Engineering Commons^™

Development And Optimization Of An Innovative Hvac System With Integrated Pvt And Pcm Thermal Storage For A Net-Zero Energy Retrofitted House, Massimo Fiorentini, Paul Cooper, Zhenjun Ma

Faculty of Engineering and Information Sciences - Papers: Part A

This paper describes a novel solar-assisted HVAC system developed for the Team UOW 'Illawarra Flame' Solar Decathlon house, the winner of the Solar Decathlon China 2013 competition. This HVAC system consists of an air-based photovoltaic-thermal (PVT) collector and a phase change material (PCM) thermal storage unit integrated with a reverse cycle heat pump, in a ducted system. The system was designed for operation during both winter and summer using daytime solar radiation and night-time sky radiative cooling, respectively. The PVT collector heats or cools fresh air from ambient and thereby provides heating or cooling either directly to the indoor space, …

Optimization Of The Number Of Rays In Interpolation For Light Field Based Free Viewpoint Systems, Hooman Shidanshidi, Farzad Safaei, Wanqing Li

Faculty of Engineering and Information Sciences - Papers: Part A

Light field (LF) rendering is widely used in free viewpoint video systems (FVV). Different methods have been proposed to employ depth maps to improve the rendering quality. However, estimation of depth is often error-prone. In this paper, a new method based on the concept of effective sampling density (ESD) is proposed for evaluating the depth-based LF rendering algorithms at different levels of errors in the depth estimation. In addition, for a given rendering quality, we provide an estimation of number of rays required in the interpolation algorithm to compensate for the adverse effect caused by errors in depth maps. The …

Direct Power Control Of Dfig Based Wind Turbine Based On Wind Speed Estimation And Particle Swarm Optimization, Mehrdad Tarafdar Hagh, S Roozbehani, F Najaty, S Ghaemi, Yingjie Tan, Kashem M. Muttaqi

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a direct power control (DPC) design of a grid connected doubly fed induction generator (DFIG) based wind turbine system in order to track maximum absorbable power in different wind speeds. A generalized regression neural network (GRNN) is used to estimate wind speed and thereby the maximum absorbable power is determined online as a function of wind speed. Finally the proposed DPC strategy employs a nonlinear robust sliding mode control (SMC) scheme to calculate the required rotor control voltage directly. The concept of sliding mode control is incorporated into particle swarm optimization (PSO) to determine inertial weights. The …

Role Based Hedonic Games, Matthew Spradling

Theses and Dissertations--Computer Science

In the hedonic coalition formation game model Roles Based Hedonic Games (RBHG), agents view teams as compositions of available roles. An agent's utility for a partition is based upon which role she fulfills within the coalition and which additional roles are being fulfilled within the coalition. I consider optimization and stability problems for settings with variable power on the part of the central authority and on the part of the agents. I prove several of these problems to be NP-complete or coNP-complete. I introduce heuristic methods for approximating solutions for a variety of these hard problems. I validate heuristics on …

Superior Decoupled Control Of Active And Reactive Power For Three-Phase Voltage Source Converters, Hesam Rahbarimagham, Erfan Maali Amiri, Behrooz Vahidi, Gevorg Babamalek Gharehpetian, Mehrdad Abedi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents an active-reactive power control strategy for voltage source converters (VSCs) based on derivation of the direct and quadrature components of the VSC output current. The proposed method utilizes a multivariable proportional-integral controller and provides almost completely decoupled control capability of the active and reactive power with almost full disturbance rejection due to step changes in the power exchanged between the VSC and the grid. It also imposes fast transient response and zero steady-state error as compared to the conventional power control approaches. The applicability of the proposed power control strategy for providing the robust stability of the …

Numerical And Field Data Analysis Of Drill Stem Vibration, Mohammed Fayez Al Dushaishi

Doctoral Dissertations

"Drill stem vibration is a major cause of premature failure of drill stem components and drilling inefficiency. In severe cases, drill stem vibration may lead to wellbore instability that could lead to increased operational cost. Drill stem vibrations are affected by design decisions and the drilling environment. Examples are; bottom hole assembly configurations, selection of operational parameters, and frequent changes in lithology. Vibration modeling, analysis of vibration data, and specialized vibration reduction tools are methods in use to prevent and mitigate severe vibrations.

