Article Per Year (5 Year)
p-Index From 2021 - 2026
3.816
P-Index
This Author published in this journals
All Journal ComEngApp : Computer Engineering and Applications Journal Jurnal Ilmu Komputer dan Informasi ILMU KELAUTAN: Indonesian Journal of Marine Sciences POSITRON Jurnal Neutrino : jurnal fisika dan aplikasinya Jurnal Pendidikan Fisika Indonesia Jurnal IPTEK Jurnal Hukum IUS QUIA IUSTUM Journal of Mechanical Engineering Science and Technology Jurnal RESTI (Rekayasa Sistem dan Teknologi Informasi) JIPF (Jurnal Ilmu Pendidikan Fisika) Jurnal Filsafat Spektra: Jurnal Fisika dan Aplikasinya JRST (Jurnal Riset Sains dan Teknologi) Journal of Physics and Its Applications Eksakta : Berkala Ilmiah Bidang MIPA Kappa Journal Journal of Environmental Science and Sustainable Development Jurnal Ilmu Pendidikan Dasar Indonesia Jurnal Natural Time in Physics: Journal for Theoretical, Instrumentation, Material-Molecular, and Education Physics Aliansi : Jurnal Politik, Keamanan Dan Hubungan Internasional Security Intelligence Terrorism Journal (SITJ) Scientific Contributions Oil and Gas
Siagian, Ruben Cornelius
Unknown Affiliation
Aerospace Engineering Agriculture, Biological Sciences & Forestry Arts Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Neuroscience Physics Social Sciences Other

Published : 25 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 25 Documents
Search

 1   2   3 
Relativistic Effects and Stellar Properties in Hipparcos Binary Stars, White Dwarfs, and Neutron Stars Yasin, Verdi; Sahroni, Taufik Roni; Siagian, Ruben Cornelius; Mardiyati, Sri; Pramarta, Pandhu; Wujarso, Riyanto; Saprudin, Saprudin; Alfin, Edward
Journal of Physics and Its Applications Vol 8, No 1 (2026): February 2026
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v8i1.29176

Abstract

The research analyzes astrophysical phenomena in binary stars, fast stars, white dwarfs, and neutron stars, taking relativistic effects into account using Hipparcos catalog data. The objectives are to evaluate the relativistic precession of binary stars, the Shapiro delay due to the supermassive black hole Sgr A, the relativistic correction of neutron star luminosity, the distribution of star populations in the Hertzsprung–Russell diagram, the gravitational redshift of white dwarfs, and the characteristics of stars with extreme transverse velocities. Data from 10,726 binary star systems and 602 white dwarfs were processed numerically using R for data manipulation, visualization, and statistical calculations. The results show that relativistic precession in binary stars is generally small, increases in narrow orbits, and follows a power law with respect to the semi-major axis (exponent −0.453). Shapiro delay varies with projected distance to Sgr A, with most stars experiencing small delays, while some experience delays of up to 310 seconds. Neutron star luminosity shows a relativistic correction of ~0.03%, consistent with gravitational redshift and time dilation. The Hertzsprung–Russell diagram shows a clear separation between giants, main sequence stars, and white dwarfs, with a significant linear relationship between absolute magnitude and color index (B−V). The gravitational redshift of white dwarfs is controlled by radius (exponent −1.0001), while stars with extreme velocities form a heterogeneous and evenly distributed population. In conclusion, Hipparcos data support general relativity predictions and enable quantitative evaluation of stellar physics and evolution. Research novelties include systematic measurements of relativistic precession, Shapiro delay, neutron star luminosity corrections, white dwarf radius–redshift relationships, and kinematic characteristics of extreme stars.
BLACK HOLE EVAPORATION AND THE RECONSTRUCTION OF THE ONTOLOGY OF PHYSICAL REALITY FROM A RELATIONAL AND COSMOLOGICAL EMERGENCE PERSPECTIVE Ariefka, Reza; Sahroni, Taufik Roni; Siagian, Ruben Cornelius; Nurahman, Arip; Raisal, Abu Yazid
Jurnal Filsafat "WISDOM" Vol 36, No 1 (2026): (Article in Press)
Publisher : Fakultas Filsafat, Universitas Gadjah Mada Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jf.108753

