View All Items
(1 - 15 of 15)
- Title
- Smart Grid Demonstration: Distributed Active and Reactive Power Control.
- Creator
-
Vellakovil Rajamani, Siddarth, Qu, Zhihua, Simaan, Marwan, Sun, Wei, University of Central Florida
- Abstract / Description
-
The present infrastructure of energy delivery was designed over 60 years ago with the goal to be centralized. However, it is aging and is under-utilized, which will potentially limit the world's ability to achieve its energy objective. The lack of vibrant control on the grid makes it difficult to stop cascading power failure, and to achieve high penetration of renewable energy resources, such as wind and solar thus resulting in grid instability. A decentralized and distributed control...
Show moreThe present infrastructure of energy delivery was designed over 60 years ago with the goal to be centralized. However, it is aging and is under-utilized, which will potentially limit the world's ability to achieve its energy objective. The lack of vibrant control on the grid makes it difficult to stop cascading power failure, and to achieve high penetration of renewable energy resources, such as wind and solar thus resulting in grid instability. A decentralized and distributed control mechanism implemented with a definite communication protocol solves the issues mentioned above. The electric power grid going into the future is expected to consists of distributed generators and loads. The implementation of a distributed control will benefit utility services and will create financial advantages. One of the best solutions is to organize these distributed generators (DG) in a micro-grid structure which will then connect to the main grid through the point of common coupling (PCC). A proper organization and control of the Microgrid is always a big challenge. To overcome this, using cooperative control makes it possible to bring together different agents in the networked systems as a group and realize the desired objective. The micro grid power objective is set by a virtual leader and is transferred to the other agents in the system through a local communication channel. A distributed cooperative control is formulated to effectively organize all the DGs in the Microgrid to produce the necessary active and reactive power to satisfy multiple objectives. It not only satisfies the active power flow from the main grid to a constant but also reduces the reactive power flow to the main grid. Moreover, the algorithm can be used to implement the demand response continuously using a combination of DGs and their local controllable loads. The approach is to use distributed inverters with the aid of multiple local communication channels for active power compensation of the micro-grid in real-time in a distributed and cooperative manner.
Show less - Date Issued
- 2016
- Identifier
- CFE0006513, ucf:51362
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006513
- Title
- SMART MATERIAL ACTUATION AND MORPHING FOR UNMANNED AIRCRAFT SYSTEMS.
- Creator
-
Da Silva Lima, Caio H, Kauffman, Jeffrey L., University of Central Florida
- Abstract / Description
-
The intent of this thesis is to outline the design, analysis, and characterization of an axially compressed piezocomposite actuator and, in particular, to determine the correlation and accuracy of two models used to predict deflection of an axially compressed piezocomposite bimorph. Restrictions in material properties lead to vehicle inefficiencies caused by the discontinuous geometry of deflected control surfaces in unmanned aircraft systems. This performance disadvantage in discrete control...
Show moreThe intent of this thesis is to outline the design, analysis, and characterization of an axially compressed piezocomposite actuator and, in particular, to determine the correlation and accuracy of two models used to predict deflection of an axially compressed piezocomposite bimorph. Restrictions in material properties lead to vehicle inefficiencies caused by the discontinuous geometry of deflected control surfaces in unmanned aircraft systems. This performance disadvantage in discrete control surfaces is caused in part by the sharp edges that are formed when the surface is pivoted. Flow continuity over the body of a vehicle is important in minimizing the effects of drag and, in turn, increasing aerodynamic performance. An efficient alternative to discrete control surface actuation is axially compressed piezocomposite actuation which could potentially improve the efficiency of the vehicle in all environments. Bimorph performance in angular deflection and displacement for the PA16N and MFC-M8528-P1 piezocomposites is analyzed using a Classical Laminate Plate Theory (CLPT) model and an Elastica model. Model accuracy is verified through experimental testing of a PA16N bimorph. CLPT model is shown to be accurate to within .05 mm and Elastica model is shown to be accurate to within .04 mm for axial forces below 30 N. Correlation between the mathematical models is confirmed. Experimental results for the PA16N show that a 30 N compression force applied to the bimorph can increase the maximum displacement by approximately 2.5 times the original displacement.
