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Kubik
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Articles 131 Documents
On the Forgotten Index and Jacobson Graphs Associated with Integer Rings Modulo n Jauhari, Mohammad Nafie; Jannah, Shahnaz Latifatul; Turmudi, Turmudi; Nisfulaila, Intan
KUBIK Vol 9 No 2 (2024): KUBIK: Jurnal Publikasi Ilmiah Matematika
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v9i2.39585

Abstract

This paper investigates the connections between the Jacobson graph and the algebraic properties of rings through the analysis of the Jacobson graph of the ring \mathbb{Z}_{3p}, where p is a prime number greater than 3. The Jacobson graph of a commutative ring R is constructed by taking the elements of R, excluding its Jacobson Radical, as vertices, and connecting two distinct vertices if 1 minus their product is not a unit in R. The F-Index is utilized to capture and represent the structural properties of the ring through its associated graph. A detailed examination of the Jacobson Radical, maximal ideals, and vertex degrees in \mathbb{Z}_{3p} leads to the calculation of the F-Index, providing insights into the graph’s connectivity and underlying algebraic structure. This study contributes to the intersection of algebra and graph theory, offering a foundation for further research into more complex algebraic structures.
Analisis Pola Konvergensi Transpor Kelembapan Udara di Indonesia Bagian Barat Menggunakan K-Means dengan Pembobotan Statistik dan Hierarchical Shape-Based Clustering Pratiwi, Asri; Azis, Tukhfatur Rizmah; Fitrianto, Anwar; Erfiani, Erfiani; Jumansyah, L.M. Risman Dwi
KUBIK Vol 9 No 2 (2024): KUBIK: Jurnal Publikasi Ilmiah Matematika
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v9i2.39753

Abstract

This study analyzes the convergence patterns of Vertically Integrated Moisture Transport (VIMT) in the western region of Indonesia using the K-Means method with statistical weighting and Hierarchical Shape-Based Clustering based on Dynamic Time Warping (DTW). Daily data on specific humidity, zonal wind speed, and meridional wind speed from 2020–2023 were used to calculate VIMT. Clustering methods were utilized to identify grouping patterns in moisture transport data. The results showed that moisture convergence significantly increased during the rainy season (November–February). Using the K-Means method, five clusters with clearer separations were obtained compared to the four clusters produced by the Hierarchical Clustering method. Performance evaluation using Silhouette and Calinski-Harabasz scores indicated that the K-Means method was superior, with scores of 0.37 and 104.88 compared to 0.13 and 96.34 for the Hierarchical method. This provides an understanding of the moisture transport patterns, serving as a reference for predicting weather and climate patterns, thereby supporting efforts to mitigate the impacts of extreme weather in Western Indonesia.
ANALISIS PERSAINGAN E-COMMERCE MENGGUNAKAN METODE GAME THEORY DAN MARKOV CHAIN DALAM PENENTUAN STRATEGI PEMASARAN OPTIMAL Rahmadani, Devy; Rakhmawati, Fibri
KUBIK Vol 9 No 2 (2024): KUBIK: Jurnal Publikasi Ilmiah Matematika
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v9i2.40273

Abstract

Dalam dunia teknologi yang terus berkembang, penjualan barang melalui media sosial (e-commerce) sudah banyak dilakukan oleh banyak orang. Platform e-commerce telah menjadi bagian penting dalam perdagangan global. Penelitian ini bertujuan untuk menganalisis persaingan antara Shopee dan TikTok Shop menggunakan metode Game Theory dan Markov Chain guna menemukan strategi pemasaran yang optimal. Penelitian ini menggunakan pendekatan kuantitatif dengan pengumpulan data melalui kuesioner yang disebarkan kepada 82 responden di Kota Medan, Sumatera Utara. Analisis data yang digunakan pada penelitian ini menggunakan uji validitas dan uji reabilitas serta melihat nilai maksimum dan minimum dari data yang didapat. Hasil penelitian menunjukkan bahwa probabilitas pergeseran aplikasi Shopee meningkat selama empat minggu sebesar 0,78 (78%) dimana strategi optimalnya adalah voucher. Sebaliknya, TikTok Shop hanya mengalami peningkatan sebesar 0,22 (22%) dimana strategi optimal berupa promo. Penelitian ini menyimpulkan bahwa strategi pemasaran berbasis voucher dan promo dapat meningkatkan daya saing kedua platform, dengan implikasi signifikan bagi pengembangan strategi pemasaran berbasis data dalam e-commerce.
PARAMETER ESTIMATION AND ANALYSIS OF AVERAGE YEARS OF SCHOOLING IN MERAUKE DISTRICT WITH BIRNBAUM-SAUNDERS DISTRIBUTION APPROACH Langowuyo, Agustinus; Yokhu, Sara; Reba, Felix
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v10i1.42992

