Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This paper deals with the Oligo-Miocene coral reefs in the Mohammadabad Area, W Baft, SW Kerman. The studied coral reefs include 11 families, 25 genera and 33 species of the scleractinian corals. The coral reef successions have deposited in three cycles on a mixed siliciclastic-carbonate platform. To understanding the paleoecology, reef architecture and depositional model of studied reefal successions, statistical analyses based on the coral niches, sedimentology analyses based on the grain size of the marly strata and microfacies analyses on limestone strata have used. Based on the statistical analyses, the coral community includes eight ecotypes. The distribution of these ecotypes indicates that, despite of various thicknesses, in all three coral reef successions, the branching and fast growth ecotypes are present at the basal parts and the massive, placoid and meandroid colonies are recorded in the slope, crest and distal parts of the reefs. The main disruptive phenomenon that stopped the reef development and affected the reef architecture has been the addition of clastic deposits to the carbonate system. This sediment load increase is recorded as marly strata. By The addition of clastic sediment load to the system, the carbonate content of the system has diluted, the salinity, water transparency and photic level is decreased, the favorable attachment hard substrate for coral polyps is limited, the nutrient and oxygen flux is disrupted and the coral reefs are suffocated.

Fuzzy decision trees are techniques used for fault diagnosis of industrial systems. Its advantages include simplicity and ease of interpretation. However, most of the methods for its induction require going through the tedious task of classifying all the observations that compose the fault tree training database. Even those methods that do not require this stage definitely require obtaining a large data set that contains the behavior of the system for each fault that is expected to be diagnosed. This last characteristic is not always easy to achieve, since it implies taking the process out of its normal operation. Then, the present investigation has the objective of presenting a proposal of methodology for fault diagnosis in industries based on decision trees and fuzzy logic. This new methodology takes advantage of the capabilities provided by fuzzy logic to manage the uncertainty of the knowledge provided by the process experts. In addition, it makes the contribution of offering a method to avoid the need of having a large training database during the process of development of the fault diagnosis system, which will imply the use of a fault symptom table. The effectiveness of the methodology is analyzed in a real case, specifically in the fault diagnosis of a water treatment process for injection in the pharmaceutical industry.

This article proposes the design and simulation of a microstrip antenna with circular polarization in two frequency bands 2.4GHz and 5.2GHz, suppressor of the second and third harmonics of the fundamental frequencies through the use of metamaterials, using a microstrip power line and the grooved ground plane. A study of the main techniques to suppress harmonics was carried out. Among the most innovative are the insertion of metamaterials, these structures present novel properties in the area of traditional electromagnetism. Such properties have allowed the design of microwave antennas with new radiation characteristics that have served as the main stimulus to develop this research. Circular polarization is achieved in both frequency bands throught asymmetric slots and optimized by introducing disturbances in the radiating structure. With the proposed design, a miniturization of the dimensions of the antenna is obtained, gains of approximately 3.00dB in the two frequencies of interest, coupling bandwidths and circular polarization of 364 MHz in 5.2GHz, which represents 15%, 16 % and 11.57% respectively, enough to cover the requirements of WLAN applications. The entire design, simulation and optimization process was carried out in the CST Studio Suite 2017 software.

This paper shows the obtaining process of a digital beamformer of multiple simultaneous directional patterns for the reception of signals using the evaluation board ARRadio, which is based on the integrated transceiver AD9361. This board guarantees the reception process and digitization of the radio waves acquired by each radiofrequency channel and their sending, through a high speed connector, to the Development Boars TR4; in which, using the FPGA (Field Programmable Gate Array) present in it, are made the configuration and control of the AD9361, the calibration process based on the Fourier transform (as method of measuring the delay between channels), and the beamforming of multiple simultaneous directional patterns digitally. Furthermore, it is using Simulink as a tool for design the digital system and are made the implementation and experimental verification of the simultaneous beamformer system.

The current work presents the first algorithm to detect bursts in water pipes automatically, focused on its implementation in low-power embedded devices. The algorithm was implemented in an MSP430FR5994 microcontroller and it does not require computer devices with the processing capability to execute high-complexity mathematical operations, unlike most of the existing algorithms. The developed algorithm uses the approach of detecting bursts by enhancing the singularities they create and making decisions based on the application of thresholds. Instead of applying a single mathematically-complex threshold, two simpler ones are used that are compatible with the processing capability of low-power embedded devices. Two implementations for the convolution operation were tested using the microcontroller’s Low Energy Accelerator module; it was found that the convolution in the time domain is faster than the FFT-based method in an average of 65.3%. The algorithm detects bursts with a detection probability of 100% and a probability of false positives of 0.13% on the performed tests.

