Improved Method For Measurement Research Articles

Combining Lexical and Semantic Features for Short Text Classification

In this paper, we propose a novel approach to classify short texts by combining both their lexical and semantic features. We present an improved measurement method for lexical feature selection and furthermore obtain the semantic features with the background knowledge repository which covers target category domains. The combination of lexical and semantic features is achieved by mapping words to topics with different weights. In this way, the dimensionality of feature space is reduced to the number of topics. We here use Wikipedia as background knowledge and employ Support Vector Machine (SVM) as classifier. The experiment results show that our approach has better effectiveness compared with existing methods for classifying short texts.

Improving Measurement Methods in Rehabilitation: Core Concepts and Recommendations for Scale Development

Velozo CA, Seel RT, Magasi S, Heinemann AW, Romero S. Improving measurement methods in rehabilitation: core concepts and recommendations for scale development.Validated measurement scales are essential to evaluating clinical outcomes and conducting meaningful and reliable research. The purpose of this article is to present the clinician and researcher with a contemporary 8-stage framework for measurement scale development based on a mixed-methods qualitative and quantitative approach. Core concepts related to item response theory are presented. Qualitative methods are described to conceptualize scale constructs; obtain patient, family, and other stakeholder perspectives; and develop item pools. Item response theory statistical methodologies are presented, including approaches for testing the assumptions of unidimensionality, local independence, monotonicity, and indices of model fit. Lastly, challenges faced by scale developers in implementing these methodologies are discussed. While rehabilitation research has recently started to apply mixed-methods qualitative and quantitative methodologies to scale development, these approaches show considerable promise in advancing rehabilitation measurement.

Non-bar, an optical calibration system for five-axis CNC machine tools

Five-axis CNC machine tools comprise three linear axes and two rotary axes, enabling the fabrication of complex workpieces, such as dies, turbo blades, and cams. Improved measurement methods are continually being researched to increase the accuracy of five-axis CNC machine tools. This paper presents a novel optical calibration system, called non-bar, with no linkage bars. The system comprises a master detector module, a ball lens module, and a signal module. The proposed measurement system was implemented according to ISO/CD 10791-6 to measure A-type, B-type, and C-type five-axis CNC machine tools from three different manufacturers. The results demonstrate that the proposed non-bar measurement scheme provides high accuracy, high reproducibility, and simultaneous multi-axis measurement.

The Effect of an Edge on the Measured Scattering Coefficients in a Reverberation Chamber Based on ISO 17497-1

The scattering coefficient has been regarded as one of the important factors to be considered in the acoustic design of a room. ISO 17497-1 provides a method for measuring the random-incidence scattering coefficients in a reverberation chamber. However, the uncertainties of this method due to the lack of details with respect to the measurement conditions have been reported. It is necessary to provide more specific guidelines for this method. The present study suggests an improved measurement method by investigating the edge effects. The scattering coefficients of a simple 1-dimensional diffuser were measured in a 1/5 scale model of the reverberation chamber based on ISO 17497-1. The effects of an edge strip on the scattering coefficients were measured and analysed. Further, several issues with respect to the sample diameter, the air gap below the turntable and the absorption of the test sample were discussed.

Removal of Microconstituents by Adsorption focusing on the Separation of Powdered Activated Carbon

Removal of Microconstituents by Adsorption focusing on the Separation of Powdered Activated CarbonDue to improved measurement methods microconstituents can be detected in the range of nanograms nowadays. These substances can be found ubiquitously in the aquatic environment. Source of these contaminants are industrial and communal waste water treatment plants (WWTP) and the agricultural sector. By adding 10-20 mg/l of powdered activated carbon (PAC) to the WWTP effluents microconstituents can...Author(s)Sebastian PlatzUwe MenzelMartin WettSourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Sep, 2012ISSN1938-6478DOI10.2175/193864712811708239Volume / Issue2012 / 12Content sourceWEFTECCopyright2012Word count192

Diffusion and scattering: An improved method of measuring both at the same time

ISO-17497-1 and ISO-17497-2 describe methods of measuring the properties of diffusers and scattering devices. The result of these measurements is a description of the quality of the diffuser and the quantity of energy scattered. This paper will describe an improved method of measurement that enables both properties being simultaneously measured using the same procedure. The hope is that this method will produce a simplified database mimicking the directivity measurements of sound sources for use in simulation programs and in comparing various diffuser designs.

