Article Per Year (5 Year)
p-Index From 2021 - 2026
0.751
P-Index
This Author published in this journals
All Journal Inferensi Basis : Jurnal Ilmiah Matematika Al-Aqlu : Jurnal Matematika, Teknik dan Sains Diophantine Journal of Mathematics and Its Applications
Kurniawan, Andro
Department Of Mathematics, Faculty Of Information Technology, Batam Institute Of Technology, Batam, Indonesia
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Computer Science & IT Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Engineering Industrial & Manufacturing Engineering Mathematics Social Sciences

Published : 4 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 4 Documents
Search

 1 
Comparison of Robust Regression Methods: Least Trimmed Squares and Maximum Likelihood for Handling Outliers Kurniawan, Andro; Oktarina, Cinta Rizki; Sabarinsyah, Sabarinsyah
Diophantine Journal of Mathematics and Its Applications Vol. 4 No. 2 (2025): Vol. 4 No. 2 (2025)
Publisher : UNIB Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33369/diophantine.v4i2.46149

Abstract

This study investigates the determinants of per capita expenditure in 154 regencies and cities across Sumatra Island. The use of the Ordinary Least Squares method is deemed inappropriate due to violations of classical assumptions and the presence of outliers within the dataset. To address these issues, robust regression approaches are applied, specifically M-estimation and Least Trimmed Squares (LTS). The dependent variable in the analysis is per capita expenditure, while the explanatory variables include poverty line, human development index, average years of schooling, and expected years of schooling. The estimation procedures are performed using both raw and standardized data. The empirical results demonstrate that each independent variable significantly influences per capita expenditure under both robust estimation techniques. To determine the most reliable method, the residual standard error is used as the evaluation criterion. The outcomes indicate that the LTS estimator applied to standardized data provides the lowest error value, suggesting that it is the most suitable approach for estimating the regression parameters associated with per capita expenditure in Sumatra.
ANALISIS INTEGRAL FRAKSIONAL FUNGSI HIPERBOLIK: KASUS TANGEN DAN COTANGEN: Fractional Integral Analysis of Hyperbolic Function: The Case of Tangent and Cotangent Janan, Syifaul; Kurniawan, Andro
Al-Aqlu: Jurnal Matematika, Teknik dan Sains Vol. 4 No. 1 (2026): Januari 2026
Publisher : Yayasan Al-Amin Qalbu

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59896/aqlu.v4i1.539

Abstract

This study examines the Riemann-Liouville fractional integral for hyperbolic tangent and cotangent functions with order  using Maclaurin series division method and power function fractional integral theorem. Results show the fractional integral of hyperbolic tangent is expressed as a fractional power series with gamma function coefficients, while hyperbolic cotangent has a singular term . MATLAB visualization shows α variations produce different growth characteristics. Hyperbolic tangent is regular with odd function symmetry, while hyperbolic cotangent is singular around the origin. This research provides explicit formulas for fractional calculus applications
Representasi Integral Fraksional Fungsi Secan Hiperbolik dan Cosecan Hiperbolik Syifaul Janan; Didi Harlianto; Andro Kurniawan
Basis : Jurnal Ilmiah Matematika Vol. 5 No. 1 (2026): BASIS: Jurnal Ilmiah Matematika
Publisher : Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jhq2s746

Abstract

Penelitian ini mengkaji representasi integral fraksional Riemann–Liouville pada fungsi secan hiperbolik dan cosecan hiperbolik menggunakan pendekatan deret Maclaurin. Kebaruan penelitian ini terletak pada perolehan bentuk eksplisit integral fraksional kedua fungsi tersebut serta analisis peran singularitas terhadap validitas representasi analitis. Hasil analisis menunjukkan bahwa fungsi secan hiperbolik dapat direpresentasikan secara analitis melalui deret pangkat yang konvergen pada domain |t| < π/2 sehingga integral fraksionalnya konsisten dengan integral klasik. Sebaliknya, fungsi cosecan hiperbolik memiliki singularitas di titik asal yang membatasi representasi analitisnya hanya pada suku non-singular. Implikasi matematis dari hasil ini menunjukkan adanya keterbatasan pendekatan deret untuk fungsi bersingular. Simulasi numerik menggunakan Matlab mendukung hasil teoritis dan memperlihatkan kesesuaian perilaku integral fraksional pada kedua fungsi tersebut.
Modeling Industrial and Maritime Sector Effects on Economic Growth in Riau Island Using GWNR-P Spline Cinta Rizki Oktarina; Andro Kurniawan; Sandy Salomo Saruan; Putri Suci Aria; Winalia Agwil
Inferensi Vol 9 No 2 (2026)
Publisher : Department of Statistics ITS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j27213862.v9i2.10050

Abstract

Economic growth is an important indicator of regional development and is influenced by various socioeconomic factors. In the Riau Islands Province, the effects of the Labor Force Participation Rate (LFPR) and Capture Fishery Production Value on the Gross Regional Domestic Product (GRDP) percentage distribution may vary across districts and cities due to spatial heterogeneity and nonlinear relationships. Therefore, this study applies the GWNR-PSpline model to analyze these relationships. The optimal Penalized Spline model was obtained using knot points of 67.83 and 15.67 with a smoothing parameter of 50, as indicated by the minimum Generalized Cross Validation (GCV) value of 1245.917. Subsequently, the Manhattan distance and Bisquare kernel weighting scheme produced the minimum Cross Validation (CV) value of 64.51, indicating the lowest prediction error among the evaluated weighting combinations. The estimated local parameters varied across districts and cities, indicating spatial heterogeneity in the relationships between the explanatory variables and economic growth. Spatial analysis revealed that Natuna and Anambas Island exhibited stronger local effects than other regions. Furthermore, the local coefficients of determination ranged from 0.3944 to 0.8603, substantially exceeding the global P-Spline model (R2=0.158). These findings demonstrate that the GWNR-PSpline model effectively captures both nonlinear and spatially varying relationships.
Co-Authors Cinta Rizki Oktarina Cinta Rizki Oktarina Didi Harlianto Putri Suci Aria Sabarinsyah, Sabarinsyah Sandy Salomo Saruan Syifaul Janan Winalia Agwil