Minimally Stochastic Schemes for Singular Diffusion Equations

Burgeth, Bernhard
Weıckert, Joachım
Tarı, Zehra Sibel


Scheduling jobs on unrelated parallel machines to minimize regular total cost functions
Azizoğlu, Meral; Kirca, O (1999-02-01)
In this paper we consider unrelated parallel machine scheduling problems that involve the minimization of regular total cost functions. We first present some properties of optimal solutions and then provide a lower bound. These mechanisms are tested on the well-known practical problem of minimizing total weighted flow time on unrelated parallel machines. In doing so, we design a branch and bound algorithm incorporating the mechanisms derived for the general total cost function along with the ones derived sp...
Hybrid excited synchronous generator design and comparison of direct drive wind turbines
Akgemci, Aysel; Keysan, Ozan; Department of Electrical and Electronics Engineering (2019)
Various types of electrical generators are used in wind turbines and there is not an agreement on the best generator type. Although, high speed Doubly Fed Induction Generators (DFIGs) are still the most common generator topology utilized in wind turbine systems, there is a trends toward direct-drive Permanent Magnet Synchronous Generators (PMSGs), as they are more efficient and reliable. However, permanent magnets (PMs) induce uncontrollable voltage due to the fixed flux resulting from PM excitation. Conven...
Numerical simulations of wind turbine wake interactions using actuator line and les models
Önel, Hüseyin Can; Tuncer, İsmail Hakkı; Department of Aerospace Engineering (2019)
Wind is one of the most promising renewable energy resources of the future. After years of optimization studies, Horizontal Axis Wind Turbines shine out as the most efficient type and have been the only model used in large scale commercial wind farms. Layout planning plays an important role in getting the most power out of a wind farm as much as turbine blade design. Most important parameter in this planning phase is the inevitable wake generated by rotors and its impact on other wind turbines which results...
Stochastic modelling of wind energy generation
Alişar, İbrahim; Sevaioğlu, Osman; Department of Electrical and Electronics Engineering (2012)
In this thesis work, electricty generation modeling of the wind energy -one type of the renewable energy sources- is studied. The wind energy characteristics and the distribution of wind speed in a specific region is also examined. In addition, the power curves of the wind turbines are introduced and the relationship between the wind speed and wind power is explained. The generation characteristics of the wind turbines from various types of producers are also investigated. In this study, the main wind power...
Dynamic modelling and simulation of a wind turbine
Altuğ, Ayşe Hazal; Yavrucuk, İlkay; Department of Aerospace Engineering (2015)
In this thesis, a dynamic model for a horizontal axis wind turbine is developed for an upwind configuration using the MATLAB/Simulink environment. Blade Element Momentum Theory is used to model the rotor. It is assumed that the rotor blades are rigid and wind speed is uniform. Aerodynamic and gravitational forces are calculated as distributed loads. Verification of the model is done by using the LMS Samtech, Samcef for Wind Turbines software. Aerodynamic properties of the blades, sectional loads and moments...
Citation Formats
B. Burgeth, J. Weıckert, and Z. S. Tarı, Minimally Stochastic Schemes for Singular Diffusion Equations. 2007, p. 339.