Assessing and improving health in the workplace: an integration of subjective and objective measures with the STress Assessment and Research Toolkit (St.A.R.T.) method

PubMed Central

2012-01-01

Background The aim of this work was to introduce a new combined method of subjective and objective measures to assess psychosocial risk factors at work and improve workers’ health and well-being. In the literature most of the research on work-related stress focuses on self-report measures and this work represents the first methodology capable of integrating different sources of data. Method An integrated method entitled St.A.R.T. (STress Assessment and Research Toolkit) was used in order to assess psychosocial risk factors and two health outcomes. In particular, a self-report questionnaire combined with an observational structured checklist was administered to 113 workers from an Italian retail company. Results The data showed a correlation between subjective data and the rating data of the observational checklist for the psychosocial risk factors related to work contexts such as customer relationship management and customer queue. Conversely, the factors related to work content (workload and boredom) measured with different methods (subjective vs. objective) showed a discrepancy. Furthermore, subjective measures of psychosocial risk factors were more predictive of workers’ psychological health and exhaustion than rating data. The different objective measures played different roles, however, in terms of their influence on the two health outcomes considered. Conclusions It is important to integrate self-related assessment of stressors with objective measures for a better understanding of workers’ conditions in the workplace. The method presented could be considered a useful methodology for combining the two measures and differentiating the impact of different psychological risk factors related to work content and context on workers’ health. PMID:22995286

Magnetic imager and method

DOEpatents

Powell, James; Reich, Morris; Danby, Gordon

1997-07-22

A magnetic imager 10 includes a generator 18 for practicing a method of applying a background magnetic field over a concealed object, with the object being effective to locally perturb the background field. The imager 10 also includes a sensor 20 for measuring perturbations of the background field to detect the object. In one embodiment, the background field is applied quasi-statically. And, the magnitude or rate of change of the perturbations may be measured for determining location, size, and/or condition of the object.

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy

PubMed Central

Göhler, Daniel; Wessely, Benno; Stintz, Michael; Lazzerini, Giovanni Mattia; Yacoot, Andrew

2017-01-01

Dimensional measurements on nano-objects by atomic force microscopy (AFM) require samples of safely fixed and well individualized particles with a suitable surface-specific particle number on flat and clean substrates. Several known and proven particle preparation methods, i.e., membrane filtration, drying, rinsing, dip coating as well as electrostatic and thermal precipitation, were performed by means of scanning electron microscopy to examine their suitability for preparing samples for dimensional AFM measurements. Different suspensions of nano-objects (with varying material, size and shape) stabilized in aqueous solutions were prepared therefore on different flat substrates. The drop-drying method was found to be the most suitable one for the analysed suspensions, because it does not require expensive dedicated equipment and led to a uniform local distribution of individualized nano-objects. Traceable AFM measurements based on Si and SiO2 coated substrates confirmed the suitability of this technique. PMID:28904839

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy.

PubMed

Fiala, Petra; Göhler, Daniel; Wessely, Benno; Stintz, Michael; Lazzerini, Giovanni Mattia; Yacoot, Andrew

2017-01-01

Dimensional measurements on nano-objects by atomic force microscopy (AFM) require samples of safely fixed and well individualized particles with a suitable surface-specific particle number on flat and clean substrates. Several known and proven particle preparation methods, i.e., membrane filtration, drying, rinsing, dip coating as well as electrostatic and thermal precipitation, were performed by means of scanning electron microscopy to examine their suitability for preparing samples for dimensional AFM measurements. Different suspensions of nano-objects (with varying material, size and shape) stabilized in aqueous solutions were prepared therefore on different flat substrates. The drop-drying method was found to be the most suitable one for the analysed suspensions, because it does not require expensive dedicated equipment and led to a uniform local distribution of individualized nano-objects. Traceable AFM measurements based on Si and SiO 2 coated substrates confirmed the suitability of this technique.

Line segment confidence region-based string matching method for map conflation

NASA Astrophysics Data System (ADS)

Huh, Yong; Yang, Sungchul; Ga, Chillo; Yu, Kiyun; Shi, Wenzhong

2013-04-01

In this paper, a method to detect corresponding point pairs between polygon object pairs with a string matching method based on a confidence region model of a line segment is proposed. The optimal point edit sequence to convert the contour of a target object into that of a reference object was found by the string matching method which minimizes its total error cost, and the corresponding point pairs were derived from the edit sequence. Because a significant amount of apparent positional discrepancies between corresponding objects are caused by spatial uncertainty and their confidence region models of line segments are therefore used in the above matching process, the proposed method obtained a high F-measure for finding matching pairs. We applied this method for built-up area polygon objects in a cadastral map and a topographical map. Regardless of their different mapping and representation rules and spatial uncertainties, the proposed method with a confidence level at 0.95 showed a matching result with an F-measure of 0.894.

System and method for measuring residual stress

DOEpatents

Prime, Michael B.

2002-01-01

The present invention is a method and system for determining the residual stress within an elastic object. In the method, an elastic object is cut along a path having a known configuration. The cut creates a portion of the object having a new free surface. The free surface then deforms to a contour which is different from the path. Next, the contour is measured to determine how much deformation has occurred across the new free surface. Points defining the contour are collected in an empirical data set. The portion of the object is then modeled in a computer simulator. The points in the empirical data set are entered into the computer simulator. The computer simulator then calculates the residual stress along the path which caused the points within the object to move to the positions measured in the empirical data set. The calculated residual stress is then presented in a useful format to an analyst.

Real-time color measurement using active illuminant

NASA Astrophysics Data System (ADS)

Tominaga, Shoji; Horiuchi, Takahiko; Yoshimura, Akihiko

2010-01-01

This paper proposes a method for real-time color measurement using active illuminant. A synchronous measurement system is constructed by combining a high-speed active spectral light source and a high-speed monochrome camera. The light source is a programmable spectral source which is capable of emitting arbitrary spectrum in high speed. This system is the essential advantage of capturing spectral images without using filters in high frame rates. The new method of real-time colorimetry is different from the traditional method based on the colorimeter or the spectrometers. We project the color-matching functions onto an object surface as spectral illuminants. Then we can obtain the CIE-XYZ tristimulus values directly from the camera outputs at every point on the surface. We describe the principle of our colorimetric technique based on projection of the color-matching functions and the procedure for realizing a real-time measurement system of a moving object. In an experiment, we examine the performance of real-time color measurement for a static object and a moving object.

Accuracy and reliability testing of two methods to measure internal rotation of the glenohumeral joint.

PubMed

Hall, Justin M; Azar, Frederick M; Miller, Robert H; Smith, Richard; Throckmorton, Thomas W

2014-09-01

We compared accuracy and reliability of a traditional method of measurement (most cephalad vertebral spinous process that can be reached by a patient with the extended thumb) to estimates made with the shoulder in abduction to determine if there were differences between the two methods. Six physicians with fellowship training in sports medicine or shoulder surgery estimated measurements in 48 healthy volunteers. Three were randomly chosen to make estimates of both internal rotation measurements for each volunteer. An independent observer made objective measurements on lateral scoliosis films (spinous process method) or with a goniometer (abduction method). Examiners were blinded to objective measurements as well as to previous estimates. Intraclass coefficients for interobserver reliability for the traditional method averaged 0.75, indicating good agreement among observers. The difference in vertebral level estimated by the examiner and the actual radiographic level averaged 1.8 levels. The intraclass coefficient for interobserver reliability for the abduction method averaged 0.81 for all examiners, indicating near-perfect agreement. Confidence intervals indicated that estimates were an average of 8° different from the objective goniometer measurements. Pearson correlation coefficients of intraobserver reliability for the abduction method averaged 0.94, indicating near-perfect agreement within observers. Confidence intervals demonstrated repeated estimates between 5° and 10° of the original. Internal rotation estimates made with the shoulder abducted demonstrated interobserver reliability superior to that of spinous process estimates, and reproducibility was high. On the basis of this finding, we now take glenohumeral internal rotation measurements with the shoulder in abduction and use a goniometer to maximize accuracy and objectivity. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Dual-wavelength digital holographic imaging with phase background subtraction

NASA Astrophysics Data System (ADS)

Khmaladze, Alexander; Matz, Rebecca L.; Jasensky, Joshua; Seeley, Emily; Holl, Mark M. Banaszak; Chen, Zhan

2012-05-01

Three-dimensional digital holographic microscopic phase imaging of objects that are thicker than the wavelength of the imaging light is ambiguous and results in phase wrapping. In recent years, several unwrapping methods that employed two or more wavelengths were introduced. These methods compare the phase information obtained from each of the wavelengths and extend the range of unambiguous height measurements. A straightforward dual-wavelength phase imaging method is presented which allows for a flexible tradeoff between the maximum height of the sample and the amount of noise the method can tolerate. For highly accurate phase measurements, phase unwrapping of objects with heights higher than the beat (synthetic) wavelength (i.e. the product of the original two wavelengths divided by their difference), can be achieved. Consequently, three-dimensional measurements of a wide variety of biological systems and microstructures become technically feasible. Additionally, an effective method of removing phase background curvature based on slowly varying polynomial fitting is proposed. This method allows accurate volume measurements of several small objects with the same image frame.

Magnetic Moment Quantifications of Small Spherical Objects in MRI

PubMed Central

Cheng, Yu-Chung N.; Hsieh, Ching-Yi; Tackett, Ronald; Kokeny, Paul; Regmi, Rajesh Kumar; Lawes, Gavin

2014-01-01

Purpose The purpose of this work is to develop a method for accurately quantifying effective magnetic moments of spherical-like small objects from magnetic resonance imaging (MRI). A standard 3D gradient echo sequence with only one echo time is intended for our approach to measure the effective magnetic moment of a given object of interest. Methods Our method sums over complex MR signals around the object and equates those sums to equations derived from the magnetostatic theory. With those equations, our method is able to determine the center of the object with subpixel precision. By rewriting those equations, the effective magnetic moment of the object becomes the only unknown to be solved. Each quantified effective magnetic moment has an uncertainty that is derived from the error propagation method. If the volume of the object can be measured from spin echo images, the susceptibility difference between the object and its surrounding can be further quantified from the effective magnetic moment. Numerical simulations, a variety of glass beads in phantom studies with different MR imaging parameters from a 1.5 T machine, and measurements from a SQUID (superconducting quantum interference device) based magnetometer have been conducted to test the robustness of our method. Results Quantified effective magnetic moments and susceptibility differences from different imaging parameters and methods all agree with each other within two standard deviations of estimated uncertainties. Conclusion An MRI method is developed to accurately quantify the effective magnetic moment of a given small object of interest. Most results are accurate within 10% of true values and roughly half of the total results are accurate within 5% of true values using very reasonable imaging parameters. Our method is minimally affected by the partial volume, dephasing, and phase aliasing effects. Our next goal is to apply this method to in vivo studies. PMID:25490517

Validity of Questionnaire and Representativeness of Objective Methods for Measurements of Mechanical Exposures in Construction and Health Care Work

PubMed Central

Koch, Markus; Lunde, Lars-Kristian; Gjulem, Tonje; Knardahl, Stein; Veiersted, Kaj Bo

2016-01-01

Objectives To determine the criterion validity of a questionnaire on physical exposures compared to objective measurements at construction and health care sites and to examine exposure variation over several working days. Methods Five hundred ninety-four construction and health care workers answered a baseline questionnaire. The daily activities (standing, moving, sitting, number of steps), postures (inclination of the arm and the trunk), and relative heart rate of 125 participants were recorded continuously over 3–4 working days. At the end of the first measurement day, the participants answered a second questionnaire (workday questionnaire). Results All objective activity measurements had significant correlations to their respective questions. Among health care workers, there were no correlations between postures and relative heart rate and the baseline questionnaire. The questionnaires overestimated the exposure durations. The highest explained variance in the adjusted models with self-reported variables were found for objectively measured sitting (R2 = 0.559) and arm inclination > 60° (R2 = 0.420). Objective measurements over several days showed a higher reliability compared to single day measurements. Conclusions Questionnaires cannot provide an accurate description of mechanical exposures. Objective measurements over several days are recommended in occupations with varying tasks. PMID:27649499

Full-field 3D shape measurement of specular object having discontinuous surfaces

NASA Astrophysics Data System (ADS)

Zhang, Zonghua; Huang, Shujun; Gao, Nan; Gao, Feng; Jiang, Xiangqian

2017-06-01

This paper presents a novel Phase Measuring Deflectometry (PMD) method to measure specular objects having discontinuous surfaces. A mathematical model is established to directly relate the absolute phase and depth, instead of the phase and gradient. Based on the model, a hardware measuring system has been set up, which consists of a precise translating stage, a projector, a diffuser and a camera. The stage locates the projector and the diffuser together to a known position during measurement. By using the model-based and machine vision methods, system calibration is accomplished to provide the required parameters and conditions. The verification tests are given to evaluate the effectiveness of the developed system. 3D (Three-Dimensional) shapes of a concave mirror and a monolithic multi-mirror array having multiple specular surfaces have been measured. Experimental results show that the proposed method can obtain 3D shape of specular objects having discontinuous surfaces effectively

Assessing and improving health in the workplace: an integration of subjective and objective measures with the STress Assessment and Research Toolkit (St.A.R.T.) method.

PubMed

Panari, Chiara; Guglielmi, Dina; Ricci, Aurora; Tabanelli, Maria Carla; Violante, Francesco Saverio

2012-09-20

The aim of this work was to introduce a new combined method of subjective and objective measures to assess psychosocial risk factors at work and improve workers' health and well-being. In the literature most of the research on work-related stress focuses on self-report measures and this work represents the first methodology capable of integrating different sources of data. An integrated method entitled St.A.R.T. (STress Assessment and Research Toolkit) was used in order to assess psychosocial risk factors and two health outcomes. In particular, a self-report questionnaire combined with an observational structured checklist was administered to 113 workers from an Italian retail company. The data showed a correlation between subjective data and the rating data of the observational checklist for the psychosocial risk factors related to work contexts such as customer relationship management and customer queue. Conversely, the factors related to work content (workload and boredom) measured with different methods (subjective vs. objective) showed a discrepancy. Furthermore, subjective measures of psychosocial risk factors were more predictive of workers' psychological health and exhaustion than rating data. The different objective measures played different roles, however, in terms of their influence on the two health outcomes considered. It is important to integrate self-related assessment of stressors with objective measures for a better understanding of workers' conditions in the workplace. The method presented could be considered a useful methodology for combining the two measures and differentiating the impact of different psychological risk factors related to work content and context on workers' health.

Multi-camera digital image correlation method with distributed fields of view

NASA Astrophysics Data System (ADS)

Malowany, Krzysztof; Malesa, Marcin; Kowaluk, Tomasz; Kujawinska, Malgorzata

2017-11-01

A multi-camera digital image correlation (DIC) method and system for measurements of large engineering objects with distributed, non-overlapping areas of interest are described. The data obtained with individual 3D DIC systems are stitched by an algorithm which utilizes the positions of fiducial markers determined simultaneously by Stereo-DIC units and laser tracker. The proposed calibration method enables reliable determination of transformations between local (3D DIC) and global coordinate systems. The applicability of the method was proven during in-situ measurements of a hall made of arch-shaped (18 m span) self-supporting metal-plates. The proposed method is highly recommended for 3D measurements of shape and displacements of large and complex engineering objects made from multiple directions and it provides the suitable accuracy of data for further advanced structural integrity analysis of such objects.

25 CFR 30.116 - If a school fails to achieve its annual measurable objectives, what other methods may it use to...

Code of Federal Regulations, 2011 CFR

2011-04-01

... participated in the assessment. (b) Method B—Uniform Averaging Procedure. A school may use uniform averaging... 25 Indians 1 2011-04-01 2011-04-01 false If a school fails to achieve its annual measurable... Adequate Yearly Progress § 30.116 If a school fails to achieve its annual measurable objectives, what other...

25 CFR 30.116 - If a school fails to achieve its annual measurable objectives, what other methods may it use to...

Code of Federal Regulations, 2012 CFR

2012-04-01

... participated in the assessment. (b) Method B—Uniform Averaging Procedure. A school may use uniform averaging... 25 Indians 1 2012-04-01 2011-04-01 true If a school fails to achieve its annual measurable... Adequate Yearly Progress § 30.116 If a school fails to achieve its annual measurable objectives, what other...

25 CFR 30.116 - If a school fails to achieve its annual measurable objectives, what other methods may it use to...

Code of Federal Regulations, 2013 CFR

2013-04-01

... participated in the assessment. (b) Method B—Uniform Averaging Procedure. A school may use uniform averaging... 25 Indians 1 2013-04-01 2013-04-01 false If a school fails to achieve its annual measurable... Adequate Yearly Progress § 30.116 If a school fails to achieve its annual measurable objectives, what other...

25 CFR 30.116 - If a school fails to achieve its annual measurable objectives, what other methods may it use to...

Code of Federal Regulations, 2010 CFR

2010-04-01

... participated in the assessment. (b) Method B—Uniform Averaging Procedure. A school may use uniform averaging... 25 Indians 1 2010-04-01 2010-04-01 false If a school fails to achieve its annual measurable... Adequate Yearly Progress § 30.116 If a school fails to achieve its annual measurable objectives, what other...

25 CFR 30.116 - If a school fails to achieve its annual measurable objectives, what other methods may it use to...

Code of Federal Regulations, 2014 CFR

2014-04-01

... participated in the assessment. (b) Method B—Uniform Averaging Procedure. A school may use uniform averaging... 25 Indians 1 2014-04-01 2014-04-01 false If a school fails to achieve its annual measurable... Adequate Yearly Progress § 30.116 If a school fails to achieve its annual measurable objectives, what other...

Monitoring the athlete training response: subjective self-reported measures trump commonly used objective measures: a systematic review

PubMed Central

Saw, Anna E; Main, Luana C; Gastin, Paul B

2016-01-01

Background Monitoring athlete well-being is essential to guide training and to detect any progression towards negative health outcomes and associated poor performance. Objective (performance, physiological, biochemical) and subjective measures are all options for athlete monitoring. Objective We systematically reviewed objective and subjective measures of athlete well-being. Objective measures, including those taken at rest (eg, blood markers, heart rate) and during exercise (eg, oxygen consumption, heart rate response), were compared against subjective measures (eg, mood, perceived stress). All measures were also evaluated for their response to acute and chronic training load. Methods The databases Academic search complete, MEDLINE, PsycINFO, SPORTDiscus and PubMed were searched in May 2014. Fifty-six original studies reported concurrent subjective and objective measures of athlete well-being. The quality and strength of findings of each study were evaluated to determine overall levels of evidence. Results Subjective and objective measures of athlete well-being generally did not correlate. Subjective measures reflected acute and chronic training loads with superior sensitivity and consistency than objective measures. Subjective well-being was typically impaired with an acute increase in training load, and also with chronic training, while an acute decrease in training load improved subjective well-being. Summary This review provides further support for practitioners to use subjective measures to monitor changes in athlete well-being in response to training. Subjective measures may stand alone, or be incorporated into a mixed methods approach to athlete monitoring, as is current practice in many sport settings. PMID:26423706

Measuring Positions of Objects using Two or More Cameras

NASA Technical Reports Server (NTRS)

Klinko, Steve; Lane, John; Nelson, Christopher

2008-01-01

An improved method of computing positions of objects from digitized images acquired by two or more cameras (see figure) has been developed for use in tracking debris shed by a spacecraft during and shortly after launch. The method is also readily adaptable to such applications as (1) tracking moving and possibly interacting objects in other settings in order to determine causes of accidents and (2) measuring positions of stationary objects, as in surveying. Images acquired by cameras fixed to the ground and/or cameras mounted on tracking telescopes can be used in this method. In this method, processing of image data starts with creation of detailed computer- aided design (CAD) models of the objects to be tracked. By rotating, translating, resizing, and overlaying the models with digitized camera images, parameters that characterize the position and orientation of the camera can be determined. The final position error depends on how well the centroids of the objects in the images are measured; how accurately the centroids are interpolated for synchronization of cameras; and how effectively matches are made to determine rotation, scaling, and translation parameters. The method involves use of the perspective camera model (also denoted the point camera model), which is one of several mathematical models developed over the years to represent the relationships between external coordinates of objects and the coordinates of the objects as they appear on the image plane in a camera. The method also involves extensive use of the affine camera model, in which the distance from the camera to an object (or to a small feature on an object) is assumed to be much greater than the size of the object (or feature), resulting in a truly two-dimensional image. The affine camera model does not require advance knowledge of the positions and orientations of the cameras. This is because ultimately, positions and orientations of the cameras and of all objects are computed in a coordinate system attached to one object as defined in its CAD model.

Quantitative method for measuring heat flux emitted from a cryogenic object

DOEpatents

Duncan, Robert V.

1993-01-01

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infra-red sensing devices.

Quantitative method for measuring heat flux emitted from a cryogenic object

DOEpatents

Duncan, R.V.

1993-03-16

The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

Magnetic moment quantifications of small spherical objects in MRI.

PubMed

Cheng, Yu-Chung N; Hsieh, Ching-Yi; Tackett, Ronald; Kokeny, Paul; Regmi, Rajesh Kumar; Lawes, Gavin

2015-07-01

The purpose of this work is to develop a method for accurately quantifying effective magnetic moments of spherical-like small objects from magnetic resonance imaging (MRI). A standard 3D gradient echo sequence with only one echo time is intended for our approach to measure the effective magnetic moment of a given object of interest. Our method sums over complex MR signals around the object and equates those sums to equations derived from the magnetostatic theory. With those equations, our method is able to determine the center of the object with subpixel precision. By rewriting those equations, the effective magnetic moment of the object becomes the only unknown to be solved. Each quantified effective magnetic moment has an uncertainty that is derived from the error propagation method. If the volume of the object can be measured from spin echo images, the susceptibility difference between the object and its surrounding can be further quantified from the effective magnetic moment. Numerical simulations, a variety of glass beads in phantom studies with different MR imaging parameters from a 1.5T machine, and measurements from a SQUID (superconducting quantum interference device) based magnetometer have been conducted to test the robustness of our method. Quantified effective magnetic moments and susceptibility differences from different imaging parameters and methods all agree with each other within two standard deviations of estimated uncertainties. An MRI method is developed to accurately quantify the effective magnetic moment of a given small object of interest. Most results are accurate within 10% of true values, and roughly half of the total results are accurate within 5% of true values using very reasonable imaging parameters. Our method is minimally affected by the partial volume, dephasing, and phase aliasing effects. Our next goal is to apply this method to in vivo studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Neutron Based Non-Destructive Assay (NDA) Measurement Systems for Safeguard

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swinhoe, Martyn Thomas

2017-09-21

The objectives of this project are to introduce the assay methods for plutonium measurements using the HLNC; introduce the assay method for bulk uranium measurements using the AWCC; and introduce the assay method for fuel assembly measurements using the UNCL.

Absolute surface reconstruction by slope metrology and photogrammetry

NASA Astrophysics Data System (ADS)

Dong, Yue

Developing the manufacture of aspheric and freeform optical elements requires an advanced metrology method which is capable of inspecting these elements with arbitrary freeform surfaces. In this dissertation, a new surface measurement scheme is investigated for such a purpose, which is to measure the absolute surface shape of an object under test through its surface slope information obtained by photogrammetric measurement. A laser beam propagating toward the object reflects on its surface while the vectors of the incident and reflected beams are evaluated from the four spots they leave on the two parallel transparent windows in front of the object. The spots' spatial coordinates are determined by photogrammetry. With the knowledge of the incident and reflected beam vectors, the local slope information of the object surface is obtained through vector calculus and finally yields the absolute object surface profile by a reconstruction algorithm. An experimental setup is designed and the proposed measuring principle is experimentally demonstrated by measuring the absolute surface shape of a spherical mirror. The measurement uncertainty is analyzed, and efforts for improvement are made accordingly. In particular, structured windows are designed and fabricated to generate uniform scattering spots left by the transmitted laser beams. Calibration of the fringe reflection instrument, another typical surface slope measurement method, is also reported in the dissertation. Finally, a method for uncertainty analysis of a photogrammetry measurement system by optical simulation is investigated.

Measurement of vibration using phase only correlation technique

NASA Astrophysics Data System (ADS)

Balachandar, S.; Vipin, K.

2017-08-01

A novel method for the measurement of vibration is proposed and demonstrated. The proposed experiment is based on laser triangulation: consists of line laser, object under test and a high speed camera remotely controlled by a software. Experiment involves launching a line-laser probe beam perpendicular to the axis of the vibrating object. The reflected probe beam is recorded by a high speed camera. The dynamic position of the line laser in camera plane is governed by the magnitude and frequency of the vibrating test-object. Using phase correlation technique the maximum distance travelled by the probe beam in CCD plane is measured in terms of pixels using MATLAB. An actual displacement of the object in mm is measured by calibration. Using displacement data with time, other vibration associated quantities such as acceleration, velocity and frequency are evaluated. The preliminary result of the proposed method is reported for acceleration from 1g to 3g, and from frequency 6Hz to 26Hz. The results are closely matching with its theoretical values. The advantage of the proposed method is that it is a non-destructive method and using phase correlation algorithm subpixel displacement in CCD plane can be measured with high accuracy.

[Comparisons of manual and automatic refractometry with subjective results].

PubMed

Wübbolt, I S; von Alven, S; Hülssner, O; Erb, C

2006-11-01

Refractometry is very important in everyday clinical practice. The aim of this study is to compare the precision of three objective methods of refractometry with subjective dioptometry (Phoropter). The objective methods with the smallest deviation to subjective refractometry results are evaluated. The objective methods/instruments used were retinoscopy, Prism Refractometer PR 60 (Rodenstock) and Auto Refractometer RM-A 7000 (Topcon). The results of monocular dioptometry (sphere, cylinder and axis) of each objective method were compared to the results of the subjective method. The examination was carried out on 178 eyes, which were divided into 3 age-related groups: 6 - 12 years (103 eyes), 13 - 18 years (38 eyes) and older than 18 years (37 eyes). All measurements were made in cycloplegia. The smallest standard deviation of the measurement error was found for the Auto Refractometer RM-A 7000. Both the PR 60 and retinoscopy had a clearly higher standard deviation. Furthermore, the RM-A 7000 showed in three and retinoscopy in four of the nine comparisons a significant bias in the measurement error. The Auto Refractometer provides measurements with the smallest deviation compared to the subjective method. Here it has to be taken into account that the measurements for the sphere have an average deviation of + 0.2 dpt. In comparison to retinoscopy the examination of children with the RM-A 7000 is difficult. An advantage of the Auto Refractometer is the fast and easy handling, so that measurements can be performed by medical staff.

Objectivity in psychosocial measurement: what, why, how.

PubMed

Fisher, W P

2000-01-01

This article raises and tries to answer questions concerning what objectivity in psychosocial measurement is, why it is important, and how it can be achieved. Following in the tradition of the Socratic art of maiuetics, objectivity is characterized by the separation of meaning from the geometric, metaphoric, or numeric figure carrying it, allowing an ideal and abstract entity to take on a life of its own. Examples of objective entities start from anything teachable and learnable, but for the purposes of measurement, the meter, gram, volt, and liter are paradigmatic because of their generalizability across observers, instruments, laboratories, samples, applications, etc. Objectivity is important because it is only through it that distinct conceptual entities are meaningfully distinguished. Seen from another angle, objectivity is important because it defines the conditions of the possibility of shared meaning and community. Full objectivity in psychosocial measurement can be achieved only by attending to both its methodological and its social aspects. The methodological aspect has recently achieved some notice in psychosocial measurement, especially in the form of Rasch's probabilistic conjoint models. Objectivity's social aspect has only recently been noticed by historians of science, and has not yet been systematically incorporated in any psychosocial science. An approach to achieving full objectivity in psychosocial measurement is adapted from the ASTM Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method (ASTM Committee E-11 on Statistical Methods, 1992).

Extracting contours of oval-shaped objects by Hough transform and minimal path algorithms

NASA Astrophysics Data System (ADS)

Tleis, Mohamed; Verbeek, Fons J.

2014-04-01

Circular and oval-like objects are very common in cell and micro biology. These objects need to be analyzed, and to that end, digitized images from the microscope are used so as to come to an automated analysis pipeline. It is essential to detect all the objects in an image as well as to extract the exact contour of each individual object. In this manner it becomes possible to perform measurements on these objects, i.e. shape and texture features. Our measurement objective is achieved by probing contour detection through dynamic programming. In this paper we describe a method that uses Hough transform and two minimal path algorithms to detect contours of (ovoid-like) objects. These algorithms are based on an existing grey-weighted distance transform and a new algorithm to extract the circular shortest path in an image. The methods are tested on an artificial dataset of a 1000 images, with an F1-score of 0.972. In a case study with yeast cells, contours from our methods were compared with another solution using Pratt's figure of merit. Results indicate that our methods were more precise based on a comparison with a ground-truth dataset. As far as yeast cells are concerned, the segmentation and measurement results enable, in future work, to retrieve information from different developmental stages of the cell using complex features.

Topography measurements of high NA aspherical microlenses by digital holographic microscopy with spherical illumination

NASA Astrophysics Data System (ADS)

Józwik, Michal; Mikuła, Marta; Kozacki, Tomasz; Kostencka, Julianna; Gorecki, Christophe

2017-06-01

In this contribution, we propose a method of digital holographic microscopy (DHM) that enables measurement of high numerical aperture spherical and aspherical microstructures of both concave and convex shapes. The proposed method utilizes reflection of the spherical illumination beam from the object surface and the interference with a spherical reference beam of the similar curvature. In this case, the NA of DHM is fully utilized for illumination and imaging of the reflected object beam. Thus, the system allows capturing the phase coming from larger areas of the quasi-spherical object and, therefore, offers possibility of high accuracy characterization of its surface even in the areas of high inclination. The proposed measurement procedure allows determining all parameters required for the accurate shape recovery: the location of the object focus point and the positions of the illumination and reference point sources. The utility of the method is demonstrated with characterization of surface of high NA focusing objects. The accuracy is firstly verified by characterization of a known reference sphere with low error of sphericity. Then, the method is applied for shape measurement of spherical and aspheric microlenses. The results provide a full-field reconstruction of high NA topography with resolution in the nanometer range. The surface sphericity is evaluated by the deviation from the best fitted sphere or asphere, and the important parameters of the measured microlens: e.g.: radius of curvature and conic constant.

Evaluation of Learning Environments for Object-Oriented Programming: Measuring Cognitive Load with a Novel Measurement Technique

ERIC Educational Resources Information Center

Uysal, Murat Pasa

2016-01-01

Various methods and tools have been proposed to overcome the learning obstacles for Object-Oriented Programming (OOP). However, it remains difficult especially for novice learners. The problem may be not only adopting an instructional method, but also an Integrated Development Environment (IDE). Learners employ IDEs as a means to solve programming…

Optical versus tactile geometry measurement: alternatives or counterparts

NASA Astrophysics Data System (ADS)

Lehmann, Peter

2003-05-01

This contribution deals with measuring strategies and methods for the determination of several geometrical features, covering the surface micro-topography and the form of mechanical objects. The measuring principles used in optical surface metrology include optical focusing profilers, confocal point measuring and areal measuring sensors as well as interferometrical principles such as white light interferometry and speckle techniques. In comparison with stylus instruments optical techniques provide certain advantages such as a fast data acquisition, in-process applicability or contactless measurement. However, the frequency response characteristics of optical and tactile measurement differ significantly. In addition, optical sensors are commonly more influenced by critical geometrical conditions and optical properties of an object. For precise form measurement mechanical instruments dominate till now. One reason for this may be, that commonly the complete 360 degrees geometry of the measuring object has to be analyzed. Another point is that optical principles such as form measuring interferometry fail in cases of complex object geometry or rougher object surfaces. Other methods, e.g. fringe projection or digital holography, till now do not meet the accuracy demands of precision engineered workpieces. Hence, a combination of mechanical concepts and optical sensors represents an interesting potential for current and future measuring tasks, which require high accuracy and maximum flexibility.

Object Permanence and Method of Disappearance: Looking Measures Further Contradict Reaching Measures

ERIC Educational Resources Information Center

Charles, Eric P.; Rivera, Susan M.

2009-01-01

Piaget proposed that understanding permanency, understanding occlusion events, and forming mental representations were synonymous; however, accumulating evidence indicates that those concepts are "not" unified in development. Infants reach for endarkened objects at younger ages than for occluded objects, and infants' looking patterns suggest that…

Laser-ultrasound spectroscopy apparatus and method with detection of shear resonances for measuring anisotropy, thickness, and other properties

DOEpatents

Levesque, Daniel; Moreau, Andre; Dubois, Marc; Monchalin, Jean-Pierre; Bussiere, Jean; Lord, Martin; Padioleau, Christian

2000-01-01

Apparatus and method for detecting shear resonances includes structure and steps for applying a radiation pulse from a pulsed source of radiation to an object to generate elastic waves therein, optically detecting the elastic waves generated in the object, and analyzing the elastic waves optically detected in the object. These shear resonances, alone or in combination with other information, may be used in the present invention to improve thickness measurement accuracy and to determine geometrical, microstructural, and physical properties of the object. At least one shear resonance in the object is detected with the elastic waves optically detected in the object. Preferably, laser-ultrasound spectroscopy is utilized to detect the shear resonances.

Nondestructive analysis of three-dimensional objects using a fluid displacement method

USDA-ARS?s Scientific Manuscript database

Quantification of three-dimensional (3-D) objects has been a real challenge in agricultural, hydrological and environmental studies. We designed and tested a method that is capable of quantifying 3-D objects using measurements of fluid displacement. The device consists of a stand that supports a mov...

Link-Based Similarity Measures Using Reachability Vectors

PubMed Central

Yoon, Seok-Ho; Kim, Ji-Soo; Ryu, Minsoo; Choi, Ho-Jin

2014-01-01

We present a novel approach for computing link-based similarities among objects accurately by utilizing the link information pertaining to the objects involved. We discuss the problems with previous link-based similarity measures and propose a novel approach for computing link based similarities that does not suffer from these problems. In the proposed approach each target object is represented by a vector. Each element of the vector corresponds to all the objects in the given data, and the value of each element denotes the weight for the corresponding object. As for this weight value, we propose to utilize the probability of reaching from the target object to the specific object, computed using the “Random Walk with Restart” strategy. Then, we define the similarity between two objects as the cosine similarity of the two vectors. In this paper, we provide examples to show that our approach does not suffer from the aforementioned problems. We also evaluate the performance of the proposed methods in comparison with existing link-based measures, qualitatively and quantitatively, with respect to two kinds of data sets, scientific papers and Web documents. Our experimental results indicate that the proposed methods significantly outperform the existing measures. PMID:24701188

Optical derotator alignment using image-processing algorithm for tracking laser vibrometer measurements of rotating objects.

PubMed

Khalil, Hossam; Kim, Dongkyu; Jo, Youngjoon; Park, Kyihwan

2017-06-01

An optical component called a Dove prism is used to rotate the laser beam of a laser-scanning vibrometer (LSV). This is called a derotator and is used for measuring the vibration of rotating objects. The main advantage of a derotator is that it works independently from an LSV. However, this device requires very specific alignment, in which the axis of the Dove prism must coincide with the rotational axis of the object. If the derotator is misaligned with the rotating object, the results of the vibration measurement are imprecise, owing to the alteration of the laser beam on the surface of the rotating object. In this study, a method is proposed for aligning a derotator with a rotating object through an image-processing algorithm that obtains the trajectory of a landmark attached to the object. After the trajectory of the landmark is mathematically modeled, the amount of derotator misalignment with respect to the object is calculated. The accuracy of the proposed method for aligning the derotator with the rotating object is experimentally tested.

Landmark-aided localization for air vehicles using learned object detectors

NASA Astrophysics Data System (ADS)

DeAngelo, Mark Patrick

This research presents two methods to localize an aircraft without GPS using fixed landmarks observed from an optical sensor. Onboard absolute localization is useful for vehicle navigation free from an external network. The objective is to achieve practical navigation performance using available autopilot hardware and a downward pointing camera. The first method uses computer vision cascade object detectors, which are trained to detect predetermined, distinct landmarks prior to a flight. The first method also concurrently explores aircraft localization using roads between landmark updates. During a flight, the aircraft navigates with attitude, heading, airspeed, and altitude measurements and obtains measurement updates when landmarks are detected. The sensor measurements and landmark coordinates extracted from the aircraft's camera images are combined into an unscented Kalman filter to obtain an estimate of the aircraft's position and wind velocities. The second method uses computer vision object detectors to detect abundant generic landmarks referred as buildings, fields, trees, and road intersections from aerial perspectives. Various landmark attributes and spatial relationships to other landmarks are used to help associate observed landmarks with reference landmarks. The computer vision algorithms automatically extract reference landmarks from maps, which are processed offline before a flight. During a flight, the aircraft navigates with attitude, heading, airspeed, and altitude measurements and obtains measurement corrections by processing aerial photos with similar generic landmark detection techniques. The method also combines sensor measurements and landmark coordinates into an unscented Kalman filter to obtain an estimate of the aircraft's position and wind velocities.

Measuring the circular motion of small objects using laser stroboscopic images.

PubMed

Wang, Hairong; Fu, Y; Du, R

2008-01-01

Measuring the circular motion of a small object, including its displacement, speed, and acceleration, is a challenging task. This paper presents a new method for measuring repetitive and/or nonrepetitive, constant speed and/or variable speed circular motion using laser stroboscopic images. Under stroboscopic illumination, each image taken by an ordinary camera records multioutlines of an object in motion; hence, processing the stroboscopic image will be able to extract the motion information. We built an experiment apparatus consisting of a laser as the light source, a stereomicroscope to magnify the image, and a normal complementary metal oxide semiconductor camera to record the image. As the object is in motion, the stroboscopic illumination generates a speckle pattern on the object that can be recorded by the camera and analyzed by a computer. Experimental results indicate that the stroboscopic imaging is stable under various conditions. Moreover, the characteristics of the motion, including the displacement, the velocity, and the acceleration can be calculated based on the width of speckle marks, the illumination intensity, the duty cycle, and the sampling frequency. Compared with the popular high-speed camera method, the presented method may achieve the same measuring accuracy, but with much reduced cost and complexity.

Magnetogate: Using an iPhone Magnetometer for Measuring Kinematic Variables

ERIC Educational Resources Information Center

Temiz, Burak Kagan; Yavuz, Ahmet

2016-01-01

This paper presents a method to measure the movement of an object from specific locations on a straight line using an iPhone's magnetometer. In this method, called "magnetogate," an iPhone is placed on a moving object (in this case a toy car) and small neodymium magnets are arranged at equal intervals on one side of a straight line. The…

Passive Seismic for Hydrocarbon Indicator : Between Expectation and Reality

NASA Astrophysics Data System (ADS)

Pandito, Riky H. B.

2018-03-01

In between 5 – 10 years, in our country, passive seismic method became more popular to finding hydrocarbon. Low price, nondestructive acquisition and easy to mobilization is the best reason for choose the method. But in the other part, some people are pessimistically to deal with the result. Instrument specification, data condition and processing methods is several points which influence characteristic and interpretation passive seismic result. In 2010 one prospect in East Java Basin has been measurement constist of 112 objective points and several calibration points. Data measurement results indicate a positive response. Furthermore, in 2013 exploration drliing conducted on the prospect. Drill steam test showes 22 MMCFD in objective zone, upper – late oligocene. In 2015, remeasurement taken in objective area and show consistent responses with previous measurement. Passive seismic is unique method, sometimes will have difference results on dry, gas and oil area, in field production and also temporary suspend area with hidrocarbon content.

Angle Measurement of Objects outside the Linear Field of View of a Strapdown Semi-Active Laser Seeker.

PubMed

Zheng, Yongbin; Chen, Huimin; Zhou, Zongtan

2018-05-23

The accurate angle measurement of objects outside the linear field of view (FOV) is a challenging task for a strapdown semi-active laser seeker and is not yet well resolved. Considering the fact that the strapdown semi-active laser seeker is equipped with GPS and an inertial navigation system (INS) on a missile, in this work, we present an angle measurement method based on the fusion of the seeker’s data and GPS and INS data for a strapdown semi-active laser seeker. When an object is in the nonlinear FOV or outside the FOV, by solving the problems of space consistency and time consistency, the pitch angle and yaw angle of the object can be calculated via the fusion of the last valid angles measured by the seeker and the corresponding GPS and INS data. The numerical simulation results demonstrate the correctness and effectiveness of the proposed method.

Background oriented schlieren measurement of the refractive index field of air induced by a hot, cylindrical measurement object.

PubMed

Beermann, Rüdiger; Quentin, Lorenz; Pösch, Andreas; Reithmeier, Eduard; Kästner, Markus

2017-05-10

To optically capture the topography of a hot measurement object with high precision, the light deflection by the inhomogeneous refractive index field-induced by the heat transfer from the measurement object to the ambient medium-has to be considered. We used the 2D background oriented schlieren method with illuminated wavelet background, an optical flow algorithm, and Ciddor's equation to quantify the refractive index field located directly above a red-glowing, hot measurement object. A heat transfer simulation has been implemented to verify the magnitude and the shape of the measured refractive index field. Provided that no forced external flow is disturbing the shape of the convective flow originating from the hot object, a laminar flow can be observed directly above the object, resulting in a sharply bounded, inhomogeneous refractive index field.

Dynamic Reconstruction Algorithm of Three-Dimensional Temperature Field Measurement by Acoustic Tomography

PubMed Central

Li, Yanqiu; Liu, Shi; Inaki, Schlaberg H.

2017-01-01

Accuracy and speed of algorithms play an important role in the reconstruction of temperature field measurements by acoustic tomography. Existing algorithms are based on static models which only consider the measurement information. A dynamic model of three-dimensional temperature reconstruction by acoustic tomography is established in this paper. A dynamic algorithm is proposed considering both acoustic measurement information and the dynamic evolution information of the temperature field. An objective function is built which fuses measurement information and the space constraint of the temperature field with its dynamic evolution information. Robust estimation is used to extend the objective function. The method combines a tunneling algorithm and a local minimization technique to solve the objective function. Numerical simulations show that the image quality and noise immunity of the dynamic reconstruction algorithm are better when compared with static algorithms such as least square method, algebraic reconstruction technique and standard Tikhonov regularization algorithms. An effective method is provided for temperature field reconstruction by acoustic tomography. PMID:28895930

Determining characteristics of artificial near-Earth objects using observability analysis

NASA Astrophysics Data System (ADS)

Friedman, Alex M.; Frueh, Carolin

2018-03-01

Observability analysis is a method for determining whether a chosen state of a system can be determined from the output or measurements. Knowledge of state information availability resulting from observability analysis leads to improved sensor tasking for observation of orbital debris and better control of active spacecraft. This research performs numerical observability analysis of artificial near-Earth objects. Analysis of linearization methods and state transition matrices is performed to determine the viability of applying linear observability methods to the nonlinear orbit problem. Furthermore, pre-whitening is implemented to reformulate classical observability analysis. In addition, the state in observability analysis is typically composed of position and velocity; however, including object characteristics beyond position and velocity can be crucial for precise orbit propagation. For example, solar radiation pressure has a significant impact on the orbit of high area-to-mass ratio objects in geosynchronous orbit. Therefore, determining the time required for solar radiation pressure parameters to become observable is important for understanding debris objects. In order to compare observability analysis results with and without measurement noise and an extended state, quantitative measures of observability are investigated and implemented.

Kinematic measurement from panned cinematography.

PubMed

Gervais, P; Bedingfield, E W; Wronko, C; Kollias, I; Marchiori, G; Kuntz, J; Way, N; Kuiper, D

1989-06-01

Traditional 2-D cinematography has used a stationary camera with its optical axis perpendicular to the plane of motion. This method has constrained the size of the object plane or has introduced potential errors from a small subject image size with large object field widths. The purpose of this study was to assess a panning technique that could overcome the inherent limitations of small object field widths, small object image sizes and limited movement samples. The proposed technique used a series of reference targets in the object field that provided the necessary scales and origin translations. A 102 m object field was panned. Comparisons between criterion distances and film measured distances for field widths of 46 m and 22 m resulted in absolute mean differences that were comparable to that of the traditional method.

How far is it? Distance measurements and their consequences

NASA Astrophysics Data System (ADS)

Krełowski, Jacek

2017-08-01

Methods of measuring distances to objects in our Milky Way are briefly discussed. They generally base on three principles: of using a standard rod, of standard candle and of column density of interstellar matter. Weak and strong points of these methods are presented. The presence of gray extinction towards some objects is suggested which makes the most universal method of standard candle (spectroscopic parallax) very uncertain. Hard to say whether gray extinc-tion appears only in the form of circumstellar debris discs or is present also in the general interstellar medium. The application of the method of measuring column densities of interstellar gases suggests that the rotation curve of our Milky Way system is rather Keplerian than flat which creates doubts as to whether any Dark Matter halo is present around our Galaxy. It is emphasized that the most universal method, i.e. that of standard candle, used to estimate distances to cosmological objects, may suffer serious errors because of improper subtraction of extinction effects.

Method for resonant measurement

DOEpatents

Rhodes, George W.; Migliori, Albert; Dixon, Raymond D.

1996-01-01

A method of measurement of objects to determine object flaws, Poisson's ratio (.sigma.) and shear modulus (.mu.) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson's ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson's ratio using other modes dependent on both the shear modulus and Poisson's ratio.

Objective Versus Subjective Military Pilot Selection Methods in the United States of America

DTIC Science & Technology

2015-12-14

a computerized test designed to assess pilot skills by measuring spatial orientation and psychomotor skills and multitasking . The second is the...AFRL-SA-WP-SR-2015-0028 Objective Versus Subjective Military Pilot Selection Methods in the United States of America Joe...September 2014 4. TITLE AND SUBTITLE Objective Versus Subjective Military Pilot Selection Methods in the United States of America 5a. CONTRACT

Vibration mode imaging.

PubMed

Zhang, Xiaoming; Zeraati, Mohammad; Kinnick, Randall R; Greenleaf, James F; Fatemi, Mostafa

2007-06-01

A new method for imaging the vibration mode of an object is investigated. The radiation force of ultrasound is used to scan the object at a resonant frequency of the object. The vibration of the object is measured by laser and the resulting acoustic emission from the object is measured by a hydrophone. It is shown that the measured signal is proportional to the value of the mode shape at the focal point of the ultrasound beam. Experimental studies are carried out on a mechanical heart valve and arterial phantoms. The mode images on the valve are made by the hydrophone measurement and confirmed by finite-element method simulations. Compared with conventional B-scan imaging on arterial phantoms, the mode imaging can show not only the interface of the artery and the gelatin, but also the vibration modes of the artery. The images taken on the phantom surface suggest that an image of an interior artery can be made by vibration measurements on the surface of the body. However, the image of the artery can be improved if the vibration of the artery is measured directly. Imaging of the structure in the gelatin or tissue can be enhanced by small bubbles and contrast agents.

An orthogonal return method for linearly polarized beam based on the Faraday effect and its application in interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Benyong, E-mail: chenby@zstu.edu.cn; Zhang, Enzheng; Yan, Liping

2014-10-15

Correct return of the measuring beam is essential for laser interferometers to carry out measurement. In the actual situation, because the measured object inevitably rotates or laterally moves, not only the measurement accuracy will decrease, or even the measurement will be impossibly performed. To solve this problem, a novel orthogonal return method for linearly polarized beam based on the Faraday effect is presented. The orthogonal return of incident linearly polarized beam is realized by using a Faraday rotator with the rotational angle of 45°. The optical configuration of the method is designed and analyzed in detail. To verify its practicabilitymore » in polarization interferometry, a laser heterodyne interferometer based on this method was constructed and precision displacement measurement experiments were performed. These results show that the advantage of the method is that the correct return of the incident measuring beam is ensured when large lateral displacement or angular rotation of the measured object occurs and then the implementation of interferometric measurement can be ensured.« less

Measurement of susceptibility artifacts with histogram-based reference value on magnetic resonance images according to standard ASTM F2119.

PubMed

Heinrich, Andreas; Teichgräber, Ulf K; Güttler, Felix V

2015-12-01

The standard ASTM F2119 describes a test method for measuring the size of a susceptibility artifact based on the example of a passive implant. A pixel in an image is considered to be a part of an image artifact if the intensity is changed by at least 30% in the presence of a test object, compared to a reference image in which the test object is absent (reference value). The aim of this paper is to simplify and accelerate the test method using a histogram-based reference value. Four test objects were scanned parallel and perpendicular to the main magnetic field, and the largest susceptibility artifacts were measured using two methods of reference value determination (reference image-based and histogram-based reference value). The results between both methods were compared using the Mann-Whitney U-test. The difference between both reference values was 42.35 ± 23.66. The difference of artifact size was 0.64 ± 0.69 mm. The artifact sizes of both methods did not show significant differences; the p-value of the Mann-Whitney U-test was between 0.710 and 0.521. A standard-conform method for a rapid, objective, and reproducible evaluation of susceptibility artifacts could be implemented. The result of the histogram-based method does not significantly differ from the ASTM-conform method.

Understanding Interdependencies between Heterogeneous Earth Observation Systems When Applied to Federal Objectives

NASA Astrophysics Data System (ADS)

Gallo, J.; Sylak-Glassman, E.

2017-12-01

We will present a method for assessing interdependencies between heterogeneous Earth observation (EO) systems when applied to key Federal objectives. Using data from the National Earth Observation Assessment (EOA), we present a case study that examines the frequency that measurements from each of the Landsat 8 sensors are used in conjunction with heterogeneous measurements from other Earth observation sensors to develop data and information products. This EOA data allows us to map the most frequent interactions between Landsat measurements and measurements from other sensors, identify high-impact data and information products where these interdependencies occur, and identify where these combined measurements contribute most to meeting a key Federal objective within one of the 13 Societal Benefit Areas used in the EOA study. Using a value-tree framework to trace the application of data from EO systems to weighted key Federal objectives within the EOA study, we are able to estimate relative contribution of individual EO systems to meeting those objectives, as well as the interdependencies between measurements from all EO systems within the EOA study. The analysis relies on a modified Delphi method to elicit relative levels of reliance on individual measurements from EO systems, including combinations of measurements, from subject matter experts. This results in the identification of a representative portfolio of all EO systems used to meet key Federal objectives. Understanding the interdependencies among a heterogeneous set of measurements that modify the impact of any one individual measurement on meeting a key Federal objective, especially if the measurements originate from multiple agencies or state/local/tribal, international, academic, and commercial sources, can impact agency decision-making regarding mission requirements and inform understanding of user needs.

[Metrological analysis of measuring systems in testing an anticipatory reaction to the position of a moving object].

PubMed

Aksiuta, E F; Ostashev, A V; Sergeev, E V; Aksiuta, V E

1997-01-01

The methods of the information (entropy) error theory were used to make a metrological analysis of the well-known commercial measuring systems for timing an anticipative reaction (AR) to the position of a moving object, which is based on the electromechanical, gas-discharge, and electron principles. The required accuracy of measurement was ascertained to be achieved only by using the systems based on the electron principle of moving object simulation and AR measurement.

Wavefront-aberration measurement and systematic-error analysis of a high numerical-aperture objective

NASA Astrophysics Data System (ADS)

Liu, Zhixiang; Xing, Tingwen; Jiang, Yadong; Lv, Baobin

2018-02-01

A two-dimensional (2-D) shearing interferometer based on an amplitude chessboard grating was designed to measure the wavefront aberration of a high numerical-aperture (NA) objective. Chessboard gratings offer better diffraction efficiencies and fewer disturbing diffraction orders than traditional cross gratings. The wavefront aberration of the tested objective was retrieved from the shearing interferogram using the Fourier transform and differential Zernike polynomial-fitting methods. Grating manufacturing errors, including the duty-cycle and pattern-deviation errors, were analyzed with the Fourier transform method. Then, according to the relation between the spherical pupil and planar detector coordinates, the influence of the distortion of the pupil coordinates was simulated. Finally, the systematic error attributable to grating alignment errors was deduced through the geometrical ray-tracing method. Experimental results indicate that the measuring repeatability (3σ) of the wavefront aberration of an objective with NA 0.4 was 3.4 mλ. The systematic-error results were consistent with previous analyses. Thus, the correct wavefront aberration can be obtained after calibration.

Magnetogate: using an iPhone magnetometer for measuring kinematic variables

NASA Astrophysics Data System (ADS)

Kağan Temiz, Burak; Yavuz, Ahmet

2016-01-01

This paper presents a method to measure the movement of an object from specific locations on a straight line using an iPhone’s magnetometer. In this method, called ‘magnetogate’, an iPhone is placed on a moving object (in this case a toy car) and small neodymium magnets are arranged at equal intervals on one side of a straight line. The magnetometer sensor of the iPhone is switched on and then the car starts moving. The iPhone’s magnetometer is stimulated throughout its movement along a straight line. A ‘sensor Kinetics’ application on the iPhone saves the magnetic stimulations and produces a graph of the changing magnetic field near the iPhone. At the end of motion, data from the magnetometer is interpreted and peaks on the graph are detected. Thus, position-time changes can be analysed and comments about the motion of the object can be made. The position, velocity and acceleration of the object can be easily measured with this method.

Performance analysis and evaluation of direct phase measuring deflectometry

NASA Astrophysics Data System (ADS)

Zhao, Ping; Gao, Nan; Zhang, Zonghua; Gao, Feng; Jiang, Xiangqian

2018-04-01

Three-dimensional (3D) shape measurement of specular objects plays an important role in intelligent manufacturing applications. Phase measuring deflectometry (PMD)-based methods are widely used to obtain the 3D shapes of specular surfaces because they offer the advantages of a large dynamic range, high measurement accuracy, full-field and noncontact operation, and automatic data processing. To enable measurement of specular objects with discontinuous and/or isolated surfaces, a direct PMD (DPMD) method has been developed to build a direct relationship between phase and depth. In this paper, a new virtual measurement system is presented and is used to optimize the system parameters and evaluate the system's performance in DPMD applications. Four system parameters are analyzed to obtain accurate measurement results. Experiments are performed using simulated and actual data and the results confirm the effects of these four parameters on the measurement results. Researchers can therefore select suitable system parameters for actual DPMD (including PMD) measurement systems to obtain the 3D shapes of specular objects with high accuracy.

