5,896 research outputs found
Comparison and Performance Analysis of DS-CDMA Systems by Genetic, Neural and GaNN (hybrid) Models
Direct Sequence-Code Division Multiple Access (DS-CDMA) technique is used in cellular systems where users in the cell are separated from each other with their unique spreading codes. DS-CDMA has been used extensively which suffers from multiple access interference (MAI) and inter symbol interference (ISI) due to multipath nature of channels in presence of additive white Gaussian noise (AWGN). Spreading codes play an important role in multiple access capacity of DS-CDMA system and Walsh sequences are used as spreading codes in DS-CDMA. DS CDMA receiver namely genetic algorithm neural network and GaNN (hybrid) based MUD receiver for DS-CDMA communication using Walsh sequences is designed. The performance of the same will be compared among themselves
Algorithmic music composition: a survey
This paper surveys some of the methods used for algorithmic composition and their evolution during the last decades. Algorithmic composition was motivated by the natural need to assist and to develop the process of music creation. Techniques and applications of algorithmic composition are broad spectrum, ranging from methods that produce entire works with no human intervention, up to methods were both composer and computer work closely together in real-time. Common algorithms used for music composition are based in stochastic, deterministic, chaotic and artificial intelligence methods.N/
Determining the Biomechanical Behavior of the Liver Using Medical Image Analysis and Evolutionary Computation
Modeling the liver deformation forms the basis for the development of
new clinical applications that improve the diagnosis, planning and guidance
in liver surgery. However, the patient-specific modeling of this organ and its
validation are still a challenge in Biomechanics. The reason is the difficulty
to measure the mechanical response of the in vivo liver tissue. The current
approach consist of performing minimally invasive or open surgery aimed at
estimating the elastic constant of the proposed biomechanical models.
This dissertation presents how the use of medical image analysis and evolutionary
computation allows the characterization of the biomechanical behavior
of the liver, avoiding the use of these minimally invasive techniques. In particular,
the use of similarity coefficients commonly used in medical image analysis
has permitted, on one hand, to estimate the patient-specific biomechanical
model of the liver avoiding the invasive measurement of its mechanical response.
On the other hand, these coefficients have also permitted to validate
the proposed biomechanical models.
Jaccard coefficient and Hausdorff distance have been used to validate the
models proposed to simulate the behavior of ex vivo lamb livers, calculating
the error between the volume of the experimentally deformed samples of the
livers and the volume from biomechanical simulations of these deformations.
These coefficients has provided information, such as the shape of the samples
and the error distribution along their volume. For this reason, both coefficients
have also been used to formulate a novel function, the Geometric Similarity
Function (GSF). This function has permitted to establish a methodology to
estimate the elastic constants of the models proposed for the human liver using
evolutionary computation. Several optimization strategies, using GSF as cost
function, have been developed aimed at estimating the patient-specific elastic
constants of the biomechanical models proposed for the human liver.
Finally, this methodology has been used to define and validate a biomechanical
model proposed for an in vitro human liver.MartĂnez MartĂnez, F. (2014). Determining the Biomechanical Behavior of the Liver Using Medical Image Analysis and Evolutionary Computation [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39337TESI
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