Classical Measurement Methods Research Articles

KALİBRASYON BAZINDA FARKLI YÖNTEMLERİN MESAFE ÖLÇME HASSASİYETLERİNİN KARŞILAŞTIRILMASI

Satellite-based measurements have been performed on EDM Calibration Base by Classic GPS, Network RTK and Static GPS methods and terrestrial measurements have been conducted with Total Stations in this study. FKP, VRS and MAC correction methods were used in the Network RTK method. The objective of this study was to make statistical comparisons of distances obtained by using all combinations between different measurement methods. Analysis of Variance (ANOVA) was utilized for this purpose. It was determined that there was a statistically significant difference between the measuring methods used in the one-way ANOVA test. The differences and standard deviations obtaind by the comparison of distances based on different measurement methods between benchmarks have been varied from mm to cm. The results obtained by the static GNSS surveying method are better than the standard deviations obtained by other methods of measurement and equipments when compared. The methods according to the distance measurement precision have been listed from the highest precision to low as Static GNSS, terrestrial surveying, classical RTK, FKP, VRS and MAC respectively. The distance measurement precision of Terrestrial measurement was found to be better than the classical RTK and NRTK measurement methods. The distance measurement precision of the classic RTK method was better than NRTK methods obtained by the different correction methods. In comparison, of NRTK correction methods in itself, the best results were obtained by FKP method. Keywords : GNSS, NRTK, MAC, FKP, VRS, Total Station, precision

Method for material characterization in a non-anechoic environment

This paper presents a characterization method for extracting the reflection coefficient of materials and the real part of their permittivity. The characterization is performed in a real environment, as opposed to the classical measurement methods that require an anechoic chamber. In order to reduce the effects of the multipath propagation, a free space bistatic measurement was performed at different distances material-antennas in far field. By using a Teflon sample and a commercial absorbing material sample, measurements have been performed in order to validate the characterization technique.

Identification of the Moisture Distribution in the Intensively Heated Porous Sand Mould

The problem presented in the paper concerns physical properties of porous multi-component mould material, into which a liquid metal is poured. The aim of the study was to determine the distribution of moisture in an intensively heated porous sand mould. In the past, several measuring methods have been developed, consisting in water evaporation out of a test sample (at a given time moment , the selected position coordinates of a sample), to determine the accumulated amount of water in the sample, which is a percentage of moisture content. The study described in the paper includes experiments of heating a green sand sample. Moisture distribution in a moisture transfer zone of the sample (temperature of the molding sand is approx. 100°C) was determined. In order to determine the moisture distribution, an original method was used. This method allows interfere in various layers of material of predetermined thickness, parallel to the surface of the mould in contact with a heat source. The classical measurement method (gravimetric method) was used for determining the moisture content of each layer.

Use of targets to track 3D displacements in highly vegetated areas affected by landslides

Monitoring landslides with terrestrial laser scanning (TLS) is currently a well-known technique. One problem often encountered is the vegetation that produces shadow areas on the scans. Indeed, the points behind a given obstacle are hidden and thus occluded on the point cloud. Thereby, locations monitored with terrestrial laser scanner are mostly rock instabilities and few vegetated landslides, being difficult or even impossible to survey vegetated slopes using this method with its classical non-full wave form. The Peney landslide (Geneva, Switzerland) is partially vegetated by bushes and trees, and in order to monitor its displacements during the drawdown of the Verbois reservoir located at its base, an alternative solution has been found. We combined LiDAR technique with 14 targets made of polystyrene placed at different locations inside and outside the landslide area. The obtained displacements were compared with classical measurement methods (total station and extensometer), showing good resemblance of results, indicating that the use of targets in highly vegetated areas could be an efficient alternative for mass movements monitoring.

