https://journal.itera.ac.id/index.php/indojam/issue/feedIndonesian Journal of Applied Mathematics2026-10-31T16:36:36+00:00Gusrian Putra, S.Si., M.Si.[email protected]Open Journal Systems<p><img src="/public/site/images/bprasetyo/Cover_Gabung_22.jpg" alt=""></p> <p>Indonesian Journal of Applied Mathematics is a scientific publication media that publishes articles from the results of research or studies in the field of applied mathematics, focusing on Computational Mathematics, Optimation, Actuarial, Statistics, Numerical Modelling, Mathematical Physics, Financial Mathematics and Combinatorics. This journal publish twice in a year August and December. <strong>Indonesian Journal of Applied Mathematics</strong> is fully supported by Mathematics Study Program and Actuarial Study Program of Institut Teknologi Sumatera. IndoJAM publishes article twice a year on April and October.</p>https://journal.itera.ac.id/index.php/indojam/article/view/2747Perhitungan Cadangan Premi Asuransi Jiwa Berjangka Menggunakan Metode Premium Sufficiency Dan Metode Full Preliminary Term Dengan Tingkat Suku Bunga Hull White 2026-10-31T13:46:55+00:00Cindy Faradilla[email protected]Tiara Yulita[email protected]Amalia Listiani[email protected]<p class="Abstract">In daily life, humans engage in various activities that can pose risks, such as death, accidents, and financial risks. Therefore, humans need to prepare themselves to face unexpected risks to avoid significant losses. Insurance is an effort that can be done to obtain protection from risks. Insurance companies, as the insurer, are required to set aside premium reserves to ensure the availability of funds to pay the insured's benefits in the event of a future claim. In this study, the Premium Sufficiency method and the Full Preliminary Term method were used to calculate premium reserves. Reserve calculations take place over a fairly long period, so it is necessary to consider interest rate fluctuations that occur due to economic activity. To model these fluctuations, the Hull-White interest rate model can be used. The purpose of this study is to determine the comparative analysis of the premium reserve values from the two methods calculated using the Hull-White interest rate model. Based on the results obtained, the premium reserve value using the Premium Sufficiency method is greater than the Full Preliminary Term method. This is because the Full Preliminary Term method assumes that the first year's reserve is zero because it is used to cover costs<span lang="EN-US">.</span></p>2026-10-31T09:51:46+00:00Copyright (c) 2026 Indonesian Journal of Applied Mathematicshttps://journal.itera.ac.id/index.php/indojam/article/view/2992Elliptic Curve Digital Signature Algorithm dan Secure Hash Algorithm-256 untuk Autentikasi Transaksi Berbasis PIN pada Aplikasi Mobile Banking2026-10-31T14:03:07+00:00Alvina Hardiyanti[email protected]Siti Fatimah[email protected]Rini Marwati[email protected]<p>Conventional security models in mobile banking applications remain vulnerable to the theft of Personal Identification Numbers (PINs) transmitted to the server. This research integrates the Elliptic Curve Digital Signature Algorithm (ECDSA) and Secure Hash Algorithm-256 (SHA-256) for more secure transaction authentication in mobile banking applications. The PIN is no longer sent to the server, but rather combined with the username and device ID to generate a private key using the Password-Based Key Derivation Function 2 (PBKDF2). The application prototype was built using the Python programming language with a client-server architecture. The client performs hashing on the transaction data using SHA-256 and signs it with ECDSA, while the server verifies the signature. The application's performance evaluation was conducted through three testing scenarios, namely normal transactions, access from unregistered devices, and transaction nominal manipulation. The test results indicate that the application is capable of executing signing and verification accurately across all scenarios. This proves that the applied method is effective in ensuring authentication security, data integrity, and non-repudiation in mobile banking transactions.<br>Keywords: Authentication, Digital Signature, ECDSA, Mobile Banking, PBKDF2, PIN, SHA-256.