874 research outputs found

    Online Signature Verification and Authentication using Smart Phones

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    The proposed system is designed to determine whether the person signing on any touch screen device is authenticated user or not. This can be done by verifying his/her handwritten signature which is a socially accepted biometric trait for authenticating an individual. There are two types of handwritten signature verification systems: offline and online systems. In an off-line system, just an image of the user?s signature is acquired without additional attributes, whereas, in an online system, a sequence of x-y coordinates of the user?s signature, along with many other attributes are also acquired. In our paper, we have created a client (mobile) application which captures the user?s signature and extracts various features like pressure, time and x-y co-ordinates and the server application verifies these features to find whether the signature has been done by an authenticated user or a forger. The implementation is done using Python and the GUI is coded using Xcode

    Accuracy of Goldmann, ocular response analyser, Pascal and TonoPen XL tonometry in keratoconic and normal eyes

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    Aim: The aim of this study was to evaluate the practicality and accuracy of tonometers used in routine clinical practice for established keratoconus (KC). Methods: This was a prospective study of 118 normal and 76 keratoconic eyes where intraocular pressure (IOP) was measured in random order using the Goldman applanation tonometer (GAT), Pascal dynamic contour tonometer (DCT), Reichert ocular response analyser (ORA) and TonoPen XL tonometer. Corneal hysteresis (CH) and corneal resistance factor (CRF), as calculated by the ORA, were recorded. Central corneal thickness (CCT) was measured using an ultrasound pachymeter. Results: The difference in IOP values between instruments was highly significant in both study groups (p<0.001). All other IOP measures were significantly higher than those for GAT, except for the Goldmann-correlated IOP (average of the two applanation pressure points) (IOPg) as measured by ORA in the control group and the CH-corrected IOP (corneal-compensated IOP value) (IOPcc) measures in the KC group. CCT, CH and CRF were significantly less in the KC group (p<0.001). Apart from the DCT, all techniques tended to measure IOP higher in eyes with thicker corneas. Conclusion: The DCT and the ORA are currently the most appropriate tonometers to use in KC for the measurement of IOPcc. Corneal factors such as CH and CRT may be of more importance than CCT in causing inaccuracies in applanation tonometry techniques

    Optimal scaling of average queue sizes in an input-queued switch: an open problem

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    We review some known results and state a few versions of an open problem related to the scaling of the total queue size (in steady state) in an n×n input-queued switch, as a function of the port number n and the load factor ρ. Loosely speaking, the question is whether the total number of packets in queue, under either the maximum weight policy or under an optimal policy, scales (ignoring any logarithmic factors) as O(n/(1 − ρ)).National Science Foundation (U.S.) (Grant CCF-0728554

    Spin polarization and magneto-luminescence of confined electron-hole systems

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    A BCS-like variational wave-function, which is exact in the infinite field limit, is used to study the interplay among Zeeman energies, lateral confinement and particle correlations induced by the Coulomb interactions in strongly pumped neutral quantum dots. Band mixing effects are partially incorporated by means of field-dependent masses and g-factors. The spin polarization and the magneto-luminescence are computed as functions of the number of electron-hole pairs present in the dot and the applied magnetic field.Comment: To appear in Phys. Rev.

    Non-invasive detection and chemical mapping of trace metal residues on the skin

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    Residual traces of the metals copper and lead on an individual's skin may be elucidated by reaction of rubeanic acid with a gelatine lift taken from the target area in question, yielding intensely coloured reaction products. This non-invasive technique has been shown to offer promise in chemically mapping the distribution of the minute metal residues across an individual's hand deposited through touching metal items, a technique with potential forensic significance

    Impact of baseline hemodynamics on the effects of a transcatheter interatrial shunt device in heart failure with preserved ejection fraction

