Event(s) on May 2007

• 2/5/2007

  題目:	CMIV Lecture Series: Optimization for Image Processing (Lecture 8)
  講員:	Prof. Mila Nikolova, CMLA ENS de Cachan, France
  時間/地點:	14:30  -  16:30 FSC 1111

  
  

• 8/5/2007

  題目:	Real-Time Pose Tracking and Model Reconstruction
  講員:	Prof. Kin Hong Wong, Department of Computer Science and Engineering, The Chinese University of Hong Kong, HKSAR, China
  時間/地點:	11:30  -  12:30 FSC 1217
  摘要:	Structure from motion (SFM) is a technique for finding the pose and model of an object from images. It is an essential part of many virtual reality and augmented reality applications. In my talk I will summarize our work on developing real-time algorithms for SFM. Kalman filter is a core technology for our investigations because of its suitability for real-time implementations. Traditional approaches of using Kalman filter for SFM will first be discussed. I will then introduce a special technique for integrating multiple Kalman filters called Interacting Multiple Model (IMM) to enhance the robustness of pose tracking. It is also found that Kalman pose tracking can also be applied to stereo image sequences, the formulation and performance will be discussed. The talk will also include live demonstrations of our SFM systems and their applications to augmented reality. Experiences and programming techniques for implementing real-time SFM will also be mentioned.

  
  

• 8/5/2007

  題目:	Tikhonov Regularization by a Reproducing Kernel Hilbert Space for the Cauchy Problem for an Elliptic Equation
  講員:	Dr. Tomoya Takeuchi, Graduate School of Mathematical Sciences, The University of Tokyo, Japan
  時間/地點:	14:30  -  15:30 FSC 1217
  摘要:	We propose a discretized Tikhonov regularization for a Cauchy problem for an elliptic equation by a reproducing kernel Hilbert space. We prove the convergence of discretized regularized solutions to an exact solution. Our numerical results demonstrate that our method can stably reconstruct solutions to the Cauchy problems.

  
  

• 15/5/2007

  題目:	Assessing Surrogate Endpoints in Vaccine Trials
  講員:	Dr. Li Qin, Statistical Center for HIV/AIDS Research and Prevention, Fred Hutchinson Cancer Research Center, USA
  時間/地點:	11:30  -  12:30 FSC 1217
  摘要:	Assessing immune responses to study vaccines as surrogates endpoints (SoPs) plays a central role in vaccine clinical trials. Motivated by three ongoing or pending HIV vaccine efficacy trials, we consider such surrogate endpoint assessment in a randomized placebo-controlled trial with case-cohort sampling of immune responses and a time to event endpoint. We extend the principal surrogate definition under the principal strata framework proposed by Frangakis and Rubin (2002) and Gilbert and Hudgens (2006), and introduce a causal estimand that measures the value of an immune response as a SoP in the context of the Cox proportional hazards model. The estimand is not identifiable because the immune response to vaccine is not measured in placebo recipients. We formulate the problem as a Cox model with missing covariates, and employ novel trial designs for predicting the missing immune responses and thereby identifying the estimand. A maximum estimated likelihood approach is proposed for estimation. Simulated data examples are given to evaluate the proposed designs and study their properties.

  
  

• 29/5/2007

  題目:	An Introduction to Kinetic Relations for Undercompressive Shocks
  講員:	Prof. Philippe G. LeFloch, University of Paris VI and CNRS, France
  時間/地點:	11:30  -  12:30 FSC 1217
  摘要:	This will be an introduction to the theory of undercompressive shock waves. I will explain the importance of small scale effects in solutions to systems of conservation laws arising in continuum physics. Undercompressive waves are fundamental in phase transition dynamics (van der Waals fluids, martensitic materials), especially when both viscosity and capillarity effects come into play. The proper selection of physically meaningful, discontinuous, entropy solutions requires the concept of a kinetic relation. In the last ten years, various tools have been developed for, both, the theoretical analysis and the numerical discretization of these solutions.