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- Title
- AN ANALYSIS OF ACCREDITATION PROCESSES, QUALITY CONTROL CRITERIA, HISTORICAL EVENTS, AND STUDENT PERFORMANCE.
- Creator
-
Burris, Robert, Murray, Barbara, University of Central Florida
- Abstract / Description
-
The purpose of this study was to determine to what extent student performance has been influenced by historical events, legislative mandates, and accreditation processes. This study consists of comparing the Southern Association of Colleges and Schools accreditation processes with those of the Association of Christian Schools International. In completing this qualitative study, the following procedures were implemented: Related research was used to provide a background of the role that...
Show moreThe purpose of this study was to determine to what extent student performance has been influenced by historical events, legislative mandates, and accreditation processes. This study consists of comparing the Southern Association of Colleges and Schools accreditation processes with those of the Association of Christian Schools International. In completing this qualitative study, the following procedures were implemented: Related research was used to provide a background of the role that historical events, legislation, and accreditation processes have on student performance; data were collected to establish time line shifts in an historical perspective. The data collected included assessment, accountability, high school drop out rates, high school graduation rates, academic readiness for higher education, standardized testing, grade inflation, acceleration of dual enrollment and advanced placement courses, and national SAT and ACT averages. Data were also collected from historical record of accreditation processes, which included standards, teacher certification requirements, committee responsibilities, visiting team responsibilities, and self-study materials. As a result of content analysis, the researcher decided to focus on three key areas that were integral to the study. The three categories identified in the review of literature were used to analyze the content of these events and processes. The categories were: (a) Student Performance, (b) Historical Events, and (c) SACS and ACSI Accreditation Processes. The following results were obtained from this research. Findings indicated that a criterion-based accreditation process potentially results in more consistent student performance outcomes than an open-ended process.
Show less - Date Issued
- 2008
- Identifier
- CFE0002052, ucf:47569
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002052
- Title
- CONGESTION AVOIDANCE AND FAIRNESS IN WIRELESS SENSOR NETWORKS.
- Creator
-
Ahmad, Mohammad, Turgut, Damla, University of Central Florida
- Abstract / Description
-
Sensor network congestion avoidance and control primarily aims to reduce packet drops while maintaining fair bandwidth allocation to existing network flows. The design of a congestion control algorithm suited for all types of applications in sensor networks is a challenging task due to the application-specific nature of these networks. With numerous sensors transmitting data simultaneously to one or more base stations (also called sinks), sensor nodes located near the base station will most...
Show moreSensor network congestion avoidance and control primarily aims to reduce packet drops while maintaining fair bandwidth allocation to existing network flows. The design of a congestion control algorithm suited for all types of applications in sensor networks is a challenging task due to the application-specific nature of these networks. With numerous sensors transmitting data simultaneously to one or more base stations (also called sinks), sensor nodes located near the base station will most likely experience congestion and packet loss. In this thesis, we propose a novel distributed congestion avoidance algorithm which calculates the ratio of the number of downstream and upstream nodes. This ratio value (named Characteristic ratio) is used to take a routing decision and incorporate load balancing while also serving as a pointer to the congestion state of the network. Available queue sizes of the downstream nodes are used to detect incipient congestion. Queue characteristics of candidate downstream nodes are used collectively to implement both congestion avoidance and fairness by adjusting the node's forwarding rate and next hop destination. Such an approach helps to minimize packet drops, improve energy efficiency and load balancing. In cases of severe congestion, the source is signaled to reduce its sending rate and enable the network recovery process. This is essentially a transport layer algorithm and would work best with a multi-path routing protocol and almost any MAC layer standard. We present the design and implementation of the proposed protocol and compare it with the existing avoidance protocols like Global rate control and Lightweight buffering. Our simulation results show a higher packet delivery ratio with greater node buffer utilization for our protocol in comparison with the conventional mechanisms.
Show less - Date Issued
- 2007
- Identifier
- CFE0001755, ucf:47255
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001755
- Title
- BI-DIRECTIONAL DCM DC-TO-DC CONVERTER FOR HYBRID ELECTRIC VEHICLES.
- Creator
-
Pepper, Michael, Batarseh, Issa, University of Central Florida
- Abstract / Description
-
With the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many...
