soft' interventions on one or multiple variables at a time. The algorithm is `online' in the sense that it combines the results from (...) any set of available experiments, can incorporate background knowledge and resolves conflicts that arise from combining results from different experiments. In addition we provide a necessary and sufficient condition that determines when the algorithm can uniquely return the true graph, and can be used to select the next best experiment until this condition is satisfied. We demonstrate the method by applying it to simulated data and the flow cytometry data of Sachs et al. (shrink)

Many causal systems studied by sciences such as biology, pharmacology, and economics feature causal cycles. Most accounts of causal modelling currently on the market are, however, explicitly designed to study acyclic structures. This chapter focuses on causal cycles and the challenges such cycles pose for causal modelling. First, we distinguish between different types of causal cycles. Then we introduce causal models and discuss a selection of general challenges for cyclic models when it comes to representation, prediction, and causal discovery. (...) Finally, we zoom in on a concrete case from biochemistry: the PI3K/mTOR signalling network that plays a crucial role in regulating the cell cycle. Using this case we discuss some possible pitfalls for the application of causal modelling tools to complex biological cases. (shrink)

Recursive linear structural equation models can be represented by directed acyclic graphs. When represented in this way, they satisfy the Markov Condition. Hence it is possible to use the graphical d-separation to determine what conditional independence relations are entailed by a given linear structural equation model. I prove in this paper that it is also possible to use the graphical d-separation applied to a cyclic graph to determine what conditional independence relations are entailed to hold by a given (...) non-recursive linear structural equation model. I also give a causal intepretation to the linear coefficients in a non- recursive structural equation models, and explore the relationships between cyclic graphs and undirected graphs, directed acyclic graphs with latent variables, and chain independence graphs. (shrink)

Peter Spirtes. Conditional Independence in Directed Cyclical Graphical Models Representing Feedback or Mixtures.

Peter Spirtes. Conditional Independence in Directed Cyclic Graphical Models for Feedback.

In the post-Soviet context, various cyclical models of recurrent Russian “Times of Troubles” have become increasingly popular. This perspective emerged first in Soviet dissident circles, who used it as a means to expose as mistaken the Soviet belief in continual historical progress on Russian soil. In post-Soviet Russia this critical approach has been continued by members of the “Akhezier circle,” the economist Egor Gaidar, and others. Meanwhile it was given an affirmative, conservative reinterpretation by Aleksandr Panarin, according to whom Russia (...) has always managed to overcome its phases of devastating Westernization and state collapse. This idea of Russian history has become influential; even Vladimir Putin has talked about Russia as a strong state able to survive various “Times of Troubles” from the early seventeenth century to the early post-Soviet period. It also figures prominently among members of the neoconservative Izborsk Club. This article analyzes different conceptions of Russian history as cyclical and their prominent place in the prevailing civilizational discourse of post-Soviet Russia. By means of postcolonial perspectives, this discourse is seen on the one hand as an attempt to question and reject Western hegemony, attempts that on the other hand nevertheless seem unable to liberate themselves from a normative dependence on the West. (shrink)

This paper proposes an architecture for the mapping between syntax and phonology — in particular, that aspect of phonology that determines ordering. In Fox and Pesetsky (in prep.), we will argue that this architecture, when combined with a general theory of syntactic domains ("phases"), provides a new understanding of a variety of phenomena that have received diverse accounts in the literature. This shorter paper focuses on two processes, both drawn from Scandinavian: the familiar process of Object Shift and the less (...) well-known process of Quantifier Movement. We will argue that constraints on these operations can be seen as instances of the same property of grammar that explains the fact that movement is local and successive cyclic. We begin by sketching a model in which locality and successive cyclicity are consequences of the architecture that we propose, rather than specific facts about movement itself. We next present our proposal in somewhat greater detail, and show how it can account for a wide range of apparent limitations on movement — in particular, superficially contradictory restrictions on Object Shift and Quantifier Movement. The restrictions on Object Shift include those grouped under the rubric of Holmberg's Generalization, which Quantifier Movement does not seem to obey. We will argue that Quantifier Movement instead obeys a near mirror-image of Holmberg's Generalization (an "Inverse Holmberg Effect"), but that both Holmberg's Generalization and its mirror image are expected if our proposed architecture is correct. (shrink)

