scholarly journals Qoala-T: A supervised-learning tool for quality control of automatic segmented MRI data

2018 ◽  
Author(s):  
Eduard T. Klapwijk ◽  
Ferdi van de Kamp ◽  
Mara van der Meulen ◽  
Sabine Peters ◽  
Lara M. Wierenga
Keyword(s):  
Quality Control ◽  
Supervised Learning ◽  
Area Under The Curve ◽  
High Sensitivity ◽  
Poor Quality ◽  
Developmental Studies ◽  
Quality Ratings ◽  
Control Procedures ◽  
Processing Errors

AbstractPerforming quality control to detect image artifacts and data-processing errors is crucial in structural magnetic resonance imaging, especially in developmental studies. Currently, many studies rely on visual inspection by trained raters for quality control. The subjectivity of these manual procedures lessens comparability between studies, and with growing study sizes quality control is increasingly time consuming. In addition, both inter-rater as well as intra-rater variability of manual quality control is high and may lead to inclusion of poor quality scans and exclusion of scans of usable quality. In the current study we present the Qoala-T tool, which is an easy and free to use supervised-learning model to reduce rater bias and misclassification in manual quality control procedures. First, we manually rated quality of N = 784 FreeSurfer-processed T1-weighted scans. Different supervised-learning models were then compared to predict manual quality ratings. Results show that the Qoala-T tool using random forests is able to predict scan quality with both high sensitivity and specificity (mean area under the curve (AUC) = 0.98). In addition, the Qoala-T tool was also able to adequately predict the quality of a novel unseen dataset (N = 112; mean AUC = 0.95). These outcomes indicate that using Qoala-T in other datasets could greatly reduce the time needed for quality control. More importantly, this procedure could further help to reduce variability related to manual quality control, thereby benefiting the comparability of data quality between studies.

scholarly journals SMOS Brightness Temperature Monitoring Quality Control Review and Enhancements

2021 ◽  
Vol 13 (20) ◽  
pp. 4081
Author(s):  
Peter Weston ◽  
Patricia de Rosnay
Keyword(s):  
Quality Control ◽  
Brightness Temperature ◽  
Weather Prediction ◽  
European Space Agency ◽  
Poor Quality ◽  
Quality Data ◽  
Space Agency ◽  
Control Procedures ◽  
Land Data Assimilation System ◽  
Nwp Model

Brightness temperature (Tb) observations from the European Space Agency (ESA) Soil Moisture Ocean Salinity (SMOS) instrument are passively monitored in the European Centre for Medium-range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). Several quality control procedures are performed to screen out poor quality data and/or data that cannot accurately be simulated from the numerical weather prediction (NWP) model output. In this paper, these quality control procedures are reviewed, and enhancements are proposed, tested, and evaluated. The enhancements presented include improved sea ice screening, coastal and ambiguous land-ocean screening, improved radio frequency interference (RFI) screening, and increased usage of observation at the edge of the satellite swath. Each of the screening changes results in improved agreement between the observations and model equivalent values. This is an important step in advance of future experiments to test the direct assimilation of SMOS Tbs into the ECMWF land data assimilation system.

scholarly journals Quality Control of Pre-1948 Cooperative Observer Network Data

2005 ◽  
Vol 22 (11) ◽  
pp. 1691-1705 ◽  
Author(s):  
Kenneth E. Kunkel ◽  
David R. Easterling ◽  
Kenneth Hubbard ◽  
Kelly Redmond ◽  
Karen Andsager ◽  
...  
Keyword(s):  
Quality Control ◽  
Limited Resources ◽  
Second Step ◽  
Precipitation Data ◽  
Screening Criteria ◽  
Temperature And Precipitation ◽  
Data Value ◽  
Control Procedures ◽  
Special Quality

Abstract A recent comprehensive effort to digitize U.S. daily temperature and precipitation data observed prior to 1948 has resulted in a major enhancement in the computer database of the records of the National Weather Service’s cooperative observer network. Previous digitization efforts had been selective, concentrating on state or regional areas. Special quality control procedures were applied to these data to enhance their value for climatological analysis. The procedures involved a two-step process. In the first step, each individual temperature and precipitation data value was evaluated against a set of objective screening criteria to flag outliers. These criteria included extreme limits and spatial comparisons with nearby stations. The following data were automatically flagged: 1) all precipitation values exceeding 254 mm (10 in.) and 2) all temperature values whose anomaly from the monthly mean for that station exceeded five standard deviations. Additional values were flagged based on differences with nearby stations; in this case, metrics were used to rank outliers so that the limited resources were concentrated on those values most likely to be invalid. In the second step, each outlier was manually assessed by climatologists and assigned one of the four following flags: valid, plausible, questionable, or invalid. In excess of 22 400 values were manually assessed, of which about 48% were judged to be invalid. Although additional manual assessment of outliers might further improve the quality of the database, the procedures applied in this study appear to have been successful in identifying the most flagrant errors.

