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All Journal Ecotrophic, Journal of Environmental Science Matrix : Jurnal Manajemen Teknologi dan Informatika JTT (Jurnal Teknologi Terapan)
I Ketut Swardika
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Civil Engineering, Building, Construction & Architecture Computer Science & IT Electrical & Electronics Engineering Environmental Science Mechanical Engineering

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STUDY OF ESTIMATE CONCENTRATION OF WATER CONSTITUENTS AT BADUNG STRAIT BALI USING INVERSE MODEL I Ketut Swardika; Takahiro Osawa; I Wayan Arthana
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 1 No 2
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (634.615 KB)

Abstract

An algorithm was employed to retrieve the concentrations of three water constituents, chlorophyll-a,suspended matter and colored dissolved organic matter (CDOM) from MODIS (Moderate-ResolutionImaging Spectrometer) in wide range covering from oligotrophic case-1 to turbid case-2 waters at theBadung Strait Bali. The algorithm is a neural network (NN) which is used to parameterize the inverse of aradiative transfer model. It’s used in this study as a multiple nonlinear regression technique. The NN is a feedforward back propagation model with two hidden layers. The NN was trained with computed radiancecovering the range of chlorophyll-a from 0.001 to 64.0 ?g/l, inorganic suspended matter from 0.01 to 50.0mg/l, and CDOM absorption at 440nm from 0.001 to 5.0 m-1. Inputs to the NN are the radiance of the fivespectral channels which were under discussion for MODIS. The outputs are the three water constituentconcentrations. The NN algorithm was tested using in-situ data set on May, September, November 2005 atthe Badung Strait Bali and the north sea of Sumbawa Island and applied to MODIS. The coefficient ofdetermination (R2) between chlorophyll-a concentrations derived from simulation and in-situ data is 0.327,for suspended matter R2 is 0.408. No in-situ measurements of CDOM available for validation. Also, in-situdata were compared with the corresponding distribution obtained by the NASA standard OC4 (OC3M) forMODIS chlorophyll-a algorithm and giving R2 0.188. This study gives better accuracy compare withstandard algorithm. How ever both studies are giving over estimate chlorophyll-a concentration. Since thereare no standard MODIS products available for suspended matter and CDOM, the result of the retrieval by theNN for these two variables could only be assessed by a general knowledge of their concentrations anddistribution patterns
KARAKTERISTIK POTENSI ANGIN SEBAGAI SUMBER ENERGI TERBARUKAN DI INDONESIA DARI DATA SATELIT REMOTE SENSING Swardika, I Ketut
Jurnal Teknologi Terapan Vol 5, No 1 (2019): Jurnal Teknologi Terapan
Publisher : P3M Politeknik Negeri Indramayu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (63.611 KB) | DOI: 10.31884/jtt.v5i1.164

Abstract

Global warming, climate changes mostly associates with solar-renewable energy; however wind-energy potential has no detail reports in Indonesia. This study aims to mapping of characteristics and potential of wind as renewable-energy from long-term (1997-2009) satellite remote-sensing. Wind direction (WD), speed (WS) derives from microwave/ scatterometer sensor on satellite operational years as follows: ADEOS (1997), DMSP (1998-1999), AMI (1997-1999), QuikSCAT (1999- 2009). Data processed into 0.25o grid, monthly temporal resolution. The regional characteristics of WD/WS, seasonal and zonal-longitudinal reveals by statistic. Electrical energy derives from kinetic energy of turbine-blades per-unit time. Energy conversion uses power-curves and technical parameters of 1.50 and 3.40 MW (GE 1.5s, 3.4-137 models) onshore installations with 25km2 per point, 15% availability area. Result shows WS has low characteristics in Indonesian-waters (<3.7ms-1). WS has high at north-south Java-Sumatra, Banda waters (<6.9ms-1). The zonal-seasonal wind variability of WD, WS stables at equator. Increases of degree-zonal (>5deg), wind curve follows north-south hemisphere characteristics and crosses in April, October. The north-west, south-east monsoon shows clearly only on north-western of Java-Sumatra waters. WS has range of 0-25.20ms-1, average 6.64ms-1 with Std. 1.64ms-1. With these WS, generation of electrical energy has range from 104.0 to 2230.5 kWh per-point installation grid.
ANALISA KECEPATAN SPATIAL QUERY DATA SATELIT PADA BEBERAPA STORAGE ENGINE MYSQL DATABASE I Ketut Swardika
Matrix : Jurnal Manajemen Teknologi dan Informatika Vol 6 No 1 (2016): MATRIX - Jurnal Manajemen Teknologi dan Informatika
Publisher : Unit Publikasi Ilmiah, P3M Politeknik Negeri Bali

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Abstract

Penerapan spatial database untuk data satellite remote sensing, membutuhkan struktur data yang memungkinkan proses spatial query dilakukan dengan kecepatan tinggi, oleh karena volume data satelit biasanya sangat besar. Data-data satelit disimpan kedalam spatial database MySQL, karena MySQL adalah open-source database server yang sangat populer saat ini. Pemilihan tipe mesin penyimpan atau storage engine pada MySQL mempengaruhi perfomance sebuah spatial query. Pada paper ini, dilakukan pengujian kecepatan spatial query pada storage engine MySQL. Data pengujian berupa data radian beberapa band sensor MODIS pada satelit AQUA/TERRA. Sebuah store procedure dibuat yang akan memberikan informasi kecepatan query. Spatial database diimplementasikan dengan memilih database table dengan tipe storage engine yang mendukung kolom tipe geometry. Untuk mendapatkan perfomance yang baik, storage engine harus mendukung spatial index. Spatial query dilakukan dengan bantuan spatial function yang sudah terstandarisasi. Hasil test menunjukan tipe storage engine MyISAM secara umum memberikan kecepatan spatial query yang lebih cepat dari tipe storage engine InnoDB dan ditemukan delay yang besar pada kecepatan transfer InnoDB yang menyebabkan kecepatan query total menjadi lebih lama dari MyISAM. Telah dikembangkan tipe storage engine ARIA pada MariaDB yang memiliki keunggulan lebih baik dari MyISAM dan mendukung fitur transaksional seperti pada InnoDB
Co-Authors I Wayan Arthana Takahiro Osawa