An effective method for calculating crossed span distance of overhead line based on three-dimensional inclination algorithm

The double-ended excitation self-balancing bridge excitation method is a capacitance measurement method with rather a high measurement accuracy currently. However, the reference impedance of the electric bridge limits the traditional self-balancing excitation measurement method, making it difficult to achieve high accuracy and a wide range of capacitance sensor measurements. In the proposed paper, frequency adjustment method is introduced to enable impedance matching between the measured capacitance and the reference resistance. The measurement range is broadened as well as maintaining the accuracy of the capacitance measurement. The measurement circuit is composed of a reference resistor, a bridge in series with the measured capacitance and an operational amplifier follower circuit. First, we roughly measure the input impedance of the operational amplifier and the capacitive reactance of the capacitance under test using a two-step excitation method. Then, the best excitation frequency is calculated to match the reference resistor according to the capacitive reactance under test, and the input impedance of the operational amplifier is re-estimated with the best frequency. Finally, we complete the accurate measurement of the capacitive reactance under test through the use of dual excitation. The experimental results demonstrate the method’s high accuracy measurement within the range of 1.6 pF–16 nF, with the reference resistance set at 1 MΩ and the excitation frequency adjusted between 10 and 100 kHz. Additionally, dual excitation stability testing verifies relative standard deviations in the range of 0.01%–0.12%. Experiments on filter capsule sensing detection show that the proposed frequency adjustment measurement method can perform highly sensitive capacitive sensing measurements under the influence of parasitic effects.

The authors have developed a slit-lamp mounted digital photography system. This ensures that the patient's head is consistently positioned in the same plane in relation to the camera and generates standardized images of the eyelids, which are then analyzed using commercially available computer measurement software. The aim of this study was to assess the repeatability and reproducibility of this system compared with traditional methods of eyelid measurement. Both eyes of 10 patients were photographed and then measured by three clinicians using a handheld ruler for five eyelid parameters (i.e., palpebral aperture, superior marginal reflex distance, inferior scleral show, levator function, and upper eyelid skin crease height). The photographs were then assessed using computer software by the same clinicians (twice by a consultant and once by a clinical fellow and a specialist registrar). At all times, each observer was masked to their colleagues' results. Data were analyzed using Bland-Altman plots. There was a good level of agreement between measurements obtained by computer analysis of digital photographs and measurements obtained by traditional methods. A higher level of reproducibility (interobserver variability) was demonstrated in all digital measurements compared with those obtained by handheld ruler. Repeatability (intraobserver variability) with the digital photograph technique was also high and consistent for each of the five eyelid parameters. These results suggest that a digital photography system with computer analysis is comparable to, and offers advantages over, traditional methods of measurement. This system offers a simple, standardized, and rapid method of patient assessment with important applications in electronic patient records, audit, and research.

Background: Vehicle centroid height is an important parameter in vehicle control systems. It plays an important role in vehicle roll stability and handling stability. At present, there are mainly static and dynamic measurement methods such as swing method, mass reaction method, marking method and so on. These static measurement methods often require a fixed suspension to make the measurement process time-consuming and laborious, and measurement errors will occur when the suspension is not fixed firmly, and it is impossible to measure the mass center position of spring-loaded mass and non-spring-loaded mass. Objective: Therefore, it is of great practical significance to study a high accuracy, low cost and fast measurement method of vehicle centroid height. We revised and summarized all patents relating to methods for estimating vehicle centroid height. And a new method of centroid measurement is designed in this paper. Methods: According to the change of tire flattening radius and suspension, the change of spring and non-spring mass center height when vehicle axle load changes, the method of delineation is used to calculate the change of tire flattening radius and suspension; According to the relationship between vehicle tilt angle and front and rear axle load, the principle of moment balance and the principle of mass balance, it determines the geometric relationship between the variables, and to take the moment of the contact point between the front wheel and the ground, the moment balance equation is established, and the height of the vehicle mass center, spring load and non-spring load mass center in the horizontal position of the vehicle are obtained. Results: This measurement method is different from the existing static measurement of vehicle centroid height, it does not need the fixed suspension, only need to measure several dimensions, we can avoid heavy labor and safety accidents brought by the fixed suspension, it can also reduce the measurement error caused by fixation, but also can draw the centroid location of the sprung mass and unsprung mass. The measurement method is simple, economical and accurate, and is widely applicable on two-axle vehicles. Conclusion: The purpose of this paper is to provide a static and accurate measurement method of vehicle centroid height, so as to solve the problem that the current static measurement method of vehicle centroid height needs fixed suspension, and measurement errors will occur when the suspension is not fixed properly, so it is impossible to measure the centroid position of spring-loaded mass and non-spring-loaded mass.

