scholarly journals Design and Validation of a Device Attached to a Conventional Bicycle to Measure the Three-Dimensional Forces Applied to a Pedal

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4590
Author(s):  
Ezequiel Martín-Sosa ◽  
Víctor Chaves ◽  
Ignacio Alvarado ◽  
Juana Mayo ◽  
Joaquín Ojeda

Knowledge of the forces applied to the pedals during cycling is of great importance both from the point of view of improving sporting performance and medical analysis of injuries. The most common equipment for measuring pedal forces is usually limited to the study of forces in the sagittal plane. Equipment that measures three-dimensional forces tends to be bulky and to be incorporated into bicycles that are modified to accommodate it, which can cause the measurements taken to differ from those obtained in real pedalling conditions. This work presents a device for measuring the 3D forces applied to the pedal, attachable to a conventional bicycle and pedals, which does not alter the natural pedalling of cyclists. The equipment consists of four gauges located on the pedal axis and two on the crank, controlled by a microcontroller. Pedal forces measurements were made for six cyclists, with results similar to those shown in the literature. The correct estimation of the lateral-medial direction force is of great interest when evaluating a possible overload at the joints; it will also allow a comparison of the effectiveness index during pedalling, showing the role of this component in this index from a mechanical standpoint.

2009 ◽  
Vol 2 (1) ◽  
Author(s):  
Yaron Levinson ◽  
Reuven Segev

The kinematics of the octopus’s arm is studied from the point of view of robotics. A continuum three-dimensional kinematic model of the arm, based on a nonlinear rod theory, is proposed. The model enables the calculation of the strains in various muscle fibers that are required in order to produce a given configuration of the arm—a solution to the inverse kinematics problem. The analysis of the forward kinematics problem shows that the strains in the muscle fibers at two distinct points belonging to a cross section of the arm determine the curvature and the twist of the arm at that cross section. The octopus’s arm lacks a rigid skeleton and the role of material incompressibility in enabling the configuration control is studied.


1996 ◽  
Vol 11 (29) ◽  
pp. 5261-5277 ◽  
Author(s):  
OMDUTH COCEAL ◽  
STEVEN THOMAS

Following the previous work of Ferretti and Yang on the role of magnetic fields in the theory of conformal turbulence, we show that nonunitary minimal model solutions to two-dimensional magnetohydrodynamics (MHD) obtained by dimensional reduction from three dimensions exist under different (and more restrictive) conditions. From a three-dimensional point of view, these conditions are equivalent to perpendicular flow, in which the magnetic and velocity fields are orthogonal. We extend the analysis to the finite conductivity case and present some approximate solutions, whose connection with the exact ones of the infinite conductivity case is also discussed.


2012 ◽  
Vol 1 (33) ◽  
pp. 101
Author(s):  
Brice Blossier ◽  
Christophe Brière ◽  
J.A. Roelvink ◽  
D.J.R. Walstra

Sand beach profiles can exhibit nearshore sandbars with complex 3D patterns. Under energetic conditions, these patterns disappear and the bars get to a certain extent alongshore uniform. This phenomenon is called a reset. The existing literature mainly concerns the development of the bar patterns (3D) or the cross-shore migration of sandbars (2D). Studies on reset-events from a three dimensional point of view are limited but can be found for instance in Reniers et al. (2004) and Smit (2010). This paper describes an analysis that is aimed at determining the relevant processes involved in the reset of three dimensional subtidal bars and at describing the relative influence of each of these processes. To perform this study, data collected during the ECORS campaign at Le Truc Vert (France) in 2008 are analyzed. In addition, a numerical approach is performed using a research Delft3D model forced by the Xbeach wave generator to investigate the processes involved in a reset-event. The effects of the hydrodynamic external conditions on the flow patterns in the surfzone are investigated. Then the reset is studied in details in order to understand the role of the different processes taken into account by the numerical model. The incident wave energy controls the intensity of the reset. The bar cross-shore migration is controlled by the wave breaking process. The wave breaking position and the dissipation rate of the roller energy controls the generation of Shoreward Propagating Accretionary Waves (SPAW). The straightening of the subtidal bar occurs when the conditions induce a significant longshore current in the surfzone.


Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.


2009 ◽  
pp. 4-27
Author(s):  
A. Cohen ◽  
G. Harcourt

The article written by the well-known theorists and historians of economic thought contains a detailed overview of the Cambridge capital controversy, which had raged from the mid-1950-s through the mid-1970-s. The authors track the origins of the controversy and cover arguments of both sides in chronological order. From their point of view, the discussion hasnt been resolved, and its main underlying aspects were ideological beliefs and fundamental methodological controversies on the nature of equilibrium and on the role of time in economic theory. The article is published with comments written by other leading theoreticians.


