DATA SMOOTHING TECHNIQUES APPLIED TO PROTON MICROPROBE SCANS OF TELEOST HARD PARTS

1992 ◽  
Vol 02 (03) ◽  
pp. 313-323 ◽  
Author(s):  
I.F. WEST ◽  
G.E. COOTE ◽  
R.W. GAULDIE
Keyword(s):  
Life Histories ◽  
Moving Average ◽  
Sampling Point ◽  
Smoothing Techniques ◽  
Data Smoothing ◽  
X Ray ◽  
Proton Microprobe ◽  
Median Filters ◽  
Data Points ◽  
Hard Structures

We use a proton microprobe to examine the distribution of elements in otoliths and scales of teleost (bony) fish. The elements of principal interest are calcium and strontium in otoliths and calcium and fluorine in scales. Changes in the distribution of these elements across hard structures may allow inferences about the life histories of fish. Otoliths and scales of interest are up to a centimeter in linear dimension and to reveal the structures of interest up to 200 sampling points are required in each dimension. The time needed to accumulate high X-ray counts at each sampling point can be large, particularly for strontium. To reduce microprobe usage we use data smoothing techniques to reveal changing patterns with modest X-ray count accumulations at individual data points. In this paper we review performance for revealing pattern at modest levels of X-ray count accumulations of a selection of digital filters (moving average smoothers), running median filters, robust locally weighted regression filters and adaptive spline filters.

point-Analysis Using the Extrapolation Method in the Analytical Electron microscope

1990 ◽  
Vol 48 (2) ◽  
pp. 430-431
Author(s):  
Zenji Horita ◽  
Ryuzo Nishimachi ◽  
Takeshi Sano ◽  
Minoru Nemoto
Keyword(s):  
Electron Microscope ◽  
Extrapolation Method ◽  
X Ray ◽  
Absorption Correction ◽  
Point Analysis ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Data Points ◽  
Identical Composition ◽  
X Ray Absorption

Absorption correction is often required in quantitative x-ray microanalysis of thin specimens using the analytical electron microscope. For such correction, it is convenient to use the extrapolation method[l] because the thickness, density and mass absorption coefficient are not necessary in the method. The characteristic x-ray intensities measured for the analysis are only requirement for the absorption correction. However, to achieve extrapolation, it is imperative to obtain data points more than two at different thicknesses in the identical composition. Thus, the method encounters difficulty in analyzing a region equivalent to beam size or the specimen with uniform thickness. The purpose of this study is to modify the method so that extrapolation becomes feasible in such limited conditions. Applicability of the new form is examined by using a standard sample and then it is applied to quantification of phases in a Ni-Al-W ternary alloy.The earlier equation for the extrapolation method was formulated based on the facts that the magnitude of x-ray absorption increases with increasing thickness and that the intensity of a characteristic x-ray exhibiting negligible absorption in the specimen is used as a measure of thickness.

Forecast of COVID-19 Cases in Nigeria: An implementation of an ARIMA model (Preprint)

2020 ◽  
Author(s):  
Sanyaolu Ameye ◽  
Michael Awoleye ◽  
Emmanuel Agogo ◽  
Ette Etuk
Keyword(s):  
Predictive Model ◽  
Time Series Data ◽  
Moving Average ◽  
Arima Model ◽  
Epidemiological Data ◽  
Series Data ◽  
Global Pandemic ◽  
First Case ◽  
Epidemiological Trend ◽  
Data Points

BACKGROUND The Coronavirus disease 2019 (COVID-2019) is a global pandemic and Nigeria is not left out in being affected. Though, the disease is just over three months since first case was identified in the country, we present a predictive model to forecast the number of cases expected to be seen in the country in the next 100 days. OBJECTIVE To implement a predictive model in forecasting the near future number of positive cases expected in the country following the present trend METHODS We performed an Auto Regressive Integrated Moving Average (ARIMA) model prediction on the epidemiological data obtained from Nigerian Centre for Disease Control to predict the epidemiological trend of the prevalence and incidence of COVID-2019. RESULTS There were 93 time series data points which lacked stationarity. From our ARIMA model, it is expected that the number of new cases declared per day will keep rising and towards the early September, 2020, Nigeria is expected to have well above sixty thousand confirmed cases. CONCLUSIONS We however believe that as we have more data points our model will be better fine-tuned.