An improved method for measurement of change in skin roughness caused by cleansing products under mild application conditions

The aim of this study was to develop a method for the evaluation of subtle change in skin roughness caused by cleansing products under mild application conditions using a non-invasive three-dimensional (3D) analysis system. A double-blind comparative study of the modified soap chamber test was performed using two soap bars and a syndet bar. Skin changes were evaluated by visual scoring [mean cumulative irritation index (MCII)] and by bioengineering measurements [transepidermal water loss (TEWL), skin capacitance, and skin surface roughness]. MCII of the syndet bar was statistically higher than that of one soap bar, and TEWL increase after application of the syndet bar was statistically higher than that of both soap bars. Skin capacitance decreased significantly only after application of the syndet bar. The change in the average roughness of the skin surface was significantly greater after the application of the syndet bar than with classic soap bars. A simple, fast, and objective evaluation of skin surface topography was performed using a modified soap chamber test and a non-invasive 3D analysis system. The results suggest that measurement of skin roughness using a non-invasive 3D analysis system might be a good method for the evaluation of a subtle change caused by cleansing products under mild application conditions.

Improvements in the Measurement of Distillation Curves. 5. Reduced Pressure Advanced Distillation Curve Method

The distillation curve is the only practical measurement used to characterize the vapor/liquid equilibrium (volatility) of a complex mixture. In earlier work, we described an improved method and apparatus for measurement of distillation curves at atmospheric pressure, called the advanced distillation curve (ADC) that is especially applicable to the characterization of fuels and complex mixtures. While the ADC method has greatly improved volatility measurements performed at atmospheric pressure, it still encounters problems with applications to fluids of very low volatility. Performing atmospheric pressure distillations on fluids with high boiling temperatures (350 °C−450 °C) can lead to thermal degradation, cracking, or polymerization of the sample. By performing the distillation at reduced pressures, one can reduce such thermal effects by reducing the component boiling temperatures. In this paper, we present a new apparatus and method that provides precise volatility measurements at reduced pressures. This new apparatus allows for nearly complete control of state variables (temperature, pressure, and composition) while volatility measurements are performed and also provides a composition-explicit data channel for each distillate fraction. Volatility measurements using the reduced pressure ADC apparatus were made on multiple samples, including two well characterized validation mixtures and a commercially available soy derived biodiesel fuel. In addition, chemical analyses were performed on the distillate fraction aliquots by use of gas chromatography-mass spectrometry. The results from the reduced pressure ADC were compared to predicted data by use of an equation of state model as well as distillation data measured at atmospheric pressure.

Discrete Cosine Transform Technique for Measuring Domain Widths in Magneto-Optic Garnet Films

One use of engineered magneto-optic garnet thin films is to visualize magnetic patterns with high spatial resolution. Of these engineered films, films with out-of-plane anisotropy exhibiting a stripe domain pattern are found to work well for resolving patterns in digital storage magnetic media. The width of the stripe domains in garnet films has become a performance metric for the films' ability to visualize high spatial-frequency magnetic patterns. Current manual image-based methods for measuring stripe domain width are tedious, complicated, and susceptible to bias and human error. In this paper, an improved measurement method with repeatable precision utilizing the discrete cosine transform is presented and compared with the manual measurement of the same sample image. The measurements were in agreement.

一种改进的三维CT系统射线源焦点投影坐标测量方法

一种改进的三维CT系统射线源焦点投影坐标测量方法

Three-dimensional measurement of fractures in heterogeneous materials using high-resolution X-ray computed tomography

When present, fractures tend to dominate fluid flow though rock bodies, and characterizing fracture networks is necessary for understanding these flow regimes. X-ray computed tomography (CT) has long been successfully used to image fractures in solid samples, but interpretation of CT data is complicated by the inevitable blurring that occurs when fractures are thin compared to the data resolution. This issue is particularly acute when attempting to quantify fine fractures in scans of larger samples, as typically required for characterizing flow systems on a meaningful scale. A number of methods have been proposed to account for CT blurring, but do not include the ability to account for material inhomogeneity and fracture orientation. We here propose an improved method for fracture measurement that consists of characterizing the blurring as a point-spread function (PSF), and using it, in combination with a calibration for the CT number for void space, in an iterative procedure to reconstruct the fracture and material configuration; we call this the inverse PSF (IPSF) method. Tests on CT scans of homogeneous natural samples show that the IPSF method provides more precise results than others. Further testing demonstrates that it can also recover accurate measurements in heterogeneous materials, although particularly severe inhomogeneities may lead to a locally noisy signal. The accuracy, generality, and adaptability of the IPSF method make it very well suited for characterizing fractures and fractures surfaces in natural materials. The principles behind the IPSF method also apply to the reverse problem of measuring thin features that are denser than their surroundings, such as veins or membranes, when they have one dimension that is small compared to CT data resolution.

Hysteresis in traffic flow revisited: An improved measurement method

This paper presents new insights on the hysteresis phenomenon in congested freeway traffic. It is found that existing theories based on different driver behavior for acceleration and deceleration are incomplete. The data suggests that one needs to consider aggressive and timid driver behavior as well. These findings are based on an improved method for measuring traffic flow variables from trajectory data consistently with kinematic wave theory.

