On Multiple-Resonator-based Implementation of IEC/IEEE Standard P-Class Compliant PMUs

This article deals with the implementation of the P-Class PMU compliant with IEC/IEEE Standard 60255-118-1:2018 by usage of a multiple-resonator (MR)-based approach for harmonic analysis having been proposed recently. In previously published articles, it has been shown that a trade-off between opposite requirements is possible by shifting a measurement time stamp along the filter window. Positioning the time stamp in a proximity of the time window center assures flat-top frequency responses. In this article, through simulation tests carried out under various conditions, it is shown that requirements of the IEC/IEEE Standard 60255-118-1:2018 can be satisfied by the second and third order MR structure for particular conditions of the time stamp location.

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Measurement time versus accuracy trade-off analyzed for electrochemical impedance measurements by means of sine, white noise and step signals

Journal of Electroanalytical Chemistry ◽

10.1016/0022-0728(82)87141-6 ◽

1982 ◽

Vol 138 (1) ◽

pp. 201-208 ◽

Cited By ~ 38

Author(s):

C. Gabrielli ◽

F. Huet ◽

M. Keddam ◽

J.F. Lizee

Keyword(s):

White Noise ◽

Electrochemical Impedance ◽

Measurement Time ◽

Impedance Measurements ◽

Trade Off

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Pores versus spores: competition between photosynthesis and reproduction is constrained by leaf mass per unit area (LMA) in ferns

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blaa189 ◽

2020 ◽

Author(s):

K G Srikanta Dani ◽

Jose Mathew ◽

T M Nila-Mohan ◽

Raju Antony ◽

S Suresh ◽

...

Keyword(s):

Life Histories ◽

Resource Constraints ◽

Time Window ◽

Unit Area ◽

Stomatal Density ◽

High Fertility ◽

Leaf Lifespan ◽

Trade Off ◽

Terrestrial Species ◽

Leaf Mass

Abstract Diversity in plant life histories is primarily that found in the rate and duration of photosynthetic (vegetative) and reproductive growth. However, direct evidence for an anticipated trade-off between photosynthesis and reproduction is lacking in any plant lineage. Ferns allocate leaf space and resources to both photosynthesis and reproduction, potentially leading to competition for leaf resources between stomatal pores and reproductive spores. We hypothesized that a trade-off between stomatal density (StD; a proxy for photosynthetic capacity) and sporangial density (SpD; a measure of fertility) has evolved in monomorphic ferns due to the common space, time and resource constraints imposed by a highly conserved and globally low leaf mass per unit area (LMA) in ferns, where any increase in LMA indicated greater construction cost and longer leaf lifespan. We measured LMA, StD and SpD in 40 fern species in India that represented both monomorphic and dimorphic conditions from both terrestrial and epiphytic habits. Both StD and SpD showed a 50-fold range in monomorphic species whereas LMA was more conserved (six-fold range). LMA of terrestrial ferns was significantly lower than that of epiphytic ferns. Linear regression between LMA and StD was significantly positive in dimorphic terrestrial ferns (showing the lowest LMA among all ferns) and significantly negative in monomorphic epiphytic ferns (showing the highest LMA among all ferns). Dimorphic terrestrial ferns were highly fecund on their fertile leaves and showed a significantly higher StD to LMA ratio on their sterile leaves compared to monomorphic terrestrial ferns. Dimorphic ferns seem to maximize both StD and SpD by physical separation of photosynthesis and reproduction, and their characteristically low LMA (shorter leaf lifespan = smaller time window) potentially selects for high StD and high fertility. The regression between StD and SpD in monomorphic ferns was significantly linear and positive, although comparisons among closely related species (within families) showed negative correlations when both StD and SpD were high, captured also by a significant quadratic regression between StD and SpD in monomorphic ferns. Monomorphic terrestrial species bearing more spores per stomata showed relatively low LMA whereas those producing fewer spores per stomata possessed leaves with relatively high LMA. Monomorphic epiphytes produced as many spores as terrestrial species but showed significantly low StD for their high LMA. We discuss the evolutionary reasons behind these trends and conclude that monomorphic terrestrial ferns with high LMA (long leaf lifespan) tend to prioritize photosynthesis over reproduction, while monomorphic epiphytes (always high LMA) are significantly more fertile for lower photosynthesis. The role of LMA in framing the rules of competition between stomata and sporangia in monomorphic ferns provides a template for how photosynthesis may directly or indirectly influence reproductive strategies (and vice versa) in all land plants.

