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- Title
- Stochastic Optimization for Integrated Energy System with Reliability Improvement Using Decomposition Algorithm.
- Creator
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Huang, Yuping, Zheng, Qipeng, Xanthopoulos, Petros, Pazour, Jennifer, Liu, Andrew, University of Central Florida
- Abstract / Description
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As energy demands increase and energy resources change, the traditional energy system has beenupgraded and reconstructed for human society development and sustainability. Considerable studies have been conducted in energy expansion planning and electricity generation operations bymainly considering the integration of traditional fossil fuel generation with renewable generation.Because the energy market is full of uncertainty, we realize that these uncertainties have continuously challenged...
Show moreAs energy demands increase and energy resources change, the traditional energy system has beenupgraded and reconstructed for human society development and sustainability. Considerable studies have been conducted in energy expansion planning and electricity generation operations bymainly considering the integration of traditional fossil fuel generation with renewable generation.Because the energy market is full of uncertainty, we realize that these uncertainties have continuously challenged market design and operations, even a national energy policy. In fact, only a few considerations were given to the optimization of energy expansion and generation taking into account the variability and uncertainty of energy supply and demand in energy markets. This usually causes an energy system unreliable to cope with unexpected changes, such as a surge in fuel price, a sudden drop of demand, or a large renewable supply fluctuation. Thus, for an overall energy system, optimizing a long-term expansion planning and market operation in a stochastic environment are crucial to improve the system's reliability and robustness.As little consideration was paid to imposing risk measure on the power management system, this dissertation discusses applying risk-constrained stochastic programming to improve the efficiency,reliability and economics of energy expansion and electric power generation, respectively. Considering the supply-demand uncertainties affecting the energy system stability, three different optimization strategies are proposed to enhance the overall reliability and sustainability of an energy system. The first strategy is to optimize the regional energy expansion planning which focuses on capacity expansion of natural gas system, power generation system and renewable energy system, in addition to transmission network. With strong support of NG and electric facilities, the second strategy provides an optimal day-ahead scheduling for electric power generation system incorporating with non-generation resources, i.e. demand response and energy storage. Because of risk aversion, this generation scheduling enables a power system qualified with higher reliability and promotes non-generation resources in smart grid. To take advantage of power generation sources, the third strategy strengthens the change of the traditional energy reserve requirements to risk constraints but ensuring the same level of systems reliability In this way we can maximize the use of existing resources to accommodate internal or/and external changes in a power system.All problems are formulated by stochastic mixed integer programming, particularly consideringthe uncertainties from fuel price, renewable energy output and electricity demand over time. Taking the benefit of models structure, new decomposition strategies are proposed to decompose the stochastic unit commitment problems which are then solved by an enhanced Benders Decomposition algorithm. Compared to the classic Benders Decomposition, this proposed solution approachis able to increase convergence speed and thus reduce 25% of computation times on the same cases.
Show less - Date Issued
- 2014
- Identifier
- CFE0005506, ucf:50339
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005506
- Title
- The effects of four weeks of high intensity interval training and (&)#223;-hydroxy-(&)#223;-methylbutyric free acid on the onset of neuromuscular fatigue.
- Creator
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Miramonti, Amelia, Stout, Jeffrey, Hoffman, Jay, Fukuda, David, University of Central Florida
- Abstract / Description
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This study investigated the effects of high intensity interval training (HIIT) and ?-hydroxy-?-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean (&)#177; SD age = 22.8 (&)#177; 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of...
