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Modified Newton Kantorovich Methods for Solving Microwave Inverse Scattering Problems Agung Tjahjo Nugroho
Jurnal ILMU DASAR Vol 10 No 2 (2009)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (553.028 KB)

Abstract

The Modified Newton-Kantorovich method (MNK) was formulated due to the limitation of The Newton-Kantorovich method (NK) in reconstructing the imitation of bone muscle and fat object. It was sensitive to contrast and cell size. In this research MNK and NK methods were applied to reconstruct the dielectric properties distribution of homogeneous and inhomogeneous objects from simulated scattered field dataset to know how the results of image reconstruction using both methods were. The results revealed that the MNK method was more flexible than the NK one. 
Deteksi sebaran gas metana (CH4) di TPA Pakusari Jember menggunakan sensor TGS 2611 (Detection of methane gas (CH4) distributionin at TPA Pakusari Jember using TGS 2611 sensor) Sri Indariyatul Masruroh; Bowo Eko Cahyono; Agung Tjahjo Nugroho
PILLAR OF PHYSICS Vol 12, No 1 (2019)
Publisher : Department of Physics – Universitas Negeri Padang UNP

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1035.475 KB) | DOI: 10.24036/6317171074

Abstract

Waste is an important issue in urban environments and will continue to be faced by governments and communities. Most waste disposal sites are concentrated in the Final Disposal Site (TPA). Waste accumulation in the landfill can create methane gas which can spread to the environment. The purpose of this research is to know the application of TGS 2611 sensor as methane gas detector and use it to measure methane gas distribution at TPA Pakusari Jember. This research is conducted by detecting the distribution of methane gas in TPA Pakusari. Data retrieval is performed by placing the sensor directly above the garbage pile and then observe the voltage value that appears on the LCD screen. The obtained data of voltage values are normalized and then they are visualized into 2 dimension contoure graph by using Matlab application. The results show that methane gas in TPA Pakusari is not spread evenly but it spreads randomly. This is due to the unequal garbage composition and the height random garbage at each measurement point. The largest methane gas is located in the area of the pile of organic waste that suffers from decay and the lowest methane gas is located in areas with little piles of rubbish and dominant with the soil. Thus it can be concluded that TGS 2611 sensor can be applied to detect the spread of methane gas in TPA Pakusari Jember.
GREENESS ANALYSIS OF FOREST IN MINING AREA OF SAWAHLUNTO USING NDVI METHOD BASED ON LANDSAT IMAGERIES IN 2006-2016 Bowo Eko Cahyono; Yazella Feni Frahma; Agung Tjahjo Nugroho
Spektra: Jurnal Fisika dan Aplikasinya Vol 3 No 1 (2018): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 3 Issue 1, April 2018
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/SPEKTRA.031.06