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    Background: Interatrial shunt device (IASD) effects have been described in patients with heart failure and ejection fractions (EFs) ≥40%. However, baseline characteristics that correlate with greatest hemodynamic effects are unknown. On the basis of fundamental principles, we hypothesized that larger pressure gradients between left and right atria would yield greater shunt flow and greater hemodynamic effects. Methods and Results: REDUCE LAP-HF (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) was a multicenter study that investigated IASD safety and performance. Sixty-four patients with EF ≥40% underwent device implantation followed by hemodynamic assessments at rest and exercise, including pulmonary capillary wedge pressure (PCWP, surrogate for left atrial pressure) and central venous pressure (CVP). At 6 months, IASD resulted in an average pulmonary-to-systemic blood flow ratio of 1.27 and increased exercise tolerance. The PCWP-CVP gradient (ie, the driving pressure for shunt flow) decreased at peak exercise from 16.8±6.9 to 11.4±5.5 mm Hg, because of increased CVP (17.5±5.4 to 20.3±7.9 mm Hg; P=0.04) and decreased PCWP (34.1±7.6 to 31.6±8.0 mm Hg; P=0.025). Baseline PCWP-CVP gradient during exercise correlated with changes of both PCWP-CVP and PCWP: Δ(PCWP-CVP)=10.0−0.89·(PCWP-CVP)baseline (r2=0.56) and ΔPCWP=7.54−0.60·(PCWP-CVP)baseline (P=0.001). Hemodynamics of patients with EF ≥50% and those with EF <50% responded similarly to IASD. Conclusions: In heart failure patients with EF ≥40%, IASD significantly reduced PCWP and PCWP-CVP at peak exercise. Patients with higher baseline PCWP-CVP gradient had greater reductions in both parameters at follow-up. Results were sustained through 12 months and were independent of whether EF was ≥50% or between 40% and 49%. Additional studies will help further define the baseline hemodynamic predictors of exercise, hemodynamic, and clinical efficacy of the IASD. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01913613

    Pengaruh Komunikasi Kesehatan Reproduksi oleh Orang Tua terhadap Perilaku Pacaran Remaja di Daerah Istimewa Yogyakarta

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    Penelitian ini membahas mengenai pengaruh komunikasi kesehatan reproduksi oleh orang tua terhadap perilaku pacaran remaja di Daerah Istimewa Yogyakarta. Peneliti menggunakan metode dasar yaitu metode deskriptif dengan menggunakan mixed method, dan strategi eksplanatoris sekuensial. Teknik pengumpulan data dilakukan menggunakan kuesioner terhadap 60 responden di Kabupaten Sleman, Kabupaten Kota Yogyakarta, dan Kabupaten Kulonprogo secara random. Analisis data yang digunakan oleh peneliti adalah software spss 24 dan sebagai pelengkap pembahasan dilakukan analisis kualitatif. Hasil penelitian menunjukkan bahwa faktor-faktor yang berpengaruh terhadap perilaku pacaran remaja di Daerah Istimewah Yogyakarta adalah akses media informasi dan lingkungan. Dari dua faktor yang berpengaruh tersebut, yang memiliki pengaruh positif paling tinggi kepada perubahan perilaku adalah lingkungan

    Erratum to: Localization of Fatty Acyl and Double Bond Positions in Phosphatidylcholines Using a Dual Stage CID Fragmentation Coupled with Ion Mobility Mass Spectrometry.

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    A high content molecular fragmentation for the analysis of phosphatidylcholines (PC) was achieved utilizing a two-stage [trap (first generation fragmentation) and transfer (second generation fragmentation)] collision-induced dissociation (CID) in combination with travelling-wave ion mobility spectrometry (TWIMS). The novel aspects of this work reside in the fact that a TWIMS arrangement was used to obtain a high level structural information including location of fatty acyl substituents and double bonds for PCs in plasma, and the presence of alkali metal adduct ions such as [M + Li](+) was not required to obtain double bond positions. Elemental compositions for fragment ions were confirmed by accurate mass measurements. A very specific first generation fragment ion m/z 577 (M-phosphoryl choline) from the PC [16:0/18:1 (9Z)] was produced, which by further CID generated acylium ions containing either the fatty acyl 16:0 (C(15)H(31)CO(+), m/z 239) or 18:1 (9Z) (C(17)H(33)CO(+), m/z 265) substituent. Subsequent water loss from these acylium ions was key in producing hydrocarbon fragment ions mainly from the α-proximal position of the carbonyl group such as the hydrocarbon ion m/z 67 (+H(2)C-HC = CH-CH = CH(2)). Formation of these ions was of important significance for determining double bonds in the fatty acyl chains. In addition to this, and with the aid of (13)C labeled lyso-phosphatidylcholine (LPC) 18:1 (9Z) in the ω-position (methyl) TAP fragmentation produced the ion at m/z 57. And was proven to be derived from the α-proximal (carboxylate) or distant ω-position (methyl) in the LPC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13361-011-0172-2) contains supplementary material, which is available to authorized users
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