SHUTTER-LESS TEMPERATURE-DEPENDENT CORRECTION FOR UNCOOLED THERMAL CAMERA UNDER FAST CHANGING FPA TEMPERATURE

Conventional temperature-dependant correction methods for uncooled cameras are not so valid for images under the condition of fast changing FPA temperature as usual, therefore, a shutter-less temperature-dependant correction method is proposed here to compensate for these errors and stabilize camera's response only related to the object surface temperature. Firstly, sequential images are divided into the following three categories according to the changing speed of FPA temperature: stable (0&deg;C/min), relatively stable (&lt;0.5&deg;C/min), unstable (&gt;0.5&deg;C/min). Then all of the images are projected into the same level using a second order polynomial relation between FPA temperatures and gray values from stable images. Next, a third order polynomial relation between temporal differences of FPA temperatures and the above corrected images is implemented to eliminate the deviation caused by fast changing FPA temperature. Finally, radiometric calibration is applied to convert image gray values into object temperature values. Experiment results show that our method is more effective for fast changing FPA temperature data than FLIR GEV.

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Correction Method for RS80-A Humicap Humidity Profiles and Their Validation by Lidar Backscattering Profiles in Tropical Cirrus Clouds

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-1684.1 ◽

2005 ◽

Vol 22 (1) ◽

pp. 18-29 ◽

Cited By ~ 27

Author(s):

Ulrich Leiterer ◽

Horst Dier ◽

Dagmar Nagel ◽

Tatjana Naebert ◽

Dietrich Althausen ◽

...

Keyword(s):

Evaluation Method ◽

Time Lag ◽

Correction Method ◽

Cirrus Clouds ◽

Temperature Dependent ◽

Upper Troposphere ◽

Statistical Comparison ◽

Daily Show ◽

Tropical Tropopause ◽

Humidity Profiles

Abstract Routine radiosonde relative humidity (RH) measurements are not reliable as they are presently used in the global upper-air network. The new Lindenberg measuring and evaluation method, which provides RH profile measurements with an accuracy of ±1% RΗ in the temperature range from 35° to −70°C near the tropical tropopause is described. This Standardized Frequencies (FN) method uses a thin-film capacitive polymer sensor of a modified RS90-H Humicap radiosonde. These research humidity reference radiosondes (FN sondes) are used to develop a correction method for operational RS80-A Humicap humidity profiles. All steps of correction and quality control for RS80-A radiosondes are shown: ground-check correction, time-lag and temperature-dependent correction, and the recognition of icing during the ascent. The results of a statistical comparison between FN sondes and RS80-A sondes are presented. Corrected humidity data of operational RS80-A sondes used in Lindenberg (4 times daily) show no bias when compared to FN radiosondes and have an uncertainty of about ±3% RH at the 1 σ or 68% confidence level from 1000 to about 150 hPa. Only a small dry bias of at most −2% RH remains in the lowest part of the boundary layer (up to 500-m height). Finally, some examples of corrected RS80-A RH profiles in cirrus clouds validated by lidar backscattering profiles in a region of the intertropical convergence (Maldive Islands) are demonstrated. The soundings indicate that ice-saturated and ice-supersaturated air above 10-km height were connected with cirrus clouds in all 47 investigated cases, and, second, that the corrected RS80-A RH profiles also provide good quality information on water vapor in the upper troposphere.

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Thermal Error Modeling of Precision Positioning Stage

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.694-697.767 ◽

2013 ◽

Vol 694-697 ◽

pp. 767-770

Author(s):

Jing Shu Wang ◽

Ming Chi Feng

Keyword(s):

Thermal Deformation ◽

Thermal Error ◽

Error Modeling ◽

Precision Positioning ◽

Third Order ◽

Element Analysis ◽

The Finite Element Analysis ◽

Positioning Stage ◽

Order Polynomial ◽

The Relationship

As the thermal deformation significantly impacts the accuracy of precision positioning stage, it is necessary to realize the thermal error. The thermal deformation of the positioning stage is simulated by the finite element analysis. The relationship between the temperature variation and thermal error is fitted third-order polynomial function whose parameters are determined by genetic algorithm neural network (GANN). The operators of the GANN are optimized through a parametric study. The results show that the model can describe the relationship between the temperature and thermal deformation well.