scholarly journals X-ray Observations of Blazars with Ginga and ASCA

1994 ◽  
Vol 159 ◽  
pp. 383-383 ◽  
Author(s):  
M. Tashiro ◽  
K. Makishima ◽  
Y. Kohmura ◽  
T. Ohashi ◽  
C. Otani ◽  
...  
Keyword(s):  
Correlation Function ◽  
Cross Correlation ◽  
Cross Correlation Function ◽  
Function Technique ◽  
X Ray ◽  
Data Points ◽  
Bl Lacs ◽  
Clockwise Hysteresis

Among 13 BL Lacs observed with Ginga, 1H 0323+022, Mkn 421 and PKS 2155-304 exhibited significant variablity during each (typically one day) observation. On the flux-hardness plane, the data points obtained from each source draw a sort of clockwise hysteresis motion. It means that the spectrum hardens before the source gets brighter, while the spectrum softens before the source becomes fainter. Such a soft-lag behavior, first pointed out for PKS2155-304 by Sembay et al. These properties were also confirmed with the discrete cross correlation function technique.

Posterior Thoracic Stab Wounds: Evaluating the Value of Commonly Used Radiologic Modalities

2018 ◽  
Vol 84 (8) ◽  
pp. 1363-1367
Author(s):  
William M. Brigode ◽  
Michael Masteller ◽  
Rishi Chaudhuri ◽  
Ryan Sullivan ◽  
Amir Vafa
Keyword(s):  
Injury Severity ◽  
Demographic Data ◽  
Inclusion Criteria ◽  
Stab Wounds ◽  
X Ray ◽  
Asymptomatic Patients ◽  
Data Points ◽  
Chest X Ray ◽  
Posterior Mediastinal ◽  
Stab Injuries

This study was performed to assess our institution's experience with stab injuries to the posterior mediastinal box. We examine the value of performing CT of the chest and esophagram in conjunction with a chest X-ray (CXR) over performing CXR(s) alone in evaluating this group of patients. We performed a retrospective study covering a 10-year period consisting of patients with stab wounds to the posterior mediastinal box. Age, gender, and injury severity score as demographic data points were collected. CXR, CT, and esophagram results; identified injuries; and subsequent interventions were analyzed. Of 78 patients who met the inclusion criteria, a total of 55 patients underwent esophagram, one had a false-positive result, and zero had their course altered by the study. Sixty-six patients underwent CT imaging, and there were nine missed findings on initial CXR. Five of these were clinically insignificant and the remaining four were managed with a chest tube alone. There were no tracheobronchial, esophageal, cardiac, or great vessel injuries. Hemodynamically stable, asymptomatic patients with stab wounds to the posterior mediastinal box do not require routine CT and esophagram in the absence of CXR and cardiac ultrasonographic abnormalities.

A full-pattern fitting algorithm for energy-dispersive X-ray diffraction

2003 ◽  
Vol 36 (5) ◽  
pp. 1123-1127 ◽  
Author(s):  
Yu-Hui Dong ◽  
Jing Liu ◽  
Yan-Chun Li ◽  
Xiao-Dong Li
Keyword(s):  
High Pressure ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Fitting Algorithm ◽  
Diffraction Angle ◽  
Data Points ◽  
Diffraction Peaks ◽  
Very High

A full-pattern fitting algorithm for energy-dispersive X-ray diffraction is proposed, especially for high-pressure X-ray diffraction studies. The algorithm takes into account the errors in measuring the energy and the diffraction angle. A lognormal function is introduced to represent the background. All the peaks that are detectable in the diffraction spectra, including fluorescence and diffraction peaks, are considered together. Because all the data points in the spectra are used, the accuracy of the cell parameters obtained by this method is very high. This is very helpful in the analysis of the equation of state and the identification of new phases under high pressure.

