University of Central Florida

About: University of Central Florida is a education organization based out in Orlando, Florida, United States. It is known for research contribution in the topics: Laser & Population. The organization has 18822 authors who have published 48679 publications receiving 1234422 citations. The organization is also known as: UCF.

Collaborative Decision-Making in Emergency and Disaster Management

Abstract: Decision-making in emergencies requires non-traditional approach and tools characterized by non-hierarchical structure and flexibility. The dynamic environment of disasters makes it imperative to invest in inter-sector and inter-agency cooperation and coordination. Focusing on the Emergency Management Assistance Compact's (EMAC) response to Hurricanes Katrina and Rita in 2005, this article examines the decision-making structure of the agreement. EMAC is an inter-state mutual aid agreement that facilitates sharing of resources during and after disasters. While EMAC's overall decision-making performance was relatively satisfactory and flawless, investment in communication, trust-building, and eradication of inter-agency value differences and discrepancies is imperative.

Review of Challenges and Research Opportunities for Voltage Control in Smart Grids

Abstract: In this paper, we review the emerging challenges and research opportunities for voltage control in smart grids. For transmission grids, the voltage control for accommodating wind and solar power, fault-induced delayed voltage recovery, and measurement-based Thevenin equivalent for voltage stability analysis are reviewed. For distribution grids, the impact of high penetration of distributed energy resources is analyzed, typical control strategies are reviewed, and the challenges for local inverter Volt–Var control is discussed. In addition, the motivation, state-of-the-art, and future directions of the coordination of transmission system operators (TSO) and distribution system operators (DSO) are also thoroughly discussed.

Earnings Management: The Effect of Ex Ante Earnings Expectations

Abstract: This paper examines the utilization of discretionary accruals to adjust reported earnings toward analysts' expectations regarding firm profitability. The variance in analysts' earnings forecasts is used as our firm specific measure for analysts' forecasts consensus. Our findings indicate that managers use discretionary accruals to achieve market expectations for earnings. Managers behave as though they have greater incentives to use income increasing discretionary accruals in settings where analysts have reached a consensus regarding firm earnings, particularly in settings where pre-discretionary accrual earnings are below analysts' expectations. When pre-discretionary accrual earnings are above analysts' expectations and analysts are not in consensus, managers use strategies to retain their ability to manage (increase) earnings in future periods by recording income decreasing discretionary accruals in the current period. Two alternative specifications to control for possible measurement error in our design produced results consistent with our primary analysis.

Dependence of the Yb 3+ emission cross section and lifetime on temperature and concentration in yttrium aluminum garnet

Abstract: Measurements are reported of the spectroscopic properties (absorption and emission spectra, stimulated-emission cross section, and radiative lifetime) of (YbxY1-x)3Al5O12 for nominal x values of 0.025, 0.05, 0.1, 0.2 and 0.3 at temperatures of 15–300 K. The emission cross sections of Yb:YAG with different Yb3+ concentrations were determined by use of the Fuchtbauer–Ladenburg formula and the reciprocity method. At low temperatures, the product (στ) of the effective stimulated-emission cross section and the radiative lifetime is greater than at room temperature for all concentrations. Product στ is nearly independent of Yb3+ concentration at a given temperature. These results will aid in the design of high-power thin disk lasers by use of highly doped Yb:YAG.