Article Per Year (5 Year)
p-Index From 2021 - 2026
0.888
P-Index
This Author published in this journals
All Journal Jurnal Matematika & Sains Journal of Mathematical and Fundamental Sciences Journal of Engineering and Technological Sciences JLBG (Jurnal Lingkungan dan Bencana Geologi) (Journal of Environment and Geological Hazards) JURNAL METEOROLOGI DAN GEOFISIKA Indonesian Journal of Physics (IJP) Journal of Engineering and Technological Sciences
Hendra Grandis
Faculty Of Mining And Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132
Aerospace Engineering Astronomy Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Mathematics Physics

Published : 22 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 22 Documents
Search

 1   2   3 
Integrated Magnetotelluric (MT), Gravity and Seismic Study of Lower Kutai Basin Configuration Selvi Misnia Irawati; Hidayat Hidayat; Edy Wijanarko; Hendra Grandis
Journal of Engineering and Technological Sciences Vol. 54 No. 1 (2022)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2022.54.1.3

Abstract

This work describes a subsurface basin configuration of the Lower Kutai Basin (hereinafter LKB) in East Kalimantan, Indonesia, as inferred from combination of magnetotelluric (MT), seismic, and gravity data. LKB is structurally controlled mainly by the Samarinda Anticlinorium extending in a NNE-SSW direction and is one of the most prolific hydrocarbon basins in Indonesia. The phase tensor analysis of MT data from most stations and frequencies exhibited a 2D character with a relatively low skew (-3° < β < 3°).  The geo-electrical strike direction was estimated at N30°E, which is in good agreement with the regional geological strike with a NNE-SSW direction. 2D MT inversion modeling was performed to infer the subsurface resistivity distribution associated with LKB’s configuration. From the integration of MT, seismic and gravity models it was shown that LKB’s configuration is composed mainly of sandstone, black shale, claystone, and basement rocks. The conductive zones of the MT models are associated with thermal alteration of black shale, which changes its mineralization, leading to lower resistivity. Hence, the black shale may be interpreted as potential hydrocarbon source rock in LKB.
Improved Modified Symbiosis Organisms Search (IMSOS): A New and Adaptive Approach for Determining Model Parameters from Geoelectrical Data Sungkono Sungkono; Hendra Grandis
Journal of Engineering and Technological Sciences Vol. 53 No. 5 (2021)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2021.53.5.5

Abstract

Symbiotic Organisms Search (SOS) is a global optimization algorithm inspired by the natural synergy between the organisms in an ecosystem. The interactive behavior among organisms in nature simulated in SOS consists of mutualism, commensalism, and parasitism strategies to find the global optimum solution in the search space. The SOS algorithm does not require a tuning parameter, which is usually used to balance explorative and exploitative search by providing posterior sampling of the model parameters. This paper proposes an improvement of the Modified SOS (MSOS) algorithm, called IMSOS, to enhance exploitation along with exploration strategies via a modified parasitism vector. This improves the search efficiency in finding the global minimum of two multimodal testing functions. Furthermore, the algorithm is proposed for solving inversion problems in geophysics. The performance of IMSOS was tested on the inversion of synthetic and field data sets from self-potential (SP) and vertical electrical sounding (VES) measurements. The IMSOS results were comparable to those of other global optimization algorithms, including the Particle Swarm Optimization, the Differential Evolution and the Black Holes Algorithms. IMSOS accurately determined the model parameters and their uncertainties. It can be adapted and can potentially be used to solve the inversion of other geophysical data as well.
Constrained Two-Dimensional Inversion of Gravity Data Hendra Grandis; Darharta Dahrin
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 1 (2014)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2014.46.1.1

Abstract

The non-uniqueness in the solution of gravity inversion poses a major problem in the interpretation of gravity data. To overcome this ambiguity, "a priori" information is introduced by minimizing a functional that describes the geometrical or physical properties of the solution. This paper presents a 2D gravity inversion technique incorporating axes of anomalous mass concentration as constraints. The inverse problem is formulated as a minimization of the moment of inertia of the causative body with respect to the axes of the mass concentration. The proposed method is particularly applicable to homogeneous, linear mass distributions, such as mineralization along faults and intruded sills or dikes. Inversions of synthetic and field data illustrate the versatility of the implemented algorithm.
Full Tensor Gradient of Simulated Gravity Data for Prospect Scale Delineation Hendra Grandis; Darharta Dahrin
Journal of Mathematical and Fundamental Sciences Vol. 46 No. 2 (2014)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2014.46.2.1