Show less - Date Issued
- 2016
- Identifier
- CFH2000095, ucf:45563
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000095
- Title
- INCREASED LEVELS OF ANXIETY REVEALING CHARACTERISTICS OF SOCIAL PHOBIA ELUCIDATED BY SMART PHONE USE.
- Creator
-
Richardson , Mark, Beidel, Deborah, University of Central Florida
- Abstract / Description
-
Students at the University of Central Florida completed two self-report inventories: the SPAI-23, (Social Phobia and Anxiety Inventory - 23) and MPPUS (Mobile Phone Problem Use Scale) to determine if there is a relationship between social phobia and problematic mobile phone use. Fifty one students (N = 51) completed both surveys and the results indicated that there was a small but positive relationship between problematic cell phone use and social phobia symptoms, r=.28, p=.05. The results...
Show moreStudents at the University of Central Florida completed two self-report inventories: the SPAI-23, (Social Phobia and Anxiety Inventory - 23) and MPPUS (Mobile Phone Problem Use Scale) to determine if there is a relationship between social phobia and problematic mobile phone use. Fifty one students (N = 51) completed both surveys and the results indicated that there was a small but positive relationship between problematic cell phone use and social phobia symptoms, r=.28, p=.05. The results are discussed in terms of how social phobia might increase problematic phone use.
Show less - Date Issued
- 2012
- Identifier
- CFH0004241, ucf:44931
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004241
- Title
- A Smart UAV Platform for Railroad Inspection.
- Creator
-
Debevec, Ryan, Elgohary, Tarek, Xu, Yunjun, Lin, Kuo-Chi, University of Central Florida
- Abstract / Description
-
Using quadcopters for analysis of an environment has been an intriguing subject of study recently. The purpose of this work is to develop a fully autonomous UAV platform for Railroad inspection The dynamics of the quadrotor is derived using Euler's and Newton's laws and then linearized around the hover position. A PID controller is designed to control the states of the quadrotor in a manner to effectively follow a vision-based path, using the down facing camera on a Parrot Mambo quadrotor....
Show moreUsing quadcopters for analysis of an environment has been an intriguing subject of study recently. The purpose of this work is to develop a fully autonomous UAV platform for Railroad inspection The dynamics of the quadrotor is derived using Euler's and Newton's laws and then linearized around the hover position. A PID controller is designed to control the states of the quadrotor in a manner to effectively follow a vision-based path, using the down facing camera on a Parrot Mambo quadrotor. Using computer vision the distance from the position of the quadrotor to the position of the center of the path was found. Using the yaw controller to minimize this distance was found to be an adequate method of vision-based path following, by keeping the area of interest in the field of view of the camera. The downfacing camera is also simultaneously observing the path to detect defects using machine learning. This technique was able to detect simulated defects on the path with around 90% accuracy.
Show less - Date Issued
- 2019
- Identifier
- CFE0007623, ucf:52555
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007623
- Title
- BEHAVIORAL INTERVENTIONS VERSUS PHARMACEUTICAL INTERVENTIONS TO REDUCE PREOPERATIVE ANXIETY IN SCHOOL AGED CHILDREN.
- Creator
-
Cline, Jennifer J, D'Amato-Kubiet, Leslee, University of Central Florida
- Abstract / Description
-
Surgical procedures that require general anesthesia can be stressful and create needless anxiety for school-age children. Interventions aimed at reducing preoperative anxiety can improve cooperation and enhance postoperative outcomes by lowering anxiety levels prior to induction of general anesthesia. The purpose of this study was to examine the effects of behavioral interventions versus drug therapy in reducing pre-operative anxiety in children. The secondary purpose was to compare methods...
