Conversion error analysis
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Since 2010 the LVR-15 reactor has been gradually converted from highly enriched fuel (36wt% (235)U) to low enriched fuel with the enrichment of 19.75wt% (235)U. Paper presents influence of the core pattern changes on the neutron characteristics of the epithermal beam. The determination of neutron spectrum free in the beam was done with a set of neutron activation monitors. After the reactor conversion the change in neutron spectrum is not provable as differences are in the range of measurement errors.
- MeSH
- analýza selhání vybavení MeSH
- atomové reaktory přístrojové vybavení MeSH
- design vybavení MeSH
- neutrony * MeSH
- radiometrie přístrojové vybavení MeSH
- terapie metodou neutronového záchytu (bor-10) přístrojové vybavení MeSH
- uran analýza MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
INTRODUCTION: The process of fabricating physical medical skull models requires many steps, each of which is a potential source of geometric error. The aim of this study was to demonstrate inaccuracies and differences caused by DICOM to STL conversion in additively manufactured medical skull models. MATERIAL AND METHODS: Three different institutes were requested to perform an automatic reconstruction from an identical DICOM data set of a patients undergoing tumour surgery into an STL file format using their software of preference. The acquired digitized STL data sets were assessed and compared and subsequently used to fabricate physical medical skull models. The three fabricated skull models were then scanned, and differences in the model geometries were assessed using established CAD inspection software methods. RESULTS: A large variation was noted in size and anatomical geometries of the three physical skull models fabricated from an identical (or "a single") DICOM data set. CONCLUSIONS: A medical skull model of the same individual can vary markedly depending on the DICOM to STL conversion software and the technical parameters used. Clinicians should be aware of this inaccuracy in certain applications.
- MeSH
- algoritmy MeSH
- anatomické modely * MeSH
- design s pomocí počítače statistika a číselné údaje MeSH
- kefalometrie statistika a číselné údaje MeSH
- lebka anatomie a histologie MeSH
- lidé MeSH
- mandibula anatomie a histologie MeSH
- nosní dutina anatomie a histologie MeSH
- orbita anatomie a histologie MeSH
- počítačová tomografie s kuželovým svazkem statistika a číselné údaje MeSH
- počítačové zpracování obrazu statistika a číselné údaje MeSH
- povrchové vlastnosti MeSH
- radiologické informační systémy statistika a číselné údaje MeSH
- sinus maxillaris anatomie a histologie MeSH
- software MeSH
- zobrazování trojrozměrné statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
BACKGROUND: Only three inherited metabolic defects have been identified in purine de novo synthesis (PDNS). We present here CE methods for diagnosing defects in the second half of PDNS (from sixth to tenth enzymatic conversion) based on analysis of aminoimidazole ribosides - dephosphorylated intermediates - in urine. METHODS: Assays were performed in an uncoated fused-silica capillary using two electrophoretic separation systems: 60 mmol/l borate - 2-amino-2-methyl-1-propanol-80 mmol/l sodium dodecylsulfate (pH 9.6) and 200 mmol/l phosphate - sodium (pH 1.8). RESULTS: The reported conditions allowed separation of all metabolites from major urinary constituents with analysis time less than 10 min and separation efficiency of 220 and 350 thousands theoretical plates per meter for borate and phosphate system, respectively. The intra- and interday imprecisions were less than 4.4% and 9.9% CV. Potential usefulness of the methods was demonstrated on samples from a patient with adenylosuccinate lyase deficiency and Chinese hamster ovary cell lines defective in PDNS. CONCLUSIONS: CE is a useful and effective tool in the analysis of aminoimidazole ribosides which enables diagnosis of known as well as not so far identified inherited defects of PDNS pathway.
- MeSH
- adenylsukcinátlyasa nedostatek MeSH
- biosyntetické dráhy MeSH
- buněčné linie MeSH
- časové faktory MeSH
- CHO buňky MeSH
- Cricetulus MeSH
- dítě MeSH
- elektroforéza kapilární metody MeSH
- financování organizované MeSH
- imidazoly moč MeSH
- kojenec MeSH
- křečci praví MeSH
- lidé MeSH
- mladiství MeSH
- molekulární struktura MeSH
- předškolní dítě MeSH
- purinové nukleosidy biosyntéza MeSH
- referenční hodnoty MeSH
- vrozené poruchy metabolismu aminokyselin diagnóza MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- křečci praví MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- zvířata MeSH
It has been widely reported that men have a lower ratio of the 2nd and 4th human finger lengths (2D : 4D). Size-scaling ratios, however, have the seldom-appreciated potential for providing biased estimates. Using an information-theoretic approach, we compared 12 candidate models, with different assumptions and error structures, for scaling untransformed 2D to 4D lengths from 154 men and 262 women. In each hand, the two-parameter power function and the straight line with intercept models, both with normal, homoscedastic error, were superior to the other models and essentially equivalent to each other for normalizing 2D to 4D lengths. The conventional 2D : 4D ratio biased relative 2D length low for the generally bigger hands of men, and vice versa for women, thereby leading to an artefactual indication that mean relative 2D length is lower in men than women. Conversely, use of the more appropriate allometric or linear regression models revealed that mean relative 2D length was, in fact, greater in men than women. We conclude that 2D does not vary in direct proportion to 4D for both men and women, rendering the use of the simple 2D : 4D ratio inappropriate for size-scaling purposes and intergroup comparisons.