Deformation Measurement of a Driven Pile Using Distributed Fibre-optic Sensing

AbstractNew developments in distributed fibre-optic sensing allow the measurement of strain with a very high precision of about 1 µm / m and a spatial resolution of 10 millimetres or even better. Thus, novel applications in several scientific fields may be realised, e. g. in structural monitoring or soil and rock mechanics. Especially due to the embedding capability of fibre-optic sensors, fibre-optic systems provide a valuable extension to classical geodetic measurement methods, which are limited to the surface in most cases.In this paper, we report about the application of an optical backscatter reflectometer for deformation measurements along a driven pile. In general, pile systems are used in civil engineering as an efficient and economic foundation of buildings and other structures. Especially the length of the piles is crucial for the final loading capacity. For optimization purposes, the interaction between the driven pile and the subsurface material is investigated using pile testing methods. In a field trial, we used a distributed fibre-optic sensing system for measuring the strain below the surface of an excavation pit in order to derive completely new information.Prior to the field trial, the fibre-optic sensor was investigated in the laboratory. In addition to the results of these lab studies, we briefly describe the critical process of field installation and show the most significant results from the field trial, where the pile was artificially loaded up to 800 kN. As far as we know, this is the first time that the strain is monitored along a driven pile with such a high spatial resolution.

An Innovative Procedure for the Rolling Noise Evaluation

Noise is often generated by pressure changes in the air induced by mechanical vibrations. The study of these phenomena is known as structural acoustics or, in a more fashionable way, virboacoustics. Vibroacoustics is the study of the mechanical waves in structures and how they interact with, and radiate into, adjacent media. In railway the most important noise source, based on fluid and structure interaction is the rolling noise. The aim of the paper is the development and implementation of a numerical method for the rail decay rate and combined roughness calculation according to the FprCEN/TR 16891:2015 and a subsequent evaluation of the excess noise level in accordance with the ISO/FDIS 3095: 2013. The tool, as a final results, will make possible the evaluation of the rail parameters without the involvement of long and expensive test campaign based on classical roughness measurement methods and will permit the compensation of the roughness induced excess noise level for a comparative comprehension of the acoustic experimental data.

A new method to determine dissolved CO 2 concentration of lakes Nyos and Monoun using the sound speed and electrical conductivity of lake water

Abstract A new method to measure the CO 2 concentration in lakes Nyos and Monoun using sound speed (SS) and electrical conductivity (EC) of the lake water was developed. Limnic eruptions at lakes Monoun and Nyos in Cameroon, characterized by a risk related to possible sudden release of magmatic CO 2 gas dissolved in the lake water, occurred in 1984 and 1986 respectively, killing about 1800 residents. CO 2 monitoring of the lake waters was initiated to prevent further disasters. Classical methods of CO 2 measurement, which require chemical analysis of water samples, are not suitable for frequent and multi-point monitoring. Inspired by the method of measuring salt concentration using SS, we obtained data for dissolved CO 2 (CO 2 (aq) ) assuming the following formula Δ v = k 1 [ C O 2 ( aq ) ] + k 2 [ HCO 3 − ] , where Δ v is additional SS due to dissolved ions and k 1 and k 2 are coefficients determined through experiments. The coefficient k 1 was determined with temperature T (°C) dependence as 0.0323–0.000523 T [l m s −1 mmol −1 ]. k 2 was estimated to be 0.132 at Lake Nyos and 0.0930 at Lake Monoun. Once k 1 and k 2 values are obtained, [CO 2(aq) ] and [ HCO 3 − ] are calculated using the SS, T and EC.

Contactless Measurement Of Rectilinearity Of An Elongated Object Based On The Example A Crane Rail

Abstract The common aim of engineering surveys is to determine deviations from rectilinearity for elongated objects. We have developed a number of methods for measuring points that represent an elongated object. These are the constant straight (optical, laser, mechanical-string) method, the trigonometric method, geometric levelling method, photogrammetric methods and terrestrial laser scanning. When taking these measurements, it is crucial to have a direct access to the survey points of the measured object. Factors impeding the measurements include: adverse lighting conditions, vibration, dust, refractory effects, lack of direct access to the survey points, etc. The authors have developed a measurement methodology and designed a measuring set for taking measurements that enable to determine the location of survey points on an elongated object. The measurement is based on the constant straight method and the measuring set consists of the horizontal levelling staff and two laser pointers. The measuring set relies on the angular intersection (fixed angle) method. Intersection occurs when two laser beams meet. To determine the location of the survey point indicated by the mentioned laser beams, we used levelling staff readings taken with the surveying instrument that establishes the reference constant straight. Experimental studies carried out in the laboratory and in the field helped to determine the accuracy of measurements taken with the designed measuring set (the accuracy was below ± 1 mm) and revealed that this accuracy is comparable to accuracies achieved with famous classical measurement methods.

