9,860 research outputs found
Metadata Representations for Queryable ML Model Zoos
No full textMachine learning (ML) practitioners and organizations are building model zoos of pre-trained models, containing metadata describing properties of the ML models and datasets that are useful for reporting, auditing, reproducibility, and interpretability purposes. The metatada is currently not standardised; its expressivity is limited; and there is no interoperable way to store and query it. Consequently, model search, reuse, comparison, and composition are hindered. In this paper, we advocate for standardized ML model metadata representation and management, proposing a toolkit supported to help practitioners manage and query that metadata.Web Information SystemsHuman-Centred Artificial Intelligenc
A Manifesto of Nodalism
No full textThis paper proposes the notion of Nodalism as a means describing contemporary culture and of understanding my own creative practice in electronic music composition. It draws on theories and ideas from Kirby, Bauman, Bourriaud, Deleuze, Guatarri, and Gochenour, to demonstrate how networks of ideas or connectionist neural models of cognitive behaviour can be used to contextualize, understand and become a creative tool for the creation of contemporary electronic music
Electrochemical NOx Sensors Based on Interfacing Nanosized LaFeO3 Perovskite-Type Oxide and Ionic Conductors
No full textElectrochemical NOx sensors based on coupling different ionic conductors with perovskite-type LaFeO3 as auxiliary phase were prepared. The ionic conductors used were yttria-stabilized zirconia that is an oxygen ion conductor and sodium superionic conductor whose charge carriers are sodium ions. Thick films of LaFeO3 powders were deposited using a screen printing oil on one side of the solid electrolyte pellets, using powders having different grain sizes. The obtained sensors were wholly exposed to the same atmosphere. Electromotive force (emf), polarization curves, and amperometric measurements were performed in air and at different concentrations of NO2 in air, at selected temperatures. Quite stable emf values and fast response times were obtained. The NO2 response was much larger when powders with nanosized grains were used for the preparation of the electrodes. From polarization curves, all sensors showed a nonlinear behavior. The role played by the electrolyte/electrode interface was determined by electrochemical impedance spectroscopy measurements; exposure to NO2 did not affect the bulk but only the electrolyte/electrode interface. © 2001 The Electrochemical Society. [DOI: 10.1149/1.1386921] All rights reserved
Pediocin A modulates intestinal microflora metabolism in swine in vitro intestinal fermentations
No full textThe aim of this study was to investigatein vitro the effects of pediocin A [a bacteriocinproduced by lactic acid bacteria (LAB) Pediococcuspentosaceus FBB61] on microbial metabolism inthe small and large intestine of pigs. Pediocin A waspartially purified by ion exchange chromatography andadded to an in vitro fermentation system. The intestinalinoculum was collected from pigs immediately afterslaughter, diluted with a buffer, and dispensed intofermentation syringes and vessels of the 2 experimentalgroups: 1) Bac+ = cecal liquor + predigested diet +pediocin A (final concentration 160 activity units/mL);2) Bac− = cecal liquor + predigested diet + partiallypurified supernatant of P. pentosaceus FBB61–2. Intestinalmicrobial growth was monitored using the cumulativegas production technique; the kinetics of fermentation,bacterial counts, VFA, ammonia, polyamines,and p-cresol production were analyzed. Pediocin A hadalmost no effects on small intestine fermentation parameters,whereas in the cecum pediocin A decreasedgas production (−16%; P < 0.05), ammonia, and VFAproduction (−52 and −21%, respectively, after 24 h;P < 0.001) compared with the control group. Significantinhibition of clostridia and LAB occurred in cecalfermentations: the Bac+ group yielded a decreasednumber of clostridia and LAB in cecal fermentations(8.19 and 7.80 cfu/mL, respectively) compared withBac− (9.32 and 8.95 cfu/mL, respectively; P < 0.001).The low clostridia counts in the pediocin-treated groupmay also explain the reduced concentration of the carcinogeniccompound p-cresol (−88%; P < 0.01). Ourresults suggest that pediocin A could be an alternativeto replace antibiotic growth promoters for the prophylaxisof enteric diseases and to improve production offarm animals.[...