Show moreWith the recent revival of the hybrid vehicle much advancement in power management has been made. The most popular hybrid vehicle, the hybrid electric vehicle, has many topologies developed to realize this hybrid vehicle. From these topologies, as sub set was created to define a particular group of vehicles where the converter discussed in this thesis has the most advantage. This sub set is defined by two electric sources of power coupled together at a common bus. This set up presents many unique operating conditions which can be handled seamlessly by the DC-to-DC converter when designed properly. The DC-to-DC converter discussed in this thesis is operated in Discontinuous Conduction Mode (DCM) of operation because of its unique advantages over the Continuous Conduction Mode (CCM) operated converter. The most relevant being the reduction of size of the magnetic components such as inductor, capacitor and transformers. However, the DC-to-DC converter operated in DCM does not have the inherent capability of bi-directional power flow. This problem can be overcome with a unique digital control technique developed here. The control is developed in a hierarchical fashion to separate the functions required for this sub set of hybrid electric vehicle topologies. This layered approach for the controller allows for the seamless integration of this converter into the vehicle. The first and lowest level of control includes a group of voltage and controller regulators. The average and small signal model of these controllers were developed here to be stable and have a relatively fast recovery time to handle the transient dynamics of the vehicle system. The second level of control commands and organizes the regulators from the first level of control to perform high level task that is more specific to the operation of the vehicle. This level of control is divided into three modes called hybrid boost, hybrid buck and electric vehicle mode. These modes are developed to handle the specific operating conditions found when the vehicle is operated in the specific mode. The third level of control is used to command the second level of control and is left opened via a communication area network (CAN) bus controller. This level of control is intended to come from the vehicle's system controller. Because the DC-to-DC converter is operated in DCM, this introduces added voltage ripple on the output voltage as well as higher current ripple demand from the input voltage. Since this is generally undesirable, the converter is split into three phases and properly interleaved. The interleaving operation is used to counteract the effects of the added voltage and current ripple. Finally, a level of protection is added to protect the converter and surrounding components from harm. All protection is designed and implemented digitally in DSP.
Show less - Date Issued
- 2008
- Identifier
- CFE0002496, ucf:47676
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002496
- Title
- DSP IMPLEMENTATION OF DC VOLTAGE REGULATION USING ADAPTIVE CONTROL FOR 200 KW 62000 RPM INDUCTION GENERATOR.
- Creator
-
Elkhomri, Othman, Wu, Thomas, University of Central Florida
- Abstract / Description
-
The thesis discusses the development of closed loop system to control the DC voltage for 200 kW induction generator rated at a speed of 62000 RPM under different load conditions. The voltage regulation has been implemented using PI controller. A gain scheduling control algorithm has been developed to select the appropriate controller gains with respect to the generator load. Further, a relationship between the generator loads and the controller gains has been established. This relationship...
Show moreThe thesis discusses the development of closed loop system to control the DC voltage for 200 kW induction generator rated at a speed of 62000 RPM under different load conditions. The voltage regulation has been implemented using PI controller. A gain scheduling control algorithm has been developed to select the appropriate controller gains with respect to the generator load. Further, a relationship between the generator loads and the controller gains has been established. This relationship has been modeled using adaptive control technique to vary the gains automatically at any load condition. The adaptive control technique has been successfully generalized for real time DSP implementation to regulate the DC voltage for high speed induction generators rated from 5 kW to 200 kW.
Show less - Date Issued
- 2006
- Identifier
- CFE0001076, ucf:46787
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001076
- Title
- ANALOG TEMPERATURE CONTROL CIRCUIT FOR A THIN-FILM PIEZOELECTRIC-ON-SUBSTRATE MICROELECTROMECHANICAL SYSTEMS OSCILLATOR.
- Creator
-
Hofstee, Heather, Abdolvand, Reza, University of Central Florida
- Abstract / Description
-
The objective and motivation for this project is to design a low-power, low-noise oven-control circuit to optimize the stability of a MEMS oscillator. MEMS oscillators can be fabricated using conventional semiconductor manufacturing methods and can often be assembled in packages smaller than those of traditional crystal oscillators. However, one of their largest disadvantages currently is their high temperature coefficient of frequency (TCF), causing MEMS oscillators to be especially...
Show moreThe objective and motivation for this project is to design a low-power, low-noise oven-control circuit to optimize the stability of a MEMS oscillator. MEMS oscillators can be fabricated using conventional semiconductor manufacturing methods and can often be assembled in packages smaller than those of traditional crystal oscillators. However, one of their largest disadvantages currently is their high temperature coefficient of frequency (TCF), causing MEMS oscillators to be especially sensitive to temperature changes. Hence, this project focuses on designing a printed circuit board that will allow the user to manually tune a current passing through a resonator wire-bonded to the board to elevate the resonator temperature. This will ensure that the device's resonance frequency stays largely constant and that the oscillator provides a very stable signal.
Show less - Date Issued
- 2018
- Identifier
- CFH2000419, ucf:45748
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000419
- Title
- THE EFFECT OF CONTROLLING MESSAGES ON DOCTOR-PATIENT COMMUNICATION.
- Creator
-
LaDez, Kayla A, Sims, Valerie, University of Central Florida
- Abstract / Description
-
The doctor-patient relationship is a very important aspect of a patient's health and wellbeing. It is a complex relationship that requires trust and understanding by both parties. Doctor shopping and changes in technology that allow patients to independently learn about their health have further complicated this relationship. This study looks at how participants perceive controlling language depending on the gender of the doctor. Participants were 339 University of Central Florida...
