Range as a Measure of Dispersion in Forest Sampling

1972 ◽  
Vol 2 (1) ◽  
pp. 40-44
Author(s):  
L. Heger
Keyword(s):  
Standard Deviation ◽  
Root Mean Square ◽  
Mean Square ◽  
Parent Population ◽  
Normal Parent ◽  
Random Samples ◽  
Population Standard Deviation

The assumption of randomness, underlying the use of range as an estimator of the standard deviation in a normal parent population, was deliberately violated in order to assess how restrictive is this assumption in sampling tree diameters and heights. In only four, out of 34 non-random samples, were the estimates of population standard deviation using range significantly lower than the corresponding root-mean-square estimates. These underestimates were reduced by randomizing the collected data.

scholarly journals Validation of Operational WAVEWATCH III Wave Model Against Satellite Altimetry Data Over South West Indian Ocean Off-Coast of Tanzania

2018 ◽  
Vol 10 (4) ◽  
pp. 55 ◽  
Author(s):  
Chuki Sangalugeme ◽  
Philbert Luhunga ◽  
Agness Kijazi ◽  
Hamza Kabelwa
Keyword(s):  
Standard Deviation ◽  
Indian Ocean ◽  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Mean Square ◽  
Wavewatch Iii ◽  
Mean Error ◽  
South West ◽  
Wave Heights

The WAVEWATCH III model is a third generation wave model and is commonly used for wave forecasting over different oceans. In this study, the performance of WAVEWATCH III to simulate Ocean wave characteristics (wavelengths, and wave heights (amplitudes)) over the western Indian Ocean in the Coast of East African countries was validated against satellite observation data. Simulated significant wave heights (SWH) and wavelengths over the South West Indian Ocean domain during the month of June 2014 was compared with satellite observation. Statistical measures of model performance that includes bias, Mean Error (ME), Root Mean Square Error (RMSE), Standard Deviation of error (SDE) and Correlation Coefficient (r) are used. It is found that in June 2014, when the WAVEWATCH III model was forced by wind data from the Global Forecasting System (GFS), simulated the wave heights over the Coast of East African countries with biases, Mean Error (ME), Root Mean Square Error (RMSE), Correlation Coefficient (r) and Standard Deviation of error (SDE) in the range of -0.25 to -0.39 m, 0.71 to 3.38 m, 0.84 to 1.84 m, 0.55 to 0.76 and 0.38 to 0.44 respectively. While, when the model was forced by wind data from the European Centre for Medium Range Weather Foresting (ECMWF) simulated wave height with biases, Mean Error (ME), Root Mean Square Error (RMSE), Correlation Coefficient (r) and Standard Deviation of error (SDE) in the range of -0.034 to 0.008 m, 0.0006 to 0.049 m, 0.026 to 0.22 m, 0.76 to 0.89 and 0.31 to 0.41 respectively. This implies that the WAVEWATCH III model performs better in simulating wave characteristics over the South West of Indian Ocean when forced by the boundary condition from ECMWF than from GFS.

Variability in ground motions: Root mean square acceleration and peak acceleration for the 1971 San Fernando, California, earthquake

1983 ◽  
Vol 73 (2) ◽  
pp. 615-632
Author(s):  
Martin W. McCann ◽  
David M. Boore
Keyword(s):  
Standard Deviation ◽  
Root Mean Square ◽  
Ground Motion ◽  
Ground Motions ◽  
Propagation Path ◽  
Embedment Depth ◽  
Mean Square ◽  
Stable Measure ◽  
Building Effects ◽  
San Fernando