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Calibration of pneumotachographs using a calibrated syringe

Journal of Applied Physiology ◽

10.1152/japplphysiol.00196.2003 ◽

2003 ◽

Vol 95 (2) ◽

pp. 571-576 ◽

Cited By ~ 14

Author(s):

Yongquan Tang ◽

Martin J. Turner ◽

Johnny S. Yem ◽

A. Barry Baker

Keyword(s):

Calibration Method ◽

Linear Range ◽

Data Sets ◽

Constant Flow ◽

Calibration Constant ◽

Third Order ◽

Polynomial Coefficients ◽

Calibration Curves ◽

Order Polynomial ◽

Better Than

Pneumotachograph require frequent calibration. Constant-flow methods allow polynomial calibration curves to be derived but are time consuming. The iterative syringe stroke technique is moderately efficient but results in discontinuous conductance arrays. This study investigated the derivation of first-, second-, and third-order polynomial calibration curves from 6 to 50 strokes of a calibration syringe. We used multiple linear regression to derive first-, second-, and third-order polynomial coefficients from two sets of 6–50 syringe strokes. In part A, peak flows did not exceed the specified linear range of the pneumotachograph, whereas flows in part B peaked at 160% of the maximum linear range. Conductance arrays were derived from the same data sets by using a published algorithm. Volume errors of the calibration strokes and of separate sets of 70 validation strokes ( part A) and 140 validation strokes ( part B) were calculated by using the polynomials and conductance arrays. Second- and third-order polynomials derived from 10 calibration strokes achieved volume variability equal to or better than conductance arrays derived from 50 strokes. We found that evaluation of conductance arrays using the calibration syringe strokes yields falsely low volume variances. We conclude that accurate polynomial curves can be derived from as few as 10 syringe strokes, and the new polynomial calibration method is substantially more time efficient than previously published conductance methods.

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Mechanical and thermophysical properties of actinide monocarbides

Modern Physics Letters B ◽

10.1142/s0217984918502482 ◽

2018 ◽

Vol 32 (21) ◽

pp. 1850248 ◽

Cited By ~ 2

Author(s):

Devraj Singh ◽

Amit Kumar ◽

Vyoma Bhalla ◽

Ram Krishna Thakur

Keyword(s):

Thermophysical Properties ◽

Room Temperature ◽

Nearest Neighbor ◽

Ultrasonic Attenuation ◽

Thermal Relaxation ◽

Nonlinearity Parameter ◽

Micro Hardness ◽

Temperature Dependent ◽

Third Order ◽

Pressure Derivative

This paper describes the mechanical and thermophysical properties of actinide monocarbides AnCs (An=Np and Cm) as a function of temperature and crystallographic direction. The temperature-dependent second- and third-order elastic constant (SOECs and TOECs) have been computed first using Coulomb and Born–Mayer potential up to second nearest neighbor. SOECs have been applied to find out mechanical constant such as bulk modulus, shear modulus, tetragonal modulus, Poisson’s ratio and Zener anisotropy for the prediction of futuristic performance of the NpC and CmC. We also found the value of G/B [Formula: see text] 0.59 for the chosen materials, which indicates that NpC and CmC have brittle nature. The computed elastic constants are further applied directly to indirectly find out the ultrasonic velocity, Grüneisen parameters, pressure derivative, Debye temperature, micro-hardness, Breazeale’s nonlinearity parameter, thermal relaxation time and thermal conductivity. These evaluated parameters were finally used to compute ultrasonic attenuation of the NpC and CmC along [Formula: see text], [Formula: see text] and [Formula: see text] directions at room temperature. The behavior of the obtained results of this investigation has been compared with similar type of materials.

