ITB Graduate School Conference

Convolutional Neural Network and Interpretable Deep Learning for Concrete Crack Image Classification

2023-09-30T09:35:28+08:00

The development of unmanned aerial vehicles (UAVs) makes automation of visual tasks possible, such as crack detection. Crack detection has many challenges and, in this work, the utilization of image processing through deep learning-based computer vision is conducted for concrete surface image classification. The widely used deep learning architecture for computer vision is the convolutional neural network (CNN). This paper discusses the creation of CNN models for concrete crack image classification and the role of interpretable deep learning in the model’s evaluation. Three convolutional architectures combined with a proposed classifier architecture were trained and evaluated quantitatively and qualitatively. The quantitative evaluation metrics are precision, recall, F1-score, and accuracy. The qualitative evaluation concerns the feature highlight of the model using SmoothGrad. The result is that even though the model with InceptionV3 has the best quantitative classification metric values (accuracy of 96%), the one with EfficientNetV2S has the best feature highlight. Thus, the model considered the best is the one with EfficientNetV2S since the accuracy is already considered high (94%). This highlights the importance of qualitative evaluation on a deep learning-based computer vision model to ensure the correct feature is considered as the deciding point of classification.

2D Incompressible Flow Numerical Modeling of LSMPS Vortex Particle Method using Ellipsoidal Particle

2023-09-30T09:51:34+08:00

Particle-based fluid simulation has been vastly developed in the recent age. In our groups, a vortex particle method (VPM) is developed using LSMPS method and Brinkman penalization. One of the issues in our program is to enhance performance since it still has a high computational cost. The particle distribution technique of ellipsoidal particles is a new method that intrigues this work. In this paper, the LSMPS–VPM fluid simulation program is being modified by ellipsoidal particle distribution. It was tested on a laminar boundary layer on a flat plate. The results have a significant computation cost reduction with computation time saved up to 53% and even more. The error increase is low and linearly proportional towards the elliptical ratio. By this result, it is very potential to implement this ellipsoidal particle technique on other fluid solvers in reducing the computational cost.

Mapping of the Board Game with App-Assisted Gameplay

2023-09-30T10:05:23+08:00

Boardgame is one form of game that is presently popular. The development of board games is also interesting from board games which were originally just paper and boards, now they are starting to penetrate the digital world. Starting from board games that are present digitally, implementing a hybrid concept between physical and digital, to those that use the latest technology such as VR (Virtual Reality). The addition of digital tools or applications to board games seeks to enhance the playing experience by making games more exciting, fascinating and interactive. The existence of digital media in a board game, it is possible for intervention from digital media in the game, such as the use of audio, video, or even interactive displays. Currently there are many board games with digital applications on the market. Based on this phenomenon, with the guidance of a literature review, research was conducted on mapping board games with app-assisted gameplay. Gameplay observations are made to find out how application-assisted gameplay is implemented from the filtered board game. The results of the mapping and findings in this study can then be a propelling force for further research on the phenomenon of utilizing digital media to board games.

Synthesis and Characterization of Zeolite A-Calcium Carbonate for Carbon Capture

2023-09-30T10:21:47+08:00

Carbon capture by solid adsorbents is one of the most promising ways to implement carbon capture. Zeolites, a class of aluminosilicate minerals with a honeycomb-like framework structure, has excellent carbon dioxide adsorption characteristics, attributed to its microporous nature. However, challenges remain to improve its adsorption characteristics, mainly related to its kinetics and selectivity. In this paper, zeolite A was treated with NaOH (zeolite-NaOH) and intercalated with calcium carbonate (CaCO3) (zeolite-CaCO3). The resultant material was then characterized by its morphology, crystallography, and its CO2 adsorption characteristics. The results showed that treatment with NaOH did not change the morphology and crystallography of zeolite A, while intercalation with CaCO3 showed that CaCO3 formed nanoflowers in the surface of zeolite A and CaCO3 exist in zeolite-CaCO3 in both amorphous and crystalline form, co-existing with Ca(OH)2 and CaO. Adsorption characteristics measured using thermogravimetric methods showed that zeolite-CaCO3 had superior adsorption capacity, selectivity, and kinetics compared to zeolite A and zeolite-NaOH, especially by accounting for zeolite mass only in zeolite-CaCO3.

LSMPS Method for Solving Steady Heat Conduction Equation in Orthotropic Materials

2023-09-30T10:34:19+08:00

Heat conduction in orthotropic materials has been an important topic in engineering. In this study, LSMPS method was used to solve steady heat conduction problem for orthotropic medium. Two methods were proposed in this paper, one using coordinate transformation and one without coordinate transformation. The numerical results were then compared to the analytical solution. The results from both methods showed good agreement with the analytical solution. The coordinate transformation method had slightly better accuracy, though it also took slightly longer computation time. However, the direct method, without coordinate transformation is more practical when dealing with non-orthogonality and non-homogeneity over the domain. In general, the proposed methods have been able to solve steady heat conduction problem for orthotropic medium.

Development of Pressure Estimator and Velocity Field Corrections for Particle Image Velocimetry Using Physics- Informed Neural Network

2023-09-30T10:57:03+08:00

Flow diagnostics using particle image velocimetry (PIV) has always been a viable option, but errors or faults in the experiment can lead to misinterpreted data. Meanwhile, physics-informed neural network (PINN) usage has been on the rise because of its versatility. This work intends to analyze the possibilities of implementing PINN for PIV and test on a couple of flow cases to observe whether misinterpretations in PIV output can be minimized, along with providing pressure prediction in the analysis domain. This work modifies an already existing PINN program to better suit PIV applications which is then implemented on uniform flow and backstep flow. The PINN was tested on uniform flow and backstep flow which show that the PINN can produce a denser velocity prediction and predict a pressure field without any prior pressure data. Also, it is capable of filling in gaps of missing data and correct invalid velocity data. results for individual cases are satisfactory for both velocity and pressure predictions but can be improved further.

Deep Learning for Data-Driven Turbulence Modeling in Flow over Periodic Hills

2023-09-30T11:10:26+08:00

Data-driven method has gained rapid growth in recent years. It is driven by the rise of big data in various fields. Nowadays, Deep learning is the most famous data-driven method used in wide range of applications such as in fluid mechanics. Turbulence modeling is an unsolved problem in fluid mechanics. Reynolds-averaged Navier-Stokes (RANS) is the most popular method for turbulence modeling in real-world problems. The objective of RANS turbulence modeling is to relate the Reynolds stress with the mean flow properties. The weakness of the RANS model has driven the research to develop another approach. The application of deep learning in turbulence modeling has shown promising results in recent years. In this work, deep learning is used to develop a model for turbulence closure modeling. The performance of this model is compared with RANS k-ω model as the classical turbulence model. From the results of this work, it is shown that the neural network model proposed by the author could give better performance on giving the closure relation for turbulent flow over periodic hills which gives 57% RMSE improvement from the RANS model and could capture the separation phenomenon when RANS model is struggling.

