scholarly journals A comparison of alternative curve fitting techniques for different earthquake fault parameters of Iranian earthquakes

2021 ◽  
Vol 24 (4) ◽  
pp. 459-472
Author(s):  
Serkan Ozturk ◽  
Mohammad R. Ghassemi ◽  
Mahmut Sarı
Keyword(s):  
Curve Fitting ◽  
Robust Regression ◽  
Correlation Coefficients ◽  
The Other ◽  
Empirical Relationships ◽  
Surface Rupture ◽  
Earthquake Fault ◽  
Orthogonal Regression ◽  
Rupture Length ◽  
Fault Parameters

In this study, we tried to estimate the optimum linear equations among the parameters associated with different earthquake fault mechanisms for Iranian earthquakes. For this purpose, we tested different curve fitting methods in order to present the most proper empirical relationships between several seismic parameters for different fault systems. In the present paper, 46 large and destructive Iranian earthquakes whose magnitudes change between 5.8 and 7.8 from 1900 to 2014 were used for the analyses. A comparison was made by using four types of curve fitting techniques. The estimation procedures are considered as (1) L2 or Least Squares Regression, (2) L1 or Least Sum of Absolute Deviations Regression, (3) Robust Regression and, (4) Orthogonal Regression. Confidence intervals were selected as 95% for all types of regression relationships. In the selection of the best probability distribution, we considered the correlation coefficients of the linear regressions as a powerful and conceptually simple method. Correlation coefficients of all relationships change between 0.299 and 0.986 with Orthogonal regression, between 0.168 and 0.792 with L1 regression, between 0.059 and 0.829 with Robust regression. For Iranian earthquakes, the most suitable and reliable empirical relationships between moment magnitude (Mw) and surface wave magnitude (Ms), Mw and surface rupture length (SRL), Mw and maximum displacement (MD), and SRL and MD were obtained by Orthogonal regression since it supplies stronger correlation coefficients than those of the other regression techniques in most estimates. The results show that estimated empirical relationships among the different fault parameters by using the Orthogonal regression method can be accepted as more up-to-date and more appropriate in comparison with the other regression norms. Consequently, these equations were suggested as more reliable in the estimation of the maximum surface displacement, maximum surface rupture length and associated with the maximum credible earthquakes for different areas of Iran. Furthermore, obtained relationships can be statistically significant for the assessment of seismic, tectonic and geologic activities, and they can be used to evaluate the rupture hazard of the Iranian Plateau.

SERUM GONADOTROPHINS, TESTOSTERONE AND SPERMATOGENESIS IN SUBFERTILE MEN

1977 ◽  
Vol 86 (3) ◽  
pp. 651-658 ◽  
Author(s):  
J. H. Aafjes ◽  
J. C. M. van der Vijver ◽  
R. Docter ◽  
P. E. Schenck
Keyword(s):  
Partial Correlation ◽  
Sperm Count ◽  
Correlation Coefficients ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
The Other ◽  
Sperm Production ◽  
Positive Correlation ◽  
Natural Logarithm ◽  
Biopsy Score

ABSTRACT In 210 subfertile men there existed a significant positive correlation between serum FSH and LH (0.41). No correlation was observed between the gonadotrophin levels and testosterone. In contrast to this FSH as well as LH were negatively correlated with the natural logarithm (In) of the sperm count/ml ejaculate (−0.44 and −0.18, respectively). When the positive correlation which existed between FSH and LH was used to calculate partial correlation coefficients, the coefficient between FSH and ln sperm count did hardly change (−0.41) the coefficient between LH and ln sperm count on the other hand became insignificant (−0.05). This suggests that spermatogenesis influences FSH serum levels in subfertile men by a decreased suppression when sperm production is diminished. Testicular biopsies taken from 97 of these patients were used to determine biopsy scores. These scores showed a significant negative correlation with FSH (−0.34) and a positive one with ln sperm count/ml ejaculate (0.45). Interestingly the biopsy score of 16 patients who fertilized their wives, was found to be higher compared with the score of the other patients who did not fertilize. The number of sperm/ml ejaculate and the FSH values of these 2 groups of biopsied patients were, however, not significantly different. This leads to the conclusion that the biopsy score is a better parameter for the evaluation of oligospermic men than either sperm count or FSH serum values.

