scholarly journals Non-Contact Respiration Measurement Method Based on RGB Camera Using 1D Convolutional Neural Networks

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3456
Author(s):  
Hyeon-Sang Hwang ◽  
Eui-Chul Lee
Keyword(s):  
Measurement Method ◽  
Respiratory Diseases ◽  
Region Of Interest ◽  
Average Error ◽  
Measurement Technology ◽  
Altman Analysis ◽  
Clinical Scenarios ◽  
Actual Environment ◽  
Error Bias ◽  
Robust To Noise

Conventional respiration measurement requires a separate device and/or can cause discomfort, so it is difficult to perform routinely, even for patients with respiratory diseases. The development of contactless respiration measurement technology would reduce discomfort and help detect and prevent fatal diseases. Therefore, we propose a respiration measurement method using a learning-based region-of-interest detector and a clustering-based respiration pixel estimation technique. The proposed method consists of a model for classifying whether a pixel conveys respiration information based on its variance and a method for classifying pixels with clear breathing components using the symmetry of the respiration signals. The proposed method was evaluated with the data of 14 men and women acquired in an actual environment, and it was confirmed that the average error was within approximately 0.1 bpm. In addition, a Bland–Altman analysis confirmed that the measurement result had no error bias, and regression analysis confirmed that the correlation of the results with the reference is high. The proposed method, designed to be inexpensive, fast, and robust to noise, is potentially suitable for practical use in clinical scenarios.

scholarly journals Cut-Edge Detection Method for Rice Harvesting Based on Machine Vision

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 590
Author(s):  
Zhenqian Zhang ◽  
Ruyue Cao ◽  
Cheng Peng ◽  
Renjie Liu ◽  
Yifan Sun ◽  
...  
Keyword(s):  
Machine Vision ◽  
Edge Detection ◽  
Detection Method ◽  
Region Of Interest ◽  
Average Error ◽  
Vertical Projection ◽  
Cut Edge ◽  
Fitting Method ◽  
Combine Harvester ◽  
Edge Detection Method

A cut-edge detection method based on machine vision was developed for obtaining the navigation path of a combine harvester. First, the Cr component in the YCbCr color model was selected as the grayscale feature factor. Then, by detecting the end of the crop row, judging the target demarcation and getting the feature points, the region of interest (ROI) was automatically gained. Subsequently, the vertical projection was applied to reduce the noise. All the points in the ROI were calculated, and a dividing point was found in each row. The hierarchical clustering method was used to extract the outliers. At last, the polynomial fitting method was used to acquire the straight or curved cut-edge. The results gained from the samples showed that the average error for locating the cut-edge was 2.84 cm. The method was capable of providing support for the automatic navigation of a combine harvester.

scholarly journals Turbine Blade Three-Wavelength Radiation Temperature Measurement Method Based on Reflection Error Correction

2021 ◽  
Vol 11 (9) ◽  
pp. 3913
Author(s):  
Kaifeng Zheng ◽  
Jinguang Lü ◽  
Yingze Zhao ◽  
Jin Tao ◽  
Yuxin Qin ◽  
...  
Keyword(s):  
Temperature Measurement ◽  
Turbine Blade ◽  
Measurement Method ◽  
Turbine Blades ◽  
Target Surface ◽  
Maximum Error ◽  
Radiation Temperature ◽  
Average Error ◽  
Real Surface ◽  
Wavelength Radiation

The turbine blade is a key component in an aeroengine. Currently, measuring the turbine blade radiation temperature always requires obtaining the emissivity of the target surface in advance. However, changes in the emissivity and the reflected ambient radiation cause large errors in measurement results. In this paper, a three-wavelength radiation temperature measurement method was developed, without known emissivity, for reflection correction. Firstly, a three-dimensional dynamic reflection model of the turbine blade was established to describe the ambient radiation of the target blade based on the real surface of the engine turbine blade. Secondly, based on the reflection correction model, a three-wavelength radiation temperature measurement algorithm, independent of surface emissivity, was proposed to improve the measurement accuracy of the turbine blade radiation temperature in the engine. Finally, an experimental platform was built to verify the temperature measurement method. Compared with three conventional colorimetric methods, this method achieved an improved performance on blade temperature measurement, demonstrating a decline in the maximum error from 6.09% to 2.13% and in the average error from 2.82% to 1.20%. The proposed method would benefit the accuracy in the high-temperature measurement of turbine blades.

scholarly journals A Parallel-Phase Demodulation-Based Distance-Measurement Method Using Dual-Frequency Modulation

2019 ◽  
Vol 10 (1) ◽  
pp. 293
Author(s):  
In-Gyu Jang ◽  
Sung-Hyun Lee ◽  
Yong-Hwa Park
Keyword(s):  
Frequency Modulation ◽  
Measurement Method ◽  
Continuous Wave ◽  
Measurement Range ◽  
Distance Measurement ◽  
Measurement Technology ◽  
Dual Frequency ◽  
Distance Measurements ◽  
Time Required ◽  
Phase Demodulation

