Computational Engineering Commons^™

Metal Casting Furnace Design Development Using Computer Simulation, Ramadhan Wahyu Irianto, Yanuar R.A. Pradana, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

Metal foundries still rely heavily on crucible furnaces. The current furnace design, which is currently being used by the partner industry, has been found to be not properly designed and will result in a reduction in efficiency. CFD simulation will be used to find the optimal melting furnace design. This research simulation consists of 3 stages: pre-processing, solving, and post-processing. There are two furnace geometries, cylindrical and hexagonal, while the burner location will be divided into 3 positions, namely P1, P2, and P3. The most optimal furnace design will be used as a basis for the verification testing process. The …

Evolution Of Residual Stress, Crystal Orientation, And Texture On Preheating Weld Treatment Of Low Carbon Steel Astm A572 Grade 42, Suratno Adi Saputro, Andoko Andoko, Poppy Puspitasari

Journal of Mechanical Engineering Science and Technology (JMEST)

Preheating is one type of heat treatment on the material prior to starting the welding process by increasing the temperature of the material. It is used to reduce the cooling rate during the welding processes to minimize the risk of residual stress and cracking during welding. Besides the benefits of welding, it also has a negative impact, especially on the integrity of the material, because the heating process at high temperatures will cause residual stress, which will affect the mechanical properties, chemical composition, and microstructure of the material, especially on Heat Affected Zone (HAZ). This study aims to analyze the …

Static And Modal Analysis Of A Box Structured Satellite Deployment Mechanism With Self-Actuated Torsion Joint, Dongping Sheng, Renzhe Ma, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

A brand-new satellite deployment mechanism with boxed structure and self-actuated torsion joints is proposed and an effective method to verify the feasibility of this mechanism is established in this paper. This mechanism has the characteristics of high base frequency, high ratio of deployed and folded space occupation ratio. In order to meet the design requirements, the related analysis and optimization need to be conducted, and several conclusions are obtained. Firstly, the modal analysis of deployment mechanism at folded and fully deployed state is analyzed, and the result showed that the proper wall thickness is the key parameter to satisfy the …

A Review Of Fault Detecting Devices For Belt Conveyor Idlers, Fahad Alharbi, Suhuai Luo

Journal of Mechanical Engineering Science and Technology (JMEST)

The shift towards automated inspection methods represents considerable progress in conveyor system maintenance, enhancing safety and efficiency while posing challenges in data analysis and implementation costs. This study critically analyses sensor technologies and inspection methods for detecting faults in conveyor belt idlers, highlighting their essential role in preserving the operational integrity of industrial conveyor systems. By synthesizing various research findings, the study assesses the effectiveness of different sensor devices in identifying defects, including built-in sensors, fixed sensor options like acoustic, ultrasonic sensors, cameras, accelerometers, and Distributed Optical Fibre Sensors (DOFS), as well as mobile sensor systems. Our findings emphasize the …

Simulation Of The Performance Of Kevlar Impregnated Shear Thickening Fluid Ballistic Test Results, Ridwan Prasetya, Andoko Andoko, Suprayitno Suprayitno

Journal of Mechanical Engineering Science and Technology (JMEST)

This study explores the enhancement of Kevlar fabric’s ballistic performance through impregnation with Shear Thickening Fluid (STF) for potential application in soft body armor. The experimental approach often fails to elucidate mechanical phenomena critical for the development of lightweight and high-strength body armor designs. To address this limitation, the finite element method, specifically using ANSYS/LS-DYNA R.13, was employed for a comprehensive analysis. The simulation aimed to evaluate the impact of STF on Kevlar fabric by assessing projectile velocity, force exerted by the projectile onto the fabric, displacement, stress distribution, and fabric failure mechanisms. Kevlar yarn was modeled as a shell …

Analysis Of Avgas Fuel Spraying Schemes Using The Ansys Application Approach, Dimas Endrawan Putra, Nasrul Ilminnafik, M Fahrur Rozy Hentihu, Muh. Nurkoyim Kustanto, Danang Yudistiro, Skriptyan N.H. Syuhri

Journal of Mechanical Engineering Science and Technology (JMEST)

Avgas fuel consumption on Cessna trainer aircraft is very high. However, there has been little research regarding spray impacts in Cessna aircraft engines. The phenomenon of avgas spray colliding with the cylinder wall may occur during fuel injection, resulting in a changed spray radius and height, which will affect the mixing of fuel and air. In several aspects, this affects engine performance and exhaust emissions on Cessna aircraft. This research aims to determine and study the phenomenon of spray impact on avgasfueled aircraft engines. The fuel spray in the study occurred in the combustion chamber using pressure from a fuel …

