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31,456 Article Results

The analysis of MF resin and CaCO3 diffuser-loaded encapsulations to enhance the homogeneity of correlated color temperature for phosphor-converted LEDs

10.12928/telkomnika.v19i2.16519
My Hanh Nguyen; Industrial University of Ho Chi Minh City Thi , Phung Ton; Industrial University of Ho Chi Minh City That
The most popular method used in the production of phosphor-converted LEDs (pc-LEDs) is dispensing phosphor freely. However, this method is inferior in generating good angular correlated color temperature (CCT) homogeneity. Thus, in this article, a diffuser-loaded encapsulation is proposed as a potential solution for better CCT uniformity. The paper provides a detailed investigation on how melamine formaldehyde (MF) resin and CaCO3 loaded encapsulations impact the uniformity of CCT, as well as the lumen efficacy of pc-LEDs. The results demonstrate that between MF resin and CaCO3 loaded encapsulations, the MF resin yields a higher light diffusion efficiency while the CaCO3 maintains greater lumen efficacy. The photon scattering development is the key force behind the enhancement of the angular CCT uniformity in pc-LEDs’ output when using the loaded encapsulations of MF resin and CaCO3 particles. Since this package utilized mineral, it has reasonable cost and is quite easy to control while still being effective in enhancing the angular CCT homogeneity of pc-LEDs. Diffusers with 1% concentration of MF resin or 10% concentration of CaCO3 are determined as an optimal solution for reducing the variance of angular CCT and increasing the lumen output.
Volume: 19
Issue: 2
Page: 608-615
Publish at: 2021-04-01

Organizing sports matches with a hybrid monkey search algorithm

10.11591/ijeecs.v22.i1.pp542-551
Ruqaya Zedan Shaban , Isra Natheer Alkallak
This academic piece of the paper illustrates an approach of organizing sports matches to be as a tool of sports schedule maker via a proposed hybrid Monkey search algorithm by doubles elimination tournament. Input are a set of teams represented by monkeys. It states that the natural behavior of monkeys and its climbing to obtain (solution) through uphill (climbing), watch-jumping, and somersault process. The parameters in the climb were represented by whether or not sports team won. The distribution of the teams, whether in the upper or the lower half, represented in the watch-jumping by mathematical equations, in addition to representing the variables in somersault process. The consequences behind the suggested algorithm used have tackled steps to reach an optimal schedule for a variety of teams for the same championship. The team cannot play more than two consecutive matches with the condition of starting with a random population of feasible solutions. The performance of the presented algorithm was very well through providing a flexible and easy organization of sports matches without using classic or manual routine. Furthermore, the search space reduced so that can give a guarantee to achieve a globally optimum solution. The software platform was MATLAB m-files.
Volume: 22
Issue: 1
Page: 542-551
Publish at: 2021-04-01

Delineation of electrocardiogram morphologies by using discrete wavelet transforms

10.11591/ijeecs.v22.i1.pp159-167
Annisa Darmawahyuni , Siti Nurmaini , Hanif Habibie Supriansyah , Muhammad Irham Rizki Fauzi , Muhammad Naufal Rachmatullah , Firdaus Firdaus , Bambang Tutuko
The accuracy of electrocardiogram (ECG) delineation can affect the precise diagnose for cardiac disorders interpretation. Some nonideal ECG presentation can make a false decision in precision medicine. Besides, the physiological variation of heart rate and different characteristics of the different ECG waves in terms of shape, frequency, amplitude, and duration is also affected. This paper proposes a discrete wavelet transform (DWT), non-stationary signal analysis for noise removal, and onset-offset of PQRST feature extraction. A well-known database from Physionet: QT database (QTDB) is used to validate the DWT function for detecting the onset and offset of P-wave, QRS-complex, and T-wave localization. From the results, P-peak detection gets the highest result that achieves 2.19 and 13.62 milliseconds of mean error and standard deviation, respectively. In contrast, Toff has obtained the highest error value due to differences in the T-wave morphology. It can be affected by inverted or biphasic T-waves and others.
Volume: 22
Issue: 1
Page: 159-167
Publish at: 2021-04-01

High speed modulated wavelength division optical fiber transmission systems performance signature

