Operations Research, Systems Engineering and Industrial Engineering Commons^™

A Systems Engineering Approach For Mitigating Space Debris In Earth's Orbital Regimes, Manuel Soto

Open Access Theses & Dissertations

Space debris in Earth's orbital regimes is a complex threat that originates with human space activity and is maintained by Earth's gravitational force. Space debris poses the risk of colliding with and destroying operational space assets. These collisions, in turn, pose the risk of compounding space debris fragments by turning operational space entities involved in collisions into additional space debris. In other words, the space debris impact does not end with a fragment colliding with a space entity. Instead, the collision is a new space-debris birth since the entities colliding are likely to become multiple fragments. Depending on the collision's …

Multistage Random Key Genetic Algortihm Optimization For Scheduling Flexible Flow Lines With Sequence Depenedent Setup Times, Aadithan Anbuvanan

All Theses

This thesis proposes a new variation to the Random Key Genetic Algorithm (RKGA) for scheduling optimization in flexible flow line manufacturing with sequence dependent setup times. The proposed RKGA representation decodes scheduling information independently at each stage, unlike the traditional RKGA, which is only sequenced based on the first stage, limiting flexibility. The proposed method's performance is compared to the traditional method with varying numbers of jobs and stages. It is compared regarding performance ratio and statistical significance of differences through the Wilcoxon Signed Rank Test. Results show that the proposed RKGA outperformed traditional RKGA in high complexity (8 Stage …

Remaining Life Analysis Of Pipeline Gas With Extreme Value Theory, Rony Prayitno Simeon, Eddy Sumarno Siradj, Tedi Kurniawan

Journal of Materials Exploration and Findings

Energy and chemical companies use pipelines to transfer oil, gas, and other materials from one place to another, within and between their plants. Pipeline integrity is an important concern because pipeline leakage could result in serious economic or environmental losses. Some research has applied to understand the effect of extrapolation value of the minimum thickness of pipeline by using the Extreme Value Theory. In this research, both statistical models and Extreme Value methods were applied and developed for the reliability of the pipeline by assuming the constant corrosion rate and deviation due to measuring devices were neglected. The research obtained …

Integrity Assessment Of Shipping Line Pipelines Using Risk-Based Analysis To Determine Risk And Maintenance Strategies, Ade Ratih Anggraini, Dwi Marta Nurjaya

Journal of Materials Exploration and Findings

Pipeline Shipping Lines X, Y & Z are classified as critical infrastructure, being the only transportation through the crude oil lifting from P and R location to the transfer station in NM Area. To maintain the workflow of the Shipping Line, integrity assessments and risk evaluation are required to ensure the operational and safety. Anomalies were found by analysing inspection, monitoring, and repair data, while the pipelines' future integrity was assessed by calculating the remaining life. Risk-Based Analysis (RBA), which is a modification of Kent Muhlbaeur's method, is employed to conduct the risk assessment using the Probability of Failure (POF) …

Assessment Of H2s-Induced Cracking Susceptibility In Steam Line Pipes And Weld Zones During Geothermal Well Construction, Riene Kaelamanda Pragitta, Yudha Pratesa

Journal of Materials Exploration and Findings

The susceptibility of steam line pipes, especially in the HAZ (heat-affected zone) and weldment areas, to hydrogen sulfide in the geothermal industry is crucial to understand from the early stages, particularly during construction. The combination of tensile stress from residual stresses after welding and metallurgical phase transformation makes the joint areas vulnerable to sulfide stress cracking. This condition becomes even more extreme when the equipment operates during the well stimulation phase. This research assesses the severity of H₂S-induced cracking using NACE MR0175 and ISO 15156-1 standards, focusing on the effects of pH and partial pressure of H₂S (p_{H₂S …}

The Food Truck: A Multi-Product Newsvendor With Trans-Shipment Cost, Samuel Ajibola

Electronic Theses and Dissertations

The Newsvendor Problem is a key model in supply chain management that focuses on determining the optimal order quantity to minimize costs under uncertain demand. This thesis introduces the Food Truck Problem, an extension of the Newsvendor model that incorporates nonlinear transshipment costs for inventory transportation. In this context, a Food Truck must determine the optimal stock levels for multiple products while minimizing costs related to stock shortages, excess inventory, and transportation. Unlike traditional Newsvendor models, our approach explicitly considers a quadratic transshipment cost, which necessitates the use of Lagrangian duality and Karush-Kuhn-Tucker (KKT) conditions for analysis. Moreover, we apply …

Spin Coater Design With Pid Algorithm Using Polynomial Regression Approach And Bias Tuning For Tio2 Deposition Process, Geo Surya Andika, Nofrijon Sofyan, Donanta Dhaneswara, Akhmad Herman Yuwono

