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ANALISIS SINYAL SEISMIK GUNUNG MERAPI, JAWA TENGAH - INDONESIA MENGGUNAKAN METODE ADAPLET (TAPIS ADAPTIF BERBASIS WAVELET) Agfianto Eko Putra; Adi Susanto; Kirbani Sri Brotopuspito; Jazi Eko Istiyanto
Seminar Nasional Informatika (SEMNASIF) Vol 1, No 1 (2008): Computational
Publisher : Jurusan Teknik Informatika

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Abstract

Telah dikembangkan suatu metode analisis sinyal non-stasioner, khususnya sinyal seismik Gunung Merapi, Jawa Tengah, Indonesia, melalui proses Tapisan Adaptif  berbasis  Wavelet,  yang  selanjutnya  dinamakan  Adaplet.  Proses  ini  diawali dengan melakukan penundaan pada sinyal asli d(n) untuk  mendapatkan x(n) yang  diumpankan ke  tapis  adaptif  sehingga  menghasilkan  keluaran  y(n).  Kemudian  keluaran  ini  dibandingkan dengan  masukan  sinyal  asli  d(n),  sebagai  sinyal  yang  dikehendaki  (expected  signal) dan selisihnya berupa keluaran  ralat  e(n)  yang  kemudian  digunakan  sebagai  tuner  untuk memperbaiki kerja tapis adaptif tersebut, sedemikian hingga ralat e(n) bisa mendekati 0 (nol).Hasil untuk data-data seismik volkanik yang mewakili 3 jenis event yang berbeda menunjukkan adanya pola-pola tertentu, yang ditunjukkan dari plot hingga 4 koefisien polinomial  3-komponen  (Sn,  Se  dan  Sz)  dan  hubungan antar  koefisien yang dinyatakan dalam persamaan garis linear dalam format bentuk y=ax+b. Serta pengelompokan (klaster) semua koefisien untuk semua tipe memperkuat adanya fitur-fitur khusus pada sinyal yang bersangkutan.
Analisis Hasil Proses Pemampatan JPEG dengan Metode Discrete Cosine Transform Adi Prasetio Utomo; Agfianto Eko Putra; Catur Atmaji
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 2, No 1 (2012): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (424.075 KB) | DOI: 10.22146/ijeis.2335

Abstract

AbstrakJPEG merupakan standar kompresi digital yang dikembangkan oleh Group Joints Photograpic Experts yang menggunakan kombinasi DCT dan pengkodean Huffman untuk mengkompresi suatu citra digital.[1]. Pemampatan JPEG merupakan algoritme pemampatan secara lossy. [2]. JPEG bekerja dengan mengubah gambar spasial dan merepresentasikan ke dalam pemetaan frekuensi. Salah satu metode dalam pemampatan JPEG yang dapat digunakan adalah metode DCT (Discrete Cosine Transform), dengan memisahkan antara informasi frekuensi yang rendah dan tinggi dari sebuah gambar.[3]            File yang digunakan adalah gambar grayscale dengan format bitmap, memiliki ukuran 26,422 bytes, resolusi 176x144 piksel.  Gambar diproses sesuai standar pemampatan JPEG, dianalisis hasil pemampatan berdasarkan variasi yang dilakukan pada tahapan block image transformation dan DCT quantization. Pengukuran kualitas gambar hasil pemampatan dilakukan secara subjektif melalui pandangan visual mata manusia dan secara objektif dengan parameter nilai PSNR dan rasio pemampatan            Dari penelitian dapat disimpulkan bahwa nilai PSNR dan rasio pemampatan gambar dapat digunakan sebagai parameter untuk mengukur kualitas gambar dan dapat diketahui penggunaan macroblock serta nilai step kuantisasi yang tepat untuk mendapatkan hasil optimal dalam pemampatan gambar grayscale. Kata kunci—JPEG,DCT,pemampatan JPEG, gamabr grauscale, PSNR, rasio pemampatan  Abstract JPEG is a digital compression standard developed by the Group of Experts Photograpic Joints using a combination of DCT and Huffman coding to compress a digital image.[1]. JPEG compression is a lossy compression algorithm. [2]. JPEG works by converting the spatial images and to represent frequency mapping.One of the methods in JPEG compression that can be used is a DCT method (Discrete Cosine Transform), with a separate low frequency information and high of an image. High frequency information will be selected to be eliminated which related to image compression and measurement quality of the image.[3]Files used are grayscale images with a bitmap format, has a size of 26.422 bytes, 176x144 pixel resolution. Image processed according to standard JPEG compression, the compression results are analyzed based on variations performed on block image  transformationandquantization. Measurement of quality of image compression is done subjectively through visual view of the human eye and objectively with the parameter value of PSNR and compression ratio.From the study it can be concluded that the value of PSNR and compression ratio of an image can be used as a parameter to measure the image quality and can be detected using macroblock  and value of quantization step which the right to obtain optimal results in compression of grayscale images Keywords—JPEG, DCT, JPEG compression, grayscale images, PSNR, compression ratio
Sistem Kontrol Keseimbangan Statis Robot Humanoid Joko Klana Berbasis Pengontrol PID Pramudita Johan Iswara; Agfianto Eko Putra
IJEIS (Indonesian Journal of Electronics and Instrumentation Systems) Vol 2, No 1 (2012): April
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (656.998 KB) | DOI: 10.22146/ijeis.2341

