scholarly journals Recognition of Human Face Regions under Adverse Conditions—Face Masks and Glasses—In Thermographic Sanitary Barriers through Learning Transfer from an Object Detector

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 43
Author(s):  
Joabe R. da Silva ◽  
Gustavo M. de Almeida ◽  
Marco Antonio de S. L. Cuadros ◽  
Hércules L. M. Campos ◽  
Reginaldo B. Nunes ◽  
...  
Keyword(s):  
Learning Transfer ◽  
Region Of Interest ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Human Face ◽  
Disease Symptoms ◽  
Adverse Conditions ◽  
Shared Spaces ◽  
Body Surface Temperature ◽  
Areas Of Interest

The COVID-19 pandemic has detrimentally affected people’s lives and the economies of many countries, causing disruption in the health, education, transport, and other sectors. Several countries have implemented sanitary barriers at airports, bus and train stations, company gates, and other shared spaces to detect patients with viral symptoms in an effort to contain the spread of the disease. As fever is one of the most recurrent disease symptoms, the demand for devices that measure skin (body surface) temperature has increased. The thermal imaging camera, also known as a thermal imager, is one such device used to measure temperature. It employs a technology known as infrared thermography and is a noninvasive, fast, and objective tool. This study employed machine learning transfer using You Only Look Once (YOLO) to detect the hottest temperatures in the regions of interest (ROIs) of the human face in thermographic images, allowing the identification of a febrile state in humans. The algorithms detect areas of interest in the thermographic images, such as the eyes, forehead, and ears, before analyzing the temperatures in these regions. The developed software achieved excellent performance in detecting the established areas of interest, adequately indicating the maximum temperature within each region of interest, and correctly choosing the maximum temperature among them.

scholarly journals Experimental Study on Infrared Temperature Characteristics and Failure Modes of Marble with Prefabricated Holes under Uniaxial Compression

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 713
Author(s):  
Yanyan Peng ◽  
Qunchao Lin ◽  
Manchao He ◽  
Chun Zhu ◽  
Haijiang Zhang ◽  
...  
Keyword(s):  
Uniaxial Compression ◽  
Failure Modes ◽  
Rock Sample ◽  
Vertical Axis ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Infrared Thermal Imaging ◽  
Average Temperature ◽  
Observation Area ◽  
Evolution Behavior

In rock engineering, it is of great significance to study the failure mechanical behavior of rocks with holes. Using a combination of experiment and infrared detection, the strength, deformation, and infrared temperature evolution behavior of marble with elliptical holes under uniaxial compression were studied. The test results showed that as the vertical axis b of the ellipse increased, the peak intensity first decreased and then increased, and the minimum value appeared when the horizontal axis was equal to the vertical axis. The detection results of the infrared thermal imager showed that the maximum temperature, minimum temperature, and average temperature of the observation area in the loading stage showed a downward trend, and the range of change was between 0.02 °C and 1 °C. It was mainly due to the accumulation of energy in the loading process of the rock sample that caused the surface temperature of the specimen to decrease. In the brittle failure stage, macroscopic cracks appeared on the surface of the rock sample, which caused the energy accumulated inside to dissipate, thereby increasing the maximum temperature and average temperature of the rock sample. The average temperature increase was about 0.05 °C to about 0.19 °C. The evolution of infrared temperature was consistent with the mechanical characteristics of rock sample failure, indicating that infrared thermal imaging technology can provide effective monitoring for the study of rock mechanics. The research in this paper provides new ideas for further research on the basic characteristics of rock failure under uniaxial compression.