Twin Study on Heritability of Activity, Attention, and Impulsivity as Assessed by Objective Measures

ERIC Educational Resources Information Center

Heiser, Philip; Heinzel-Gutenbrunner, Monika; Frey, Joachim; Smidt, Judith; Grabarkiewicz, Justyna; Friedel, Susann; Kuhnau, Wolfgang; Schmidtke, Jorg; Remschmidt, Helmut; Hebebrand, Johannes

2006-01-01

Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…

Ability of College Students to Simulate ADHD on Objective Measures of Attention

ERIC Educational Resources Information Center

Booksh, Randee Lee; Pella, Russell D.; Singh, Ashvind N.; Gouvier, William Drew

2010-01-01

Objective: The authors examined the ability of college students to simulate ADHD symptoms on objective and self-report measures and the relationship between knowledge of ADHD and ability to simulate ADHD. Method: Undergraduate students were assigned to a control or a simulated ADHD malingering condition and compared with a clinical AD/HD group.…

Measuring Cognitive Load: A Comparison of Self-Report and Physiological Methods

ERIC Educational Resources Information Center

Joseph, Stacey

2013-01-01

This study explored three methods to measure cognitive load in a learning environment using four logic puzzles that systematically varied in level of intrinsic cognitive load. Participants' perceived intrinsic load was simultaneously measured with a self-report measure-a traditional subjective measure-and two objective, physiological measures…

Microwave measurement of the mass of frozen hydrogen pellets

DOEpatents

Talanker, Vera; Greenwald, Martin

1990-01-01

A nondestructive apparatus and method for measuring the mass of a moving object, based on the perturbation of the dielectric character of a resonant microwave cavity caused by the object passing through the cavity. An oscillator circuit is formed with a resonant cavity in a positive feedback loop of a microwave power amplifier. The moving object perturbs the resonant characteristics of the cavity causing a shift in the operating frequency of the oscillator proportional to the ratio of the pellet volume to the volume of the cavity. Signals from the cavity oscillation are mixed with a local oscillator. Then the IF frequency from the mixer is measured thereby providing a direct measurement of pellet mass based upon known physical properties and relationships. This apparatus and method is particularly adapted for the measurement of frozen hydrogen pellets.

3-D surface profilometry based on modulation measurement by applying wavelet transform method

NASA Astrophysics Data System (ADS)

Zhong, Min; Chen, Feng; Xiao, Chao; Wei, Yongchao

2017-01-01

A new analysis of 3-D surface profilometry based on modulation measurement technique by the application of Wavelet Transform method is proposed. As a tool excelling for its multi-resolution and localization in the time and frequency domains, Wavelet Transform method with good localized time-frequency analysis ability and effective de-noizing capacity can extract the modulation distribution more accurately than Fourier Transform method. Especially for the analysis of complex object, more details of the measured object can be well remained. In this paper, the theoretical derivation of Wavelet Transform method that obtains the modulation values from a captured fringe pattern is given. Both computer simulation and elementary experiment are used to show the validity of the proposed method by making a comparison with the results of Fourier Transform method. The results show that the Wavelet Transform method has a better performance than the Fourier Transform method in modulation values retrieval.

Imaging method based on attenuation, refraction and ultra-small-angle-scattering of x-rays

DOEpatents

Wernick, Miles N.; Chapman, Leroy Dean; Oltulu, Oral; Zhong, Zhong

2005-09-20

A method for detecting an image of an object by measuring the intensity at a plurality of positions of a transmitted beam of x-ray radiation emitted from the object as a function of angle within the transmitted beam. The intensity measurements of the transmitted beam are obtained by a crystal analyzer positioned at a plurality of angular positions. The plurality of intensity measurements are used to determine the angular intensity spectrum of the transmitted beam. One or more parameters, such as an attenuation property, a refraction property and a scatter property, can be obtained from the angular intensity spectrum and used to display an image of the object.

Exploring Dance Movement Data Using Sequence Alignment Methods

PubMed Central

Chavoshi, Seyed Hossein; De Baets, Bernard; Neutens, Tijs; De Tré, Guy; Van de Weghe, Nico

2015-01-01

Despite the abundance of research on knowledge discovery from moving object databases, only a limited number of studies have examined the interaction between moving point objects in space over time. This paper describes a novel approach for measuring similarity in the interaction between moving objects. The proposed approach consists of three steps. First, we transform movement data into sequences of successive qualitative relations based on the Qualitative Trajectory Calculus (QTC). Second, sequence alignment methods are applied to measure the similarity between movement sequences. Finally, movement sequences are grouped based on similarity by means of an agglomerative hierarchical clustering method. The applicability of this approach is tested using movement data from samba and tango dancers. PMID:26181435

Object-based change detection method using refined Markov random field

NASA Astrophysics Data System (ADS)

Peng, Daifeng; Zhang, Yongjun

2017-01-01

In order to fully consider the local spatial constraints between neighboring objects in object-based change detection (OBCD), an OBCD approach is presented by introducing a refined Markov random field (MRF). First, two periods of images are stacked and segmented to produce image objects. Second, object spectral and textual histogram features are extracted and G-statistic is implemented to measure the distance among different histogram distributions. Meanwhile, object heterogeneity is calculated by combining spectral and textual histogram distance using adaptive weight. Third, an expectation-maximization algorithm is applied for determining the change category of each object and the initial change map is then generated. Finally, a refined change map is produced by employing the proposed refined object-based MRF method. Three experiments were conducted and compared with some state-of-the-art unsupervised OBCD methods to evaluate the effectiveness of the proposed method. Experimental results demonstrate that the proposed method obtains the highest accuracy among the methods used in this paper, which confirms its validness and effectiveness in OBCD.

Object permanence and method of disappearance: looking measures further contradict reaching measures.

PubMed

Charles, Eric P; Rivera, Susan M

2009-11-01

Piaget proposed that understanding permanency, understanding occlusion events, and forming mental representations were synonymous; however, accumulating evidence indicates that those concepts are not unified in development. Infants reach for endarkened objects at younger ages than for occluded objects, and infants' looking patterns suggest that they expect occluded objects to reappear at younger ages than they reach for them. We reaffirm the latter finding in 5- to 6-month-olds and find similar responses to faded objects, but we fail to find that pattern in response to endarkened objects. This suggests that looking behavior and reaching behavior are both sensitive to method of disappearance, but with opposite effects. Current cognition-oriented (i.e. representation-oriented) explanations of looking behavior cannot easily accommodate these results; neither can perceptual-preference explanations, nor the traditional ecological reinterpretations of object permanence. A revised ecological hypothesis, invoking affordance learning, suggests how these differences could arise developmentally.

Film thickness measurement based on nonlinear phase analysis using a Linnik microscopic white-light spectral interferometer.

PubMed

Guo, Tong; Chen, Zhuo; Li, Minghui; Wu, Juhong; Fu, Xing; Hu, Xiaotang

2018-04-20

Based on white-light spectral interferometry and the Linnik microscopic interference configuration, the nonlinear phase components of the spectral interferometric signal were analyzed for film thickness measurement. The spectral interferometric signal was obtained using a Linnik microscopic white-light spectral interferometer, which includes the nonlinear phase components associated with the effective thickness, the nonlinear phase error caused by the double-objective lens, and the nonlinear phase of the thin film itself. To determine the influence of the effective thickness, a wavelength-correction method was proposed that converts the effective thickness into a constant value; the nonlinear phase caused by the effective thickness can then be determined and subtracted from the total nonlinear phase. A method for the extraction of the nonlinear phase error caused by the double-objective lens was also proposed. Accurate thickness measurement of a thin film can be achieved by fitting the nonlinear phase of the thin film after removal of the nonlinear phase caused by the effective thickness and by the nonlinear phase error caused by the double-objective lens. The experimental results demonstrated that both the wavelength-correction method and the extraction method for the nonlinear phase error caused by the double-objective lens improve the accuracy of film thickness measurements.

Measurement of Cognitive Load in Multimedia Learning: A Comparison of Different Objective Measures

ERIC Educational Resources Information Center

Korbach, Andreas; Brünken, Roland; Park, Babette

2017-01-01

Different indicators are interesting for analyzing human learning processes. Recent studies analyze learning performance in combination with cognitive load, as an indicator for learners' invested mental effort. In order to compare different measures of cognitive load research, the present study uses three different objective methods and one…

Using rate of divergence as an objective measure to differentiate between voice signal types based on the amount of disorder in the signal

PubMed Central

Calawerts, William M; Lin, Liyu; Sprott, JC; Jiang, Jack J

2016-01-01

Objective/Hypothesis The purpose of this paper is to introduce rate of divergence as an objective measure to differentiate between the four voice types based on the amount of disorder present in a signal. We hypothesized that rate of divergence would provide an objective measure that can quantify all four voice types. Study Design 150 acoustic voice recordings were randomly selected and analyzed using traditional perturbation, nonlinear, and rate of divergence analysis methods. ty Methods We developed a new parameter, rate of divergence, which uses a modified version of Wolf’s algorithm for calculating Lyapunov exponents of a system. The outcome of this calculation is not a Lyapunov exponent, but rather a description of the divergence of two nearby data points for the next three points in the time series, followed in three time delayed embedding dimensions. This measure was compared to currently existing perturbation and nonlinear dynamic methods of distinguishing between voice signals. Results There was a direct relationship between voice type and rate of divergence. This calculation is especially effective at differentiating between type 3 and type 4 voices (p<0.001), and is equally effective at differentiating type 1, type 2, and type 3 signals as currently existing methods. Conclusion The rate of divergence calculation introduced is an objective measure that can be used to distinguish between all four voice types based on amount of disorder present, leading to quicker and more accurate voice typing as well as an improved understanding of the nonlinear dynamics involved in phonation. PMID:26920858

Using Vision Metrology System for Quality Control in Automotive Industries

NASA Astrophysics Data System (ADS)

Mostofi, N.; Samadzadegan, F.; Roohy, Sh.; Nozari, M.

2012-07-01

The need of more accurate measurements in different stages of industrial applications, such as designing, producing, installation, and etc., is the main reason of encouraging the industry deputy in using of industrial Photogrammetry (Vision Metrology System). With respect to the main advantages of Photogrammetric methods, such as greater economy, high level of automation, capability of noncontact measurement, more flexibility and high accuracy, a good competition occurred between this method and other industrial traditional methods. With respect to the industries that make objects using a main reference model without having any mathematical model of it, main problem of producers is the evaluation of the production line. This problem will be so complicated when both reference and product object just as a physical object is available and comparison of them will be possible with direct measurement. In such case, producers make fixtures fitting reference with limited accuracy. In practical reports sometimes available precision is not better than millimetres. We used a non-metric high resolution digital camera for this investigation and the case study that studied in this paper is a chassis of automobile. In this research, a stable photogrammetric network designed for measuring the industrial object (Both Reference and Product) and then by using the Bundle Adjustment and Self-Calibration methods, differences between the Reference and Product object achieved. These differences will be useful for the producer to improve the production work flow and bringing more accurate products. Results of this research, demonstrate the high potential of proposed method in industrial fields. Presented results prove high efficiency and reliability of this method using RMSE criteria. Achieved RMSE for this case study is smaller than 200 microns that shows the fact of high capability of implemented approach.

AN OBJECTIVE CLIMATOLOGY OF CAROLINA COASTAL FRONTS

EPA Science Inventory

This study describes a simple objective method to identify cases of coastal frontogenesis offshore of the Carolinas and to characterize the sensible weather associated with frontal passage at measurement sites near the coast. The identification method, based on surface hourly d...

Moving Object Control System

NASA Technical Reports Server (NTRS)

Arndt, G. Dickey (Inventor); Carl, James R. (Inventor)

2001-01-01

A method is provided for controlling two objects relatively moveable with respect to each other. A plurality of receivers are provided for detecting a distinctive microwave signal from each of the objects and measuring the phase thereof with respect to a reference signal. The measured phase signal is used to determine a distance between each of the objects and each of the plurality of receivers. Control signals produced in response to the relative distances are used to control the position of the two objects.

Methods for obtaining true particle size distributions from cross section measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lord, Kristina Alyse

2013-01-01

Sectioning methods are frequently used to measure grain sizes in materials. These methods do not provide accurate grain sizes for two reasons. First, the sizes of features observed on random sections are always smaller than the true sizes of solid spherical shaped objects, as noted by Wicksell [1]. This is the case because the section very rarely passes through the center of solid spherical shaped objects randomly dispersed throughout a material. The sizes of features observed on random sections are inversely related to the distance of the center of the solid object from the section [1]. Second, on a planemore » section through the solid material, larger sized features are more frequently observed than smaller ones due to the larger probability for a section to come into contact with the larger sized portion of the spheres than the smaller sized portion. As a result, it is necessary to find a method that takes into account these reasons for inaccurate particle size measurements, while providing a correction factor for accurately determining true particle size measurements. I present a method for deducing true grain size distributions from those determined from specimen cross sections, either by measurement of equivalent grain diameters or linear intercepts.« less

A comparison of electronic heterodyne moire deflectometry and electronic heterodyne holographic interferometry for flow measurements

NASA Technical Reports Server (NTRS)

Decker, A. J.; Stricker, J.

1985-01-01

Electronic heterodyne moire deflectometry and electronic heterodyne holographic interferometry are compared as methods for the accurate measurement of refractive index and density change distributions of phase objects. Experimental results are presented to show that the two methods have comparable accuracy for measuring the first derivative of the interferometric fringe shift. The phase object for the measurements is a large crystal of KD*P, whose refractive index distribution can be changed accurately and repeatably for the comparison. Although the refractive index change causes only about one interferometric fringe shift over the entire crystal, the derivative shows considerable detail for the comparison. As electronic phase measurement methods, both methods are very accurate and are intrinsically compatible with computer controlled readout and data processing. Heterodyne moire is relatively inexpensive and has high variable sensitivity. Heterodyne holographic interferometry is better developed, and can be used with poor quality optical access to the experiment.

A coarse-to-fine kernel matching approach for mean-shift based visual tracking

NASA Astrophysics Data System (ADS)

Liangfu, L.; Zuren, F.; Weidong, C.; Ming, J.

2009-03-01

Mean shift is an efficient pattern match algorithm. It is widely used in visual tracking fields since it need not perform whole search in the image space. It employs gradient optimization method to reduce the time of feature matching and realize rapid object localization, and uses Bhattacharyya coefficient as the similarity measure between object template and candidate template. This thesis presents a mean shift algorithm based on coarse-to-fine search for the best kernel matching. This paper researches for object tracking with large motion area based on mean shift. To realize efficient tracking of such an object, we present a kernel matching method from coarseness to fine. If the motion areas of the object between two frames are very large and they are not overlapped in image space, then the traditional mean shift method can only obtain local optimal value by iterative computing in the old object window area, so the real tracking position cannot be obtained and the object tracking will be disabled. Our proposed algorithm can efficiently use a similarity measure function to realize the rough location of motion object, then use mean shift method to obtain the accurate local optimal value by iterative computing, which successfully realizes object tracking with large motion. Experimental results show its good performance in accuracy and speed when compared with background-weighted histogram algorithm in the literature.

Non-contact local temperature measurement inside an object using an infrared point detector

NASA Astrophysics Data System (ADS)

Hisaka, Masaki

2017-04-01

Local temperature measurement in deep areas of objects is an important technique in biomedical measurement. We have investigated a non-contact method for measuring temperature inside an object using a point detector for infrared (IR) light. An IR point detector with a pinhole was constructed and the radiant IR light emitted from the local interior of the object is photodetected only at the position of pinhole located in imaging relation. We measured the thermal structure of the filament inside the miniature bulb using the IR point detector, and investigated the temperature dependence at approximately human body temperature using a glass plate positioned in front of the heat source.

Speckle-based three-dimensional velocity measurement using spatial filtering velocimetry.

PubMed

Iversen, Theis F Q; Jakobsen, Michael L; Hanson, Steen G

2011-04-10

We present an optical method for measuring the real-time three-dimensional (3D) translational velocity of a diffusely scattering rigid object observed through an imaging system. The method is based on a combination of the motion of random speckle patterns and regular fringe patterns. The speckle pattern is formed in the observation plane of the imaging system due to reflection from an area of the object illuminated by a coherent light source. The speckle pattern translates in response to in-plane translation of the object, and the presence of an angular offset reference wave coinciding with the speckle pattern in the observation plane gives rise to interference, resulting in a fringe pattern that translates in response to the out-of-plane translation of the object. Numerical calculations are performed to evaluate the dynamic properties of the intensity distribution and the response of realistic spatial filters designed to measure the three components of the object's translational velocity. Furthermore, experimental data are presented that demonstrate full 3D velocity measurement. © 2011 Optical Society of America

Method for resonant measurement

DOEpatents

Rhodes, G.W.; Migliori, A.; Dixon, R.D.

1996-03-05

A method of measurement of objects to determine object flaws, Poisson`s ratio ({sigma}) and shear modulus ({mu}) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson`s ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson`s ratio using other modes dependent on both the shear modulus and Poisson`s ratio. 1 fig.

How Prevalent Is Object-Based Attention?

PubMed Central

Pilz, Karin S.; Roggeveen, Alexa B.; Creighton, Sarah E.; Bennett, Patrick J.; Sekuler, Allison B.

2012-01-01

Previous research suggests that visual attention can be allocated to locations in space (space-based attention) and to objects (object-based attention). The cueing effects associated with space-based attention tend to be large and are found consistently across experiments. Object-based attention effects, however, are small and found less consistently across experiments. In three experiments we address the possibility that variability in object-based attention effects across studies reflects low incidence of such effects at the level of individual subjects. Experiment 1 measured space-based and object-based cueing effects for horizontal and vertical rectangles in 60 subjects comparing commonly used target detection and discrimination tasks. In Experiment 2 we ran another 120 subjects in a target discrimination task in which rectangle orientation varied between subjects. Using parametric statistical methods, we found object-based effects only for horizontal rectangles. Bootstrapping methods were used to measure effects in individual subjects. Significant space-based cueing effects were found in nearly all subjects in both experiments, across tasks and rectangle orientations. However, only a small number of subjects exhibited significant object-based cueing effects. Experiment 3 measured only object-based attention effects using another common paradigm and again, using bootstrapping, we found only a small number of subjects that exhibited significant object-based cueing effects. Our results show that object-based effects are more prevalent for horizontal rectangles, which is in accordance with the theory that attention may be allocated more easily along the horizontal meridian. The fact that so few individuals exhibit a significant object-based cueing effect presumably is why previous studies of this effect might have yielded inconsistent results. The results from the current study highlight the importance of considering individual subject data in addition to commonly used statistical methods. PMID:22348018

Floor Sensing System Using Laser Reflectivity for Localizing Everyday Objects and Robot

PubMed Central

Pyo, Yoonseok; Hasegawa, Tsutomu; Tsuji, Tokuo; Kurazume, Ryo; Morooka, Ken'ichi

2014-01-01

This paper describes a new method of measuring the position of everyday objects and a robot on the floor using distance and reflectance acquired by laser range finder (LRF). The information obtained by this method is important for a service robot working in a human daily life environment. Our method uses only one LRF together with a mirror installed on the wall. Moreover, since the area of sensing is limited to a LRF scanning plane parallel to the floor and just a few centimeters above the floor, the scanning covers the whole room with minimal invasion of privacy of a resident, and occlusion problem is mitigated by using mirror. We use the reflection intensity and position information obtained from the target surface. Although it is not possible to identify all objects by additionally using reflection values, it would be easier to identify unknown objects if we can eliminate easily identifiable objects by reflectance. In addition, we propose a method for measuring the robot's pose using the tag which has the encoded reflection pattern optically identified by the LRF. Our experimental results validate the effectiveness of the proposed method. PMID:24763253

Adaptive projection intensity adjustment for avoiding saturation in three-dimensional shape measurement

NASA Astrophysics Data System (ADS)

Chen, Chao; Gao, Nan; Wang, Xiangjun; Zhang, Zonghua

2018-03-01

Phase-based fringe projection methods have been commonly used for three-dimensional (3D) measurements. However, image saturation results in incorrect intensities in captured fringe pattern images, leading to phase and measurement errors. Existing solutions are complex. This paper proposes an adaptive projection intensity adjustment method to avoid image saturation and maintain good fringe modulation in measuring objects with a high range of surface reflectivities. The adapted fringe patterns are created using only one prior step of fringe-pattern projection and image capture. First, a set of phase-shifted fringe patterns with maximum projection intensity value of 255 and a uniform gray level pattern are projected onto the surface of an object. The patterns are reflected from and deformed by the object surface and captured by a digital camera. The best projection intensities corresponding to each saturated-pixel clusters are determined by fitting a polynomial function to transform captured intensities to projected intensities. Subsequently, the adapted fringe patterns are constructed using the best projection intensities at projector pixel coordinate. Finally, the adapted fringe patterns are projected for phase recovery and 3D shape calculation. The experimental results demonstrate that the proposed method achieves high measurement accuracy even for objects with a high range of surface reflectivities.

Methods and Systems for Measurement and Estimation of Normalized Contrast in Infrared Thermography

NASA Technical Reports Server (NTRS)

Koshti, Ajay M. (Inventor)

2017-01-01

Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

Methods and Systems for Measurement and Estimation of Normalized Contrast in Infrared Thermography

NASA Technical Reports Server (NTRS)

Koshti, Ajay M. (Inventor)

2015-01-01

Methods and systems for converting an image contrast evolution of an object to a temperature contrast evolution and vice versa are disclosed, including methods for assessing an emissivity of the object; calculating an afterglow heat flux evolution; calculating a measurement region of interest temperature change; calculating a reference region of interest temperature change; calculating a reflection temperature change; calculating the image contrast evolution or the temperature contrast evolution; and converting the image contrast evolution to the temperature contrast evolution or vice versa, respectively.

Field methods to measure surface displacement and strain with the Video Image Correlation method

NASA Technical Reports Server (NTRS)

Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.

1994-01-01

The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.

Method for separating video camera motion from scene motion for constrained 3D displacement measurements

NASA Astrophysics Data System (ADS)

Gauthier, L. R.; Jansen, M. E.; Meyer, J. R.

2014-09-01

Camera motion is a potential problem when a video camera is used to perform dynamic displacement measurements. If the scene camera moves at the wrong time, the apparent motion of the object under study can easily be confused with the real motion of the object. In some cases, it is practically impossible to prevent camera motion, as for instance, when a camera is used outdoors in windy conditions. A method to address this challenge is described that provides an objective means to measure the displacement of an object of interest in the scene, even when the camera itself is moving in an unpredictable fashion at the same time. The main idea is to synchronously measure the motion of the camera and to use those data ex post facto to subtract out the apparent motion in the scene that is caused by the camera motion. The motion of the scene camera is measured by using a reference camera that is rigidly attached to the scene camera and oriented towards a stationary reference object. For instance, this reference object may be on the ground, which is known to be stationary. It is necessary to calibrate the reference camera by simultaneously measuring the scene images and the reference images at times when it is known that the scene object is stationary and the camera is moving. These data are used to map camera movement data to apparent scene movement data in pixel space and subsequently used to remove the camera movement from the scene measurements.

Distance Measurements In X-Ray Pictures

NASA Astrophysics Data System (ADS)

Forsgren, Per-Ola

1987-10-01

In this paper, a measurement method for the distance between binary objects will be presented. It has been developed for a specific purpose, the evaluation of rheumatic disease, but should be useful also in other applications. It is based on a distance map in the area between binary objects. A skeleton is extracted from the distance map by searching for local maxima. The distance measure is based on the average of skelton points in a defined measurement area. An objective criterion for selection of measurement points on the skeleton is proposed. Preliminary results indicate that good repeatability is attained.

A novel approach to segmentation and measurement of medical image using level set methods.

PubMed

Chen, Yao-Tien

2017-06-01

The study proposes a novel approach for segmentation and visualization plus value-added surface area and volume measurements for brain medical image analysis. The proposed method contains edge detection and Bayesian based level set segmentation, surface and volume rendering, and surface area and volume measurements for 3D objects of interest (i.e., brain tumor, brain tissue, or whole brain). Two extensions based on edge detection and Bayesian level set are first used to segment 3D objects. Ray casting and a modified marching cubes algorithm are then adopted to facilitate volume and surface visualization of medical-image dataset. To provide physicians with more useful information for diagnosis, the surface area and volume of an examined 3D object are calculated by the techniques of linear algebra and surface integration. Experiment results are finally reported in terms of 3D object extraction, surface and volume rendering, and surface area and volume measurements for medical image analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Tunnel effect measuring systems and particle detectors

NASA Technical Reports Server (NTRS)

Kaiser, William J. (Inventor); Waltman, Steven B. (Inventor); Kenny, Thomas W. (Inventor)

1994-01-01

Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.

Tunnel effect measuring systems and particle detectors

NASA Technical Reports Server (NTRS)

Kaiser, William J. (Inventor); Waltman, Steven B. (Inventor); Kenny, Thomas W. (Inventor)

1993-01-01

Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.

Single-beam, dual-view digital holographic interferometry for biomechanical strain measurements of biological objects

NASA Astrophysics Data System (ADS)

Pantelić, Dejan V.; Grujić, Dušan Ž.; Vasiljević, Darko M.

2014-12-01

We describe a method for dual-view biomechanical strain measurements of highly asymmetrical biological objects, like teeth or bones. By using a spherical mirror, we were able to simultaneously record a digital hologram of the object itself and the mirror image of its (otherwise invisible) rear side. A single laser beam was sufficient to illuminate both sides of the object, and to provide a reference beam. As a result, the system was mechanically very stable, enabling long exposure times (up to 2 min) without the need for vibration isolation. The setup is simple to construct and adjust, and can be used to interferometrically observe any object that is smaller than the mirror diameter. Parallel data processing on a CUDA-enabled (compute unified device architecture) graphics card was used to reconstruct digital holograms and to further correct image distortion. We used the setup to measure the deformation of a tooth due to mastication forces. The finite-element method was used to compare experimental results and theoretical predictions.

Single-beam, dual-view digital holographic interferometry for biomechanical strain measurements of biological objects.

PubMed

Pantelić, Dejan V; Grujić, Dušan Ž; Vasiljević, Darko M

2014-12-01

We describe a method for dual-view biomechanical strain measurements of highly asymmetrical biological objects, like teeth or bones. By using a spherical mirror, we were able to simultaneously record a digital hologram of the object itself and the mirror image of its (otherwise invisible) rear side. A single laser beam was sufficient to illuminate both sides of the object, and to provide a reference beam. As a result, the system was mechanically very stable, enabling long exposure times (up to 2 min) without the need for vibration isolation. The setup is simple to construct and adjust, and can be used to interferometrically observe any object that is smaller than the mirror diameter. Parallel data processing on a CUDA-enabled (compute unified device architecture) graphics card was used to reconstruct digital holograms and to further correct image distortion. We used the setup to measure the deformation of a tooth due to mastication forces. The finite-element method was used to compare experimental results and theoretical predictions.

Bayesian learning

NASA Technical Reports Server (NTRS)

Denning, Peter J.

1989-01-01

In 1983 and 1984, the Infrared Astronomical Satellite (IRAS) detected 5,425 stellar objects and measured their infrared spectra. In 1987 a program called AUTOCLASS used Bayesian inference methods to discover the classes present in these data and determine the most probable class of each object, revealing unknown phenomena in astronomy. AUTOCLASS has rekindled the old debate on the suitability of Bayesian methods, which are computationally intensive, interpret probabilities as plausibility measures rather than frequencies, and appear to depend on a subjective assessment of the probability of a hypothesis before the data were collected. Modern statistical methods have, however, recently been shown to also depend on subjective elements. These debates bring into question the whole tradition of scientific objectivity and offer scientists a new way to take responsibility for their findings and conclusions.

Application of composite small calibration objects in traffic accident scene photogrammetry.

PubMed

Chen, Qiang; Xu, Hongguo; Tan, Lidong

2015-01-01

In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies.

Bootstrap and Counter-Bootstrap approaches for formation of the cortege of Informative indicators by Results of Measurements

NASA Astrophysics Data System (ADS)

Artemenko, M. V.; Chernetskaia, I. E.; Kalugina, N. M.; Shchekina, E. N.

2018-04-01

This article describes the solution of the actual problem of the productive formation of a cortege of informative measured features of the object of observation and / or control using author's algorithms for the use of bootstraps and counter-bootstraps technologies for processing the results of measurements of various states of the object on the basis of different volumes of the training sample. The work that is presented in this paper considers aggregation by specific indicators of informative capacity by linear, majority, logical and “greedy” methods, applied both individually and integrally. The results of the computational experiment are discussed, and in conclusion is drawn that the application of the proposed methods contributes to an increase in the efficiency of classification of the states of the object from the results of measurements.

Method of performing MRI with an atomic magnetometer

DOEpatents

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A.; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2012-11-06

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

Method of performing MRI with an atomic magnetometer

DOEpatents

Savukov, Igor Mykhaylovich; Matlashov, Andrei Nikolaevich; Espy, Michelle A; Volegov, Petr Lvovich; Kraus, Jr., Robert Henry; Zotev, Vadim Sergeyevich

2013-08-27

A method and apparatus are provided for performing an in-situ magnetic resonance imaging of an object. The method includes the steps of providing an atomic magnetometer, coupling a magnetic field generated by magnetically resonating samples of the object through a flux transformer to the atomic magnetometer and measuring a magnetic resonance of the atomic magnetometer.

[Comparison study on subjective and objective measurements of the accommodative convergence to accommodation ratio].

PubMed

Xu, Jing-jing; Xu, Dan; Huang, Tao; Jiang, Jian; Lü, Fan

2012-05-01

To detect the accommodative convergence to accommodation (AC/A) ratios measured respectively by objective and subjective methods. The differences and its relative factors were explored. Forty young volunteers were measured by eye tracker to get the amount of convergence when fixating at the target at 100 cm, 50 cm, 33 cm and 25 cm and were measured by infrared auto-refractor to get corresponding accommodative responses. AC/A ratio based on these two measurements were compared with the calculated and the gradient AC/A ratio from Von Graefe tests. Mean value of stimulated AC/A ratio measured by eye tracker was higher than the calculated and gradient AC/A ratio by Von Graefe method (P = 0.003, 0.001). There are statistic correlation (r = 0.871, P = 0.000) and difference (P = 0.000) between stimulated AC/A ratio and response AC/A ratios both measured by eye tracker, and the difference trends to be greater with the higher AC/A ratio. The objective AC/A ratio is usually higher than the clinical subjective measurement because of more proximal effect. The response AC/A ratio measured objectively may reveal realistically the mutual effect and relationship between accommodation and convergence and it seems to be more credible to be the monitor parameter on progression of myopia in clinics.

Spatial-Heterodyne Interferometry For Reflection And Transm Ission (Shirt) Measurements

DOEpatents

Hanson, Gregory R [Clinton, TN; Bingham, Philip R [Knoxville, TN; Tobin, Ken W [Harriman, TN

2006-02-14

Systems and methods are described for spatial-heterodyne interferometry for reflection and transmission (SHIRT) measurements. A method includes digitally recording a first spatially-heterodyned hologram using a first reference beam and a first object beam; digitally recording a second spatially-heterodyned hologram using a second reference beam and a second object beam; Fourier analyzing the digitally recorded first spatially-heterodyned hologram to define a first analyzed image; Fourier analyzing the digitally recorded second spatially-heterodyned hologram to define a second analyzed image; digitally filtering the first analyzed image to define a first result; and digitally filtering the second analyzed image to define a second result; performing a first inverse Fourier transform on the first result, and performing a second inverse Fourier transform on the second result. The first object beam is transmitted through an object that is at least partially translucent, and the second object beam is reflected from the object.

Objective and subjective treatment evaluation of scars using optical coherence tomography, sonography, photography, and standardised questionnaires.

PubMed

Reinholz, Markus; Schwaiger, Hannah; Poetschke, Julian; Epple, Andreas; Ruzicka, Thomas; Von Braunmühl, Tanja; Gauglitz, Gerd G

2016-12-01

Currently, different types of treatments for pathological scars are available, however, to date, there is no established method of measurement to objectively assess therapeutic outcome. Treatment success is usually evaluated clinically by the physician and patient. Non-invasive imaging techniques, such as HD-OCT (high-definition optical coherence tomography), may represent a valuable diagnostic tool to objectively measure therapeutic outcome. To compare HD-OCT with ultrasound and subjective evaluation tools, such as questionnaires. In total, eight patients with pathological scars were treated in this pilot study with cryotherapy and intralesional steroid injections, and evaluated pre- and post-treatment using clinical examination, photography, sonography, and HD-OCT. The analysis of objective and subjective measuring methods was used to draw direct comparisons. HD-OCT revealed reduced epidermal and dermal thickness of the scar after four treatments with triamcinolone acetonide and cryotherapy. Based on sonography, a total reduction in scar height and reduction in scar depth was demonstrated. Both methods correlated well with the injected amount of triamcinolone acetonide. In addition, a positive correlation between well-established subjective and objective evaluation methods was found. We demonstrate that HD-OCT may be used as an objective diagnostic instrument to evaluate skin thickness under therapy for pathological scars, and serves as a valuable adjunctive device in combination with ultrasound and subjective evaluation tools. This provides additional information for the therapist concerning the quality and success of the applied treatment.

Observations Regarding Scatter Fraction and NEC Measurements for Small Animal PET

NASA Astrophysics Data System (ADS)

Yang, Yongfeng; Cherry, S. R.

2006-02-01

The goal of this study was to evaluate the magnitude and origin of scattered radiation in a small-animal PET scanner and to assess the impact of these findings on noise equivalent count rate (NECR) measurements, a metric often used to optimize scanner acquisition parameters and to compare one scanner with another. The scatter fraction (SF) was measured for line sources in air and line sources placed within a mouse-sized phantom (25 mm /spl phi//spl times/70 mm) and a rat-sized phantom (60 mm /spl phi//spl times/150 mm) on the microPET II small-animal PET scanner. Measurements were performed for lower energy thresholds ranging from 150-450 keV and a fixed upper energy threshold of 750 keV. Four different methods were compared for estimating the SF. Significant scatter fractions were measured with just the line source in the field of view, with the spatial distribution of these events consistent with scatter from the gantry and room environment. For mouse imaging, this component dominates over object scatter, and the measured SF is strongly method dependent. The environmental SF rapidly increases as the lower energy threshold decreases and can be more than 30% for an open energy window of 150-750 keV. The object SF originating from the mouse phantom is about 3-4% and does not change significantly as the lower energy threshold increases. The object SF for the rat phantom ranges from 10 to 35% for different energy windows and increases as the lower energy threshold decreases. Because the measured SF is highly dependent on the method, and there is as yet no agreed upon standard for animal PET, care must be exercised when comparing NECR for small objects between different scanners. Differences may be methodological rather than reflecting any relevant difference in the performance of the scanner. Furthermore, these results have implications for scatter correction methods when the majority of the detected scatter does not arise from the object itself.

Geophysics-based method of locating a stationary earth object

DOEpatents

Daily, Michael R [Albuquerque, NM; Rohde, Steven B [Corrales, NM; Novak, James L [Albuquerque, NM

2008-05-20

A geophysics-based method for determining the position of a stationary earth object uses the periodic changes in the gravity vector of the earth caused by the sun- and moon-orbits. Because the local gravity field is highly irregular over a global scale, a model of local tidal accelerations can be compared to actual accelerometer measurements to determine the latitude and longitude of the stationary object.

The better way to determine the validity, reliability, objectivity and accuracy of measuring devices.

PubMed

Pazira, Parvin; Rostami Haji-Abadi, Mahdi; Zolaktaf, Vahid; Sabahi, Mohammadfarzan; Pazira, Toomaj

2016-06-08

In relation to statistical analysis, studies to determine the validity, reliability, objectivity and precision of new measuring devices are usually incomplete, due in part to using only correlation coefficient and ignoring the data dispersion. The aim of this study was to demonstrate the best way to determine the validity, reliability, objectivity and accuracy of an electro-inclinometer or other measuring devices. Another purpose of this study is to answer the question of whether reliability and objectivity represent accuracy of measuring devices. The validity of an electro-inclinometer was examined by mechanical and geometric methods. The objectivity and reliability of the device was assessed by calculating Cronbach's alpha for repeated measurements by three raters and by measurements on the same person by mechanical goniometer and the electro-inclinometer. Measurements were performed on "hip flexion with the extended knee" and "shoulder abduction with the extended elbow." The raters measured every angle three times within an interval of two hours. The three-way ANOVA was used to determine accuracy. The results of mechanical and geometric analysis showed that validity of the electro-inclinometer was 1.00 and level of error was less than one degree. Objectivity and reliability of electro-inclinometer was 0.999, while objectivity of mechanical goniometer was in the range of 0.802 to 0.966 and the reliability was 0.760 to 0.961. For hip flexion, the difference between raters in joints angle measurement by electro-inclinometer and mechanical goniometer was 1.74 and 16.33 degree (P<0.05), respectively. The differences for shoulder abduction measurement by electro-inclinometer and goniometer were 0.35 and 4.40 degree (P<0.05). Although both the objectivity and reliability are acceptable, the results showed that measurement error was very high in the mechanical goniometer. Therefore, it can be concluded that objectivity and reliability alone cannot determine the accuracy of a device and it is preferable to use other statistical methods to compare and evaluate the accuracy of these two devices.

Objective measures of situation awareness in a simulated medical environment

PubMed Central

Wright, M; Taekman, J; Endsley, M

2004-01-01

One major limitation in the use of human patient simulators is a lack of objective, validated measures of human performance. Objective measures are necessary if simulators are to be used to evaluate the skills and training of medical practitioners and teams or to evaluate the impact of new processes or equipment design on overall system performance. Situation awareness (SA) refers to a person's perception and understanding of their dynamic environment. This awareness and comprehension is critical in making correct decisions that ultimately lead to correct actions in medical care settings. An objective measure of SA may be more sensitive and diagnostic than traditional performance measures. This paper reviews a theory of SA and discusses the methods required for developing an objective measure of SA within the context of a simulated medical environment. Analysis and interpretation of SA data for both individual and team performance in health care are also presented. PMID:15465958

Optical characteristics of the earth's surface and atmosphere from the point of view of the remote sensing of natural resources: Review of the contemporary status of the problem

NASA Technical Reports Server (NTRS)

Tarnopolskiy, V. I.

1978-01-01

Widely used remote probing methods, and especially the multispectral method, for studying the earth from aerospace platforms necessitate the systematization and accumulation of data on the relationships between remote observations and measured parameters and characteristic properties and conditions of phenomena on the earth's surface. Data were presented on the optical characteristics of natural objects which arise during observations of these objects over a wide spectral interval which encompasses solar radiation reflected by the object as well as the object's inherent thermal radiation. The influence of the earth's atmosphere on remote measurements and several problems in simulation and calculation are discussed.

Differentiation and Exploration of Model MACP for HE VER 1.0 on Prototype Performance Measurement Application for Higher Education

NASA Astrophysics Data System (ADS)

El Akbar, R. Reza; Anshary, Muhammad Adi Khairul; Hariadi, Dennis

2018-02-01

Model MACP for HE ver.1. Is a model that describes how to perform measurement and monitoring performance for Higher Education. Based on a review of the research related to the model, there are several parts of the model component to develop in further research, so this research has four main objectives. The first objective is to differentiate the CSF (critical success factor) components in the previous model, the two key KPI (key performance indicators) exploration in the previous model, the three based on the previous objective, the new and more detailed model design. The final goal is the fourth designed prototype application for performance measurement in higher education, based on a new model created. The method used is explorative research method and application design using prototype method. The results of this study are first, forming a more detailed new model for measurement and monitoring of performance in higher education, differentiation and exploration of the Model MACP for HE Ver.1. The second result compiles a dictionary of college performance measurement by re-evaluating the existing indicators. The third result is the design of prototype application of performance measurement in higher education.

Examining techniques for measuring the effects of nutrients on mental performance and mood state.

PubMed

Hamer, Mark; Dye, Louise; Siobhan Mitchell, E; Layé, Sophie; Saunders, Caroline; Boyle, Neil; Schuermans, Jeroen; Sijben, John

2016-09-01

Intake of specific nutrients has been linked to mental states and various indices of cognitive performance although the effects are often subtle and difficult to interpret. Measurement of so-called objective variables (e.g. reaction times) is often considered to be the gold standard for assessing outcomes in this field of research. It can, however, be argued that data on subjective experience (e.g. mood) are also important and may enrich existing objective data. The aim of this review is to evaluate methods for measuring mental performance and mood, considering the definition of subjective mood and the validity of measures of subjective experience. A multi-stakeholder expert group was invited by ILSI Europe to come to a consensus around the utility of objective and subjective measurement in this field, which forms the basis of the paper. Therefore, the present review reflects a succinct overview of the science but is not intended to be a systematic review. The proposed approach extends the traditional methodology using standard 'objective' measurements to also include the consumers' subjective experiences in relation to food. Specific recommendations include 1) using contemporary methods to capture transient mood states; 2) using sufficiently sensitive measures to capture effects of nutritional intervention; 3) considering the possibility that subjective and objective responses will occur over different time frames; and 4) recognition of the importance of expectancy and placebo effects for subjective measures. The consensus reached was that the most informative approach should involve collection and consideration of both objective and subjective data.

Assessing ADHD symptoms in children and adults: evaluating the role of objective measures.

PubMed

Emser, Theresa S; Johnston, Blair A; Steele, J Douglas; Kooij, Sandra; Thorell, Lisa; Christiansen, Hanna

2018-05-18

Diagnostic guidelines recommend using a variety of methods to assess and diagnose ADHD. Applying subjective measures always incorporates risks such as informant biases or large differences between ratings obtained from diverse sources. Furthermore, it has been demonstrated that ratings and tests seem to assess somewhat different constructs. The use of objective measures might thus yield valuable information for diagnosing ADHD. This study aims at evaluating the role of objective measures when trying to distinguish between individuals with ADHD and controls. Our sample consisted of children (n = 60) and adults (n = 76) diagnosed with ADHD and matched controls who completed self- and observer ratings as well as objective tasks. Diagnosis was primarily based on clinical interviews. A popular pattern recognition approach, support vector machines, was used to predict the diagnosis. We observed relatively high accuracy of 79% (adults) and 78% (children) applying solely objective measures. Predicting an ADHD diagnosis using both subjective and objective measures exceeded the accuracy of objective measures for both adults (89.5%) and children (86.7%), with the subjective variables proving to be the most relevant. We argue that objective measures are more robust against rater bias and errors inherent in subjective measures and may be more replicable. Considering the high accuracy of objective measures only, we found in our study, we think that they should be incorporated in diagnostic procedures for assessing ADHD.

Using the Bootstrap Method for a Statistical Significance Test of Differences between Summary Histograms

NASA Technical Reports Server (NTRS)

Xu, Kuan-Man

2006-01-01

A new method is proposed to compare statistical differences between summary histograms, which are the histograms summed over a large ensemble of individual histograms. It consists of choosing a distance statistic for measuring the difference between summary histograms and using a bootstrap procedure to calculate the statistical significance level. Bootstrapping is an approach to statistical inference that makes few assumptions about the underlying probability distribution that describes the data. Three distance statistics are compared in this study. They are the Euclidean distance, the Jeffries-Matusita distance and the Kuiper distance. The data used in testing the bootstrap method are satellite measurements of cloud systems called cloud objects. Each cloud object is defined as a contiguous region/patch composed of individual footprints or fields of view. A histogram of measured values over footprints is generated for each parameter of each cloud object and then summary histograms are accumulated over all individual histograms in a given cloud-object size category. The results of statistical hypothesis tests using all three distances as test statistics are generally similar, indicating the validity of the proposed method. The Euclidean distance is determined to be most suitable after comparing the statistical tests of several parameters with distinct probability distributions among three cloud-object size categories. Impacts on the statistical significance levels resulting from differences in the total lengths of satellite footprint data between two size categories are also discussed.

Measurement and Analysis of Olfactory Responses with the Aim of Establishing an Objective Diagnostic Method for Central Olfactory Disorders

NASA Astrophysics Data System (ADS)

Uno, Tominori; Wang, Li-Qun; Miwakeichi, Fumikazu; Tonoike, Mitsuo; Kaneda, Teruo

In order to establish a new diagnostic method for central olfactory disorders and to identify objective indicators, we measured and analyzed brain activities in the parahippocampal gyrus and uncus, region of responsibility for central olfactory disorders. The relationship between olfactory stimulation and brain response at region of responsibility can be examined in terms of fitted responses (FR). FR in these regions may be individual indicators of changes in brain olfactory responses. In the present study, in order to non-invasively and objectively measure olfactory responses, an odor oddball task was conducted on four healthy volunteers using functional magnetic resonance imaging (fMRI) and a odorant stimulator with blast-method. The results showed favorable FR and activation in the parahippocampal gyrus or uncus in all subjects. In some subjects, both the parahippocampal gyrus and uncus were activated. Furthermore, activation was also confirmed in the cingulate gyrus, middle frontal gyrus, precentral gyrus, postcentral gyrus, superior temporal gyrus and insula. The hippocampus and uncus are known to be involved in the olfactory disorders associated with early-stage Alzheimer's disease and other olfactory disorders. In the future, it will be necessary to further develop the present measurement and analysis method to clarify the relationship between central olfactory disorders and brain activities and establish objective indicators that are useful for diagnosis.

Evaluation of a modified method to measure total starch in animal feeds

USDA-ARS?s Scientific Manuscript database

The AOAC method 996.11 has been recognized as an accurate, repeatable, and efficient method to measure total starch in animal feeds. However, analyzing starch using the AOAC method can be expensive and associated with technical challenges. The objective of this study was to determine if an alternati...

IAEA Sampling Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geist, William H.

2017-09-15

The objectives for this presentation are to describe the method that the IAEA uses to determine a sampling plan for nuclear material measurements; describe the terms detection probability and significant quantity; list the three nuclear materials measurement types; describe the sampling method applied to an item facility; and describe multiple method sampling.

Collinearity and Sample Coverage Issues in the Objective Measurement of Vocal Quality: The Case of Roughness and Breathiness

ERIC Educational Resources Information Center

Ferrer, Carlos A.; Haderlein, Tino; Maryn, Youri; de Bodt, Marc S.; Nöth, Elmar

2018-01-01

Purpose: The aim of the study was to address the reported inconsistencies in the relationship between objective acoustic measures and perceptual ratings of vocal quality. Method: This tutorial moves away from the more widely examined problems related to obtaining the perceptual ratings and the acoustic measures and centers in less scrutinized…

The Development and Validation of the Protective Factors Survey: A Self-Report Measure of Protective Factors against Child Maltreatment

ERIC Educational Resources Information Center

Counts, Jacqueline M.; Buffington, Elenor S.; Chang-Rios, Karin; Rasmussen, Heather N.; Preacher, Kristopher J.

2010-01-01

Objective: The objective of this study was to evaluate the internal structure of a self-report measure of multiple family-level protective factors against abuse and neglect and explore the relationship of this instrument to other measures of child maltreatment. Methods: For the exploratory factor analysis, 11 agencies from 4 states administered…

Application of coordinate transform on ball plate calibration

NASA Astrophysics Data System (ADS)

Wei, Hengzheng; Wang, Weinong; Ren, Guoying; Pei, Limei

2015-02-01

For the ball plate calibration method with coordinate measurement machine (CMM) equipped with laser interferometer, it is essential to adjust the ball plate parallel to the direction of laser beam. It is very time-consuming. To solve this problem, a method based on coordinate transformation between machine system and object system is presented. With the fixed points' coordinates of the ball plate measured in the object system and machine system, the transformation matrix between the coordinate systems is calculated. The laser interferometer measurement data error due to the placement of ball plate can be corrected with this transformation matrix. Experimental results indicate that this method is consistent with the handy adjustment method. It avoids the complexity of ball plate adjustment. It also can be applied to the ball beam calibration.

System and method for automated object detection in an image

DOEpatents

Kenyon, Garrett T.; Brumby, Steven P.; George, John S.; Paiton, Dylan M.; Schultz, Peter F.

2015-10-06

A contour/shape detection model may use relatively simple and efficient kernels to detect target edges in an object within an image or video. A co-occurrence probability may be calculated for two or more edge features in an image or video using an object definition. Edge features may be differentiated between in response to measured contextual support, and prominent edge features may be extracted based on the measured contextual support. The object may then be identified based on the extracted prominent edge features.

A practical material decomposition method for x-ray dual spectral computed tomography.

PubMed

Hu, Jingjing; Zhao, Xing

2016-03-17

X-ray dual spectral CT (DSCT) scans the measured object with two different x-ray spectra, and the acquired rawdata can be used to perform the material decomposition of the object. Direct calibration methods allow a faster material decomposition for DSCT and can be separated in two groups: image-based and rawdata-based. The image-based method is an approximative method, and beam hardening artifacts remain in the resulting material-selective images. The rawdata-based method generally obtains better image quality than the image-based method, but this method requires geometrically consistent rawdata. However, today's clinical dual energy CT scanners usually measure different rays for different energy spectra and acquire geometrically inconsistent rawdata sets, and thus cannot meet the requirement. This paper proposes a practical material decomposition method to perform rawdata-based material decomposition in the case of inconsistent measurement. This method first yields the desired consistent rawdata sets from the measured inconsistent rawdata sets, and then employs rawdata-based technique to perform material decomposition and reconstruct material-selective images. The proposed method was evaluated by use of simulated FORBILD thorax phantom rawdata and dental CT rawdata, and simulation results indicate that this method can produce highly quantitative DSCT images in the case of inconsistent DSCT measurements.

Objective Sleep Measurement in Typically and Atypically Developing Preschool Children with ADHD-Like Profiles

ERIC Educational Resources Information Center

Goodlin-Jones, Beth L.; Waters, Sara; Anders, Thomas F.

2009-01-01

Objective: This study investigated the association between preschool children's sleep patterns measured by actigraphy and parent-reported hyperactivity symptoms. Many previous studies have reported sleep problems in children with attention deficit hyperactivity disorder (ADHD)-like symptoms. Methods: This study examined a cross-sectional sample of…

Association of objectively measured physical activity with cardiovascular risk in mobility-limited older adults

USDA-ARS?s Scientific Manuscript database

Background: Data are sparse regarding the impacts of habitual physical activity (PA) and sedentary behavior on cardiovascular (CV) risk in older adults with mobility limitations. Methods and Results: This study examined the baseline, cross-sectional association between CV risk and objectively measur...

Noninvasive quantification of human brain antioxidant concentrations after an intravenous bolus of vitamin C

USDA-ARS?s Scientific Manuscript database

Background: Until now, antioxidant based initiatives for preventing dementia have lacked a means to detect deficiency or measure pharmacologic effect in the human brain in situ. Objective: Our objective was to apply a novel method to measure key human brain antioxidant concentrations throughout the ...

Objective Measure of Nasal Air Emission Using Nasal Accelerometry

ERIC Educational Resources Information Center

Cler, Meredith J.; Lien, Yu-An, S.; Braden, Maia N.; Mittleman, Talia; Downing, Kerri; Stepp, Cara, E.

2016-01-01

Purpose: This article describes the development and initial validation of an objective measure of nasal air emission (NAE) using nasal accelerometry. Method: Nasal acceleration and nasal airflow signals were simultaneously recorded while an expert speech language pathologist modeled NAEs at a variety of severity levels. In addition, microphone and…

Waist Circumference and Objectively Measured Sedentary Behavior in Rural School Adolescents

ERIC Educational Resources Information Center

Machado-Rodrigues, Aristides M.; Coelho e Silva, Manuel J.; Ribeiro, Luís P.; Fernandes, Romulo; Mota, Jorge; Malina, Robert M.

2016-01-01

Background: Research on relationships between lifestyle behaviors and adiposity in school youth is potentially important for identifying subgroups at risk. This study evaluates the associations between waist circumference (WC) and objective measures of sedentary behavior (SB) in a sample of rural school adolescents. Methods: The sample included…

Assessment methods for the evaluation of vitiligo.

PubMed

Alghamdi, K M; Kumar, A; Taïeb, A; Ezzedine, K

2012-12-01

There is no standardized method for assessing vitiligo. In this article, we review the literature from 1981 to 2011 on different vitiligo assessment methods. We aim to classify the techniques available for vitiligo assessment as subjective, semi-objective or objective; microscopic or macroscopic; and as based on morphometry or colorimetry. Macroscopic morphological measurements include visual assessment, photography in natural or ultraviolet light, photography with computerized image analysis and tristimulus colorimetry or spectrophotometry. Non-invasive micromorphological methods include confocal laser microscopy (CLM). Subjective methods include clinical evaluation by a dermatologist and a vitiligo disease activity score. Semi-objective methods include the Vitiligo Area Scoring Index (VASI) and point-counting methods. Objective methods include software-based image analysis, tristimulus colorimetry, spectrophotometry and CLM. Morphometry is the measurement of the vitiliginous surface area, whereas colorimetry quantitatively analyses skin colour changes caused by erythema or pigment. Most methods involve morphometry, except for the chromameter method, which assesses colorimetry. Some image analysis software programs can assess both morphometry and colorimetry. The details of these programs (Corel Draw, Image Pro Plus, AutoCad and Photoshop) are discussed in the review. Reflectance confocal microscopy provides real-time images and has great potential for the non-invasive assessment of pigmentary lesions. In conclusion, there is no single best method for assessing vitiligo. This review revealed that VASI, the rule of nine and Wood's lamp are likely to be the best techniques available for assessing the degree of pigmentary lesions and measuring the extent and progression of vitiligo in the clinic and in clinical trials. © 2012 The Authors. Journal of the European Academy of Dermatology and Venereology © 2012 European Academy of Dermatology and Venereology.

Holographic particle size extraction by using Wigner-Ville distribution

NASA Astrophysics Data System (ADS)

Chuamchaitrakool, Porntip; Widjaja, Joewono; Yoshimura, Hiroyuki

2014-06-01

A new method for measuring object size from in-line holograms by using Wigner-Ville distribution (WVD) is proposed. The proposed method has advantages over conventional numerical reconstruction in that it is free from iterative process and it can extract the object size and position with only single computation of the WVD. Experimental verification of the proposed method is presented.

Measuring Distances Using Digital Cameras

ERIC Educational Resources Information Center

Kendal, Dave

2007-01-01

This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

Creating objects and object categories for studying perception and perceptual learning.

