Search results for " Detection"
showing 10 items of 1676 documents
Learning Temporal Regularities of User Behavior for Anomaly Detection
2001
Fast expansion of inexpensive computers and computer networks has dramatically increased number of computer security incidents during last years. While quite many computer systems are still vulnerable to numerous attacks, intrusion detection has become vitally important as a response to constantly increasing number of threats. In this paper we discuss an approach to discover temporal and sequential regularities in user behavior. We present an algorithm that allows creating and maintaining user profiles relying not only on sequential information but taking into account temporal features, such as events' lengths and possible temporal relations between them. The constructed profiles represent …
Highly selective detection of Epinephrine at oxidized Single-Wall Carbon Nanohorns modified Screen Printed Electrodes (SPEs)
2014
Oxidized Single-Wall Carbon Nanohorns (o-SWCNHs) were used, for the first time, to assemble chemically modified Screen Printed Electrodes (SPEs) selective towards the electrochemical detection of Epinephrine (Ep), in the presence of Serotonine-5-HT (S-5HT), Dopamine (DA), Nor-Epineprhine (Nor-Ep), Ascorbic Acid (AA), Acetaminophen (Ac) and Uric Acid (UA). The Ep neurotransmitter was detected by using Differential Pulse Voltammetry (DPV), in a wide linear range of concentration (2-2500 μM) with high sensitivity (55.77 A M(-1) cm(-2)), very good reproducibility (RSD% ranging from 2 to 10 for different SPEs), short response time for each measurement (only 2s) and low detection of limit (LOD=0.…
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
2020
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…
NEMESIS Setup for Indirect Detection of WIMPs
2022
We summarize the evidence for DM-like anomalies in neutron multiplicity spectra collected underground with Pb targets by three independent experiments: NEMESIS (at 210 m.w.e.) NMDS (at 583 m.w.e.), and ZEPLIN-II (at 2850 m.w.e.). A new analysis shows small but persistent anomalies at high neutron multiplicities. Adjusted for differences in detection efficiencies, the positions of the anomalies are consistent between the three systems. Also, the intensities match when corrected for the acquisition time and estimated detection efficiency. While the three measurements are inconclusive when analyzed separately, together, they exclude a statistical fluke to better than one in a million. To prove…
Highly sensitive monoclonal antibody-based immunoassays for boscalid analysis in strawberries
2018
Boscalid is an agrochemical recently developed for crop protection and the most significant member of the succinate dehydrogenase inhibitor group of fungicides. In this study, a collection of high-affinity monoclonal antibodies was generated to boscalid. By using a series of haptens with a linker at alternative tethering sites of the boscalid framework, specific antibodies were isolated as well as antibodies that also recognized the main boscalid metabolite. Two immunoassays were developed using different ELISA formats. Optimized assays displayed very high sensitivities (limits of detection were near 0.01 µg/L). Trueness and precision for the determination of the target analyte in strawberr…
Chapter 8 Nicotinic receptors of the vertebrate CNS: introductory remarks
1996
Publisher Summary This chapter focuses on the nicotinic receptors of the vertebrate central nervous system (CNS). In vertebrates, nicotinic cholinergic neurotransmission is found in both the CNS and the periphery (muscle endplate). Although muscle and neuronal nicotinic acetylcholine receptors (nAChR) have evolved from a common ancestor, it is striking that the muscle receptor has remained rather stable in evolution, whereas the neuronal receptor has evolved to a wide diversity of subtypes. As an attractive hypothesis, neurotransmitters and neurohormones may not only interact with their archetypic cognate receptors but also with other neuroreceptor, albeit in a modulatory fashion. By modula…
Combining poly(dimethyldiphenylsiloxane) and nitrile phases for improving the separation and quantitation of benzalkonium chloride homologues: In-tub…
2013
The retention and separation of four homologues of benzalkonium chloride (alkyl (C12, C14, C16, C18) dimethylbenzylammonium chloride) have been studied in poly(dimethyldiphenylsiloxane) (TRB) and nitrile capillary phases, respectively. Under the optimized conditions (50% acetonitrile in processed samples, 35% of diphenyl content of the TRB, capillary length 43 cm and water:methanol 60:40 as replacing solvent), the extraction efficiency was similar for all the homologues with satisfactory reproducibility and independently of the amount and proportion of homologues. Industrial samples with high viscosity or with complex composition and washes waters have been analyzed without previous treatme…
Footprint of carbonyl compounds in hand scent by in-tube solid-phase microextraction coupled to nano-liquid chromatography/diode array detection
2019
Abstract In the present work, the footprint of carbonyl compounds in hand scent was achieved by a miniaturized method consisting of sampling with cotton gauze, extraction and derivatization using 2,4-dinitrophenylhydrazine (DNPH) and preconcentration, separation and detection by in-tube solid-phase microextraction (IT-SPME) coupled to nano-liquid chromatography/Uv–vis diode array detection. The coupling IT-SPME-nanoLC-DAD was solved by using a two-valve system: the first valve for loading the sample and the second one to perform IT-SPME. To this aim, a nanoparticle-based capillary column was employed. Firstly, the transfer time from the load loop to the NP-based capillary column in the IT-S…
Overview of Other Results and Open Problems
2014
This chapter presents an overview of results related to error control methods, which were not considered in previous chapters. In the first part, we discuss possible extensions of the theory exposed in Chaps. 3 and 4 to nonconforming approximations and certain classes of nonlinear problems. Also, we shortly discuss some results related to explicit evaluation of modeling errors. The remaining part of the chapter is devoted to a posteriori estimates of errors in iteration methods. Certainly, the overview is not complete. A posteriori error estimation methods are far from having been fully explored and this subject contains many unsolved problems and open questions, some of which we formulate …
Data Compression with ENO Schemes: A Case Study
2001
Abstract We study the compresion properties of ENO-type nonlinear multiresolution transformations on digital images. Specific error control algorithms are used to ensure a prescribed accuracy. The numerical results reveal that these methods strongly outperform the more classical wavelet decompositions in the case of piecewise smooth geometric images.