Abstract

AbstrakPengontrol Proporsional – Intergral - Derivatif  merupakan kontrol loop umpan balik umum yang digunakan secara luas dalam sistem kontrol industri. Pengontrol PID menghitung nilai eror sebagai perbedaan antara variabel proses terukur dan nilai yang diinginkan. Pengontrol akan mengurangi eror dengan mengatur masukan kontrol proses.Subsistem yang telah dibuat yaitu sistem kontrol keseimbangan robot humanoid Joko Klana berbasis Pengontrol PID sederhana menggunakan akselerometer ADXL202 sebagai masukan. ADXl202 akan membaca kemiringan pada sumbu X ( depan – belakang ) robot Joko Klana dan sumbu Y ( kanan – kiri ) terhadap sumbu referensi  X dan Y. Nilai eror dari kemiringan kemudian digunakan sebagai input pada proses kontrol keseimbangan. Keluarannya berupa posisi angular dari beberapa motor servo pada sendi kaki Joko Klana untuk memperoleh posisi paling stabil.Pengontrol PID mempunyai 3 komponen penting untuk melakukan proses kontrol. Komponennya terdiri dari Kp ( propotional gain ), Ki ( integral gain ), dan Kd ( derivative gain ). Nilai optimal untuk komponen tersebut dari eksperimen ini yaitu : Kp_x = 10, Ki_x = 1, Kd_x = 10, Kp_x = 3, Ki_y = 1, Kd_y = 10, dan Time Sampling = 300mS. Kata kunci—Pengontrol PID, Sistem Kontrol Keseimbangan, Robot Joko Klana, Akselerometer 202  AbstractA Proportional – Integral – Derivative Controller (PID Controller) is a generic control loop feedback mechanism widely used in industrial control systems.  A PID Controller calculates an "Error" value as the difference between a measured process variable and a desired set point. The Controller attempts to minimize the Error by adjusting the process control inputs.The subsystem that have been made is the Joko Klana humanoid robot’s balance control system by applying a simple PID Controller using an ADXL202 accelerometer as an input device. ADXL202 will read the Joko Klana robot’s slope on the X axis (front -  rear) and the Y axis (right – left) to the referenced X and Y axes. The error value of the slope then will be used as input to the balance control process. The outputs is  the angular position of some servo motors in the Joko Klana’s leg joints to acquire the most stable position.PID Controller has three main components to do the control process. The components are : Kp (proportional gain), Ki (integral gain), and Kd (derivative gain). The optimal value for those components from this experiments are : Kp_x = 10, Ki_x = 1, Kd_x = 10, Kp_x = 3, Ki_y = 1, Kd_y = 10, and Time Sampling = 300mS. Keywords—PID Controller, Balance Control System, Joko Klana Robot, ADXL202 Accelerometer
Perbandingan Mother Wavelet dalam Proses Denoising pada Suara Rahmat Ramadhan; Agfianto Eko Putra
IJCCS (Indonesian Journal of Computing and Cybernetics Systems) Vol 8, No 1 (2014): January
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijccs.3497