Show moreThe doctor-patient relationship is a very important aspect of a patient's health and wellbeing. It is a complex relationship that requires trust and understanding by both parties. Doctor shopping and changes in technology that allow patients to independently learn about their health have further complicated this relationship. This study looks at how participants perceive controlling language depending on the gender of the doctor. Participants were 339 University of Central Florida undergraduate students (112 men and 227 women, age M= 19.29, SD = 3.60) recruited through SONA. Participants first listened to a recording of a male or female doctor speaking to a patient using high or low level controlling language. They then answered questions about their opinion of the doctor, how they would behave in the patient's situation, and their beliefs about the role of doctors in the doctor-patient relationship. Results indicated both level of controlling language and doctor gender had significant effects on participants' perception of the doctor. Doctors who spoke with high level controlling language were seen as less helpful and supportive than doctors who spoke with low level controlling language. Participants also were less likely to recommend them to another person. Male doctors were seen as ruder than female doctors. These results suggest that doctors must communicate with each patient in that makes them both the most comfortable, and that male doctors may need to work harder to communicate empathy to their patients.
Show less - Date Issued
- 2018
- Identifier
- CFH2000336, ucf:45910
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000336
- Title
- PERCEIVED LOCUS OF CONTROL IN THE CHILDREN OF MILITARY AND CIVILIAN FAMILIES AFFECTED BY DEPLOYMENT AND DIVORCE.
- Creator
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Kanefsky, Rebekah, Neer, Sandra, University of Central Florida
- Abstract / Description
-
This study was designed to explore the differences between locus of control (LOC) in children from civilian and military families and to investigate whether military deployment is associated with an external locus of control more than other family dynamics. The literature has focused on the negative implications of external LOC for children's mental health and achievement as well as in childhood chronic illness, parental absence, and parental alcoholism. However, prior research regarding this...
Show moreThis study was designed to explore the differences between locus of control (LOC) in children from civilian and military families and to investigate whether military deployment is associated with an external locus of control more than other family dynamics. The literature has focused on the negative implications of external LOC for children's mental health and achievement as well as in childhood chronic illness, parental absence, and parental alcoholism. However, prior research regarding this construct related to children of military families is significantly lacking. In the present study, LOC was measured by the Nowicki-Strickland Locus of Control Scale for Children, a 40 question scale designed for individuals within the range of 3rd to 12th grade. The 54 participants in this study ranged in age from 7 to 17 and came from either a military family with a deployed parent, a civilian family with two caregivers in the home, or a divorced - separated civilian family. A univariate one-way ANOVA was conducted on the data. It was found that children of deployed military families did not score significantly different for mean locus of control than civilian separated/divorced families, or civilian intact families. A correlation comparing age and LOC scores found no significant relationship. Limitations of this study included a small sample size due to time restrictions, and subsequently reduced statistical power. Future investigations into LOC should continue to explore its relationship with children in military families, as future studies correcting for sampling may obtain significant results. Further research should also probe more deeply into the negative and positive consequences that external and internal attributional tendencies may have for children's development, academic performance, and overall well-being.
Show less - Date Issued
- 2015
- Identifier
- CFH0004884, ucf:45416
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004884
- Title
- Real-Time Open Source Traffic Control Software for the Advance Traffic Controller.
- Creator
-
Key, Justin, Radwan, Ahmed, Hua, Kien, Kincaid, John, Leonessa, Alexander, University of Central Florida
- Abstract / Description
-
Under the initiative of Department of Transportation (DOT) a safety-critical, dual redundant, open source traffic signal control application is currently being developed. The system named SCOPE, for Signal Control Program Environment, currently implements standard 8-phase NEMA logic and the National Cooperative Highway Research Program 3-66 preemption logic. SCOPE is designed to be part of the Advanced Traffic Controller (ATC), making use of API standard 2.06b to integrate with the hardware....
Show moreUnder the initiative of Department of Transportation (DOT) a safety-critical, dual redundant, open source traffic signal control application is currently being developed. The system named SCOPE, for Signal Control Program Environment, currently implements standard 8-phase NEMA logic and the National Cooperative Highway Research Program 3-66 preemption logic. SCOPE is designed to be part of the Advanced Traffic Controller (ATC), making use of API standard 2.06b to integrate with the hardware. Safety-critical status is achieved through redundancy of application logic that constantly compares expected signal phase information. From baseline requirements, engineers independently program application code, one using Ada95 and the other using C++.The Traffic EXperimental Analytical Simulation Model, a microscopic single-intersection vehicular simulation, was used for initial validation and testing of the functionality of the system. The second demonstration of the SCOPE, used actuated detector data collected from a recording of a live intersection. Actuator calls were placed on SCOPE at the same times the vehicles triggered the detectors in the video (assuming the vehicles were not in-queue). Using SCOPE the real-world traffic was not only right-of-way safely yielded, but the traffic flow state time average time in-queue reduced. The final phase of testing will occur when the DOT performs Formal Qualification Testing, which is scheduled for 2013.Upon validation and subsequent release to the open source community SCOPE will provide users the ability to replace the proprietary application software residing in ATC cabinets. Transparency will be provided into another aspect of the traffic control signal thus taking the initiative of ATC one step further.
