Papers by Revista Maskay (ISSN: 1390-6712)
Maskay, 2020
The present investigation focused on the design and implementation of a system for monitoring sol... more The present investigation focused on the design and implementation of a system for monitoring solar radiation levels, in the city of Loja, Ecuador. The solar radiation levels monitoring system is based on the development of a sensor network, in which two ultraviolet (UV) sensors have been placed, representing the nodes of the network, these are communicated in a wired way and wireless, with the base station, which represents the core of the network, where data processing, acquisition, and management is performed. The base station manages the data collected by the UV sensors, these data are linked to an application for mobile phones, with Android operating system, in the application you can visualize the level of solar radiation in real time, the history of the data and the respective preventions, according to the level of the ultraviolet index (IUV) presented. In turn, the implementation of a solar light was included, for direct visualization of solar radiation levels.
Maskay, 2020
Phototherapy is the treatment indicated for the management of neonatal jaundice. There are differ... more Phototherapy is the treatment indicated for the management of neonatal jaundice. There are different technologies to provide this treatment, including LED devices. For this study, a LED phototherapy lamp is developed to be used in neonatal jaundice. Its efficacy is compared with other devices by measuring the speed in reducing bilirubin levels. This lamp is built with an LED light source composed of a 15×25 LED array that generates 460nm. This device is characterized by being a very compact source of low energy consumption, long duration, and low cost. The obtained results are comparable with industrial manufacturing devices, but less expensive, therefore, more efficient in terms of health costs.
Maskay, 2020
Many applications on the Internet of things require portable nodes, with mobile connectivity, pow... more Many applications on the Internet of things require portable nodes, with mobile connectivity, powered by batteries to be able of transmitting video of good quality for long periods. Maximizing the operating time of portable nodes that work with batteries is a challenge today. We present the results of the evaluation of the operating time of a small size wireless node that uses batteries and transmits the video over IPv6 to devices connected to the Internet. The tools used for the implementation, configuration of the prototype elements, and the descriptions of the different scenarios are presented, where the current and the operating voltage of the node are measured to calculate the energy consumed and the operating time of the node. The calculated value is compared with the operating time measured in a real environment validating the simple expressions used to evaluate the operating time of a node.
Maskay, 2020
This article describes the design of a wireless network of sensors for monitoring CO2 in the air ... more This article describes the design of a wireless network of sensors for monitoring CO2 in the air and noise levels developed for the urban area of the city of Loja. The design starts with the analysis of the functionality, protocols, and characteristics of the Wireless Sensor Networks (WSN) with the implementation of Zigbee communication technology. For the design of the network, the monitoring scenario was determined through the greater concentration of socio-economic activity within the city, from these scenarios the sectorization of the city center was preceded, establishing the main sources of emission of CO2 and noise levels. Then, the simulation was carried out in the Riverbed Modeler software to determine the evaluation parameters, such as the transmission speed, the delay and the packets received from the chosen technology. Also, the sensor nodes and the coordinating node were designed, which allows the establishment and communication of the network, through the XBee PRO S2B module, of the Zigbee technology. Finally, to evaluate the designed network, two types of tests were performed: a reception power level test and a validation test of the operation of the network, based on the construction and implementation of prototypes of the proposed sensors, a node coordinator and two sensor nodes (one node for CO2 monitoring and one for noise). The generated information is displayed in a graphical interface developed in the VS Express 2017 software.
Maskay, 2020
Here, we propose a novel scheme based on advanced techniques of digital modulation in optical com... more Here, we propose a novel scheme based on advanced techniques of digital modulation in optical communications to achieve a single-channel transmission rate above 100 Gb/s. We utilize a hybrid scheme amplitude/phase/frequency/dual polarization, combined with multidimensional dual lattice and a low-density parity-check-coded modulation. The Stokes parameters are applied to the proposed scheme to map the four-dimensional classical polarization IX, QX, IY, QY in a three-dimensional space. In addition, in the proposed system, the packing theory is applied to the bit interleaver process. Three wavelengths are packaged before being transmitted over a wavelength-division multiplexing optical channel. This modulation process is carried out using symmetrical geometric shapes, such as a hypercube or a polyhedron, based on the molecular links theory using a grouping of 12 and 13/15 bits for the cubic and spherical lattices, respectively. The proposed technique is evaluated in the context of long-distance communications over distances up to 100km. The bit error rate (BER) results showed that the optical signal-to-noise ratio was approximately 4dB over a distance of 50km. In addition, the power spectral efficiency was found to be 3 lambdas, which is considered good performance considering the effects of distance and the non-linear effects influencing the number of lambdas. Also, we use an optical time-division multiplexing scheme (OTDM) in order to achieve a transmission rate beyond 1Tbit/s, where the speed effect is evaluated, taking into consideration that the power spectral efficiency is degraded.
