Linear Algebra Applications in 3D Computer Graphics

Linear Transformations, Homogenous Coordinates, World Matrix, Project Matrices, Normalized Device Coordinates, View Matri

Dust growth in molecular cloud envelopes: a numerical approach

Variations in the grain size distribution are to be expected in the interstellar medium (ISM) due to grain growth and destruction. In this work, we present a dust collision model to be implemented inside a magnetohydrodynamical (MHD) code that takes into account grain growth and shattering of charged dust grains of a given composition (silicate or graphite). We integrate this model in the MHD code Athena, and builds on a previous implementation of the dynamics of charged dust grains in the same code. To demonstrate the performance of this coagulation model, we study the variations in the grain size distribution of a single-sized population of dust with radius 0.05 $\mu$m inside several dust filaments formed during a 2D MHD simulation. We also consider a realistic dust distribution with sizes ranging from 50 \AA~to 0.25 $\mu$m and analyze both the variations in the size distribution for graphite and silicates, as well as of the far ultraviolet extinction curve. From the obtained results, we conclude that the methodology here presented, based on the MHD evolution of the equation of motion for a charged particle, is optimal for studying the coagulation of charged dust grains in a diffuse regime such as a molecular cloud envelope. Observationally, these variations in the dust size distribution are translated into variations in the far ultraviolet extinction curve, and they are mainly caused by small graphite dust grains.Comment: Accepted for publication in Ap

Materiality, affect, and space : dialogues with discursive social psychology

Peer reviewe

Materiality, affect, and space : dialogues with discursive social psychology

Peer reviewe

Derivation of Index Theorems by Localization of Path Integrals

We review the derivation of the Atiyah-Singer and Callias index theorems using the recently developed localization method to calculate exactly the relevant supersymmetric path integrals. (Talk given at the III International Conference on Mathematical Physics, String Theory and Quantum Gravity, Alushta, Ukraine, June 13-24, 1993)Comment: 11 pages in LaTeX, HU-TFT-93-3

Cooperative Behaviour of specific tasks in multi-agent systems and robot control using dynamic approach

In order to foster research and development in a multi-agent robotic environment three fundamental improvements on the robots need to be carried out: a) a very reliable and robot control which works at high speeds and a dynamic approach is described in this work; b) Cooperative behaviour is very important since without it there is no ball pass, and that is becoming more and more necessary; c) Upwards kick, since traditional horizontal kickers are already very common. Other improvements were carried out in the robots but due to lack of space in this paper are not described. This paper describes how these three issues were tackled by the MINHO team and shows their next directions

High accuracy navigation in unknown environment using adaptive control

Aiming to reduce cycle time and improving the accuracy on tracking, a modified adaptive control was developed, which adapts autonomously to changing dynamic parameters. The platform used is based on a robot with a vision based sensory system. Goal and obstacles angles are calculated relatively to robot orientation from image processing software. Autonomous robots are programmed to navigate in unknown and unstructured environments where there are multiple obstacles which can readily change their position. This approach underlies in dynamic attractor and repulsive forces. This theory uses differential equations that produce vector fields to control speed and direction of the robot. This new strategy was compared with existing PID method experimentally and it proved to be more effective in terms of behaviour and time-response. Calibration parameters used in PID control are in this case unnecessary. The experiments were carried out in robot Middle Size League football players built for RoboCup. Target pursuit, namely, ball, goal or any absolute position, was tested. Results showed high tracking accuracy and rapid response to moving targets. This dynamic control system enables a good balance between fast movements and smooth behaviour

Kohdennetut nanolääkkeet voivat muokata tulevaisuuden terveydenhoitoa

Kohdennettu nanolääke on nanokokoisen kantajahiukkasen ja lääkeainemolekyylin yhdistelmä. Tällaisten lääkkeiden etu tavanomaisiin lääkkeisiin nähden on se, että ne voivat kuljettaa lääkkeet oikeaan kudokseen tai soluun ja vapauttaa ne vasta siellä. Ideaaliset nanolääkkeet ovat yhteensopivia kudosten kanssa (bioyhteensopivia) ja biohajoavia. Ne voivat tunkeutua syvälle syöpäkudokseen ja niitä voidaan muokata siten, että ne kiinnittyvät vain tiettyihin kohdesoluihin. Ensimmäinen nanolääkesukupolvi on jo markkinoilla, ja seuraavia tutkitaan kliinisissä kokeissa.Kohdennettu nanolääke on nanokokoisen kantajahiukkasen ja lääkeainemolekyylin yhdistelmä. Tällaisten lääkkeiden etu tavanomaisiin lääkkeisiin nähden on se, että ne voivat kuljettaa lääkkeet oikeaan kudokseen tai soluun ja vapauttaa ne vasta siellä. Ideaaliset nanolääkkeet ovat yhteensopivia kudosten kanssa (bioyhteensopivia) ja biohajoavia. Ne voivat tunkeutua syvälle syöpäkudokseen ja niitä voidaan muokata siten, että ne kiinnittyvät vain tiettyihin kohdesoluihin. Ensimmäinen nanolääkesukupolvi on jo markkinoilla, ja seuraavia tutkitaan kliinisissä kokeissa.Peer reviewe