additional measurement
Recently Published Documents


TOTAL DOCUMENTS

72
(FIVE YEARS 23)

H-INDEX

9
(FIVE YEARS 1)

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0255414
Author(s):  
E. F. Haghish ◽  
Werner Vach ◽  
Anders Højen ◽  
Dorthe Bleses

Measurement error is a ubiquitous element of social science studies. In large-scale effectiveness intervention studies on child language, administration of the assessment of language and preliteracy outcomes by speech and language pathologists is costly in money and human resources. Alternatively, daycare educators can administer the assessment, which preserves considerable resources but may increase the measurement error. Using data from two nationwide child language intervention studies in Denmark, this article evaluates daycare educators’ measurement error when administering a test of language and preliteracy skills of 3 to 5 year old children that in part is used in a national screening program. Since children were randomly assigned to educators, hierarchical linear models can estimate the amount of additional measurement error caused by educators’ language assessments. The result shows that the amount of additional measurement error varied between different language subscales, ranging from 4% to 19%, which can be compensated for by increasing the sample size by the latter percentage. The benefits and risks of having daycare educators administer language assessments are discussed.


2021 ◽  
pp. bjophthalmol-2021-320003
Author(s):  
Lucas Baldissera Tochetto ◽  
Dalton de Freitas Santoro ◽  
Flavio Hirai ◽  
Danielle Dias Conte ◽  
Ana Luisa Höfling-Lima ◽  
...  

Individuals with suspected COVID-19 symptoms (n=202) were tested using nasopharyngeal RT-qPCR. All individuals underwent corneal esthesiometry measurements using the Cochet-Bonnet esthesiometer during their first visit; 50 participants underwent an additional measurement at a mean interval of 32.5 (17.8) days. COVID-19 was confirmed in 101 subjects (50%) using nasopharyngeal PCR. The mean time from symptom onset to disease diagnosis and corneal esthesiometry was 4.2 (2.1) days. Mean corneal esthesiometry findings based on the positive and negative PCR status indicated no statistical difference. This study demonstrated that COVID-19 had no effect on corneal esthesiometry in individuals with acute-phase COVID-19.


2021 ◽  
Vol 26 (3) ◽  
pp. 503-518
Author(s):  
Ibrahim Tekin ◽  
He Yang

In this paper, the classical Euler-Bernoulli beam equation is considered by utilizing fractional calculus. Such an equation is called the time-fractional EulerBernoulli beam equation. The problem of determining the time-dependent coefficient for the fractional Euler-Bernoulli beam equation with homogeneous boundary conditions and an additional measurement is considered, and the existence and uniqueness theorem of the solution is proved by means of the contraction principle on a sufficiently small time interval. Numerical experiments are also provided to verify the theoretical findings.


Author(s):  
Andrea Vranić ◽  
Marina Martinčević ◽  
Vedran Prpić

Numerous studies have investigated the efficacy of various cognitive trainings, with working memory being the most often trained cognitive aspect. In this regard, executive aspects of working memory have received the most attention, with updating training being vastly explored. In this study, we aimed to examine the differential contribution of some individual characteristics to the efficacy of updating training using a well-established n-back training paradigm. More specifically, we examined the contribution of fluid reasoning (gf), and personality (neuroticism, conscientiousness) to training efficacy. Participants (N = 47) took part in a 15-session, dual n-back training, spread over 4 weeks. They were pretested for fluid reasoning (CFT-3), personality (IPIP-100), and performed the initial testing on the OSPAN task. OSPAN was measured in three additional measurement points (after 5th, 10th, 15th session). The data was analyzed within the multilevel modeling approach. Initial hypotheses were partly confirmed, in that: 1) training was efficient in terms of OSPAN score, which grew linearly over time and the trajectory was similar between participants, 2) although the growth was similar for all participants, differences were found in intercepts, and 3) these differences could be partly explained by differences in fluid reasoning, but not with personality traits of conscientiousness and neuroticism.


2021 ◽  
Vol 10 (1) ◽  
pp. 109-119
Author(s):  
Tobias Pohl ◽  
Peter Meindl ◽  
Lutz Werner ◽  
Uwe Johannsen ◽  
Dieter Taubert ◽  
...  

Abstract. The Physikalisch-Technische Bundesanstalt (PTB) has set up an additional measurement approach for the absolute calibration of the spectral responsivity of detectors in the near-infrared (NIR) and mid-infrared (MIR) spectral range. This alternative method uses the radiation of a blackbody operating at about 1200 K with a precision aperture. The blackbody radiation can be calculated by Planck's law and is additionally spectrally selected by accurately characterized optical bandpass filters. Thus, a calibration of the spectral responsivity of a detector with respect to irradiance can be achieved at the bandpass wavelength of the applied transmission filters. If the aperture of the detector is known, the spectral responsivity can also be calculated with respect to radiant power. Thermopile detectors with known aperture size were calibrated in terms of their spectral responsivity with several bandpass filters in the spectral range between 1.5 µm up to 14 µm with relative standard measurement uncertainties between 5 % and 19 %. The obtained results are consistent with previous calibrations at PTB's national primary detector standard. Therefore, this additional measurement approach is a further validation of the existing primary method which is based on a cryogenic radiometer and extends the usable wavelength range.


