Jurnal Rekayasa Elektrika
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Design and Simulation of Single Input Double Output Coupled Inductor Boost Converter with Bisection Method for Independent Home Application
Full text linkThis paper proposed a converter design that functions as a voltage booster, increasing the input voltage while supplying two load outputs from a single voltage input using only one switch. Known as a single input double output (SIDO) converter, it aims to enhance power efficieny. The bisection method is employed as an output voltage controller through pulse width modulation (PWM) to achieve an optimal voltage value, adjusted to meet the load requirements. The loads used for independent home applications include a 72 V/12 Ah battery and a 24 V/22 W water circulation pump. The output of the high voltage level acts as a battery charger while the output of the low voltage level serves as an energy supply for the water cir-culation pump. The two loads were chosen because they are widely used, aligning with the goal of realizing independent home applications. The simulation test results showed that the voltage output for battery charging in constant voltage mode was 80.6 V, with an error of 0.0515%, and the voltage output for the water circulation pump was 24 V, with an error of 0.33%
The Effect of Partial Shadings on the Output Power of the Photovoltaic Modules Connected with Different Current and Voltage Characteristics
Full text linkA mismatch in the output power of photovoltaic (PV) modules in a PV array can occur due to partial shading or a module replacement. Substitution of a module in a PV array with a new one might lead to different current and voltage characteristics between the new and existing modules and result in power losses. The amount of power loss might be increased more if the PV array experiences partial shading. For this reason, this study aims to investigate the effect of partial shadings on the power output of photovoltaic arrays with different current and voltage characteristics. The PV array under test consists of 25 units of solar modules with a total cross-tied (TCT) configuration. There are five shading conditions applied to the test PV array, i.e., the short narrow (ShN), the short wide (ShW), the long narrow (LnN), the long wide (LnW), and the diagonal. A magic square method is applied to reduce the power loss when the PV modules experience partial shading conditions. The results show that the power loss due to partial shadings, either on all identical modules or partially identical, is the same. The most significant power loss occurs in the long comprehensive shading scenario, where 80% of the modules experience shading, which is 41.30%
Scalability of MIMO Antennas: Assessing Gain and HPBW for Different Antenna Element Configurations
Full text linkThe design of Massive MIMO Antennas presents challenges due to their large size, which can impede the design process. Additionally, the arrangement of multiple antenna elements in Massive MIMO Antennas poses a challenge, as it surpasses the capabilities of simulation software and involves complex procedures. Therefore, to address these issues, a scalability technique utilizing array factor theory is employed to determine the relationship between the configuration of MIMO antennas and the corresponding values of gain and half-power beamwidth (HPBW). By utilizing a simpler MIMO Antenna array with incremental configurations, such as 2x2, 4x4, 8x8, and 16x16 MIMO element schemes, the array factor theory allows for the prediction of the gain and HPBW values for a Massive MIMO Antenna array with a specific configuration. This research aims to explore the scalability process and derive equations that relate the gain and HPBW values to the different MIMO configurations. The designed MIMO antenna arrangement is based on rectangular antennas with truncated corners and circular antennas with X slots, allowing for the investigation of various configurations operating at a frequency of 3.5 GHz
Anomaly Detection for Security in Children's Play Areas Based on Image Using Multiple Lines Detection Method
Full text linkThis study aims to build a device as a security system to detect anomalies of children moving in play areas based on the Multiple Line Detection (MLD) method in a streaming image. We developed this device to help parents monitor their children's activities when playing in dangerous areas of the home to protect children from kidnapping. In this study, the MLD method can detect the children's activities when playing in three zones: the safe zone with green lines in the image, the caution zone with yellow lines, and the danger zone with red lines. The hardware used to build the devices in this study consists of three components: a camera to stream the image activities of children, a Raspberry Pi to process the image using OpenCV, and a buzzer for early security systems. The results of this study show that when the device detected the children playing in the safe zone, the system commanded the buzzer to turn off. Furthermore, when the camera detects that the children are playing in the caution and danger zone, the device then commands the buzzer to turn on as an early warning security system for the parents
