Management of interstate rail rollingstock

The Study Group was asked to develop a methodology to allow more efficient and effective direction of empty wagon movements. The Study Group chose to develop two linear programming approaches. One was for allocating empty wagons, and the other modelled both empty and full wagons. Although large in size, the models were otherwise feasible, showing that, conceptually, the method would work. However, there is still a major amount of development work required to implement the system

Teleological computer graphics modeling

Summary form only give. Teleological modeling, a developing approach for creating abstractions and mathematical representations of physically realistic time-dependent objects, is described. In this approach, geometric constraint-properties, mechanical properties of objects, the parameters representing an object, and the control of the object are incorporated into a single conceptual framework. A teleological model incorporates time-dependent goals of behavior of purpose as the primary abstraction and representation of what the object is. A teleological implementation takes a geometrically incomplete specification of the motion, position, and shape of an object, and produces a geometrically complete description of the object's shape and behavior as a function of time. Teleological modeling techniques may be suitable for consideration in computer vision algorithms by extending the current notions about how to make mathematical representations of objects. Teleological descriptions can produce compact representations for many of the physically derivable quantities controlling the shapes, combining-operations, and constraints which govern the formation and motion of objects

Superquadrics and Angle-Preserving Transformations

Over the past 20 years, a great deal of interest has developed in the use of computer graphics and numerical methods for three-dimensional design. Significant progress in geometric modeling is being made, predominantly for objects best represented by lists of edges, faces, and vertices. One long-term goal of this work is a unified mathematical formalism, to form the basis of an interactive and intuitive design environment in which designers can simulate three-dimensional scenes with shading and texture, produce usable design images, verify numerical machining-control commands, and set up finite-element meshwork for structural and dynamic analysis. A new collection of smooth parametric objects and a new set of three-dimensional parametric modifiers show potential for helping to achieve this goal. The superquadric primitives and angle-preserving transformations extend the traditional geometric primitives-quadric surfaces and parametric patches-used in existing design packages, producing a new spectrum of flexible forms. Their chief advantage is that they allow complex solids and surfaces to be constructed and altered easily from a few interactive parameters

Oriented tensor reconstruction: tracing neural pathways from diffusion tensor MRI

In this paper we develop a new technique for tracing anatomical fibers from 3D tensor fields. The technique extracts salient tensor features using a local regularization technique that allows the algorithm to cross noisy regions and bridge gaps in the data. We applied the method to human brain DT-MRI data and recovered identifiable anatomical structures that correspond to the white matter brain-fiber pathways. The images in this paper are derived from a dataset having 121x88x60 resolution. We were able to recover fibers with less than the voxel size resolution by applying the regularization technique, i.e., using a priori assumptions about fiber smoothness. The regularization procedure is done through a moving least squares filter directly incorporated in the tracing algorithm

Research in the development effort of an improved multiplier phototube Seventh quarterly report

Test data on effective photocathode size, response uniformity, and pulse amplitude distribution of multiplier phototube

Bimaximal Mixing in an SO(10) Minimal Higgs Model

An SO(10) SUSY GUT model was previously presented based on a minimal set of Higgs fields. The quark and lepton mass matrices derived fitted the data extremely well and led to large mixing of muon- and tau-neutrinos in agreement with the atmospheric neutrino data and to the small-angle MSW solution for the solar neutrinos. Here we show how a slight modification leading to a non-zero up quark mass can result in bimaximal mixing for the atmospheric and solar neutrinos. The "just-so" vacuum solution is slightly favored over the large-angle MSW solution on the basis of the hierarchy required for the right-handed Majorana matrix and the more nearly-maximal mixing angles obtained.Comment: 10 pages, LaTeX, several references adde

SO(10) and Large nu_mu - nu_tau Mixing

A general approach to understanding the large mixing seen in atmospheric neutrinos is explained, as well as a highly predictive SO(10) model which implements this approach. It is also seen how bimaximal mixing naturally arises in this scheme. (Talk presented at NNN99, SUNY Stony Brook, Sept. 22-26, 1999)Comment: 10 pages, LaTe

Research in the development of an improved multiplier phototube Final report

Cascade aperture design, gas pressure effects, gain calibration, and photon counting efficiency of multiplier phototub