18 research outputs found
Geometric representation of neuroanatomical data observed in mouse brain at cellular and gross levels
This dissertation studies two problems related to geometric representation of
neuroanatomical data: (i) spatial representation and organization of individual neurons,
and (ii) reconstruction of three-dimensional neuroanatomical regions from sparse two-dimensional
drawings. This work has been motivated by nearby development of new
technology, Knife-Edge Scanning Microscopy (KESM), that images a whole mouse
brain at cellular level in less than a month.
A method is introduced to represent neuronal data observed in the mammalian brain at
the cellular level using geometric primitives and spatial indexing. A data representation
scheme is defined that captures the geometry of individual neurons using traditional
geometric primitives, points and cross-sectional areas along a trajectory. This
representation captures inferred synapses as directed links between primitives and
spatially indexes observed neurons based on the locations of their cell bodies. This
method provides a set of rules for acquisition, representation, and indexing of KESMgenerated
data.
Neuroanatomical data observed at the gross level provides the underlying regional
framework for neuronal circuits. Accumulated expert knowledge on neuroanatomical organization is usually given as a series of sparse two-dimensional contours. A data
structure and an algorithm are described to reconstruct separating surfaces among
multiple regions from these sparse cross-sectional contours. A topology graph is defined
for each region that describes the topological skeleton of the region’s boundary surface
and that shows between which contours the surface patches should be generated. A
graph-directed triangulation algorithm is provided to reconstruct surface patches
between contours. This graph-directed triangulation algorithm combined together with
a piecewise parametric curve fitting technique ensures that abutting or shared surface
patches are precisely coincident. This method overcomes limitations in i) traditional
surfaces-from-contours algorithms that assume binary, not multiple, regionalization of
space, and in ii) few existing separating surfaces algorithms that assume conversion of
input into a regular volumetric grid, which is not possible with sparse inter-planar
resolution
An extensive English language bibliography on graph theory and its applications
Bibliography on graph theory and its application
Using MapReduce Streaming for Distributed Life Simulation on the Cloud
Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp
Untangling hotel industry’s inefficiency: An SFA approach applied to a renowned Portuguese hotel chain
The present paper explores the technical efficiency of four hotels from Teixeira Duarte Group - a renowned Portuguese hotel chain. An efficiency ranking is established from these four hotel units located in Portugal using Stochastic Frontier Analysis. This methodology allows to discriminate between measurement error and systematic inefficiencies in the estimation process enabling to investigate the main inefficiency causes. Several suggestions concerning efficiency improvement are undertaken for each hotel studied.info:eu-repo/semantics/publishedVersio
LIPIcs, Volume 248, ISAAC 2022, Complete Volume
LIPIcs, Volume 248, ISAAC 2022, Complete Volum
LIPIcs, Volume 261, ICALP 2023, Complete Volume
LIPIcs, Volume 261, ICALP 2023, Complete Volum
MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications
Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described
Generalized averaged Gaussian quadrature and applications
A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal
Raising public awareness of mathematics
This book arose from the presentations given at the international workshop held in Óbidos, 26–29 September 2010, as a result of a joint initiative of the Centro Internacional de Matemática and the Raising Public Awareness (RPA) committee of the European Mathematical Society (EMS). The objective was to provide a forum for general reflection with an international mix of experts on building the image of mathematics, ten years after the World Mathematical Year 2000 (WMY 2000). Óbidos, a charming town situated one hour by car to the north of Lisbon, Portugal, was also the site of the re-creation in the year 2000 of the international mathematics exhibition “Beyond the Third Dimension” (http://alem3d.obidos.org/en/) and a meeting of the EMS WMY2000 Committee. The opening of the workshop was also a public “mathematical afternoon” organised by the Portuguese Mathematical Society (SPM) in cooperation with the town of Óbidos. At this event mathematical films and lectures to the general public were presented. The first lecture was given by H. Leitão, from the University of Lisbon, on mathematics in the “Age of Discoveries”, and the second one by G.-M. Greuel, the current president of ERCOM (the EMS committee of the European Research Centres on Mathematics), on the topic “Mathematics between Research, Application and Communication”, which text is included in this book.info:eu-repo/semantics/publishedVersio