The rotary Left Ventricular Assist Device (LVAD) is a mechanical pump surgically implanted in patients with end-stage congestive heart failure to help maintain the flow of blood from the sick heart. The rotary type pumps are controlled by varying the impeller speed to control the amount of blood flowing through the LVAD. One important challenge in using these devices is to prevent the occurrence of excessive pumping of blood from the left ventricle (known as suction) that may cause it to collapse due to the high pump speed. The development of a proper feedback controller for the pump speed is therefore crucial to meet this challenge. In this thesis, some theoretical and practical issues related to the development of such a controller are discussed. First, a basic nonlinear, time-varying cardiovascular-LVAD circuit model that will be used to develop the controller is reviewed. Using this model, a suction index is tested to detect suction. Finally we propose a feedback controller that uses the pump flow signal to regulate the pump speed based on the suction index and an associated threshold. The objective of this controller is to continuously update the pump speed to adapt to the physiological changes of the patient while at the same time avoiding suction. Simulation results are presented under different conditions of the patient activities. Robustness of the controller to measurement noise is also discussed.

In the United States, there are two schemes of operating traffic signal controls for permitted protected left turns (PPLT) namely the traditional five-section head system (known as Dog-House) and the flashing yellow arrow system (FYA). Past studies have agreed that these controls lead to decrease the average delay per left turn vehicle, decrease the protected green time, increase the left turn capacity, and enhance the intersection overall operation. The flashing yellow arrow (FYA) has been approved by the Federal Highway Administration as the national standard for the PPLT operations at signalized intersections. So, the Florida Department of Transportation also approved this new system and they are extensively replacing the traditional system with the new system on the area of Central Florida (Lin, et al, 2010). Both these systems have been used for a long time and there are some studies that evaluated these systems but there are limited number of projects that evaluated and/or compared between the two PPLT systems from the operational perspective. The main goal of this research is to study the characteristics of traffic operations and evaluate the effectiveness of the conversion from five-section head signal to the FYA treatments at 13 intersections located in Orlando, Florida. To reach this goal, detailed data collection efforts were conducted at 13 selected intersections in the central Florida area and appropriate statistical tests were conducted using the Minitab 17 Software. Statistical tests were attempted to fit different new regression models that correlate delay and left turn volumes as response variables against a set of independent variables that included permitted green time, opposing volume, percent of trucks, time gaps, speed, and land use type. In addition to fitting the data to regression models, these models were also analyzed for the purpose of detecting any significant differences between the five-section head treatment and FYA treatment. The statistical differences of converting the five-section head system to FYA system were discussed. The results in this thesis agreed with some of the previous studies and did not agree with others. In general, the flashing yellow arrow system was found to enhance the intersection operation, increase the number of left turn vehicles, and reduce the delay. Also, some suggestions and recommendations were made based on this study results.

This thesis aims to examine the existence of populism in Swedish party politics, specifically inthe cases of The Sweden democrats on the right and The Left party on the left side. Two partiesthat can be considered each other's opposites in Sweden. The research questions revolve aroundif both parties can be considered to populist, if there are any differences in the type of populismthat the parties express and finally if there have been any changes of populism within the partiesin recent years. The definition of populism that is applied is created by Mudde & Kaltwassser (2017) and seespopulism as a thin-centered ideology with “the pure people” versus “the corrupt elite,” andargues that politics should be an expression of the will of the people. The thesis also usespopulist subtypes from Jagers & Walgrave (2007) to discern different types of populism. The methods used consist of a comparative research design and a qualitative content analysis toexamine the questions of the thesis, based on speeches made by the parties in Almedalen. Theresult shows that both parties can be considered to be populists, but there are differences betweenthe parties based on subtypes and in who they see as the people or the elite. There have not beenany considerable changes in the expressed populism in any of the parties.

In this thesis, I investigate the amount of underpricing in FinTech companies compared to non-FinTech companies. Both data sets contain thirty companies spanning from 1993 to 2018. Each FinTech company is matched to a non-FinTech company by year and comparatively similar revenue. Prior research explores underpricing on different industries, but it hasn’t yet explored underpricing in the FinTech segment. The variables considered in this paper are offer price, close price, shares offered, number of banks involved, fees per share, and money left on the table. I find some evidence that the average amount of underpricing in both dollars and by percent is higher with non-FinTech companies than FinTech companies. However, difference in means tests show statistically significant differences only for the number of shares offered. It cannot be reliably said whether investors perceive a higher risk in FinTech companies or non-FinTech companies.

Increased accountability mandates from the No Child Left Behind Act of 2001 and the Individuals with Disabilities Education Improvement Act of 2004 have resulted in general education teachers with disabled students in their classrooms. Within the inclusive classroom, the special education teacher and the general education teacher must develop a collaborative relationship that will consider the needs of the special education students and general education students. Villa and Thousand (1996) described the benefits of collaboration in schools: “Collaboration enables school personnel to meet diverse student needs through shared expertise and ownership of problem definitions and solutions” (p. 170). The purpose of this qualitative case study was to examine how special education teachers and general education teachers in inclusive classrooms collaborate regarding the needs of students. The participants for this study were four special education teachers, four general education teachers, and the administrator in one elementary school located in Mississippi. The research questions for this study were derived from six defining characteristics of collaboration as described by Friend and Cook (1996). The six defining characteristics are: (a) collaboration is voluntary; (b) collaboration requires parity among participants; (c) collaboration is based on mutual goals; (d) collaboration depends on shared responsibility for participation and decision making; (e)collaboration requires individuals to share responsibility for outcomes. There were two research questions posed for this study: (1) How do special education teachers collaborate, as defined by Friend and Cook (1996), when working with general education teachers? (2) How do general education teachers collaborate, as defined by Friend and Cook (1996), when working with special education teachers?

With the declining presence of African-American teachers in the teacher workforce, it is necessary to examine plausible causes for this phenomenon. Previous research suggests that most African-American teachers teach in high minority, high poverty schools. Consequently, they face substantial challenges related to student achievement and social and cultural disparities. No Child Left Behind is an education reform policy designed to bridge the gap between the educational disparities which exist, placing emphasis on teacher accountability and student achievement. The accountability requirements established by NCLB have generated significant pressure for teachers, particularly African-American teachers in struggling schools who must make Adequate Yearly Progress in order to avoid federal sanctions and public labeling as failing schools. Therefore, since African-American teachers often teach in schools most affected by NCLB, an examination of their experiences regarding various aspects of the law and its affect on teacher morale is essential to understanding the far-reaching implications of education reform. The focus of this study was to gain a deeper understanding of how NCLB has affected teacher morale for African-American teachers in low-performing middle schools. Specifically, a phenomenological, qualitative method was used to capture their experiences in an effort to uncover the realities these teachers face in the classroom. The overall objective of this study was to develop a richer awareness of what it means to teach in underperforming schools, while seeking academic excellence within them. Results from this study generated five themes related to teacher morale among African-American teachers in low performing middle schools. An examination of these themes indicated that teacher morale among African-American teachers in low performing middle schools was influenced by NCLB due to published test scores and NCLB’s inability to address the social and cultural disparities that exist in education. However, despite the challenges of NCLB, African-American teachers remained dedicated to their calling as teachers seeking to help their students succeed despite the odds.

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