- MeSH
- antropometrie MeSH
- lidé MeSH
- lineární modely MeSH
- pohlavní dimorfismus * MeSH
- prsty ruky anatomie a histologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Plaster casts of individual patients are important for orthodontic specialists during the treatment process and their analysis is still a standard diagnostical tool. But the growing capabilities of information technology enable their replacement by digital models obtained by complex scanning systems. METHOD: This paper presents the possibility of using a digital camera as a simple instrument to obtain the set of digital images for analysis and evaluation of the treatment using appropriate mathematical tools of image processing. The methods studied in this paper include the segmentation of overlapping dental bodies and the use of different illumination sources to increase the reliability of the separation process. The circular Hough transform, region growing with multiple seed points, and the convex hull detection method are applied to the segmentation of orthodontic plaster cast images to identify dental arch objects and their sizes. RESULTS: The proposed algorithm presents the methodology of improving the accuracy of segmentation of dental arch components using combined illumination sources. Dental arch parameters and distances between the canines and premolars for different segmentation methods were used as a measure to compare the results obtained. CONCLUSION: A new method of segmentation of overlapping dental arch components using digital records of illuminated plaster casts provides information with the precision required for orthodontic treatment. The distance between corresponding teeth was evaluated with a mean error of 1.38% and the Dice similarity coefficient of the evaluated dental bodies boundaries reached 0.9436 with a false positive rate [Formula: see text] and false negative rate [Formula: see text].
- MeSH
- algoritmy * MeSH
- analogově digitální konverze MeSH
- datové soubory jako téma MeSH
- elektronické zdravotní záznamy * MeSH
- fotografování metody MeSH
- lidé MeSH
- osvětlení metody MeSH
- počítačové zpracování obrazu metody MeSH
- poměr signál - šum MeSH
- ukládání a vyhledávání informací MeSH
- zubní oblouk anatomie a histologie MeSH
- zubní odlitky - technika * MeSH
- zubní záznamy * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
A large-scale, double-stream gas puff target has been illuminated by sub-kJ, near-infrared (NIR) focused laser pulses at the PALS facility (Prague Asterix Laser System) to produce high-energy pulses of soft X rays from hot, dense plasma. The double-puff arrangement ensures high gas density and conversion efficiency from NIR to X rays approaching that typical for solid targets. In addition, its major advantage over solid targets is that it is free of debris and has substantially suppressed charged-particle emission. The X-ray emission characteristics of the source were determined for a range of gases that included krypton, xenon, N(2), CO and N(2)-CO. A demonstrated application of the xenon-based source is a single-shot damage induction to plasmid DNA. The yields of single-strand breaks (SSBs) and double-strand breaks (DSBs) were determined as a function of energy fluence adjusted by varying distance of sample from the source and thickness of aluminum filters.
- MeSH
- analýza selhání vybavení MeSH
- dávka záření MeSH
- design vybavení MeSH
- lasery MeSH
- nanotechnologie metody přístrojové vybavení MeSH
- odběr biologického vzorku metody přístrojové vybavení MeSH
- plazmidy chemie účinky léků MeSH
- poškození DNA účinky záření MeSH
- radiobiologie metody přístrojové vybavení MeSH
- rentgenové záření MeSH
- výzkum přístrojové vybavení MeSH
- výzkumný projekt MeSH
- Publikační typ
- hodnotící studie MeSH
The aim of this study is to identify the optimum thermal conversion of Chlorella vulgaris with neuro-evolutionary approach. A Progressive Depth Swarm-Evolution (PDSE) neuro-evolutionary approach is proposed to model the Thermogravimetric analysis (TGA) data of catalytic thermal degradation of Chlorella vulgaris. Results showed that the proposed method can generate predictions which are more accurate compared to other conventional approaches (>90% lower in Root Mean Square Error (RMSE) and Mean Bias Error (MBE)). In addition, Simulated Annealing is proposed to determine the optimal operating conditions for microalgae conversion from multiple trained ANN. The predicted optimum conditions were reaction temperature of 900.0 °C, heating rate of 5.0 °C/min with the presence of HZSM-5 zeolite catalyst to obtain 88.3% of Chlorella vulgaris conversion.
