Earthquake Point Clustering Using Self Organizing Maps (SOM) In Sulawesi and Maluku Regions

Earthquakes pose a major threat in Indonesia, particularly in complex tectonic regions like Sulawesi and Maluku. To support disaster mitigation, this research employs the Self Organizing Maps (SOM) method—an unsupervised technique that reduces data dimensionality into an intuitive two-dimensional form—to cluster earthquake data using four key variables: longitude, latitude, magnitude, and depth. The dataset includes 5,275 earthquake records from 2022, sourced from the Meteorology, Climatology, and Geophysics Agency (BMKG). SOM training produced 25 neurons, which were then grouped into three optimal clusters using hierarchical clustering, validated by internal metrics: the lowest Connectivity Index (296.1512), highest Silhouette Index (0.3304), and a Dunn Index of 0.0058. Cluster 1, with 13 neurons, covers eastern Sulawesi and Maluku, featuring medium magnitude and depth. Cluster 2, with 11 neurons, represents central to southern Sulawesi, characterized by low magnitude and shallow depth. Cluster 3, comprising a single neuron, includes western regions with high-magnitude, very deep earthquakes. Keywords⎯ Clustering, Earthquake, Internal Validation, Self Organizing Maps (SOM)

The Role of High-Income Households and Tourism in Advancing Energy Affordability and Financial Inclusion for Small Islands

Energy affordability and financial inclusion remain critical challenges for small island communities, where reliance on imported fossil fuels and high energy costs disproportionately impact low-income households. At the same time, high-income households and the growing tourism sector on these islands hold significant financial capacity to drive equitable energy transitions. This perspective explores the role of high-income stakeholders and tourism operators in promoting energy affordability through retribution mechanisms, adaptive service assets, and flexible organizational models. By leveraging financial resources and investing in clean energy solutions, high-income households and tourism businesses can contribute to a sustainable energy future that benefits all members of the community, bridging the gap between economic growth, energy equity, and environmental sustainability

A Nonparametric Regression Approach Address Poverty Problems in East Nusa Tenggara Province

The administration is focused on reducing poverty, which is still a significant issue. Since the regression curve is unknown and the truncated spline nonparametric regression approach offers a high degree of flexibility, the study was conducted to determine what factors influence it, particularly in the East Nusa Tenggara area. The goal of this study is to develop a nonparametric regression model. The average length of schooling, life expectancy, percentage of the illiterate population aged 15 and over, labor force participation rate, percentage of households based on the information source, and population density affect poverty in the East Nusa Tenggara area. With a minimum GCV of 39.57, it was determined that 1 knot point were the ideal knot point. To some extent, the characteristics that influenced poverty were life expectancy, labor force participation rate, percentage of households with a proper light source, and population density. The best model met these criteria with an R2 of 81.28%. The findings suggest that targeted interventions to improve these factors can significantly reduce poverty in East Nusa Tenggara

Design and performance testing of a safety instrumented system for water level control simulator using plc with cause-effect matrix implementation

Safety Instrumented Systems (SIS) are widely employed in industrial settings to ensure operational safety and prevent system failures that could pose risks to the environment, personnel, and assets. This research presents the design of an SIS for a water level control system, utilizing Programmable Logic Control (PLC) to enhance safety and mitigate the risk of leakage or flooding. The SIS design is developed based on the Layers of Protection Analysis (LOPA) methodology, incorporating multiple protective layers, including water level measurement instruments, controllers, and final control elements to manage risk effectively. Following the LOPA-based design process, system testing was conducted using a cause-and-effect matrix to evaluate performance under various operational scenarios. The findings indicate that implementing SIS in water level control systems significantly enhances operational safety. In simulated test conditions, the SIS effectively detected potentially hazardous situations, such as excessive water levels that could lead to overflow or dangerously low levels that might disrupt process continuity. The system then executed appropriate mitigation measures, such as alerting operators or automatically shutting off water flow, to prevent accidents and equipment damage. The results demonstrate that integrating an SIS into water level control systems provides substantial benefits in managing operational risk, ensuring system reliability, and safeguarding industrial processes

