2,114 research outputs found
A Survey on Users' Perspectives to Functionalities of Web-Based Construction Collaboration Extranets
Construction collaboration extranets (CCEs) provide various functionalities depending on the vendors' origins, history, experiences, and financial status. Previous research has listed and described the functionalities that extranet systems can be capable of providing. However, no publication was found so far to systematically analyze users' perspectives to the provided functionalities. This article is to bridge this gap through a questionnaire survey to the users. It aims at examining user's attitude to functionalities of CCEs. The result may be useful to information system vendors, end-users and researchers involved in CCEs development and implementation
Normally Elliptic Singular Perturbations and Persistence of Homoclinic Orbits
We consider a dynamical system, possibly infinite dimensional or
non-autonomous, with fast and slow time scales which is oscillatory with high
frequencies in the fast directions. We first derive and justify the limit
system of the slow variables. Assuming a steady state persists, we construct
the stable, unstable, center-stable, center-unstable, and center manifolds of
the steady state of a size of order O(1) and give their leading order
approximations. Finally, using these tools, we study the persistence of
homoclinic solutions in this type of normally elliptic singular perturbation
problems
Nonequilibrium Green's function approach to mesoscopic thermal transport
We present a formulation of a nonequilibrium Green's function method for
thermal current in nanojunction atomic systems with nonlinear interactions.
This first-principle approach is applied to the calculation of the thermal
conductance in carbon nanotube junctions. It is shown that nonlinearity already
becomes important at low temperatures. Nonlinear interactions greatly suppress
phonon transmission at room temperature. The peak of thermal conductance is
found to be around 400K, in good agreement with experiments. High-order phonon
scattering processes are important for diffusive heat transport.Comment: 4 pages, 4 figure
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