scholarly journals Monitoring of regional lake water clarity using Landsat imagery

2014 ◽  
Vol 46 (5) ◽  
pp. 661-670 ◽  
Author(s):  
Matias Bonansea ◽  
Raquel Bazán ◽  
Claudia Ledesma ◽  
Claudia Rodriguez ◽  
Lucio Pinotti
Keyword(s):  
Landsat Imagery ◽  
Low Cost ◽  
Pearson Correlation ◽  
Regional Scale ◽  
Correlation Coefficients ◽  
Lake Management ◽  
Water Clarity ◽  
Water Quality Monitoring ◽  
Measurement Tool ◽  
Secchi Disk Transparency

The application of remote sensing technology to water quality monitoring has special significance for lake management at regional scale. Water clarity expressed in terms of Secchi disk transparency (SDT) is a highly useful indicator of trophic status and ecosystem health. In this study, we related Landsat TM and ETM+ data with ground observations to develop a model for the estimation of SDT which can be used as a standardized procedure for regional-scale lake clarity assessment in the central region of Argentina. Samples were taken from two reservoirs of the region. Pearson correlation coefficients and step-wise multiple regression analysis were used to evaluate correlation between Landsat bands and measured SDT. Results suggested that Landsat band 3 plus the ratio 1/3 was a consistent and reliable predictor of SDT (R2 = 0.80). The algorithm was validated (R2 = 0.81) and applied to the November 10, 2010 ETM+ image obtaining a map that characterized water clarity of reservoirs within the study area. The procedure presented here could become a low cost measurement tool for water management authorities and decision-makers, obtaining simpler and practical results for regional water clarity monitoring.

scholarly journals Use of Global Reanalysis Data in the Study of the Aridity Index in the Magdalena-Cauca Macro-Basin, Colombia

10.29007/92l9 ◽  
2018 ◽  
Author(s):  
Carolina Vega-Viviescas ◽  
David A. Zamora ◽  
Erasmo A. Rodríguez
Keyword(s):  
Southern Oscillation ◽  
Pearson Correlation ◽  
Regional Scale ◽  
Correlation Coefficients ◽  
Aridity Index ◽  
Remote Sensing Data ◽  
Reanalysis Data ◽  
In Situ Data ◽  
Global Reanalysis

The Magdalena-Cauca macro-basin (MCMB) in Colombia, by its tropical location, annually experiences the effects of movement of the Intertropical Convergence Zone, and it is highly affected by interannual macro-climatic phenomena, such as El Niño– Southern Oscillation (ENSO). With the aim of increasing the use of global reanalysis and remote sensing data for supporting water management decisions at the watershed scale and within the framework of the eartH2Observe research project, the aridity index (AI) was calculated with three different data sources. Precipitation products and AI results were compared with their corresponding in-situ national official data. The comparison shows high correlations between the AI derived from observed data and AI obtained from the reanalysis, with Pearson correlation coefficients above 0.8 for two of the products investigated. This shows the importance of using global reanalysis data in water availability studies on a regional scale for the MCMB and the potential of this information in others macrobasins in Colombia including the Orinoquia and Amazon regions, where in-situ data is scarce.

scholarly journals A Comparison of Three Trapezoid Models Using Optical and Thermal Satellite Imagery for Water Table Depth Monitoring in Estonian Bogs

2020 ◽  
Vol 12 (12) ◽  
pp. 1980 ◽  
Author(s):  
Iuliia Burdun ◽  
Michel Bechtold ◽  
Valentina Sagris ◽  
Viacheslav Komisarenko ◽  
Gabrielle De Lannoy ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Table ◽  
Satellite Imagery ◽  
Landsat Imagery ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Temporal Correlation ◽  
Water Table Depth ◽  
P Value

