15 research outputs found
16 tons of petition-data mining in the on-line administration system of the University of Szeged : [absztrakt]
Környezeti folyamatok modellezése "Soft Computing" módszerekkel = Modeling of environmental processes by soft computing methods
A környezeti folyamatok összetettsĂ©ge, Ă©s nemlineáris volta miatt tanulmányozásukhoz adekvát modellek szĂĽksĂ©gesek. Az Ăşn. soft computing mĂłdszerek (rács alapĂş celluláris neurális hálĂłzatok, sejtautomaták Ă©s fuzzy szabályok) a környezeti folyamatok modellezĂ©sĂ©nek ĂgĂ©retes eszközei [8, 19]. LĂ©trehoztunk egy általános celluláris neuronhálĂłzat (CNN) modellt szennyezĹ‘dĂ©sek terjedĂ©sĂ©nek vizsgálatára [1, 5, 10, 20], amely alapját kĂ©pezheti egy hatĂ©kony döntĂ©stámogatĂł rendszer lĂ©trehozásának. A rendszer finomĂtása Ă©rdekĂ©ben a környezeti rendszer egyes komponenseiben zajlĂł folyamatokat is megvizsgáltuk, hangsĂşlyt fektetve a folyadĂ©k Ă©s gázáramlás áramlás modelljeire [6, 7, 23]. Vizsgálatukhoz közelĂtĹ‘ numerikus mĂłdszereket fejlesztetĂĽnk [5, 16, 17, 25] Megvizsgáltuk a zavarás (Ă©lĹ‘hely vesztĂ©s Ă©s invázĂv fajok) hatását a populáciĂł szintű folyamatokra sejtautomata modellek Ă©s szimuláciĂłk segĂtsĂ©gĂ©vel. Kimutattuk, hogy az Ă©lĹ‘helyek számának csökkenĂ©sĂ©vel az invázĂv (gyom jellegű) fajok elĹ‘nyösebb helyzetbe kerĂĽlnek [4]. KiderĂĽlt, hogy az invázĂv fajok visszaszorĂtásának sikeressĂ©ge a kolonizáciĂłs kĂ©pessĂ©gĂĽk visszaszorĂtásán mĂşlik Ă©s fĂĽgg a tĂ©rbeli aggregáciĂłtĂłl [2, 3, 14, 18, 21, 24]. AlkalmazáskĂ©nt sor kerĂĽlt egy fejlett numerikus szimuláciĂłs technolĂłgiákra Ă©pĂĽlĹ‘ informatikai rendszer prototĂpusának megalkotására, amely tetszĹ‘leges ĂşthálĂłzatok gĂ©pjárműforgalmának, Ă©s a társult környezeti terhelĂ©s eloszlásának számĂtĂłgĂ©pes modellezĂ©sĂ©re használhatĂł. | Studying environmental processes requires adequate models, because of their high level of complexity and nonlinearity. Soft computing methods (such as cellular neural networks, cellular automata and fuzzy rules) provide reliable tools of modeling environmental systems [8, 19]. We have created a general model of cellular neural network (CNN) in order to investigate the propagation of pollutions [1, 5, 10, 20]. Effective decision support systems can be constructed on the base of this model. Processes in the particular components of the environmental system were also studied, in particular models of liquid and gas flow [6, 7, 23]. New numerical methods have been developed for their investigation [5, 16, 17, 25]. The effect of disturbance (such as habitat destruction and invasive species) on population level processes has been investigated with the help of cellular automaton models and simulations. We have demonstrated that decreasing number of habitats promotes invasive (weed) species [4]. As it turned out, the success of eradication of invasive species depends mainly on depression of colonization ability and also depends on spatial aggregation of species [2, 3, 14, 18, 21, 24]. As a particular application, a prototype of an advanced simulation technology-based IT system has been created. It is reliable to model the distribution of environmental pollution over an arbitrary road-system with traffic
Characterization of the microstructure of tin-silver lead free solder
Reliability and lifetime are the two most relevant design considerations in the production
of safety critical assemblies. For example in a modern automobile dozens of electronic assemblies
are integrated in which thousands of solder joints are mounting the
electronic components to the
printed circuit boards. There
exists no standardised and universal observation method
for
characterising the fine micro
structure of such solder joints.
Previously we have developed a new
method for the quantitative characteriz
ation of lead
-
free solder alloys and in
present study the
validity of the proposed method is demonstrated.
M
icrostructure of Sn
-
3.5Ag lead free solder alloy
was investigated by electrochemical impedance spectroscopy.
Solder samples were solidified with
dif
ferent cooling rates in order to induce differences in the microstructure.
M
icrostructure of the
ingots was revealed by selective electrochemical etching. Electrochemical impedance spectr
a (EIS)
were
measured before and after
the
selective etching process.
The complex impedance
spectra
contain
information about microstructure of the solder alloys.
Comparison and mode
l
ling
of two
EIS spectra allowed
obtaining
a
characteristic parameter of
surface structure of the etched
specimens.
The EIS measurements were c
omplemented with small angle neutron scattering
measurements
and scanning electron microscopy
, in order to correlate the EIS parameter with the
magnitude of the interface of the
β
-
Sn and Ag
3
Sn
phases
ValĂłszĂnűsĂ©gszámĂtási problĂ©mák az oktatás támakörĂ©ben
A határĂ©rtĂ©k-tĂ©telek vizsgálatával eljuthatunk a szimmetrikus vĂ©letlen bolyongás tĂ©makörĂ©nek feltárásához. Ennek egyik reprezentánsa a fej vagy Ărás játĂ©k, mely szoros kapcsolatban áll a bolyongással. Ezt vizsgálom meg több pĂ©lda Ă©s szemlĂ©ltetĂ©s használatával.BscMatematika-Fizika tanárig