Abstract

This research is motivated by developments in modern physics which show that black holes, which in classical general relativity are considered the most stable and permanent entities in the universe, actually undergo evaporation through Hawking radiation. This phenomenon has profound philosophical implications regarding the nature of physical existence, the status of information, the structure of space-time, and the direction of cosmological time. This study aims to analyze the ontological and epistemological implications of black hole evaporation in the context of micro-macro relationships, relational ontology, and the concept of time as an emergent phenomenon. This study uses a qualitative method based on literature review and conceptual analysis by integrating the perspectives of theoretical physics, philosophy of science, and modern cosmology. The results of this study show that black hole evaporation confirms that there are no physical entities that are absolute and permanent. Physical existence is more accurately understood as a relational phenomenon that depends on the interaction between space-time geometry, quantum fluctuations, and cosmic thermodynamic processes. Furthermore, the black hole information paradox can be understood as a limitation of human epistemological description, rather than an ontological loss of physical reality. This research also confirms that the direction of time is a consequence of the emergence of increased entropy in the universe. The novelty of this research lies in the integration of the phenomenon of black hole evaporation with a structural-relational ontological approach to explain physical reality as a dynamic and emergent process.
Do Surges in Civil Mobilization Serve as Early Warnings for Political Conflict? Rajagukguk, Michael Haratua; Siagian, Ruben Cornelius
Security Intelligence Terrorism Journal (SITJ) Vol. 3 No. 1 (2026)
Publisher : Pusat Studi Politik dan Kebijakan Strategis Indonesia (POLKASI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.70710/sitj.v3i1.87

Abstract

Political conflict and mass violence are major threats to security stability, especially in developing countries such as Indonesia. Civil mobilization through demonstrations is often considered an expression of social dissatisfaction, but its role as an early indicator of political violence escalation has not been analyzed quantitatively across countries and time. This study aims to explore the temporal relationship between an increase in demonstrations, the escalation of political violence, and the number of fatalities, as well as to develop an Early Warning Index as a counterintelligence tool. Using cross-country ACLED panel data from 1997 to 2026, the study applies a fixed effects model with one and two period lags, logarithmic transformation, and Granger causality tests to assess temporal causal relationships. The results show that a surge in demonstrations in the previous period significantly predicts an increase in political violence (coefficient = 0.592, t = 11.62, p < 0.001) and fatalities (coefficient = 0.475, t = 6.90, p < 0.001). The Granger causality test confirmed that demonstrations systematically led to an escalation in violence and fatalities. The Early Warning Index shows significant variations in risk, with maximum values indicating high social pressure that can serve as an early signal of conflict escalation. These findings fill a gap in quantitative research on the role of demonstrations as a leading indicator of political conflict. The index provides counterintelligence decision makers with an analytical tool for proactively detecting the risk of destabilization, particularly in the pre-election period or when sensitive identity-based issues arise.
Evaluating Global Oil Data Reporting Consistency and Stability with Insights from Indonesia Taufik Roni Sahroni; Lulut Alfaris; Siagian, Ruben Cornelius; Andri Wahyudi; Anas Noor Firdaus; Ukta Indra Nyuswantoro
Scientific Contributions Oil and Gas Vol 49 No 1 (2026)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/scog.v49i1.2010

Abstract

Transparent and consistent oil data reporting is a critical component of global energy governance and market stability. This study evaluates the consistency, stability, and overall quality of global oil data reporting from 2002 to 2025 using the dataset of the Joint Organizations Data Initiative (JODI), with Indonesia employed as a regional reference case. The principal indicators applied include the Index of Reporting Consistency (IRC), the Reporting Volatility Index (RVI), and the Oil Data Availability Index (ODAI). Countries are classified according to market role (producer or importer), economic grouping, and geographical region. The analysis further incorporates K-means clustering and structural change detection to assess temporal stability and responsiveness to major global shocks. The findings reveal substantial variation in reporting performance across countries. Nations exhibiting high IRC values and low RVI scores generally possess more mature institutional and statistical capacities, whereas those with low IRC scores tend to face governance or data management constraints. Oil-producing countries typically demonstrate higher ODAI values but display greater vulnerability to systemic crises, while importing countries show relatively more stable reporting patterns. Major global shocks in 2008, 2014, 2020, and 2022 exerted asymmetric impacts on producers and importers, highlighting structural vulnerabilities within the global energy reporting system. Indonesia demonstrates consistently strong reporting performance, with an ODAI value of 0.944, exceeding the averages of ASEAN (0.889) and OPEC (0.829). The country records a non-reporting rate of only 5.6% and a maximum non-reporting duration of ten months. This study addresses a gap in long-term, shock-sensitive analyses and introduces an integrated framework combining IRC, RVI, and ODAI as a novel approach for assessing oil data reporting quality. The findings provide a foundation for strengthening institutional capacity, enhancing regional coordination, and developing crisis-resilient reporting systems, while positioning ODAI as a practical indicator for evaluating energy governance and policy transparency.
Numerical Analysis of Metric Perturbations, Spacetime Curvature, and Gravitational Wave Polarizations in Linearized General Relativity Using the Finite Difference Method Ariefka, Reza; Siagian, Ruben Cornelius; Sahroni, Taufik Roni; Nurahman, Arip
POSITRON Vol 16, No 1 (2026): Vol. 16 No. 1 Edition
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam, Univetsitas Tanjungpura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/positron.v16i1.92372