Developing Integrated Marketing Communication (IMC) Plan for The Intercultural School in North Jakarta

2023-09-30T12:29:45+08:00

Parents will have a lot of things to think about when choosing a school for their children, especially an intercultural school in North Jakarta. [1],[2]Parents need to take into account a number of crucial elements, including the curriculum being used, the facilities, and the school climate. Segmentation, targeting, and positioning (STP) is an important strategic approach for any educational institution looking to attract and retain students. By combining traditional marketing strategies with digital marketing tactics, intercultural schools can create a comprehensive integrated marketing campaign that reaches their target audience effectively. [4]By conducting a comprehensive Integrated Marketing Communication (IMC) analysis, the intercultural school can identify the most effective communication channels, develop a messaging strategy that resonates with the target audience, and create a budget and timeline for executing the plan.

NoTrail: Graph Construction as a Trail Former in Bandung Institute of Technology Hymn Song

2023-09-30T12:52:01+08:00

Music is a sound created in such a way that it creates rhythm, tone, song, and harmony. Musical notation is commonly known as a note. Notes are musical symbols that depict tone visually. A song can be represented in the form of a graph constructed as a trail formed by determining the points and sides of the corresponding notes. The representation of the point is the notation itself, whereas the side weight is obtained from the beat value of each note. The movement of the graph construction that represents the song can be determined by the shape of the trail obtained by following the generated weighted and directional graph that has been made. The graph model is called a Notrail, which means that the notes are graphs and trails. This study was conducted to determine how graph construction can be determined as a trail that represents the hymn notation of the Bandung Institute of Technology (ITB), and how to read or sing and know the movement of the notation represented by the graph construction as a trail former. The graph model is constructed with several constructions to determine and examine how the model looks at and knows the level of difficulty in reading and knowing its movement. The construction can represent the ITB Hymn song as a whole notation, and its movement can be read and sung as well as sheet music in general.

Influence of the performance of Gel Polymer Electrolyte (GPE) with the addition of SiO2 and Carboxy Methyl Cellulose (CMC) for Zinc-Air Batteries (ZABs)

2023-09-30T13:04:10+08:00

PVA is a non-toxic, semi-crystalline polymer with good hydrophilicity that is also simple to produce. Consequently, PVA is strongly suggested as a potential material in GPE synthesis. GPE was created by converting the host polymer Poly-Vinyl Alcohol (PVA), which was utilized as a matrix and expanded when exposed to a 6M KOH solution. The thermal stability, mechanical toughness, and electrochemical toughness of GPE have all been proven to be improved by SiO2. SiO2 works as a plasticizer and crosslinker to make GPE more elastic. It also tends to make PVA more amorphous, which is predicted to make GPE more absorbent to 6M KOH. The SiO2 surface's hydroxyl groups offer water-resistance characteristics that enable the zinc-air battery to operate at its best. It has been demonstrated that cellulose may significantly enhance the structure of GPE, which is more amorphous, and is anticipated to be able to raise the GPE's ionic conductivity value. The highest GPE-3 ionic conductivity is 6.288 mS/cm meanwhile the highest GPE-6 ionic conductivity is 5.645 mS/cm and the highest GPE-0A ionic conductivity is 0.997 mS/cm.

Zoning Analysis of Temporary Landfill in Bandung City Based on Geographic Information System

2023-09-30T13:26:46+08:00

The growing population has resulted in an increased demand for basic human needs such as food and shelter, therefore this leads to higher production waste and environmental pollution. The existance of temporary waste disposal site (TPS) zoning becomes crucial in addressing environmental pollution through the implementation of Reduce, Reuse, and Recycle practices. In the mapping of TPS zoning in Bandung City using Geographic Information System, data analysis is conducted to solve the problem through spatial analysis approach and the DPSIR theory (Driving Force, Pressure, State, Impact, Response). The analysis findings of TPS mapping in Bandung City reveal the presence of TPS areas in Gedebage District and Rancasari District. The close proximity of residential areas to waste disposal sites causes alterations in the air quality, water quality, and soil quality in the surrounding areas of the temporary waste disposal sites. There are many temporary waste disposal sites still fail to meet the criteria established in accordance with Regulation of the Ministry of Public Works and Housing of the Republic of Indonesia No. 24/PRT/M/2016, and there is also a lack of public awareness and education regarding waste segregation and utilization in Bandung City.

Analysis of Lead Time in The Upstream Citarum River Using Satellite and Stream Gauge Data

2023-09-30T13:39:47+08:00

Floods in the upstream Citarum, Majalaya, generally occur quickly and experience a rapid rise in the water level, termed flash floods. The short notice and event duration of flash floods often does not allow the affected community to carry out adequate early warning and disaster emergency response. In disaster events, lead time is the interval between the issuance of a forecast and the event itself. Minimizing the risk of flood hazards in the community requires an increase in the lead time. This study analyzed the lead time between rainfall events (from JAXA’s GSMaP data) and water level rise in Citarum’s Majalaya and Sapan. The water level rise used river authority’s gauge records data from 2018 through 2022. The current study shows several differences in the lead time for each event. In 2018, Majalaya to Sapan lead time was 4 hours; in 2019 Majalaya to Sapan lead time was 3 hours; in 2020 Majalaya to Sapan lead time was 3 hours; in 2021, Majalaya to Sapan lead time was 6 hours and in 2022, Majalaya to Sapan lead time was 2 hours. Determining the differences in lead time can be pursued for further refinement.

The Effect of Cross-Sectional Shape on the Roughness Coefficient

2023-09-30T13:49:54+08:00

This study examines the effect of cross-sectional shape on the value of the Manning’s roughness coefficient of a channel. The study was conducted using hydraulic laboratory experiment. There were 120 scenarios with 4 different types of sections (90º, 60º, 45º and 35º) and 2 types of channel roughness (coated roughness only at the bottom of the channel and roughness coated with wire mesh on the walls and on the of the channel). To get the coefficient value, it is necessary to get a uniform flow from the experiment. From the experiments results there is a correlation between the average Manning coefficient value of each section with the difference in the shape of the cross section. Then it can be concluded from the experiment that the greatest value of the roughness coefficient is at a cross section of 90° and with the roughness being coated with wire on the walls and bottom of the channel. Chart the explaining the relathionship between the average value of the Manning coefficient obtained with the shape of the cross section, so that the equation is obtained from the graph.Then from the research it can be concluded the cross-sectional shape of the channel greatly influences the roughness coefficient.

