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INDENTIFYING PATTERNS OF SATTELITE IMAGERY USING AN ARTIFICIAL NEURAL NETWORK Iskandar, Iskhaq; Affandi, Azhar; Setiabudidaya, Dedi; Irfan, Muhammad; Mardiansyah, Wijaya; Syamsuddin, Fadli
International Journal of Remote Sensing and Earth Sciences (IJReSES) Vol 9, No 1 (2012)
Publisher : National Institute of Aeronautics and Space of Indonesia (LAPAN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (620.1 KB) | DOI: 10.30536/j.ijreses.2012.v9.a1824

Abstract

An artificial neural network analysis based on the self-organizing map (SOM)  was used  to  examine  patterns  of  satellite  imagery.  This  study  used  3  ×  4  SOM  array  to  extract patterns  of  satellite-observed  chlorophyll-a  (chl-a)  along  the  southern  coast  of  the  Lesser Sunda Islands from 1998 to 2006. The analyses indicated two characteristic spatial patterns, namely the northwest and the southeast monsoon patterns. The northwest monsoon pattern was characterized by a low  chl-a concentration. In contrast, the southeast monsoon pattern was  indicated  by  a  high  chl-a  distributed  along  the  southern  coast  of  the  Lesser  Sunda Islands.  Furthermore,  this  study  demonstrated  that  the  seasonal  variations  of  those  two patterns  were  related  to  the  variations  of  winds  and  sea  surface  temperature  (SST).  The winds  were  predominantly  southeasterly  (northwesterly)  during  southeast  (northwest) monsoon, drived  offshore (onshore) Ekman transport and  produced  upwelling (downwelling) along  the  southern  coasts  of  the  Lesser  Sunda  Islands.  Consequently,  upwelling  reduce dSST  and  helped  replenish  the  surface  water  nutrients,  thus  supporting  high  chl-a concentration. Finally, this study demonstrated that the SOM method was very useful for the identifications of patterns in various satellite imageries.
Spatial and Temporal Variability of Sea Surface Height in the Southeastern Tropical Indian Ocean Based on the Satellite Altimeter Data Iskandar, Iskhaq; Mardiansyah, Wijaya; Setiabudidaya, Dedi
Jurnal Matematika dan Sains Vol 19 No 2 (2014)
Publisher : Institut Teknologi Bandung

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Abstract

Sea surface height (SSH) data from merged-satellite observations (e.g. TOPEX/Poseidon, JASON and ERS) were used to evaluate the spatial and temporal variations of sea surface circulations in the southeastern tropical Indian Ocean (SETIO). A Complex Empirical Orthogonal Function (CEOF) was used to extract the dominant mode of variability in the SETIO region. The results show that the first mode accounts for 41.2% of the total variance dominates the variation. The second mode accounts for 18.2% of the total variance, while the third and the fourth modes explain 6.5% and 2.6% of the total variance, respectively. The spectrum analysis indicates that the 35-day variations is a prominent feature in all CEOF modes. Furthermore, semiannual variation at period of about 180-day was observed in the first third modes, while the annual variation of about 300-day was only observed in the first two modes. A relatively strong variation at period of around 500-day was observed in the first, second and fourth modes. It is suggested that the spatial and phase pattern of the first and third modes are related to the propagation of the Kelvin waves generated by wind stress over the equatorial Indian Ocean. On the other hand, the second was likely related to the local upwelling and downwelling generated by the seasonal changes in the alongshore winds. Furthermore, the fourth mode represents the oceanic eddy generated from the downstream straits of the Indonesian Throughflow.Variasi Spasial dan Temporal Tinggi Muka Laut di Wilayah Tropis Samudera India Bagian Tenggara Berdasarkan Data Satelit AltimetriAbstrak Data tinggi permukaan laut hasil observasi dari beberapa satelit (yaitu: TOPEX/Poseidon, JASON dan ERS) digunakan untuk evaluasi variasi spasial dan variasi temporal sirkulasi permukaan laut di wilayah tropis Samudera Hindia bagian tenggara. Analysis dilakukan menggunakan metode Complex Empirical Orthogonal Function (CEOF) untuk mendapatkan mode variasi yang dominan di wilayah ini. Hasil analisis menunjukkan bahwa mode CEOF pertama menjelaskan 41,2% dari variasi total dan merupakan mode yang paling dominan. Mode CEOF kedua mengandung 18,2% dari variasi total, sedangkan mode ketiga dan keempat menjelaskan masing-masing 6,5% dan 2,6% dari variasi total. Analisis spektrum terhadap deret waktu masing-masing mode CEOF menunjukkan bahwa variasi dalam skala 35 hari merupakan variasi yang signifikan untuk setiap mode. Selanjutnya, variasi setengah-tahunan dengan periode osilasi sekitar 180 hari terekam pada tiga mode pertama, sementara variasi tahunan dengan periode osilasi sekitar 300 hari hanya terekam pada mode pertama dan mode kedua. Variasi yang cukup kuat pada periode osilasi sekitar 500 hari terekam pada mode pertama, mode kedua dan mode keempat. Hasil analisis ini juga menunjukkan bahwa pola spasial dan fase gelombang pada mode pertama dan mode ketiga adalah terkait dengan penjalaran gelombang Kelvin yang dibangkitkan oleh stres angin di wilayah ekuator Samudera Hindia. Sementara itu, mode kedua terkait dengan proses upwelling dan downwelling yang dibangkitkan oleh angin muson di sepanjang pantai. Selanjutnya, mode keempat merepresentasikan oceanic eddy yang terbentuk dari selat-selat arus lintas Indonesia (ARLINDO).  Kata kunci: Complex empirical orthogonal function, Analisis Fourier, Samudera Hindia, Tinggi permukaan laut. 
Jupyter Notebook App: Alternatif Teknologi Pembelajaran Fisika Berbasis Web Browser Setiabudidaya, Dedi
Annual Research Seminar (ARS) Vol 1, No 1 (2015)
Publisher : Annual Research Seminar (ARS)