abstract Data from the 1971 San Fernando, California, earthquake provided the opportunity to study the variation of ground motions on a local scale. The uncertainty in ground motion was analyzed by studying the residuals about a regression with distance and by utilizing the network of strong-motion instruments in three local geographic regions in the Los Angeles area. Our objectives were to compare the uncertainty in the peak ground acceleration (PGA) and root mean square acceleration (RMSa) about regressions on distance, and to isolate components of the variance. We find that the RMSa has only a slightly lower logarithmic standard deviation than the PGA and conclude that the RMSa does not provide a more stable measure of ground motion than does the PGA (as is commonly assumed). By conducting an analysis of the residuals, we have estimated contributions to the scatter in high-frequency ground motion due to phenomena local to the recording station, building effects defined by the depth of instrument embedment, and propagation-path effects. We observe a systematic decrease in both PGA and RMSa with increasing embedment depth. After removing this effect, we still find a significant variation (a standard deviation equivalent to a factor of up to 1.3) in the ground motions within small regions (circles of 0.5 km radius). We conclude that detailed studies which account for local site effects, including building effects, could reduce the uncertainty in ground motion predictions (as much as a factor of 1.3) attributable to these components. However, an irreducible component of the scatter in attenuation remains due to the randomness of stress release along faults during earthquakes. In a recent paper, Joyner and Boore (1981) estimate that the standard deviation associated with intra-earthquake variability corresponds to a factor of 1.35.

scholarly journals Influence of mentalis muscle relaxation on oronasal breathing

Revista CEFAC ◽  
2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Mara Letícia Gobbis ◽  
Bruno Luis Amoroso Borges ◽  
Karina Aparecida Tramonti ◽  
Cynthia Lopes da Silva ◽  
Mirian Hideko Nagae
Keyword(s):  
Standard Deviation ◽  
Root Mean Square ◽  
Analysis Of Variance ◽  
Muscle Relaxation ◽  
Massage Therapy ◽  
Control Group ◽  
Mean Square ◽  
Significance Level ◽  
Significant Difference ◽  
Experimental Group

ABSTRACT Purpose: to investigate the existence of changes in the electromyographic patterns of the mentalis and inferior orbicularis oris muscles in oronasal breathers, submitted to massage therapy on the mentalis muscle. Methods: a controlled blind placebo experiment, with a sample of 19 oronasal breathers (1 man and 18 women), mean age (standard deviation) 22.3 (2.63) years, randomly divided into control and experimental groups, respectively with 7 and 12 volunteers. The experimental group alone underwent myotherapy with massages for 3 months, while electromyographic data were collected from both groups at the beginning and end of the treatment, both at rest and when swallowing water. The analysis of variance was conducted to test the existence of differences between the means; the 5% significance level was used. Results: the analysis of variance revealed signs of interaction between the group and phase effects when analyzing the root mean square values of both the inferior orbicularis oris and the mentalis muscles. As expected, no signs of significant differences were found between the means of the phases in the control group. On the other hand, signs of significant difference were found in the experimental group, with reduced root mean square values in both muscles. The inferior orbicularis oris muscle, which in the pre-phase had a mean (standard deviation) of 202.10 (161.47) µV, had, in the post-phase, values of 131.49 (159.18) µV. The mentalis muscle, in its turn, had in the pre- and post-phase, respectively, a mean (standard deviation) of 199.31 (279.77) µV and 114.58 (253.56) µV. Conclusion: given that no effect was detected in the control group, the decrease in the root mean square values of the mentalis and inferior orbicularis oris muscles in oronasal breathers was attributed to the massage therapy on the mentalis muscle.

Repeatability of force signals in aerial circus straps

2017 ◽  
Vol 232 (3) ◽  
pp. 225-235
Author(s):  
Marion Cossin ◽  
Annie Ross ◽  
Frédérick P Gosselin
Keyword(s):  
Standard Deviation ◽  
Root Mean Square Error ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Intraclass Correlation ◽  
Mean Square ◽  
Movement Variability ◽  
Perfect Agreement ◽  
Error Method ◽  
Good Agreement