Continuous-scan capability at SSRL and applications to X-ray diffraction

2016 ◽  
Vol 23 (4) ◽  
pp. 909-918 ◽  
Author(s):  
Chunlei Li ◽  
Andrew M. Kiss ◽  
Douglas G. Van Campen ◽  
Alex Garachtchenko ◽  
Yuriy Kolotovsky ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
X Ray Diffraction ◽  
Scanning Method ◽  
X Ray ◽  
Motor Controller ◽  
Acceleration And Deceleration ◽  
Data Points ◽  
Total Measurement Time ◽  
Zno Powder ◽  
Deceleration Time

Typical X-ray diffraction measurements are made by moving a detector to discrete positions in space and then measuring the signal at each stationary position. This step-scanning method can be time-consuming, and may induce vibrations in the measurement system when the motors are accelerated and decelerated at each position. Furthermore, diffraction information between the data points may be missed unless a fine step-scanning is used, which further increases the total measurement time. To utilize beam time efficiently, the motor acceleration and deceleration time should be minimized, and the signal-to-noise ratio should be maximized. To accomplish this, an integrated continuous-scan system was developed at the Stanford Synchrotron Radiation Lightsource (SSRL). The continuous-scan system uses an in-house integrated motor controller system and counter/timer electronics.SPECsoftware is used to control both the hardware and data acquisition systems. The time efficiency and repeatability of the continuous-scan system were tested using X-ray diffraction from a ZnO powder and compared with the step-scan technique. Advantages and limitations of the continuous-scan system and a demonstration of variable-velocity continuous scan are discussed.

scholarly journals Calibration of Radiocarbon Ages by Computer

Radiocarbon ◽  
1989 ◽  
Vol 31 (03) ◽  
pp. 805-816 ◽  
Author(s):  
Johannes Van Der Plicht ◽  
W G Mook
Keyword(s):  
Computer Program ◽  
Calibration Curve ◽  
Spline Function ◽  
Moving Average ◽  
Age Distribution ◽  
Automatic Calibration ◽  
Calibration Data ◽  
Average Procedure ◽  
Data Points ◽  
Radiocarbon Calibration

A PC-based computer program for automatic calibration of 14C dates has been developed in Turbo-Pascal (version 4.0). It transforms the Gaussian 14C dating result on the 3σ level into a real calendar age distribution. It uses as a calibration curve a spline function, generated along the calibration data points as published in the Radiocarbon Calibration Issue. Special versions of the code can average several 14C dates into one calibrated result, generate smoothed curves by a moving average procedure and perform wiggle matching.

scholarly journals A Study on Stereoscopic X-ray Imaging Data Set on the Accuracy of Real-Time Tumor Tracking in External Beam Radiotherapy

2016 ◽  
Vol 16 (2) ◽  
pp. 167-177 ◽  
Author(s):  
Ahmad Esmaili Torshabi ◽  
Leila Ghorbanzadeh
Keyword(s):  
External Beam Radiotherapy ◽  
Training Data ◽  
Imaging Data ◽  
Data Set ◽  
X Ray ◽  
Tumor Tracking ◽  
X Ray Imaging ◽  
Additional Imaging ◽  
Data Points ◽  
Imaging Dose

