70 research outputs found
GF(q) LDPC encoder and decoder FPGA implementation using group shuffled belief propagation algorithm
This paper presents field programmable gate array (FPGA) exercises of the GF(q) low-density parity-check (LDPC) encoder and interpreter utilizing the group shuffled belief propagation (GSBP) algorithm are presented in this study. For small blocks, non-dual LDPC codes have been shown to have a greater error correction rate than dual codes. The reduction behavior of non-binary LDPC codes over GF (16) (also known as GF(q)-LDPC codes) over the additive white Gaussian noise (AWGN) channel has been demonstrated to be close to the Shannon limit and employs a short block length (N=600 bits). At the same time, it also provides a non-binary LDPC (NB-LDPC) code set program. Furthermore, the simplified bubble check treasure event count is implemented through the use of first in first out (FIFO), which is based on an elegant design. The structure of the interpreter and the creation of the residential area he built were planned in very high speed integrated circuit (VHSIC) hardware description language (VHDL) and simulated in MODELSIM 6.5. The combined output of the Cyclone II FPGA is combined with the simulation output
Cloud Computing Solution for Monitoring Arid Rangeland Dynamics: Case of Moroccan Highlands and Southern Acacia Ecosystems
The wide availability of free satellite imagery, the recent development of cloud platforms dedicated to big spatial data (Big Data) that integrates both image archives from different providers, processing algorithms, distributed processing capabilities as well as an application programming interface (API) that facilitate scripting and automation process opened new perspectives for the use of vegetation observation time series over long timestamps and over large spatial scales (almost planetary).
This work aims at harnessing these technologies and building up an automated solution to monitor rangeland rehabilitation dynamics in arid lands and to assess the effectiveness of stakeholder’s management strategies. Such solution is based on graphical user interface that facilitate the process and on the use of analysis functions relaying on analysing temporal trajectories (time series) of different spectral indices derived from satellite images (Landsat or Sentinel) at the required spatial analysis scale.
The solution is implemented using java script as scripting language using the functions offered by GEE API. The graphical user interface of the first prototype is exploitable by the means of a standard web browser and it is accessible even to people without any background in regard to programming languages or to remote sensing skills. The process was tested for two arid sites on Morocco: acacia ecosystems on the southern part of Morocco and the highlands on Moroccan eastern parts mainly on sites recently rehabilitated. It has been qualified is promising solution
A Graph-based approach to derive the geodesic distance on Statistical manifolds: Application to Multimedia Information Retrieval
In this paper, we leverage the properties of non-Euclidean Geometry to define
the Geodesic distance (GD) on the space of statistical manifolds. The Geodesic
distance is a real and intuitive similarity measure that is a good alternative
to the purely statistical and extensively used Kullback-Leibler divergence
(KLD). Despite the effectiveness of the GD, a closed-form does not exist for
many manifolds, since the geodesic equations are hard to solve. This explains
that the major studies have been content to use numerical approximations.
Nevertheless, most of those do not take account of the manifold properties,
which leads to a loss of information and thus to low performances. We propose
an approximation of the Geodesic distance through a graph-based method. This
latter permits to well represent the structure of the statistical manifold, and
respects its geometrical properties. Our main aim is to compare the graph-based
approximation to the state of the art approximations. Thus, the proposed
approach is evaluated for two statistical manifolds, namely the Weibull
manifold and the Gamma manifold, considering the Content-Based Texture
Retrieval application on different databases
Optimal Cluster Head in DTN Routing Hierarchical Topology (DRHT)
In delay tolerant networking (DTN), nodes are autonomous and behave in an unpredictable way. Consequently, a control mechanism of topology is necessary. This mechanism should ensure the overall connectivity of the network taking into account nodes’ mobility. In this paper, we study the problem of data routing with an optimal delay in the bundle layer, by exploiting: the clustering, the messages ferries and the optimal election of cluster head (CH). We first introduce the DTN routing hierarchical topology (DRHT) which incorporates these three factors into the routing metric. We propose an optimal approach to elect a CH based on four criteria: the residual energy, the intra-cluster distance, the node degree and the head count of probable CHs. We proceed then to model a Markov decision process (MDP) to decide the optimal moment for sending data in order to ensure a higher delivery rate within a reasonable delay. At the end, we present the simulation results demonstrating the effectiveness of the DRHT. Our simulation shows that while using the DRHT which is based on the optimal election of CH, the traffic control during the TTL interval (Time To Live) is balanced, which greatly increases the delivery rate of bundles and decreases the loss rate