Show moreSurgical procedures that require general anesthesia can be stressful and create needless anxiety for school-age children. Interventions aimed at reducing preoperative anxiety can improve cooperation and enhance postoperative outcomes by lowering anxiety levels prior to induction of general anesthesia. The purpose of this study was to examine the effects of behavioral interventions versus drug therapy in reducing pre-operative anxiety in children. The secondary purpose was to compare methods used to integrate anxiety reduction interventions into pre-operative care and to evaluate the most widely used and effective strategy for clinical practice. A literature review exploring behavioral based stress reduction interventions and drug therapy targeted at reducing preoperative anxiety was conducted from various online databases. Peer reviewed articles, published in the English-language between 2006 and 2015 that focused on postoperative outcomes in which preoperative interventions to reduce anxiety in children age two years and older, as well as the parent's perspective of the outcome, were included for synthesis. Results from 9 randomized controlled trials that used behavioral based interventions implemented on the day of surgery, prior to anesthesia induction were compared for effectiveness at anxiety reduction versus the use of drug therapy prior to surgery. The studies suggest more successful post-surgical outcomes related to shorter length of stay and post-operative delirium for behavioral interventions to reduce anxiety prior to surgery and demonstrated even greater optimal outcomes for combined behavioral interventions. Drug therapy alone to decrease anxiety prior to anesthesia induction showed mixed results in reduction of physiologic and general outcomes following surgery. No significant difference between behavioral based interventions versus drug therapy was shown in any of the reviewed studies to have a significant effect on post-surgical outcomes. However, potentially promising behavioral based interventions such as clowns, electronic devices, parental presence and music over drug therapy prior to surgery, require further evaluation for their use in decreasing pre-operative anxiety in school-age children and having a positive impact on post-operative outcomes.
Show less - Date Issued
- 2016
- Identifier
- CFH2000090, ucf:45566
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000090
- Title
- COMMUTING IN PORTLAND OREGON: THE ADVANTAGES OF LIVING WITHIN A TRANSIT ORIENTED DEVELOPMENT COMMUNITY COMPARED TO TRADITIONAL SUBURBAN DEVELOPMENT BY COMPARING ENVIRONMENTAL, ECONOMIC AND HEALTH FACTORS.
- Creator
-
Simpson, Kyle, Hawkins, Christopher, University of Central Florida
- Abstract / Description
-
Transportation is a function that affects nearly all life decisions, but is often not given much thought by the average individual throughout their daily routines. Most of this complacency streams from the mainstream development patterns in the United States that have changed little from the end of World War II. During the immediate post-war years a perfect mix for suburban living came together: the mass production of automobiles, guaranteed mortgages from the federal government through the G...
Show moreTransportation is a function that affects nearly all life decisions, but is often not given much thought by the average individual throughout their daily routines. Most of this complacency streams from the mainstream development patterns in the United States that have changed little from the end of World War II. During the immediate post-war years a perfect mix for suburban living came together: the mass production of automobiles, guaranteed mortgages from the federal government through the G.I. Bill, and in 1956 the passage of the National Interstate and Defense Highways Act. These factors, along with the dominate social paradigm that the "American Dream" was to have a personal front and back yard, helped profoundly transform development in the country. Over half a century later, the United States is now experiencing the consequences of this sprawled, auto-dependent development pattern. Energy prices have increased substantially over the past decade, which were only contained momentarily by a worldwide recession that was arguably caused by the same development patterns. Environmental consequences are becoming increasingly evident, ranging from contaminated storm-water runoff, to global climate change. Similarly, mental and physical health has degraded rapidly, with a soaring depression and obesity rates. The United States can, and should do better than this. Transit Oriented Development (TOD) offers a solution to help alleviate many of the complex issues that many communities must address. While there is no perfect template, TOD is an important step forward for the overall quality of life for individuals throughout the nation. This report will look at the steps that have been taken in the Portland Oregon Metropolitan Area to discourage sprawl development, measuring the effects of their actions on environmental, economic and health factors.
Show less - Date Issued
- 2013
- Identifier
- CFH0004431, ucf:45143
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004431
- Title
- A framework to generate a smart manufacturing system configurations using agents and optimization.
- Creator
-
Nagadi, Khalid, Rabelo, Luis, Lee, Gene, Elshennawy, Ahmad, Ahmad, Ali, University of Central Florida
- Abstract / Description
-
Manufacturing is a crucial element in the global economy. During the last decade, the national manufacturing sector loses nearly 30% of its workforce and investments. Consequently, the quality of the domestic goods, global share, and manufacturing capabilities has been declined. Therefore, innovative ways to optimize the usage of the Smart Manufacturing Systems (SMS) are required to form a new manufacturing era. This research is presenting a framework to optimize the design of SMS. This...