Abstract

Average years of schooling is an important indicator in assessing the success of education development in a region. This study aims to analyze data on average years of schooling in Merauke Regency, Papua Province, using the Birnbaum-Saunders (BS) Distribution approach. This distribution was chosen because of its ability to model data that has asymmetric characteristics and low variability. The parameters resulting from the analysis include a scale parameter (β) of 8.35, which reflects the average years of schooling of the population, and a shape parameter (α) of 0.0545, which indicates the low degree of dispersion of the data around the mean. The results of the analysis show that the average length of schooling in Kabupaten Merauke is at the junior high school (SMP) level, with a homogeneous data distribution. This homogeneity reflects good equity in access to education, but also indicates the potential for stagnation at certain levels of education. The Birnbaum-Saunders distribution proved to be effective in modeling education data in this region, providing a more accurate picture than traditional approaches. This research makes an important contribution in understanding the distribution pattern of average years of schooling in Merauke district. The results can be used as a basis for designing more targeted policies in improving the quality and access to education, especially at the senior secondary level. In addition, this approach can serve as a reference for analyzing education in other regions with similar geographical and socio-economic challenges
Courses Scheduling using Graph Labeling Ramdani, Rismawati; Nursyahida, Salwa
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v10i1.44243

Abstract

At the beginning of each academic semester, universities are routinely required to develop course schedules that minimize or eliminate conflicts. Scheduling conflicts typically arise when multiple courses are taught by the same lecturer, taken by the same group of students, or require the use of the same classroom. As a result, an efficient and systematic method is needed to generate conflict-free schedules while optimizing the use of available time slots. One alternative approach is to apply graph theory, particularly graph coloring techniques, to the scheduling process. In this approach, each course is represented as a vertex in a graph, and an edge is established between two vertices if the corresponding courses cannot be held simultaneously. Graph coloring is then used to assign different time slots (represented as colors) to adjacent vertices, ensuring that no conflicting courses are scheduled at the same time. This paper proposes a course scheduling algorithm based on graph coloring, aiming to produce feasible schedules that reduce conflicts and enhance resource utilization. The approach provides a mathematical framework that can support automated and scalable scheduling systems in academic institutions.
Penerapan Model Seasonal Autoregressive Integrated Moving Average (SARIMA) dalam Peramalan Curah Hujan di Kabupaten Bandung Barat nadhira, valda azka; Ruchjana, Budi Nurani; Parmikanti, Kankan
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

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Abstract

The expansion of the Kabupaten Bandung, namely Kabupaten Bandung Barat (KBB) is located in hilly and lowland areas. Rainfall in Kabupaten Bandung Barat has an impact on the productivity and performance of key sectors, such as agriculture, plantations and tourism. Low rainfall can lead prolonged dry seasons and result in drought. Conversely, extreme rainfall can also have negative impacts, such as causing soil erosion and potentially affecting the appeal and smooth operation of tourist destinations. Therefore, rainfall forecasting is needed in making appropriate policies, especially regarding the impacts of rainfall changes in KBB. The Seasonal Autoregressive Integrated Moving Average (SARIMA) method is applied in this study to forecast rainfall in KBB. The aims of this research are to estimate the parameters of the SARIMA model using the Maximum Likelihood Estimation (MLE) method and to apply the SARIMA method in forecasting rainfall in KBB, particularly during the December-January-February (DJF) period. The results of the analysis show that the SARIMA model can be applied to forecast rainfall in KBB. The best SARIMA model obtained ARIMA(2,1,0)(0,0,1)3 with a MAPE value 17,80%, which indicates an accurate forecasting criterion. Keywords: SARIMA, MLE, Rainfall.
Bellman-Ford Algorithm for Optimizing Drinking Water Distribution by Perumda Air Minum Tirta Raharja in Cicalengka Lusiani, Anie; Sartika, Euis; Nuryati, Neneng; Hedi, Hedi
KUBIK Vol 10 No 2 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

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Abstract

Access to clean water in Cicalengka District, Bandung Regency, remains limited, with current coverage reaching only 5.08% of the population. Perumda Air Minum Tirta Raharja has set a target to expand drinking water service to 44% by 2030. To support this goal, this study investigates the optimization of the water distribution pipe network in Cicalengka. The research applies the Bellman-Ford algorithm to model the distribution network as a weighted, undirected, and connected graph, where customer houses are represented as vertices, pipe connections as edges, and pipe lengths as weights. Using data from the existing network and customer locations, the algorithm was implemented to identify optimal distribution paths. The results yielded two shortest path alternatives between the specified source and destination nodes. These findings demonstrate the potential of graph-based optimization in improving distribution planning and can serve as a reference for the development and management of future water supply infrastructure.
Probabilistic Model of Back Order Policy on Dodol Pulut Raw Material Inventory Control With Linear Programming Br Siahaan, Erika Handayani; Riri Syafitri Lubis
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v10i1.49121

