Computational Engineering Commons^™

Towards Computational Methods In Medical Data Analysis: From Speech And Text To Imaging, Kristin Qi

Graduate Doctoral Dissertations

Early detection of cognitive decline and efficient medical image analysis remain critical challenges in healthcare. Traditional clinical assessments are infrequent and resource-intensive, while everyday speech data and unlabeled medical images remain largely unexploited. This dissertation develops computational methods integrating machine learning and artificial intelligence across speech, text, and imaging modalities to address challenges in medical data processing. For cognitive monitoring, this work first introduces methods using voice assistant systems to collect longitudinal speech data in home environments, demonstrating that incorporating historical session patterns significantly enhances detection of mild cognitive impairment. Building on this foundation, a framework combining large language model-driven …

Analysis Of Leakage In Nearshore Pipelines Using Fitness For Service Method To Ensure Mechanical Integrity Based On Api-579 Level 3, Elriandri Elriandri, Dedi Priadi

Journal of Materials Exploration and Findings

The Fitness for Service (FFS) analysis is performed as a quantitative assessment to evaluate the integrity condition of a pipeline. Essentially, FFS assessment helps determine whether equipment components can operate safely despite existing deficiencies. This evaluation is carried out using the Finite Element Method (FEM). In the case of an underwater pipeline that experiences leak due to anchor pull at the flange connection, it undergoes plastic deformation and is lifted approximately 1 meter. As a mitigation step, inspection and repairs have been carried out by the company. Subsequently, modeling is performed to reconstruct the deformation process of the pipeline. Then, …

Assessment Of The Melt Quality Of A 30% Scrap Adc12 Aluminium Alloy Using The Inclusion And Fluidity Measurement Instrument (Ifmi) With Mullite Ceramic Filters, Gusti Ruri Ruri Lestari, Sandya Ananda Riswan, Muhammad Anis, Ahmad Ashari, Paramita Vidya Ayuningtyas, Bambang Suharno Prof, Donanta Dhaneswara

Journal of Materials Exploration and Findings

The increasing demand for sustainable practices in the metal casting industry has driven the use of recycled aluminum alloys such as ADC12. However, the addition of aluminum scrap tends to increase oxide inclusions, which reduce melt fluidity and compromise casting quality. This study utilizes the Inclusion and Fluidity Measurement Instrument (IFMI), equipped with mullite ceramic filters, to assess the melt quality of ADC12 aluminum alloy containing 30% scrap. Fluidity and inclusion characteristics were evaluated at five pouring temperatures (660°C, 680°C, 700°C, 720°C, and 740°C). The results show that fluidity increased with temperature, reaching a peak of 84.6 g·s⁻¹ at 740°C, …

Equipment Criticality Analysis To Determine Asset Integrity Management System Scheme In Supporting Production Optimization Scenarios In The Aeging Field, Donny Andryanto, Donanta Dhaneswara

Journal of Materials Exploration and Findings

This research investigates the production decline and cost increase in the X&Y oil and gas fields from 2022 to 2023. Production fell by 34%, while production costs per barrel rose by 79%. To address these issues, a series of optimization processes are proposed. These aim to restructure and enhance the production facilities to reduce current production costs. The optimizations include reducing pressure at the PPP Platform in 2024. Additional steps include shutting down CPP-ORF 14” pipelines and most processes at CPP 2 Platform by 2027 to convert it into an accommodation platform. Further, the plan involves optimizing the release of …

Morphological Test Of Areca Nut Fiber Ceramic Membrane Using Scanning Electron Microscopy Energy Dispersive X-Ray Mapping Spectroscopy, Amelia Marzain, Siti Umi Kalsum, Marhadi Marhadi, Ahmad Nabil Shahab

Journal of Materials Exploration and Findings

This study investigates the potential of ceramic membranes derived from areca nut fiber as a cost-effective and environmentally sustainable material for the removal of iron (Fe) and manganese (Mn) from groundwater. Two types of membranes were fabricated: one without activation and one chemically activated using 10% sodium hydroxide (NaOH). The morphological and elemental characteristics of both membranes were analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) mapping. The concentrations of Fe and Mn before and after treatment were measured using Atomic Absorption Spectroscopy (AAS). The NaOH-activated membrane exhibited a more porous surface structure and higher oxygen content, …

