Invariant Submanifolds of Genus 5 and a Cantor Staircase in the Nonholonomic Model of a Snakeboard

2019 ◽  
Vol 29 (03) ◽  
pp. 1930008 ◽  
Author(s):  
Alexey Borisov ◽  
Alexander Kilin ◽  
Ivan Mamaev

In this paper, we address the free (uncontrolled) dynamics of a snakeboard consisting of two wheel pairs fastened to a platform. The snakeboard is one of the well-known sports vehicles on which the sportsman executes necessary body movements. From the theoretical point of view, this system is a direct generalization of the classical nonholonomic system of the Chaplygin sleigh. We carry out a topological and qualitative analysis of trajectories of this dynamical system. An important feature of the problem is that the common level set of first integrals is a compact two-dimensional surface of genus 5. We specify conditions under which the reaction forces infinitely increase during motion and the so-called phenomenon of nonholonomic jamming is observed. In this case, the nonholonomic model ceases to work and it is necessary to use more complex mechanical models incorporating sliding, elasticity, etc.

2015 ◽  
Vol 37 (4) ◽  
pp. 597-614 ◽  
Author(s):  
Carlo Cristiano

Before the publication of Ronald Coase’s “The Nature of the Firm,” new developments in the theory of the firm were under way in the works of Arnold Plant at the LSE, and Dennis Robertson, Frederick Lavington, and Austin Robinson among the Cambridge Marshallians. Although in disagreement on industrial policy, these economists shared the belief that the common view that bigger firms are always more efficient—a very popular view within the movement for industrial ‘rationalization’—was untenable from a theoretical point of view. In the works of these economists the ‘make or buy’ scheme is sometimes employed, and Coase’s idea of a cost for using the market can be found, in implicit form, in some writings of Plant that appeared before Coase’s article. But the fundamental principle that we now call “transaction costs” was hardly of any help to any of those who, at Cambridge as well as at the LSE, were insisting on the costs of coordination as a limit to the growth of the firm.


Problemos ◽  
2006 ◽  
Vol 69 ◽  
Author(s):  
Viktorija Daujotytė-Pakerienė

Straipsnyje, remiantis moksline ir menine medžiaga, aptariama humanistikos metodų problema. Keliama mintis, kad vaisingiausi metodai yra susiję su bendresniu mąstymu, su teorija. Jei metodas tik perimamas, jis virsta įrankiu, metodologijos dažnai, ypač disertacijose, tik imituojamos. Pasiremiama A. J. Greimo mintimi apie „apglėbiantį mąstymo būdą“. Trumpai aptariant pirmą kartą lietuviškai pasirodžiusias E. Husserlio „Karteziškąsias meditacijas“, ieškoma ir fenomenologinio tako humanistikoje, ypač literatūros moksle. Pabrėžiamas filosofijos ir literatūros ryšys. Keliama mintis, kad humanistikos metodologinės nuostatos turėtų labiau remtis pačia kūryba.Reikšminiai žodžiai: metodas, teorija, mąstymas, filosofija, poezija, fenomenologija. THE EMBRACING MODE OF THINKING Viktorija Daujotytė-Pakerienė Summary The author sets out to reconsider the problem of humanistic methods. It expresses the doubt as to the application of the methods which are detached from theories and a more general mode of thought. The title of the article is taken from the Lithuanian edition of the preface to “Semiotics” (1989) written by A. J. Greimas. The mode of thought, embracing the multifarious worlds of meaning, is considered as a humanistic universal, it is also perceived as a bridge of thought to prevailing phenomenology. The concept of embrace encompasses the dimension of the body and the full mental participation of the individual. A brief review of the first translation of Edmund Husserl’s “Cartesian Meditations” into Lithuanian by Tomas Sodeika (2005) are presented. Meditation is viewed as the common ground-substratum shared by philosophy and poetry. “Meditations” (1997) of Donaldas Kajokas are introduced. Algis Mickūnas and Arūnas Sverdiolas’s dialogues “The All-Embracing Present” (2004) are referred to as a personal testimony of the inner participation in the theories. The significance of A. Ðliogeris’s study “Thing and Art“ (1988), which discusses the creative work of P. Cezanne and R. M. Rilke, is reflected within the framework of the tradition of phenomenological thought; here the concept of theoretical point of view was first formulated in Lithuanian humanistics. The article suggests that in approaching the problems of method in humanistics, and especially in literary criticism, the participation of creation itself is very important, and particularly the experiences that open up in original texts (like in the writings of Marcel Proust, Jorge Luis Borges). It is important to reveal the equivalents, to reflect them, to extract the method from the texts. The article arrives at the conclusion that the recognition of the organizing inner text system is the essential principle of humanistic methodology, which is in close connection with the embracing mode of thought.Keywords: method, theory, thought, philosophy, poetry, phenomenology.


2015 ◽  
Vol 37 (2) ◽  
pp. 225-243
Author(s):  
József Popp ◽  
Attila Jámbor

The latest reform of the Common Agricultural Policy (CAP) has recently been accepted, identifying important challenges for EU agriculture, but proposing only limited changes to the previous CAP. Now it is time for the implementation of the new measures. However, from a theoretical point of view, it seems that the CAP can hardly meet the challenges it faces due to the inconsistencies between the predefined challenges and the measures proposed to meet them. The aim of the paper is to systematically analyse the consistency between the challenges of European agriculture and the policy measures aimed at meeting them. It seems that not all measures are consistent with the challenges.