This paper presents a super resolution Direction of Arrival (DOA) estimation system based on a combined hardware-software implementation for radio frequency signals. After computational simulation of the chosen method, the system is designed and implemented using two multichannel wideband microwave transceivers controlled by a FPGA board connected to a host computer with a PCI Express adapter. A graphic interface is developed to visualize the spatial spectrum and validate the right system performance. The followed procedure shows up the main issues and requirements when this kind of method is implemented. Moreover, a generic modular and flexible hardware solution is proposed where no custom printed circuit board design and fabrication is needed. 

This paper presents the use of biphasic code compression technique for its application as an excitatory signal of a pulse compression radar. Main characteristics are exposed and is described the modulation, receiving and compression blocks, achieved by means of digital technics. Was employed Very High-Speed Integrated Circuit Hardware Description Language (VHDL) for digital implementation and MATLAB® for simulation, modelling and VHDL Synthesis. A 32-bits code is used which sidelobes are not greater than 3, guaranteeing 20.56 dB of Peak to Sidelobe Level Ratio (PSL). The contribution of this purpose yields in the use of FPGA to generate and compress pulse compression radar signals and the use of high order Nyquist Bands in transmission and reception process.

Cardiovascular diseases are one of the leading causes of death in the world and in Cuba. Hypertension has a very considerable prevalence in the Cuban population, being the risk factor with the highest occurrence. As part of the process of computerization and distribution of knowledge, the objective of the work is to present an application for the Android operating system to contribute to the diagnosis, evaluation and treatment of Hypertension in a more accessible way to the population and medical staff, including other tools for the best hypertension control. This tool is targeted to, fundamentally, to primary health care and focuses on the Patient Pathway. The application contains a guiding text, calculators of medical interest, pharmacological and non-pharmacological recommendations depending on the clinical evaluation. In addition, it includes the strategy of hypertension treatment in Cuba according to the individual clinical evaluation, clarifying the drugs to be used. It also includes an interface for the acquisition of data from individuals. The application obtained an average SUS score of 93.61, after being evaluated by cardiology specialists and non-specialists.

The healing of skin lesions is a complex process that can be supervised through periodic inspection of the condition of the lesions. With the estimation of their areas, it is possible to evaluate the response to the applied treatment, predict possible healing results and differentiate a lesion that will heal easily from another that will require prolonged treatment. This information is used in drug candidate studies, therefore high-precision measurements are required. Manual techniques that involve contact with the lesions are usually used for measurements, which is risky, prone to errors and inter- and intra-specialist variations. In this research, the segmentation of photographic images of lesions on the skin of laboratory animals was developed to select the most appropriate alternative among possible algorithms implemented for estimating the area of the lesions. To this end, the quality of several segmentation by  thresholding methods to detect lesions was evaluated in a supervised manner, with the help of reference images previously segmented by experts. Different quality indicators were used, such as the Jaccard coefficient, the relative error in the automatic estimation of the area with respect to the reference, and non-parametric statistical tests. The results showed differences between the applied algorithms and coincidences between descriptive statistics and non-parametric statistics and might contribute to select an appropriate alternative among those tested. This research has a direct application in the pharmaceutical and health sector.

autonomous surface vehicles (ASV). In this sense, the Nonlinear guidance law algorithm (NLGL), emerged in recent years for his use in aerial vehicles, is presented as an interesting option for path following of marine vehicles by not using the yaw angle to achieve their control objectives. The biggest problem that these vehicles present to path following is the influence of environmental disturbances on them, mainly sea currents and wind. In this work a guide and control scheme is presented to achieve the tracking of straight paths by marine vehicles, it presents a cascade structure with an internal rateyaw loop, which has a PID controller as his main element, and the NLGL algorithm on the outer loop. An analysis of how ocean currents and wind influence this system is also carried out from the linearization of the scheme presented, in addition a stability analysis of the scheme is presented. Finally, the results of simulation and real experiments of the implementation of this scheme in a small ASV are presented, where it can be seen that the vehicle converges to the desired path with precision in the presence of multiple environmental disturbances.