The aim of this study is to develop a method for assessing movement variability of circus acrobats. An analysis of the repeatability of force signals is used to quantify variability. Six students from the National Circus School of Montréal performed 5–10 trials of an acrobatic movement called dislock in aerial circus straps while tension force was measured at the hanging point of the aerial apparatus. The repeatability of force signals was calculated with three statistical methods: time-averaged standard deviation, intraclass correlation and root mean square error. These methods were compared with the ratings of a circus coach who ranked each acrobat’s trial with regard to the movement variability. The standard deviation and the intraclass correlation methods are commonly used to quantify the agreement between measurements in biomechanics, while the root mean square error method is regularly employed to quantify the agreement between measurements and a model. All participants performed the movement with little variability (intraclass correlation ⩾ 0.8). The results of the three methods were in good agreement with the coach’s assessment. The root mean square error method, in particular, showed perfect agreement and is therefore considered the best measure of repeatability. In the future, the proposed method could be used by coaches or artists training alone, allowing a new form of feedback.

scholarly journals The Influence of Heat Input on the Surface Quality of Wire and Arc Additive Manufacturing

2021 ◽  
Vol 11 (21) ◽  
pp. 10201
Author(s):  
Jiayi Zeng ◽  
Wenzhong Nie ◽  
Xiaoxuan Li
Keyword(s):  
Additive Manufacturing ◽  
Standard Deviation ◽  
Root Mean Square ◽  
Surface Quality ◽  
Heat Input ◽  
Quantitative Description ◽  
Mean Square ◽  
Profile Model ◽  
The Ideal

Wire and arc additive manufacturing has unique process characteristics, which make it have great potential in many fields, but the large amount of heat input brought by this feature limits its practical application. The influence of heat input on the performance of parts has been extensively studied, but the quantitative description of the influence of heat input on the surface quality of parts by wire and arc additive manufacturing has not received enough attention. According to different heat input, select the appropriate process parameters for wire and arc additive manufacturing, reversely shape the profile model, select the appropriate function model to establish the ideal profile model according to the principle of minimum error, and compare the two models to analyze the effect of heat input on the surface quality of the parts manufactured by wire and arc additive manufacturing. The results show that, when the heat input is high or low, the standard deviation value and the root mean square value reach 1.908 and 1.963, respectively. The actual profile is larger than the ideal profile. When the heat input is moderate, the standard deviation value and the root mean square value are only 1.634 and 1.713, respectively, and the actual contour is in good agreement with the ideal contour. Combined with the analysis of the transverse and longitudinal sections, it is shown that the heat input has a high degree of influence on the surface quality of the specimen manufactured by wire and arc additive manufacturing, and higher or lower heat input is disadvantageous to it.

scholarly journals Mathematical models for predicting final achieved height and its standard deviation rate in children with growth hormone deficiency in the Russian population

2017 ◽  
Vol 63 (5) ◽  
pp. 282-290
Author(s):  
Anna E. Gavrilova ◽  
Elena V. Nagaeva ◽  
Olga Yu. Rebrova ◽  
Tatiana Yu. Shiryaeva
Keyword(s):  
Standard Deviation ◽  
Linear Regression ◽  
Root Mean Square Error ◽  
Mathematical Models ◽  
Mean Square Error ◽  
Root Mean Square ◽  
Gh Deficiency ◽  
Bone Age ◽  
Mean Square ◽  
Explained Variance

Background. Predicting the efficacy of rGH therapy in patients with GH deficiency, based on the final achieved height (FAH) criterion, is an important tool for the clinician. It enables a personalized approach to the treatment of patients with GH deficiency: to recommend careful adherence to the regimen and dosage of the drug, evaluate the efficacy of therapy in different groups of patients, and clearly demonstrate the factors affecting the FAH indicator. Aim — to develop mathematical models for predicting FAH and its standard deviation score (SDS) in patients with GH deficiency in the Russian population. Material and methods. For simulation, we used the data of 121 patients diagnosed with GH deficiency who received rGH since the time of diagnosis to the time of final height and were followed-up at the Institute of Pediatric Endocrinology of the Endocrinology Research Centre in the period between 1978 and 2016. As model predictors, we used 11 indicators: the gender, chronological age at the time of GH deficiency diagnosis, puberty status, disease form, regularity of rGH therapy, height SDS at birth, height SDS at the time of GH deficiency diagnosis, bone age at the time of GH deficiency diagnosis, bone age/chronological index, SDS of a genetically predicted height, and maximum stimulated GH level in a clonidine test. To generate models, we used multiple linear regression, artificial neural networks (ANNs), and the Statistica 13 software. Results. The developed ANNs demonstrated a high accuracy of predicting FAH (the root-mean-square error was 4.4 cm, and the explained variance fraction was 76%) and a lower accuracy of predicting the FAH SDS (the root-mean-square error was 0.601 SDS, and the explained variance fraction was 42%). Linear regression models that were based on quantitative predictors only had a substantially worse quality. Free software implementation was developed for the best produced ANN. Conclusion. An ANN-based software-implemented model for predicting FAH uses indicators available for any clinician as predictors and can be used for individual prediction of FAH. In the future, the use of larger databases for simulation will improve the quality of predicting the efficacy of rGH therapy.