Automatic Detection of Periodic Limb Movements in Sleep (PLMS), And Analysis of Their Relationship to Heart Rate Signals

2021 ◽  
Author(s):  
Sharadha Kolappan
Keyword(s):  
Heart Rate ◽  
Correlation Coefficients ◽  
Limb Movement ◽  
The Other ◽  
Screening Tools ◽  
Periodic Limb Movements ◽  
Periodic Limb Movement ◽  
Related Disorder ◽  
The Relationship ◽  
Core Features

Periodic Limb Movement in Sleep (PLMS) are a sleep-related disorder of the limbs that increasingly more research has begun to associate with severe Cardiovascular Diseases (CVD). With that said, Polysomnography (PSG), followed by manual scoring, is the conventional approach being used to monitor the disorder. However, patient inconvenience, and the high costs associated with PSG, has probed the need for alternative screening tools to be developed. Moreover, due to the cumbersome and time-consuming nature of manually scoring for PLMS, more studies have begun to look into automated means of detecting PLMS. Hence, while one of the goals of the current thesis was to use the latest clinical specifications to develop an automated Periodic Limb Movement (PLM) detector, the other goal was to look into alternative signals to monitor PLMS. With that said, in the current thesis, an automated PLM detector was developed and tested on two datasets. In fact, the results were promising in that, correlation coefficients of 0.78 and 0.8, and absolute differences not greater than 9 and 6 (not including the extreme outliers) respectively, were found when comparing the clinical PLM scores with that of the automated algorithm’s PLM scores. Moreover, not only did the automated PLM detector compute PLM scores, it also provided us with PLM segmentation information, i.e., localization of PLM with respect to time. On the other hand, with regards to finding alternative signals to monitor PLMS, the etiology of PLMS was used in order to validate the use of relatively easily acquirable signals, such as Heart Rate (HR) signals, to monitor the condition. Moreover, core features were extracted from the HR signals and the PLM segmentation information from the developed PLM detector was used in order to perform individuaized classification between PLM and non-PLM segments (per subject). Although the results were promising in that, the percent of correctly identifying a given segment as PLM or non-PLM, using the HR features, across most of the subjects, i.e., especially those with PLM Index ≥ 15, were around and well above the 70% range, due to the possibility of other factors interfering with HR during sleep, a more immediate application of the observed PLMS vs HR distinction was, to be able to monitor the autonomic health of an individual, given their PLM information. Specifically, the latter was anticipated to be useful for studies looking into the relationship between PLMS and HR, and thus CVD, or more significantly, those looking into preventing CVD by treating PLM.

scholarly journals NEAR-FIELD TSUNAMI FORECASTING BASED ON A TSUNAMI RUN-UP RESPONSE FUNCTION

2020 ◽  
pp. 5
Author(s):  
Juh-Whan Lee ◽  
Jennifer L. Irish ◽  
Robert Weiss
Keyword(s):  
Real Time ◽  
Response Function ◽  
Near Field ◽  
Coastal Communities ◽  
Tsunami Forecast ◽  
Earthquake Fault ◽  
Tsunami Forecasting ◽  
Fault Parameters ◽  
Run Up ◽  
Tsunami Run Up

Since near-field-generated tsunamis can arrive within a few minutes to coastal communities and cause immense damage to life and property, tsunami forecasting systems should provide not only accurate but also rapid tsunami run-up estimates. For this reason, most of the tsunami forecasting systems rely on pre-computed databases, which can forecast tsunamis rapidly by selecting the most closely matched scenario from the databases. However, earthquakes not included in the database can occur, and the resulting error in the tsunami forecast may be large for these earthquakes. In this study, we present a new method that can forecast near-field tsunami run-up estimates for any combination of earthquake fault parameters on a real topography in near real-time, hereafter called the Tsunami Run-up Response Function (TRRF).Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/tw1D29dDxmY

scholarly journals Motion of Multiple Robot in a Curved Boundary & Obstacles

2019 ◽  
Vol 9 (1) ◽  
pp. 6011-6014
Keyword(s):  
Curve Fitting ◽  
The Other ◽  
Multiple Robots ◽  
Curved Boundary ◽  
Medical Supplies ◽  
Straight Line ◽  
Multiple Robot ◽  
Assembly Operations ◽  
Curve Equation ◽  
Made In