Abstract

The general theory of relativity states that small perturbations in the spacetime metric in a weak gravitational field can be treated as perturbations propagating on the Minkowski background. Although the analytical formulation of Einstein's linear equations has been well developed, numerical studies that integrate local metric perturbations, the curvature structure of space-time through the Ricci tensor, the dynamics of gravitational wave polarization, and reduction to Newton's law of gravity in a two-dimensional domain are still limited. This research aims to numerically analyze the behavior of metric perturbations and space-time curvature in the framework of linear general relativity and verify its consistency with gravitational wave theory and Newtonian gravity at weak field and low velocity limits. The study is limited to a linearized approach, two-dimensional flat spacetime, harmonic and transverse–traceless gauge conditions, and ideal sources in the form of Gaussian perturbations and source-free waves. The methods used include the theoretical formulation of linearized general relativity and the Finite Difference Method (FDM) numerical approach to discretize the Laplace operator and wave equation with the FTCS scheme. The results show that Gaussian perturbations produce highly localized curvature with a global Ricci tensor contribution approaching zero. Gravitational wave simulations show the dominance of energy in polarization (h_+)\ over (h_\times), as well as numerical verification of the relationship (h_{00}=-2\phi), which confirms the reduction of general relativity to Newton's laws. This research fills a research gap by integrating metric analysis, curvature, and gravitational waves into a single consistent numerical framework. The novelty of this research lies in Gaussian modeling and integrated FDM-based numerical analysis as a conceptual bridge between general relativity and classical mechanics.
Co-Authors Abu Yazid Raisal Alatif, Yahya Halim Aldi Cahya Muhammad Andri Wahyudi Ariefka, Reza Aunzo, Jr., Rodulfo T. Bayu Dwi Anggono Budiman Nasution Dominikus Rato Edward Alfin Fadhilah, Dimas Imam Firdaus, Anas Noor Goldbert Harmuda Duva Sinaga Harahap, Veryyon Hassan, Rohana I Gede Widhiana Suarda Isnan, M Abdurrahman Ridwan Jaya, Pratama Jubaidah, Jubaidah Karim, Mohammad Alfin Kasim, Mohd Shahir Laeiq, Nazish Lubis, Putri Rahmadani Lulut Alfaris Malun, Nicholaus Ola Muhlis, Dasep Nasution, Habibi Azka Nurahman, Arip Nyuswantoro, Ukta Indra Nyuswantoro, Ukta Indra Nyuswantoro Pandara, Dolfie Paulus Pramarta, Pandhu Pribadi, Pandu Purwanto, Romdhon Putra, Steinly Suwanto Rahdiana, Nana Rajagukguk, Michael Haratua Rancak, Gendewa Tunas Rionaldy, Rizqy Sahroni, Taufik Roni Sahroni, Taufik Roni, Mr. Saprudin Saprudin, Saprudin Silalahi, Christeven Simamora, Ursulla Duti Oktria Sinaga, Mardame Pangihutan Sri Mardiyati Suhara, Ade Taufik Roni Sahroni Ukta Indra Nyuswantoro Wardana, Febriansyah Wibowo, Arnowo Hari Wibowo, Firdaus Andi Wibowo, Rizky Tri winsyahputra Ritonga Wujarso, Riyanto Yasin, Verdi Yulianto, Tomi