A drill stem vibration model was created using nonlinear strain formulation which couples the axial, lateral and …

A Framework And System For A Multi-Model Decision Aid For Sustainable Farming Practices, Kasi Bharath Vegesana

Computational Modeling & Simulation Engineering Theses & Dissertations

Decision support systems (DSS) for farmers address the need for modeling multiple processes and scenarios that affect farmer decision making. Existing DSS have various drawbacks that stop them from being deployed as decision support tools. This research proposes a multi-model simulation framework that can be used to analyze farm management practices at the crop level, individual farm level and at the community level to show the impact and alternatives for smallholder farming practices. A generic crop growth model is proposed, based on existing equations. We run sensitivity analysis on the model to identify important variables. The outputs from the crop …

Determination Of Explosive Energy Partition Values In Rock Blasting Through Small-Scale Testing, Joshua Calnan

Theses and Dissertations--Mining Engineering

Blasting is a critical part of most mining operations. The primary function of blasting is to fragment and move rock. For decades, attempts have been made at increasing the efficiency of blasting to reduce costs and increase production. Most of these attempts involve trial and error techniques that focus on changing a single output. These techniques are costly and time consuming and it has been shown that as one output is optimized other outputs move away from their optimum level. To truly optimize a blasting program, the transfer of explosive energy into individual components must be quantified. Explosive energy is …

Design And Optimization Of Nanoplasmonic Waveguide Devices, Pouya Dastmalchi

LSU Doctoral Dissertations

In this dissertation, we introduce compact absorption switches consisting of plasmonic metal-dielectric-metal (MDM) waveguides coupled to multisection cavities. The optimized multisection cavity switches lead to greatly enhanced modulation depth compared to optimized conventional Fabry-Perot cavity switches. We find that the modulation depth of the optimized multisection cavity switches is greatly enhanced compared to the optimized conventional Fabry-Perot cavity switches due to the great enhancement of the total electromagnetic field energy in the cavity region. We then investigate how to improve the computational efficiency of the design of nanoplasmonic devices. More specifically, we show that the space mapping algorithm, originally developed …

Improving Processing By Adaption To Conditional Geostatistical Simulation Of Block Compositions, R. Tolosana-Delgado, Ute A. Mueller, K. G. Van Den Boogaart, C. Ward, J. Gutzmer

Research outputs 2014 to 2021

Exploitation of an ore deposit can be optimized by adapting the beneficiation processes to the properties of individual ore blocks. This can involve switching in and out certain treatment steps, or setting their controlling parameters. Optimizing this set of decisions requires the full conditional distribution of all relevant physical parameters and chemical attributes of the feed, including concentration of value elements and abundance of penalty elements. As a first step towards adaptive processing, the mapping of adaptive decisions is explored based on the composition, in value and penalty elements, of the selective mining units. Conditional distributions at block support are …

Determination Of Electromagnetic Properties Of Steel For Prediction Of Stray Losses In Power Transformers, Leonardo Strac, Damir Zarko

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a method for determination of equivalent linear electromagnetic parameters (constant complex permeability and electrical conductivity) of nonlinear magnetic steel, which can be used in a time-harmonic finite-element simulation to yield the same losses in the volume of that material as the measured ones. The conductivity and the static hysteresis loop of the steel have been measured, from which complex permeability as a function of flux density has been extracted. The indirect measurement of losses in various samples of nonmagnetic and magnetic steel has been carried out using a physical model of a transformer core with a coil. …

Mathematical Models And Solution Approach For Staff Scheduling With Cross-Training At Call Centers, Taskiran, Gamze Kilincli

Browse all Theses and Dissertations

Call centers face demand that varies throughout the week across multiple service categories and typically employ non-standard workforce schedules to meet this demand. In call centers, cross-training provides a buffer against fluctuation of demand between categories and is widely used. Full cross-training, however, is financially impractical in most cases, which has created a challenging problem in how to optimize a cross-trained workforce, i.e., a) what categories should be cross-trained, b) what portion of the workforce should be cross-trained, and c) how to schedule their weekly assignments. This problem is motivated by the need of a Fortune 50 company's technology support …