Effect Of Addition Titanium Dioxide Nanoparticle On Properties Of Pineapple Leaf Fiber Mediated Tempo Oxidation, Rahmad Ikrom Ramadhan, Heru Suryanto, Ahmad Atif Fikri, Aminnudin Aminnudin, Jibril Maulana, Faqih Fadillah, Mohamed T. Mito, Kemal Masera

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is an agricultural country with the potential to grow many plants as natural fiber sources. In order to improve its properties, natural fiber needs to be treated by applying nanomaterial so that it can compete with the characteristics of synthetic fibers. The study aims to determine the influence of adding titanium dioxide (TiO2) nanoparticles on pineapple leaf fiber (PALF) characteristics. The PALF was collected from the Subang plantation (Indonesia). The chemical treatment was carried out with pre-treatment using an alkalization process for 3 hours, and the oxidation process was carried out with TEMPO. TiO2 nanoparticle grafting was carried out …

Computational Fluid Dynamics Analysis Of Temperature Distribution In Solar Distillation Panel With Various Flat Plate Materials, Trismawati Trismawati, Hendry Y. Nanlohy, Helen Riupassa, Susi Marianingsih

Journal of Mechanical Engineering Science and Technology (JMEST)

As the world population continues to grow, the demand for clean water is increasing daily, making it a crucial resource to access. However, there are ways to harness abundant resources like solar energy and seawater to produce clean water. The present studies have conducted experimental investigations to convert seawater into freshwater using solar stills, where solar energy is utilized as the primary heat source for evaporation. The temperature distribution inside the solar stills was analyzed using a flat plate made of three different materials: copper, stainless steel, and aluminum. To examine the temperature distribution and performance of the solar stills, …

Performance Enhancement Of Dye Sensitized Solar Cell (Dssc) Through Tio2/Rgo Hybrid: Comprehensive Study On Synthesis And Characterization, Rustan Hatib, Khairil Anwar, Ramang Magga, Muh Anjas Astak, Denny Widhiyanuriyawan, Wardoyo Wardoyo

Journal of Mechanical Engineering Science and Technology (JMEST)

The TiO2 film is immersed in a graphite oxide solution, preparing it for thermal reduction, which converts the graphite oxide to reduced graphene oxide (rGO). This process produces rGO hybrid TiO2 photoanodes for dye-sensitized solar cells (DSSC). rGO in the TiO2 structure prevents electron recombination and improves overall efficiency. The main advantage of this method is its ability to prevent loss of rGO during the sintering process, which is a common problem with other methods. The study investigated heating temperatures ranging between 300˚C, 350˚C, 400˚C, 450˚C, and 500˚C to determine optimal conditions. The presence of rGO in the photoanode structure …

Pyrolysis Kinetics Of Spirulina Platensis And Non-Condensable Gas Product Distribution In A Fixed-Bed Reactor, Ahmad Yusril Aminullah, Sukarni Sukarni, Retno Wulandari, Muhammad Shahbaz

Journal of Mechanical Engineering Science and Technology (JMEST)

Energy is a fundamental factor for civilization development and sustainability. However, energy sources are dominated by non-renewable fractions, such as fossil fuels. Renewable biomass is projected to be a future fuel source. Spirulina platensis (SP) has numerous advantages compared to other biomass, and it is considered 3rd generation biomass that does not interfere with food and land usage and has a relatively low main decomposition temperature at 325.7℃. Thermogravimetric analysis (TGA) was conducted to observe SP kinetics parameters, especially activation energy. Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Starink iso-conversional methods reveal that SP has an activation energy of 152.33, 154.56, and …

Crashworthiness And Deformation Pattern Analysis Of Single And Double Wall With Addition Infill Structure, Redyarsa Dharma Bintara, Moch. Agus Choiron, Yahya Zakariya, M. Hasbi Ash Shiddieqy, Fajar Adi Pratama

Journal of Mechanical Engineering Science and Technology (JMEST)

Ship collisions are a phenomenon that often occurs in maritime transportation. One part of the ship that often experiences damage is the ship's wall (hull). This research aims to analyze and compare deformation patterns, stress distribution, and energy absorption in three wall models, single wall, double wall, and double wall, with the addition of infill structures. The infill structure used Polylactic Acid (PLA) polymer material because it provided convenience in the manufacturing process, while the walls of the test model used Aluminum 6063 material. The test model was developed by carrying out the design process using CAD software. Furthermore, a …