Is the second harmonic method applicable for thin films mechanical properties characterization by nanoindentation?

The second harmonic method is a dynamic indentation technique independent of the direct indentation depth measurement. It can be used to determine near-surface mechanical properties of bulk materials more precisely than classical dynamic nanoindentation. In this paper, the second harmonic method is extended to the measurement of the mechanical properties of thin poly(methyl methacrylate) (PMMA) layers deposited onto silicon wafers. It is shown that this new technique gives precise results at small depths (less than 100 nm), even for films with a thickness lower than 500 nm, which was not possible to achieve with the classical continuous stiffness measurement method. However, experimental and numerical results obtained both with classical nanoindentation and second harmonic methods differ at high indentation depth. Using finite element (FE) simulations and AFM measurements, it is shown that the contact depth calculation with classical models can explain this difference.

Performance Measurement of Logistics Service Supply Chain Using Bijective Soft Set

In the logistics service supply chain (LSSC), performance measurement is an important approach that can improve competitiveness of the overall supply chain. In the complicated measurement system, it includes various quantitative and qualitative indices with uncertain problems. However, classical measurement methods were based on subjective suggestion to weigh each index in the measurement system; moreover, there is no well-established performance measurement system (PMS) for evaluation of LSSC. For those reasons, this paper aims to present Bijective soft set approach to deal with the performance measurement of LSSC, which ensures the objective of the weight of each index and gets the core indices of the PMS. Based on the overall LSSC operation, customer service, and corporate management — the three parts in the proposed system of LSSC — the indices, and consistency of the metrics have been selected. Finally, an empirical analysis of developed framework for performance measurement is conducted and tested.

Prediction of Sky and Surface Wave Radiation of a Wideband HF Antenna

In this letter, the prediction of the radiation of wideband HF antennas is investigated. The ground upon which they are placed mainly influences the sky wave and the surface wave mode radiated by these antennas. Classical methods of simulation or measurement applied to microwave radiating structures are not suitable for this kind of antenna. Thus, this letter proposes a method to perform a near field to far field transformation, adapted to the problem of interest, and based on a power criterion. This criterion requires both the electric and magnetic near fields, but by using an appropriate approximation, it is possible to assert that only the measurement of the electric near field is required. Far field radiation has been computed at two different frequencies within a bandwidth of 1.3:1 (28.5%).

Sampling based State of Health estimation methodology for Li-ion batteries

Storage and management of energy is becoming a more and more important problem every day, especially for electric and hybrid vehicle applications. Li-ion battery is one of the most important technological alternatives for high capacity energy storage and related industrial applications. State of Health (SoH) of Li-ion batteries plays a critical role in their deployment from economic, safety, and availability aspects. Most, if not all, of the studies related to SoH estimation focus on the measurement of a new parameter/physical phenomena related to SoH, or development of new statistical/computational methods using several parameters. This paper presents a new approach for SoH estimation for Li-ion battery systems with multiple battery cells: The main idea is a new circuit topology which enables separation of battery cells into two groups, main and test batteries, whenever a SoH related measurement is to be conducted. All battery cells will be connected to the main battery during the normal mode of operation. When a measurement is needed for SoH estimation, some of the cells will be separated from the main battery, and SoH estimation related measurements will be performed on these units. Compared to classical SoH measurement methods which deal with whole battery system, the proposed method estimates the SoH of the system by separating a small but representative set of cells. While SoH measurements are conducted on these isolated cells, remaining cells in the main battery continue to function in normal mode, albeit in slightly reduced performance levels. Preliminary experimental results are quite promising, and validate the feasibility of the proposed approach. Technical details of the proposed circuit architecture are also summarized in the paper.

