Existence of finitely many solution branches and nested hysteresis loops in ferroelectric materials

1 online resource (PDF, 22 pages, includes illustrations)Park, Jinhae. (2008). Existence of finitely many solution branches and nested hysteresis loops in ferroelectric materials. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/179963

LOWER EXTREMITY KINEMATICS OF SKI MOTION ON HILLS

This research study aimed to collect thre- dimensional joint angles of the lower extremity during a basic ski motion in order to provide more quantitative teaching guide-lines for ski instructors. Eleven infrared cameras were placed to cover the capture volume of three different stopping movements (e.g. “Pflug Fahren”) on hills. Six ski instructors participated in the test. Three trials of each stop were selected for comparison. Based on the results, skiers tended to use the edge of the ski and maintain a wider “V” shape at the shortest stop distance (e.g. 2m) compared to the other stops. Also, each skier had to invert the foot with a less flexed and more abducted knee and hip position as the stopping distance was decreased. This information will be useful for the development of more objective teaching guide-lines for beginner skiers

Analysis of Nematic Liquid Crystals with Disclination Lines

We investigate the structure of nematic liquid crystal thin films described by the Landau--de Gennes tensor-valued order parameter with Dirichlet boundary conditions of nonzero degree. We prove that as the elasticity constant goes to zero a limiting uniaxial texture forms with disclination lines corresponding to a finite number of defects, all of degree 1/2 or all of degree -1/2. We also state a result on the limiting behavior of minimizers of the Chern-Simons-Higgs model without magnetic field that follows from a similar proof.Comment: 40 pages, 1 figur

A variational Problem for the Isotropic-Nematic Phase Transition

In this talk, we consider Landau-de Gennes theory for liquid crystals and investigate the structure and stability of the isotropic-nematic interface in 1-D. In the absence of the anisotropic energy, we show that the uniaxial solution is the only global minimizer. In the presence of the anisotropic energy, the uniaxial solution may lose stability. We will talk about the role of the anisotropic energy term in the stability of the uniaxial solution. If time permits, we also plan to present some interesting open questions, which are related to De Giorgi conjecture. This is a joint work with Wei Wang, Pingwen Zhang and Zhifei Zhang.Non UBCUnreviewedAuthor affiliation: Chungnam National UniversityFacult

Modeling and Simulation of Switchings in Ferroelectric liquid crystals

Mathematical modeling and numerical simulation of smectic C liquid crystals which possess the spontaneous polarization are considered in this paper. In particular, the model allows for a system with a zero net polarization which is one of the ubiquitous systems of the polarized liquid crystals. Theoretical and numerical investigations are conducted to study effects of the energy associated with the polarization, switching patterns between two uniform states by an externally applied field and random noise, as well as a relation between polarization and applied field near the phase transition from the smectic A and smectic C