Irregularities In The Dynamics Of Large Networks: Cases On Social Networks And The Internet, Dheeman Saha, Abdullah Mueen, Shuang Luan, Afsah Anwar, Yangsun Hong

Computer Science ETDs

Dynamic networks capture evolving relationships among entities, and irregularities in their behavior often signal significant events. This dissertation investigates such irregularities across social and infrastructural networks. First, we analyze Twitter (prior to its rebranding to X) to characterize influencers, introducing a follower-overlap similarity measure that identifies micro-influencers beyond content-based methods.

We then examine election-related irregularities by comparing suspended and non-suspended accounts during the 2020 U.S. presidential election, revealing behavioral patterns linked to misinformation and coordinated manipulation.

Next, we develop an algorithm to infer post-specific diffusion networks, reconstructing who-saw-from-whom pathways for tweets at scale. This method uncovers structural differences in diffusion …

Prism (Proxy Recognition And Inclusion Scoring Method), Destiny Raburnel, Crystal Tubbs, Md Abdullah Al Hafiz Khan

Symposium of Student Scholars

AI-driven automated hiring tools are reshaping how companies find talent, but they often reproduce the hidden biases embedded in their training data. Our project, PRISM (Proxy Recognition and Inclusion Scoring Method), investigates how subtle demographic signals, specifically first names associated with gender and race, influence AI resume screening even when candidates have identical qualifications. We built a controlled dataset of resumes that are identical in every way except for the applicant's first name, with each resume using a racially neutral surname to isolate how first names alone affect scoring. We tested these resumes against job postings in technology, healthcare, and …

A Predictive Model For Multi- Week Respiratory Risk From Red Tide On Florida’S Gulf Coast., Elmer S. Ochaeta

Computer Science and Engineering Faculty Publications

Florida’s Gulf Coast red tide (Karenia brevis) can put toxins into the air, making people cough, irritating the throat, and worsening asthma or other breathing problems especially when winds blow from the ocean toward the beach. Right now, most public updates don’t really help with the question people actually ask when planning a weekend or vacation: “Will going to or close to the beach be risky in the next few weeks?”.

In this project, I build a weekly early warning system that estimates respiratory risk for specific beaches and predicts that risk 2 to 4 weeks ahead. The study covers …

Iso-Detr: A Novel Detection Transformer For Industrial Small Object Detection, Faisal Saeed, Anand Paul

School of Public Health Faculty Publications

Effectively detecting and assessing real-time structural and ecological parameters in contemporary manufacturing environments poses significant challenges, particularly in identifying minute objects within product images. The swift evolution of the industrial sector underscores the necessity for intelligent manufacturing environments to uphold stringent product quality standards. However, accelerating production processes at high speeds heightens the risk of defective product outcomes. This research addresses the challenges inherent in small object detection within industrial contexts, proposing an innovative detection transformer model tailored to modern manufacturing environments. The proposed model integrates a feature-enhanced multi-head self-attention block (FEMSA), merging cross-channel communication network and multiple multi-head self-attention …

Universal Systems Simulation Via Constraint Hypergraphs With Applications To Digital Twins, John Morris

All Dissertations

The characterization of systems encompasses a variety of modeling frameworks designed to capture specific behaviors and components of various system domains. Whatever the framework, the core elements of a system representation are the information of the system and a description of how that information is related. The relations in deterministic systems are functions, which, when composed to form executable processes, can be used to simulate system data. A declarative modeling framework is one that encodes mechanisms for preparing these simulations within the model structure, allowing an external agent to form the execution processes required for a given context. To date, …

Integrating Machine Learning With An Fps Aim Trainer For Optimal Sensitivity Finding, Sharan Krishna

Computer Science and Software Engineering

First-person shooter (FPS) games often demand high levels of skill in aiming, which leads players to look for external tools to improve their performance. This is where the concepts of aim training and aim trainers come in, becoming an easily accessible outside source for players to strengthen their performance with custom scenarios outside a set game. While many aim trainers exist, they offer limited insight into player performance metrics or adaptability to varying aiming styles. Furthermore, most existing aim trainers lack a standardized way of correlating aim skill with real-world performance or personalized feedback. This aim trainer addresses these limitations …

