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All Journal Jurnal Simetris INFORMAL: Informatics Journal Jurnal Teknologi dan Sistem Komputer Jurnal Listrik, Instrumentasi, dan Elektronika Terapan
Rifai, Isnan Nur
Department Of Electrical Engineering And Informatics, Vocational College, Universitas Gadjah Mada. Yacaranda St., Sekip Unit IV, Yogyakarta 55281|Universitas Gadjah Mada
Computer Science & IT Control & Systems Engineering Electrical & Electronics Engineering Energy Engineering

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Sampled and discretized of short-time Fourier transform and non-negative matrix factorization: the single-channel source separation case Jans Hendry; Isnan Nur Rifai; Yoga Mileniandi
Jurnal Teknologi dan Sistem Komputer Volume 9, Issue 1, Year 2021 (January 2021)
Publisher : Department of Computer Engineering, Engineering Faculty, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jtsiskom.2020.13858

Abstract

The Short-time Fourier transform (STFT) is a popular time-frequency representation in many source separation problems. In this work, the sampled and discretized version of Discrete Gabor Transform (DGT) is proposed to replace STFT within the single-channel source separation problem of the Non-negative Matrix Factorization (NMF) framework. The result shows that NMF-DGT is better than NMF-STFT according to Signal-to-Interference Ratio (SIR), Signal-to-Artifact Ratio (SAR), and Signal-to-Distortion Ratio (SDR). In the supervised scheme, NMF-DGT has a SIR of 18.60 dB compared to 16.24 dB in NMF-STFT, SAR of 13.77 dB to 13.69 dB, and SDR of 12.45 dB to 11.16 dB. In the unsupervised scheme, NMF-DGT has a SIR of 0.40 dB compared to 0.27 dB by NMF-STFT, SAR of -10.21 dB to -10.36 dB, and SDR of -15.01 dB to -15.23 dB.
Pendeteksi Flashover dan Aplikasi Android pada TPSS LRT Jabodebek Berbasis Computer Vision dan Android Studio Nerissa Diana Resty; Galuh Triyanto; Isnan Nur Rifai
Jurnal Listrik, Instrumentasi, dan Elektronika Terapan Vol 3, No 2 (2022)
Publisher : Departemen Teknik Elektro dan Informatika Sekolah Vokasi UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/juliet.v3i2.77741

Abstract

Abstract – The traffic jam in Jakarta and the cities around it, namely Bogor, Depok, and Bekasi, became the government’s background in developing the Jabodebek light rail transit (LRT) project. In Jabodebek LRT construction, there is a TPSS which is short for Traction Power Substation, often known as a Traction substation. The Traction Substation is an electric power source for electric railroad trains, including the Jabodebek LRT. Inside the Traction station, there is a 20 kV Cubicle which is a power cable compartment. Some disturbances often occur in this 20 kV cubicle, one of which is the flashover. If the flashover remains, this is disturbing and detrimental to many people, including Jabodebek LRT passengers. Flashover can be caused by air humidity so that water vapor is attached to the power cable isolator. So this research was conducted as a preventative measure for the damage to cubicles due to flashover. Besides creating a system to detect flashovers, an Android application is also made to display the results of flashover detection. Raspberry Pi as the main controller of the flashover detection system, using the Hough Circle Transformation and Python programming language, as for the application using the Java programming language based on Android Studio. The data analysis method used is the Confusion Matrix. Based on the experimental results, the system works well to detect the flashover, with an average accuracy of the system reaching 80.18%. The distance, lighting factors, and barrier media affect the detection results.Keywords – Jabodebek LRT, flashover, Hough Circle, android applicationIntisari – Kemacetan yang terjadi di Jakarta berserta kota-kota di sekitarnya yakni Bogor, Depok, dan Bekasi menjadi latar belakang pemerintah dalam membangun proyek light rail transit (LRT) Jabodebek. Pada pembangunan LRT Jabodebek ini terdapat TPSS atau yang sering dikenal dengan istilah Gardu Traksi. Gardu Traksi merupakan sumber daya listrik untuk mengoperasikan kereta rel listrik termasuk LRT Jabodebek. Di dalam Gardu Traksi terdapat cubicle 20 kV yang di dalamnya terdapat kompartemen kabel daya. Beberapa gangguan sering terjadi pada cubicle 20 kV ini, salah satunya gangguan berupa flashover. Hal ini cukup mengganggu dan merugikan banyak orang termasuk penumpang LRT Jabodebek apabila adanya flashover ini terus dibiarkan. Flashover dapat disebabkan adanya kelembaban udara sehingga uap air melekat pada isolator kabel daya. Sehingga penelitian ini dilakukan sebagai langkah pencegahan terjadinya kerusakan cubicle akibat dari flashover. Selain membuat sistem untuk mendeteksi flashover dibuat juga aplikasi android untuk menampilkan hasil deteksi flashover. Raspberry Pi sebagai pengendali utama sistem pendeteksi flashover, dengan menggunakan Transformasi Hough Circle dan pemrograman bahasa Python, adapun untuk aplikasinya menggunakan bahasa pemrograman Java dengan basis Android Studio. Metode analisa data yang digunakan adalah confusion matrix. Hasil dari penelitian ini adalah sistem atau alat pendeteksi flashover dapat bekerja dengan baik dan sesuai fungsi, diperoleh rata-rata akurasi sistem yang mencapai 80,18%. Di mana jarak, faktor pencahayaan, serta medium penghalang berpengaruh terhadap hasil deteksi. Selain itu telah dibuat aplikasi guna menampilkan hasil deteksi flashover, aplikasi ini dapat bekerja dengan baik pula.Kata kunci – LRT Jabodebek, flashover, Hough Circle, aplikasi android
Modifikasi Motor Brushless Berbasis Lilitan pada Sistem Propulsi untuk Meningkatkan Performa Terbang Unmanned Aerial Vehicle Subekti, Ilham Riska; Rifai, Isnan Nur
Jurnal Listrik, Instrumentasi, dan Elektronika Terapan Vol 5, No 1 (2024)
Publisher : Departemen Teknik Elektro dan Informatika Sekolah Vokasi UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/juliet.v5i1.89008

