Operations Research, Systems Engineering and Industrial Engineering Commons^™

Study Protocol To Analyze The Effects Of Occupational Exoskeleton Use On Balance Control, Vishnu Sai Prabhakarababu

Graduate Research Theses & Dissertations

Work-related musculoskeletal disorders (MSDs) represent a prevalent concern affecting a wide range of industries. Occupational exoskeletons have garnered attention as a potential solution to alleviate the risk of MSDs by reducing mechanical loads on susceptible body regions. A critical knowledge gap exists regarding the complex interactions between exoskeleton use and the human body, particularly in work environments prone to slips, trips and falls. This thesis work was part of a funded research aiming to determine the effects of exoskeleton use on balance control. The primary purpose of this thesis work was to determine a reliable maker placement protocol that will …

Part Design Geometry-Driven Toolpath Optimization For Additive Manufacturing Energy Sustainability Improvement, David Kolawole Somade

Graduate Research Theses & Dissertations

One of the most promising new manufacturing technologies in the past three decades isadditive manufacturing (AM), also commonly known as three-dimensional (3D) printing or rapid prototyping. The energy consumption problem in AM can be significant when it is adopted at the industrial scale or used under resource-restricted conditions. The energy consumption of an AM process is influenced by several factors including bed heating, filament extrusion, material infill, component cooling, etc. All these factors are further determined by the equipment and the toolpath for a specific printing task. Build orientation and tool-path direction are frequently used to optimize part and process …

Simulation, Optimization, And Economic Assessment Of Pelamis Wave Energy Converter, Hana Ghaneei, Mohammadreza Mahmoudi

Faculty Peer-Reviewed Publications

Wave energy and power is accessible on almost any body of water. One of the most widely known floating structures to generate renewable energy from the seas and the ocean is wave energy converter Pelamis. In this study, an attempt was made to simulate the dynamic behaviour of Pelamis P2 in the software AQWA under the influence of a nonlinear second-order Stokes wave. Pelamis P2 was simulated in different marine conditions including different water depths, wave heights, periods, and angles to assess its optimal operation. With the results in mind, it can be argued that with an increase in water …

A New Boundary Interlock Geometry Design Method For Fdm Multi-Material Part Strengthening, Shivaram Sree Venkata Shanmukha Kakaraparthi

Graduate Research Theses & Dissertations

Multi-material Fused Deposition Modelling (FDM) enables the cost-effective realization of designs in complex geometries built with multiple materials. However, achieving an adequate level of bonding strength between different materials remains a significant challenge. Besides the traditional way of addressing this challenge by strengthening material bonding at the molecular scale by optimizing the printing parameters, introducing a new design methodology that creates stronger multi-material interface geometry could also offer effective solutions. This work studied the mechanical properties of multi-material printed objects, with a particular focus on the interface zone formed between different materials at their geometrical boundaries. A new mathematical simulation …

Biomechanical Evaluation Of Hand Representation For Typing In Virtual Reality, Mobasshira Zaman

Graduate Research Theses & Dissertations

Virtual reality (VR) is becoming popular in the workplace recently. Text entry is thus now important for efficient office use and occupational use of VR, and VR paired with a conventional keyboard is suitable for long text entry. There has been a lack of research on physical demand, posture, motion, and cognitive demand, along with the performance of typing on VR. Presence of virtual hands while typing in VR may affect typing performance, physical demand, and posture. The focus of this study was to evaluate the biomechanical effect of hand representation for typing on VR using a conventional keyboard. Fifteen …

Particle Swarm Optimization And Ant Colony Optimization For Bi-Objective Optimization For A Single Batch Processing Machine, Sajith Gopinathan

Graduate Research Theses & Dissertations

This research studies the scheduling of jobs with unequal ready times, unequal processing times, and unequal sizes on a single batch processing machine, with the objectives of minimizing makespan and maximum tardiness. For the batch process, the jobs are required to be grouped into batches and further these batches are scheduled on the machine to minimize the objectives, without violating the machine capacity. The problem under study can be denoted as 1|p-batch, sj, rj| Cmax,Tmax in the standard three-field notation. A thorough review of literature pertinent to the field of research has been conducted and two new approaches have been …

Goal Programming Approach For Bi-Objective Optimization For A Single Batch Processing Machine, Dheeban Kumar Srinivasan Sampathi

Graduate Research Theses & Dissertations

This research considers a real-time problem where jobs need to be batched and scheduled to a single batch processing machine to minimize makespan and maximum tardiness. Jobs must be placed in batches such that the machine capacity is not violated. The jobs considered have unequal ready times, unequal processing times, and unequal sizes. This research aims to develop an effective solution approach for the proposed problem. The problem under study can be denoted as 1|p-batch, sj, rj| Cmax, Tmax.