Many models of evolution are implicitly causal processes. Features such as causal feedback between evolutionary variables and evolutionary processes acting at multiple levels, though, mean that conventional causal models miss important phenomena. We develop here a general theoretical framework for analyzing evolutionary processes drawing on recent approaches to causal modeling developed in the machine-learning literature, which have extended Pearls do-calculus to incorporate cyclic causal interactions and multilevel causation. We also develop information-theoretic notions necessary to analyze causal information dynamics in (...) our framework, introducing a causal generalization of the Partial Information Decomposition framework. We show how our causal framework helps to clarify conceptual issues in the contexts of complex trait analysis and cancer genetics, including assigning variation in an observed trait to genetic, epigenetic and environmental sources in the presence of epigenetic and environmental feedback processes, and variation in fitness to mutation processes in cancer using a multilevel causal model respectively, as well as relating causally-induced to observed variation in these variables via information theoretic bounds. In the process, we introduce a general class of multilevel causal evolutionary processes which connect evolutionary processes at multiple levels via coarse-graining relationships. Further, we show how a range of fitness models can be formulated in our framework, as well as a causal analog of Prices equation, clarifying the relationships between realized/probabilistic fitness and direct/indirect selection. Finally, we consider the potential relevance of our framework to foundational issues in biology and evolution, including supervenience, multilevel selection and individuality. Particularly, we argue that our class of multilevel causal evolutionary processes, in conjunction with a minimum description length principle, provides a conceptual framework in which identification of multiple levels of selection may be reduced to a model selection problem. (shrink)

This paper proposes an architecture for the mapping between syntax and phonology — in particular, that aspect of phonology that determines ordering. In Fox and Pesetsky (in prep.), we will argue that this architecture, when combined with a general theory of syntactic domains ("phases"), provides a new understanding of a variety of phenomena that have received diverse accounts in the literature. This shorter paper focuses on two processes, both drawn from Scandinavian: the familiar process of Object Shift and the less (...) well-known process of Quantifier Movement. We will argue that constraints on these operations can be seen as instances of the same property of grammar that explains the fact that movement is local and successive cyclic. We begin by sketching a model in which locality and successive cyclicity are consequences of the architecture that we propose, rather than specific facts about movement itself. We next present our proposal in somewhat greater detail, and show how it can account for a wide range of apparent limitations on movement — in particular, superficially contradictory restrictions on Object Shift and Quantifier Movement. The restrictions on Object Shift include those grouped under the rubric of Holmberg's Generalization, which Quantifier Movement does not seem to obey. We will argue that Quantifier Movement instead obeys a near mirror-image of Holmberg's Generalization (an "Inverse Holmberg Effect"), but that both Holmberg's Generalization and its mirror image are expected if our proposed architecture is correct. (shrink)

Our synthetic review of the relevant and related literatures on the ethics and effects of using AI in education reveals five qualitatively distinct and interrelated divides associated with access, representation, algorithms, interpretations, and citizenship. We open our analysis by probing the ethical effects of algorithms and how teams of humans can plan for and mitigate bias when using AI tools and techniques to model and inform instructional decisions and predict learning outcomes. We then analyze the upstream divides that feed (...) into and fuel the algorithmic divide, first investigating access and then representation. After that, we analyze the divides that are downstream of the algorithmic divide associated with interpretation and citizenship. At present, lacking ongoing reflection and action by learners, educators, educational leaders, designers, scholars, and policymakers, the five divides collectively create a vicious cycle and perpetuate structural biases in teaching and learning. However, increasing human responsibility and control over these divides can create a virtuous cycle that improves diversity, equity, and inclusion in education. We conclude the article by looking forward and discussing ways to increase educational opportunity and effectiveness for all by mitigating bias through a cycle of progressive improvement. (shrink)

To formally understand cyclicity in innovation and to tie to Schumpeter’s idea about waves of creative destruction, we elaborate upon Thomas Kuhn’s (1962) hypothesis that science evolves through a succession of paradigm life cycles by noting that entrepreneurs recognize the profitability of new scientific theories through a delay. The delay from innovation to entrepreneurship may be due to technological inertia, the time taken in recognizing the applications of basic research, or related to how quickly technological change evolves over time and (...) its returns are realized. In our model, a profit-maximizing entrepreneur uses the latest scientific knowledge to create innovative technologies, which generates cycles between science and innovation. The necessary conditions for the existence of cycles are that human capital employed in science creation and high valued innovations is high, and the interest rate is low. The findings also tie to the notion about the variability of innovation over the business cycle and can provide useful inputs into the formulation of more effective technology policies. (shrink)

The collapse models of arithmetic are inconsistent, nontrivial models obtained from ℕ and set out in the Logic of Paradox (LP). They are given a general treatment by Priest (Priest, 2000). Finite collapse models are decidable, and thus axiomatizable, because finite. LP, however, is ill-suited to normal axiomatic reasoning, as it invalidates Modus Ponens, and almost all other usual conditional inferences. I set out a logic, A3, first given by Avron (Avron, 1991), and give a first order axiom system for (...) the finite collapse models. I present some standard arithmetical axioms in addition to a cyclic axiom and prove that these axioms are sound and complete for the cyclic models, reporting a similar result for the heap models. The state of the situation for the each of the kinds of infinite collapse model is, however, left an open question. (shrink)

The paper establishes the general structure of the inconsistent models of arithmetic of [7]. It is shown that such models are constituted by a sequence of nuclei. The nuclei fall into three segments: the first contains improper nuclei: the second contains proper nuclei with linear chromosomes: the third contains proper nuclei with cyclical chromosomes. The nuclei have periods which are inherited up the ordering. It is also shown that the improper nuclei can have the order type of any ordinal, of (...) the rationals, or of any other order type that can be embedded in the rationals in a certain way. (shrink)

I argue that we can generate intransitive preference orderings for a single person on the model of Sen's Libertarian Paradox.