2021 ◽  
Author(s):  
Saniya Behzadpour ◽  
Andreas Kvas ◽  
Torsten Mayer-Gürr

<p>Besides a K-Band Ranging System (KBR), GRACE-FO carries a Laser Ranging Interferometer (LRI) as a technology demonstration to provide measurements of inter-satellite range changes. This additional measurement technology provides supplementary observations, which allow for cross-instrument diagnostics with the KBR system and, to some extent, the separation of ranging noise from other sources such as noise in the on-board accelerometer (ACC) measurements.</p><p>The aim of this study is to incorporate the two ranging systems (LRI and KBR) observations in ITSG-Grace2018 gravity field recovery. The two observation groups are combined in an iterative least-squares adjustment with variance component estimation used to determine the unknown noise covariance functions for KBR, LRI, and ACC measurements. We further compare the gravity field solutions obtained from the combined solutions to KBR-only results and discuss the differences with a focus on the global gravity field and LRI calibration parameters.</p>


2021 ◽  
Author(s):  
Vitali Müller ◽  
Malte Misfeldt ◽  
Laura Müller ◽  
Henry Wegener ◽  
Gerhard Heinzel

<p>The GRACE Follow-On satellites were launched <span>on</span> <span>22</span>nd May <span>2018</span> <span>to</span> <span>continue</span> the measurement of Earth’s gravity field from the GRACE satellites (<span>2002</span>-<span>2017</span>). A few weeks <span>later</span>, <span>an</span> inter-satellite laser link was established with the novel Laser Ranging Interferometer (LRI), which offers <span>an</span> additional measurement of the inter-satellite <span>range</span> <span>next</span> <span>to</span> the one provided by the conventional microwave ranging instrument. The LRI <span>is</span> the <span>first</span> optical interferometer in space between orbiters, which <span>has</span> demonstrated <span>to</span> measure distance variations with <span>a</span> noise below <span>1</span> <span>nm</span>/√Hz at Fourier frequencies around <span>1</span> Hz, well below the requirement of <span>80</span> <span>nm</span>/√Hz. In this talk, we provide <span>an</span> overview <span>on</span> the LRI, present the current status of the instrument <span>and</span> show results regarding the characterization of the instrument. We will address impulse events that are apparent in the accelerometer <span>and</span> LRI <span>range</span> acceleration data, most of which are expected <span>to</span> <span>be</span> micro-meteorites. Other short-term disturbances in the ranging data will <span>be</span> addressed <span>as</span> well. We conclude with some learned lessons <span>and</span> potential modifications of the interferometry <span>for</span> future geodetic missions.</p>


2021 ◽  
Author(s):  
Wolfgang Durner ◽  
Miller Alina ◽  
Pertassek Thomas ◽  
Iden Sascha C.

<p>The integral suspension pressure method (ISP) is an automated method to evaluate sedimentation experiments for particle size analysis of soil materials. In contrast to the traditional pipette and hydrometer methods, it is based on the continuous measurement of the suspension pressure at one depth in the sedimentation cylinder. The particle size distribution is determined by inverse simulation (Durner et al., 2017). The ISP is promising because it is semi-automated, continuous, based on process simulation, and does not hinge on oversimplifying assumptions. Most importantly, disturbance of the settling particles is minimized whereas disturbance is unavoidable when applying the traditional methods. ISP has been made commercially available by the METER Group AG (Munich) with a device called PARIO<sup>TM</sup>. This implementation of ISP leads to a computerized system which yields quasi-continuous particle-size distribution curves.</p><p>Practical experience with PARIO has shown that, despite cutting-edge pressure sensor technology with a resolution of 0.1 Pa, the accuracy of the particle-size analysis was less than expected from a theoretical analysis, and that the time required to determine the clay content exceeded theoretical expectations. In this contribution, we analyze the reasons for disturbances of the methodology in practical applications and show ways to improve accuracy by compensating different errors. Furthermore, we show how an extended version of ISP called ISP+, which considers a single additional measurement in the objective function (Durner and Iden, 2019), leads to stable estimates of the clay fraction while considerably reducing the measurement time.</p><p>References:</p><p>Durner, W., S.C. Iden, and G. von Unold (2017): The integral suspension pressure method (ISP) for precise particle-size analysis by gravitational sedimentation., Water Resources Research, 53, 33-48, doi:10.1002/2016WR019830.</p><p>Durner, W., and S.C. Iden: ISP+: improving the Integral Suspension Pressure method by an additional measurement, Geophysical Research Abstracts Vol. 21, EGU2019-12761, 2019.</p>


Sign in / Sign up

Export Citation Format

Share Document