3,713 research outputs found
Comment on: Reply to comment on `Perfect imaging without negative refraction'
Whether or not perfect imaging is obtained in the mirrored version of
Maxwell's fisheye lens is debated in the comment/reply sequence
[Blaikie-2010njp, Leonhardt-2010njp] discussing Leonhardt's original paper
[Leonhardt-2009njp]. Here we show that causal solutions can be obtained without
the need for an "active localized drain", contrary to the claims in
[Leonhardt-2010njp].Comment: v2 (added MEEP ctl file), v3 (publisher statement
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AQUAS: A project to bridge the gaps between safety and security processes
Four Poynting Theorems
The Poynting vector is an invaluable tool for analysing electromagnetic
problems. However, even a rigorous stress-energy tensor approach can still
leave us with the question: is it best defined as \Vec{E} \cross \Vec{H} or
as \Vec{D} \cross \Vec{B}? Typical electromagnetic treatments provide yet
another perspective: they regard \Vec{E} \cross \Vec{B} as the appropriate
definition, because \Vec{E} and \Vec{B} are taken to be the fundamental
electromagnetic fields. The astute reader will even notice the fourth possible
combination of fields: i.e. \Vec{D} \cross \Vec{H}. Faced with this diverse
selection, we have decided to treat each possible flux vector on its merits,
deriving its associated energy continuity equation but applying minimal
restrictions to the allowed host media. We then discuss each form, and how it
represents the response of the medium. Finally, we derive a propagation
equation for each flux vector using a directional fields approach; a useful
result which enables further interpretation of each flux and its interaction
with the medium.Comment: 8 pages. Updated slightly from EJP versio
Business Value Is not only Dollars - Results from Case Study Research on Agile Software Projects
Business value is a key concept in agile software development. This paper presents results of a case study on how business value and its creation is perceived in the context of agile projects. Our overall conclusion is that the project participants almost never use an explicit and structured approach to guide the value creation throughout the project. Still, the application of agile methods in the studied cases leads to satisfied clients. An interesting result of the study represents the fact that the agile process of many projects differs significantly from what is described in the agile practitioners’ books as best practices. The key implication for research and practice is that we have an incentive to pursue the study of value creation in agile projects and to complement it by providing guidelines for better client’s involvement, as well as by developing structured methods that will enhance the value-creation in a project
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