The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This article presents a new approach for Fourier-based modeling of bone anatomies for compression and smoothing. By treating the bone surface as a level set of a 3D scalar field, we can model topologically complex models such as bones. In particular, we experiment with five different alternatives, and prove that 3D scalar field which allows monotonous continuity around the boundary can be a good choice...
A new algorithm is developed here for blind extraction of periodic signals. It is assumed that the fundamental frequencies of the sources (or alternatively one of the harmonics for each source) are known a priori. Necessary and sufficient conditions for blind source extraction of cyclostationary signals are introduced and the optimization problem is solved using steepest descent method for complex...
A wheeze is a continuous, coarse, whistling sound produced in the respiratory airways during breathing, commonly experienced by persons suffering from asthma. In this paper, we present a new method for the detection of wheezing sounds in the normal breathing sounds. In our study we perform an accurate statistical analysis of breathing signals. We suggest a modeling for wheezing and normal sounds in...
We consider the problem of reconstructing finite energy stimuli from a finite number of contiguous spikes. The reconstructed signal satisfies a consistency condition: when passed through the same neuron, it triggers the same spike train as the original stimulus. The recovered stimulus has to also minimize a quadratic smoothness criterion. We show that under these conditions, the problem of recovery...
Detection of a nuclear radioactive source is considered using a parallel sensor network architecture and a fusion center. A Poisson-Gamma hierarchical model is used to represent the distribution of the count data received by the sensors. Local sensors are assumed to be single threshold binary quantizers that send a vector of sensor decisions over time to the fusion center for global decision-making...
Multiview 3D displays have to multiplex a set of views on a single LCD panel. Due to this, each view has to be downsampled by a considerable amount leading to loss of details. In this paper, we extend the seam carving technique for adaptive resizing of images. It is proposed that the depth information be used along with the image pixel intensity values for resizing. This results in better resized...
In this paper, an efficient architecture for a parallel pruned turbo interleaver for 3GPP2/UMB physical layer standard is presented. Turbo interleaving in UMB turbo codes is based on filling a 2D array row by row, interleaving each row using a linear congruential sequence, bit-reversing the order of the rows, and then reading the interleaved addresses column by column. Pruning creates a serial bottleneck...
Digital designs implemented using SOI processes employ separated bodies for each transistor. This approach is not usually considered in digital bulk-CMOS design because of its obvious area penalty. However, the advantages obtained can justify its utilization in selected parts of the circuits. This is discussed in this paper.
Cognitive radio has the ability to listen to the wireless channel, detect the vacant spectrum bands, and make use of them. However, the sensing ability of this smart radio may not be perfect which may induce interference to the primary system. One of the main challenges in cognitive communication lies therefore in striking a balance between the conflicting goals of minimizing the interference to the...
The overall relay channel from the source to the destination via relays has temporal properties quite different from any cellular channel. This work presents a study for time-dependent performance of relay channels for both fast-fading and log-normal shadow fading in terms of average outage duration, frequency of outage and probability of outage. Results show that there is a good agreement between...
In this paper, we address a sub-optimum distributed power allocation (SODPA) scheme for two-hop parallel relay networks, which includes a source-destination pair and multiple relay nodes. The system employs Decode-and-Forward (DF) as relaying protocol. In the proposed scheme, each relay is assumed to be able to decode the received signal if it satisfies the given SNR threshold and may make decision...
Switching rate is an important parameter in selection diversity receiver design because the switching transients increase the system outage. An exact closed-form solution for the switching rate of dual selection diversity in kappa-mu and alpha-mu distributed fadings is derived. Independent and identically distributed (i.i.d.) kappa-mu and alpha-mu fading channels are considered. The switching rate...
Using the Nakagami probability density function (PDF) to model multipath fading and the Gamma PDF to model shadowing, in a wireless channel, has led to a closed-form expression for the composite fading PDF, known as the generalized-.fi" PDF (also called Gamma-Gamma PDF). However, further derivations have shown that the cumulative distribution function (CDF) and the characteristic function of...
Erroneous local geometric realizations in some parts of the network due to their sensitivity to certain distance measurement errors is a major problem in wireless sensor network localization. This may in turn affect the localization of either the entire network or a large portion of it. This phenomenon is well-described using the notion of "flip ambiguity" in rigid graph theory. In this...
We consider the problem of counting mobile stations based on feedback they provide. For this problem we propose an anonymous contentious feedback mechanism which permits efficient counting and relate the resulting estimation problem to a well know combinatorial problem of "coupon collection." Using this relationship, we analyze the estimation problem in an idealized setting. We find the...
The multiple access interference (MAI) in a time-hopping (TH) ultra-wideband (UWB) system is known to be non-Gaussian even when the system has a moderately large number of active users. Therefore, the conventional matched filter (CMF) receiver, the optimal structure for Gaussian noise which maximizes the signal-to-noise ratio (SNR) and minimizes the probability of detection error in the absence of...
In this paper, we derive analytical expressions for the inphase/quadrature Cramer-Rao lower bounds (I/Q CRLB) for the non-data-aided (NDA) signal-to-noise ratio (SNR) estimation of square quadrature amplitude modulated (QAM) signals. The channel is supposed to be slowly time-varying so that it can be assumed constant over the observation interval. The signal is assumed to be corrupted by additive...
In order to secure RFID transactions, an authentication scheme has originally been included as part of the "EPC Gen2" industrial standard. This scheme, however, has been found to have some weaknesses. To overcome such weaknesses, some authors have proposed new schemes to improve its security. Two of the latest proposals are the Lim-Li protocol and the Konidala-Kim-Kim protocol presented...
An integrated RF-powered Li-ion battery charger solution has been developed for biomedical applications. RF energy received through an antenna is rectified, regulated, and passed on to a battery charger circuit that charges a Li-ion battery efficiently and accurately. The charger system has been implemented using UMC 90 nm BiCMOS process library. Experimental results show that a battery model with...
Conners Adult ADHD Rating Scale (CAARS) is one of the reliable questionnaires in evaluating ADHD in adults. The goal of this study is to extract principal components of the screening version of questionnaire and evaluate the validity of missed answers estimation. This study is performed on 380 volunteers. Eight principal components are extracted by means of PCA. In the next step, for each question,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.