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Investigation of the trade-off between time window length, classifier update rate and classification accuracy for restorative brain-computer interfaces

2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) ◽

10.1109/embc.2013.6609813 ◽

2013 ◽

Cited By ~ 4

Author(s):

Sam Darvishi ◽

Michael C. Ridding ◽

Derek Abbott ◽

Mathias Baumert

Keyword(s):

Classification Accuracy ◽

Time Window ◽

Window Length ◽

Brain Computer Interfaces ◽

Trade Off ◽

Computer Interfaces ◽

Update Rate

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Development of a Measuring Device and Software for Measurement of Electric Power Quantities Based on IEEE Standard 1459-2010

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.732-733.830 ◽

2013 ◽

Vol 732-733 ◽

pp. 830-834

Author(s):

Chamaiporn Tanthadiloke ◽

Thavatchai Tayjasanant

Keyword(s):

Harmonic Analysis ◽

Electric Power ◽

Power Quality ◽

Phase Measurement ◽

Measuring Device ◽

Result Verification ◽

Technical Paper ◽

Adjustable Speed Drive ◽

Ieee Standard ◽

Adjustable Speed

This paper presents a development of measuring device and software for 3-phase measurement of electric power quantities according to IEEE Std. 1459-2010. Blackman-Harris windowed FFT algorithm is used for the harmonic analysis to reduce the errors from leakage problems. Result verification with a technical paper has been made. Actual implementation with an adjustable speed drive at a laboratory has been carried out and crosschecked with a commercial power quality meter.

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Multi-Timescale Drowsiness Characterization Based on a Video of a Driver’s Face

Sensors ◽

10.3390/s18092801 ◽

2018 ◽

Vol 18 (9) ◽

pp. 2801 ◽

Cited By ~ 6

Author(s):

Quentin Massoz ◽

Jacques Verly ◽

Marc Van Droogenbroeck

Keyword(s):

Real Time ◽

Facial Expressions ◽

Cross Validation ◽

Time Window ◽

Reaction Times ◽

Ground Truth ◽

Trade Off ◽

Trade Offs ◽

Psychomotor Vigilance ◽

Long Timescales

Drowsiness is a major cause of fatal accidents, in particular in transportation. It is therefore crucial to develop automatic, real-time drowsiness characterization systems designed to issue accurate and timely warnings of drowsiness to the driver. In practice, the least intrusive, physiology-based approach is to remotely monitor, via cameras, facial expressions indicative of drowsiness such as slow and long eye closures. Since the system’s decisions are based upon facial expressions in a given time window, there exists a trade-off between accuracy (best achieved with long windows, i.e., at long timescales) and responsiveness (best achieved with short windows, i.e., at short timescales). To deal with this trade-off, we develop a multi-timescale drowsiness characterization system composed of four binary drowsiness classifiers operating at four distinct timescales (5 s, 15 s, 30 s, and 60 s) and trained jointly. We introduce a multi-timescale ground truth of drowsiness, based on the reaction times (RTs) performed during standard Psychomotor Vigilance Tasks (PVTs), that strategically enables our system to characterize drowsiness with diverse trade-offs between accuracy and responsiveness. We evaluated our system on 29 subjects via leave-one-subject-out cross-validation and obtained strong results, i.e., global accuracies of 70%, 85%, 89%, and 94% for the four classifiers operating at increasing timescales, respectively.

