scholarly journals A Reference Matching-Based Temperature Compensation Method for Ultrasonic Guided Wave Signals

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5174
Author(s):  
Geng Wang ◽  
Yuhang Wang ◽  
Hu Sun ◽  
Bingrong Miao ◽  
Yishou Wang

The ultrasonic guided wave-based structural damage diagnosis method has broad application prospects in different fields. However, some environmental factors such as temperature and loads will significantly affect the monitoring results. In this paper, a reference matching-based temperature compensation for ultrasonic guided wave signals is proposed to eliminate the effect of temperature. Firstly, the guided wave signals measured at different temperatures are used as reference signals to establish the relationship between the features of the reference signals and temperature. Then the matching algorithm based on Gabor function is used to establish the relationship between the amplitude influence coefficient obtained by the reference signal and the corresponding temperature. Finally, through these two relationships, the values of the phase and amplitude influence coefficients of the guided wave signals at other temperatures are obtained in a way of interpolation in order to reconstruct the compensation signals at the temperature. The effect of temperature on the amplitude and phase of the guided wave signal is eliminated. The proposed temperature compensation method is featured such that the compensation performance can be improved by multiple iteration compensation of the residual signal. The ultrasonic guided wave test results at different temperatures show that the first iterative compensation of the proposed method can achieve compensation within the temperature range greater than 7 °C, and the compensation within the temperature range greater than 18 °C can be achieved after three iterations.


Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.



Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3685 ◽  
Author(s):  
Marcin Adamczyk ◽  
Paweł Liberadzki ◽  
Robert Sitnik

This paper presents the results of several studies concerning the effect of temperature on digital cameras. Experiments were performed using three different camera models. The presented results conclusively demonstrate that the typical camera design does not adequately take into account the effect of temperature variation on the device’s performance. In this regard, a modified camera design is proposed that exhibits a highly predictable behavior under varying ambient temperature and facilitates thermal compensation. A novel temperature compensation method is also proposed. This compensation model can be applied in almost every existing camera application, as it is compatible with every camera calibration model. A two-dimensional (2D) and three-dimensional (3D) application of the proposed compensation model is also described. The results of the application of the proposed compensation approach are presented herein.



Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 362 ◽  
Author(s):  
Marcin Adamczyk ◽  
Paweł Liberadzki ◽  
Robert Sitnik

The effect of temperature on three-dimensional (3D) structured light scanners is a very complex issue that, under some conditions, can lead to significant deterioration of performed measurements. In this paper, we present the results of several studies concerning the effect of temperature on the mechanical base of 3D-structured light scanners. We also propose a software compensation method suitable for implementation in any existing scanner. The most significant advantage of the described method is the fact that it does not require any specialized artifact or any additional equipment, nor access to the thermal chamber. It uses a simulation of mechanical base thermal deformations and a virtual 3D measurement environment that allows for conducting virtual measurements. The results from the verification experiments show that the developed method can extend the range of temperatures in which 3D-structured light scanners can perform valid measurements by more than six-fold.





2013 ◽  
Vol 351-352 ◽  
pp. 460-466
Author(s):  
Chao Chen ◽  
Ying She Luo ◽  
Song Hua Tang ◽  
Xuan Zhang

In order to investigate the effect of temperature (from normal temperature to 850°C) coursed by fire on the strength damage of concrete, thermal compression tests for concrete specimens named C35 have been performed under different temperature conditions. Emphasis is laid on the relationship between temperature and thermal damage strength; and the relevant formula is proposed in this paper. The regularity and mechanism of thermal damage evolution in concrete on strength under high temperature are analyzed. Combined the result of tests with the residual strength thermal damage model, we obtain the specific damage variable value D under different temperatures. Finally, we compare the fitting formula curve to relevant reference; there are some important conclusions which can be partly applied to fire design of concrete structure.



IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 67530-67541 ◽  
Author(s):  
Yishou Wang ◽  
Geng Wang ◽  
Di Wu ◽  
Yue Wang ◽  
Bingrong Miao ◽  
...  


2012 ◽  
Vol 460 ◽  
pp. 411-414
Author(s):  
Yin Fang Jiang ◽  
Zhen Ning Guo ◽  
Yong Qi Yan ◽  
Qin Huang

The difference between inside circumferential defects and outside circumferential defects was proved using the theory of reflection waves, the course of propagation and reflection from inside circumferential defects and outside circumferential defects in steel pipes was simulated with L(0,2) mode by the numerical simulation program ANSYS, and the curves of the reflection waves were obtained. The investigation indicated that the relationship between reflection coefficient of each kind of circumferential defects and the circumference of the defects was linear; in additional, it was found that the reflection coefficient of outside circumferential defects was a little higher than the reflection coefficient of inside circumferential defects; the difference between inside and outside circumferential defect became more obvious as the thickness of the defect increases. So the results provide a basis for detecting and distinguishing circumferential defects of pipes.



2016 ◽  
Vol 73 (10) ◽  
pp. 2518-2525 ◽  
Author(s):  
D. Sobotka ◽  
K. Czerwionka ◽  
J. Makinia

The aim of this study was to determine a short-term and long-term effect of temperature on the anammox rate and determination of temperature coefficients in the Arrhenius and Ratkowsky equations. The short-term effects of temperature on the anammox granular biomass were investigated in batch tests at ten different temperatures in the range of 10–55 °C. The maximum overall nitrogen removal rate of 1.3 gN gVSS−1·d−1 was observed at 40 °C (VSS: volatile suspended solids). The minimum rate, close to 0 gN gVSS−1·d−1, was observed for the limits of the analyzed temperature range (10 and 55 °C). The activity tests carried out at 55 °C showed an irreversible loss of the activity due to the observed biomass lysis. Subsequently to the batch tests, a sequencing batch reactor (SBR) was operated at different temperatures (from 30 to 11 °C) to determine the long-term effects of temperature. The system was successfully operated at 15 °C, but when temperature was decreased to 11 °C, nitrite started to accumulate and the system lost its stability. The temperature coefficient (θ) was 1.07 for the batch tests carried out in the temperature range of 10–40 °C. In contrast, during the long-term SBR operation, substantially different θ had to be estimated for two temperature ranges, 1.07 (T = 15–30 °C) and 1.65 (T = 11–15 °C).



1973 ◽  
Vol 62 (3) ◽  
pp. 423-438 ◽  
Author(s):  
R. J. Phelps

Analyses were carried out at Salisbury, Rhodesia, on the relationship between fat content and residual dry weight in newly emerged adults ofGlossina morsitans morsitansWestw., following incubation at constant temperatures between 16 and 32°C for laboratory material, and between 20 and 30°C for field material. The same relationship was investigated for field-collected and laboratory-produced larvae. Sizespecific rates of fat consumption were calculated from these data, and it was shown that the rate of change at temperatures below 20°C was of a different order to that at higher temperatures. Fat reserves in teneral flies reared in the laboratory at 16–32°C were shown to be adequate in flies of 4 mg residual dry weight for survival at rest for at least 24 h after emergence, over the temperature range likely to be encountered in the field. Considerably longer periods of survival were indicated for flies of the same size emerging from field-collected puparia. The latter exhibited a marked seasonal variation in size with the largest puparia occurring at the time of lower temperatures. Smallest puparia occur in the hot-dry season, but even under these adverse conditions fat reserves of most tenerals are adequate for survival for at least 24 h. It was concluded that lack of fat was not likely to cause heavy mortality of stages passed within the puparium over the temperature range 16–32°C. After emergence, survival of smaller flies would depend on their ability to obtain a blood-meal within 24 h.



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