The problem under study is NP-Hard. A new Mixed Integer Linear Programming (MILP) formulation using Goal programming (MILP-G) and Column Generation …

Adaptive Vehicle Routing Under Dynamic Uncertain Network Conditions, Upala Junaida Islam

Graduate Research Theses & Dissertations

Routing problems, such as traveling salesman problem, vehicle routing problem, and their variants, have been extensively studied in operations research because of their wide application in transportation and logistics. In this thesis, we consider routing problems in a road network of which the traveling conditions change over time and sometimes are uncertain. Such problems can arise in humanitarian logistics, resident evacuation, and emergency resource delivery after severe weather events and natural disasters. We provide a methodology to support routing decisions including route planning with limited information of the network conditions and route updating as new information becomes available. The dynamic …

Bi-Objective Optimization For A Single Batch Processing Machine, Leena Omar Ghrayeb

Graduate Research Theses & Dissertations

This research proposes a methodology for solving the problem of scheduling jobs with unequal ready times, unequal processing times, and unequal sizes on a single batch processing machine, with the objectives of minimizing makespan and maximum tardiness. Jobs must be placed into batches and scheduled on the machine such that both objectives are minimized, and machine capacity is not violated. The problem under study can be denoted as 1|p-batch, sj, rj| Cmax,Tmax. Based on a review of relevant literature, this problem has not been considered before.

The problem under study is NP-hard. Consequently, meta-heuristics such as Simulated Annealing (SA) and …

Knot Optimization For Univariate Cubic L^1 Spline Fits With Application In Change Point Detection, Manfei Xie

Graduate Research Theses & Dissertations

Cubic $L^1$ spline fits, as a type of $L^1$ approximating splines, have shown superior performance in shape preservation of geometric data with great changes. To better construct a cubic $L^1$ spline fit, the number and the location of the spline knots should be optimized rather than predetermined. This research investigates knot optimization methods for univariate cubic $L^1$ spline fits. When the number of knots is given, we design an optimization-based method to determine the best location of the knots. When the number and the location are unknown, we propose a heuristic method to find proper knot number and location. Numerical …

Sky Surveys Scheduling Using Reinforcement Learning, Andres Felipe Alba Hernandez

Graduate Research Theses & Dissertations

Modern cosmic sky surveys (e.g., CMB S4, DES, LSST) collect a complex diversity of astronomical objects. Each of class of objects presents different requirements for observation time and sensitivity. For determining the best sequence of exposures for mapping the sky systematically, conventional scheduling methods do not optimize the use of survey time and resources. Dynamic sky survey scheduling is an NP-hard problem that has been therefore treated primarily with heuristic methods. We present an alternative scheduling method based on reinforcement learning (RL) that aims to optimize the use of telescope resources for scheduling sky surveys.

We present an exploration of …

Minimizing Total Number Of Tardy Jobs In Parallel Batch Processing Machines Using Column Generation And Simulated Annealing, Sameer Neupane

Graduate Research Theses & Dissertations

This research considers a scheduling problem where jobs need to be grouped into batches and the batches need to be scheduled on parallel batch processing machines with an objective to minimize the total number of tardy jobs. The jobs are assigned to batches in such a way that machine capacity is not violated. This research considers jobs with unequal ready times, unequal processing times and unequal sizes. The machines are identical in processing capabilities; however, their capacities are different. This research aims to develop effective solution approaches to solve the problem under study. A Mixed Integer Linear Programming (MILP) model …

A Lagrangian-Based Heuristic To Consolidate Perishable Products, Samir Babu Bhetwal

Graduate Research Theses & Dissertations

A consolidation center with multiple suppliers and multiple destinations for a perishable product is considered in this research. Perishable products deteriorate with time and this research includes a deterioration cost to measure this behavior. The model considers a variety of suppliers ranging from small to mid-sized. Due to dependencies of inventory and shipment release decisions, an integrated approach of making the operational decisions is necessary. This coordinated approach considers deterioration cost, inventory cost, and transportation cost.