The Jiangmen Underground Neutrino Observation (JUNO) will build a polymethyl methacrylate (PMMA) spherical vessel of a diameter of 35.4 meters. The constitutive model of PMMA is a key parameter for the design of PMMA structure. The bulk polymerization bonding area is often the weak point of the PMMA structure, so it is useful to understand the constitutive model of bonding areas for FEA. However, the traditional contact strain measurement methods, such as the strain extensometer and resistance strain gauge, will have an impact on the strain of PMMA, as the lossy measurement. Traditional measuring methods also can’t measure the small-sized bonding areas as 3 mm in most structures. The non-contact strain measurement method based on the CCD camera is studied. The tensile test result shows that the influence of environment on the strain value is less than 0.01%. The two strain measurement methods, the CCD camera and strain extensometer, are compared. The strain curves obtained by the two methods are highly consistent, and the maximum strain difference is 8.53 e-4. The fracture strain of the PMMA tensile specimen is 4.32% and slight plastic deformation has occurred. The Zhu-Wang-Tang (ZWT) nonlinear viscoelastic constitutive model of PMMA is obtained by fitting the stress-strain data. The tensile test result of PMMA specimen with bulk polymerization bonding area shows that the constitutive equations are different when the length ratio of the bonding area is different. By analyzing the relationship between the length ratio and the coefficients of constitutive equation, the constitutive equation of the bonding area is finally obtained. The results show that the coefficient of the constitutive equation of the bonding area is smaller than that of the mother material. The fracture strain of PMMA specimen with bonding area is 2.60%, lower than that of mother material, which makes the coefficient of the bonding area constitutive equation opposite to the sign of the mother material. The tensile strength of specimen with bonding area is about 85.68% of that of the mother material. The lower tensile strength makes the bonding area become one of the weak points of the structure.

Given the traditional method of direct measurement which is of high cost, difficult installation and poor reliability,this paper is presented a new model of the torque soft measure method based on least squares support vector machine using genetic algorithms optimization:genetic algorithms replaces the previous cross-validation method for model parameter’s optimization, in order to avoid the blindness of the parameter choices.Verified by simulation, the model can effectively address the deficiencies of traditional measurement methods and obtain better measurement accuracy and speed , possessing benefits of an outstanding ability for small sample study and being easy to compute.

SOFCs need to be able to operate for long periods of time without significant degradation in performance, and mechanical reliability and durability are problems that need to be addressed.Since SOFC operate at high temperatures and in oxidizing and reducing atmospheres, it is difficult to measure residual stress in-situ under actual operating conditions. Therefore, evaluation methods during operation have not been fully developed. Current methods for measuring residual stress in SOFC include curvature method, X-ray stress measurement method, and Raman scattering spectroscopy.In the curvature method, the stress is obtained by combining curvature, anode substrate thickness, and elastic modulus. Therefore, it is not suitable for residual stress measurement during reduction and re-oxidation of anodes, where physical properties such as elastic modulus change with time.In the X-ray stress measurement method, the change in lattice strain is measured, and the stress is obtained by multiplying the strain by an elastic constant. Typical methods of X-ray stress measurement are sin2ψ method and cosα method. The characteristics of the sin2ψ method are as follows;(1)By using several measuring points to determine the stress value, the variation of the measured value can be suppressed, resulting in high measurement accuracy. Furthermore, the reliability limit of the measured value can be quickly evaluated from the linearity.(2)A goniometer mechanism is used to measure the diffraction profile, which requires a large device.(3)Measurement time is long because several points are measured by moving the angle of incidence.Thus, although the sin2ψ method has high measurement accuracy, it is not very suitable for in-situ measurements.The method devised to solve these problems is cosα method. The characteristics of the cosα method are as follows;(1) Since it is single-incidence, the optical system is simple and does not require goniometric scanning, making it possible to reduce the size and weight of the measurement system. It is also possible to measure in a short time.(2) From the slope of the cosα and sinα diagrams, vertical stress and shear stress can be measured simultaneously. In addition, the reliability of the stress values can be evaluated from the linearity of the diagram.(3) In the case of coarse grains or strongly aggregated structure, only continuous rings can be obtained, or the strength may be significantly non-uniform, making stress measurement difficult.It has been demonstrated that the measurement accuracy of the cosα method for vertical stress is comparable to that of the sin2ψ method, and moreover, it is suitable for in-situ residual stress measurement because of its rapidity and simplicity.In Raman scattering spectroscopy, the change in lattice volume, i.e., the change in stress conditions, can be obtained by measuring the Raman shift. The characteristics of the Raman scattering spectroscopy are as follows;(1) Since the measurement can be performed under atmospheric pressure and through glass, it is suitable for in-situ measurement in the SOFC operating environment where atmosphere control is usual.(2)High spatial resolution (up to ~1µm resolution is possible with micro-Raman spectrometers) enables measurement of small areas.(3) Since Raman peaks with sufficiently strong intensity need to appear in the Raman spectrum, there is a limit to the number of materials that can be measured. Among the SOFC constituent materials, ceria-based materials are the most suitable for observation.As mentioned in (3), Raman scattering spectroscopy is used to calculate the stress value of the interlayer (ceria-based material). Therefore, the stress in the electrolyte is calculated by assuming that the electrolyte and the interlayer are rigid bodies under the operating conditions. In this study, we performed in-situ measurement of residual stress in the anode-supported cell using sin2ψ method, cosα method and Raman scattering spectroscopy. And then we compared the results and summarized the advantages and disadvantages of each method. We used a commercially available general cell and a cell fabricated at Tsinghua University. In order to reproduce the actual operating conditions, the measurements were carried out under elevated temperature and under reduced temperature. Since the anode may be re-oxidized when the fuel runs out or during an emergency shutdown, the measurements were also conducted under re-oxidation. Furthermore, we proposed suitable conditions for each measurement method and conducted experiments under those conditions.

