New Method For Measurement Research Articles

A new method for measurement of motor unit action potential duration based on correlation, a pilot study.

We present a new, automatic, correlation-based method for measuring the duration of motor unit action potentials (MUAPs). The method seeks to replicate the way an expert elctromyographer uses his or her eyes, calculating the start and end of the MUAP waveform on the basis of the degree of similarity of non-excluded discharges. We analysed 68 potentials from normal deltoid muscles during slight contraction. For each MUAP, two experienced electromyographers manually determined start and end marker positions, which were used as gold standard duration positions (GSP) in our subsequent tests. The novel method was compared with Nandedkar's method and a wavelet transform-based method. To compare the three methods, the differences between the automatic marker positions and GSPs were statistically evaluated using one-factor ANOVA, the estimated mean square error, and a Chi-square test on the numbers of automatic marker placements with gross errors. All these parameters showed smaller values for the novel method and in most of the cases were statistically significant. In addition, the parameters of the new method were subjected to a sensitivity study, showing its good performance within a range of clinically useful parameter values. The new automatic method determined start and end markers in a more accurate and reliable manner than both of the acknowledged state-of-the art methods used in our comparison study. Graphical abstract The description of a new automatic duration measurement algorithm based on the similarity among discharges of the same MUAP. This method gave better results than the Nandedkar method and a highly regarded wavelet-based method. The new correlation-based method also had the lowest rate of gross aberrant errors in automatic placements.

A new method for measurement of lithium isotopes with nuclear applications

Extreme isotope abundance ratios occur naturally, but also result from enrichment processes required for various industrial applications. The range of elements used for these industrial applications spans essentially the entire periodic table; thus, the need for a low cost (both in labor and finance) analytical technique to measure isotopic enrichments that create extreme isotope abundance ratios has never been greater. Molten salt reactors are one such application, where high purity 7Li is required for cooling processes due to its low neutron cross-section compared to 6Li. Several new technologies are required for these reactors to be viable, both technically and financially, including an efficient method for enrichment of 7Li. Many methods are being tested, but there is a need for a high-performance, high-throughput method for determination of extreme lithium isotope abundance ratios. High abundance sensitivity mass spectrometry provides a path forward for measurement of lithium isotopes. Here, we present a new method for measuring enriched lithium isotope ratios by using multi-collector inductively coupled plasma mass spectrometry and combined faraday-ion counting detectors. We carefully characterize the abundance sensitivity and background signals associated with combined Faraday-ion counting techniques. To test the accuracy of the method, we measured lithium isotopic compositions of a suite of pure lithium salts using the standard static faraday measurement and compare those results to isotope ratios measured using the new method. Isotope ratios of the two techniques agree to within 1.5‰. We also achieved 7Li isotope abundance for a previously characterized enriched lithium salts within 0.0035%, indicating that the technique will provide a way forward for measuring enriched lithium isotope ratios in nuclear materials. The technique can be applied to any element with unnatural isotopic compositions and/or extreme abundance ratios.

A new method for measurement and quantification of tracer diffusion in nanoconfined liquids.

We report development of a novel instrument to measure tracer diffusion in water under nanoscale confinement. A direct optical access to the confinement region, where water is confined between a tapered fiber and a flat substrate, is made possible by coating the probe with metal and opening a small aperture (0.1 μm-1 μm) at its end. A well-controlled cut using an ion beam ensures desired lateral confinement area as well as adequate illumination of the confinement gap. The probe is mounted on a tuning-fork based force sensor to control the separation between the probe and the substrate with nanometer precision. Fluctuations in fluorescence intensity due to diffusion of a dye molecule in water confined between the probe and the sample are recorded using a confocal arrangement with a single photon precision. A Monte Carlo method is developed to determine the diffusion coefficient from the measured autocorrelation of intensity fluctuations which accommodates the specific geometry of confinement and the illumination profile. The instrument allows for measurement of diffusion laws under confinement. We found that the diffusion of a tracer molecule is slowed down by more than 10 times for the probe-substrate separations of 5 nm and below.