Human Identification And Action Recognition Using Small Data And Deep Domain Adaptation, Alexander M. Glandon

Electrical & Computer Engineering Theses & Dissertations

Human identification and human action recognition problems are two important research areas for real-world security and surveillance applications. In both human identification and action recognition, it is necessary to operate by collecting small datasets in the field, possibly in a short time window of observation. This dissertation studies and develops computational modeling and high-performance machine learning (ML) and deep learning (DL) models for human identification and human action recognition using small amounts of data. These methods and computational models may be useful for different security and surveillance applications.

This dissertation on human recognition develops a ML computational model to estimate …

Comparative Analysis Of Emergent Behaviors Of Three Drone Swarm System Models For Targeting Using Agent-Based Modeling And Simulation, Arsenio T. Gumahad Ii

Engineering Management & Systems Engineering Theses & Dissertations

This dissertation introduces a novel computational simulation framework for evaluating the emergent behaviors of three swarm drone models using Agent-Based Modeling and Simulation (ABMS). The three swarm models are a Leader-Follower swarm model based on Bruckstein's antline theory, a Flocking model based on a simplified Reynolds 'Boids’ model, and a Stigmergic model with pheromone-based coordination. The primary objective of the simulation is to evaluate the performance of these models in delivering a user-defined number of drones of each type to a target area of interest in four separate scenarios, resulting in 50,000 separate simulation trials. Each scenario was structured to …

User Evaluation Of A Virtual Patient For Philippine Medical Education, Ma. Mercedes T. Rodrigo, Samantha Castaneda, James Alvir Maclin V. Alaan, Paolo Santino P. Caoile

Department of Information Systems & Computer Science Faculty Publications

Caladrius is a virtual patient system designed for use in Philippine medical schools. It responds to the need for medical interview training, for greater variety in teaching-learning strategies, and for culturally appropriate technologies. It has two versions: a text-only version whose interface is similar to a chat interface, and an audio version that accepts speech input and responds with speech output. In a prior test of Caladrius, users requested improved audio response time and the inclusion of different patient personalities. A subsequent version of Caladrius was created to comply with these requests. As much of the lag was attributable to …

Thermal Heterogeneity And Lithium Plating During Fast Charging Of Lithium-Ion Battery., Ayodeji Avis Adeniran

Electronic Theses and Dissertations

Presently, widespread adoption of electric vehicles (EVs) is hindered by challenges associated with XFC, including heat generation, lithium plating, and accelerated battery degradation. This dissertation addresses these barriers through two coordinated themes—lithium plating and thermal management—spanning four manuscripts that integrate operando diagnostics, physics-based simulation, and module-level design optimization. The first theme seeks a fundamental investigation into the dynamic interplay between temperature heterogeneity and lithium plating during fast charging, a phenomenon that poses significant limitations on the performance of graphite-based anodes. Firstly, a custom operando cell with a sapphire window was designed to enable synchronized MWIR thermography and optical imaging of …

Analyzing Patterns In Hofstede’S Cultural Dimensions Towards Individual Ai Receptiveness For Affective Experiences, Maggie Yang

Master's Theses

The use of artificial intelligence (AI) has significantly advanced efficient decision-making, with trust in algorithmic decisions shown to vary by cultural upbringing [1]. As AI becomes increasingly embedded in everyday life, it is essential to examine how cultural values affect trust in AI in subjective contexts that extend beyond purely quantitative analysis, like the personal interpretation of art. This work utilizes Hofstede’s cultural dimensions to investigate potential patterns in receptiveness towards AI predictions during art interpretation, providing insight into individual susceptibility to bias in AI-assisted affective analysis.