Show moreManufacturing is a crucial element in the global economy. During the last decade, the national manufacturing sector loses nearly 30% of its workforce and investments. Consequently, the quality of the domestic goods, global share, and manufacturing capabilities has been declined. Therefore, innovative ways to optimize the usage of the Smart Manufacturing Systems (SMS) are required to form a new manufacturing era. This research is presenting a framework to optimize the design of SMS. This includes the determination of the suitable machines that can perform the job efficiently, the quantity of those machines, and the potential messaging system required for sharing information.Multiple reviews are used to form the framework. Expert machine selection matrix identifies the required machines and machine parameter matrix defines the specifications of those machines. While business process modeling and notation (BPMN) captures the process plan in object-oriented fashion. In addition, to agent unified modeling language (AUML) that guides the application of message sequence diagram and statecharts. Finally, the configuration is obtained from a hybrid simulation model. Agent based-modeling is used to capture the behavior of the machines where discrete event simulation mimics the process flow. A case study of a manufacturing system is used to verify the study. As a result, the framework shows positive outcomes in supporting upper management in the planning phase of establishing a SMS or evaluating an existing one.
Show less - Date Issued
- 2016
- Identifier
- CFE0006540, ucf:51311
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006540
- Title
- cooperative control and advanced management of distributed generators in a smart grid.
- Creator
-
Maknouninejad, Ali, Qu, Zhihua, Lotfifard, Saeed, Haralambous, Michael, Wu, Xinzhang, Kutkut, Nasser, University of Central Florida
- Abstract / Description
-
Smart grid is more than just the smart meters. The future smart grids are expected to include ahigh penetration of distributed generations (DGs), most of which will consist of renewable energysources, such as solar or wind energy. It is believed that the high penetration of DGs will resultin the reduction of power losses, voltage profile improvement, meeting future load demand, andoptimizingthe use of non-conventionalenergy sources. However, more serious problems will ariseif a decent control...
Show moreSmart grid is more than just the smart meters. The future smart grids are expected to include ahigh penetration of distributed generations (DGs), most of which will consist of renewable energysources, such as solar or wind energy. It is believed that the high penetration of DGs will resultin the reduction of power losses, voltage profile improvement, meeting future load demand, andoptimizingthe use of non-conventionalenergy sources. However, more serious problems will ariseif a decent control mechanism is not exploited. An improperly managed high PV penetration maycause voltage profile disturbance, conflict with conventional network protection devices, interferewith transformer tap changers, and as a result, cause network instability.Indeed, it is feasible to organize DGs in a microgrid structure which will be connected to the maingrid through a point of common coupling (PCC). Microgrids are natural innovation zones for thesmart grid because of their scalability and flexibility. A proper organization and control of theinteraction between the microgrid and the smartgrid is a challenge.Cooperative control makes it possible to organize different agents in a networked system to actas a group and realize the designated objectives. Cooperative control has been already appliedto the autonomous vehicles and this work investigates its application in controlling the DGs in amicro grid. The microgrid power objectives are set by a higher level control and the application ofthe cooperative control makes it possible for the DGs to utilize a low bandwidth communicationnetwork and realize the objectives.Initially, the basics of the application of the DGs cooperative control are formulated. This includesorganizing all the DGs of a microgrid to satisfy an active and a reactive power objective. Then, thecooperative control is further developed by the introduction of clustering DGs into several groupsto satisfy multiple power objectives. Then, the cooperative distribution optimization is introducedto optimally dispatch the reactive power of the DGs to realize a unified microgrid voltage profileand minimizethelosses. Thisdistributedoptimizationis agradient based techniqueand itis shownthat when the communication is down, it reduces to a form of droop. However, this gradient baseddroop exhibits a superior performance in the transient response, by eliminating the overshootscaused by the conventional droop.Meanwhile, the interaction between each microgrid and the main grid can be formulated as aStackelberg game. The main grid as the leader, by offering proper energy price to the micro grid,minimizes its cost and secures the power. This not only optimizes the economical interests ofboth sides, the microgrids and the main grid, but also yields an improved power flow and shavesthe peak power. As such, a smartgrid may treat microgrids as individually dispatchable loads orgenerators.
Show less - Date Issued
- 2013
- Identifier
- CFE0004712, ucf:49817
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004712
- Title
- Vision-Based Testbeds for Control System Applicaitons.