PubMed

Hauffen, Karin; Bart, Eugene; Brady, Mark; Kersten, Daniel; Hegdé, Jay

2012-11-02

In order to quantitatively study object perception, be it perception by biological systems or by machines, one needs to create objects and object categories with precisely definable, preferably naturalistic, properties. Furthermore, for studies on perceptual learning, it is useful to create novel objects and object categories (or object classes) with such properties. Many innovative and useful methods currently exist for creating novel objects and object categories (also see refs. 7,8). However, generally speaking, the existing methods have three broad types of shortcomings. First, shape variations are generally imposed by the experimenter, and may therefore be different from the variability in natural categories, and optimized for a particular recognition algorithm. It would be desirable to have the variations arise independently of the externally imposed constraints. Second, the existing methods have difficulty capturing the shape complexity of natural objects. If the goal is to study natural object perception, it is desirable for objects and object categories to be naturalistic, so as to avoid possible confounds and special cases. Third, it is generally hard to quantitatively measure the available information in the stimuli created by conventional methods. It would be desirable to create objects and object categories where the available information can be precisely measured and, where necessary, systematically manipulated (or 'tuned'). This allows one to formulate the underlying object recognition tasks in quantitative terms. Here we describe a set of algorithms, or methods, that meet all three of the above criteria. Virtual morphogenesis (VM) creates novel, naturalistic virtual 3-D objects called 'digital embryos' by simulating the biological process of embryogenesis. Virtual phylogenesis (VP) creates novel, naturalistic object categories by simulating the evolutionary process of natural selection. Objects and object categories created by these simulations can be further manipulated by various morphing methods to generate systematic variations of shape characteristics. The VP and morphing methods can also be applied, in principle, to novel virtual objects other than digital embryos, or to virtual versions of real-world objects. Virtual objects created in this fashion can be rendered as visual images using a conventional graphical toolkit, with desired manipulations of surface texture, illumination, size, viewpoint and background. The virtual objects can also be 'printed' as haptic objects using a conventional 3-D prototyper. We also describe some implementations of these computational algorithms to help illustrate the potential utility of the algorithms. It is important to distinguish the algorithms from their implementations. The implementations are demonstrations offered solely as a 'proof of principle' of the underlying algorithms. It is important to note that, in general, an implementation of a computational algorithm often has limitations that the algorithm itself does not have. Together, these methods represent a set of powerful and flexible tools for studying object recognition and perceptual learning by biological and computational systems alike. With appropriate extensions, these methods may also prove useful in the study of morphogenesis and phylogenesis.

Designing an experiment to measure cellular interaction forces

NASA Astrophysics Data System (ADS)

McAlinden, Niall; Glass, David G.; Millington, Owain R.; Wright, Amanda J.

2013-09-01

Optical trapping is a powerful tool in Life Science research and is becoming common place in many microscopy laboratories and facilities. The force applied by the laser beam on the trapped object can be accurately determined allowing any external forces acting on the trapped object to be deduced. We aim to design a series of experiments that use an optical trap to measure and quantify the interaction force between immune cells. In order to cause minimum perturbation to the sample we plan to directly trap T cells and remove the need to introduce exogenous beads to the sample. This poses a series of challenges and raises questions that need to be answered in order to design a set of effect end-point experiments. A typical cell is large compared to the beads normally trapped and highly non-uniform - can we reliably trap such objects and prevent them from rolling and re-orientating? In this paper we show how a spatial light modulator can produce a triple-spot trap, as opposed to a single-spot trap, giving complete control over the object's orientation and preventing it from rolling due, for example, to Brownian motion. To use an optical trap as a force transducer to measure an external force you must first have a reliably calibrated system. The optical trapping force is typically measured using either the theory of equipartition and observing the Brownian motion of the trapped object or using an escape force method, e.g. the viscous drag force method. In this paper we examine the relationship between force and displacement, as well as measuring the maximum displacement from equilibrium position before an object falls out of the trap, hence determining the conditions under which the different calibration methods should be applied.

Testing and Validation of the Dynamic Interia Measurement Method

NASA Technical Reports Server (NTRS)

Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

2015-01-01

This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

Method of making self-calibrated displacement measurements

DOEpatents

Pedersen, Herbert N.

1977-01-01

A method for monitoring the displacement of an object having an acoustically reflective surface at least partially submerged in an acoustically conductive medium. The reflective surface is designed to have a stepped interface responsive to an incident acoustic pulse to provide separate discrete reflected pulses to a receiving transducer. The difference in the time of flight of the reflected acoustic signals corresponds to the known step height and the time of travel of the signals to the receiving transducer provides a measure of the displacement of the object. Accordingly, the reference step length enables simultaneous calibration of each displacement measurement.

Research on measurement method of optical camouflage effect of moving object

NASA Astrophysics Data System (ADS)

Wang, Juntang; Xu, Weidong; Qu, Yang; Cui, Guangzhen

2016-10-01

Camouflage effectiveness measurement as an important part of the camouflage technology, which testing and measuring the camouflage effect of the target and the performance of the camouflage equipment according to the tactical and technical requirements. The camouflage effectiveness measurement of current optical band is mainly aimed at the static target which could not objectively reflect the dynamic camouflage effect of the moving target. This paper synthetical used technology of dynamic object detection and camouflage effect detection, the digital camouflage of the moving object as the research object, the adaptive background update algorithm of Surendra was improved, a method of optical camouflage effect detection using Lab-color space in the detection of moving-object was presented. The binary image of moving object is extracted by this measurement technology, in the sequence diagram, the characteristic parameters such as the degree of dispersion, eccentricity, complexity and moment invariants are constructed to construct the feature vector space. The Euclidean distance of moving target which through digital camouflage was calculated, the results show that the average Euclidean distance of 375 frames was 189.45, which indicated that the degree of dispersion, eccentricity, complexity and moment invariants of the digital camouflage graphics has a great difference with the moving target which not spray digital camouflage. The measurement results showed that the camouflage effect was good. Meanwhile with the performance evaluation module, the correlation coefficient of the dynamic target image range 0.1275 from 0.0035, and presented some ups and down. Under the dynamic condition, the adaptability of target and background was reflected. In view of the existing infrared camouflage technology, the next step, we want to carry out the camouflage effect measurement technology of the moving target based on infrared band.

Automatic Topography Using High Precision Digital Moire Methods

NASA Astrophysics Data System (ADS)

Yatagai, T.; Idesawa, M.; Saito, S.

1983-07-01

Three types of moire topographic methods using digital techniques are proposed. Deformed gratings obtained by projecting a reference grating onto an object under test are subjected to digital analysis. The electronic analysis procedures of deformed gratings described here enable us to distinguish between depression and elevation of the object, so that automatic measurement of 3-D shapes and automatic moire fringe interpolation are performed. Based on the digital moire methods, we have developed a practical measurement system, with a linear photodiode array on a micro-stage as a scanning image sensor. Examples of fringe analysis in medical applications are presented.

Measuring landscape esthetics: the scenic beauty estimation method

Treesearch

Terry C. Daniel; Ron S. Boster

1976-01-01

The Scenic Beauty Estimation Method (SBE) provides quantitative measures of esthetic preferences for alternative wildland management systems. Extensive experimentation and testing with user, interest, and professional groups validated the method. SBE shows promise as an efficient and objective means for assessing the scenic beauty of public forests and wildlands, and...

Characterization of Laser Cleaning of Artworks

PubMed Central

Marczak, Jan; Koss, Andrzej; Targowski, Piotr; Góra, Michalina; Strzelec, Marek; Sarzyński, Antoni; Skrzeczanowski, Wojciech; Ostrowski, Roman; Rycyk, Antoni

2008-01-01

The main tasks of conservators of artworks and monuments are the estimation and analysis of damages (present condition), object conservation (cleaning process), and the protection of an object against further degradation. One of the physical methods that is becoming more and more popular for dirt removal is the laser cleaning method. This method is non-contact, selective, local, controlled, self-limiting, gives immediate feedback and preserves even the gentlest of relief - the trace of a paintbrush. Paper presents application of different, selected physical sensing methods to characterize condition of works of art as well as laser cleaning process itself. It includes, tested in our laboratories, optical surface measurements (e.g. colorimetry, scatterometry, interferometry), infrared thermography, optical coherent tomography and acoustic measurements for “on-line” evaluation of cleaning progress. Results of laser spectrometry analyses (LIBS, Raman) will illustrate identification and dating of objects superficial layers. PMID:27873884

Quantized phase coding and connected region labeling for absolute phase retrieval.

PubMed

Chen, Xiangcheng; Wang, Yuwei; Wang, Yajun; Ma, Mengchao; Zeng, Chunnian

2016-12-12

This paper proposes an absolute phase retrieval method for complex object measurement based on quantized phase-coding and connected region labeling. A specific code sequence is embedded into quantized phase of three coded fringes. Connected regions of different codes are labeled and assigned with 3-digit-codes combining the current period and its neighbors. Wrapped phase, more than 36 periods, can be restored with reference to the code sequence. Experimental results verify the capability of the proposed method to measure multiple isolated objects.

Exploration of complex visual feature spaces for object perception

PubMed Central

Leeds, Daniel D.; Pyles, John A.; Tarr, Michael J.

2014-01-01

The mid- and high-level visual properties supporting object perception in the ventral visual pathway are poorly understood. In the absence of well-specified theory, many groups have adopted a data-driven approach in which they progressively interrogate neural units to establish each unit's selectivity. Such methods are challenging in that they require search through a wide space of feature models and stimuli using a limited number of samples. To more rapidly identify higher-level features underlying human cortical object perception, we implemented a novel functional magnetic resonance imaging method in which visual stimuli are selected in real-time based on BOLD responses to recently shown stimuli. This work was inspired by earlier primate physiology work, in which neural selectivity for mid-level features in IT was characterized using a simple parametric approach (Hung et al., 2012). To extend such work to human neuroimaging, we used natural and synthetic object stimuli embedded in feature spaces constructed on the basis of the complex visual properties of the objects themselves. During fMRI scanning, we employed a real-time search method to control continuous stimulus selection within each image space. This search was designed to maximize neural responses across a pre-determined 1 cm3 brain region within ventral cortex. To assess the value of this method for understanding object encoding, we examined both the behavior of the method itself and the complex visual properties the method identified as reliably activating selected brain regions. We observed: (1) Regions selective for both holistic and component object features and for a variety of surface properties; (2) Object stimulus pairs near one another in feature space that produce responses at the opposite extremes of the measured activity range. Together, these results suggest that real-time fMRI methods may yield more widely informative measures of selectivity within the broad classes of visual features associated with cortical object representation. PMID:25309408

Tensor-based dynamic reconstruction method for electrical capacitance tomography

NASA Astrophysics Data System (ADS)

Lei, J.; Mu, H. P.; Liu, Q. B.; Li, Z. H.; Liu, S.; Wang, X. Y.

2017-03-01

Electrical capacitance tomography (ECT) is an attractive visualization measurement method, in which the acquisition of high-quality images is beneficial for the understanding of the underlying physical or chemical mechanisms of the dynamic behaviors of the measurement objects. In real-world measurement environments, imaging objects are often in a dynamic process, and the exploitation of the spatial-temporal correlations related to the dynamic nature will contribute to improving the imaging quality. Different from existing imaging methods that are often used in ECT measurements, in this paper a dynamic image sequence is stacked into a third-order tensor that consists of a low rank tensor and a sparse tensor within the framework of the multiple measurement vectors model and the multi-way data analysis method. The low rank tensor models the similar spatial distribution information among frames, which is slowly changing over time, and the sparse tensor captures the perturbations or differences introduced in each frame, which is rapidly changing over time. With the assistance of the Tikhonov regularization theory and the tensor-based multi-way data analysis method, a new cost function, with the considerations of the multi-frames measurement data, the dynamic evolution information of a time-varying imaging object and the characteristics of the low rank tensor and the sparse tensor, is proposed to convert the imaging task in the ECT measurement into a reconstruction problem of a third-order image tensor. An effective algorithm is developed to search for the optimal solution of the proposed cost function, and the images are reconstructed via a batching pattern. The feasibility and effectiveness of the developed reconstruction method are numerically validated.

Laser Doppler pulp vitality measurements: simulation and measurement

NASA Astrophysics Data System (ADS)

Ertl, T.

2017-02-01

Frequently pulp vitality measurement is done in a dental practice by pressing a frozen cotton pellet on the tooth. This method is subjective, as the patient's response is required, sometimes painful and has moderate sensitivity and specificity. Other methods, based on optical or electrical measurement have been published, but didńt find wide spread application in the dental offices. Laser Doppler measurement of the blood flow in the pulp could be an objective method to measure pulp vitality, but the influence of the gingival blood flow on the measurements is a concern. Therefore experiments and simulations were done to learn more about the gingival blood flow in relation to the pulpal blood flow and how to minimize the influence. First patient measurements were done to show the feasibility clinically. Results: Monte Carlo simulations and bench experiments simulating the blood flow in and around a tooth show that both basic configurations, transmission and reflection measurements are possible. Most favorable is a multi-point measurement with different distances from the gingiva. Preliminary sensitivity / specificity are promising and might allow an objective and painless measurement of tooth vitality.

Measurement of in vivo local shear modulus using MR elastography multiple-phase patchwork offsets.

PubMed

Suga, Mikio; Matsuda, Tetsuya; Minato, Kotaro; Oshiro, Osamu; Chihara, Kunihiro; Okamoto, Jun; Takizawa, Osamu; Komori, Masaru; Takahashi, Takashi

2003-07-01

Magnetic resonance elastography (MRE) is a method that can visualize the propagating and standing shear waves in an object being measured. The quantitative value of a shear modulus can be calculated by estimating the local shear wavelength. Low-frequency mechanical motion must be used for soft, tissue-like objects because a propagating shear wave rapidly attenuates at a higher frequency. Moreover, a propagating shear wave is distorted by reflections from the boundaries of objects. However, the distortions are minimal around the wave front of the propagating shear wave. Therefore, we can avoid the effect of reflection on a region of interest (ROI) by adjusting the duration of mechanical vibrations. Thus, the ROI is often shorter than the propagating shear wavelength. In the MRE sequence, a motion-sensitizing gradient (MSG) is synchronized with mechanical cyclic motion. MRE images with multiple initial phase offsets can be generated with increasing delays between the MSG and mechanical vibrations. This paper proposes a method for measuring the local shear wavelength using MRE multiple initial phase patchwork offsets that can be used when the size of the object being measured is shorter than the local wavelength. To confirm the reliability of the proposed method, computer simulations, a simulated tissue study and in vitro and in vivo studies were performed.

Nasendoscopy: an analysis of measurement uncertainties.

PubMed

Gilleard, Onur; Sommerlad, Brian; Sell, Debbie; Ghanem, Ali; Birch, Malcolm

2013-05-01

Objective : The purpose of this study was to analyze the optical characteristics of two different nasendoscopes used to assess velopharyngeal insufficiency and to quantify the measurement uncertainties that will occur in a typical set of clinical data. Design : The magnification and barrel distortion associated with nasendoscopy was estimated by using computer software to analyze the apparent dimensions of a spatially calibrated test object at varying object-lens distances. In addition, a method of semiquantitative analysis of velopharyngeal closure using nasendoscopy and computer software is described. To calculate the reliability of this method, 10 nasendoscopy examinations were analyzed two times by three separate operators. The measure of intraoperator and interoperator agreement was evaluated using Pearson's r correlation coefficient. Results : Over an object lens distance of 9 mm, magnification caused the visualized dimensions of the test object to increase by 80%. In addition, dimensions of objects visualized in the far-peripheral field of the nasendoscopic examinations appeared approximately 40% smaller than those visualized in the central field. Using computer software to analyze velopharyngeal closure, the mean correlation coefficient for intrarater reliability was .94 and for interrater reliability was .90. Conclusion : Using a custom-designed apparatus, the effect object-lens distance has on the magnification of nasendoscopic images has been quantified. Barrel distortion has also been quantified and was found to be independent of object-lens distance. Using computer software to analyze clinical images, the intraoperator and interoperator correlation appears to show that ratio-metric measurements are reliable.

Noise and analyzer-crystal angular position analysis for analyzer-based phase-contrast imaging

NASA Astrophysics Data System (ADS)

Majidi, Keivan; Li, Jun; Muehleman, Carol; Brankov, Jovan G.

2014-04-01

The analyzer-based phase-contrast x-ray imaging (ABI) method is emerging as a potential alternative to conventional radiography. Like many of the modern imaging techniques, ABI is a computed imaging method (meaning that images are calculated from raw data). ABI can simultaneously generate a number of planar parametric images containing information about absorption, refraction, and scattering properties of an object. These images are estimated from raw data acquired by measuring (sampling) the angular intensity profile of the x-ray beam passed through the object at different angular positions of the analyzer crystal. The noise in the estimated ABI parametric images depends upon imaging conditions like the source intensity (flux), measurements angular positions, object properties, and the estimation method. In this paper, we use the Cramér-Rao lower bound (CRLB) to quantify the noise properties in parametric images and to investigate the effect of source intensity, different analyzer-crystal angular positions and object properties on this bound, assuming a fixed radiation dose delivered to an object. The CRLB is the minimum bound for the variance of an unbiased estimator and defines the best noise performance that one can obtain regardless of which estimation method is used to estimate ABI parametric images. The main result of this paper is that the variance (hence the noise) in parametric images is directly proportional to the source intensity and only a limited number of analyzer-crystal angular measurements (eleven for uniform and three for optimal non-uniform) are required to get the best parametric images. The following angular measurements only spread the total dose to the measurements without improving or worsening CRLB, but the added measurements may improve parametric images by reducing estimation bias. Next, using CRLB we evaluate the multiple-image radiography, diffraction enhanced imaging and scatter diffraction enhanced imaging estimation techniques, though the proposed methodology can be used to evaluate any other ABI parametric image estimation technique.

Noise and Analyzer-Crystal Angular Position Analysis for Analyzer-Based Phase-Contrast Imaging

PubMed Central

Majidi, Keivan; Li, Jun; Muehleman, Carol; Brankov, Jovan G.

2014-01-01

The analyzer-based phase-contrast X-ray imaging (ABI) method is emerging as a potential alternative to conventional radiography. Like many of the modern imaging techniques, ABI is a computed imaging method (meaning that images are calculated from raw data). ABI can simultaneously generate a number of planar parametric images containing information about absorption, refraction, and scattering properties of an object. These images are estimated from raw data acquired by measuring (sampling) the angular intensity profile (AIP) of the X-ray beam passed through the object at different angular positions of the analyzer crystal. The noise in the estimated ABI parametric images depends upon imaging conditions like the source intensity (flux), measurements angular positions, object properties, and the estimation method. In this paper, we use the Cramér-Rao lower bound (CRLB) to quantify the noise properties in parametric images and to investigate the effect of source intensity, different analyzer-crystal angular positions and object properties on this bound, assuming a fixed radiation dose delivered to an object. The CRLB is the minimum bound for the variance of an unbiased estimator and defines the best noise performance that one can obtain regardless of which estimation method is used to estimate ABI parametric images. The main result of this manuscript is that the variance (hence the noise) in parametric images is directly proportional to the source intensity and only a limited number of analyzer-crystal angular measurements (eleven for uniform and three for optimal non-uniform) are required to get the best parametric images. The following angular measurements only spread the total dose to the measurements without improving or worsening CRLB, but the added measurements may improve parametric images by reducing estimation bias. Next, using CRLB we evaluate the Multiple-Image Radiography (MIR), Diffraction Enhanced Imaging (DEI) and Scatter Diffraction Enhanced Imaging (S-DEI) estimation techniques, though the proposed methodology can be used to evaluate any other ABI parametric image estimation technique. PMID:24651402

Reliability, minimal detectable change and responsiveness to change: Indicators to select the best method to measure sedentary behaviour in older adults in different study designs.

PubMed

Dontje, Manon L; Dall, Philippa M; Skelton, Dawn A; Gill, Jason M R; Chastin, Sebastien F M

2018-01-01

Prolonged sedentary behaviour (SB) is associated with poor health. It is unclear which SB measure is most appropriate for interventions and population surveillance to measure and interpret change in behaviour in older adults. The aims of this study: to examine the relative and absolute reliability, Minimal Detectable Change (MDC) and responsiveness to change of subjective and objective methods of measuring SB in older adults and give recommendations of use for different study designs. SB of 18 older adults (aged 71 (IQR 7) years) was assessed using a systematic set of six subjective tools, derived from the TAxonomy of Self report Sedentary behaviour Tools (TASST), and one objective tool (activPAL3c), over 14 days. Relative reliability (Intra Class Correlation coefficients-ICC), absolute reliability (SEM), MDC, and the relative responsiveness (Cohen's d effect size (ES) and Guyatt's Responsiveness coefficient (GR)) were calculated for each of the different tools and ranked for different study designs. ICC ranged from 0.414 to 0.946, SEM from 36.03 to 137.01 min, MDC from 1.66 to 8.42 hours, ES from 0.017 to 0.259 and GR from 0.024 to 0.485. Objective average day per week measurement ranked as most responsive in a clinical practice setting, whereas a one day measurement ranked highest in quasi-experimental, longitudinal and controlled trial study designs. TV viewing-Previous Week Recall (PWR) ranked as most responsive subjective measure in all study designs. The reliability, Minimal Detectable Change and responsiveness to change of subjective and objective methods of measuring SB is context dependent. Although TV viewing-PWR is the more reliable and responsive subjective method in most situations, it may have limitations as a reliable measure of total SB. Results of this study can be used to guide choice of tools for detecting change in sedentary behaviour in older adults in the contexts of population surveillance, intervention evaluation and individual care.

Documentation of Historical Underground Object in Skorkov Village with Selected Measuring Methods, Data Analysis and Visualization

NASA Astrophysics Data System (ADS)

Dlesk, A.

2016-06-01

The author analyzes current methods of 3D documentation of historical tunnels in Skorkov village, which lies at the Jizera river, approximately 30 km away from Prague. The area is known as a former military camp from Thirty Years' War in 17th Century. There is an extensive underground compound with one entrance corridor and two transverse, situated approximately 2 to 5 m under the local development. The object has been partly documented by geodetic polar method, intersection photogrammetry, image-based modelling and laser scanning. Data have been analyzed and methods have been compared. Then the 3D model of object has been created and compound with cadastral data, orthophoto, historical maps and digital surface model which was made by photogrammetric method using remotely piloted aircraft system. Then the measuring has been realized with ground penetrating radar. Data have been analyzed and the result compared with real status. All the data have been combined and visualized into one 3D model. Finally, the discussion about advantages and disadvantages of used measuring methods has been livened up. The tested methodology has been also used for other documentation of historical objects in this area. This project has been created as a part of research at EuroGV. s.r.o. Company lead by Ing. Karel Vach CSc. in cooperation with prof. Dr. Ing. Karel Pavelka from Czech Technical University in Prague and Miloš Gavenda, the renovator.

Application of Classical Land Surveying Measurement Methods for Determining the Vertical Displacement of Railway Bridges

NASA Astrophysics Data System (ADS)

Gawronek, Pelagia; Makuch, Maria

2017-12-01

The classical measurements of stability of railway bridge, in the context of determining the vertical displacements of the object, consisted on precise leveling of girders and trigonometric leveling of controlled points (fixed into girders' surface). The construction elements, which were measured in two ways, in real terms belonged to the same vertical planes. Altitude measurements of construction were carried out during periodic structural stability tests and during static load tests of bridge by train. The specificity of displacement measurements, the type of measured object and the rail land surveying measurement conditions were determinants to define methodology of altitude measurement. The article presents compatibility of vertical displacements of steel railway bridge, which were developed in two measurement methods. In conclusion, the authors proposed the optimum concept of determining the vertical displacements of girders by using precise and trigonometric leveling (in terms of accuracy, safety and economy of measurement).

Technical support for creating an artificial intelligence system for feature extraction and experimental design

NASA Technical Reports Server (NTRS)

Glick, B. J.

1985-01-01

Techniques for classifying objects into groups or clases go under many different names including, most commonly, cluster analysis. Mathematically, the general problem is to find a best mapping of objects into an index set consisting of class identifiers. When an a priori grouping of objects exists, the process of deriving the classification rules from samples of classified objects is known as discrimination. When such rules are applied to objects of unknown class, the process is denoted classification. The specific problem addressed involves the group classification of a set of objects that are each associated with a series of measurements (ratio, interval, ordinal, or nominal levels of measurement). Each measurement produces one variable in a multidimensional variable space. Cluster analysis techniques are reviewed and methods for incuding geographic location, distance measures, and spatial pattern (distribution) as parameters in clustering are examined. For the case of patterning, measures of spatial autocorrelation are discussed in terms of the kind of data (nominal, ordinal, or interval scaled) to which they may be applied.

Application of Composite Small Calibration Objects in Traffic Accident Scene Photogrammetry

PubMed Central

Chen, Qiang; Xu, Hongguo; Tan, Lidong

2015-01-01

In order to address the difficulty of arranging large calibration objects and the low measurement accuracy of small calibration objects in traffic accident scene photogrammetry, a photogrammetric method based on a composite of small calibration objects is proposed. Several small calibration objects are placed around the traffic accident scene, and the coordinate system of the composite calibration object is given based on one of them. By maintaining the relative position and coplanar relationship of the small calibration objects, the local coordinate system of each small calibration object is transformed into the coordinate system of the composite calibration object. The two-dimensional direct linear transformation method is improved based on minimizing the reprojection error of the calibration points of all objects. A rectified image is obtained using the nonlinear optimization method. The increased accuracy of traffic accident scene photogrammetry using a composite small calibration object is demonstrated through the analysis of field experiments and case studies. PMID:26011052

Measuring Parenting Practices among Parents of Elementary School-Age Youth

ERIC Educational Resources Information Center

Randolph, Karen A.; Radey, Melissa

2011-01-01

Objectives: The objective of this study is to establish the factor structure of the Alabama Parenting Questionnaire (APQ), an instrument designed to measure parenting practices among parents of elementary school children. Methods: Exploratory (EFA) and confirmatory factor analytic (CFA) procedures are used to validate the APQ with 790 parents of…

Flow Measurement. Training Module 3.315.2.77.

ERIC Educational Resources Information Center

Kirkwood Community Coll., Cedar Rapids, IA.

This document is an instructional module package prepared in objective form for use by an instructor familiar with the principles of liquid flow and the methods of measuring open channel and fuel pipe flow rates. Included are objectives, instructor guides, student handouts, and transparency masters. The module addresses the basic flow formula, and…

Electronic heterodyne moire deflectometry: A method for transient and three dimensional density fields measurements

NASA Technical Reports Server (NTRS)

Stricker, Josef

1987-01-01

Effects of diffraction and nonlinear photographic emulsion characteristics on the performance of deferred electronic heterodyne moire deflectometry are investigated. The deferred deflectometry is used for measurements of nonsteady phase objects where it is difficult to complete the analysis of the field in real time. The sensitivity, accuracy and resolution of the system are calculated and it is shown that they are weakly affected by diffraction and by nonlinear recording. The feactures of the system are significantly improved compared with the conventional deferred intensity moire technique, and are comparable with the online heterodyne moire. The system was evaluated experimentally by deferred measurements of the refractive index gradients of a weak phase object consisting of a large KD*P crystal. This was done by photographing the phase object through a Ronchi grating and analyzing the tranparency with the electronic heterodyne readout system. The results are compared with the measurements performed on the same phase object with online heterodyne moire deflectometry and with heterodyne holographic interferometry methods. Some practical considerations for system improvement are discussed.

dftools: Distribution function fitting

NASA Astrophysics Data System (ADS)

Obreschkow, Danail

2018-05-01

dftools, written in R, finds the most likely P parameters of a D-dimensional distribution function (DF) generating N objects, where each object is specified by D observables with measurement uncertainties. For instance, if the objects are galaxies, it can fit a mass function (D=1), a mass-size distribution (D=2) or the mass-spin-morphology distribution (D=3). Unlike most common fitting approaches, this method accurately accounts for measurement in uncertainties and complex selection functions.

An objective method and measuring equipment for noise control and acoustic diagnostics of motorcars. [acoustic diagnostics on automobile engines

NASA Technical Reports Server (NTRS)

Kacprowski, J.; Motylewski, J.; Miazga, J.

1974-01-01

An objective method and apparatus for noise control and acoustic diagnostics of motorcar engines are reported. The method and apparatus let us know whether the noisiness of the vehicle under test exceeds the admissible threshold levels given by appropriate standards and if so what is the main source of the excessive noise. The method consists in measuring both the overall noise level and the sound pressure levels in definite frequency bands while the engine speed is controlled as well and may be fixed at prescribed values. Whenever the individually adjusted threshold level has been exceeded in any frequency band, a self-sustaining control signal is sent.

Empirical Analysis of the Subjective Impressions and Objective Measures of Domain Scientists’ Visual Analytic Judgments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasgupta, Aritra; Burrows, Susannah M.; Han, Kyungsik

2017-05-08

Scientists often use specific data analysis and presentation methods familiar within their domain. But does high familiarity drive better analytical judgment? This question is especially relevant when familiar methods themselves can have shortcomings: many visualizations used conventionally for scientific data analysis and presentation do not follow established best practices. This necessitates new methods that might be unfamiliar yet prove to be more effective. But there is little empirical understanding of the relationships between scientists’ subjective impressions about familiar and unfamiliar visualizations and objective measures of their visual analytic judgments. To address this gap and to study these factors, we focusmore » on visualizations used for comparison of climate model performance. We report on a comprehensive survey-based user study with 47 climate scientists and present an analysis of : i) relationships among scientists’ familiarity, their perceived lev- els of comfort, confidence, accuracy, and objective measures of accuracy, and ii) relationships among domain experience, visualization familiarity, and post-study preference.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scaduto, DA; Hu, Y-H; Zhao, W

Purpose: Spatial resolution in digital breast tomosynthesis (DBT) is affected by inherent/binned detector resolution, oblique entry of x-rays, and focal spot size/motion; the limited angular range further limits spatial resolution in the depth-direction. While DBT is being widely adopted clinically, imaging performance metrics and quality control protocols have not been standardized. AAPM Task Group 245 on Tomosynthesis Quality Control has been formed to address this deficiency. Methods: Methods of measuring spatial resolution are evaluated using two prototype quality control phantoms for DBT. Spatial resolution in the detector plane is measured in projection and reconstruction domains using edge-spread function (ESF), point-spreadmore » function (PSF) and modulation transfer function (MTF). Spatial resolution in the depth-direction and effective slice thickness are measured in the reconstruction domain using slice sensitivity profile (SSP) and artifact spread function (ASF). An oversampled PSF in the depth-direction is measured using a 50 µm angulated tungsten wire, from which the MTF is computed. Object-dependent PSF is derived and compared with ASF. Sensitivity of these measurements to phantom positioning, imaging conditions and reconstruction algorithms is evaluated. Results are compared from systems of varying acquisition geometry (9–25 projections over 15–60°). Dependence of measurements on feature size is investigated. Results: Measurements of spatial resolution using PSF and LSF are shown to depend on feature size; depth-direction spatial resolution measurements are shown to similarly depend on feature size for ASF, though deconvolution with an object function removes feature size-dependence. A slanted wire may be used to measure oversampled PSFs, from which MTFs may be computed for both in-plane and depth-direction resolution. Conclusion: Spatial resolution measured using PSF is object-independent with sufficiently small object; MTF is object-independent. Depth-direction spatial resolution may be measured directly using MTF or indirectly using ASF or SSP as surrogate measurements. While MTF is object-independent, it is invalid for nonlinear reconstructions.« less

Comparison of RCS prediction techniques, computations and measurements

NASA Astrophysics Data System (ADS)

Brand, M. G. E.; Vanewijk, L. J.; Klinker, F.; Schippers, H.

1992-07-01

Three calculation methods to predict radar cross sections (RCS) of three dimensional objects are evaluated by computing the radar cross sections of a generic wing inlet configuration. The following methods are applied: a three dimensional high frequency method, a three dimensional boundary element method, and a two dimensional finite difference time domain method. The results of the computations are compared with the data of measurements.

Objective measurement of bread crumb texture

NASA Astrophysics Data System (ADS)

Wang, Jian; Coles, Graeme D.

1995-01-01

Evaluation of bread crumb texture plays an important role in judging bread quality. This paper discusses the application of image analysis methods to the objective measurement of the visual texture of bread crumb. The application of Fast Fourier Transform and mathematical morphology methods have been discussed by the authors in their previous work, and a commercial bread texture measurement system has been developed. Based on the nature of bread crumb texture, we compare the advantages and disadvantages of the two methods, and a third method based on features derived directly from statistics of edge density in local windows of the bread image. The analysis of various methods and experimental results provides an insight into the characteristics of the bread texture image and interconnection between texture measurement algorithms. The usefulness of the application of general stochastic process modelling of texture is thus revealed; it leads to more reliable and accurate evaluation of bread crumb texture. During the development of these methods, we also gained useful insights into how subjective judges form opinions about bread visual texture. These are discussed here.

Imaging photorefractive optical vibration measurement method and device

DOEpatents

Telschow, Kenneth L.; Deason, Vance A.; Hale, Thomas C.

2000-01-01

A method and apparatus are disclosed for characterizing a vibrating image of an object of interest. The method includes providing a sensing media having a detection resolution within a limited bandwidth and providing an object of interest having a vibrating medium. Two or more wavefronts are provided, with at least one of the wavefronts being modulated by interacting the one wavefront with the vibrating medium of the object of interest. The another wavefront is modulated such that the difference frequency between the one wavefront and the another wavefront is within a response range of the sensing media. The modulated one wavefront and another wavefront are combined in association with the sensing media to interfere and produce simultaneous vibration measurements that are distributed over the object so as to provide an image of the vibrating medium. The image has an output intensity that is substantially linear with small physical variations within the vibrating medium. Furthermore, the method includes detecting the image. In one implementation, the apparatus comprises a vibration spectrum analyzer having an emitter, a modulator, sensing media and a detector configured so as to realize such method. According to another implementation, the apparatus comprises a vibration imaging device.

Scientific Ground of a New Optical Device for Contactless Measurement of the Small Spatial Displacements of Control Object Surfaces

NASA Astrophysics Data System (ADS)

Miroshnichenko, I. P.; Parinov, I. A.

2017-06-01

It is proposed the computational-experimental ground of newly developed optical device for contactless measurement of small spatial displacements of control object surfaces based on the use of new methods of laser interferometry. The proposed device allows one to register linear and angular components of the small displacements of control object surfaces during the diagnosis of the condition of structural materials for forced elements of goods under exploring by using acoustic non-destructive testing methods. The described results are the most suitable for application in the process of high-precision measurements of small linear and angular displacements of control object surfaces during experimental research, the evaluation and diagnosis of the state of construction materials for forced elements of goods, the study of fast wave propagation in layered constructions of complex shape, manufactured of anisotropic composite materials, the study of damage processes in modern construction materials in mechanical engineering, shipbuilding, aviation, instrumentation, power engineering, etc.

Three-dimensional sensing methodology combining stereo vision and phase-measuring profilometry based on dynamic programming

NASA Astrophysics Data System (ADS)

Lee, Hyunki; Kim, Min Young; Moon, Jeon Il

2017-12-01

Phase measuring profilometry and moiré methodology have been widely applied to the three-dimensional shape measurement of target objects, because of their high measuring speed and accuracy. However, these methods suffer from inherent limitations called a correspondence problem, or 2π-ambiguity problem. Although a kind of sensing method to combine well-known stereo vision and phase measuring profilometry (PMP) technique simultaneously has been developed to overcome this problem, it still requires definite improvement for sensing speed and measurement accuracy. We propose a dynamic programming-based stereo PMP method to acquire more reliable depth information and in a relatively small time period. The proposed method efficiently fuses information from two stereo sensors in terms of phase and intensity simultaneously based on a newly defined cost function of dynamic programming. In addition, the important parameters are analyzed at the view point of the 2π-ambiguity problem and measurement accuracy. To analyze the influence of important hardware and software parameters related to the measurement performance and to verify its efficiency, accuracy, and sensing speed, a series of experimental tests were performed with various objects and sensor configurations.

Simultaneous acquisition of corrugator electromyography and functional magnetic resonance imaging: A new method for objectively measuring affect and neural activity concurrently

PubMed Central

Heller, Aaron S.; Greischar, Lawrence L; Honor, Ann; Anderle, Michael J; Davidson, Richard J.

2011-01-01

The development of functional neuroimaging of emotion holds the promise to enhance our understanding of the biological bases of affect and improve our knowledge of psychiatric diseases. However, up to this point, researchers have been unable to objectively, continuously and unobtrusively measure the intensity and dynamics of affect concurrently with functional magnetic resonance imaging (fMRI). This has hindered the development and generalizability of our field. Facial electromyography (EMG) is an objective, reliable, valid, sensitive, and unobtrusive measure of emotion. Here, we report the successful development of a method for simultaneously acquiring fMRI and facial EMG. The ability to simultaneously acquire brain activity and facial physiology will allow affective neuroscientists to address theoretical, psychiatric, and individual difference questions in a more rigorous and generalizable way. PMID:21742043

Validity of Questionnaire and Representativeness of Objective Methods for Measurements of Mechanical Exposures in Construction and Health Care Work.

PubMed

Koch, Markus; Lunde, Lars-Kristian; Gjulem, Tonje; Knardahl, Stein; Veiersted, Kaj Bo

2016-01-01

To determine the criterion validity of a questionnaire on physical exposures compared to objective measurements at construction and health care sites and to examine exposure variation over several working days. Five hundred ninety-four construction and health care workers answered a baseline questionnaire. The daily activities (standing, moving, sitting, number of steps), postures (inclination of the arm and the trunk), and relative heart rate of 125 participants were recorded continuously over 3-4 working days. At the end of the first measurement day, the participants answered a second questionnaire (workday questionnaire). All objective activity measurements had significant correlations to their respective questions. Among health care workers, there were no correlations between postures and relative heart rate and the baseline questionnaire. The questionnaires overestimated the exposure durations. The highest explained variance in the adjusted models with self-reported variables were found for objectively measured sitting (R2 = 0.559) and arm inclination > 60° (R2 = 0.420). Objective measurements over several days showed a higher reliability compared to single day measurements. Questionnaires cannot provide an accurate description of mechanical exposures. Objective measurements over several days are recommended in occupations with varying tasks.

Differential evolution-based multi-objective optimization for the definition of a health indicator for fault diagnostics and prognostics

NASA Astrophysics Data System (ADS)

Baraldi, P.; Bonfanti, G.; Zio, E.

2018-03-01

The identification of the current degradation state of an industrial component and the prediction of its future evolution is a fundamental step for the development of condition-based and predictive maintenance approaches. The objective of the present work is to propose a general method for extracting a health indicator to measure the amount of component degradation from a set of signals measured during operation. The proposed method is based on the combined use of feature extraction techniques, such as Empirical Mode Decomposition and Auto-Associative Kernel Regression, and a multi-objective Binary Differential Evolution (BDE) algorithm for selecting the subset of features optimal for the definition of the health indicator. The objectives of the optimization are desired characteristics of the health indicator, such as monotonicity, trendability and prognosability. A case study is considered, concerning the prediction of the remaining useful life of turbofan engines. The obtained results confirm that the method is capable of extracting health indicators suitable for accurate prognostics.

A high precision ultrasonic system for vibration measurements

NASA Astrophysics Data System (ADS)

Young, M. S.; Li, Y. C.

1992-11-01

A microcomputer-aided ultrasonic system that can be used to measure the vibratory displacements of an object is presented. A pair of low cost 40-kHz ultrasonic transducers is used to transmit ultrasound toward an object and receive the ultrasound reflected from the object. The relative motion of the object modulates the phase angle difference between the transmitted and received ultrasound signals. A single-chip microcomputer-based phase detector was designed to record and analyze the phase shift information which is then sent to a PC-AT microcomputer for processing. We have developed an ingenious method to reconstruct the relative motion of an object from the acquired data of the phase difference changes. A digital plotter based experiment was also designed for testing the performance of the whole system. The measured accuracy of the system in the reported experiments is within +/- 0.4 mm and the theoretical maximal measurable speed of the object is 89.6 cm/s. The main advantages of this ultrasonic vibration measurement system are high resolution, low cost, noncontact measurement, and easy installation.

FBK Optical Data Association in a Multi-Hypothesis Framework with Maneuvers

NASA Astrophysics Data System (ADS)

Faber, W. R.; Hussein, I. I.; Kent, J. T.; Bhattacharjee, S. Jah, M. K.

In Space Situational Awareness (SSA), one may encounter scenarios where the measurements received at a certain time do not correlate to a known Resident Space Object (RSO). Without information that uniquely assigns the measurement to a particular RSO there can be no certainty on the identity of the object. It could be that the measurement was produced by clutter or perhaps a newly birthed RSO. It is also a possibility that the measurement came from a previously known object that maneuvered away from its predicted location. Typically, tracking methods tend to associate uncorrelated measurements to new objects and wait for more information to determine the true RSO population. This can lead to the loss of object custody. The goal of this paper is to utilize a multiple hypothesis framework coupled with some knowledge of RSO maneuvers that allows the user to maintain object custody in scenarios with uncorrelated optical measurement returns. This is achieved by fitting a Fisher-Bingham-Kent type distribution to the hypothesized maneuvers for accurate data association using directional discriminant analysis.

Motion-induced error reduction by combining Fourier transform profilometry with phase-shifting profilometry.

PubMed

Li, Beiwen; Liu, Ziping; Zhang, Song

2016-10-03

We propose a hybrid computational framework to reduce motion-induced measurement error by combining the Fourier transform profilometry (FTP) and phase-shifting profilometry (PSP). The proposed method is composed of three major steps: Step 1 is to extract continuous relative phase maps for each isolated object with single-shot FTP method and spatial phase unwrapping; Step 2 is to obtain an absolute phase map of the entire scene using PSP method, albeit motion-induced errors exist on the extracted absolute phase map; and Step 3 is to shift the continuous relative phase maps from Step 1 to generate final absolute phase maps for each isolated object by referring to the absolute phase map with error from Step 2. Experiments demonstrate the success of the proposed computational framework for measuring multiple isolated rapidly moving objects.

Creating Objects and Object Categories for Studying Perception and Perceptual Learning

PubMed Central

Hauffen, Karin; Bart, Eugene; Brady, Mark; Kersten, Daniel; Hegdé, Jay

2012-01-01

In order to quantitatively study object perception, be it perception by biological systems or by machines, one needs to create objects and object categories with precisely definable, preferably naturalistic, properties1. Furthermore, for studies on perceptual learning, it is useful to create novel objects and object categories (or object classes) with such properties2. Many innovative and useful methods currently exist for creating novel objects and object categories3-6 (also see refs. 7,8). However, generally speaking, the existing methods have three broad types of shortcomings. First, shape variations are generally imposed by the experimenter5,9,10, and may therefore be different from the variability in natural categories, and optimized for a particular recognition algorithm. It would be desirable to have the variations arise independently of the externally imposed constraints. Second, the existing methods have difficulty capturing the shape complexity of natural objects11-13. If the goal is to study natural object perception, it is desirable for objects and object categories to be naturalistic, so as to avoid possible confounds and special cases. Third, it is generally hard to quantitatively measure the available information in the stimuli created by conventional methods. It would be desirable to create objects and object categories where the available information can be precisely measured and, where necessary, systematically manipulated (or 'tuned'). This allows one to formulate the underlying object recognition tasks in quantitative terms. Here we describe a set of algorithms, or methods, that meet all three of the above criteria. Virtual morphogenesis (VM) creates novel, naturalistic virtual 3-D objects called 'digital embryos' by simulating the biological process of embryogenesis14. Virtual phylogenesis (VP) creates novel, naturalistic object categories by simulating the evolutionary process of natural selection9,12,13. Objects and object categories created by these simulations can be further manipulated by various morphing methods to generate systematic variations of shape characteristics15,16. The VP and morphing methods can also be applied, in principle, to novel virtual objects other than digital embryos, or to virtual versions of real-world objects9,13. Virtual objects created in this fashion can be rendered as visual images using a conventional graphical toolkit, with desired manipulations of surface texture, illumination, size, viewpoint and background. The virtual objects can also be 'printed' as haptic objects using a conventional 3-D prototyper. We also describe some implementations of these computational algorithms to help illustrate the potential utility of the algorithms. It is important to distinguish the algorithms from their implementations. The implementations are demonstrations offered solely as a 'proof of principle' of the underlying algorithms. It is important to note that, in general, an implementation of a computational algorithm often has limitations that the algorithm itself does not have. Together, these methods represent a set of powerful and flexible tools for studying object recognition and perceptual learning by biological and computational systems alike. With appropriate extensions, these methods may also prove useful in the study of morphogenesis and phylogenesis. PMID:23149420

Assessing children's ultraviolet radiation exposure: the potential usefulness of a colorimeter.

PubMed Central

Eckhardt, L; Mayer, J A; Creech, L; Johnston, M R; Lui, K J; Sallis, J F; Elder, J P

1996-01-01

OBJECTIVES: This study evaluated the colorimeter as an objective measure of children's ultraviolet (UV) radiation exposure. METHODS: Fifty-eight children, ages 6 to 9 years, attended two summer measurement sessions, with 46 attending a subsequent winter session. RESULTS: Comparisons between summer sessions for the L* scale showed that only the upper arm significantly changed in the tanner direction, while b* scale values indicated significant tanning for all body sites. All exposed body sites changed significantly in the less tan direction between summer and winter measurements. CONCLUSIONS: Using colorimeters to objectively measure children's UV exposure has potential applications for skin cancer prevention programs. PMID:9003142

A Tool for the Automated Design and Evaluation of Habitat Interior Layouts

NASA Technical Reports Server (NTRS)

Simon, Matthew A.; Wilhite, Alan W.

2013-01-01

The objective of space habitat design is to minimize mass and system size while providing adequate space for all necessary equipment and a functional layout that supports crew health and productivity. Unfortunately, development and evaluation of interior layouts is often ignored during conceptual design because of the subjectivity and long times required using current evaluation methods (e.g., human-in-the-loop mockup tests and in-depth CAD evaluations). Early, more objective assessment could prevent expensive design changes that may increase vehicle mass and compromise functionality. This paper describes a new interior design evaluation method to enable early, structured consideration of habitat interior layouts. This interior layout evaluation method features a comprehensive list of quantifiable habitat layout evaluation criteria, automatic methods to measure these criteria from a geometry model, and application of systems engineering tools and numerical methods to construct a multi-objective value function measuring the overall habitat layout performance. In addition to a detailed description of this method, a C++/OpenGL software tool which has been developed to implement this method is also discussed. This tool leverages geometry modeling coupled with collision detection techniques to identify favorable layouts subject to multiple constraints and objectives (e.g., minimize mass, maximize contiguous habitable volume, maximize task performance, and minimize crew safety risks). Finally, a few habitat layout evaluation examples are described to demonstrate the effectiveness of this method and tool to influence habitat design.

An examination of presenteeism measures: the association of three scoring methods with health, work life, and consumer activation.

PubMed

Terry, Paul E; Xi, Min

2010-12-01

The objective of this study was to assess the validity of 3 scoring techniques for presenteeism measures by exploring their relationship with patient activation, health, job satisfaction, and socioeconomic characteristics. The sample consisted of 631 employees from 2 predominantly white-collar employee groups in the northern Midwest. Employees completed the World Health Organization's Health and Work Performance Questionnaire, a wellness profile, and the Patient Activation Measure. Absolute measures reflect self-rated performance, while relative and stratified measures compare self-rated performance to that of co-workers. Multivariate analyses were used to validate scoring measures. All measures of presenteeism were positively correlated with being nonwhite, income, and smoking. The significance of age, employment, mental health, and patient activation depends on how presenteeism is defined. Practitioners must carefully consider which scoring method best addresses their program goals and objectives. Clearer measurement guidelines are needed.

Singular-value decomposition of a tomosynthesis system

PubMed Central

Burvall, Anna; Barrett, Harrison H.; Myers, Kyle J.; Dainty, Christopher

2010-01-01

Tomosynthesis is an emerging technique with potential to replace mammography, since it gives 3D information at a relatively small increase in dose and cost. We present an analytical singular-value decomposition of a tomosynthesis system, which provides the measurement component of any given object. The method is demonstrated on an example object. The measurement component can be used as a reconstruction of the object, and can also be utilized in future observer studies of tomosynthesis image quality. PMID:20940966

Objective Evaluation of Muscle Strength in Infants with Hypotonia and Muscle Weakness

ERIC Educational Resources Information Center

Reus, Linda; van Vlimmeren, Leo A.; Staal, J. Bart; Janssen, Anjo J. W. M.; Otten, Barto J.; Pelzer, Ben J.; Nijhuis-van der Sanden, Maria W. G.

2013-01-01

The clinical evaluation of an infant with motor delay, muscle weakness, and/or hypotonia would improve considerably if muscle strength could be measured objectively and normal reference values were available. The authors developed a method to measure muscle strength in infants and tested 81 typically developing infants, 6-36 months of age, and 17…

Reliability and Validity of a Questionnaire to Measure Consumer Knowledge regarding Safe Practices to Prevent Microbiological Contamination in Restaurants

ERIC Educational Resources Information Center

Uggioni, Paula Lazzarin; Salay, Elisabette

2013-01-01

Objective: The objective of this study was to develop a validated and reliable questionnaire to measure consumer knowledge regarding safe practices to prevent microbiological contamination in restaurants and commercial kitchens. Methods: Non-probabilistic samples of individuals were interviewed in the city of Campinas, Brazil. Questionnaire items…

Prevalence, Patterns, and Predictors of Sleep Problems and Daytime Sleepiness in Young Adolescents with Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Langberg, Joshua M.; Molitor, Stephen J.; Oddo, Lauren E.; Eadeh, Hana-May; Dvorsky, Melissa R.; Becker, Stephen P.

2017-01-01

Objective: The primary objective of this study was to evaluate the prevalence of multiple types of sleep problems in young adolescents with ADHD. Method: 262 adolescents comprehensively diagnosed with ADHD and their caregivers completed well-validated measures of sleep problems and daytime sleepiness. Participants also completed measures related…

Measurement and Socio-Demographic Variation of Social Capital in a Large Population-Based Survey

ERIC Educational Resources Information Center

Nieminen, Tarja; Martelin, Tuija; Koskinen, Seppo; Simpura, Jussi; Alanen, Erkki; Harkanen, Tommi; Aromaa, Arpo

2008-01-01

Objectives: The main objective of this study was to describe the variation of individual social capital according to socio-demographic factors, and to develop a suitable way to measure social capital for this purpose. The similarity of socio-demographic variation between the genders was also assessed. Data and methods: The study applied…

Scatter measurement and correction method for cone-beam CT based on single grating scan

NASA Astrophysics Data System (ADS)

Huang, Kuidong; Shi, Wenlong; Wang, Xinyu; Dong, Yin; Chang, Taoqi; Zhang, Hua; Zhang, Dinghua

2017-06-01

In cone-beam computed tomography (CBCT) systems based on flat-panel detector imaging, the presence of scatter significantly reduces the quality of slices. Based on the concept of collimation, this paper presents a scatter measurement and correction method based on single grating scan. First, according to the characteristics of CBCT imaging, the scan method using single grating and the design requirements of the grating are analyzed and figured out. Second, by analyzing the composition of object projection images and object-and-grating projection images, the processing method for the scatter image at single projection angle is proposed. In addition, to avoid additional scan, this paper proposes an angle interpolation method of scatter images to reduce scan cost. Finally, the experimental results show that the scatter images obtained by this method are accurate and reliable, and the effect of scatter correction is obvious. When the additional object-and-grating projection images are collected and interpolated at intervals of 30 deg, the scatter correction error of slices can still be controlled within 3%.

Location of geographical objects in crisis situations

NASA Astrophysics Data System (ADS)

Rybansky, M.; Kratochvil, V.

2014-02-01

This article summarizes the various expressions of object positioning using different coordinate data and different methods, such as use of maps, exploiting the properties of digital Global System for Mobile Communications (GSM) networks, Global Navigational Satellite Systems (GNSS), Inertial Navigation Systems (INS), Inertial Measurement Systems (IMS), hybrid methods and non-contact (remote sensing) methods; all with varying level of accuracy. Furthermore, the article describes some geographical identifiers and verbal means to describe location of geographical objects such as settlements, rivers, forest, roads, etc. All of the location methods have some advantages and disadvantages, especially in emergency situations, when usually the crisis management has a lack of time in a decision process.

Adolescent Girls' Reactions to Nutrition and Physical Activity Assessment Tools and Insight into Lifestyle Habits

ERIC Educational Resources Information Center

Metos, Julie; Gren, Lisa; Brusseau, Timothy; Moric, Endi; O'Toole, Karen; Mokhtari, Tahereh; Buys, Saundra; Frost, Caren

2018-01-01

Objective: The objective of this study was to understand adolescent girls' experiences using practical diet and physical activity measurement tools and to explore the food and physical activity settings that influence their lifestyle habits. Design: Mixed methods study using quantitative and qualitative methods. Setting: Large city in the western…

Is an objective refraction optimised using the visual Strehl ratio better than a subjective refraction?

PubMed Central

Hastings, Gareth D.; Marsack, Jason D.; Nguyen, Lan Chi; Cheng, Han; Applegate, Raymond A.

2017-01-01

Purpose To prospectively examine whether using the visual image quality metric, visual Strehl (VSX), to optimise objective refraction from wavefront error measurements can provide equivalent or better visual performance than subjective refraction and which refraction is preferred in free viewing. Methods Subjective refractions and wavefront aberrations were measured on 40 visually-normal eyes of 20 subjects, through natural and dilated pupils. For each eye a sphere, cylinder, and axis prescription was also objectively determined that optimised visual image quality (VSX) for the measured wavefront error. High contrast (HC) and low contrast (LC) logMAR visual acuity (VA) and short-term monocular distance vision preference were recorded and compared between the VSX-objective and subjective prescriptions both undilated and dilated. Results For 36 myopic eyes, clinically equivalent (and not statistically different) HC VA was provided with both the objective and subjective refractions (undilated mean ±SD was −0.06 ±0.04 with both refractions; dilated was −0.05 ±0.04 with the objective, and −0.05 ±0.05 with the subjective refraction). LC logMAR VA provided by the objective refraction was also clinically equivalent and not statistically different to that provided by the subjective refraction through both natural and dilated pupils for myopic eyes. In free viewing the objective prescription was preferred over the subjective by 72% of myopic eyes when not dilated. For four habitually undercorrected high hyperopic eyes, the VSX-objective refraction was more positive in spherical power and VA poorer than with the subjective refraction. Conclusions A method of simultaneously optimising sphere, cylinder, and axis from wavefront error measurements, using the visual image quality metric VSX, is described. In myopic subjects, visual performance, as measured by HC and LC VA, with this VSX-objective refraction was found equivalent to that provided by subjective refraction, and was typically preferred over subjective refraction. Subjective refraction was preferred by habitually undercorrected hyperopic eyes. PMID:28370389

Tradeoff studies in multiobjective insensitive design of airplane control systems

NASA Technical Reports Server (NTRS)

Schy, A. A.; Giesy, D. P.

1983-01-01

A computer aided design method for multiobjective parameter-insensitive design of airplane control systems is described. Methods are presented for trading off nominal values of design objectives against sensitivities of the design objectives to parameter uncertainties, together with guidelines for designer utilization of the methods. The methods are illustrated by application to the design of a lateral stability augmentation system for two supersonic flight conditions of the Shuttle Orbiter. Objective functions are conventional handling quality measures and peak magnitudes of control deflections and rates. The uncertain parameters are assumed Gaussian, and numerical approximations of the stochastic behavior of the objectives are described. Results of applying the tradeoff methods to this example show that stochastic-insensitive designs are distinctly different from deterministic multiobjective designs. The main penalty for achieving significant decrease in sensitivity is decreased speed of response for the nominal system.