Evaluation and Analysis of Manhour Rate in Maintenance of Gas Turbine Engine for Industry

2023-09-30T19:43:11+08:00

The industrial gas turbine engine maintenance unit PT XYZ has a significant difference in the rate of man-hours with its core business, namely the maintenance of airframe and engines. This study aims to determine the factors that cause differences in the rate of man-hours in the two units and provide suggestions for the rate of man-hours. This study uses the IATA Labor Rate and Productivity Calculation for Commercial Aircraft Maintenance to produce the rate of man-hours. The factor which most affects the difference in the rate of man-hours is the overhead. A breakdown analysis of the overhead cost is then carried out by comparing the costs contributing to overhead costs. The calculation results show that the rate of man-hours for aviation engine maintenance is USD 55.80, while for industrial engine maintenance is USD 16.22. In addition, the most contributing overhead costs are the costs of production facilities.

Hybrid Moving Image as a Medium for Informing Inner Child Trauma for Young Adult

2023-10-01T17:51:20+08:00

Childhood experiences, both positive and negative, are stored in memory. They remain in adulthood as one grows up. These experiences are referred to as the inner child, the spirit of children that exists in adults. Evidently, these various experiences create a lasting impact, especially in the way people behave. However, what is concerning are the negative childhood experiences that have not been resolved properly. This condition has a potential to cause inner child trauma that affects negatively in one's adulthood. Therefore, one method that can be employed to inform about this issue is hybrid moving image. Hybrid moving image is a combination of audiovisual media (live action and animation) that still maintains its characteristics. Live action represents things in a realistic way, while animation represents things in an imaginative way. For example, humans and the real world are represented in live action, while the inner child that exists within oneself is represented in animation. This phenomenon of inner child trauma occurs within a person can be displayed concretely. The aim of this research is to examine the potential of hybrid moving images in informing young adults about inner child trauma. With this media, it is expected that young adults increase their awareness and empathy towards inner child trauma that may occur around them. The method employed is literature study and previous research.

A Stepwise Synthesis of Methylammonium Lead Bromide (MAPbBr3) Perovskite Using Lead Acetate Trihydrate as a Precursor

2023-10-01T18:12:31+08:00

Methylammonium lead bromide (MAPbBr3) has been successfully synthesized in an aqueous solution using lead acetate trihydrate as a precursor. The synthesis process was conducted in a stepwise manner, first lead acetate was combined with hydrogen bromide to produce lead bromide. Subsequently, methylammonium bromide, which was obtained from the reaction of methylamine and hydrogen bromide was added to the lead bromide to form methylammonium lead bromide. The red-orange solid product has a chemical formula of CH3NH3PbBr3 based on SEM-EDS (scanning electron microscopy with energy dispersive spectroscopy), AAS (atomic absorption spectroscopy), and argentometric titration. The perovskite structure of the product has been confirmed by PXRD (powder X-ray diffraction) measurements and the thermal stability of the product was performed by TGA (thermal gravimetric analysis). The yield of each reaction step was found to be approximately 80%.

Correction to the Inflationary Power Spectrum from Spatial Curvature

2023-10-01T18:27:52+08:00

In this work, we calculate the corrections to the inflationary power spectrum of primordial curvature perturbations arising from small initial spatial curvature prior to inflation. The universe is described by the Friedman-Lemaître-Robertson-Walker (FLRW) model with spatial curvature and undergoing single-field slow-roll inflation. The presence of spatial curvature introduces additional terms to the second-order action of perturbations, which are proportional to the spatial curvature. We specifically focus our investigation on spatial curvature that is of the same order as the slow-roll parameter. The contribution of these additional terms to the power spectrum is evaluated perturbatively around the usual free part of the action in flat space. The Bunch-Davies boundary condition is applied to normalize the mode function. We find that the corrections are proportional to the spatial curvature for the short-wavelength modes. However, these corrections can be enhanced when the largest observable scale is comparable to the curvature scale.

Assessment of CO2 Emission of Electric Vehicles based on Life Cycle Assessment and System Dynamics Methodology

2023-10-01T19:05:24+08:00

The promotion of electric vehicles (EV) adoption has emerged as a prevalent policy approach in numerous countries for reducing CO2 emission. Given the significant contribution of road transportation to CO2 emissions, the replacement of fossil fuel-based conventional vehicles with EV represents a viable strategy to mitigate emissions. However, the successful implementation of EV necessitates a comprehensive assessment throughout its entire life cycle. The use of EVs may reduce CO2 emission from the vehicles, however the increasing consumption of eletric power during its use may potentially potentially lead to higher CO2 emissions from the electric power generation, in particular in countries wherein fossil-based energy soures yet dominate the electric mix such as Indonesia. This study aims to conduct an assessment of CO2 emission of EV adoption in comparison to that of internal combustion engine vehicle (ICE) throughout their life cyles in Indonesia. Simultaneously, a system dynamics model is developed to depict the adoption process of EV and ICE based on Bass diffusion model. The system dynamics model is also used to simulate the impact of government policies in promoting the use of EVs.

2D Fluid Motion Simulation Using the Smooth Particle Hydrodynamic Method

2023-10-01T19:16:40+08:00

2D virtual fluid simulation can help in simulating fluids directly in various problems, such as fluid simulations for education, geological simulations for landslides, and so on. This study aims to simulate the fluid behavior of water in an unhindered medium and observe the fluid particle interactions that occur. This research is simulated using the Python programming language to simulate fluids and using the Wondershare Filmora X application to combine images. This research method uses the Smooth Particle Hydrodynamics method to simulate fluids in a 2-dimensional container with a total of 10,000 particles. The Smooth Particle Hydrodynamics method is used to help model fluids in particle form by deriving the direct force density field from the Navier-Stokes equation. The Navier-Stokes equation is used to find the acceleration and velocity of fluid particles by including external forces, internal forces, and gravity through the Smooth Particle Hydrodynamics method. Acceleration and velocity will be validated due to wall collisions which cause changes in particle position and particle velocity. At the time of visualization, the fluid velocity slows down over time due to damping caused by interactions between fellow particles and particles with walls. And here you can see the fluid behavior of water flowing from a high place to a lower place and the water fluid particles are shaped to follow the container.

Printmaking Triennial as a Parameter for The Development of Indonesian Printmaking

2023-10-01T19:30:32+08:00

The Indonesian Printmaking Triennial is a competition held in a three-year period by Bentara Budaya as the organizer. Bentara Budaya chose printmaking as the main focus in organizing this competition because its existence is seen as something important and needs to be observed considering that printmaking itself has become an important part of the development of Indonesian modern art since the 40s. The printmaking triennial has been held six times, in 2003, 2006, 2009, 2012, 2015 and most recently in 2018. The competition is open to the public, both nationally and internationally (for 2015 and 2018).

