Article Per Year (5 Year)
p-Index From 2020 - 2025
0.659
P-Index
This Author published in this journals
All Journal Indonesian Physical Review Jurnal Hidrografi Indonesia Indonesian Journal of Statistics and Its Applications
Herho, Sandy
Unknown Affiliation
Computer Science & IT Earth & Planetary Sciences Education Mathematics Physics Other

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Perbandingan Data Pasang Surut, Arus, dan Angin dengan Prediksi pada Musim Peralihan Kedua di Laut Timor Tahun 2023: Comparison Between Tide, Current, and Wind Data with Prediction During Second Monsoon Transition in Timor Sea 2023 Dharma, Candrasa Surya; Rizki Khair, Deirus; Abimanyu, Alin; Fadhilah, Affan; Budi Sukoco, Nawanto; Arochim; Ronaldy, Tomy; Sugiyanto, Dedi; Setiyo Pranowo, Widodo; Herho, Sandy; Yusron, Ahmad; Alfahmi, Furqon; Fahim, Akhmad; Andika; Cahyono, Sigit
Jurnal Hidrografi Indonesia Vol 7 No 1 (2025): Jurnal hidrografi Indonesia
Publisher : Pusat Hidro-Oseanografi TNI Angkatan Laut

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62703/jhi.v7i1.156

Abstract

Laut Timor memiliki peran geostrategis yang sangat tinggi bagi negara Indonesia dan Australia. Latihan survey bersama perdana antara kedua negara diberi nama Coordinated Hydrography Survey Exercise (CHSE) diselenggarakan pada tahun 2023. CHSE dilaksanakan dengan menggerakkan kapal riset perang KRI Spica milik TNI-AL Indonesia dan HMS Leeuwin milik Royal Navy Australia, yang masing-masing melakukan survey hidro-oseanografi dan meteorologi di wilayah teritorialnya. Data arus dan angin dari hasil survey kemudian dibandingkan dengan data sekunder Copernicus, sedangkan untuk data angin terhadap prediksi BMKG. Tidak terjadi kemunculan siklon selama kegiatan latihan, Kondisi batimetri di Perairan Laut Timor dalam penelitian ini bervariasi dari kedalaman 16,8 s.d. 218,7meter, dengan luas area sebesar 302NM2. Sirkulasi arus diukur menggunakan underway vessel mounted ADCP hingga kedalaman 40 meter, dengan interval rekaman data bervariasi antara 1 menit sampai 45 menit. Selain itu dipasang pula fix mooring current meter pada satu stasiun tetap. Hasil pengukuran menunjukkan pola sirkulasi arus dominan bergerak antara Timur Laut dan Barat Daya, dengan pola keseragaman secara vertikal. Kecepatan arus maksimum 0,273m/s, dan minimum 0,005m/s ke arah Barat Daya. Hal ini sejalan dengan data klimatologis yang menunjukkan pola arus dominan menuju ke Barat Daya dengan kecepatan 0,1 – 0,5 knot. Pola sirkulasi tersebut menunjukkan bahwa Laut Timor dipengaruhi oleh Indonesian Throughflow (ITF), dengan 30% dari variabilitasnya dipengaruhi oleh siklus musiman dari angin monsoon. Laut Timor, pada lapisan kolom airnya, mendapatkan pengaruh lokal dari gelombang kelvin pada kedalaman di bawah 600 meter, dilapisan yang lebih dangkal, arus dibangkitkan oleh kopling siklus gaya pasang surut diurnal dari Laut Banda, semidiurnal dari Samudera Hindia, dan siklus musiman dari gaya angin monsoon.
COMPARING SCIENTIFIC COMPUTING ENVIRONMENTS FOR SIMULATING 2D NON-BUOYANT FLUID PARCEL TRAJECTORY UNDER INERTIAL OSCILLATION: A PRELIMINARY EDUCATIONAL STUDY Herho, Sandy; Anwar, Iwan; Herho, Katarina; Dharma, Candrasa; Irawan, Dasapta
Indonesian Physical Review Vol. 7 No. 3 (2024)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v7i3.335

Abstract

This study presents a preliminary numerical investigation of the two-dimensional trajectory of a non-buoyant fluid parcel subjected to inertial oscillations and abrupt external forcing events. The simulations were implemented using Python, GNU Octave, R, Julia, and Fortran open-source scientific computing environments. By running 1,000 iterations in each environment, we evaluated the computational performance of these languages in tackling this idealized problem. The results, visualized through static plots and animation, validate the numerical model's ability to represent the fundamental physics governing fluid motion. Statistical analysis using the Kruskal-Wallis test and Dunn's post-hoc test with Bonferroni correction revealed that Fortran exhibits significantly faster execution times than other environments. However, the choice of programming language should also consider factors such as coding expertise, library availability, and scalability requirements. This study focuses on the performance of scientific computing environments within each language rather than the languages themselves. The observed execution times should be interpreted in the context of the specific environments used, as they often leverage optimized libraries written in lower-level languages. Despite the limitations of this work, such as the simplified 2D model and the use of a single hardware configuration, this study provides valuable insights into selecting appropriate computational tools. It contributes to educational resources for teaching idealized fluid dynamics models. Future studies could explore more complex scenarios, a more comprehensive range of programming environments, and the impact of different numerical schemes and physical parameterizations.
On the Statistical Learning Analysis of Rain Gauge Data over the Natuna Islands Herho, Sandy; Fajary, Faiz; Irawan, Dasapta
Indonesian Journal of Statistics and Applications Vol 6 No 2 (2022)
Publisher : Statistics and Data Science Program Study, IPB University, IPB University, in collaboration with the Forum Pendidikan Tinggi Statistika Indonesia (FORSTAT) and the Ikatan Statistisi Indonesia (ISI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/ijsa.v6i2p347-357

Abstract

Located in the middle of South China Sea with distance more than 700 m to nearby main lands, Natuna Islands settings remain the focus of scientific conversation. This article presents state-of-the-art statistical learning methods for analyzing rain gauge data over the Natuna Islands. By using shape preserving piecewise cubic interpolation, we managed to interpolate 671 null values from the daily precipitation data. Dominant periodicity analysis of daily precipitation signals using Lomb-Scargle Power Spectral Density shows annual, intraseasonal, and interannual precipitation patterns over the Natuna Islands. Unsupervised anomaly analysis using the Isolation Forest algorithm shows there are 146 anomaly daily precipitation data points. We also conducted an experiment to predict the accumulation of monthly precipitation over the Natuna Islands using the Bayesian structural time series algorithm. The results show that the local linear trend with seasonality model is able to model the value of accumulated monthly precipitation for a twelve-month prediction horizon. The work presented here has profound implications for rainfall observations in this area.
Co-Authors ABIMANYU, ALIN Ahmad Yusron, Ahmad Alfahmi, Furqon ANDIKA Anwar, Iwan Arochim Budi Sukoco, Nawanto Cahyono, Sigit Dharma, Candrasa Dharma, Candrasa Surya Fadhilah, Affan Fahim, Akhmad Fajary, Faiz Herho, Katarina Irawan, Dasapta Rizki Khair, Deirus Ronaldy, Tomy Sugiyanto, Dedi Widodo S Pranowo