We investigate the one-dimensional dynamics of alternatives of the Axelrod model (ξ(t)), where t is the time, with k binary features and confidence parameter ε = 0, 1,…, k. Simultaneously, the simple Axelrod model is also critically examined. Specifically, for small and large ε, simulations suggest that the convergent model (ξ(t)) is emulated by a corresponding attractive model (η(t)) with the same parameters (conditional on bounded confidence). (η(t)) is more mathematically tractable than (ξ(t)), and the very (...) definitions of the two qualitative behaviors of cyclic particle systems (fluctuation and fixation) are applicable in special cases. Moreover, we observe a complementarity: for not too small k and equation image, (η(t)) fixates (each site has a final type independent of the possibly infinite size of the lattice), whereas (ξ(t)) fluctuates (each site changes type at arbitrarily larger times t as the size of the lattice increases). (shrink)

Mechanistic philosophy of science views a large part of scientific activity as engaged in modelling mechanisms. While science textbooks tend to offer qualitative models of mechanisms, there is increasing demand for models from which one can draw quantitative predictions and explanations. Casini et al. (Theoria 26(1):5–33, 2011) put forward the Recursive Bayesian Networks (RBN) formalism as well suited to this end. The RBN formalism is an extension of the standard Bayesian net formalism, an extension that allows for modelling the hierarchical (...) nature of mechanisms. Like the standard Bayesian net formalism, it models causal relationships using directed acyclic graphs. Given this appeal to acyclicity, causal cycles pose a prima facie problem for the RBN approach. This paper argues that the problem is a significant one given the ubiquity of causal cycles in mechanisms, but that the problem can be solved by combining two sorts of solution strategy in a judicious way. (shrink)

We extend the analysis of the decision problem for modules over a group ring ℤ[G] to the case when G is a cyclic group of squarefree order. We show that separated ℤ[G]-modules have a decidable theory, and we discuss the model theoretic role of these modules within the class of all ℤ[G]-modules. The paper includes a short analysis of the decision problem for the theories of modules over ℤ[ζm], where m is a positive integer and ζm is a (...) primitive mth root of 1. (shrink)

Managers in ethnic businesses are confronted with ethical dilemmas when taking action based on ethnic ties; and often as a result, they increase the already vulnerable positions of these businesses and their stakeholders. Many of these dilemmas concern the capital that is generated through variations in the use of ethnic stakeholder social ties. The purpose of this paper is to suggest a stakeholder-based model of social capital formation, mediated by various forms of ethnic ties, to explore the duality of (...) ethnicity: it can aid and hinder an ethnic business. Drawing upon the social capital/economic development, stakeholder salience, ethnic businesses literatures, and on social identity theory, we develop a cyclical model of relationships among ethnic business stakeholder attributes and social capital, as mediated by three-way Simmelian bonding and bridging ties, which then, in turn, affects the ethnic stakeholder attributes. We argue that the development of bridging yet strong ties through this cyclical process is relevant for the improvement of the positions of ethnic businesses in terms of both economic success and social responsibility. Specifically, we suggest that, given the duality of ethnicity in business, managers can prioritize stakeholder relationships based upon how these stakeholder ties affect social capital. (shrink)

first-order HMM, the current tag t0 is predicted based on the previous tag t−1 (and the current word).1 The back- We present a new part-of-speech tagger that ward interaction between t0 and the next tag t+1 shows demonstrates the following ideas: (i) explicit up implicitly later, when t+1 is generated in turn. While unidirectional models are therefore able to capture both use of both preceding and following tag con-.

Current theories of the division of cognitive labor are confined to the “context of justification,” assuming exogenous theories. But new theories are made from the same labor that is used for developing existing theories, and if none of this labor is ever allocated to create new alternatives, then scientific progress is impossible. A unified model is proposed in which theories are no longer given but a function of the division of labor in the model itself. The interactions of (...) individuals balancing the exploitation of existing theories and the exploration of new theories results in a robust cyclical pattern. (shrink)