The measured performance of the electrolyte-insulator-semiconductor capacitor (EISCAP) is related not only to the device structure and technology, but also to the measurement methods. For the conventional amplitude measurement method, since the capacitance of EISCAP is very small, the measurement procedure is easily affected by the fluctuation of reference electrode and solution impedance, which leads to low sensitivity and poor repeatability. In this study, a measurement method with impedance conversion is proposed for enhancing the measured sensitivity and repeatability of the EISCAP. Different from the conventional measurement method, an impedance conversion stage is inserted in front of the transimpedance amplifier in this approach; thus, the fluctuation of impedance of solution and reference electrode is suppressed, and the measurement repeatability is improved. At the same time, the capacitance of the sensor has been significantly amplified, so that the sensitivity can be improved. Under the condition of 2 kHz, compared with the traditional measurement method, the measurement sensitivity and repeatability with the proposed approach were improved by 13.81% and 63.64%, respectively.

In recent years, lots of measurement methods have been proposed for measuring the network QoS. However those measurement methods are most concentrated in the IP layer or transport layer. In this paper, we propose a HTTP-based active measurement method which is used to find network QoS problems occurred in application layer. A system called MLM is implemented by utilizing our new measurement method and traditional measurement methods together, and the system also has capabilities of measurement results collection and measurement results analysis. The experimental data shows that our system works effectively.

The traditional measurement method for viscoelastic creep strain and mechanical adsorption creep strain has relatively low accuracy, making it difficult to ensure the data accuracy of specimen strain measurements. In this study, 50-mm-thick Pinus sylvestris sawn timber was used as the research object. Along the thickness direction of the test material, the relationship between the free shrinkage coefficient and the moisture content of the test material was studied to optimize the measurement methods of viscoelastic creep strain and mechanical adsorption creep strain during drying process. The results showed that the optimized measurement method for viscoelastic creep strain, which compensates for dimensional change caused by moisture content changes during the creep recovery phase, was applied to different layers in the thickness direction of the test material. The average relative error at the end of the drying stage was reduced 20.1% compared to the traditional method. For the mechanical adsorption creep strain in different layers of the test material’s thickness, the optimized measurement method, based on the free shrinkage size calculated from the free shrinkage coefficient and moisture content, reduced the average relative error 59.1% compared to the traditional method.

As one of the measurement instruments for petrochemical trade handover, the accuracy of ship's liquid cargo tank capacity measurement is particularly important. Aiming at the shortcomings of traditional measurement methods, such as fewer feature points, low efficiency and large errors, a method of measuring ship's liquid cargo tank based on scene replication technology is proposed. This method uses 3D laser scanning system to acquire and process massive point cloud data of ship's liquid cargo tank, and generates capacity table. Two tanks are selected as the research object for the testing. Compared with the traditional capacity measurement method, the testing proves that the maximum capacity difference between the two methods is 0.18% (bottom), and the minimum is 0.04%. The validity of the method is verified.