Abstract

The high production costs of Dodol Pulut Raya further emphasize the importance of implementing a systematic, measurable, and effective inventory control strategy to maintain profitability, operational efficiency, and long-term business stability. This study applies the Probabilistic Back Order Policy Model combined with the Simplex Linear Programming method to determine the most optimal raw material management policy, taking into account demand uncertainty, supply variability, and the risk of stock shortages that could disrupt production smoothness. This approach comprehensively integrates precise safety stock calculations to minimize stockouts, reduce production delays, and ensure raw material availability so that customer needs can be consistently, timely, and sustainably met. The analysis results show that the implementation of this model can significantly reduce annual production costs from IDR 509,941,040 to IDR 338,719,300, resulting in cost efficiency of IDR 171,221,740 per year. This finding demonstrates the model's effectiveness in minimizing total inventory costs while enhancing competitiveness and operational sustainability. Additionally, this study provides a practical framework for small and medium-sized enterprises facing fluctuating demand, balancing service levels, safety stock, and overall cost optimization.
Application of the Clarke and Wright Savings Algorithm to Solve the Vehicle Routing Problem in Optimizing Chip Distribution Sitompul, Apri Yani; Husein, Ismail
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v10i1.49162

Abstract

Efficiency in the distribution process is crucial for companies to reduce operational costs while maintaining service satisfaction. This research aims to optimize the product delivery route for the Keripik Cinta Mas Hendro business by applying the Clarke and Wright Savings algorithm approach to solve the Vehicle Routing Problem (VRP). This method works by calculating the distance savings from combining distribution points, then constructing optimal routes based on the order of highest savings while still considering vehicle capacity. The data used consists of customer coordinates, which are processed into distances between locations using the Euclidean formula. The results show that the distribution route, which was initially divided into three lanes with a total length of 403.54 km, can be simplified into two lanes with a total length of 272 km. This study proves that the Clarke and Wright Savings algorithm is able to provide a more cost-effective distribution solution. Keywords: Distribution, Optimization, Chips, VRP, Clarke and Wright SavingsMSC2020:  90B06, 68W40, 90C59 Abstrak Efisiensi dalam proses distribusi sangat penting bagi perusahaan agar dapat menekan biaya operasional sekaligus menjaga kepuasan pelayan. Penelitian ini bertujuan untuk mengoptimalkan jalur pengiriman produk keripik pada usaha Keripik Cinta Mas Hendro dengan menerapkan pendekatan algoritma Clarke and Wright Savings dalam menyelesaikan permasalahan Vehicle Routing Problem (VRP). Metode ini bekerja dengan menghitung nilai penghematan jarak dari penggabungan titik-titik distribusi, lalu menyusun rute optimal berdasarkan urutan penghematan tertinggi yang tetap memperhatikan kapasitas kendaraan. Data yang digunakan berupa koordinat pelanggan yang diolah menjadi jarak antar lokasi menggunakan rumus euclidean. Hasil menunjukkan bahwa rute distribusi yang semula terbagi tiga jalur dengan total 403,54 km dapat disederhanakan menjadi dua jalur dengan total 272 km. Penelitian ini membuktikan bahwa algoritma Clarke and Wright Savings mampu memberikan solusi distribusi yang lebih hemat. Kata kunci: Distribusi, Optimasi, Keripik, VRP, Clarke and Wright Savings MSC2020:  90B06, 68W40, 90C59  
Optimization of Potato and Carrot Production in Karo District Using the Beale Method riezky, riezkyfadhillah; Rina Filia Sari
KUBIK Vol 10 No 1 (2025): IN PRESS
Publisher : Jurusan Matematika, Fakultas Sains dan Teknologi, UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/kubik.v10i1.49213

Abstract

This study aims to optimize land allocation for potato and carrot production in Karo Regency, North Sumatra, using a quadratic programming approach using the Beale method. Secondary data from the Karo Regency Agriculture Office for 2018-2024 are used to construct a quadratic objective function using the least squares method. The Beale method is applied iteratively to solve optimization problems with linear constraints. The results show that the optimal land allocation of 0.5382 hectares for carrots and 0.4005 hectares for potatoes provides a maximum yield of 1.6239 tons. These findings demonstrate the effectiveness of the mathematical optimization approach in improving land use efficiency and supporting data driven decision making in the horticultural agricultural sector.