Estimation Of The Effect Of Catalyst Physical Characteristics On Fenton-Like Oxidation Efficiency Using Adaptive Neuro-Fuzzy Computing Technique

Faculty of Engineering University of Malaya

Catalyst size, which determines surface area, is one of the major factors in catalytic performance. In this study, response surface methodology (RSM) and an adaptive neuro-fuzzy inference system (ANFIS) were applied to quantify the effects of physical characteristics of magnetite on Fenton-like oxidation efficiency of methylene blue. For this purpose, two magnetite samples (M and N) were used and characterized by XRD, BET surface area, particle size analyzer and FE-SEM. Central composite design (CCD) was applied to design the experiments, develop regression models, optimize and evaluate the individual and interactive effects of five independent variables: H2O2 and catalyst concentrations, pH, …

Finite Element Analysis Simulations Of Micro And Nano-Electromechanical Sensors For Design Optimization, Nicholas Frank Deroller

Theses and Dissertations

Micro and Nano-electromechanical sensors (MEMS and NEMS) provide a means of actively sensing minute changes in the surrounding environment. Small changes in temperature, momentum, and strain may be sensed in passive modes while greater sensing possibilities exist in active modes. Theoretical femto-gram resolution mass detection and heated element sensing methods may be used while volatile organic compound (VOC) sensing may be achieved when combined with a functionalization layer or device heating. These devices offer a great reduction in cost and offer increased mobility by allowing a "lab-on-chip" solution for the prospective user while also greatly reducing the amount of energy …

On The Application Of Mechanical Vibration In Robotics-Assisted Soft Tissue Intervention, Iman Khalaji

Electronic Thesis and Dissertation Repository

Mechanical vibration as a way of transmitting energy has been an interesting subject to study. While cyclic oscillation is usually associated with fatigue effect, and hence a detrimental factor in failure of structures and machineries, by controlled transmission of vibration, energy can be transferred from the source to the target. In this thesis, the application of such mechanical vibration in a few surgical procedures is demonstrated.

Three challenges associated with lung cancer diagnosis and treatment are chosen for this purpose, namely, Motion Compensation, tumor targeting in lung Needle Insertion and Soft Tissue Dissection:

1. A robotic solution is proposed …

Truckload Shipment Planning And Procurement, Neo Nguyen

Graduate Theses and Dissertations

This dissertation presents three issues encountered by a shipper in the context of truckload transportation. In all of the studies, we utilize optimization techniques to model and solve the problems. Each study is inspired from the real world and much of the data used in the experiments is real data or representative of real data.

The first topic is about the freight consolidation in truckload transportation. We integrate it with a purchase incentive program to increase truckload utilization and maximize profit. The second topic is about supporting decision making collaboration among departments of a manufacturer. It is a bi-objective optimization …

Optimized Photogrammetric Network Design With Flight Path Planner For Uav-Based Terrain Surveillance, Ivan Yair Rojas

Theses and Dissertations

This work demonstrates the use of genetic algorithms as a stochastic optimization technique for developing a camera network design and the flight path for photogrammetricapplications using Small Unmanned Aerial Vehicles. This study develops a Virtual Optimizer for Aerial Routes (VOAR) as a new photogrammetric mapping tool for acquisition of images to be used in 3D reconstruction. 3D point cloud models provide detailed information on infrastructure from places where human access may be difficult. This algorithm allows optimized flight paths to monitor infrastructure using GPS coordinates and optimized camera poses ensuring that the set of images captured is improved for 3D …

Analysis Of Advanced Supercritical Carbon Dioxide Power Cycles For Concentrated Solar Power Applications, Saeb Mostaghim Besarati

USF Tampa Graduate Theses and Dissertations

Solar power tower technology can achieve higher temperatures than the most common commercial technology using parabolic troughs. In order to take advantage of higher temperatures, new power cycles are needed for generating power at higher efficiencies. Supercritical carbon dioxide (S-CO₂) power cycle is one of the alternatives that have been proposed for the future concentrated solar power (CSP) plants due to its high efficiency. On the other hand, carbon dioxide can also be a replacement for current heat transfer fluids (HTFs), i.e. oil, molten salt, and steam. The main disadvantages of the current HTFs are maximum operating temperature …

