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We introduce a method for detecting strongly monotone evolutionary trends of gene expression from a temporal sequence of microarray data. In this method we perform gene filtering via multi-objective optimization to reveal genes which have the properties of: strong monotonic increase, high end-to-end slope and low slope deviation. Both a global Pareto optimization and a pair-wise local Pareto optimization...
A new particle filtering detector is proposed for joint estimation of channel model coefficients, channel tracking, and signal detection over flat Rayleigh fading channels. The detector employs a hybrid importance function and a mixture Kalman filter which result in a highly efficient implementation. In addition, by considering the practical limitation of the system and physical interpretation of...
We present an automatic technique for contour detection of the abdominal aorta on a medical images sequence. We apply the method of region based active contours using local parameter estimation related to the object region. This method allows the automation of the detection process. The initialization of our algorithm is only done on the first image of the sequence. Our method, consists in defining...
This paper deals with the analysis of auditory evoked potentials recorded in presence of radiofrequency fields emitted by a mobile phone. During measurements, spurious frequencies appear on the one hand at 50, 100, 150 Hz but and on the other hand around 83.3, 133.4 and 216.7 Hz. The first ones are due to the mains and that at 216.7 Hz comes from the GSM modulation. We show that the two others (83...
There are many existing methods for reducing the VLSI implementation cost of the adaptation arithmetic in stochastic gradient adaptive filters. Some of them cause significant performance impairments (such as slower convergence or increased misadjustment noise). However the replacement of multiplications by Power-of-Two Quantisers (PTQ), together with shifters, has been shown to reduce cost with very...
Shadows are often integral parts of natural scenes and their identification is an important task in image analysis. In this paper, we propose an algorithm for recognition of shadows cast by objects on the scene's background. The proposed approach is based on the use of color information by means of photometric invariant color transformations. The method is divided into two levels: first, object and...
The existing ADSL standard allows for two possible transmission systems: frequency division duplexing (FDD) and echo cancelling (EC). Echo cancelling is particularly attractive for its ability to achieve higher data rates compared with FDD schemes. A disadvantage of EC is that adaptive schemes exhibit slow tracking properties in the presence of a far end signal or double talker. This paper presents...
Speech is the primary means of communication between people. Speech synthesis, automatic generation of speech waveforms has been under development for several decades [1, 2]. Recent progress in speech synthesis has produced synthesizers with very high intelligibility but the sound quality and naturalness still remain a major problem. The goal of this work is to develop a new speech synthesis system,...
As a complement to the periodogram, low-complexity frequency estimators are of interest. One such estimator is based on Prony's method and rely on phase information of the auto-correlations. Both performance and computational complexity are functions of the choice of correlations used in the estimator and often we have a trade off situation. In this paper, frequency estimation from an arbitrary set...
A new class of video format conversion between interlaced and progressive scan formats is discussed. It is a kind of the deinterlacing problem and is defined as follows: format conversion of an interlaced scan signal to a progressive scan signal of half the temporal sampling rate to the interlaced signal, and vice versa, under the criterion of equal sampling density. This offers a reversible scan...
This paper introduces an algorithm simulating a moving sound image as a time-variant acoustic event and reports on the results of an investigation of methods for interpolation of binaural responses. As moving sound images require numerous binaural responses, the use of interpolation methods is necessary. We investigated two interpolation methods; one is a linear waveform interpolation method considering...
Some communication systems embed pilot tones into the data spectrum to aid the receiver in synchronization, which may result in a DC offset of the baseband data. This paper motivates the use for adaptive estimation of the DC offset at the receiver, and proposes a Constant Modulus cost function that is jointly minimized over the DC offset estimate and the equalizer parameters. It is shown that for...
Panoramic video is a simple representation of a dynamic scene or static environment. It allows the users to change their viewpoints interactively in time or along a given path in space. For better users' experience, it is desirable to incorporate synthetic or real objects into a panoramic video. This paper studies the coding and rendering of these objects in panoramic video using the concept of video...
In this paper we investigate an alternative characterization of the inverse AM/AM and AM/PM transfer curves of a high power amplifier (HPA), defining an adaptive algorithm for the optimum adjustment of the coefficients in a memoryless rational-based model used to pre-distort a base band signal with complex modulation in a quadrature non-linear model. Input signal statistics are unknown so its influence...
In the paper it has been shown that when data vector size is odd, then the discrete cosine transform (DCT) can be computed by a real-valued DFT algorithm for appropriately permuted data samples. The same is true for the DST. Moreover, for composite transform sizes prime factor DCT algorithms can be constructed consisting of odd size real-valued DFT algorithms and DCT/DST algorithms which sizes are...
Multiplierless filters are natural extensions of the low-sensitivity structures. Some low-sensitivity structures are associated with structural alteration and the resulting multiplier coefficients are different than the initial designed values in these structures. For the cases when coefficient values are quite small, they can be implemented in a multiplierless manner, i.e., by using only few bit...
This work derives the multichannel Bussgang restoration algorithm for blind image restoration problems. In its basic outline, the derived Bussgang restoration algorithm is based on iteratively filtering the measurements by means of a bank of FIR filters, and updating the filter-bank on the base of a nonlinear estimate of the original image. The filters are updated by solving a linear system (multichannel...
This paper studies a space-time generalization of decorrelating RAKE receiver recently proposed by Liu and Li for blind multiuser detection of direct sequence code division multiple access (DS-CDMA) signals under frequency selective fading channel. Multiple receiving antennas are employed to further enhance the performance of the DRAKE receiver through diversity combining. Simulations show that the...
This paper studies the restoration of color quantized images. Restoration of color quantized images is rarely addressed in the literature, and direct applications of existing restoration techniques are generally inadequate to deal with this problem. We propose a restoration algorithm specific to color quantized images, which makes a good use of the available color palette to derive useful a priori...
In this paper, we present an unbiased adaptive modelling approach to feedback cancellation in hearing aids. The approach is based on a closed loop identification of the feedback path as well as the (linear prediction) model of the near-end input signal. In general, both models are not simultaneously identifiable in the closed loop system at hand. We show that -under certain conditions e.g. if a delay...
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