Learning object correspondences with the observed transport shape measure.

PubMed

Pitiot, Alain; Delingette, Hervé; Toga, Arthur W; Thompson, Paul M

2003-07-01

We propose a learning method which introduces explicit knowledge to the object correspondence problem. Our approach uses an a priori learning set to compute a dense correspondence field between two objects, where the characteristics of the field bear close resemblance to those in the learning set. We introduce a new local shape measure we call the "observed transport measure", whose properties make it particularly amenable to the matching problem. From the values of our measure obtained at every point of the objects to be matched, we compute a distance matrix which embeds the correspondence problem in a highly expressive and redundant construct and facilitates its manipulation. We present two learning strategies that rely on the distance matrix and discuss their applications to the matching of a variety of 1-D, 2-D and 3-D objects, including the corpus callosum and ventricular surfaces.

Methods of Measurement in epidemiology: Sedentary Behaviour

PubMed Central

Atkin, Andrew J; Gorely, Trish; Clemes, Stacy A; Yates, Thomas; Edwardson, Charlotte; Brage, Soren; Salmon, Jo; Marshall, Simon J; Biddle, Stuart JH

2012-01-01

Background Research examining sedentary behaviour as a potentially independent risk factor for chronic disease morbidity and mortality has expanded rapidly in recent years. Methods We present a narrative overview of the sedentary behaviour measurement literature. Subjective and objective methods of measuring sedentary behaviour suitable for use in population-based research with children and adults are examined. The validity and reliability of each method is considered, gaps in the literature specific to each method identified and potential future directions discussed. Results To date, subjective approaches to sedentary behaviour measurement, e.g. questionnaires, have focused predominantly on TV viewing or other screen-based behaviours. Typically, such measures demonstrate moderate reliability but slight to moderate validity. Accelerometry is increasingly being used for sedentary behaviour assessments; this approach overcomes some of the limitations of subjective methods, but detection of specific postures and postural changes by this method is somewhat limited. Instruments developed specifically for the assessment of body posture have demonstrated good reliability and validity in the limited research conducted to date. Miniaturization of monitoring devices, interoperability between measurement and communication technologies and advanced analytical approaches are potential avenues for future developments in this field. Conclusions High-quality measurement is essential in all elements of sedentary behaviour epidemiology, from determining associations with health outcomes to the development and evaluation of behaviour change interventions. Sedentary behaviour measurement remains relatively under-developed, although new instruments, both objective and subjective, show considerable promise and warrant further testing. PMID:23045206

Measuring ambivalence to science

NASA Astrophysics Data System (ADS)

Gardner, P. L.

Ambivalence is a psychological state in which a person holds mixed feelings (positive and negative) towards some psychological object. Standard methods of attitude measurement, such as Likert and semantic differential scales, ignore the possibility of ambivalence; ambivalent responses cannot be distinguished from neutral ones. This neglect arises out of an assumption that positive and negative affects towards a particular psychological object are bipolar, i.e., unidimensional in opposite directions. This assumption is frequently untenable. Conventional item statistics and measures of test internal consistency are ineffective as checks on this assumption; it is possible for a scale to be multidimensional and still display apparent internal consistency. Factor analysis is a more effective procedure. Methods of measuring ambivalence are suggested, and implications for research are discussed.

Examining the Association between Patient-Reported Symptoms of Attention and Memory Dysfunction with Objective Cognitive Performance: A Latent Regression Rasch Model Approach.

PubMed

Li, Yuelin; Root, James C; Atkinson, Thomas M; Ahles, Tim A

2016-06-01

Patient-reported cognition generally exhibits poor concordance with objectively assessed cognitive performance. In this article, we introduce latent regression Rasch modeling and provide a step-by-step tutorial for applying Rasch methods as an alternative to traditional correlation to better clarify the relationship of self-report and objective cognitive performance. An example analysis using these methods is also included. Introduction to latent regression Rasch modeling is provided together with a tutorial on implementing it using the JAGS programming language for the Bayesian posterior parameter estimates. In an example analysis, data from a longitudinal neurocognitive outcomes study of 132 breast cancer patients and 45 non-cancer matched controls that included self-report and objective performance measures pre- and post-treatment were analyzed using both conventional and latent regression Rasch model approaches. Consistent with previous research, conventional analysis and correlations between neurocognitive decline and self-reported problems were generally near zero. In contrast, application of latent regression Rasch modeling found statistically reliable associations between objective attention and processing speed measures with self-reported Attention and Memory scores. Latent regression Rasch modeling, together with correlation of specific self-reported cognitive domains with neurocognitive measures, helps to clarify the relationship of self-report with objective performance. While the majority of patients attribute their cognitive difficulties to memory decline, the Rash modeling suggests the importance of processing speed and initial learning. To encourage the use of this method, a step-by-step guide and programming language for implementation is provided. Implications of this method in cognitive outcomes research are discussed. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

An eigenfunction method for reconstruction of large-scale and high-contrast objects.

PubMed

Waag, Robert C; Lin, Feng; Varslot, Trond K; Astheimer, Jeffrey P

2007-07-01

A multiple-frequency inverse scattering method that uses eigenfunctions of a scattering operator is extended to image large-scale and high-contrast objects. The extension uses an estimate of the scattering object to form the difference between the scattering by the object and the scattering by the estimate of the object. The scattering potential defined by this difference is expanded in a basis of products of acoustic fields. These fields are defined by eigenfunctions of the scattering operator associated with the estimate. In the case of scattering objects for which the estimate is radial, symmetries in the expressions used to reconstruct the scattering potential greatly reduce the amount of computation. The range of parameters over which the reconstruction method works well is illustrated using calculated scattering by different objects. The method is applied to experimental data from a 48-mm diameter scattering object with tissue-like properties. The image reconstructed from measurements has, relative to a conventional B-scan formed using a low f-number at the same center frequency, significantly higher resolution and less speckle, implying that small, high-contrast structures can be demonstrated clearly using the extended method.

A comparison of subjective and objective measures of physical activity from the Newcastle 85+ study.

PubMed

Innerd, Paul; Catt, Michael; Collerton, Joanna; Davies, Karen; Trenell, Michael; Kirkwood, Thomas B L; Jagger, Carol

2015-07-01

Little is known about physical activity (PA) in the very old, the fastest growing age group in the population. We aimed to examine the convergent validity of subjective and objective measures of PA in adults aged over 85 years. A total of 484 participants aged 87-89 years recruited to the Newcastle 85+ study completed a purpose-designed physical activity questionnaire (PAQ), which categorised participants as mildly active, moderately active and very active. Out of them, 337 participants wore a triaxial, raw accelerometer on the right wrist over a 5-7-day period to obtain objective measures of rest/activity, PA intensity and PA type. Data from subjective and objective measurement methods were compared. Self-reported PA was significantly associated with objective measures of the daily sedentary time, low-intensity PA and activity type classified as sedentary, activities of daily living and walking. Objective measures of PA were significantly different when low, moderate and high self-reported PA categories were compared (all P < 0.001). The Newcastle 85+ PAQ demonstrated convergent validity with objective measures of PA. Our findings suggest that this PAQ can be used in the very old to rank individuals according to their level of total PA. © The Author 2015. Published by Oxford University Press on behalf of the British Geriatrics Society.

Use of Objective Metrics in Dynamic Facial Reanimation: A Systematic Review.

PubMed

Revenaugh, Peter C; Smith, Ryan M; Plitt, Max A; Ishii, Lisa; Boahene, Kofi; Byrne, Patrick J

2018-06-21

Facial nerve deficits cause significant functional and social consequences for those affected. Existing techniques for dynamic restoration of facial nerve function are imperfect and result in a wide variety of outcomes. Currently, there is no standard objective instrument for facial movement as it relates to restorative techniques. To determine what objective instruments of midface movement are used in outcome measurements for patients treated with dynamic methods for facial paralysis. Database searches from January 1970 to June 2017 were performed in PubMed, Embase, Cochrane Library, Web of Science, and Scopus. Only English-language articles on studies performed in humans were considered. The search terms used were ("Surgical Flaps"[Mesh] OR "Nerve Transfer"[Mesh] OR "nerve graft" OR "nerve grafts") AND (face [mh] OR facial paralysis [mh]) AND (innervation [sh]) OR ("Face"[Mesh] OR facial paralysis [mh]) AND (reanimation [tiab]). Two independent reviewers evaluated the titles and abstracts of all articles and included those that reported objective outcomes of a surgical technique in at least 2 patients. The presence or absence of an objective instrument for evaluating outcomes of midface reanimation. Additional outcome measures were reproducibility of the test, reporting of symmetry, measurement of multiple variables, and test validity. Of 241 articles describing dynamic facial reanimation techniques, 49 (20.3%) reported objective outcome measures for 1898 patients. Of those articles reporting objective measures, there were 29 different instruments, only 3 of which reported all outcome measures. Although instruments are available to objectively measure facial movement after reanimation techniques, most studies do not report objective outcomes. Of objective facial reanimation instruments, few are reproducible and able to measure symmetry and multiple data points. To accurately compare objective outcomes in facial reanimation, a reproducible, objective, and universally applied instrument is needed.

A method of camera calibration in the measurement process with reference mark for approaching observation space target

NASA Astrophysics Data System (ADS)

Zhang, Hua; Zeng, Luan

2017-11-01

Binocular stereoscopic vision can be used for space-based space targets near observation. In order to solve the problem that the traditional binocular vision system cannot work normally after interference, an online calibration method of binocular stereo measuring camera with self-reference is proposed. The method uses an auxiliary optical imaging device to insert the image of the standard reference object into the edge of the main optical path and image with the target on the same focal plane, which is equivalent to a standard reference in the binocular imaging optical system; When the position of the system and the imaging device parameters are disturbed, the image of the standard reference will change accordingly in the imaging plane, and the position of the standard reference object does not change. The camera's external parameters can be re-calibrated by the visual relationship of the standard reference object. The experimental results show that the maximum mean square error of the same object can be reduced from the original 72.88mm to 1.65mm when the right camera is deflected by 0.4 degrees and the left camera is high and low with 0.2° rotation. This method can realize the online calibration of binocular stereoscopic vision measurement system, which can effectively improve the anti - jamming ability of the system.

Velocity measurement by vibro-acoustic Doppler.

PubMed

Nabavizadeh, Alireza; Urban, Matthew W; Kinnick, Randall R; Fatemi, Mostafa

2012-04-01

We describe the theoretical principles of a new Doppler method, which uses the acoustic response of a moving object to a highly localized dynamic radiation force of the ultrasound field to calculate the velocity of the moving object according to Doppler frequency shift. This method, named vibro-acoustic Doppler (VAD), employs two ultrasound beams separated by a slight frequency difference, Δf, transmitting in an X-focal configuration. Both ultrasound beams experience a frequency shift because of the moving objects and their interaction at the joint focal zone produces an acoustic frequency shift occurring around the low-frequency (Δf) acoustic emission signal. The acoustic emission field resulting from the vibration of the moving object is detected and used to calculate its velocity. We report the formula that describes the relation between Doppler frequency shift of the emitted acoustic field and the velocity of the moving object. To verify the theory, we used a string phantom. We also tested our method by measuring fluid velocity in a tube. The results show that the error calculated for both string and fluid velocities is less than 9.1%. Our theory shows that in the worst case, the error is 0.54% for a 25° angle variation for the VAD method compared with an error of -82.6% for a 25° angle variation for a conventional continuous wave Doppler method. An advantage of this method is that, unlike conventional Doppler, it is not sensitive to angles between the ultrasound beams and direction of motion.

A method for remote sounding of a bottom relief of water objects with using GPS

NASA Astrophysics Data System (ADS)

Mamontova, L. S.

2014-12-01

The no-fly automated system of small rivers' depth's measurement which is based on a combination of a differential method GPS-definition of the pro-measured vessel's coordinates both the method of depth's measurement with sonic depth finder and the method of the vessel's management was examined in this article.On the central station the digital card with a relief for a pro-measured zone of the reservoir is formed and the position of a pro-measured vessel on the tacks is controlled thanks to the coordinates of a pro-measured vessel and depth's measurements with sonic depth finder.The offered system allows to raise the level of depth's pro-measured works.

Three-dimensional object surface identification

NASA Astrophysics Data System (ADS)

Celenk, Mehmet

1995-03-01

This paper describes a computationally efficient matching method for inspecting 3D objects using their serial cross sections. Object regions of interest in cross-sectional binary images of successive slices are aligned with those of the models. Cross-sectional differences between the object and the models are measured in the direction of the gradient of the cross section boundary. This is repeated in all the cross-sectional images. The model with minimum average cross-sectional difference is selected as the best match to the given object (i.e., no defect). The method is tested using various computer generated surfaces and matching results are presented. It is also demonstrated using Symult S-2010 16-node system that the method is suitable for parallel implementation in massage passing processors with the maximum attainable speedup (close to 16 for S-2010).

COMPARISON OF NONLINEAR DYNAMICS OPTIMIZATION METHODS FOR APS-U

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Y.; Borland, Michael

Many different objectives and genetic algorithms have been proposed for storage ring nonlinear dynamics performance optimization. These optimization objectives include nonlinear chromaticities and driving/detuning terms, on-momentum and off-momentum dynamic acceptance, chromatic detuning, local momentum acceptance, variation of transverse invariant, Touschek lifetime, etc. In this paper, the effectiveness of several different optimization methods and objectives are compared for the nonlinear beam dynamics optimization of the Advanced Photon Source upgrade (APS-U) lattice. The optimized solutions from these different methods are preliminarily compared in terms of the dynamic acceptance, local momentum acceptance, chromatic detuning, and other performance measures.

Measuring attention using flash-lag effect.

PubMed

Shioiri, Satoshi; Yamamoto, Ken; Oshida, Hiroki; Matsubara, Kazuya; Yaguchi, Hirohisa

2010-08-13

We investigated the effect of attention on the flash-lag effect (FLE) in order to determine whether the FLE can be used to estimate the effect of visual attention. The FLE is the effect that a flash aligned with a moving object is perceived to lag the moving object, and several studies have shown that attention reduces its magnitude. We measured the FLE as a function of the number or speed of moving objects. The results showed that the effect of cueing, which we attributed the effect of attention, on the FLE increased monotonically with the number or the speed of the objects. This suggests that the amount of attention can be estimated by measuring the FLE, assuming that more amount of attention is required for a larger number or faster speed of objects to attend. On the basis of this presumption, we attempted to measure the spatial spread of visual attention by FLE measurements. The estimated spatial spreads were similar to those estimated by other experimental methods.

Exact analytical approach for six-degree-of-freedom measurement using image-orientation-change method.

PubMed

Tsai, Chung-Yu

2012-04-01

An exact analytical approach is proposed for measuring the six-degree-of-freedom (6-DOF) motion of an object using the image-orientation-change (IOC) method. The proposed measurement system comprises two reflector systems, where each system consists of two reflectors and one position sensing detector (PSD). The IOCs of the object in the two reflector systems are described using merit functions determined from the respective PSD readings before and after motion occurs, respectively. The three rotation variables are then determined analytically from the eigenvectors of the corresponding merit functions. After determining the three rotation variables, the order of the translation equations is downgraded to a linear form. Consequently, the solution for the three translation variables can also be analytically determined. As a result, the motion transformation matrix describing the 6-DOF motion of the object is fully determined. The validity of the proposed approach is demonstrated by means of an illustrative example.

Tracer Methods for Characterizing Fracture Creation in Engineered Geothermal Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rose, Peter; Harris, Joel

2014-05-08

The aim of this proposal is to develop, through novel high-temperature-tracing approaches, three technologies for characterizing fracture creation within Engineered Geothermal Systems (EGS). The objective of a first task is to identify, develop and demonstrate adsorbing tracers for characterizing interwell reservoir-rock surface areas and fracture spacing. The objective of a second task is to develop and demonstrate a methodology for measuring fracture surface areas adjacent to single wells. The objective of a third task is to design, fabricate and test an instrument that makes use of tracers for measuring fluid flow between newly created fractures and wellbores. In one methodmore » of deployment, it will be used to identify qualitatively which fractures were activated during a hydraulic stimulation experiment. In a second method of deployment, it will serve to measure quantitatively the rate of fluid flowing from one or more activated fracture during a production test following a hydraulic stimulation.« less

Adaption from LWIR to visible wavebands of methods to describe the population of GEO belt debris

NASA Astrophysics Data System (ADS)

Meng, Kevin; Murray-Krezan, Jeremy; Seitzer, Patrick

2018-05-01

Prior efforts to characterize the number of GEO belt debris objects by statistically analyzing the distribution of debris as a function of size have relied on techniques unique to infrared measurements of the debris. Specifically the infrared measurement techniques permitted inference of the characteristic size of the debris. This report describes a method to adapt the previous techniques and measurements to visible wavebands. Results will be presented using data from a NASA optical, visible band survey of objects near the geosynchronous orbit, GEO belt. This survey used the University of Michigan's 0.6-m Curtis-Schmidt telescope, Michigan Orbital DEbris Survey Telescope (MODEST), located at Cerro Tololo Inter-American Observatory in Chile. The system is equipped with a scanning CCD with a field of view of 1.6°×1.6°, and can detect objects smaller than 20 cm diameter at GEO.

Perceived and Objective Measures of Neighborhood Environment for Physical Activity Among Mexican Adults, 2011

PubMed Central

Salvo, Deborah; Lamadrid-Figueroa, Héctor; Hernández, Bernardo; Rivera-Dommarco, Juan A.; Pratt, Michael

2016-01-01

Introduction Environmental supports for physical activity may help residents to be physically active. However, such supports might not help if residents’ perceptions of the built environment do not correspond with objective measures. We assessed the associations between objective and perceived measures of the built environment among adults in Cuernavaca, Mexico, and examined whether certain variables modified this relationship. Methods We conducted a population-based (n = 645) study in 2011 that used objective (based on geographic information systems) and perceived (by questionnaire) measures of the following features of the built environment: residential density, mixed-land use, intersection density, and proximity to parks and transit stops. We used linear regression to assess the adjusted associations between these measures and to identify variables modifying these relationships. Results Adjusted associations were significant for all features (P < .05) except intersection density and proximity to transit stops. Significantly stronger associations between perceived and objective measures were observed among participants with low socioeconomic status, participants who did not own a motor vehicle or did not meet physical activity recommendations, and participants perceiving parks as safe. Conclusion Perceived measures of residential density, mixed-land use, and proximity to parks are associated with objective environmental measures related to physical activity. However, in Mexico, it should not be assumed that perceived measures of intersection density and proximity to transit stops are the same as objective measures. Our results are consistent with those from high-income countries in that associations between perceived and objective measures are modified by individual sociodemographic and psychosocial factors. PMID:27281391

Comparison of self-report and objective measures of driving behavior and road safety: A systematic review.

PubMed

Kaye, Sherrie-Anne; Lewis, Ioni; Freeman, James

2018-06-01

This research systematically reviewed the existing literature in regards to studies which have used both self-report and objective measures of driving behavior. The objective of the current review was to evaluate disparities or similarities between self-report and objective measures of driving behavior. Searches were undertaken in the following electronic databases, PsycINFO, PubMed, and Scopus, for peer-reviewed full-text articles that (1) focused on road safety, and (2) compared both subjective and objective measures of driving performance or driver safety. A total of 22,728 articles were identified, with 19 articles, comprising 20 studies, included as part of the review. The research reported herein suggested that for some behaviors (e.g., driving in stressful situations) there were similarities between self-report and objective measures while for other behaviors (e.g., sleepiness and vigilance states) there were differences between these measurement techniques. In addition, findings from some studies suggested that in-vehicle devices may be a valid measurement tool to assess driving exposure in older drivers. Further research is needed to examine the correspondence between self-report and objective measures of driving behavior. In particular, there is a need to increase the number of studies which compare "like with like" as it is difficult to draw comparisons when there are variations in measurement tools used. Incorporating a range of objective and self-report measurements tools in research would help to ensure that the methods used offer the most reliable measures of assessing on-road behaviors. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Measuring sensitivity to viewpoint change with and without stereoscopic cues.

PubMed

Bell, Jason; Dickinson, Edwin; Badcock, David R; Kingdom, Frederick A A

2013-12-04

The speed and accuracy of object recognition is compromised by a change in viewpoint; demonstrating that human observers are sensitive to this transformation. Here we discuss a novel method for simulating the appearance of an object that has undergone a rotation-in-depth, and include an exposition of the differences between perspective and orthographic projections. Next we describe a method by which human sensitivity to rotation-in-depth can be measured. Finally we discuss an apparatus for creating a vivid percept of a 3-dimensional rotation-in-depth; the Wheatstone Eight Mirror Stereoscope. By doing so, we reveal a means by which to evaluate the role of stereoscopic cues in the discrimination of viewpoint rotated shapes and objects.

Tunnel effect wave energy detection

NASA Technical Reports Server (NTRS)

Kaiser, William J. (Inventor); Waltman, Steven B. (Inventor); Kenny, Thomas W. (Inventor)

1995-01-01

Methods and apparatus for measuring gravitational and inertial forces, magnetic fields, or wave or radiant energy acting on an object or fluid in space provide an electric tunneling current through a gap between an electrode and that object or fluid in space and vary that gap with any selected one of such forces, magnetic fields, or wave or radiant energy acting on that object or fluid. These methods and apparatus sense a corresponding variation in an electric property of that gap and determine the latter force, magnetic fields, or wave or radiant energy in response to that corresponding variation, and thereby sense or measure such parameters as acceleration, position, particle mass, velocity, magnetic field strength, presence or direction, or wave or radiant energy intensity, presence or direction.

Spatial-heterodyne interferometry for transmission (SHIFT) measurements

DOEpatents

Bingham, Philip R.; Hanson, Gregory R.; Tobin, Ken W.

2006-10-10

Systems and methods are described for spatial-heterodyne interferometry for transmission (SHIFT) measurements. A method includes digitally recording a spatially-heterodyned hologram including spatial heterodyne fringes for Fourier analysis using a reference beam, and an object beam that is transmitted through an object that is at least partially translucent; Fourier analyzing the digitally recorded spatially-heterodyned hologram, by shifting an original origin of the digitally recorded spatially-heterodyned hologram to sit on top of a spatial-heterodyne carrier frequency defined by an angle between the reference beam and the object beam, to define an analyzed image; digitally filtering the analyzed image to cut off signals around the original origin to define a result; and performing an inverse Fourier transform on the result.

Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

NASA Technical Reports Server (NTRS)

Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

2015-01-01

This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

Multi-classification of cell deformation based on object alignment and run length statistic.

PubMed

Li, Heng; Liu, Zhiwen; An, Xing; Shi, Yonggang

2014-01-01

Cellular morphology is widely applied in digital pathology and is essential for improving our understanding of the basic physiological processes of organisms. One of the main issues of application is to develop efficient methods for cell deformation measurement. We propose an innovative indirect approach to analyze dynamic cell morphology in image sequences. The proposed approach considers both the cellular shape change and cytoplasm variation, and takes each frame in the image sequence into account. The cell deformation is measured by the minimum energy function of object alignment, which is invariant to object pose. Then an indirect analysis strategy is employed to overcome the limitation of gradual deformation by run length statistic. We demonstrate the power of the proposed approach with one application: multi-classification of cell deformation. Experimental results show that the proposed method is sensitive to the morphology variation and performs better than standard shape representation methods.

Simulating the nasal cycle with computational fluid dynamics

PubMed Central

Patel, Ruchin G.; Garcia, Guilherme J. M.; Frank-Ito, Dennis O.; Kimbell, Julia S.; Rhee, John S.

2015-01-01

Objectives (1) Develop a method to account for the confounding effect of the nasal cycle when comparing pre- and post-surgery objective measures of nasal patency. (2) Illustrate this method by reporting objective measures derived from computational fluid dynamics (CFD) models spanning the full range of mucosal engorgement associated with the nasal cycle in two subjects. Study Design Retrospective Setting Academic tertiary medical center. Subjects and Methods A cohort of 24 nasal airway obstruction patients was reviewed to select the two patients with the greatest reciprocal change in mucosal engorgement between pre- and post-surgery computed tomography (CT) scans. Three-dimensional anatomic models were created based on the pre- and post-operative CT scans. Nasal cycling models were also created by gradually changing the thickness of the inferior turbinate, middle turbinate, and septal swell body. CFD was used to simulate airflow and to calculate nasal resistance and average heat flux. Results Before accounting for the nasal cycle, Patient A appeared to have a paradoxical worsening nasal obstruction in the right cavity postoperatively. After accounting for the nasal cycle, Patient A had small improvements in objective measures postoperatively. The magnitude of the surgical effect also differed in Patient B after accounting for the nasal cycle. Conclusion By simulating the nasal cycle and comparing models in similar congestive states, surgical changes in nasal patency can be distinguished from physiological changes associated with the nasal cycle. This ability can lead to more precise comparisons of pre and post-surgery objective measures and potentially more accurate virtual surgery planning. PMID:25450411

Objective Amplitude of Accommodation Computed from Optical Quality Metrics Applied to Wavefront Outcomes

PubMed Central

López-Gil, Norberto; Fernández-Sánchez, Vicente; Thibos, Larry N.; Montés-Micó, Robert

2010-01-01

Purpose We studied the accuracy and precision of 32 objective wavefront methods for finding the amplitude of accommodation obtained in 180 eyes. Methods Ocular accommodation was stimulated with 0.5 D steps in target vergence spanning the full range of accommodation for each subject. Subjective monocular amplitude of accommodation was measured using two clinical methods, using negative lenses and with a custom Badal optometer. Results Both subjective methods gave similar results. Results obtained from the Badal optometer where used to test the accuracy of the objective methods. All objective methods showed lower amplitude of accommodation that the subjective ones by an amount that varied from 0.2 to 1.1 D depending on the method. The precision in this prediction also varied between subjects, with an average standard error of the mean of 0.1 D that decreased with age. Conclusions Depth of field increases subjective of amplitude of accommodation overestimating the objective amplitude obtained with all the metrics used. The change in the negative direction of spherical aberration during accommodation increases the amplitude of accommodation by an amount that varies with age.

A method of immediate detection of objects with a near-zero apparent motion in series of CCD-frames

NASA Astrophysics Data System (ADS)

Savanevych, V. E.; Khlamov, S. V.; Vavilova, I. B.; Briukhovetskyi, A. B.; Pohorelov, A. V.; Mkrtichian, D. E.; Kudak, V. I.; Pakuliak, L. K.; Dikov, E. N.; Melnik, R. G.; Vlasenko, V. P.; Reichart, D. E.

2018-01-01

The paper deals with a computational method for detection of the solar system minor bodies (SSOs), whose inter-frame shifts in series of CCD-frames during the observation are commensurate with the errors in measuring their positions. These objects have velocities of apparent motion between CCD-frames not exceeding three rms errors (3σ) of measurements of their positions. About 15% of objects have a near-zero apparent motion in CCD-frames, including the objects beyond the Jupiter's orbit as well as the asteroids heading straight to the Earth. The proposed method for detection of the object's near-zero apparent motion in series of CCD-frames is based on the Fisher f-criterion instead of using the traditional decision rules that are based on the maximum likelihood criterion. We analyzed the quality indicators of detection of the object's near-zero apparent motion applying statistical and in situ modeling techniques in terms of the conditional probability of the true detection of objects with a near-zero apparent motion. The efficiency of method being implemented as a plugin for the Collection Light Technology (CoLiTec) software for automated asteroids and comets detection has been demonstrated. Among the objects discovered with this plugin, there was the sungrazing comet C/2012 S1 (ISON). Within 26 min of the observation, the comet's image has been moved by three pixels in a series of four CCD-frames (the velocity of its apparent motion at the moment of discovery was equal to 0.8 pixels per CCD-frame; the image size on the frame was about five pixels). Next verification in observations of asteroids with a near-zero apparent motion conducted with small telescopes has confirmed an efficiency of the method even in bad conditions (strong backlight from the full Moon). So, we recommend applying the proposed method for series of observations with four or more frames.

Development of congestion performance measures using ITS information.

DOT National Transportation Integrated Search

2003-01-01

The objectives of this study were to define a performance measure(s) that could be used to show congestion levels on critical corridors throughout Virginia and to develop a method to select and calculate performance measures to quantify congestion in...

An objective method for measuring face detection thresholds using the sweep steady-state visual evoked response

PubMed Central

Ales, Justin M.; Farzin, Faraz; Rossion, Bruno; Norcia, Anthony M.

2012-01-01

We introduce a sensitive method for measuring face detection thresholds rapidly, objectively, and independently of low-level visual cues. The method is based on the swept parameter steady-state visual evoked potential (ssVEP), in which a stimulus is presented at a specific temporal frequency while parametrically varying (“sweeping”) the detectability of the stimulus. Here, the visibility of a face image was increased by progressive derandomization of the phase spectra of the image in a series of equally spaced steps. Alternations between face and fully randomized images at a constant rate (3/s) elicit a robust first harmonic response at 3 Hz specific to the structure of the face. High-density EEG was recorded from 10 human adult participants, who were asked to respond with a button-press as soon as they detected a face. The majority of participants produced an evoked response at the first harmonic (3 Hz) that emerged abruptly between 30% and 35% phase-coherence of the face, which was most prominent on right occipito-temporal sites. Thresholds for face detection were estimated reliably in single participants from 15 trials, or on each of the 15 individual face trials. The ssVEP-derived thresholds correlated with the concurrently measured perceptual face detection thresholds. This first application of the sweep VEP approach to high-level vision provides a sensitive and objective method that could be used to measure and compare visual perception thresholds for various object shapes and levels of categorization in different human populations, including infants and individuals with developmental delay. PMID:23024355

Development and Factor Analysis of an Instrument to Measure Preservice Teachers' Perceptions of Learning Objects

ERIC Educational Resources Information Center

Sahin, Sami

2010-01-01

The purpose of this study was to develop a questionnaire to measure student teachers' perception of digital learning objects. The participants included 308 voluntary senior students attending courses in a college of education of a public university in Turkey. The items were extracted to their related factors by the principal axis factoring method.…

Comments on Professor Bloom's Paper Entitled "Toward a Theory of Testing Which Includes Measurement-Evaluation-Assessment."

ERIC Educational Resources Information Center

Glass, Gene V.

The objective of evaluation in education is distinct from the objectives of measurement and assessment or testing. Accordingly, a synthesis of the three procedures into a single theory is not viable. Evaluation is a method of gathering empirical evidence for decision making by answering questions about the worth of educational materials,…

Association between Accelerometer-Assessed Physical Activity and Objectively Measured Hearing Sensitivity among U.S. Adults with Diabetes

ERIC Educational Resources Information Center

Loprinzi, Paul D.; Gilham, Ben; Cardinal, Bradley J.

2014-01-01

Purpose: The purpose of this study was to examine the association between objectively measured physical activity and hearing sensitivity among a nationally representative sample of U.S. adults with diabetes. Method: Data from the 2003-2006 National Health and Nutrition Examination Survey were used. One hundred eighty-four U.S. adults with diabetes…

Fourier transform magnetic resonance current density imaging (FT-MRCDI) from one component of magnetic flux density.

PubMed

Ider, Yusuf Ziya; Birgul, Ozlem; Oran, Omer Faruk; Arikan, Orhan; Hamamura, Mark J; Muftuler, L Tugan

2010-06-07

Fourier transform (FT)-based algorithms for magnetic resonance current density imaging (MRCDI) from one component of magnetic flux density have been developed for 2D and 3D problems. For 2D problems, where current is confined to the xy-plane and z-component of the magnetic flux density is measured also on the xy-plane inside the object, an iterative FT-MRCDI algorithm is developed by which both the current distribution inside the object and the z-component of the magnetic flux density on the xy-plane outside the object are reconstructed. The method is applied to simulated as well as actual data from phantoms. The effect of measurement error on the spatial resolution of the current density reconstruction is also investigated. For 3D objects an iterative FT-based algorithm is developed whereby the projected current is reconstructed on any slice using as data the Laplacian of the z-component of magnetic flux density measured for that slice. In an injected current MRCDI scenario, the current is not divergence free on the boundary of the object. The method developed in this study also handles this situation.

Use of Image Based Modelling for Documentation of Intricately Shaped Objects

NASA Astrophysics Data System (ADS)

Marčiš, M.; Barták, P.; Valaška, D.; Fraštia, M.; Trhan, O.

2016-06-01

In the documentation of cultural heritage, we can encounter three dimensional shapes and structures which are complicated to measure. Such objects are for example spiral staircases, timber roof trusses, historical furniture or folk costume where it is nearly impossible to effectively use the traditional surveying or the terrestrial laser scanning due to the shape of the object, its dimensions and the crowded environment. The actual methods of digital photogrammetry can be very helpful in such cases with the emphasis on the automated processing of the extensive image data. The created high resolution 3D models and 2D orthophotos are very important for the documentation of architectural elements and they can serve as an ideal base for the vectorization and 2D drawing documentation. This contribution wants to describe the various usage of image based modelling in specific interior spaces and specific objects. The advantages and disadvantages of the photogrammetric measurement of such objects in comparison to other surveying methods are reviewed.

Optimization of Exposure Time Division for Multi-object Photometry

NASA Astrophysics Data System (ADS)

Popowicz, Adam; Kurek, Aleksander R.

2017-09-01

Optical observations of wide fields of view entail the problem of selecting the best exposure time. As many objects are usually observed simultaneously, the quality of photometry of the brightest ones is always better than that of the dimmer ones, even though all of them are frequently equally interesting for astronomers. Thus, measuring all objects with the highest possible precision is desirable. In this paper, we present a new optimization algorithm, dedicated for the division of exposure time into sub-exposures, which enables photometry with a more balanced noise budget. The proposed technique increases the photometric precision of dimmer objects at the expense of the measurement fidelity of the brightest ones. We have tested the method on real observations using two telescope setups, demonstrating its usefulness and good consistency with theoretical expectations. The main application of our approach is a wide range of sky surveys, including ones performed by space telescopes. The method can be used to plan virtually any photometric observation of objects that show a wide range of magnitudes.

Extrinsic Calibration of a Laser Galvanometric Setup and a Range Camera.

PubMed

Sels, Seppe; Bogaerts, Boris; Vanlanduit, Steve; Penne, Rudi

2018-05-08

Currently, galvanometric scanning systems (like the one used in a scanning laser Doppler vibrometer) rely on a planar calibration procedure between a two-dimensional (2D) camera and the laser galvanometric scanning system to automatically aim a laser beam at a particular point on an object. In the case of nonplanar or moving objects, this calibration is not sufficiently accurate anymore. In this work, a three-dimensional (3D) calibration procedure that uses a 3D range sensor is proposed. The 3D calibration is valid for all types of objects and retains its accuracy when objects are moved between subsequent measurement campaigns. The proposed 3D calibration uses a Non-Perspective-n-Point (NPnP) problem solution. The 3D range sensor is used to calculate the position of the object under test relative to the laser galvanometric system. With this extrinsic calibration, the laser galvanometric scanning system can automatically aim a laser beam to this object. In experiments, the mean accuracy of aiming the laser beam on an object is below 10 mm for 95% of the measurements. This achieved accuracy is mainly determined by the accuracy and resolution of the 3D range sensor. The new calibration method is significantly better than the original 2D calibration method, which in our setup achieves errors below 68 mm for 95% of the measurements.

ABSCISSA ASSESSMENT WITH ALGAE: A COMPARISON OF LOCAL AND LANDSCAPE IMPAIRMENT MEASURES FOR BIOLOGICAL ASSESSMENT USING BENTHIC DIATOMS

EPA Science Inventory

The development of rigorous biological assessments is dependent upon well-constructed abscissa, and various methods, both subjective and objective, exist to measure expected impairment at both the landscape and local scale. A new, landscape-scale method has recently been offered...

Microwave determination of location and speed of an object inside a pipe

DOEpatents

Sinha, Dipen N.

2010-12-14

Apparatus and method are described for measuring the location and speed of an object, such as instrumentation on a movable platform, disposed within a pipe, using continuous-wave, amplitude-modulated microwave radiation.

Measuring chromatic aberrations in imaging systems using plasmonic nanoparticles.

PubMed

Gennaro, Sylvain D; Roschuk, Tyler R; Maier, Stefan A; Oulton, Rupert F

2016-04-01

We demonstrate a method to measure chromatic aberrations of microscope objectives with metallic nanoparticles using white light. Extinction spectra are recorded while scanning a single nanoparticle through a lens's focal plane. We show a direct correlation between the focal wavelength and the longitudinal chromatic focal shift through our analysis of the variations between the scanned extinction spectra at each scan position and the peak extinction over the entire scan. The method has been tested on achromat and apochromat objectives using aluminum disks varying in size from 260-520 nm. Our method is straightforward, robust, low cost, and broadband with a sensitivity suitable for assessing longitudinal chromatic aberrations in high-numerical-aperture apochromatic corrected lenses.

Moire technique utilization for detection and measurement of scoliosis

NASA Astrophysics Data System (ADS)

Zawieska, Dorota; Podlasiak, Piotr

1993-02-01

Moire projection method enables non-contact measurement of the shape or deformation of different surfaces and constructions by fringe pattern analysis. The fringe map acquisition of the whole surface of the object under test is one of the main advantages compared with 'point by point' methods. The computer analyzes the shape of the whole surface and next user can selected different points or cross section of the object map. In this paper a few typical examples of an application of the moire technique in solving different medical problems will be presented. We will also present to you the equipment the moire pattern analysis is done in real time using the phase stepping method with CCD camera.

Objective-lens-free Fiber-based Position Detection with Nanometer Resolution in a Fiber Optical Trapping System.

PubMed

Ti, Chaoyang; Ho-Thanh, Minh-Tri; Wen, Qi; Liu, Yuxiang

2017-10-13

Position detection with high accuracy is crucial for force calibration of optical trapping systems. Most existing position detection methods require high-numerical-aperture objective lenses, which are bulky, expensive, and difficult to miniaturize. Here, we report an affordable objective-lens-free, fiber-based position detection scheme with 2 nm spatial resolution and 150 MHz bandwidth. This fiber based detection mechanism enables simultaneous trapping and force measurements in a compact fiber optical tweezers system. In addition, we achieved more reliable signal acquisition with less distortion compared with objective based position detection methods, thanks to the light guiding in optical fibers and small distance between the fiber tips and trapped particle. As a demonstration of the fiber based detection, we used the fiber optical tweezers to apply a force on a cell membrane and simultaneously measure the cellular response.

Micro-vibration detection with heterodyne holography based on time-averaged method

NASA Astrophysics Data System (ADS)

Qin, XiaoDong; Pan, Feng; Chen, ZongHui; Hou, XueQin; Xiao, Wen

2017-02-01

We propose a micro-vibration detection method by introducing heterodyne interferometry to time-averaged holography. This method compensates for the deficiency of time-average holography in quantitative measurements and widens its range of application effectively. Acousto-optic modulators are used to modulate the frequencies of the reference beam and the object beam. Accurate detection of the maximum amplitude of each point in the vibration plane is performed by altering the frequency difference of both beams. The range of amplitude detection of plane vibration is extended. In the stable vibration mode, the distribution of the maximum amplitude of each point is measured and the fitted curves are plotted. Hence the plane vibration mode of the object is demonstrated intuitively and detected quantitatively. We analyzed the method in theory and built an experimental system with a sine signal as the excitation source and a typical piezoelectric ceramic plate as the target. The experimental results indicate that, within a certain error range, the detected vibration mode agrees with the intrinsic vibration characteristics of the object, thus proving the validity of this method.

Exploring the construct validity of the social cognition and object relations scale in a clinical sample.

PubMed

Stein, Michelle B; Slavin-Mulford, Jenelle; Sinclair, S Justin; Siefert, Caleb J; Blais, Mark A

2012-01-01

The Social Cognition and Object Relations Scale-Global rating method (SCORS-G; Stein, Hilsenroth, Slavin-Mulford, & Pinsker, 2011; Westen, 1995) measures the quality of object relations in narrative material. This study employed a multimethod approach to explore the structure and construct validity of the SCORS-G. The Thematic Apperception Test (TAT; Murray, 1943) was administered to 59 patients referred for psychological assessment at a large Northeastern U.S. hospital. The resulting 301 TAT narratives were rated using the SCORS-G method. The 8 SCORS variables were found to have high interrater reliability and good internal consistency. Principal components analysis revealed a 3-component solution with components tapping emotions/affect regulation in relationships, self-image, and aspects of cognition. Next, the construct validity of the SCORS-G components was explored using measures of intellectual and executive functioning, psychopathology, and normal personality. The 3 SCORS-G components showed unique and theoretically meaningful relationships across these broad and diverse psychological measures. This study demonstrates the value of using a standardized scoring method, like the SCORS-G, to reveal the rich and complex nature of narrative material.

Scene analysis for effective visual search in rough three-dimensional-modeling scenes

NASA Astrophysics Data System (ADS)

Wang, Qi; Hu, Xiaopeng

2016-11-01

Visual search is a fundamental technology in the computer vision community. It is difficult to find an object in complex scenes when there exist similar distracters in the background. We propose a target search method in rough three-dimensional-modeling scenes based on a vision salience theory and camera imaging model. We give the definition of salience of objects (or features) and explain the way that salience measurements of objects are calculated. Also, we present one type of search path that guides to the target through salience objects. Along the search path, when the previous objects are localized, the search region of each subsequent object decreases, which is calculated through imaging model and an optimization method. The experimental results indicate that the proposed method is capable of resolving the ambiguities resulting from distracters containing similar visual features with the target, leading to an improvement of search speed by over 50%.

High accuracy position method based on computer vision and error analysis

NASA Astrophysics Data System (ADS)

Chen, Shihao; Shi, Zhongke

2003-09-01

The study of high accuracy position system is becoming the hotspot in the field of autocontrol. And positioning is one of the most researched tasks in vision system. So we decide to solve the object locating by using the image processing method. This paper describes a new method of high accuracy positioning method through vision system. In the proposed method, an edge-detection filter is designed for a certain running condition. Here, the filter contains two mainly parts: one is image-processing module, this module is to implement edge detection, it contains of multi-level threshold self-adapting segmentation, edge-detection and edge filter; the other one is object-locating module, it is to point out the location of each object in high accurate, and it is made up of medium-filtering and curve-fitting. This paper gives some analysis error for the method to prove the feasibility of vision in position detecting. Finally, to verify the availability of the method, an example of positioning worktable, which is using the proposed method, is given at the end of the paper. Results show that the method can accurately detect the position of measured object and identify object attitude.

Wearable 3D measurement

NASA Astrophysics Data System (ADS)

Manabe, Yoshitsugu; Imura, Masataka; Tsuchiya, Masanobu; Yasumuro, Yoshihiro; Chihara, Kunihiro

2003-01-01

Wearable 3D measurement realizes to acquire 3D information of an objects or an environment using a wearable computer. Recently, we can send voice and sound as well as pictures by mobile phone in Japan. Moreover it will become easy to capture and send data of short movie by it. On the other hand, the computers become compact and high performance. And it can easy connect to Internet by wireless LAN. Near future, we can use the wearable computer always and everywhere. So we will be able to send the three-dimensional data that is measured by wearable computer as a next new data. This paper proposes the measurement method and system of three-dimensional data of an object with the using of wearable computer. This method uses slit light projection for 3D measurement and user"s motion instead of scanning system.

Digital x-ray tomosynthesis with interpolated projection data for thin slab objects

NASA Astrophysics Data System (ADS)

Ha, S.; Yun, J.; Kim, H. K.

2017-11-01

In relation with a thin slab-object inspection, we propose a digital tomosynthesis reconstruction with fewer numbers of measured projections in combinations with additional virtual projections, which are produced by interpolating the measured projections. Hence we can reconstruct tomographic images with less few-view artifacts. The projection interpolation assumes that variations in cone-beam ray path-lengths through an object are negligible and the object is rigid. The interpolation is performed in the projection-space domain. Pixel values in the interpolated projection are the weighted sum of pixel values of the measured projections considering their projection angles. The experimental simulation shows that the proposed method can enhance the contrast-to-noise performance in reconstructed images while sacrificing the spatial resolving power.

Methods for identification and verification using vacuum XRF system

NASA Technical Reports Server (NTRS)

Kaiser, Bruce (Inventor); Schramm, Fred (Inventor)

2005-01-01

Apparatus and methods in which one or more elemental taggants that are intrinsically located in an object are detected by x-ray fluorescence analysis under vacuum conditions to identify or verify the object's elemental content for elements with lower atomic numbers. By using x-ray fluorescence analysis, the apparatus and methods of the invention are simple and easy to use, as well as provide detection by a non line-of-sight method to establish the origin of objects, as well as their point of manufacture, authenticity, verification, security, and the presence of impurities. The invention is extremely advantageous because it provides the capability to measure lower atomic number elements in the field with a portable instrument.

The Effects of Directional Processing on Objective and Subjective Listening Effort

ERIC Educational Resources Information Center

Picou, Erin M.; Moore, Travis M.; Ricketts, Todd A.

2017-01-01

Purpose: The purposes of this investigation were (a) to evaluate the effects of hearing aid directional processing on subjective and objective listening effort and (b) to investigate the potential relationships between subjective and objective measures of effort. Method: Sixteen adults with mild to severe hearing loss were tested with study…

Chirped pulse digital holography for measuring the sequence of ultrafast optical wavefronts

NASA Astrophysics Data System (ADS)

Karasawa, Naoki

2018-04-01

Optical setups for measuring the sequence of ultrafast optical wavefronts using a chirped pulse as a reference wave in digital holography are proposed and analyzed. In this method, multiple ultrafast object pulses are used to probe the temporal evolution of ultrafast phenomena and they are interfered with a chirped reference wave to record a digital hologram. Wavefronts at different times can be reconstructed separately from the recorded hologram when the reference pulse can be treated as a quasi-monochromatic wave during the pulse width of each object pulse. The feasibility of this method is demonstrated by numerical simulation.

Using compressive measurement to obtain images at ultra low-light-level

NASA Astrophysics Data System (ADS)

Ke, Jun; Wei, Ping

2013-08-01

In this paper, a compressive imaging architecture is used for ultra low-light-level imaging. In such a system, features, instead of object pixels, are imaged onto a photocathode, and then magnified by an image intensifier. By doing so, system measurement SNR is increased significantly. Therefore, the new system can image objects at ultra low-ligh-level, while a conventional system has difficulty. PCA projection is used to collect feature measurements in this work. Linear Wiener operator and nonlinear method based on FoE model are used to reconstruct objects. Root mean square error (RMSE) is used to quantify system reconstruction quality.

Non-contact measurement of facial surface vibration patterns during singing by scanning laser Doppler vibrometer.

PubMed

Kitamura, Tatsuya; Ohtani, Keisuke

2015-01-01

This paper presents a method of measuring the vibration patterns on facial surfaces by using a scanning laser Doppler vibrometer (LDV). The surfaces of the face, neck, and body vibrate during phonation and, according to Titze (2001), these vibrations occur when aerodynamic energy is efficiently converted into acoustic energy at the glottis. A vocalist's vibration velocity patterns may therefore indicate his or her phonatory status or singing skills. LDVs enable laser-based non-contact measurement of the vibration velocity and displacement of a certain point on a vibrating object, and scanning LDVs permit multipoint measurements. The benefits of scanning LDVs originate from the facts that they do not affect the vibrations of measured objects and that they can rapidly measure the vibration patterns across planes. A case study is presented herein to demonstrate the method of measuring vibration velocity patterns with a scanning LDV. The objective of the experiment was to measure the vibration velocity differences between the modal and falsetto registers while three professional soprano singers sang sustained vowels at four pitch frequencies. The results suggest that there is a possibility that pitch frequency are correlated with vibration velocity. However, further investigations are necessary to clarify the relationships between vibration velocity patterns and phonation status and singing skills.

Non-contact measurement of facial surface vibration patterns during singing by scanning laser Doppler vibrometer

PubMed Central

Kitamura, Tatsuya; Ohtani, Keisuke

2015-01-01

This paper presents a method of measuring the vibration patterns on facial surfaces by using a scanning laser Doppler vibrometer (LDV). The surfaces of the face, neck, and body vibrate during phonation and, according to Titze (2001), these vibrations occur when aerodynamic energy is efficiently converted into acoustic energy at the glottis. A vocalist's vibration velocity patterns may therefore indicate his or her phonatory status or singing skills. LDVs enable laser-based non-contact measurement of the vibration velocity and displacement of a certain point on a vibrating object, and scanning LDVs permit multipoint measurements. The benefits of scanning LDVs originate from the facts that they do not affect the vibrations of measured objects and that they can rapidly measure the vibration patterns across planes. A case study is presented herein to demonstrate the method of measuring vibration velocity patterns with a scanning LDV. The objective of the experiment was to measure the vibration velocity differences between the modal and falsetto registers while three professional soprano singers sang sustained vowels at four pitch frequencies. The results suggest that there is a possibility that pitch frequency are correlated with vibration velocity. However, further investigations are necessary to clarify the relationships between vibration velocity patterns and phonation status and singing skills. PMID:26579054

Radiographic angles in hallux valgus: Comparison between protractor and iPhone measurements.

PubMed

Meng, Hong-Zheng; Zhang, Wei-Lin; Li, Xiu-Cheng; Yang, Mao-Wei

2015-08-01

Radiographic angles are used to assess the severity of hallux valgus deformity, make preoperative plans, evaluate outcomes after surgery, and compare results between different methods. Traditionally, hallux valgus angle (HVA) has been measured by using a protractor and a marker pen with hardcopy radiographs. The main objective of this study is to compare HVA measurements performed using a smartphone and a traditional protractor. The secondary objective was to compare the time taken between those two methods. Six observers measured major HVA on 20 radiographs of hallux valgus deformity with both a standard protractor and an Apple iPhone. Four of the observers repeated the measurements at least a week after the original measurements. The mean absolute difference between pairs of protractor and smartphone measurements was 3.2°. The 95% confidence intervals for intra-observer variability were ±3.1° for the smartphone measurement and ±3.2° for the protractor method. The 95% confidence intervals for inter-observer variability were ±9.1° for the smartphone measurement and ±9.6° for the protractor measurement. We conclude that the smartphone is equivalent to the protractor for the accuracy of HVA measurement. But, the time taken in smartphone measurement was also reduced. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Factors Associated with Objectively Measured Physical Activity and Sedentary Time of 5-6-Year-Old Children in the STEPS Study

ERIC Educational Resources Information Center

Matarma, Tanja; Tammelin, Tuija; Kulmala, Janne; Koski, Pasi; Hurme, Saija; Lagström, Hanna

2017-01-01

Background: The factors associated with preschool-aged children's physical activity (PA) remains unclear. The aim of this cross-sectional study was to examine how different factors were associated with preschool-aged children's objectively measured PA and sedentary time. Methods: The study population was 5-6-year-old children (n = 140) and their…

Fundamental Movement Skill Proficiency and Body Composition Measured by Dual Energy X-Ray Absorptiometry in Eight-Year-Old Children

ERIC Educational Resources Information Center

Slotte, Sari; Sääkslahti, Arja; Metsämuuronen, Jari; Rintala, Pauli

2015-01-01

Objective: The main aim was to examine the association between fundamental movement skills (FMS) and objectively measured body composition using dual energy X-ray absorptiometry (DXA). Methods: A study of 304 eight-year-old children in Finland. FMS were assessed with the "Test of gross motor development," 2nd ed. Total body fat…

Seabed-Structure Interaction: Workshop Report and Recommendations for Future Research Held in Metairie, Louisiana on 5-6 November 1991.

DTIC Science & Technology

1992-02-01

14 Measurements of Sediment Properties and Data Analysis ............................................. 15 object...Object Sensing Methods (Detect/Classification) and (B) Sediment Properties Measurements and Data Analysis . Although important to the understanding of S...characterized by a variety of geological materials, seabed properties, and hydrodynamic processes, the problems of I modeling, analysis , and prediction of S-SI

An Objective Method of Measuring Psychological States Associated With Changes in Neural Function: Content Analysis of Verbal Behavior.

ERIC Educational Resources Information Center

Gottschalk, Louis A.

This paper examines the use of content analysis of speech in the objective recording and measurement of changes in emotional and cognitive function of humans in whom natural or experimental changes in neural status have occurred. A brief description of the data gathering process, details of numerous physiological effects, an anxiety scale, and a…

Videogrammetry Using Projected Circular Targets: Proof-of-Concept Test

NASA Technical Reports Server (NTRS)

Pappa, Richard S.; Black, Jonathan T.

2003-01-01

Videogrammetry is the science of calculating 3D object coordinates as a function of time from image sequences. It expands the method of photogrammetry to multiple time steps enabling the object to be characterized dynamically. Photogrammetry achieves the greatest accuracy with high contrast, solid-colored, circular targets. The high contrast is most often effected using retro-reflective targets attached to the measurement article. Knowledge of the location of each target allows those points to be tracked in a sequence of images, thus yielding dynamic characterization of the overall object. For ultra-lightweight and inflatable gossamer structures (e.g. solar sails, inflatable antennae, sun shields, etc.) where it may be desirable to avoid physically attaching retro-targets, a high-density grid of projected circular targets - called dot projection - is a viable alternative. Over time the object changes shape or position independently of the dots. Dynamic behavior, such as deployment or vibration, can be characterized by tracking the overall 3D shape of the object instead of tracking specific object points. To develop this method, an oscillating rigid object was measured using both retroreflective targets and dot projection. This paper details these tests, compares the results, and discusses the overall accuracy of dot projection videogrammetry.

Videogrammetry Using Projected Circular Targets: Proof-of-Concept Test

NASA Technical Reports Server (NTRS)

Black, Jonathan T.; Pappa, Richard S.

2003-01-01

Videogrammetry is the science of calculating 3D object coordinates as a function of time from image sequences. It expands the method of photogrammetry to multiple time steps enabling the object to be characterized dynamically. Photogrammetry achieves the greatest accuracy with high contrast, solid-colored circular targets. The high contrast is most often effected using retro-reflective targets attached to the measurement article. Knowledge of the location of each target allows those points to be tracked in a sequence of images, thus yielding dynamic characterization of the overall object. For ultra-lightweight and inflatable gossamer structures (e.g. solar sails, inflatable antennae, sun shields, etc.) where it may be desirable to avoid physically attaching retro-targets, a high-density grid of projected circular targets - called dot projection - is a viable alternative. Over time the object changes shape or position independently of the dots. Dynamic behavior, such as deployment or vibration, can be characterized by tracking the overall 3D shape of the object instead of tracking specific object points. To develop this method, an oscillating rigid object was measured using both retro- reflective targets and dot projection. This paper details these tests, compares the results, and discusses the overall accuracy of dot projection videogrammetry.