<br><br></p> <p>Abstrak:</p> <p>Model keamanan konvensional pada aplikasi mobile banking masih rentan terhadap pencurian Personal Identification Number (PIN) yang dikirimkan ke server. Penelitian ini mengintegrasikan Elliptic Curve Digital Signature Algorithm (ECDSA) dan Secure Hash Algorithm-256 (SHA-256) untuk autentikasi transaksi yang lebih aman pada aplikasi mobile banking. PIN tidak lagi dikirimkan ke server, melainkan digabungkan bersama username dan device ID untuk membangkitkan kunci privat menggunakan Password-Based Key Derivation Function 2 (PBKDF2). Prototipe aplikasi dibangun menggunakan bahasa pemrograman Python dengan arsitektur klien-server. Klien melakukan hashing data transaksi menggunakan SHA-256 dan menandatanganinya dengan ECDSA, sementara server memverifikasi tanda tangan tersebut. Evaluasi kinerja aplikasi dilakukan melalui tiga skenario pengujian, yaitu transaksi normal, akses dari perangkat tidak terdaftar, dan manipulasi nominal transaksi. Hasil pengujian menunjukkan bahwa aplikasi mampu mengeksekusi penandatanganan dan verifikasi secara akurat pada seluruh skenario. Hal ini membuktikan bahwa metode yang digunakan efektif dalam menjamin keamanan autentikasi, integritas data, dan nirsangkal pada transaksi mobile banking.</p> <p> </p>2026-10-31T00:00:00+00:00Copyright (c) 2026 Indonesian Journal of Applied Mathematicshttps://journal.itera.ac.id/index.php/indojam/article/view/2993Kontrol Optimal pada Model Predator–Prey dengan Respons Fungsional Holling Tipe II untuk Pengendalian Hama Berbasis Predator Alami2026-10-31T14:13:35+00:00Dewi Suhika[email protected]Nurul Indah Safitri[email protected]Nela Rizka[email protected]<p>Hama tanaman merupakan salah satu faktor utama yang dapat menurunkan produktivitas pertanian, sehingga diperlukan strategi pengendalian yang efektif, terukur, dan tetap mempertimbangkan keberlanjutan ekosistem. Penggunaan pengendalian kimia secara berlebihan dapat memberikan dampak negatif terhadap lingkungan dan organisme bukan sasaran, termasuk predator alami. Oleh karena itu, diperlukan pendekatan pengendalian yang mampu menekan populasi hama sekaligus menjaga keberadaan predator alami dalam sistem. Penelitian ini membahas model kontrol optimal pada dinamika interaksi hama dan predator alami dengan dua strategi pengendalian, yaitu pengendalian hama dan pelepasan predator alami. Model yang digunakan berbentuk sistem predator-prey dengan respons fungsional Holling tipe II. Fungsi tujuan dirancang untuk meminimumkan kepadatan hama, biaya pengendalian hama, biaya pelepasan predator alami, serta penalti terminal terhadap populasi hama pada akhir waktu simulasi. Prinsip Maksimum Pontryagin digunakan untuk memperoleh sistem optimalitas yang terdiri atas sistem <em>state</em>, sistem adjoint, syarat transversal, dan karakterisasi kontrol optimal. Selanjutnya, solusi numerik diperoleh menggunakan metode forward-backward sweep. Hasil simulasi menunjukkan bahwa penerapan dua kontrol optimal mampu menekan kepadatan hama secara signifikan. Pada akhir simulasi, kepadatan hama tanpa kontrol sebesar , sedangkan dengan dua kontrol optimal turun menjadi , atau mengalami penurunan sekitar . Selain itu, kepadatan predator alami dengan kontrol tetap bernilai positif sebesar , sehingga predator alami masih dapat dipertahankan dalam sistem. Nilai fungsi objektif juga menurun dari tanpa kontrol menjadi dengan kontrol. Dengan demikian, kombinasi pengendalian hama dan pelepasan predator alami efektif dalam menekan populasi hama dengan tetap mempertimbangkan biaya kontrol dan keberlanjutan predator alami.</p>2026-10-31T14:13:35+00:00Copyright (c) 2026 Indonesian Journal of Applied Mathematicshttps://journal.itera.ac.id/index.php/indojam/article/view/3001PREDIKSI BANYAK HARI HUJAN DI KOTA JAMBI MENGGUNAKAN ALGORITMA RANDOM FOREST REGRESSION BERBASIS DATA IKLIM2026-10-31T14:36:36+00:00Ferdinand Manurung[email protected]Sherli Yurinanda[email protected]Sarmada[email protected]<p>Banyak hari hujan merupakan salah satu indikator klimatologi penting yang memengaruhi sektor pertanian, pengelolaan sumber daya air, serta mitigasi bencana hidrometeorologi. Variasi banyak hari hujan dipengaruhi oleh beberapa faktor klimatologi, antara lain curah hujan, kelembapan udara, suhu udara, dan LPM, yang memiliki hubungan kompleks