Heuristic Approach To Comparing The Environmental Impacts Of Carbon Nanotube Production Methods, Ahmad Atif Fikri, Irham Fadlika, Albarrobi Nabila Saeful, Krisna Dwipa Muhdi, Daniel Febrian Pratama, Nasir Garba Bello

Journal of Mechanical Engineering Science and Technology (JMEST)

Carbon Nanotubes (CNTs) production so far has its own advantages and disadvantages. Some methods that can be used in producing CNTs are chemical vapor deposition (CVD), laser ablation, and arc discharge. The three methods have their own requirements, this causes different environmental impacts on each method. Studies into the environmental impact of the CNTs production process found that during thermal pretreatment of the reactant gas, more than 45 by-products were formed, including methane, volatile organic compounds, and polycyclic aromatic hydrocarbons. Calculating the environmental impact of CNTs production method often has challenges in implementation, because each production process has different systems …

Mechanical Properties Of Corner Lap-45 Types Joined Using Friction Stir Welding, Widia Setiawan, Nugroho Santoso, Felixianus Eko Wismo Winarto, Radhian Krisnaputra, Wirawan Widya Mandala, Jibril Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

Solid welding has always been concerned with probe design, pins, and joint strength. Many researchers have conducted studies on joints, such as butt joints, lap joints, and T joints, but the results show low strength. This study analyzes the mechanical properties of a new design of a 90o angle joint joined by friction stir welding. This study connected aluminum 6061 using the friction stir welding method using a rectifying jig and a probe with EMS 45 material. The corner joint designs used corner-lap 45 with feed rate as independent variables in 6, 8, 10, 15, and 30 mm/min and dependent …

Study Of A Remote Wind Resource Assessment System Integrated With Internet Of Things, Filian Arbiyani, Filbert Filbert, Anthony Nathanael Theo

Journal of Mechanical Engineering Science and Technology (JMEST)

Wind energy is an emerging and popular source of clean energy due to its non-polluting nature and low cost. The efficient use of wind energy requires accurate and precise wind parameter measurements, which is where wind resource assessment (WRA) comes into play. The IoT and cloud-based systems have been applied to remote monitoring systems and provide crucial solutions for data acquisition, storage, and analytics in wind energy technology. This study aims to build a remote WRA system integrated with the Internet of Things. This study utilizes an Arduino Uno microcontroller, RK100-01 wind speed sensor, BMP280 temperature and pressure sensor, and …

Comparative Analysis Of The Effect Dual Spark Ignition And Single Spark Ignition On Performance And Exhaust Emissions In Bioethanol-Fueled Engines, Avita Ayu Permanasari, Ahmad Faizal Wahidin, Hasan Ismail, Erwin Komara, Poppy Puspitasari, Gina A. Lorenzo

Journal of Mechanical Engineering Science and Technology (JMEST)

Bioethanol is an alternative fuel that has a high octane value of around 100 to 110, making it difficult to be applied to spark ignition engines directly. So, it is necessary to make adjustments, including increasing combustion efficiency and thermal efficiency of the combustion chamber by increasing the compression ratio and adjusting the ignition system, both in single spark ignition (SSI) and dual spark ignition (DSI) types. The study aims to determine the effect of SSI and DSI applications on engine performance, specific fuel consumption (SFC), and exhaust emissions using 96% and 99% levels of bioethanol fuel. The results showed …

Analysis Of Ballistic Capability In Making Bulletproof Multilayers Using Woven Ramie Fiber, Hardfacing Metal With Epoxy Matrix For Bulletproof Vests, Rizal Wahyu Permana, Syamsul Hadi, Bima Cahya Maula Dana

Journal of Mechanical Engineering Science and Technology (JMEST)

Bulletproof material in level III bulletproof vests must be created using hard and soft materials to prevent bullet penetration. Kevlar and SiC + PE are imported materials used as armor in bulletproof vests. The use of Kevlar and SiC is very dependent on foreign sources with high prices. An innovation was carried out by making bulletproof material using cheaper multilayer methods involving metal from hardfacing welding as a hard layer and ramie fiber as a soft layer with an epoxy matrix. To see the level of penetration and surface morphology structure in the specimens, 9 variations were made: 3 layers …

Durability Of Thermoplastic Polyurethane Round Belt Joint With Variations In Heating Methods And Cutting Shapes, Achmad Sabilarrosyad Prawiro Kusumo, Anggit Murdani

Journal of Mechanical Engineering Science and Technology (JMEST)