Handling Selection of Settlement and Embankment Stability Issues Based on Variations in Embankment Height and Soft Subgrade Thickness Case Study: Pekanbaru Junction - Pekanbaru Bypass Sta. 176+775 - Sta. 176+975

Trans Sumatra Toll Road (JTTS) is one of the most important infrastructure projects in Indonesia. One of the main sections of JTTS is the Rengat - Pekanbaru Toll Road, Pekanbaru Ring Section (Pekanbaru Junction - Pekanbaru Bypass). Existing conditions at Sta 176+775 - Sta 176+975 are dominated by oil palm plantations with soft soil layers in the form of organic soil to a depth of 1.0 meter; the layer below is clay with medium to stiff consistency. The existing treatment plan is preloading embankment with PVD and 1,0 m deep subgrade replacement. In this study, alternative planning calculations were carried out with variations of subgrade replacement up to 0.5 m and 1,0 m thickness. The study results show that the most cost-optimal treatment design is the treatment design without replacement with geotextile reinforcement. The thicker the subgrade replacement, the smaller the compression and rate of settlement. In terms of embankment reinforcement, the thicker the subgrade replacement, the less reinforcement is required. The thickness of subgrade replacement also affects the cost of the work, the thicker the subgrade replacement, the higher the cost of the work

Intelligent Fault Prediction in Diesel Engines: A Comparative Study of SVM and BPNN for Condition-Based Maintenance

This study discusses the application of Support Vector Machine (SVM) and Backpropagation Neural Network (BPNN) in predicting diesel engine health based on operational data that has been relabeled using K-Means Clustering. Two types of SVM kernels were tested, namely Radial Basis Function (RBF) and Sigmoid, with various parameter combinations. The results indicate that SVM with a Sigmoid kernel achieved an accuracy of 94.06% but was less sensitive in detecting unhealthy engine conditions. In comparison, the BPNN method with a three-hidden-layer configuration (1-2-1 neurons) and the tansig activation function demonstrated superior performance, achieving an accuracy of 97.13%, MSE of 0.03, recall of 94%, precision of 100%, and an F1-score of 97%. These results confirm that BPNN outperforms SVM in capturing complex data patterns and is more accurate in detecting unhealthy engine conditions. Furthermore, dataset relabeling significantly improved prediction accuracy from 72.3% to 97.13%, emphasizing the importance of data balance in modeling. Overall, this study demonstrates that BPNN with an optimal configuration is more effective in predicting diesel engine health than SVM, making it a more reliable approach for engine condition monitoring.Keywords: Diesel Engine; Machine Health Prediction; Support Vector Machine; Backpropagation Neural Network; Condition-Based Maintenance; Artificial Intelligenc

A Participatory Risk-Matrix Framework for User-Centered Validation of a Manual Standing Wheelchair

This study presents a participatory, risk-based validation framework for a manually actuated standing wheelchair. The standing function offers both physical and psychosocial benefits, including greater independence, improved social interaction, and better access to vertical space. However, adoption of such devices remains limited, especially in low-resource settings, due to concerns about usability, comfort, and safety. Rather than emphasizing technical novelty, the contribution of this study lies in applying a user-centered risk-matrix approach to systematically translate stakeholder concerns into design priorities. Through engagement with eight stakeholders, including direct users and institutional representatives, the study collected qualitative feedback on user experience. This feedback was organized into eight thematic risk categories. Among them, stability during transitions and the level of physical effort required were identified as the most pressing concerns. Each risk type was then evaluated using a qualitative 5×5 matrix to assess its likelihood and potential impact. This structured process enabled the design team to prioritize and implement targeted improvements, effectively reducing the likelihood of tipping-related risks. However, physical accessibility, particularly for users with limited upper-body strength, remained a high, unmitigated risk due to inherent limitations of manual operation. The study highlights the importance of integrating structured risk analysis with real user input to inform assistive technology development that is not only functional, but also contextually responsive

Perencanaan Pengembangan Aset Fasilitas Berdasarkan Incremental Innovation Di Taman Kota Soreang

