Standard deviation of the mean and other time series properties of voltages measured with a digital lock-in amplifier

Metrologia ◽  
2010 ◽  
Vol 47 (5) ◽  
pp. 616-630 ◽  
Author(s):  
Thomas J Witt ◽  
N E Fletcher
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
The Mean ◽  
Lock In

scholarly journals Distance variable improvement of time-series big data stream evaluation

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Ari Wibisono ◽  
Petrus Mursanto ◽  
Jihan Adibah ◽  
Wendy D. W. T. Bayu ◽  
May Iffah Rizki ◽  
...  
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Standard Method ◽  
Time Series Data ◽  
Series Data ◽  
Percentage Error ◽  
Traffic Demand ◽  
Incremental Model ◽  
Chernoff Bound ◽  
The Mean

Abstract Real-time information mining of a big dataset consisting of time series data is a very challenging task. For this purpose, we propose using the mean distance and the standard deviation to enhance the accuracy of the existing fast incremental model tree with the drift detection (FIMT-DD) algorithm. The standard FIMT-DD algorithm uses the Hoeffding bound as its splitting criterion. We propose the further use of the mean distance and standard deviation, which are used to split a tree more accurately than the standard method. We verify our proposed method using the large Traffic Demand Dataset, which consists of 4,000,000 instances; Tennet’s big wind power plant dataset, which consists of 435,268 instances; and a road weather dataset, which consists of 30,000,000 instances. The results show that our proposed FIMT-DD algorithm improves the accuracy compared to the standard method and Chernoff bound approach. The measured errors demonstrate that our approach results in a lower Mean Absolute Percentage Error (MAPE) in every stage of learning by approximately 2.49% compared with the Chernoff Bound method and 19.65% compared with the standard method.

scholarly journals Annual and seasonal fructuations of bare soil temperature values In Thessaloniki-Greece

MAUSAM ◽  
2021 ◽  
Vol 43 (3) ◽  
pp. 321-324
Author(s):  
Y.A. GOUTSIDOU ◽  
T.J. MAKROGIANNIS ◽  
A.A. FLOCAS ◽  
C.S. SAHSAMANOGLOU
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Soil Temperature ◽  
Bare Soil ◽  
Seasonal Fluctuations ◽  
The Mean

The data. used for this study form the time series of the annual and seasonal fluctuations of bare soil temperature values In Thessaloniki-Greece. The mean arrival value IS 20°C with a standard deviation of 1 .3°C. The winter is the most variable season. The analysis of these time series has shown that there were notable spells of years with values above or below the normal one. Negative trends were observed for the annual and seasonal values with the exception of winters. The well known QBO was found in the annual and spring time series.  

scholarly journals Predictability of Characteristics of Temporal Variation in Surface Solar Irradiance Using Cloud Properties Derived from Satellite Observations

2018 ◽  
Vol 57 (11) ◽  
pp. 2661-2677 ◽  
Author(s):  
Takeshi Watanabe ◽  
Daisuke Nohara
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Solar Irradiance ◽  
Texture Features ◽  
Sample Entropy ◽  
Prediction Skill ◽  
Observation Data ◽  
Explanatory Variables ◽  
Cloud Properties ◽  
The Mean

AbstractUnderstanding of the characteristics of variation in surface solar irradiance on time scales shorter than several hours has been limited because ground-based observation stations are located coarsely. However, satellite observation data can be used to bridge this gap. We propose an approach for predicting characteristics of a time series of surface solar irradiance in a 121-min time window for areas without ground-based measurement systems. Time series features—mean, standard deviation, and sample entropy—are used to represent the characteristics of variation in surface solar irradiance quantitatively. We examine cloud properties over the area to design prediction models of these time series features. Cloud properties averaged over the defined domain and texture features that represent characteristics of the spatial distribution of clouds are used as measures of cloud features. Predictors for time series features, where explanatory variables are cloud features, are constructed employing the random-forest regression method. The performance test for predictions indicates that the mean and standard deviation can be predicted with higher prediction skill, whereas the predictor for sample entropy has lower prediction skill. The importance of cloud features for predictors and partial dependence of the predictors on explanatory variables are also analyzed. Cloud optical thickness (COT) and cloud fraction (CFR) were important for predicting the mean. Two texture features—contrast and local homogeneity (LHM)—and COT were important for predicting the standard deviation, and COT, LHM, and CFR were important for predicting the sample entropy. These results indicate which satellite-derived cloud field properties are useful for predicting time series features of surface solar irradiance.

