Voice Conversion Approach through Feature Statistical Mapping

Over the past few decades the field of speech processing has undergone tremendous changes and grown to be important both theoretically and technologically. Great advances have already been made in a broad range of applications such as speech analysis and synthesis techniques, voice recognition, text to speech conversion and speech coding techniques to name a few. On the process of development of these applications, voice conversion (VC) technique has recently emerged as a new branch of speech synthesis dealing with the speaker identity. The basic idea behind VC is to modify one person's speech so that it is recognized as being uttered by another person. There are numerous applications of voice conversion technique. Examples include the personalization of text to speech (TTS) systems to reduce the need for a large speech database. It could also be used in the entertainment industry. VC technology could be used to dub movies more effectively by allowing the dubbing actor to speak with the voice of the original actor but in a different language. Voice conversion can also be used in the language translation applications to create the identity of a foreign speaker. This project proposes a simple parametric approach to VC through the use of the well-known speech analysis technique namely Linear Prediction (LP). LP is used as analysis tool to extract the most important acoustic parameters of a person's speech signal. These parameters are the pitch period, LP coefficients, the voicing decision and the speech signal energy. Then, the features of the source speaker are mapped to match those of the target speaker through the use of statistical mapping technique. To illustrate the feasibility of the proposed approach. a simple to use voice conversion software was developed. The program code was written in C++ and implemented using Microsoft Foundation C lass (MFC). The proposed scheme to the problem has shown satisfactory results, where the synthesized speech signal has come as c lose as possible to match that of a target speaker

Long-range sediment transport in the world’s oceans by stably stratified turbidity currents

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Field effect on surface states in a doped Mott-Insulator thin film

Surface effects of a doped thin film made of a strongly correlated material are investigated both in the absence and presence of a perpendicular electric field. We use an inhomogeneous Gutzwiller approximation for a single band Hubbard model in order to describe correlation effects. For low doping, the bulk value of the quasiparticle weight is recovered exponentially deep into the slab, but with increasing doping, additional Friedel oscillations appear near the surface. We show that the inverse correlation length has a power-law dependence on the doping level. In the presence of an electrical field, considerable changes in the quasiparticle weight can be realized throughout the system. We observe a large difference (as large as five orders of magnitude) in the quasiparticle weight near the opposite sides of the slab. This effect can be significant in switching devices that use the surface states for transport

Performance of an Echo Canceller and Channel Estimator for On-Channel Repeaters in DVB-T/H Networks

This paper investigates the design and performance of an FIR echo canceller for on-channel repeaters in DVB-T/H network within the framework of the PLUTO project. The possible approaches for echo cancellation are briefly reviewed and the main guidelines for the design of such systems are presented. The main system parameters are discussed. The performance of an FIR echo canceller based on an open loop feedforward approach for channel estimation is tested for different radio channel conditions and for different number of taps of the FIR filter. It is shown that a minimum number of taps is recommended to achieve a certain mean rejection ratio or isolation depending on the type of channel. The expected degradation in performance due to the use of fixed point rather than floating point arithmetic in hardware implementation is presented for different number of bits. Channel estimation based on training sequences is investigated. The performance of Maximum Length Sequences and Constant Amplitude Zero Autocorrelation (CAZAC) Sequences is compared for different channels. Recommendations are given for training sequence type, length and level for DVB-T/H on-channel repeater deployment

Managing nitrate pollution in a Tunisian irrigated area: A multi-criteria analysis approach

In Tunisia, the extension of irrigated area is justified by its important role in the development and diversification of agricultural production. Nevertheless, the strong intensification of the agricultural activities may lead to the pollution of underground water resources due to an excess use of fertilisers and other chemical products. In fact, the high nitrate concentrations observed in some Tunisian irrigated areas, are related to the excessive use of nitrate fertilizers in intensive agriculture. The objective of the present study is to implement decision-making methods allowing a better combination of factors production by optimization of an economic objective and an environmental objective. This research is based on multi-criteria modelling through the optimization of two conflict objectives: an economic objective as settled by farmer in the short or medium-run (Gross margin), and an environmental objective (nitrate pollution reduction) as a long-run objective of the decision maker in order to ensure the continuity of agriculture activities and ecosystems sustainability. Data were collected through a survey conducted in the irrigated area of Kalaât El Andalous in Tunisia with a sample containing 57 farms. Efficient solutions were obtained and compared through the "constraints", "NISE" and "compromises" methods. Main results obtained indicate a significant degree of conflict between these two objectives. Indeed the maximization of the total gross margin involves an increase in the degrees of nitrate pollution and conversely. Finally, some policy implications are presented.Nitrate pollution, environmental impact, multicriteria analysis, Environmental Economics and Policy,

Non-linear response to electric field in extended Hubbard models

The electric-field response of a one-dimensional ring of interacting fermions, where the interactions are described by the extended Hubbard model, is investigated. By using an accurate real-time propagation scheme based on the Chebyshev expansion of the evolution operator, we uncover various non-linear regimes for a range of interaction parameters that allows modeling of metallic and insulating (either charge density wave or spin density wave insulators) rings. The metallic regime appears at the phase boundary between the two insulating phases and provides the opportunity to describe either weakly or strongly correlated metals. We find that the {\it fidelity susceptibility} of the ground state as a function of magnetic flux piercing the ring provides a very good measure of the short-time response. Even completely different interacting regimes behave in a similar manner at short time-scales as long as the fidelity susceptibility is the same. Depending on the strength of the electric field we find various types of responses: persistent currents in the insulating regime, dissipative regime or damped Bloch-like oscillations with varying frequencies or even irregular in nature. Furthermore, we also consider the dimerization of the ring and describe the response of a correlated band insulator. In this case the distribution of the energy levels is more clustered and the Bloch-like oscillations become even more irregular