Taman kota sebagai ruang terbuka hijau memberikan manfaat ekologis dan sosial bagi Masyarakat. Namun, kurangnya pemeliharaan, kurangnya ketersediaan fasilitas, dan kondisi fasilitas yang rusak membuat taman kota kurang diminati dan tidak dapat memenuhi kebutuhan pengunjung.  Taman Kota Soreang merupakan salah satu Ruang Terbuka Hijau di Kabupaten Bandung yang memiliki luas kurang lebih 5.000 m². Taman Kota Soreang dikelola oleh Dinas Perumahan, Kawasan Permukiman, dan Pertanahan Kabupaten Bandung. Taman Kota Soreang memiliki permasalahan pada fasilitas yang meliputi: tidak memenuhi standar, rusak, dan ketidaklengkapan fasilitas. Tujuan dari penelitian terapan ini yaitu menghasilkan rencana pengembangan aset Taman Kota Soreang Kabupaten Bandung berdasarkarkan inovasi incremental untuk fasilitas di taman kota. Metode deskriptif dengan pendekatan kualitatif dan kuantitatif digunakan pada peneltian ini.  Teknik pengumpulan data menggunakan wawancara, observasi, dokumentasi, dan benchmarking. Hasil penelitian ini adalah perlu disediakan fasilitas yang meliputi:  1) Aksesibilitas terdiri dari area parkir taman dan pagar taman; 2) Kenyamanan terdiri dari tempat duduk, Jalur pejalan kaki, Papan informasi digital, Vegetasi, toilet umum, Halaman rumput terbuka, dan WiFi; 3) keamanan terdiri Lampu taman, CCTV dua arah, dan terakhir; 4) Aktivitas sosial terdiri dari Fasilitas bermain, pangggung budaya, dan Trek Jogging.  Biaya yang dihitung meliputi biaya biaya pembongkaran, biaya pembangunan, dan biaya pengadaan

Effect of Flow Rate NaOH on CO₂ Absorption Efficiency Using a Column Tray Absorber

CO₂ in industrial gas streams reduces process efficiency, corrodes equipment, and affects product quality. Additionally, CO₂ emissions contribute to climate change and global warming. To mitigate these effects, CO₂ removal through absorption is essential. Absorption involves contacting a gas mixture with a liquid absorbent to dissolve the gas component. This study examines the effect of CO₂ flow rate (V) and NaOH flow rate (L) on CO₂ absorption efficiency. The experiment involved preparing 33 liters of 0.1N NaOH and 250 ml of 0.1N HCl, followed by solution standardization using methyl orange. CO₂ was introduced through valve V-4 while NaOH was pumped into the absorption column. Samples were taken after steady state was reached, and titration with 0.1N HCl determined residual NaOH concentration. Flow rate variations of 1, 3, 5, 7, and 9 L/min were tested. Results align with literature, indicating that as CO₂ flow rate increases, NaOH flow rate also rises. However, the L/V ratio and absorbed CO₂ amount decrease due to reduced contact time, lowering absorption efficiency. This study highlights the importance of optimizing flow rates to enhance CO₂ capture

2D Magnetotelluric (MT) Modelling for Geothermal System Interpretation

Geothermal systems are areas beneath the earth's surface that store circulating heat energy. The heat energy stored in the geothermal system can be utilized by humans as an environmentally friendly alternative energy. Determining the geothermal system area requires geophysical exploration methods that have deep enough penetration and can distinguish soil structures based on the value of specific resistance. One method that is effective in determining geothermal systems is the magnetotelluric (MT) method. This method receives electric and magnetic field signals from the induction of subsurface rocks to the electromagnetic wave activity of solar storms and lightning. The signal is then processed to produce a specific gravity value. This type of resistance data can then present the structure of the geothermal system, including impermeable rocks, reservoirs and magmatic intrusion zones. This study also collaborated with supporting geological and geochemical data. The results of the magnetotelluric method analysis for the geothermal system of this study area are suspected to have host rocks with a specific gravity of less than 10 Ωm spread near the surface. Reservoirs that have a specific gravity of 10-40 Ωm are located at a depth of about 1000 m below the surface based on the interpretation of all data