Thermoplastic polyurethane round belts are widely used for conveyors in various industries, particularly in the food and beverage industry, due to their flexible and abrasion-resistant characteristics. These belts are also popular in manufacturing industries because of their ease of joint. However, a common issue arises when the conveyor belt breaks during the production process. This problem can be attributed to the lack of parameters in the belt joining process at companies. Operators do not have a standard parameter for the joining process. When there is an improper joining operation of an operator, the conveyor belt could fail earlier than the …

Deep Learning For Multiple Unmanned Aerial Vehicle Coordination In Air Corridors, Liangkun Yu

Electrical and Computer Engineering ETDs

In the future, city skies will be filled with Unmanned Aerial Vehicles (UAVs) for rapid urban transport, including parcel deliveries and air taxis. NASA's Urban Air Mobility (UAM) envisions UAVs navigating air corridors. These virtual pathways ensure safety and compliance with regulations. However, current research on UAM practical applications is limited. This dissertation focuses on designing air corridors, developing UAV control systems, and ensuring the robustness of control algorithms against disturbances in real-world environments.

Our design features an air corridor system with horizontal lanes and on-off ramps, conceptualized as cylindrical spaces and tori, respectively. To enable each UAV to locally …

Auxiliary Diagnosis Of Dental Calculus Based On Deep Learning And Image Enhancement By Bitewing Radiographs, Tai Jung Lin, Yen Ting Lin, Yuan Jin Lin, Ai Yun Tseng, Chien Yu Lin, Li Ting Lo, Tsung Yi Chen, Shih Lun Chen, Chiung An Chen, Kuo Chen Li, Patricia Angela R. Abu

Ateneo Laboratory for Intelligent Visual Environments

In the field of dentistry, the presence of dental calculus is a commonly encountered issue. If not addressed promptly, it has the potential to lead to gum inflammation and eventual tooth loss. Bitewing (BW) images play a crucial role by providing a comprehensive visual representation of the tooth structure, allowing dentists to examine hard-to-reach areas with precision during clinical assessments. This visual aid significantly aids in the early detection of calculus, facilitating timely interventions and improving overall outcomes for patients. This study introduces a system designed for the detection of dental calculus in BW images, leveraging the power of YOLOv8 …

Safe And Efficient Operation Of Mobile Robots In Indoor Environments: A User-Centric Shared Control System With High-Level Navigation Capabilities, Ahmet Saglam

Electrical & Computer Engineering Theses & Dissertations

Hospitalization and isolation can be a traumatic experience for immunocompromised children, especially because they are separated from their families and friends. Social robots have been proposed as a way to improve the quality of care for children hospitalized in isolation by providing alternative means of social interaction and support. Remote control of such robots in a hospital setting, particularly where safety is a major concern, can be a daunting task for young patients.

This dissertation introduces a multilevel shared control system for mobile robots, specifically companion robots in hospital-like indoor spaces. The system integrates user inputs with algorithmic semi-autonomous control …

Development Of A Rule-Based Monitoring System For Autonomous Heavy Equipment Safety, Amirpooya Shirazi

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Roadway construction work zones are constantly exposed to interactions among construction equipment, workers, and vehicles. Furthermore, ensuring safety in these areas is considered a challenging task due to the complexity of the environment. As shown in the rising trend of fatal accidents in roadway work zones, current OSHA regulations in construction safety are insufficient in effectively detecting unsafe situations and mitigating the risks. Furthermore, best practices, such as internal traffic control planning (ITCP), exhibit critical limitations requiring continuous monitoring of active work zones as well as adjustments to the site coordination plans due to the dynamic nature of work zone …

Problem Solving / Javascript Programming, Sarah Zelikovitz, Orit D. Gruber

Open Educational Resources

This Lab Experiment focuses on JavaScript Programming. Upon completing the lab, you will be able to understand the following:

· The definition of Algorithmic Problem Solving.

· The role of JavaScript in web pages.

· The concept of Iteration in computer programming.

Finding The Shortest Path Using Dijkstra’S Algorithm, Orit D. Gruber, Deborah Sturm

Open Educational Resources

This lab experiment explores an algorithm which is used to find the shortest path between two or more locations. After completing the lab, you will be able to answer the following questions in the final lab report:

1. What is an Algorithm?
2. What is a Graph ?
3. What is the purpose and operation of Dijkstra’s Algorithm ?

Advancing Omnimodality: Expanding Human Creativity Through Adaptable And Accessible Multimodal Computing Systems, Joshua Urban Davis