10.12928/telkomnika.v19i2.16871
Aadel M.; Tabuk University Alatwi , Ahmed Nabih Zaki; Menoufia University Rashed , Ismail A. Abd El; Benha University Aziz
This study presents modulated-wavelength division radio signals over fiber with mixed modulation techniques in the transmitter stage. Hybrid optical sources are used to achieve optimal performance and enhancement for an optical fiber communication network. The proposed modulation techniques work at a frequency of 250 GHz. Optical quadrature phase shift keying (OQPSK) and phase modulation (PM) techniques were merged to create OQPSKPM. This was in addition to the minimum shift keying (MSK) modulation scheme that was applied in the proposed model. The modulated wavelength division multiplexing design to four subscribers was examined with a single mode optical fiber at a 1550 nm wavelength. The proposed and previous simulation models were executed, investigated and measured on important operating parameter quantities that expressed the behavior of the optical fiber network in detail, like maximum quality factor, minimum bit error rate, and output power. The obtained simulation results demonstrated the priority of the proposed simulation model.
Volume: 19
Issue: 2
Page: 380-389
Publish at: 2021-04-01

Cloud radio access network fronthaul solution using optimized dynamic bandwidth allocation algorithm

10.11591/ijece.v11i2.pp1395-1404
Ebude Carine Awasume , Stephen Musyoki , Vitalice Kalecha Oduol
In order to address the challenges that have come with the exploding demand for higher speed, traffic growth and mobile wireless devices, Mobile network operators have decided to move to the notion of small cells based on cloud radio access network. The merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective the merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective. Notwithstanding, cloud radio access network comes with so many strict requirements to be fulfilled for its fronthaul network. In this paper, we have presented these requirements for a 5G fronthaul network. Particular interest on the time division multiplex passive optical network’s challenge of latency was treated by proposing an optimized version of the round robin dynamic bandwidth allocation algorithm. Results obtained show an improvement in the latency of the original algorithm which meets the fronthaul requirement. Other test parameters like jitter and BER were also improved by our proposed optimized algorithm.
Volume: 11
Issue: 2
Page: 1395-1404
Publish at: 2021-04-01

The cascade equivalent A-H-circuit of the salient-pole generator on the base of the anisotropic model

10.11591/ijece.v11i2.pp1123-1129
Alexey Blanc
In the scientific studies of the electric machines, cylindrical and Cartesian laminated models have long proved their operability when it is necessary to transform the general solutions of the partial differential equations into four-terminal network equations and to create the cascade equivalent circuits of the electric machines. In the case of the salient-pole machines, piecewise continuous Sturm-Liouville eigenfunctions are usually used as the general solution. Unfortunately, we cannot create the cascade equivalent circuit of the salient-pole electric machine when (to ensure both the uniqueness and the accuracy of the solution) the field is modeled with many piecewise continuous Sturm-Liouville eigenfunctions (in the zone of poles) and many sinusoidal functions (in the air gap). Nevertheless, the author developed the approximate method for modeling the magnetic field of the salient-pole electric machines when only one piecewise continuous Sturm-Liouville eigenfunction is used and many sinusoidal functions. In this case, it becomes possible to transform the general solution of the partial differential equation into four-terminal network equations and to create the cascade equivalent circuit of the salient-pole electric machine. In this paper, the cascade equivalent A-H-circuit of the synchronous salient-pole machine is considered (without using piecewise continuous Sturm-Liouville eigenfunctions but also without properties averaging).
Volume: 11
Issue: 2
Page: 1123-1129
Publish at: 2021-04-01

An analytic study of the fractional order model of HIV-1 virus and CD4+ T-cells using adomian method

10.11591/ijece.v11i2.pp1460-1468
Kamel Al-Khaled , Maha Yousef
In this article, we study the fractional mathematical model of HIV-1 infection of CD4+ T-cells, by studying a system of fractional differential equations of first order with some initial conditions, we study the changing effect of many parameters. The fractional derivative is described in the caputo sense. The adomian decomposition method (Shortly, ADM) method was used to calculate an approximate solution for the system under study. The nonlinear term is dealt with the help of adomian polynomials. Numerical results are presented with graphical justifications to show the accuracy of the proposed methods.
Volume: 11
Issue: 2
Page: 1460-1468
Publish at: 2021-04-01

Speed control of an SPMSM using a tracking differentiator-PID controller scheme with a genetic algorithm

10.11591/ijece.v11i2.pp1728-1741
Noor Hameed Hadi , Ibraheem Kasim Ibraheem
In this paper, a tracking differentiator-proportional integral and derivative (TD-PID) control scheme is proposed to control the speed of a surface mount permanent magnet synchronous motor (SPMSM). The TD is used to generate the necessary transient profile for both the reference and the output speed, which are compared with each other to produce the error signals that feed into the PID controller. In addition to the TD unit parameters, the PID controller’s parameters are tuned to achieve the optimum new multi-objective performance index, comprised of the integral of the time absolute error (ITAE), the absolute square of the control energy signal (USQR), and the absolute value of the control energy signal (UABS) and utilizing a genetic algorithm (GA). A nonlinear model of the SPMSM is considered in the design and the performance of the proposed TD-PID scheme was validated by comparing its performance with that of a traditional PI controller in a MATLAB environment. Different case studies were tested to show the effectiveness of the proposed scheme, results including peak overshoot, energy consumption, control signal chatter, and 30% improvement in the OPI, with variable reference speeds, load torque, and parameters uncertainties. Illustrate the proposed scheme's success compared with PI controller.
Volume: 11
Issue: 2
Page: 1728-1741
Publish at: 2021-04-01