Show moreThis study investigated the effects of high intensity interval training (HIIT) and ?-hydroxy-?-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean (&)#177; SD age = 22.8 (&)#177; 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of neuromuscular fatigue (PWCFT), and peak wattage was used to assign individual training loads.After baseline testing (PRE), subjects were randomly assigned to one of three groups: control (C, n = 9), training with placebo (P, n = 14), or training with supplementation (S, n = 14). Subjects assigned to P and S completed 12 HIIT sessions over 4 weeks while subjects assigned to C were asked to maintain their normal diet and activity patterns. After 4 weeks, subjects returned for post-testing (POST). The PWCFT values (W) were determined using a DMAX method. The EMG amplitude root mean square ((&)#181;Vrms) values were used to generate a third-order polynomial regression (3PR) representing the increase in (&)#181;Vrms versus time of the GXT. The onset of fatigue (TF) was defined as the x-value (time, s) of the point on the 3PR that measured the maximal perpendicular distance from the line between the first and last data points. TF was used to estimate PWCFT according to the equation: PWCFT = PO + a ? (n/N), where PO is the power output of the stage in which TF occurred, a is the increment in power output between GXT stages (25W), n is the difference (s) between TF and the beginning of the stage during which TF occurred, and N is the duration of a stage (120s).A two-way repeated measures ANOVA was used to identify group (&)#215; time interaction for PWCFT. If a significant interaction occurred, one-way factorial ANOVAs were used. Fisher's least significant difference post hoc comparisons were performed between groups. If a significant main effect occurred, dependent samples t-tests with Bonferroni corrections (p = [0.05/3] = 0.017) were performed across time for each group.The two-way ANOVA resulted in a significant interaction (F = 6.69, p = 0.004). Follow-up analysis with one-way ANOVA resulted in no difference among groups at PRE (F = 0.87, p = 0.43), however a significant difference was shown for POST values (F = 5.46, p = 0.009). Post-hoc analysis among POST values showed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes following HIIT for S (p (<) 0.001) and P (p = 0.016), but no change in C (p = 0.473).Results of this study indicate that HIIT was effective in delaying the onset of fatigue, but supplementation with HMBFA in conjunction with HIIT was more effective than HIIT alone. An increase in PWCFT represents an increase in the maximal power output an individual can sustain without eliciting fatigue. Therefore, HIIT can be used to improve performance in both endurance activities as well as intermittent sports. In addition, HMBFA supplementation is a simple method that can be used to maximize the benefits of HIIT.Acknowledgments: Metabolic Technologies, Inc. provided the supplement and funding for this study.
Show less - Date Issued
- 2015
- Identifier
- CFE0006043, ucf:50968
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006043
- Title
- Faculty Perspectives and Participation in Implementing an Early Alert System and Intervention in a Community College.
- Creator
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Bentham, Claudine, King, Kathy (Kathleen), Cox, Dr. Thomas, Hopp, Carolyn, Bosley, Michael, University of Central Florida
- Abstract / Description
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Early alert systems have been recognized as a high impact practice designed to improve student engagement and student success. Early alert is designed to identify students with at-risk behaviors early in the semester before they decide to drop-out, withdraw, or fail their classes, using resources such as a predictive analysis tool or advising. For an early alert to be successful and efficient, faculty should be included in the process of early alert. This qualitative study examined faculty's...
Show moreEarly alert systems have been recognized as a high impact practice designed to improve student engagement and student success. Early alert is designed to identify students with at-risk behaviors early in the semester before they decide to drop-out, withdraw, or fail their classes, using resources such as a predictive analysis tool or advising. For an early alert to be successful and efficient, faculty should be included in the process of early alert. This qualitative study examined faculty's perspective and experiences when implementing early alert strategies and intervention in a two-year institution. Using Cranton's seven facets of transformative learning as a conceptual framework, this study examined the changes, perception, and experiences of faculty as a result of implementation. The literature reviews best practices that can be considered when faculty designs their early alert strategies and intervention. Participants shared their During and After Implementation Journal experience by completing reflection journals. After careful analysis of their journals and initial interview, the following major themes emerged: a) at-risk behaviors, b) high-impact practices, c) intentionality, d) personal connection, e) perspective transformation, and f) value. As a result of these themes, recommendations were provided to assist faculty development and change agents in two-year institutions in improving early alert methods to increase student success.
Show less - Date Issued
- 2017
- Identifier
- CFE0006857, ucf:51742
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006857
- Title
- An Investigation of the Academic Impact of the Freshman Transition Course at One Urban Central Florida High School.