Methodical approaches to value assessment and determination of the capitalization level of high-rise construction

NASA Astrophysics Data System (ADS)

Smirnov, Vitaly; Dashkov, Leonid; Gorshkov, Roman; Burova, Olga; Romanova, Alina

2018-03-01

The article presents the analysis of the methodological approaches to cost estimation and determination of the capitalization level of high-rise construction objects. Factors determining the value of real estate were considered, three main approaches for estimating the value of real estate objects are given. The main methods of capitalization estimation were analyzed, the most reasonable method for determining the level of capitalization of high-rise buildings was proposed. In order to increase the value of real estate objects, the author proposes measures that enable to increase significantly the capitalization of the enterprise through more efficient use of intangible assets and goodwill.

SU-F-I-80: Correction for Bias in a Channelized Hotelling Model Observer Caused by Temporally Variable Non-Stationary Noise

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favazza, C; Fetterly, K

2016-06-15

Purpose: Application of a channelized Hotelling model observer (CHO) over a wide range of x-ray angiography detector target dose (DTD) levels demonstrated substantial bias for conditions yielding low detectability indices (d’), including low DTD and small test objects. The purpose of this work was to develop theory and methods to correct this bias. Methods: A hypothesis was developed wherein the measured detectability index (d’b) for a known test object is positively biased by temporally variable non-stationary noise in the images. Hotelling’s T2 test statistic provided the foundation for a mathematical theory which accounts for independent contributions to the measured d’bmore » value from both the test object (d’o) and non-stationary noise (d’ns). Experimental methods were developed to directly estimate d’o by determining d’ns and subtracting it from d’b, in accordance with the theory. Specifically, d’ns was determined from two sets of images from which the traditional test object was withheld. This method was applied to angiography images with DTD levels in the range 0 to 240 nGy and for disk-shaped iodine-based contrast targets with diameters 0.5 to 4.0 mm. Results: Bias in d’ was evidenced by d’b values which exceeded values expected from a quantum limited imaging system and decreasing object size and DTD. d’ns increased with decreasing DTD, reaching a maximum of 2.6 for DTD = 0. Bias-corrected d’o estimates demonstrated sub-quantum limited performance of the x-ray angiography for low DTD. Findings demonstrated that the source of non-stationary noise was detector electronic readout noise. Conclusion: Theory and methods to estimate and correct bias in CHO measurements from temporally variable non-stationary noise were presented. The temporal non-stationary noise was shown to be due to electronic readout noise. This method facilitates accurate estimates of d’ values over a large range of object size and detector target dose.« less

Photogrammetric Technique for Center of Gravity Determination

NASA Technical Reports Server (NTRS)

Jones, Thomas W.; Johnson, Thomas H.; Shemwell, Dave; Shreves, Christopher M.

2012-01-01

A new measurement technique for determination of the center of gravity (CG) for large scale objects has been demonstrated. The experimental method was conducted as part of an LS-DYNA model validation program for the Max Launch Abort System (MLAS) crew module. The test was conducted on the full scale crew module concept at NASA Langley Research Center. Multi-camera photogrammetry was used to measure the test article in several asymmetric configurations. The objective of these measurements was to provide validation of the CG as computed from the original mechanical design. The methodology, measurement technique, and measurement results are presented.

Simultaneous 3D-vibration measurement using a single laser beam device

NASA Astrophysics Data System (ADS)

Brecher, Christian; Guralnik, Alexander; Baümler, Stephan

2012-06-01

Today's commercial solutions for vibration measurement and modal analysis are 3D-scanning laser doppler vibrometers, mainly used for open surfaces in the automotive and aerospace industries and the classic three-axial accelerometers in civil engineering, for most industrial applications in manufacturing environments, and particularly for partially closed structures. This paper presents a novel measurement approach using a single laser beam device and optical reflectors to simultaneously perform 3D-dynamic measurement as well as geometry measurement of the investigated object. We show the application of this so called laser tracker for modal testing of structures on a mechanical manufacturing shop floor. A holistic measurement method is developed containing manual reflector placement, semi-automated geometric modeling of investigated objects and fully automated vibration measurement up to 1000 Hz and down to few microns amplitude. Additionally the fast set up dynamic measurement of moving objects using a tracking technique is presented that only uses the device's own functionalities and does neither require a predefined moving path of the target nor an electronic synchronization to the moving object.

Interferometric studies of the refractive indices of some fluorine compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, Jim Gorden; Rogers, Max T.; Speirs, John L.

1954-08-01

It is the object of this investigation to construct an interferometer of the Rayleigh type and adapt it for two purposes; first, the measurement of the refractive indices of gases by an absolute method and, and second, the measurement of the refractive indices of very dilute solutions by the difference method.

A Multi-Method Approach to Studying the Relationship between Character Strengths and Vocational Interests in Adolescents

ERIC Educational Resources Information Center

Proyer, Rene T.; Sidler, Nicole; Weber, Marco; Ruch, Willibald

2012-01-01

The relationship between character strengths and vocational interests was tested. In an online study, 197 thirteen to eighteen year-olds completed a questionnaire measuring character strengths and a multi-method measure for interests (questionnaire, nonverbal test, and objective personality tests). The main findings were that intellectual…

Using Rapid Indicators for Enterococcus to assess the Risk of Illness after Exposure to Urban Runoff Contaminated Marine Water

EPA Science Inventory

BACKGROUND: Traditional fecal indicator bacteria (FIB) measurement is too slow (>18 h) for timely swimmer warnings. OBJECTIVES: Assess relationship of rapid indicator methods (qPCR) to illness at a marine beach impacted by urban runoff. METHODS: We measured baseline and two...

Remote sensing imagery classification using multi-objective gravitational search algorithm

NASA Astrophysics Data System (ADS)

Zhang, Aizhu; Sun, Genyun; Wang, Zhenjie

2016-10-01

Simultaneous optimization of different validity measures can capture different data characteristics of remote sensing imagery (RSI) and thereby achieving high quality classification results. In this paper, two conflicting cluster validity indices, the Xie-Beni (XB) index and the fuzzy C-means (FCM) (Jm) measure, are integrated with a diversity-enhanced and memory-based multi-objective gravitational search algorithm (DMMOGSA) to present a novel multi-objective optimization based RSI classification method. In this method, the Gabor filter method is firstly implemented to extract texture features of RSI. Then, the texture features are syncretized with the spectral features to construct the spatial-spectral feature space/set of the RSI. Afterwards, cluster of the spectral-spatial feature set is carried out on the basis of the proposed method. To be specific, cluster centers are randomly generated initially. After that, the cluster centers are updated and optimized adaptively by employing the DMMOGSA. Accordingly, a set of non-dominated cluster centers are obtained. Therefore, numbers of image classification results of RSI are produced and users can pick up the most promising one according to their problem requirements. To quantitatively and qualitatively validate the effectiveness of the proposed method, the proposed classification method was applied to classifier two aerial high-resolution remote sensing imageries. The obtained classification results are compared with that produced by two single cluster validity index based and two state-of-the-art multi-objective optimization algorithms based classification results. Comparison results show that the proposed method can achieve more accurate RSI classification.

Objective techniques for psychological assessment, phase 2. [techniques for measuring human performance during space flight stress

NASA Technical Reports Server (NTRS)

Wortz, E. C.; Saur, A. J.; Nowlis, D. P.; Kendall, M. P.

1974-01-01

Results are presented of an initial experiment in a research program designed to develop objective techniques for psychological assessment of individuals and groups participating in long-duration space flights. Specifically examined is the rationale for utilizing measures of attention as an objective assessment technique. Subjects participating in the experiment performed various tasks (eg, playing matrix games which appeared on a display screen along with auditory stimuli). The psychophysiological reactions of the subjects were measured and are given. Previous research of various performance and psychophysiological methods of measuring attention is also discussed. The experiment design (independent and dependent variables) and apparatus (computers and display devices) are described and shown. Conclusions and recommendations are presented.

Heat and Moisture transport of socks

NASA Astrophysics Data System (ADS)

Komárková, P.; Glombíková, V.; Havelka, A.

2017-10-01

Investigating the liquid moisture transport and thermal properties is essential for understanding physiological comfort of clothes. This study reports on an experimental investigation of moisture management transport and thermal transport on the physiological comfort of commercially available socks. There are subjective evaluation and objective measurements. Subjective evaluation of the physiological comfort of socks is based on individual sensory perception of probands during and after physical exertion. Objective measurements were performed according to standardized methods using Moisture Management tester for measuring the humidity parameters and C-term TCi analyzer for thermal conductivity and thermal effusivity. The obtained values of liquid moisture transport and thermal properties were related to the material composition and structure of the tested socks. In summary, these results show that objective measurement corresponds with probands feelings.

Endoscopic pulsed digital holography for 3D measurements

NASA Astrophysics Data System (ADS)

Saucedo, A. Tonatiuh; Mendoza Santoyo, Fernando; de La Torre-Ibarra, Manuel; Pedrini, Giancarlo; Osten, Wolfgang

2006-02-01

A rigid endoscope and three different object illumination source positions are used in pulsed digital holography to measure the three orthogonal displacement components from hidden areas of a harmonically vibrating metallic cylinder. In order to obtain simultaneous 3D information from the optical set up, it is necessary to match the optical paths of each of the reference object beam pairs, but to incoherently mismatch the three reference object beam pairs, such that three pulsed digital holograms are incoherently recorded within a single frame of the CCD sensor. The phase difference is obtained using the Fourier method and by subtracting two digital holograms captured for two different object positions.

Close range fault tolerant noncontacting position sensor

DOEpatents

Bingham, D.N.; Anderson, A.A.

1996-02-20

A method and system are disclosed for locating the three dimensional coordinates of a moving or stationary object in real time. The three dimensional coordinates of an object in half space or full space are determined based upon the time of arrival or phase of the wave front measured by a plurality of receiver elements and an established vector magnitudes proportional to the measured time of arrival or phase at each receiver element. The coordinates of the object are calculated by solving a matrix equation or a set of closed form algebraic equations. 3 figs.

Quantitative phase retrieval with arbitrary pupil and illumination

DOE PAGES

Claus, Rene A.; Naulleau, Patrick P.; Neureuther, Andrew R.; ...

2015-10-02

We present a general algorithm for combining measurements taken under various illumination and imaging conditions to quantitatively extract the amplitude and phase of an object wave. The algorithm uses the weak object transfer function, which incorporates arbitrary pupil functions and partially coherent illumination. The approach is extended beyond the weak object regime using an iterative algorithm. Finally, we demonstrate the method on measurements of Extreme Ultraviolet Lithography (EUV) multilayer mask defects taken in an EUV zone plate microscope with both a standard zone plate lens and a zone plate implementing Zernike phase contrast.

Evaluating a Model of Youth Physical Activity

ERIC Educational Resources Information Center

Heitzler, Carrie D.; Lytle, Leslie A.; Erickson, Darin J.; Barr-Anderson, Daheia; Sirard, John R.; Story, Mary

2010-01-01

Objective: To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. Methods: Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a…

Objective methods for developing indices of pilot workload.

DOT National Transportation Integrated Search

1977-07-01

This paper discusses the various types of objective methodologies that either have been or have the potential of being applied to the general problem of the measurement of pilot workload as it occurs on relatively short missions or mission phases. Se...

A Comparative Analysis of Three Monocular Passive Ranging Methods on Real Infrared Sequences

NASA Astrophysics Data System (ADS)

Bondžulić, Boban P.; Mitrović, Srđan T.; Barbarić, Žarko P.; Andrić, Milenko S.

2013-09-01

Three monocular passive ranging methods are analyzed and tested on the real infrared sequences. The first method exploits scale changes of an object in successive frames, while other two use Beer-Lambert's Law. Ranging methods are evaluated by comparing with simultaneously obtained reference data at the test site. Research is addressed on scenarios where multiple sensor views or active measurements are not possible. The results show that these methods for range estimation can provide the fidelity required for object tracking. Maximum values of relative distance estimation errors in near-ideal conditions are less than 8%.

3D modeling of underground objects with the use of SLAM technology on the example of historical mine in Ciechanowice (Ołowiane Range, The Sudetes)

NASA Astrophysics Data System (ADS)

Wajs, Jaroslaw; Kasza, Damian; Zagożdżon, Paweł P.; Zagożdżon, Katarzyna D.

2018-01-01

Terrestrial Laser Scanning is a currently one of the most popular methods for producing representations of 3D objects. This paper presents the potential of applying the mobile laser scanning method to inventory underground objects. The examined location was a historic crystalline limestone mine situated in the vicinity of Ciechanowice village (Kaczawa Mts., SW Poland). The authors present a methodology for performing measurements and for processing the obtained results, whose accuracy is additionally verified.

A technique for fast and accurate measurement of hand volumes using Archimedes' principle.

PubMed

Hughes, S; Lau, J

2008-03-01

A new technique for measuring hand volumes using Archimedes principle is described. The technique involves the immersion of a hand in a water container placed on an electronic balance. The volume is given by the change in weight divided by the density of water. This technique was compared with the more conventional technique of immersing an object in a container with an overflow spout and collecting and weighing the volume of overflow water. The hand volume of two subjects was measured. Hand volumes were 494 +/- 6 ml and 312 +/- 7 ml for the immersion method and 476 +/- 14 ml and 302 +/- 8 ml for the overflow method for the two subjects respectively. Using plastic test objects, the mean difference between the actual and measured volume was -0.3% and 2.0% for the immersion and overflow techniques respectively. This study shows that hand volumes can be obtained more quickly than the overflow method. The technique could find an application in clinics where frequent hand volumes are required.

Measuring niacin-associated skin toxicity (NASTy) stigmata along with symptoms to aid development of niacin mimetics[S

PubMed Central

Dunbar, Richard L.; Goel, Harsh; Tuteja, Sony; Song, Wen-Liang; Nathanson, Grace; Babar, Zeeshan; Lalic, Dusanka; Gelfand, Joel M.; Rader, Daniel J.; Grove, Gary L.

2017-01-01

Though cardioprotective, niacin monotherapy is limited by unpleasant cutaneous symptoms mimicking dermatitis: niacin-associated skin toxicity (NASTy). Niacin is prototypical of several emerging drugs suffering off-target rubefacient properties whereby agonizing the GPR109A receptor on cutaneous immune cells provokes vasodilation, prompting skin plethora and rubor, as well as dolor, tumor, and calor, and systemically, heat loss, frigor, chills, and rigors. Typically, NASTy effects are described by subjective patient-reported perception, at best semi-quantitative and bias-prone. Conversely, objective, quantitative, and unbiased methods measuring NASTy stigmata would facilitate research to abolish them, motivating development of several objective methods. In early drug development, such methods might better predict clinical tolerability in larger clinical trials. Measuring cutaneous stigmata may also aid investigations of vasospastic, ischemic, and inflammatory skin conditions. We present methods to measure NASTy physical stigmata to facilitate research into novel niacin mimetics/analogs, detailing characteristics of each technique following niacin, and how NASTy stigmata relate to symptom perception. We gave niacin orally and measured rubor by colorimetry and white-light spectroscopy, plethora by laser Doppler flowmetry, and calor/frigor by thermometry. Surprisingly, each stigma’s abruptness predicted symptom perception, whereas peak intensity did not. These methods are adaptable to study other rubefacient drugs or dermatologic and vascular disorders. PMID:28119443

Accuracy assessment of the Precise Point Positioning method applied for surveys and tracking moving objects in GIS environment

NASA Astrophysics Data System (ADS)

Ilieva, Tamara; Gekov, Svetoslav

2017-04-01

The Precise Point Positioning (PPP) method gives the users the opportunity to determine point locations using a single GNSS receiver. The accuracy of the determined by PPP point locations is better in comparison to the standard point positioning, due to the precise satellite orbit and clock corrections that are developed and maintained by the International GNSS Service (IGS). The aim of our current research is the accuracy assessment of the PPP method applied for surveys and tracking moving objects in GIS environment. The PPP data is collected by using preliminary developed by us software application that allows different sets of attribute data for the measurements and their accuracy to be used. The results from the PPP measurements are directly compared within the geospatial database to different other sets of terrestrial data - measurements obtained by total stations, real time kinematic and static GNSS.

Analyzing course objectives: assessing critical thinking in the pharmacy curriculum.

PubMed

Vuchetich, Phillip J; Hamilton, William R; Ahmad, S Omar; Makoid, Michael C

2006-01-01

Assessment of critical thinking objectives in a pharmacy program curriculum is an important part of program assessment. This study measures the proportion of cognitive learning objectives at various levels of Bloom's taxonomy throughout the required curriculum using the stated objectives in course syllabi (the explicit curriculum). In one entry level doctor of pharmacy program, 54.90% of cognitive objectives identified critical thinking outcomes using the rubric of Bloom's level 3 or higher as an indicator of critical thinking. In this program, there was a similar percent of critical thinking objectives in each of the first three years, but the final year of the curriculum had a higher percent of critical thinking objectives than each of the first three years (p = 0.0018, Kruskal-Wallis test). The increase in critical thinking in the final year suggests that the explicit expectations in the syllabi are weighted toward a higher percent of critical thinking objectives during clinical rotations. The methods described in the study may serve as tools for a curriculum committee or program assessment team to compare critical thinking in the curriculum at different points in time, and may assist in curricular mapping efforts. These methods may complement studies measuring the implicit curriculum (that which the faculty actually teach, which may not be stated in the explicit curriculum.).

Self-perceived versus objectively measured competence in performing clinical practical procedures by final year medical students

PubMed Central

Banda, Sekelani

2016-01-01

Objectives To determine and compare the self-perceived and objectively measured competence in performing 14 core-clinical practical procedures by Final Year Medical Students of the University of Zambia. Methods The study included 56 out of 60 graduating University of Zambia Medical Students of the 2012/2013 academic year. Self-perceived competence: students rated their competence on 14 core- clinical practical procedures using a self-administered questionnaire on a 5-point Likert scale. Objective competence: it was measured by Objective Structured Clinical Examination (OSCE) by faculty using predetermined rating scales. Rank order correlation test was performed for self-perceived and objectively measured competence. Results Two thirds 36 (66.7%) of the participants perceived themselves as moderately competent, 15 (27.8%) rated themselves as highly competent while 3 (5.6%) had low self-perception. With objective competence, the majority 52 (92.8%) were barely competent while 4 (7.2%) were absolutely competent. When overall self-perception was compared to objectively measured competence, there was a discordance which was demonstrated by a negative correlation (Spearman rho -.123). Conclusions Significant numbers of students reported low self-competence in performing procedures such as endotracheal intubation, gastric lavage and cardiopulmonary resuscitation which most never performed during the clinical years of medical education. In addition, the negative correlation between self-perceived and objectively measured competence demonstrated the inability of students to assess and rate themselves objectively due to fear that others may know their weaknesses and realize that they are not as competent as expected at a specific level of training. PMID:27132255

Comparison of full-field interferometric measurement techniques applied to small vibration amplitudes determination

NASA Astrophysics Data System (ADS)

Styk, Adam

2014-07-01

Classical time-averaging and stroboscopic interferometry are widely used for MEMS/MOEMS dynamic behavior investigations. Unfortunately both methods require an amplitude magnitude of at least 0.19λ to be able to detect resonant frequency of the object. Moreover the precision of measurement is limited. That puts strong constrains on the type of element to be tested. In this paper the comparison of two methods of microobject vibration measurements that overcome aforementioned problems are presented. Both methods maintain high speed measurement time and extend the range of amplitudes to be measured (below 0.19λ), moreover can be easily applied to MEMS/MOEMS dynamic parameters measurements.

A layered modulation method for pixel matching in online phase measuring profilometry

NASA Astrophysics Data System (ADS)

Li, Hongru; Feng, Guoying; Bourgade, Thomas; Yang, Peng; Zhou, Shouhuan; Asundi, Anand

2016-10-01

An online phase measuring profilometry with new layered modulation method for pixel matching is presented. In this method and in contrast with previous modulation matching methods, the captured images are enhanced by Retinex theory for better modulation distribution, and all different layer modulation masks are fully used to determine the displacement of a rectilinear moving object. High, medium and low modulation masks are obtained by performing binary segmentation with iterative Otsu method. The final shifting pixels are calculated based on centroid concept, and after that the aligned fringe patterns can be extracted from each frame. After performing Stoilov algorithm and a series of subsequent operations, the object profile on a translation stage is reconstructed. All procedures are carried out automatically, without setting specific parameters in advance. Numerical simulations are detailed and experimental results verify the validity and feasibility of the proposed approach.

Shape Measurement by Means of Phase Retrieval using a Spatial Light Modulator

NASA Astrophysics Data System (ADS)

Agour, Mostafa; Huke, Philipp; Kopylow, Christoph V.; Falldorf, Claas

2010-04-01

We present a novel approach to investigate the shape of a diffusely reflecting technical object. It is based on a combination of a multiple-illumination contouring procedure and phase retrieval from a set of intensity measurements. Special consideration is given to the design of the experimental configuration for phase retrieval and the iterative algorithm to extract the 3D phase map. It is mainly based on a phase-only spatial light modulator (SLM) in the Fourier domain of a 4f-imaging system. The SLM is used to modulate the light incident in the Fourier plane with the transfer function of propagation. Thus, a set of consecutive intensity measurements of the wave field scattered by the investigated object in various propagation states can be realized in a common recording plane. In contrast to already existing methods, no mechanical adjustment is required during the recording process and thus the measuring time is considerably reduced. The method is applied to investigate the shape of micro-objects obtained from a metalforming process. Finally, the experimental results are compared to those provided by a standard interferometric contouring procedure.

Methods and apparatus for extraction and tracking of objects from multi-dimensional sequence data

NASA Technical Reports Server (NTRS)

Hill, Matthew L. (Inventor); Chang, Yuan-Chi (Inventor); Li, Chung-Sheng (Inventor); Castelli, Vittorio (Inventor); Bergman, Lawrence David (Inventor)

2008-01-01

An object tracking technique is provided which, given: (i) a potentially large data set; (ii) a set of dimensions along which the data has been ordered; and (iii) a set of functions for measuring the similarity between data elements, a set of objects are produced. Each of these objects is defined by a list of data elements. Each of the data elements on this list contains the probability that the data element is part of the object. The method produces these lists via an adaptive, knowledge-based search function which directs the search for high-probability data elements. This serves to reduce the number of data element combinations evaluated while preserving the most flexibility in defining the associations of data elements which comprise an object.

Methods and apparatus for extraction and tracking of objects from multi-dimensional sequence data

NASA Technical Reports Server (NTRS)

Hill, Matthew L. (Inventor); Chang, Yuan-Chi (Inventor); Li, Chung-Sheng (Inventor); Castelli, Vittorio (Inventor); Bergman, Lawrence David (Inventor)

2005-01-01

An object tracking technique is provided which, given: (i) a potentially large data set; (ii) a set of dimensions along which the data has been ordered; and (iii) a set of functions for measuring the similarity between data elements, a set of objects are produced. Each of these objects is defined by a list of data elements. Each of the data elements on this list contains the probability that the data element is part of the object. The method produces these lists via an adaptive, knowledge-based search function which directs the search for high-probability data elements. This serves to reduce the number of data element combinations evaluated while preserving the most flexibility in defining the associations of data elements which comprise an object.

Active retroreflector with in situ beam analysis to measure the rotational orientation in conjunction with a laser tracker

NASA Astrophysics Data System (ADS)

Hofherr, O.; Wachten, C.; Müller, C.; Reinecke, H.

2013-04-01

High precision optical non-contact position measurement is a key technology in modern engineering. Laser trackers (LT) can determine accurately x-y-z coordinates of passive retroreflectors. Next-generation systems answer the additional need to measure an object`s rotational orientation (pitch, yaw, roll). These devices are based either on photogrammetry or on enhanced retroreflectors. However, photogrammetry relies on costly camera systems and time-consuming image processing. Enhanced retroreflectors analyze the LT`s beam but are restricted in roll angle measurements. In the past we have presented a new method [1][2] to measure all six degrees of freedom in conjunction with a LT. Now we dramatically optimized the method and designed a new prototype, e.g. taking into consideration optical alignment, reduced power loss, highly optimized measuring signals and higher resolution. A method is described that allows compensating the influence of the LT's beam offset during tracking the active retroreflector. We prove the functionality of the active retroreflector with the LT and, furthermore, demonstrate the capability of the system to characterize the tracking behavior of a LT. The measurement range for the incident laser beam is +/-12° with a resolution of 0.6".

Comparison of Methods for Evaluating Urban Transportation Alternatives

DOT National Transportation Integrated Search

1975-02-01

The objective of the report was to compare five alternative methods for evaluating urban transportation improvement options: unaided judgmental evaluation cost-benefit analysis, cost-effectiveness analysis based on a single measure of effectiveness, ...

Checking an integrated model of web accessibility and usability evaluation for disabled people.

PubMed

Federici, Stefano; Micangeli, Andrea; Ruspantini, Irene; Borgianni, Stefano; Corradi, Fabrizio; Pasqualotto, Emanuele; Olivetti Belardinelli, Marta

2005-07-08

A combined objective-oriented and subjective-oriented method for evaluating accessibility and usability of web pages for students with disability was tested. The objective-oriented approach is devoted to verifying the conformity of interfaces to standard rules stated by national and international organizations responsible for web technology standardization, such as W3C. Conversely, the subjective-oriented approach allows assessing how the final users interact with the artificial system, accessing levels of user satisfaction based on personal factors and environmental barriers. Five kinds of measurements were applied as objective-oriented and subjective-oriented tests. Objective-oriented evaluations were performed on the Help Desk web page for students with disability, included in the website of a large Italian state university. Subjective-oriented tests were administered to 19 students labeled as disabled on the basis of their own declaration at the University enrolment: 13 students were tested by means of the SUMI test and six students by means of the 'Cooperative evaluation'. Objective-oriented and subjective-oriented methods highlighted different and sometimes conflicting results. Both methods have pointed out much more consistency regarding levels of accessibility than of usability. Since usability is largely affected by individual differences in user's own (dis)abilities, subjective-oriented measures underscored the fact that blind students encountered much more web surfing difficulties.

Contribution of the Multi-attribute Value Theory to conflict resolution in groundwater management. Application to the Mancha Oriental system (Spain)

NASA Astrophysics Data System (ADS)

Apperl, B.; Pulido-Velazquez, M.; Andreu, J.; Llopis-Albert, C.

2012-04-01

The implementation of the EU Water Framework Directive, with consideration of environmental, economic and social objectives, claims for participatory water resource management methods. To deal with different conflicting objectives it is necessary to apply a method for clarifying stakeholders' positions (identifying values and opinions of stakeholders, and quantifying their valuations), improving transparency with respect to outcomes of alternatives, and moving the discussion from alternatives towards fundamental objectives (value-thinking approach) and valuing trade-offs, facilitating negotiation. The method allows the incorporation of stakeholders in the planning process, which should guarantee a higher acceptance of the policies to be implemented. This research has been conducted in the Mancha Oriental groundwater system Spain, subject to an intensive use of groundwater for irrigation. The main goals according to the WFD are: a good qualitative and quantitative status of the aquifer and a good quantitative and ecological status of related surface water resources (mainly the Jucar river and dependent ecosystems). The aim is to analyze the contribution of the MAVT for conflict resolution and a sustainable groundwater management, involving the stakeholders in the valuation process. A complex set of objectives and attributes has been defined. The alternatives have been evaluated according to the compliance of ecological, economic and social interests. Results show that the acceptation of alternatives depends strongly on the combination of measures and the implementation status. A high conflict potential is expected from alternatives consisting of one unique measure. Uncertainties of the results are notable, but do not influence heavily on the alternative ranking. Different future scenarios also influence on the preference of alternatives. For instance, an expected reduction of future groundwater resources by climate change increases the conflict potential, with two observed reactions: acceptance of more rigorous measures, on one hand, and a tendency to soft measures with the same cost, as a reaction to the decreased effectiveness of the alternatives. The implementation of the method to a very complex case study, with many conflicting objectives and alternatives and uncertain outcomes, including future scenarios (climate change) illustrate the potential of the method for supporting management decisions.

Laser flare photometry: a noninvasive, objective, and quantitative method to measure intraocular inflammation.

PubMed

Tugal-Tutkun, Ilknur; Herbort, Carl P

2010-10-01

Aqueous flare and cells are the two inflammatory parameters of anterior chamber inflammation resulting from disruption of the blood-ocular barriers. When examined with the slit lamp, measurement of intraocular inflammation remains subjective with considerable intra- and interobserver variations. Laser flare cell photometry is an objective quantitative method that enables accurate measurement of these parameters with very high reproducibility. Laser flare photometry allows detection of subclinical alterations in the blood-ocular barriers, identifying subtle pathological changes that could not have been recorded otherwise. With the use of this method, it has been possible to compare the effect of different surgical techniques, surgical adjuncts, and anti-inflammatory medications on intraocular inflammation. Clinical studies of uveitis patients have shown that flare measurements by laser flare photometry allowed precise monitoring of well-defined uveitic entities and prediction of disease relapse. Relationships of laser flare photometry values with complications of uveitis and visual loss further indicate that flare measurement by laser flare photometry should be included in the routine follow-up of patients with uveitis.

Empirical Analysis of the Subjective Impressions and Objective Measures of Domain Scientists’ Analytical Judgment Using Visualizations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dasgupta, Aritra; Burrows, Susannah M.; Han, Kyungsik

Scientists working in a particular domain often adhere to conventional data analysis and presentation methods and this leads to familiarity with these methods over time. But does high familiarity always lead to better analytical judgment? This question is especially relevant when visualizations are used in scientific tasks, as there can be discrepancies between visualization best practices and domain conventions. However, there is little empirical evidence of the relationships between scientists’ subjective impressions about familiar and unfamiliar visualizations and objective measures of their effect on scientific judgment. To address this gap and to study these factors, we focus on the climatemore » science domain, specifically on visualizations used for comparison of model performance. We present a comprehensive user study with 47 climate scientists where we explored the following factors: i) relationships between scientists’ familiarity, their perceived levels of com- fort, confidence, accuracy, and objective measures of accuracy, and ii) relationships among domain experience, visualization familiarity, and post-study preference.« less

Automatic trajectory measurement of large numbers of crowded objects

NASA Astrophysics Data System (ADS)

Li, Hui; Liu, Ye; Chen, Yan Qiu

2013-06-01

Complex motion patterns of natural systems, such as fish schools, bird flocks, and cell groups, have attracted great attention from scientists for years. Trajectory measurement of individuals is vital for quantitative and high-throughput study of their collective behaviors. However, such data are rare mainly due to the challenges of detection and tracking of large numbers of objects with similar visual features and frequent occlusions. We present an automatic and effective framework to measure trajectories of large numbers of crowded oval-shaped objects, such as fish and cells. We first use a novel dual ellipse locator to detect the coarse position of each individual and then propose a variance minimization active contour method to obtain the optimal segmentation results. For tracking, cost matrix of assignment between consecutive frames is trainable via a random forest classifier with many spatial, texture, and shape features. The optimal trajectories are found for the whole image sequence by solving two linear assignment problems. We evaluate the proposed method on many challenging data sets.

Detection of buried magnetic objects by a SQUID gradiometer system

NASA Astrophysics Data System (ADS)

Meyer, Hans-Georg; Hartung, Konrad; Linzen, Sven; Schneider, Michael; Stolz, Ronny; Fried, Wolfgang; Hauspurg, Sebastian

2009-05-01

We present a magnetic detection system based on superconducting gradiometric sensors (SQUID gradiometers). The system provides a unique fast mapping of large areas with a high resolution of the magnetic field gradient as well as the local position. A main part of this work is the localization and classification of magnetic objects in the ground by automatic interpretation of geomagnetic field gradients, measured by the SQUID system. In accordance with specific features the field is decomposed into segments, which allow inferences to possible objects in the ground. The global consideration of object describing properties and their optimization using error minimization methods allows the reconstruction of superimposed features and detection of buried objects. The analysis system of measured geomagnetic fields works fully automatically. By a given surface of area-measured gradients the algorithm determines within numerical limits the absolute position of objects including depth with sub-pixel accuracy and allows an arbitrary position and attitude of sources. Several SQUID gradiometer data sets were used to show the applicability of the analysis algorithm.

Measuring Health Literacy in Individuals with Diabetes: A Systematic Review and Evaluation of Available Measures

ERIC Educational Resources Information Center

Al Sayah, Fatima; Williams, Beverly; Johnson, Jeffrey A.

2013-01-01

Objective: To identify instruments used to measure health literacy and numeracy in people with diabetes; evaluate their use, measurement scope, and properties; discuss their strengths and weaknesses; and propose the most useful, reliable, and applicable measure for use in research and practice settings. Methods" A systematic literature review…

Combined use of a priori data for fast system self-calibration of a non-rigid multi-camera fringe projection system

NASA Astrophysics Data System (ADS)

Stavroulakis, Petros I.; Chen, Shuxiao; Sims-Waterhouse, Danny; Piano, Samanta; Southon, Nicholas; Bointon, Patrick; Leach, Richard

2017-06-01

In non-rigid fringe projection 3D measurement systems, where either the camera or projector setup can change significantly between measurements or the object needs to be tracked, self-calibration has to be carried out frequently to keep the measurements accurate1. In fringe projection systems, it is common to use methods developed initially for photogrammetry for the calibration of the camera(s) in the system in terms of extrinsic and intrinsic parameters. To calibrate the projector(s) an extra correspondence between a pre-calibrated camera and an image created by the projector is performed. These recalibration steps are usually time consuming and involve the measurement of calibrated patterns on planes, before the actual object can continue to be measured after a motion of a camera or projector has been introduced in the setup and hence do not facilitate fast 3D measurement of objects when frequent experimental setup changes are necessary. By employing and combining a priori information via inverse rendering, on-board sensors, deep learning and leveraging a graphics processor unit (GPU), we assess a fine camera pose estimation method which is based on optimising the rendering of a model of a scene and the object to match the view from the camera. We find that the success of this calibration pipeline can be greatly improved by using adequate a priori information from the aforementioned sources.

Laterally modulated excitation microscopy: improvement of resolution by using a diffraction grating

NASA Astrophysics Data System (ADS)

Heintzmann, Rainer; Cremer, Christoph G.

1999-01-01

High spatial frequencies in the illuminating light of microscopes lead to a shift of the object spatial frequencies detectable through the objective lens. If a suitable procedure is found for evaluation of the measured data, a microscopic image with a higher resolution than under flat illumination can be obtained. A simple method for generation of a laterally modulated illumination pattern is discussed here. A specially constructed diffraction grating was inserted in the illumination beam path at the conjugate object plane (position of the adjustable aperture) and projected through the objective into the object. Microscopic beads were imaged with this method and evaluated with an algorithm based on the structure of the Fourier space. The results indicate an improvement of resolution.

Method and apparatus of a portable imaging-based measurement with self calibration

DOEpatents

Chang, Tzyy-Shuh [Ann Arbor, MI; Huang, Hsun-Hau [Ann Arbor, MI

2012-07-31

A portable imaging-based measurement device is developed to perform 2D projection based measurements on an object that is difficult or dangerous to access. This device is equipped with self calibration capability and built-in operating procedures to ensure proper imaging based measurement.

A comparison of latent class, K-means, and K-median methods for clustering dichotomous data.

PubMed

Brusco, Michael J; Shireman, Emilie; Steinley, Douglas

2017-09-01

The problem of partitioning a collection of objects based on their measurements on a set of dichotomous variables is a well-established problem in psychological research, with applications including clinical diagnosis, educational testing, cognitive categorization, and choice analysis. Latent class analysis and K-means clustering are popular methods for partitioning objects based on dichotomous measures in the psychological literature. The K-median clustering method has recently been touted as a potentially useful tool for psychological data and might be preferable to its close neighbor, K-means, when the variable measures are dichotomous. We conducted simulation-based comparisons of the latent class, K-means, and K-median approaches for partitioning dichotomous data. Although all 3 methods proved capable of recovering cluster structure, K-median clustering yielded the best average performance, followed closely by latent class analysis. We also report results for the 3 methods within the context of an application to transitive reasoning data, in which it was found that the 3 approaches can exhibit profound differences when applied to real data. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Comparison of experimental three-band IR detection of buried objects and multiphysics simulations

NASA Astrophysics Data System (ADS)

Rabelo, Renato C.; Tilley, Heather P.; Catterlin, Jeffrey K.; Karunasiri, Gamani; Alves, Fabio D. P.

2018-04-01

A buried-object detection system composed of a LWIR, a MWIR and a SWIR camera, along with a set of ground and ambient temperature sensors was constructed and tested. The objects were buried in a 1.2x1x0.3 m3 sandbox and surface temperature (using LWIR and MWIR cameras) and reflection (using SWIR camera) were recoded throughout the day. Two objects (aluminum and Teflon) with volume of about 2.5x10-4 m3 , were placed at varying depths during the measurements. Ground temperature sensors buried at three different depths measured the vertical temperature profile within the sandbox, while the weather station recorded the ambient temperature and solar radiation intensity. Images from the three cameras were simultaneously acquired in five-minute intervals throughout many days. An algorithm to postprocess and combine the images was developed in order to maximize the probability of detection by identifying thermal anomalies (temperature contrast) resulting from the presence of the buried object in an otherwise homogeneous medium. A simplified detection metric based on contrast differences was established to allow the evaluation of the image processing method. Finite element simulations were performed, reproducing the experiment conditions and, when possible, incorporated with data coming from actual measurements. Comparisons between experiment and simulation results were performed and the simulation parameters were adjusted until images generated from both methods are matched, aiming at obtaining insights of the buried material properties. Preliminary results show a great potential for detection of shallowburied objects such as land mines and IEDs and possible identification using finite element generated maps fitting measured surface maps.

Object's optical geometry measurements based on Extended Depth of Field (EDoF) approach

NASA Astrophysics Data System (ADS)

Szydłowski, Michał; Powałka, Bartosz; Chady, Tomasz; Waszczuk, Paweł

2017-02-01

The authors propose a method of using EDoF in macro inspections using bi-telecentric lenses and a specially designed experimental machine setup, allowing accurate focal distance changing. Also a software method is presented allowing EDoF image reconstruction using the continuous wavelet transform (CWT). Exploited method results are additionally compared with measurements performed with Keyence's LJ-V Series in-line Profilometer for reference matters.

Objective evaluation by reflectance spectrophotometry can be of clinical value for the verification of blanching/non blanching erythema in the sacral area.

PubMed

Sterner, Eila; Fossum, Bjöörn; Berg, Elisabeth; Lindholm, Christina; Stark, André

2014-08-01

Early detection of non blanching erythema (pressure ulcer category I) is necessary to prevent any further skin damage. An objective method to discriminate between blanching/non blanching erythema is presently not available. The purpose of this investigation was to explore if a non invasive objective method could differentiate between blanching/non blanching erythema in the sacral area of patients undergoing hip fracture surgery. Seventy-eight patients were included. The sacral area of all patients was assessed using (i) conventional finger-press test and (ii) digital reading of the erythema index assessed with reflectance spectrophotometry. The patients were examined at admission and during 5 days postsurgery. Reflectance spectrophotometry measurements proved able to discriminate between blanching/non blanching erythema. The reliability, quantified by the intra-class correlation coefficient, was excellent between repeated measurements over the measurement period, varying between 0·82 and 0·96, and a significant change was recorded in the areas from day 1 to day 5 (P < 0·0001). The value from the reference point did not show any significant changes over the same period (P = 0·32). An objective method proven to identify early pressure damage to tissue can be a valuable tool in clinical practice. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Validity of questionnaire self‐reports on computer, mouse and keyboard usage during a four‐week period

PubMed Central

Mikkelsen, Sigurd; Vilstrup, Imogen; Lassen, Christina Funch; Kryger, Ann Isabel; Thomsen, Jane Frølund; Andersen, Johan Hviid

2007-01-01

Objective To examine the validity and potential biases in self‐reports of computer, mouse and keyboard usage times, compared with objective recordings. Methods A study population of 1211 people was asked in a questionnaire to estimate the average time they had worked with computer, mouse and keyboard during the past four working weeks. During the same period, a software program recorded these activities objectively. The study was part of a one‐year follow‐up study from 2000–1 of musculoskeletal outcomes among Danish computer workers. Results Self‐reports on computer, mouse and keyboard usage times were positively associated with objectively measured activity, but the validity was low. Self‐reports explained only between a quarter and a third of the variance of objectively measured activity, and were even lower for one measure (keyboard time). Self‐reports overestimated usage times. Overestimation was large at low levels and declined with increasing levels of objectively measured activity. Mouse usage time proportion was an exception with a near 1:1 relation. Variability in objectively measured activity, arm pain, gender and age influenced self‐reports in a systematic way, but the effects were modest and sometimes in different directions. Conclusion Self‐reported durations of computer activities are positively associated with objective measures but they are quite inaccurate. Studies using self‐reports to establish relations between computer work times and musculoskeletal pain could be biased and lead to falsely increased or decreased risk estimates. PMID:17387136

Directional MTF measurement using sphere phantoms for a digital breast tomosynthesis system

NASA Astrophysics Data System (ADS)

Lee, Changwoo; Baek, Jongduk

2015-03-01

The digital breast tomosynthesis (DBT) has been widely used as a diagnosis imaging modality of breast cancer because of potential for structure noise reduction, better detectability, and less breast compression. Since 3D modulation transfer function (MTF) is one of the quantitative metrics to assess the spatial resolution of medical imaging systems, it is very important to measure 3D MTF of the DBT system to evaluate the resolution performance. In order to do that, Samei et al. used sphere phantoms and applied Thornton's method to the DBT system. However, due to the limitation of Thornton's method, the low frequency drop, caused by the limited data acquisition angle and reconstruction filters, was not measured correctly. To overcome this limitation, we propose a Richardson-Lucy (RL) deconvolution based estimation method to measure the directional MTF. We reconstructed point and sphere objects using FDK algorithm within a 40⁰ data acquisition angle. The ideal 3D MTF is obtained by taking Fourier transform of the reconstructed point object, and three directions (i.e., fx-direction, fy-direction, and fxy-direction) of the ideal 3D MTF are used as a reference. To estimate the directional MTF, the plane integrals of the reconstructed and ideal sphere object were calculated and used to estimate the directional PSF using RL deconvolution technique. Finally, the directional MTF was calculated by taking Fourier transform of the estimated PSF. Compared to the previous method, the proposed method showed a good agreement with the ideal directional MTF, especially at low frequency regions.

Estimation of muscle strength during motion recognition using multichannel surface EMG signals.

PubMed

Nagata, Kentaro; Nakano, Takemi; Magatani, Kazushige; Yamada, Masafumi

2008-01-01

The use of kinesiological electromyography is established as an evaluation tool for various kinds of applied research, and surface electromyogram (SEMG) has been widely used as a control source for human interfaces such as in a myoelectric prosthetic hand (we call them 'SEMG interfaces'). It is desirable to be able to control the SEMG interfaces with the same feeling as body movement. The existing SEMG interface mainly focuses on how to achieve accurate recognition of the intended movement. However, detecting muscular strength and reduced number of electrodes are also an important factor in controlling them. Therefore, our objective in this study is the development of and the estimation method for muscular strength that maintains the accuracy of hand motion recognition to reflect the result of measured power in a controlled object. Although the muscular strength can be evaluated by various methods, in this study a grasp force index was applied to evaluate the muscular strength. In order to achieve our objective, we directed our attention to measuring all valuable information for SEMG. This work proposes an application method of two simple linear models, and the selection method of an optimal electrode configuration to use them effectively. Our system required four SEMG measurement electrodes in which locations differed for every subject depending on the individual's characteristics, and those were selected from a 96ch multi electrode using the Monte Carlo method. From the experimental results, the performance in six normal subjects indicated that the recognition rate of four motions were perfect and the grasp force estimated result fit well with the actual measurement result.

Graph-Based Object Class Discovery

NASA Astrophysics Data System (ADS)

Xia, Shengping; Hancock, Edwin R.

We are interested in the problem of discovering the set of object classes present in a database of images using a weakly supervised graph-based framework. Rather than making use of the ”Bag-of-Features (BoF)” approach widely used in current work on object recognition, we represent each image by a graph using a group of selected local invariant features. Using local feature matching and iterative Procrustes alignment, we perform graph matching and compute a similarity measure. Borrowing the idea of query expansion , we develop a similarity propagation based graph clustering (SPGC) method. Using this method class specific clusters of the graphs can be obtained. Such a cluster can be generally represented by using a higher level graph model whose vertices are the clustered graphs, and the edge weights are determined by the pairwise similarity measure. Experiments are performed on a dataset, in which the number of images increases from 1 to 50K and the number of objects increases from 1 to over 500. Some objects have been discovered with total recall and a precision 1 in a single cluster.

Evaluation and comparison of current fetal ultrasound image segmentation methods for biometric measurements: a grand challenge.

PubMed

Rueda, Sylvia; Fathima, Sana; Knight, Caroline L; Yaqub, Mohammad; Papageorghiou, Aris T; Rahmatullah, Bahbibi; Foi, Alessandro; Maggioni, Matteo; Pepe, Antonietta; Tohka, Jussi; Stebbing, Richard V; McManigle, John E; Ciurte, Anca; Bresson, Xavier; Cuadra, Meritxell Bach; Sun, Changming; Ponomarev, Gennady V; Gelfand, Mikhail S; Kazanov, Marat D; Wang, Ching-Wei; Chen, Hsiang-Chou; Peng, Chun-Wei; Hung, Chu-Mei; Noble, J Alison

2014-04-01

This paper presents the evaluation results of the methods submitted to Challenge US: Biometric Measurements from Fetal Ultrasound Images, a segmentation challenge held at the IEEE International Symposium on Biomedical Imaging 2012. The challenge was set to compare and evaluate current fetal ultrasound image segmentation methods. It consisted of automatically segmenting fetal anatomical structures to measure standard obstetric biometric parameters, from 2D fetal ultrasound images taken on fetuses at different gestational ages (21 weeks, 28 weeks, and 33 weeks) and with varying image quality to reflect data encountered in real clinical environments. Four independent sub-challenges were proposed, according to the objects of interest measured in clinical practice: abdomen, head, femur, and whole fetus. Five teams participated in the head sub-challenge and two teams in the femur sub-challenge, including one team who tackled both. Nobody attempted the abdomen and whole fetus sub-challenges. The challenge goals were two-fold and the participants were asked to submit the segmentation results as well as the measurements derived from the segmented objects. Extensive quantitative (region-based, distance-based, and Bland-Altman measurements) and qualitative evaluation was performed to compare the results from a representative selection of current methods submitted to the challenge. Several experts (three for the head sub-challenge and two for the femur sub-challenge), with different degrees of expertise, manually delineated the objects of interest to define the ground truth used within the evaluation framework. For the head sub-challenge, several groups produced results that could be potentially used in clinical settings, with comparable performance to manual delineations. The femur sub-challenge had inferior performance to the head sub-challenge due to the fact that it is a harder segmentation problem and that the techniques presented relied more on the femur's appearance.

On the magnetic polarizability tensor of US coinage

NASA Astrophysics Data System (ADS)

Davidson, John L.; Abdel-Rehim, Omar A.; Hu, Peipei; Marsh, Liam A.; O'Toole, Michael D.; Peyton, Anthony J.

2018-03-01

The magnetic dipole polarizability tensor of a metallic object gives unique information about the size, shape and electromagnetic properties of the object. In this paper, we present a novel method of coin characterization based on the spectroscopic response of the absolute tensor. The experimental measurements are validated using a combination of tests with a small set of bespoke coin surrogates and simulated data. The method is applied to an uncirculated set of US coins. Measured and simulated spectroscopic tensor responses of the coins show significant differences between different coin denominations. The presented results are encouraging as they strongly demonstrate the ability to characterize coins using an absolute tensor approach.

Probabilistic Evaluation of Three-Dimensional Reconstructions from X-Ray Images Spanning a Limited Angle

PubMed Central

Frost, Anja; Renners, Eike; Hötter, Michael; Ostermann, Jörn

2013-01-01

An important part of computed tomography is the calculation of a three-dimensional reconstruction of an object from series of X-ray images. Unfortunately, some applications do not provide sufficient X-ray images. Then, the reconstructed objects no longer truly represent the original. Inside of the volumes, the accuracy seems to vary unpredictably. In this paper, we introduce a novel method to evaluate any reconstruction, voxel by voxel. The evaluation is based on a sophisticated probabilistic handling of the measured X-rays, as well as the inclusion of a priori knowledge about the materials that the object receiving the X-ray examination consists of. For each voxel, the proposed method outputs a numerical value that represents the probability of existence of a predefined material at the position of the voxel while doing X-ray. Such a probabilistic quality measure was lacking so far. In our experiment, false reconstructed areas get detected by their low probability. In exact reconstructed areas, a high probability predominates. Receiver Operating Characteristics not only confirm the reliability of our quality measure but also demonstrate that existing methods are less suitable for evaluating a reconstruction. PMID:23344378

Energy Information Systems

Science.gov Websites

Energy Analytics Campaign > 2014-2018 Assessment of Automated M&V Methods > 2012-2018 Better Assessment of automated measurement and verification methods. Granderson, J. et al. Lawrence Berkeley . PDF, 726 KB Performance Metrics and Objective Testing Methods for Energy Baseline Modeling Software

High-Sensitivity Measurement of Density by Magnetic Levitation.

PubMed

Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

2016-03-01

This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density <10(-4) g/cm(3) for macroscopic objects (>mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

Method for visualization and presentation of priceless old prints based on precise 3D scan

NASA Astrophysics Data System (ADS)

Bunsch, Eryk; Sitnik, Robert

2014-02-01

Graphic prints and manuscripts constitute main part of the cultural heritage objects created by the most of the known civilizations. Their presentation was always a problem due to their high sensitivity to light and changes of external conditions (temperature, humidity). Today it is possible to use an advanced digitalization techniques for documentation and visualization of mentioned objects. In the situation when presentation of the original heritage object is impossible, there is a need to develop a method allowing documentation and then presentation to the audience of all the aesthetical features of the object. During the course of the project scans of several pages of one of the most valuable books in collection of Museum of Warsaw Archdiocese were performed. The book known as "Great Dürer Trilogy" consists of three series of woodcuts by the Albrecht Dürer. The measurement system used consists of a custom designed, structured light-based, high-resolution measurement head with automated digitization system mounted on the industrial robot. This device was custom built to meet conservators' requirements, especially the lack of ultraviolet or infrared radiation emission in the direction of measured object. Documentation of one page from the book requires about 380 directional measurements which constitute about 3 billion sample points. The distance between the points in the cloud is 20 μm. Provided that the measurement with MSD (measurement sampling density) of 2500 points makes it possible to show to the publicity the spatial structure of this graphics print. An important aspect is the complexity of the software environment created for data processing, in which massive data sets can be automatically processed and visualized. Very important advantage of the software which is using directly clouds of points is the possibility to manipulate freely virtual light source.

Face Validity of the Single Work Ability Item: Comparison with Objectively Measured Heart Rate Reserve over Several Days

PubMed Central

Gupta, Nidhi; Jensen, Bjørn Søvsø; Søgaard, Karen; Carneiro, Isabella Gomes; Christiansen, Caroline Stordal; Hanisch, Christiana; Holtermann, Andreas

2014-01-01

Purpose: The purpose of this study was to investigate the face validity of the self-reported single item work ability with objectively measured heart rate reserve (%HRR) among blue-collar workers. Methods: We utilized data from 127 blue-collar workers (Female = 53; Male = 74) aged 18–65 years from the cross-sectional “New method for Objective Measurements of physical Activity in Daily living (NOMAD)” study. The workers reported their single item work ability and completed an aerobic capacity cycling test and objective measurements of heart rate reserve monitored with Actiheart for 3–4 days with a total of 5,810 h, including 2,640 working hours. Results: A significant moderate correlation between work ability and %HRR was observed among males (R = −0.33, P = 0.005), but not among females (R = 0.11, P = 0.431). In a gender-stratified multi-adjusted logistic regression analysis, males with high %HRR were more likely to report a reduced work ability compared to males with low %HRR [OR = 4.75, 95% confidence interval (95% CI) = 1.31 to 17.25]. However, this association was not found among females (OR = 0.26, 95% CI 0.03 to 2.16), and a significant interaction between work ability, %HRR and gender was observed (P = 0.03). Conclusions: The observed association between work ability and objectively measured %HRR over several days among male blue-collar workers supports the face validity of the single work ability item. It is a useful and valid measure of the relation between physical work demands and resources among male blue-collar workers. The contrasting association among females needs to be further investigated. PMID:24840350

Optical contact micrometer

DOEpatents

Jacobson, Steven D.

2014-08-19

Certain examples provide optical contact micrometers and methods of use. An example optical contact micrometer includes a pair of opposable lenses to receive an object and immobilize the object in a position. The example optical contact micrometer includes a pair of opposable mirrors positioned with respect to the pair of lenses to facilitate viewing of the object through the lenses. The example optical contact micrometer includes a microscope to facilitate viewing of the object through the lenses via the mirrors; and an interferometer to obtain one or more measurements of the object.

Using Rate of Divergence as an Objective Measure to Differentiate between Voice Signal Types Based on the Amount of Disorder in the Signal.

PubMed

Calawerts, William M; Lin, Liyu; Sprott, J C; Jiang, Jack J

2017-01-01

The purpose of this paper is to introduce the rate of divergence as an objective measure to differentiate between the four voice types based on the amount of disorder present in a signal. We hypothesized that rate of divergence would provide an objective measure that can quantify all four voice types. A total of 150 acoustic voice recordings were randomly selected and analyzed using traditional perturbation, nonlinear, and rate of divergence analysis methods. We developed a new parameter, rate of divergence, which uses a modified version of Wolf's algorithm for calculating Lyapunov exponents of a system. The outcome of this calculation is not a Lyapunov exponent, but rather a description of the divergence of two nearby data points for the next three points in the time series, followed in three time-delayed embedding dimensions. This measure was compared to currently existing perturbation and nonlinear dynamic methods of distinguishing between voice signals. There was a direct relationship between voice type and rate of divergence. This calculation is especially effective at differentiating between type 3 and type 4 voices (P < 0.001) and is equally effective at differentiating type 1, type 2, and type 3 signals as currently existing methods. The rate of divergence calculation introduced is an objective measure that can be used to distinguish between all four voice types based on the amount of disorder present, leading to quicker and more accurate voice typing as well as an improved understanding of the nonlinear dynamics involved in phonation. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Pose estimation of industrial objects towards robot operation

NASA Astrophysics Data System (ADS)

Niu, Jie; Zhou, Fuqiang; Tan, Haishu; Cao, Yu

2017-10-01

With the advantages of wide range, non-contact and high flexibility, the visual estimation technology of target pose has been widely applied in modern industry, robot guidance and other engineering practices. However, due to the influence of complicated industrial environment, outside interference factors, lack of object characteristics, restrictions of camera and other limitations, the visual estimation technology of target pose is still faced with many challenges. Focusing on the above problems, a pose estimation method of the industrial objects is developed based on 3D models of targets. By matching the extracted shape characteristics of objects with the priori 3D model database of targets, the method realizes the recognition of target. Thus a pose estimation of objects can be determined based on the monocular vision measuring model. The experimental results show that this method can be implemented to estimate the position of rigid objects based on poor images information, and provides guiding basis for the operation of the industrial robot.