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Abstract

Dalam beberapa dekade ke belakang, perangkat keras dan perangkat lunak komputer mengalami perkembangan yang sangat cepat. Bagi sebagian besar pemerhati sejarah ilmu pengetahuan, perkembangan yang sangat cepat ini memposisikan komputasi sebagai pilar ketiga dari sains setelah teori dan eksperimen. Sebagai contoh, Perez dan Granger (2007) menciptakan aplikasi IPython Notebook  berbasis web browser yang telah digunakan oleh banyak orang di bidang pendidikan dan penelitian. Aplikasi ini kini telah bertransformasi menjadi Jupyter Notebook App, dengan menggunakan bahasa pemograman utama yang lebih beragam, yaitu Julia, Python dan R. Shen (2014) memperkirakan satu juta peneliti dan pendidik telah menggunakan aplikasi ini untuk menunjang kegiatan profesinya. Makalah ini membahas pemanfaatan Jupyter Notebook App sebagai teknologi pembelajaran fisika khususnya di bidang fisika bumi dan fisika bahan dengan menggunakan bahasa pemograman python. Hasil survey terbaru menunjukkan bahwa Python kini telah menjadi bahasa pemograman favorit di beberapa perguruan tinggi ternama di Amerika Serikat (Guo, 2014).
Analisis Data Magnetisasi Remanen Isotermal dengan Software IRMUNMIX Setiabudidaya, Dedi
Jurnal Fisika dan Aplikasinya Vol 2, No 1 (2006)
Publisher : Jurnal Fisika dan Aplikasinya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (88.787 KB) | DOI: 10.12962/j24604682.v2i1.981

Abstract

Telah dilakukan kajian kinerja software IRMUNMIX terhadap sampel yang terindikasi hanya memiliki satu komponen mineral magnetik. Hasil menunjukkan bahwa software IRMUNMIX mampu mendeteksi komponen mineral magnetik dengan kontribusi yang sangat minimal.
Efektivitas Elektroda pada Proses Elektrokoagulasi untuk Pengolahan Air Asam Tambang Ashari, Ashari; Budianta, Dedik; Setiabudidaya, Dedi
Jurnal Penelitian Sains Vol 17, No 2 (2015)
Publisher : Faculty of Mathtmatics and Natural Sciences