Abstract

Gravity gradiometry measurement allows imaging of anomalous sources in more detail than conventional gravity data. The availability of this new technique is limited to airborne gravity surveys using very specific instrumentation. In principle, the gravity gradients can be calculated from the vertical component of the gravity commonly measured in a ground-based gravity survey. We present a calculation of the full tensor gradient (FTG) of the gravity employing the Fourier transformation. The calculation was applied to synthetic data associated with a simple block model and also with a more realistic model. The latter corresponds to a 3D model in which a thin coal layer is embedded in a sedimentary environment. Our results show the utility of the FTG of the gravity for prospect scale delineation.
Quasi-2D Resistivity Model from Inversion of Vertical Electrical Sounding (VES) Data using Guided Random Search Algorithm Diky Irawan; Hendra Grandis; Prihadi Sumintadiredja
Journal of Mathematical and Fundamental Sciences Vol. 47 No. 3 (2015)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2015.47.3.5

Abstract

Vertical electrical sounding (VES) data are usually interpreted in terms of a 1D resistivity model using linearized inversion. The local approach of a non-linear inverse problem has fundamental limitations, i.e. the necessity of a starting model close to the solution and possible convergence to a local rather than a global minimum solution. We studied the application of a global search approach for non-linear inversion using the guided random search method to model VES data. A quasi-2D resistivity model can be created by stitching 1D models obtained from VES data along a profile. Both vertical and lateral resistivity variations are minimized to incorporate a 2D smoothness constraint. The proposed method was applied to invert synthetic VES data as well as field data from a sedimentary environment. Both synthetic and field data inversions resulted in models that correlated well with the known synthetic model and with the geology of the study area, respectively.
STUDI PERIODISITAS GEMPABUMI DI ZONA SUBDUKSI JAWA DENGAN METODE WAVELET Supriyanto Rohadi; Hendra Grandis; Mezak Arnold Ratag
Jurnal Meteorologi dan Geofisika Vol 8, No 2 (2007)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1926.986 KB) | DOI: 10.31172/jmg.v8i2.15

Abstract

Gempabumi merupakan proses titik (point process) yang berarti setiap kejadian merepresentasikan waktu dan ruang masing-masing. Oleh karena itu, analisis katalog gempabumi secara metodologi lebih sulit daripada analisis model deret waktu lain. Dalam pelaksanaanya aplikasi model deret waktu pada katalog gempabumi memerlukan perubahan sementara, misalnya kedalam bentuk akar kuadrat energi (strain energy release). Selain itu, dalam analisis deret waktu ini biasanya dihadapkan pada permasalahan resolusi frekuensi-waktu dimana dalam paper ini suatu metode multi resolusi wavelet digunakan untuk mensiasati permasalahan frekuensi-waktu. Transformasi Box-Cox, maksimum entropi, transformasi wavelet digunakan untuk mendeteksi periodisitas dari strain energy release gempabumi. Data yang digunakan adalah katalog gempabumi NEIC tahun 1973-2006 untuk Zona Subduksi Jawa dengan batas 6,5° LS - 12° LS dan 105° BT - 115° BT. Dari periodisitas energi dapat diketahui aktivitas gempabumi berdasarkan kedalaman dimana dominan siklus kegempaan adalah empat tahun, sedangkan berdasarkan zona wilayah memiliki siklus kegempaan dua hingga delapan tahunan.
STUDI POTENSI SEISMOTEKTONIK SEBAGAI PRECURSOR TINGKAT KEGEMPAAN DI WILAYAH SUMATERA Supriyanto Rohadi; Hendra Grandis; Mezak Arnold Ratag
Jurnal Meteorologi dan Geofisika Vol 9, No 2 (2008)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31172/jmg.v9i2.27

Abstract

Distribusi parameter seismotektonik dari relasi Gutenberg-Richter memegang peranan penting terkait dengan mitigasi  bencana gempabumi. Pada penelitian ini, analisis parameter seismotektonik menggunakan data gempabumi dari katalog BMG dan National Earthquake Information Center (NEIC), tahun 1973 - 2008, dengan batas 5,0° LS - 8° LU dan 92° BT -106° BT, yaitu meliputi wilayah Sumatera-Andaman. Dari analisis menggunakan softaware analisis ZMAP diperoleh variasi nilai-b berkisar antara 0.5 - 2.2, variasi nilai-a berkisar antara 4-12 sedangkan periode ulang gempabumi dengan magnitude 6,8 secara umum adalah berkisar antara 5-23 tahun. Gempa-gempa besar pada kurun waktu 2004 - 2008 diindikasikan terjadi di wilayah dengan parameter seisotektonikk yang relatif rendah.
Studi Variasi Spatial Seismisitas Zona Subduksi Jawa Supriyanto Rohadi; Hendra Grandis; Mezak Arnold Ratag
Jurnal Meteorologi dan Geofisika Vol 8, No 1 (2007)
Publisher : Pusat Penelitian dan Pengembangan BMKG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31172/jmg.v8i1.4