- MeSH
- Chlorella vulgaris * MeSH
- katalýza MeSH
- mikrořasy * MeSH
- neuronové sítě MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
Spiking Neural Network (SNN) is a promising energy-efficient neural architecture when implemented on neuromorphic hardware. The Artificial Neural Network (ANN) to SNN conversion method, which is the most effective SNN training method, has successfully converted moderately deep ANNs to SNNs with satisfactory performance. However, this method requires a large number of time-steps, which hurts the energy efficiency of SNNs. How to effectively covert a very deep ANN (e.g., more than 100 layers) to an SNN with a small number of time-steps remains a difficult task. To tackle this challenge, this paper makes the first attempt to propose a novel error analysis framework that takes both the "quantization error" and the "deviation error" into account, which comes from the discretization of SNN dynamicsthe neuron's coding scheme and the inconstant input currents at intermediate layers, respectively. Particularly, our theories reveal that the "deviation error" depends on both the spike threshold and the input variance. Based on our theoretical analysis, we further propose the Threshold Tuning and Residual Block Restructuring (TTRBR) method that can convert very deep ANNs (>100 layers) to SNNs with negligible accuracy degradation while requiring only a small number of time-steps. With very deep networks, our TTRBR method achieves state-of-the-art (SOTA) performance on the CIFAR-10, CIFAR-100, and ImageNet classification tasks.
- MeSH
- neuronové sítě * MeSH
- počítače * MeSH
- Publikační typ
- časopisecké články MeSH
Východiska: Fenomén replikační krize ve vědě se týká dlouhodobé neschopnosti zopakovat výsledky dřívějších vědeckých studií. To pochopitelně vede ke snižování důvěry ve vědu. Ukazuje se, že i renomovaní vědci využívají pochybné vědecké praktiky (např. záměrné manipulace s datovými analýzami) tak, aby dosáhli kýžených, statisticky významných, tedy publikovatelných výsledků. Tato pochybení jsou spojována s problematickým nastavením pobídek ve vědě, které vytvářejí nepřiměřený tlak na vědce a ti jsou nuceni k produkci zajímavých výsledků. Naopak studie s negativními výsledky (výsledky, které nejsou v souladu se stanovenou hypotézou), nejsou obvykle publikovány, což vede k publikačnímu zkreslení. Cíle: Cílem tohoto článku je popsat hlavní faktory, které přispívají k replikační krizi a nabídnout možná řešení jak tyto faktory mírnit. Závěry: Domníváme se, že problémy spojené s replikační krizí jsou natolik závažné, že je nebude možno řešit jinak než významnými změnami v systému hodnocení a financování vědy. Zapotřebí bude také široká diskuze na toto téma spojená s hlubší edukací vědců v oblasti statistického zpracovávání dat, neboť mnohá pochybení jsou výsledkem neznalosti, nikoliv záměrné manipulace s daty. Nedílnou součástí těchto změn bude vedle apelu na morální integritu vědce, také nutná větší transparentnost vědeckých postupů v duchu tzv. Open Science.
Background: The phenomenon of the replication crisis in science refers to the long-term inability to replicate the results of earlier scientific studies. This naturally leads to a reduction in trust in science. It turns out that even reputable scientists use questionable scientific practices (e.g. deliberate manipulation of data analyses) to achieve the desired statistically significant, i. e. publishable, results. This misconduct has been linked to the problematic setting of incentives in science, which creates undue pressure on scientists to produce interesting results. Conversely, studies with negative results (results that are consistent with the hypothesis) are usually not published, leading to publication bias. Objective: This article aims to describe the main factors that contribute to the replication crisis and to offer possible solutions to mitigate these factors. Conclusions: : We believe that the problems associated with the replication crisis are so severe that they cannot be addressed except through significant changes to the science assessment system and funding. A broad discussion on this topic coupled with deeper education of scientists in statistical data processing will also be needed, as many errors are the result of ignorance, not deliberate manipulation of data. An integral part of these changes, in addition to the appeal to the moral integrity of the scientist, will be the need for greater transparency of scientific procedures in the spirit of Open Science.