To evaluate the effect of different inflation volume on the measurement accuracy of the modified cuff pressure measurement method in different shapes of cuffs, so as to provide reference for the correct monitoring of cuff pressure in clinic. In vitro study: The traditional cuff pressure measurement method (the cuff pressure gauge before measurement shows 0 cm H2O) and the modified cuff pressure measurement method (the cuff pressure before measurement shows 25 cm H2O, 28 cm H2O, 30 cm H2O or 32 cm H2O) were used to measure cylindrical and tapered cuffs, and the effect of different inflation volume on cuff pressure was analyzed statistically. Clinical study: patients with the artificial airway established by orotracheal intubation or tracheotomy in Neuro-ICU were prospectively selected as subjects, and the measurement procedure was the same as in vitro study. In vitro study showed that the pressure loss values of cylindrical cuff and tapered cuff using the traditional cuff pressure measurement method were (3.75 ± 0.31) cm H2O and (4.92 ± 0.44) cm H2O, respectively, and clinical study showed that the pressure loss values were (5.07 ± 0.83) cm H2O and (5.17 ± 0.93) cm H2O, respectively. The actual measured values measured by the traditional cuff pressure measurement method of the two cuff shapes were compared with the corrected target value of 28 cm H2O, and the differences were statistically significant (P < 0.000). Both in vitro and clinical study had shown that all differences between the actual measured value and the corrected target value using the modified cuff pressure measurement method (measured with 25 cm H2O, 30 cm H2O, 32 cm H2O) were statistically significant (P < 0.000), and the range of overall differences was (0–1.23 ± 0.25) cm H2O. In vitro study had shown that the pressure variation coefficient (CV) of the tapered cuff was greater than that of the cylindrical cuff, and the difference was statistically significant (3.08 ± 0.25 VS 2.41 ± 0.21, P < 0.000). The traditional cuff pressure measurement method can directly lead to the cuff pressure drop, which is easy to cause the leakage of secretions on the cuffs and the misjudgment of the cuff pressure by medical personnel. However, the modified cuff pressure measurement method can effectively reduce cuff pressure loss, and taking the actual cuff pressure value as the inflation volume is the highest measurement accuracy.The tapered cuff is more susceptible to air volume, so it is necessary to pay attention to its measurement and correction in clinical practice.

The technology for the measurement of colour rendering and colour quality is not new, but many parameters related to this issue are currently changing. A number of standard methods were developed and are used by different specialty areas of the lighting industry. CIE 13.3 has been the accepted standard implemented by many users and used for many years. Light-emitting Diode (LED) technology moves at a rapid pace and, as this lighting source finds wider acceptance, it appears that traditional colour-rendering measurement methods produce inconsistent results. Practical application of various types of LEDs yielded results that challenged conventional thinking regarding colour measurement of light sources. Recent studies have shown that the anatomy and physiology of the human eye is more complex than formerly accepted. Therefore, the development of updated measurement methodology also forces a fresh look at functioning and colour perception of the human eye, especially with regard to LEDs. This paper includes a short description of the history and need for the measurement of colour rendering. Some of the traditional measurement methods are presented and inadequacies are discussed. The latest discoveries regarding the functioning of the human eye and the perception of colour, especially when LEDs are used as light sources, are discussed. The unique properties of LEDs when used in practical applications such as luminaires are highlighted.

In this paper, the carbide tool wear in micro milling is investigated and a new tool wear measurement method is proposed. Al7075 alloy and C45 steel is used as the work-piece materials due to their common application. The cutting tools with different machining time are obtained by experiments and the states of tool wear with different work-piece materials are compared. The influence of tool wear on micro milling forces and surface topographies is studied through experiments. The traditional tool wear measurement methods based on the tool edge radius, tool diameter and flank wear width are introduced. For a more complete explanation of the tool wear, a new tool wear measurement method based on the wear area is proposed. The carbide tool wear values based on the tool edge radius, tool diameter, and flank wear width and wear area are measured and the tool wear process is obtained. Compared with the traditional methods, the new tool wear measurement method based on the wear area can explain the tool wear process more reasonable.

This paper introduces a new colorimetric measurement method for the transition width of the precision approach path indicator. The measurement system consists of a spectrometer, a fiber probe, a moving means and a ruler. The spectrometer is used to measure the chromaticity coordinates to distinguish the white and red light. The fiber probe is the input of the spectrometer. It is fixed to the moving means, which can move along with the upright rule. The precision approach path indicator certain distance away projects the light to the fiber probe. By moving the fiber probe crossing the transition sector up and down, the chromaticity coordinate of the light moves from the white area to the red area. The intermediate distance of the fiber probe is the width of the transition sector. Use the ruler to measure it and then calculate it to angle. With the measurement distance of 10 meter and the precision of the ruler 1 millimeter, the precision of the system can be 21 seconds of arc. Compared with the traditional measurement methods, the method introduced in this paper is more precise and it strictly accords with the ICAO standard Annex 14.

The software industry is always striving for new technologies to improve the productivity of software and meet the requirement of improving the quality, flexibility, and scalability of systems. In the field of software engineering, the software development paradigm is shifting towards ever-increasing flexibility and quality of software products. A measure of the quality of software is therefore essential. Measurement methods must be changed to accommodate the new paradigm as traditional measurement methods are no longer suitable. This paper discusses the significant measurement factors as they relate to agent-based systems, and proposes some metrics suitable for use in agent-based systems.