Time-of-flight (ToF) measurement technology based on the amplitude-modulated continuous-wave (AMCW) model has emerged as a state-of-the-art distance-measurement method for various engineering applications. However, many of the ToF cameras employing the AMCW process phase demodulation sequentially, which requires time latency for a single distance measurement. This can result in significant distance errors, especially in non-static environments (e.g., robots and vehicles) such as those containing objects moving relatively to the sensors. To reduce the measurement time required for a distance measurement, this paper proposes a novel, parallel-phase demodulation method. The proposed method processes phase demodulation of signal in parallel rather than sequentially. Based on the parallel phase demodulation, 2π ambiguity problem is also solved in this work by adopting dual frequency modulation to increase the maximum range while maintaining the accuracy. The performance of proposed method was verified through distance measurements under various conditions. The improved distance measurement accuracy was demonstrated throughout an extended measurement range (1–10 m).

scholarly journals Vision-based Deformation Measurement for Pile-soil Testing

2019 ◽  
Vol 275 ◽  
pp. 03009
Author(s):  
Kun Zhou ◽  
Linhua Chen ◽  
Shanshan Yu
Keyword(s):  
Measurement Method ◽  
Optical Measurement ◽  
High Sensitivity ◽  
Steel Tube ◽  
Image Features ◽  
Deformation Measurement ◽  
Measurement Technology ◽  
Full Field ◽  
Progressive Development ◽  
Point Tracking

Image measurement technology has been widely used in monitoring the deformation of the soil field around the pile with its advantages of no damage, no contact, full-field measurement, no added quality and high sensitivity. But there are few researches on image-based bearing deformation measurement of the pile. Through an indoor pile-soil semi-model test, the rigid body displacement and load-bearing deformation of a new type of prefabricated steel tube pile foundation under horizontal load was measured based on image features. In this study, the concept of optical extensometer is first applied to the measurement of local average strain of a non-uniform deformed structure. Based on an improved feature point tracking algorithm SURF-BRISK, non-contact measurement of tiny strain of pile body is realized. In addition, based on DIC technology, this study also obtained the progressive development of displacement field of soil around pile. The above work fully reflects the non-contact convenience and full-field richness of the optical measurement method compared with the traditional measurement method.

Design and Precision Analysis of Muzzle Angle Measurement System

2011 ◽  
Vol 128-129 ◽  
pp. 1378-1381
Author(s):  
Jian Ping Zhou ◽  
Xiao Yun Wu ◽  
Peng Fei Zhang ◽  
Guo Hua Gu
Keyword(s):  
Light Source ◽  
Measurement System ◽  
Measurement Method ◽  
Angle Measurement ◽  
Measurement Technology ◽  
Optical Range ◽  
Precision Analysis ◽  
Traditional Methods ◽  
Two Dimension ◽  
New System

The traditional muzzle angle measurement method measured by optical range quadrant can’t satisfy the demand. A muzzle angle auto-measurement method based on collimation light source and PSD two-dimension sensors is provided. Adopted by the auto-measurement technology, the precision, efficiency and velocity of measurement are all improved, which solves the problems of traditional methods. The errors and precision of the new system are analyzed. According these analysis and calculation, the precision of this measurement system can gain the measurement ends.

Uniformity Assessment of Digital Prints based on NPS and CSF

2011 ◽  
Vol 291-294 ◽  
pp. 2922-2926
Author(s):  
Ling Jun Kong ◽  
Zhong Ming Jiang ◽  
Xue Ling Gao
Keyword(s):  
Quality Factor ◽  
Measurement Method ◽  
Quantitative Measurement ◽  
Visual Assessment ◽  
Measurement Technology ◽  
Print Quality ◽  
Essential Quality ◽  
Digital Print ◽  
Digital Prints

The standard for digital print quality and its measurement technology is now under consideration, and uniformity evaluation should be an important and essential quality factor. The paper provides a practical quantitative measurement method for traditional visual assessment on uniformity, and proposes a simple and effective IUI index to evaluate the uniformity of digital prints through NPS curve of the printed flat areas and CSF of HVS. The validity of the IUI is demonstrated through its applications in the uniformity assessment of the digital prints.

scholarly journals Multiposition Rotation Interference Absolute Measurement Method for High-Precision Optical Component Surfaces

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xueliang Zhu ◽  
Fengming Nie ◽  
Bingcai Liu ◽  
Ruikun Liu ◽  
Ailing Tian
Keyword(s):  
High Precision ◽  
Measurement Method ◽  
Absolute Measurement ◽  
Optical Component ◽  
Computational Method ◽  
Surface Measurement ◽  
Measurement Technology ◽  
Reference Mirror ◽  
Large Aperture ◽  
Absolute Measurements

