Ratio Measurement Method Research Articles

Point Cloud Measurement of Rubber Tread Dimension Based on RGB-Depth Camera

To achieve an accurate measurement of tread size after fixed-length cutting, this paper proposes a point-cloud-based tread size measurement method. Firstly, a mathematical model of corner points and a reprojection error is established, and the optimal solution of the number of corner points is determined by the non-dominated sorting genetic algorithm II (NSGA-II), which reduces the reprojection error of the RGB-D camera. Secondly, to address the problem of the low accuracy of the traditional pixel metric ratio measurement method, the random sampling consensus point cloud segmentation algorithm (RANSAC) and the oriented bounding box (OBB) collision detection algorithm are introduced to complete the accurate detection of the tread size. By comparing the absolute error and relative error data of several groups of experiments, the accuracy of the detection method in this paper reaches 1 mm, and the measurement deviation is between 0.14% and 2.67%, which is in line with the highest accuracy standard of the national standard. In summary, the RGB-D visual inspection method constructed in this paper has the characteristics of low cost and high inspection accuracy, which is a potential solution to enhance the pickup guidance of tread size measurement.

Coaxial-Tube Quantitative Nuclear Magnetic Resonance for Various Solutions Using SI-Traceable Concentration References.

Quantitative nuclear magnetic resonance (qNMR) is an accepted method for determining analyte concentrations using quantitative substances in one spectrum. Conventional qNMR is performed using a mixture of analytes and reference substances. In coaxial-tube NMR, two tubes are used as different solutions, similar to normal NMR spectra. Currently, coaxial tubes with various diameters are available; however, coaxial-tube qNMR is limited, and a general analytical protocol is yet to be proposed. In this study, we established an effective volume ratio (EVR) measurement method using the weight density and qNMR methods. Various analyte concentrations were determined using coaxial-tube qNMR and an SI-traceable reagent. The EVR required for the qNMR concentration calculation was determined using a coefficient of variation (CV) of <1% for an inner tube of ϕ 3 mm or less. The peak integral of each substance was correlated with the effective volume, depending on the abundance of the tube and matched 1H in the solution. The T1 relaxation times differed depending on the substructure, and the T1 values of the formate and OH groups varied for each tube set. Thus, each partial structural characteristic of the peak must be understood before qNMR is performed. The concentrations of various substances, including hygroscopic substances, were determined using coaxial-tube qNMR. Coaxial tubes eliminate the need to mix the analyte with the reference substance; thus, we can quantify the analyte without causing pH and structural changes caused by other mixtures and reuse the analyte for other test systems.

The Financial Health Analysis and Income Diversification Case Study on Indonesia Corruption Watch (ICW)

NGOs are agents of change that were formed with the aim of meeting social development needs that have not been able to be carried out or fulfilled by the government as state administrator. To maintain their existence, NGOs are required to maintain healthy financial conditions and diversified funding to ensure the survival of the organization so that it can provide a sustainable impact for its beneficiaries. Therefore, measuring NGO financial performance is very important. The aim of this research is to determine the financial performance and funding diversification of the NGO Indonesia Corruption Watch (ICW). The method used in this research is qualitative descriptive using financial ratio analysis and funding diversification on secondary data obtained from the website https://antikorup.org, in the form of financial reports for 2017-2021. The financial ratios calculated to measure ICW's financial performance use the ratio measurement method developed by Ritchie and Kolodinsky (2003), as well as funding diversification which will be measured using the Hirschman Herfindahl Index (HHI). The research results show that the financial health of ICW is in the good category with diversified income, it is known that the level of dependency on main donors is small. This has a positive impact on the sustainability of ICW to be able to continue to advocate for strengthening the people's bargaining position to control the state and participate in decisions to realize democratic governance, free from corruption, with economic, social and gender justice.