Show less - Date Issued
- 2012
- Identifier
- CFE0004562, ucf:49254
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004562
- Title
- Direct and Indirect Controls as Measures of Attachment: Gender, Delinquency, and the Parental Social Bond.
- Creator
-
Hazlett-Knudsen, Rebekah, Ronnau, John, Surette, Raymond, Lawrence, Shawn, Bricout, John, University of Central Florida
- Abstract / Description
-
Research specific to gender and violent juvenile delinquency is sparse due to two factors: a substantially higher incidence of delinquent male violence and the cost associated with drawing adequate female samples is frequently prohibitive (Howell, 2003). Gender-differences are explored in a sample of arrested juveniles using an expanded measure of parental attachment [bond]. The dimensions of emotional attachment, supervision, and time-involvement with a self-reported caregiver are explored...
Show moreResearch specific to gender and violent juvenile delinquency is sparse due to two factors: a substantially higher incidence of delinquent male violence and the cost associated with drawing adequate female samples is frequently prohibitive (Howell, 2003). Gender-differences are explored in a sample of arrested juveniles using an expanded measure of parental attachment [bond]. The dimensions of emotional attachment, supervision, and time-involvement with a self-reported caregiver are explored for between group differences and association with recognized risk factors for juvenile delinquency. Findings indicate that while statistically significant between-group differences are not found in the presentation of attachment, descriptive differences do exist. Females demonstrated a higher level of impairment in emotional attachment to a caregiver than their male counterparts; females arrested for a violent offense reported the highest level of problem in this area. Findings also indicate that the mechanism of attachment appears to function differently by gender group in terms of association with risk factors for delinquency. Time-involvement emerged as an important predictor for the full group and the female group, particularly in relationship with higher risk for antisocial peer involvement. Support for a gendered experience of parental attachment [social bond] is provided. Emotional attachment and time-involvement were found to be important predictors for the full group, while supervision was not indicated as important to any risk factor or to recidivism. The current research advances knowledge on gender-related differences within delinquency. Through enhancing the understanding of the complex gender-specific influences on juvenile crime, criminal justice and human service systems may better learn to address these needs thereby reducing both entrance rates into the juvenile justice system and recidivism.
Show less - Date Issued
- 2012
- Identifier
- CFE0004218, ucf:48990
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004218
- Title
- CHANGES TO OPERATIONAL, FINANCIAL, AND ORGANIZATIONAL STRUCTURES OF SCHOOL DISTRICTS DURING MAYORAL TAKEOVERS.
- Creator
-
Shanoff, Mark, Bozeman, William, University of Central Florida
- Abstract / Description
-
The focus of this research was to examine the effects of mayoral control on operational and financial structures within school systems. Furthermore, this study focused on the public perception and political implications of the mayorÃÂ's position on local education. The four systems chosen for this study were: Boston, Chicago, District of Columbia, and New York City. All four systems were total control districts, which allowed for each mayor to appoint a majority to the...
Show moreThe focus of this research was to examine the effects of mayoral control on operational and financial structures within school systems. Furthermore, this study focused on the public perception and political implications of the mayorÃÂ's position on local education. The four systems chosen for this study were: Boston, Chicago, District of Columbia, and New York City. All four systems were total control districts, which allowed for each mayor to appoint a majority to the school board and appoint a superintendent or chancellor to oversee the day to day operations of the school district. This study focused on operational and financial structures, which make up a sizable portion of the larger organizational structure. These indicators often drive how services and expenditures eventually affect the core business of these school systems. From an operational perspective, this study was focused on expenditures, both in aggregate form and for instructional related services, pre and post takeover. From a financial perspective, this study focused on changes to revenue sources, return on investment, interest on school debt, and capital outlay. From a political perspective, this study examined the data from the various State of the City addresses over the last four years in each of the four cities, along with polling data available for New York City and the District of Columbia. This study was concluded with a summary of findings, and implications for future research, policy, and practitioners. The research showed that New York City and Boston generally outperformed the District of Columbia and Chicago in the operational and financial metrics used in the study. Furthermore, the number of years a city had been under mayoral control and operational and financial indicators had no significant relationship. It was recommended that future researchers should continue to study the benefit of benchmarking metrics of organizational performance to ensure mayors are held accountable for the reforms they espouse during election cycles. Ultimately, mayorsÃÂ' success in managing their school systems will be based on where they prioritize. This research offered a cross section of metrics by which mayors can benchmark their effectiveness as they change operational, financial, and organizational structures to bring about better, overall organizational performance from their school system.
Show less - Date Issued
- 2010
- Identifier
- CFE0003469, ucf:48957
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003469
- Title
- DOES RELIGIOSITY DETER JUVENILE DELINQUENCY?.
- Creator
-
Murray, Brittany, Jasinski, Jana, University of Central Florida
- Abstract / Description
-
The study presented here uses data from the National Longitudinal Study of Adolescent Health Wave I (Add Health) to examine the association between juvenile delinquency and religiosity. Juvenile delinquency is an area that has received increasing research interest over the last decade; however, much of this research has primarily focused on family, peers, and education as factors that may reduce delinquent involvement. While all of these are influential in the lives of youth, it is possible...