EXPERIMENTAL STUDIES OF THE HEATING TEMPERATURE OF THE GREENHOUSE RADIATOR INSTALLATIONS

2020 ◽  
Vol 15 (1) ◽  
pp. 76-80
Author(s):  
Nadezhda Kondrat'eva ◽  
Dmitriy Filatov ◽  
Pavel Terent'ev ◽  
Bulat Ziganshin
Keyword(s):  
Energy Efficiency ◽  
Supply Voltage ◽  
Heating Temperature ◽  
Experimental Studies ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Voltage Level ◽  
Radiation Sources ◽  
Measurement Results ◽  
Nominal Mode

The thermal regime of plants determines the temperature of the environment, the evaporation of moisture by plants, and the heating of plants by radiation from irradiation plants. Today, induction and LED greenhouse irradiators are promising for replacing irradiators with sodium lamps in terms of energy efficiency. Experimental studies were performed to assess the possibility of proximity of irradiators with induction lamps and LED irradiators to plants to increase their level of irradiation, in comparison with sodium radiation sources. When setting up the experiment, a complex was used, including a Fluke ti32 thermal imager, PHO-250-2-M linear autotransformer, 220V power supply, and a greenhouse irradiator. Processing of the measurement results was carried out in the Fluke SmartView 3.1 program. The heating temperature was determined when reaching the nominal mode, with the nominal mode of operation of the irradiators, with a change in the supply voltage level. Sodium and induction irradiators heat up to a maximum temperature 10 times faster than LED ones. The heating temperature of optical radiation sources with sodium lamps is 5 times higher than LED and 2.5 times higher than induction. A change in the supply voltage level affects the heating temperature of the sodium irradiator with electromagnetic ballasts, the heating temperature of sodium and induction irradiators with electronic ballasts, as well as LED irradiators, remains unchanged and equal to the nominal value at a supply voltage level of ± 10% of Unom.. Low heating temperatures of induction and LED irradiators can reduce the height of their suspension and bring them closer to plants, which will increase the irradiation of plants by increasing the level of illumination or reduce the power of irradiators, that is, increase the energy efficiency of irradiation systems

scholarly journals The Study of the Electrospark Coating Effect on the Heat Removal Property of Hard Alloy

2020 ◽  
pp. 133-143
Author(s):  
Yaroslav A. Vostrikov ◽  
Sardana A. Sleptsova
Keyword(s):  
Hard Alloy ◽  
Protective Coating ◽  
Heat Removal ◽  
Front Surface ◽  
Heat Propagation ◽  
Cutting Edge ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Surface Cooling ◽  
Electrospark Coating

The effect of a protective coating on the heat removal properties of a cutting plate made of VK8 tungsten-containing hard alloy has been studied. The article provides a sequence of measurements made by a thermal imager and a thermograph to install a mechanism for heat removal by a protective coating. The factors affecting the fault in temperature measurements in a static experiment by means of a thermal imager are described. The time to maximum temperature transferred from the heated counterbody to the hard alloy with and without coating has been obtained. The exposure time of the maximum temperature transmitted from the counterbody to the alloys under study has been fixed. It has been demonstrated that a multilayer electrospark coating based on Ni, Cu, Fe, Cr, W reduces the maximum temperature under the same test conditions by 42%, while the surface cooling rate at the point close to the cutting edge increases by 53%. The data obtained show the effect of the protective coating on the heat removal property of the hard alloy. The time of heat propagation over the entire surface of the test sample and the cooling time have been studied by means of a thermograph. There is a temperature difference of 103°С for the alloy without coating that has been calculated simultaneously between the points on the cutting edge and at a distance of 2 mm lower along the front surface, while for the alloy with a protective coating the difference was 79°С, it is less by 24%. The thermograms of alloys with and without coating are clearly shown at time to maximum temperature on the surface. The work of the coating to remove heat from the point of contact with the heated counterbody has been proven, and the heat removal property is explained by the composition of the coating obtained by electrospark alloying with electrodes based on Cu, Ni, Fe, W, and Cr

scholarly journals Honey Bee Tracheal Mite, Acarapis woodi (Rennie) (Arachnida: Acarina: Tarsonemidae)

EDIS ◽  
1969 ◽  
Vol 2004 (2) ◽  
Author(s):  
Harold A. Denmark ◽  
Harvey L. Cromroy ◽  
Malcolm T. Stanford
Keyword(s):  
Honey Bee ◽  
The United States ◽  
Cooperative Extension Service ◽  
Acarapis Woodi ◽  
University Of Florida ◽  
Disease Symptoms ◽  
Isle Of Wight ◽  
Adverse Conditions ◽  
Tracheal Mite ◽  
Mite Infestations