The study leveraged a cultural dimension survey and a custom Java program connected …

Spray Angle On The Performance Of Split-Type Ac Condenser Installed On Concrete Rooftop In Tropical Climate, Kennedy Kennedy, I N Frenki Aryana, Basri Basri

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigated the influence of different water spray angles (0°, 15°, and 30°) on the thermal and energy performance of a split-type air-conditioning (AC) condenser installed on a concrete rooftop in a tropical climate. An experimental setup was designed to replicate actual concrete rooftop conditions, focusing on the condenser inlet temperature, compressor power consumption, and system coefficient of performance (COP). A 6-minute ON and 6-minute OFF intermittent spray cycle was employed to optimise water usage and minimise excessive humidity. Experimental measurements were conducted on a 9,000 Btu/h split-type unit equipped with a nozzle system connected to a 200 L …

Effect Of Argon Gas Flow Rate On Crystal Structure, Morphology, And Optical Properties Of Cigs Film For Photodetector Applications, Nurul Lathi’I Fatul Chamidah, Fadilah Wulan Cahyani, I Gusti Ayu Isnaini Fatha Ramadhani, Erma Surya Yuliana, Nasikhudin Nasikhudin, Safwan Abd. Aziz, Nandang Mufti

Journal of Mechanical Engineering Science and Technology (JMEST)

CIGS material can be used as a material for photodetector applications. The deposition of CIGS thin films remains challenging. Generally, argon is used as a gas to bombard the CIGS material through the sputtering method. This study fabricated photodetectors by varying the argon gas flow rate (50-80 sccm) to investigate its effect on device performance. XRD, SEM, UV-Vis, and photoresponse tests were characterized. Structural analysis using XRD showed a weak (112) diffraction peak, indicating that the resulting film was not fully crystalline, but rather consisted of a nanocrystalline phase, even partly amorphous, with small crystallite sizes. According to the SEM …

Numerical Analysis Of The Effect Of Vortex Generator On The Aerodynamic Performance Of Naca 6412 Airfoils Using Large Eddy Simulation, Dedet Hermawan Setiabudi, Joan Bayuaji Nugroho, Eli Kumolosari, Lazuardy Rahendra Pinandhita, Okto Dinaryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Aerodynamic performance of an airfoil is significantly affected by flow separation, especially at high angles of attack. One common strategy to control flow separation is adding a triangular vortex generator (VG), which creates small vortices that help keep the airflow attached. The present study investigated the impact of triangular vortex generators on a NACA 6412 airfoil using Computational Fluid Dynamics (CFD) method. Large Eddy Simulation (LES) was applied due to its ability to show the vortices more clearly than other methods. It can also accurately capture the flow separation. To obtain the lift, drag, and lift-to-drag ratio (CL/CD) data, four …

Impact Of Cpo And B35 On Diesel Engine Rocker Arm Wear During Long-Term Operation, Fawwaz Aqilah Nurmansyah, Nur Fadilah Rizky Supramono, Muhammad Ikhsan, Erwan Adi Saputro, Wiliandi Saputro

Journal of Mechanical Engineering Science and Technology (JMEST)

The increasing number of motor vehicles has led to higher fossil fuel consumption, contributing to greenhouse gas emissions, climate change, and environmental degradation. As a renewable alternative, biodiesel offers a way to reduce these impacts. Indonesia, with its abundant natural resources, has significant potential for biodiesel production. Crude palm oil (CPO) is a promising feedstock due to its availability and relatively low environmental impact. However, the high costs associated with the transesterification process make direct use of pre-heated CPO an area worth exploring. This study investigates the impact of pre-heated pure CPO compared to B35 ("Dexlite") on rocker arm wear …

The Effect Of Heat Treatment Duration On The Psychochemical, Mechanical, And Biodegradability Of Polyvinyl Alcohol/Gambir Extract Biocomposite Films, Ainul Kahfi Muhlasin, Poppy Puspitasari, Heru Suryanto, Diki Dwi Pramono, Dieter Rahmadiawan, Billie Jack Pasion

Journal of Mechanical Engineering Science and Technology (JMEST)

This study investigates PVA-based films with the addition of gambir and heat treatment to improve the characteristics of the film. Methods include the synthesis of PVA film with gambir addition (0.5%), treated by heat treatment for 40 minutes and 60 minutes. The film was characterised by physicochemical, mechanical properties, and biodegradability. Data was analyzed using ANOVA with a significance of 95%. Results indicate that the surface of PVA/gambir films is smoother and more homogeneous as the heat treatment duration increases. New peaks of functional groups were identified after the addition of gambir at the C-C and C-O groups. After heat …