Direct Measurements of Protein-Stabilized Gold Nanoparticle Interactions

We report integrated video and total internal reflection microscopy measurements of protein stabilized 110 nm Au nanoparticles confined in 280 nm gaps in physiological media. Measured potential energy profiles display quantitative agreement with Brownian dynamic simulations that include hydrodynamic interactions and camera exposure time and noise effects. Our results demonstrate agreement between measured nonspecific van der Waals and adsorbed protein interactions with theoretical potentials. Confined, lateral nanoparticle diffusivity measurements also display excellent agreement with predictions. These findings provide a basis to interrogate specific biomacromolecular interactions in similar experimental configurations and to design future improved measurement methods.

An improved method for shallow water flow velocity measurement with practical electrolyte inputs

summary The measurement of shallow water flow velocity is of interest to hill-slope hydrology and soil erosion mechanics. Lei et al. [Lei, T., Xia, W., Zhao, J., 2005. Method for measuring velocity of shallow water flow for soil erosion with an electrolyte tracer. Journal of Hydrology 301, 139–145] proposed an electrolyte pulse method for the purpose but found that the velocity measured at short distances from the salt injector was not as well estimated as those further away from the injector, though it is desirable to estimate velocity at short distances for the purpose of portable device development. In this study, the system was improved over the previous development. An additional sensor was added at the salt injection location to register the input signal as the actual boundary condition function instead of using the pulse assumption. Two function forms, a Normal distribution function (Normal Model) and a Sine function (Sine Model) were suggested to approximate the measured boundary conditions. These two determined boundary models were used to fit the experimentally obtained data using the least square method to determine the model parameters of the boundary conditions. The determined Normal Model and the Sine Model were both used to solve the transport processes as the convolution integrals of the pulse response and the actually determined boundary functions, so as to determine the shallow water flow velocity. Laboratory experiments were conducted to get data to verify the proposed methods and computational procedures. The experiment device included a flume, 4 m long and 15 cm wide, a solute injector, a data logger for control and data acquisition and a computer with specially designed software for data measurement and velocity estimation. The experiments involved three flow rates (12, 24 and 48 L min � 1 ) and three slope gradients (4 ,8 and 12). Six sensors were used to measure the solute transport processes at 5, 30, 60, 90, 120 and 150 cm from the location where the salt solute was injected into the water flow. The solutions of both the Normal Model and Sine Model fitted the measured data very well for all the experimental conditions. The velocities at different distances from the salt solution injector and under different flow rates and slope gradients, as computed by the two models were almost identical, which indicated the feasibility of the method and the computational procedures as well as the two suggested models for velocity estimation. The velocity values estimated by the Normal and Sine Models agreed also with those measured by using the floating objects and the volumetric method. These demonstrated the rationality of the improved methods for shallow water flow velocity measurement. The results will be useful to design a practical system for the measurement of shallow water flow velocity.

Improved measurement method for electron energy distribution functions with high accuracy and reliability

An improved ac superimposed method for measuring the electron energy distribution function (EEDF) with high accuracy is proposed. Although high amplitude of the superimposed ac voltage provides a higher signal-to-noise ratio (SNR), it causes the distortion in the EEDF. To correct the distortion, we used two different EEDFs measured by applying two different amplitudes. The distortion was accurately corrected over the entire electron energy region, and the corrected EEDF had the better SNR. The reliability of the corrected EEDF was proved by comparing the effective electron temperatures obtained from the measured EEDFs, and as a result, the corrected EEDF was very reliable.

An improved method for measurement of target-to-background ratio in assessing mediastinal lesions on 18F-FDG coincidence SPECT/CT imaging

Target-to-background ratio (T/B) is a commonly used semiquantitative index in F-FDG dual-head coincidence single-photon emission computed tomography (c-SPECT) imaging. However, because of different methods of measurement, T/B varies. This study used F-FDG c-SPECT/CT imaging of mediastinal lesions to analyze the impact of different backgrounds for determining T/Bs. Thirty-five patients with mediastinal lesions underwent thoracic F-FDG c-SPECT/CT with 1-inch crystals. According to integrated CT, five types of backgrounds were precisely positioned as airway, fat, mediastinal space, vascular blood, and heart areas. Corresponding T/Bs (T/BA, T/BF, T/BM, T/BV, and T/BH) of benign and malignant lesions were calculated. Two-way analysis of variance, receiver-operating characteristic curves, and coefficient of variation were performed for statistical analyses. Seventeen benign lesions and 23 malignant lesions were identified in patients with histological confirmation. Only T/BA was significantly different from other T/Bs in both the benign and malignant groups; yet, there were no significant differences in the remaining T/Bs (P<0.01). On the basis of receiver-operating characteristic curves, cutoff values, sensitivity, specificity, positive predictive value and negative predictive value, the accuracy of diagnosis followed the order of T/BV>T/BM> T/BA>T/BF>T/BH, and T/BV showed optimal sensitivity (87.0%), specificity (76.5%), and accuracy (82.5%) of diagnosis. Vascular blood and mediastinal space areas, which were in the same homogeneous subset, possessed the significantly lowest coefficient of variation, indicating good homogeneity in the regions. Choosing different backgrounds has a great impact on the diagnostic accuracies of F-FDG c-SPECT/CT imaging of mediastinal lesions. The large blood vessel area is the best background choice for optimization of T/B calculation.

