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All Journal Journal of Science and Applicative Technology Seminar Nasional Teknologi Informasi Komunikasi dan Industri Jurnal Ilmiah Soulmath : Jurnal Edukasi Pendidikan Matematika BAREKENG: Jurnal Ilmu Matematika dan Terapan Jurnal Matematika UNAND AMMA : Jurnal Pengabdian Masyarakat Indonesian Journal of Applied Mathematics Transcendent Journal of Mathematics and Applications TeknoKreatif: Jurnal Pengabdian kepada Masyarakat Mathematical Sciences and Applications Journal Journal of Mathematics, Computation and Statistics (JMATHCOS)
Eristia Arfi
Program Studi Matematika, Fakultas Sains, Institut Teknologi Sumatera, Lampung Selatan, 35365
Humanities Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Mechanical Engineering Nursing Physics Transportation Other

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Penerapan Metode Multiple Scales untuk Masalah Galloping pada Mooring Cable FPSO Arfi, Eristia; Utomo, Tri
Jurnal Ilmiah Soulmath : Jurnal Edukasi Pendidikan Matematika Vol 7 No 1 (2019)
Publisher : Universitas Dr. Soetomo

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (604.879 KB) | DOI: 10.25139/smj.v7i1.1421

Abstract

In essence, all objects in the universe have a natural frequency and when an object get an external force same with their natural frequency a resonance phenomenon will occur. In this study will be examined how the dynamic behavior of the mooring cable type Catenary Anchor Leg Mooring (CALM) on the Floating Production Storage Offloading (FPSO) when it gets external force with a very small frequency but near to the natural frequency itself. In the case of transmission cable, the phenomenon that describe this event is called the Galloping Phenomenon. The mathematics model of CALM system with the very small frequency will be solved using Multiple Scales method. The equilibrium point obtained is in the form of a center (stable). For negative, the amplitude value will be positive when the phase is zero (in-phase), at this condition if the initial conditions are chosen close enough to the equilibrium point then the cable will periodically oscillate with a limited phase value. Then if the initial conditions are selected a little further from the point of equilibrium, the cable will oscillate with amplitude the initial is the maximum amplitude and the value added of the dependent phase against time.
Penerapan Metode Multiple Scales untuk Masalah Galloping pada DuaSpans Kabel Transmisi Eristia Arfi
Seminar Nasional Teknologi Informasi Komunikasi dan Industri 2015: SNTIKI 7
Publisher : UIN Sultan Syarif Kasim Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (492.896 KB)

Abstract

In this paper, galloping model is derived by using of Hooke's Law and Newton's Law. Furthermore galloping model is reduced in order to obtain a set of integro-differential equations. Analysis of system response observed with the assumption that the frequency of the external force is very close to the natural frequency of the system. Second-order expansion of analytic solutions for stationary problem from integro-differential equationsare determined using the method of multiple scales. Analysis of the behavior of the system to stability point and dynamic of solutions that depend on the parameter indicates that the initial conditions of the system affect the oscillation behavior of cable.Keywords: galloping, multiple scales, perturbation, resonace.
Hubungan antara Ketercapaian dan Keterkontrolan Sistem Diskrit Linier Eristia Arfi
Jurnal Matematika UNAND Vol 1, No 1 (2012)
Publisher : Jurusan Matematika FMIPA Universitas Andalas Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jmu.1.1.67-70.2012

Abstract

Tulisan ini membicarakan hubungan antara ketercapaian danketerkontrolan sistem linier diskrit linier. HUbungan ini dijelaskan den-gan kaidah-kaidah aljabar linier. Hasil akhir menunjukkan sistem terca-pai jika dan hanya jika sistem terkontrol.
The Delay Simulation on Hierarchical Structure for Semi-Double Track of Railway Line Using Max-Plus Algebra Tri Utomo; Eristia Arfi
Journal of Science and Applicative Technology Vol 2 No 1 (2019): ICoSITeR Special Edition
Publisher : Lembaga Penelitian dan Pengabdian Masyarakat (LPPM), Institut Teknologi Sumatera, Lampung Selatan, Lampung, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (335.852 KB) | DOI: 10.35472/281421

Abstract

The persistently inequality of development between major cities and surrounding areas caused the displacement process, that are transport of supplies or human itself (urbanization) or commonly known as the transportation. The government has set a number of policies to overcome transportation problems, for example construct a double track railway line. This study aimed to find an alternative solution to overcome the problems of transportation, especially railway line by optimizing of using single track railway line which is given the term semi-double track using Petri Nets and Max-Plus Algebra. In the previous research, a Max-Plus algebra model has been developed based on the hierarchical structure of semi-double track railway line. In this research, the model is simulated against the problem of delay.
Penerapan Manpower Planning (MPP) dan Full Time Equivalent (FTE) pada Bagian Produksi PT. Lampung Sukses Bersama (Lampung Banana Foster) Tia Riski Rahmadhani; Eristia Arfi
Mathematical Sciences and Applications Journal Vol. 4 No. 2 (2024): Mathematical Sciences and Applications Journal
Publisher : Department of Mathematics, Faculty of Science and Technology Universitas Jambi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/msa.v4i2.32291