Investigation Of Enhanced Titanium And Zinc Oxide Semiconductors For The Photodegradation Of Aqueous Organic Compounds, Innocent Udom

USF Tampa Graduate Theses and Dissertations

Growing demand and shortages of potable water sources due to industrialization have become a great concern worldwide. Various approaches and solutions have been adopted to provide cleaner and quality water. In a preliminary study, a method of treating wastewater was investigated in which algae were used to remove nutrients (nitrogen and phosphorous) from wastewater and then the algae were harvested for use as a biofuel. The results from this investigation are included in the Appendix B. Employing traditional oxidants, such as hydrogen peroxide, chlorine, and ozone, for treatment of recalcitrant organic compounds have achieved less promising results. However, photocatalysis, an …

Development And Integration Of Mems Based Inductive Sensors, Luyang Zhang

Electronic Thesis and Dissertation Repository

Inductive sensors are one of the most widely used sensors especially in automotive. However, with the current PCB manufacture process, the large size of the sensor limits its usage in different applications. In this thesis, a novel method of fabricating bi-layer copper micro inductive sensor is demonstrated to solve the size issue. The two coil layers were built by UV LIGA process respectively, and a polyimide insulation film sandwiched in between. At the beginning, seeding layer was deposited on the substrate as electrode, and then the copper coil layer was created through electroplating in the patterned micromold. The coil was …

Optimal Sizing And Power Management Strategies Of Islanded Microgrids For Remote Electrification Systems, Faruk A. Bhuiyan

Electronic Thesis and Dissertation Repository

Over the past few years, electrification of remote communities with an efficient utilization of on-site energy resources has entered a new phase of evolution. However, the planning tools and studies for the remote microgrids are considered inadequate. Moreover, the existing techniques have not taken into account the impact of reactive power on component sizes. Thus, this thesis concentrates on optimal sizing design of an islanded microgrid (IMG), which is composed of renewable energy resources (RERs), battery energy storage system (BESS), and diesel generation system (DGS), for the purpose of electrifying off-grid communities. Owing to the utilization of both BESS and …

Runway Operations Management: Models, Enhancements, And Decomposition Techniques, Farbod Farhadi

Doctoral Dissertations

Air traffic loads have been on the rise over the last several decades and are expected to double, and possibly triple in some regions, over the coming decade. With the advent of larger aircraft and ever-increasing air traffic loads, aviation authorities are continually pressured to examine capacity expansions and to adopt better strategies for capacity utilization. However, this growth in air traffic volumes has not been accompanied by adequate capacity expansions in the air transport infrastructure. It is, therefore, predicted that flight delays costing multi-billion dollars will continue to negatively impact airline companies and consumers. In airport operations management, runways …

Optimization Of Electrical Discharge Machining Parameters For Niti Shape Memory Alloy By Using The Taguchi Method, Saeed Daneshmand, Ehsan Farahmand Kahrizi, Ali Akbar Lotfineyestanak, Vahid Monfared

Journal of Marine Science and Technology

Electrical discharge machining (EDM) is among the most essential nontraditional machining processes. Material removal rate (MRR) and surface roughness are the two main parameters applied in this method. A desired surface roughness can be achieved at the maximal MRR by selecting the optimal input parameters. Because of the mechanical properties and hardness of shape-memory nickel titanium (NiTi) alloy, material can be removed using an EDM method. NiTi alloy is widely used in marine science and aerospace industries. Surface roughness is a critical parameter affecting the machining of this alloy. This study examined the effect the input parameters (pulse current, gap …

Optimization Of Acid Production In Food Waste Via Anaerobic Respiration, Charles Daniels, Raymond Red Corn, Abigail S. Engelberth Phd.