THE CONCEPT OF A FLYING ELECTROMAGNETIC FIELD MEASURING PLATFORM

Nowadays, humans are surrounded by more and more devices that artificially generate an electromagnetic field. According to law, supervision of the level of the electromagnetic field requires specific measurements. Measurement performed by traditional methods have several limitations, which come from the infrastructure and time taken to perform the measurement. New methods of measurement are being developed in order to execute the research relatively quickly and repeatedly without any limitations. One of the methods is to use a flying mobile measurement platform.

Measuring rock surface strength based on spectrograms with deep convolutional networks

One of the most widely accepted field methods used by geological engineers to measure rock surface strengths is by striking a rock with a geological hammer and using the emitted sound frequencies to determine strength. While the method is a convenient, it is also subjective. To this end, we propose a new method of measurement based on spectrograms using deep convolutional networks. The spectrograms collected through striking rocks with a geological hammer is the input variable to a deep learning model, which is the Inception-v3 model in this study and has a 93% classification accuracy. We then introduced a probability matrix and an error correction model to estimate the surface strength of rocks from the classification results. The experimental results show our method has high potential to underpin the implementation of efficient and objective measurements of rock surface strength in the field.

Comparative analysis of the Lang Stereopad in a non-clinic population

ABSTRACTAim: New methods of measurement require testing to evaluate test validity. This study compares stereoacuity results of the Lang Stereopad to other common clinical stereoacuity assessments in a normal vision population.Methods: A prospective cross-sectional study was conducted comparing the Lang Stereopad stereoacuity results to results from the Lang II, Frisby, and TNO stereo tests. Mean stereoacuity values and their correlation with inter-ocular visual acuity difference were compared for each stereo test.Results: 98 subjects (mean age of 33.5 years, SD 14.1; 39 males and 59 females) with normal parameters of visual function underwent multiple stereotest assessments. Median stereoacuity values were the lowest (i.e. more detailed stereoacuity) when using the Frisby stereotest (median 40”; 20–170” [minimum-maximum]) and TNO stereotest (median 60”; 15–480”). In comparison, medians were about double at 100” (50–800”) for the Lang Stereopad and greater at 200” (200–200”) for the Lang II stereotest. There was no correlation for each stereotest with interocular visual acuity differences.Conclusions: The Lang Stereopad test is easy to administer and it has certain advantages such as no requirement for additional test glasses. It is a useful assessment to add to the clinical armamentarium for binocular assessment of stereopsis. The Lang Stereopad does not agree well with other stereo tests such as the TNO and Frisby but provides a greater stereoacuity test range than the Lang II. The Lang Stereopad now requires testing in a clinical population in which stereoacuity is a pre-requisite part of the assessment.

A New Method for Grounding Resistance Measurement Based on the Drained Net Charge

This paper presents a new method for measuring grounding resistances, which is based on the measured net charge drained by the grounding system when excited by an impulse generator. The circuit property used by the method is briefly described, alongside with the method itself. An advantage of this method with respect to the traditional ones is that it is not affected by the self and mutual reactances present in the grounding system and in the measuring wires. Moreover, the proposed method does not require the measurement of surface potentials, which are prone to interference due to soil non-homogeneities, buried conductive bodies, and stray currents. This paper presents experimental results from the method using lumped components and using actual grounding systems. The results show that the method provides consistent and accurate values of grounding resistances.

Circular fringe projection technique for out-of-plane deformation measurements

Fringe projection is a widely used technique for measurement of out-of-plane deformation of diffusely reflecting objects. Among the various fringe patterns employed for projection, usage of linear fringes is most common. However, the phase function of linear fringes has 2π periodicity, thereby leading to ambiguity in determining whole-field out-of-plane deformation of dynamic objects. This paper presents a new method of measurement of whole-field out-of-plane deformation of targets by projecting a circular fringe pattern. New technique of fringe analysis is introduced to estimate the underlying phase distribution of the fringe pattern from a single image. In this technique, the fringe pattern is coordinate transformed into polar coordinates, and then Fourier fringe analysis technique is employed to obtain its phase. Subsequent to unwrapping, the phase map is re-transformed to Cartesian coordinates. The phase map obtained after coordinate transformation is converted to out-of-plane deformation map using camera calibration parameters. Simulations are carried out to establish the analysis method. Experimental validation is performed with the development of circular grating based fringe projection system.