This study explored the potential of optical and thermal satellite imagery to monitor temporal and spatial changes in the position of the water table depth (WTD) in the peat layer of northern bogs. We evaluated three different trapezoid models that are proposed in the literature for soil moisture monitoring in regions with mineral soils. Due to the tight capillary connection between water table and surface soil moisture, we hypothesized that the soil moisture indices retrieved from these models would be correlated with WTD measured in situ. Two trapezoid models were based on optical and thermal imagery, also known as Thermal-Optical TRApezoid Models (TOTRAM), and one was based on optical imagery alone, also known as the OPtical TRApezoid Model (OPTRAM). The models were applied to Landsat imagery from 2008 to 2019 and the derived soil moisture indices were compared with in-situ WTD from eight locations in two Estonian bogs. Our results show that only the OPTRAM index was significantly (p-value < 0.05) correlated in time with WTD (average Pearson correlation coefficient of 0.41 and 0.37, for original and anomaly time series, respectively), while the two tested TOTRAM indices were not. The highest temporal correlation coefficients (up to 0.8) were observed for OPTRAM over treeless parts of the bogs. An assessment of the spatial correlation between soil moisture indices and WTD indicated that all three models did not capture the spatial variation in water table depth. Instead, the spatial patterns of the indices were primarily attributable to vegetation patterns.

scholarly journals Design and Performance Analysis of an Ultrasonic System for Health Monitoring of Concrete Structure

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6606
Author(s):  
Jinhui Zhao ◽  
Tianyu Hu ◽  
Ruifang Zheng ◽  
Penghui Ba ◽  
Qichun Zhang
Keyword(s):  
Health Monitoring ◽  
Low Cost ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Theoretical Data ◽  
Mean Values ◽  
Output Performance ◽  
System Output ◽  
And Performance ◽  
Tunable Frequency

The development and research of an ultrasonic-based concrete structural health monitoring system encounters a variety of problems, such as demands of decreasing complexity, high accuracy, and extendable system output. Aiming at these requirements, a low-cost extendable system based on FPGA with adjustable system output has been designed, and the performance has been evaluated by different assessment parameters set in this paper. Besides the description of the designed system and the experiments in air medium, the residual similarity and Pearson correlation coefficients of experimental and theoretical data have been used to evaluate the submodules’ output. The output performance of the overall system is evaluated by the Pearson correlation coefficient, root-mean-square error (RMSE), and magnitude-squared coherence with 40 experimental data. The maximum, median, minimum, and mean values in three-parameter datasets are analyzed for discussing the working condition of the system. The experimental results show that the system works stably and reliably with tunable frequency and amplitude output.

scholarly journals Reliability and Validity of the INFOOT Three-dimensional Foot Digitizer for Patients with Rheumatoid Arthritis

2011 ◽  
Vol 101 (3) ◽  
pp. 198-207 ◽  
Author(s):  
Sophie De Mits ◽  
Pascal Coorevits ◽  
Dirk De Clercq ◽  
Dirk Elewaut ◽  
James Woodburn ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Measurement Tool ◽  
Intraclass Correlation Coefficients ◽  
Detectable Difference ◽  
Smallest Detectable Difference ◽  
Clinical Measurements

Background: Abnormal foot posture and deformities are identified as important features in rheumatoid arthritis. There is still no consensus regarding the optimum technique(s) for quantifying these features; hence, a foot digitizer might be used as an objective measurement tool. We sought to assess the validity and reliability of the INFOOT digitizer. Methods: To investigate the validity of the INFOOT digitizer compared with clinical measurements, we calculated Pearson correlation coefficients. To investigate the reliability of the INFOOT digitizer, we calculated intraclass correlation coefficients, SEMs, smallest detectable differences, and smallest detectable difference percentages. Results: Most of the 38 parameters showed good intraclass correlation coefficients, with values greater than 0.9 for 30 parameters and greater than 0.8 for seven parameters. The left heel bone angle expressed a moderate correlation, with a value of 0.609. The SEM values varied between 0.31 and 3.51 mm for the length and width measures, between 0.74 and 5.58 mm for the height data, between 0.75 and 5.9 mm for the circumferences, and between 0.78° and 2.98° for the angles. The smallest detectable difference values ranged from 0.86 to 16.36 mm for length, width, height, and circumference measures and from 2.17° to 8.26° for the angle measures. For the validity of the INFOOT three-dimensional foot digitizer, Pearson correlation coefficients varied between 0.750 and 0.997. Conclusions: In this rheumatoid arthritis population, good validity was demonstrated compared with clinical measurements, and most of the obtained parameters proved to be reliable. (J Am Podiatr Med Assoc 101(3): 198–207, 2011)

scholarly journals Elemental and organic carbon in PM<sub>10</sub>: a one year measurement campaign within the European Monitoring and Evaluation Programme EMEP