Interrogation of an object for dimensional and topographical information

DOEpatents

McMakin, Douglas L.; Severtsen, Ronald H.; Hall, Thomas E.; Sheen, David M.; Kennedy, Mike O.

2004-03-09

Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine one or more body measurements at least partially covered by the individual's clothing. The invention further includes techniques to interrogate an object with electromagnetic radiation in the millimeter and/or microwave range to provide a volumetric representation of the object. This representation can be used to display images and/or determine dimensional information concerning the object.

Interrogation of an object for dimensional and topographical information

DOEpatents

McMakin, Doug L [Richland, WA; Severtsen, Ronald H [Richland, WA; Hall, Thomas E [Richland, WA; Sheen, David M [Richland, WA

2003-01-14

Disclosed are systems, methods, devices, and apparatus to interrogate a clothed individual with electromagnetic radiation to determine one or more body measurements at least partially covered by the individual's clothing. The invention further includes techniques to interrogate an object with electromagnetic radiation in the millimeter and/or microwave range to provide a volumetric representation of the object. This representation can be used to display images and/or determine dimensional information concerning the object.

Subsurface Exploration Methods for Soft Ground Rapid Transit Tunnels : Volume 1. Sections 1-6 and references.

DOT National Transportation Integrated Search

1976-04-01

The objectives of the Urban Mass Transportation Administration (UMTA) Tunneling Program are to lower subway construction costs and reduce construction hazards and damage to the environment. Some measure of each of these objectives for bored tunnels a...

A stepwise, multi-objective, multi-variable parameter optimization method for the APEX model

USDA-ARS?s Scientific Manuscript database

Proper parameterization enables hydrological models to make reliable estimates of non-point source pollution for effective control measures. The automatic calibration of hydrologic models requires significant computational power limiting its application. The study objective was to develop and eval...

NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 48: Valuing information in an interactive environment

NASA Technical Reports Server (NTRS)

Brinberg, Herbert R.; Pinelli, Thomas E.; Barclay, Rebecca O.

1995-01-01

Consideration effort has been devoted over the past 30 years to developing methods and means of assessing the value of information. Two approaches - value in exchange and value in use - dominate; however, neither approach enjoys much practical application because validation schema for decision-making is missing. The approaches fail to measure objectively the real costs of acquiring information and the real benefits that information will yield. Moreover, these approaches collectively fail to provide economic justification to build and/or continue to support an information product or service. In addition, the impact of Cyberspace adds a new dimension to the problem. A new paradigm is required to make economic sense in this revolutionary information environment. In previous work, the authors explored the various approaches to measuring the value of information and concluded that, in large measure, these methods were unworkable concepts and constructs. Instead, they proposed several axioms for valuing information. Most particularly they concluded that the 'value of information cannot be measured in the absence of a specific task, objective, or goal.' This paper builds on those axioms and describes under which circumstances information can be measured in objective and actionable terms. This paper also proposes a methodology for undertaking such measures and validating the results.

Methodological Challenges in Measuring Child Maltreatment

ERIC Educational Resources Information Center

Fallon, Barbara; Trocme, Nico; Fluke, John; MacLaurin, Bruce; Tonmyr, Lil; Yuan, Ying-Ying

2010-01-01

Objective: This article reviewed the different surveillance systems used to monitor the extent of reported child maltreatment in North America. Methods: Key measurement and definitional differences between the surveillance systems are detailed and their potential impact on the measurement of the rate of victimization. The infrastructure…

Interior Temperature Measurement Using Curved Mercury Capillary Sensor Based on X-ray Radiography

NASA Astrophysics Data System (ADS)

Chen, Shuyue; Jiang, Xing; Lu, Guirong

2017-07-01

A method was presented for measuring the interior temperature of objects using a curved mercury capillary sensor based on X-ray radiography. The sensor is composed of a mercury bubble, a capillary and a fixed support. X-ray digital radiography was employed to capture image of the mercury column in the capillary, and a temperature control system was designed for the sensor calibration. We adopted livewire algorithms and mathematical morphology to calculate the mercury length. A measurement model relating mercury length to temperature was established, and the measurement uncertainty associated with the mercury column length and the linear model fitted by least-square method were analyzed. To verify the system, the interior temperature measurement of an autoclave, which is totally closed, was taken from 29.53°C to 67.34°C. The experiment results show that the response of the system is approximately linear with an uncertainty of maximum 0.79°C. This technique provides a new approach to measure interior temperature of objects.

Assessment of Gamma-Ray-Spectra Analysis Method Utilizing the Fireworks Algorithm for Various Error Measures

DOE PAGES

Alamaniotis, Miltiadis; Tsoukalas, Lefteri H.

2018-01-01

The analysis of measured data plays a significant role in enhancing nuclear nonproliferation mainly by inferring the presence of patterns associated with special nuclear materials. Among various types of measurements, gamma-ray spectra is the widest utilized type of data in nonproliferation applications. In this paper, a method that employs the fireworks algorithm (FWA) for analyzing gamma-ray spectra aiming at detecting gamma signatures is presented. In particular, FWA is utilized to fit a set of known signatures to a measured spectrum by optimizing an objective function, where non-zero coefficients express the detected signatures. FWA is tested on a set of experimentallymore » obtained measurements optimizing various objective functions—MSE, RMSE, Theil-2, MAE, MAPE, MAP—with results exhibiting its potential in providing highly accurate and precise signature detection. Finally and furthermore, FWA is benchmarked against genetic algorithms and multiple linear regression, showing its superiority over those algorithms regarding precision with respect to MAE, MAPE, and MAP measures.« less

Measurement of Flat Slab Deformations by the Multi-Image Photogrammetry Method

NASA Astrophysics Data System (ADS)

Marčiš, Marián; Fraštia, Marek; Augustín, Tomáš

2017-12-01

The use of photogrammetry during load tests of building components is a common practise all over the world. It is very effective thanks to its contactless approach, 3D measurement, fast data collection, and partial or full automation of image processing; it can deliver very accurate results. Multi-image convergent photogrammetry supported by artificial coded targets is the most accurate photogrammetric method when the targets are detected in an image with a higher degree of accuracy than a 0.1 pixel. It is possible to achieve an accuracy of 0.03 mm for all the points measured on the object observed if the camera is close enough to the object, and the positions of the camera and the number of shots are precisely planned. This contribution deals with the design of a special hanging frame for a DSLR camera used during the photogrammetric measurement of the deformation of flat concrete slab. The results of the photogrammetric measurements are compared to the results from traditional contact measurement techniques during load tests.

[The validation of the effect of correcting spectral background changes based on floating reference method by simulation].

PubMed

Wang, Zhu-lou; Zhang, Wan-jie; Li, Chen-xi; Chen, Wen-liang; Xu, Ke-xin

2015-02-01

There are some challenges in near-infrared non-invasive blood glucose measurement, such as the low signal to noise ratio of instrument, the unstable measurement conditions, the unpredictable and irregular changes of the measured object, and etc. Therefore, it is difficult to extract the information of blood glucose concentrations from the complicated signals accurately. Reference measurement method is usually considered to be used to eliminate the effect of background changes. But there is no reference substance which changes synchronously with the anylate. After many years of research, our research group has proposed the floating reference method, which is succeeded in eliminating the spectral effects induced by the instrument drifts and the measured object's background variations. But our studies indicate that the reference-point will changes following the changing of measurement location and wavelength. Therefore, the effects of floating reference method should be verified comprehensively. In this paper, keeping things simple, the Monte Carlo simulation employing Intralipid solution with the concentrations of 5% and 10% is performed to verify the effect of floating reference method used into eliminating the consequences of the light source drift. And the light source drift is introduced through varying the incident photon number. The effectiveness of the floating reference method with corresponding reference-points at different wavelengths in eliminating the variations of the light source drift is estimated. The comparison of the prediction abilities of the calibration models with and without using this method shows that the RMSEPs of the method are decreased by about 98.57% (5%Intralipid)and 99.36% (10% Intralipid)for different Intralipid. The results indicate that the floating reference method has obvious effect in eliminating the background changes.

A Mobile Outdoor Augmented Reality Method Combining Deep Learning Object Detection and Spatial Relationships for Geovisualization

PubMed Central

Rao, Jinmeng; Qiao, Yanjun; Ren, Fu; Wang, Junxing; Du, Qingyun

2017-01-01

The purpose of this study was to develop a robust, fast and markerless mobile augmented reality method for registration, geovisualization and interaction in uncontrolled outdoor environments. We propose a lightweight deep-learning-based object detection approach for mobile or embedded devices; the vision-based detection results of this approach are combined with spatial relationships by means of the host device’s built-in Global Positioning System receiver, Inertial Measurement Unit and magnetometer. Virtual objects generated based on geospatial information are precisely registered in the real world, and an interaction method based on touch gestures is implemented. The entire method is independent of the network to ensure robustness to poor signal conditions. A prototype system was developed and tested on the Wuhan University campus to evaluate the method and validate its results. The findings demonstrate that our method achieves a high detection accuracy, stable geovisualization results and interaction. PMID:28837096

A Mobile Outdoor Augmented Reality Method Combining Deep Learning Object Detection and Spatial Relationships for Geovisualization.

PubMed

Rao, Jinmeng; Qiao, Yanjun; Ren, Fu; Wang, Junxing; Du, Qingyun

2017-08-24

The purpose of this study was to develop a robust, fast and markerless mobile augmented reality method for registration, geovisualization and interaction in uncontrolled outdoor environments. We propose a lightweight deep-learning-based object detection approach for mobile or embedded devices; the vision-based detection results of this approach are combined with spatial relationships by means of the host device's built-in Global Positioning System receiver, Inertial Measurement Unit and magnetometer. Virtual objects generated based on geospatial information are precisely registered in the real world, and an interaction method based on touch gestures is implemented. The entire method is independent of the network to ensure robustness to poor signal conditions. A prototype system was developed and tested on the Wuhan University campus to evaluate the method and validate its results. The findings demonstrate that our method achieves a high detection accuracy, stable geovisualization results and interaction.

Reuse Metrics for Object Oriented Software

NASA Technical Reports Server (NTRS)

Bieman, James M.

1998-01-01

One way to increase the quality of software products and the productivity of software development is to reuse existing software components when building new software systems. In order to monitor improvements in reuse, the level of reuse must be measured. In this NASA supported project we (1) derived a suite of metrics which quantify reuse attributes for object oriented, object based, and procedural software, (2) designed prototype tools to take these measurements in Ada, C++, Java, and C software, (3) evaluated the reuse in available software, (4) analyzed the relationship between coupling, cohesion, inheritance, and reuse, (5) collected object oriented software systems for our empirical analyses, and (6) developed quantitative criteria and methods for restructuring software to improve reusability.

A simple and novel grading method for retraction and overshoot in Duane retraction syndrome.

PubMed

Kekunnaya, Ramesh; Moharana, Ruby; Tibrewal, Shailja; Chhablani, Preeti-Patil; Sachdeva, Virender

2016-11-01

Strabismus in Duane retraction syndrome is frequently associated with significant globe retraction and overshoots. However, there is no method to objectively grade retraction and overshoot. Our purpose is to describe a novel objective grading method. This novel and simple grading method has excellent agreement. It will help standardise measurements and guide the clinician in taking the decision for surgery and predicting its outcome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

New methodology of measurement the unsteady thermal cooling of objects

NASA Astrophysics Data System (ADS)

Winczek, Jerzy

2018-04-01

The problems of measurements of unsteady thermal turbulent flow affect a many of domains, such as heat energy, manufacturing technologies, and many others. The subject of the study is focused on the analysis of current state of the problem, overview of the design solutions and methods to measure non-stationary thermal phenomena, presentation, and choice of adequate design of the cylinder, development of the method to measure and calculate basic values that characterize the process of heat exchange on the model surface.

A modified multi-objective particle swarm optimization approach and its application to the design of a deepwater composite riser

NASA Astrophysics Data System (ADS)

Zheng, Y.; Chen, J.

2017-09-01

A modified multi-objective particle swarm optimization method is proposed for obtaining Pareto-optimal solutions effectively. Different from traditional multi-objective particle swarm optimization methods, Kriging meta-models and the trapezoid index are introduced and integrated with the traditional one. Kriging meta-models are built to match expensive or black-box functions. By applying Kriging meta-models, function evaluation numbers are decreased and the boundary Pareto-optimal solutions are identified rapidly. For bi-objective optimization problems, the trapezoid index is calculated as the sum of the trapezoid's area formed by the Pareto-optimal solutions and one objective axis. It can serve as a measure whether the Pareto-optimal solutions converge to the Pareto front. Illustrative examples indicate that to obtain Pareto-optimal solutions, the method proposed needs fewer function evaluations than the traditional multi-objective particle swarm optimization method and the non-dominated sorting genetic algorithm II method, and both the accuracy and the computational efficiency are improved. The proposed method is also applied to the design of a deepwater composite riser example in which the structural performances are calculated by numerical analysis. The design aim was to enhance the tension strength and minimize the cost. Under the buckling constraint, the optimal trade-off of tensile strength and material volume is obtained. The results demonstrated that the proposed method can effectively deal with multi-objective optimizations with black-box functions.

The convergent validity between two objective methods for quantifying training load in young taekwondo athletes.

PubMed

Haddad, Monoem; Chaouachi, Anis; Castagna, Carlo; Wong, Del P; Chamari, Karim

2012-01-01

Various studies used objective heart rate (HR)-based methods to assess training load (TL). The common methods were Banister's Training Impulse (TRIMP; weights the duration using a weighting factor) and Edwards' TL (a summated HR zone score). Both the methods use the direct physiological measure of HR as a fundamental part of the calculation. To eliminate the redundancy of using various methods to quantify the same construct (i.e., TL), we have to verify if these methods are strongly convergent and are interchangeable. Therefore, the aim of this study was to investigate the convergent validity between Banister's TRIMP and Edwards' TL used for the assessment of internal TL. The HRs were recorded and analyzed during 10 training weeks of the preseason period in 10 male Taekwondo (TKD) athletes. The TL was calculated using Banister's TRIMP and Edwards' TL. Pearson product moment correlation coefficient was used to evaluate the convergent validity between the 2 methods for assessing TL. Very large to nearly perfect relationships were found between individual Banister's TRIMP and Edwards' TL (r values from 0.80 to 0.99; p < 0.001). Pooled Banister's TRIMP and pooled Edwards' TL (pooled data n = 284) were nearly largely correlated (r = 0.89; p < 0.05; 95% confidence interval: 0.86-0.91). In conclusion, these findings suggest that these 2 objective methods, measuring a similar construct, are interchangeable.

Assessment of Sensory Function in the National Social Life, Health, and Aging Project

PubMed Central

McClintock, Martha; Williams, Sharon; Leitsch, Sara; Lundstrom, Johan; Hummel, Thomas; Lindau, Stacy Tessler

2009-01-01

Objectives The National Social Life, Health, and Aging Project assessed functioning of all 5 senses using both self-report and objective measures. We evaluate the performance of the objective measures and model differences in sensory function by gender and age. In the process, we demonstrate how to use and interpret these measures. Methods Distance vision was assessed using a standard Sloan eye chart, and touch was measured using a stationary 2-point discrimination test applied to the index fingertip of the dominant hand. Olfactory function (both intensity detection and odor identification) was assessed using odorants administered via felt-tip pens. Gustatory function was measured via identification of four taste strips. Results The performance of the objective measures was similar to that reported for previous studies, as was the relationship between sensory function and both gender and age. Discussion Sensory function is important in studies of aging and health both because it is an important health outcome and also because a decline in functioning can be symptomatic of or predict other health conditions. Although the objective measures provide considerably more precision than the self-report items, the latter can be valuable for imputation of missing data and for understanding differences in how older adults perceive their own sensory ability. PMID:19549923

Probabilistic resident space object detection using archival THEMIS fluxgate magnetometer data

NASA Astrophysics Data System (ADS)

Brew, Julian; Holzinger, Marcus J.

2018-05-01

Recent progress in the detection of small space objects, at geosynchronous altitudes, through ground-based optical and radar measurements is demonstrated as a viable method. However, in general, these methods are limited to detection of objects greater than 10 cm. This paper examines the use of magnetometers to detect plausible flyby encounters with charged space objects using a matched filter signal existence binary hypothesis test approach. Relevant data-set processing and reduction of archival fluxgate magnetometer data from the NASA THEMIS mission is discussed in detail. Using the proposed methodology and a false alarm rate of 10%, 285 plausible detections with probability of detection greater than 80% are claimed and several are reviewed in detail.

Objective comparison of particle tracking methods.

PubMed

Chenouard, Nicolas; Smal, Ihor; de Chaumont, Fabrice; Maška, Martin; Sbalzarini, Ivo F; Gong, Yuanhao; Cardinale, Janick; Carthel, Craig; Coraluppi, Stefano; Winter, Mark; Cohen, Andrew R; Godinez, William J; Rohr, Karl; Kalaidzidis, Yannis; Liang, Liang; Duncan, James; Shen, Hongying; Xu, Yingke; Magnusson, Klas E G; Jaldén, Joakim; Blau, Helen M; Paul-Gilloteaux, Perrine; Roudot, Philippe; Kervrann, Charles; Waharte, François; Tinevez, Jean-Yves; Shorte, Spencer L; Willemse, Joost; Celler, Katherine; van Wezel, Gilles P; Dan, Han-Wei; Tsai, Yuh-Show; Ortiz de Solórzano, Carlos; Olivo-Marin, Jean-Christophe; Meijering, Erik

2014-03-01

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Because manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized an open competition in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to notable practical conclusions for users and developers.

Probing optimal measurement configuration for optical scatterometry by the multi-objective genetic algorithm

NASA Astrophysics Data System (ADS)

Chen, Xiuguo; Gu, Honggang; Jiang, Hao; Zhang, Chuanwei; Liu, Shiyuan

2018-04-01

Measurement configuration optimization (MCO) is a ubiquitous and important issue in optical scatterometry, whose aim is to probe the optimal combination of measurement conditions, such as wavelength, incidence angle, azimuthal angle, and/or polarization directions, to achieve a higher measurement precision for a given measuring instrument. In this paper, the MCO problem is investigated and formulated as a multi-objective optimization problem, which is then solved by the multi-objective genetic algorithm (MOGA). The case study on the Mueller matrix scatterometry for the measurement of a Si grating verifies the feasibility of the MOGA in handling the MCO problem in optical scatterometry by making a comparison with the Monte Carlo simulations. Experiments performed at the achieved optimal measurement configuration also show good agreement between the measured and calculated best-fit Mueller matrix spectra. The proposed MCO method based on MOGA is expected to provide a more general and practical means to solve the MCO problem in the state-of-the-art optical scatterometry.

Are Self-report Measures Able to Define Individuals as Physically Active or Inactive?

PubMed

Steene-Johannessen, Jostein; Anderssen, Sigmund A; van der Ploeg, Hidde P; Hendriksen, Ingrid J M; Donnelly, Alan E; Brage, Søren; Ekelund, Ulf

2016-02-01

Assess the agreement between commonly used self-report methods compared with objectively measured physical activity (PA) in defining the prevalence of individuals compliant with PA recommendations. Time spent in moderate and vigorous PA (MVPA) was measured at two time points in 1713 healthy individuals from nine European countries using individually calibrated combined heart rate and movement sensing. Participants also completed the Recent Physical Activity Questionnaire (RPAQ), short form of the International Physical Activity Questionnaire (IPAQ), and short European Prospective Investigation into Cancer and Nutrition Physical Activity Questionnaire (EPIC-PAQ). Individuals were categorized as active (e.g., reporting ≥150 min of MVPA per week) or inactive, based on the information derived from the different measures. Sensitivity and specificity analyses and Kappa statistics were performed to evaluate the ability of the three PA questionnaires to correctly categorize individuals as active or inactive. Prevalence estimates of being sufficiently active varied significantly (P for all <0.001) between self-report measures (IPAQ 84.2% [95% confidence interval {CI}, 82.5-85.9], RPAQ 87.6% [95% CI, 85.9-89.1], EPIC-PAQ 39.9% [95% CI, 37.5-42.1] and objective measure 48.5% [95% CI, 41.6-50.9]. All self-report methods showed low or moderate sensitivity (IPAQ 20.0%, RPAQ 18.7%, and EPIC-PAQ 69.8%) to correctly classify inactive people and the agreement between objective and self-reported PA was low (ĸ = 0.07 [95% CI, 0.02-0.12], 0.12 [95% CI, 0.06-0.18], and 0.19 [95% CI, 0.13-0.24] for IPAQ, RPAQ, and EPIC-PAQ, respectively). The modest agreement between self-reported and objectively measured PA suggests that population levels of PA derived from self-report should be interpreted cautiously. Implementation of objective measures in large-scale cohort studies and surveillance systems is recommended.

Application of econometric and ecology analysis methods in physics software

NASA Astrophysics Data System (ADS)

Han, Min Cheol; Hoff, Gabriela; Kim, Chan Hyeong; Kim, Sung Hun; Grazia Pia, Maria; Ronchieri, Elisabetta; Saracco, Paolo

2017-10-01

Some data analysis methods typically used in econometric studies and in ecology have been evaluated and applied in physics software environments. They concern the evolution of observables through objective identification of change points and trends, and measurements of inequality, diversity and evenness across a data set. Within each analysis area, various statistical tests and measures have been examined. This conference paper summarizes a brief overview of some of these methods.

Uncovering the identities of compact objects in high-mass X-ray binaries and gamma-ray binaries by astrometric measurements

NASA Astrophysics Data System (ADS)

Yamaguchi, M. S.; Yano, T.; Gouda, N.

2018-03-01

We develop a method for identifying a compact object in binary systems with astrometric measurements and apply it to some binaries. Compact objects in some high-mass X-ray binaries and gamma-ray binaries are unknown, which is responsible for the fact that emission mechanisms in such systems have not yet confirmed. The accurate estimate of the mass of the compact object allows us to identify the compact object in such systems. Astrometric measurements are expected to enable us to estimate the masses of the compact objects in the binary systems via a determination of a binary orbit. We aim to evaluate the possibility of the identification of the compact objects for some binary systems. We then calculate probabilities that the compact object is correctly identified with astrometric observation (= confidence level) by taking into account a dependence of the orbital shape on orbital parameters and distributions of masses of white dwarfs, neutron stars and black holes. We find that the astrometric measurements with the precision of 70 μas for γ Cas allow us to identify the compact object at 99 per cent confidence level if the compact object is a white dwarf with 0.6 M⊙. In addition, we can identify the compact object with the precision of 10 μas at 97 per cent or larger confidence level for LS I +61° 303 and 99 per cent or larger for HESS J0632+057. These results imply that the astrometric measurements with the 10 μas precision level can realize the identification of compact objects for γ Cas, LS I +61° 303, and HESS J0632+057.

Information Measures for Statistical Orbit Determination

ERIC Educational Resources Information Center

Mashiku, Alinda K.

2013-01-01

The current Situational Space Awareness (SSA) is faced with a huge task of tracking the increasing number of space objects. The tracking of space objects requires frequent and accurate monitoring for orbit maintenance and collision avoidance using methods for statistical orbit determination. Statistical orbit determination enables us to obtain…

Optical calculation of correlation filters for a robotic vision system

NASA Technical Reports Server (NTRS)

Knopp, Jerome

1989-01-01

A method is presented for designing optical correlation filters based on measuring three intensity patterns: the Fourier transform of a filter object, a reference wave and the interference pattern produced by the sum of the object transform and the reference. The method can produce a filter that is well matched to both the object, its transforming optical system and the spatial light modulator used in the correlator input plane. A computer simulation was presented to demonstrate the approach for the special case of a conventional binary phase-only filter. The simulation produced a workable filter with a sharp correlation peak.

Coherent diffraction imaging by moving a lens.

PubMed

Shen, Cheng; Tan, Jiubin; Wei, Ce; Liu, Zhengjun

2016-07-25

A moveable lens is used for determining amplitude and phase on the object plane. The extended fractional Fourier transform is introduced to address the single lens imaging. We put forward a fast algorithm for the transform by convolution. Combined with parallel iterative phase retrieval algorithm, it is applied to reconstruct the complex amplitude of the object. Compared with inline holography, the implementation of our method is simple and easy. Without the oversampling operation, the computational load is less. Also the proposed method has a superiority of accuracy over the direct focusing measurement for the imaging of small size objects.

Objective Measurement of Erythema in Psoriasis using Digital Color Photography with Color Calibration

PubMed Central

Raina, Abhay; Hennessy, Ricky; Rains, Michael; Allred, James; Hirshburg, Jason M; Diven, Dayna; Markey, Mia K.

2016-01-01

Background Traditional metrics for evaluating the severity of psoriasis are subjective, which complicates efforts to measure effective treatments in clinical trials. Methods We collected images of psoriasis plaques and calibrated the coloration of the images according to an included color card. Features were extracted from the images and used to train a linear discriminant analysis classifier with cross-validation to automatically classify the degree of erythema. The results were tested against numerical scores obtained by a panel of dermatologists using a standard rating system. Results Quantitative measures of erythema based on the digital color images showed good agreement with subjective assessment of erythema severity (κ = 0.4203). The color calibration process improved the agreement from κ = 0.2364 to κ = 0.4203. Conclusions We propose a method for the objective measurement of the psoriasis severity parameter of erythema and show that the calibration process improved the results. PMID:26517973

An Automated Measurement of Ciliary Beating Frequency using a Combined Optical Flow and Peak Detection.

PubMed

Kim, Woojae; Han, Tae Hwa; Kim, Hyun Jun; Park, Man Young; Kim, Ku Sang; Park, Rae Woong

2011-06-01

The mucociliary transport system is a major defense mechanism of the respiratory tract. The performance of mucous transportation in the nasal cavity can be represented by a ciliary beating frequency (CBF). This study proposes a novel method to measure CBF by using optical flow. To obtain objective estimates of CBF from video images, an automated computer-based image processing technique is developed. This study proposes a new method based on optical flow for image processing and peak detection for signal processing. We compare the measuring accuracy of the method in various combinations of image processing (optical flow versus difference image) and signal processing (fast Fourier transform [FFT] vs. peak detection [PD]). The digital high-speed video method with a manual count of CBF in slow motion video play, is the gold-standard in CBF measurement. We obtained a total of fifty recorded ciliated sinonasal epithelium images to measure CBF from the Department of Otolaryngology. The ciliated sinonasal epithelium images were recorded at 50-100 frames per second using a charge coupled device camera with an inverted microscope at a magnification of ×1,000. The mean square errors and variance for each method were 1.24, 0.84 Hz; 11.8, 2.63 Hz; 3.22, 1.46 Hz; and 3.82, 1.53 Hz for optical flow (OF) + PD, OF + FFT, difference image [DI] + PD, and DI + FFT, respectively. Of the four methods, PD using optical flow showed the best performance for measuring the CBF of nasal mucosa. The proposed method was able to measure CBF more objectively and efficiently than what is currently possible.

Estimation of railroad capacity using parametric methods.

DOT National Transportation Integrated Search

2013-12-01

This paper reviews different methodologies used for railroad capacity estimation and presents a user-friendly method to measure capacity. The objective of this paper is to use multivariate regression analysis to develop a continuous relation of the d...

An Objective Comparison of Cell Tracking Algorithms

PubMed Central

Ulman, Vladimír; Maška, Martin; Magnusson, Klas E. G.; Ronneberger, Olaf; Haubold, Carsten; Harder, Nathalie; Matula, Pavel; Matula, Petr; Svoboda, David; Radojevic, Miroslav; Smal, Ihor; Rohr, Karl; Jaldén, Joakim; Blau, Helen M.; Dzyubachyk, Oleh; Lelieveldt, Boudewijn; Xiao, Pengdong; Li, Yuexiang; Cho, Siu-Yeung; Dufour, Alexandre C.; Olivo-Marin, Jean-Christophe; Reyes-Aldasoro, Constantino C.; Solis-Lemus, Jose A.; Bensch, Robert; Brox, Thomas; Stegmaier, Johannes; Mikut, Ralf; Wolf, Steffen; Hamprecht, Fred. A.; Esteves, Tiago; Quelhas, Pedro; Demirel, Ömer; Malmström, Lars; Jug, Florian; Tomancak, Pavel; Meijering, Erik; Muñoz-Barrutia, Arrate; Kozubek, Michal; Ortiz-de-Solorzano, Carlos

2017-01-01

We present a combined report on the results of three editions of the Cell Tracking Challenge, an ongoing initiative aimed at promoting the development and objective evaluation of cell tracking algorithms. With twenty-one participating algorithms and a data repository consisting of thirteen datasets of various microscopy modalities, the challenge displays today’s state of the art in the field. We analyze the results using performance measures for segmentation and tracking that rank all participating methods. We also analyze the performance of all algorithms in terms of biological measures and their practical usability. Even though some methods score high in all technical aspects, not a single one obtains fully correct solutions. We show that methods that either take prior information into account using learning strategies or analyze cells in a global spatio-temporal video context perform better than other methods under the segmentation and tracking scenarios included in the challenge. PMID:29083403

An objective comparison of cell-tracking algorithms.

PubMed

Ulman, Vladimír; Maška, Martin; Magnusson, Klas E G; Ronneberger, Olaf; Haubold, Carsten; Harder, Nathalie; Matula, Pavel; Matula, Petr; Svoboda, David; Radojevic, Miroslav; Smal, Ihor; Rohr, Karl; Jaldén, Joakim; Blau, Helen M; Dzyubachyk, Oleh; Lelieveldt, Boudewijn; Xiao, Pengdong; Li, Yuexiang; Cho, Siu-Yeung; Dufour, Alexandre C; Olivo-Marin, Jean-Christophe; Reyes-Aldasoro, Constantino C; Solis-Lemus, Jose A; Bensch, Robert; Brox, Thomas; Stegmaier, Johannes; Mikut, Ralf; Wolf, Steffen; Hamprecht, Fred A; Esteves, Tiago; Quelhas, Pedro; Demirel, Ömer; Malmström, Lars; Jug, Florian; Tomancak, Pavel; Meijering, Erik; Muñoz-Barrutia, Arrate; Kozubek, Michal; Ortiz-de-Solorzano, Carlos

2017-12-01

We present a combined report on the results of three editions of the Cell Tracking Challenge, an ongoing initiative aimed at promoting the development and objective evaluation of cell segmentation and tracking algorithms. With 21 participating algorithms and a data repository consisting of 13 data sets from various microscopy modalities, the challenge displays today's state-of-the-art methodology in the field. We analyzed the challenge results using performance measures for segmentation and tracking that rank all participating methods. We also analyzed the performance of all of the algorithms in terms of biological measures and practical usability. Although some methods scored high in all technical aspects, none obtained fully correct solutions. We found that methods that either take prior information into account using learning strategies or analyze cells in a global spatiotemporal video context performed better than other methods under the segmentation and tracking scenarios included in the challenge.

Technical and investigative support for high density digital satellite recording systems

NASA Technical Reports Server (NTRS)

Schultz, R. A.

1982-01-01

Methods and results of examinations and tests conducted on magnetic recording tapes under consideration for a high density digital (HDDR) satellite recording system are described. The examinations and tests investigate the performance of tapes with respect to their physical, magnetic and electrical characteristics. The objective of the tests, the likely significance of typical results, and the importance of the characteristics under investigation to the application are included. Theoretical discussions of measurement methods are provided where appropriate. Methods and results are discussed; the results of some sections are tabulated together to facilitate their comparison. The conclusion of each test section relates the test results to their possible significance and attempts to correlate the results of that section with the results of other tests. Some of the sections analyze sources of error inherent in the measurement methods or relate the value of the information obtained to the objectives of the test or the overall purpose of the project.

PRESBYOPIA OPTOMETRY METHOD BASED ON DIOPTER REGULATION AND CHARGE COUPLE DEVICE IMAGING TECHNOLOGY.

PubMed

Zhao, Q; Wu, X X; Zhou, J; Wang, X; Liu, R F; Gao, J

2015-01-01

With the development of photoelectric technology and single-chip microcomputer technology, objective optometry, also known as automatic optometry, is becoming precise. This paper proposed a presbyopia optometry method based on diopter regulation and Charge Couple Device (CCD) imaging technology and, in the meantime, designed a light path that could measure the system. This method projects a test figure to the eye ground and then the reflected image from the eye ground is detected by CCD. The image is then automatically identified by computer and the far point and near point diopters are determined to calculate lens parameter. This is a fully automatic objective optometry method which eliminates subjective factors of the tested subject. Furthermore, it can acquire the lens parameter of presbyopia accurately and quickly and can be used to measure the lens parameter of hyperopia, myopia and astigmatism.

Inter-relationships between objective and subjective measures of the residential environment among urban African American women

PubMed Central

Sealy-Jefferson, Shawnita; Messer, Lynne; Slaughter-Acey, Jaime; Misra, Dawn P.

2016-01-01

Background The inter-relationships between objective (census-based) and subjective (resident reported) measures of the residential environment is understudied in African American (AA) populations. Methods Using data from the Life Influences on Fetal Environments Study (2009–2011) (n=1,387) of AA women, we quantified the area-level variation in subjective reports of residential healthy food availability, walkability, safety and disorder that can be accounted for with an objective neighborhood disadvantage index (NDI). Two-level generalized linear models estimated associations between objective and subjective measures of the residential environment, accounting for individual-level covariates. Results In unconditional models, intraclass correlation coefficients for block-group variance in subjective reports ranged from 11% (healthy food availability) to 30% (safety). Models accounting for the NDI (versus both NDI and individual level covariates) accounted for more variance in healthy food availability (23% versus 8%) and social disorder (40% versus 38%). The NDI and individual level variables accounted for 39% and 51% of the area-level variation in walkability and safety. Associations between subjective and objective measures of the residential environment were significant and in the expected direction. Conclusions Future studies on neighborhood effects on health, especially among AAs, should include a wide range of residential environment measures, including subjective, objective and spatial contextual variables. PMID:28160971

Ultrasonic Measurement of Strain Distribution Inside Object Cyclically Compressed by Dual Acoustic Radiation Force

NASA Astrophysics Data System (ADS)

Odagiri, Yoshitaka; Hasegawa, Hideyuki; Kanai, Hiroshi

2008-05-01

One possible way to evaluate acupuncture therapy quantitatively is to measure the change in the elastic property of muscle after application of the therapy. Many studies have been conducted to measure mechanical properties of tissues using ultrasound-induced acoustic radiation force. To assess mechanical properties, strain must be generated in an object. However, a single radiation force is not effective because it mainly generates translational motion when the object is much harder than the surrounding medium. In this study, two cyclic radiation forces are simultaneously applied to a muscle phantom from two opposite horizontal directions so that the object is cyclically compressed in the horizontal direction. By the horizontal compression, the object is expanded vertically based on its incompressibility. The resultant vertical displacement is measured using another ultrasound pulse. Two ultrasonic transducers for actuation were both driven by the sum of two continuous sinusoidal signals at two slightly different frequencies [1 MHz and (1 M + 5) Hz]. The displacement of several micrometers in amplitude, which fluctuated at 5 Hz, was measured by the ultrasonic phased tracking method. Increase in thickness inside the object was observed just when acoustic radiation forces increased. Such changes in thickness correspond to vertical expansion due to horizontal compression.

Approaches to chronic disease management evaluation in use in Europe: a review of current methods and performance measures.

PubMed

Conklin, Annalijn; Nolte, Ellen; Vrijhoef, Hubertus

2013-01-01

An overview was produced of approaches currently used to evaluate chronic disease management in selected European countries. The study aims to describe the methods and metrics used in Europe as a first to help advance the methodological basis for their assessment. A common template for collection of evaluation methods and performance measures was sent to key informants in twelve European countries; responses were summarized in tables based on template evaluation categories. Extracted data were descriptively analyzed. Approaches to the evaluation of chronic disease management vary widely in objectives, designs, metrics, observation period, and data collection methods. Half of the reported studies used noncontrolled designs. The majority measure clinical process measures, patient behavior and satisfaction, cost and utilization; several also used a range of structural indicators. Effects are usually observed over 1 or 3 years on patient populations with a single, commonly prevalent, chronic disease. There is wide variation within and between European countries on approaches to evaluating chronic disease management in their objectives, designs, indicators, target audiences, and actors involved. This study is the first extensive, international overview of the area reported in the literature.

Development of Decision Making Algorithm for Control of Sea Cargo Containers by ``TAGGED'' Neutron Method

NASA Astrophysics Data System (ADS)

Anan'ev, A. A.; Belichenko, S. G.; Bogolyubov, E. P.; Bochkarev, O. V.; Petrov, E. V.; Polishchuk, A. M.; Udaltsov, A. Yu.

2009-12-01

Nowadays in Russia and abroad there are several groups of scientists, engaged in development of systems based on "tagged" neutron method (API method) and intended for detection of dangerous materials, including high explosives (HE). Particular attention is paid to possibility of detection of dangerous objects inside a sea cargo container. Energy gamma-spectrum, registered from object under inspection is used for determination of oxygen/carbon and nitrogen/carbon chemical ratios, according to which dangerous object is distinguished from not dangerous one. Material of filled container, however, gives rise to additional effects of rescattering and moderation of 14 MeV primary neutrons of generator, attenuation of secondary gamma-radiation from reactions of inelastic neutron scattering on objects under inspection. These effects lead to distortion of energy gamma-response from examined object and therefore prevent correct recognition of chemical ratios. These difficulties are taken into account in analytical method, presented in the paper. Method has been validated against experimental data, obtained by the system for HE detection in sea cargo, based on API method and developed in VNIIA. Influence of shielding materials on results of HE detection and identification is considered. Wood and iron were used as shielding materials. Results of method application for analysis of experimental data on HE simulator measurement (tetryl, trotyl, hexogen) are presented.

An instrumented object for hand exercise and assessment using a pneumatic pressure sensor

NASA Astrophysics Data System (ADS)

Mohan, A.; Tharion, G.; Kumar, R. K.; Devasahayam, S. R.

2018-05-01

Measurement of grip force is important for both exercise training and assessment of the hand during physical rehabilitation. The standard method uses a grip dynamometer which measures the force between the fingers and opposing thumb. The primary limitation of the grip dynamometer is the restriction of measurement to cylindrical grasps. Any deformation of the hand due to muscular or skeletal disease makes the grip dynamometer difficult or impossible to use. An alternative to the grip dynamometer is a sealed pneumatic object that can be gripped by the hand. Measurement of the internal pressure in the object can be related to the grip force. In this paper, we analyze such a pneumatic pressure sensing object for hand grip assessment and also describe an easy fabrication of the grip sensor. The instrumented object presented in this paper is designed to assess both the maximal voluntary grip forces and continuous grip force to monitor control of hand function during exercise under instruction from a therapist. Potential uses of such a pneumatic pressure sensing object for hand grip are in physical rehabilitation of patients following paralysing illnesses like stroke and spinal cord injury.

A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix.

PubMed

Saito, Akira; Numata, Yasushi; Hamada, Takuya; Horisawa, Tomoyoshi; Cosatto, Eric; Graf, Hans-Peter; Kuroda, Masahiko; Yamamoto, Yoichiro

2016-01-01

Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity. In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features. CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image analysis.

Vibration analysis based on electronic stroboscopic speckle-shearing pattern interferometry

NASA Astrophysics Data System (ADS)

Jia, Dagong; Yu, Changsong; Xu, Tianhua; Jin, Chao; Zhang, Hongxia; Jing, Wencai; Zhang, Yimo

2008-12-01

In this paper, an electronic speckle-shearing pattern interferometer with pulsed laser and pulse frequency controller is fabricated. The principle of measuring the vibration in the object using electronic stroboscopic speckle--shearing pattern interferometer is analyzed. Using a metal plate, the edge of which is clamped, as an experimental specimen, the shear interferogram are obtained under two experimental frequencies, 100 Hz and 200 Hz. At the same time, the vibration of this metal plate under the same experimental conditions is measured using the time-average method in order to test the performance of this electronic stroboscopic speckle-shearing pattern interferometer. The result indicated that the fringe of shear interferogram become dense with the experimental frequency increasing. Compared the fringe pattern obtained by the stroboscopic method with the fringe obtained by the time-average method, the shearing interferogram of stroboscopic method is clearer than the time-average method. In addition, both the time-average method and stroboscopic method are suited for qualitative analysis for the vibration of the object. More over, the stroboscopic method is well adapted to quantitative vibration analysis.

Single-pixel non-imaging object recognition by means of Fourier spectrum acquisition

NASA Astrophysics Data System (ADS)

Chen, Huichao; Shi, Jianhong; Liu, Xialin; Niu, Zhouzhou; Zeng, Guihua

2018-04-01

Single-pixel imaging has emerged over recent years as a novel imaging technique, which has significant application prospects. In this paper, we propose and experimentally demonstrate a scheme that can achieve single-pixel non-imaging object recognition by acquiring the Fourier spectrum. In an experiment, a four-step phase-shifting sinusoid illumination light is used to irradiate the object image, the value of the light intensity is measured with a single-pixel detection unit, and the Fourier coefficients of the object image are obtained by a differential measurement. The Fourier coefficients are first cast into binary numbers to obtain the hash value. We propose a new method of perceptual hashing algorithm, which is combined with a discrete Fourier transform to calculate the hash value. The hash distance is obtained by calculating the difference of the hash value between the object image and the contrast images. By setting an appropriate threshold, the object image can be quickly and accurately recognized. The proposed scheme realizes single-pixel non-imaging perceptual hashing object recognition by using fewer measurements. Our result might open a new path for realizing object recognition with non-imaging.

Objective Assessment of Spectral Ripple Discrimination in Cochlear Implant Listeners Using Cortical Evoked Responses to an Oddball Paradigm

PubMed Central

Lopez Valdes, Alejandro; Mc Laughlin, Myles; Viani, Laura; Walshe, Peter; Smith, Jaclyn; Zeng, Fan-Gang; Reilly, Richard B.

2014-01-01

Cochlear implants (CIs) can partially restore functional hearing in deaf individuals. However, multiple factors affect CI listener's speech perception, resulting in large performance differences. Non-speech based tests, such as spectral ripple discrimination, measure acoustic processing capabilities that are highly correlated with speech perception. Currently spectral ripple discrimination is measured using standard psychoacoustic methods, which require attentive listening and active response that can be difficult or even impossible in special patient populations. Here, a completely objective cortical evoked potential based method is developed and validated to assess spectral ripple discrimination in CI listeners. In 19 CI listeners, using an oddball paradigm, cortical evoked potential responses to standard and inverted spectrally rippled stimuli were measured. In the same subjects, psychoacoustic spectral ripple discrimination thresholds were also measured. A neural discrimination threshold was determined by systematically increasing the number of ripples per octave and determining the point at which there was no longer a significant difference between the evoked potential response to the standard and inverted stimuli. A correlation was found between the neural and the psychoacoustic discrimination thresholds (R2 = 0.60, p<0.01). This method can objectively assess CI spectral resolution performance, providing a potential tool for the evaluation and follow-up of CI listeners who have difficulty performing psychoacoustic tests, such as pediatric or new users. PMID:24599314

Objective assessment of spectral ripple discrimination in cochlear implant listeners using cortical evoked responses to an oddball paradigm.

PubMed

Lopez Valdes, Alejandro; Mc Laughlin, Myles; Viani, Laura; Walshe, Peter; Smith, Jaclyn; Zeng, Fan-Gang; Reilly, Richard B

2014-01-01

Cochlear implants (CIs) can partially restore functional hearing in deaf individuals. However, multiple factors affect CI listener's speech perception, resulting in large performance differences. Non-speech based tests, such as spectral ripple discrimination, measure acoustic processing capabilities that are highly correlated with speech perception. Currently spectral ripple discrimination is measured using standard psychoacoustic methods, which require attentive listening and active response that can be difficult or even impossible in special patient populations. Here, a completely objective cortical evoked potential based method is developed and validated to assess spectral ripple discrimination in CI listeners. In 19 CI listeners, using an oddball paradigm, cortical evoked potential responses to standard and inverted spectrally rippled stimuli were measured. In the same subjects, psychoacoustic spectral ripple discrimination thresholds were also measured. A neural discrimination threshold was determined by systematically increasing the number of ripples per octave and determining the point at which there was no longer a significant difference between the evoked potential response to the standard and inverted stimuli. A correlation was found between the neural and the psychoacoustic discrimination thresholds (R2=0.60, p<0.01). This method can objectively assess CI spectral resolution performance, providing a potential tool for the evaluation and follow-up of CI listeners who have difficulty performing psychoacoustic tests, such as pediatric or new users.

Reliability and validity of the AutoCAD software method in lumbar lordosis measurement

PubMed Central

Letafatkar, Amir; Amirsasan, Ramin; Abdolvahabi, Zahra; Hadadnezhad, Malihe

2011-01-01

Objective The aim of this study was to determine the reliability and validity of the AutoCAD software method in lumbar lordosis measurement. Methods Fifty healthy volunteers with a mean age of 23 ± 1.80 years were enrolled. A lumbar lateral radiograph was taken on all participants, and the lordosis was measured according to the Cobb method. Afterward, the lumbar lordosis degree was measured via AutoCAD software and flexible ruler methods. The current study is accomplished in 2 parts: intratester and intertester evaluations of reliability as well as the validity of the flexible ruler and software methods. Results Based on the intraclass correlation coefficient, AutoCAD's reliability and validity in measuring lumbar lordosis were 0.984 and 0.962, respectively. Conclusions AutoCAD showed to be a reliable and valid method to measure lordosis. It is suggested that this method may replace those that are costly and involve health risks, such as radiography, in evaluating lumbar lordosis. PMID:22654681

Mark Tracking: Position/orientation measurements using 4-circle mark and its tracking experiments

NASA Technical Reports Server (NTRS)

Kanda, Shinji; Okabayashi, Keijyu; Maruyama, Tsugito; Uchiyama, Takashi

1994-01-01

Future space robots require position and orientation tracking with visual feedback control to track and capture floating objects and satellites. We developed a four-circle mark that is useful for this purpose. With this mark, four geometric center positions as feature points can be extracted from the mark by simple image processing. We also developed a position and orientation measurement method that uses the four feature points in our mark. The mark gave good enough image measurement accuracy to let space robots approach and contact objects. A visual feedback control system using this mark enabled a robot arm to track a target object accurately. The control system was able to tolerate a time delay of 2 seconds.

Validation of the Physical Activity Scale for individuals with physical disabilities.

PubMed

van den Berg-Emons, Rita J; L'Ortye, Annemiek A; Buffart, Laurien M; Nieuwenhuijsen, Channah; Nooijen, Carla F; Bergen, Michael P; Stam, Henk J; Bussmann, Johannes B

2011-06-01

To determine the criterion validity of the Physical Activity Scale for Individuals With Physical Disabilities (PASIPD) by means of daily physical activity levels measured by using a validated accelerometry-based activity monitor in a large group of persons with a physical disability. Cross-sectional. Participants' home environment. Ambulatory and nonambulatory persons with cerebral palsy, meningomyelocele, or spinal cord injury (N=124). Not applicable. Self-reported physical activity level measured by using the PASIPD, a 2-day recall questionnaire, was correlated to objectively measured physical activity level measured by using a validated accelerometry-based activity monitor. Significant Spearman correlation coefficients between the PASIPD and activity monitor outcome measures ranged from .22 to .37. The PASIPD overestimated the duration of physical activity measured by using the activity monitor (mean ± SD, 3.9±2.9 vs 1.5±0.9h/d; P<.01). Significant correlation (ρ=-.74; P<.01) was found between average number of hours of physical activity per day measured by using the 2 methods and difference in hours between methods. This indicates larger overestimation for persons with higher activity levels. The PASIPD correlated poorly with objective measurements using an accelerometry-based activity monitor in people with a physical disability. However, similar low correlations between objective and subjective activity measurements have been found in the general population. Users of the PASIPD should be cautious about overestimating physical activity levels. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Adherence to Pharmacological Treatment for Juvenile Bipolar Disorder

ERIC Educational Resources Information Center

Drotar, Dennis; Greenley, Rachel Neff; Demeter, Christine A.; McNamara, Nora K.; Stansbrey, Robert J.; Calabrese, Joseph R.; Stange, Jonathan; Vijay, Priya; Findling, Robert L.

2007-01-01

Objective: The objective of this study was to describe the prevalence and correlates of adherence to divalproex sodium (DVPX) and lithium carbonate (Li) combination treatment during the initial stabilization treatment phase. Method: Adherence to Li/DVPX combination therapy was measured by the presence or absence of minimum serum concentrations of…

Psychometric Structure of a Comprehensive Objective Structured Clinical Examination: A Factor Analytic Approach

ERIC Educational Resources Information Center

Volkan, Kevin; Simon, Steven R.; Baker, Harley; Todres, I. David

2004-01-01

Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An…

Is there a correlation of sonographic measurements of true vocal cords with gender or body mass indices in normal healthy volunteers?

PubMed Central

Bright, Leah; Secko, Michael; Mehta, Ninfa; Paladino, Lorenzo; Sinert, Richard

2014-01-01

Background: Ultrasound is a readily available, non-invasive technique to visualize airway dimensions at the patient's bedside and possibly predict difficult airways before invasively looking; however, it has rarely been used for emergency investigation of the larynx. There is limited literature on the sonographic measurements of true vocal cords in adults and normal parameters must be established before abnormal parameters can be accurately identified. Objectives: The primary objective of the following study is to identify the normal sonographic values of human true vocal cords in an adult population. A secondary objective is to determine if there is a difference in true vocal cord measurements in people with different body mass indices (BMIs). The third objective was to determine if there was a statistical difference in the measurements for both genders. Materials and Methods: True vocal cord measurements were obtained in healthy volunteers by ultrasound fellowship trained emergency medicine physicians using a high frequency linear transducer orientated transversely across the anterior surface of the neck at the level of the thyroid cartilage. The width of the true vocal cord was measured perpendicularly to the length of the cord at its mid-portion. This method was duplicated from a previous study to create a standard of measurement acquisition. Results: A total of 38 subjects were enrolled. The study demonstrated no correlation between vocal cord measurements and patient's characteristics of height, weight, or BMI's. When accounting for vocal cord measurements by gender, males had larger BMI's and larger vocal cord measurements compared with females subjects with a statistically significant different in right vocal cord measurements for females compared with male subjects. Conclusion: No correlation was seen between vocal cord measurements and person's BMIs. In the study group of normal volunteers, there was a difference in size between the male and female vocal cord size. PMID:24812456

Method and apparatus for measuring surface movement of a solid object that is subjected to external vibrations

DOEpatents

Schultz, Thomas J.; Kotidis, Petros A.; Woodroffe, Jaime A.; Rostler, Peter S.

1995-01-01

A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading.

Method and apparatus for measuring surface movement of an object using a polarizing interfeometer

DOEpatents

Schultz, Thomas J.; Kotidis, Petros A.; Woodroffe, Jaime A.; Rostler, Peter S.

1995-01-01

A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading.

Method and apparatus for measuring surface movement of an object using a polarizing interferometer

DOEpatents

Schultz, T.J.; Kotidis, P.A.; Woodroffe, J.A.; Rostler, P.S.

1995-05-09

A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading. 38 figs.

Method and apparatus for measuring surface movement of a solid object that is subjected to external vibrations

DOEpatents

Schultz, T.J.; Kotidis, P.A.; Woodroffe, J.A.; Rostler, P.S.

1995-04-25

A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading. 38 figs.

Panoramic Images Mapping Tools Integrated Within the ESRI ArcGIS Software

NASA Astrophysics Data System (ADS)

Guo, Jiao; Zhong, Ruofei; Zeng, Fanyang

2014-03-01

There is a general study on panoramic images which are presented along with appearance of the Google street map. Despite 360 degree viewing of street, we can realize more applications over panoramic images. This paper developed a toolkits plugged in ArcGIS, which can view panoramic photographs at street level directly from ArcMap and measure and capture all visible elements as frontages, trees and bridges. We use a series of panoramic images adjoined with absolute coordinate through GPS and IMU. There are two methods in this paper to measure object from these panoramic images: one is to intersect object position through a stereogram; the other one is multichip matching involved more than three images which all cover the object. While someone wants to measure objects from these panoramic images, each two panoramic images which both contain the object can be chosen to display on ArcMap. Then we calculate correlation coefficient of the two chosen panoramic images so as to calculate the coordinate of object. Our study test different patterns of panoramic pairs and compare the results of measurement to the real value of objects so as to offer the best choosing suggestion. The article has mainly elaborated the principles of calculating correlation coefficient and multichip matching.

Post-PRK corneal scatter measurements with a scanning confocal slit photon counter

NASA Astrophysics Data System (ADS)

Taboada, John; Gaines, David; Perez, Mary A.; Waller, Steve G.; Ivan, Douglas J.; Baldwin, J. Bruce; LoRusso, Frank; Tutt, Ronald C.; Perez, Jose; Tredici, Thomas; Johnson, Dan A.

2000-06-01

Increased corneal light scatter or 'haze' has been associated with excimer laser photorefractive surgery of the cornea. The increased scatter can affect visual performance; however, topical steroid treatment post surgery substantially reduces the post PRK scatter. For the treatment and monitoring of the scattering characteristics of the cornea, various methods have been developed to objectively measure the magnitude of the scatter. These methods generally can measure scatter associated with clinically observable levels of haze. For patients with moderate to low PRK corrections receiving steroid treatment, measurement becomes fairly difficult as the haze clinical rating is non observable. The goal of this development was to realize an objective, non-invasive physical measurement that could produce a significant reading for any level including the background present in a normal cornea. As back-scatter is the only readily accessible observable, the instrument is based on this measurement. To achieve this end required the use of a confocal method to bias out the background light that would normally confound conventional methods. A number of subjects with nominal refractive errors in an Air Force study have undergone PRK surgery. A measurable increase in corneal scatter has been observed in these subjects whereas clinical ratings of the haze were noted as level zero. Other favorable aspects of this back-scatter based instrument include an optical capability to perform what is equivalent to an optical A-scan of the anterior chamber. Lens scatter can also be measured.