- Creator
-
Sivilli, Robert, Xu, Yunjun, Gou, Jihua, Cho, Hyoung, Pham, Khanh, University of Central Florida
- Abstract / Description
-
In the field of control systems, testbeds are a pivotal step in the validation and improvement of new algorithms for different applications. They provide a safe, controlled environment typically having a significantly lower cost of failure than the final application. Vision systems provide nonintrusive methods of measurement that can be easily implemented for various setups and applications. This work presents methods for modeling, removing distortion, calibrating, and rectifying single and...
Show moreIn the field of control systems, testbeds are a pivotal step in the validation and improvement of new algorithms for different applications. They provide a safe, controlled environment typically having a significantly lower cost of failure than the final application. Vision systems provide nonintrusive methods of measurement that can be easily implemented for various setups and applications. This work presents methods for modeling, removing distortion, calibrating, and rectifying single and two camera systems, as well as, two very different applications of vision-based control system testbeds: deflection control of shape memory polymers and trajectory planning for mobile robots. First, a testbed for the modeling and control of shape memory polymers (SMP) is designed. Red-green-blue (RGB) thresholding is used to assist in the webcam-based, 3D reconstruction of points of interest. A PID based controller is designed and shown to work with SMP samples, while state space models were identified from step input responses. Models were used to develop a linear quadratic regulator that is shown to work in simulation. Also, a simple to use graphical interface is designed for fast and simple testing of a series of samples. Second, a robot testbed is designed to test new trajectory planning algorithms. A template-based predictive search algorithm is investigated to process the images obtained through a low-cost webcam vision system, which is used to monitor the testbed environment. Also a user-friendly graphical interface is developed such that the functionalities of the webcam, robots, and optimizations are automated. The testbeds are used to demonstrate a wavefront-enhanced, B-spline augmented virtual motion camouflage algorithm for single or multiple robots to navigate through an obstacle dense and changing environment, while considering inter-vehicle conflicts, obstacle avoidance, nonlinear dynamics, and different constraints. In addition, it is expected that this testbed can be used to test different vehicle motion planning and control algorithms.
Show less - Date Issued
- 2012
- Identifier
- CFE0004601, ucf:49187
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004601
- Title
- HIGHLY INTEGRATED DC-DC CONVERTERS.
- Creator
-
Jia, Hongwei, Shen, Zhen, University of Central Florida
- Abstract / Description
-
A monolithically integrated smart rectifier has been presented first in this work. The smart rectifier, which integrates a power MOSFET, gate driver and control circuitry, operates in a self-synchronized fashion based on its drain-source voltage, and does not need external control input. The analysis, simulation, and design considerations are described in detail. A 5V, 5-μm CMOS process was used to fabricate the prototype. Experimental results show that the proposed rectifier functions...
Show moreA monolithically integrated smart rectifier has been presented first in this work. The smart rectifier, which integrates a power MOSFET, gate driver and control circuitry, operates in a self-synchronized fashion based on its drain-source voltage, and does not need external control input. The analysis, simulation, and design considerations are described in detail. A 5V, 5-μm CMOS process was used to fabricate the prototype. Experimental results show that the proposed rectifier functions as expected in the design. Since no dead-time control needs to be used to switch the sync-FET and ctrl-FET, it is expected that the body diode losses can be reduced substantially, compared to the conventional synchronous rectifier. The proposed self-synchronized rectifier (SSR) can be operated at high frequencies and maintains high efficiency over a wide load range. As an example of the smart rectifierÂÂÂÂ's application in isolated DC-DC converter, a synchronous flyback converter with SSR is analyzed, designed and tested. Experimental results show that the operating frequency could be as high as 4MHz and the efficiency could be improved by more than 10% compared to that when a hyper fast diode rectifier is used. Based on a new current-source gate driver scheme, an integrated gate driver for buck converter is also developed in this work by using a 0.35μm CMOS process with optional high voltage (50V) power MOSFET. The integrated gate driver consists both the current-source driver for high-side power MOSFET and low-power driver for low-side power iv MOSFET. Compared with the conventional gate driver circuit, the current-source gate driver can recovery some gate charging energy and reduce switching loss. So the current-source driver (CSD) can be used to improve the efficiency performance in high frequency power converters. This work also presents a new implementation of a power supply in package (PSiP) 5MHz buck converter, which is different from all the prior-of-art PSiP solutions by using a high-Q bondwire inductor. The high-Q bondwire inductor can be manufactured by applying ferrite epoxy to the common bondwire during standard IC packaging process, so the new implementation of PSiP is expected to be a cost-effective way of power supply integration.