Fiber Optic Sensor-Based Bearing Defect Detection and Its Usages in Computer Vision

This work focuses on the investigation of surface defects in small bearings. Based on the theory of rough surface scattering and the dual-beam ratio measurement method, fiber optic sensing technology is applied in identifying surface defects in bearings. To facilitate the extraction of features for surface defects in bearings, a sensor probe fiber array with three concentric circles around the central emission is determined. A reflective intensity-modulated fiber optic sensor (FOS) is employed to detect surface defects on bearings. The structural parameters of the FOS are simulated through Matlab, considering the inner/outer diameter, numerical aperture, and axial spacing of the sensor. This work involves designing modulation light source excitation circuits, photoelectric conversion module circuits, pre-amplification differential amplifier circuits, infinite gain bandpass filtering circuits, and window function comparison circuits. This effectively amplifies the defect feature signals and eliminates noise interference. In experiments, the sensor probe is fixed on the support of a micro-displacement measurement platform. By adjusting the distance between the probe and the side surface through rotation, initial tests are conducted using standard roughness samples. The results indicate that installing the sensor probe at a distance of 0.92 mm from the side surface provides better measurement of surface roughness. The oscilloscope waveform reveals that the FOS can identify defects on different bearing surfaces. Furthermore, the bearing surface is divided into sections with engraved text (seal cover part) and without engraved text (inner and outer rings of the bearing). Using computer vision (CV) technology, a FOS detection system is designed, achieving a defect recognition rate of 99% for bearings, in line with the intended design goals.

Image Error Detection: A Systematic Literature Review

The advancement of technology, as well as the creation of new techniques and methodologies for image analysis, is rapid. However, image detection may face some errors. Image error detection will be discussed in this comprehensive literature review. Throughout the papers, this work attempts to learn about the types of images used, algorithms that are frequently used, techniques that are frequently used, and metrics used to test the correctness of the suggested approach. The most commonly used image type is medical images such as Magnetic Resonance Imaging, the algorithm that is widely used is a Convolutional Neural Networks based algorithm. The method that is widely used is a machine learning-based method, and the measurement that is widely used is a Peak Signal Noise Ratio measurement method to measure the accuracy of the algorithm.

Modal-Based Analysis for Aiding 3D Elastic Metastructure Design

The engineered topological structures of the unit cell endow elastic metamaterials (EMMs) with the extraordinary capability to attenuate elastic waves. In real-life scenarios, a practical EMM (i.e., metastructure), consisting of a limited number of unit cells, is the truncation of the infinite EMM, which may detriment seriously the attenuation capability. To understand the mechanism behind the detriment, an efficient way to evaluate and analyze the stopbands for metastructures is essential. Instead of relying on the commonly adopted frequency response analysis to characterize stopbands for metastructures, which are sensitive to frequency sweeping steps and short of information of truncated resonance affecting wave attenuation performance, a novel modal-based method (MM) is proposed to assess the wave attenuation of 3D metastructures. Specifically, the modal-based analysis scheme incorporating the modal superposition principle and a freshly developed layer-based strain energy ratio (SER) measurement method is proposed. Through employing the MM, the opening and ceasing of the stopbands are evaluated by characterizing dominant eigenmodes developed in metastructures. Accordingly, the influences of eigenmodes induced by different mechanisms on wave attenuation performance are investigated, and the stopband formation mechanisms are elaborated. Furthermore, under the guidance of a freshly proposed modal-based design framework, metastructures with modified geometrical parameter settings (GPSs) are demonstrated with enlarged normalized bandwidths (NBs) at lower frequencies, which show improved applicability in multiple engineering disciplines.

Frequency modulation laser spectroscopy method for methane isotopologue ratio and total concentration measurements at 1661 nm

Source identification and accurate measurements of methane gas concentration are key tools necessary for climate change management. Here we present a method for methane isotopologue ratio measurement using a laser-based frequency modulation (FM) spectroscopy technique in the near infrared at 1661 nm. We provide line shape analysis and discuss a fitting algorithm for accurate isotopologue ratio metrology and investigate and minimize the effects of residual amplitude modulation on the experimentally produced FM signal line shape. This FM technique is further evaluated for future development of a cavity-enhanced and noise-immune system capable of isotopologue ratio as well as ultrasensitive trace gas measurements, all accessible using a single distributed feedback laser.