This research aims to look at the Triennial printmaking competition by Bentara Budaya as a parameter for the development of printmaking in Indonesia. By using a descriptive quantitative method by looking at the dynamics of participants, finalists and winners of the competition towards the quantification of the type of print technique and the quantity of appreciation.

This research found that relief print is a popular technique for Indonesian printmakers. Meanwhile, the lithography technique should be taken into consideration by reflecting on the last event, where all the winners from other countries used the technique when the competition was opened internationally.

Determination of Optimal Discharge at SB-2 Production Well at PT Calbee Wings Food in Walahar Village, Klari District, Karawang Regency, West Java Province

2023-10-01T19:41:07+08:00

PT Calbee Wings Food is a company engaged in the food industry, especially snacks, located on Jl. Raya Curug-Kosambi, Walahar Village, Klari District, Karawang Regency, West Java Province. The company utilises groundwater for production purposes, and to support the provision of clean water, a pumping test was carried out on the existing borehole (SB-2). Pumping aims to determine the optimal well capacity in groundwater utilisation using boreholes. The method used in this observation is a vertical downhole and the Hantush-Bierschenk method is used to analyse the step drawdown test data. The values of the Aquifer Loss Coefficient (B) and Well Loss Coefficient (C) are 0.0926 and 0.0002, respectively. Assuming that the efficiency of the well of 75% is an efficient condition, the optimum pumping discharge value is 1.85 liter/second. The decrease in groundwater level occurs due to pumping which can be classified in a safe zone condition which is <40% or 34.82% in the situation of maximum pumping discharge (2.38 liter/second).

A Comprehensive Approach to Optimizing Production Capacity through Integrated Evaluation of Well Performance and Pump Setting Scenarios

2023-10-02T23:13:14+08:00

This paper evaluates the performance of a groundwater well by analyzing its well development, pump setting scenarios, and production capacity. The well's condition is assessed by calculating its well development factor, and pump setting analysis is conducted to determine the best pump position for maximum yield and safe drawdown. Pumping tests are performed to measure water levels and predict future well performance, sustainability, and maintenance needs. The specific capacity of the well equation is used to describe productivity, and steady-state drawdown values are calculated for four different pumping rates. The well development factor is excellent, and well efficiency values range from 82% to 72% for flow rates of 22.6 L/s to 39.5 L/s. The optimal discharge rate is calculated, and the appropriate pump location is determined to accommodate the desired discharge rate and water table decrease. The results provide valuable information for future well management and maintenance planning.

Relationship Between Safe Discharge and Groundwater Zoning in Production Wells at PT Monokem Surya Rengasdengklok District, Karawang Regency West Java Province

2023-10-03T22:36:35+08:00

PT Monokem Surya utilizes water to process zircon ore which is entirely sourced from groundwater with a minimum requirement of 550 m3/day. The source of groundwater comes from 7 drilled wells, all of which extracted a water from the confined aquifer layer. A study is needed to determine the potential of groundwater and aquifer parameters from wells with a pumping test. After discovering the aquifer parameters and optimum discharge, simultaneous pumping simulations were carried out for all wells and resulted in drawdowns that were generally not classified as safe criteria. Furthermore, a trial and error re-simulation is carried out by changing the discharge and pumping duration to make drawdown that fall within the safe criteria with a well efficiency limit of not less than 70%. The simulation resulted in drawdown classified as safe criteria (<40%) and the amount of groundwater produced was 513.68 m3/day. These results do not meet the minimum water needs, so other water sources are needed to cover these needs. Based on the values of several aquifer parameters, the groundwater potential at the research location can be classified into the moderate class

Estimation of Aquifer Hydraulic Parameters and Operational Discharge of Raw Water in Woyla District, West Aceh District, Aceh Province

2023-10-04T08:39:55+08:00

Groundwater is one of the most important natural resources because it fulfills the needs of daily life, agriculture, irrigation and industry. Population growth and regional development also increase the demand for and service levels of drinking water, which requires management of water distribution. According to reports, 25 villages in Woyla district are still facing water shortages and the water debt to meet this need is around 559,800 L/day. In terms of regional geology, the study area includes young floodplain strata consisting of silt deposits, sandy loam, fine sand, and coarse sand. The geoelectric method is a method for studying the nature of current flow in the earth according to the laws of electricity. The power log is a recorder for SP and resistivity is a record that must be kept at each well formation interval. The pumping test is the stage of testing the runoff capacity and physical parameters of the aquifer before the production stage is carried out on the well. The average MAT of the three villages is 2.26 meters from north to south. According to geoelectrical data GL7, GL8, GL9, GL10, GL11 and GL12, the resistivity of the sandy aquifer ranges from 59 – 809 ohm.m and a total thickness of 99 m. Cot Punti Village 430.27 m3/day, Jawi Village 473.27 m3/day and Alue Village 477.52 m3/day Well efficiency is 95.3 when using the Hantush-Bierschenk method (1964) assuming the average value of Cot village Punti processed test data for the multi-stage discharge pump %, which was 89.73% in Jawi village and 99.97% in Alue village, so that pumping was still effective. The average well efficiency based on the Ghost Bierschenk method is 94.9%, 1.76 m3/day for Cot Punti village, 3.73 m3/day for Jawi village and 3.66 m3/day for Alue village. The transmission rate is 56.5 m²/day in Cot Punti village, 149.4 m²/day in Jawi village and 88.1 m²/day in Alue village. Woyla District has a resource load of 1,380,000 liters/day.

A Redundant Electromechanical Elevator System

2023-10-04T08:51:47+08:00

Current trend towards sustainable aviation has led to development of more- and all-electric aircraft and its systems. However, the usage of electrical alternatives in flight still limited due to safety and reliability concern, especially jamming failure. Hence, this paper proposed an architecture for redundant electromechanical elevator systems (EMA) and a decoupling method to release an actuator from the entire system at jamming failure. This paper also discusses the potential advantage of using EMA over existing hydraulic actuator system in aircraft. It is shown that EMA system proposed in this paper satisfy the regulatory requirements to power aircraft elevator system. The comparison to other type of actuator also shown improvement in reliability, with failure rate for the proposed EMA systems around 2.25×10^-8 failure per flight hour.