Tradeoff decisions between different supply chain costs are not straightforward as the problem contains constraints like inventory capacity and transportation constraints from suppliers to …

Computational Methods For Bicubic L1 Splines, Priyesh Koyu Rai

Graduate Research Theses & Dissertations

The past two decades have seen the development of L1 splines for interpolation and approximation of geometric data. L1 splines have been shown to preserve shapes better than the conventional L2 splines, especially for data with abrupt changes in the magnitude of spacing. Efficient computation plays an important role in the practical application of L1 splines. This thesis creates new computational methods for constructing bicubic L1 interpolating splines and bicubic L1 spline fits. The bicubic splines in this study are piecewise bicubic polynomials defined on a rectangular grid generated by the tensor product of nodes. We developed a hybrid computational …

Validation Of A Low-Cost Sensor For Development Of Wearable And Handheld Spectrometers, Justin Leslie Cathey

Graduate Research Theses & Dissertations

This study examined the possibility of creating a quantitative radiometric spectrometer from a low-cost relative radiometric spectrometer sensor through the use of statistical analysis and development of a correction factor (p > 0.05). Radiometric spectrometers are able to measure and fully characterize the radiometric and photometric characteristics of light, while relative spectrometers are not able to fully, quantitatively characterize the radiometric response from a light source, thus they are less expensive. The spectrometer created in this research is able to measure and produce comparative lighting parameters as well as an actual radiometer spectrometer.

The photoreceptors cells within the human eye allow …

Biomechanical Exposures Of Neck And Shoulder In Virtual Reality, Sai Akhil Penumudi

Graduate Research Theses & Dissertations

Virtual Environment pose certain potential postural discomfort or pain of the neck and shoulder that could be different from a real environment. There has been a lack of ergonomic guidelines for the Virtual Reality (VR) usage with the hand gesture interaction. The purpose of this study was to evaluate the effect of the vertical target locations on biomechanical exposures of the neck and shoulder and task performance during VR interactions. Twenty subjects performed standardized pointing and painting tasks with five different target locations (15° upward, neutral, 15° downward, 30° downward, and self-selected). Users’ postures, gravitational moments, muscle activities of the …

Driving Under Weather: An Exploration Of The Traveling Salesman Problem With Probabilistic Unfavorable Driving Conditions, Andrew Wright

Graduate Research Theses & Dissertations

Inclement weather has a visceral impact on transportation systems, but it has been made undeniably clear. Reliable ground transportation is absolutely fundamental in global logistics, and the need to deliver goods to customers in a timely manner has never been more important. The field of operations research offers some quality logistics problems with the foresight to provide efficient transportation solutions. One of the most prevalent problems in operations research is the Traveling Salesman Problem (TSP). Although much research has gone into solving the classic TSP and some of its variants, none have been truly dedicated to integrating meteorological sciences.

The …

Biomechanical Evaluation Of Friction-Reducing Devices For Transferring Patients, Veera Aneesh Kuppam

Graduate Research Theses & Dissertations

Professional caregivers and nurses are prone to a greater risk of work-related musculoskeletal disorders, which is primarily related to manual patient handling. In common various transfer devices are used to transfer patients, the efficacy of friction-reducing devices in reducing biomechanical stress in the low back and upper extremities has not been systematically evaluated. Twenty professional caregivers performed standardized lateral pulling, pushing and sliding up tasks with selected transfer devices (draw sheet, slide sheet, slide board, and air-assisted transfer device). Caregivers’ hand-pull force, shoulder, and trunk posture, shoulder moment, muscle activity in wrist flexor, wrist extensor, biceps, triceps, trapezius, and erector …

Evaluating The Role Of Energy Demand Prediction And Renewable Energy Utilization On Energy Dependency Management: A Generic System Dynamics Model, Emad Rabiei Hosseinabad

Graduate Research Theses & Dissertations

Supplying energy has become one of the biggest concerns of developed countries due to the growing energy needs in the last decades. Security of energy supply has forced countries to rely more on energy imports from external sources, and become energy dependent to a greater extent. Utilizing available renewable energy resources has been characterized as a reliable indicator to mitigate energy dependency in countries as well as securing the supplying of energy-based needs in the future. This research explores the impact of renewable energies as trustful resources in mitigating energy imports form external sources with investigation of its viability with …