Abstract

Pesatnya perkembangan teknologi unmanned aerial vehicle (UAV) telah membuka peluang baru dalam berbagai aplikasi, termasuk pemantauan udara dan pemetaan. Salah satu faktor kunci yang memengaruhi kinerja UAV adalah kemampuan motor yang digunakan untuk menghasilkan thrust yang cukup. Penelitian ini bertujuan untuk meningkatkan thrust pada UAV dengan memodifikasi motor brushless. Fokus modifikasi berada pada aspek lilitan, seperti pergantian jenis kawat, diameter, jumlah, dan lilitan pada motor tersebut. Dalam eksperimen ini, jenis kawat yang digunakan adalah Hellenic dengan diameter 0,2 mm. Setiap lilitan berjumlah 15 kawat dengan 6 lilitan setiap pole pada stator. Sistem ini bekerja dengan mengalirkan arus pada lilitan, sehingga dihasilkan kuat medan magnet pada stator. Gaya tolak-menolak antara medan magnet pada stator dengan medan magnet pada rotor menyebabkan motor brushless berputar. Motor brushless lilitan baru memiliki kecepatan 10146 rpm dan rating kecepatan sebesar 603 rpm/volt. Pengujian motor brushless lilitan baru dengan propeller model 1407 menghasilkan thrust maksimal sebesar 2.507 gram dengan daya 942,7 watt dan arus 66,3 ampere. Motor brushless lilitan baru memiliki daya dan arus yang lebih kecil dibandingkan motor brushless pabrikan pada kondisi thrust sama.
Microlidar Application for Object Detector to Support The Navigation System in Self-Driving Vehicle Rifai, Isnan Nur; Ratnoto, Tri; Subari, Subari
INFORMAL: Informatics Journal Vol 8 No 3 (2023): Informatics Journal (INFORMAL)
Publisher : Faculty of Computer Science, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/isj.v8i3.44188