Abstract

Variasi nila-b dari relasi Gutenberg-Richter memegang peranan penting dalam sebagian besar model prakiraan gempabumi yang terkait dengan resiko bencana. Dari relasi Gutenberg-Richter yaitu log N = a - bM, slope dari hukum pangkat ini merupakan nilai-b yaitu sebuah paremeter tektonik yang menggambarkan ukuran distribusi dari gempabumi. Nilai-b yang tinggi mengindikasikan suatu proporsional yang relatif besar dari gempa-gempa kecil dan nilai-b yang rendah sebaliknya. Di dalam analisis kegempaan ini, kelengkapan katalog gempabumi merupakan faktor penting yang dapat mereduksi timbulnya deviasi linearitas. Katalog gempabumi NEIC dari tahun 1973-2006 dan katalog gempabumi BMG digunakan untuk analisis variasi nilai-a, nilai-b dan periode ulang gempabumi di Zona Subduksi Jawa dengan batas 6,5° LS - 12° LS dan 105° BT - 115° BT. Dari analisis katalog gempabumi di wilayah penelitian diperoleh variasi nilai-b berkisar antara 0,8-2,5, variasi nilai-a berkisar antara 6-12 sedangkan periode ulang gempabumi dengan magnitude 6 secara umum adalah sekitar 5 tahun.
Inversi Data Magnetotellurik 1-D Menggunakan Metoda Simulated Annealing Akhmad Syaripudin; Hendra Grandis
Indonesian Journal of Physics Vol 12 No 2 (2001): Vol. 12 No. 2, April 2001
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (92.19 KB)

Abstract

This paper describes a non-linear inversion method employing simulated annealing technique that imitates a thermodynamic process in which a substance is cooled down slowly to achieve an equilibrium state with a minimum energy. The method was applied to invert 1-D magnetotelluric data in which the model parameter is resistivity varied with depth. Model perturbations carried out in search for a minimum data misfit. Inversions of synthetic and field data showed satisfactory results. By considering equivalence problems, synthetic models were resolved relatively well with data misfit around 10%. Inversions of field data showed subsurface resistivity distribution that agrees well with the geological condition of the surveyed area.
Pemodelan Inversi Non-Linier dalam Geofisika Menggunakan Algoritma Rantai Markov Hendra Grandis
Indonesian Journal of Physics Vol 13 No 2 (2002): Vol. 13 No.2, April 2002
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (189.31 KB)

Abstract

In the frame of Bayesian inference, the inverse problem solution is described by posterior probability density function (PDF) in the model space. Estimation of PDF in a multidimensional space is based on a Markov chain having invariant probability identical to the posterior PDF of the model. Extensive exploration of the model space using a stochastic technique is expected to circumvent local minima. The Markov chain algorithm has been applied to non-linear inversion of magnetotelluric (MT) data using 1-D and 2-D models with satisfactory results, i.e. synthetic models have been recovered.
Co-Authors Accep Handyarso Akhmad Syaripudin Azhari, Na'ila Yuni Dahrin, Darharta Darharta Dahrin Darharta Dahrin Diky Irawan Djoko Santoso Edy Wijanarko Edy Wijanarko Handyarso, Accep Hidayat Hidayat Ilham Arisbaya Irawati, Selvi Misnia Mezak Arnold Ratag Nanang T. Puspito Prihadi Sumintadiredja Prihadi Sumintadireja Prihadi Sumintadireja Prihadi Sumintadireja Rahadinata, Tony Riski Ananda, Riski Saiful Akhyar Lubis Sumintadireja, Prihadi Sumintadireja, Prihadi Sungkono Sungkono Supriyanto Rohadi Wahyudi W. Parnadi Wahyudi W. Parnadi Wahyudi W. Parnadi Warsa warsa Warsa Warsa Warsa Warsa Willy Hermawan