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Abstract

Air limpasan dari aktivitas pertambangan batubara sangat berpotensi pada pembentukan air asam tambang. Air asam tambang yang berasal dari mine sump area tambang Air Laya PT. Bukit Asam (Persero), Tbk. mempunyai nilai pH rendah yaitu berkisar dari 3 sampai 5, kondisi ini akan melarutkan unsur-unsur logam seperti Fe dan Mn pada batuan yang dilalui oleh air asam tambang tersebut. Elektrokoagulasi merupakan metode untuk melakukan proses koagulasi dengan menggunakan tegangan listrik searah yang didasarkan pada peristiwa elektrokimia. Penelitian dilakukan dengan sistem batch skala laboratorium yaitu menggunakan volume air asam tambang 1,8 L, elektroda besi (Fe) 8 cm x 11 cm x 0,8 mm sebanyak 3 lempeng sebagai katoda dan elektroda aluminium (Al) 8 cm x 11 cm x 0,8 mm sebanyak 3 lempeng sebagai anoda. Percobaan dilakukan dengan interval waktu 15 menit, 30 menit, 45 menit dan 60 menit, lalu menggunakan tegangan 6 V, 12 V, dan 24 V untuk jarak elektroda yaitu 1,5 cm dan 2 cm. Dengan tetap mempertimbangkan faktor ekonomi maka diketahui waktu, jarak dan tegangan DC yang paling efektif digunakan untuk proses elektrokoagulasi adalah 12 Volt dan 45 menit yang akan menghasilkan persen peningkatan nilai pH = 32,96 ; persen penurunan logam Fe = 94,0111 ; dan persen penurunan logam Mn = 88,2878, akan tetapi faktor jarak antara elektroda tidak berpengaruh pada proses ini.
EFFECT OF ARCHITECTURAL TREE MODEL TO THE NOISE LEVEL OF MOTOR VEHICLE ON DEMANG LEBAR DAUN STREET PALEMBANG Jumingan, -; Dahlan, Zulkifli; Setiabudidaya, Dedi
BIOVALENTIA: Biological Research Journal Vol 2, No 2 (2016)
Publisher : Biology Department, Faculty of Mathematics and Natural Sciences, Sriwijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (69.747 KB) | DOI: 10.24233/BIOV.2.2.2016.35

Abstract

The research on the effect of architectural tree model to the noise level of motor vehicles on Demang Lebar Daun Street Palembang has been conducted. The purpose of this study was to analyze kind of architectural tree model can reduce the highest noise levels among the architectural tree models encountered and identify the architectural tree model. The method used was purposive sampling. Measurement of the noise level and architectural models were selected according to the type of the tree encountered on the left or right side of the street. The noise level measurement during the daylight was carried out simultaneously at a point of 1 meter in front of the tree, 1 and 5 meters behind the tree,for 10 minutes with the readings for every 5 seconds at 07:00, 10:00, 15:00 and 20:00. The results showed that The architectural model of Switenia magahoni tree was Rauh model, Lagerstroemia sp. tree was Troll model and Thyrsostachys siamensis tree was McClure model. The highest noise level reduction was from bamboo tree, respectively by 4,88 dB (A) and 8,52 dB (A) at the distances of 1 and 5 m. Keywords: noise level, reduction, architectural tree model
Effect of Ground Vibration to Slope Stability, Case Study Landslide on The Mouth of Railway Tunnel, Gunung Gajah Village, Lahat District Ghadafi, Moamar Aprilian; Toha, Muhammad Taufik; Setiabudidaya, Dedi
Sriwijaya Journal of Environment Vol 2, No 3 (2017): Low Land
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (563.901 KB) | DOI: 10.22135/sje.2017.2.3.67-71

Abstract

Slope stability around railway tunnel in Gunung Gajah Village, Lahat District needs to be analysed due to landslide which occurred on January, 23th 2016. That analysis needs to be done so that the railway transportation system can run safely. The purposes of this research are: to find out the factors that cause slope instability, to find out peak acceleration caused by railway traffic and earthquakes and its effects to the safety factor of slope, and determine stabilization method in order to prevent the occurrence of further landslide. The research activities include surveying, sampling, laboratory testing and analyzing slope stability using pseudo-static approach. Based on research result, the main factors that cause slope instability are morphology, structural geology, and ground vibration caused by earthquakes. Ground vibration are correlated to the slope instability. It shows that the higher of peak acceleration the lower of safety factor of slope. To prevent the occurrence of further landslide around research area, stabilization method should be applied in accordance with the conditions in that area such as building a retaining wall to increase safety factor of slope, building draining channels to reduce run off and performing shotcrete in the wall of landslide in order to avoid weathering.Keywords: ground vibration, slope stability, stabilization method
On the Influence of Enso And IOD on Rainfall Variability Over The Musi Basin, South Sumatra Mardiansyah, Wijaya; Setiabudidaya, Dedi; Khakim, M. Yusup Nur; Yustian, Indra; Dahlan, Zulkifli; Iskandar, Iskhaq
Science and Technology Indonesia Vol 3 No 4 (2018): October
Publisher : ARTS Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4342.559 KB) | DOI: 10.26554/sti.2018.3.4.157-163

