696 research outputs found
Responsibility modelling for civil emergency planning
This paper presents a new approach to analysing and understanding civil emergency planning based on the notion of responsibility modelling combined with HAZOPS-style analysis of information requirements. Our goal is to represent complex contingency plans so that they can be more readily understood, so that inconsistencies can be highlighted and vulnerabilities discovered. In this paper, we outline the framework for contingency planning in the United Kingdom and introduce the notion of responsibility models as a means of representing the key features of contingency plans. Using a case study of a flooding emergency, we illustrate our approach to responsibility modelling and suggest how it adds value to current textual contingency plans
Black holes and a scalar field in an expanding universe
We consider a model of an inhomogeneous universe including a massless scalar
field, where the inhomogeneity is assumed to consist of many black holes. This
model can be constructed by following Lindquist and Wheeler, which has already
been investigated without including scalar field to show that an averaged scale
factor coincides with that of the Friedmann model. In this work we construct
the inhomogeneous universe with an massless scalar field, where we assume that
the averaged scale factor and scalar field are given by those of the Friedmann
model including a scalar field. All of our calculations are carried out in the
framework of Brans-Dicke gravity. In constructing the model of an inhomogeneous
universe, we define the mass of a black hole in the Brans-Dicke expanding
universe which is equivalent to ADM mass if the mass evolves adiabatically, and
obtain an equation relating our mass to the averaged scalar field and scale
factor. As the results we find that the mass has an adiabatic time dependence
in a sufficiently late stage of the expansion of the universe, and that the
time dependence is qualitatively diffenrent according to the sign of the
curvature of the universe: the mass increases decelerating in the closed
universe case, is constant in the flat case and decreases decelerating in the
open case. It is also noted that the mass in the Einstein frame depends on
time. Our results that the mass has a time dependence should be retained even
in the general scalar-tensor gravitiy with a scalar field potential.
Furthermore, we discuss the relation of our results to the uniqueness theorem
of black hole spacetime and gravitational memory effect.Comment: 16 pages, 3 tables, 5 figure
Infection dynamics of two renal myxozoans in hatchery reared fry and juvenile Atlantic cod Gadus morhua L.
In order to study the infection dynamics of 2 renal myxozoans, Zschokkella hildae Auerbach, 1910 and Gadimyxa atlantica Køie, Karlsbakk and Nylund, 2007 in cultured Atlantic cod, Gadus morhua L. aged 3–19 months, a specific single-round PCR assay and a double-label in situ hybridization protocol were developed. The results demonstrated that the 2 myxozoans show spatial separation of their development with regard to spore formation inside the renal tubules versus the collecting ducts and ureters, as well as temporal separation with Z. hildae proliferating and developing spores only once the G. atlantica infection decreases, despite the presence of both myxozoans in the smallest fry studied. These results strongly suggest within-host competition of the 2 myxozoans with potential suppression of Z. hildae by G. atlantica until G. morhua acquires immunity against G. atlantica. The quantification of the G. atlantica infection inside the renal tubules before and after a 29-day experimental growth performance study using fry from hatcheries with differing filtration systems showed that the intensity of infection with G. atlantica seems to be controlled if prolonged exposure to the myxozoan transmission stages takes place from hatching onwards. Surprisingly, growth rates in the trial were inversely affected suggesting that G. atlantica does not negatively influence cod fry growth performance
Historical roots of Agile methods: where did “Agile thinking” come from?