Quantum estimation of the Schwarzschild spacetime parameters of the Earth

We propose a quantum experiment to measure with high precision the Schwarzschild space-time parameters of the Earth. The scheme can also be applied to measure distances by taking into account the curvature of the Earth's space-time. As a wave-packet of (entangled) light is sent from the Earth to a satellite it is red-shifted and deformed due to the curvature of space-time. Measurements after the propagation enable the estimation of the space-time parameters. We compare our results with the state of the art, which involves classical measurement methods, and discuss what developments are required in space-based quantum experiments to improve on the current measurement of the Schwarzschild radius of the Earth.

Comparison of classical and two-stage methods of Barkhausen noise measurement

The purpose of the article was to investigate properties of the two-stage methods of the Barkhausen noise (BN) measurement used in non-destructive testing. The principle of the two-stage method is based on subtraction of two successive instances of the electromotive force (EMF) signal with the same non-stochastic (continuous) component. The subtraction can be accomplished in a hardware (hardware two-stage method) or in a software (software two-stage method). The experiments proved that, with these methods, we are able to significantly suppress the dominant continuous component from the induced EMF signal without using filters and thus simplify the measurement. On the other hand, with the classical one-stage method, to achieve similar suppression of the continuous component and, simultaneously, to not suppress the BN, it was necessary to adjust the cut-off frequency of the high-pass filter.

A Visual Obstruction Method to Estimate Wet Meadow Aboveground Biomass in Marshes of the Boreal Plains, Canada

Vegetation aboveground biomass, a measure of net primary productivity, is an important indicator of ecosystem health. We sought a rapid but accurate, non-destructive alternative to traditional aboveground biomass dry-weight measurement for natural and constructed wetlands in the Boreal Plains Ecoregion of Alberta. We sampled 16 wetlands in 2008 during the period of peak aboveground biomass, using the classic biomass measurement method of clipping, drying, and weighing standing vegetation, as well as a visual obstruction measurement technique called Robel height. Visual obstruction has been used extensively in grassland assessments; however, its use in wet meadow marshes of the Boreal Plains has not previously been reported. To evaluate the effectiveness of visual obstruction in estimating aboveground biomass we used general linear modeling, and found a strong and highly significant relationship (R2 = 0.68, F1.94 = 195.5, p < 0.000001). Power analyses indicated that a nine replicate sample would provide a power of 0.85 to distinguish a visual obstruction difference of 30 cm between two samples. Visual obstruction measurement took considerably less time than clipping, drying, and weighing biomass. Our results indicate that visual obstruction is a rapid, reliable, and effective vegetation bioassessment technique in Boreal Plains wet meadow marshes.

Lymph node metastasis in early gastric cancer: evaluation of a novel method for measuring submucosal invasion and development of a nodal predicting index

After endoscopic resection of early gastric cancer (EGC), it is imperative to accurately determine whether follow-up surgery is indicated, since this technique is used as a first line of treatment. Herein, we developed a scoring system to indicate the risk of lymph node metastasis in submucosal EGC (smEGC), and present a novel method to measure depth of submucosal invasion. In our series, 15.9% of the smEGC presented with lymph node metastasis. A nodal prediction index, based on the variables extracted from the univariate analysis and defined as nodal prediction index = (2.128 × lymphovascular tumor emboli) + (1.083 × submucosal invasion width ≥ 0.75 cm) + (0.507 × submucosal invasion depth ≥ 1000 μm) + (0.515 × infiltrative growth pattern), yielded an area under the receiver operating characteristic curve of 0.809 (P =.000, 95% CI = 0.713-0.096) in a training group, and showed comparable result in validation group (0.886, P =.000, 95% CI = 0.796-0.977). Depth of invasion was statistically higher in the metastatic group when measured from the lowest point of an imaginary line in continuity with the adjacent muscularis mucosa to the point of deepest tumor penetration, but not when using the classic measurement method. The area under the receiver operating characteristic curve of the alternative measurement method was 0.652 (P =.013, 95% CI = 0.550-0.754) compared to 0.620 for the classic measurement method (P =.0480, 95% CI = 0.509-0.731). In deciding whether surgery is indicated after endoscopic submucosal dissection for smEGCs, we recommend to test our alternative method of measuring submucosal invasion and to evaluate our nodal prediction index as an adjunct tool.