The theory of Yin and Yang and the Five Movements is based on the concept of cyclical time. This ancient cosmological model postulates that when expansive energy reaches its apex, mutual life-saving relations prevail over mutually conflictual societal relations, and that this cycle repeats. This cosmic change model was first presented in ancient Korea and China, by Hado-Nakseo, via numerological configurations and symbols. The Hado diagram was drawn by a Korean thinker, Bok-hui (?-BC3413), also known as Great Empeor (...) Fuzi or Fu-hsi in Chinese mythology. Confucius once recognized him as the father of I Ching (Book of Changes). The Eastern cosmology was further developed by King Wen and the Duke of Zhou and compiled by Confucius (BC551?-BC 479) during the Spring and Autumn Period and the Warring States Period. Nakseo diagram was first discovered by the famous King Wu of China, who founded the Xia dynasty. In contrast to the harmonious mathematical matrix of Hado, Nakseo symbolizes the conflictual and dynamic expansion of the universe. In the Nakseo world, masculine energy is structurally greater than feminine energy, continuously breeding disequilibrium and conflict. The Yin and Yang model suggests that everything in the universe exists as a combination of opposing dynamics. At any given time, one of the two dynamics grows while the other declines. When Yang energy is at its peak, Yin energy is at its nadir; then, a reversal occurs; and envetually the whole cycle repeats. It would thus be logical to express that when conflictual energy has reached its apex harmonious energy begins to wax. It can be argued that since the state of disequilibrium within the universe represented by Nakseo cannot indefinitely sustain its dynamic of expansion, harmonious international relationships eventually come to pervade the world. This argument represents a unique applicationof the concept of Yin and Yang logic to international arms race and arms control. This cyclical dynamics can explain the long-term process of arms build-up followed by eventually by nuclear standoff and subsequent nuclear arms control regimes as NPT, CTBT, MTCR, SALT, START, PSI and etc. One can boldly claim that Yin and Yang logic offers a clue to creating a theory of structural peace by discovering a constructivist element in the model. The esoteric matrixes of ancient Korea and China thus provide humanity with an new vision for nuclear disarmament and a sustainable peace. (shrink)

The Ouroboros Model proposes a brain inspired cognitive architecture including detailed suggestions for the main processing steps in an overall conceptualization of cognition as embodied and embedded computing. All memories are structured into schemata, which are firmly grounded in the body of an actor. A cyclic and iterative data-acquisition and -processing loop forms the backbone of all cognitive activity. Ever more sophisticated schemata are built up incrementally from the wide combination of neural activity, concurrent at the point in (...) time when the memory is established; i.e., distinct representations are accrued. Later on, an entire schema can be reinstated from diverse subsets of its constituent features. In order to decode or compile ever more elaborate constructions, extant building blocks are concatenated. They are serially linked via common or “connection-attributes” of different representations and symbols, and they are employed for serial perception, processing and action, in particular, also for language production. At various levels, commonalities between different schemata lead to a similar preferred use of their respective tokens and subsequently shared categorizations. Rules, for the concatenation of words, akin to the ones governing chemical reactions, can be abstracted. As special kinds of symbols, words and word-classes along with the whole grammar of a language can thus be seen as a direct consequence of the processes outlined in the Ouroboros Model. Strong emphasis is put on the dimension of time over short intervals during active experience and performance, and, in particular, during interactions with other agents. (shrink)

The Mental Capacity Act 2005 gives statutory force to the common law principle that all adults are assumed to have capacity to make decisions unless proven otherwise. In accord with best practice, this principle places the evidential burden on researchers rather than participants and requires researchers to take account of short-term and transient understandings common among some research populations. The aim of this paper is to explore some of the implications of the MCA 2005 for researchers working with 'vulnerable' populations (...) in health and social care settings. The Cyclical Consent Model is described and offered as a process by which researchers might develop good practice when engaged in research involving vulnerable people. (shrink)

We give a proof of the finite model property of some fragments of commutative and noncommutative linear logic: the Lambek calculus, BCI, BCK and their enrichments, MALL and Cyclic MALL. We essentially simplify the method used in [4] for proving fmp of BCI and the Lambek ca culus and in [5] for proving fmp of MALL. Our construction of finite models also differs from that used in Lafont [8] in his proof of fmp of MALL.