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Synthetic Esters and Dynamics of Pressure Compensated Proportional Directional Control Valves

BATH/ASME 2018 Symposium on Fluid Power and Motion Control ◽

10.1115/fpmc2018-8933 ◽

2018 ◽

Cited By ~ 1

Author(s):

J. H. Jakobsen ◽

M. R. Hansen

Keyword(s):

Closed Loop ◽

Closed Loop Control ◽

Third Order ◽

Loop Control ◽

Synthetic Ester ◽

Frequency Responses ◽

Directional Control ◽

Test Parameters ◽

The Difference

The purpose of this paper is to help reduce the uncertainty in behavior introduced when changing hydraulic oil from mineral oil (HLP) to biodegradable oil (synthetic esters - HEES) by comparing the behavior of proportional valves with HLP and with HEES at various temperatures. The focus of this article is on classic proportional valves used in the industry. The study is based on tests and modelling with characterization of dynamic behavior in mind. The characterization is based on tests of two pressure compensated proportional valves, one with closed loop control of the spool position, and one without. The two ester types tested are one based on a saturated, fully synthetic ester and a regular fully synthetic ester. The tests consist of steps and frequency responses. Both valves are tested at oil temperatures 20°C, 40°C and 60°C. The adopted models are based on a third order linear model with parameters identified using frequency responses from actual valve tests. The variation of amplitude and bias has some influence on the resulting frequency response especially at lower temperatures. But the general tendencies are unaffected by amplitude and bias. As expected a clear tendency for both valves of increasing dampening at decreasing temperatures is seen regardless of oil type, but the increase in dampening is similar for all oil types. The saturated ester leads to less bandwidth at lower temperatures for both valves, but the overall variations between all oil types stay within 1.66Hz of each other when tested with the same test parameters. The investigation indicates that the difference in dynamic characteristics at 20°C caused by the different oil types can not be explained with variations in any single one of the classic liquid properties density and viscosity and more investigations are needed to identify the cause.

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Modal Experiment on Structural Condition Monitoring Using Cumulative Harmonic Analysis

Advances in Acoustics and Vibration ◽

10.1155/2012/327135 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Yoshinori Takahashi ◽

Satoru Goto ◽

Mikio Tohyama

Keyword(s):

Harmonic Analysis ◽

Condition Monitoring ◽

Spectral Distribution ◽

Time Window ◽

Short Interval ◽

Structural Condition ◽

Scale Model ◽

Transient Vibration ◽

Monitoring Method ◽

Spectral Peaks

This paper describes a cumulative harmonic analysis (CHA) that replaces the stepwise time window function of Berman and Fincham's cumulative spectral analysis with a spectral accumulation function, thereby enabling a new structural health monitoring method. CHA estimates and visualizes system damping conditions without the need of transient-vibration records. The damping conditions are closely related to the spectral distribution around the dominant spectral peaks due to structural resonance. This type of spectral distribution can be visualized with CHA even within a short interval of random vibration samples. The effect of CHA on monitoring the damping conditions was reported by the authors in a previous study. In the current study, the authors confirmed the usefulness of CHA for structural condition monitoring by conducting scale-model experiments.

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Intestinal CD8αα IELs derived from two distinct thymic precursors have staggered ontogeny

Journal of Experimental Medicine ◽

10.1084/jem.20192336 ◽

2020 ◽

Vol 217 (8) ◽

Cited By ~ 1

Author(s):

Roland Ruscher ◽

S. Thera Lee ◽

Oscar C. Salgado ◽

Elise R. Breed ◽

Sara H. Osum ◽

...

Keyword(s):

Early Life ◽

Time Window ◽

Type A ◽

Intraepithelial Lymphocytes ◽

Time Stamp ◽

Type B ◽

Initial Wave ◽

Gut Epithelium ◽

Insight Into ◽

Young Mice

CD8αα intraepithelial lymphocytes (IELs) are abundant T cells that protect the gut epithelium. Their thymic precursors (IELps) include PD-1+ type A and Tbet+ type B populations, which differ in their antigen-receptor specificities. To better understand CD8αα IEL ontogeny, we performed “time-stamp” fate mapping experiments and observed that it seeds the intestine predominantly during a narrow time window in early life. Adoptively transferred IELps parked better in the intestines of young mice than in adults. In young mice, both type A and type B IELps had an S1PR1+ and α4β7+ emigration- and mucosal-homing competent phenotype, while this was restricted to type A IELps in adults. Only CD8αα IELs established in early life were enriched in cells bearing type B IELp TCR usage. Together, our results suggest that the young intestine facilitates CD8αα IEL establishment and that early IELs are distinct from IELs established after this initial wave. These data provide novel insight into the ontogeny of CD8αα IELs.

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