Search results for "Manifold"

Some results about operators in nested Hilbert spaces

2005

With the use of interpolation methods we obtain some results about the domain of an operator acting on the nested Hilbert space {ℋf}f∈∑ generated by a self-adjoint operatorA and some estimates of the norms of its representatives. Some consequences in the particular case of the scale of Hilbert spaces are discussed.

Minor Losses and Best Manifold Position in the Optimal Design of Paired Sloped Drip Laterals

2018

Explicit relationships for optimal designing rectangular microirrigation units on uniform slopes: The IRRILAB software application

2018

Abstract Many attempts have been made to provide easy tools for designing microirrigation units. However, most of these have dealt with numerical solutions, which require many trial-and-error attempts and time-consuming iterations, performed by applying the basic hydraulic equations from the manifold to the end of both the downhill and the uphill sides of the laterals. Recently, analytical procedures to optimally design paired drip laterals on uniform slopes were proposed, providing readily obtainable results and energy saving. Although these analytical solutions can be practically applied, they only make it possible to design a one-lateral unit; to be really interesting for practical appli…

Design of concave and convex paired sloped drip laterals

2017

Abstract Properly designed microirrigation plants allow water use efficiency to be optimized and quite high values of emission uniformity to be obtained in the field. Disposing paired laterals so that two distribution pipes extend in opposite directions from a common manifold contributes to provide more uniform pressure to all laterals in thesystem. Towards this end, an analytical procedure to optimize the uniform pressure when designing paired drip laterals on uniform slopes has recently been proposed, based on the assumption that the variations of the emitters’ flow rate along the lateral and the local losses due to the emitters’ insertions could be neglected. More recently, an easy metho…

2020

This work introduces a method to estimate reflectance, shading, and specularity from a single image. Reflectance, shading, and specularity are intrinsic images derived from the dichromatic model. Estimation of these intrinsic images has many applications in computer vision such as shape recovery, specularity removal, segmentation, or classification. The proposed method allows for recovering the dichromatic model parameters thanks to two independent quadratic programming steps. Compared to the state of the art in this domain, our approach has the advantage to address a complex inverse problem into two parallelizable optimization steps that are easy to solve and do not require learning. The p…

On the volume of unit vector fields on spaces of constant sectional curvature

2004

A unit vector field X on a Riemannian manifold determines a submanifold in the unit tangent bundle. The volume of X is the volume of this submanifold for the induced Sasaki metric. It is known that the parallel fields are the trivial minima.

Fuzzy selecting local region level set algorithm

2015

In this work, we introduced a novel localized region based level set model which is simultaneously effective for heterogeneous object or/and background and robust against noise. As such, we propose to minimize an energy functional based on a selective local average, i.e., when computing the local average, instead to use the intensity of all the pixels surrounding a given pixel, we first give a local Gaussian fuzzy membership to be a background or an object pixel to each of these surrounding pixels and then, we use the fuzzy weighted local average of these pixels to replace the traditional local average. With the graphics processing units' acceleration, the local lattice Boltzmann method is …

General Introduction to Computer Simulation Methods

1986

Computer simulation methods are now an established tool in many branches of science. The motivation for computer simulations of physical systems are manifold. One of the main motivations is that one eliminates approximations with computer simulations. Usually to treat a problem analytically (if it can be done at all) one needs to resort to some kind of approximation; for exam- ple a mean-field-type approximation. With a computer simulation we have the ability to study systems not yet tractable with analytical methods. The computer simulation approach allows one to study complex systems and gain insight into their behaviour. Indeed, the complexity can go far beyond the reach of present analy…

Transportation-cost inequality on path spaces with uniform distance

2008

Abstract Let M be a complete Riemannian manifold and μ the distribution of the diffusion process generated by 1 2 ( Δ + Z ) where Z is a C 1 -vector field. When Ric − ∇ Z is bounded below and Z has, for instance, linear growth, the transportation-cost inequality with respect to the uniform distance is established for μ on the path space over M . A simple example is given to show the optimality of the condition.

Fostering creative thinking : the role of primary teachers

2014

Τα τελευταία χρόνια παρατηρείται μια αυξανόμενη απαίτηση για δημιουργικότητα σε όλους τους τομείς της ανθρώπινης δραστηριότητας. Η πρωτοβάθμια εκπαίδευση πασχίζει να συμβαδίσει με τις νέες κοινωνικοοικονομικές ανάγκες και να προετοιμάσει τους δημιουργικούς πολίτες του μέλλοντος. Αν και οι εκπαιδευτικοί της πρωτοβάθμιας εκπαίδευσης παίζουν καθοριστικό ρόλο, άλλοτε θετικό και άλλοτε αρνητικό, στην καλλιέργεια της δημιουργικότητας των μαθητών, λίγες έρευνες έχουν διεξαχθεί σχετικά με τη συμβολή τους στην καλλιέργεια της δημιουργικής σκέψης των μαθητών και τις απόψεις τους για το θέμα αυτό. Η θεμελιωμένη γνώση (situated knowledge) των Ελλήνων εκπαιδευτικών πρωτοβάθμιας εκπαίδευσης και η εμπειρί…