The article presents a verbal and mathematical model of medium-term business cycles (with a characteristic period of 7–11 years) known as Juglar cycles. The model takes into account a number of approaches to the analysis of such cycles; in the meantime it also takes into account some of the authors' own generalizations and additions that are important for understanding the internal logic of the cycle, its variability and its peculiarities in the present-time conditions. The authors argue that the (...) most important cause of cyclical crises stems from strong structural disproportions that develop during economic booms. These are not only disproportions between different economic sectors, but also disproportions between different societal subsystems; at present these are also disproportions within the World System as a whole. The proposed model of business cycle is based on its subdivision into four phases: – recovery phase (which could be subdivided into the start sub-phase and the acceleration sub-phase); – upswing/prosperity/expansion phase (which could be subdivided into the growth sub-phase and the boom/overheating sub-phase); – recession phase (within which one may single out the crash/bust/acute crisis subphase and the downswing sub-phase); – depression/stagnation phase (which we could subdivide into the stabilization subphase and the breakthrough sub-phase). The article provides a detailed qualitative description of macroeconomic dynamics at all the phases; it specifies driving forces of cyclical dynamics and the causes of transition from one phase to another (including psychological causes); a special attention is paid to the turning point from the peak of overheating to the acute crisis, as well as to the turning point from the downswing to recovery. The proposed mathematical model of Juglar cycle takes into account the following effects that are typical for the market economy: • positive feedbacks between various economic processes; • presence of a certain inertia, time lags in reactions of the economic subsystem to the change in conditions; • amplification by the financial subsystem of positive feedbacks and time lags in the economic subsystem; • excessive reaction to changing conditions during the acute crisis sub-phase. The authors suggest that the current crisis turns out to be rather similar to classical Juglar crises; however, there is also a significant difference, as the current crisis occurs at a truly global scale. Yet, due to this truly global scale of the current crisis, the possibilities of regulation with the national state's measures have turned out to be ineffective,whereas the suprastate regulation of financial processes hardly exists. It is shown that all these have led to the reproduction of the current crisis according to a classical Juglar scenario. (shrink)

The standard model of cosmology is acclaimed in physics as accurate, robust, well-tested, our best scientific theory of the cosmos, but it has had serious anomalies for a while, including the Hubble tension, anomalous galaxies, and the completely unexplained nature of dark energy and dark matter. And lurking behind it all is the lack of a unified theory: General Relativity (GR) and quantum mechanics (QM) are inconsistent. Now startling new observations by the James Webb Space Telescope (JWST) in 2022 (...) of the early universe present the strongest challenge yet to the standard model, and whispers have started that this shows there is something wrong with the fundamental theory, General Relativity itself. This would be a crisis for cosmology. But haven’t they tested this theory already, and shown it is correct? How could it turn out wrong at this late stage? Here we compare the standard cosmology with an alternative fundamental theory, that has a strikingly different overall cosmological behavior: a simple cyclic expansion function. It is simple and deterministic. There are only two or three general parameters. The interesting result is that this alternative cosmology: (A) closely matches the expansion observed and modelled through the CDM standard model, now going back to red-shifts of 5-15; and (B) it also predicts unexpected early galaxy formation now being reported by the JWST. The point here is not to try to prove this alternative theory however, but rather show how it compares to the conventional cosmology. This show us clearly how weak the empirical evidence for the standard model really is against a counterfactual fundamental theory. Some results established in science are robust against theory change, but we find the standard cosmological model and the implications drawn from it are not robust at all. (shrink)

Inspired by the application of CycleGAN networks to the image style conversion problem Zhu et al., this paper proposes an end-to-end network, DefogNet, for solving the single-image dehazing problem, treating the image dehazing problem as a style conversion problem from a fogged image to a nonfogged image, without the need to estimate a priori information from an atmospheric scattering model. DefogNet improves on CycleGAN by adding a cross-layer connection structure in the generator to enhance the network’s multiscale feature extraction (...) capability. The loss function was redesigned to add detail perception loss and color perception loss to improve the quality of texture information recovery and produce better fog-free images. In this paper, the novel Defog-SN algorithm is presented. This algorithm adds a spectral normalization layer to the discriminator’s convolution layer to make the discriminant network conform to a 1-Lipschitz continuum and further improve the model’s stability. In this study, the experimental process is completed based on the O-HAZE, I-HAZE, and RESIDE datasets. The dehazing results show that the method outperforms traditional methods in terms of PSNR and SSIM on synthetic datasets and Avegrad and Entropy on naturalistic images. (shrink)

A model is proposed to explain how emotional and cognitive processes drive epistemic activities within individual scientists. In this account, emotion–cognition interactions produce cyclical phases of accommodative and assimilative epistemic activities, called thought experiments and empirical experiments, respectively. During thought experiments, scientists ruminate over troubling anomalies in order to generate the theoretical ingredients necessary for constructing new conjectures. During empirical experiments, scientists explore exciting conjectures in order to cover the empirical ground necessary to discover new anomalies. Critically, epistemic activities (...) are accompanied and sustained by positive and negative emotional moods. The main virtue of the model is its specification of a coupled feedback mechanism that explains the dynamics and the temporal dependencies between empirical and theoretical activities underlying scientific discovery. (shrink)

In these two lectures, first published in 1994, Peter Diamond explores how time is modelled in theoretical analyses of individual industries and of an entire economy. In the first lecture he considers equilibrium in a single market by examining the distinction between the short run and the long run in Marshallian analysis. He proposes an explicit modelling of time in place of Marshall's use of different atemporal models for different time frames. In the second lecture he turns to models of (...) an entire economy, and begins by considering how and why models of an entire economy should differ from models of a single industry. Both cyclical and seasonal data on the behaviour of macro-economies are examined. (shrink)