Show moreThe study presented here uses data from the National Longitudinal Study of Adolescent Health Wave I (Add Health) to examine the association between juvenile delinquency and religiosity. Juvenile delinquency is an area that has received increasing research interest over the last decade; however, much of this research has primarily focused on family, peers, and education as factors that may reduce delinquent involvement. While all of these are influential in the lives of youth, it is possible there are other factors as well. Religiosity has been shown to have influential effects throughout the life course; however, little research has focused specifically on the relationship between religiosity and juvenile delinquency and even less has centered on this relationship in terms of gender and race/ethnicity. The results of this study will contribute to the literature on juvenile delinquency by providing an in-depth look at the effects of religiosity in adolescence, gender and racial/ethnic trends, as well as possibly provide information valuable to prevention efforts.
Show less - Date Issued
- 2011
- Identifier
- CFE0003644, ucf:48877
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003644
- Title
- Integrating Multiobjective Optimization with the Six Sigma Methodology for Online Process Control.
- Creator
-
Abualsauod, Emad, Geiger, Christopher, Elshennawy, Ahmad, Thompson, William, Moore, Karla, University of Central Florida
- Abstract / Description
-
Over the past two decades, the Define-Measure-Analyze-Improve-Control (DMAIC) framework of the Six Sigma methodology and a host of statistical tools have been brought to bear on process improvement efforts in today's businesses. However, a major challenge of implementing the Six Sigma methodology is maintaining the process improvements and providing real-time performance feedback and control after solutions are implemented, especially in the presence of multiple process performance objectives...
Show moreOver the past two decades, the Define-Measure-Analyze-Improve-Control (DMAIC) framework of the Six Sigma methodology and a host of statistical tools have been brought to bear on process improvement efforts in today's businesses. However, a major challenge of implementing the Six Sigma methodology is maintaining the process improvements and providing real-time performance feedback and control after solutions are implemented, especially in the presence of multiple process performance objectives. The consideration of a multiplicity of objectives in business and process improvement is commonplace and, quite frankly, necessary. However, balancing the collection of objectives is challenging as the objectives are inextricably linked, and, oftentimes, in conflict.Previous studies have reported varied success in enhancing the Six Sigma methodology by integrating optimization methods in order to reduce variability. These studies focus these enhancements primarily within the Improve phase of the Six Sigma methodology, optimizing a single objective. The current research and practice of using the Six Sigma methodology and optimization methods do little to address the real-time feedback and control for online process control in the case of multiple objectives.This research proposes an innovative integrated Six Sigma multiobjective optimization (SSMO) approach for online process control. It integrates the Six Sigma DMAIC framework with a nature-inspired optimization procedure that iteratively perturbs a set of decision variables providing feedback to the online process, eventually converging to a set of tradeoff process configurations that improves and maintains process stability. For proof of concept, the approach is applied to a general business process model (-) a well-known inventory management model (-) that is formally defined and specifies various process costs as objective functions. The proposed SSMO approach and the business process model are programmed and incorporated into a software platform. Computational experiments are performed using both three sigma (3?)-based and six sigma (6?)-based process control, and the results reveal that the proposed SSMO approach performs far better than the traditional approaches in improving the stability of the process. This research investigation shows that the benefits of enhancing the Six Sigma method for multiobjective optimization and for online process control are immense.
Show less - Date Issued
- 2013
- Identifier
- CFE0004968, ucf:49561
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004968
- Title
- Reduction of Lunchroom Noise and Other Behavior Using Feedback and Group Contingent Reinforcement.
- Creator
-
LaRowe, Lottie N., Tucker, Richard, Social Sciences
- Abstract / Description
-
Florida Technological University College of Social Sciences Thesis; Reduction of noise levels in an elementary school lunchroom was examined as a function of feedback and feedback plus reinforcement using group contingency procedures. Feedback consisted of signals from a traffic light with green indicating acceptable levels, yellow indicating slightly higher levels and red indicating unacceptable levels. Other behaviors, running, hitting, pushing and kicking, were measured incidentally....
Show moreFlorida Technological University College of Social Sciences Thesis; Reduction of noise levels in an elementary school lunchroom was examined as a function of feedback and feedback plus reinforcement using group contingency procedures. Feedback consisted of signals from a traffic light with green indicating acceptable levels, yellow indicating slightly higher levels and red indicating unacceptable levels. Other behaviors, running, hitting, pushing and kicking, were measured incidentally. Results indicate that feedback plus reinforcement was effective in reducing noise levels. Feedback alone was also effective, but to a lesser degree. No response - response relationship was found to exist between noise level and the other behaviors.
Show less - Date Issued
- 1978
- Identifier
- CFR0004324, ucf:52988
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFR0004324
- Title
- Decentralized Consensus-based Control Allocation For Some Dynamical Systems.