scholarly journals A Bayesian ANOVA Scheme for Calculating Climate Anomalies, with Applications to the Instrumental Temperature Record

2012 ◽  
Vol 25 (2) ◽  
pp. 777-791 ◽  
Author(s):  
Martin P. Tingley
Keyword(s):  
Time Series ◽  
Standard Deviation ◽  
Missing Values ◽  
Reference Interval ◽  
Temperature Record ◽  
Uncertainty Interval ◽  
Common Reference ◽  
Climate Anomalies ◽  
Spatial Moment ◽  
The Mean

Abstract Climate datasets with both spatial and temporal components are often studied after removing from each time series a temporal mean calculated over a common reference interval, which is generally shorter than the overall length of the dataset. The use of a short reference interval affects the temporal properties of the variability across the records, by reducing the standard deviation within the reference interval and inflating it elsewhere. For an annually averaged version of the Climate Research Unit’s (CRU) temperature anomaly product, the mean standard deviation is 0.67°C within the 1961–90 reference interval, and 0.81°C elsewhere. The calculation of anomalies can be interpreted in terms of a two-factor analysis of variance model. Within a Bayesian inference framework, any missing values are viewed as additional parameters, and the reference interval is specified as the full length of the dataset. This Bayesian scheme is used to re-express the CRU dataset as anomalies with respect to means calculated over the entire 1850–2009 interval spanned by the dataset. The mean standard deviation is increased to 0.69°C within the original 1961–90 reference interval, and reduced to 0.76°C elsewhere. The choice of reference interval thus has a predictable and demonstrable effect on the second spatial moment time series of the CRU dataset. The spatial mean time series is in this case largely unaffected: the amplitude of spatial mean temperature change is reduced by 0.1°C when using the 1850–2009 reference interval, while the 90% uncertainty interval of (−0.03, 0.23) indicates that the reduction is not statistically significant.

At Least One Standard Deviation Above the Mean

1969 ◽  
Vol 14 (9) ◽  
pp. 470-471
Author(s):  
M. DAVID MERRILL
Keyword(s):  
Standard Deviation ◽  
The Mean

The Estimation of Blood Platelet Survival

1972 ◽  
Vol 28 (03) ◽  
pp. 447-456 ◽  
Author(s):  
E. A Murphy ◽  
M. E Francis ◽  
J. F Mustard
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Experimental Error ◽  
Blood Platelet ◽  
Least Squares Estimation ◽  
Systematic Relationship ◽  
Platelet Survival ◽  
The Mean ◽  
Normally Distributed

SummaryThe characteristics of experimental error in measurement of platelet radioactivity have been explored by blind replicate determinations on specimens taken on several days on each of three Walker hounds.Analysis suggests that it is not unreasonable to suppose that error for each sample is normally distributed ; and while there is evidence that the variance is heterogeneous, no systematic relationship has been discovered between the mean and the standard deviation of the determinations on individual samples. Thus, since it would be impracticable for investigators to do replicate determinations as a routine, no improvement over simple unweighted least squares estimation on untransformed data suggests itself.