Abstract

PT. Lampung Sukses Bersama, commonly known as Lampung Banana Foster, is a specialized retail establishment dedicated to promoting indigenous Nusantara products, particularly those hailing from the Lampung region. The core values of Lampung Banana Foster revolve around ensuring top-notch product quality, premium service, and a modern aesthetic. In line with its organizational strategy, it places significant emphasis on the importance of effective human resource management. Through empirical research, a noticeable misalignment between available human resources and actual production output has been uncovered. The research data, focuses on the production output of the production department from April to June 2020, coinciding with the emergence of the Covid-19 pandemic and its consequential impacts on business operations. Analysis of this dataset highlights a significant disparity between employee headcount and Full-Time Equivalent (FTE) value. Using the framework of Manpower Planning (MPP), the study reveals that shortages in employee numbers vary on a monthly basis. Consequently, we suggest that augmenting the workforce through new employee recruitment is necessary to ensure an equitable distribution of workload among all staff members. This finding underscores the importance of strategic human resource interventions to maintain operational efficiency and organizational resilience amidst changing circumstances.
Pelatihan Tes Potensi Skolastik (TPS) di SMA Al Huda Jati Agung, Lampung Selatan Mustika, Mira; Noor, Dear Michiko Mutiara; Arfi, Eristia; Muliawati, Triyana; Anggraini, Retno
TeknoKreatif: Jurnal Pengabdian kepada Masyarakat Vol 3 No 1 (2023): TEKNOKREATIF : Jurnal Pengabdian kepada Masyarakat
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LP2M), Institut Teknologi Sumatera, Lampung, Indonesia.

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35472/teknokreatif.v3i1.776

Abstract

Salah satu permasalahan calon mahasiswa yang mengikuti Ujian Tulis Berbasis Komputer (UTBK) yakni dihadapkan pada soal tes potensi skolastik (TPS) yang secara khusus tidak dipelajari selama sekolah. TPS merupakan ukuran referensi standar yang menggabungkan komponen kemampuan dan kecepatan. Hal ini pula yang dirasakan oleh siswa-siswa SMA Al Huda Jati Agung, Lampung Selatan. Di sisi lain, soal TPS memberikan kontribusi yang relatif besar dalam UTBK. Oleh sebab itu, diperlukan pelatihan TPS sebagai bentuk pengabdian masyarakat untuk meningkatkan kemampuan siswa dalam penalaran dan kemampuan umum lainnya. Pelatihan TPS dilaksanakan secara luring, sebanyak tiga kali. Dari evaluasi akhir, hasil pelatihan tes potensi skolastik (TPS) di SMA Al Huda Jati Agung yakni terjadi peningkatan jumlah siswa yang berhasil menjawab benar dibandingkan sebelum diberikan pelatihan.
Penerapan Algoritma K-Means Clustering dalam Memetakan Produktivitas Lokasi Perkebunan Nanas PT Great Giant Pineapple Fitriani, Anisa; Arfi, Eristia; Huda, Anwar
Journal of Mathematics, Computations and Statistics Vol. 7 No. 2 (2024): Volume 07 Nomor 02 (Oktober 2024)
Publisher : Jurusan Matematika FMIPA UNM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35580/jmathcos.v7i2.4200

Abstract

Abstrak. PT Great Giant Pineapple (GGP) ialah perusahaan nanas terbesar di Indonesia. PT GGP memiliki tiga Plantation Group (PG) yang berfokus pada nanas proses. Pada PG terdapat lokasi-lokasi yang memiliki luas serta produktivitas yang berbeda-beda. Tujuan penelitian ini adalah untuk mengklaster lokasi pada PG dengan menggunakan algoritma k-means clustering kemudian menganalisis strategi untuk setiap klaster. Dalam menentukan jumlah klaster optimal penulis menerapkan metode elbow dan metode silhouette coefficient. Dari penerapan kedua metode diperoleh jumlah klaster yang optimal ketika . Dengan menggunakan diperoleh anggota untuk masing-masing PG secara berturut-turut, anggota klaster 1 sebanyak 134 lokasi, 166 lokasi, dan 115 lokasi kemudian anggota klaster 2 sebanyak 41 lokasi, 49 lokasi, dan 79 lokasi. Klaster lokasi yang memiliki produktivitas tinggi terdapat di klaster 1 pada PG 1 dan PG 2 kemudian klaster 2 pada PG 3. Kelompok lokasi yang memiliki produktivitas rendah terdapat di klaster 2 pada PG 1 dan PG 2 kemudian klaster 1 pada PG 3. Analisis strategi untuk klaster rendah yakni dengan melakukan manajemen air, pengendalian hama, pemupukan yang lebih efektif serta pengontrolan waktu forcing secara berkala serta pengawasan supaya tidak terjadi pencurian pada klaster yang memiliki produktivitas tinggi. Kata Kunci: Algoritma K-Means, Metode Elbow, Metode Silhouette Coefficient, PT GGP
Analisis Efisiensi Proses Penentuan Harga Perkiraan Sendiri menggunakan Teori Antrian pada PTPN I Regional 7 Azzahra, Iqlima Dita; Arfi, Eristia
Transcendent Journal of Mathematics and Applications Vol 3, No 2 (2024)
Publisher : Syiah Kuala University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/tjoma.v3i2.41205

