Soft MIMO detection through sphere decoding and box optimization

[EN] Achieving optimal detection performance with low complexity is one of the major challenges, mainly in multiple-input multiple-output (MIMO) detection. This paper presents three low-complexity Soft-Output MIMO detection algorithms that are based mainly on Box Optimization (BO) techniques. The proposed methods provide good performance with low computational cost using continuous constrained optimization techniques. The rst proposed algorithm is a non-optimal Soft-Output detector of reduced complexity. This algorithm has been compared with the Soft-Output Fixed Complexity (SFSD) algorithm, obtaining lower complexity and similar performance. The two remaining algorithms are employed in a turbo receiver, achieving the max-log Maximum a Posteriori (MAP) performance. The two Soft-Input Soft-Output (SISO) algorithms were proposed in a previous work for soft-output MIMO detection. This work presents its extension for iterative decoding. The SISO algorithms presented are developed and compared with the SISO Single Tree Search algorithm (STS), in terms of efficiency and computational cost. The results show that the proposed algorithms are more efficient for high order constellation than the STS algorithm.Simarro, MA.; García Mollá, VM.; Vidal Maciá, AM.; Martínez Zaldívar, FJ.; Gonzalez, A. (2018). Soft MIMO detection through sphere decoding and box optimization. Signal Processing. 145:48-58. https://doi.org/10.1016/j.sigpro.2017.11.010S485814

The Impact of the Multi-core Revolution on Signal Processing

This paper analyzes the influence of new multi- core and many-core architectures on Signal Processing. The article covers both the architectural design and the programming models of current general-purpose multi-core processors and graphics processors (GPU), with the goal of identifying their possibilities and impact on signal processing applications

Environmental and anthropogenic factors affecting the probability of occurrence of Oncomegas wageneri (Cestoda: Trypanorhyncha) in the southern Gulf of Mexico

BACKGROUND: Understanding the environmental and anthropogenic factors influencing the probability of occurrence of the marine parasitic species is fundamental for determining the circumstances under which they can act as bioindicators of environmental impact. The aim of this study was to determine whether physicochemical variables, polyaromatic hydrocarbons or sewage discharge affect the probability of occurrence of the larval cestode Oncomegas wageneri, which infects the shoal flounder, Syacium gunteri, in the southern Gulf of Mexico. METHODS: The study area included 162 sampling sites in the southern Gulf of Mexico and covered 288,205 km(2), where the benthic sediments, water and the shoal flounder individuals were collected. We used the boosted generalised additive models (boosted GAM) and the MaxEnt to examine the potential statistical relationships between the environmental variables (nutrients, contaminants and physicochemical variables from the water and sediments) and the probability of the occurrence of this parasite. The models were calibrated using all of the sampling sites (full area) with and without parasite occurrences (n = 162) and a polygon area that included sampling sites with a depth of 1500 m or less (n = 134). RESULTS: Oncomegas wageneri occurred at 29/162 sampling sites. The boosted GAM for the full area and the polygon area accurately predicted the probability of the occurrence of O. wageneri in the study area. By contrast, poor probabilities of occurrence were obtained with the MaxEnt models for the same areas. The variables with the highest frequencies of appearance in the models (proxies for the explained variability) were the polyaromatic hydrocarbons of high molecular weight (PAHH, 95 %), followed by a combination of nutrients, spatial variables and polyaromatic hydrocarbons of low molecular weight (PAHL, 5 %). CONCLUSIONS: The contribution of the PAHH to the variability was explained by the fact that these compounds, together with N and P, are carried by rivers that discharge into the ocean, which enhances the growth of hydrocarbonoclastic bacteria and the productivity and number of the intermediate hosts. Our results suggest that sites with PAHL/PAHH ratio values up to 1.89 promote transmission based on the high values of the prevalence of O. wageneri in the study area. In contrast, PAHL/PAHH ratio values ≥ 1.90 can be considered harmful for the transmission stages of O. wageneri and its hosts (copepods, shrimps and shoal flounders). Overall, the results indicate that the PAHHs affect the probability of occurrence of this helminth parasite in the southern Gulf of Mexico. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-015-1222-6) contains supplementary material, which is available to authorized users