Modeling and Measuring Link Capacity in Communication Networks

The capacity of a link is a fundamental parameter in communication networks. Its knowledge is needed for both network planning and management. This is why capacity estimation was one of the first measurement challenges in wired communication networks. In the recent past, some experimental tests permitted imputing the poor performance of capacity measurement techniques in wireless networks to some pitfalls of the capacity model that they are based on. This paper is the natural evolution of those experimental findings. It presents a new multilayer capacity model that is consistent with the classical capacity definition but does not suffer from such pitfalls, along with an improved measurement method based on the deployment of proper software probes. The results of experiments that are conducted on IEEE 802.11x wireless links are also given.

Determination of Reduced Nicotinamide Adenine Dinucleotide Phosphate Concentration Using High-Performance Liquid Chromatography with Fluorescence Detection: Ratio of the Reduced Form as a Biomarker of Oxidative Stress

Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is the principal source of reducing power in numerous processes of physiological importance. We examined the influence of oxidative stress on the relative amounts of NADPH in human red blood cells (RBCs). To determine the homeostasis of the NADPH existing in the reduced form following oxidation, we developed an improved method for measurement of NADPH in human RBCs using high-performance liquid chromatography (HPLC). The present method with fluorescent detection is reproducible and selective than enzymatic cycling method and HPLC methods with spectrometric detection. The calibration curve is linear over the range of 0.1-5.0 muM with a correlation coefficient of 0.999. The within-run precision of the assays for total NADPH (NADPH+NADP(+)) and NADPH concentrations in human RBC were 2.4% and 8.6%, respectively (n=5). After the RBC suspension was exposed to tert-butyl hydroperoxide (t-BHP), which is scavenged by glutathione peroxidase (GPX) along with NADPH consumption, a significant decrease in the NADPH ratio [(NADPH/(NADPH+NADP(+))] was observed after a transient decrease and rapid recovery of the reduced form of glutathione. The marked decrease in the NADPH ratio induced by t-BHP exposure was observed in the absence of glucose. However, the NADPH ratio was not decreased by t-BHP exposure after pre-treatment with a glutathione reductase inhibitor. This method may be useful for the measurement of small amounts of NADPH from various biological sources.

Noise modelling of improved detection scheme for displacement optic sensors

PurposeThe purpose of this paper is to propose modelling of the noise of an improved method for the measurement of small displacement and vibrations. It is based on a novel method for overcoming DC drift in RF subcarrier phase detection scheme.Design/methodology/approachThe method works in open loop and is characterized by low distortions, good signal‐to‐noise ratio and rather low cost.FindingsConsidering a stationary Gaussian stochastic process, the paper evaluated and modelled the power spectral density and the probability density against the phase error and the phase noise parameter.Practical implicationsThis offers an improvement of vibration, displacement and seismic sensors.Originality/valueBased on a novel method for overcoming DC drift in RF sub‐carrier phase detection scheme for fibre optic sensors, an improved method for displacement and vibration measurement is proposed. The presented method is characterized by rather low distortions in the modulation process and small distances measurement, low distortions and low‐cost electronic systems.

A novel quantitative method for measuring obstruction in the upper urinary tract: The ‘obstruction coefficient’

To define an exact pressure-flow correlation in the upper urinary tract using an improved measurement method, to quantitatively characterize the degree of postrenal obstruction and to find a simple way of calculating it in everyday urological practice. The data of 112 cases were included in the analysis. The dynamic method of a multistep, constant pressure perfusion study was used to precisely measure a wide range of pressure-flow dependences. Values of established parameters measuring the degree of obstruction were compared: the intrapelvic pressure, the ureteral opening pressure and the newly introduced 'obstruction coefficient'. Pressure-flow relations can be best presented by a parabolic curve described by the simple formula Y = AX(2) + B. Depending on the degree of obstruction, the shape of this curve can be characterized by a single number, that we defined as the 'obstruction coefficient'. Computer-based evaluation software for the easy calculation of this coefficient is presented here and freely available on demand. The Whitaker-test, the ureteral opening pressure, and the 'obstruction coefficient' showed significant correlation proving that the latter was clinically applicable in measuring the degree of obstruction. Calculation of the 'obstruction coefficient' enables us to exactly define the degree of upper urinary tract obstruction and to safely monitor for a long period conditions inhibiting ureteric passage.