Abstract

The southern Sumatera region experiences one rainy season and one dry season in a year associated with seasonal change in monsoonal winds. The peak of rainy season is occurring in November-December-January during the northwest monsoon season, while the dry season comes in June-July-August during the southeast monsoon season. This study is designed to evaluate possible influence of the coupled ocean-atmospheric modes in the tropical Indo-Pacific region, namely the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) on the rainfall variability over the catchment area of the Music Basin, South Sumatera. The ENSO and IOD occurrences were reflected by the variability of sea surface temperature (SST) in the tropical Pacific and Indian Ocean, respectively. During El Niño and/or positive IOD episode, negative SST anomalies cover the eastern tropical Indian Ocean and western tropical Pacific including the Indonesian seas, leading to suppress convective activities that result in reduce precipitation over the maritime continent. The situation is reversed during La Niña and/or negative IOD event. The results revealed that the high topography area (e.g. Bukit Barisan) was shown to be instrumental to the pattern of rainfall variability. During the 2010 negative IOD co-occurring with La Niña event, the rainfall was significantly increase over the region. This excess rainfall was associated with warm SST anomaly over the eastern tropical Indian Ocean and the Indonesian seas. On the other hand, extreme drought event tends to occur during the 2015 positive IOD simultaneously with the occurrence of the El Niño events Investigation on the SST patterns revealed that cold SST anomalies covered the Indonesian seas during the peak phase of the 2015 positive IOD and El Niño event.
Validasi Areal Terbakar dengan Metode Normalized Burning Ratio Menggunkan UAV (Unmanned Aerial Vehicle): Studi Kasus Saputra, Agus Dwi; Setiabudidaya, Dedi; Setyawan, Dwi; Iskandar, Iskhaq
Jurnal Penelitian Sains Vol 19, No 2 (2017)
Publisher : Faculty of Mathtmatics and Natural Sciences

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (905.42 KB)

Abstract

Kebakaran hutan merupakan suatu bentuk bencana yang di picu oleh faktor alam maupun faktor kelalaian ma-nusia, bencana ini mempunyai dampak terhadap aspek-aspek kehidupan masyarakat. Salah satu dampaknya adalah de-gradasi hutan dan lahan terutama keanekaragaman hayati didalamnya. Untuk dapat menyusun rencana rehabilitasi pasca kebakaran pada wilayah yang luas dibutuhkan data area terbakar yang sudah terklasifikasi tingkat keparahan terbakarnya. Pada penelitian ini akan melakukan validasi tingkat keparahan terbakar pada kebakaran tahun 2015 di kawasan hutan gambut Merang-Kepayang. Data areal terbakar diturunkan dengan metoda Normalized Burning Ratio dari Citra Landsat 8 yang menggunakan kanal Near Infra Red (NIR) dan kanal Short Wave Infra Red (SWIR), dari perhitungan metoda NBR dihasilkan nilai ambang batas keparahan terbakar yang diklasifikasikan berdasarkan rentang nilai reflektansi yaitu unburned bernilai -1.02 - 0.29 μm, low bernilai 0.29 - 0.42 μm, moderate bernilai 0.42 - 0.55 μm, dan moderate extreme 0.55 - 0.80 μm. Setelah dilakukan klasifikasi tingat keparahan terbakar, kemudian dilakukan validasi hasil klasifikasi menggunakan foto udara dari Unmanned Aerial Vehicle (UAV) dengan 31 titik pengamatan lapangan dengan ketinggian terbang rata-rata 100 m dari permukaan tanah. Validasi menggunakan confusion matrix antara nilai reflektansi dan klasi-fikasi visual foto udara. Hasil validasi menyatakan bahwa akurasi keseluruhan adalah 70.97 % artinya tidak ditemukan perbedaan yang signifikan antara nilai indeks NBR dan klasifikasi lapangan. Dan juga nilai Koefisen Kappa 0.59 yang berarti hasil klasifikasi tersebut mampu mampu menghindari 59.2% kesalahan yang akan muncul pada klasifikasi lapangan.