Abstract

Abstrak Pembukaan lahan hutan yang dijadikan lokasi pertambangan merupakan salah satu kegiatan yang dapat merubah jenis tutupan lahan atau sering disebut dengan konversi lahan. Salah satu daerah yang telah mengalami konversi lahan tersebut adalah Sawahlunto. Konversi lahan yang tidak menggunakan prinsip kelestarian lingkungan dapat mengakibatkan banyak hal negatif misalnya degradasi atau penurunan kualitas hutan. Tujuan dari penelitian ini adalah melakukan analisis tingkat degradasi hutan daerah pertambangan Sawahlunto tahun 2006 sampai 2016. Penelitian ini menggunakan teknologi penginderaan jauh berbasis citra satelit landsat. Citra satelit landsat ini diklasifikasikan dengan metode Normalized Difference Vegetation Index (NDVI) berdasarkan kerapatan vegetasi. Kemudian hasil klasifikasi ini dibuat dalam bentuk pemetaan. Klasifikasi pertama dikategorikan menjadi dua yakni hutan dan non hutan. Hasil yang didapatkan dari penelitian ini menunjukkan bahwa terjadi perubahan tutupan lahan yang semula hutan menjadi non hutan meningkat sebesar 7,5% selama kurun waktu sepuluh tahun. Klasifikasi selanjutnya yakni berdasarkan enam kategori yakni vegetasi sangat rapat, rapat, cukup rapat, non vegetasi 1, 2 dan 3. Dari klasifikasi ini, juga terlihat perubahan nilai NDVI maksimum maupun minimumnya. Tahun 2006 memiliki kisaran nilai NDVI maksimum 0,71 dan tahun 2016 memiliki kisaran nilai NDVI maksimum 0,56. Hal ini mengidentifikasi bahwa tingkat kehijauan yang ada di daerah pertambangan Sawahlunto menurun. Kata Kunci : degradasi, hutan, landsat, ndvi, klasifikasi, Sawahlunto. Abstract The clearing of forest land that is used as a mining site is one of the activities that can change the type of land cover or often called land conversion. One of the forest areas that convert the land is Sawahlunto. Conversion of land that does not use the principles of environmental sustainability can lead to many negative things one of which is the degradation. The purpose of this research is to analyze the level of forest degradation of Sawahlunto mining area in 2006 until 2016. This research uses a remote sen sing technology based on landsat satellite imagery. This landsat satellite image is classified by Normalized Difference Vegetation Index (NDVI) method based on vegetation density. Then the results of this classification is made in the form of mapping. The first classification is categorized into two namely forest and non forest. The results obtained from this study indicate that a change in land cover from forest to non-forest increased by 7.5% over a period of ten years. The next classification is based on six categories namely very dense vegetation, dense vegetation, fairly dense, non vegetation 1, 2 and 3. From this classification, also seen the change in NDVI maximum and minimum value. The year 2006 has a maximum NDVI value range of 0.71 and 2016 has a maximum NDVI value range of 0.56. This identifies that the existing greenness in the mining area of Sawahlunto is decreasing. Keyword : degradation, forest, landsat, ndvi, classification, Sawahlunto.
Klasifikasi Down Syndrome Menggunakan Tekstur LBP dengan Tiga Variasi Distance Classifiers Agung Tjahjo Nugroho; Yustisi Wulandari; Bowo Eko Cahyono
STRING (Satuan Tulisan Riset dan Inovasi Teknologi) Vol 7, No 1 (2022)
Publisher : Universitas Indraprasta PGRI Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30998/string.v7i1.13532

Abstract

Down syndrome is the most easily identified and most common genetic disorder. Down syndrome variation of trisomy 21 has characteristics that are common to people with Down syndrome. But, children with this Down syndrome variation have slight differences in the mouth and appearance because they tend to have similar oral features with their parents and siblings so that distinguishing them is quite complex. Therefore, it is important to know in more details the special characteristics of children with Down syndrome. This study aims to create an innovative image processing-based system so that it is more practical to classify people with down syndrome and normal people. The method that can be used is the Local Binary Pattern (LBP) method. This study used 2400 mouth frames of children with Down syndrome and normal children for data training. Then, it also uses 3600 mouth frames for children with Down syndrome and normal children for testing data. The results obtained are the threshold value which gives a good classification of 0.1-0.2 for the three variations of the distance calculation method. The Euclidean and Chebychev methods have an accuracy quality of 100% while the City block method at the threshold of 0.1-0.2 has an accuracy of 91.6. So, it can be said that the most accurate method in this research is the Chebychev, Euclidean, then City Block method.
Analisis Usia Tebu Terhadap Pola Nilai GNDVI (Green Normalized Difference Vegetation Index) Berdasarkan Data Citra Landsat-8 Bowo Eko Cahyono; Agung Tjahjo Nugroho; Niken Dwi Wulandari
Teknotan: Jurnal Industri Teknologi Pertanian Vol 16, No 3 (2022): TEKNOTAN, Desember 2022
Publisher : Fakultas Teknologi Industri Pertanian