New investigation of an E-mode metal-insulator-semiconductor AlInN/AlN/GaN HEMT with an Au-T-gate

10.12928/telkomnika.v19i2.15914
Asmae; Moulay Ismail University Meknes Babaya , Adil; Moulay Ismail University Meknes Saadi , Seddik; Moulay Ismail University Meknes Bri
In a high electron mobility transistor (HEMT), the density of the two-dimensional electron gas (2DEG) channel is modulated by the application of a bias to a Schottky metal gate. These devices are depletion mode (D-mode), which means that a negative bias must be applied to the gate to deplete the electron channel and turn. The most challenging aspect in the present research activity on based-GaN devices is the development of a reliable way to achieve an enhancement-mode (E-mode) HEMT. Enhancement-mode GaN HEMTs would offer a simplified circuitry by eliminating the negative power supply. In this work, the aim is to investigate the different techniques which can influence the threshold voltage and shift it to a positive value. A novel E-mode metal-insulator-semiconductor (MIS) AlInN/GaN HEMT with an Au-T-gate has been investigated. The impacts of window-recess and deep-recess have been discussed, it was found that for dp=28 nm and wn=1.8 μm the threshold voltage achieves 0.7 V and the transconductance (Gm) peak value of 523 mS at Vgs=3.5 V. The drain current characteristic has been demonstrated.
Volume: 19
Issue: 2
Page: 531-539
Publish at: 2021-04-01

A 9.38-bit, 422nW, high linear SAR-ADC for wireless implantable system

10.12928/telkomnika.v19i2.18318
Silpa Kesav; CVR College of Engineering Velagaleti , Nayanathara; CVR College of Engineering K. S. , Madhavi; Siddhartha Institute of Engineering & Technology B. K.
In wireless implantable systems (WIS) low power consumption and linearity are the most prominent performance metrics in data acquisition systems. successive approximation register-analog to digital converter (SAR-ADC) is used for data processing in WIS. In this research work, a 10-bit low power high linear SAR-ADC has been designed for WIS. The proposed SAR-ADC architecture is designed using the sample and hold (S/H) circuit consisting of a bootstrap circuit with a dummy switch. This SAR-ADC has a dynamic latch comparator, a split capacitance digital to analog converter (SC-DAC) with mismatch calibration, and a SAR using D-flipflop. This architecture is designed in 45 nm CMOS technology. This ADC reduces non-linearity errors and improve the output voltage swing due to the usage of a clock booster and dummy switch in the sample and hold. The calculated outcomes of the proposed SAR ADC display that with on-chip calibration an ENOB of 9.38 (bits), spurious free distortion ratio (SFDR) of 58.621 dB, and ± 0.2 LSB DNL and ± 0.4LSB INL after calibration.
Volume: 19
Issue: 2
Page: 547-555
Publish at: 2021-04-01

Classification of rice plant nitrogen nutrient status using k-nearest neighbors (k-NN) with light intensity data

10.11591/ijeecs.v22.i1.pp179-186
Muliady Muliady , Lim Tien Sze , Koo Voon Chet , Suhadra Patra
Crop management including the efficient use of nitrogen (N) fertilizer is important to ensure crop productivity. Human error in judging the leaf greenness when using the leaf color chart (LCC) to estimate the rice plant N nutrient status has encouraged numerous researchers to implement a machine-learning algorithm but experienced some issues in calibration and lighting. The datasets are created at 6.00-7.00AM (consistent lighting) and including light intensity, so each dataset contains RGB value and light intensity as inputs, and LCC value as a target. A system consists of a smartphone with an application that prevents user from taking an image if the light intensity is not in 2000-3500 lux, and a computer for preprocessing and classification purposes were developed. The preprocessing included cropping, splitting the rice leaf images, and calculating the average RGB values. A k-NN classifier is implemented and by using a cross-validation method is found k=5 gives the best accuracy of 97,22%. The in-site test of the system also works with an accuracy of 96.40%. 
Volume: 22
Issue: 1
Page: 179-186
Publish at: 2021-04-01