A generalization of a Burridge-Knopoff spring-block model is investigated to illustrate the dynamics of transform faults. The model can undergo Hopf bifurcation and fold bifurcation of limit cycles. Considering the cyclical nature of the spring stiffness, the model with periodic perturbation is further explored via a continuation technique and numerical bifurcation analysis. It is shown that the periodic perturbation induces abundant dynamics, the existence, the switch, and the coexistence of multiple attractors including periodic solutions with various periods, (...) quasiperiodic solutions, chaotic solutions through torus destruction, or cascade of period doublings. Throughout the results obtained, one can see that the system manifests complex dynamical behaviors such as chaos, self-organized criticality, and the transition of dynamical behaviors when it comes to periodic perturbations. Even very small variation of a parameter can result in radical changes of the dynamics, which provides a new insight into the fault dynamics. (shrink)

The Ouroboros Model features a biologically inspired cognitive architecture. At its core lies a self-referential recursive process with alternating phases of data acquisition and evaluation. Memory entries are organized in schemata. The activation at a time of part of a schema biases the whole structure and, in particular, missing features, thus triggering expectations. An iterative recursive monitor process termed "consumption analysis" is then checking how well such expectations fit with successive activations. Mismatches between anticipations based on previous experience and (...) actual current data are highlighted and used for controlling the allocation of attention. In case no directly fitting filler for an open slot is found, activation spreads more widely and includes data relating to the actor, and Higher-Order Personality Activation, HOPA, ensues. It is briefly outlined how the Ouroboros Model produces many diverse characteristics and thus addresses established criteria for consciousness. Coarse-grained relationships to selected previous conceptualizations of consciousness and a sketch of how the Ouroboros Model could shed light on current research themes in artificial general intelligence and consciousness conclude this paper. (shrink)

The Biliu River is the largest river in Dalian. The occurrence of floods and droughts in this basin has extremely important impacts on local industry, agriculture, and urban development. For a long time, the annual distribution of precipitation in the Biliu River Basin is extremely uneven, the river runoff varies greatly from year to year and season to year, floods and droughts occur frequently, and serious soil erosion results in fragile ecological environment and severe shortage of water resources. In this (...) paper, the spatial and temporal changes of rainfall and runoff in the Biliu River Basin are studied through the coupling of the MIKE 11 model and the MIKE SHE model. The hydrological changes in the Biliu River Basin are simulated. The coupled model is verified by monthly runoff data from 1996 to 2015, and the simulation values are found to be true. The values match well. Based on the cyclical pattern of precipitation and runoff in the Biliu River Basin, the rainfall and runoff data in the Biliu River Basin from 2016 to 2030 are derived. The MIKE SHE/MIKE 11 coupling model is used to predict the Biliu River from 2016 to 2030. The results show that flood disasters are expected to occur in August 2020, July 2025, and July 2030, which can provide a basis for hydrological management in the Biliu River Basin. (shrink)

Let equation image denote the inverse limit of all finite cyclic groups. Let F, G and H be abelian groups with H ≤ G. Let FβH denote the abelian group , where +βis defined by +β = + β — β) for a certain β : F → G linear mod H meaning that β = 0 and β + β — β ∈ H for all a, b in F. In this paper we show that the following hold: (...) The additive group of any nonstandard model ℤ* of the ring ℤ is isomorphic to βH for a certain β : ℤ*+/H → equation image linear mod H. equation image is isomorphic to βH for some β : equation image/H →ℚ linear mod H, though equation image is not the additive group of any model of Th and the exact sequence H → equation image → equation image/H is not splitting. (shrink)

Ayahuasca is an Amazonian psychoactive shamanic brew that often elicits spontaneous, intense, and meaningful imagery narratives related to psychological and physical healing, problem solving, knowledge acquisition, community cohesion, creativity, and spiritual development. My EEG and phenomenology ayahuasca research found it caused the greatest changes in EEG beta coherence from 25 to 30 cycles per second compared to a resting state before ayahuasca ingestion. Enhanced beta coherence indexes significantly greater information exchange between cortical regions and is congruent with the reported enhanced (...) richness, complexity, and profundity of ayahuasca experiences. I developed the creative cycle processes model that identifies in ayahuasca reports distinct experiential change processes and describes how these processes, neuroscience, psychotherapy, mythological, and other transdisciplinary evidence can be coherently integrated to explain ayahuasca benefits. The model suggests three change process stages together underlie one emergent dynamic creative cycle process. The sequential stages are Form dismantling and healing processes, form creation processes, where novel forms spontaneously combine, and form expression processes, where emergent experiences are embodied. The model suggests that these three stages repeat cyclically in human development in an ongoing process of dismantling and generation producing more creative experiences and expressive forms. (shrink)