The Summer Undergraduate Research Fellowship (SURF) Symposium

According to the Food and Agriculture Organization of the United Nations, one third of all food produced in world is wasted; 1.63 * 10⁹ metric tons of nutrition is lost to transportation, contamination, or neglect every year (FAO 2013). This wasted food, however, could be repurposed as a substrate for microbial conversion into useful chemicals. This research is aimed at finding the optimal conditions for bacterial colonies to generate volatile fatty acids (VFAs): resources that are used as solvents, medicines, and chemical intermediates usually generated from petroleum based resources (Drumright et al., 2000) (Roscher 2000) (Kolt et al., 2007). …

Make Or Buy Analysis Model Based On Tolerance Design To Minimize Manufacturing Cost And Quality Loss, Cucuk Nur Rosyidi, Reza Rizkichani Akbar, Wakhid Ahmad Jauhari

Makara Journal of Technology

In a manufacturing company, manufacturing costs, or component prices, and tolerance will affect the price and the quality of a product. Companies must produce high-quality products with low manufacturing costs in order to keep their products competitive in the market; however, it is difficult to produce a high-quality product with a low manufacturing cost. Companies have difficulties in determining the components to be produced using their own manufacturing facilities (make) or outsourced to their suppliers (buy). Hence, a make or buy analysis is needed to minimize the manufacturing costs and quality loss and to determine the optimum alternative regarding make …

Optimizing Boat Hull And Deck Mold Storage Scheduling With Linear Programming, Tron Bjorn Dareing

Masters Theses

With a wide range of products, Sea Ray uses a vast amount of large boat molds for each of the different boat models. Storing and transporting these molds can be an issue with introducing high variability in the production process. One of the largest problems deals with the utilization of the employees’ time with the large amount of boat production. Having the boat molds being ready for production is a critical part of the manufacturing of quality boats. There is non-value added time spent on preparing the molds for the lamination process and storing them in various areas. This problem …

Coupled Electromagnetic And Thermal Analysis And Design Optimization Of Synchronous Electric Machines, Yi Wang

Theses and Dissertations

A new technique for coupling the electromagnetic, thermal, and air-flow analysis is proposed for electronically controlled synchronous machines. A computationally efficient finite element analysis (CE-FEA) technique is employed for the electromagnetic field analysis. An equivalent circuit network is used for thermal and air-flow analysis. An iterative algorithm, which exploits the fact that the type of machines studied have very low rotor losses and also a relatively reduced dependency of core losses with temperature and load, has been developed. The overall computational time is significantly reduced in comparison with the conventional coupling method, such that the new technique is highly suitable …

A Stochastic Model For Self-Scheduling Problem, Lili Zhang

Masters Theses

The unit commitment (UC) problem is a typical application of optimization techniques in the power generation and operation. Given a planning horizon, the UC problem is to find an optimal schedule of generating units, including on/off status and production level of each generating unit at each time period, in order to minimize operational costs, subject to a series of technical constraints. Because technical constraints depend on the characteristics of energy systems, the formulations of the UC problem vary with energy systems. The self-scheduling problem is a variant of the UC problem for the power generating companies to maximize their profits …

Reducing Carbon Emission Of Ocean Shipments By Optimizing Container Size Selection, Edwin Lik Ming Chong, Nang Laik Ma, Kar Way Tan

Research Collection School Of Computing and Information Systems

Human’s impact on earth through global warming is more or less an accepted fact. Ocean freight is estimated to contribute 4-5% of global carbon emissions and manufacturing companies can aid in reducing this amount. Many companies that ship goods through full container loads do not have the capabilities to ensure the containers they are using minimizes their carbon footprint. One of the reasons is the choice of non-ideal container sizes for their shipments. This paper provides a mathematical model to minimize companies’ shipping carbon footprints by selecting the ideal container sizes appropriate for their shipment volumes. Using data from a …

Trajectory Optimization For A Misson To The Trojan Asteroids, Shivaji Senapati Gadsing

Masters Theses

The problem of finding a minimum-fuel trajectory for a mission to the Jovian Trojan asteroids is considered. The problem is formulated as a modified traveling salesman problem. Two different types of algorithms such as an exhaustive search algorithm and a serial rendezvous search algorithm are developed. The General Mission Analysis Tool (GMAT) is employed for finding optimum trajectories with minimal fuel consumption. The selection of a minimum-fuel mission trajectory, and the associated target asteroids, will be a key factor in determining feasibility and scientific value of a Trojan tour and rendezvous mission.

The transfer trajectory followed by a spacecraft between …