Model-based sphere localization (MBSL) in x-ray projections

NASA Astrophysics Data System (ADS)

Sawall, Stefan; Maier, Joscha; Leinweber, Carsten; Funck, Carsten; Kuntz, Jan; Kachelrieß, Marc

2017-08-01

The detection of spherical markers in x-ray projections is an important task in a variety of applications, e.g. geometric calibration and detector distortion correction. Therein, the projection of the sphere center on the detector is of particular interest as the used spherical beads are no ideal point-like objects. Only few methods have been proposed to estimate this respective position on the detector with sufficient accuracy and surrogate positions, e.g. the center of gravity, are used, impairing the results of subsequent algorithms. We propose to estimate the projection of the sphere center on the detector using a simulation-based method matching an artificial projection to the actual measurement. The proposed algorithm intrinsically corrects for all polychromatic effects included in the measurement and absent in the simulation by a polynomial which is estimated simultaneously. Furthermore, neither the acquisition geometry nor any object properties besides the fact that the object is of spherical shape need to be known to find the center of the bead. It is shown by simulations that the algorithm estimates the center projection with an error of less than 1% of the detector pixel size in case of realistic noise levels and that the method is robust to the sphere material, sphere size, and acquisition parameters. A comparison to three reference methods using simulations and measurements indicates that the proposed method is an order of magnitude more accurate compared to these algorithms. The proposed method is an accurate algorithm to estimate the center of spherical markers in CT projections in the presence of polychromatic effects and noise.

Devices and tasks involved in the objective assessment of standing dynamic balancing - A systematic literature review.

PubMed

Petró, Bálint; Papachatzopoulou, Alexandra; Kiss, Rita M

2017-01-01

Static balancing assessment is often complemented with dynamic balancing tasks. Numerous dynamic balancing assessment methods have been developed in recent decades with their corresponding balancing devices and tasks. The aim of this systematic literature review is to identify and categorize existing objective methods of standing dynamic balancing ability assessment with an emphasis on the balancing devices and tasks being used. Three major scientific literature databases (Science Direct, Web of Science, PLoS ONE) and additional sources were used. Studies had to use a dynamic balancing device and a task described in detail. Evaluation had to be based on objectively measureable parameters. Functional tests without instrumentation evaluated exclusively by a clinician were excluded. A total of 63 articles were included. The data extracted during full-text assessment were: author and date; the balancing device with the balancing task and the measured parameters; the health conditions, size, age and sex of participant groups; and follow-up measurements. A variety of dynamic balancing assessment devices were identified and categorized as 1) Solid ground, 2) Balance board, 3) Rotating platform, 4) Horizontal translational platform, 5) Treadmill, 6) Computerized Dynamic Posturography, and 7) Other devices. The group discrimination ability of the methods was explored and the conclusions of the studies were briefly summarized. Due to the wide scope of this search, it provides an overview of balancing devices and do not represent the state-of-the-art of any single method. The identified dynamic balancing assessment methods are offered as a catalogue of candidate methods to complement static assessments used in studies involving postural control.

Perceptual video quality assessment in H.264 video coding standard using objective modeling.

PubMed

Karthikeyan, Ramasamy; Sainarayanan, Gopalakrishnan; Deepa, Subramaniam Nachimuthu

2014-01-01

Since usage of digital video is wide spread nowadays, quality considerations have become essential, and industry demand for video quality measurement is rising. This proposal provides a method of perceptual quality assessment in H.264 standard encoder using objective modeling. For this purpose, quality impairments are calculated and a model is developed to compute the perceptual video quality metric based on no reference method. Because of the shuttle difference between the original video and the encoded video the quality of the encoded picture gets degraded, this quality difference is introduced by the encoding process like Intra and Inter prediction. The proposed model takes into account of the artifacts introduced by these spatial and temporal activities in the hybrid block based coding methods and an objective modeling of these artifacts into subjective quality estimation is proposed. The proposed model calculates the objective quality metric using subjective impairments; blockiness, blur and jerkiness compared to the existing bitrate only calculation defined in the ITU G 1070 model. The accuracy of the proposed perceptual video quality metrics is compared against popular full reference objective methods as defined by VQEG.

A novel 360-degree shape measurement using a simple setup with two mirrors and a laser MEMS scanner

NASA Astrophysics Data System (ADS)

Jin, Rui; Zhou, Xiang; Yang, Tao; Li, Dong; Wang, Chao

2017-09-01

There is no denying that 360-degree shape measurement technology plays an important role in the field of threedimensional optical metrology. Traditional optical 360-degree shape measurement methods are mainly two kinds: the first kind, by placing multiple scanners to achieve 360-degree measurements; the second kind, through the high-precision rotating device to get 360-degree shape model. The former increases the number of scanners and costly, while the latter using rotating devices lead to time consuming. This paper presents a low cost and fast optical 360-degree shape measurement method, which possesses the advantages of full static, fast and low cost. The measuring system consists of two mirrors with a certain angle, a laser projection system, a stereoscopic calibration block, and two cameras. And most of all, laser MEMS scanner can achieve precise movement of laser stripes without any movement mechanism, improving the measurement accuracy and efficiency. What's more, a novel stereo calibration technology presented in this paper can achieve point clouds data registration, and then get the 360-degree model of objects. A stereoscopic calibration block with special coded patterns on six sides is used in this novel stereo calibration method. Through this novel stereo calibration technology we can quickly get the 360-degree models of objects.

Measurement of RF lightning emissions

NASA Technical Reports Server (NTRS)

Lott, G. K., Jr.; Honnell, M. A.; Shumpert, T. H.

1981-01-01

A lightning radio emission observation laboratory is described. The signals observed and recorded include HF, VHF and UHF radio emissions, optical signature, electric field measurements, and thunder. The objectives of the station, the equipment used, and the recording methods are discussed.

Studying Food Reward and Motivation in Humans

PubMed Central

Ziauddeen, Hisham; Subramaniam, Naresh; Cambridge, Victoria C.; Medic, Nenad; Farooqi, Ismaa Sadaf; Fletcher, Paul C.

2014-01-01

A key challenge in studying reward processing in humans is to go beyond subjective self-report measures and quantify different aspects of reward such as hedonics, motivation, and goal value in more objective ways. This is particularly relevant for the understanding of overeating and obesity as well as their potential treatments. In this paper are described a set of measures of food-related motivation using handgrip force as a motivational measure. These methods can be used to examine changes in food related motivation with metabolic (satiety) and pharmacological manipulations and can be used to evaluate interventions targeted at overeating and obesity. However to understand food-related decision making in the complex food environment it is essential to be able to ascertain the reward goal values that guide the decisions and behavioral choices that people make. These values are hidden but it is possible to ascertain them more objectively using metrics such as the willingness to pay and a method for this is described. Both these sets of methods provide quantitative measures of motivation and goal value that can be compared within and between individuals. PMID:24686284

Studying food reward and motivation in humans.

PubMed

Ziauddeen, Hisham; Subramaniam, Naresh; Cambridge, Victoria C; Medic, Nenad; Farooqi, Ismaa Sadaf; Fletcher, Paul C

2014-03-19

A key challenge in studying reward processing in humans is to go beyond subjective self-report measures and quantify different aspects of reward such as hedonics, motivation, and goal value in more objective ways. This is particularly relevant for the understanding of overeating and obesity as well as their potential treatments. In this paper are described a set of measures of food-related motivation using handgrip force as a motivational measure. These methods can be used to examine changes in food related motivation with metabolic (satiety) and pharmacological manipulations and can be used to evaluate interventions targeted at overeating and obesity. However to understand food-related decision making in the complex food environment it is essential to be able to ascertain the reward goal values that guide the decisions and behavioral choices that people make. These values are hidden but it is possible to ascertain them more objectively using metrics such as the willingness to pay and a method for this is described. Both these sets of methods provide quantitative measures of motivation and goal value that can be compared within and between individuals.

Guide to the expression of uncertainty in measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathew, Kattathu Joseph

The enabling objectives of this presentation are to: Provide a working knowledge of the ISO GUM method to estimation of uncertainties in safeguards measurements; Introduce GUM terminology; Provide brief historical background of the GUM methodology; Introduce GUM Workbench software; Isotope ratio measurements by MS will be discussed in the next session.

Mindfulness Is Associated with Fewer PTSD Symptoms, Depressive Symptoms, Physical Symptoms, and Alcohol Problems in Urban Firefighters

ERIC Educational Resources Information Center

Smith, Bruce W.; Ortiz, J. Alexis; Steffen, Laurie E.; Tooley, Erin M.; Wiggins, Kathryn T.; Yeater, Elizabeth A.; Montoya, John D.; Bernard, Michael L.

2011-01-01

Objective: This study investigated the association between mindfulness, other resilience resources, and several measures of health in 124 urban firefighters. Method: Participants completed health measures of posttraumatic stress disorder (PTSD) symptoms, depressive symptoms, physical symptoms, and alcohol problems and measures of resilience…

Two-dimensional (2D) displacement measurement of moving objects using a new MEMS binocular vision system

NASA Astrophysics Data System (ADS)

Di, Si; Lin, Hui; Du, Ruxu

2011-05-01

Displacement measurement of moving objects is one of the most important issues in the field of computer vision. This paper introduces a new binocular vision system (BVS) based on micro-electro-mechanical system (MEMS) technology. The eyes of the system are two microlenses fabricated on a substrate by MEMS technology. The imaging results of two microlenses are collected by one complementary metal-oxide-semiconductor (CMOS) array. An algorithm is developed for computing the displacement. Experimental results show that as long as the object is moving in two-dimensional (2D) space, the system can effectively estimate the 2D displacement without camera calibration. It is also shown that the average error of the displacement measurement is about 3.5% at different object distances ranging from 10 cm to 35 cm. Because of its low cost, small size and simple setting, this new method is particularly suitable for 2D displacement measurement applications such as vision-based electronics assembly and biomedical cell culture.

Objective measurement of the optical image quality in the human eye

NASA Astrophysics Data System (ADS)

Navarro, Rafael M.

2001-05-01

This communication reviews some recent studies on the optical performance of the human eye. Although the retinal image cannot be recorded directly, different objective methods have been developed, which permit to determine optical quality parameters, such as the Point Spread Function (PSF), the Modulation Transfer Function (MTF), the geometrical ray aberrations or the wavefront distortions, in the living human eye. These methods have been applied in both basic and applied research. This includes the measurement of the optical performance of the eye across visual field, the optical quality of eyes with intraocular lens implants, the aberrations induced by LASIK refractive surgery, or the manufacture of customized phase plates to compensate the wavefront aberration in the eye.

High-accuracy optical extensometer based on coordinate transform in two-dimensional digital image correlation

NASA Astrophysics Data System (ADS)

Lv, Zeqian; Xu, Xiaohai; Yan, Tianhao; Cai, Yulong; Su, Yong; Zhang, Qingchuan

2018-01-01

In the measurement of plate specimens, traditional two-dimensional (2D) digital image correlation (DIC) is challenged by two aspects: (1) the slant optical axis (misalignment of the optical camera axis and the object surface) and (2) out-of-plane motions (including translations and rotations) of the specimens. There are measurement errors in the results measured by 2D DIC, especially when the out-of-plane motions are big enough. To solve this problem, a novel compensation method has been proposed to correct the unsatisfactory results. The proposed compensation method consists of three main parts: 1) a pre-calibration step is used to determine the intrinsic parameters and lens distortions; 2) a compensation panel (a rigid panel with several markers located at known positions) is mounted to the specimen to track the specimen's motion so that the relative coordinate transformation between the compensation panel and the 2D DIC setup can be calculated using the coordinate transform algorithm; 3) three-dimensional world coordinates of measuring points on the specimen can be reconstructed via the coordinate transform algorithm and used to calculate deformations. Simulations have been carried out to validate the proposed compensation method. Results come out that when the extensometer length is 400 pixels, the strain accuracy reaches 10 με no matter out-of-plane translations (less than 1/200 of the object distance) nor out-of-plane rotations (rotation angle less than 5°) occur. The proposed compensation method leads to good results even when the out-of-plane translation reaches several percents of the object distance or the out-of-plane rotation angle reaches tens of degrees. The proposed compensation method has been applied in tensile experiments to obtain high-accuracy results as well.

Validity and inter-observer reliability of subjective hand-arm vibration assessments.

PubMed

Coenen, Pieter; Formanoy, Margriet; Douwes, Marjolein; Bosch, Tim; de Kraker, Heleen

2014-07-01

Exposure to mechanical vibrations at work (e.g., due to handling powered tools) is a potential occupational risk as it may cause upper extremity complaints. However, reliable and valid assessment methods for vibration exposure at work are lacking. Measuring hand-arm vibration objectively is often difficult and expensive, while often used information provided by manufacturers lacks detail. Therefore, a subjective hand-arm vibration assessment method was tested on validity and inter-observer reliability. In an experimental protocol, sixteen tasks handling powered tools were executed by two workers. Hand-arm vibration was assessed subjectively by 16 observers according to the proposed subjective assessment method. As a gold standard reference, hand-arm vibration was measured objectively using a vibration measurement device. Weighted κ's were calculated to assess validity, intra-class-correlation coefficients (ICCs) were calculated to assess inter-observer reliability. Inter-observer reliability of the subjective assessments depicting the agreement among observers can be expressed by an ICC of 0.708 (0.511-0.873). The validity of the subjective assessments as compared to the gold-standard reference can be expressed by a weighted κ of 0.535 (0.285-0.785). Besides, the percentage of exact agreement of the subjective assessment compared to the objective measurement was relatively low (i.e., 52% of all tasks). This study shows that subjectively assessed hand-arm vibrations are fairly reliable among observers and moderately valid. This assessment method is a first attempt to use subjective risk assessments of hand-arm vibration. Although, this assessment method can benefit from some future improvement, it can be of use in future studies and in field-based ergonomic assessments. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Stereoscopic visual fatigue assessment and modeling

NASA Astrophysics Data System (ADS)

Wang, Danli; Wang, Tingting; Gong, Yue

2014-03-01

Evaluation of stereoscopic visual fatigue is one of the focuses in the user experience research. It is measured in either subjective or objective methods. Objective measures are more preferred for their capability to quantify the degree of human visual fatigue without being affected by individual variation. However, little research has been conducted on the integration of objective indicators, or the sensibility of each objective indicator in reflecting subjective fatigue. The paper proposes a simply effective method to evaluate visual fatigue more objectively. The stereoscopic viewing process is divided into series of sessions, after each of which viewers rate their visual fatigue with subjective scores (SS) according to a five-grading scale, followed by tests of the punctum maximum accommodation (PMA) and visual reaction time (VRT). Throughout the entire viewing process, their eye movements are recorded by an infrared camera. The pupil size (PS) and percentage of eyelid closure over the pupil over time (PERCLOS) are extracted from the videos processed by the algorithm. Based on the method, an experiment with 14 subjects was conducted to assess visual fatigue induced by 3D images on polarized 3D display. The experiment consisted of 10 sessions (5min per session), each containing the same 75 images displayed randomly. The results show that PMA, VRT and PERCLOS are the most efficient indicators of subjective visual fatigue and finally a predictive model is derived from the stepwise multiple regressions.

Laser Doppler vibrometry: new ENT applications

NASA Astrophysics Data System (ADS)

Stasche, Norbert; Baermann, M.; Kempe, C.; Hoermann, Karl; Foth, Hans-Jochen

1996-12-01

Common audiometry often does not really allow a reliable and objective differential diagnosis of hearing disorders such as otosclerosis, adhesive otitis, ossicular interruption or tinnitus, even though several methods might be used complementarily. In recent years, some experimental studies on middle ear mechanics established laser Doppler vibrometry (LDV) as a useful method allowing objective measurement of human tympanic membrane displacement. The present study on LDV investigated the clinical use of this new method under physiological conditions. LDV proved to be a fast, reproducible, non-invasive and very sensitive instrument to characterize ear-drum vibrations in various middle ear dysfunctions, except in tinnitus patients. For future applications, improved optical characteristics of the vibrometer might result in a better differential diagnosis of subjective and objective tinnitus, otoacoustic emissions or Morbus Meniere.

A general purpose wideband optical spatial frequency spectrum analyzer

NASA Technical Reports Server (NTRS)

Ballard, G. S.; Mellor, F. A.

1972-01-01

The light scattered at various angles by a transparent media is studied. An example of these applications is the optical Fourier spectrum measurement resulting from various spatial frequencies which were recorded on a photographic emulsion. A method for obtaining these measurements consists of illuminating the test object with parallel monochromatic light. A stationary lens, placed in the resulting wavefield at a distance of one focal length from the object, will focus parallel waves emanating from the test object at a point lying in the focal plane of the lens. A light detector with a small filtering aperture is then used to measure the intensity variation of the light in the focal or transform plane of the lens. Such measurements require the use of a lens which is highly corrected for all of the common aberrations except chromatic aberration.

Objective Assessment of Vergence after Treatment of Concussion-Related CI: A Pilot Study

PubMed Central

Scheiman, Mitchell; Talasan, Henry; Mitchell, Gladys L; Alvarez, Tara L.

2016-01-01

Purpose To evaluate changes in objective measures of disparity vergence after office-based vision therapy (OBVT) for concussion-related convergence insufficiency (CI), and determine the feasibility of using this objective assessment as an outcome measure in a clinical trial. Methods This was a prospective, observational trial. All participants were treated with weekly OBVT with home reinforcement. Participants included two adolescents and three young adults with concussion-related, symptomatic CI. The primary outcome measure was average peak velocity for 4-degree symmetrical convergence steps. Other objective outcome measures of disparity vergence included time to peak velocity, latency, accuracy, settling time, and main sequence. We also evaluated saccadic eye movements using the same outcome measures. Changes in clinical measures (near point of convergence, positive fusional vergence at near, Convergence Insufficiency Symptom Survey (CISS) score) were evaluated. Results There were statistically significant and clinically meaningful changes in all clinical measures for convergence. Four of the five subjects met clinical success criteria. For the objective measures, we found a statistically significant increase in peak velocity, response accuracy to 4° symmetrical convergence and divergence step stimuli and the main sequence ratio for convergence step stimuli. Objective saccadic eye movements (5° and 10°) appeared normal pre-OBVT, and did not show any significant change after treatment. Conclusions This is the first report of the use of objective measures of disparity vergence as outcome measures for concussion-related convergence insufficiency. These measures provide additional information that is not accessible with clinical tests about underlying physiological mechanisms leading to changes in clinical findings and symptoms. The study results also demonstrate that patients with concussion can tolerate the visual demands (over 200 vergence and versional eye movements) during the 25-minute testing time and suggest that these measures could be used in a large-scale randomized clinical trial of concussion-related CI as outcome measures. PMID:27464574

Verification of micro-scale photogrammetry for smooth three-dimensional object measurement

NASA Astrophysics Data System (ADS)

Sims-Waterhouse, Danny; Piano, Samanta; Leach, Richard

2017-05-01

By using sub-millimetre laser speckle pattern projection we show that photogrammetry systems are able to measure smooth three-dimensional objects with surface height deviations less than 1 μm. The projection of laser speckle patterns allows correspondences on the surface of smooth spheres to be found, and as a result, verification artefacts with low surface height deviations were measured. A combination of VDI/VDE and ISO standards were also utilised to provide a complete verification method, and determine the quality parameters for the system under test. Using the proposed method applied to a photogrammetry system, a 5 mm radius sphere was measured with an expanded uncertainty of 8.5 μm for sizing errors, and 16.6 μm for form errors with a 95 % confidence interval. Sphere spacing lengths between 6 mm and 10 mm were also measured by the photogrammetry system, and were found to have expanded uncertainties of around 20 μm with a 95 % confidence interval.

Measurement of Harm Outcomes in Older Adults after Hospital Discharge: Reliability and Validity

PubMed Central

Douglas, Alison; Letts, Lori; Eva, Kevin; Richardson, Julie

2012-01-01

Objectives. Defining and validating a measure of safety contributes to further validation of clinical measures. The objective was to define and examine the psychometric properties of the outcome “incidents of harm.” Methods. The Incident of Harm Caregiver Questionnaire was administered to caregivers of older adults discharged from hospital by telephone. Caregivers completed daily logs for one month and medical charts were examined. Results. Test-retest reliability (n = 38) was high for the occurrence of an incident of harm (yes/no; kappa = 1.0) and the type of incident (agreement = 100%). Validation against daily logs found no disagreement regarding occurrence or types of incidents. Validation with medical charts found no disagreement regarding incident occurrence and disagreement in half regarding incident type. Discussion. The data support the Incident of Harm Caregiver Questionnaire as a reliable and valid estimation of incidents for this sample and are important to researchers as a method to measure safety when validating clinical measures. PMID:22649728

Irregular and adaptive sampling for automatic geophysic measure systems

NASA Astrophysics Data System (ADS)

Avagnina, Davide; Lo Presti, Letizia; Mulassano, Paolo

2000-07-01

In this paper a sampling method, based on an irregular and adaptive strategy, is described. It can be used as automatic guide for rovers designed to explore terrestrial and planetary environments. Starting from the hypothesis that a explorative vehicle is equipped with a payload able to acquire measurements of interesting quantities, the method is able to detect objects of interest from measured points and to realize an adaptive sampling, while badly describing the not interesting background.

Simple Radiowave-Based Method For Measuring Peripheral Blood Flow Project

NASA Technical Reports Server (NTRS)

Oliva-Buisson, Yvette J.

2014-01-01

Project objective is to design small radio frequency based flow probes for the measurement of blood flow velocity in peripheral arteries such as the femoral artery and middle cerebral artery. The result will be the technological capability to measure peripheral blood flow rates and flow changes during various environmental stressors such as microgravity without contact to the individual being monitored. This technology may also lead to an easier method of detecting venous gas emboli during extravehicular activities.

MR Image Analytics to Characterize the Upper Airway Structure in Obese Children with Obstructive Sleep Apnea Syndrome

PubMed Central

Tong, Yubing; Udupa, Jayaram K.; Sin, Sanghun; Liu, Zhengbing; Wileyto, E. Paul; Torigian, Drew A.; Arens, Raanan

2016-01-01

Purpose Quantitative image analysis in previous research in obstructive sleep apnea syndrome (OSAS) has focused on the upper airway or several objects in its immediate vicinity and measures of object size. In this paper, we take a more general approach of considering all major objects in the upper airway region and measures pertaining to their individual morphological properties, their tissue characteristics revealed by image intensities, and the 3D architecture of the object assembly. We propose a novel methodology to select a small set of salient features from this large collection of measures and demonstrate the ability of these features to discriminate with very high prediction accuracy between obese OSAS and obese non-OSAS groups. Materials and Methods Thirty children were involved in this study with 15 in the obese OSAS group with an apnea-hypopnea index (AHI) = 14.4 ± 10.7) and 15 in the obese non-OSAS group with an AHI = 1.0 ± 1.0 (p<0.001). Subjects were between 8–17 years and underwent T1- and T2-weighted magnetic resonance imaging (MRI) of the upper airway during wakefulness. Fourteen objects in the vicinity of the upper airways were segmented in these images and a total of 159 measurements were derived from each subject image which included object size, surface area, volume, sphericity, standardized T2-weighted image intensity value, and inter-object distances. A small set of discriminating features was identified from this set in several steps. First, a subset of measures that have a low level of correlation among the measures was determined. A heat map visualization technique that allows grouping of parameters based on correlations among them was used for this purpose. Then, through T-tests, another subset of measures which are capable of separating the two groups was identified. The intersection of these subsets yielded the final feature set. The accuracy of these features to perform classification of unseen images into the two patient groups was tested by using logistic regression and multi-fold cross validation. Results A set of 16 features identified with low inter-feature correlation (< 0.36) yielded a high classification accuracy of 96% with sensitivity and specificity of 97.8% and 94.4%, respectively. In addition to the previously observed increase in linear size, surface area, and volume of adenoid, tonsils, and fat pad in OSAS, the following new markers have been found. Standardized T2-weighted image intensities differed between the two groups for the entire neck body region, pharynx, and nasopharynx, possibly indicating changes in object tissue characteristics. Fat pad and oropharynx become less round or more complex in shape in OSAS. Fat pad and tongue move closer in OSAS, and so also oropharynx and tonsils and fat pad and tonsils. In contrast, fat pad and oropharynx move farther apart from the skin object. Conclusions The study has found several new anatomic bio-markers of OSAS. Changes in standardized T2-weighted image intensities in objects may imply that intrinsic tissue composition undergoes changes in OSAS. The results on inter-object distances imply that treatment methods should respect the relationships that exist among objects and not just their size. The proposed method of analysis may lead to an improved understanding of the mechanisms underlying OSAS. PMID:27487240

AEGIS and Ship Self-Defense System (SSDS) Platforms: Using KVA Analysis, Risk Simulation and Strategic Real Options to Assess Operational Effectiveness

DTIC Science & Technology

2007-04-30

numerous reengineering projects and developed a new objective method for objectively measuring the value-added by reengineering. His last assignment...in the corporate world was as the Chief of Consumer Market Research for Telecom Italia in Venice, Italy, where he developed new methods for ...predicting the adoption rates for new interactive multimedia broadband applications. He is Managing Partner for Business Process Auditors, a firm that

Evaluation of Psychological Hardiness and Coping Style as Risk/Resilience Factors for Health Risk Behaviour

DTIC Science & Technology

2011-04-01

205 RESEARCH DESIGN & METHODS Objective/Hypothesis: The objective of the study is to evaluate the utility of a short hardiness-resilience...problems. Study Design & Methods : This research will evaluate the utility of hardiness, as measured by the DRS-15R, as a screening tool for...may take a toll on defense workers. This research points the way to new approaches for early identification of military workers at risk for stress

Automated Calibration For Numerical Models Of Riverflow

NASA Astrophysics Data System (ADS)

Fernandez, Betsaida; Kopmann, Rebekka; Oladyshkin, Sergey

2017-04-01

Calibration of numerical models is fundamental since the beginning of all types of hydro system modeling, to approximate the parameters that can mimic the overall system behavior. Thus, an assessment of different deterministic and stochastic optimization methods is undertaken to compare their robustness, computational feasibility, and global search capacity. Also, the uncertainty of the most suitable methods is analyzed. These optimization methods minimize the objective function that comprises synthetic measurements and simulated data. Synthetic measurement data replace the observed data set to guarantee an existing parameter solution. The input data for the objective function derivate from a hydro-morphological dynamics numerical model which represents an 180-degree bend channel. The hydro- morphological numerical model shows a high level of ill-posedness in the mathematical problem. The minimization of the objective function by different candidate methods for optimization indicates a failure in some of the gradient-based methods as Newton Conjugated and BFGS. Others reveal partial convergence, such as Nelder-Mead, Polak und Ribieri, L-BFGS-B, Truncated Newton Conjugated, and Trust-Region Newton Conjugated Gradient. Further ones indicate parameter solutions that range outside the physical limits, such as Levenberg-Marquardt and LeastSquareRoot. Moreover, there is a significant computational demand for genetic optimization methods, such as Differential Evolution and Basin-Hopping, as well as for Brute Force methods. The Deterministic Sequential Least Square Programming and the scholastic Bayes Inference theory methods present the optimal optimization results. keywords: Automated calibration of hydro-morphological dynamic numerical model, Bayesian inference theory, deterministic optimization methods.

Mobile micro-colorimeter and micro-spectrometer sensor modules as enablers for the replacement of subjective inspections by objective measurements for optically clear colored liquids in-field

NASA Astrophysics Data System (ADS)

Dittrich, Paul-Gerald; Grunert, Fred; Ehehalt, Jörg; Hofmann, Dietrich

2015-03-01

Aim of the paper is to show that the colorimetric characterization of optically clear colored liquids can be performed with different measurement methods and their application specific multichannel spectral sensors. The possible measurement methods are differentiated by the applied types of multichannel spectral sensors and therefore by their spectral resolution, measurement speed, measurement accuracy and measurement costs. The paper describes how different types of multichannel spectral sensors are calibrated with different types of calibration methods and how the measurement values can be used for further colorimetric calculations. The different measurement methods and the different application specific calibration methods will be explained methodically and theoretically. The paper proofs that and how different multichannel spectral sensor modules with different calibration methods can be applied with smartpads for the calculation of measurement results both in laboratory and in field. A given practical example is the application of different multichannel spectral sensors for the colorimetric characterization of petroleum oils and fuels and their colorimetric characterization by the Saybolt color scale.

Effects of Objective 3-Dimensional Measures of Facial Shape and Symmetry on Perceptions of Facial Attractiveness.

PubMed

Hatch, Cory D; Wehby, George L; Nidey, Nichole L; Moreno Uribe, Lina M

2017-09-01

Meeting patient desires for enhanced facial esthetics requires that providers have standardized and objective methods to measure esthetics. The authors evaluated the effects of objective 3-dimensional (3D) facial shape and asymmetry measurements derived from 3D facial images on perceptions of facial attractiveness. The 3D facial images of 313 adults in Iowa were digitized with 32 landmarks, and objective 3D facial measurements capturing symmetric and asymmetric components of shape variation, centroid size, and fluctuating asymmetry were obtained from the 3D coordinate data using geo-morphometric analyses. Frontal and profile images of study participants were rated for facial attractiveness by 10 volunteers (5 women and 5 men) on a 5-point Likert scale and a visual analog scale. Multivariate regression was used to identify the effects of the objective 3D facial measurements on attractiveness ratings. Several objective 3D facial measurements had marked effects on attractiveness ratings. Shorter facial heights with protrusive chins, midface retrusion, faces with protrusive noses and thin lips, flat mandibular planes with deep labiomental folds, any cants of the lip commissures and floor of the nose, larger faces overall, and increased fluctuating asymmetry were rated as significantly (P < .001) less attractive. Perceptions of facial attractiveness can be explained by specific 3D measurements of facial shapes and fluctuating asymmetry, which have important implications for clinical practice and research. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

A kernel-based novelty detection scheme for the ultra-fast detection of chirp evoked Auditory Brainstem Responses.

PubMed

Corona-Strauss, Farah I; Delb, Wolfgang; Schick, Bernhard; Strauss, Daniel J

2010-01-01

Auditory Brainstem Responses (ABRs) are used as objective method for diagnostics and quantification of hearing loss. Many methods for automatic recognition of ABRs have been developed, but none of them include the individual measurement setup in the analysis. The purpose of this work was to design a fast recognition scheme for chirp-evoked ABRs that is adjusted to the individual measurement condition using spontaneous electroencephalographic activity (SA). For the classification, the kernel-based novelty detection scheme used features based on the inter-sweep instantaneous phase synchronization as well as energy and entropy relations in the time-frequency domain. This method provided SA discrimination from stimulations above the hearing threshold with a minimum number of sweeps, i.e., 200 individual responses. It is concluded that the proposed paradigm, processing procedures and stimulation techniques improve the detection of ABRs in terms of the degree of objectivity, i.e., automation of procedure, and measurement time.

Robust Dynamic Multi-objective Vehicle Routing Optimization Method.

PubMed

Guo, Yi-Nan; Cheng, Jian; Luo, Sha; Gong, Dun-Wei

2017-03-21

For dynamic multi-objective vehicle routing problems, the waiting time of vehicle, the number of serving vehicles, the total distance of routes were normally considered as the optimization objectives. Except for above objectives, fuel consumption that leads to the environmental pollution and energy consumption was focused on in this paper. Considering the vehicles' load and the driving distance, corresponding carbon emission model was built and set as an optimization objective. Dynamic multi-objective vehicle routing problems with hard time windows and randomly appeared dynamic customers, subsequently, were modeled. In existing planning methods, when the new service demand came up, global vehicle routing optimization method was triggered to find the optimal routes for non-served customers, which was time-consuming. Therefore, robust dynamic multi-objective vehicle routing method with two-phase is proposed. Three highlights of the novel method are: (i) After finding optimal robust virtual routes for all customers by adopting multi-objective particle swarm optimization in the first phase, static vehicle routes for static customers are formed by removing all dynamic customers from robust virtual routes in next phase. (ii)The dynamically appeared customers append to be served according to their service time and the vehicles' statues. Global vehicle routing optimization is triggered only when no suitable locations can be found for dynamic customers. (iii)A metric measuring the algorithms' robustness is given. The statistical results indicated that the routes obtained by the proposed method have better stability and robustness, but may be sub-optimum. Moreover, time-consuming global vehicle routing optimization is avoided as dynamic customers appear.

Quantitative vibro-acoustography of tissue-like objects by measurement of resonant modes

NASA Astrophysics Data System (ADS)

Mazumder, Dibbyan; Umesh, Sharath; Mohan Vasu, Ram; Roy, Debasish; Kanhirodan, Rajan; Asokan, Sundarrajan

2017-01-01

We demonstrate a simple and computationally efficient method to recover the shear modulus pertaining to the focal volume of an ultrasound transducer from the measured vibro-acoustic spectral peaks. A model that explains the transport of local deformation information with the acoustic wave acting as a carrier is put forth. It is also shown that the peaks correspond to the natural frequencies of vibration of the focal volume, which may be readily computed by solving an eigenvalue problem associated with the vibrating region. Having measured the first natural frequency with a fibre Bragg grating sensor, and armed with an expedient means of computing the same, we demonstrate a simple procedure, based on the method of bisection, to recover the average shear modulus of the object in the ultrasound focal volume. We demonstrate this recovery for four homogeneous agarose slabs of different stiffness and verify the accuracy of the recovery using independent rheometer-based measurements. Extension of the method to anisotropic samples through the measurement of a more complete set of resonant modes and the recovery of an elasticity tensor distribution, as is done in resonant ultrasound spectroscopy, is suggested.

Analysis of pressure-flow data in terms of computer-derived urethral resistance parameters.

PubMed

van Mastrigt, R; Kranse, M

1995-01-01

The simultaneous measurement of detrusor pressure and flow rate during voiding is at present the only way to measure or grade infravesical obstruction objectively. Numerous methods have been introduced to analyze the resulting data. These methods differ in aim (measurement of urethral resistance and/or diagnosis of obstruction), method (manual versus computerized data processing), theory or model used, and resolution (continuously variable parameters or a limited number of classes, the so-called monogram). In this paper, some aspects of these fundamental differences are discussed and illustrated. Subsequently, the properties and clinical performance of two computer-based methods for deriving continuous urethral resistance parameters are treated.

Gamma/x-ray linear pushbroom stereo for 3D cargo inspection

NASA Astrophysics Data System (ADS)

Zhu, Zhigang; Hu, Yu-Chi

2006-05-01

For evaluating the contents of trucks, containers, cargo, and passenger vehicles by a non-intrusive gamma-ray or X-ray imaging system to determine the possible presence of contraband, three-dimensional (3D) measurements could provide more information than 2D measurements. In this paper, a linear pushbroom scanning model is built for such a commonly used gamma-ray or x-ray cargo inspection system. Accurate 3D measurements of the objects inside a cargo can be obtained by using two such scanning systems with different scanning angles to construct a pushbroom stereo system. A simple but robust calibration method is proposed to find the important parameters of the linear pushbroom sensors. Then, a fast and automated stereo matching algorithm based on free-form deformable registration is developed to obtain 3D measurements of the objects under inspection. A user interface is designed for 3D visualization of the objects in interests. Experimental results of sensor calibration, stereo matching, 3D measurements and visualization of a 3D cargo container and the objects inside, are presented.

WE-AB-209-07: Explicit and Convex Optimization of Plan Quality Metrics in Intensity-Modulated Radiation Therapy Treatment Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engberg, L; KTH Royal Institute of Technology, Stockholm; Eriksson, K

Purpose: To formulate objective functions of a multicriteria fluence map optimization model that correlate well with plan quality metrics, and to solve this multicriteria model by convex approximation. Methods: In this study, objectives of a multicriteria model are formulated to explicitly either minimize or maximize a dose-at-volume measure. Given the widespread agreement that dose-at-volume levels play important roles in plan quality assessment, these objectives correlate well with plan quality metrics. This is in contrast to the conventional objectives, which are to maximize clinical goal achievement by relating to deviations from given dose-at-volume thresholds: while balancing the new objectives means explicitlymore » balancing dose-at-volume levels, balancing the conventional objectives effectively means balancing deviations. Constituted by the inherently non-convex dose-at-volume measure, the new objectives are approximated by the convex mean-tail-dose measure (CVaR measure), yielding a convex approximation of the multicriteria model. Results: Advantages of using the convex approximation are investigated through juxtaposition with the conventional objectives in a computational study of two patient cases. Clinical goals of each case respectively point out three ROI dose-at-volume measures to be considered for plan quality assessment. This is translated in the convex approximation into minimizing three mean-tail-dose measures. Evaluations of the three ROI dose-at-volume measures on Pareto optimal plans are used to represent plan quality of the Pareto sets. Besides providing increased accuracy in terms of feasibility of solutions, the convex approximation generates Pareto sets with overall improved plan quality. In one case, the Pareto set generated by the convex approximation entirely dominates that generated with the conventional objectives. Conclusion: The initial computational study indicates that the convex approximation outperforms the conventional objectives in aspects of accuracy and plan quality.« less

Optical methods for non-contact measurements of membranes

NASA Astrophysics Data System (ADS)

Roose, S.; Stockman, Y.; Rochus, P.; Kuhn, T.; Lang, M.; Baier, H.; Langlois, S.; Casarosa, G.

2009-11-01

Structures for space applications very often suffer stringent mass constraints. Lightweight structures are developed for this purpose, through the use of deployable and/or inflatable beams, and thin-film membranes. Their inherent properties (low mass and small thickness) preclude the use of conventional measurement methods (accelerometers and displacement transducers for example) during on-ground testing. In this context, innovative non-contact measurement methods need to be investigated for these stretched membranes. The object of the present project is to review existing measurement systems capable of measuring characteristics of membrane space-structures such as: dot-projection videogrammetry (static measurements), stereo-correlation (dynamic and static measurements), fringe projection (wrinkles) and 3D laser scanning vibrometry (dynamic measurements). Therefore, minimum requirements were given for the study in order to have representative test articles covering a wide range of applications. We present test results obtained with the different methods on our test articles.

A method of measuring rainfall on windy slopes

Treesearch

G. L. Hayes

1944-01-01

The object of precipitation measurement, as stated by Brooks (1), is to obtain "a fair sample of the fall reaching the earth's surface over the area represented by the measurement." The area referred to is horizontal, or map area. Even when measured on a slope, precipitation is always expressed as depth of water on a horizontal area.

Library Objectives and Performance Measures and Their Use in Decision Making

ERIC Educational Resources Information Center

Hamburg, Morris; And Others

1972-01-01

For optimal allocations of limited funds, it is necessary for libraries to develop measures of output. Various forms of user exposure to documents are discussed in an effort to develop such measures for public libraries. It is suggested that the accrual method of accounting be used to compare such measures with costs. (40 references) (Author/NH)

Validation of a Measure of College Students' Intoxicated Behaviors: Associations with Alcohol Outcome Expectancies, Drinking Motives, and Personality

ERIC Educational Resources Information Center

Westmaas, Johann; Moeller, Scott; Woicik, Patricia Butler

2007-01-01

Objective: The authors aimed to develop a measure of college students' intoxicated behaviors and to validate the measure using scales assessing alcohol outcome expectancies, motives for drinking, and personality traits. Participants and Method Summary: The authors administered these measures and an inventory describing 50 intoxicated behaviors to…

The Inventory Of High Objects Applying Laser Scanning, Focus On The Cataloguing A Reinforced Concrete Industrial Chimney

NASA Astrophysics Data System (ADS)

Gawałkiewicz, Rafał

2015-12-01

There are many surveying methods to measure the inclination of a chimney with the use of classical protractor instruments (Theo 010A/B, T2 Wild), electronic theodolites (TC2002 Wild-Leica), electronic total stations, including mirrorless ones, allowing to define indirectly the course of the construction's axis on the selected observation levels. The methods are the following: indentations, direct projection, double-edged method, polar method with the option of mirrorless measurement. At the moment a very practical and quick measurement technology, significantly eliminating the influence of human errors on the observation results, is laser scanning. The article presents the results of the scanning of 120-metres high reinforced concrete industrial chimney of the Cement Plant "Ożarów", with the application of modern scanning total station VX Spatial Station by Trimble, as an alternative to the methods applied so far. The advantage of scanning is the possibility to obtain a point cloud, which, apart from the information on the course of the chimney axis in the space, provides detail information on the real shape and deformations of the coating of the object's core.

Acoustic Treatment Design Scaling Methods. Volume 1; Overview, Results, and Recommendations

NASA Technical Reports Server (NTRS)

Kraft, R. E.; Yu, J.

1999-01-01

Scale model fan rigs that simulate new generation ultra-high-bypass engines at about 1/5-scale are achieving increased importance as development vehicles for the design of low-noise aircraft engines. Testing at small scale allows the tests to be performed in existing anechoic wind tunnels, which provides an accurate simulation of the important effects of aircraft forward motion on the noise generation. The ability to design, build, and test miniaturized acoustic treatment panels on scale model fan rigs representative of the fullscale engine provides not only a cost-savings, but an opportunity to optimize the treatment by allowing tests of different designs. The primary objective of this study was to develop methods that will allow scale model fan rigs to be successfully used as acoustic treatment design tools. The study focuses on finding methods to extend the upper limit of the frequency range of impedance prediction models and acoustic impedance measurement methods for subscale treatment liner designs, and confirm the predictions by correlation with measured data. This phase of the program had as a goal doubling the upper limit of impedance measurement from 6 kHz to 12 kHz. The program utilizes combined analytical and experimental methods to achieve the objectives.

Measuring the Environment for Friendliness Toward Physical Activity: A Comparison of the Reliability of 3 Questionnaires

PubMed Central

Brownson, Ross C.; Chang, Jen Jen; Eyler, Amy A.; Ainsworth, Barbara E.; Kirtland, Karen A.; Saelens, Brian E.; Sallis, James F.

2004-01-01

Objectives. We tested the reliability of 3 instruments that assessed social and physical environments. Methods. We conducted a test–retest study among US adults (n = 289). We used telephone survey methods to measure suitableness of the perceived (vs objective) environment for recreational physical activity and nonmotorized transportation. Results. Most questions in our surveys that attempted to measure specific characteristics of the built environment showed moderate to high reliability. Questions about the social environment showed lower reliability than those that assessed the physical environment. Certain blocks of questions appeared to be selectively more reliable for urban or rural respondents. Conclusions. Despite differences in content and in response formats, all 3 surveys showed evidence of reliability, and most items are now ready for use in research and in public health surveillance. PMID:14998817

The production and quality of tomato concentrates.

PubMed

Hayes, W A; Smith, P G; Morris, A E

1998-10-01

The standards and specifications for the quality and composition of tomato concentrates are reviewed. The main quality parameters of tomato puree and paste are color, consistency and flavor. Overall, there is an absence of standardization of methods and instruments to define quality. While color can now be measured objectively, there are currently no standard color requirements for tomato concentrates. Rheological measurements on both tomato juice and concentrates are reviewed; the power law finds wide applicability, although other rheological characteristics, particularly time dependency, have received far less attention and there has been little effort to relate rheological understanding to the commonly used empirical tests such as consistency measurements. The volatiles responsible for flavor and odor have been identified to the point where the natural odor of tomato paste can be imitated. Attempts to develop objective methods as a substitute for sensory assessment are reviewed.

Discharge rate measurements in a canal using radiotracer methods.

PubMed

Pant, H J; Goswami, Sunil; Biswal, Jayashree; Samantray, J S; Sharma, V K

2016-06-01

Discharge rates of water were measured in a canal using radiotracer methods with an objective to validate the efficacy of Concrete Volute Pumps (CVPs) installed at various pumping stations along the canal. Pulse velocity and dilution methods were applied to measure the discharge rates using Iodine-131 as a radiotracer. The discharge rate measured in one of the sections of the canal using the pulse velocity method was found to be 22.5m(3)/s, whereas the discharge rates measured using the dilution method in four different sections of the canal varied from 20.27 to 20.62m(3)/s with single CVP in operation. The standard error in discharge rate measurements using dilution method ranged from ±1.1 to ±1.8%. The experimentally measured values of the discharge rate were in good agreement with the design value of the discharge rate (20m(3)/s) thus validating the performance of the CVPs used in the canal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Associations between Moderate-to-Vigorous Physical Activity and Neighbourhood Recreational Facilities: The Features of the Facilities Matter

PubMed Central

Lee, Ka Yiu; Lee, Paul H.; Macfarlane, Duncan

2014-01-01

Objectives: To examine the associations between objectively-assessed moderate-to-vigorous physical activity (MVPA) and perceived/objective measures of neighbourhood recreational facilities categorized into indoor or outdoor, public, residential or commercial facilities. The associations between facility perceptions and objectively-assessed numbers of recreational facilities were also examined. Method: A questionnaire was used on 480 adults to measure local facility perceptions, with 154 participants wearing ActiGraph accelerometers for ≥4 days. The objectively-assessed number of neighbourhood recreational facilities were examined using direct observations and Geographical Information System data. Results: Both positive and negative associations were found between MVPA and perceived/objective measures of recreational facilities. Some associations depended on whether the recreational facilities were indoor or outdoor, public or residential facilities. The objectively-assessed number of most public recreational facilities was associated with the corresponding facility perceptions, but the size of effect was generally lower than for residential recreational facilities. Conclusions: The objectively-assessed number of residential outdoor table tennis courts and public indoor swimming pools, the objectively-assessed presence of tennis courts and swimming pools, and the perceived presence of bike lanes and swimming pools were positive determinants of MVPA. It is suggested to categorize the recreational facilities into smaller divisions in order to identify unique associations with MVPA. PMID:25485980

Review of 3d GIS Data Fusion Methods and Progress

NASA Astrophysics Data System (ADS)

Hua, Wei; Hou, Miaole; Hu, Yungang

2018-04-01

3D data fusion is a research hotspot in the field of computer vision and fine mapping, and plays an important role in fine measurement, risk monitoring, data display and other processes. At present, the research of 3D data fusion in the field of Surveying and mapping focuses on the 3D model fusion of terrain and ground objects. This paper summarizes the basic methods of 3D data fusion of terrain and ground objects in recent years, and classified the data structure and the establishment method of 3D model, and some of the most widely used fusion methods are analysed and commented.

Highlight removal based on the regional-projection fringe projection method

NASA Astrophysics Data System (ADS)

Qi, Zhaoshuai; Wang, Zhao; Huang, Junhui; Xing, Chao; Gao, Jianmin

2018-04-01

In fringe projection profilometry, highlight usually causes the saturation and blooming in captured fringes and reduces the measurement accuracy. To solve the problem, a regional-projection fringe projection (RP-FP) method is proposed. Regional projection patterns (RP patterns) are projected onto the tested object surface to avoid the saturation and blooming. Then, an image inpainting technique is employed to reconstruct the missing phases in the captured RP patterns and a complete surface of the tested object is obtained. Experiments verified the effectiveness of the proposed method. The method can be widely used in industrial inspections and quality controlling in mechanical and manufacturing industries.

Multi-objective and Perishable Fuzzy Inventory Models Having Weibull Life-time With Time Dependent Demand, Demand Dependent Production and Time Varying Holding Cost: A Possibility/Necessity Approach

NASA Astrophysics Data System (ADS)

Pathak, Savita; Mondal, Seema Sarkar

2010-10-01

A multi-objective inventory model of deteriorating item has been developed with Weibull rate of decay, time dependent demand, demand dependent production, time varying holding cost allowing shortages in fuzzy environments for non- integrated and integrated businesses. Here objective is to maximize the profit from different deteriorating items with space constraint. The impreciseness of inventory parameters and goals for non-integrated business has been expressed by linear membership functions. The compromised solutions are obtained by different fuzzy optimization methods. To incorporate the relative importance of the objectives, the different cardinal weights crisp/fuzzy have been assigned. The models are illustrated with numerical examples and results of models with crisp/fuzzy weights are compared. The result for the model assuming them to be integrated business is obtained by using Generalized Reduced Gradient Method (GRG). The fuzzy integrated model with imprecise inventory cost is formulated to optimize the possibility necessity measure of fuzzy goal of the objective function by using credibility measure of fuzzy event by taking fuzzy expectation. The results of crisp/fuzzy integrated model are illustrated with numerical examples and results are compared.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence

NASA Astrophysics Data System (ADS)

Krishnendu, N. V.; Arun, K. G.; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

Testing the Binary Black Hole Nature of a Compact Binary Coalescence.

PubMed

Krishnendu, N V; Arun, K G; Mishra, Chandra Kant

2017-09-01

We propose a novel method to test the binary black hole nature of compact binaries detectable by gravitational wave (GW) interferometers and, hence, constrain the parameter space of other exotic compact objects. The spirit of the test lies in the "no-hair" conjecture for black holes where all properties of a Kerr black hole are characterized by its mass and spin. The method relies on observationally measuring the quadrupole moments of the compact binary constituents induced due to their spins. If the compact object is a Kerr black hole (BH), its quadrupole moment is expressible solely in terms of its mass and spin. Otherwise, the quadrupole moment can depend on additional parameters (such as the equation of state of the object). The higher order spin effects in phase and amplitude of a gravitational waveform, which explicitly contains the spin-induced quadrupole moments of compact objects, hence, uniquely encode the nature of the compact binary. Thus, we argue that an independent measurement of the spin-induced quadrupole moment of the compact binaries from GW observations can provide a unique way to distinguish binary BH systems from binaries consisting of exotic compact objects.

MRT letter: Guided filtering of image focus volume for 3D shape recovery of microscopic objects.

PubMed

Mahmood, Muhammad Tariq

2014-12-01

In this letter, a shape from focus (SFF) method is proposed that utilizes the guided image filtering to enhance the image focus volume efficiently. First, image focus volume is computed using a conventional focus measure. Then each layer of image focus volume is filtered using guided filtering. In this work, the all-in-focus image, which can be obtained from the initial focus volume, is used as guidance image. Finally, improved depth map is obtained from the filtered image focus volume by maximizing the focus measure along the optical axis. The proposed SFF method is efficient and provides better depth maps. The improved performance is highlighted by conducting several experiments using image sequences of simulated and real microscopic objects. The comparative analysis demonstrates the effectiveness of the proposed SFF method. © 2014 Wiley Periodicals, Inc.

Calibration and evaluation of a nuclear density and moisture measuring apparatus.

DOT National Transportation Integrated Search

1963-11-01

The research objectives of this project were to investigate a new : method of in-place determination of soils densities and moisture levels : employing a nuclear physics principle of the gamma radiation function as : the measurement technique, with s...

Objective comparison of particle tracking methods

PubMed Central

Chenouard, Nicolas; Smal, Ihor; de Chaumont, Fabrice; Maška, Martin; Sbalzarini, Ivo F.; Gong, Yuanhao; Cardinale, Janick; Carthel, Craig; Coraluppi, Stefano; Winter, Mark; Cohen, Andrew R.; Godinez, William J.; Rohr, Karl; Kalaidzidis, Yannis; Liang, Liang; Duncan, James; Shen, Hongying; Xu, Yingke; Magnusson, Klas E. G.; Jaldén, Joakim; Blau, Helen M.; Paul-Gilloteaux, Perrine; Roudot, Philippe; Kervrann, Charles; Waharte, François; Tinevez, Jean-Yves; Shorte, Spencer L.; Willemse, Joost; Celler, Katherine; van Wezel, Gilles P.; Dan, Han-Wei; Tsai, Yuh-Show; de Solórzano, Carlos Ortiz; Olivo-Marin, Jean-Christophe; Meijering, Erik

2014-01-01

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Since manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized, for the first time, an open competition, in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to important practical conclusions for users and developers. PMID:24441936

Self-recalibration of a robot-assisted structured-light-based measurement system.

PubMed

Xu, Jing; Chen, Rui; Liu, Shuntao; Guan, Yong

2017-11-10

The structured-light-based measurement method is widely employed in numerous fields. However, for industrial inspection, to achieve complete scanning of a work piece and overcome occlusion, the measurement system needs to be moved to different viewpoints. Moreover, frequent reconfiguration of the measurement system may be needed based on the size of the measured object, making the self-recalibration of extrinsic parameters indispensable. To this end, this paper proposes an automatic self-recalibration and reconstruction method, wherein a robot arm is employed to move the measurement system for complete scanning; the self-recalibration is achieved using fundamental matrix calculations and point cloud registration without the need for an accurate calibration gauge. Experimental results demonstrate the feasibility and accuracy of our method.

Tele-autonomous control involving contacts: The applications of a high precision laser line range sensor

NASA Technical Reports Server (NTRS)

Volz, R. A.; Shao, L.; Walker, M. W.; Conway, L. A.

1989-01-01

The object localization algorithm based on line-segment matching is presented. The method is very simple and computationally fast. In most cases, closed-form formulas are used to derive the solution. The method is also quite flexible, because only few surfaces (one or two) need to be accessed (sensed) to gather necessary range data. For example, if the line-segments are extracted from boundaries of a planar surface, only parameters of one surface and two of its boundaries need to be extracted, as compared with traditional point-surface matching or line-surface matching algorithms which need to access at least three surfaces in order to locate a planar object. Therefore, this method is especially suitable for applications when an object is surrounded by many other work pieces and most of the object is very difficult, is not impossible, to be measured; or when not all parts of the object can be reached. The theoretical ground on how to use line range sensor to located an object was laid. Much work has to be done in order to be really useful.

Relevant Scatterers Characterization in SAR Images

NASA Astrophysics Data System (ADS)

Chaabouni, Houda; Datcu, Mihai

2006-11-01

Recognizing scenes in a single look meter resolution Synthetic Aperture Radar (SAR) images, requires the capability to identify relevant signal signatures in condition of variable image acquisition geometry, arbitrary objects poses and configurations. Among the methods to detect relevant scatterers in SAR images, we can mention the internal coherence. The SAR spectrum splitted in azimuth generates a series of images which preserve high coherence only for particular object scattering. The detection of relevant scatterers can be done by correlation study or Independent Component Analysis (ICA) methods. The present article deals with the state of the art for SAR internal correlation analysis and proposes further extensions using elements of inference based on information theory applied to complex valued signals. The set of azimuth looks images is analyzed using mutual information measures and an equivalent channel capacity is derived. The localization of the "target" requires analysis in a small image window, thus resulting in imprecise estimation of the second order statistics of the signal. For a better precision, a Hausdorff measure is introduced. The method is applied to detect and characterize relevant objects in urban areas.

Digital imaging and image analysis applied to numerical applications in forensic hair examination.

PubMed

Brooks, Elizabeth; Comber, Bruce; McNaught, Ian; Robertson, James

2011-03-01

A method that provides objective data to complement the hair analysts' microscopic observations, which is non-destructive, would be of obvious benefit in the forensic examination of hairs. This paper reports on the use of objective colour measurement and image analysis techniques of auto-montaged images. Brown Caucasian telogen scalp hairs were chosen as a stern test of the utility of these approaches. The results show the value of using auto-montaged images and the potential for the use of objective numerical measures of colour and pigmentation to complement microscopic observations. 2010. Published by Elsevier Ireland Ltd. All rights reserved.