Journal of Materials Exploration and Findings

The thin-film deposition technique using spin coating offers a cost-effective alternative to Chemical Vapor Deposition (CVD) and Physical Vapor Deposition (PVD). The spin-coating process requires precise control of the motor drive system to ensure that the rotational speed, measured in rotations per minute (RPM), aligns with the set point and remains stable. This study presents the design and development of a spin coater prototype to achieve uniform thin-film deposition. The control method employed utilizes a Proportional-Integral-Derivative (PID) algorithm, incorporating a polynomial approach with bias tuning. The PID control was chosen to achieve stable operation in a non-linear system. The performance …

An Msbe–Driven Advanced Air Mobility Post–Disaster Response System, Olabode A. Olanipekun

Graduate Theses and Dissertations (2019 - present)

In this work, an overarching conceptual design model towards the realization of a proposed Advanced Air Mobility Post–Disaster Response System (AAMPDR system) was explored through the focal lenses of systems thinking (ST), socio–technical systems (STS) and model–based systems engineering (MBSE) paradigms. Initially aimed at providing intervention for casualties and aerial support to emergency rescue workers on the ground in the event of a hurricane disaster around the Gulf shore of the Mobile bay area, Mobile city, AL., the scope of this research subsequently expanded to include a global outlook. Thereafter, culminating in the development of a generalized AAMPDR system model …

Decision Space Decomposition For Multiobjective Programs, Emma Soriano

All Dissertations

Being inspired by the parametric decomposition theorem for multiobjective optimization problems (MOPs) of Cuenca and Miguel (2017), and by the block- coordinate descent for single objective optimization problems, we present a decom- position theorem for computing the set of minimal elements of a partially ordered set. This set is decomposed into subsets whose minimal elements are used to retrieve the overall minimal elements. We apply this approach to strictly convex MOPs de- composing their decision space into lines. The line decomposition benefits from the fact that a multiobjective line search problem is equivalent to solving a collection of single objective …

Compartmental Disaggregation: Bridging Simulation And Sampling Methods For Synthetic Population Data Generation, Dylan Mack

McKelvey School of Engineering Graduate Student Theses & Dissertations

As agent-based models (ABMs) grow increasingly widespread in public health, their associated challenges have become all the more significant. Lauded for their ability to capture population heterogeneity, nonlinear dynamics, and emergent behaviors, disease ABMs are also computationally expensive and often require detailed inputs that describe each agent at the individual-level, known as synthetic population data. Current approaches for synthetic population data generation generally fall into one of two categories: sampling or simulation. These methods are both feasible only under restricted conditions and suffer from challenges surrounding data availability and computing power. This thesis proposes compartmental disaggregation, an intermediate method for …

Hierarchical Frameworks For Scaling-Up Multi-Agent Coordination, Minghong Geng

Research Collection School Of Computing and Information Systems

Multi-agent reinforcement learning has emerged as a powerful framework for developing collaborative behaviors in autonomous systems. However, existing MARL methods often struggle with scalability in terms of both the number of agents and decision-making horizons. My research focuses on developing hierarchicalapproaches to scale up MARL systems through two complementary directions: structural scaling by increasing the number of coordinated agents and temporal scaling by extending planning horizons. My initial work introduced HiSOMA, a hierarchical framework integrating self-organizing neural networks with MARL forlong-horizon planning, and MOSMAC, a benchmark for evaluating MARL methods on multi-objective MARL scenarios. Building on these foundations, my recent …

Survival Signature Estimation For All-Terminal Networks By Solving The Multi-Objective Bottleneck Spanning Tree Problem, Dewan Maisha Zaman

Graduate Theses and Dissertations

This research examines the problem of estimating the survival signature of all-terminal networks using Monte Carlo (MC) simulation. Following a recent similar result for twoterminal networks, we show that the work required within each MC replication corresponds to solving a multi-objective bottleneck spanning tree (MOBST) problem. We implement the resulting MC procedure using a “Blocks” algorithm from the literature to solve the MOBST in each replication by identifying its minimal set of non-dominated points. We compare this implementation against intuitive benchmark procedures for completing the work within an MC replication. We conduct numerical experiments to assess the efficacy of multi-objective …

Enhancing Patient Safety: Exploring Virtual Sitters' Role In Fall Prevention Through Remote Virtual Monitoring, Adama Diallo, Awatef Ergai Dr., Leeanna Spiva Dr., Meriel Mccollum Dr.

Symposium of Student Scholars

Remote Virtual Monitoring (RVM) technology enhances safety for both patients and care teams by reducing falls, improving the efficiency and effectiveness of continuous patient observation, and lowering costs associated with falls and staff support. The success of fall reduction efforts largely depends on the role of virtual sitters, individuals who remotely monitor high-risk patients to prevent falls. This study aims to explore the experiences of virtual sitters, identifying key themes, challenges, and opportunities to improve the intervention. Specifically, the research investigates how technology, work shifts, and institutional support impact the effectiveness and job satisfaction of virtual sitters.

Bridging The Gap: Care Team’S Perspectives On Technology And Ai Integration In Healthcare, Sarah Fernandes, Pranathi Boyina, Awatef Ergai Dr., Wellstar Health System, Mohammad Yousef Mousa Naser, Sylvia Bhattacharya Dr.