Optimizing ML Inference Queries Under Constraints
No full textThe proliferation of pre-trained ML models in public Web-based model zoos facilitates the engineering of ML pipelines to address complex inference queries over datasets and streams of unstructured content. Constructing optimal plan for a query is hard, especially when constraints (e.g. accuracy or execution time) must be taken into consideration, and the complexity of the inference query increases. To address this issue, we propose a method for optimizing ML inference queries that selects the most suitable ML models to use, as well as the order in which those models are executed. We formally define the constraint-based ML inference query optimization problem, formulate it as a Mixed Integer Programming (MIP) problem, and develop an optimizer that maximizes accuracy given constraints. This optimizer is capable of navigating a large search space to identify optimal query plans on various model zoos.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Web Information SystemsHuman-Centred Artificial Intelligenc
Sensing mechanism of potentiometric gas sensors based on stabilized zirconia with oxide electrodes, is it always mixed potential?
No full textThe non-Nernstian behavior of zirconia-based electrochemical NOx and CO sensors with various semiconducting oxides as
sensing electrodes was extensively studied in the temperature range 450-700°C. Both pellets and tape-cast layers of yttriastabilized
zirconia were used for the fabrication of the sensors. It was found that the gas-sensing mechanism of the sensors cannot
be explained always by the mixed potential theory. When semiconducting oxides are used as sensing electrodes, the semiconductor
sensing mechanism and the adsorption-desorption behavior of the different oxides dominate the sensor response if both metal and oxide are exposed to the same environment
NOx sensors based on interfacing yttria stabilized zirconia with p and n-type semiconducting oxides
No full textElectrochemical NOx sensors based on coupling yttria stabilized zirconia (YSZ), an oxygen-ion conductor, with different semiconducting oxides as auxiliary phase were studied. Nanosized LaFeO3 perovskite-type oxide, a p-type semiconductor, and n-type WO3 were used as auxiliary phases because of their NO2 sensing properties in resistive-type devices. LaFeO3 or WO3 thick films were deposited using a screen printing oil on one side of the solid-electrolyte pellets. The sensors were fully exposed to the same atmosphere. Electromotive force (EMF), polarization curves, amperometric and electrochemical impedance spectroscopy (EIS) measurements, were performed in air and at different concentrations of NO2 in air, at selected temperatures
Planar electrochemical sensors based on YSZ with WO3 electrode prepared by different chemical routes
No full textPlanar electrochemical sensors based on tape-cast yttria stabilized zirconia (YSZ, 8 wt.% of Y2O3) layers with two Pt parallel electrodes, one coated with WO3 powders were prepared. The WO 3 powders were synthesized in the laboratory using different chemical routes. The NO2 and CO potentiometric response of the sensors was measured at high temperature and compared to the response of the sensors fabricated using commercial WO3 powders. Promising results in terms of selectivity, sensitivity, stability, reproducibility and response time were obtained for synthesized WO3-based sensors in comparison to the response of commercial WO3-based sensors. © 2005 Published by Elsevier B.V
sp. (Chroococcales)
No full textChroococcidiopsis sp. cells from hot desert rock (Timna National Park, Israel) were grown in modified BG-11 medium which was either N-free or which contained different concentrations of nitrogen, provided as nitrate. The life cycle, ultrastructure and physiological activities of the cyanobacterium were investigated over a period of 4 months. No alterations were detected in cells grown in medium containing 250 or 125 Î1⁄4g N ml-1. In contrast, cells grown in medium with 62 Î1⁄4g N ml-1 or lacking nitrogen occurred only as isolated viable forms, after 3 months and 1 month of growth, respectively. In these cells a decrease in the content of cellular chlorophyll and phycocyanin paralleled undetectable O2 evolution and depressed O2 uptake. In addition, such isolated cells were characterized by a multilayered envelope, whereas, in the cytoplasm, vesiculated thylakoids and glycogen granules were observed. N-limited and N-starved cells recovered their cellular organization and physiological activities upon N repletion. These 'survival' cells had a spore-like form, and were functionally comparable to akinetes
- …