Flooding Management with System Dynamic Approach (Case Study: Citarik Sub Watershed)

2023-10-04T09:04:43+08:00

Citarik Sub Watershed (Upper Citarum Watershed) is a critical and priority sub watershed indicated by the occurrence of hydrological degradation, the annual flood phenomenon. Floods occur due to runoff increase, influenced by natural and many anthropogenical factors. A necessary study is conducted to model the dynamic system using STELLA related to floods in Citarik Sub Watershed to study the flood phenomenon, its influential components, and their interactions by simulated scenario and become a consideration in determining policies based on the flood discharge. The model shows based on the sensitivity analysis that the low leverage variables include growth and mortality rate, while the high leverage variables include forest conversion rate. According to the case analysis, the RPJMN (26 m³/s) and river normalization (16.82 m³/s) policies are considered to be enhanced with other scenario and the most effective scenario based on STELLA running result by maintaining a minimum forest area of 30% of the watershed's total area and reducing the forest conversion rate to zero by making the forest a conservation forest and conducting reforestation, the model predicted that this scenario could avoid flooding occurred (0 m³/s) in the area for the next 20 years.

Study on Extending the Lifetime of MASARO Fertilizer and Feed Concentrate Products

2023-10-04T09:22:32+08:00

Waste is one of the environmental issues that need to be given more attention. In addition, based on the Central Statistics Agency, about 86.5% of Indonesian farmers use inorganic fertilizers. This will lead to environmental and economic problems. The viable option to solve these problems is by applying Masaro (Manajemen Sampah Zero) to enhance the abundant organic waste as organic liquid fertilizer and improve the agricultural industry's productivity. The fertilizer and feed concentrate are made by enzymatically fermenting decomposing waste using the MASARO catalyst through two fermentation stages where the macro nutrient is converted into organic acid on the first stage and continued with the amino acid decomposition on the second stage. An important indicator of the complete fermentation process of both products is pH which is required in the range 3.9 – 4.2 within four weeks. The lifetime of these products is around one year with the condition stored in a shaded location and is not exposed directly to sunlight. Therefore, the implementation of a system that can extend the lifespan of both products is necessary, so that the lifespan is not solely dependent on the storage methods of the products, which can be advantageous for both consumers and producers.

Potential debris flow of the Tuva River in Sigi Regency, Central Sulawesi Province

2023-10-06T14:17:52+08:00

Flash floods/debris floods that occur in the Tuva River of Sigi Regency are streams of water mixed with various materials such as wood, rocks, mud, and others that have a very fast flow speed. Flash floods submerged the residential area of the community with a water presence of 3 m which had claimed the lives of 2 people. Flash floods occur after catastrophic earthquakes and soil liquefaction. Where the topographic conditions around the Tuva River are very steep and the characteristics of the river widens upstream and narrows downstream, there is the potential for avalanches of liquefaction of mountain ridge land that enters the river which forms a natural weir in the Tuva River. The modeling conducted in this research utilized a Digital Elevation Model (DEM) map with a resolution of 5-10 meters using Hec-RAS software. The modeling focused on the dam break of a natural dam, resulting in a debris flow volume of 104.663 m3/s. With the non-Newtonian flow model, the study determined a flooded area of 58.978 hectares or 0.589 square kilometers with a maximum flow velocity of 2645.33 m/s. This has the potential to erode the riverbed and supply sediment transport to the Miu River.

Mapping of Content, Visual, and Interactive Elements of Children’s Mobile Apps with Theme About Disease

2023-10-06T14:33:48+08:00

The rise in the use of electronic devices has pushed digital media to become familiar tool in children's daily lives. The flexibility of mobile devices combined with the advantages of application features make mobile apps suitable as a media to support children's learning processes, one of which is education about disease. Disease-themed children's mobile apps are interesting to be analyzed because of the possibility of particular approaches that are taken to develop and deliver disease-themed content into digital media designed for children. An analysis was carried out on contents, visual elements, and interactive elements on 43 disease-themed children's mobile apps using qualitative exploratory approach. Textual analysis method was used with the stages that includes identification, categorization, and interpretation using a mapping model made from the results of a literature study. Of the various types, there are three most common models of disease-themed children's mobile apps; role-play game models to introduce medical practice, interactive environment models to introduce health care facilities, and narrative models to introduce disease. It is hoped the research’s results can provide insights regarding children's mobile apps with theme about disease and become a reference for researchers and developers of disease-themed children's mobile apps

Inundation Height Prediction using Machine Learning with Artificial Neural Network (ANN)

2023-10-07T15:05:29+08:00

Predicting the water level of inundation for the Majalaya Area is important for preventing huge losses because of floods. Because the water level increases rapidly when it rains within one to two hours, and people have time to mitigate. In this study, Machine Learning (ML) with Artificial Neural Network (ANN) method is applied to predict the inundation map in Majalaya Area. Satellite rainfall data from 2014 until 2020, distance to the nearest river, and distance to inflow from Merit DEM are the dependent variables. The inundation height from HEC-RAS extreme rainfall simulation from 2017 until 2020 is the independent variable. All data for the ANN model is divided into training and testing data for machine learning, with 75% data for training and 25% for testing. The results of training machine learning are the inundation height by ANN and inundation height by HEC-RAS have Multiple R-Square (R2) is 0.9212, and for testing data, the R2 is 0.9277. The conclusion is that the machine learning model can predict the inundation height with a high correlation coefficient result. The development of this idea and model is expected to reduce the loss of flooding and improve mitigation.

Development of Sulfonated Aromatic Proton Exchange Membranes Containing Biphenyl Moieties for Water Electrolysers

2023-10-07T14:55:19+08:00

Hydrogen is the most efficient energy carrier that can be obtained from various feedstock sources, including water. One environmentally friendly method for producing high-purity hydrogen is water electrolysis. Polymer electrolyte membranes, or proton exchange membranes (PEMs), are semipermeable membranes that conduct ions while preventing the mixing of reactant materials across the membrane. This study proposes a method for synthesizing proton exchange membranes through post-sulfonation polymer synthesis. The aromatic compound biphenyl is used as the monomer in this synthesis. The advantages of this method are its simplicity, low production cost, and performance equivalent to Nafion® membranes at room temperature. The biphenyl membranes are characterized through FTIR, NMR, Fenton Test, Water uptake, Swelling ratio, IEC, and conductivity analysis. The resulting sulfonated biphenyl membranes exhibit good mechanical strength and oxidation stability. The Weight Loss in the Fenton Test of the sulfonated biphenyl membranes shows a value of 10%, similar to Nafion 212 based on previous studies. Furthermore, the sulfonated biphenyl membranes demonstrate a water uptake of 60%, swelling ratio of 7.5%, Ion Exchange Capacity of 3.31 meq/g, and 40 mS/cm conductivity.

Electric Car Battery Swapping Station Potential Application in Indonesia: A Review

2023-10-08T14:16:21+08:00

Swapping battery is one of electric car charging mechanism and the place to do it called Battery Swapping Station which is one of kind electric vehicle’s infrastructure. In this transition to electric vehicle era, Indonesia is also taking part in this, electric car swapping station is still lack applied in Indonesia, but through some regulations Indonesia is working to increase the number and quality of electric vehicle’s infrastructure. This study is giving information and insight about electric car swapping station potential application in Indonesia. Other countries application is discussed to give insight adoption for Indonesia, strategies and suggestions are also presented in this study.

