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Whole Building LCA With WLC: A New Commercial Software Development For Product Specification In The UK
In 2000, BRE launched a software tool called Envest. This tool allowed designers to gauge the environmental impacts of a whole building design at the initial stage of the design process, comparing the embodied impact of the building fabric to the impact from operation. The simplicity of the tool hinges upon the use of a single score approach to measuring environmental impacts. The measure is known as Ecopoints. In response to pressure from the market, BRE has developed Envest further to include a Whole Life Costing function that enables the designer to consider the costs of the building delivery and its maintenance scheme together with the environmental impact. Acknowledging that there is a role for generic and specific costs, the new tool will enable users to enter their own costs or use default data. In early 2002, Envest II will go on line. Web based, the tool will be inherently more flexible than its CD ROM predecessor and, for the first time, creates the possibility of adding new products as data becomes available from manufacturers. This function has been developed in parallel with the BRE Certification Scheme for Environmental profiles of Construction Products which allows manufacturers to make independently verified claims about their product. Envest scores can already be used to obtain "material" credits in BREEAM, the whole building assessment scheme and the new version will continue to be used in this way
A Hilbert Scheme in Computer Vision
Multiview geometry is the study of two-dimensional images of
three-dimensional scenes, a foundational subject in computer vision. We
determine a universal Groebner basis for the multiview ideal of n generic
cameras. As the cameras move, the multiview varieties vary in a family of
dimension 11n-15. This family is the distinguished component of a multigraded
Hilbert scheme with a unique Borel-fixed point. We present a combinatorial
study of ideals lying on that Hilbert scheme.Comment: 26 page
Deterministic Annealing and Nonlinear Assignment
For combinatorial optimization problems that can be formulated as Ising or
Potts spin systems, the Mean Field (MF) approximation yields a versatile and
simple ANN heuristic, Deterministic Annealing. For assignment problems the
situation is more complex -- the natural analog of the MF approximation lacks
the simplicity present in the Potts and Ising cases. In this article the
difficulties associated with this issue are investigated, and the options for
solving them discussed. Improvements to existing Potts-based MF-inspired
heuristics are suggested, and the possibilities for defining a proper
variational approach are scrutinized.Comment: 15 pages, 3 figure
Ehrenfest regularization of Hamiltonian systems
Imagine a freely rotating rigid body. The body has three principal axes of
rotation. It follows from mathematical analysis of the evolution equations that
pure rotations around the major and minor axes are stable while rotation around
the middle axis is unstable. However, only rotation around the major axis (with
highest moment of inertia) is stable in physical reality (as demonstrated by
the unexpected change of rotation of the Explorer 1 probe). We propose a
general method of Ehrenfest regularization of Hamiltonian equations by which
the reversible Hamiltonian equations are equipped with irreversible terms
constructed from the Hamiltonian dynamics itself. The method is demonstrated on
harmonic oscillator, rigid body motion (solving the problem of stable minor
axis rotation), ideal fluid mechanics and kinetic theory. In particular, the
regularization can be seen as a birth of irreversibility and dissipation. In
addition, we discuss and propose discretizations of the Ehrenfest regularized
evolution equations such that key model characteristics (behavior of energy and
entropy) are valid in the numerical scheme as well
Bipolynomial Hilbert functions
Let X be a closed subscheme and let HF(X,-) and hp(X,-) denote, respectively,
the Hilbert function and the Hilbert polynomial of X. We say that X has
bipolynomial Hilbert function if HF(X,d)=min{hp(P^n,d),hp(X,d)} for every
non-negative integer d. We show that if X consists of a plane and generic
lines, then X has bipolynomial Hilbert function. We also conjecture that
generic configurations of non-intersecting linear spaces have bipolynomial
Hilbert function
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