2007 ◽  
Vol 7 (2) ◽  
pp. 3859-3899 ◽  
Author(s):  
K. E. Yttri ◽  
W. Aas ◽  
A. Bjerke ◽  
D. Ceburnis ◽  
C. Dye ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Pearson Correlation ◽  
Regional Scale ◽  
Correlation Coefficients ◽  
Monitoring And Evaluation ◽  
Total Carbon ◽  
Rural Background ◽  
Evaluation Programme ◽  
Sampling Campaign ◽  
One Year

Abstract. In the present study, ambient aerosol (PM10) concentrations of elemental carbon (EC), organic carbon (OC), and total carbon (TC) are reported for 12 European rural background sites and two urban background sites following a one-year (1 July 2002–1 July 2003) sampling campaign within the European Monitoring and Evaluation Programme, EMEP (http://www.emep.int/). The purpose of the campaign was to assess the feasibility of performing EC and OC monitoring on a regular basis and to obtain an overview of the spatial and seasonal variability on a regional scale in Europe. Analyses were performed using the thermal-optical transmission (TOT) instrument from Sunset Lab Inc., operating according to a NIOSH derived temperature program. The annual mean mass concentration of EC ranged from 0.17±0.19 μg m−3 (mean ± SD) at Birkenes (Norway) to 1.83±1.32 μg m−3 at Ispra (Italy). The corresponding range for OC was 1.20±1.29 μg m−3 at Mace Head (Ireland) to 7.79±6.80 μg m−3 at Ispra. On average, annual concentrations of EC, OC, and TC were three times higher for rural background sites in Central, Eastern and Southern Europe compared to those situated in the Northern and Western parts of Europe. Wintertime concentrations of EC and OC were higher than those recorded during summer for the majority of the sites. Moderate to high Pearson correlation coefficients (rp) (0.50–0.94) were observed for EC versus OC for the sites investigated. The lowest correlation coefficients were noted for the three Scandinavian sites: Aspvreten (SE), Birkenes (NO), and Virolahti (FI), and the Slovakian site Stara Lesna, and are suggested to reflect biogenic sources, wild and prescribed fires. This suggestion is supported by the fact that higher concentrations of OC are observed for summer compared to winter for these sites. For the rural background sites, total carbonaceous material accounted for 30±9% of PM10, of which 27±9% could be attributed to organic matter (OM) and 3.4±1.0% to elemental matter (EM). OM was found to be more abundant than SO42− for sites reporting both parameters.

scholarly journals Photographic assessment of cephalometric measurements

2013 ◽  
Vol 83 (6) ◽  
pp. 1049-1058 ◽  
Author(s):  
Liliane de Carvalho Rosas Gomes ◽  
Karla Orfelina Carpio Horta ◽  
Luiz Gonzaga Gandini ◽  
Marcelo Gonçalves ◽  
João Roberto Gonçalves
Keyword(s):  
Low Cost ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Facial Profile ◽  
Intraclass Correlation Coefficients ◽  
Standardized Protocol ◽  
Lateral Cephalograms ◽  
Cephalometric Measurements ◽  
The Relationship