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/jt.vol16n3.2

Abstract

Tebu adalah salah satu tanaman yang dapat memproduksi gula serta bioenergi bagi lingkungan yang masa tanamnya selama ±12 bulan. Kondisi pertumbuhan tanaman tebu berdasarkan usia tanamnya dapat dipantau dengan menggunakan teknologi penginderaan jauh. Penelitian ini bertujuan untuk mengetahui pola reflektansi spektra yang dinyatakan melalui indeks vegetasi GNDVI. Penelitian ini menghubungkan nilai GNDVI terhadap usia tanaman tebu dengan menggunakan data citra Landsat 8 tahun 2019-2020 di Kabupaten Jember yang terbagi menjadi 11 lokasi lahan. Tahap awal yang dilakukan yaitu mengumpulkan data citra lalu dikoreksi radiometrik ToA. Selanjutnya menghitung nilai GNDVI pada lokasi lahan tebu yang ditinjau. Nilai GNDVI dari setiap lokasi lahan ini dihitung nilai mediannya dan dibuat grafik hubungan antara nilai GNDVI terhadap usia tanam tebu. Dari hasil penelitian didapatkan pola nilai GNDVI terhadap usia tebu berbentuk kurva parabolik. Hasil dari pola tersebut menunjukkan bahwa nilai GNDVI berada pada maksimum di usia sekitar 8, 9, dan 10, dimana nilai GNDVInya dalam rentang 0.43 sampai 0.54. Secara rata-rata hubungan usia tebu dengan nilai GNDVI dinyatakan dengan persamaan   dimana X dan Y berturut-turut adalah usia tebu dan nilai GNDVI dengan puncak nilai GNDVI berada pada bulan ke 9. Secara umum dapat dikatakan bahwa semakin besar usia tebu maka semakin besar nilai GNDVI hingga pada keadaan maksimum dan kembali menurun.
Effect of Nylon Membrane Thickness on the Value of Sound Transmission Loss as an Alternative Insulation Material Wenny Maulina; Totok Wicaksono; Agung Tjahjo Nugroho
Jurnal Fisika Flux: Jurnal Ilmiah Fisika FMIPA Universitas Lambung Mangkurat Vol 20, No 2 (2023): Jurnal Fisika Flux: Jurnal Ilmiah Fisika FMIPA Universitas Lambung Mangkurat
Publisher : Lambung Mangkurat University Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20527/flux.v20i2.12810

Abstract

Measurements of sound transmission loss have been successfully carried out on various thicknesses of nylon membrane as an absorbing material. Nylon membrane were prepared using hydrogen chloride (HCl) and acetyl aceton in the casting solution by phase inversion methods. Nylon membrane with different thickness used in this reseach were 1 mm, 2 mm, 3 mm, 4 mm, and 5 mm. Measurement of sound transmission loss was carried out using a reverberation chamber with sound frequencies of 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz. The results show that, with the increase of thickness of nylon membrane, sound transmission loss of nylon membran was improved. The sound transmission loss of nylon membrane with thickness of 4 mm is the best, whose sound trasnmission loss was up to 46.39 dB at 4000 Hz. This nylon membrane is suitable for lightweight sound barriers and is promising and worthy of further study.
Klasifikasi Tangisan Bayi Menggunakan Parameter Pitch Dengan K-Nearest Neighbors Ainayya Halifah; Agung Tjahjo Nugroho; Wenny Maulina
Journal of Electronics and Instrumentation Vol. 1 No. 2 (2024)
Publisher : Fakultas MIPA, Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/jei.v1i2.880

Abstract

Baby crying is a basic and important thing for mothers or caregivers to understand. In general, young mothers who do not receive guidance from experienced people, usually interpret baby crying as a sign of hunger only, even though crying in babies has different meanings or types of crying depending on the trigger/cause of crying. This study was conducted to establish the characteristics of the cause of infant crying through pitch parameters formed in the Bag of Features and determine the accuracy of the resulting classification. The feature extraction and classification methods used in this research are pitch, Bag of Features and K-Nearest Neighbor. Pitch feature extraction is done by changing the range parameters and methods in estimating the fundamental frequency. The range and method used in this research are (70,170) and PEF. The baby cries used for this study were taken in two ways, namely downloading Dunstan Baby Language and field measurements based on the perception of mothers and medical personnel. The types of infant cries used in this study were burpme, hungry, lower wind pain, tired, uncomfortable and pain. The results of this study show that the sequence of DBL baby cry labels that have a high average fundamental frequency probability value based on the Bag of Features histogram are tired (0.290), lower wind pain (0.207), hungry (0.206), burpme (0.182) and uncomfortable (0.090) while the sequence of baby cry labels from measurement data shows that the sick label has a higher average fundamental frequency, which is 0.200 when compared to the hungry label whose average fundamental frequency is 0.064. The classification accuracy results obtained between the DBL database test and the measurement database using K-Nearest Neighbor look optimal, which is 92% and 98%.
The Effect of Arrive Angle of External Magnetic Field on The Shape of Hysteresis Curve Permalloy Ni80Fe20 By Simulation Lestari, Merinda; Nursiyanto, Widia; Nugroho, Agung Tjahjo
Computational And Experimental Research In Materials And Renewable Energy Vol 4 No 2 (2021): November
Publisher : Physics Department, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/cerimre.v4i2.28377

