In this paper, we investigate the performance of a downlink multiple-input multiple-output (MIMO) multicarrier code division multiple access (MC-CDMA) system employing a receiver with iterative channel estimation (ICE). The MC-CDMA system transmits several data symbols per user and per orthogonal frequency division multiplexing (OFDM) symbol in parallel, with each data symbol being spread with ...

This paper presents a model to predict the phrase commands of the Fujisaki Model for F0 contour for the Portuguese Language. Phrase commands location in text is governed by a set of weighted rules. The amplitude (Ap) and timing (T0) of the phrase commands are predicted in separate neural networks. The features for both neural networks are discussed. Finally a comparison between target and predi...

Developing applications for parallel and distributed systems is hard due to their nondeterministic nature; developing debugging tools for such systems and applications is even harder. A number of distributed debugging tools and techniques exist; however, we believe that they lack the infrastructure to scale to large-scale distributed systems, systems with hundreds and thousands of nodes, such a...

This paper intends to summarize some of the robust feature extraction and acoustic modeling technologies used at Multitel, together with their assessment on some of the ETSI Aurora reference tasks. Ongoing work and directions for further research are also presented. For feature extraction (FE), we are using PLP coefficients. Additive and convolutional noise are addressed using a cascade of spec...

The navigation of axons to their final destination can involve a sequence of steps that require different sets of guidance receptors. In this issue, Colak et al. show that regulated intra-axonal protein synthesis coupled to nonsense-mediated mRNA decay (NMD) controls a switch in Robo3.2 expression that is critical for navigation.

In the last years, CDMA has been established as a standard multiple access scheme in mobile radio communications. However, high spectral efficiency can only be achieved by applying multi-user detection schemes combatting the inherent multi-user interference. Since the optimum maximum likelihood approach is far to complex for practical implementations, suboptimum iterative strategies are applied...

Factorization of large numbers has been a constant source of interest in cryptanalysis. The fastest known algorithm for factoring large numbers is the Number Field Sieve (NFS). The two most time consuming phases of NFS are Sieving and Matrix Step. In this paper, we propose an efficient way of implementing the Matrix step in reconfigurable hardware. Our solution is based on the MeshRouting metho...

The WWW increasingly allows people to create and update content for public access. Some of this information is collaboratively owned (created and maintained), while other information is privately owned and maintained (but still publicly accessible). Whereas it is unethical to modify the former for covert communication, it is quite legitimate to do so with the latter, and this paper gives a desi...

Bipartisan interest is growing in Congress for using federal tax credits to help low-income families buy health insurance. Regardless of the approach taken, tax credit policies must address risk selection issues to ensure coverage for the chronically ill. Proposals that link tax credits to purchasing pools would avoid risk selection by grouping risks similar to the way large employers do. Volun...

Solutions proposed in bibliography for multiple user allocation on the sub-bands of an OFDM system, adopting multiple antennas, require highly computational effort and consider delay insensitive applications. Our approach tends to overcome all these limitations relaxing some hypothesis in order to give a feasible solution. The proposed algorithm can be applied to a real multiple antenna OFDM sy...