Accurate C/D ratio estimation with elliptical fitting for OCT image based on joint segmentation and detection network

Proper estimation of the cup-to-disc ratio (C/D ratio) plays a significant role in ophthalmic examinations, and it is urgent to improve the efficiency of C/D ratio automatic measurement. Therefore, we propose a new method for measuring the C/D ratio of OCTs in normal subjects. Firstly, the end-to-end deep convolution network is used to segment and detect the inner limiting membrane (ILM) and the two Bruch's membrane opening (BMO) terminations. Then, we introduce an ellipse fitting technique to post-process the edge of the optic disc. Finally, the proposed method is evaluated on 41 normal subjects using the optic-disc-area scanning mode of three machines: BV1000, Topcon 3D OCT-1, and Nidek ARK-1. In addition, pairwise correlation analyses are carried out to compare the C/D ratio measurement method of BV1000 to existing commercial OCT machines as well as other state-of-the-art methods. The correlation coefficient between the C/D ratio calculated by BV1000 and the C/D ratio calculated by manual annotation is 0.84, which indicates that the proposed method has a strong correlation with the results of manual annotation by ophthalmologists. Moreover, in comparison between BV1000, Topcon and Nidek in practical screening among normal subjects, the proportion of the C/D ratio less than 0.6 calculated by BV1000 accounts for 96.34%, which is the closest to the clinical statistics among the three OCT machines. The above experimental results and analysis show that the proposed method performs well in cup and disc detection and C/D ratio measurement, and compared with the existing commercial OCT equipment, the C/D ratio measurement results are relatively close to reality, which has certain clinical application value.

Proposal of leaf chlorophyll content and its a/b ratio measurement method using a filter-free multiple wavelength sensor

In this study, we proposed a miniaturized system that can detect chlorophyll content and its a/b ratio simultaneously to measure the health condition of plants. In order to solve the problems of general measurement systems such as large-scale equipment and fracture measurement, a filter-free multiple wavelength sensor was used to evaluate the current ratio due to wavelength changes. Current characteristics demonstrated that the sensor due to the chlorophyll a/b ratio and changes in their concentrations are proportional to the spectral characteristics. As a result of measuring the extracted chlorophyll of plants and leaves, the centroid wavelength value of the transmission spectrum showed linear data from the current ratio of the sensor. The proposed method enabled simultaneous measurement of the chlorophyll content and its a/b ratio of plants with a non-destructive and compact device and is expected to be applied to the agricultural field.

Early severity prediction of BPD for premature infants from chest X-ray images using deep learning: A study at the 28th day of oxygen inhalation

Background and objectiveBronchopulmonary dysplasia is a common respiratory disease in premature infants. The severity is diagnosed at the 56th day after birth or discharge by analyzing the clinical indicators, which may cause the delay of the best treatment opportunity. Thus, we proposed a deep learning-based method using chest X-ray images of the 28th day of oxygen inhalation for the early severity prediction of bronchopulmonary dysplasia in clinic. MethodsWe first adopted a two-step lung field extraction method by combining digital image processing and human-computer interaction to form the one-to-one corresponding image and label. The designed XSEG-Net model was then trained for segmenting the chest X-ray images, with the results being used for the analysis of heart development and clinical severity. Therein, Six-Point cardiothoracic ratio measurement algorithm based on corner detection was designed for the analysis of heart development; and the transfer learning of deep convolutional neural network models were used for the early prediction of clinical severities. ResultsThe dice and cross-entropy loss value of the training of XSEG-Net network reached 0.9794 and 0.0146. The dice, volumetric overlap error, relative volume difference, precision, and recall were used to evaluate the trained model in testing set with the result being 98.43 ± 0.39%, 0.49 ± 0.35%, 0.49 ± 0.35%, 98.67 ± 0.40%, and 98.20 ± 0.47%, respectively. The errors between the Six-Point cardiothoracic ratio measurement method and the gold standard were 0.0122 ± 0.0084. The deep convolutional neural network model based on VGGNet had the promising prediction performance, with the accuracy, precision, sensitivity, specificity, and F1 score reaching 95.58 ± 0.48%, 95.61 ± 0.55%, 95.67 ± 0.44%, 96.98 ± 0.42%, and 95.61±0.48%, respectively. ConclusionsThese experimental results of the proposed methods in lung field segmentation, cardiothoracic ratio measurement and clinic severity prediction were better than previous methods, which proved that this method had great potential for clinical application.