Show less - Date Issued
- 2010
- Identifier
- CFE0003040, ucf:48354
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003040
- Title
- Smart Grasping using Laser and Tactile Array Sensors for UCF-MANUS- An Intelligent Assistive Robotic Manipulator.
- Creator
-
Prakash, Kiran, Behal, Aman, Boloni, Ladislau, Haralambous, Michael, University of Central Florida
- Abstract / Description
-
This thesis presents three improvements in the UCF MANUS Assistive Robotic Manipulator's grasping abilities. Firstly, the robot can now grasp objects that are deformable, heavy and have uneven contact surfaces without undergoing slippage during robotic operations, e.g. paper cup, filled water bottle. This is achieved by installing a high precision non-contacting Laser sensor1 that runs with an algorithm that processes raw-input data from the sensor, registers smallest variation in the...
Show moreThis thesis presents three improvements in the UCF MANUS Assistive Robotic Manipulator's grasping abilities. Firstly, the robot can now grasp objects that are deformable, heavy and have uneven contact surfaces without undergoing slippage during robotic operations, e.g. paper cup, filled water bottle. This is achieved by installing a high precision non-contacting Laser sensor1 that runs with an algorithm that processes raw-input data from the sensor, registers smallest variation in the relative position of the object with respect to the gripper. Secondly, the robot can grasp objects that are as light and small as single cereal grain without deforming it. To achieve this a MEMS Barometer based tactile sensor array device that can measure force that are as small as 1 gram equivalent is embedded into the gripper to enhance pressure sensing capabilities. Thirdly, the robot gripper gloves are designed aesthetically and conveniently to accommodate existing and newly added sensors using a 3D printing technology that uses light weight ABS plastic as a fabrication material. The newly designed system was experimented and found that a high degree of adaptability for different kinds of objects can be attained with a better performance than the previous system.
Show less - Date Issued
- 2016
- Identifier
- CFE0006164, ucf:51119
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006164
- Title
- Data-driven Predictive Analytics For Distributed Smart Grid Control: Optimization of Energy Storage, Voltage and Demand Response.
- Creator
-
Valizadehhaghi, Hamed, Qu, Zhihua, Behal, Aman, Atia, George, Turgut, Damla, Pensky, Marianna, University of Central Florida
- Abstract / Description
-
The smart grid is expected to support an interconnected network of self-contained microgrids. Nonetheless, the distributed integration of renewable generation and demand response adds complexity to the control and optimization of smart grid. Forecasts are essential due to the existence of stochastic variations and uncertainty. Forecasting data are spatio-temporal which means that the data correspond to regular intervals, say every hour, and the analysis has to take account of spatial...
Show moreThe smart grid is expected to support an interconnected network of self-contained microgrids. Nonetheless, the distributed integration of renewable generation and demand response adds complexity to the control and optimization of smart grid. Forecasts are essential due to the existence of stochastic variations and uncertainty. Forecasting data are spatio-temporal which means that the data correspond to regular intervals, say every hour, and the analysis has to take account of spatial dependence among the distributed generators or locations. Hence, smart grid operations must take account of, and in fact benefit from the temporal dependence as well as the spatial dependence. This is particularly important considering the buffering effect of energy storage devices such as batteries, heating/cooling systems and electric vehicles. The data infrastructure of smart grid is the key to address these challenges, however, how to utilize stochastic modeling and forecasting tools for optimal and reliable planning, operation and control of smart grid remains an open issue.Utilities are seeking to become more proactive in decision-making, adjusting their strategies based on realistic predictive views into the future, thus allowing them to side-step problems and capitalize on the smart grid technologies, such as energy storage, that are now being deployed atscale. Predictive analytics, capable of managing intermittent loads, renewables, rapidly changing weather patterns and other grid conditions, represent the ultimate goal for smart grid capabilities.Within this framework, this dissertation develops high-performance analytics, such as predictive analytics, and ways of employing analytics to improve distributed and cooperative optimization software which proves to be the most significant value-add in the smart grid age, as new network management technologies prove reliable and fundamental. Proposed optimization and control approaches for active and reactive power control are robust to variations and offer a certain level of optimality by combining real-time control with hours-ahead network operation schemes. The main objective is managing spatial and temporal availability of the energy resources in different look-ahead time horizons. Stochastic distributed optimization is realized by integrating a distributed sub-gradient method with conditional ensemble predictions of the energy storage capacity and distributed generation. Hence, the obtained solutions can reflect on the system requirements for the upcoming times along with the instantaneous cooperation between distributed resources. As an important issue for smart grid, the conditional ensembles are studied for capturing wind, photovoltaic, and vehicle-to-grid availability variations. The following objectives are pursued:- Spatio-temporal adaptive modeling of data including electricity demand, electric vehicles and renewable energy (wind and solar power)- Predictive data analytics and forecasting- Distributed control- Integration of energy storage systemsFull distributional characterization and spatio-temporal modeling of data ensembles are utilized in order to retain the conditional and temporal interdependence between projection data and available capacity. Then, by imposing measures of the most likely ensembles, the distributed control method is carried out for cooperative optimization of the renewable generation and energy storage within the smart grid.