The analysis of social communication in other-than-human animals poses several theoretical challenges due to the complexity of individual and extra-individual variables. Some previous studies have found a valuable solution in Uexküll’s work by expanding and adapting its usage for the study of communication in a heurtistic manner. An Umwelt analysis provides a theoretical toolbox, which allows researchers to take an emic perspective on the lives and phenomenal world of other animals. However, Umwelt and its elaborations do not allow for a (...) clear distinction between acts of perception and communication and seem to ignore factors that escape the specific communication contexts under analysis. Thus, moving away from the existing linear and cyclical approaches to communication, we propose a complementary approach to the study of social communication by combining Barnlund’s transactional model of communication with Umwelt theory and the functional circle more specifically. Our elaborated model conceives social communication as the process of creating meaning through the interaction of two subjects and emphasizes the role of species-specific and individual features in its creation. Our goal is to re-evaluate the research on social communication of other-than-human animals by advocating for the theoretical and empirical potential of Umwelt, especially pertaining to animals with complex Umwelten. Our model offers a valuable solution to the analysis of intraspecies communication that accounts for the role of private and public cues as well as the subjects’ specific behaviors, messages, and context in the creation of meaning. (shrink)

The basic premise of this paper originates from the contention that the hegemony of the West is unsustainable because of its grounding on a way of life and life vision not in conformity with the eternal laws of Mother Nature. It is losing its sheen under the impact of unsustainable lifestyle and consumerist culture and the resultant ecological hazards, violence, wars, racial animosity, and religion-induced extremism. These trends are giving way to the emergence of a new humane civilization, and the (...) new civilization shall evolve out of the wisdom accumulated over the past several centuries of human efforts to achieve prosperity and happiness. It should be inclusive and should respect all cultures by providing appropriate space to grow and develop in conformity with the laws of Mother Nature. Santhigiri movement grounded on the revelatory spirituality of Navajyothisree Karunakara Guru offers hope for ushering in of a humane civilization ensuring solidarity beyond religion, race, caste, and region. The view that the academic hegemony of the West has been stifling the voices of varied cultural and religious traditions in other parts of the world and denying due space in the mainstream is examined in the larger context of the unalterable law of cyclical view of history. A historical examination of the hitherto civilizations shows that they have grown in particular directions in parts instead of the whole. A civilization on achieving maximum efficiency in particular directions starts decaying and disintegrating giving way to the shifting of creativity, power, and wealth to another region or continent. This shifting of power, creativity, and wealth from one place to another, one civilization to another has been an unavoidable law of human history. A new civilization that will foster the total efficiency of whole segments of humanity instead of maximum efficiency of parts in particular directions alone can offer human sustainability. The rising Santhigiri Parampara exemplifies the possibility to achieve the goal of human harmony based on the living guidance of wisdom of an Atmajnani Guru. If we can shed our biases and feeling of superiority on any counts and realize our limitations and come out of our unsustainable world view structured by modern science, technology, and instrumental rationality and seek the whole, we all can enjoin in this global mission of raising human consciousness into higher levels of attainment which can lead to an egalitarian and enlightened culture. (shrink)

The susceptible-transmissible-removed (STR) model is a deterministic compartment model, based on the susceptible-infected-removed (SIR) prototype. The STR replaces 2 SIR assumptions. SIR assumes that the emigration rate (due to death or recovery) is directly proportional to the infected compartment’s size. The STR replaces this assumption with the biologically appropriate assumption that the emigration rate is the same as the immigration rate one infected period ago. This results in a unique delay differential equation epidemic model with the delay (...) equal to the infected period. Hamer’s mass action law for epidemiology is modified to resemble its chemistry precursor—the law of mass action. Constructing the model for an isolated population that exists on a surface bounded by the extent of the population’s movements permits compartment density to replace compartment size. The STR reduces to a SIR model in a timescale that negates the delay—the transmissible timescale. This establishes that the SIR model applies to an isolated population in the disease’s transmissible timescale. Cyclical social interactions will define a rhythmic timescale. It is demonstrated that the geometric mean maps transmissible timescale properties to their rhythmic timescale equivalents. This mapping defines the hybrid incidence (HI). The model validation demonstrates that the HI-STR can be constructed directly from the disease’s transmission dynamics. The basic reproduction number (R0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{R}}_0$$\end{document}) is an epidemic impact property. The HI-STR model predicts that R0∝ρnB\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{R}}_0 \propto \root \mathfrak{B} \of {\rho_n}$$\end{document} where ρn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho_n$$\end{document} is the population density, and B\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathfrak{B}}$$\end{document} is the ratio of time increments in the transmissible- and rhythmic timescales. The model is validated by experimentally verifying the relationship. R0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathcal{R}}_0$$\end{document}’s dependence on ρn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\rho_n$$\end{document} is demonstrated for droplet-spread SARS in Asian cities, aerosol-spread measles in Europe and non-airborne Ebola in Africa. (shrink)