In October 1984, the honey bee tracheal mite, Acarapis woodi (Rennie), was found in Florida. Although it was first described by Rennie in 1921, the mite was not found in the United States until 1984. Rennie described the mite from bees on the Isle of Wight and associated it with the "Isle of Wight" disease. Symptoms of this infestation were described as "bees crawling about unable to fly, and with wings disjointed; dwindling and mortality of colonies have been said to occur rapidly with colonies dying within a month." It was later shown that the tracheal mite was not the cause of the "Isle of Wight" disease (Bailey 1964), and later reports (Bailey 1968, Morse 1978) indicate that A. woodi is not as serious a pest of honey bees as previously thought. In combination with other adverse conditions, however, heavy mite infestations may cause a reduction in bee activity. This document is EENY-172 (originally published as DPI Entomology Circular 267), one of the Featured Creatures series of the Entomology and Nematology Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: November 2000. EENY-172/IN329: Honey Bee Tracheal Mite, Acarapis woodi (Rennie) (Arachnida: Acari: Tarsonemidae) (ufl.edu)

scholarly journals APPLICATION OF KOHONEN SELF-ORGANIZING MAP TO SEARCH FOR REGION OF INTEREST IN THE DETECTION OF OBJECTS

2020 ◽  
Vol 1 ◽  
pp. 62-69 ◽  
Author(s):  
Victor Skuratov ◽  
Konstantin Kuzmin ◽  
Igor Nelin ◽  
Mikhail Sedankin
Keyword(s):  
Region Of Interest ◽  
Input Image ◽  
Self Organizing Map ◽  
Convolutional Network ◽  
Self Organizing Maps ◽  
Sobel Operator ◽  
Detection Of Objects ◽  
Minimum Number ◽  
Areas Of Interest ◽  
Self Organizing

Today, there is a serious need to improve the performance of algorithms for detecting objects in images. This process can be accelerated with the help of preliminary processing, having found areas of interest on the images where the probability of object detection is high. To this end, it is proposed to use the algorithm for distinguishing the boundaries of objects using the Sobel operator and Kohonen self-organizing maps, described in this paper and shown by the example of determining zones of interest when searching and recognizing objects in satellite images. The presented algorithm allows 15–100 times reduction in the amount of data arriving at the convolutional neural network, which provides the final recognition. Also, the algorithm can significantly reduce the number of training images, since the size of the parts of the input image supplied to the convolution network is tied to the image scale and equal to the size of the largest recognizable object, and the object is centered in the frame. This allows to accelerate network learning by more than 5 times and increase recognition accuracy by at least 10 %, as well as halve the required minimum number of layers and neurons of the convolutional network, thereby increasing its speed.

scholarly journals Research on the Interrelation between Temperature Distribution and Dry Band on Wet Contaminated Insulators

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4289
Author(s):  
Da Zhang ◽  
Fancui Meng
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Relative Humidity ◽  
Moisture Absorption ◽  
Maximum Temperature ◽  
Water Evaporation ◽  
Thermal Imager ◽  
Insulator Surface ◽  
The Law ◽  
Dry Bands

In this paper, the interrelation between temperature distribution and dry band on wet contaminated insulators is studied by theoretical analysis, numerical simulation, and a high-voltage artificial contamination experiment. The influences of the composition of the contaminant and the relative humidity of the environment on the moisture absorption of the contamination layer are studied. It is indicated that the critical relative humidity (CRH) of the soluble mixture in the contamination layer decreases with the increase of the variety of soluble substances. This can be considered as a previously neglected reason for the inconsistency between the result of an artificial contamination test and that of a natural contamination test. Furthermore, the influences of the maximum temperature, wind speed, altitude, relative humidity, and the composition of the contamination on the water evaporation rate of the contaminated layer are also studied. The formation of dry band is predicted by studying the law of water transport in the contamination layer. The influence of the location, width, drying degree, and quantity of dry bands on the insulator surface temperature are studied by numerical simulation. An infrared thermal imager and ultraviolet camera are adopted to measure the temperature distribution and the discharge phenomenon on the insulator surface separately, which verifies the above numerical simulation. The study results deepen the research on the moisture absorption characteristics, the law of temperature distribution, the formation of dry bands, and the influence of dry bands on the temperature distribution of wet contaminated insulators.