ABSTRACT Objective: To investigate the relationship between craniofacial measurements obtained from cephalometric radiographs and analogous measurements from profile photographs. Materials and Methods: Lateral cephalograms and standardized facial profile photographs were obtained from a sample of 123 subjects (65 girls, 58 boys; age 7–12 years). Intraclass correlation coefficients (ICCs) were calculated from repeated photographic measurements to evaluate method reliability. Analogous cephalometric and photographic measurements were compared to assess Pearson correlation coefficients. Linear regression analyses were conducted between the measurements that achieved correlation coefficients greater than r  =  0.7. Results: The reliability of the photographic technique was satisfactory. Most measurements showed ICCs above 0.80 and highly significant correlations (P ≤ .001) with cephalometric variables. Among all measurements used, the A'N'B' angle was the most effective in explaining the variability of its analogous cephalometric, mainly for female subjects (r2  =  0.80). The FMA' angle showed the best results for vertical assessment (r2  =  0.65). Conclusions: The photographic method has proven to be a repeatable and reproducible tool provided that a standardized protocol is followed. Therefore, it may be considered a feasible and practical diagnostic alternative, particularly if there is a need for a low-cost and noninvasive method.

scholarly journals Elemental and organic carbon in PM<sub>10</sub>: a one year measurement campaign within the European Monitoring and Evaluation Programme EMEP

2007 ◽  
Vol 7 (22) ◽  
pp. 5711-5725 ◽  
Author(s):  
K. E. Yttri ◽  
W. Aas ◽  
A. Bjerke ◽  
J. N. Cape ◽  
F. Cavalli ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Pearson Correlation ◽  
Regional Scale ◽  
Correlation Coefficients ◽  
Monitoring And Evaluation ◽  
Total Carbon ◽  
Rural Background ◽  
Evaluation Programme ◽  
Sampling Campaign ◽  
One Year

Abstract. In the present study, ambient aerosol (PM10) concentrations of elemental carbon (EC), organic carbon (OC), and total carbon (TC) are reported for 12 European rural background sites and two urban background sites following a one-year (1 July 2002–1 July 2003) sampling campaign within the European Monitoring and Evaluation Programme, EMEP http://www.emep.int/). The purpose of the campaign was to assess the feasibility of performing EC and OC monitoring on a regular basis and to obtain an overview of the spatial and seasonal variability on a regional scale in Europe. Analyses were performed using the thermal-optical transmission (TOT) instrument from Sunset Lab Inc., operating according to a NIOSH derived temperature program. The annual mean mass concentration of EC ranged from 0.17±0.19 μg m−3 (mean ± SD) at Birkenes (Norway) to 1.83±1.32 μg m−3 at Ispra (Italy). The corresponding range for OC was 1.20±1.29 μg m−3 at Mace Head (Ireland) to 7.79±6.80 μg m−3 at Ispra. On average, annual concentrations of EC, OC, and TC were three times higher for rural background sites in Central, Eastern and Southern Europe compared to those situated in the Northern and Western parts of Europe. Wintertime concentrations of EC and OC were higher than those recorded during summer for the majority of the sites. Moderate to high Pearson correlation coefficients (rp) (0.50–0.94) were observed for EC versus OC for the sites investigated. The lowest correlation coefficients were noted for the three Scandinavian sites: Aspvreten (SE), Birkenes (NO), and Virolahti (FI), and the Slovakian site Stara Lesna, and are suggested to reflect biogenic sources, wild and prescribed fires. This suggestion is supported by the fact that higher concentrations of OC are observed for summer compared to winter for these sites. For the rural background sites, total carbonaceous material accounted for 30±9% of PM10, of which 27±9% could be attributed to organic matter (OM) and 3.4±1.0% to elemental matter (EM). OM was found to be more abundant than SO42- for sites reporting both parameters.

Reliability of the Minimum Masking Level as Outcome Variable in Tinnitus Clinical Research

2020 ◽  
Vol 29 (3) ◽  
pp. 429-435
Author(s):  
Patricia C. Mancini ◽  
Richard S. Tyler ◽  
Hyung Jin Jun ◽  
Tang-Chuan Wang ◽  
Helena Ji ◽  
...  
Keyword(s):  
Standard Deviation ◽  
High Frequency ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Outcome Variable ◽  
Reliable Estimate ◽  
Moderate Correlation ◽  
Trained Subjects ◽  
The Relationship ◽  
Minimum Intensity

