Search results for "Ar system"
showing 10 items of 6176 documents
Numerical methods for a nonlinear impact model: A comparative study with closed-form corrections
2011
A physically based impact model-already known and exploited in the field of sound synthesis-is studied using both analytical tools and numerical simulations. It is shown that the Hamiltonian of a physical system composed of a mass impacting on a wall can be expressed analytically as a function of the mass velocity during contact. Moreover, an efficient and accurate approximation for the mass outbound velocity is presented, which allows to estimate the Hamiltonian at the end of the contact. Analytical results are then compared to numerical simulations obtained by discretizing the system with several numerical methods. It is shown that, for some regions of the parameter space, the trajectorie…
Multimode Representation of the Magnetic Field for the Analysis of the Nonlinear Behavior of Solar Activity as a Driver of Space Weather
2022
ISSP UL as the Center of Excellence is supported through the Framework Program for European universities Union Horizon 2020, H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, CAMART2 project; Internal Foundation of University of Maryland.
Percutaneous Recanalization of Chronic Total Occlusions : 2019 Consensus Document from the EuroCTO Club
2019
Since its inception in December 2006, the EuroCTO Club has strived to provide the framework for state-of-the-art chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in Europe and nearby regions. Among its initiatives, the EuroCTO Club has published a set of recommendations regarding the technical aspects of CTO PCI, whose last edition dates to 2012. The EuroCTO Club consensus document discusses CTO PCI clinical indications, techniques and equipment use, as well as the qualifications of operators/centres. Given the considerable amount of progress made by this subspecialty in recent years, there is a need for an updated document that includes data from recent clinical trial…
Stability of stochastic nonlinear systems with state-dependent switching
2013
In this paper, the problem of stability on stochastic systems with state-dependent switching is investigated. To analyze properties of the switched system by means of Itô’s formula and Dynkin’s formula, it is critical to show switching instants being stopping times. When the given active-region set can be replaced by its interior, the local solution of the switched system is constructed by defining a series of stopping times as switching instants, and the criteria on global existence and stability of solution are presented by Lyapunov approach. For the case where the active-region set can not be replaced by its interior, the switched systems do not necessarily have solutions, thereby quasi-…
Vascular structure of the earliest shark teeth
2018
Here we use synchrotron tomography to characterise dental vasculature in the oldest known tooth-bearing sharks, Leonodus carlsi Mader, 1986 and Celtiberina maderi Wang, 1993. Three dimensional reconstruction of the vascular system and microstructure of both taxa revealed a complex and dense network of canals, including horizontal, ascending and secondary bifurcated canals, as well as histological features consistent with an osteodont histotype. However, L. carlsi and C. maderi also exhibit significant morphological differences, showing Leonodus a typical diplodont tooth morphology with a linguo-labially elongated base, that contrast with Celtiberina’s teeth that show a single conical cusp c…
Voimaharjoittelun vaikutukset dynaamiseen ja staattiseen tasapainoon nuorilla ja ikääntyneillä
2017
Tasapainolle ei ole olemassa universaalia määritelmää mutta se tiedetään, että sitä kontrolloivat useat eri mekanismit. Ikääntyminen aiheuttaa siinä heikkenemistä, joka aiheutuu muutoksista sekä sensorisissa että motorisissa prosesseissa. Kaatumisesta aiheutuneiden vammojen määrä kasvaa koko ajan ikääntyneillä. Heidän onkin havaittu pärjäävän nuoria huonommin sekä staattisissa että dynaamisissa testeissä mutta dynaamisissa testeissä ero on vieläkin suurempi. Erityisesti dynaamisten ominaisuuksin tutkiminen on tärkeää sillä staattiset testit eivät välttämättä paljasta tasapaino-ongelmia tai ikääntymiseen liittyviä eroja yhtä hyvin kuin dynaamiset testit. Tämän tutkimuksen suoritti loppuun 4 …
A Sub-Supersolution Approach for Robin Boundary Value Problems with Full Gradient Dependence
2020
The paper investigates a nonlinear elliptic problem with a Robin boundary condition, which exhibits a convection term with full dependence on the solution and its gradient. A sub- supersolution approach is developed for this type of problems. The main result establishes the existence of a solution enclosed in the ordered interval formed by a sub-supersolution. The result is applied to find positive solutions.
Designing and Evaluating Ubicomp Characteristics of Intelligent In-Car Systems
2022
In this paper, we present a preliminary taxonomy for designing and evaluating intelligent systems from the viewpoint of ubiquitous computing (ubicomp). As an example of intelligent systems, we examine a few novel in-car systems, which are already commercially available. We also discuss some ergonomics issues related to the design of in-car systems and argue that rationale for solving these issues can be found from the ideal qualities of ubicomp systems. The five characteristics we define to be ideal for genuine ubicomp systems are context-awareness, natural interaction methods, invisibility, support for everyday tasks, and interconnectivity. Based on these characteristics, we create a frame…
Physiological and autonomic stress responses after prolonged sleep restriction and subsequent recovery sleep in healthy young men
2018
Purpose Sleep restriction is increasingly common and associated with the development of health problems. We investigated how the neuroendocrine stress systems respond to prolonged sleep restriction and subsequent recovery sleep in healthy young men. Methods After two baseline (BL) nights of 8 h time in bed (TIB), TIB was restricted to 4 h per night for five nights (sleep restriction, SR, n = 15), followed by three recovery nights (REC) of 8 h TIB, representing a busy workweek and a recovery weekend. The control group (n = 8) had 8 h TIB throughout the experiment. A variety of autonomic cardiovascular parameters, together with salivary neuropeptide Y (NPY) and cortisol levels, were assessed.…
Hysteretic Systems Subjected to Delta Correlated Input
1994
The paper deals with the evaluation of the probabilistic response of a single degree of freedom elastic-perfectly plastic system subjected to a delta correlated input process. The probabilistic characterisation of the response is here obtained by considering the accumulated plastic deformations as a compound homogeneous Poisson process independent of the external input. In this case the former can be considered as an external noise acting on the linear system. A closed form solution is also obtained and the analytic expression is compared with the customary Monte-Carlo method.