Cloud-based platforms for LoRa internet of things: a survey

10.11591/ijict.v10i1.pp54-64
Mouna Gassara , Manel Elleuchi , Mohamed Abid
Internet of Things (IoT) establishes a smart communication system between the human being and the surrounding objects (or “things”) while using the internet as the backbone of this system. Cloud is the fundamental constituent of IoT. It offers important application services in numerous application domains. Indeed, many IoT cloud platforms are competing to provide appropriate and very specific IoT services. The LoRa platform in particular presents a long-range, low-bit rate, low-power, wireless telecommunication protocol for IoT. As such, end-devices make use of LoRa through a sole wireless hop in order to communicate to the gateway(s) that is (are) considered as relay messages and transparent bridges between these end-devices and an IoT cloud while connecting to the Internet. This article surveys the most used IoT cloud platforms suitable for the LoRa communication protocol through a deep and detailed study of previously published works related to this topic. Moreover, a comparison is made between these IoT cloud platforms according to their characteristics and application domains. The overall aim of the present paper is to provide researchers in the field with detailed knowledge concerning the IoT cloud platforms appropriate to the LoRa communication system including the advantages and drawbacks of each one of them.
Volume: 10
Issue: 1
Page: 54-64
Publish at: 2021-04-01

The design of an efficient class E-LCCL capacitive power transfer system through frequency tuning method

10.11591/ijece.v11i2.pp1095-1104
Khairul Kamarudin Hasan , Shakir Saat , Yusmarnita Yusop , Huzaimah Husin , Nor Diyana Md Sin
In this work, the optimum zero voltage switching (ZVS) of Class E-LCCL capacitive power transfer (CPT) was determined via frequency tuning method. Through this an efficient system can be guanranteed although there is a change in the capacitive plates distance. This study used a Class-E LCCL inverter, as it can operate at a high alternate current frequency, besides producing low switching losses and minimal power losses. Specifically, this study conducted simulations and experiments to analyse the performance of an LCCL CPT System at 1 MHz operating frequency and 24 V DC supply voltage. Using an air gap distance of 0.1 cm, the designed CPT system prototype successfully achieved an output power of 10W and an efficiency of 95.45%. This study also found that by tuning the resonant frequency of the Class E-LCCL system, the optimum ZVS can be obtained although capacitive plate distance was varied from 1-3 cm via experimental. The results of this study could benefit medical implant and portable device development, consumer electronics, and environments that involve electrical hazards.
Volume: 11
Issue: 2
Page: 1095-1104
Publish at: 2021-04-01

Maximum power point tracking control for wind turbines with battery storage system

10.12928/telkomnika.v19i2.16346
Ismail Sh. B.; Wasit University Hburi , Hasan Fahad Al; Wasit University Kazaali , Ogoz; Altınbaş University BAYAT , Nibras Hazim Abbas Sarray; Altinbas University Atab
In wind energy conversation systems (WECS), power quality and energy conversion efficiency are crucial aims of control algorithms. These two points are self-contradictory and difficult to trade off where enhancing the efficiency of conversion may also enhance instability of output signal as well. In current work, we submit a wind turbines control scheme to ensure regular power and achieve variable load requests in battery based variable speed PMGS system. In the submitted scheme, model predictive control (MPC) is joint with fuzzy logic to achieve the advantages of these two diverse approaches. The suggested controller could enhance the power reliability performance of the wind turbine. According to obtained results, the proposed topology overcomes the traditional proportional/integral (PI) model by achieving profits in the context of step-overshoot response and the measure of total harmonic-distortion of nearly 1.1 percent and 1.13 percent, respectively.
Volume: 19
Issue: 2
Page: 564-574
Publish at: 2021-04-01

Power dissipation analysis of PV module under partial shading

10.11591/ijece.v11i2.pp1029-1035
Byunggyu Yu , Seok-Cheol Ko
Photovoltaic (PV) generation has been growing dramatically over the last years and it ranges from small, rooftop-mounted or building integrated systems, to large utility scale power stations. Especially for rooftop-mounted PV system, PV modules are serially connected to match with PV inverter input voltage specification. For serially connected PV system, shading is a problem since the shaded PV module reduces the output whole string of PV modules. The excess power from the unshaded PV module is dissipated in the shaded PV module. In this paper, power dissipation of PV module under partial shading is analyzed with circuit analysis for series connected PV modules. The specific current and voltage operating point of the shaded PV module are analyzed under shading. PSIM simulation tool is used to verify the power dissipation analysis. When there is no bypass diode and three solar modules are connected in series, upto 39.1% of the total maximum PV power is dissipated in the shaded PV module. On the other hand, when the bypass is attached, 0.3% of the total maximum power is generated as a loss in the shaded PV module. The proposed analysis technique of shaded PV module could be used in PV system performance analysis, especially for maximum power point tracking (MPPT) performance.
Volume: 11
Issue: 2
Page: 1029-1035
Publish at: 2021-04-01
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