Surface Modification Of Local Natural Fibers Via Alkali Treatment For Improved Mechanical And Molecular Properties Of Bamboo Fiber, Pineapple Leaf Fiber, And Sisal Fiber, Jibril Maulana, Muhammad Ilman Nur Sasongko, Dewi Izzatus Tsamroh, Muchammad Yafis, Syekhan Maulana

Journal of Mechanical Engineering Science and Technology (JMEST)

A major development in materials science toward reinforcement materials in biopolymer composites has been caused by a worldwide trend toward sustainable manufacturing and the rise of the circular economy. However, their mechanical properties can often be affected by their hydrophilic properties, lack of surface compatibility, and their presence of molecular bonding, such as lignin and hemicellulose. Alkaline surface modification has been widely reported as an effective technique to increase structural stability and fibermatrix adhesion. This study evaluated the effects of alkalizing three types of local natural fibers—bamboo fiber (BF), pineapple leaf fiber (PALF), and sisal (SF)—with sodium hydroxide (NaOH) at …

Thermophysical, Rheological And Wear Resistance Of Canola Oil Biolubricant With Calcium Carbonate Additive Nanoparticle As Coolant In Cnc Machining, Alfandi Jaelani, Poppy Puspitasari, Diki Dwi Pramono, Alief Muhammad, Muhammad Kozin, Muhammad Kashif

Journal of Mechanical Engineering Science and Technology (JMEST)

Vegetable oil-based cutting fluids are of great importance in supporting green and sustainable manufacturing. This research introduces a new groundbreaking vegetable lubricant formulated with canola oil as the base material, coupled with CaCO3 nanoparticles synthesized from scallop shell waste and used as a cutting fluid in the AISI 1045 CNC machining process steel sprayed with minimum quantity lubrication (MQL). This investigation delves into the thermophysical, rheological, and wear resistance of the developed bio-lubricant. The results of this analysis show density value increased in the canola + CaCO3 0.15% sample by 3.28% of the pure canola sample, as did the viscosity …

Improvement Of Thermal Energy Storage Performance In Al-Al2o3 Composites Through Additions Of Copper: Evaluation Of Microstructure And Thermal Properties, Muhammad Hasan Basri, Ramang Magga, Muhammad Syaiful Fadly, Zikri Arifansyah Djaba, Muhammad Iqbal Ibrahim, Hidayat Hidayat, Yandi Yandi

Journal of Mechanical Engineering Science and Technology (JMEST)

The study aims to evaluate the influence of adding copper aluminum–alumina composite (Al–Al₂O₃) against characteristic thermal properties through metallurgical powder. Three variations of the composition of weight copper were used, namely 5%, 10%, and 15%, with aluminum as the matrix and alumina as the reinforcement. Thermal test covering analysis of thermal conductivity, specific heat, and microstructure characterization using SEM-EDX. The results show that adding Cu increases thermal conductivity significantly, with the highest mark achieved in the 15% Cu composite (6.47 W/m.°C). However, the increase in Cu content above 10% causes the agglomeration of particles and enhancements in porosity, which harms …

Optimizing Zeolite Catalysts For Efficient Ldpe Plastic Waste Pyrolysis, Hilda Porawati, Mazwan Mazwan, Sukadi Sukadi

Journal of Mechanical Engineering Science and Technology (JMEST)

The problem of plastic waste, particularly from low-density polyethylene (LDPE) plastic bags, poses a significant challenge in environmental management due to its non-biodegradable nature and widespread use in daily life. This study evaluates the influence of catalyst types on the characteristics and energy efficiency of liquid fuel products produced from LDPE waste pyrolysis. The three treatments compared were no catalysts, natural zeolite catalyst, and synthetic zeolite catalysts, each subjected to three different temperature variations: 250°C, 300°C, and 350°C. The observed parameters in this study were volume, product mass, cetane index, density, sulfur content, viscosity, flash point, calorific value, and energy …