Abstract

Magnetic sensor is a type of sensor that utilizes changes in resistance caused by changes in the magnetic field H or B. One of the suitable magnetic materials to be used as a study material for making magnetic sensors is permalloy Ni80Fe20. The reading error of the magnetic sensor of the Ni80Fe20 permalloy material affects hysteresis curve of the material and requires correction of the angle of incidence of the external magnetic field in order to provide accurate results on the storage media. In this our current research using Finite Difference OOMMF, we investigated the effect of the angle of incidence of the external magnetic field (H) on the hysteresis curve was carried out on an application based on. The research was conducted by reviewing the parameter literature of the Ni80Fe20 permalloy material and then compiling it in a script and simulating it on an application based on Finite Difference OOMMF. The data obtained from the simulation are normalized magnetization (m), external magnetic field H and coercivity field (Hc) which have been influenced by the angle of incidence. The results of the hysteresis curve at a size of 5 nm with a variation of the angle of incidence 0o are indicated by the value of the external magnetic field H of 10000 mT to -10000 mT with a coercive field Hc of 5000 mT to -5000 mT. The normalized magnetization value m is 1 to -1. The variation of the angle of incidence of 30o produces a coercive field Hc of -108.3 mT to 108.3 mT and a normalized magnetization of 0.86 to -0.86. The 45o incident angle variation produces a coercive field Hc -88.4 mT to 88.4 mT and a normalized magnetization of -0.7 to 0.7
Study of Dielectric and Adsorption Properties of Activated Carbon Prepared from Water Hyacinth using KOH as an Activating Agent Ghiffari, Mochammad; Maulina, Wenny; Nugroho, Agung Tjahjo
Computational And Experimental Research In Materials And Renewable Energy Vol 3 No 1 (2020): May
Publisher : Physics Department, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/cerimre.v3i1.26417

Abstract

Activated carbon can be produced from the combustion of a materials containing carbon that has been activated using activator substances. In this paper, potassium hydroxide (KOH) was selected as an activating agent. The influence of KOH concentration was investigated to determine the dielectric and adsorption properties of activated carbon derived from water hyacinth. Drying water hyacinth was carbonize in the furnace at a temperature of 400°C followed by chemical activation with variation concentration of KOH solution that used are 25%, 30%, and 35% (w/v) respectively. The results show that the best activated carbon derived from water hyacinth was obtained using 35% (w/v) KOH solution as an activating agent with the dielectric constant is 4,04 while iodine number of 514,6 mg/g.
Effective Communication for Doctor-Patient Narrative Inquiry on TBC Musli Ariani; Arief Rijadi; Agung Tjahjo Nugroho; Bonanza Vidya Rashmi Nugroho
Jurnal Inovasi Sains dan Teknologi untuk Masyarakat Vol. 1 No. 1 (2023): Mei
Publisher : Faculty of Mathematics and Natural Sciences, University of Jember. Jl. Kalimantan No.37, Krajan Timur, Jemberlor, Kec. Sumbersari, Jember Regency, East Java 68121

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/instem.v1i1.362

Abstract

The community service aims at training the internship medical doctor on effective communication for doctor-patient narrative inquiry on TBC. This workshop was held due to need for the achievement on TBC contact investigation. Four-step training was conducted including exposure to effective communication and narrative inquiry, focus group discussion on problems and alternative solutions, peer doctor-patient communication practice, and reflection. The results of the current community service reveal that the achievement on TBC investigation rises due to the internship medical doctors willingness to do the follow through of the program. They have initially followed the standard norms of doctor-patient communication, and even improve their method of communication by utilizing their knowledge and understanding of the conversational maxims and use it in the narrative inquiry on TBC.