An adaptive serial search pseudonoise (PN) code acquisition scheme is proposed, in which the detection threshold is scaled by the instantaneous received power measured prior to PN code correlation. We observe that the proposed scheme achieves significantly improved mean acquisition times compared to the conventional nonadaptive schemes under Rayleigh fading and pulsed Gaussian noise jamming. Fu...

We consider noise-assisted spike propagation in myelinated axons within a multicompartment stochastic Hodgkin-Huxley model. The noise originates from a finite number of ion channels in each node of Ranvier. For the subthreshold internodal electric coupling, we show that (i) intrinsic noise removes the sharply defined threshold for spike propagation from node to node and (ii) there exists an opt...

The channel estimation algorithms play a vital role in third generation (3G) communication systems to support efficient spectrum utilization. The transition from 3G to 4G systems is to provide high data rate, error free low complexity system with efficient adaptive techniques. A noisy Channel estimation and feedback error introduces imperfect Channel State Information (CSI). This paper introduc...

Image segmentation of pulmonary parenchyma can be detected from multisliced CT images using image segmentation. It can be modeled as a nonlinear multimodal global optimization problem. The traditional 2D Otsu algorithm, though effective, is quite time consuming for determining the optimum threshold values. In this paper we propose a combination of 2D Otsu method with modified ABC algorithm (cal...

Tompa and Woll considered a problem of cheaters in (k; n) threshold secret sharing schemes. We rst derive a tight lower bound on the size of shares jV i j for this problem: jV i j (jSj 1)= + 1, where V i denotes the set of shares of participant P i , S denotes the set of secrets, and denotes the cheating probability. We next present an optimum scheme which meets the equality of our bound by usi...

In computer vision and image processing, Otsu's method is used to automatically perform histogram shape-based image thresholding, or, the reduction of a graylevel image to a binary image. The algorithm assumes that the image to be thresholded contains two classes of pixels (e.g. for eground and background) then calculates the optimum threshold separating those two classes so that their combined...

In this paper, we study the adaptive version of the asymptotical Bayesian Optimum Radar Detector (BORD) built with a covariance matrix estimate. We investigate its properties, when the noise is modelled as a non-Gaussian complex process, such as Spherically Invariant Random Process (SIRP). We derive, for appropriate covariance matrix estimates, the analytical expression of the relationship betw...

The electron field-emission properties of hydrogenated amorphous carbon and nitrogenated tetrahedral amorphous carbon thin films are examined by measuring the field-emission current as a function of the applied macroscopic electric field. The experimental results indicate the existence of an optimum film thickness for low-threshold electron field emission. The predictions of various emission mo...

INTRODUCTION The purpose of this study was to re-evaluate the findings of a smaller cohort study on the functional definition and characteristics of acute traumatic coagulopathy (ATC). We also aimed to identify the threshold values for the most accurate identification of ATC and prediction of massive transfusion (MT) using rotational thromboelastometry (ROTEM) assays. METHODS In this prospect...

OBJECTIVE Lutetium oxyorthosilicate (LSO) contains natural radioactivity that emits beta particles and three gamma photons simultaneously. These beta particles and gamma photons increase the single and random rates in a positron emission tomography (PET) system while a beta particle and gamma photon produced in the same decay of Lu-176 and detected by another detector can be beta-gamma coincide...