2019 ◽  
pp. 22-29
Author(s):  
Н. В. Фрадкіна

The purpose and tasks of the work are to analyze the contemporary Ukrainian mass culture in terms of its value and humanistic components, as well as the importance of cultural studies and Ukrainian studies in educational disciplines for the formation of a holistic worldview of modern youth.Analysis of research and publications. Scientists repeatedly turned to the problems of the role of spirituality in the formation of society and its culture. This problem is highlighted in the publications by O. Losev, V. Lytvyn, D. Likhachev, S. Avierintsev, M. Zakovych, I. Stepanenko and E. Kostyshyn.Experts see the main negative impact of mass culture on the quality approach, which determines mass culture through the market, because mass culture, from our point of view, is everything that is sold and used in mass demand.One of the most interesting studies on this issue was the work by the representatives of Frankfurt School M. Horkheimer and T. Adorno «Dialectics of Enlightenment» (1947), devoted to a detailed analysis of mass culture. Propaganda at all socio-cultural levels in the form is similar in both totalitarian and democratic countries. It is connected, according to the authors, with the direction of European enlightenment. The tendency to unify people is a manifestation of the influence of mass culture, from cinema to pop. Mass culture is a phenomenon whose existence is associated with commerce (accumulation in any form – this is the main feature of education), in general, the fact that it exists in this form is related to the direction of the history of civilization.Modern mass culture, with its externally attractive and easily assimilated ideas and symbols, appealing to the trends of modern fashion, becomes a standard of prestigious consumption, does not require intense reflection, allows you to relax, distract, not teach, but entertains, preaches hedonism as the main spiritual value. And as a consequence, there are socio-cultural risks: an active rejection of other people, which leads to the formation of indifference; cruelty as a character trait; increase of violent and mercenary crime; increase in the number of alcohol and drug addicts; anti-patriotism; indifference to the values of the family and as a result of social orphanhood and prostitution.Conclusions, perspectives of research. Thus, we can conclude that modern Ukrainian education is predominantly formed by the values of mass culture. Namely, according to the «Dialectic» by Horkheimer and Adorno, «semi-enlightenment becomes an objective spirit» of our modern society.It is concluded that only high-quality education can create the opposite of the onset of mass culture and the destruction of spirituality in our society. It is proved that only by realizing the importance of cultivating disciplines in the educational process and the spiritual upbringing of the nation, through educational reforms, humanitarian knowledge will gradually return to student audiences.Formation of youth occurs under the influence of social environment, culture, education and self-education. The optimal combination of these factors determines both the process of socialization itself and how successful it will be. In this context, one can see the leading role of education and upbringing. It turns out that the main task of modern education is to spread its influence on the development of spiritual culture of the individual, which eventually becomes a solid foundation for the formation of the individual. Such a subject requires both philosophical and humanitarian approaches in further integrated interdisciplinary research, since the availability of such research will provide the theoretical foundation for truly modern educational and personal development.


2020 ◽  
pp. 75-79
Author(s):  
R. M. Gambarova

Relevance. Grain is the key to strategic products to ensure food security. From this point of view, the creation of large grain farms is a matter for the country's selfsufficiency and it leading to a decrease in financial expense for import. Creation of such farms creates an abundance of productivity from the area and leads to obtaining increased reproductive seeds. The main policy of the government is to minimize dependency from import, create abundance of food and create favorable conditions for export potential.The purpose of the study: the development of grain production in order to ensure food security of the country and strengthen government support for this industry.Methods: comparative analysis, systems approach.Results. As shown in the research, if we pay attention to the activities of private entrepreneurship in the country, we can see result of the implementation of agrarian reforms after which various types of farms have been created in republic.The role of privateentrepreneurshipinthedevelopmentofproduction is great. Тhe article outlines the sowing area, production, productivity, import, export of grain and the level of selfsufficiency in this country from 2015 till 2017.


1996 ◽  
Vol 34 (1) ◽  
pp. 27
Author(s):  
Sue Yon Shim ◽  
Ki Joon Sung ◽  
Young Ju Kim ◽  
In Soo Hong ◽  
Myung Soon Kim ◽  
...  

2019 ◽  
Vol 16 (2-3) ◽  
pp. 161-179
Author(s):  
Outi Paloposki

The article looks at book production and circulation from the point of view of translators, who, as purchasers and readers of foreign-language books, are an important mediating force in the selection of literature for translation. Taking the German publisher Tauchnitz's series ‘Collection of British Authors’ and its circulation in Finland in the nineteenth and early twentieth century as a case in point, the article argues that the increased availability of English-language books facilitated the acquiring and honing of translators' language skills and gradually diminished the need for indirect translating. Book history and translation studies meet here in an examination of the role of the Collection in Finnish translators' work.


2005 ◽  
Vol 55 (2) ◽  
pp. 201-221 ◽  
Author(s):  
Andrea Szalavetz

This paper discusses the relation between the quality and quantity indicators of physical capital and modernisation. While international academic literature emphasises the role of intangible factors enabling technology generation and absorption rather than that of physical capital accumulation, this paper argues that the quantity and quality of physical capital are important modernisation factors, particularly in the case of small, undercapitalised countries that recently integrated into the world economy. The paper shows that in Hungary, as opposed to developed countries, the technological upgrading of capital assets was not necessarily accompanied by the upgrading of human capital i.e. the thesis of capital skill complementarity did not apply to the first decade of transformation and capital accumulation in Hungary. Finally, the paper shows that there are large differences between the average technological levels of individual industries. The dualism of the Hungarian economy, which is also manifest in terms of differences in the size of individual industries' technological gaps, is a disadvantage from the point of view of competitiveness. The increasing differences in the size of the technological gaps can be explained not only with industry-specific factors, but also with the weakness of technology and regional development policies, as well as with institutional deficiencies.


Sign in / Sign up

Export Citation Format

Share Document