- Creator
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Flynn, Timothy, Taylor, Rosemarye, Baldwin, Lee, Doherty, Walter, Bradshaw, Leigh, University of Central Florida
- Abstract / Description
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The purpose of this research was to identify the extent to which a high school freshman transition program aligned with research based recommendations and to determine the extent to which the intervention impacted persistence to the tenth grade, on-track-to-graduation status, and academic success. Documents relevant to the program were collected and analyzed for research based themes. Students in the program at the target school were compared to students in a similar high school and a...
Show moreThe purpose of this research was to identify the extent to which a high school freshman transition program aligned with research based recommendations and to determine the extent to which the intervention impacted persistence to the tenth grade, on-track-to-graduation status, and academic success. Documents relevant to the program were collected and analyzed for research based themes. Students in the program at the target school were compared to students in a similar high school and a historical cohort of students who attended the target school. The impact of the course was statistically significant for persistence to the tenth grade, on-track to graduation status, and academic success; however ANOVA found statistical significance favored Algebra 1 EOC and not FCAT Reading. Effect size statistics revealed little to no effect among Freshman Experience and the dependent variables. These findings will help school-level and district administrators design research-based transition interventions which encourage academic success and graduation.
Show less - Date Issued
- 2016
- Identifier
- CFE0006684, ucf:51902
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006684
- Title
- Youth Labor Market Conditions and the NEET Population in the EU: Do Poor Labor Market Opportunities Discourage Youth?.
- Creator
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Hudson, Jennifer, Hamann, Kerstin, Kinsey, Barbara, Powell, Jonathan, University of Central Florida
- Abstract / Description
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This study examines how poor labor market opportunities discourage youth between the ages of 15 and 24 and 15 to 29 from participating in the labor market in the European Union between 2005 and 2013. A critical portion of inactive NEETs (youth not in employment, education, or training) reports to be discouraged due to a recognized (")lack of opportunities in the labor market.(") Despite indications from descriptive analyses that the conditions that drive the distinct subsets of the NEET...
Show moreThis study examines how poor labor market opportunities discourage youth between the ages of 15 and 24 and 15 to 29 from participating in the labor market in the European Union between 2005 and 2013. A critical portion of inactive NEETs (youth not in employment, education, or training) reports to be discouraged due to a recognized (")lack of opportunities in the labor market.(") Despite indications from descriptive analyses that the conditions that drive the distinct subsets of the NEET population vary, empirical examinations of the effects of these conditions on the rates of different NEET groups across countries and over time are lacking. The policies prescribed for the NEET group as a whole tend to ignore the special needs of discouraged, inactive NEETs. Beyond the fundamental problem of engaging these individuals in the labor market, neglecting this group has a variety of implications, ranging from social exclusion, to poverty, and even radicalism. A central goal of this project is to determine what a recognized (")lack of opportunities(") means. What is known concretely is that fellow youth are increasingly vulnerable to a range of labor market outcomes and conditions beyond unemployment, including difficulty transitioning into the labor market (school-to-work transitions), in-work poverty risk, non-standard employment opportunities (involuntary and voluntary), limited ability to transition into secure employment (i.e. upward mobility), lower wage levels, atypical employment, limited job security and support, and long-term unemployment. Utilizing aggregated survey data from the EU Labor Force Survey and EU Survey on Income and Living Conditions, I examine how a range of labor market outcomes and conditions for youth, representative of the poor labor market opportunities, affect the frequency of discouraged NEETs across 24 EU countries between 2005 and 2013. Findings suggest that the incidence of involuntary non-standard work, in-work poverty risk, and atypical employment among fellow youth and the incidence of decreased work security among the adult working age population are associated with an increase in discouraged, inactive NEETs. This suggests that engaging this hard to reach subgroup of the NEET population requires a greater emphasis on creating improved labor market opportunities.
Show less - Date Issued
- 2017
- Identifier
- CFE0006605, ucf:51292
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006605
