21,174 research outputs found
The Theory of Money and Financial Institutions
A sketch of a game theoretic approach to the Theory of Money and Financial Institutions is presented in a nontechnical, nonmathematical manner. The detailed argument and specifics are presented in previous articles and in a forthcoming book.
The Evolutionary Reorganization of Ontogeny and Origin of Multicellularity
The formation of morphogenetic mechanisms during emergence of multicellularity is discussed
in this article
Innovation and Equilibrium?
A discussion is given of the problems involved in the formal modeling of the innovation process. The link between innovation and finance is stressed. The nature of how the circular flow of funds is broken and the role of finance in evaluation and control is discussed.Innovation, Invention, Circular flow, Finance
Generative grammar
Generative Grammar is the label of the most influential research program in linguistics and related fields in the second half of the 20. century. Initiated by a short book, Noam Chomsky's Syntactic Structures (1957), it became one of the driving forces among the disciplines jointly called the cognitive sciences. The term generative grammar refers to an explicit, formal characterization of the (largely implicit) knowledge determining the formal aspect of all kinds of language behavior. The program had a strong mentalist orientation right from the beginning, documented e.g. in a fundamental critique of Skinner's Verbal behavior (1957) by Chomsky (1959), arguing that behaviorist stimulus-response-theories could in no way account for the complexities of ordinary language use. The "Generative Enterprise", as the program was called in 1982, went through a number of stages, each of which was accompanied by discussions of specific problems and consequences within the narrower domain of linguistics as well as the wider range of related fields, such as ontogenetic development, psychology of language use, or biological evolution. Four stages of the Generative Enterprise can be marked off for expository purposes
Null Geodesics and Wave Front Singularities in the Godel Space-time
We explore wave fronts of null geodesics in the Godel metric emitted from
point sources both at, and away from, the origin. For constant time wave fronts
emitted by sources away from the origin, we find cusp ridges as well as blue
sky metamorphoses where spatially disconnected portions of the wave front
appear, connect to the main wave front, and then later break free and vanish.
These blue sky metamorphoses in the constant time wave fronts highlight the
non-causal features of the Godel metric. We introduce a concept of physical
distance along the null geodesics, and show that for wave fronts of constant
physical distance, the reorganization of the points making up the wave front
leads to the removal of cusp ridges
Systems Analysis by Graph-theoretic Techniques: Assessment of Institutional Linkages in the Agricultural Innovation System of Azerbaijan
This paper develops a quantitative, graph-theoretic method for analysing systems of institutions. With an application to the agricultural innovation system of Azerbaijan, the method is illustrated in detail. An assessment of existing institutional linkages in the system suggests that efforts should be placed on the development of intermediary institutions to facilitate quick and effective flow of knowledge between the public and the private components of the system. Furthermore, significant accomplishments are yet to come in policy-making, research and education, and credit institutions.Graph theory, systems approach, agricultural innovation system, Azerbaijan., Research and Development/Tech Change/Emerging Technologies, Q2, C8,
Scaling behaviour of three-dimensional group field theory
Group field theory is a generalization of matrix models, with triangulated
pseudomanifolds as Feynman diagrams and state sum invariants as Feynman
amplitudes. In this paper, we consider Boulatov's three-dimensional model and
its Freidel-Louapre positive regularization (hereafter the BFL model) with a
?ultraviolet' cutoff, and study rigorously their scaling behavior in the large
cutoff limit. We prove an optimal bound on large order Feynman amplitudes,
which shows that the BFL model is perturbatively more divergent than the
former. We then upgrade this result to the constructive level, using, in a
self-contained way, the modern tools of constructive field theory: we construct
the Borel sum of the BFL perturbative series via a convergent ?cactus'
expansion, and establish the ?ultraviolet' scaling of its Borel radius. Our
method shows how the ?sum over trian- gulations' in quantum gravity can be
tamed rigorously, and paves the way for the renormalization program in group
field theory
A novel model for one-dimensional morphoelasticity. Part I - Theoretical foundations
While classical continuum theories of elasticity and viscoelasticity have long been used to describe the mechanical behaviour of solid biological tissues, they are of limited use for the description of biological tissues that undergo continuous remodelling. The structural changes to a soft tissue associated with growth and remodelling require a mathematical theory of ‘morphoelasticity’ that is more akin to plasticity than elasticity. However, previously-derived mathematical models for plasticity are difficult to apply and interpret in the context of growth and remodelling: many important concepts from the theory of plasticity do not have simple analogues in biomechanics.\ud
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In this work, we describe a novel mathematical model that combines the simplicity and interpretability of classical viscoelastic models with the versatility of plasticity theory. While our focus here is on one-dimensional problems, our model builds on earlier work based on the multiplicative decomposition of the deformation gradient and can be adapted to develop a three-dimensional theory. The foundation of this work is the concept of ‘effective strain’, a measure of the difference between the current state and a hypothetical state where the tissue is mechanically relaxed. We develop one-dimensional equations for the evolution of effective strain, and discuss a number of potential applications of this theory. One significant application is the description of a contracting fibroblast-populated collagen lattice, which we further investigate in Part II
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