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

PENGARUH PENDIDIKAN KESEHATAN REPRODUKSI PADA PEER GROUP (TEMAN SEBAYA) TERHADAP PENGETAHUAN DAN PERSEPSI REMAJA TENTANG PENDEWASAAN USIA PERKAWINAN DI SMA NEGERI 1 KECAMATAN NAMORAMBE KAB. DELI SERDANG 2018

2020 ◽  
Vol 1 (2) ◽  
pp. 56-66
Author(s):  
Irma Linda
Keyword(s):  
Standard Deviation ◽  
Health Education ◽  
Reproductive Health ◽  
Peer Group ◽  
Peer Groups ◽  
A Value ◽  
Significant Difference ◽  
Reproductive Health Education ◽  
The Mean ◽  
Adolescent Perceptions

Background: Early marriages are at high risk of marital failure, poor family quality, young pregnancies at risk of maternal death, and the risk of being mentally ill to foster marriage and be responsible parents. Objective: To determine the effect of reproductive health education on peer groups (peers) on the knowledge and perceptions of adolescents about marriage age maturity. Method: This research uses the Quasi experimental method with One group pre and post test design, conducted from May to September 2018. The statistical analysis used in this study is a paired T test with a confidence level of 95% (α = 0, 05). Results: There is an average difference in the mean value of adolescent knowledge between the first and second measurements is 0.50 with a standard deviation of 1.922. The mean difference in mean scores of adolescent perceptions between the first and second measurements was 4.42 with a standard deviation of 9.611. Conclusion: There is a significant difference between adolescent knowledge on the pretest and posttest measurements with a value of P = 0.002, and there is a significant difference between adolescent perceptions on the pretest and posttest measurements with a value of p = 0.001. Increasing the number of facilities and facilities related to reproductive health education by peer groups (peers) in adolescents is carried out on an ongoing basis at school, in collaboration with local health workers as prevention of risky pregnancy.

Regularity and latency of units in ventral cochlear nucleus: implications for unit classification and generation of response properties

1988 ◽  
Vol 60 (1) ◽  
pp. 1-29 ◽  
Author(s):  
E. D. Young ◽  
J. M. Robert ◽  
W. P. Shofner
Keyword(s):  
Standard Deviation ◽  
Cochlear Nucleus ◽  
Interspike Interval ◽  
Rate Adaptation ◽  
Stellate Cells ◽  
Instantaneous Rate ◽  
Ventral Cochlear Nucleus ◽  
Bushy Cell ◽  
Low Pass ◽  
The Mean

1. The responses of neurons in the ventral cochlear nucleus (VCN) of decerebrate cats are described with regard to their regularity of discharge and latency. Regularity is measured by estimating the mean and standard deviation of interspike intervals as a function of time during responses to short tone bursts (25 ms). This method extends the usual interspike-interval analysis based on interval histograms by allowing the study of temporal changes in regularity during transient responses. The coefficient of variation (CV), equal to the ratio of standard deviation to mean interspike interval, is used as a measure of irregularity. Latency is measured as the mean and standard deviation of the latency of the first spike in response to short tone bursts, with 1.6-ms rise times. 2. The regularity and latency properties of the usual PST histogram response types are shown. Five major PST response type classes are used: chopper, primary-like, onset, onset-C, and unusual. The presence of a prepotential in a unit's action potentials is also noted; a prepotential implies that the unit is recorded from a bushy cell. 3. Units with chopper PST histograms give the most regular discharge. Three varieties of choppers are found. Chop-S units (regular choppers) have CVs less than 0.35 that are approximately constant during the response; chop-S units show no adaptation of instantaneous rate, as measured by the inverse of the mean interspike interval. Chop-T units have CVs greater than 0.35, show an increase in irregularity during the response and show substantial rate adaptation. Chop-U units have CVs greater than 0.35, show a decrease in irregularity during the response, and show a variety of rate adaptation behaviors, including negative adaptation (an increase in rate during a short-tone response). Irregular choppers (chop-T and chop-U units) rarely have CVs greater than 0.5. Choppers have the longest latencies of VCN units; all three groups have mean latencies at least 1 ms longer than the shortest auditory nerve (AN) fiber mean latencies. 4. Chopper units are recorded from stellate cells in VCN (35, 42). Our results for chopper units suggest a model for stellate cells in which a regularly firing action potential generator is driven by the summation of the AN inputs to the cell, where the summation is low-pass filtered by the membrane capacitance of the cell.(ABSTRACT TRUNCATED AT 400 WORDS)

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