What is the quality of quality control procedures?

1981 ◽  
Vol 41 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Carl-Henric de Verdier ◽  
Torgny Groth ◽  
James O. Westgard
Keyword(s):  
Quality Control ◽  
Control Procedures

scholarly journals Book review – Standards, quality control, and measurement sciences in 3D printing and additive manufacturing

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
Tuan Anh Tran
Keyword(s):  
Quality Control ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Fast Pace ◽  
Control Procedures ◽  
3D Printed

There is a gap between 3D Printing’s fast pace of development and the acceptance of 3D Printing technologies by other industries and applications. This hesitation comes mostly from unanswered questions about the consistency, reproducibility, and quality of 3D printed products. Although the list of excellent examples demonstrating its potential keeps expanding, a wide and thorough adoption of the technology requires crucial, yet currently missing elements including consensus standards, quality control procedures, and measuring methodologies. Progress in developing these elements, however, has been rather limited.

scholarly journals Method for constructing an equivalent mechanical model of an elastic system of a machine with various technological equipment

2018 ◽  
Vol 224 ◽  
pp. 02008 ◽  
Author(s):  
Sergey L. Vasilevykh ◽  
Alexandr V. Udalov ◽  
Evgeniy S. Shelihov
Keyword(s):  
Mechanical Model ◽  
Elastic System ◽  
High Sensitivity ◽  
Technological Equipment ◽  
Machined Surface ◽  
Technology System ◽  
Equivalent Mechanical Model ◽  
Additional Support ◽  
Processing Errors

The article deals with the construction of an equivalent mechanical model of the elastic system of the machine for turning non-rigid shafts with various technological equipment, including machining in centers and machining in a chuck with the rear rotating center being clamped without using additional support and using a vibration-damper lunette. The relevance of this study due to the fact that in view of low stiffness processed non-rigid shaft technology system machine-tool-tool-workpiece is extremely sensitive to the deformations caused by the action of cutting forces. As a result, significant processing errors are generated. High sensitivity to deformations serves as a source of intensive vibrations of the workpiece, which leads to deterioration of the quality of the machined surface of the part, a decrease in the durability and durability of the cutting tool, accelerated wear and loss of guaranteed machine accuracy parameters. This makes it essential to significantly reduce the cutting conditions, to resort to multi-pass processing, which greatly increases the laboriousness and cost of manufacturing products. In this context, the aim of this study – the creation of an equivalent mechanical model of the machine, allowing the process of studies to determine the boundaries of sustainable non-rigid turning shafts considering the different ways of mounting the workpiece on the machine. The materials of the article can be useful for engineers and scientists in the field of engineering.

PENGENDALIAN KUALITAS PROSES PRODUKSI PAKAN IKAN DENGAN MENERAPKAN QUALITY CONTROL PRODUKSI (QCP) DI PT CENTRAL PERTIWI BAHARI

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Putri Endah Suwarni ◽  
Keyword(s):  
Quality Control ◽  
Control Chart ◽  
Poor Quality ◽  
Fish Feed ◽  
Feed Production ◽  
Machine Productivity ◽  
Fish Feeds ◽  
Product Defect ◽  
Major Defect

Abstract The research method used is P-Chart method, with diagram of upper and lower control chart, check sheet, pareto diagram, and cause and effect diagram. The result of analysis using Pareto Diagram can be seen that from 199,880 kg or 0.6097% defective product, it is dominant defect 0.4282% in Size, 0.0981% in Floating, 0.0633% in Moisture, 0.0150% in Belang, and Others 0.0051%. Occurrence of fish feeds product defect caused by material factors, machine, methods, and man. Based on these factors that affect the quality of fish feeds are lack of training and lack of skill, exhaustion and negligence, lack of socialization of SOP (Standard Operating Procedures) and techniques in improper mixing, poor quality materials and material storage is too long , decreased machine productivity and lack of maintenance or maintenance of machinery. Application of quality control of fish feed production process at PT Central Pertiwi Bahari has been running well, this is proved by the percentage of major defect that does not exceed the maximum standards specified by the company. Keywords: quality control, check sheet, pareto diagram, cause-effect diagram, control chart (p-chart).

