Search results for "JOINT"
showing 10 items of 1472 documents
El alcance de la responsabilidad solidaria prevista en el artículo 42 ET
2020
El artículo 42 ET impone sobre el empresario que contrata o subcontrata con otros la realización de obras o servicios pertenecientes a su propia actividad una responsabilidad solidaria sobre ciertas obligaciones contraídas por el contratista y el subcontratista con sus trabajadores, siempre que hayan nacido durante la vigencia de la contrata. En principio, el significado de la previsión normativa se presenta como relativamente sencillo; no obstante, su aplicación práctica suscita diferentes dudas interpretativas. Pues bien, el objeto de este trabajo se dirige a perfilar el contorno y contenido de la responsabilidad solidaria recogida en el art. 42 ET, lo que exige delimitar con claridad su …
On the moving load problem in beam structures equipped with tuned mass dampers
2017
This paper proposes an original and efficient approach to the moving load problem on Euler–Bernoulli beams, with Kelvin–Voigt viscoelastic translational supports and rotational joints, and in addition, equipped with Kelvin–Voigt viscoelastic tuned mass dampers (TMDs). While supports are taken as representative of external devices such as grounded dampers or in-span supports with flexibility and damping, the rotational joints may model rotational dampers or connections with flexibility and damping arising from imperfections or damage. The theory of generalised functions is used to treat the discontinuities of the response variables, which involves deriving exact complex eigenvalues and eigen…
Change of Direction Biomechanics in a 180-Degree Pivot Turn and the Risk for Noncontact Knee Injuries in Youth Basketball and Floorball Players.
2021
Background: Studies investigating biomechanical risk factors for knee injuries in sport-specific tasks are needed. Purpose: To investigate the association between change of direction (COD) biomechanics in a 180-degree pivot turn and knee injury risk among youth team sport players. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 258 female and male basketball and floorball players (age range, 12-21 years) participated in the baseline COD test and follow-up. Complete data were obtained from 489 player-legs. Injuries, practice, and game exposure were registered for 12 months. The COD test consisted of a quick ball pass before and after a high-speed 180-degree pivot turn o…
Epiphysäre Dysplasie des Hüftgelenks, Diagnostik und Differentialdiagnostik mit der MRT
1992
Sixteen hip joints of eight patients with multiple epiphyseal dysplasia were examined by clinical investigation, plain films and by magnetic resonance imaging (MRI), using T1- and T2-weighted images and gradient echoes. MRI is useful in demonstrating the congruity of the joint, in the changes of the epiphyseal signal intensities and the epiphyseal line. Individual changes of the signal intensity patterns on T1- and T2-weighted scans are described. Although MRI exhibits a variety of patterns in different patients, a clearcut differentiation from Legg-Calve-Perthes' disease is possible.
Minimally Invasive Sacroiliac Joint Arthrodesis: Experience in a Prospective Series with 24 Patients
2014
Background: Sacroiliac (SI) joint pain conservative treatments show poor outcomes. Hypothesis: surgical treatment will show better results. Patients and methods: Prospective series: 24 patients undergoing SI fusion after failure of medical treatment and showing temporary relief with SI infiltration. Period: Nov 2009-July 2013. Gender: 9/15. 11 cases bilaterally (all ). Age: 32-71 years (mean 47.4 years). Height: 161-178 cm (mean 168.2 cm). Weight: 56-84 kg (mean 68.4 kg). Etiology: 12 degenerative/spontaneous, 7 fall on buttocks, 3 coincident with lumbar disc and 2 with lumbar posterolateral fusion. Exclusion criteria: ankylosing spondylitis, osteitis condensans ilii, sacro-iliac joint arth…
Numerical study of the components positioning influence on the stability of a reverse shoulder prosthesis
2014
Aim of this paper is to setup a novel procedure able to analyze performances of a reverse shoulder prosthesis when different geometrical configurations are assumed. Nowadays, such a prosthesis is widely used but, because of its novelty, data in literature give poor information about performances and limits to its applicability. The activity has been divided into the following steps. At the beginning the shape of the prosthesis has been digitally acquired via a 3D scanner. Then, CAD models of all prosthetic components have been geometrically optimized in a way to obtain final entities suitable for numerical simulations. After that, CAD assemblies have been created between prosthetic componen…
Sensorimotor Communication for Humans and Robots: Improving Interactive Skills by Sending Coordination Signals
2018
During joint actions, humans continuously exchange coordination signals and use nonverbal, sensorimotor forms of communication. Here we discuss a specific example of sensorimotor communication-"signaling"-which consists in the intentional modification of one's own action plan (e.g., a plan for reaching a glass of wine) to make it more predictable or discriminable from alternative action plans that are contextually plausible (e.g., a plan for reaching another glass on the same table). We first review the existing evidence on signaling in human-human interactions, discussing under which conditions humans use signaling. Successively, we distill these insights into a computational theory of sig…
Poisson-Nijenhuis structures and the Vinogradov bracket
1994
We express the compatibility conditions that a Poisson bivector and a Nijenhuis tensor must fulfil in order to be a Poisson-Nijenhuis structure by means of a graded Lie bracket. This bracket is a generalization of Schouten and Frolicher-Nijenhuis graded Lie brackets defined on multivector fields and on vector valued differential forms respectively.
Teachers’ perspectives on collaboration with didacticians to create an inquiry community
2009
A research and development project, Learning Communities in Mathematics (LCM)1 was designed to create opportunities for ‘co-learning inquiry’ between mathematics teachers in eight schools and didacticians in a university in Norway (UiA). The focus has been on improving mathematics teaching and learning at school levels from lower primary to upper secondary and on the developmental processes and partnerships involved. A central aim was to create a community of inquiry through which aspects of mathematics teaching and learning could be explored, and through which both teachers and didacticians could learn in practice. Theoretically, ‘Community of Inquiry’ derives from ‘Community of Practice’ …
Review of Classical Non-self-adjoint Spectral Theory
2019
The first section of this chapter deals with Fredholm theory in the spirit of Appendix A in Helffer and Sjostrand (Mm Soc Math Fr (NS) 24–25:1–228, 1986), see also an appendix in Melin and Sjostrand (Asterique 284:181–244, 2003) and Sjostrand and Zworski (Ann Inst Fourier 57:2095–2141, 2007). The remaining sections give a brief account of the very beautiful classical theory of non-self-adjoint operators, taken from a section in Sjostrand (Lectures on Resonances) which is a brief account of parts of the classical book by Gohberg and Krein (Introduction to the Theory of Linear Non-Selfadjoint Operators. Translations of Mathematical Monographs, vol 18. AMS, Providence, 1969).