The Use of Interactive Media with 3-Dimensional Virtual Environment for Indonesian History Lesson About Indonesian Proclamation for Eleventh Grade Students

2023-10-08T14:30:15+08:00

Previous studies have found several problems in history lesson process for students, including the lack of variety on how the lesson is taught. Which shows that there needs to be innovations or alternatives in the way history lessons can be taught to students. Meanwhile, 3D virtual environment technology has been used for various aspects of life. Previous studies have also found several benefits of 3D virtual environment and interactive media for learning. As such, the aim of this research is to examine the combined potential of interactive media with 3-dimensional virtual environment as an alternative learning tool for formal learning, and to identify design recommendations that can be used for designing such media. This research chose Indonesian history lesson about Indonesian Proclamation event for eleventh grade students as a case study because of its relevancy with Indonesian curriculum and citizens. This research uses qualitative approach that uses triangulation analysis of data collected from literature study, interview, and questionnaire. This research found that interactive media with 3D virtual environment has good potential to be used as an alternative tool/medium for formal learnings, more so for the chosen case study. This research also found various design recommendations that are categorized into method, concept, and visual recommendations.

Analysis of Horizontal and Vertical Distribution of Metal Contaminants in Water and Soil in Sumobito Area, Jombang District, East Java Province

2023-10-10T21:46:07+08:00

Jombang Regency is known as one of the districts that has become a center for smelting electronic waste to extract aluminum metal since 1970. However, many industry owners are ignorant and dispose of waste carelessly into house foundations, village roads and rice field boundaries. The purpose of this study is to determine how the distribution of metal contaminant concentrations in water and soil horizontally and vertically, and what factors affect the distribution pattern of these contaminants. The methods used in this study were water and soil sampling to determine the total concentration and TCLP of As, Cd, Cu, Hg, Pb, Zn, Al, and Ni ions, and XRD analysis to determine soil mineralogy. The data was processed to analyze the type of metal fractionation. Laboratory results show that the metal content in water is below the quality standard and moves following the direction of groundwater flow. Then the distribution of metal concentrations in the soil horizontally is that the farther away from the waste slag the concentration are lower, but vertically the highest metal concentration is found at a depth of 30-60 cm. Based on the analysis conducted, it is known that the distribution of metal ions in water and soil is influenced by climatology, advection-retardation, metal fractionation, preferential flow, and reduction by plant.

Regional Hydraulic Geometry of Banger River Related to Sediment Prediction and River Morphology Stability

2023-10-10T22:23:25+08:00

Pekalongan City is located in the lowlands which has a very gentle slope of the land surface. In some northern areas, most of the land surface is below sea level, making it difficult for water to flow into the sea because it is held back by water from the sea (rob). In this paper an analysis will be carried out regarding the distribution of floods and see how the regional hydraulic geometry occurs in the Banger River. Furthermore, this research aims to examine the conditions of sediment transport and the stability of river morphology that occur in the Banger River. Flood modeling and sediment transport analysis in this study were conducted using HEC-RAS software. The results of this research indicate that during a 2-year return period flood, approximately 400.14 hectares of area, mainly in downstream areas will be inundated due to the river's morphological instability related to its width, depth, and slope. This study is highly valuable because the stability of the river regime, which may contribute to flood occurrences, is often overlooked in river management planning

Prospective Application of Flue Gas Washing Liquid from the Wet Scrubber Unit at Masaro Plastic Refinery for Pesticides

2023-10-10T22:50:41+08:00

The plastic refinery represents an advanced technology designed to effectively manage residual waste. This innovative approach integrates the principles of incineration and pyrolysis to yield valuable products, including fuel and flue gas washing liquid obtained from a wet scrubber unit as wastewater. The flue gas washing liquid contains various compounds, such as ammonia, which did not meet the quality standards stipulated by the Ministry of Environment. Furthermore, it also encompasses phenolic compounds, nitrates, and nitrites. These chemical constituents impede the direct discharge into the environment due to their inherent toxicity towards aquatic organisms. However, within the agricultural domain, ammonia, phenol, nitrate, and nitrite are extensively employed as pivotal ingredients, serving as valuable sources of nitrogen in the production of fertilizers and pesticide raw materials. This research endeavors to conduct a comprehensive analysis of the composition of the flue gas washing liquid. The primary objective is to evaluate the potential utilization of its components as principal ingredients in pesticide formulations. To augment the effectiveness of the pesticides, supplementary active ingredients are incorporated, derived from various plant species recognized for their efficacy in combatting plant pests and insects. The extraction process involves combining the flue gas washing liquid with selected plants, such as bintaro fruit, garlic, citronella, neem leaves, and tobacco. This approach not only addresses the issue of environmentally friendly disposal of liquid waste but also provides a sustainable solution to meet the agricultural sector's demand for efficient pesticides.

Geothermal Conceptual Model of Talu-Tombang West Pasaman, West Sumatera Based on 3G Data Studies

2023-10-10T23:09:46+08:00

Talu-Tombang geothermal system is one of the potential geothermal resources in West Sumatera. This geothermal system is indicated by the presence of warm water pool as surface manifestation at Talu (TA 1 and TA 2) and Tombang (TO 1 and TO 2). This study aimed to develop a conceptual model of the Talu-Tombang geothermal system. This study includes geology, fluid chemistry, gravity, and geoelectrical DC resistivity survey. Lithology present in the study area is Pre-Tertiary metamorphic rock, Tertiary sedimentary rock, Quaternary volcanic rock and alluvial. The existence of manifestations in this area is associated with NW-SE and NE-SW fault systems. The chemical analyses show that Talu waters have HCO3-Cl type and Tombang waters are SO4-HCO3 type. Result from the gravity survey shows the high residual anomalies of more than 30 mGal in the middle of the study area indicating an intrusion rock; the intrusion might act as a heat source. Reservoir fluid is meteoric water origin. Based on resistivity data, the low resistivity value below 100 Ohm-m is associated with alluvium product at the eastern area. Based on 3G data, the geothermal system has two reservoirs, i.e. Talu and Tombang reservoirs. Geothermometer of K/Mg show reservoirs have temperatures of 150±10°C.