Prospects for practice-based philosophy of logic

We explore prospects for practice-based approaches to logical theory, in particular the link between classical and intuitionistic logic and the inferential structure of traditional practices of representation & argument in science and mathematics. After discussing some key notions about practice, we outline the connection between representation practices and classical logic, and then consider a spectrum of actual practices followed or proposed by (real) scientists. Intuitionistic logic helps to clarify the potential of practice-based approaches for understanding pluralism, and to hammer some key points about the general thesis.Ministerio de Economía y Competitividad FFI2009-1002

Tratamiento multimodal de contextos

We take as starting point the context logic studied in (Grossi, Meyer, and Dignum 2008) and (Aucher et al. 2009), which was concerned with the development of a dynamic logic of rules. Here we focus on issues of Formal Epistemology and omit the addition of deontic operators.We define some basic logics that are useful for the study of epistemic actions such as expanding, contracting or revising a theory taking into account different kinds of inferential results

Application of Multi-core and GPU Architectures on Signal Processing: Case Studies

In this article part of the techniques and developments we are carrying out within the INCO2 group are reported. Results follow the interdisciplinary approach with which we tackle signal processing applications. Chosen case studies show different stages of development: We present algorithms already completed which are being used in practical applications as well as new ideas that may represent a starting point, and which are expected to deliver good results in a short and medium term

First record of entomopathogenic nematodes from Yucatán State, México and their infectivity capacity against Aedes aegypti

Background Biological control using entomopathogenic nematodes (EPN) has demonstrated good potential to contribute to the integral control of mosquito larvae, which as adults are vectors of diseases such as Dengue fever, Zika and Chikungunya. However, until now there are no records of the presence of EPN or their killing capacity in Yucatán state, southern México. The objectives of the current study were: (1) to report the entomopathogenic nematodes present in Yucatán soils and (2) to determine the killing capacity of the most frequent and abundant EPN against Aedes aegypti mosquito larvae and the microbial community developed by Ae. Aegypti exposed to this EPN. Methods The nematodes were collected by the insect trap technique using the great wax moth Galleria mellonella. Internal transcribed spacer (ITS), 28S gene of ribosomal DNA and phylogenetic analyses were performed to identify the EPN. For the bioassay, four concentrations of the most frequent and abundant EPN were tested: 1,260:1 infective juveniles (IJs) per mosquito larvae, 2,520 IJs:1, 3,780 IJs:1 and 5,040 IJs:1. High-throughput sequencing of the 16S rRNA gene was used to identify bacterial amplicon sequences in the mosquito larvae infected with EPN. Results Six isolates of Heterorhabditis were recovered from 144 soil samples. Heterorhabditis indica (four isolates) was the most frequent and abundant EPN, followed by Heterorhabditis n. sp. (two isolates). Both nematodes are reported for the first time for Yucatán state, Mexico. The concentration of 2,520 IJs:1 produced 80% of mosquito larvae mortality in 48 h. Representative members of Photorhabdus genus were numerically dominant (74%) in mosquito larvae infected by H. indica. It is most likely that these bacteria produce secondary toxic metabolites that enhance the mortality of these mosquito larvae

Experiments with the NNMFPACK library: influence of beta parameter in the NNMF approximation error

[EN] NnmfPack is a numerical library designed to compute efficiently the Non-Negative Matrix Factorization (NNMF). It has been conceived for shared memory heterogeneous parallel systems, and it supports, from its conception, both conventional multi-core processors and many-core coprocessors. NnmfPack offers different algorithms which allow to handle different metrics options such as beta-divergence or Frobenius norm. In real applications the choice of the beta parameter presents a problem for the users of the NNMF that must decide which value to use to obtain the best approximation. In this paper, the influence of the parameter beta in the NNMF approximation error for different problems is empirically evaluated. Different datasets have been used in order to analyze and evaluate the dependency between the quality of the approximation provided by NnmfPack and the value of the beta parameter used.This work has been partially supported by Ministerio de Economía y Competitividad from Spain, under the projects TEC2012-38142-C04-01 and TEC2012-38142-C04-04 and by PROMETEO FASE II 2014/003 projects of Generalitat Valenciana.San Juan Sebastián, P.; Vidal Maciá, AM.; García Mollá, VM.; Martínez Zaldívar, FJ.; Ranilla, J.; Alonso, P.; Alonso-González, M.... (2015). Experiments with the NNMFPACK library: influence of beta parameter in the NNMF approximation error. CMMSE. http://hdl.handle.net/10251/75307