Herzratenvariabilitätsbasiertes Lifestyle-Coaching bei Patient*innen mit subakromialem Schmerzsyndrom – eine Pilotstudie

physioscience ◽  
2021 ◽  
Author(s):  
Matthias Kalmring
Keyword(s):  
Standard Deviation ◽  
Root Mean Square ◽  
High Frequency ◽  
Low Frequency ◽  
Mean Square ◽  
Eine Analyse

Zusammenfassung Hintergrund Mehrere Studien konnten einen Einfluss von psychologischem Stress auf Schmerzmodulation und Wundheilung aufzeigen. Die Erweiterung der physiotherapeutischen Behandlung um die psychosoziale Ebene des biopsychosozialen Modells stellt komplexe Anforderungen an die behandelnden Physioherapeut*innen. Ziel Untersucht wurde der Einfluss von auf Herzratenvariabilität (HRV) basierendem Lifestyle-Coaching auf die Entwicklung der funktionellen Einschränkungen und das Schmerzempfinden bei Patient*innen mit subakromialem Schmerzsyndrom (SAPS). Es erfolgte zudem eine Analyse der Machbarkeit für Folgestudien. Methode 15 Proband*innen mit SAPS wurden randomisiert in 2 Gruppen eingeteilt. Die Interventionsgruppe erhielt zusätzlich zu der in beiden Gruppen durchgeführten übungstherapeutischen Intervention ein Lifestyle-Coaching. Als Kontrollparameter wurden der SPADI-Score (SPADI), das maximale Schmerzempfinden (NRSmax) und anhand der Kurzzeit-HRV-Messung die High Frequency (HF), Low Frequency (LF), LF/HF-Ratio, Root Mean Square of Successive Difference (Rmssd) sowie die Standard Deviation NN (SdNN) erhoben. Bezüglich der Machbarkeit wurden mögliche Störfaktoren, Optimierungsmöglichkeiten und eine adäquate Stichprobengröße eruiert. Ergebnisse Einen signifikanten Unterschied zeigten die Variablen des SPADI-Scores, SPADI (95 % CI –59,3 bis –4,6; p = 0,026; d = –1,5), NRSmax (95 % CI –5,5 bis –0,1; p = 0,042; d = –1,35) und der HRV-Messwert HF (95 % CI 505,3–1753,3; p = 0,002; d = 2,23) im Vergleich zur Kontrollgruppe. Schlussfolgerung Das Design dieser Studie ist machbar und für Folgestudien mit größeren Stichproben geeignet. Anpassungen bei der Randomisierung sowie den verwendeten Assessments sollten dabei vorgenommen werden. Für eine gültige Aussagekraft der Ergebnisse wurde die dafür nötige Stichprobengröße mit n = 66 ermittelt. Die Auswertung der klinischen Parameter weisen auf eine Steigerung der parasympathischen Aktivität (HF) sowie einer Reduktion von SPADI und NRSmax hin. Letztere können hierbei als potentiell positive Wirkung auf die Funktion und Schmerzreduktion in der Interventionsgruppe eingeschätzt werden.

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