An Energy Profile Model For Fused Deposition Modeling 3d Printing Process, 2019 Wayne State University
An Energy Profile Model For Fused Deposition Modeling 3d Printing Process, Calvin Hawkins
This project develops a strategy to monitor and estimate the energy consumption of fused deposition modeling (FDM) additive manufacturing, which will benefit manufacturers and designers seeking to design and manufacture products with minimal energy consumption.
Weld Penetration Identification Based On Convolutional Neural Network, 2019 University of Kentucky
Weld Penetration Identification Based On Convolutional Neural Network, Chao Li
Theses and Dissertations--Electrical and Computer Engineering
Weld joint penetration determination is the key factor in welding process control area. Not only has it directly affected the weld joint mechanical properties, like fatigue for example. It also requires much of human intelligence, which either complex modeling or rich of welding experience. Therefore, weld penetration status identification has become the obstacle for intelligent welding system. In this dissertation, an innovative method has been proposed to detect the weld joint penetration status using machine-learning algorithms.
A GTAW welding system is firstly built. Project a dot-structured laser pattern onto the weld pool surface during welding process, the reflected laser pattern ...
Distributed Algorithms In Large-Scaled Empirical Risk Minimization: Non-Convexity, Adaptive-Sampling, And Matrix-Free Second-Order Methods, Xi He
Theses and Dissertations
The rising amount of data has changed the classical approaches in statistical modeling significantly. Special methods are designed for inferring meaningful relationships and hidden patterns from these large datasets, which build the foundation of a study called Machine Learning (ML). Such ML techniques have already applied widely in various areas and achieved compelling success. In the meantime, the huge amount of data also requires a deep revolution of current techniques, like the availability of advanced data storage, new efficient large-scale algorithms, and their distributed/parallelized implementation.There is a broad class of ML methods can be interpreted as Empirical Risk ...
Conic Optimization: Optimal Partition, Parametric, And Stability Analysis, 2019 Lehigh University
Conic Optimization: Optimal Partition, Parametric, And Stability Analysis, Ali Mohammad-Nezhad
Theses and Dissertations
A linear conic optimization problem consists of the minimization of a linear objective function over the intersection of an affine space and a closed convex cone. In recent years, linear conic optimization has received significant attention, partly due to the fact that we can take advantage of linear conic optimization to reformulate and approximate intractable optimization problems. Steady advances in computational optimization have enabled us to approximately solve a wide variety of linear conic optimization problems in polynomial time. Nevertheless, preprocessing methods, rounding procedures and sensitivity analysis tools are still the missing parts of conic optimization solvers. Given the output ...
A Game-Theoretic Approach To Share The Costs Of Cooperating Healthcare Networks, 2019 University of Northern Colorado
A Game-Theoretic Approach To Share The Costs Of Cooperating Healthcare Networks, Jay M. Lightfoot
Journal of International Technology and Information Management
The growing demand for healthcare services combined with the disarray in the health insurance market in the United States has created a situation where rival health networks are aggressively competing by building duplicate health facilities and providing redundant services in localized geographic regions. Unfortunately, this strategy can reduce the quality of patient care and decrease profits (Kaissi & Charland, 2013). A solution to this problem is for health networks to cooperate and share healthcare equipment, facilities, and personnel. Toward that end, this paper presents a game-theoretic method that can share these costs in a fair, efficient, and repeatable manner.
Routing Algorithm For The Ground Team In Transmission Line Inspection Using Unmanned Aerial Vehicle, 2019 Missouri University of Science and Technology
Routing Algorithm For The Ground Team In Transmission Line Inspection Using Unmanned Aerial Vehicle, Yu Li
"With the rapid development of robotics technology, robots are increasingly used to conduct various tasks by utility companies. An unmanned aerial vehicle (UAV) is an efficient robot that can be used to inspect high-voltage transmission lines. UAVs need to stay within a data transmission range from the ground station and periodically land to replace the battery in order to ensure that the power system can support its operation. A routing algorithm must be used in order to guide the motion and deployment of the ground station while using UAV in transmission line inspection. Most existing routing algorithms are dedicated to ...