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Third-Order Polynomial Normal Transform Applied to Multivariate Hydrologic Extremes

Water ◽

10.3390/w11030490 ◽

2019 ◽

Vol 11 (3) ◽

pp. 490 ◽

Cited By ~ 1

Author(s):

Yeou-Koung Tung ◽

Lingwan You ◽

Chulsang Yoo

Keyword(s):

Flood Control ◽

Random Variables ◽

Rainfall Data ◽

Normal Space ◽

Modeling Framework ◽

Third Order ◽

Maximum Rainfall ◽

Normal Distributions ◽

Order Polynomial ◽

Hydrologic Extremes

Hydro-infrastructural systems (e.g., flood control dams, stormwater detention basins, and seawalls) are designed to protect the public against the adverse impacts of various hydrologic extremes (e.g., floods, droughts, and storm surges). In their design and safety evaluation, the characteristics of concerned hydrologic extremes affecting the hydrosystem performance often are described by several interrelated random variables—not just one—that need to be considered simultaneously. These multiple random variables, in practical problems, have a mixture of non-normal distributions of which the joint distribution function is difficult to establish. To tackle problems involving multivariate non-normal variables, one frequently adopted approach is to transform non-normal variables from their original domain to multivariate normal space under which a large wealth of established theories can be utilized. This study presents a framework for practical normal transform based on the third-order polynomial in the context of a multivariate setting. Especially, the study focuses on multivariate third-order polynomial normal transform (TPNT) with explicit consideration of sampling errors in sample L-moments and correlation coefficients. For illustration, the modeling framework is applied to establish an at-site rainfall intensity–duration-frequency (IDF) relationship. Annual maximum rainfall data analyzed contain seven durations (1–72 h) with 27 years of useable records. Numerical application shows that the proposed modeling framework can produce reasonable rainfall IDF relationships by simultaneously treating several correlated rainfall data series and is a viable tool in dealing with multivariate data with a mixture of non-normal distributions.

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Derivation of rainfall IDF relations by third-order polynomial normal transform

Stochastic Environmental Research and Risk Assessment ◽

10.1007/s00477-018-1583-4 ◽

2018 ◽

Vol 32 (8) ◽

pp. 2309-2324 ◽

Cited By ~ 1

Author(s):

Lingwan You ◽

Yeou-Koung Tung

Keyword(s):

Third Order ◽

Order Polynomial

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Design and calibration of unicapillary pneumotachographs

Journal of Applied Physiology ◽

10.1152/jappl.1998.84.1.335 ◽

1998 ◽

Vol 84 (1) ◽

pp. 335-343 ◽

Cited By ~ 8

Author(s):

A. Giannella-Neto ◽

C. Bellido ◽

R. B. Barbosa ◽

M. F. Vidal Melo

Keyword(s):

Respiratory Mechanics ◽

Ambient Pressure ◽

Animal Experiments ◽

Small Animal ◽

Positive Pressure ◽

Linear Calibration ◽

Third Order ◽

Order Polynomial ◽

Internal Radius ◽

Volume Measurements

Giannella-Neto, A., C. Bellido, R. B. Barbosa, and M. F. Vidal Melo. Design and calibration of unicapillary pneumotachographs. J. Appl. Physiol.84(1): 335–343, 1998.—This study presents a method for design and calibration of unicapillary pneumotachographs for small-animal experiments. The design, based on Poiseuille’s law, defines a set of internal radius and length values that allows for laminar flow, measurable pressure differences, and minimal interference with animal’s respiratory mechanics and gas exchange. A third-order polynomial calibration (Pol) of the pressure-flow relationship was employed and compared with linear calibration (Lin). Tests were done for conditions of ambient pressure (Pam) and positive pressure (Ppos) ventilation at different flow ranges. A physical model designed to match normal and low compliance in rats was used. At normal compliance, Pol provided lower errors than Lin for mixed (1–12 ml/s), mean (4–10 ml/s), and high (8–12 ml/s) flow rate calibrations for both Pam and Ppos inspiratory tests (P < 0.001 for all conditions) and expiratory tests ( P < 0.001 for all conditions). At low compliance, they differed significantly with 8.6 ± 4.1% underestimation when Lin at Pam was used in Ppos tests. Ppos calibration, preferably in combination with Pol, should be used in this case to minimize errors (Pol = 0.8 ± 0.5%, Lin = 6.5 ± 4.0%, P < 0.0005). Nonlinear calibration may be useful for improvement of flow and volume measurements in small animals during both Pam and Ppos ventilation.

