Multiple Trajectory Smoothing for Teams of Closely Cooperating Micro Aerial Vehicles

Tato práce je zaměřena na plánovací a zkracovací algoritmus produkující hladké trajektorie pro roje vzájemně kooperujících bezpilotních helikoptér podléhajících omezením na vzájemné vzdálenosti a kolize s překážkami. Jejich úkolem je nalézt cestu prostředím s překážkami a monitorovat cílovou oblast pomocí zabudovaných kamer. Následující postup byl inspirován několika vyhlazujícími a optimalizačními algoritmy používanými v mobilní robotice. Algoritmus generuje trajektorii v prostředí s překážkami použitím variace rapidně rostoucího náhodného stromu. Pro vyhlazení trajektorie na ní algoritmus opakovaně vybírá dva body a snaží se nahradit díl mezi nimi kratší, splnitelnou trajektorií. Body trajektorie jsou následně posouvány v jejich nejbližším okolí pro nalezení lokální nejkratší splnitelné trajektorie. Výsledky ukazují účinnost optimalizační části. Vzhledem k nedostatku funkčního vybavení bylo experimentální testování provedeno jen v robotickém simulátoru.This thesis considers a planning and shortcutting algorithm producing smooth trajectories for swarm of closely cooperating micro aerial vehicles subjected to proximity constraints and collision constraints. Their task is to find a way through environment with obstacles and use their onboard cameras for surveillance of targeted zone. The following approach takes inspiration in number of various trajectory smoothing and optimization algorithms used in mobile robotics. The algorithm generates a trajectory in environment with obstacles using a variation of rapidly exploring random tree. To smooth the trajectory it repeatedly picks two points on it. Then it attempts to replace the segment between these points with a shorter, feasible trajectory. The points of the trajectory are then shifted in their proximity to find the local shortest feasible trajectory. The results show efficiency of the optimization part. Due to lack of functioning equipment, experimental testing has been done only in robotic simulator

Effects of the Internal Magnetic Field on the Magneto-Mechanical Properties of Magnetic Shape Memory Alloys

Shape memory alloys are a class of functional material which recover from large strains without permanent deformation. The strain is accommodated by the displacement of twin boundaries in the martensite phase. The shape memory alloy Ni-Mn-Ga is also ferromagnetic. Ni-Mn-Ga preferentially magnetizes along a certain crystallographic axis. This direction of easy magnetization changes across twin boundaries, such that the directions in neighboring twin domains are nearly perpendicular. The interaction of magnetic moments and interfaces including the crystal surface and twin boundary interfaces has a large role in the magnetization process of the material. The goal of this study is to characterize the relative influence of twin boundaries on the magnetization of the material, and the dependence of the magnetization on the twin domain microstructure. The torque on a single crystal specimen in a homogeneous external magnetic field was characterized with experimental methods. The torque is the negative first derivative of the magnetic energy as a function of angle between the specimen and magnetic field. The torque and magnetic energy strongly depends on the twin domain microstructure. For specimen with two twin boundaries at 3% strain in an external magnetic field of 50 mT, one twin microstructure required 1.7 times more torque to rotate than another twin microstructure. At fields above 100 mT, the torque was asymmetric depending on the direction the direction the sample was rotated. Numerical micromagnetic simulations were performed to gain a qualitative understanding of the difference in magnetization and magnetic energy in different twin microstructures. At low fields, the continuity of magnetization across the twin boundary results in one twin microstructure having completely saturated twin domains, while the other microstructures contained 180° magnetic domains. At larger fields, the asymmetry in torque was due to the angle of the twin boundary with the crystal surface. Both the dependence on magnetization and torque asymmetry are due to the internal magnetic field at the twin boundary. The interaction of magnetic moments across the twin boundary drives the internal magnetic field and magnetization. The twin domain microstructure can be manipulated to drive the magnetization process in order to optimize the performance of the material in a device. The role of the internal magnetic field and specimen magnetization is discussed regarding a low power strain sensing measurement technique

‘I am not your justification for existence:’ Mourning, Fascism, Feminism and the Amputation of Mothers and Daughters in Atwood, Ziervogel, and Ozick

