Search results for "SPEED"

Contribution and effectiveness of ski and pole forces in selected roller skiing techniques on treadmill at moderate inclines

2023

BackgroundMost of the studies about the effects of incline on cross-country skiing are related to the metabolic efficiency. The effective skiing biomechanics has also been indicated to be among the key factors that may promote good performance. The aims of this study were to provide biomechanical characteristics and investigate the relative contribution and effectiveness of ski and pole forces in overcoming the total external resistance with double poling (DP) and Gear 3 (G3) techniques at varying moderate uphill inclines.Methods10 male cross-country skiers participated in this study. Custom-made force measurement bindings, pole force sensors, and an 8-camera Vicon system were used to colle…

Visual scale factor for speed perception rendering in car driving simulation

2010

Speed perception is an important task that the driver must perform continuously to control his/her vehicle. It appears that many factors influence this perception: height of the point of view, field of view, realism of the environment, but also realism of audio and proprioceptive rendering. If some high-performance car driving simulators are able to render motion satisfactorily according to all these criteria, it is not always the case. As a result, speed perception is thus often under estimated, leading into producing higher speeds than in real conditions. Perceptual validity is then not good enough to study driver's behavior. To solve this problem, a technique has recently seen the light,…

Transient stability simulation of a fixed speed wind turbine by Matlab/Simulink

2007

This paper describes the dynamic behavior of a typical fixed speed wind turbine connected to the grid; the model is developed in the simulation tool Matlab/Simulink and created as a modular structure. The pitch control system is used for stabilization of the wind turbine at grid faults. In this way, voltage stability of the system with grid-connected wind turbines can be improved by using blade-angle control for a temporary reduction of the wind turbine power during a short-circuit fault in the grid. This paper shows a new variable control for maintaining of voltage stability, when a three-phase fault is applied close to the wind turbine and cleared by disconnecting the affected line. In th…

The Mediating Role of C-Reactive Protein and Handgrip Strength Between Obesity and Walking Limitation

2008

OBJECTIVES: To study the association between different obesity indicators and walking limitation and to examine the role of C-reactive protein (CRP) and handgrip strength in that association. DESIGN: A cross-sectional, population-based study. SETTING: The Health 2000 Survey with a representative sample of the Finnish population. PARTICIPANTS: Subjects aged 55 and older with complete data on body composition, CRP, handgrip strength, and walking limitation (N=2,208). MEASUREMENTS: Body composition, anthropometrics, CRP, medical conditions, handgrip strength, and maximal walking speed were measured in the health examination. Walking limitation was defined as maximal walking speed less than 1.2…

KIELELLINEN ERITYISVAIKEUS – EI PELKÄSTÄÄN KIELELLISTEN TAITOJEN ONGELMA

2016

Kielellisen erityisvaikeuden ajatellaan olevan ensisijaisesti kielellisten taitojen ongelma. On kuitenkin todennäköistä, että kielelliseen erityisvaikeuteen liittyy myös ei-kielellisiä vaikeuksia. Tämän artikkelin tavoitteena on luoda katsaus eksekutiivisiin toimintoihin ja prosessointinopeuteen osana kielellistä erityisvaikeutta. Tutkimusten perusteella näyttää siltä, että kielelliseen erityisvaikeuteen liittyy kognitiiviseen joustavuuteen, inhibitioon, työmuistiin, tarkkaavuuteen sekä prosessointinopeuteen liittyviä vaikeuksia ainakin osalla kielihäiriöistä lapsista. Kielellisen erityisvaikeuden kliinisessä diagnostiikassa ja kuntoutuksessa on syytä huomioida myös ei-kielelliset vaikeudet…

Optimization of Delayed-State Kalman-Filter-based Algorithm via Differential Evolution for Sensorless Control of Induction Motors

2010

This paper proposes the employment of the differential evolution (DE) to offline optimize the covariance matrices of a new reduced delayed-state Kalman-filter (DSKF)-based algorithm which estimates the stator-flux linkage components, in the stationary reference frame, to realize sensorless control of induction motors (IMs). The DSKF-based algorithm uses the derivatives of the stator-flux components as mathematical model and the stator-voltage equations as observation model so that only a vector of four variables has to be offline optimized. Numerical results, carried out using a low-speed training test, show that the proposed DE-based approach is very promising and clearly outperforms a cla…

FLUMO: FLexible Underwater MOdem

2019

The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …

Visual word recognition in fluent and dysfluent readers in the transparent Finnish orthography

2012

Sex-specific genetic differences in endurance swimming of Trinidadian guppies

2015

Swim performance is considered a main fitness-determining trait in many aquatic organisms. Swimming is generally the only way most aquatic prey can escape predation, and swimming capacity is directly linked to food capture, habitat shifts, and reproduction. Therefore, evolutionary studies of swim performance are important to understand adaptation to aquatic environments. Most studies, however, concentrate on the importance of burst-swim responses to predators, and little is known about its effect on endurance. Even fewer studies associate differences in organism swim capabilities to key gender-specific responses. In this experiment, we assess the gender-specific genetic basis of swimming en…

Persistence in complex systems

2022

Persistence is an important characteristic of many complex systems in nature, related to how long the system remains at a certain state before changing to a different one. The study of complex systems' persistence involves different definitions and uses different techniques, depending on whether short-term or long-term persistence is considered. In this paper we discuss the most important definitions, concepts, methods, literature and latest results on persistence in complex systems. Firstly, the most used definitions of persistence in short-term and long-term cases are presented. The most relevant methods to characterize persistence are then discussed in both cases. A complete literature r…