The Impact Of Pine Resin-Epoxy Ratios On Fire Resistance And Acoustic Performance Of Banana Fiber Composites, Cokorda Istri Putri Kusuma Kencanawati, Dewa Ngakan Ketut Putra Negara, I Gede Andy Andika Parahita

Journal of Mechanical Engineering Science and Technology (JMEST)

Because of their low environmental impact and biodegradability, composite materials derived from natural fibers and resins have drawn interest as sustainable substitutes for synthetic materials in thermal and acoustic applications. Two promising natural components are banana stem fiber and pine resin, but they need to be modified due to their mechanical limitations and flammability. Epoxy resin is commonly used to enhance structural performance; however, its effects on acoustic and fire resistance properties require further investigation. This study examined how different epoxy resin contents affected the sound absorption and fire resistance of composites made from banana stem fiber and pine resin. …

Simulation Of Stress, Deformation, And Vibration In Unlubricated Ball Bearings At Varying Rotational Speeds, Billy Dwiki, Moh. Hartono

Journal of Mechanical Engineering Science and Technology (JMEST)

Bearings are critical components in rotating machinery, and their performance is highly influenced by operational factors such as rotational speed, load, and lubrication. This study aims to analyze the deformation, stress, and dynamic behavior of SAE 52100 bearings under dry operating conditions at various rotational speeds, as well as to propose mitigation strategies for high-speed industrial applications. A finite element simulation was conducted using ANSYS R19.2 to evaluate the total deformation, equivalent elastic strain, Von Mises stress, and vibrational characteristics of a 6204-type SAE 52100 bearing. The simulations were performed across a speed range of 600 to 2000 RPM under …

Numerical Investigation Of Ethanol-Enriched Diesel And Biodiesel Fuels In A Diesel Engine, Annisa Bhikuning, Hezron Elyakim Potto, Sandi Apriandi Setiawan, Jamal F. Jati

Journal of Mechanical Engineering Science and Technology (JMEST)

This study explores the effects of ethanol blending on the performance and emissions of a compression ignition (CI) engine using both diesel and biodiesel as base fuels. Motivated by increasing environmental concerns regarding pollutant emissions from conventional diesel engines, ethanol was introduced as an oxygenated additive to improve combustion characteristics and reduce the formation of harmful exhaust emissions. Ethanol’s high oxygen content promotes more complete combustion, potentially lowering carbon-based emissions such as carbon monoxide (CO), particulate matter (PM), and unburned hydrocarbons. In this study, performance and emission parameters were simulated using Diesel-RK software at various engine speeds of 1500, 2000, …

One-Way Thermal-Fluid-Solid Coupling Analysis Of Helicopter Tail Reducer With Spiral Bevel Gear, Dongping Sheng, Zhongyuan Ma, Chenqi Zhou, Haidong Feng, Hun Guo, Chun Su

Journal of Mechanical Engineering Science and Technology (JMEST)

This research focuses on investigating the thermal-fluid-solid coupling behavior within spiral bevel gears to enhance the bearing capacity and extend the operational service life of the gear reducer located in the helicopter tail gearbox. The study commences by constructing detailed, parametrically defined threedimensional digital models. These models accurately represent the critical components: the spiral bevel gear itself, the surrounding gearbox housing, and the supporting gear shaft, based directly on the specifications of an actual helicopter tail reducer assembly. Subsequently, the analysis proceeds with a one-way, steadystate thermal-solid coupling simulation performed on the established model assembly. This critical simulation phase aims …

The Effect Of Preheater On Heat And Mass Transfer Efficiency Using Rotating Drum Roaster, Melisa Surya Andini, Retno Wulandari, Heru Suryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Indonesia is the third-largest coffee producer globally, facing challenges including rising raw material costs, increased energy consumption, and unpredictable weather conditions. One potential solution is optimizing energy efficiency during roasting. This study investigates the effect of preheating on time and energy efficiency in heat and mass transfer by utilizing waste heat to preheat green Robusta coffee beans. The experiment was conducted on a laboratory scale using a rotating drum roaster with a double-layer drum made of stainless steel and clay, at 200 °C under atmospheric pressure. Two treatments were applied: roasting with a preheater and without, each repeated three times …