dan nonlinier. Penelitian ini bertujuan untuk memprediksi banyak hari hujan di Kota Jambi menggunakan metode Random Forest Regression serta mengidentifikasi faktor-faktor klimatologi yang paling berpengaruh. Penelitian ini menggunakan data sekunder bulanan yang diperoleh dari Stasiun Meteorologi Kelas I Sultan Thaha Jambi pada periode 2018 hingga 2025 sebanyak 96 pengamatan. Metodologi penelitian meliputi eksplorasi data, penentuan hyperparameter menggunakan Grid Search dengan 5-Fold Cross Validation, pembangunan model Random Forest Regression, evaluasi model menggunakan RMSE dan R², serta analisis feature importance. Hasil penelitian menunjukkan bahwa model memperoleh nilai RMSE sebesar 2,769 dan R² sebesar 0,695 pada data testing, yang mengindikasikan bahwa model mampu menjelaskan 69,5% variasi banyak hari hujan dengan rata-rata kesalahan prediksi sekitar tiga hari. Analisis feature importance menunjukkan bahwa curah hujan merupakan faktor yang paling berpengaruh, diikuti oleh LPM, kelembapan udara, dan suhu udara. Temuan ini menunjukkan efektivitas Random Forest Regression dalam memodelkan hubungan klimatologi yang nonlinier serta memprediksi banyak hari hujan di Kota Jambi.</p>2026-10-31T14:36:36+00:00Copyright (c) 2026 Indonesian Journal of Applied Mathematicshttps://journal.itera.ac.id/index.php/indojam/article/view/3029Evidence-First Data Management for Trustworthy AI: A Database Architecture for Ecological Tourism Intelligence2026-10-31T16:36:36+00:00Ardika Satria[email protected]Mika Alvionita S[email protected]Ira Safitri[email protected]Febri Dwi Irawati[email protected]<p><span lang="EN-GB">Multi-source operational data, in this study, tourism-village records from Indonesia’s national JADESTA portal is rarely stored with enough structure to support trustworthy artificial-intelligence consumption: values are overwritten, provenance is recorded per record rather than per attribute, and unverified data reaches downstream consumers indistinguishably from verified data. This paper proposes P1, a database-driven data management architecture that stores every attribute value as a <em>claim</em> carrying source, time, and confidence; accumulates corrections as new, non-destructive <em>evidence events</em>; computes a confidence score per claim; and enforces a <em>policy gate</em> before any value is published to an AI-facing <em>semantic view</em>. P1 is compared against two realistic baselines B0, an overwrite ETL pipeline, and B1, a record-level lineage pipeline on the full 21,461-record JADESTA corpus under five injected synthetic failure scenarios (duplicate, conflict, missing, late update, and schema drift), and against a 304-pair manually labelled gold sample (Cohen’s <em>κ</em> = 0.742) for entity-resolution quality. The results show that P1’s provenance is not merely nominally complete like B1’s but substantively so: B1 reports a provenance coverage of 1.000 yet a provenance precision of only 0.471, quantifying a "phantom provenance" gap that attribute-level claims avoid by construction. P1’s entity resolution achieves an F1 of 0.849 (precision 0.900, recall 0.804) on the merge decision, and its conservative refusal to auto-merge ambiguous record pairs is empirically justified in 78.6 per cent of the labelled pairs it deferred. P1’s policy gate reduces unverified data reaching the semantic view from 1.000 in both baselines, by construction, to 0.000. These gains carry a scale-dependent performance cost: P1 is approximately 151 times slower than B0 at 500 records, growing to approximately 5,447 times slower on the full corpus, traced to the quadratic per-block complexity of its entity resolution a concrete direction for future optimisation. The evaluation is scoped explicitly: entity-resolution quality claims cover the merge decision only, not the reject threshold, and policy-gate claims cover the gating mechanism only, not the calibration of the confidence function against independent ground truth. The data model, the confidence and policy contracts, and the evaluation protocol are architecture- and technology-independent, and the experiment code, gold sample, and raw results are released as a reproducible benchmark.</span></p>2026-10-31T16:36:36+00:00Copyright (c) 2026 Indonesian Journal of Applied Mathematics