Maskay, Mar 20, 2020
The introduction of digital terrestrial television (DTT) brings multiple advantages. On the one h... more The introduction of digital terrestrial television (DTT) brings multiple advantages. On the one hand, there are those advantages that allow optimizing the use of the radioelectric spectrum, such as (i) the possibility of transmitting in adjacent channels, (ii) transmission of multiple contents through the same radio channel, and (iii) the use of single frequency networks (SFN). On the other hand, another advantage, not fully exploited, is to offer interactive content and value-added services, such as learning (T-Learning), voting (T Voting), commerce (T-Commerce), etc. In ISDB-Tb interactivity, it is possible to use the GINGA middleware, developed in Brazil. In Ecuador, ISDB-Tb was adopted as a DTT standard in 2010. Nowadays, and despite having passed several years, the implementation of ISDB-Tb in Ecuador is still in its early stages. Therefore, none of its most important features has yet been exploited. This article presents the design of an interactive application that allows products to be commercialized through DTT. The application design was developed in Ginga-J to allow security options. In addition, the company's database was developed in MySQL with an APACHE server. The application allows the user to pay by credit card or by PAYPAL. The use of digital certificates and signatures was included to encode the information, protect the data, and verify the identity of both parties, making the purchase a safe process. The use of digital signatures prevents the company from storing user financial data or the company making a fraudulent transaction, and vice versa. Through user acceptance tests (UAT), it was determined that the application is useful, the content is organized and understandable, and its handling is like making a purchase online. Finally, the purchase is verified with the discount on the balance of the user's account.
Maskay, 2020
This prototype was carried out in the lab environment at ESPOCH in Ecuador, using USRP B210 worki... more This prototype was carried out in the lab environment at ESPOCH in Ecuador, using USRP B210 working at 5GHz and including two ZJL6G+ amplifiers in cascade connection with 20dB of total gain, in order to improve the overall system power. In the measurement stage, three different samples with different humidity levels were used to determine the risk in diverse conditions. The sample materials were macadam, soil, and sand. Depending on their humidity level, risks oscillate between maximum and minimum, where high humidity led to high risk and inversely. Macadam was the best material for a landslide area since it showed the lowest permittivity indexes, in consequence, lowest risk. Results were processed in order to get reflection and relative permittivity values and afterwards they were stored in a database to be analyzed and determine levels of risks simulating landslides as function of humidity level.
Maskay, Oct 11, 2019
Here, we propose a novel scheme based on advanced techniques of digital modulation in optical com... more Here, we propose a novel scheme based on advanced techniques of digital modulation in optical communications to achieve a single-channel transmission rate above 100 Gb/s. We utilize a hybrid scheme amplitude/phase/frequency/dual polarization, combined with multidimensional dual lattice and a low-density parity-check-coded modulation. The Stokes parameters are applied to the proposed scheme to map the four-dimensional classical polarization IX, QX, IY, QY in a three-dimensional space. In addition, in the proposed system, the packing theory is applied to the bit interleaver process. Three wavelengths are packaged before being transmitted over a wavelength-division multiplexing optical channel. This modulation process is carried out using symmetrical geometric shapes, such as a hypercube or a polyhedron, based on the molecular links theory using a grouping of 12 and 13/15 bits for the cubic and spherical lattices, respectively. The proposed technique is evaluated in the context of long-distance communications over distances up to 100km. The bit error rate (BER) results showed that the optical signal-to-noise ratio was approximately 4dB over a distance of 50km. In addition, the power spectral efficiency was found to be 3 lambdas, which is considered good performance considering the effects of distance and the non-linear effects influencing the number of lambdas. Also, we use an optical time-division multiplexing scheme (OTDM) in order to achieve a transmission rate beyond 1Tbit/s, where the speed effect is evaluated, taking into consideration that the power spectral efficiency is degraded.
Maskay, May 24, 2019
Sudden changes in a greenhouse environment negatively impact the development and production of cr... more Sudden changes in a greenhouse environment negatively impact the development and production of crops, especially in greenhouses with natural ventilation when temperatures are low at night and change rapidly due to wet winds. To mitigate these variations, a design of a robust controller based on Quantitative Feedback Theory (QFT) as from a Smith predictor structure for the dead-time system is proposed. This structure offers high stability based on the gain margin, the phase margin, and the rejection of disturbances in the system output. This design was contrasted with a PID controller based on performance indices, according to the transient response and error in the presence of changes in the point of operation and charge disturbances. Final results showed that the dynamic response of the QFT controller improved compared to PID controller results.