We desperately need to know more of the biological details of the onset and progression of breast cancer. The disease is of startlingly high incidence (approaching 1 in 9 women), our current therapies for the disease are inadequate once it has metastasized, and the disease is characterized by excessive morbidity and mortality.Most of the growth and differentiation of the mammary gland occurs relatively late in life: during sexual maturation, and then cyclically during pregnancy and lactation. Normal as well as malignant (...) growth is regulated by endocrine hormones as well as by local tissue factors, such as polypeptide growth factors, Cancer seems to progress as hyperplastic ductal or lobular epithelial growth, acquiring progressive genetic changes (including those of oncogenes and tumor suppressor genes) leading to clonal outgrowths of progressively more malignant cells. The nature of proliferative controls and the relevant genetic changes are the subjects of the current review. (shrink)

The life cycle of Dictyostelium discoideum offers a unique opportunity to study signal transduction in eukaryotic cells at both the unicellular and multicellular levels of organization. Adding to the already extensive knowledge of the unicellular stages, classical and molecular genetics have begun to unravel transduction of signals controlling morphogenesis and behaviour (phototaxis and thermotaxis) in the multicellular ‘slug’ stage of the life cycle. Distributed over all seven genetic linkage groups are probably about 20, but possibly as many as 55, genes (...) of importance for slug behaviour. The encoded proteins appear from pharmacological studies and mutant phenotypes to govern transduction pathways involving the intracellular second messengers cyclic AMP, cyclic GMP, IP3 and Ca2+. Pathways from the photo‐ and thermoreceptors converge first with each other and thence, at the level of the second messengers, with those from extracellular tip activation (cyclic AMP) and inhibition (Slug Turning Factor and/or ammonia and/or adenosine) signals that control slug movement and morphogenesis. (shrink)

In photoreceptors of a dark adapted eye, the inward flux of sodium and calcium ions in the outer segment is balanced by the outward flux of potassium ions. But in the presence of light the creation of cyclic guanosine monophosphate in the outer segment decreases. Due to low concentration of cG the channels in the outer segment open relatively less and thus the influx of calcium ion decreases, leading finally to hyperpolarization of the photoreceptors. We have analyzed theoretically the (...) effect of oxidizing iron ions on the photoreceptors. In order to explain the effects of iron-induced oxidative stress, the different molecules and ions involved in phototransduction are quantified leading to a differential equation for calculating the electroretinogram a-wave voltage. The theoretical results are compared with published experimental data. In the presence of light, the iron ions could push outward the similarly charged calcium ions resulting in a small increase in the amount of inward calcium flux. Again, the presence of iron ions generates Reactive Oxygen Species, and ROS could attract the calcium ions which also increases the calcium flux. This will result in a reduction in the amplitude and slope of the a-wave voltage in the electroretinogram. These results are parametrized in terms of calcium ion concentrations. As the amplitude of the a-wave shows how much electrical signal is produced, its reduction indicates reduction in the visual signal. Thus, the increase in iron ions could explain the reduction in the electrical signal due to iron-induced oxidative stress. (shrink)

In his sociological works Pareto developed a theory of cyclical social change within the general equilibrium framework. Building on an earlier propositional formalization, we translate Pareto's theory into a series of simultaneous equations and simulate the equation system. The dynamic behavior of the simulation is consistent with Pareto's predictions and demonstrates the internal logic of the theory.

In recent decades, there has been astonishing growth in scientific theorizing about multiverses. Once considered outré or absurd, multiple universe theories appear to be gaining considerable scientific respectability. There are, of course, many such theories, including (i) Everett’s (1957) many worlds interpretation of quantum mechanics, defended by Deutsch (1997) and others; (ii) Linde’s (1986) eternal inflation view, which suggests that universes form like bubbles in a chaotically inflating sea; (iii) Smolin’s (1997) fecund universe theory, which proposes that universes are generated (...) through black holes; (iv) the cyclic model, recently defended using string/M theory by Steinhardt and Turok (2007), which holds that distinct universes are formed in a never-ending sequence of Big Bangs and Big Crunches; and (v) Tegmark’s (2007) “Level IV” multiverse, which contains many universes governed by distinct mathematical and scientific laws. While not all of these preclude each other, the details and implications of each one are hotly contested. In one area within the philosophy of religion (the debate concerning the “fine-tuning” argument), scientific multiverse theories are widely held to be hostile to theism. This is because such theories appear to account for the relevant data – the biophilic parameters of the universe we inhabit – without appeal to an intelligent designer. Yet, in recent years, several philosophers and one physicist have offered reasons for thinking that if theism is true, the actual world comprises (or probably comprises) many universes. I first set out some requirements – both scientific and otherwise – for such a theory. I then survey some problems such theories are held to face, and some prospects they are thought to have. Finally, I examine arguments both for and against the claim that multiverse theories can help theists respond to the problem of evil. I conclude that such theories advantage neither the theist or the atheist in the debate about evil: they merely require reframing arguments from evil. (shrink)