In the generic CDM cosmogony, dark-matter halos emerge too lumpy and centrally concentrated to host observed galactic disks. Moreover, disks are predicted to be smaller than those observed. We argue that the resolution of these problems may lie with a combination of the effects of protogalactic disks which would have had a mass comparable to that of the inner dark halo and be plausibly non-axis...

Isolated barred galaxies evolve by redistributing their internal angular momentum, which is emitted mainly at the inner disc resonances and absorbed mainly at the resonances in the outer disc and the halo. This causes the bar to grow stronger and its pattern speed to decrease with time. A massive, responsive halo enhances this process. I show correlations and trends between the angular momentum...

Knowledge discover in Data bases (KDD) concerns the development of models which allow the representation and organization of the knowledge hidden in data. Machine learning systems are an alternative to automate the KDD process. In particular, incremental concept formation systems construct hierarchical abstract representations from observations (non-classified description of specific entities, ...

In this paper we present a conceptual data model, called SDM, which is able to represent the relationships between elementary and statistical data at a conceptual level. SDM borrows elements from research both in Object Oriented Databases and in Knowledge Representation. In addition it has suitable mechanisms to form classes of individuals by classifying the instances of a target class accordin...

The tightness of the observed colour-magnitude and Mg2velocity dispersion relations for elliptical galaxies has often been cited as an argument against a picture in which ellipticals form by the merging of spiral disks. A common view is that merging would mix together stars of disparate ages and produce a large scatter in these relations. Here I use semi-analytic models of galaxy formation to d...

Abstract Towards addressing ontological issues in design cognition research, this paper presents the first generic classification of cognitive processes investigated in protocol studies on conceptual design cognition. The classification is based on a systematic review of 47 studies published over the past 30 years. Three viewpoints on the nature of design cognition are outlined (search, explora...

for last years, the evolution of new issues has incited a great development of the transportation system. in this paper, we discuss ingredients of its (intelligent transportation system) that are inter-vehicle communication (ivc) or what can call vehicular ad hoc networks (vanet), which are special type of manet. we will survey the main issues relevant to vanet in detail with providing a concep...

Semantic Web documents that encode facts about entities on the Web have been growing rapidly in size and evolving over time. Creating summaries on lengthy Semantic Web documents for quick identification of the corresponding entity has been of great contemporary interest. In this paper, we explore automatic summarization techniques that characterize and enable identification of an entity and cre...

It has been argued in light of concessions made at Bonn and Marrakech, the market for Clean Development Mechanism (CDM) projects will be small compared to greenhouse gas (GHG) emissions in developing countries and that it will be characterised by low demand and low prices. This paper examines these arguments in the context of India and the likely nature and extent of India’s involvement in CDM ...

We derive inner dark matter halo density profile slopes for a sample of 200 dwarf galaxies by inverting rotation curves obtained from high-quality, long-slit optical spectra. Using simulations to assess the impact of long-slit observing and data processing errors on our measurements, we conclude that our observations are consistent with the cuspy halos predicted by the CDM paradigm.