The appearance of Agile methods has been the most noticeable change to software process thinking in the last fifteen years [16], but in fact many of the “Agile ideas” have been around since 70’s or even before. Many studies and reviews have been conducted about Agile methods which ascribe their emergence as a reaction against traditional methods. In this paper, we argue that although Agile methods are new as a whole, they have strong roots in the history of software engineering. In addition to the iterative and incremental approaches that have been in use since 1957 [21], people who criticised the traditional methods suggested alternative approaches which were actually Agile ideas such as the response to change, customer involvement, and working software over documentation. The authors of this paper believe that education about the history of Agile thinking will help to develop better understanding as well as promoting the use of Agile methods. We therefore present and discuss the reasons behind the development and introduction of Agile methods, as a reaction to traditional methods, as a result of people's experience, and in particular focusing on reusing ideas from histor
On the bicrossproduct structures for the family of algebras
It is shown that the family of deformed algebras has a different bicrossproduct
structure for each in analogy to the undeformed case.Comment: Latex2e file. 14 page
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Implementing a compliance manager
Many companies claim to adhere to standards for software project development. This is often used as a marketing tool when eliciting business. But how does the customer or project manager know that these standards are being completely and consistently applied in their projects? In the paper ’Managing Standards Compliance’, we identify this problem and describe a support environment to provide identification and correction of non-compliance to standards. This paper details the experiences gained while implementing such a tolerant support system
Graded contractions and bicrossproduct structure of deformed inhomogeneous algebras
A family of deformed Hopf algebras corresponding to the classical maximal
isometry algebras of zero-curvature N-dimensional spaces (the inhomogeneous
algebras iso(p,q), p+q=N, as well as some of their contractions) are shown to
have a bicrossproduct structure. This is done for both the algebra and, in a
low-dimensional example, for the (dual) group aspects of the deformation.Comment: LaTeX file, 20 pages. Trivial changes. To appear in J. Phys.
Generic competences for the IT knowledge workers: a study from the field.
Proceedings of: Third World Summit on the Knowledge Society (WSKS 2010), Corfu, Greece, September 22-24, 2010This paper aims to identify generic competency levels relevant to a particular kind of knowledge workers: software engineers. Based on previous works, and in particular in the description of a professional career, authors review of the literature related to the characterization of the labor force in the Software Engineering (SE) domain. Subsequently, using a quantitative analysis based on investigative surveys administered to a number of representative professionals, authors provide with a generic competency ladder adapted to the given career description.Publicad
Trigonometry of spacetimes: a new self-dual approach to a curvature/signature (in)dependent trigonometry
A new method to obtain trigonometry for the real spaces of constant curvature
and metric of any (even degenerate) signature is presented. The method
encapsulates trigonometry for all these spaces into a single basic
trigonometric group equation. This brings to its logical end the idea of an
absolute trigonometry, and provides equations which hold true for the nine
two-dimensional spaces of constant curvature and any signature. This family of
spaces includes both relativistic and non-relativistic homogeneous spacetimes;
therefore a complete discussion of trigonometry in the six de Sitter,
minkowskian, Newton--Hooke and galilean spacetimes follow as particular
instances of the general approach. Any equation previously known for the three
classical riemannian spaces also has a version for the remaining six
spacetimes; in most cases these equations are new. Distinctive traits of the
method are universality and self-duality: every equation is meaningful for the
nine spaces at once, and displays explicitly invariance under a duality
transformation relating the nine spaces. The derivation of the single basic
trigonometric equation at group level, its translation to a set of equations
(cosine, sine and dual cosine laws) and the natural apparition of angular and
lateral excesses, area and coarea are explicitly discussed in detail. The
exposition also aims to introduce the main ideas of this direct group
theoretical way to trigonometry, and may well provide a path to systematically
study trigonometry for any homogeneous symmetric space.Comment: 51 pages, LaTe
Contractions, deformations and curvature
The role of curvature in relation with Lie algebra contractions of the
pseudo-ortogonal algebras so(p,q) is fully described by considering some
associated symmetrical homogeneous spaces of constant curvature within a
Cayley-Klein framework. We show that a given Lie algebra contraction can be
interpreted geometrically as the zero-curvature limit of some underlying
homogeneous space with constant curvature. In particular, we study in detail
the contraction process for the three classical Riemannian spaces (spherical,
Euclidean, hyperbolic), three non-relativistic (Newtonian) spacetimes and three
relativistic ((anti-)de Sitter and Minkowskian) spacetimes. Next, from a
different perspective, we make use of quantum deformations of Lie algebras in
order to construct a family of spaces of non-constant curvature that can be
interpreted as deformations of the above nine spaces. In this framework, the
quantum deformation parameter is identified as the parameter that controls the
curvature of such "quantum" spaces.Comment: 17 pages. Based on the talk given in the Oberwolfach workshop:
Deformations and Contractions in Mathematics and Physics (Germany, january
2006) organized by M. de Montigny, A. Fialowski, S. Novikov and M.
Schlichenmaie
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