- Creator
-
Mark, August, Xu, Yunjun, Gou, Jihua, Lin, Kuo-Chi, University of Central Florida
- Abstract / Description
-
In this dissertation, three separate studies, wherein techniques from graph theory and consensus control are used to address control allocation problems, are presented. In the first study, a decentralized allocator is presented for synthetic jet actuators and control surfaces onboard a small unmanned aerial vehicle to cooperatively generate desired aerodynamic moments. First order linear dynamics are assumed for both the synthetic jet actuators and control surfaces. A weighted consensus...
Show moreIn this dissertation, three separate studies, wherein techniques from graph theory and consensus control are used to address control allocation problems, are presented. In the first study, a decentralized allocator is presented for synthetic jet actuators and control surfaces onboard a small unmanned aerial vehicle to cooperatively generate desired aerodynamic moments. First order linear dynamics are assumed for both the synthetic jet actuators and control surfaces. A weighted consensus algorithm with limited feedback is used for the aerodynamic moment contribution allocator considering constraints. In the second study, the same allocation problem as in the first study is considered, but the actuator dynamics are now assumed to behave according to second order nonlinear dynamics. In the third study, a spray allocator is presented for an array of nozzles used to cool a large heated surface in order to address the local disagreement in surface temperature within sprayed sections. Within each study, the stability of each system is proven, and the performance of each allocator is demonstrated via simulations.
Show less - Date Issued
- 2019
- Identifier
- CFE0007496, ucf:52636
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007496
- Title
- Design and characterization of system level electrostatic discharge (ESD) protection solutions.
- Creator
-
Xi, Yunfeng, Liou, Juin, Yuan, Jiann-Shiun, Sundaram, Kalpathy, Jin, Yier, Salcedo, Javier, University of Central Florida
- Abstract / Description
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Electrostatic Discharges (ESD) are one of the main reliability threats in modern electronics. Design, implementation, and characterization of ESD and transient protection of these modern electronics are increasingly challenging due to the process, packaging and cost constraints. Growing communication between 'objects' to be sensed and controlled remotely is creating opportunities for greater integration with computer systems, resulting in improved efficiency, accuracy and economic benefits...
Show moreElectrostatic Discharges (ESD) are one of the main reliability threats in modern electronics. Design, implementation, and characterization of ESD and transient protection of these modern electronics are increasingly challenging due to the process, packaging and cost constraints. Growing communication between 'objects' to be sensed and controlled remotely is creating opportunities for greater integration with computer systems, resulting in improved efficiency, accuracy and economic benefits across existing and emerging network infrastructures. This tendency is driving an expansion in data communication as well as industrial applications environment. To keep up with the interconnectivity expansion, the industry requires new devices to support more effectively high speed signals processing over long distances and be able to reliably operate in harsh and noisy environments. Electrical over-stress transients caused by ESD or switching of inductive loads can corrupt data transmission and damage bus transceivers unless effective measures are taken to address the impact of such high energy transient stress conditions. Today's industry specifications for integrated circuits require 1kV HBM on all pins, but selected pins with direct contact to the external environment must comply with levels as high as 8kV for IEC 61000-4-2 and ISO 10605 standards. The rapid evolution of the handheld and mobile device market segment, dramatic increase of electronic content in automotive products, and substantial progress in industrial and medical applications created a new need for on-chip protection against system level ESD stresses. This PhD work investigates the impact of system-level type of ESD stress on components. Firstly, correlation factors between different ESD pulse types for different BEOL metal line topologies have been studied to support system level on-chip ESD design. The component level (HMM, HBM and TLP on wafer) and system level (IEC gun contact on package) ESD stresses were correlated followed by extraction of correlation factors between the IEC/HMM and TLP, as well as the HBM and TLP supported by analytical approximation. The major conclusions were verified using the thermal coupled mixed-mode simulations analysis. Secondly, operation of NLDMOS-SCR devices under the HMM and IEC air gap electrostatic discharge (ESD) stresses has been studied based on both the pulsed measurements and mixed-mode simulations. Under the IEC air gap testing, the devices are found to suffer the non-uniform multi-finger turn-on behavior and hence a relatively low passing level, while both the IEC contact and HMM stresses do not give rise to such an adversary effect and result in a considerably higher passing level. It is further shown that the non-uniform multi-finger turn-on effect depends on the stress pulse rise time. Such a dependency has also been examined and verified using the transmission line pulsing (TLP) technique with rise times ranging from 10 to 40ns. In the last section, a new silicon-controlled rectifier (SCR) fabricated in a 30 V mixed-signal CDMOS (CMOS/DMOS) technology is presented. This device allows for robust EMI (electromagnetic interference) and ESD (electrostatic discharge) protection solution for high speed industrial interface applications operating in variable voltage swing range from -7V to +12V. This new SCR has reduced overshoot voltage and leakage current when electrically stressed under different pulse widths and temperatures. Analysis of the device physics is complemented via numerical TCAD mixed-mode simulations. A 200 x 200 (&)#181;m2 device designed in an annular configuration achieved (>) (&)#177; 8 kV IEC robustness by handling (>) (&)#177; 20 Amp of TLP current while clamping the voltage to (&)#177;3V within 2-nsec.