AIR MONITOR SITING BY OBJECTIVE

EPA Science Inventory

A method is developed whereby measured pollutant concentrations can be used in conjunction with a mathematical air quality model to estimate the full spatial and temporal concentration distributions of the pollutants over a given region. The method is based on the application of ...

Automated delay estimation at signalized intersections : phase I concept and algorithm development.

DOT National Transportation Integrated Search

2011-07-01

Currently there are several methods to measure the performance of surface streets, but their capabilities in dynamically estimating vehicle delay are limited. The objective of this research is to develop a method to automate traffic delay estimation ...

WATER CHEMISTRY ASSESSMENT METHODS

EPA Science Inventory

This section summarizes and evaluates the surfce water column chemistry assessment methods for USEPA/EMAP-SW, USGS-NAQA, USEPA-RBP, Oho EPA, and MDNR-MBSS. The basic objective of surface water column chemistry assessment is to characterize surface water quality by measuring a sui...

A study of methods to predict and measure the transmission of sound through the walls of light aircraft

NASA Technical Reports Server (NTRS)

Bernhard, R. J.; Bolton, J. S.

1988-01-01

The objectives are: measurement of dynamic properties of acoustical foams and incorporation of these properties in models governing three-dimensional wave propagation in foams; tests to measure sound transmission paths in the HP137 Jetstream 3; and formulation of a finite element energy model. In addition, the effort to develop a numerical/empirical noise source identification technique was completed. The investigation of a design optimization technique for active noise control was also completed. Monthly progress reports which detail the progress made toward each of the objectives are summarized.

Comparative analysis of autofocus functions in digital in-line phase-shifting holography.

PubMed

Fonseca, Elsa S R; Fiadeiro, Paulo T; Pereira, Manuela; Pinheiro, António

2016-09-20

Numerical reconstruction of digital holograms relies on a precise knowledge of the original object position. However, there are a number of relevant applications where this parameter is not known in advance and an efficient autofocusing method is required. This paper addresses the problem of finding optimal focusing methods for use in reconstruction of digital holograms of macroscopic amplitude and phase objects, using digital in-line phase-shifting holography in transmission mode. Fifteen autofocus measures, including spatial-, spectral-, and sparsity-based methods, were evaluated for both synthetic and experimental holograms. The Fresnel transform and the angular spectrum reconstruction methods were compared. Evaluation criteria included unimodality, accuracy, resolution, and computational cost. Autofocusing under angular spectrum propagation tends to perform better with respect to accuracy and unimodality criteria. Phase objects are, generally, more difficult to focus than amplitude objects. The normalized variance, the standard correlation, and the Tenenbaum gradient are the most reliable spatial-based metrics, combining computational efficiency with good accuracy and resolution. A good trade-off between focus performance and computational cost was found for the Fresnelet sparsity method.

Automatic joint alignment measurements in pre- and post-operative long leg standing radiographs.

PubMed

Goossen, A; Weber, G M; Dries, S P M

2012-01-01

For diagnosis or treatment assessment of knee joint osteoarthritis it is required to measure bone morphometry from radiographic images. We propose a method for automatic measurement of joint alignment from pre-operative as well as post-operative radiographs. In a two step approach we first detect and segment any implants or other artificial objects within the image. We exploit physical characteristics and avoid prior shape information to cope with the vast amount of implant types. Subsequently, we exploit the implant delineations to adapt the initialization and adaptation phase of a dedicated bone segmentation scheme using deformable template models. Implant and bone contours are fused to derive the final joint segmentation and thus the alignment measurements. We evaluated our method on clinical long leg radiographs and compared both the initialization rate, corresponding to the number of images successfully processed by the proposed algorithm, and the accuracy of the alignment measurement. Ground truth has been generated by an experienced orthopedic surgeon. For comparison a second reader reevaluated the measurements. Experiments on two sets of 70 and 120 digital radiographs show that 92% of the joints could be processed automatically and the derived measurements of the automatic method are comparable to a human reader for pre-operative as well as post-operative images with a typical error of 0.7° and correlations of r = 0.82 to r = 0.99 with the ground truth. The proposed method allows deriving objective measures of joint alignment from clinical radiographs. Its accuracy and precision are on par with a human reader for all evaluated measurements.

Applying graph partitioning methods in measurement-based dynamic load balancing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatele, Abhinav; Fourestier, Sebastien; Menon, Harshitha

Load imbalance leads to an increasing waste of resources as an application is scaled to more and more processors. Achieving the best parallel efficiency for a program requires optimal load balancing which is a NP-hard problem. However, finding near-optimal solutions to this problem for complex computational science and engineering applications is becoming increasingly important. Charm++, a migratable objects based programming model, provides a measurement-based dynamic load balancing framework. This framework instruments and then migrates over-decomposed objects to balance computational load and communication at runtime. This paper explores the use of graph partitioning algorithms, traditionally used for partitioning physical domains/meshes, formore » measurement-based dynamic load balancing of parallel applications. In particular, we present repartitioning methods developed in a graph partitioning toolbox called SCOTCH that consider the previous mapping to minimize migration costs. We also discuss a new imbalance reduction algorithm for graphs with irregular load distributions. We compare several load balancing algorithms using microbenchmarks on Intrepid and Ranger and evaluate the effect of communication, number of cores and number of objects on the benefit achieved from load balancing. New algorithms developed in SCOTCH lead to better performance compared to the METIS partitioners for several cases, both in terms of the application execution time and fewer number of objects migrated.« less

Photogrammetry for rapid prototyping: development of noncontact 3D reconstruction technologies

NASA Astrophysics Data System (ADS)

Knyaz, Vladimir A.

2002-04-01

An important stage of rapid prototyping technology is generating computer 3D model of an object to be reproduced. Wide variety of techniques for 3D model generation exists beginning with manual 3D models generation and finishing with full-automated reverse engineering system. The progress in CCD sensors and computers provides the background for integration of photogrammetry as an accurate 3D data source with CAD/CAM. The paper presents the results of developing photogrammetric methods for non-contact spatial coordinates measurements and generation of computer 3D model of real objects. The technology is based on object convergent images processing for calculating its 3D coordinates and surface reconstruction. The hardware used for spatial coordinates measurements is based on PC as central processing unit and video camera as image acquisition device. The original software for Windows 9X realizes the complete technology of 3D reconstruction for rapid input of geometry data in CAD/CAM systems. Technical characteristics of developed systems are given along with the results of applying for various tasks of 3D reconstruction. The paper describes the techniques used for non-contact measurements and the methods providing metric characteristics of reconstructed 3D model. Also the results of system application for 3D reconstruction of complex industrial objects are presented.

Reconstruction of vibroacoustic responses of a highly nonspherical structure using Helmholtz equation least-squares method.

PubMed

Lu, Huancai; Wu, Sean F

2009-03-01

The vibroacoustic responses of a highly nonspherical vibrating object are reconstructed using Helmholtz equation least-squares (HELS) method. The objectives of this study are to examine the accuracy of reconstruction and the impacts of various parameters involved in reconstruction using HELS. The test object is a simply supported and baffled thin plate. The reason for selecting this object is that it represents a class of structures that cannot be exactly described by the spherical Hankel functions and spherical harmonics, which are taken as the basis functions in the HELS formulation, yet the analytic solutions to vibroacoustic responses of a baffled plate are readily available so the accuracy of reconstruction can be checked accurately. The input field acoustic pressures for reconstruction are generated by the Rayleigh integral. The reconstructed normal surface velocities are validated against the benchmark values, and the out-of-plane vibration patterns at several natural frequencies are compared with the natural modes of a simply supported plate. The impacts of various parameters such as number of measurement points, measurement distance, location of the origin of the coordinate system, microphone spacing, and ratio of measurement aperture size to the area of source surface of reconstruction on the resultant accuracy of reconstruction are examined.

Cheap non-toxic non-corrosive method of glass cleaning evaluated by contact angle, AFM, and SEM-EDX measurements.

PubMed

Dey, Tania; Naughton, Daragh

2017-05-01

Glass surface cleaning is the very first step in advanced coating deposition and it also finds use in conserving museum objects. However, most of the wet chemical methods of glass cleaning use toxic and corrosive chemicals like concentrated sulfuric acid (H 2 SO 4 ), piranha (a mixture of concentrated sulfuric acid and 30% hydrogen peroxide), and hydrogen fluoride (HF). On the other hand, most of the dry cleaning techniques like UV-ozone, plasma, and laser treatment require costly instruments. In this report, five eco-friendly wet chemical methods of glass cleaning were evaluated in terms of contact angle (measured by optical tensiometer), nano-scale surface roughness (measured by atomic force microscopy or AFM), and elemental composition (measured by energy dispersive x-ray spectroscopy or SEM-EDX). These glass cleaning methods are devoid of harsh chemicals and costly equipment, hence can be applied in situ in close proximity with plantation such as greenhouse or upon subtle objects such as museum artifacts. Out of these five methods, three methods are based on the chemical principle of chelation. It was found that the citric acid cleaning method gave the greatest change in contact angle within the hydrophilic regime (14.25° for new glass) indicating effective cleansing and the least surface roughness (0.178 nm for new glass) indicating no corrosive effect. One of the glass sample showed unique features which were traced backed to the history of the glass usage.

Comparative evaluation of ultrasound scanner accuracy in distance measurement

NASA Astrophysics Data System (ADS)

Branca, F. P.; Sciuto, S. A.; Scorza, A.

2012-10-01

The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

Computer method for identification of boiler transfer functions

NASA Technical Reports Server (NTRS)

Miles, J. H.

1971-01-01

An iterative computer method is described for identifying boiler transfer functions using frequency response data. An objective penalized performance measure and a nonlinear minimization technique are used to cause the locus of points generated by a transfer function to resemble the locus of points obtained from frequency response measurements. Different transfer functions can be tried until a satisfactory empirical transfer function to the system is found. To illustrate the method, some examples and some results from a study of a set of data consisting of measurements of the inlet impedance of a single tube forced flow boiler with inserts are given.

Effect of Lisdexamfetamine Dimesylate on Sleep in Children with ADHD

ERIC Educational Resources Information Center

Giblin, John M.; Strobel, Aaron L.

2011-01-01

Objective: This study evaluated the potential effects of short-term treatment with lisdexamfetamine dimesylate (LDX) on both subjective and objective sleep characteristics in children aged 6 to 12 years (n = 24) with ADHD. Method: Polysomnography (PSG) and actigraph measures as well as assessments of subjective sleep parameters were examined in…

Implementing Project Approach in Hong Kong. Preschool.

ERIC Educational Resources Information Center

Ho, Rose

The primary objective of this action research was to shift the teaching method used by preschool teachers in Hong Kong from a teacher-directed mode by training them to use the project approach. The secondary objective was to measure children's achievement while using the project approach, focusing on their language ability, social development, and…

Project Approach: Teaching. Second Edition.

ERIC Educational Resources Information Center

Ho, Rose

The primary objective of the action research chronicled (in English and Chinese) in this book was to shift the teaching method used by preschool teachers in Hong Kong from a teacher-directed mode by training them to use the Project Approach. The secondary objective was to measure children's achievement while using the Project Approach, focusing on…

Application of neutron-gamma analysis for determination of C/N ratio in compost

USDA-ARS?s Scientific Manuscript database

Neutron-gamma analysis is based on the acquisition of gamma rays from neutron irradiated study objects. The intensity and energy of the registered gamma rays gives information on the types and amounts of elements in the studied object. The use of this method for measurements of soil carbon demonstra...

Evaluating a Lecture on Cultural Competence in the Medical School Preclinical Curriculum

ERIC Educational Resources Information Center

Lim, Russell F.; Wegelin, Jacob; Hua, Lisa L.; Kramer, Elizabeth J.; Servis, Mark E.

2008-01-01

Objective: The authors aim to evaluate the effectiveness of a presentation designed to increase cultural competence. Methods: A measure was developed to evaluate the attainment of knowledge and attitude objectives by first-year medical students who watched a presentation on the effect of culture on the doctor-patient relationship and effective…

34 CFR 607.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2010 CFR

2010-07-01

... development plan must include the following: (1) An analysis of the strengths, weaknesses, and significant...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods...-year plan for improving its services to Indian students, increasing the rates at which Indian secondary...

34 CFR 606.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2010 CFR

2010-07-01

... comprehensive development plan must include the following: (1) An analysis of the strengths, weaknesses, and...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods... proposed project. (5) Its five year plan to improve its services to Hispanic and other low-income students...

34 CFR 606.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2012 CFR

2012-07-01

... comprehensive development plan must include the following: (1) An analysis of the strengths, weaknesses, and...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods... proposed project. (5) Its five year plan to improve its services to Hispanic and other low-income students...

34 CFR 607.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2013 CFR

2013-07-01

... development plan must include the following: (1) An analysis of the strengths, weaknesses, and significant...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods...-year plan for improving its services to Indian students, increasing the rates at which Indian secondary...

34 CFR 606.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2011 CFR

2011-07-01

... comprehensive development plan must include the following: (1) An analysis of the strengths, weaknesses, and...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods... proposed project. (5) Its five year plan to improve its services to Hispanic and other low-income students...

34 CFR 607.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2014 CFR

2014-07-01

... development plan must include the following: (1) An analysis of the strengths, weaknesses, and significant...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods...-year plan for improving its services to Indian students, increasing the rates at which Indian secondary...

34 CFR 606.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2014 CFR

2014-07-01

... comprehensive development plan must include the following: (1) An analysis of the strengths, weaknesses, and...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods... proposed project. (5) Its five year plan to improve its services to Hispanic and other low-income students...

34 CFR 607.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2011 CFR

2011-07-01

... development plan must include the following: (1) An analysis of the strengths, weaknesses, and significant...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods...-year plan for improving its services to Indian students, increasing the rates at which Indian secondary...

34 CFR 606.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2013 CFR

2013-07-01

... comprehensive development plan must include the following: (1) An analysis of the strengths, weaknesses, and...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods... proposed project. (5) Its five year plan to improve its services to Hispanic and other low-income students...

34 CFR 607.8 - What is a comprehensive development plan and what must it contain?

Code of Federal Regulations, 2012 CFR

2012-07-01

... development plan must include the following: (1) An analysis of the strengths, weaknesses, and significant...) Measurable objectives related to reaching each goal and timeframes for achieving the objectives. (4) Methods...-year plan for improving its services to Indian students, increasing the rates at which Indian secondary...

Surface pressure measurement by oxygen quenching of luminescence

NASA Technical Reports Server (NTRS)

Gouterman, Martin P. (Inventor); Kavandi, Janet L. (Inventor); Gallery, Jean (Inventor); Callis, James B. (Inventor)

1993-01-01

Methods and compositions for measuring the pressure of an oxygen-containing gas on an aerodynamic surface, by oxygen-quenching of luminescence of molecular sensors is disclosed. Objects are coated with luminescent films containing a first sensor and at least one of two additional sensors, each of the sensors having luminescences that have different dependencies on temperature and oxygen pressure. Methods and compositions are also provided for improving pressure measurements (qualitative or quantitive) on surfaces coated with a film having one or more types of sensor.

Surface pressure measurement by oxygen quenching of luminescence

NASA Technical Reports Server (NTRS)

Gouterman, Martin P. (Inventor); Kavandi, Janet L. (Inventor); Gallery, Jean (Inventor); Callis, James B. (Inventor)

1994-01-01

Methods and compositions for measuring the pressure of an oxygen-containing gas on an aerodynamic surface, by oxygen-quenching of luminescence of molecular sensors is disclosed. Objects are coated with luminescent films containing a first sensor and at least one of two additional sensors, each of the sensors having luminescences that have different dependencies on temperature and oxygen pressure. Methods and compositions are also provided for improving pressure measurements (qualitative or quantitive) on surfaces coated with a film having one or more types of sensor.

Determination of the direction of motion on the basis of CW-homodyne laser Doppler radar

NASA Astrophysics Data System (ADS)

Biselli, Eugen; Werner, Christian

1989-03-01

Four methods for measuring the direction of a moving object using homodyne laser Doppler techniques are reviewed. The dynamic ranges of the signals for two methods that make use of the transmitter laser resonator characteristics or gain cell characteristics are shown to be limited. The resonance effects observed using a rotating wheel as an auxiliary target are discussed. The method employing eccentric scanner movement bidirectional scanning provides information concerning the direction of the velocity component to be measured.

Development of a Scale to Measure Lifelong Learning

ERIC Educational Resources Information Center

Kirby, John R.; Knapper, Christopher; Lamon, Patrick; Egnatoff, William J.

2010-01-01

Primary objective: to develop a scale to measure students' disposition to engage in lifelong learning. Research design, methods and procedures: using items that reflected the components of lifelong learning, we constructed a 14-item scale that was completed by 309 university and vocational college students, who also completed a measure of deep and…

Normative Study of Wideband Acoustic Immittance Measures in Newborn Infants

ERIC Educational Resources Information Center

Aithal, Sreedevi; Kei, Joseph; Aithal, Venkatesh; Manuel, Alehandrea; Myers, Joshua; Driscoll, Carlie; Khan, Asaduzzaman

2017-01-01

Objective: The purpose of this study was to describe normative aspects of wideband acoustic immittance (WAI) measures obtained from healthy White neonates. Method: In this cross-sectional study, wideband absorbance (WBA), admittance magnitude, and admittance phase were measured under ambient pressure condition in 326 ears from 203 neonates (M age…

Emotional Expression in Children Treated with ADHD Medication: Development of a New Measure

ERIC Educational Resources Information Center

Perwien, Amy R.; Kratochvil, Christopher J.; Faries, Douglas; Vaughan, Brigette; Busner, Joan; Saylor, Keith E.; Buermeyer, Curtis M.; Kaplan, Stuart; Swindle, Ralph

2008-01-01

Objective: Although existing instruments contain items addressing the effect of ADHD medications on emotional expression, a review of measures did not yield any instruments that thoroughly evaluated positive and negative aspects of emotional expression. Method: The Expression and Emotion Scale for Children (EESC), a parent-report measure, was…

Measured Gene-by-Environment Interaction in Relation to Attention-Deficit/Hyperactivity Disorder

ERIC Educational Resources Information Center

Nigg, Joel; Nikolas, Molly; Burt, S. Alexandra

2010-01-01

Objective: To summarize and evaluate the state of knowledge regarding the role of measured gene-by-environment interactions in relation to attention-deficit/hyperactivity disorder. Method: A selective review of methodologic issues was followed by a systematic search for relevant articles on measured gene-by-environment interactions; the search…

Abdominal near-infrared spectroscopy measurements are lower in preterm infants at risk for necrotizing enterocolitis

USDA-ARS?s Scientific Manuscript database

Near-infrared spectroscopy is a noninvasive method of measuring local tissue oxygenation (StO[2]). Abdominal StO[2] measurements in preterm piglets are directly correlated with changes in intestinal blood flow and markedly reduced by necrotizing enterocolitis. The objectives of this study were to us...

A modified conjugate gradient method based on the Tikhonov system for computerized tomography (CT).

PubMed

Wang, Qi; Wang, Huaxiang

2011-04-01

During the past few decades, computerized tomography (CT) was widely used for non-destructive testing (NDT) and non-destructive examination (NDE) in the industrial area because of its characteristics of non-invasiveness and visibility. Recently, CT technology has been applied to multi-phase flow measurement. Using the principle of radiation attenuation measurements along different directions through the investigated object with a special reconstruction algorithm, cross-sectional information of the scanned object can be worked out. It is a typical inverse problem and has always been a challenge for its nonlinearity and ill-conditions. The Tikhonov regulation method is widely used for similar ill-posed problems. However, the conventional Tikhonov method does not provide reconstructions with qualities good enough, the relative errors between the reconstructed images and the real distribution should be further reduced. In this paper, a modified conjugate gradient (CG) method is applied to a Tikhonov system (MCGT method) for reconstructing CT images. The computational load is dominated by the number of independent measurements m, and a preconditioner is imported to lower the condition number of the Tikhonov system. Both simulation and experiment results indicate that the proposed method can reduce the computational time and improve the quality of image reconstruction. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashida, Misa; Malac, Marek; Egerton, Ray F.

Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy ofmore » the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than ±1°.« less

Automatic 3D inspection metrology for high-temperature objects

NASA Astrophysics Data System (ADS)

Han, Liya; Li, Zhongwei; Zhong, Kai; Yi, Jie; Shi, Yusheng; Cheng, Xu; Zhan, Guomin; Chen, Ran

2017-06-01

3D Visual Inspection for high-temperature objects has attracted more and more attention in the industrial and manufacture field. Until now it is still difficult to measure the shape of high-temperature objects due to the following problems: 1) the radiation and heat transfer through the air seriously affect both human and measurement equipment, so the manual measurement is not capable in this situation. 2) Because of the difficulties to handle the surfaces of the hot objects, it is hard to use artificial markers to align different pieces of data. In order to solve these problems, an automatic 3D shape measurement system for high-temperature objects is proposed by combing an industrial robot with a structured blue light 3D scanner. In this system, the route for inspection is planned with the cooled object and then executed automatically with the same object in hot state to avoid artificial operations. The route is carefully planned to reduce the exposure time of the measurement equipment under the high-temperature situation. Then different pieces of data are premapped during the planning procedure. In the executing procedure, they can be aligned accurately thanks to the good repeatability of the industrial robot. Finally, different pieces of data are merged without artificial markers and the results are better than methods with traditional hand-eye calibration. Experiments verify that the proposed system can conduct the inspection of forging parts under the temperature of 900°C and the alignment precision is 0.0013rad and 0.28mm.

Establishing System Measures of Effectiveness

DTIC Science & Technology

2001-03-01

Halpin, 1991] Andriole, Stephen J. and Stanley M. Halpin, editors. Information Technology for Command and Control: Methods and Tools for Systems...Systems with Models and Objects, New York: Mc Graw -Hill, 1997. [Pawlowski, 1993a] Pawlowski, Thomas J. III, LTC. C3IEW Measures of Effectiveness

The startle response and toxicology: Methods, use and interpretation.

EPA Science Inventory

The startle response (SR) is a sensory-evoked motor reflex that has been used successfully in toxicology for decades. Advantages of this procedure include: rapidly objective measurement of a defined neural circuit, measurement of habituation of the response, and a high potential ...

METHOD FOR MEASURING AIR-IMMISCIBLE LIQUID PARTITION COEFFICIENTS

EPA Science Inventory

The principal objective of this work was to measure nonaqueous phase liquid-air partition coefficients for various gas tracer compounds. Known amounts of trichloroethene (TCE) and tracer, as neat compounds, were introduced into glass vials and allowed to equilibrate. The TCE and ...

DEVELOPMENT OF DECISION MAKING ALGORITHM FOR CONTROL OF SEA CARGO CONTAINERS BY 'TAGGED' NEUTRON METHOD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anan'ev, A. A.; Belichenko, S. G.; Bogolyubov, E. P.

Nowadays in Russia and abroad there are several groups of scientists, engaged in development of systems based on 'tagged' neutron method (API method) and intended for detection of dangerous materials, including high explosives (HE). Particular attention is paid to possibility of detection of dangerous objects inside a sea cargo container. Energy gamma-spectrum, registered from object under inspection is used for determination of oxygen/carbon and nitrogen/carbon chemical ratios, according to which dangerous object is distinguished from not dangerous one. Material of filled container, however, gives rise to additional effects of rescattering and moderation of 14 MeV primary neutrons of generator, attenuationmore » of secondary gamma-radiation from reactions of inelastic neutron scattering on objects under inspection. These effects lead to distortion of energy gamma-response from examined object and therefore prevent correct recognition of chemical ratios. These difficulties are taken into account in analytical method, presented in the paper. Method has been validated against experimental data, obtained by the system for HE detection in sea cargo, based on API method and developed in VNIIA. Influence of shielding materials on results of HE detection and identification is considered. Wood and iron were used as shielding materials. Results of method application for analysis of experimental data on HE simulator measurement (tetryl, trotyl, hexogen) are presented.« less

Handheld laser scanner automatic registration based on random coding

NASA Astrophysics Data System (ADS)

He, Lei; Yu, Chun-ping; Wang, Li

2011-06-01

Current research on Laser Scanner often focuses mainly on the static measurement. Little use has been made of dynamic measurement, that are appropriate for more problems and situations. In particular, traditional Laser Scanner must Keep stable to scan and measure coordinate transformation parameters between different station. In order to make the scanning measurement intelligently and rapidly, in this paper ,we developed a new registration algorithm for handleheld laser scanner based on the positon of target, which realize the dynamic measurement of handheld laser scanner without any more complex work. the double camera on laser scanner can take photograph of the artificial target points to get the three-dimensional coordinates, this points is designed by random coding. And then, a set of matched points is found from control points to realize the orientation of scanner by the least-square common points transformation. After that the double camera can directly measure the laser point cloud in the surface of object and get the point cloud data in an unified coordinate system. There are three major contributions in the paper. Firstly, a laser scanner based on binocular vision is designed with double camera and one laser head. By those, the real-time orientation of laser scanner is realized and the efficiency is improved. Secondly, the coding marker is introduced to solve the data matching, a random coding method is proposed. Compared with other coding methods,the marker with this method is simple to match and can avoid the shading for the object. Finally, a recognition method of coding maker is proposed, with the use of the distance recognition, it is more efficient. The method present here can be used widely in any measurement from small to huge obiect, such as vehicle, airplane which strengthen its intelligence and efficiency. The results of experiments and theory analzing demonstrate that proposed method could realize the dynamic measurement of handheld laser scanner. Theory analysis and experiment shows the method is reasonable and efficient.

Noncontact localized internal infrared radiation measurement using an infrared point detector

NASA Astrophysics Data System (ADS)

Hisaka, Masaki

2017-12-01

The techniques for temperature measurement within the human body are important for clinical applications. A method for noncontact local infrared (IR) radiation measurements was investigated deep within an object to simulate how the core human body temperature can be obtained. To isolate the IR light emitted from a specific area within the object from the external noise, the radiating IR light was detected using an IR point detector, which comprises a pinhole and a thermopile positioned at an imaging relation with the region of interest within the object. The structure of the helical filament radiating IR light inside a light bulb was thermally imaged by scanning the bulb in two dimensions. Moreover, this approach was used to effectively measure IR light in the range of human body temperature using a glass plate placed in front of the heat source, mimicking the ocular fundus.

Emissivity independent optical pyrometer

DOEpatents

Earl, Dennis Duncan; Kisner, Roger A.

2017-04-04

Disclosed herein are representative embodiments of methods, apparatus, and systems for determining the temperature of an object using an optical pyrometer. Certain embodiments of the disclosed technology allow for making optical temperature measurements that are independent of the surface emissivity of the object being sensed. In one of the exemplary embodiments disclosed herein, a plurality of spectral radiance measurements at a plurality of wavelengths is received from a surface of an object being measured. The plurality of the spectral radiance measurements is fit to a scaled version of a black body curve, the fitting comprising determining a temperature of the scaled version of the black body curve. The temperature is then output. The present disclosure is not to be construed as limiting and is instead directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone or in various combinations and subcombinations with one another.

Noncontact localized internal infrared radiation measurement using an infrared point detector

NASA Astrophysics Data System (ADS)

Hisaka, Masaki

2018-06-01

The techniques for temperature measurement within the human body are important for clinical applications. A method for noncontact local infrared (IR) radiation measurements was investigated deep within an object to simulate how the core human body temperature can be obtained. To isolate the IR light emitted from a specific area within the object from the external noise, the radiating IR light was detected using an IR point detector, which comprises a pinhole and a thermopile positioned at an imaging relation with the region of interest within the object. The structure of the helical filament radiating IR light inside a light bulb was thermally imaged by scanning the bulb in two dimensions. Moreover, this approach was used to effectively measure IR light in the range of human body temperature using a glass plate placed in front of the heat source, mimicking the ocular fundus.

Improving Cluster Analysis with Automatic Variable Selection Based on Trees

DTIC Science & Technology

2014-12-01

regression trees Daisy DISsimilAritY PAM partitioning around medoids PMA penalized multivariate analysis SPC sparse principal components UPGMA unweighted...unweighted pair-group average method ( UPGMA ). This method measures dissimilarities between all objects in two clusters and takes the average value

Accuracy, repeatability, and reproducibility of Artemis very high-frequency digital ultrasound arc-scan lateral dimension measurements

PubMed Central

Reinstein, Dan Z.; Archer, Timothy J.; Silverman, Ronald H.; Coleman, D. Jackson

2008-01-01

Purpose To determine the accuracy, repeatability, and reproducibility of measurement of lateral dimensions using the Artemis (Ultralink LLC) very high-frequency (VHF) digital ultrasound (US) arc scanner. Setting London Vision Clinic, London, United Kingdom. Methods A test object was measured first with a micrometer and then with the Artemis arc scanner. Five sets of 10 consecutive B-scans of the test object were performed with the scanner. The test object was removed from the system between each scan set. One expert observer and one newly trained observer separately measured the lateral dimension of the test object. Two-factor analysis of variance was performed. The accuracy was calculated as the average bias of the scan set averages. The repeatability and reproducibility coefficients were calculated. The coefficient of variation (CV) was calculated for repeatability and reproducibility. Results The test object was measured to be 10.80 mm wide. The mean lateral dimension bias was 0.00 mm. The repeatability coefficient was 0.114 mm. The reproducibility coefficient was 0.026 mm. The repeatability CV was 0.38%, and the reproducibility CV was 0.09%. There was no statistically significant variation between observers (P = .0965). There was a statistically significant variation between scan sets (P = .0036) attributed to minor vertical changes in the alignment of the test object between consecutive scan sets. Conclusion The Artemis VHF digital US arc scanner obtained accurate, repeatable, and reproducible measurements of lateral dimensions of the size commonly found in the anterior segment. PMID:17081860

Draft version 1.0 final report : evaluation methods and lessons learned from the Minnesota Department of Transportation intelligent vehicle initiative field operational test

DOT National Transportation Integrated Search

2003-09-26

This report on the Evaluation Methods and Lessons Learned for the Mn/DOT Intelligent Vehicle Initiative (IVI) Field Operational Test (FOT) documents the goals and objectives, research approach, methods, and findings of a program to measure the feasib...

A Comparison of Methods for Transforming Sentences into Test Questions for Instructional Materials. Technical Report #1.

ERIC Educational Resources Information Center

Roid, Gale; And Others

Several measurement theorists have convincingly argued that methods of writing test questions, particularly for criterion-referenced tests, should be based on operationally defined rules. This study was designed to examine and further refine a method for objectively generating multiple-choice questions for prose instructional materials. Important…

A potential tool for clinicians; evaluating a computer-led dietary assessment method in overweight and obese women during weight loss

USDA-ARS?s Scientific Manuscript database

Background: Dietary assessment methods used in overweight/obese participants have been scrutinized for underreporting energy. Objective: Evaluate the effectiveness of a computer-administered, 24-hour recall method (ASA24) to measure energy and nutrient intake in overweight/obese women and to further...

Optimal Information Extraction of Laser Scanning Dataset by Scale-Adaptive Reduction

NASA Astrophysics Data System (ADS)

Zang, Y.; Yang, B.

2018-04-01

3D laser technology is widely used to collocate the surface information of object. For various applications, we need to extract a good perceptual quality point cloud from the scanned points. To solve the problem, most of existing methods extract important points based on a fixed scale. However, geometric features of 3D object come from various geometric scales. We propose a multi-scale construction method based on radial basis function. For each scale, important points are extracted from the point cloud based on their importance. We apply a perception metric Just-Noticeable-Difference to measure degradation of each geometric scale. Finally, scale-adaptive optimal information extraction is realized. Experiments are undertaken to evaluate the effective of the proposed method, suggesting a reliable solution for optimal information extraction of object.

A Feasibility Study into the Measurement of Physical Activity Levels of Adults with Intellectual Disabilities Using Accelerometers and the International Physical Activity Questionnaire

ERIC Educational Resources Information Center

Dairo, Yetunde M.; Collett, Johnny; Dawes, Helen

2017-01-01

Background: Few studies have measured physical activity (PA) levels of adults with intellectual disabilities using both objective and subjective methods, but none included individuals with profound intellectual disabilities. To inform effective measurement of PA across the disability spectrum, this study explored: the feasibility of measuring PA…

Physical activities at work and risk of musculoskeletal pain and its consequences: protocol for a study with objective field measures among blue-collar workers

PubMed Central

2013-01-01

Background Among blue-collar workers, high physical work demands are generally considered to be the main cause of musculoskeletal pain and work disability. However, current available research on this topic has been criticised for using self-reported data, cross-sectional design, insufficient adjustment for potential confounders, and inadequate follow-up on the recurrent and fluctuating pattern of musculoskeletal pain. Recent technological advances have provided possibilities for objective diurnal field measurements of physical activities and frequent follow-up on musculoskeletal pain. The main aim of this paper is to describe the background, design, methods, limitations and perspectives of the Danish Physical Activity cohort with Objective measurements (DPhacto) investigating the association between objectively measured physical activities capturing work and leisure time and frequent measurements of musculoskeletal pain among blue-collar workers. Methods/design Approximately 2000 blue-collar workers are invited for the study and asked to respond to a baseline questionnaire, participate in physical tests (i.e. muscle strength, aerobic fitness, back muscle endurance and flexibility), to wear accelerometers and a heart rate monitor for four consecutive days, and finally respond to monthly text messages regarding musculoskeletal pain and quarterly questionnaires regarding the consequences of musculoskeletal pain on work activities, social activities and work ability for a one-year follow-up period. Discussion This study will provide novel information on the association between physical activities at work and musculoskeletal pain. The study will provide valid and precise documentation about the relation between physical work activities and musculoskeletal pain and its consequences among blue-collar workers. PMID:23870666

Conditioning 3D object-based models to dense well data

NASA Astrophysics Data System (ADS)

Wang, Yimin C.; Pyrcz, Michael J.; Catuneanu, Octavian; Boisvert, Jeff B.

2018-06-01

Object-based stochastic simulation models are used to generate categorical variable models with a realistic representation of complicated reservoir heterogeneity. A limitation of object-based modeling is the difficulty of conditioning to dense data. One method to achieve data conditioning is to apply optimization techniques. Optimization algorithms can utilize an objective function measuring the conditioning level of each object while also considering the geological realism of the object. Here, an objective function is optimized with implicit filtering which considers constraints on object parameters. Thousands of objects conditioned to data are generated and stored in a database. A set of objects are selected with linear integer programming to generate the final realization and honor all well data, proportions and other desirable geological features. Although any parameterizable object can be considered, objects from fluvial reservoirs are used to illustrate the ability to simultaneously condition multiple types of geologic features. Channels, levees, crevasse splays and oxbow lakes are parameterized based on location, path, orientation and profile shapes. Functions mimicking natural river sinuosity are used for the centerline model. Channel stacking pattern constraints are also included to enhance the geological realism of object interactions. Spatial layout correlations between different types of objects are modeled. Three case studies demonstrate the flexibility of the proposed optimization-simulation method. These examples include multiple channels with high sinuosity, as well as fragmented channels affected by limited preservation. In all cases the proposed method reproduces input parameters for the object geometries and matches the dense well constraints. The proposed methodology expands the applicability of object-based simulation to complex and heterogeneous geological environments with dense sampling.

Non-destructive 3D shape measurement of transparent and black objects with thermal fringes

NASA Astrophysics Data System (ADS)

Brahm, Anika; Rößler, Conrad; Dietrich, Patrick; Heist, Stefan; Kühmstedt, Peter; Notni, Gunther

2016-05-01

Fringe projection is a well-established optical method for the non-destructive contactless three-dimensional (3D) measurement of object surfaces. Typically, fringe sequences in the visible wavelength range (VIS) are projected onto the surfaces of objects to be measured and are observed by two cameras in a stereo vision setup. The reconstruction is done by finding corresponding pixels in both cameras followed by triangulation. Problems can occur if the properties of some materials disturb the measurements. If the objects are transparent, translucent, reflective, or strongly absorbing in the VIS range, the projected patterns cannot be recorded properly. To overcome these challenges, we present a new alternative approach in the infrared (IR) region of the electromagnetic spectrum. For this purpose, two long-wavelength infrared (LWIR) cameras (7.5 - 13 μm) are used to detect the emitted heat radiation from surfaces which is induced by a pattern projection unit driven by a CO2 laser (10.6 μm). Thus, materials like glass or black objects, e.g. carbon fiber materials, can be measured non-destructively without the need of any additional paintings. We will demonstrate the basic principles of this heat pattern approach and show two types of 3D systems based on a freeform mirror and a GOBO wheel (GOes Before Optics) projector unit.

Agreement between self-reported sleep patterns and actigraphy in fibromyalgia and healthy women.

PubMed

Segura-Jiménez, Víctor; Camiletti-Moirón, Daniel; Munguía-Izquierdo, Diego; Álvarez-Gallardo, Inmaculada C; Ruiz, Jonatan R; Ortega, Francisco B; Delgado-Fernández, Manuel

2015-01-01

To examine the agreement between objective (accelerometer) and subjective measures of sleep in fibromyalgia women (FW) and healthy women (HW). To identify explanatory variables of the discrepancies between the objective and subjective measures in FW and in HW. 127 diagnosed FW and 53 HW filled the Fibromyalgia Impact Questionnaire (FIQ) and wore the SenseWear Pro Armband (SWA) for 7 days in order to assess sleep over the last week. Participants completed the Pittsburgh Sleep Quality Index (PSQI) when the SWA was returned. The SWA showed greater total duration (74 vs. 88 min/day) and average duration (7 vs. 9 min) of wake after sleep onset in FW compared with HW. The PSQI showed poorer sleep quality in all the variables studied in FW than in HW (all, p<0.001), except time in bed. There was a lack of inter-method agreement for total sleep time, sleep time without naps and sleep latency in FW. Age and educational status explained the inter-method mean difference in sleep time in FW. High discrepancy in sleep time between the SWA and the PSQI was related to higher FIQ scores (p<0.05). The objective measure only showed higher frequency and average duration of wake after sleep onset in FW compared with HW. The agreement between the SWA and the PSQI measures of sleep were poor in the FW group. Age, educational level and the impact of fibromyalgia might be explanatory variables of the inter-method discrepancies in FW.

Tilted Magnetic Levitation Enables Measurement of the Complete Range of Densities of Materials with Low Magnetic Permeability.

PubMed

Nemiroski, Alex; Soh, Siowling; Kwok, Sen Wai; Yu, Hai-Dong; Whitesides, George M

2016-02-03

Magnetic levitation (MagLev) of diamagnetic or weakly paramagnetic materials suspended in a paramagnetic solution in a magnetic field gradient provides a simple method to measure the density of small samples of solids or liquids. One major limitation of this method, thus far, has been an inability to measure or manipulate materials outside of a narrow range of densities (0.8 g/cm(3) < ρ < 2.3 g/cm(3)) that are close in density to the suspending, aqueous medium. This paper explores a simple method-"tilted MagLev"-to increase the range of densities that can be levitated magnetically. Tilting the MagLev device relative to the gravitational vector enables the magnetic force to be decreased (relative to the magnetic force) along the axis of measurement. This approach enables many practical measurements over the entire range of densities observed in matter at ambient conditions-from air bubbles (ρ ≈ 0) to osmium and iridium (ρ ≈ 23 g/cm(3)). The ability to levitate, simultaneously, objects with a broad range of different densities provides an operationally simple method that may find application to forensic science (e.g., for identifying the composition of miscellaneous objects or powders), industrial manufacturing (e.g., for quality control of parts), or resource-limited settings (e.g., for identifying and separating small particles of metals and alloys).

Manipulations of Wavefront Propagation: Useful Methods and Applications for Interferometric Measurements and Scanning

PubMed Central

Novoselski, Eitan; Yifrach, Ariel; Lanzmann, Emmanuel; Arieli, Yoel

2017-01-01

Phase measurements obtained by high-coherence interferometry are restricted by the 2π ambiguity, to height differences smaller than λ/2. A further restriction in most interferometric systems is for focusing the system on the measured object. We present two methods that overcome these restrictions. In the first method, different segments of a measured wavefront are digitally propagated and focused locally after measurement. The divergent distances, by which the diverse segments of the wavefront are propagated in order to achieve a focused image, provide enough information so as to resolve the 2π ambiguity. The second method employs an interferogram obtained by a spectrum constituting a small number of wavelengths. The magnitude of the interferogram's modulations is utilized to resolve the 2π ambiguity. Such methods of wavefront propagation enable several applications such as focusing and resolving the 2π ambiguity, as described in the article. PMID:29109825

Outcome assessment for spasticity management in the patient with traumatic brain injury: the state of the art.

PubMed

Elovic, Elie P; Simone, Lisa K; Zafonte, Ross

2004-01-01

The objective of this article was to (1) review the engineering and medical literature to structure the available information concerning the assessment of spasticity in the neurological population; (2) to discuss the strengths and weaknesses of the different methods currently in use in spasticity assessment; and (3) make recommendations for future efforts in spasticity outcome assessment. Spasticity textbooks, Web sites, and OVID, IEEE, and Medline searches from 1966 through 2003 of spasticity, quantitative measure, or outcome assessment in the rehabilitation population were used as data sources. Over 500 articles were reviewed. Articles that discussed outcome measures used to assess interventions and evaluation of spasticity were included. Authors reviewed the articles looking at inclusion criteria, data collection, methodology, assessment methods, and conclusions for validity and relevance to this article. Issues such as clinical relevance, real-world function and lack of objectivity, and time consumed during performance are important issues for spasticity assessment. Some measures such as the Ashworth Scale remain in common use secondary to ease of use despite their obvious functional limitations. More functional outcome goals are plagued by being more time consuming and a general inability to demonstrate changes after an intervention. This may be secondary to the other factors that combine with spasticity to cause dysfunction at that level. Quantitative metrics can provide more objective measurements but their clinical relevance is sometimes problematic. The assessment of spasticity outcome is still somewhat problematic. Further work is necessary to develop measures that have real-world functional significance to both the individuals being treated and the clinicians. A lack of objectivity is still a problem. In the future it is important for clinicians and the engineers to work together in the development of better outcome measures.

A Monocular Vision Measurement System of Three-Degree-of-Freedom Air-Bearing Test-Bed Based on FCCSP

NASA Astrophysics Data System (ADS)

Gao, Zhanyu; Gu, Yingying; Lv, Yaoyu; Xu, Zhenbang; Wu, Qingwen

2018-06-01

A monocular vision-based pose measurement system is provided for real-time measurement of a three-degree-of-freedom (3-DOF) air-bearing test-bed. Firstly, a circular plane cooperative target is designed. An image of a target fixed on the test-bed is then acquired. Blob analysis-based image processing is used to detect the object circles on the target. A fast algorithm (FCCSP) based on pixel statistics is proposed to extract the centers of object circles. Finally, pose measurements can be obtained when combined with the centers and the coordinate transformation relation. Experiments show that the proposed method is fast, accurate, and robust enough to satisfy the requirement of the pose measurement.

Multimodal and synthetic aperture approach to full-field 3D shape and displacement measurements

NASA Astrophysics Data System (ADS)

Kujawińska, M.; Sitnik, R.

2017-08-01

Recently most of the measurement tasks in industry, civil engineering and culture heritage applications require archiving, characterization and monitoring of 3D objects and structures and their performance under changing conditions. These requirements can be met if multimodal measurement (MM) strategy is applied. It rely on effective combining structured light method and 3D digital image correlation with laser scanning/ToF, thermal imaging, multispectral imaging and BDRF measurements. In the case of big size and/or complicated objects MM have to be combined with hierarchical or synthetic aperture (SA) measurements. The new solutions in MM and SA strategies are presented and their applicability is shown at interesting cultural heritage and civil engineering applications.

A study on measuring occlusal contact area using silicone impression materials: an application of this method to the bite force measurement system using the pressure-sensitive sheet.

PubMed

Ando, Katsuya; Kurosawa, Masahiro; Fuwa, Yuji; Kondo, Takamasa; Goto, Shigemi

2007-11-01

The aim of this study was to establish an objective and quantitative method of measuring occlusal contact areas. To this end, bite records were taken with a silicone impression material and a light transmission device was used to read the silicone impression material. To examine the effectiveness of this novel method, the occlusal contact area of the silicone impression material and its thickness limit of readable range were measured. Results of this study suggested that easy and highly accurate measurements of occlusal contact area could be obtained by selecting an optimal applied voltage of the light transmission device and an appropriate color of the silicone impression material.

Artificial submicron or nanometer speckle fabricating technique and electron microscope speckle photography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu Zhanwei; Xie Huimin; Fang Daining

2007-03-15

In this article, a novel artificial submicro- or nanometer speckle fabricating technique is proposed by taking advantage of submicro or nanometer particles. In the technique, submicron or nanometer particles were adhered to an object surface by using ultrasonic dispersing technique. The particles on the object surface can be regarded as submicro or nanometer speckle by using a scanning electronic microscope at a special magnification. In addition, an electron microscope speckle photography (EMSP) method is developed to measure in-plane submicron or nanometer deformation of the object coated with the artificial submicro or nanometer speckles. The principle of artificial submicro or nanometermore » speckle fabricating technique and the EMSP method are discussed in detail in this article. Some typical applications of this method are offered. The experimental results verified that the artificial submicro or nanometer speckle fabricating technique and EMSP method is feasible.« less

A Novel Method of Localization for Moving Objects with an Alternating Magnetic Field

PubMed Central

Gao, Xiang; Yan, Shenggang; Li, Bin

2017-01-01

Magnetic detection technology has wide applications in the fields of geological exploration, biomedical treatment, wreck removal and localization of unexploded ordinance. A large number of methods have been developed to locate targets with static magnetic fields, however, the relation between the problem of localization of moving objectives with alternating magnetic fields and the localization with a static magnetic field is rarely studied. A novel method of target localization based on coherent demodulation was proposed in this paper. The problem of localization of moving objects with an alternating magnetic field was transformed into the localization with a static magnetic field. The Levenberg-Marquardt (L-M) algorithm was applied to calculate the position of the target with magnetic field data measured by a single three-component magnetic sensor. Theoretical simulation and experimental results demonstrate the effectiveness of the proposed method. PMID:28430153

An Approach to Extract Moving Objects from Mls Data Using a Volumetric Background Representation

NASA Astrophysics Data System (ADS)

Gehrung, J.; Hebel, M.; Arens, M.; Stilla, U.

2017-05-01

Data recorded by mobile LiDAR systems (MLS) can be used for the generation and refinement of city models or for the automatic detection of long-term changes in the public road space. Since for this task only static structures are of interest, all mobile objects need to be removed. This work presents a straightforward but powerful approach to remove the subclass of moving objects. A probabilistic volumetric representation is utilized to separate MLS measurements recorded by a Velodyne HDL-64E into mobile objects and static background. The method was subjected to a quantitative and a qualitative examination using multiple datasets recorded by a mobile mapping platform. The results show that depending on the chosen octree resolution 87-95% of the measurements are labeled correctly.

Modern Geometric Methods of Distance Determination

NASA Astrophysics Data System (ADS)

Thévenin, Frédéric; Falanga, Maurizio; Kuo, Cheng Yu; Pietrzyński, Grzegorz; Yamaguchi, Masaki

2017-11-01

Building a 3D picture of the Universe at any distance is one of the major challenges in astronomy, from the nearby Solar System to distant Quasars and galaxies. This goal has forced astronomers to develop techniques to estimate or to measure the distance of point sources on the sky. While most distance estimates used since the beginning of the 20th century are based on our understanding of the physics of objects of the Universe: stars, galaxies, QSOs, the direct measures of distances are based on the geometric methods as developed in ancient Greece: the parallax, which has been applied to stars for the first time in the mid-19th century. In this review, different techniques of geometrical astrometry applied to various stellar and cosmological (Megamaser) objects are presented. They consist in parallax measurements from ground based equipment or from space missions, but also in the study of binary stars or, as we shall see, of binary systems in distant extragalactic sources using radio telescopes. The Gaia mission will be presented in the context of stellar physics and galactic structure, because this key space mission in astronomy will bring a breakthrough in our understanding of stars, galaxies and the Universe in their nature and evolution with time. Measuring the distance to a star is the starting point for an unbiased description of its physics and the estimate of its fundamental parameters like its age. Applying these studies to candles such as the Cepheids will impact our large distance studies and calibration of other candles. The text is constructed as follows: introducing the parallax concept and measurement, we shall present briefly the Gaia satellite which will be the future base catalogue of stellar astronomy in the near future. Cepheids will be discussed just after to demonstrate the state of the art in distance measurements in the Universe with these variable stars, with the objective of 1% of error in distances that could be applied to our closest galaxy the LMC, and better constrain the distances of large sub-structures around the Milky Way. Then exciting objects like X-Ray binaries will be presented in two parts corresponding to "low" or "high" mass stars with compact objects observed with X-ray satellites. We shall demonstrate the capability of these objects to have their distances measured with high accuracy with not only helps in the study of these objects but could also help to measure the distance of the structure they belong. For cosmological objects and large distances of megaparsecs, we shall present what has been developed for more than 20 years in the geometric distance measurements of MegaMasers, the ultimate goal being the estimation of the H0 parameter.

Qualitative Versus Quantitative Mammographic Breast Density Assessment: Applications for the US and Abroad

PubMed Central

Destounis, Stamatia; Arieno, Andrea; Morgan, Renee; Roberts, Christina; Chan, Ariane

2017-01-01

Mammographic breast density (MBD) has been proven to be an important risk factor for breast cancer and an important determinant of mammographic screening performance. The measurement of density has changed dramatically since its inception. Initial qualitative measurement methods have been found to have limited consistency between readers, and in regards to breast cancer risk. Following the introduction of full-field digital mammography, more sophisticated measurement methodology is now possible. Automated computer-based density measurements can provide consistent, reproducible, and objective results. In this review paper, we describe various methods currently available to assess MBD, and provide a discussion on the clinical utility of such methods for breast cancer screening. PMID:28561776

Hydration and Cooling Practices Among Farmworkers in Oregon and Washington

PubMed Central

Bethel, Jeffrey W.; Spector, June T.; Krenz, Jennifer

2018-01-01

Objectives Although recommendations for preventing occupational heat-related illness among farmworkers include hydration and cooling practices, the extent to which these recommendations are universally practiced is unknown. The objective of this analysis was to compare hydration and cooling practices between farmworkers in Oregon and Washington. Methods A survey was administered to a purposive sample of Oregon and Washington farmworkers. Data collected included demographics, work history and current work practices, hydration practices, access and use of cooling measures, and headwear and clothing worn. Results Oregon farmworkers were more likely than those in Washington to consume beverages containing sugar and/or caffeine. Workers in Oregon more frequently reported using various cooling measures compared with workers in Washington. Availability of cooling measures also varied between the two states. Conclusions These results highlight the large variability between workers in two states regarding access to and use of methods to stay cool while working in the heat. PMID:28402203

Ecological metrics of biomass removed by three methods of purse-seine fishing for tunas in the eastern tropical Pacific Ocean.

PubMed

Gerrodette, Tim; Olson, Robert; Reilly, Stephen; Watters, George; Perrin, William

2012-04-01

An ecosystem approach to fisheries management is a widely recognized goal, but describing and measuring the effects of a fishery on an ecosystem is difficult. Ecological information on the entire catch (all animals removed, whether retained or discarded) of both species targeted by the fishery and nontarget species (i.e., bycatch) is required. We used data from the well-documented purse-seine fishery for tunas (Thunnus albacares, T. obesus, and Katsuwonus pelamis) in the eastern tropical Pacific Ocean to examine the fishery's ecological effects. Purse-seine fishing in the eastern tropical Pacific is conducted in 3 ways that differ in the amount and composition of target species and bycatch. The choice of method depends on whether the tunas are swimming alone (unassociated sets), associated with dolphins (dolphin sets), or associated with floating objects (floating-object sets). Among the fishing methods, we compared catch on the basis of weight, number of individuals, trophic level, replacement time, and diversity. Floating-object sets removed 2-3 times as much biomass as the other 2 methods, depending on how removal was measured. Results of previous studies suggest the ecological effects of floating-object sets are thousands of times greater than the effects of other methods, but these results were derived from only numbers of discarded animals. Management of the fishery has been driven to a substantial extent by a focus on reducing bycatch, although discards are currently 4.8% of total catch by weight, compared with global averages of 7.5% for tuna longline fishing and 30.0% for midwater trawling. An ecosystem approach to fisheries management requires that ecological effects of fishing on all animals removed by a fishery, not just bycatch or discarded catch, be measured with a variety of metrics. ©2012 Society for Conservation Biology.

A METHOD OF ASSESSING AIR TOXICS CONCENTRATIONS IN URBAN AREAS USING MOBILE PLATFORM MEASUREMENTS

EPA Science Inventory

The objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxic assessments in Environmental Justice applications, epidemiological studies...

Methods and measurements in real-time air traffic control system simulation.

DOT National Transportation Integrated Search

1983-04-01

The major purpose of this work was to asses dynamic simulation of air traffic control systems as a technique for evaluating such systems in a statistically sound and objective manner. A large set of customarily used measures based on the system missi...

Measurement of bridge deck layout prior to concrete placement : final report.

DOT National Transportation Integrated Search

2017-01-01

The main objective of this research was to develop a method of measuring and : producing as built bridge drawings. This was the first step in the feasibility : assessment for automated bridge deck paving. The research goes to show the : standard meth...

Use of areal snow cover measurements from ERTS-1 imagery in snowmelt-runoff relationships in Arizona

NASA Technical Reports Server (NTRS)

Aul, J. S.; Ffolliott, P. F.

1975-01-01

Methods of interpreting ERTS-1 imagery to measure areal snow cover were analyzed. Relationship of areal snow cover and runoff were among the objectives in this study of ERTS-1 imagery use for forecasting snowmelt-runoff relationships.

Fast 3D shape measurements with reduced motion artifacts

NASA Astrophysics Data System (ADS)

Feng, Shijie; Zuo, Chao; Chen, Qian; Gu, Guohua

2017-10-01

Fringe projection is an extensively used technique for high speed three-dimensional (3D) measurements of dynamic objects. However, the motion often leads to artifacts in reconstructions due to the sequential recording of the set of patterns. In order to reduce the adverse impact of the movement, we present a novel high speed 3D scanning technique combining the fringe projection and stereo. Firstly, promising measuring speed is achieved by modifying the traditional aperiodic sinusoidal patterns so that the fringe images can be cast at kilohertz with the widely used defocusing strategy. Next, a temporal intensity tracing algorithm is developed to further alleviate the influence of motion by accurately tracing the ideal intensity for stereo matching. Then, a combined cost measure is suggested to robustly estimate the cost for each pixel. In comparison with the traditional method where the effect of motion is not considered, experimental results show that the reconstruction accuracy for dynamic objects can be improved by an order of magnitude with the proposed method.