2,888 research outputs found
How to Draw Tropical Planes
No full textThe tropical Grassmannian parameterizes tropicalizations of ordinary linear spaces, while the Dressian parameterizes all tropical linear spaces in TPn-1. We study these parameter spaces and we compute them explicitly for n <= 7. Planes are identified with matroid subdivisions and with arrangements of trees. These representations are then used to draw pictures
How to Draw Tropical Planes
No full textThe tropical Grassmannian parameterizes tropicalizations of ordinary linear spaces, while the Dressian parameterizes all tropical linear spaces in TPn-1. We study these parameter spaces and we compute them explicitly for n <= 7. Planes are identified with matroid subdivisions and with arrangements of trees. These representations are then used to draw pictures
Genocchi numbers and f-vectors of simplicial balls
No full textAbstractThe Genocchi numbers are the coefficients of the generating function 2tet+1. In this note we will give an equation for simplicial balls which involves these numbers. It relates the number of faces in the interior of the ball to the number of faces in the boundary of the ball. This is a variation of similar equations given in [P. McMullen, Triangulations of simplicial polytopes, Beiträge Algebra Geom. 45 (1) (2004) 37–46; S. Herrmann, M. Joswig, Bounds on the f-vectors of tight spans, Contrib. Discrete Math. (2006) (in press). arXiv:math.MG/0605401]
Sven Lidman: Silfverstååhl i den judiska finansvärlden
No full textSven Lidman was a Swedish author who had a great interest in the industrialization and financial growth in Sweden. In his novel Köpmän och krigare (1911) the noble family Silfverstååhl encounter what Lidman calls “the Jewish finance world”. The response to his work was of mixed character, including response of anti-Semitic character
Naturalizing institutions: Evolutionary principles and application on the case of money
No full textIn recent extensions of the Darwinian paradigm into economics, the replicator-interactor duality looms large. I propose a strictly naturalistic approach to this duality in the context of the theory of institutions, which means that its use is seen as being always and necessarily dependent on identifying a physical realization. I introduce a general framework for the analysis of institutions, which synthesizes Searle's and Aoki's theories, especially with regard to the role of public representations (signs) in the coordination of actions, and the function of cognitive processes that underly rule-following as a behavioral disposition. This allows to conceive institutions as causal circuits that connect the population-level dynamics of interactions with cognitive phenomena on the individual level. Those cognitive phenomena ultimately root in neuronal structures. So, I draw on a critical restatement of the concept of the meme by Aunger to propose a new conceptualization of the replicator in the context of institutions, namely, the replicator is a causal conjunction between signs and neuronal structures which undergirds the dispositions that generate rule-following actions. Signs, in turn, are outcomes of population-level interactions. I apply this framework on the case of money, analyzing the emotions that go along with the use of money, and presenting a stylized account of the emergence of money in terms of the naturalized Searle-Aoki model. In this view, money is a neuronally anchored metaphor for emotions relating with social exchange and reciprocity. Money as a meme is physically realized in a replicator which is a causal conjunction of money artefacts and money emotions. --Generalized Darwinism,institutions,replicator/interactor,Searle,Aoki,naturalism,memes,emotions,money
Fresh fish and amazing trees
No full textMeet John Kilaka, author and illustrator of children’s books and Tingatinga artist in a conversation with Sven Hallonsten.</p
Phylogenetic diversity and the structure of host-epiphyte interactions
No full textThis repository contains code, and data used in the paper "Phylogenetic diversity and the structure of host-epiphyte interactions!", by Marcio R. Pie, Fernanda S. Caron, Sven P. Batke, Johan Reyes-Chávez, Thom Dallimore et al. Use the following link: https://github.com/fernandacaron/epi_evo
All dödlighets sång och skrian : Studier i Sven Rosendahls naturprosa
No full textPär-Yngve Andersson,”All dödlighets sång och skrian”: Studier i Sven Rosendahls naturprosa (The song and scream of all mortality: Studies in the nature writing of Sven Rosendahl)Sven Rosendahl (1913-1990) was an author of novels as well as of various books about landscape and animals. However, his nature writing has not been devoted much attention by critics or literary scholars. Rosendahl himself expressed at many times his dissatisfaction with this. This study is exclusively devoted to his nature writing, and the aim is thereby to fill a disturbing lacuna in Swedish literary research. Several of his most important books are analysed carefully, from Räven från Krackberget (1941) to Från himmelens fåglar… (1968). Major importance is attached to analyses of style and narrative technique, and issues concerning genres and borders between fact and fiction in this kind of nature writing are discussed. I also refer to researchers in environmental literature and philosophers interested in experiences of nature. Detailed lyrical description is regarded as a kind of basis in Rosendahl’s artful language, but his nature writings are at the same time existential literature. Man is clearly seen as a part of nature, but seems to be the only specie conscious of its own mortality. The author is considering man’s place in this world, among all the other species. Confidence in nature’s reiteration is played off against the mortality of the individual. In later parts of the authorship, his awareness about environmental pollution is clearly evident. It even threats the genre of nature writing itself.</p
The evolutionary approach to entropy: Reconciling Georgescu-Roegen's natural philosophy with the maximum entropy framework
No full textIn Georgescu-Roegen's classical, though controversial discussion of entropy in relation to economics, the dualism of mechanical and subjective time plays a pivotal role. I argue that this fundamental distinction also inheres modern approaches to maximum entropy. Following Searle, I introduce the ontological dualism of observer independent and observer relative facts, and show that the notion of entropy also manifests this dualism, in the sense of the contextuality of measurements in experimental settings. Extending on the notion of observer relativity, I argue that the MaxEnt principle can be generalized into a framework of analyzing the evolution of (biological, technological etc.) functions under natural selection, if functions are equated with inference devices. Then, observer relativity is function relativity. In hierarchical evolutionary systems, this corresponds to the Maximum Entropy Production Principle, in the sense that functional evolution approximates gradients of maximum dissipation of energy. Against this background, the Georgescu-Roegen dualism of time translates into the dualism of observer independent entropy, which is the object of MEPP, and observer relative entropy, which is the object of MaxEnt. Both are two aspects under which evolution in general and economic evolution in particular can be analyzed. --Georgescu-Roegen,maximum entropy,observer relativity,time,hierarchical evolutionary systems,natural selection,physical concepts of information
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