Maskay, May 8, 2019
This paper describes a quadrature phase shift keying (QPSK) demodulator. The digital demodulator ... more This paper describes a quadrature phase shift keying (QPSK) demodulator. The digital demodulator is based on the median for recovering data bits. The results showed that the median technique reduces complexity. The modulator consists of two different techniques: direct digital synthesis technique (DDS) and stored phases in read-only memories. These techniques were compared to probe the efficiency using parameters such as power consumption and the number of used elements. The modulator based on the memories is optimal. The modulator and demodulator were designed in VHDL language and were implemented in a Virtex-5 board from Xilinx.
Maskay, May 26, 2018
Currently there are several techniques to evaluate anxiolytic behavior in laboratory animals, sin... more Currently there are several techniques to evaluate anxiolytic behavior in laboratory animals, since their behavior is very similar to that of humans, such techniques include manual and observational methods, where the evaluator must carefully observe the entire experiment and document each one of the events of interest made by the mouse, or in turn acquire electronic equipment that fulfills this function. However, the last option could be expensive. This article proposes the design and implementation of two low-cost anxiety assessment devices (Elevated Plus Maze and Light-Dark Box) using digital image processing, which after the validation of the operation delivers results automatically through an application developed in Matlab. The results provided by the application coincide with those that an observer would obtain manually and visually, facilitating the tasks of the evaluator and reducing the possible human errors and ambiguity existing in manual tests.
Maskay, May 31, 2018
This paper proposes an alternative method of wireless power supply for low power consumption devi... more This paper proposes an alternative method of wireless power supply for low power consumption devices. For the design of the antennas responsible for the transmission of energy, microstrip lines were used on an FR4 substrate (Flame Retardant 4) based on mathematical methods tested from other research contributions. Therefore, integrated circuits with MMIC (Monolithic Microwave Integrated Circuits) technology are included for the generation of radio-frequency as an energy source in the range of 16 MHz to 23 MHz. In the reception phase, a three-stage doubling voltage circuit is required with the purpose of rectifying and amplifying the transmitted signal. The results of the implementation of the system indicate an efficiency between 20% and 30% for transmission distances up to 90 millimeters without obstacles. The performance decreases between 0% and 6.67% when crossing materials such as agglomerate, plastic, glass, expanded polystyrene, fabric and wood, however, it totally loses performance with metal.
Maskay, May 16, 2018
A prototype based on development cards for the coupling of the inertial navigation system with GP... more A prototype based on development cards for the coupling of the inertial navigation system with GPS is implemented to improve the accuracy of navigation on a trajectory. Initially it is necessary to calibrate the inertial measurement unit (IMU) using the MADGWICK filter to obtain reliable raw data, the coupling of the global positioning system (GPS) and IMU signals is done through the Tight Coupling architecture using the Kalman filter to concurrently eliminate correlated errors between systems and achieve better accuracy in the general navigation solution used for unmanned aerial vehicle (UAV) applications. The final application, called LJLAB, is developed in Matlab® with the aim of processing and visualizing the measured data of both systems (independent and coupled). The application is capable of showing the error in positioning accuracy that exists between technologies being statistically verified through the experimental method ANOVA which computes the absolute error between the real points and those measured through the analysis of the mean and variance of the observed data.
Maskay, May 24, 2018
The present work focuses on a hardware-based approach to experimentally identify the best perform... more The present work focuses on a hardware-based approach to experimentally identify the best performing algorithm for the calculation of the IFFT of an OFDM symbol of the ISDBT-b standard. In order to accomplish this goal symmetric and asymmetric Split-radix algorithms are described and their entire hardware implementation is developed. The results of the test incorporate other algorithms known as radix-2 lite, radix-2, radix-4 and pipelined. The comparative evaluation of the performance of the algorithms was performed considering the following parameters: Signal to Quantize Noise Ratio (SQNR), processing time and the number of resources used of the Virtex-5 XUPV5-LX110T card. From the analysis, it is obtained that the algorithm that presents the best performance depends on the parameter analyzed.