Polarization effects in nonlinear interference of down-converted photons.

We study polarization effects in the nonlinear interference of photons generated via frequency nondegenerate spontaneous parametric-down conversion. Signal and idler photons, which are generated in the visible and infrared (IR) range, respectively, are split into different arms of a nonlinear Michelson interferometer, and the interference pattern for signal photons is detected. Due to the effect of induced coherence, the interference pattern for the signal photons depends on the polarization rotation of idler photons, which are introduced by a birefringent sample. Based on this concept, we realize two new methods of measuring sample retardation in the IR range by using well-developed and inexpensive components for visible light. The methods' accuracy reaches specifications that are reported for industrial-grade optical elements. The developed IR polarimetry technique is relevant to material research, optical inspection, and quality control.

Electric charge flow in linear circuits

This paper deals with a fundamental property of circuits that can simplify certain analysis, bring new methods of measurements and possibly other applications, which has apparently passed unnoticed until now. It shows that the net charge injected by an arbitrary source into a linear circuit is divided among the circuit branches (including transmission lines) in the same proportion as the charge would divide among the same branches, if the circuit was replaced by its equivalent circuit at direct current (DC). The DC equivalent circuit alone will govern the exact sharing of the net charge, despite current oscillations caused by reactive elements or propagation effects of transmission lines. In this paper, this property is demonstrated analytically and proved by computer simulations and laboratory experiments. The paper also exemplifies its application in the calculation of the net charge distribution among the conductors of an installation struck by lightning. Finally, the paper forecasts other possible applications for the new circuit property.

НОВЫЕ СРЕДСТВА ИЗМЕРЕНИЯ МЕЖРЕГИОНАЛЬНЫХ РАЗЛИЧИЙ

The article proposes new methods of measurement of differences between of RF regions economic development level. Currently, indicators are used for comparison such as mean, median and mode. And the choice of three options is carried out not on formal criteria, but on the basis of general reasoning. The authors propose to build a system of comparisons on the basis of Bregman divergences. They are already beginning to be used when comparing regions by biologists. These measures have not yet been applied in economic analysis. The divergence of Kulback-Leibler (KL-divergence) is investigated, primarily, the variant of the Bregman divergence. Pairwise comparisons of the level of immigration to the regions as a criterion of quality of measurement of differences are proposed. The main calculations are made on the example of the level of wages in the regions of the South of Western Siberia. The conclusion is made about the prospects of using the existing variants of Bregman divergence, as well as about the possibility of developing new divergence options that best match the comparative attractiveness of the regions for immigrants.

Suitability of time domain reflectometry (TDR) for moisture content monitoring in historic building walls

Measuring moisture content in building materials is crucial for the correct diagnosis of buildings pathologies, for the adoption of appropriate intervention measures and for the efficiency evaluation of the treatment solutions applied. There are several different techniques available to measure and monitoring the moisture content in building materials. However, it still remains a great challenge to perform those studies in historical buildings, since minor-destructive techniques are required. Furthermore, if continuous moisture content readings in space are desired, in order to study the moisture transfer phenomenon along the wall thickness, the challenge is even greater. The TDR technique is a relatively new method for measurement of moisture content in building materials with a set of unexplored potentialities capable of satisfying the two mentioned requirements. In this paper, the suitability of the TDR technique to obtain continuous cross-section moisture content profiles has started to be tested on two limestone prototype walls. Each wall was equipped with four TDR probes, designed practically with the same length of the wall thickness and placed at different heights. All the necessary equipment, installation steps, and difficulties are here presented. The preliminary results suggest that the TDR technique is suitable for moisture content monitoring in consolidated porous building materials.