Abstract

The ability to detect and measure the distance of potential obstacles is importance for navigation system in self-driving vehicles. The measurement process needs to be fast and accurate since the controller requires real-time data to make quick decisions and respond to any potential disturbances on the vehicle's track. This research aims to develop Microlidar for detection system that can accurately measure the distance of a potential obstacle object. The Microlidar utilize Lidar Lite V3 proximity sensor which have range measurement specification of up to 40 meter. Microlidar rapidly rotate 360 degrees by using a stepper motor while in the same time continuously measure the real-time distance. The measurement data are sent to a microcontroller through I2C, and the Processing software plot the 2D image which work like radar visualization. The system is assessed for ranging the various distance object in static and dynamic measurement mode. The results show that the Microlidar has a good level of accuracy with an average error value at the distance of 300 cm is 4.99 cm or 1.7% while the average error value at the distance of 1000 cm is 15.69 cm or 1.6% obtained from 100 data sets collected. The communication from the sensor to Arduino requires a minimum baud rate of 115200 bits/second to minimize data loss and ensure that the measured distance can be processed in real time by the microcontroller. Real-time data with high speed is essential since it will be used on the vehicle in order to quickly decide whether there is a barrier or not on the vehicle’s track. The sensor analysis distance expected from this research could be used as a reference to support the navigation system performance of self-driving vehicles.
Design of Direct Digital Synthesizer (DDS) Based on Field Programmable Gate Array (FPGA) for Electrical Impedance Tomography (EIT) Rifai, Isnan Nur; Astuti, Wijayanti Dwi; Hendry, Jans; Santoso, Ardhi Wicaksono; Aji, Alief Purnomo
Jurnal Listrik, Instrumentasi, dan Elektronika Terapan Vol 6, No 1 (2025)
Publisher : Departemen Teknik Elektro dan Informatika Sekolah Vokasi UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/juliet.v6i1.102579

Abstract

Direct Digital Synthesizer (DDS) systems play a critical role in high-precision signal generation for applications like medical imaging and RF communications. This research explores the development of a DDS system using Field-Programmable Gate Array (FPGA) technology, with a focus on optimizing signal accuracy, resource efficiency, and signal-to-noise ratio (SNR). The study implemented two DDS designs on an FPGA: one based on the CORDIC algorithm and the other using a Look-Up Table (LUT) approach. Key components of the system included a phase accumulator, phase register, and frequency calculation algorithms. The system's performance was evaluated by measuring signal output accuracy and SNR, utilizing the ISL6961IAZ DAC and RF Transformers PWB2010LC for signal conversion and transmission. The results showed that the DDS achieved near-target frequencies, with outputs of 100.4 kHz for a target of 100 kHz and 498.8 kHz for a target of 500 kHz. The LUT-based design demonstrated superior signal fidelity, achieving an SNR of 106 dB compared to 92 dB for the CORDIC-based design. However, resource utilization analysis revealed a trade-off between logic efficiency and memory usage: the CORDIC design consumed 26% of logic elements and only 1% of memory, while the LUT-based design used 8% of logic elements and 77% of memory. These findings highlight the importance of balancing design choices based on application-specific requirements for precision, resource constraints, and performance.
Impedance Meter Berbasis Field Programmable Gate Array (FPGA) Untuk Optimasi Respons Pengukuran Amplitudo Dan Beda Fasa Santoso, Ardhi Wicaksono; Rifai, Isnan Nur; Sumanto, Budi; Purnomo Aji, Alief
Simetris: Jurnal Teknik Mesin, Elektro dan Ilmu Komputer Vol 16, No 1 (2025): JURNAL SIMETRIS VOLUME 16 NO 1 TAHUN 2025
Publisher : Fakultas Teknik Universitas Muria Kudus

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24176/simet.v16i1.13278

Abstract

The Impedance Meter (IM) has become essential in exploring the electrical properties of materials, biological systems, and electrochemical processes. Measuring amplitude and phase difference is central to characterizing these materials and systems. This research aims to develop an amplitude and phase difference measurement system using Field-Programmable Gate Array (FPGA) technology with a cross-correlation method. Validation system is conducted by measuring the high pass response which consist of resistor and capacitor. Performance evaluation covers speed, accuracy, and system responsiveness to frequency variations. Based on the measurement and validation results, the following conclusions are drawn: The number of buffers in the data sampling process can impact accuracy and processing time. It takes 0.26 seconds for 100 phase difference measurements with a buffer count of 2000. Compared to mathematical analysis, amplitude measurements have an average error of 0.035 volts (3.5%) with a maximum error of 0.048 volts (4.8%). Phase difference measurements have an average error of 0.22° with a maximum error of 1.26°. While if compared to an oscilloscope, amplitude measurements show an average error of 0.002 volts (0.2%) with a maximum error of 0.012 volts (1.2%). Phase difference measurements show an average error of 0.18° with a maximum error of 0.86°. Mathematical analysis provides important theoretical understanding, while validation with an oscilloscope offers more accurate and realistic information under practical conditions, considering component non-idealities.
Co-Authors Aji, Alief Purnomo Astuti, Wijayanti Dwi Budi Sumanto Galuh Triyanto HENDRY, JANS Hendry, Jans Nerissa Diana Resty Purnomo Aji, Alief Ratnoto, Tri Santoso, Ardhi Wicaksono Subari Subari Subekti, Ilham Riska Yoga Mileniandi