scholarly journals Experimental study of the adiabatic wall temperature of a cylinder in a supersonic cross flow

2021 ◽  
Vol 2039 (1) ◽  
pp. 012029
Author(s):  
S S Popovich ◽  
N A Kiselev ◽  
A G Zditovets ◽  
Y A Vinogradov
Keyword(s):  
Experimental Study ◽  
Wall Temperature ◽  
High Speed ◽  
Cross Flow ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
State University ◽  
Adiabatic Wall ◽  
Speed Flow ◽  
Total Temperature

Abstract The results of an experimental study of the adiabatic wall temperature for a supersonic air flow across the cylinder are presented. The temperature was measured contactlessly using an InfraTEC ImageIR 8855 thermal imager through a ZnSe infrared illuminator. The freestream Mach number was 3.0, input flow total temperature was 295 K, and the total pressure 615 kPa. The Reynolds number calculated from the cylinder diameter (30 mm) was about 106. It is shown that it is possible in principle to determine the high-speed flow total temperature by defining the maximum temperature of a cylindrical probe at the front critical point. Thermograms of the wall temperature distribution along the profile of the cylinder were obtained. The research was performed at the experimental facilities of the Institute of Mechanics of Lomonosov Moscow State University.

SmallStore: A region-of-interest based adaptive system for compressing human face videos

2017 ◽  
Author(s):  
Karan Ahuja ◽  
Anubhav Pandey ◽  
Ferdous A. Barbhuiya ◽  
Seema Nagar ◽  
Kuntal Dey
Keyword(s):  
Adaptive System ◽  
Region Of Interest ◽  
Human Face

Accurate Predetermination of the Process Parameters for Glass/Glass Laser Bonding Based on the Temperature Distribution Analysis

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Yanyi Xiao ◽  
Wen Wang ◽  
Jianhua Zhang
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Distribution Analysis ◽  
Analysis Model ◽  
Glass Laser ◽  
Element Analysis ◽  
Laser Bonding

Temperature distribution is the key factor affecting the bonding quality in the glass/glass laser bonding process. In this work, the finite element method was used to establish three-dimensional (3D) numerical analysis model of the temperature field during bonding. Based on the result of the finite element analysis, the crucial parameters and their influences on the temperature distribution were discussed. In order to predetermine the necessary process parameter values for bonding, a nonlinear multiparameter fitting formula was established to predict the maximum temperature. The fitting model was validated experimentally by recording the maximum temperature during laser bonding via an infrared thermal imager.

scholarly journals Evaluation of the Size-of-Source Effect in Thermal Imaging Cameras

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 607
Author(s):  
Igor Pušnik ◽  
Gregor Geršak
Keyword(s):  
Thermal Imaging ◽  
Region Of Interest ◽  
Thermal Imager ◽  
Direct Evaluation ◽  
Source Effect ◽  
Quantitative Measurements ◽  
Central Pixel ◽  
Custom Made ◽  
Temperature Levels

In numerous applications, including current body temperature monitoring in viral pandemic management, thermal imaging cameras are used for quantitative measurements. These require determination of the measurement accuracy (error) and its traceability (measurement uncertainty). Within error estimation, the size-of-source effect (SSE) is an important error source. The SSE is the relation between the physical size of a target and the instrument’s nominal target size. This study presents a direct evaluation of the error due to the SSE. A stable and uniform temperature, generated by blackbodies, was measured by a high-quality thermal imager. To limit the generated radiation, custom-made blocking tiles with different apertures were used. Effects of aperture shapes and positions, camera-target distances and temperature levels on the error were investigated. The study findings suggest that due to the SSE the measured temperatures are too low, especially at longer camera-target distances. The SSE error depends on the number of pixels available and included into the region of interest, for which the accurate measurement is about to be performed. For an accurate temperature measurement, an array of at least 10 × 10 pixels should be exposed to the observed target radiation, while 3 × 3 central pixel area should be included in the temperature calculation.

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