Now showing items 21-40 of 170

    • A linear multigrid preconditioner for the solution of the Navier-Stokes equations using a discontinuous Galerkin discretization 

      Diosady, Laslo Tibor (Massachusetts Institute of Technology, 2007)
      A Newton-Krylov method is developed for the solution of the steady compressible Navier-Stokes equations using a Discontinuous Galerkin (DG) discretization on unstructured meshes. An element Line-Jacobi preconditioner is ...
    • Must linear algebra be block cyclic? : and other explorations into the expressivity of data parallel and task parallel languages 

      Sundaresh, Harish Peruvamba (Massachusetts Institute of Technology, 2007)
      Prevailing Parallel Linear Algebra software block cyclically distributes data across its processors for good load balancing and communication between its nodes. The block cyclic distribution schema characterized by cyclic ...
    • A fast 3D full-wave solver for nanophotonics 

      Zhang, Lei, Ph. D. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science. (Massachusetts Institute of Technology, 2007)
      Conventional fast integral equation solvers seem to be ideal approaches for simulating 3-D nanophotonic devices, as these devices are considered to be open structures, generating fields in both an interior channel and in ...
    • Discontinuous Galerkin solution of the Boltzmann equation in multiple spatial dimensions 

      Lian, Zhengyi (Massachusetts Institute of Technology, 2007)
      This thesis focuses on the numerical solution of a kinetic description of small scale dilute gas flows when the Navier-Stokes description breaks down. In particular, it investigates alternative solution techniques for the ...
    • Data-driven revenue management 

      Uichanco, Joline Ann Villaranda (Massachusetts Institute of Technology, 2007)
      In this thesis, we consider the classical newsvendor model and various important extensions. We do not assume that the demand distribution is known, rather the only information available is a set of independent samples ...
    • Development of discontinuous Galerkin method for nonlocal linear elasticity 

      Bala Chandran, Ram (Massachusetts Institute of Technology, 2007)
      A number of constitutive theories have arisen describing materials which, by nature, exhibit a non-local response. The formulation of boundary value problems, in this case, leads to a system of equations involving higher-order ...
    • Robust transportation network design under user equilibrium 

      Lu, Yun (Massachusetts Institute of Technology, 2007)
      We address the problem of designing a transportation network in the presence of demand uncertainty, multiple origin-destination pairs and a budget constraint for the overall construction cost, under the behavioral assumption ...
    • Fully-kinetic PIC simulations for Hall-effect thrusters 

      Fox, Justin M., 1981- (Massachusetts Institute of Technology, 2007)
      In recent years, many groups have numerically modeled the near-anode region of a Hall thruster in attempts to better understand the associated physics of thruster operation. Originally, simulations assumed a continuum ...
    • Recovery of primal solution in dual subgradient schemes 

      Ma, Jing, S.M. Massachusetts Institute of Technology (Massachusetts Institute of Technology, 2007)
      In this thesis, we study primal solutions for general optimization problems. In particular, we employ the subgradient method to solve the Lagrangian dual of a convex constrained problem, and use a primal-averaging scheme ...
    • An analysis of the TR-BDF2 integration scheme 

      Dharmaraja, Sohan (Massachusetts Institute of Technology, 2007)
      We intend to try to better our understanding of how the combined L-stable 'Trapezoidal Rule with the second order Backward Difference Formula' (TR-BDF2) integrator and the standard A-stable Trapezoidal integrator perform ...
    • Multilevel spectral clustering : graph partitions and image segmentation 

      Kong, Tian Fook (Massachusetts Institute of Technology, 2008)
      While the spectral graph partitioning method gives high quality segmentation, segmenting large graphs by the spectral method is computationally expensive. Numerous multilevel graph partitioning algorithms are proposed to ...
    • A fast enriched FEM for Poisson equations involving interfaces 

      Huynh, Thanh Le Ngoc (Massachusetts Institute of Technology, 2008)
      We develop a fast enriched finite element method for solving Poisson equations involving complex geometry interfaces by using regular Cartesian grids. The presence of interfaces is accounted for by developing suitable jump ...
    • LP-based subgradient algorithm for joint pricing and inventory control problems 

      Rao, Tingting (Massachusetts Institute of Technology, 2008)
      It is important for companies to manage their revenues and -reduce their costs efficiently. These goals can be achieved through effective pricing and inventory control strategies. This thesis studies a joint multi-period ...
    • A simulation-based resource optimization and time reduction model using design structure matrix 

      Zhang, Yifeng, S.M. Massachusetts Institute of Technology (Massachusetts Institute of Technology, 2008)
      Project scheduling is an important research and application area in engineering management. Recent research in this area addresses resource constraints as well as stochastic durations. This thesis presents a simulation-based ...
    • A comparison of discrete and flow-based models for air traffic flow management 

      Phu, Thi Vu (Massachusetts Institute of Technology, 2008)
      The steady increase of congestion in air traffic networks has resulted in significant economic losses and potential safety issues in the air transportation. A potential way to reduce congestion is to adopt efficient air ...
    • Robust scheduling in forest operations planning 

      Lim, Lui Cheng (Massachusetts Institute of Technology, 2008)
      Forest operations planning is a complex decision process which considers multiple objectives on the strategic, tactical and operational horizons. Decisions such as where to harvest and in what order over different time ...
    • Model reduction for dynamic sensor steering : a Bayesian approach to inverse problems 

      Wogrin, Sonja (Massachusetts Institute of Technology, 2008)
      In many settings, distributed sensors provide dynamic measurements over a specified time horizon that can be used to reconstruct information such as parameters, states or initial conditions. This estimation task can be ...
    • An analysis of scientific computing environments : a consumer's view 

      Soni, Amit (Massachusetts Institute of Technology, 2008)
      In the last three decades, with rapid advancements in the hardware and software industry, a large number of commercial and free open source languages and software have evolved. Many of these are Very High Level Languages ...
    • Solution of fluid-structure interaction problems using a discontinuous Galerkin technique 

      Mohnot, Anshul (Massachusetts Institute of Technology, 2008)
      The present work aims to address the problem of fluid-structure interaction using a discontinuous Galerkin approach. Starting from the Navier-Stokes equations on a fixed domain, an arbitrary Lagrangian Eulerian (ALE) ...
    • A preconditioned Newton-Krylov method for computing steady-state pulse solutions of mode-locked lasers 

      Birge, Jonathan R. (Jonathan Richards) (Massachusetts Institute of Technology, 2008)
      We solve the periodic boundary value problem for a mode-locked laser cavity using a specially preconditioned matrix-implicit Newton-Krylov solver. Solutions are obtained at least an order of magnitude faster than with ...