This thesis examines the complexities of mother-daughter relationships in twentieth-century women’s literature that includes themes about fascism and totalitarianism. Of central concern is how mothers and daughters are separated, both physically and psychically, in Margaret Atwood’s The Handmaid’s Tale, Meike Ziervogel’s Magda and Cynthia Ozick’s The Shawl. Adrienne Rich’s Of Woman Born provides the theoretical framework for considering maternity and the institution of motherhood. These separations occur through two modes: physical separation by political force; and psychical separation through ideological difference and what Rich terms as “Matrophobia.” The physical separation is analyzed through a synthesis of Rich’s theory and historical analysis of Nazi policy on maternity. The psychical separation occurs through the mothers attempts to transmit ideologies (fascism, feminism and classism) to their daughters and the disruptions of the transmissions vis á vis Matrophobia. These ideological transmissions will be analyzed through a synthesis of Rich and Chela Sandoval’s Methodology of the Oppressed. These two forms of separation and amputation erupt into acts of mourning for the loss of matrilineage, which will be analyzed with Rich and Judith Butler’s Precarious Life. From mourning arises the justification for these failed transmissions, and justifications for maternity—which will incorporate Sandoval’s work on “love.” The complications of the relationships of mothers and daughters not only show how the relationship can explore the constraints of maternity in literature, but also serve as a guide to thinking critically about how motherhood is socially constructed as an institution. In short—by examining maternity and fascist regimes, the intersections of race, class and gender show that maternity, and motherhood, while constrained, was also a privilege, as the state rigidly defined who could be a mother, and who could not. Adviser: Amelia María de la Luz Monte

On the newcomb-benford law in models of statistical data

We consider positive real valued random data X with the decadic representation X = P1i=−1 Di 10i and the first significant digit D = D(X) 2 {1, 2, . . . , 9} of X defined by the condition D = Di _ 1, Di+1 = Di+2 = . . . = 0. The data X are said to satisfy the Newcomb-Benford law if P{D = d} = log10 d+1 d for all d 2 {1, 2, . . . , 9}. This law holds for example for the data with log10 X uniformly distributed on an interval (m, n) where m and n are integers. We show that if log10 X has a distribution function G(x/_) on the real line where _ > 0 and G(x) has an absolutely continuous density g(x) which is monotone on the intervals (−1, 0) and (0,1) then ____ P{D = d} − log10 d + 1 d ____ _ 2 g(0) _ . The constant 2 can be replaced by 1 if g(x) = 0 on one of the intervals (−1, 0), (0,1). Further, the constant 2g(0) is to be replaced by R |g0(x)|dx if instead of the monotonicity we assume absolute integrability of the derivative g0(x).We consider positive real valued random data X with the decadic representation X = P1i=−1 Di 10i and the first significant digit D = D(X) 2 {1, 2, . . . , 9} of X defined by the condition D = Di _ 1, Di+1 = Di+2 = . . . = 0. The data X are said to satisfy the Newcomb-Benford law if P{D = d} = log10 d+1 d for all d 2 {1, 2, . . . , 9}. This law holds for example for the data with log10 X uniformly distributed on an interval (m, n) where m and n are integers. We show that if log10 X has a distribution function G(x/_) on the real line where _ > 0 and G(x) has an absolutely continuous density g(x) which is monotone on the intervals (−1, 0) and (0,1) then ____ P{D = d} − log10 d + 1 d ____ _ 2 g(0) _ . The constant 2 can be replaced by 1 if g(x) = 0 on one of the intervals (−1, 0), (0,1). Further, the constant 2g(0) is to be replaced by R |g0(x)|dx if instead of the monotonicity we assume absolute integrability of the derivative g0(x)

CEE Candidate countries on the way to Eurozone

Political Science; European Unio

Making It Your Own: Developing and Administrating Graduate Writing Retreats

This workshop lays out the groundwork for developing graduate writing support in the form of writing retreats or camps. Focused on the administrative aspects, it covers audience, logistics, and assessment. All material derives from the context of Purdue Writing Lab events for dissertation writers