Quantifying Restoration Costs In The Aftermath Of An Extreme Event Using System Dynamics And Dynamic Mathematical Modeling Approaches, 2019 Missouri University of Science and Technology
Quantifying Restoration Costs In The Aftermath Of An Extreme Event Using System Dynamics And Dynamic Mathematical Modeling Approaches, Akhilesh Ojha
"Extreme events such as earthquakes, hurricanes, and the like, lead to devastating effects that may render multiple supply chain critical infrastructure elements inoperable. The economic losses caused by extreme events continue well after the emergency response phase has ended and are a key factor in determining the best path for post-disaster restoration. It is essential to develop efficient restoration and disaster management strategies to ameliorate the losses from such events. This dissertation extends the existing knowledge base on disaster management and restoration through the creation of models and tools that identify the relationship between production losses and restoration costs. The ...
The Tabu Ant Colony Optimizer And Its Application In An Energy Market, 2019 Missouri University of Science and Technology
The Tabu Ant Colony Optimizer And Its Application In An Energy Market, David Donald Haynes
"A new ant colony optimizer, the 'tabu ant colony optimizer' (TabuACO) is introduced, tested, and applied to a contemporary problem. The TabuACO uses both attractive and repulsive pheromones to speed convergence to a solution. The dual pheromone TabuACO is benchmarked against several other solvers using the traveling salesman problem (TSP), the quadratic assignment problem (QAP), and the Steiner tree problem. In tree-shaped puzzles, the dual pheromone TabuACO was able to demonstrate a significant improvement in performance over a conventional ACO. As the amount of connectedness in the network increased, the dual pheromone TabuACO offered less improvement in performance over the ...
Freeform Extrusion Fabrication Of Advanced Ceramics And Ceramic-Based Composites, 2019 Missouri University of Science and Technology
Freeform Extrusion Fabrication Of Advanced Ceramics And Ceramic-Based Composites, Wenbin Li
"Ceramic On-Demand Extrusion (CODE) is a recently developed freeform extrusion fabrication process for producing dense ceramic components from single and multiple constituents. In this process, aqueous paste of ceramic particles with a very low binder content ( < 1 vol%) is extruded through a moving nozzle to print each layer sequentially. Once one layer is printed, it is surrounded by oil to prevent undesirable water evaporation from the perimeters of the part. The oil level is regulated just below the topmost layer of the part being fabricated. Infrared radiation is then applied to uniformly and partially dry the top layer so that the yield stress of the paste increases to avoid part deformation. By repeating the above steps, the part is printed in a layer-wise fashion, followed by post-processing. Paste extrusion precision of different extrusion mechanisms was compared and analyzed, with an auger extruder determined to be the most suitable paste extruder for the CODE system. A novel fabrication system was developed based on a motion gantry, auger extruders, and peripheral devices. Sample specimens were then produced from 3 mol% yttria stabilized zirconia using this fabrication system, and their properties, including density, flexural strength, Young's modulus, Weibull modulus, fracture toughness, and hardness were measured. The results indicated that superior mechanical properties were achieved by the CODE process among all the additive manufacturing processes. Further development was made on the CODE process to fabricate ceramic components that have external/internal features such as overhangs by using fugitive support material. Finally, ceramic composites with functionally graded materials (FGMs) were fabricated by the CODE process using a dynamic mixing device"--Abstract, page iv.
The Evacuation Problem In Multi-Story Buildings, 2019 University of Massachusetts Amherst
The Evacuation Problem In Multi-Story Buildings, Quang Hong Cung
The pressure from high population density leads to the creation of high-rise structures within urban areas. Consequently, the design of facilities which confront the challenges of emergency evacuation from high-rise buildings become a complex concern. This paper proposes an embedded program which combines a deterministic (GMAFLAD) and stochastic model (M/G/C/C State Dependent Queueing model) into one program, GMAF_MGCC, to solve an evacuation problem. An evacuation problem belongs to Quadratic Assignment Problem (QAP) class which will be formulated as a Quadratic Set Packing model (QSP) including the random flow out of the building and the random pairwise traffic ...