An attempt is made in this paper to gain the flexibility of movement of robots around the boundary of the workspace, where in many robots are moving at a time in the presence of the static curved obstacles. The boundary of the workspace may be a straight line or curve shaped. The obstacle may be polygonal or curved shaped. A program is developed for the motion of the multiple robots to move from its origin location to the desired location without colliding with the boundary, the other moving robots and the static obstacles. The program is based on the curve fitting technique. As and when the robot comes close to the curved boundary or curved barrier, it will trace the path formed by the curve equation using the technique of curve fitting. Since there are multiple robots, the path planning ensures the robots to reach their targets in minimum time. During tracing the path, if more than one robot is following the same path, priority is assigned to such robots. Multiple robots finds application in assembly operations, medical supplies and meals to patients, disinfecting the rooms for patients etc.

scholarly journals Phenomenological Over-Parameterization of the Triple-Fitting-Parameter Diffusion Models in Evaluation of Gas Diffusion in Coal

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 241 ◽  
Author(s):  
Zang ◽  
Wang ◽  
Liu
Keyword(s):  
Curve Fitting ◽  
Gas Diffusion ◽  
Diffusion Models ◽  
The Other ◽  
Excellent Performance ◽  
Sorption Data ◽  
Gas Diffusivity ◽  
The Future ◽  
Manometric Method ◽  
Fitting Parameters

Gas diffusivities of coal are not measured directly but are normally regressed by fitting mathematical diffusion models to fractional sorption data measured in sorption experiments. This paper firstly measured three fractional adsorption curves at various equilibrium pressures with the manometric method. The measured fractional adsorption curves were then modeled with one single-fitting-parameter (SFP) model and three triple-fitting-parameter (TFP) models. The modeling results showed that the TFP models were phenomenologically over-parameterized due to the usage of three fitting parameters, which may be excessive for curve fitting. The phenomenological over-parameterization resulted in multiple pressure-dependences of gas diffusivity for the TFP models. The TFP models should thus be carefully used. On the other hand, the dual-fitting-parameter (DFP) models also have excellent performance in curve fitting and can produce interpretable modeling results. The DFP models can be used as an alternative to the TFP model in the future.

scholarly journals Aligning Pixel Values of DMSP and VIIRS Nighttime Light Images to Evaluate Urban Dynamics

2019 ◽  
Vol 11 (12) ◽  
pp. 1463 ◽  
Author(s):  
Kang Wu ◽  
Xiaonan Wang
Keyword(s):  
Robust Regression ◽  
Infrared Imaging ◽  
Polynomial Regression ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Urban Dynamics ◽  
Low Pass ◽  
Nighttime Light

The brightness of pixels in nighttime light images (NTL) has been regarded as the proxy of the urban dynamics. However, the great difference between the pixel values of NTL from the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS) and the Suomi National Polar-orbiting Partnership satellite’s Visible Infrared Imaging Radiometer Suite (Suomi NPP/VIIRS) poses obstacles to analyze economic and social development with NTL in a continuous temporal sequence. This research proposes a methodology to align the pixel values of both NTL by calibrating annual DMSP images between the years 1992–2013 with a robust regression algorithm with a quadratic polynomial regression model and simulating annual DMSP images with VIIRS images between years 2012 and 2018 with a model consisting of a power function and a Gaussian low pass filter. As a result, DMSP annual images between years 1992–2018 can be produced. Case study of Beijing and Yiwu are conducted and evaluated with local gross domestic product (GDP). Compared with the values of DMSP and VIIRS annual composites, the Pearson correlation coefficients of DMSP and simulated DMSP annual composites in 2012 and in 2013 increase significantly, while the root mean square error (RMSE) decrease evidently. In addition, the correlation of the sum of light of NTL and local GDP is enhanced with a simulation process. These results demonstrate the feasibility of the proposed method in narrowing the gap between DMSP and VIIRS NTL in pixel values.