Direct Measuring the Amplitude Ratios of Weakly Coupled Resonators Employing Automatic Amplitude Control

Since the eigenstate-modulated weakly coupled resonators (WCRs) characterize the detected signals by measuring the amplitude ratios of weakly coupled resonant units, the convenient and accurate extraction of amplitude ratios becomes critical for high-performance applications of all mode-localized sensors. This article proposes a modular hybrid measurement and control scheme based on automatic amplitude control to measure the amplitude ratios of weakly coupled resonant systems directly. The amplitude of one resonant unit is stabilized at a constant value by the automatic gain control (AGC), and the amplitude of the other resonant unit is adopted as an alternative for the amplitude ratios. A micromachined mode-localized sensor for acceleration measurement at atmospheric pressure is adopted to verify the feasibility of the proposed measurement and control scheme. Experiment results demonstrate that the tested mode-localized accelerometer prototype has a mechanical sensitivity of 0.2693 V/g with bias stability of 30.82 mg and a noise floor of 657.59 μg/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> . Furthermore, the proposed output metric's profile is consistent with the amplitude ratios and maintains approximate background noises compared with the conventional amplitude ratio measurement method. Our proposal omits the algebraic division operations of vibration amplitudes, thereby simplifying the subsequent signal processing of mode-localized sensors.

A Simple High-Precision 2-Port Vector Analyzer

This article presents a novel concept for a highly accurate and simple two-port vector signal analyzer. A current phase ratio measurement method is defined for one independent external signal with a restriction of the measuring range ±90 or ±180°. The article presents a new way of phase ratio evaluation of two independent external signals with precise phase determination in a wide range from 0° to 360°. The new functional blocks of the analyzer circuit element act as a four-position radio frequency (RF) switcher and an algorithm for phase determination is presented. Practical application and verification of the results achieved are demonstrated by measuring the phase directional radiation pattern of a complex object such as an aircraft fuselage.

Axial super-resolution using a double-zone pinhole in a confocal microscope

A double-zone pinhole intensity ratio measurement method is proposed for confocal microscopy based on the inverse phase characteristics of the axial response between the central and annular portions of the spot. The simulation and experimental results show that when the normalized optical radius of the central region is 3.2 and the peak values of the axial response of the two regions are similar, the central lobe of the axial characteristic curve can be compressed by 72.8%, without changing the original structure of the system. This simple method can effectively suppress both the light-source intensity drift and changes in the measured surface reflectance.

Development of elasto-magnetic (EM) sensor for monitoring cable tension using an innovative ratio measurement method

The magnetic permeability changes of ferromagnetic materials under elastic stress offer the potential to measure tension based on the inverse magnetostrictive effect. The elasto-magnetic (EM) sensor is the most promising technology for monitoring tension in steel structures. Nevertheless, difference in the device channel or variation of the external wire resistance results in an inaccurate induced voltage variation of the EM sensor in tension measurement. In this paper, the EM sensor for monitoring cable tension using an innovative ratio measurement method was presented. An inductor-resistor model of the excitation system and a transformer model of the sensor system were established to obtain the explicit relationship between the ratio result and the external tension. The experimental results show that the ratio of the integral value of the induced voltage to the excitation current variation is proportional to the external tension, a finding that is consistent with the theoretical derivation. In addition, the simulation analysis and experiment result demonstrate that the ratio measurement method improves sensor performance with the comparison of the traditional induced voltage method. Finally, the EM sensor was applied in the Zhengzhou Olympic Stadium of China. The monitoring results show that the proposed ratio measurement method could accurately measure cable tension.

OA043] A new signal-to-noise ratio (SNR) measurement method based on low-pass filtering for magnetic resonance imaging (MRI) quality control (QC) purposes

Purposes Signal-to-noise ratio (SNR) is a prominent metric to assess scanners performances. SNR measurement in MRI is challenging because of the difficulty to quantify noise level from images. A gold-standard consist in pixel-by-pixel variance calculation on several images (>100) scanned in identical conditions. This method is accurate but cannot be practically implemented because of time constraints. Another gold-standard consists in scanning images without radiofrequency excitation hence collecting noise-only. This latter is also unpractical because it requires a specific and generally not-granted access to the hardware. Consequently, there is a need for designing alternative methods for accurate and precise noise quantification. This work aims to introduce a new noise level quantification method for SNR measurement. Methods Our method (Noisefilt) quantifies noise level by combining these operations: (1) subtraction of two images subsequently scanned in identical conditions, (2) Low-pass filtering to extract and suppress low-frequency remaining information, (3) (Noisefilt = standard deviation of pixels. Using a dataset of 30 exams of a head phantom scanned on a 3T MR unit with an 8-channel phased-array brain coil, we compared our method with three others from the literature: noise level quantified using one image-background region-of-interest (ROI) (Noisebgd), several background ROIs (Noisebgd+), and from the subtraction of two images (Noisediff) [6]. By means of Bland–Altman analysis, we assessed the agreement between all these methods and the noise-only standard method (NoisenoRF). We also assessed their correlation with NoisenoRF (Pearson’s correlation coefficient r, p Results Bland–Altman analysis showed that Noisefilt agrees more with the standard than the three other methods. Correlation of our Noisefilt method with the gold-standard (rfilt =0.80, p Conclusion We demonstrated that our method produces accurate measurement, is simple to implement, and is usable for instance for quality control (QC) purposes. This new metric is being tested with additional scans in QC monitoring of different MR scanners. Download : Download high-res image (87KB) Download : Download full-size image Download : Download high-res image (159KB) Download : Download full-size image

