2011
Authors
Derogarian, F; Ferreira, JC; Tavares, VMG;
Publication
SENSORCOMM 2011 - 5th International Conference on Sensor Technologies and Applications and WSNSCM 2011, 1st International Workshop on Sensor Networks for Supply Chain Management
Abstract
This paper presents a routing protocol for wireless sensor networks (WSN), established on the basis of fundamental concepts in source based routing (SBR) for ad hoc networks and minimum cost forwarding (MCF) methods for heterogeneous WSNs. Neither routing tables nor network topology information is maintained at sensor level, which makes the proposed protocol part of the reactive routing protocols class. Despite the lack of network information at the sensor, the packets from the sink node to sensors, and viceversa, always follow the optimal communication path with minimum cost. Simulation results have shown that the proposed protocol performs better than MCF protocol alone, and nodes always route the packets through the optimal path up to destination. In fact, according to the energy consumption and throughput found by simulation, this protocol improves on the MCF protocol for applications where the sink node, acting as a server or base station (BS), generates significant amounts of network traffic. All results are based on simulations and data treatment performed with OMNet++ 4, Matlab 7 and Microsoft Visual Studio2010(C#) platform tools.
2011
Authors
Cardoso, JMP; Diniz, PC; Petrov, Z; Bertels, K; Hübner, M; van Someren, H; Gonçalves, F; de Coutinho, JGF; Constantinides, GA; Olivier, B; Luk, W; Becker, J; Kuzmanov, G; Thoma, F; Braun, L; Kühnle, M; Nane, R; Sima, VM; Krátký, K; Alves, JC; Ferreira, JC;
Publication
Reconfigurable Computing
Abstract
2011
Authors
Fonseca, N; Ferreira, A; Rocha, AP;
Publication
17th DSP 2011 International Conference on Digital Signal Processing, Proceedings
Abstract
The concept of capturing the sound of something for later replication is not new, and it is used in many synthesizers. But capturing sounds and use them as an audio effect, is less common. This paper presents an approach for the resynthesis of a singing voice, based on concatenative techniques, that uses pre-recorded audio material as an high level semantic audio effect, replacing an original audio recording with the sound of a different singer, while trying to keep the same musical/phonetic performance. © 2011 IEEE.
2011
Authors
Sousa, R; Ferreira, A; Alku, P;
Publication
Models and Analysis of Vocal Emissions for Biomedical Applications - 7th International Workshop, MAVEBA 2011
Abstract
This paper describes an algorithm which enables harmonic and noise splitting of the glottal excitation of voiced speech. The algorithm utilizes a straightforward harmonic and noise splitter which is utilized prior to glottal inverse filtering. The results show improved estimates of the glottal excitation in comparison to a known inverse filtering method.
2011
Authors
Sousa, R; Ferreira, A;
Publication
12TH ANNUAL CONFERENCE OF THE INTERNATIONAL SPEECH COMMUNICATION ASSOCIATION 2011 (INTERSPEECH 2011), VOLS 1-5
Abstract
In this paper we introduce new phase-related features denoting the delay between the harmonics and the fundamental frequency of a periodic signal, notably of voiced singing. These features are identified as Normalized Relative Delay (NRD) and denote the phase contribution to the shape invariance of a periodic signal. Thus, NRDs are amenable to a physical and psychophysical interpretation and are structurally independent of the overall time shift of the signal, an important property that is shared with the magnitude spectrum in the case of a locally stationary signal. We describe the NRD and report on preliminary studies testing the discrimination capability of NRDs applied to singing signals.
2011
Authors
Carneiro, G; Fontes, H; Ricardo, M;
Publication
SIMULATION MODELLING PRACTICE AND THEORY
Abstract
In the networking research and development field, one recurring problem faced is the duplication of effort to write first simulation and then implementation code. We posit an alternative development process that takes advantage of the built in network emulation features of Network Simulator 3 (ns-3) and allows developers to share most code between simulation and implementation of a protocol. Tests show that ns-3 can handle a data plane processing large packets, but has difficulties with small packets. When using ns-3 for implementing the control plane of a protocol, we found that ns-3 can even outperform a dedicated implementation.
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