Potential application of artificial concepts to aerodynamic simulation

The concept of artificial intelligence as it applies to computational fluid dynamics simulation is investigated. How expert systems can be adapted to speed the numerical aerodynamic simulation process is also examined. A proposed expert grid generation system is briefly described which, given flow parameters, configuration geometry, and simulation constraints, uses knowledge about the discretization process to determine grid point coordinates, computational surface information, and zonal interface parameters

Using formal concept analysis to detect and monitor organised crime

This paper describes some possible uses of Formal Concept Analysis in the detection and monitoring of Organised Crime. After describing FCA and its mathematical basis, the paper suggests, with some simple examples, ways in which FCA and some of its related disciplines can be applied to this problem domain. In particular, the paper proposes FCA-based approaches for finding multiple instances of an activity associated with Organised Crime, finding dependencies between Organised Crime attributes, and finding new indicators of Organised Crime from the analysis of existing data. The paper concludes by suggesting that these approaches will culminate in the creation and implementation of an Organised Crime ‘threat score card’, as part of an overall environmental scanning system that is being developed by the new European ePOOLICE projec

Spin-charge separation in ultra-cold quantum gases

We investigate the physical properties of quasi-1D quantum gases of fermion atoms confined in harmonic traps. Using the fact that for a homogeneous gas, the low energy properties are exactly described by a Luttinger model, we analyze the nature and manifestations of the spin-charge separation. Finally we discuss the necessary physical conditions and experimental limitations confronting possible experimental implementations.Comment: 4 pages, revtex4, 2 eps figure

Stepped spillway model pressures characteristics, Susu Dam Malaysia

Susu Dam is an RCC Dam under construction in Peninsula Malaysia. The dam design has been carried out by SMEC International in its offices in Kuala Lumpur. The dam is some 90 m tall. The overfall stepped spillway provides for discharges to enter a hydraulic jump stilling basin for energy dissipation, prior to passing through a culvert under a roadway. The spillway was subject to hydraulic model testing at the Utah Water Research Laboratory of Utah State University (USA), at a length scale of 1:30. The hydraulic performance of the spillway design was evaluated up to the 4,700 m3/s Probable Maximum Flood (PMF) discharge (almost 1,000 L/s model scale). The spillway was tested through a number of configurations, prior to the development of the final arrangement. The purpose of the paper is to describe the modelling detail, and then focus on the flow behaviour at the stair-stepped spillway chute with 2.4 m high steps, in particular the piezometric pressures and transient pressures on the tread and riser of the steps. The spillway chute converged from ~100 m at the crest to 78 m at the bottom at entrance to the stilling basin; the unit discharge entering the stilling basin was ~ 60 m2/s for the PMF. Of particular interest was the occurrence of negative pressures on the steps, and the paper will describe the transients for several discharges from the AEP 1 in 1,000 up to the PMF; the results indicating very low pressures into a cavitation region. The design provides for an aerator across the spillway in order to counter the effects of possible cavitation. Results will be presented with and without the aerator operating. The paper provides useful design information for the hydraulic design of stepped spillways

Ultracool white dwarfs and the age of the Galactic disc

We present parallax observations and a detailed model atmosphere analysis of 54 cool and ultracool ($T_{\rm eff}$ < 4000 K) white dwarfs (WDs) in the solar neighbourhood. For the first time, a large number of cool and ultracool WDs have distance and tangential velocities measurements available. Our targets have distances ranging from 21 pc to >100 pc, and include five stars within 30 pc. Contrary to expectations, all but two of them have tangential velocities smaller than 150 km s$^{-1}$ thus suggesting Galactic disc membership. The oldest WDs in this sample have WD cooling ages of 10 Gyr, providing a firm lower limit to the age of the thick disc population. Many of our targets have uncharacteristically large radii, indicating that they are low mass WDs. It appears that we have detected the brighter population of cool and ultracool WDs near the Sun. The fainter population of ultracool CO-core WDs remain to be discovered in large numbers. The Large Synoptic Survey Telescope should find these elusive, more massive ultracool WDs in the solar neighbourhood.Comment: 16 pages, 11 figures, 4 tables, accepted for publication in MNRA