A Computational Simulation Model For Predicting Infectious Disease Spread Using The Evolving Contact Network Algorithm, 2019 University of Massachusetts Amherst
A Computational Simulation Model For Predicting Infectious Disease Spread Using The Evolving Contact Network Algorithm, Buyannemekh Munkhbat
Commonly used simulation models for predicting outbreaks of re-emerging infectious diseases (EIDs) take an individual-level or a population-level approach to modeling contact dynamics. These approaches are a trade-off between the ability to incorporate individual-level dynamics and computational efficiency. Agent-based network models (ABNM) use an individual-level approach by simulating the entire population and its contact structure, which increases the ability of adding detailed individual-level characteristics. However, as this method is computationally expensive, ABNMs use scaled-down versions of the full population, which are unsuitable for low prevalence diseases as the number of infected cases would become negligible during scaling-down. Compartmental models use ...
Forecasting The Cost Of Electricity Generated By Offshore Wind Turbines, 2019 University of Massachusetts Amherst
Forecasting The Cost Of Electricity Generated By Offshore Wind Turbines, Timothy Costa
To impede the progress of climate change, many policy makers are considering avenues to decarbonize electricity production. In addition to decarbonization, policy makers must consider how the cost of electricity will impact various stakeholders, balancing cost and social benefits. Offshore wind farms have the potential to produce affordable, carbon-free electricity, but they are a relatively new technology. The relative juvenescence of offshore wind lends itself to an uncertain future, regarding production costs. In this thesis, we seek to understand cost drivers behind offshore wind electricity by analyzing historic trends in offshore wind levelized cost of electricity (LCOE) through learning curves ...
Systems Approaches To Transdisciplinary Sustainable Development Issues, 2019 University of Colorado Boulder
Systems Approaches To Transdisciplinary Sustainable Development Issues, David Lawrence Zelinka
Civil Engineering Graduate Theses & Dissertations
The goals of this dissertation are twofold. The first is to advance the discipline of sustainability science through the application of systems-based tools (primarily system dynamics) and civil engineering principles. Sustainability science is fundamental to implementing effective strategies for progressing sustainable development and improving human well-being around the planet, but it is still not fully developed as a science and needs new methods and approaches due to the field’s inherent interdisciplinarity and complexity. Civil engineering as a foundation provides mathematical knowledge, computer modeling skills, and a wide breadth of technical understanding, but it lacks the societal, political, and economic ...
Solution Techniques For Non-Convex Optimization Problems, 2019 Lehigh University
Solution Techniques For Non-Convex Optimization Problems, Wei Xia
Theses and Dissertations
This thesis focuses on solution techniques for non-convex optimization problems. The first part of the dissertation presents a generalization of the completely positive reformulation of quadratically constrained quadratic programs (QCQPs) to polynomial optimization problems. We show that by explicitly handling the linear constraints in the formulation of the POP, one obtains a refinement of the condition introduced in Bai's (2015) Thoerem on QCQPs, where the refined theorem only requires nonnegativity of polynomial constraints over the feasible set of the linear constraints. The second part of the thesis is concerned with globally solving non-convex quadratic programs (QPs) using integer programming ...
Applications Of Machine Learning In Supply Chains, 2019 Lehigh University
Applications Of Machine Learning In Supply Chains, Afshin Oroojlooy
Theses and Dissertations
Advances in new technologies have resulted in increasing the speed of data generation and accessing larger data storage. The availability of huge datasets and massive computational power have resulted in the emergence of new algorithms in artificial intelligence and specifically machine learning, with significant research done in fields like computer vision. Although the same amount of data exists in most components of supply chains, there is not much research to utilize the power of raw data to improve efficiency in supply chains.In this dissertation our objective is to propose data-driven non-parametric machine learning algorithms to solve different supply chain ...
