2,567 research outputs found

    Retraction and Generalized Extension of Computing with Words

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    Fuzzy automata, whose input alphabet is a set of numbers or symbols, are a formal model of computing with values. Motivated by Zadeh's paradigm of computing with words rather than numbers, Ying proposed a kind of fuzzy automata, whose input alphabet consists of all fuzzy subsets of a set of symbols, as a formal model of computing with all words. In this paper, we introduce a somewhat general formal model of computing with (some special) words. The new features of the model are that the input alphabet only comprises some (not necessarily all) fuzzy subsets of a set of symbols and the fuzzy transition function can be specified arbitrarily. By employing the methodology of fuzzy control, we establish a retraction principle from computing with words to computing with values for handling crisp inputs and a generalized extension principle from computing with words to computing with all words for handling fuzzy inputs. These principles show that computing with values and computing with all words can be respectively implemented by computing with words. Some algebraic properties of retractions and generalized extensions are addressed as well.Comment: 13 double column pages; 3 figures; to be published in the IEEE Transactions on Fuzzy System

    Navier-Stokes flow field analysis of compressible flow in a high pressure safety relief valve

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    The objective of this study is to investigate the complex three-dimensional flowfield of an oxygen safety pressure relieve valve during an incident, with a computational fluid dynamic (CFD) analysis. Specifically, the analysis will provide a flow pattern that would lead to the expansion of the eventual erosion pattern of the hardware, so as to combine it with other findings to piece together a most likely scenario for the investigation. The CFD model is a pressure based solver. An adaptive upwind difference scheme is employed for the spatial discretization, and a predictor, multiple corrector method is used for the velocity-pressure coupling. The computational result indicated vortices formation near the opening of the valve which matched the erosion pattern of the damaged hardware

    Homogeneous point mutation detection by quantum dot-mediated two-color fluorescence coincidence analysis

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    This report describes a new genotyping method capable of detecting low-abundant point mutations in a homogeneous, separation-free format. The method is based on integration of oligonucleotide ligation with a semiconductor quantum dot (QD)-mediated two-color fluorescence coincidence detection scheme. Surface-functionalized QDs are used to capture fluorophore-labeled ligation products, forming QD-oligonucleotide nanoassemblies. The presence of such nanoassemblies and thereby the genotype of the sample is determined by detecting the simultaneous emissions of QDs and fluorophores that occurs whenever a single nanoassembly flows through the femtoliter measurement volume of a confocal fluorescence detection system. The ability of this method to detect single events enables analysis of target signals with a multiple-parameter (intensities and count rates of the digitized target signals) approach to enhance assay sensitivity and specificity. We demonstrate that this new method is capable of detecting zeptomoles of targets and achieve an allele discrimination selectivity factor >10(5)

    Mycotoxin monitoring for commercial foodstuffs in Taiwan

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    AbstractMycotoxins are toxic food contaminants that are naturally produced by certain fungi. They induce negative effects on human health by making food unsafe for consumption. In this study, analyses were performed to determine the levels and incidence of aflatoxins (AFs) in peanut products, tree nuts, spices, and Coix seeds; ochratoxin A (OTA) in wheat and roasted coffee, as well as OTA and AFs in rice; and citrinin (CIT) in red yeast rice (RYR) products. A total of 712 samples from nine different food categories were collected between 2012 and 2013. The samples were analyzed over 2 years for AFs, OTA, and CIT by methods recommended by the Ministry of Health and Welfare. These official analytical methods were extensively validated in-house and through interlaboratory trials. The analytical values of suspected contaminated specimens were confirmed by liquid chromatography – tandem mass spectrometry analysis to identify the specific mycotoxin present in the sample. We show that 689 samples (96.8%) complied with the regulations set by the Ministry of Health and Welfare. AFs were found in four peanut-candy products, one peanut-flour product, one pistachio product, one Sichuan-pepper product, and one Coix seed product. All had exceeded the maximum levels of 15 parts per billion for peanut and 10 parts per billion for other food products. Furthermore, 14 RYR samples contained CIT above 5 parts per million, and one RYR tablet exceeded the maximum amount allowed. Instances of AFs in substandard Sichuan pepper and Coix seeds were first detected in Taiwan. Measures were taken by the relevant authorities to remove substandard products from the market in order to decrease consumer exposure to mycotoxin. Border control measures were applied to importing food commodities with a higher risk of mycotoxin contamination, such as peanut, Sichuan pepper, and RYR products. Declining trends were observed in the noncompliance rate of AFs in peanut products, as well as that of CIT in RYR raw materials monitored from 2010 to 2013

    Significant association of hematinic deficiencies and high blood homocysteine levels with burning mouth syndrome

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    Background/PurposeBurning mouth syndrome (BMS) is characterized by a burning sensation of the oral mucosa in the absence of clinically apparent mucosal alterations. In this study, we evaluated whether there was an intimate association of the deficiency of hemoglobin (Hb), iron, vitamin B12, or folic acid; high blood homocysteine level; and serum gastric parietal cell antibody (GPCA) positivity with BMS.MethodsBlood Hb, iron, vitamin B12, folic acid, and homocysteine concentrations and the serum GPCA level were measured in 399 BMS patients and compared with the corresponding levels in 399 age- and sex-matched healthy control individuals.ResultsWe found that 89 (22.3%), 81 (20.3%), 10 (2.5%), and six (1.5%) BMS patients had deficiencies of Hb (men: <13 g/dL, women: <12 g/dL), iron (<60 μg/dL), vitamin B12 (<200 pg/mL), and folic acid (<4 ng/mL), respectively. Moreover, 89 (22.3%) BMS patients had abnormally high blood homocysteine level and 53 (13.3%) had serum GPCA positivity. BMS patients had a significantly higher frequency of Hb, iron, or vitamin B12 deficiency; of abnormally elevated blood homocysteine level; or of serum GPCA positivity than the healthy control group (all p < 0.001 except for vitamin B12 deficiency, for which p = 0.004). However, no significant difference in frequency of folic acid deficiency (p = 0.129) was found between BMS patients and healthy control individuals.ConclusionWe conclude that there is a significant association of deficiency of Hb, iron, and vitamin B12; abnormally high blood homocysteine level; and serum GPCA positivity with BMS

    Navier-Stokes Flow Field Analysis of Compressible Flow in a Pressure Relief Valve

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    The present study was motivated to analyze the complex flow field involving gaseous oxygen (GOX) flow in a relief valve (RV). The 9391 RV, pictured in Figure 1, was combined with the pilot valve to regulate the actuation pressure of the main valve system. During a high-pressure flow test at Marshall Space Flight Center (MSFC) the valve system developed a resonance chatter, which destroyed most of the valve body. Figures 2-4 show the valve body before and after accident. It was understood that the subject RV has never been operated at 5500 psia. In order to fully understand the flow behavior in the RV, a computational fluid dynamics (CFD) analysis is carried out to investigate the side load across the piston sleeve and the erosion patterns resulting from flow distribution around piston/nozzle interface
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