Symposium of Student Scholars

As healthcare systems increasingly integrate digital solutions, understanding the perspectives of frontline healthcare workers on technology adoption is critical. This study explores how Registered Nurses (RNs), Licensed Practical Nurses (LPNs), and Certified Nursing Assistants (CNAs), collectively referred to as the Care Team, interact with existing and emerging healthcare technologies, including artificial intelligence (AI). Given the growing reliance on digital tools for clinical and administrative tasks, this research examines the challenges and benefits perceived by healthcare professionals when incorporating AI-driven solutions into their workflows.

A cross-sectional research design was employed, involving 30 semi-structured interviews with Care Team members from an Intensive …

Algorithms For Feature Extraction And Optimisation Of Object Recognition Operator, Hudayberdiev Xakkulmirzayevich Mirzaakbar, Bobomurod Mamitjonovich Tojiboev, Feruza Komiljonovna Samadova

Chemical Technology, Control and Management

This paper deals with the development and analysis of feature extraction and optimisation algorithms for object recognition operators. Different algorithms are used to improve the efficiency of recognition operators in the automatic analysis of remote sensing images. The information model of objects and methods for selecting, extracting and optimising their features have been studied. The issue of extracting important features of objects using spectral, textural and statistical features and constructing optimal operators based on them has also been studied. Effective approaches based on the theory of convex hulls and multidimensional analysis methods have been proposed, taking into account the mutual …

Determination Of Optimal Parameters For Quality Drying Of Garlic Using The Vibro-Convective Method, Jasur Safarov, Shakhnoza Sultanova, Abdurakhmon Mirkomilov

Chemical Technology, Control and Management

This article examines the process of drying garlic using a low-temperature vibratory-convective drying system. At the "Service Technology" department of Tashkent State Technical University, a vibratory dryer was developed to ensure high-quality drying of garlic while maximizing the preservation of its biologically active compounds. Through experimental studies, optimal drying parameters were determined, including the degree of moisture removal, process duration, airflow velocity, and vibration acceleration. The results obtained contribute to enhancing the efficiency and quality of garlic drying, which holds practical significance for agricultural producers and consumers interested in healthy nutrition.

Detection Of Http Flood Attacks Based On Machine Learning Algorithms, Norbek Karimov, Furkat Rakhmatov, Oybek Xolmuminov

Chemical Technology, Control and Management

This paper analyzes the effectiveness of Random Forest and SVM models for detecting HTTP Flood attacks. Experimental results demonstrate that both models achieve high accuracy. Evaluation was conducted using Precision, Recall, and F1 Score metrics. Additionally, key features of network traffic were extracted through correlation analysis to enable real-time application of the models in attack detection. The findings provide important insights into detecting DDoS attacks using machine learning and improving model performance.

Security In Biometric Access Control Systems Based On Fingerprints, Elmurad Jamuradovich Qilichev, Baxodir Saydullaevich Achilov, Ismoil Ergash OʻGʻLi Isroilov, Mirshod Mirkomil O'G'Li Ahmadov

Chemical Technology, Control and Management

This article analyzes biometric access control systems using fingerprints. The article considers the advantages of using biometric technologies, including solutions aimed at ensuring security, protecting users' personal data, and increasing the efficiency of systems. A detailed explanation of the principles of operation of fingerprint biometric systems, their underlying algorithms, and technological advances is provided. Problems that arise when assessing the level of security, ease of use, and technological and social aspects of biometric access systems and methods for combating them are also covered. At the end of the article, opinions are expressed about the future of fingerprint-based biometric systems and …

Studying The Technology For Obtaining Zinc Chloride From Spent Supporter Waste In Ammonia Production, A.T. Dadaxo‘Jaev, Sodikjon Kadirov

Chemical Technology, Control and Management

This article presents the results of research on the recycling of spent zinc adsorbents formed during the ammonia production process, aimed at obtaining zinc chloride (ZnCl₂), which can be utilized in various industrial sectors, including electroplating. The research covers the optimization of technological parameters such as hydrochloric acid concentration, temperature, and reaction time to efficiently extract zinc chloride. The experiments revealed that the best results are achieved by using a 20% hydrochloric acid solution, at a temperature of 60°C, with a reaction time of 60 minutes. The resulting 40% zinc chloride solution was tested in electroplating production, where it met …

Research Of The Dynamic Characteristics Of A Time-Pulse Ultrasonic Sensor, Aliev Ravshan, A.U. Djalilov

Chemical Technology, Control and Management

This article investigates the dynamic characteristics of a time-pulsed ultrasonic sensor used to measure water flow in open channels. The operating principle of the sensor, its response time in various hydrodynamic conditions, speed, and factors affecting measurement accuracy are analyzed. In the process of research, the improved ultrasonic sensor was tested and its effectiveness in measuring water flow in real time was evaluated. The results obtained showed that the sensor adapts to the velocity, temperature and turbulence level of the water flow. Based on the results of the research, the possibilities of working of time-impulse ultrasound sensors in open channels …