Dartmouth College Ph.D Dissertations

Emerging technologies have given us a whole host of new ways for people to be

creative. From the immersive worlds of AR/VR to the synthesis powers of largelanguage

models and generative AI, these new tools hold the potential to reshape

human expression and creativity. But how can we ensure that these new modalities

are accessible to everyone, even those who aren’t able bodied? This thesis advocates

for a human-centered approach to the development of many-modal systems. I will

probe how our machines support, direct, or inhibit creativity as a mode of problem

solving through 6 novel multimodal prototype interfaces and …

Aligning Language Models With The Human World, Ruibo Liu

Dartmouth College Ph.D Dissertations

The field of Natural Language Processing (NLP) has undergone a significant transformation with the emergence of large language models (LMs). These models have enabled the development of human-like conversational assistants (e.g., OpenAI's ChatGPT), and expert-level AI software engineering agents (e.g., Devin from Cognition Lab). However, these models face a fundamental challenge related to their training methodology. Predominantly trained on vast datasets scraped from the web, their self-supervised learning objective---predict missing tokens---unintentionally perpetuates the biases, inaccuracies, and sensitive information inherent in their training data. These issues lead to what is termed misaligned}behaviors and pose a significant hurdle in the development of …

The Effect Of Watts-Strogatz And Barabási-Albert Graphs On Memory Formation, Ethan Irick Wolfe

Master's Theses

Understanding higher level cognitive processes is a central problem in neuroscience. The Neuroidal model provides a useful framework for posing these problems in a computer science context. There has been significant recent work trying to understand memory capacity in the Neuroidal model but this work was done assuming that the network of neurons was an Erdos-Renyi random graph. However the network of neurons in the brain has been shown to exhibit small-world properties, which are not present in Erdos-Renyi graphs. In this research we explore replacing Erdos-Renyi graphs with Watts-Strogatz and Barabasi-Albert graphs in order to more accurately model the …

Extreme Image Transformations Improve Latent Representations In Machines, Girik Malik, Ennio Mingolla

MODVIS Workshop

Shuffling pixels in an image helps machines to learn a more robust object representation. To probe the strategies used by humans and machines for object recognition, we introduce Extreme Image Transformations (EITs). Machines rely heavily on exploiting low-level features like color and texture, so their performance degrades on out-of-distribution and adversarial inputs. Humans depend on high-level features like shapes and contours, making them relatively robust to image distortions. EITs systematically shuffle the pixels in an image, parameterized by the size of grids, probability of shuffle and binary block movement, distorting the structure of objects at both local and global levels. …

Explaining The Staircase Gelb Illusion, Simultaneous Contrast, And Perceptual Fading Of Stabilized Images With A Neural Model Driven By Fixational Eye Movements, Michael E. Rudd

MODVIS Workshop

A neural model of lightness computation driven by fixational eye movements is described and used to simulate various lightness phenomenon, including the Staircase Gelb illusion and its variants, simultaneous contrast, the Chevreul illusion, and perceptual fading of stabilized images. The model provides a precise account of the lightness matches from several experiments, with an overall error of only 1.5%. In the model, spatial maps of transient ON and OFF cell activations—produced as the eyes traverse the visual scene—are sorted by eye movement direction in visual cortex. At a subsequent processing stage, the activations within these maps are summed across space …

Neuro-Symbolic Commonsense Reasoning With Resistance To Data Poisoning: A First-Order Logic And Sub-Symbolic Embeddings Framework, Bryce Shurts, King-Ip Lin

Computer Science and Engineering Theses and Dissertations

Commonsense reasoning has long presented a hurdle between conversational agents and their ability to naturally engage with humans in conversation, as the infinitely dimensional nature of a dialogue’s topics presents a significant reasoning challenge in the study of Natural Language Understanding (NLU). Such a system must conceivably be able to act as a generalizable system for evaluating and reasoning about commonsense statements, problems, and queries: in this way, the agent can attempt to quantify the reasonability of a given input. We attempt to address this through the integration of an explainable neuro-symbolic system that leverages Logical Tensor Networks (LTNs) and …

Securing The Skies: Safety-Constrained Decentralized Multi-Uav Coordination With Deep Reinforcement Learning, Jean-Elie Pierre

Electrical and Computer Engineering ETDs

In the dynamic landscape of autonomous aerial systems, the integration of uncrewed aerial vehicles (UAVs) has sparked a paradigm shift, offering unprecedented opportunities and challenges in collaborative decision-making and navigation. This thesis explores the application of multi-agent reinforcement learning (MARL) for the planning and coordination of UAVs in complex environments.

The first part of this thesis provides an introduction to single-agent reinforcement learning and MARL. We provide examples of the use of MARL for countering uncrewed aerial systems (C-UAS). We formulate the Counter-UAS problem as a multiagent partially observable Markov decision process (MAPOMDP), and we propose Multi-AGent partial observable deep …