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An empirical method to correct for temperature-dependent variations in the overlap function of CHM15k ceilometers

Atmospheric Measurement Techniques ◽

10.5194/amt-9-2947-2016 ◽

2016 ◽

Vol 9 (7) ◽

pp. 2947-2959 ◽

Cited By ~ 16

Author(s):

Maxime Hervo ◽

Yann Poltera ◽

Alexander Haefele

Keyword(s):

Boundary Layer ◽

Planetary Boundary Layer ◽

Correction Method ◽

Empirical Method ◽

Cloud Base ◽

Atmospheric Conditions ◽

Cloud Detection ◽

Temperature Dependent ◽

Night Time ◽

Gradient Based

Abstract. Imperfections in a lidar's overlap function lead to artefacts in the background, range and overlap-corrected lidar signals. These artefacts can erroneously be interpreted as an aerosol gradient or, in extreme cases, as a cloud base leading to false cloud detection. A correct specification of the overlap function is hence crucial in the use of automatic elastic lidars (ceilometers) for the detection of the planetary boundary layer or of low cloud. In this study, an algorithm is presented to correct such artefacts. It is based on the assumption of a homogeneous boundary layer and a correct specification of the overlap function down to a minimum range, which must be situated within the boundary layer. The strength of the algorithm lies in a sophisticated quality-check scheme which allows the reliable identification of favourable atmospheric conditions. The algorithm was applied to 2 years of data from a CHM15k ceilometer from the company Lufft. Backscatter signals corrected for background, range and overlap were compared using the overlap function provided by the manufacturer and the one corrected with the presented algorithm. Differences between corrected and uncorrected signals reached up to 45 % in the first 300 m above ground. The amplitude of the correction turned out to be temperature dependent and was larger for higher temperatures. A linear model of the correction as a function of the instrument's internal temperature was derived from the experimental data. Case studies and a statistical analysis of the strongest gradient derived from corrected signals reveal that the temperature model is capable of a high-quality correction of overlap artefacts, in particular those due to diurnal variations. The presented correction method has the potential to significantly improve the detection of the boundary layer with gradient-based methods because it removes false candidates and hence simplifies the attribution of the detected gradients to the planetary boundary layer. A particularly significant benefit can be expected for the detection of shallow stable layers typical of night-time situations. The algorithm is completely automatic and does not require any on-site intervention but requires the definition of an adequate instrument-specific configuration. It is therefore suited for use in large ceilometer networks.

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Oxygen equilibrium curve shape and allohemoglobin interaction in sheep whole blood

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1986.250.2.r298 ◽

1986 ◽

Vol 250 (2) ◽

pp. R298-R305 ◽

Cited By ~ 3

Author(s):

L. A. Maginniss ◽

A. J. Olszowka ◽

R. B. Reeves

Keyword(s):

Whole Blood ◽

Ovis Aries ◽

Equilibrium Curve ◽

Curve Shape ◽

Third Order ◽

Binding Characteristics ◽

Isoelectric Points ◽

Order Polynomial ◽

Oxygen Equilibrium Curve ◽

O2 Binding

Adult sheep (Ovis aries) exhibit hemoglobin heterogeneity controlled by two autosomal alleles with codominant expression (Hb AA, AB, BB). Isoelectric points for Hb A and Hb B were 6.94 and 7.15, respectively; for Hb AB animals, the two allohemoglobins were present in equimolar concentrations (Hb A = 52%, Hb B = 48%). Dynamic O2 equilibrium curves (O2ECs) were generated for sheep whole blood at 39 degrees C using thin-film techniques. Half-saturation PO2 values (P50) at pH 7.50 were 31.3, 35.7, and 40.7 Torr for Hb AA, AB, and BB, respectively. CO2 Bohr coefficients at saturation (S) = 0.5 (delta log P50/delta pH) were similar for all phenotypes, ranging from -0.38 to -0.40. The Bohr slopes were also saturation independent between 0.2 and 0.8 S. Standard O2ECs for each phenotype were accurately fitted to three-constant third-order polynomial expressions. Sheep equilibrium curves were not isomorphic with other mammalian O2ECs (e.g., human and dog); sheep curves exhibited greater sigmoidicity. Furthermore, allohemoglobin interaction was not detected in heterozygous sheep. The blood O2 binding characteristics (P50, curve shape, and delta log PO2/delta pH) for Hb AB sheep and an experimental blood mixture containing equal proportions of Hb AA and Hb BB erythrocytes were equivalent.

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