Efficiency of two decoders based on hash techniques and syndrome calculation over a Rayleigh channel
The explosive growth of connected devices demands high quality and reliability in data transmission and storage. Error correction codes (ECCs) contribute to this in ways that are not very apparent to the end user, yet indispensable and effective at the most basic level of transmission. This paper presents an investigation of the performance and analysis of two decoders that are based on hash techniques and syndrome calculation over a Rayleigh channel. These decoders under study consist of two main features: a reduced complexity compared to other competitors and good error correction performance over an additive white gaussian noise (AWGN) channel. When applied to decode some linear block codes such as Bose, Ray-Chaudhuri, and Hocquenghem (BCH) and quadratic residue (QR) codes over a Rayleigh channel, the experiment and comparison results of these decoders have shown their efficiency in terms of guaranteed performance measured in bit error rate (BER). For example, the coding gain obtained by syndrome decoding and hash techniques (SDHT) when it is applied to decode BCH (31, 11, 11) equals 34.5 dB, i.e., a reduction rate of 75% compared to the case where the exchange is carried out without coding and decoding process
UPC-USMBA at SemEval-2017 Task 3: Combining multiple approaches for CQA for Arabic
This paper presents a description of the participation of the UPC-USMBA team in the SemEval 2017 Task 3, subtask D, Arabic. Our approach for facing the task is based on a performance of a set of atomic classifiers (lexical string-based, vectorial, and rule-based) whose results are later combined. Our primary submission has obtained good results: 2nd (from 3 participants) in MAP, and 1st in inaccuracy.Peer ReviewedPostprint (published version
No todas las preguntas son (igualmente) difĂciles, una aproximaciĂłn hĂbrida a la CQA en árabe
In the past we faced the problem of Community Question Answering using an unified approach. Some of the questions, however, are easier to be approached by a conventional rule-based system. In this paper we explore this direction.En el pasado hemos abordado la bĂşsqueda de respuestas en comunidades usando un enfoque uniforme. Sin embargo, algunas preguntas pueden ser respondidas utilizando mĂ©todos basados en reglas. En este trabajo exploramos esta direcciĂłn.Dr. RodrĂguez has been partially funded by Spanish project "GraphMed" (TIN2016-77820-C3-3R)
Key sectors in the Moroccan economy: an application of input-output analysis
The exploration of the structural features and sectoral interdependences of and in an economy is fundamental for the understanding of its modes of functioning and of its transformations over time. Input-output analysis is largely used to fulfill this objective. Furthermore, information provided by the Leontief inverse matrix is useful for the identification of key sectors. This identification may guide policy makers in setting an adequate industrial strategy. In this paper, the classification of productive sectors is performed by using the Unweighted Rassmussen Approach. The ordering of sectors depends on the intensity of their links with other sectors. Two results ought to be highlighted. First, key sectors of the Moroccan economy (sectors that are classified in category II) reduced to two sectors in 2007 instead of four sectors in 1998. Second, the ordering of sectors is highly sensitive to the precision of the data and to the year in which the classification is realized
Analyse des tendances et des ruptures d’homogénéité dans les series des facteurs climatiques et de la végétation des forêts sud méditerranéennes. Cas de la suberaie de la Maâmora, Maroc
Cet article vise à analyser les chroniques des précipitations, températures et NDVI, générées d’images CHRIPS et MODIS, à l’échelle des cantons A, B et C de la Maâmora, en vérifiant si, durant la période 2001-2016, elles ont identifié des tendances et ruptures, et établi des relations de causalité. Les résultats de l’analyse statistique ont permis de (i) distinguer leur hétérogénéité spatiale et variabilité temporelle marquée par des pics, (ii) révéler un retard de deux mois pour reprendre le cycle du NDVI des cantons B et C, affectés par leur état de dégradation, l’allongement et l’accentuation de la sécheresse. Les tests de Mann-Kendall et Pettitt ont montré la présence de tendances et ruptures légèrement différentes selon les paramètres et les espaces, mais concordantes pour le NDVI du canton B caractérisant une chute depuis Mai-2005 (0.456-0.410). Elles joignent des tendances d’accentuation des Tmax d’été et Tmoy d’automne dudit canton ayant le minimum du NDVI et le maximum des précipitations. Soit l’opposé du canton A bénéficiant d’un adoucissement des Tmax repéré dès août-2008 (28.42°C-27.67°C). Il en découle l’absence de causalité explicite entre les facteurs climatiques étudiés et l’évolution du couvert végétal sous déterminisme d’autres pressions anthropozoïques
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