Modern optical engineering requires increasingly sophisticated interferometry methods capable of conducting subnanometer scale measurements of the large aperture, high-precision optical component surfaces. However, the accuracy of interferometry measurement is limited to the accuracy with which the surface of the reference mirror employed in the interferometer system is known, and the influence of gravity-induced deformation cannot be ignored. This is addressed in the present work by proposing a three-flat testing method based on multiposition rotation interference absolute surface measurement technology that combines the basic theory of N-position rotation with the separability of surface wavefront functions into sums of even and odd functions. These functions provide the rotational symmetric components of the wavefront, which then enables the absolute surface to be reconstructed based on the N-position rotation measurements. In addition, we propose a mechanical clamping combined with computational method to compensate for the gravity-induced deformations of the flats in the multiposition rotation absolute measurements. The high precision of the proposed absolute surface measurement method is demonstrated via simulations. The results of laboratory experiments indicate that the combination compensation method provides the high-precision surface reconstruction outcomes. The present work provides an important contribution for supporting the interferometry measurement of large aperture, high-precision optical component surfaces.

scholarly journals Spinal postural alignment measurements using markerless digital photography

2020 ◽  
Vol 28 (3) ◽  
pp. 230949902096083
Author(s):  
Mitsumasa Hida ◽  
Chikamune Wada ◽  
Ryota Imai ◽  
Kodai Kitagawa ◽  
Shogo Okamatsu ◽  
...  
Keyword(s):  
Measurement Method ◽  
Digital Photography ◽  
Skin Surface ◽  
Altman Analysis ◽  
Excellent Correlation ◽  
Block Method ◽  
Noninvasive Measurements ◽  
Postural Alignment ◽  
Minor Addition ◽  
Craniovertebral Angle

Background: A device that can measure posture alignment repeatedly is important for the prevention of hyperkyphosis. Objective: We devised a markerless measurement method for hyperkyphosis using digital photography and investigated the correlation with other noninvasive measurements and the validity and accuracy of this method. Methods: The study included 27 participants. The craniovertebral angle in supine (CVAS) and craniohorizontal angle in supine (CHAS) were calculated from digital photographs of the head and neck areas of the studied subjects with ImageJ. The correlations of CVAS and CHAS with the kyphosis index (KI) and block method (BM) were investigated. Intrarater correlation coefficient and Bland–Altman analyses were used to verify the reliability and accuracy of the measured results. Results: CHAS exhibited an excellent correlation with the KI and the BM. The intra- and interrater reliabilities of CHAS were almost perfect. Bland–Altman analysis revealed that CHAS was associated with minor addition errors. Conclusion: CHAS founded an excellent correlation and reliability with the conventional spinal postural alignment measurements. The addition error suggested that the manual was needed to confirm the landmark. The CHAS is a method used to measure the spinal postural alignment in a supine position without markers and without exposing the skin surface.

scholarly journals A Real-Time Measurement Method of Air Refractive Index Based on Special Material Etalon

2018 ◽  
Vol 8 (11) ◽  
pp. 2325 ◽  
Author(s):  
Guo-Ying Ren ◽  
Xing-Hua Qu ◽  
Shuang Ding
Keyword(s):  
Refractive Index ◽  
Real Time ◽  
Direct Measurement ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Laser Interferometry ◽  
Measurement Technology ◽  
Measurement Principle ◽  
Environmental Responses ◽  
Realization Process

In the precise displacement measurement based on laser interferometry, the measurement technology for the refractive index of air is widely used to improve the measurement accuracy. However, the existing measurement method of the refractive index of air based on direct measurement is not easy to realize in practical work because of its complex measurement principle and the huge volume of the measurement device; while the measurement accuracy and speed based on the indirect method cannot adapt to the real-time, fast and accurate measurement requirements of industrially changing environments, resulting in distortion of the results. In this study, a measurement method of the refractive index of air based on a special material etalon is proposed. The method enables rapid and direct measurement of the air refractive index when the environment changes and it is given the realization process. Finally, the experimental results show that the deviation between this method and the modified Edlen formula is about 2.5 × 10−7, and that this method can quickly reflect the changes of the environment, which prove the correctness of this method and its ability manage rapid environmental responses. This method is worth popularizing in industrial measurement.

Trusted Class Measurement Module - A Novel Fine-Grained Integrity Measurement Method for Java Application

2013 ◽  
Vol 760-762 ◽  
pp. 1100-1105
Author(s):  
Hai He Ba ◽  
Song Zhu Mei ◽  
Jiang Chun Ren ◽  
Zhi Ying Wang ◽  
Yong Cheng ◽  
...  
Keyword(s):  
System Performance ◽  
Measurement Method ◽  
Organization Structure ◽  
Measurement Technology ◽  
Fine Grained ◽  
Java Application

typically, integrity measurement technology for Java application is based on the whole file, which is too coarse to meet different requirements. In this paper, we propose a novel fine-grained integrity measurement method for Java application: trusted class measurement module (TCMM), which is a class integrity measurement method according to organization structure of Java application file. It not only satisfies necessary trust but also has less impact on system performance.

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