Comparative analysis of several methods for blood pressure measurement in the morning in patients with arterial hypertension

Aim. To compare the known methods of blood pressure (BP) measurement in the morning and a new method for estimating the average morning BP for fixed time intervals, comparing their reproducibility and validity.Material and methods. We analyzed database containing 983 cases of ambulatory blood pressure monitoring (ABPM). Results of ABMP in patients with hypertension without severe associated diseases and weekly cancellation of antihypertensive therapy were analyzed. Blood pressure data per 24-hour period, day and night, level and rate of morning BP surge were assessed. In addition, we proposed new method for estimating the average morning BP level for fixed time intervals, based on calculating the average BP level for the following time windows: from 5:00 to 7:00 a.m., from 7:00 to 9:00 a.m., from 9:00 to 11:00 a.m. To assess the reproducibility of the new method, we determined correlations between the first and second group results calculated by the new method based on two repeated ABPM conducted with 1-2 weeks interval (n=90). To study the validity of the new method for measurement of average morning BP level, we used an objective validation criterion — Left Ventricular Myocardium Mass Index (LVMMI). There were performed 98 echocardiographic tests with the use of Acuson 128XP. LVMMI was calculated using the L. Teichholtz method (1976).Results. The new method for measurement of average morning BP level had good reproducibility while the reproducibility of dynamic showings of ABMP (level and rate of morning BP surge) was low. A new method for assessing morning blood pressure was characterized by a high level of validity: the indicators obtained using this technique reliably correlated with the validation criteria: LVMI and the average daily blood pressure level.Conclusion. The proposed new method for estimating the average morning level of blood pressure has a high level of validity and reproducibility. Time interval from 7 to 9 a. m. seems to be the most optimal. The maximum reproducibility of the showings was noted during this period.

A New Method of Semi-automated Measurement of Shear Friction Coefficient

The paper is intended for engineer laboratory teaching and measurements in production engineering. The aim is a new method of measuring using the semi-automated measuring set and presenting the results of static shear friction coefficients and kinetic shear friction coefficients, depending on the relatively low speeds of the uniform translational movement of the body. In the framework of a specific engineering task, the methodological questions concerning the interpretation of measurement results in the context of engineering physics and its teaching are solved.

High Resolution Clinometers for Measurement of Roll Error Motion of a Precision Linear Slide

This paper proposes a new method for measurement of the roll error motion of a slide table in a precision linear slide. The proposed method utilizes a pair of clinometers in the production process of a precision linear slide, where the roll error motion measurement will be carried out repeatedly to confirm whether the surface form errors of slide guideways in the linear slide are sufficiently corrected by hand scraping process. In the proposed method, one of the clinometers is mounted on the slide table, while the other is placed on a vibration isolation table, on which the precision linear slide is mounted, so that influences of external disturbances can be cancelled. An experimental setup is built on a vibration isolation table, and some experiments are carried out to verify the feasibility of the proposed method.

A new method for measurement of the size of subacromial spurs of the shoulder by cassette tilt view.

Subacromial impingement syndrome is one of the most common causes of pain in the shoulder. To this date, there is no specific radiographic view that can be used to evaluate the size of a subacromial spur. This study aims to examine a cassette tilt view can be used to evaluate the size of a subacromial spur. A cross-sectional study was conducted between the time period of January 1, 2016, and December 31, 2016. Forty-three consecutive patients that had planned treatment of arthroscopic subacromial decompression (SAD) participated in this study. Rockwood view and cassette tilt view (caudal tilt 30 with beam and cassette) X-rays were done in all these patients. The measurements of the spur sizes were calculated from both views and were compared to the spur sizes measured intraoperatively. The size of the spurs from intraoperative measurement was not significantly different from the spur size measured using the cassette tilt view with a mean difference of 0.54 (95% confidence interval (CI): - 0.58, 1.65), but the intraoperative measurement was significantly different from the Rockwood view spur measurement, with a mean difference of 2.84 (95% CI: 1.56, 4.11). Average proportions of the size of the spur from the cassette tilt and Rockwood view compared to that from intraoperative measurements were 1.09 and 1.55, respectively. The cassette tilt view is a simple method of measurement of the size of subacromial spurs, with good inter- and intra-observer reliabilities and good validity. This can be useful clinically when setting the patient position and portals to evaluate the size of the spur when planning SAD. This is level III.