Show less - Date Issued
- 2016
- Identifier
- CFE0006408, ucf:51481
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006408
- Title
- High performance liquid crystal devices for augmented reality and virtual reality.
- Creator
-
Talukder, Md Javed Rouf, Wu, Shintson, Moharam, Jim, Amezcua Correa, Rodrigo, Dong, Yajie, University of Central Florida
- Abstract / Description
-
See-through augmented reality and virtual reality displays are emerging due to their widespread applications in education, engineering design, medical, retail, transportation, automotive, aerospace, gaming, and entertainment. For augmented reality and virtual reality displays, high-resolution density, high luminance, fast response time and high ambient contrast ratio are critically needed. High-resolution density helps eliminate the screen-door effect, high luminance and fast response time...
Show moreSee-through augmented reality and virtual reality displays are emerging due to their widespread applications in education, engineering design, medical, retail, transportation, automotive, aerospace, gaming, and entertainment. For augmented reality and virtual reality displays, high-resolution density, high luminance, fast response time and high ambient contrast ratio are critically needed. High-resolution density helps eliminate the screen-door effect, high luminance and fast response time enable low duty ratio operation, which plays a key role for suppressing image blurs. A dimmer placed in front of AR display helps to control the incident background light, which in turn improves the image contrast. In this dissertation, we have focused three crucial display metrics: high luminance, fast motion picture response time (MPRT) and high ambient contrast ratio.We report a fringe-field switching liquid crystal display, abbreviated as d-FFS LCD, by using a low viscosity material and new diamond-shape electrode configuration. Our proposed device shows high transmittance, fast motion picture response time, low operation voltage, wide viewing angle, and indistinguishable color shift and gamma shift. We also investigate the rubbing angle effects on transmittance and response time. When rubbing angle is 0 degree, the virtual wall effect is strong, resulting in fast response time but compromised transmittance. When rubbing angle is greater than 1.2 degree, the virtual walls disappear, as a result, the transmittance increases dramatically, but the tradeoff is in slower response time. We also demonstrate a photo-responsive guest-host liquid crystal (LC) dimmer to enhance the ambient contrast ratio in augmented reality displays. The LC composition consists of photo-stable chiral agent, photosensitive azobenzene, and dichroic dye in a nematic host with negative dielectric anisotropy. In this device, transmittance changes from bright state to dark state by exposing a low intensity UV or blue light. Reversal process can be carried out by red light or thermal effect. Such a polarizer-free photo-activated dimmer can also be used for wide range of applications, such as diffractive photonic devices, portable information system, vehicular head-up displays, and smart window for energy saving purpose. A dual-stimuli polarizer-free dye-doped liquid crystal (LC) device is demonstrated as a dimmer. Upon UV/blue light exposure, the LC directors and dye molecules turn from initially vertical alignment (high transmittance state) to twisted fingerprint structure (low transmittance state). The reversal process is accelerated by combining a longitudinal electric field to unwind the LC directors from twisted fingerprint to homeotropic state, and a red light to transform the cis azobenzene back to trans. Such an electric-field-assisted reversal time can be reduced from ~10s to a few milliseconds, depending on the applied voltage. Considering power consumption, low manufacturing cost, and large fabrication tolerance, this device can be used as a smart dimmer to enhance the ambient contrast ratio for augmented reality displays.
