Search results for "FREQUENCY"
showing 10 items of 2158 documents
UHF RFID humidity sensor tag based on hygroscopic polymeric load
2012
Passive UHF RFID tags, beside item labelling, are also able to exploit capability of sensing the physical state of the tagged object as well as of the surrounding environment. Here a family of polymer-doped tags are proposed and fully characterized for the detection of ambient humidity. A sensitive chemical species based on PEDOT: PSS is used to dope a properly shaped slot carved into a folded-like patch tag. The sensing capabilities of the radio-sensor are investigated by means of measurements for different quantities of sensitive material and in cyclic exposures. The device could have interesting application in the assessment of the air quality in living and controlled rooms, in the monit…
A new method to "clean up" ultra high-frequency data
2007
In the applied econometrics, the availability of ultra high-frequency databases is having an important impact on the research market microstructure theory. The ultra high-frequency databases contain detailed reports of all the financial market activity information which is available. However, ultra high-frequency databases cannot be directly used. On one hand recording mistakes can be present, on the other hand missing information has to be inferred from the available data. In this paper, we propose a simple method in order to clean up the ultra high-frequency data from possible errors and we examine the method efficacy when we analyze data by using an autoregressive conditional duration (A…
Ultrasonic guided wave propagation in long bones with varying cortical thickness
2009
The propagation of ultrasonic guided wave (GW) in the long bone is very sensitive to the bones' shapes, properties and cortical thicknesses (CTh). Most of the previous studies on the GW propagation in long bones mainly focused on the bones with uniform CTh. However, it is necessary to understand the impacts of CTh variation, such as mode conversion. Therefore, an adequate analysis on GW propagating in long bones with varying CTh is essential for the precise calibration of the quantitative measurement of it. The aim of this study is to use a modified boundary element method (BEM) to analyze the GW propagation characteristics in long bones with varying CTh. Numerical analysis implemented by t…
Multilinear Fourier multipliers related to time–frequency localization
2013
We consider multilinear multipliers associated in a natural way with localization operators. Boundedness and compactness results are obtained. In particular, we get a geometric condition on a subset A⊂R2d which guarantees that, for a fixed synthesis window ψ∈L2(Rd), the family of localization operators Lφ,ψA obtained when the analysis window φ varies on the unit ball of L2(Rd) is a relatively compact set of compact operators.
Polymorphisms of β-defensin genes in Valle del Belice dairy sheep
2011
The aim of this work was to study β-defensin 1 (SBD1) and β-defensin 2 (SBD2) genes in Valle del Belice dairy sheep in order to identify polymorphisms that can be utilized as markers of the analyzed genes, and search for the functional effects and roles of the identified polymorphisms (variation of the amino acid sequence of the protein and stability of mRNA molecule). The study was conducted on 300 randomly selected animals belonging to four flocks. A total of seven SNPs were identified, two in SBD1 and five in SBD2. The two SNPs identified in SBD2 coding region, at position 1659 and position 1667, were non-synonymous, leading to amino acid changes in the protein product. Nevertheless, the…
Syllabic composition and use frequency: how do they affect stress assignment? A comparison between slow readers and fluent readers
2013
Italian words can be stressed either on penultimate or antepenultimate syllables. In both cases, stress assignment is not predictable by rules, but requires a lexical check. Italian words with stress on the penultimate syllable are defined as regular because the proportion of these words is much larger than words with stress on the antepenultimate syllable, defined as irregular. We propose to investigate the influence (in terms of correct stress positioning) of different syllabic and stress structures during "decoding” by both slow readers and fluent readers. Forty-eight children, twenty-four slow and twenty-four fluent readers, decoded “target words” selected on the basis of frequency (hig…
Uztvertā vecāku pārraudzība, smēķēšanas un/ vai alkohola lietošanas biežums pusaudžiem no pilnām un nepilnām ģimenēm.
2018
Pētījuma mērķis bija izpētīt sakarības starp uztverto vecāku pārraudzību un alkohola lietošanas biežumu pusaudžiem no pilnām un nepilnām ģimenēm. Datu ievākšanai tika izmantota Vecāku uzraudzības aptauja ( Parental Monitoring Scale, Stattin & Kerr, 2009), kas sastāv no 24 jautājumiem, kas atspoguļo vecāku uzraudzības veidus., (t.i., ko vecāki zina, pusaudžu atklātība, kontroles sajūta, vecāku kontrole). Apgalvojumi tiek vērtēti pēc Likerta skalas 5 punktu sistēmā (1- „nekad”, 5- „vienmēr”). Un alkohola lietošanas biežuma aptauja (Youth risk behavior survey. Division of adolescent and school health, CDC, 1993.g.). Attiecīgā aptauja sastāv no 5 jautājumiem. Respondentiem tiek lūgts izvērtēt k…
Performance Analysis of Alamouti Coded OFDM Systems over Rayleigh Fading Channels Correlated in Space and Time
2010
Paper presented at the 2010 IEEE 71st Vehicular Technology Conference, Taipei.(c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Paper also available from the publisher: http://dx.doi.org/10.1109/VETECS.2010.5493855 This paper deals with the performance analysis of Alamouti coded orthogonal frequency division multiplexing (OFDM) systems over time-varying multipath Rayleigh fading channels. I…
Frequency domain control based on quantitative feedback theory for vibration suppression in structures equipped with magnetorheological dampers
2009
This is an author-created, un-copyedited version of an article accepted for publication in Smart Materials and Structures. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at http://dx.doi.org/10.1088/0964-1726/18/9/095041 This paper addresses the problem of designing quantitative feedback theory (QFT) based controllers for the vibration reduction in a structure equipped with an MR damper. In this way, the controller is designed in the frequency domain and the natural frequencies of the structure can be directly accounted for in the process. T…
Performance analysis of wideband sum-of-cisoids-based channel simulators with respect to the bit error probability of DPSK OFDM Systems
2009
In this paper, we analyze the performance of a wideband sum-of-cisoids (SOC) channel simulator w.r.t. the bit error probability (BEP) of differential phase-shift keying (DPSK) orthogonal frequency division multiplexing (OFDM) systems. Analytical BEP expressions are derived for coherent and non- coherent DPSK OFDM simulation systems in the presence of a wideband SOC channel simulator. We also study the degradations of the BEP introduced by an imperfect channel simulator. Using the deviation of the BEP as an appropriate measure, we evaluate the performance of three parameter computation methods, known as the method of exact Doppler spread (MEDS), the randomized MEDS (R-MEDS), and the Monte Ca…