A Novel in-Band OSNR Measurement Method Based on Normalized Autocorrelation Function

We propose and experimentally demonstrate a novel in-band optical signal-to-noise ratio (OSNR) measurement method based on normalized autocorrelation function. Experimental results indicate that OSNR of four-channel 32-Gbaud pulse-duration modulation-QPSK wavelength-division-multiplexing signals is precisely measured with applicability to flexible channel spacing. The measurement range is 37 dB from −15 to 22 dB with error less than $ \pm 0.5$ dB. The proposed method is also robust to bit rate, modulation format, chromatic dispersion, and input optical power. Besides, the choice of delay in calculation of normalized autocorrelation function is flexible from 1.6 to 30 ps.

Effect of dissolved organic nitrogen contamination on δ15 N-NH4 determination in water samples by modification of the diffusion method with gas-phase trapping.

The isotopic tracer technique is widely used to identify the sources and fate of nitrogen (N) in order to understand the N cycle and contamination in water environments. The stable isotope ratio of ammonium is expected to greatly enhance the tracing analysis by combining it with the traditional nitrate isotope ratio. Diffusion followed by gas-phase trapping is the most commonly applied method for ammonium isotope ratio measurement. Although dissolved organic nitrogen (DON) is abundant in natural water and its breakdown in the diffusion procedure has been reported, the interference of DON with the measurement of ammonium isotope ratios has not been fully examined. This study aims to test the effect of DON contamination by using organic N compounds, viz. humic acid and alanine. A series of diffusion experiments was conducted at a temperature of 80°C for a maximum of 7days. Ammonia was transferred from alkaline solution and trapped with an acidic filter. This method was applied for samples with ammonium concentrations between 0.5 and 2.0mg-N/L. There was no difference between the ammonium N stable isotope ratios for samples with and without added DON compounds; the fractionation between the observed value and the actual value was negligible, in the range of 0.2 to 1.0‰. The modifications of previous studies, i.e. shorter diffusion period, no vigorous shaking and using gas-phase trapping, successfully avoided any breakdown of DON in fresh water samples. The modified method provides high precision and accuracy and it is recommended for the analysis of anthropogenically influenced water samples, such as paddy fields, ground water, rivers and lakes.

SAATY 1977: THE BUILDING BLOCKS

Saaty’s 1977 article is his first comprehensive publication of the ideas behind AHP. He reveals his creativity in a new method for ratio measurement that includes pairwise ratio matrices, derived ratio scales from those matrices, and checks on the consistency of data. His ingenuity in using ratio measures is revealed by the use of hierarchical structures to display priorities and then a rescaling of them in a manner that allows synthesis for a composite ratio result. Face validity is provided by many supporting examples and mathematical validity is provided by the solution to many theorems. https://doi.org/10.13033/ijahp.v9i3.532

The Verification of the Resistive Voltage Dividers by a Resistance Ratio Measurement Method

Рассмотрена и проанализирована проблематика поверки делителей напряжения. Проанализированы основные метрологические характеристики и методы определения погрешностей резистивных делителей напряжения. Одной из основных проблем в проведении поверки делителей напряжения является необходимость использования высокоточных эталонных средств измерений. Разработана методика автономной поверки делителей напряжения, в которой реализован метод измерения отношения сопротивлений делителя. Методика позволяет определять погрешности резистивных делителей напряжения без использования прецизионных средств измерительной техники, в частности, без эталонных мер электрического сопротивления.

Chromium isotope ratio measurements in environmental matrices by MC-ICP-MS

A single column separation and concentration/isotope ratio measurement method for Cr by ICP-MS (single and multicollector) was evaluated and optimized for geological and biological matrices. Results showδ53Cr homogeneity in different urban soil profiles and suggest isotopically light signature for airborne Cr emitted by steelworks.