Performance Archery Shooting, 2019 Iowa State University
Performance Archery Shooting, Hunter Sabers
Graduate Theses and Dissertations
Bows and arrows can be traced all the way back to 65,000 BC and have evolved from a tool used for hunting, to a tool for war, and today used by hobbyists in competition. The evolution of this technology has progressed for the most part without an understanding of the effect it has on humans. The present study aims to connect how technology effects humans specifically looking at archery. The study measured the muscle activity in the bow arm of the archer and the vibration experienced on the bow arm of the archer during the shooting process. From those ...
An Analysis Of Resistance Spot Weld Quality Based On Acoustic And Electrical Signatures, 2019 University of Kentucky
An Analysis Of Resistance Spot Weld Quality Based On Acoustic And Electrical Signatures, Ivan Charles Butler
Theses and Dissertations--Manufacturing Systems Engineering
The union of a set of materials by way of Resistance Spot Welding is designed so that once fused together, a substantial amount of intentional, external force must be applied to separate the contents. Therefore, Resistance Spot Welding is often the preferred fusion method in high-volume manufacturing processes. The result of Resistance Spot Welding however is the formation of a weld nugget which is not visible to the naked eye. Destructive and/or ultrasonic methods applied off-line must be used to determine the quality of each weld; both inefficient and expensive processes. The following research analyzes the data fed back ...
Optimizing Ensemble Weights For Machine Learning Models: A Case Study For Housing Price Prediction, 2019 Iowa State University
Optimizing Ensemble Weights For Machine Learning Models: A Case Study For Housing Price Prediction, Mohsen Shahhosseini, Guiping Hu, Hieu Pham
Industrial and Manufacturing Systems Engineering Conference Proceedings and Posters
Designing ensemble learners has been recognized as one of the significant trends in the field of data knowledge especially in data science competitions. Building models that are able to outperform all individual models in terms of bias, which is the error due to the difference in the average model predictions and actual values, and variance, which is the variability of model predictions, has been the main goal of the studies in this area. An optimization model has been proposed in this paper to design ensembles that try to minimize bias and variance of predictions. Focusing on service sciences, two well-known ...
Space Dynamics Laboratory Payload Challenge: Autonomous Water Sampling Uav, 2019 The University of Akron
Space Dynamics Laboratory Payload Challenge: Autonomous Water Sampling Uav, Thomas Wheeler, Zachary Williams, Joseph Stack
Williams Honors College, Honors Research Projects
The following report has been completed over the course of the Fall 2018 and Spring 2019 semesters at The University of Akron by Joseph P. Stack (Aerospace Systems Engineering), Thomas J. Wheeler (Mechanical Engineering) and Zachary M. Williams (Mechanical Engineering). The purpose of this project was to create a payload system for the Akronauts Rocket Design Team to use at the Intercollegiate Rocket Engineering Competition (IREC) Spaceport America Cup. The Competition as a challenge that is sponsored by Space Dynamics Laboratory specifically regarding payload systems. The challenge in very open-ended and allows student to identify their own scientific experiment and ...
Compression Set Improvement Of Thermoplastic Vulcanizates For High Temperature Tubing, 2019 The University of Akron
Compression Set Improvement Of Thermoplastic Vulcanizates For High Temperature Tubing, Mitchell Valaitis
Williams Honors College, Honors Research Projects
It was hypothesized that increasing the curative level of the fluorocarbon rubber (FKM) used in manufacturing of thermoplastic vulcanizate (TPV) materials would decrease the compression set values of the TPV enough for it to be suitable as a flexible, lightweight alternative to high operating temperature thermoset rubber tubing currently being used for power steering hose. First, promising TPV formulations were identified by varying the polyamide (PA) and FKM used in a Brabender mixer. Four different types of polyamide and four different types of FKM were investigated, with two of the FKM types and one polyamide type identified as being promising ...