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The use of function points to find cost analogies
Finding effective techniques for the early estimation of project effort remains an important — and frustratingly elusive — research objective for the software development community. We have conducted an empirical study of 21 real time projects for a major software developer. The study collected a range of counts and measures derived from specification documents, including a derivative of Function Points intended for highly constrained systems. Notwithstanding the fact that the projects were drawn from a comparatively stable environment, traditional approaches for building prediction systems, (for example, regression analysis) failed to yield a useful predictive model. By contrast, estimation based upon the automated search for analogous projects produced more accurate estimates. How much this is a characteristic of this particular dataset and how much these findings might be more generally replicated is uncertain. Nevertheless, these results should act as encouragement for follow up research on a much under utilised estimation technique
Towards a geometrical interpretation of quantum information compression
Let S be the von Neumann entropy of a finite ensemble E of pure quantum
states. We show that S may be naturally viewed as a function of a set of
geometrical volumes in Hilbert space defined by the states and that S is
monotonically increasing in each of these variables. Since S is the Schumacher
compression limit of E, this monotonicity property suggests a geometrical
interpretation of the quantum redundancy involved in the compression process.
It provides clarification of previous work in which it was shown that S may be
increased while increasing the overlap of each pair of states in the ensemble.
As a byproduct, our mathematical techniques also provide a new interpretation
of the subentropy of E.Comment: 11 pages, latex2
Triplanar Model for the Gap and Penetration Depth in YBCO
YBaCuO_7 is a trilayer material with a unit cell consisting of a CuO_2
bilayer with a CuO plane of chains in between. Starting with a model of
isolated planes coupled through a transverse matrix element, we consider the
possibility of intra as well as interplane pairing within a nearly
antiferromagnetic Fermi liquid model. Solutions of a set of three coupled BCS
equations for the gap exhibit orthorhombic symmetry with s- as well as d-wave
contributions. The temperature dependence and a-b in plane anisotropy of the
resulting penetration depth is discussed and compared with experiment.Comment: To appear in Physical Review B1 01Mar97; 12 pages with 10 figures;
RevTeX+eps
An investigation of the pedology of Upper Weardale, co Durham
This thesis presents the results of a character study of the soils of Upper Weardale, Co; Durham. Part 1 presents relevant material on the soil environment of the area, emphasising the important characteristics of parent materials, relief, climate and ecology. The results of the field and laboratory investigations are summarised in the form of assoil map of the area on a scale of 2(^1)/(_2)" to one mile and in the Appendix, which presents the results of detailed field and laboratory analyses of specific profiles. The bulk of Part 2 is concerned, with discussions on the origin and properties of the different types of soil. Field and analytical characteristics are use' to assess as far as is possible with existing information, the dynamics of past and present pedogenic processes in the soil profiles. Throughout the discussions, problems of classification and interpretation are highlighted, and avenues for future research emphasised
A spectral method for elliptic equations: the Dirichlet problem
An elliptic partial differential equation Lu=f with a zero Dirichlet boundary
condition is converted to an equivalent elliptic equation on the unit ball. A
spectral Galerkin method is applied to the reformulated problem, using
multivariate polynomials as the approximants. For a smooth boundary and smooth
problem parameter functions, the method is proven to converge faster than any
power of 1/n with n the degree of the approximate Galerkin solution. Examples
in two and three variables are given as numerical illustrations. Empirically,
the condition number of the associated linear system increases like O(N), with
N the order of the linear system.Comment: This is latex with the standard article style, produced using
Scientific Workplace in a portable format. The paper is 22 pages in length
with 8 figure
Volume estimates for equiangular hyperbolic Coxeter polyhedra
An equiangular hyperbolic Coxeter polyhedron is a hyperbolic polyhedron where
all dihedral angles are equal to \pi/n for some fixed integer n at least 2. It
is a consequence of Andreev's theorem that either n=3 and the polyhedron has
all ideal vertices or that n=2. Volume estimates are given for all equiangular
hyperbolic Coxeter polyhedra.Comment: 27 pages, 11 figures; corrected typo in Theorem 2.
Empirical modelling and simulation of transmission loss between wireless sensor nodes in gas turbine engines
Transmission loss measurements between a grid of hypothetical WSN node locations on the surface of a gas turbine engine are reported for eight frequencies at 1 GHz intervals in the frequency range 3.0 to 11.0 GHz. An empirical transmission loss model is derived from the measurements. The model is incorporated into an existing system channel model implemented using Simulink as part of a wider project concerning the development of WSNs for the testing and condition monitoring of gas turbine engines
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