Maskay, Apr 20, 2018
Nowadays, wireless communication networks are substantially increasing the number of transmission... more Nowadays, wireless communication networks are substantially increasing the number of transmission information. Therefore, the development of novel technologies that supply this demand in the markets is necessary. In this context, Generalized Frequency Division Multiplexing (GFDM) arises as a solution for future wireless communication networks. The principal goal of this research is to analyze the performance of Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) modulations for different conditions of the communication channel in GFDM system. The BPSK, QPSK modulations and matrix signal model of the GFDM system is presented. The performance is evaluated in terms of Bit Error Rate (BER) and three different channels are implemented: ideal, fixed, and fixed-random. The detection simulation results depict the performance curves for different scenarios and modulations. It can be noticed that for all channels the BPSK modulation outperforms the QPSK modulation.
Maskay, Jan 5, 2018
Multivariable control systems have several inputs and several outputs, where each input controls ... more Multivariable control systems have several inputs and several outputs, where each input controls more than one output and each output is controlled by more than one input. This is a feature called coupling and presents mathematical complications for solving and controlling such systems. The goal of this work is to develop a decoupling technique using a transfer function matrix for multiple-input-multiple-output multivariable systems. The proposed technique consists of determining a compensator in such a way that the multivariate coupled system can become a set of multiple uncoupled single-input single output systems. With this transformation, each input only controls one output and each output is controlled by a single input, facilitating any control solution. The final developed technique uses a computational methodology to achieve the proposed objective. In order to demonstrate the efficiency of the implemented algorithm, experimental validation is performed through mathematical simulations of different test plants.
Maskay, Nov 26, 2018
This article contains a verbal and mathematical description of the drying process inside ATM-52 s... more This article contains a verbal and mathematical description of the drying process inside ATM-52 spray dryer for ceramic paste production. Through the application of a modeling methodology, it was defined as an objective to be able to describe, by means of a phenomenological basis, the temporal variation of humidity in the outlet stream of the ATM-52 spray dryer. This variable is the most critical in the process and it’s the most fluctuating to measure in real time and only laboratory methods are available to obtain measurements. To achieve the objective, a series of assumptions were made, allowing to describe the model by a set of differential ordinary equations, The most important assumption is that the mass transfer phenomena are significant when streams flow is in co-current. Once the set of equations were obtained, through physical-chemical relations of the process, parameters values were assigned and computational verification was applied. The model was validated using the values in the steady state obtained from the real process.
Maskay, Nov 26, 2018
An automated system was designed and implemented to perform retinoscopy examinations using artifi... more An automated system was designed and implemented to perform retinoscopy examinations using artificial vision with the correlation coefficient for the processing of retinal images. The technique of observation and experimentation was used to identify the necessary conditions involved in performing the retinoscopy examination. A mechanical, electronic and artificial vision system design was established for the selection and installation of the necessary components for the automation. For the operation of the automated system an algorithm of processing and comparison of images programmed in the LabVIEW software was developed; through a connection to the serial port, data is sent from the computer to the Arduino Uno development board, which controls actuators that are servomotors that direct the position of the lenses and effect the movement of the light beam of the retinoscope. For the automatic change of lenses, a suitable mechanical system was implemented in order to obtain a fixed image of the retina; a human-machine interface (HMI) was created, which allows the operator to view the examination process in real time. With the implementation of the system the average time of the image comparison was determined, with the result that: eyes without ametropia were compared in 162,28 ms, myopia in 166,02 ms, with farsightedness in 170,7 ms and with astigmatism in 174,75 ms, reducing the time taken to perform the retinoscopy examination of 250 to 150 seconds equivalent to 40%. It was concluded that the time of comparison of the images increase in 2.44% while the sea was the refractive damage.
Maskay, Nov 4, 2018
In this work presents a mathematical model for determining a limiting mask for equivalent power f... more In this work presents a mathematical model for determining a limiting mask for equivalent power flux density produced by the downlinks of non-GSO satellite systems in the North American region. This mask is used to protect earth stations from the interference generated by the non-GSO satellite. The mathematical model is employed to generate an EPFD↓ mask. An analysis of two systems is made to compare the behavior of the mask in the North American region.
Maskay, Oct 5, 2018
We present the progress made in the development of optical frequency combs generators (OFCG) usin... more We present the progress made in the development of optical frequency combs generators (OFCG) using Photonic Integrated Circuits (PIC). These are designed and manufactured in a Multi-project Wafer run at generic integration platform. The experimental results of the different OFCG classes are shown, highlighting the bandwidths achieved, in the order of THz. The feasibility of providing miniaturized photonic circuits in broadband systems and other future applications in the framework of nanotechnology is highlighted.
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Papers by Revista Maskay (ISSN: 1390-6712)