2015 ◽  
Vol 9 (3) ◽  
pp. 47-55 ◽  
Author(s):  
József Popp ◽  
Károly Pető ◽  
Attila Jámbor

The latest reform of the Common Agricultural Policy has just been accepted, identifying important challenges for EU agriculture but proposing only limited changes to the previous CAP. Now it is time for the implementation of the new measures. However, from a theoretical point of view, it seems that the CAP can hardly meet the challenges it faces due to the inconsistencies between the predefined challenges and the measures proposed to meet them. The aim of the paper is to analyse the consistency between the challenges of European agriculture and the policy measures aimed at meeting them. It seems that not all measures are consistent with the challenges.


2007 ◽  
pp. 86-94
Author(s):  
A. Manakov

The article provides theoretical analysis and evaluation of the timber auctions reforms in Russia. The author shows that the mechanism of the "combined auctions", which functioned until recently, is more appropriate from the theoretical point of view (and from the point of view of the Russian practice) as compared to the officially approved format of the English auction.


2015 ◽  
Vol 52 (2) ◽  
pp. 221-232
Author(s):  
Pál Dömösi ◽  
Géza Horváth

In this paper we introduce a novel block cipher based on the composition of abstract finite automata and Latin cubes. For information encryption and decryption the apparatus uses the same secret keys, which consist of key-automata based on composition of abstract finite automata such that the transition matrices of the component automata form Latin cubes. The aim of the paper is to show the essence of our algorithms not only for specialists working in compositions of abstract automata but also for all researchers interested in cryptosystems. Therefore, automata theoretical background of our results is not emphasized. The introduced cryptosystem is important also from a theoretical point of view, because it is the first fully functioning block cipher based on automata network.


2010 ◽  
Vol 55 (2) ◽  
pp. 11-25 ◽  
Author(s):  
Bernd Dollinger

Der Beitrag geht von Versuchen aus, integrative Perspektiven einer überaus heterogenen Graffitiforschung zu bestimmen. In Auseinandersetzung insbesondere mit Bruno Latours Ansatz des »Iconoclash« wird eine kulturtheoretische Referenz bestimmt, die Graffiti als Version identifiziert, d. h. als semiotisch orientierte Veränderung räumlich situierter Ordnungs- und Regulierungspraxen. Ihnen kann, wenn auch nicht zwingend, eine subversive Qualität zukommen. Durch die Ausrichtung am Konzept einer Version wird beansprucht, Forderungen einer normativ weitgehend abstinenten, nicht-essentialistischen und für komplexe Fragen der Identitäts- und Raumpolitik offenen Forschungspraxis einzulösen.<br><br>The contribution attempts to integrate multiple perspectives of current largely heterogeneous graffiti scholarship. Referring to Bruno Latour’s concept »iconoclash«, we discuss graffiti from a cultural-theoretical point of view as a »version«. It appears as a semiotically oriented modification of spatially situated practices that regulate social life. Often, but not necessarily, these practices involve subversive qualities. The concept of »version« facilitates a non-normative and non-essentialist strategy of research. This enables an explorative research practice in which the complex matters of identity and space politics that are associated with graffiti can be addressed.


Author(s):  
Mireia López-Bertran

This chapter explores the funerary rites in the Phoenician-Punic world from a comprehensive point of view, and it focuses on the common points arising from a large amount of data. The concern for burying their deceased and the belief in the soul’s afterlife show that the Phoenicians considered death as a transformation rather than as the end of a person’s life. Through our access to archaeological remains and written sources, we can reconstruct the existence of a meaningful burial program that was destined to provide a “good death” and afterlife. Funerary rituals, thus, are the actions or gestures to achieve this goal. The aim of this chapter is to explain the rites that family members undertook once someone died, in order to transform correctly the deceased person into an otherworldly being, the ancestor. The social implications of the data arising from burials are also briefly considered.


2019 ◽  
Vol 9 (5) ◽  
pp. 20190027 ◽  
Author(s):  
Dulce Oliveira ◽  
Maria Vila Pouca ◽  
João Ferreira ◽  
Teresa Mascarenhas

Childbirth-related injuries are one of the main causes of pelvic floor dysfunction. To attempt to avoid serious tears during delivery, an episiotomy can be performed. In this study, we intended to investigate the biomechanical performance of the pelvic floor muscles after performing different episiotomies using a physics-based computational model which includes the pelvic floor muscles and the fetus. Previous biomechanical studies have analysed the mechanical effects of single incisions of different lengths; in this study, we intend to analyse the implications of multiple small incisions, evaluating the reaction forces, the stress on the muscles and the loss of tissue integrity sustained by the pelvic floor. The obtained results predict that an episiotomy delivery reduces the likelihood of macroscopic levator trauma by decreasing the stress on the region of insertion of the rectal area of the levator ani in the symphysis pubis . From the mechanical point of view, multiple incisions do not bring benefits compared to larger incisions. However, nothing can be ascertained about the clinical benefit of such an approach.


2021 ◽  
Vol 13 (14) ◽  
pp. 7894
Author(s):  
Gabriela Neagu ◽  
Muhammet Berigel ◽  
Vladislava Lendzhova

This paper examines the perspectives of rural NEETs in the information society. Our analysis focuses on the situation of three European countries—Bulgaria, Romania, and Turkey—characterized by a high share of rural areas and a population of NEETs. From a methodological point of view, we use alternative research methods (secondary data analysis) with statistical methods (simple linear regression). From a theoretical point of view, we will opt for a multidimensional analysis perspective: the theory of digital divide, digital inclusion, virtual mobility, etc. Through data analysis, we expect to obtain a more complete and detailed picture of the ICT situation in rural areas (level of digital skills, level of digital inclusion) to demonstrate the importance of ICT in optimizing virtual mobility for the living conditions of the population, especially the NEET population.


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