At external beam radiotherapy, stereoscopic X-ray imaging system is responsible as tumor motion information provider. This system takes X-ray images intermittently from tumor position (1) at pretreatment step to provide training data set for model construction and (2) during treatment to control the accuracy of correlation model performance. In this work, we investigated the effect of imaging data points provided by this system on treatment quality. Because some information is still lacking about (1) the number of imaging data points, (2) shooting time for capturing each data point, and also (3) additional imaging dose delivered by this system. These 3 issues were comprehensively assessed at (1) pretreatment step while training data set is gathered for prediction model construction and (2) during treatment while model is tested and reconstructed using new arrival data points. A group of real patients treated with CyberKnife Synchrony module was chosen in this work, and an adaptive neuro-fuzzy inference system was considered as consistent correlation model. Results show that a proper model can be constructed while the number of imaging data points is highly enough to represent a good pattern of breathing cycles. Moreover, a trade-off between the number of imaging data points and additional imaging dose is considered in this study. Since breathing phenomena are highly variable at different patients, the time for taking some of imaging data points is very important, while their absence at that critical time may yield wrong tumor tracking. In contrast, the sensitivity of another category of imaging data points is not high, while breathing is normal and in the control range. Therefore, an adaptive supervision on the implementation of stereoscopic X-ray imaging is proposed to intelligently accomplish shooting process, based on breathing motion variations.

scholarly journals Forecasting Basis Levels in the Soybean Complex: A Comparison of Time Series Methods

2006 ◽  
Vol 38 (3) ◽  
pp. 513-523 ◽  
Author(s):  
Dwight R. Sanders ◽  
Mark R. Manfredo
Keyword(s):  
Time Series ◽  
Soybean Oil ◽  
Soybean Meal ◽  
Vector Autoregression ◽  
Moving Average ◽  
Exponential Smoothing ◽  
Forecast Evaluation ◽  
Time Series Modeling ◽  
Var Models ◽  
Smoothing Techniques

A battery of time series methods are compared for forecasting basis levels in the soybean futures complex: soybeans, soybean meal, and soybean oil. Specifically, nearby basis forecasts are generated with exponential smoothing techniques, autoregression moving average (ARMA), and vector autoregression (VAR) models. The forecasts are compared to those of the 5-year average, year ago, and no change methods. Using the 5-year average as the benchmark method, the forecast evaluation results suggest that alternative naive techniques may produce better forecasts, and the improvement gained by time series modeling is relatively small. In this sample, there is little evidence that the basis has become systematically more difficult to forecast in recent years.

scholarly journals Accumulation of Calcium and Loss of Potassium in the Hippocampus following Transient Cerebral Ischemia: A Proton Microprobe Study

1988 ◽  
Vol 8 (4) ◽  
pp. 531-538 ◽  
Author(s):  
Eduardo Martins ◽  
Kenji Inamura ◽  
Klas Themner ◽  
Klas G. Malmqvist ◽  
Bo K. Siesjö
Keyword(s):  
Hippocampal Neurons ◽  
Plasma Membranes ◽  
Total Calcium ◽  
Calcium Cycling ◽  
Transient Ischemia ◽  
Neuronal Necrosis ◽  
X Ray ◽  
Proton Microprobe ◽  
Calcium Accumulation ◽  
Stratum Oriens

This study explored (a) whether postischemic accumulation of calcium in hippocampal neurons precedes or occurs pari passu with light microscopical signs of delayed neuronal necrosis, and (b) whether calcium initially accumulates in dendritic domains, presumed to have a high density of agonist-operated calcium channels. Transient ischemia of 10-min duration was induced in rats, and the animals were studied after 1, 2, 3, and 4 days of recovery. We measured total calcium and potassium contents in the stratum oriens, pyramidale, radiatum, and moleculare of the CA1 and CA3 sectors, using particle induced x-ray emission (PIXE) in the proton microprobe mode. The results showed significant accumulation of calcium and loss of potassium after 3 and 4 days of recovery in the CA1 sector, which developed neuronal necrosis, but not in the CA3 sector, which showed only occasional damage. In a few animals, calcium accumulation (and loss of potassium) was observed with no or only mild visible damage, but in the majority of animals the accumulation of calcium correlated to signs of neuronal necrosis. Since calcium accumulation was similar in all strata examined, the results failed to reveal preferential accumulation in dendritic or somal regions. Based on our results and those of Dux et al., we emphasize the possibility that delayed neuronal death is, at least in part, caused by increased calcium cycling of plasma membranes and gradual calcium overload of mitochondria.

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