246 research outputs found
Industrial ecology Prosperity Game{trademark}
Industrial ecology (IE) is an emerging scientific field that views industrial activities and the environment as an interactive whole. The IE approach simultaneously optimizes activities with respect to cost, performance, and environmental impact. Industrial Ecology provides a dynamic systems-based framework that enables management of human activity on a sustainable basis by: minimizing energy and materials usage; insuring acceptable quality of life for people; minimizing the ecological impact of human activity to levels that natural systems can sustain; and maintaining the economic viability of systems for industry, trade and commerce. Industrial ecology applies systems science to industrial systems, defining the system boundary to incorporate the natural world. Its overall goal is to optimize industrial activities within the constraints imposed by ecological viability, globally and locally. In this context, Industrial systems applies not just to private sector manufacturing and services but also to government operations, including provision of infrastructure. Sandia conducted its seventeenth Prosperity Game{trademark} on May 23--25, 1997, at the Hyatt Dulles Hotel in Herndon, Virginia. The primary sponsors of the event were Sandia National Laboratories and Los Alamos National Laboratory, who were interested in using the format of a Prosperity Game to address some of the issues surrounding Industrial Ecology. Honorary game sponsors were: The National Science Foundation; the Committee on Environmental Improvement, American Chemical Society; the Industrial and Engineering Chemistry Division, American Chemical Society; the US EPA--The Smart Growth Network, Office of Policy Development; and the US DOE-Center of Excellence for Sustainable Development
The Theory of the Hydrogen Molecule Ion, Scalar Beams, and Scattering by Spheroids
Schrodinger's equation for the hydrogen molecule ion and the Helmholtz
equation are separable in prolate and oblate spheroidal coordinates respectively.
They share the same form of the angular equation. The first task
in deriving the ground state energy of the hydrogen molecule ion, and
in obtaining finite solutions of the Helmholtz equation, is to obtain the
physically allowed values of the separation of variables parameter. The
separation parameter is not known analytically, and since it can only have
certain values, it is an important parameter to quantify. Chapter 2 of this
thesis investigates an exact method of obtaining the separation parameter.
By showing that the angular equation is solvable in terms of confluent Heun
functions, a new method to obtain the separation parameter was obtained.
We showed that the physically allowed values of the separation of variables
parameter are given by the zeros of the Wronskian of two linearly dependent
solutions to the angular equation. Since the Heun functions are implemented
in Maple, this new method allows the separation parameter to be calculated
to unlimited precision.
As Schrodinger's equation for the hydrogen molecule ion is related to
Helmholtz's equation, this warranted investigation of scalar beams. Tightly
focused optical and quantum particle beams are described by exact solutions
of the Helmholtz equation. In Chapter 3 of this thesis we investigate the
applicability of the separable spheroidal solutions of the scalar Helmholtz
equation as physical beam solutions. By requiring a scalar beam solution
to satisfy certain physical constraints, we showed that the oblate spheroidal
wave functions can only represent nonparaxial scalar beams when the angular
function is odd, in terms of the angular variable. This condition ensures the
convergence of integrals of physical quantities over a cross-section of the beam
and allows for the physically necessary discontinuity in phase at z = 0 on
the ellipsoidal surfaces of otherwise constant phase. However, these solutions
were shown to have a discontinuous longitudinal derivative.
Finally, we investigated the scattering of scalar waves by oblate and
prolate spheroids whose symmetry axis is coincident with the direction of the
incident plane wave. We developed a phase shift formulation of scattering
by oblate and prolate spheroids, in parallel with the partial wave theory of
scattering by spherical obstacles. The crucial step was application of a finite
Legendre transform to the Helmholtz equation in spheroidal coordinates.
Analytical results were readily obtained for scattering of Schrodinger particle
waves by impenetrable spheroids and for scattering of sound waves by
acoustically soft spheroids. The advantage of this theory is that it enables
all that can be done for scattering by spherical obstacles to be carried over
to the scattering by spheroids, provided the radial eigenfunctions are known
Consistency and trends of technological innovations: a network approach to the international patent classification data
Classifying patents by the technology areas they pertain is important to enable information search and facilitate policy analysis and socio-economic studies. Based on the OECD Triadic Patent Family database, this study constructs a cohort network based on the grouping of IPC subclasses in the same patent families, and a citation network based on citations between subclasses of patent families citing each other. This paper presents a systematic analysis approach which obtains naturally formed network clusters identified using a Lumped Markov Chain method, extracts community keys traceable over time, and investigates two important community characteristics: consistency and changing trends. The results are verified against several other methods, including a recent research measuring patent text similarity. The proposed method contributes to the literature a network-based approach to study the endogenous community properties of an exogenously devised classification system. The application of this method may improve accuracy and efficiency of the IPC search platform and help detect the emergence of new technologies
Knowledge Integration and Diffusion: Measures and Mapping of Diversity and Coherence
I present a framework based on the concepts of diversity and coherence for
the analysis of knowledge integration and diffusion. Visualisations that help
understand insights gained are also introduced. The key novelty offered by this
framework compared to previous approaches is the inclusion of cognitive
distance (or proximity) between the categories that characterise the body of
knowledge under study. I briefly discuss the different methods to map the
cognitive dimension
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