A Surface Plasmon Resonance (SPR) Simulation Based on Kretschmann Configuration for Glucose Detection

2023-10-10T23:46:14+08:00

Numerous studies have been conducted on the detection of glucose as the prevalence of diabetes grows in both industrialized and developing countries. a poor way of living those results in a persistent buildup of blood sugar levels over the acceptable limit. Therefore, to detect glucose concentrations, high sensitivity, label-free, and high-resolution sensors are required. A biosensor is a device or device that utilizes the molecules of living things to detect chemical materials with output in the form of electrical, thermal, or optical signals. Biosensors that are now widely developed are optical biosensors. This is because optical biosensors can make real-time measurements, have high sensitivity, simpler analysis, and lower costs. One of the basic technologies in optical biosensors is the observation of the Surface Plasmon Resonance (SPR) phenomenon. SPR is an optical phenomenon where there is a resonance between light waves and free electrons (plasma) that oscillate and travel along the metal surface layer. In this study, biosensor Surface Plasmon Resonance (SPR) simulations were carried out and the effects of varying the glucose concentration on the sensor response were examined. The modeling outcomes showed that the decline in reflectance varied with glucose concentration. In the simulation analysis, the curve obtained shows that there is a shift in the angle towards the positive x-axis. This shows that with every increase in the concentration of glucose solution there is a shift in the angle and an increase in the refractive index. A range of glucose readings that might indicate diabetic symptoms were used in the study with sensitivity was 147.84 . Herefore, this sensor type may be used to detect glucose in the concentration range for diabetic patients.

Diethyl Phthalate (DEP) in Leachate End-Processing Sites Worldwide and Remediation Technologies for The Treatment

2023-10-11T13:20:08+08:00

Production of plastic is inseparable from the addition of additives in the form of plasticizer which adds the flexibility of the plastic in its final product form. One of said plasticizer is Phthalate Diester (PAEs). One PAE substance that has been declared as hazardous is Diethyl Phthalate (DEP). PAEs can easily migrate from the plastic polymer into the environment and endanger living beings. One potential site of DEP accumulation is final processing site due to it receiving huge amounts of plastic waste from domestic and industrial activities. Leachate is a transport medium for DEP substance from final processing site. Efforts must be done to reduce DEP toxicity in leachate to ensure safety of health and ecosystem. The objective of this paper is to describe the hazard of DEP towards health, correlation between landfill age and DEP concentration, and appropriate remediation technique for further treatment of DEP.

Evaluation of Structural Conditions of Rigid Pavement Using AASHTO 1993 and MDP 2017 Method (Case Study: Soekarno – Hatta Road (Bandung) Km.8+100 s/d 11+600

2023-10-11T15:11:06+08:00

The rigid pavement of Soekarno-Hatta (Bandung) road is an avoidance or bypass road where congestion often occurs after the Padaleunyi toll road and the intersection of five intersections. Therefore, it is necessary to evaluate the structural conditions and design an overlay of AC using the AASHTO 1993 and MDP 2017 methods. Evaluation of pavement stiffness using the average daily traffic data and deflection obtained from the FWD testing tool. Structural evaluation using the AASHTO 1993 back-calculation method obtained the concrete modulus of elasticity (Ec) below the typical value between 3 million and 8 million psi, so the concrete pavement strength has decreased, while the evaluation of load transfer efficiency (LTE) obtained very poor results. Analysis using the AASHTO 1993 method based on the remaining life is thinner than the condition survey. In the MDP 2017 method, the overlay option is based on the maximum deflection (D0), and CESA4 does not require overlay. Whereas the deflection curvature (D0-D200) and CESA5 approaches require a thick layer of overlay. The result of the overlay obtained for the slow lane in the AASHTO 1993 method is thinner than the MDP 2017 method. Meanwhile, the fast lane in the AASHTO 1993 method is thicker than the MDP 2017 method. The predicted remaining life with a design life of 20 years is in the Cibiru direction around 78,30% and the direction of Gede Bage around 80,00%.

Effect of Solvent Ratio and Extraction Temperature on the Purity of Vitamin E from Palm Fatty Acid Distillate Extract

2023-10-16T08:56:38+08:00

The presence of vitamin E in palm fatty acid distillate (PFAD) mixes with free fatty acids (FFA) so separation process is required. Vitamin E can be separated through a process technology that removes fat components and non-saponifiable components. The combination of separation process technology used are homogenization, neutralization and extraction. Extraction was carried out using multiple solvents including n-hexane, ethanol, and water to bind each component based on its polarity index. This study aims to determine the significant effect of solvent composition and extraction temperature on the yield and purity of vitamin E. The purity of vitamin E is strongly influenced by the variables, the lower the ethanol ratio and the higher the extraction temperature, the higher the yield and purity of vitamin E obtained. The highest yield of vitamin E to PFAD was 13.07%-w/w in the solvent composition n-hexane:ethanol:water 45:10:45 at 65◦C. A high purity vitamin E concentrate was obtained with the lowest acid number of 15.50 mg KOH/g sample and very strong antioxidant activity (IC₅₀ value 17.07 ppm) on the composition of n-hexane:ethanol:water 40:20:40 at 60◦C.

Simulation Study of Polyglycerol Separation with Distillation Column using Aspen HYSYS

2023-10-16T09:20:19+08:00

Biodiesel production results in glycerol waste can be utilized to be pure glycerol through distillation process. The bottom product of this process, also known as glycerine pitch can be extracted to obtain polyglycerol. To obtain high-purity polyglycerol for various industries, the extract solution must undergo a purification process, typically using distillation. This research investigated the possibility of utilizing extracted solution of glycerine pitch by separating polyglycerol compounds, such as diglycerol and triglycerol, using vacuum distillation. A distillation column was simulated using Aspen HYSYS software to evaluate the separation process. The operating conditions were determined using a shortcut column initially before using the distillation column. Feed concentration was varied to analyze its effect on product composition, percentage of glycerol recovery, and reboiler temperature. The simulation results showed that high-purity glycerol (99%) can be separated from polyglycerol.

Kujang, Past, and Present

2024-01-30T20:45:02+08:00

This writing aims to find out how the development of the kujang from ancient times to the present. Kujang, which is a unique weapon from the Pasundan region, certainly cannot be separated from the impact of the times. Thus, without realizing it, the development of the times has influenced the development of the Kujang itself. The focus of this research will investigate how modern developments affect the kujang itself. This study is a qualitative research with descriptive qualitative as its approach. The data collected by using literatue review and interview. Based on the results, the development or dynamics of the Kujang can be seen from its history, type, function, and manufacturing process. For example, according to the manufacturing process, on the time benchmark, the kujang has a certain time benchmark to produce kujang for certain functions such as ageman or heirloom. In addition, the function of the Kujang has also shifted. Where, in the Pajajaran era, the cleaver had various functions such as an ageman or heirloom, ceremonial tool, weapon, and agricultural tool. However, its function has now shifted to accessories such as necklaces and so on. The change of its function is considered a good way to approach today’s society and preserve Kujang.

