Search results for "Reproducibility"
showing 10 items of 1976 documents
Accuracy in Detecting Artificial Root Resorption in Panoramic Radiography versus Tomosynthetic Panoramic Radiographs.
2019
The aim of this study was to compare the detection accuracy of panoramic radiography (PAN) and tomosynthetically reconstructed panoramic radiography (TPAN) for the detection of artificial external root resorption in a multiobserver approach.Thirty-six teeth in 5 dry human mandibles were prepared with artificial root resorption by means of diamond bur defects (0.8, 1.0, and 1.2 mm). The samples were exposed in a digital panoramic radiographic unit in a predetermined appropriate position using a wax layer (6.25 mm thickness) as soft tissue scatter equivalent and a water-filled plastic bottle to mimic the absorption of the cervical spine. This resulted in 5 panoramic radiographs and 5 tomosynt…
An evaluation of a model ecosystem with DDT
1980
The reproducibility, variability, and reliability of a simple aquatic-terrtestrial model ecosystem experiment was tested with p,p'-DDT. The variation among the model replicates as well as within the units was studied by using hierarchal analysis of variance. the complete budget of the chemical was calculated and a theoretical transport model was constructed. The degradation and accumulation of DDT was followed by gas chromatographic residue analysis, which showed good reproducibility of the experimental design. The degradation of DDT in the model was similar to that found in the field, but the determination of concentration factors was questionable. The material balance tables revealed that…
The repeatability and reproducibility of calibrating signals generated by Hsu-Nielsen method
2005
During the measurements of the acoustic emission signals taken both in the laboratory and industrial conditions it is necessary to carry out calibration of the measurement paths used. One of the basic calibration methods is the one invented by Hsu-Nielsen, which consists in generating an acoustic signal during breaking a scriber placed in a special head put on an automatic pencil. The paper presents the measurement results of acoustic signals taken at various structural parameters of calibrating heads, which was done to determine their influence on the repeatability of the results obtained. Moreover, the measurements were taken for ten identical, in relation to their geometrical measurement…
Critical evaluation of two commonly used techniques for the treatment of data from extract dilution sniffing analysis
1993
The data from the extract dilution sniffing analysis of beer samples have been treated by two methods of analysis to give either «charm» or «FD» values. The results obtained from these two methods were compared and demonstrated that the rank order of intensity of the odor-active regions was different for most panelists when the data were presented as charm rather than FD values. Points of uncertainty observed while using this method such as between- and within-individual reproducibility and gaps in the coincident response five also been discussed
Coulomb blockade thermometer: Tests and instrumentation
1998
Coulomb blockade thermometry (CBT) provides a simple method for absolute thermometry in every day laboratory use at cryogenic temperatures. CBT has been found insensitive to even high magnetic fields. We review the principles and the operation of CBT and the fabrication of the sensors, and present new data on radiation hardness and stability of the sensors. We describe the instrumentation of CBT in detail. We have developed two signal conditioning units for CBT measurements. One is a modified alternating current resistance bridge, a versatile laboratory instrument operating with a PC computer, and the other one is a simple stand-alone instrument for direct temperature reading. Test results …
3He-MRI-based measurements of intrapulmonarypO2 and its time course during apnea in healthy volunteers: first results, reproducibility, and technical…
2000
We applied a recently developed method of following the time course of the intrapulmonary oxygen partial pressure p(O2)(t) during apnea by (3)He MRI to healthy volunteers. Using two imaging series with different interscan times during two breathholds (double acquisition technique), relaxation of (3)He due to paramagnetic oxygen and depolarization by RF pulses were discriminated. In all four subjects, the temporal evolution of p(O2) was found to be linear, and was described by an initial partial pressure p(0) and a decrease rate R. Also, regional differences of both p(0) and R were observed. A correlation between p(0) and R was apparent. Finally, we discuss limitations of the double acquisit…
Segmentation-Free Estimation of Aortic Diameters from MRI Using Deep Learning
2021
Accurate and reproducible measurements of the aortic diameters are crucial for the diagnosis of cardiovascular diseases and for therapeutic decision making. Currently, these measurements are manually performed by healthcare professionals, being time consuming, highly variable, and suffering from lack of reproducibility. In this work we propose a supervised deep-learning method for the direct estimation of aortic diameters. The approach is devised and tested over 100 magnetic resonance angiography scans without contrast agent. All data was expert-annotated at six aortic locations typically used in clinical practice. Our approach makes use of a 3D+2D convolutional neural network (CNN) that ta…
Eine Nierenfunktionsanalyse durch die Computertomographie
1992
The CT clearance in a number of urological patients (39 patients, 25 with normal renal function) was studied by means of an "area under curve" (AUC) method, using a region of interest. 31 patients were given meglumine ioxithalamate and 8 patients Iopamidol as a contrast medium. Both for total and partial function there was highly significant correlation with isotope clearance with good reproducibility. The difference in the pharmacokinetics of the contrast media affected the absolute clearance values.
Non-invasive determination of cardiac output by transesophageal Doppler ultrasound-clinical application and validation
2003
The authors describe the development and validation of a device using transesophageal (TE) Doppler ultrasound to provide continuous and noninvasive monitoring of cardiac output (CO) and related parameters. In intubated and artificially ventilated patients who underwent pulmonary artery catherization for hemodynamic monitoring, CO was determined by the esophageal Doppler ultrasound probe and compared to the results obtained simultaneously by means of thermodilution. A very close correlation was found between the results (r=0.99), with a standard estimate of error less than 5% as well as good reproducibility (r=0.96 and r=0.98). >
Reliability results of straylight measurements using the C-Quant
2008
Purpose Assessment of repeatability and reproducibility of straylight measures with the C-Quant straylightmeter (Oculus AG, Germany), effect of age on reliability measures and correlation of measures determined with new methods of scatter determination. Methods Results from different studies will be presented. For repeatability assessment, 20 eyes (age 26.9±2.7 years) were examined with the C-Quant, taking 10 consecutive readings. 5 subjects were also examined on 5 consecutive days to assess reproducibility. Repeated measures from 84 subjects, age range 19-86 years, were analysed to assess the effect of patient’s age. Software was developed to quantify scatter from centroid patterns obtaine…