Nutrition Temperature and TDS Control System with Fuzzy Logic on Pak Choy Hydroponics (Brassica rapa subsp. chinensis)
Full text linkHydroponics is a method of cultivation that does not use soil as a medium, allowing it to be applied in limited spaces such as urban households. One of the vegetable plants that can be grown using hydroponics is pak choy (Brassica rapa subsp. chinensis). To produce healthy pak choy plants that can efficiently absorb nutrients in a hydroponic system, several factors need to be considered, such as the level of Total Dissolved Solids (TDS) in the nutrient solution, nutrient solution temperature, and air humidity in the hydroponic environment. The ideal nutrient solution temperature for hydroponic plants falls within the range of 25-27C. In this system, a monitoring and control system will be designed to optimize the growth of pak choy plants in a Deep Flow Technique (DFT) hydroponic system. In this system, the nutrient solution temperature will be controlled with a set point of 25C using an on/off control for a peltier device. To maintain the TDS level at a set point of 1200 ppm in the nutrient solution, fuzzy logic control will be employed, generating timer-based control signals for the nutrient pump A, nutrient pump B, and water pump. The monitoring system will be displayed on an Internet of Things (IoT) dashboard platform, such as ThingSpeak
Optimization of Electrospinning Temperature Control System IoT-Based with DHT21
Full text linkElectrospinning is a method of making nanomaterials that has a fairly easy and flexible process that can produce nanofiber continuously. Nanofiber morphology from the electrospinning process is influenced by several parameters, one of them is temperature as an environmental parameter. If there is no temperature control system in the electrospinning system, it will be difficult to maintain the consistency of the morphology nanofiber and at certain temperatures, nanofibers are not formed. Therefore, this study aims to develop a temperature control system for electrospinning called the Electrospinning Temperature Control (ETC) System and connect it with an internet-of- things (IoT) platform to understand the dynamics of the temperature control process, upload temperature data to the cloud, and remote monitoring. The method used by designing and building system hardware and software, calibrating DHT21 as a temperature sensor and testing system performance. The results show that the calibration of the DHT21 sensor has an accuracy rate of 94.95% and a precision rate of 98.93%, while the results of the performance test show that the system can raise, maintain, and lower the temperature. Further performance testing reveals that the ETC system can operate within a temperature range of 2040C. The IoT system using the Blynk App allows users to remote and monitor easily, and using Google Sheets as a cloud database. The ETC system was successfully built and can be applied to electrospinning experiments
Dual-mode Antenna Tracking System for Rocket Launch Applications
Full text linkRocket launches are complex events that require tracking antennas to maintain a communication link. This study introduces a hybrid tracking strategy that combines manual and program modes by utilizing a predetermined trajectory of the rocket. Automatic switching between tracking modes ensures ongoing monitoring, even during unexpected trajectory changes with the monopulse approach. The dual parabolic antenna arrangement enables this switching. The system estimates the monopulse ratio from the signal strength of each antenna, allowing automatic program tracking to shift to manual mode when reception concerns arise. Performance evaluations included manual, programmable, and dual-mode tests. The system responded to human input and automatically aligned the antenna with slight elevation errors during the initial phase. Adjusting the initial elevation reduced the error. The mode transition was examined by measuring the antenna radiation patterns and monopulse ratio. The systems performance was evaluated in rocket launches, with the rocket trajectory input into the graphical user interface. The antenna exhibited an azimuthal movement of up to 10 , and the ratio fluctuation values remained within the antennas field of view. After 8.8 seconds, the mode switched from program to manual, indicating that the functioning of the systems functioning was stable
Augmentation of Additional Arabic Dataset for Jawi Writing and Classification Using Deep Learning