The Non-Destructive Test Method as A Simple Way to Evaluate the Quality Of Metal Core Pcbs for High Power Micro-Assemblies

2017 ◽  
Vol 8 (2) ◽  
pp. 281
Author(s):  
A.V. Sukhanov ◽  
A.I Artemova ◽  
R.S Litvinenko
Keyword(s):  
Quality Control ◽  
Heat Sink ◽  
Poor Quality ◽  
Test Method ◽  
Joint Interface ◽  
Layer By Layer ◽  
Metal Core ◽  
Before And After ◽  
Non Destructive

<p>The article describes the necessity of an incoming quality control of the delivered power electronics elements especially at the stage of choosing a reliable supplier. In particular, in the field of the metal core PCBs production, there is a need to control not only its heat sink parameters, but also to control the quality of the joint interface of the metal core PCBs. Since the use of poor-quality materials or the violation of the technological process by the manufacturer can lead to the defects in the PCBs structure. Thus it can affect the heat sink efficiency and the reliability of the entire assembly. The article proposes and describes the method of nondestructive incoming quality control of metal core PCBs. This method is based on the use of ultrasonic layer-by-layer scanning for obtaining the internal structure of PCBs. The article presents the results of applying this method for the PCBs of various manufacturers. The data of the structure visualization and the influence of environment temperatures changes were also obtained. The result pictures of the tested samples before and after the thermal circling were obtained to study the possible degradation of the PCBs structure and its parameters.</p>

scholarly journals Heparin-based ELISA reduces background reactivity in virus-like particle-based papillomavirus serology

2005 ◽  
Vol 86 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Xiaohong Wang ◽  
Martin Sapp ◽  
Neil D. Christensen ◽  
Joakim Dillner
Keyword(s):  
Quality Control ◽  
Human Papillomavirus ◽  
Poor Quality ◽  
Cross Reactivity ◽  
Heparin Binding ◽  
Binding Ability ◽  
Capture Elisa ◽  
Virus Like Particle ◽  
Variable Quality

The interaction between human papillomavirus (HPV) particles and cell surface heparan sulfate requires intact conformation of the HPV particles. Type-specific HPV serology is currently based on virus-like particles (VLPs) with intact conformation. Presence of incorrectly folded VLPs in VLP preparations is recognized as an important cause of cross-reactivity in HPV serology. Heparin-coated microtitre plates were evaluated for capturing conformationally correct VLPs and improving the type specificity of HPV serology. Hybrid VLPs between HPV16 and HPV11, which had been found to have significant reactivity with children's sera and a batch of HPV18 VLPs that had failed the quality control because of significant reactivity with sera from virginal women, were tested in parallel with heparin ELISA, ordinary ELISA and type-specific mAb capture ELISA. Control sera from children that had detectable reactivity with HPV16/11 hybrid VLPs in ordinary ELISA did not react in heparin-based ELISA, but some hybrid VLPs also had background reactivity in capture ELISAs. Control sera from virginal women that had some reactivity with a poor quality HPV18 VLP preparation in ordinary ELISA had no reactivity in heparin or capture ELISA, suggesting that certain VLP preparations expose cross-reactive epitopes that are not exposed on VLPs with heparin-binding ability. As the sensitivity was similar or only marginally affected by the use of heparin plates, use of heparin-coated plates may improve the type specificity of VLP-based ELISAs and reduce interassay variability attributable to variable quality of different VLP batches.

APPLYING EXPRESS METHOD OF DETERMINING THE FRESHNESS OF MEAT BY THE BONE MARROW

2018 ◽  
Vol 1 (1) ◽  
pp. 18-23
Author(s):  
I. M. Nityaga ◽  
◽  
B. V. Usha ◽  
Keyword(s):  
Bone Marrow ◽  
Muscle Tissue ◽  
High Sensitivity ◽  
Poor Quality ◽  
The Body ◽  
Animal Origin ◽  
Muscular Tissue ◽  
Express Method ◽  
Important Place

Nowadays, the problem of the quality of products of animal origin occupies an important place in our country and all over the world. This is due to the increasing influence of technogenic factors on the environment, crops and productive animals. One of the main indicators of the quality of meat is its freshness. The existing traditional methods for determining the freshness of meat, in spite of the rather long practice of their application, are generally inefficient, subjective, do not have high sensitivity and specificity. One of the problems of reliable evaluation of meat sold in the markets is the detection of dystrophic and edematic changes in the muscle tissue of slaughter animals, in the presence of which meat must be culled. Such processes in meat can develop at various diseases and long starvation. Generally accepted laboratory methods practically do not reveal signs of swelling of the muscular tissue. The aim of the research was to study the possibility of using the express method of freshness control during veterinary and sanitary examination of meat sold in the markets. Approbation of the express method for determining the freshness of meat using bone marrow was carried out. It is shown that this express method allowed to increase the number of rejected samples with revealed signs of poor quality in 1,5...2 times in comparison with generally accepted organoleptic and physicochemical methods of research. It is shown that with the express analysis of muscle tissue it is possible to reliably determine the poor quality of meat, associated with pathological processes in the body or with the development of signs of spoilage. Such express methods have a certain perspective of using by laboratories of veterinaty and sanitary examination in markets and fairs, as well as in production laboratories of meat processing enterprises.

Sign in / Sign up

Export Citation Format

Share Document