Abstract

AbstrakTransformasi Wavelet telah digunakan dalam proses denoising pada suara dengan tujuan untuk meningkatkan kualitas dari rekaman suara yang tercampur dengan derau. Jenis-jenis derau yang terlibat antara lain White Gaussian Noise (WGN), White Uniform Noise (WUN) dan Colored Noise. Dalam penelitian ini dilakukan perbandingan terhadap beberapa mother wavelet, diantaranya Daubechies, Coiflet dan Symlet, dalam proses denoising pada sinyal suara yang diberikan WGN, WUN dan Colored Noise. Metode thresholding yang digunakan dalam proses denoising adalah Soft Thresholding dan nilai threshold  berupa Time-Adapted Threshold (TAT) yang diperoleh dengan melakukan estimasi energi untuk membangun sinyal melalui Teager Energy Operator (TEO). Pengujian untuk mendapatkan mother wavelet terbaik dilakukan menggunakan uji Kruskal-Wallis yang dilanjutkan dengan uji Mann-Whitney. Hasil yang diperoleh menunjukkan bahwa Db20, Db30, Db40 dan Coif5 merupakan mother wavelet yang baik untuk mereduksi WGN;Db40, Db20 dan Db30 merupakan mother wavelet yang baik untuk mereduksi WUN dan untuk mereduksi Colored Noise, dapat menggunakan beberapa mother wavelet dalam penelitian ini, kecuali Db30 dan Db40.  Kata kunci—Mother wavelet, denoising, sinyal suara, TAT, Soft Thresholding.  AbstractWavelet Transform was used in denoising process on speech to enhance the quality of speech that courrupted by noise. The kinds of involved noises are White Gaussian Noise (WGN), White Uniform Noise (WUN) and Colored Noise. In this research, the comparison of mother wavelet is performed among Daubechies, Coiflet and Symlet, in denoising process on speech which given by WGN, WUN and Colored Noise. The thresholding method is used in denoising process is Soft Thresholding and threshold value is Time Adapted Threshold (TAT) which obtained by estimating the power for building the signal through Teager Energy Operator (TEO). The testing for obtaining the best moher wavelet is using Kruskal-Wallis test and followed by Mann-Whitney test. The result shows that Db20, Db30, Db40 and Coif5 mother wavelets are better than others to reduce WGN; Db40, Db20 dan Db30mother waveletsare better then the other to reduce WUN and to reduce Colored Noise can use some mother wavelets in this research, except Db30 and Db40. Keywords—Mother wavelet, denoising, speech signal, TAT, Soft Thresholding
Penapisan Derau Gaussian, Speckle dan Salt&Pepper Pada Citra Warna Ika Purwanti Ningrum; Agfianto Eko Putra; Dian Nursantika
IJCCS (Indonesian Journal of Computing and Cybernetics Systems) Vol 5, No 3 (2011): November
Publisher : IndoCEISS in colaboration with Universitas Gadjah Mada, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijccs.5209

Abstract

Quality of digital image can decrease becouse some noises. Noise can come from lower quality of image recorder, disturb when transmission data process and weather. Noise filtering can make image better becouse will filtering that noise from the image and can improve quality of digital image. This research have aim to improve color image quality with filtering noise. Noise (Gaussian, Speckle, Salt&Pepper) will apply to original image, noise from image will filtering use Bilateral Filter method, Median Filter method and Average Filter method so can improve color image quality. To know how well this research do, we use PSNR (Peak Signal to Noise Ratio) criteria with compared original image and filtering image (image after using noise and filtering noise).This research result with noise filtering Gaussian (variance = 0.5), highest PSNR value found in the Bilateral Filter method is 27.69. Noise filtering Speckle (variance = 0.5), highest PSNR value found in the Average Filter method is 34.12. Noise filtering Salt&Pepper (variance = 0.5), highest PSNR value found in the Median Filter method is 31.27. Keywords— Bilateral Filter, image restoration, derau Gaussian, Speckle dan Salt&Pepper
PURWARUPA MIKROPROSESOR BERBASIS FPGA ALTERA EPF10K10 DENGAN DESKRIPSI VHDL Agfianto Eko Putra; Arsyad Muhammad Fajri
Seminar Nasional Informatika (SEMNASIF) Vol 1, No 2 (2008): Instrumentational And Robotic
Publisher : Jurusan Teknik Informatika

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Abstract

It has been designed and implemented an FPGA-based microprocessor prototype using Altera EPF10K10 and VHDL description then compiled and simulate using MAX+Plus II software. The microprocessor prototype is implementing using the Wizard A-01 development board and its assembly program stored in ROM. To decode and execute the instruction, it used Control Unit, which will send control signal to other components. The 16 instructions is implementing in this microprocessor prototype. This microprocessor prototype has 8-bit data bus and 4-bit address bus, implemented using 375 logic cells, operating at 14.72 MHz clock (maximum) and 3.68 MIPS.
Design Multi Input Automatic Identifier System Class B for Indonesian Fishery A Sumarudin; Willy Permana Putra; Ahmad Rifai; Agfianto Eko Putra
International Journal of Quantitative Research and Modeling Vol 1, No 3 (2020)
Publisher : Research Collaboration Community (RCC)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (596.62 KB) | DOI: 10.46336/ijqrm.v1i3.19

Abstract

The need for technology that can help Indonesian fishermen is needed to improve fishing yields. Based on BPS data Indonesian fishermen dropped from 1.7 million to 64 thousand in 2013. This is due to several factors, including unfavorable professions for fishermen. This is insufficient fishing equipment for fishing. One of them is the need for navigation tools that are easily understood by traditional fishermen and in accordance with the needs in fishing.we propose the design of Class B's Automatic Identifier System (AIS) to help fishermen navigate and find fish points. In this system we also propose determining the point of fish based on information from fishermen who are collectively collected by the fishermen. With this design it is hoped that the fish point can be shared with other fishermen. The result this design, it is expected to be able to assist fishermen in navigating using AIS so that fisherman security with AIS system with multiple sensor can be improved find the point of fish obtained from sending data from several fishermen and collect data weather for safety.