Full text linkThis research aims to create an additional dataset containing Arabic characters for writing Jawi script and to train classification models using deep learning architectures such as InceptionV3 and ResNet34. The initial stage of the study involves digital image processing to obtain the additional Arabic character dataset from several sources, including HMBD, AHAWP, and HUCD, encompassing various connected and disconnected forms of Jawi script. Image processing includes steps such as preprocessing to enhance image quality, segmentation to separate Arabic characters from the background, and augmentation to increase dataset variability. Once the dataset is formed, we train the models using appropriate training data for each InceptionV3 and ResNet34 architecture. The classification evaluation results indicate that the model with ResNet34 architecture achieved the best performance with an accuracy of 96%. This model successfully recognizes Jawi script accurately and consistently, even for classes with similar shapes. The main contribution of this research is the availability of the additional Arabic character dataset that can be utilized for Jawi script recognition and performance assessment of various deep learning models. The study also emphasizes the importance of selecting the appropriate architecture for specific character recognition tasks. The research findings affirm that the model with ResNet34 architecture has excellent capability in recognizing the additional Arabic characters for writing Jawi. The results of this research have the potential to support further developments in Jawi character recognition applications and provide valuable insights for researchers in the field of character recognition sourced from Arabic characters. Dataset augmentation results can be accessed at https://singkat.usk.ac.id/g/En0skCKGA
Smart Bracelet for Tracking the Location of Dementia Patients
Full text linkThe rising number of dementia patients worldwide is a significant concern. Dementia, marked by deteriorating memory, language, problem-solving abilities, and other cognitive skills, affects millions globally. According to the World Health Organization (WHO), over 55 million people currently live with dementia. Dementia's impact on patients, their families, and healthcare systems is substantial. Patients often need continuous supervision and care, posing challenges for caregivers. Wandering is a frequent issue among dementia patients, leading to safety risks and a high chance of getting lost. Innovative technological solutions, such as portable monitoring devices, are crucial in tackling these issues. A smart bracelet with Global Positioning System (GPS) can be vital for ensuring dementia patients' safety. These devices provide real-time location tracking, giving caregivers and family members peace of mind by enabling them to quickly locate patients who wander off. This makes the bracelet highly effective for monitoring dementia patients' locations, as it will send notifications to a messenger application on a smartphone with a link to the patient's location if they move beyond a 20-meter radius from home. The bracelet uses GPS for distance and location tracking. The patient's location is pinpointed by the intersection of latitude and longitude coordinates. The device has a minimal margin of error, with a latitude error of 0.003% and a longitude error of 0.008%
Wireless Photoplethysmography (PPG) Measurement with Pulse Wave Velocity (PWV) Method for Arterial Stiffness Evaluation
Full text linkIndications of symptoms of cardiovascular disease can be seen from the level of elasticity of the arteries. The Pulse Wave Velocity (PWV) method using PPG signal analysis is used to determine the level of arterial stiffness based on the time difference between pulse waves of Photoplethysmography (PPG) signal measurements. PWV measurements use a non-invasive technique using pulse sensors on the fingers and toes, the measurement data is sent wirelessly using the ESP-NOW protocol. Analysis of the measured PPG signal is used as an approach to calculating the PWV value. Realization and testing can be used to measure the pulse in BPM and classify the index of arterial stiffness using the PWV method. The results of testing on 15 test volunteers from 3 age groups showed the results of an arterial stiffness index with indications of normal, stiff and very stiff arteries. The PWV value for the 20 year old group was 4.30-6.77 cm/s, normal arterial conditions. The age group of 30-40 years has a PWV value ranging from 5.11-8.77 cm/s, normal arterial conditions. The age group of 50-60 years had PWV values in the range of 10.69-18.43 cm/s, stiff and very stiff arterial conditions. Increasing age linearly affects the increase in PWV value. An increased PWV value may indicate an increase in arterial stiffness