Turkish translation and adaptation of Champion's Health Belief Model Scales for breast cancer mammography screening

To examine the translation and adaptation process from English to Turkish and the validity and reliability of the Champion's Health Belief Model Scales for Mammography Screening. Its aim (1) is to provide data about and (2) to assess Turkish women's attitudes and behaviours towards mammography. The proportion of women who have mammography is lower in Turkey. The Champion's Health Belief Model Scales for Mammography Screening-Turkish version can be helpful to determine Turkish women's health beliefs, particularly about mammography. Cross-sectional design was used to collect survey data from Turkish women: classical measurement method. The Champion's Health Belief Model Scales for Mammography Screening was translated from English to Turkish. Again, it was back translated into English. Later, the meaning and clarity of the scale items were evaluated by a bilingual group representing the culture of the target population. Finally, the tool was evaluated by two bilingual professional researchers in terms of content validity, translation validity and psychometric estimates of the validity and reliability. The analysis included a total of 209 Turkish women. The validity of the scale was confirmed by confirmatory factor analysis and criterion-related validity testing. The Champion's Health Belief Model Scales for Mammography Screening aligned to four factors that were coherent and relatively independent of each other. There was a statistically significant relationship among all of the subscale items: the positive and high correlation of the total item test score and high Cronbach's α. The scale has a strong stability over time: the Champion's Health Belief Model Scales for Mammography Screening demonstrated acceptable preliminary values of reliability and validity. The Champion's Health Belief Model Scales for Mammography Screening is both a reliable and valid instrument that can be useful in measuring the health beliefs of Turkish women. It can be used to provide data about healthcare practices required for mammography screening and breast cancer prevention. This scale will show nurses that nursing intervention planning is essential for increasing Turkish women's participation in mammography screening.

Implementation of Fixed Sampling Period M/T Method Based on VHDL

Take insufficiency of classical velocity measurement methods into consideration, this paper introduces a method which has a good test accuracy in a wide range, fixed sampling period M/T method, to determine velocity and position information of the encoder. Firstly, its measurement principle is analyzed in detail through logic and timing relationship. Then realization of every module is achieved with VHDL. Finally, ModelSim is used to simulation and test to verify the correctness of the method. In the future, it can be widely used in practical applications.

Multisensor Railway Track Geometry Surveying System

Linear variable differential transformers (LVDTs) and inclinometers are widely used in many industrial establishments, particularly in the metrology area. These sensors are used by many engineering disciplines because of their high-precision characteristics. In addition, Global Navigation Satellite System (GNSS) receivers and total stations are widely used in geodesy. Using GNSS receivers is very popular, particularly for navigational purposes. In this paper, a new railway track geometry surveying system, which is designed by integrating the LVDT, inclinometer, GNSS receiver, and total station, is introduced. This new surveying system is an alternative to classical geodetic measurement methods that are often used for controlling the railway track geometry. Track gauge, super-elevation, gradient, and track axis coordinates, which are railway geometrical parameters, can be instantly determined while making measurements by using the new surveying system.

Application of SH surface acoustic waves for measuring the viscosity of liquids in function of pressure and temperature

Viscosity measurements were carried out on triolein at pressures from atmospheric up to 650 MPa and in the temperature range from 10 °C to 40 °C using ultrasonic measuring setup. Bleustein–Gulyaev SH surface acoustic waves waveguides were used as viscosity sensors. Additionally, pressure changes occurring during phase transition have been measured over the same temperature range. Application of ultrasonic SH surface acoustic waves in the liquid viscosity measurements at high pressure has many advantages. It enables viscosity measurement during phase transitions and in the high-pressure range where the classical viscosity measurement methods cannot operate. Measurements of phase transition kinetics and viscosity of liquids at high pressures and various temperatures (isotherms) is a novelty. The knowledge of changes in viscosity in function of pressure and temperature can help to obtain a deeper insight into thermodynamic properties of liquids.