Show less - Date Issued
- 2019
- Identifier
- CFE0007731, ucf:52425
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007731
- Title
- The User Experience of Disney Infinity: Do Smart Toys Matter?.
- Creator
-
Welch, Shelly, Smith, Peter, McDaniel, Rudy, Vie, Stephanie, University of Central Florida
- Abstract / Description
-
?This study investigated what factors come into play when looking at the user experience involved with the commercial video game Disney Infinity (2.0 Edition), and sought to determine if the unique combination between sandbox and smart toy based gameplay present in gameplay offers an additional level of immersion.This study analyzed the effect of Disney Infinity (2.0 Edition) on immersion utilizing a Game Immersion Questionnaire modified to analyze play preference as well as video game...
Show more?This study investigated what factors come into play when looking at the user experience involved with the commercial video game Disney Infinity (2.0 Edition), and sought to determine if the unique combination between sandbox and smart toy based gameplay present in gameplay offers an additional level of immersion.This study analyzed the effect of Disney Infinity (2.0 Edition) on immersion utilizing a Game Immersion Questionnaire modified to analyze play preference as well as video game experience. The study methodology analyzed 48 users while playing in (")Toy Box(") mode both with and without the associated smart toys, or Disney characters.Results show that while there was no significant difference in immersion for either group, nor were there any significant correlations between variables, there was a preference for playing the game with the associated smart toys in both groups. Recommendations were made for continued research building on modifications to this study as well as future research exploring the potential for smart toys in other areas.
Show less - Date Issued
- 2015
- Identifier
- CFE0005904, ucf:50890
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005904
- Title
- A Value Sensitive Design Approach to Adolescent Mobile Online Safety.
- Creator
-
Ghosh, Arup Kumar, ,, University of Central Florida
- Abstract / Description
-
With the rise of adolescent smartphone use, concerns about teen online safety are also on the rise. A number of parental control apps are available for mobile devices, but adoption of these apps has been markedly low. To better understand these apps, their users, and design opportunities in the space of mobile online safety for adolescents, we have conducted four studies informed by the principles of Value Sensitive Design (VSD). In Study 1 (Chapter 2), we conducted a web-based survey of 215...
Show moreWith the rise of adolescent smartphone use, concerns about teen online safety are also on the rise. A number of parental control apps are available for mobile devices, but adoption of these apps has been markedly low. To better understand these apps, their users, and design opportunities in the space of mobile online safety for adolescents, we have conducted four studies informed by the principles of Value Sensitive Design (VSD). In Study 1 (Chapter 2), we conducted a web-based survey of 215 parents and their teens (ages 13-17) using two separate logistic regression models (parent and teen) to examine the factors that predicted parental use of technical monitoring apps on their teens' mobile devices. Both parent and teen models confirmed that low autonomy granting (e.g., authoritarian) parents were the most likely to use parental control apps. The teen model revealed additional nuances, indicating that teens who were victimized online and had peer problems were more likely to be monitored by their parents. Overall, increased parental control was associated with more (not fewer) online risks. In Study 2 (Chapter 3), we conducted a structured, qualitative feature analysis of 75 Android mobile apps designed for promoting adolescent online safety. We found that the available apps overwhelmingly supported parental control through restriction and monitoring over teen self-regulation or parental active mediation. In Study 3 (Chapter 4), we conducted a qualitative analysis of 736 reviews of 37 mobile online safety apps from Google Play that were publicly posted and written by teens. Our results indicate that teen ratings were significantly lower than that of parents with 76% of the teen reviews giving apps a single star. Teens felt that the apps were overly restrictive and invasive of their personal privacy, negatively impacting their relationships with their parents. For our final study (Chapter 5), we developed a mobile app prototype suggesting alternative designs for keeping teens safe online and conducted a user study which showed that parents and children (ages 10-17) both significantly preferred our new app design over existing parental control apps. Both parents and children reported that our VSD informed design is less privacy-invasive for children and would improve communication and trust relationship between them. Yet, more work needs to be done to improve approaches for risk detection and mediation that support online safety. In summary, this research will enable researchers and designers to create more effective solutions for teen online safety that will help promote more positive parent-teen relationships.
Show less - Date Issued
- 2018
- Identifier
- CFE0007181, ucf:52256
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007181