Flood Hydrograph Modeling Based on Rainfall Data in The Dayeuhkolot Watershed Using Hec-Hms

2023-10-16T12:30:58+08:00

Dayeuhkolot, located 9 km from the center of Bandung City or about 18 km from Soreang, is a Citarum sub-watershed that experiences flooding every year. The causes of flooding are natural factors such as high rainfall and human factors such as blocked or damaged drainage channels, inappropriate land use, deforestation in the upstream areas, etc. Floods cause loss of life and property damage. Population growth results in more urbanization, airtight areas, less infiltration, and more significant flood peaks and runoffs. The flood hydrograph projection uses this study's GSMAP rainfall data and land cover data. The flood hydrograph method used is the SCS curve number method, which obtained 12 river discharge events of more than 300 m³/second from 2018 to 2022. Then calibration and validation were carried out using the trial-and-error method using the HEC – HMS software to obtain parameter values hydrology and ArcGIS to obtain the value of the land cover curve for the next stage of calibrating the values obtained from the HEC - HMS modeling by classifying land cover for 2018 - 2022. The predictions and calibration results of hydrological parameters are input for future flood hydrograph projections.

Phenolic derivatives from heartwood of Cryptocarya pulchrinervia (Lauraceae)

2023-10-16T14:13:45+08:00

Cryptocarya is a genus of plants in the Lauraceae family with 350 species. This genus has many economic values, such as building materials, perfume, and traditional medicines. Cryptocarya were reported to contain flavonoids, pyrones, and alkaloids as main secondary metabolites, as well as phenyl propanoids, lignans, stilbenoids, terpenoids, and steroids. Isolation and bioactivity of secondary metabolites of C. pulchrinervia leaves have been recently reported. Meanwhile, the isolation of other plant parts, such as the heartwood, has never been conducted. Therefore, the objective of this research was to isolate secondary metabolites from the heartwood of C. pulchrinervia and determine their bioactivity against murine leukemia P-388 cells. The structures of the isolated compounds were determined based on 1D-NMR spectroscopy data (¹H-NMR and ¹³C-NMR). In this research, three secondary metabolites were isolated, consisting of three phenolic compounds, i.e., syringaldehyde (1), coniferaldehyde (2), and sinapaldehyde (3). The IC₅₀ values of the extract and the compound 1-3 was 57.91 mg/mL, 28.0 mg/mL, 26.47 mg/mL, and 24.00 mg/mL, respectively. The extract and all compounds were inactive against P-388 cells.

Effect of Neutralization Pre-treatment for the Production of Magnesium Salt from Palm Fatty Acid Distillate (PFAD)

2023-10-18T18:32:58+08:00

Palm Fatty Acid Distillate (PFAD) was used as raw material to produce magnesium salt of palm fatty acid distillate (Mg-PFAD), which can be used as a solid lubricant, emulsifier, and antioxidant in food and nutraceutical products. PFAD is composed of approximately 85–95% wt of free fatty acids (FFA) and 10–15% wt of triglycerides as impurities. To enhance the conversion of fatty acids into Mg-PFAD salt, the synthesis of Mg-PFAD salt was carried out by neutralizing or saponifying PFAD using magnesium oxide. Several pre-treatment methods prior to neutralization were investigated, such as hydrolysis, homogenization of PFAD in water, or direct neutralization. This research aimed to determine the effect of neutralization pre-treatment on the acid number, degree of FFA conversion, and concentration of total tocopherol. The homogenization-assisted neutralization process reduces the acid number by 15 times from the initial PFAD, or 6.97 mg total tocopherol/g Mg-PFAD, and results in a conversion of 94%.

Tackling Class Imbalance Problem with Adversarial Attention-based Variational Graph Autoencoder: Study in Fraud Detection

2023-10-18T18:51:11+08:00

Class Imbalance is often encountered in many classification problems for machine learning, resulting in bias towards the majority class. Various techniques have been developed to address this issue, focusing on oversampling the minority class or undersampling the majority class. This research aims to tackle the class imbalance problem with a different approach by using Adversarial Attention-based Variational Graph Autoencoder (AAVGA) introduced by Weng et al. in 2020. This approach is studied for fraud detection, which graph model of classification task are first constructed by mapping each entity as nodes and transaction between them as edges. The experiment is conducted by varying class distributions to analyze how imbalance class influences the prediction score. We obtained that our approach produced better precision and recall score, even for extremely imbalanced dataset.

B-Hom(Z_n,Z_n) as B-Algebras

2023-11-28T19:20:26+08:00

B-algebra is an algebraic structure that can be built from a group. Because the set of all integers completed by the addition operation satisfies the group property then B-algebra can be built from a group of the set of all integers completed by the addition operation. The set of all B-homomorphisms from B-algebra which is built from a group of the set of all integers modulo can form B-algebra if it’s certain properties.

The Effect of Ameroro Reservoir on River Morphology Stability Using Regime Theory

2024-01-02T18:50:06+08:00

The stability of river geometry is one of the considerations to determine whether a watershed is good or not. Ameroro River is a tributary of Konaweha River located in Konawe Regency, Southeast Sulawesi. The Ameroro River model uses river measurement data along 43.5% of the length of the main river and uses geological data as a model for sediment transport. In hydrological analysis using the Log-Normal distribution and daily discharge modeling with the Sacramento method calibrate by 9 years of observational data with a match rate of 52.9% and a calculation process was carried out with the help of the HECRAS program. The results of the modeling were checked and approached using 3 methods of regime theory, Blench, Lacey and Modified Regime as a reference for calculating river stability as seen from the cross-sectional width of the river. It was found that reservoir affect changes in riverbed elevation, water level elevation and degradation/aggradation compared to existing conditions. The existing condition has a stable river cross-section more than the condition of the reservoir but only 7.29% of the total river cross-section is reviewed. For overall of river, it was found that the reservoir affected the stability of the river is closer to the calculation results of 3 regime theory methods compared to existing conditions tested by NSE, RMSE and CORRELATION methods

Flood Control Study for Cikeruh River Basin in Bandung City

2024-01-30T20:33:05+08:00

The Cikeruh River is located in the regency of Bandung and is part of Citarum River tributary. Flooding’s one of the problems that occur in Cikeruh River and it became an important issue in Bandung City as the river flow through economic area of the city. The flood that occurred on the Cikeruh River was caused by a high river with the discharge of 272.53 m3/s. But not only because of the high discharge in the river, but also influenced by backwater from the Upper Citarum River which confluence with Cikeruh River. From the flood modeling on the Cikeruh River, it was found that the height of the flood overflow could reach three meters with an almost even distribution of inundation in all locations. As an effort to provide solutions, alternative solutions are provided to overcome this problem, namely by normalizing rivers, river embankments, and retention ponds. Alternatives to river normalization and the construction of retention ponds are deemed unable to completely deal with flooding, so the most effective solution in dealing with this flood is the construction of embankments.