Abstract

This study aims to analyze the efficiency of the process for determining the Estimated Own Cost (HPS) by considering the number of incoming HPS packages and the average time taken to calculate HPS. The method used in this research is queueing theory with a FIFO (First In, First Out) queue discipline and a Multi-Channel Single-Phase (M/M/S) queueing model, utilizing historical data of incoming HPS packages from February to July 2024. The results of the analysis show that the queueing system at the HPS Subdivision of PTPN I Regional 7 has a utility factor of 2.198, indicating that the queueing system is overloaded. A utility rate greater than 1 signifies that the queueing system is not operating efficiently. This provides critical insights for PTPN I Regional 7 in designing more efficient HPS determination strategies based on the profile and needs of each work unit.
Teknologi Smart Conservation Untuk Identifikasi Spesies Mangrove Di Kawasan Ekowisata Cuku Nyinyi, Lampung Muliawati, Triyana; Lestari, Fuji; Alvionita Sitinjak, Mika; Arfi, Eristia; Gahana Cindi Alfian, Devia
AMMA : Jurnal Pengabdian Masyarakat Vol. 4 No. 1 : Februari (2025): AMMA : Jurnal Pengabdian Masyarakat
Publisher : CV. Multi Kreasi Media

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Mangroves are a type of forest ecosystem that grows in coastal areas along tropical and subtropical shores throughout Indonesia, particularly in Lampung Province. This ecosystem is found in regions influenced by tidal seawater. Mangroves consist of various species of trees, shrubs, and other plants that can survive in highly saline and muddy environments. Additionally, mangroves provide numerous benefits for environmental sustainability and human well-being. A healthy mangrove ecosystem contains diverse plant species with specific characteristics that help maintain ecological balance and ensure optimal ecological functions.Lampung Province has a mangrove ecotourism site located in Sidodadi Village, Teluk Pandan District, Pesawaran Regency, known as Cuku Nyinyi. Uniquely, Cuku Nyinyi is often used as a research and learning site for students, researchers, and the general public to study mangroves.One of the challenges faced by the ecotourism management team, the Bina Jaya Lestari Forest Farmers Group (KTH), is the difficulty in identifying and classifying mangrove species planted in the Cuku Nyinyi ecotourism area. Additionally, there is a lack of adequate information about mangroves, such as their age, anatomy, habitat, environmental adaptations, benefits, and other relevant details. To address this issue, researchers are developing an automatic identification system for mangrove species based on leaf morphology using a Convolutional Neural Network (CNN) approach. CNN is one of the most effective methods for pattern recognition in images and mangrove image processing. This technology is expected to be implemented in the form of a camera application that can automatically identify information from an image of mangrove leaf morphology captured in the Cuku Nyinyi ecotourism area.The Mangrove Camera Application provides new insights to KTH and the general public regarding the potential and importance of conserving natural resources.
MATHEMATICS MODEL OF COMPACT TUMOR TO ANALYZE THE EFFECT ANTIANGIOGENIC THERAPY Arfi, Eristia; Putri, Dwi Mutiara; Wibarani, Yeni Gede; Rizka, Nela
BAREKENG: Jurnal Ilmu Matematika dan Terapan Vol 18 No 3 (2024): BAREKENG: Journal of Mathematics and Its Application
Publisher : PATTIMURA UNIVERSITY

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/barekengvol18iss3pp1585-1594

Abstract

Based on their growth, tumors are classified into benign(compact) tumors and malignant (invasive) tumors. One of the treatments used for tumors is antiangiogenic therapy because this therapy has low toxicity. This study examines the effect of antiangiogenic therapy on compact tumors. The number of tumor cells changes over time are influenced by proliferation, death, and migration tumor cell. Antiangiogenic therapy can inhibit the process of angiogenesis which affect the dynamics of glucose flow. A lack of glucose flow will cause a decrease in tumor cell proliferation process which will decrease tumor growth rate. The finding suggests that maintaining glucose levels at or below a critical threshold is effective therapy.
Co-Authors Alvionita Sitinjak, Mika Azzahra, Iqlima Dita Fitriani, Anisa Fuji Lestari Gahana Cindi Alfian, Devia Huda, Anwar Muliawati Muliawati, Triyana Mustika, Mira Noor, Dear Michiko Mutiara Putri, Dwi Mutiara Retno Anggraini Rizka, Nela Sari, Shinta Puspita Tia Riski Rahmadhani Utomo, Tri Utomo, Tri Wibarani, Yeni Gede