Pelvic obliquity and measurement of hip displacement in children with cerebral palsy

Background and purpose — Pelvic obliquity, common in individuals with cerebral palsy (CP), changes the muscle force vector on the hip joint and probably affects the risk of hip dislocation. We evaluated a new method for measurement of hip displacement in CP that takes the pelvic obliquity into account: the pelvic adjusted migration percentage (PAMP).Children and methods — From the Swedish surveillance program for cerebral palsy (CPUP), the first pelvic radiograph of 268 children <18 years in southern Sweden during a 3-year period were evaluated. Pelvic obliquity, PAMP, and the migration percentage (MP) were measured. 50 radiographs were randomly selected for analysis of interrater reliability by three raters using the intraclass correlation coefficient (ICC). The correlations between PAMP/MP and pelvic obliquity were analyzed with Pearson correlation coefficients.Results — The interrater reliability for all 3 measurements was high (ICCs 0.88–0.97). The correlation between the high side of the pelvic obliquity and the difference between right and left hip displacement was higher for PAMP (r = 0.70) than for MP (r = 0.41).Interpretation — The new PAMP measurement showed high interrater reliability and a higher correlation with pelvic obliquity than MP. We suggest the use of PAMP at least in hips with a pelvic obliquity exceeding 5°.

Location of reinforcement and moisture assessment in reinforced concrete with a double receiver GPR antenna

Ground Penetrating Radar (GPR) is a popular technique in Civil Engineering for non-destructive investigations and more especially for the diagnosis of reinforced concrete structures. Its main applications are for the location of reinforcement and for measuring the thickness of elements. The advantage of GPR compared to other techniques, such as the use of a covermeter, is its rapidity of measurement, which allows large surfaces to be covered in a shorter time than with magnetic techniques. However, in a comparison with covermeters, the main disadvantage of GPR is the difficulty of accurately assessing the depth of reinforcement without advanced processing, or/and calibration.In this study, we propose a new methodology for GPR measurement and processing that allows accurate location of reinforcement in depth and an assessment of wave velocity inside the cover concrete at the same time. The new method of measurement employs a double offset configuration by using two bi-static antennas.A specific algorithm was developed for the determination of reinforcement depth and velocity inside cover concrete at the same time. The algorithm is tested on a 3 m × 3 m reinforced concrete slab with cover thickness ranging from 15 to 80 mm. With the algorithm, it is possible to measure the depth of reinforcement to within less than 2 mm, whatever concrete thickness.By using a calibration procedure specifically developed in this study, the velocity can be used to assess the water content inside cover concrete with a core conditioned at different moisture contents. A conversion model is obtained between water content and velocity measured by transmission, which can be used at different places in the structure to assess moisture.

Investigating the Effects of Cement Type and W/C Ratio on the Concrete Corrosion Using the Electrical Resistance Assessment Method

Today, concrete is known as the most widespread material in civil projects. Up to now, many research works have been conducted concerning determination of concrete durability using various methods including the measurement of electrical resistance in concrete. The present article is an attempt for application of a new method for measurement of electrical resistance of non-conductive materials which is well suited for concrete. To determine the effects of cement type and water to cement ratio on the corrosion phenomenon the electrical resistance method was used. For this purpose use was made of 7 different water to cement ratios and two types of cement (type 2 and type 5). Drawing the electrical resistance diagrams, it was shown that with increase in the water to cement ratio, corrosion rate increases in concrete. Also application of type 5 cement results in a higher strength resistance with respect to cement type 2. On the other hand by increase in the age of concrete specimens, they showed greater resistance to the corrosion attacks.

A New Method for Measuring the Pressure Increase in Energetic Compositions in a Maximally Filled Container

A new method for direct measurement of the pressure increase in energetic compositions (propellants, powders, and explosives) upon thermal decay of energetic samples is described. This method is applicable to the control of the decay kinetics of elastic compositions during long-time storage. The testing of this method showed that the error in measuring the pressure increase in the systems under study during long-time storage at a constant temperature and the maximum filling of the reaction container did not exceed 4%.