Show less - Date Issued
- 2016
- Identifier
- CFE0006199, ucf:51113
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006199
- Title
- Stability and Control in Complex Networks of Dynamical Systems.
- Creator
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Manaffam, Saeed, Vosoughi, Azadeh, Behal, Aman, Atia, George, Rahnavard, Nazanin, Javidi, Tara, Das, Tuhin, University of Central Florida
- Abstract / Description
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Stability analysis of networked dynamical systems has been of interest in many disciplines such as biology and physics and chemistry with applications such as LASER cooling and plasma stability. These large networks are often modeled to have a completely random (Erd\"os-R\'enyi) or semi-random (Small-World) topologies. The former model is often used due to mathematical tractability while the latter has been shown to be a better model for most real life networks.The recent emergence of cyber...
Show moreStability analysis of networked dynamical systems has been of interest in many disciplines such as biology and physics and chemistry with applications such as LASER cooling and plasma stability. These large networks are often modeled to have a completely random (Erd\"os-R\'enyi) or semi-random (Small-World) topologies. The former model is often used due to mathematical tractability while the latter has been shown to be a better model for most real life networks.The recent emergence of cyber physical systems, and in particular the smart grid, has given rise to a number of engineering questions regarding the control and optimization of such networks. Some of the these questions are: \emph{How can the stability of a random network be characterized in probabilistic terms? Can the effects of network topology and system dynamics be separated? What does it take to control a large random network? Can decentralized (pinning) control be effective? If not, how large does the control network needs to be? How can decentralized or distributed controllers be designed? How the size of control network would scale with the size of networked system?}Motivated by these questions, we began by studying the probability of stability of synchronization in random networks of oscillators. We developed a stability condition separating the effects of topology and node dynamics and evaluated bounds on the probability of stability for both Erd\"os-R\'enyi (ER) and Small-World (SW) network topology models. We then turned our attention to the more realistic scenario where the dynamics of the nodes and couplings are mismatched. Utilizing the concept of $\varepsilon$-synchronization, we have studied the probability of synchronization and showed that the synchronization error, $\varepsilon$, can be arbitrarily reduced using linear controllers.We have also considered the decentralized approach of pinning control to ensure stability in such complex networks. In the pinning method, decentralized controllers are used to control a fraction of the nodes in the network. This is different from traditional decentralized approaches where all the nodes have their own controllers. While the problem of selecting the minimum number of pinning nodes is known to be NP-hard and grows exponentially with the number of nodes in the network we have devised a suboptimal algorithm to select the pinning nodes which converges linearly with network size. We have also analyzed the effectiveness of the pinning approach for the synchronization of oscillators in the networks with fast switching, where the network links disconnect and reconnect quickly relative to the node dynamics.To address the scaling problem in the design of distributed control networks, we have employed a random control network to stabilize a random plant network. Our results show that for an ER plant network, the control network needs to grow linearly with the size of the plant network.
Show less - Date Issued
- 2015
- Identifier
- CFE0005834, ucf:50902
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005834
- Title
- Helping Mothers Defend their Decision to Breastfeed.
- Creator
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Natoli, Kandis, Aroian, Karen, Covelli, Maureen, Quelly, Susan, Uddin, Nizam, Miller, Ann, University of Central Florida
- Abstract / Description
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The United States has established breastfeeding as an important health indicator within the Healthy People agenda. Healthy People target goals for breastfeeding initiation, duration, and exclusivity remain unmet. The US Surgeon General's Office reports that lack of knowledge and widespread misinformation about breastfeeding are barriers to meeting Healthy People goals. Breastfeeding mothers are vulnerable to messages that cast doubt on their ability to breastfeed. Very little research has...
Show moreThe United States has established breastfeeding as an important health indicator within the Healthy People agenda. Healthy People target goals for breastfeeding initiation, duration, and exclusivity remain unmet. The US Surgeon General's Office reports that lack of knowledge and widespread misinformation about breastfeeding are barriers to meeting Healthy People goals. Breastfeeding mothers are vulnerable to messages that cast doubt on their ability to breastfeed. Very little research has examined specific approaches to help people resist negative messages about health beliefs and behaviors. The objective of this quasi-experimental study was to test an intervention designed to help mothers defend their breastfeeding decisions and resist influences that attempted to persuade them to give formula to their babies. Women attending prenatal breastfeeding classes were recruited and assigned to comparison and intervention groups. The intervention was a board game based on McGuire's inoculation theory of resistance to influence. Controlling for intention to breastfed, intervention and comparison groups were examined for differences in maternal self-efficacy to resist persuasion to give formula and breastfeeding rates for initiation, duration, and exclusivity. Data analyses consisted of analysis of covariance and logistic regression. There was no significant difference between comparison and intervention groups, both groups had high self-efficacy to resist giving formula to their babies; nor were there significant differences regarding breastfeeding initiation, duration and exclusivity. The lack of significant differences may have been influenced by ceiling effects in all of the breastfeeding variables, possibly due to the high socioeconomic level of the sample. The intervention may have worked better in women who were more prone to dissuasive influence, such as those with lower education.