Purpose The minimum masking level (MML) is the minimum intensity of a stimulus required to just totally mask the tinnitus. Treatments aimed at reducing the tinnitus itself should attempt to measure the magnitude of the tinnitus. The objective of this study was to evaluate the reliability of the MML. Method Sample consisted of 59 tinnitus patients who reported stable tinnitus. We obtained MML measures on two visits, separated by about 2–3 weeks. We used two noise types: speech-shaped noise and high-frequency emphasis noise. We also investigated the relationship between the MML and tinnitus loudness estimates and the Tinnitus Handicap Questionnaire (THQ). Results There were differences across the different noise types. The within-session standard deviation averaged across subjects varied between 1.3 and 1.8 dB. Across the two sessions, the Pearson correlation coefficients, range was r = .84. There was a weak relationship between the dB SL MML and loudness, and between the MML and the THQ. A moderate correlation ( r = .44) was found between the THQ and loudness estimates. Conclusions We conclude that the dB SL MML can be a reliable estimate of tinnitus magnitude, with expected standard deviations in trained subjects of about 1.5 dB. It appears that the dB SL MML and loudness estimates are not closely related.

Comparative Responses to Squats Completed with Free Weights and an Exoskeleton

2020 ◽  
Vol 4 (1) ◽  
pp. 51-63
Author(s):  
Peter Neuhaus ◽  
Chris Jumonville ◽  
Rachel A. Perry ◽  
Roman Edwards ◽  
Jake L. Martin ◽  
...  
Keyword(s):  
Data Collection ◽  
Female Athletes ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Actual Data ◽  
Limited Data ◽  
Comparative Similarity ◽  
Insufficient Amount ◽  
Force Data ◽  
Familiarization Session

AbstractTo assess the comparative similarity of squat data collected as they wore a robotic exoskeleton, female athletes (n=14) did two exercise bouts spaced 14 days apart. Data from their exoskeleton workout was compared to a session they did with free weights. Each squat workout entailed a four-set, four-repetition paradigm with 60-second rest periods. Sets for each workout involved progressively heavier (22.5, 34, 45.5, 57 kg) loads. The same physiological, perceptual, and exercise performance dependent variables were measured and collected from both workouts. Per dependent variable, Pearson correlation coefficients, t-tests, and Cohen's d effect size compared the degree of similarity between values obtained from the exoskeleton and free weight workouts. Results show peak O2, heart rate, and peak force data produced the least variability. In contrast, far more inter-workout variability was noted for peak velocity, peak power, and electromyography (EMG) values. Overall, an insufficient amount of comparative similarity exists for data collected from both workouts. Due to the limited data similarity, the exoskeleton does not exhibit an acceptable degree of validity. Likely the cause for the limited similarity was due to the brief amount of familiarization subjects had to the exoskeleton prior to actual data collection. A familiarization session that accustomed subjects to squats done with the exoskeleton prior to actual data collection may have considerably improved the validity of data obtained from that device.

Leader-Member Exchange (LMX) Impact on Work-Home Interference in a South African Commuter Transport Engineering Company

2019 ◽  
Vol 43 ◽  
Author(s):  
Jan Christoff Visagie ◽  
Michael M. Jones ◽  
Herman L. Linde
Keyword(s):  
South African ◽  
Structural Equation ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Leader Member Exchange ◽  
Negative Consequences ◽  
Dyadic Relationship ◽  
Cross Sectional ◽  
Engineering Company ◽  
Member Exchange

The South African workplace is confronted with many leadership challenges, specifically those relating to the employment relationship between subordinates and their supervisors. A high-quality relationship is essential, considering the work-family spillovers employees experience. Limited research has been conducted on the potential positive and negative consequences of the leader-member exchange (LMX) dyadic relationship. In this study, we used a cross-sectional research design, and drew an employee sample (N = 120) from a commuter transport engineering company. A five-point Likert scale was employed and statistical analyses were carried out using the SAS statistical program. We calculated Pearson correlation coefficients and used structural equation modelling to test the proposed conceptual model to indicate possible correlations between the different variables. The main finding of the study was that the nature of the LMX relationship quality in the relevant company appeared to be high and positively related to work-home enrichment but negatively related to work-home conflict and role overload. The article concludes by making a number of suggestions to respond to challenges.

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