scholarly journals Analysis of Nitraria Tangutourum Bobr-Derived Fatty Acids with HPLC-FLD-Coupled Online Mass Spectrometry

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3836
Author(s):  
Na Hu ◽  
Jian Ouyang ◽  
Qi Dong ◽  
Honglun Wang
Keyword(s):  
Mass Spectrometry ◽  
Fatty Acids ◽  
Correlation Coefficients ◽  
Gradient Elution ◽  
Reversed Phase ◽  
The Other ◽  
Qualitative And Quantitative Analysis ◽  
Established Method ◽  
Qualitative And Quantitative ◽  
Pharmacological Significance

Fatty acids (FAs) are basic components in plants. The pharmacological significance of FAs has attracted attentions of nutritionists and pharmaceutists. Sensitive and accurate detection of FAs is of great importance. In the present study, a pre-column derivatization and online mass spectrometry-based qualitative and quantitative analysis of FAs was developed. Nineteen main FAs were derivatized by 2-(7-methyl-1H-pyrazolo-[3,4-b]quinoline-1-yl)ethyl-4-methyl benzenesulfonate (NMP) and separated on reversed-phase Hypersil BDS C8 column with gradient elution. All FAs showed excellent linear responses with correlation coefficients more than 0.9996. The method obtained LOQs between 0.93 ng/mL and 5.64 ng/mL. FA derivatives were identified by both retention time and protonated molecular ion corresponding to m/z [M + H]+. A comparative study based on FA contents in peel and pulp, seeds and leaves of Nitraria tangutourum Bobr (NTB) from different geographical origins was performed with the established method. Results indicated that NTB were rich in FAs, and the types and contents of FAs varied among tissues. On the other hand, the same tissue of NTB from different geographical areas differed in the content, but not in type, of FAs.

Dermatoglyphics in Twins

1973 ◽  
Vol 22 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Heloisa F. Peña ◽  
F.M. Salzano ◽  
Sidia M. Callegari
Keyword(s):  
Correlation Coefficients ◽  
The Other ◽  
Ridge Count ◽  
Genetic Determination ◽  
Qualitative Traits ◽  
Quantitative Measurements ◽  
Other Hand ◽  
Adult Twins

SummaryThe degree of genetic determination of 4 digital and 16 palmar characteristics was investigated in an unselected series of 49 MZ and 51 DZ adult twins. Low indications of heritability were obtained for the qualitative traits, but 6 of the 8 h2 estimates calculated for the quantitative measurements gave values above 0.70. In general, the results reported here are in agreement with those presented by other authors; however, the correlation coefficients observed for the A′d ridge count were lower than those of two other series. All palmar ridge counts seemed to be intercorrelated in a given individual; other expected relationships, however, were not observed. The fingerprints of MZ and DZ twins on the other hand, showed an unexplained difference.

Dynamic Behavior and Synchronization of an Automobile as a Complex System

2014 ◽  
Author(s):  
Claudia A. González-Cruz ◽  
Juan C. Jáuregui-Correa ◽  
Carlos S. López-Cajún ◽  
Mihir Sen
Keyword(s):  
Complex System ◽  
Wavelet Transforms ◽  
Cross Correlation ◽  
Correlation Coefficients ◽  
The Other ◽  
Accelerometer Data ◽  
Hilbert Transforms ◽  
The Road ◽  
The Individual ◽  
Analytical Tools

A complex system is composed of many interacting components, but the behavior of the system as a whole can be quite different from that of the individual components. An automobile is an example of a common mechanical system composed of a large number of individual components that are mechanically connected in some way and hence transmit vibrations to each other. This paper proposes a variety of inter-related analytical tools for the study of experimental data from such systems. In this work, experimental results of accelerometer data acquired at two locations in the automobile for two different kinds of tests are analyzed. One test is the response to impact on a stationary vehicle, and the other is the road-response to the vehicle being driven on a flat road at different speeds. Signals were processed via Fourier and wavelet transforms, cross-correlation coefficients were computed, and Hilbert transforms and Kuramoto order parameters were determined. A new parameter representing synchronization deficit is introduced. There is indeed some degree of synchronization that can be quantified between the accelerations measured at these two locations in the vehicle.

Sign in / Sign up

Export Citation Format

Share Document