20,522 research outputs found
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Artificial intelligence makes computers lazy
This paper looks at the age-old problem of trying to instil some degree of intelligence in computers. Genetic Algorithms (GA) and Genetic Programming (GP) are techniques that are used to evolve a solution to a problem using processes that mimic natural evolution. This paper reflects on the experience gained while conducting research applying GA and GP to two quite different problems: Medical Diagnosis and Robot Path Planning. An observation is made that when these algorithms are not applied correctly the computer seemingly exhibits lazy behaviour, arriving at a suboptimal solutions. Using examples, this paper shows how this 'lazy' behaviour can be overcome
Airborne lidar observations of Arctic polar stratospheric clouds
Polar stratospheric clouds (PSC's) have been detected repeatedly during Arctic and Antarctic winters since 1978/1979 by the SAM II (Stratospheric Aerosol Measurement II) instrument aboard the NIMBUS-7 satellite. PSC's are believed to form when supercooled sulfuric acid droplets freeze, and subsequently grow by deposition of ambient water vapor as the local stratospheric temperature falls below the frost point. In order to study the characteristics of PSC's at higher spatial and temporal resolution than that possible from the satellite observations, aircraft missions were conducted within the Arctic polar night vortex in Jan. 1984 and Jan. 1986 using the NASA Langley Research Center airborne dual polarization ruby lidar system. A synopsis of the 1984 and 1986 PSC observations is presented illustrating short range spatial changes in cloud structure, the variation of backscatter ratio with temperature, and the depolarization characterics of cloud layers. Implications are noted with regard to PSC particle characteristics and the physical process by which the clouds are thougth to form
Triplet Superconductors from the Viewpoint of Basic Elements for Quantum Computers
We discuss possibilities of utilizing superconductors with Cooper condensates
in triplet pairing states (where the spin of condensate pairs is S=1) for
practical realization of quantum computers. Superconductors with triplet
pairing condensates have features that are unique and cannot be found in the
usual (singlet pairing, S=0) superconductors. The symmetry of the order
parameter in some triplet superconductors (e.g., ruthenates) corresponds to
doubly-degenerate chiral states. These states can serve as qubit base states
for quantum computing.Comment: 4 pages, 5 figures, will be presented at ASC-2002 and submitted to
IEEE Trans. Appl. Supercon
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The use of IT to increase nutritional awareness in young children
It has been well documented that obesity amongst young children is on the increase. By the age of 5 the levels of obesity is alarming and is much greater than expected in comparison to the national standards. To address this problem an overall health programme is required encompassing healthy eating and physical activity. However, a radical change of this nature has not shown any long-term benefits and can result in a negative attitude from the child. Therefore, more subtle ways of increasing awareness in children about healthy eating were thought to be the key. Since children are spending an increasing amount of their free time playing computer games it was thought that this would be a good way of introducing them to healthy eating. Therefore, a prototype system is developed and tested to identify whether IT can be used to raise nutritional awareness in young children. The results show that the increase is marginal but the system did encourage discussion about the effects of food amongst a group of children aged between 4-5
Theory of phaselock techniques as applied to aerospace transponders
Phaselock techniques as applied to aerospace transponder
X-Ray Eclipse Timing in the LMXB EXO0748-676
Orbital period changes are an important diagnostic for understanding low mass
X-ray binary (LMXB) accretion-induced angular momentum exchange and overall
system evolution. We present our most recent results for the eclipse timing of
the LMXB EXO0748-676. Since its discovery in 1985 it has apparently undergone
three distinct orbital period "epochs", each characterized by a different
orbital period than the previous epoch. We outline the orbital period behavior
for EXO0748-676 over the past 18 years and discuss the implications of this
behavior in light of current theoretical ideas for LMXB evolution.Comment: 4 Pages, 3 Figures, Submitted to the X-Ray Timing 2003: Rossi and
Beyond conference, November 200
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