Show less - Date Issued
- 2015
- Identifier
- CFE0005981, ucf:50764
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005981
- Title
- Mahalanobis kernel-based support vector data description for detection of large shifts in mean vector.
- Creator
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Nguyen, Vu, Maboudou, Edgard, Nickerson, David, Schott, James, University of Central Florida
- Abstract / Description
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Statistical process control (SPC) applies the science of statistics to various process control in order to provide higher-quality products and better services. The K chart is one among the many important tools that SPC offers. Creation of the K chart is based on Support Vector Data Description (SVDD), a popular data classifier method inspired by Support Vector Machine (SVM). As any methods associated with SVM, SVDD benefits from a wide variety of choices of kernel, which determines the...
Show moreStatistical process control (SPC) applies the science of statistics to various process control in order to provide higher-quality products and better services. The K chart is one among the many important tools that SPC offers. Creation of the K chart is based on Support Vector Data Description (SVDD), a popular data classifier method inspired by Support Vector Machine (SVM). As any methods associated with SVM, SVDD benefits from a wide variety of choices of kernel, which determines the effectiveness of the whole model. Among the most popular choices is the Euclidean distance-based Gaussian kernel, which enables SVDD to obtain a flexible data description, thus enhances its overall predictive capability. This thesis explores an even more robust approach by incorporating the Mahalanobis distance-based kernel (hereinafter referred to as Mahalanobis kernel) to SVDD and compare it with SVDD using the traditional Gaussian kernel. Method's sensitivity is benchmarked by Average Run Lengths obtained from multiple Monte Carlo simulations. Data of such simulations are generated from multivariate normal, multivariate Student's (t), and multivariate gamma populations using R, a popular software environment for statistical computing. One case study is also discussed using a real data set received from Halberg Chronobiology Center. Compared to Gaussian kernel, Mahalanobis kernel makes SVDD and thus the K chart significantly more sensitive to shifts in mean vector, and also in covariance matrix.
Show less - Date Issued
- 2015
- Identifier
- CFE0005676, ucf:50170
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005676
- Title
- Decentralized Power Management and Transient Control in Hybrid Fuel Cell Ultra-Capacitor System.
- Creator
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Madani, Seyed Omid, Das, Tuhin, Kassab, Alain, Lin, Kuo-Chi, Simaan, Marwan, University of Central Florida
- Abstract / Description
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Solid Oxide Fuel Cells (SOFCs) are considered suitable for alternative energy solutions due to advantages such as high efficiency, fuel flexibility, tolerance to impurities, and potential for combined cycle operations. One of the main operating constraints of SOFCs is fuel starvation, which can occur under fluctuating power demands. It leads to voltage loss and detrimental effects on cell integrity and longevity. In addition, reformer based SOFCs require sufficient steam for fuel reforming to...
Show moreSolid Oxide Fuel Cells (SOFCs) are considered suitable for alternative energy solutions due to advantages such as high efficiency, fuel flexibility, tolerance to impurities, and potential for combined cycle operations. One of the main operating constraints of SOFCs is fuel starvation, which can occur under fluctuating power demands. It leads to voltage loss and detrimental effects on cell integrity and longevity. In addition, reformer based SOFCs require sufficient steam for fuel reforming to avoid carbon deposition and catalyst degradation. Steam to carbon ratio (STCR) is an index indicating availability of the steam in the reformer. This work takes a holistic approach to address the aforementioned concerns in SOFCs, in an attempt to enhance applicability and adaptability of such systems. To this end, we revisit prior investigation on the invariant properties of SOFC systems, that led to prediction of fuel utilization U and STCR in the absence of intrusive and expensive sensing. This work provides further insight into the reasons behind certain SOFC variables being invariant with respect to operating conditions. The work extends the idea of invariant properties to different fuel and reformer types.In SOFCs, transient control is essential for U, especially if the fuel cell is to be operated in a dynamic load-following mode at high fuel utilization. In this research, we formulate a generalized abstraction of this transient control problem. We show that a multi-variable systems approach can be adopted to address this issue in both time and frequency domains, which leads to input shaping. Simulations show the effectiveness of the approach through good disturbance rejection. The work further integrates the aforementioned transient control research with system level control design for SOFC systems hybridized with storage elements. As opposed to earlier works where centralized robust controllers were of interest, here, separate controllers for the fuel cell and storage have been the primary emphasis. Thus, the proposed approach acts as a bridge between existing centralized controls for single fuel cells to decentralized control for power networks consisting of multiple elements. As a first attempt, decentralized control is demonstrated in a SOFC ultra-capacitor hybrid system. The challenge of this approach lies in the absence of direct and explicit communication between individual controllers. The controllers are designed based on a simple, yet effective principle of conservation of energy. Simulations as well as experimental results are presented to demonstrate the validity of these designs.
Show less - Date Issued
- 2014
- Identifier
- CFE0005524, ucf:50305
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005524