Search results for "Power ratio"
showing 6 items of 6 documents
Similar relative decline in aerobic and anaerobic power with age with in elite endurance and power master athletes of both sexes
2019
Lower physical activity levels in old age are thought to contribute to the age-related decline in peak aerobic and anaerobic power. Master athletes maintain high levels of physical activity with advancing age and endurance or power training may influence the extent to which these physical functions decline with advancing age. To investigate, 37-90-year-old power (n=20, 45% female) and endurance (n=19, 58% female) master athletes were recruited. Maximal aerobic power was assessed when cycling two-legged (VO2 Peak2-leg ) and cycling one-legged (VO2 Peak1-leg ), while peak jumping (anaerobic) power was assessed by a countermovement jump. Men and women had a similar VO2 Peak2-leg (mL·kg-1 ·min-…
Measuring postural-related changes of spontaneous baroreflex sensitivity after repeated long-duration diving: Frequency domain approaches
2012
Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was …
A single-point approach based on nonactive power factor for the assessment of harmonic distortion sources in power systems
2022
This paper presents a study on the use of power factor indicators for the assessment of harmonic distortion sources in power systems. In detail the analysis is focused on the comparison between the proposed nonactive power factor (Q1/N) and the indicators of the IEEE Std. 1459-2010, and on the indicators feasibility in identifying the presence of harmonic distortion sources. As discussed in the paper, the proposed indicator can be evaluated with good accuracy, by means of typical power quantities measurements at the point of common coupling (PCC). Thus its measurement can be feasibly implemented in commercial platforms used for smart metering applications. To verify the proposal validity, s…
Measurement Uncertainty of Harmonic Emission Indicators based on IEEE Std. 1459-2010
2020
The study presented in this paper is aimed at analyzing the measurement uncertainty impact on the evaluation of some power ratio parameters for harmonic emissions assessment based on IEEE Std. 1459-2010 apparent power decomposition. In addition to power factors for line utilization and harmonic pollution levels evaluation defined in the Standard, the study covers also some new parameters, which have been introduced by the authors as IEEE Std. 1459-2010 power quantities ratios. The measurement of the aforesaid parameters is implemented on a PC-based wattmeter, in order to investigate the measurement uncertainty impact on the evaluation of the power ratios. The obtained results show that, in …
On improving the accuracy of Visible Light Positioning system using deep autoencoder
2020
International audience; DC-biased optical Orthogonal Frequency DivisionMultiplexing (DCO-OFDM)-based visible light positioning (VLP)technology along with the Received Signal Strength(RSS) po-sitioning algorithm is widely used to achieve centimeter levelpositioning accuracy for incoming 5G era, especially indoorenvironment. However, the DCO-OFDM has the peak-to-averagepower ratio (PAPR) issue which imposes the nonlinear distortionand it will directly affect the positioning accuracy in the VLPsystem. The PAPR reduction scheme is urgently needed. There-fore, in this paper, the impact of PAPR reduction scheme onpositioning accuracy is investigated. The positioning accuracywith and without the s…
IEEE Std. 1459 power quantities ratio approaches for simplified harmonic emissions assessment
2018
The paper investigates the suitability of using power ratio parameters for harmonic emissions assessment at the point of common coupling (PCC). The study is carried out starting from the IEEE Std. 1459-2010 apparent power decomposition, where power factors are defined for evaluating line utilization and harmonic pollution levels. In addition, the study investigates the behavior of new parameters, which are expressed in terms of ratio between IEEE Std. 1459-2010 power quantities. The study is carried out for both single-phase and three-phase case, also considering the presence of capacitors. ? 2018 IEEE.