183 research outputs found
Application of support vector machines on the basis of the first Hungarian bankruptcy model
In our study we rely on a data mining procedure known as support vector machine (SVM) on the database of the first Hungarian bankruptcy model. The models constructed are then contrasted with the results of earlier bankruptcy models with the use of classification accuracy and the area under the ROC curve. In using the SVM technique, in addition to conventional kernel functions, we also examine the possibilities of applying the ANOVA kernel function and take a detailed look at data preparation tasks recommended in using the SVM method (handling of outliers). The results of the models assembled suggest that a significant improvement of classification accuracy can be achieved on the database of the first Hungarian bankruptcy model when using the SVM method as opposed to neural networks
The cultural and geopolitical dimensions of nation-building in the Ukraine
Ukraine belongs among those young countries where the beginnings of democratisation and nation-building approximately coincided. While the development of nation states in Central Europe was usually preceded by the development of nations, the biggest dilemma in the Ukraine is whether a nation-state programme — parallel to the aim of state-building — is able to bring unfinished nation-building to completion. Ukraine sways between the EU and Russia with enormous amplitude. The alternating orientation between the West and the East can be ascribed to superpower ambitions reaching beyond Ukraine. Eventually, internal and external determinants are intertwined and mutually interact with one another. The aim of the paper is to explain the dilemmas arising from identity problems behind the Ukraine’s internal and external orientation
Spectral density asymptotics for Gaussian and Laguerre -ensembles in the exponentially small region
The first two terms in the large asymptotic expansion of the
moment of the characteristic polynomial for the Gaussian and Laguerre
-ensembles are calculated. This is used to compute the asymptotic
expansion of the spectral density in these ensembles, in the exponentially
small region outside the leading support, up to terms . The leading form
of the right tail of the distribution of the largest eigenvalue is given by the
density in this regime. It is demonstrated that there is a scaling from this,
to the right tail asymptotics for the distribution of the largest eigenvalue at
the soft edge.Comment: 19 page
Integration of new and revised chronological data to constrain the terrace evolution of the Danube River (Gerecse Hills, Pannonian Basin)
Terrace ages deduced from diverse geochronological records yielded inconsistent data in the Danube valley in
Hungary. The problem of discrepancies in the different chronological datasets has to be resolved before the Quaternary
tectonic and climatic processes leading to valley incision and terrace formation may be properly evaluated.
To establish a more robust chronology of the Danube valley in Hungary, new cosmogenic nuclide- (10Be depth
profiles, 26Al/10Be burial durations and burial depth profile) and luminescence-based (pIRIR290) terrace ages
were acquired and compared to revised paleontological and published U/Th and magnetostratigraphic data. All
the applied geo-chronometers led to concordant terrace ages, with the exception of the U/Th method applied on
travertine deposits covering terraces. U/Th ages predating the last interglacial manifest a bias towards younger
ages, and so they were ignored in relation to the quantification of terrace ages. As a result, terrace ages from
the Late Pliocene to Late Pleistocene were settled. With regard to data from the Middle Pleistocene onwards, the
combination of diverse methodologies led to a tighter bracketing of terrace ages than would be possible using
a single dating method. The modelling of cosmogenic 26Al and 10Be concentrations enabled to derive surface
denudation rates and their combination with paleontological data also allowed us to decide between diverse
landscape evolution scenarios
Diclofenac Prolongs Repolarization in Ventricular Muscle with Impaired Repolarization Reserve
Background: The aim of the present work was to characterize the electrophysiological effects of the non-steroidal anti-
inflammatory drug diclofenac and to study the possible proarrhythmic potency of the drug in ventricular muscle.
Methods: Ion currents were recorded using voltage clamp technique in canine single ventricular cells and action potentials
were obtained from canine ventricular preparations using microelectrodes. The proarrhythmic potency of the drug was
investigated in an anaesthetized rabbit proarrhythmia model.
Results: Action potentials were slightly lengthened in ventricular muscle but were shortened in Purkinje fibers by diclofenac
(20 mM). The maximum upstroke velocity was decreased in both preparations. Larger repolarization prolongation was
observed when repolarization reserve was impaired by previous BaCl 2 application. Diclofenac (3 mg/kg) did not prolong
while dofetilide (25 mg/kg) significantly lengthened the QT c interval in anaesthetized rabbits. The addition of diclofenac
following reduction of repolarization reserve by dofetilide further prolonged QT c . Diclofenac alone did not induce Torsades
de Pointes ventricular tachycardia (TdP) while TdP incidence following dofetilide was 20%. However, the combination of
diclofenac and dofetilide significantly increased TdP incidence (62%). In single ventricular cells diclofenac (30 mM) decreased
the amplitude of rapid (I Kr ) and slow (I Ks ) delayed rectifier currents thereby attenuating repolarization reserve. L-type calcium
current (I Ca ) was slightly diminished, but the transient outward (I to ) and inward rectifier (I K1 ) potassium currents were not
influenced.
Conclusions: Diclofenac at therapeutic concentrations and even at high dose does not prolong repolarization markedly and
does not increase the risk of arrhythmia in normal heart. However, high dose diclofenac treatment may lengthen
repolarization and enhance proarrhythmic risk in hearts with reduced repolarization reserve
Zeros of the i.i.d. Gaussian power series: a conformally invariant determinantal process
Consider the zero set of the random power series f(z)=sum a_n z^n with i.i.d.
complex Gaussian coefficients a_n. We show that these zeros form a
determinantal process: more precisely, their joint intensity can be written as
a minor of the Bergman kernel. We show that the number of zeros of f in a disk
of radius r about the origin has the same distribution as the sum of
independent {0,1}-valued random variables X_k, where P(X_k=1)=r^{2k}. Moreover,
the set of absolute values of the zeros of f has the same distribution as the
set {U_k^{1/2k}} where the U_k are i.i.d. random variables uniform in [0,1].
The repulsion between zeros can be studied via a dynamic version where the
coefficients perform Brownian motion; we show that this dynamics is conformally
invariant.Comment: 37 pages, 2 figures, updated proof
Magyar nyelvű időjárásjelentések nyelvi modell alapú automatizált generálása
Tanulmányunkban bemutatjuk egy olyan eszköz első változatát, amely képes az Országos Meteorológiai Szolgálat adatai alapján magyar nyelvű időjárásjelentések automatizált megírására. Az eszköz első lépésben egy szabályalapú rendszerben a nyers numerikus adatokból előállít egy listát a várható időjárási eseményekről, majd ezen listából az OpenAI GPT-3 nyelvi modelljére támaszkodva a megfelelő paraméterezés mellett kigenerál egy angol nyelvű időjárásjelentést, amit a DeepL Translate szolgáltatással magyar nyelvűre fordít. A kapott időjárásjelentések kifejezetten magas, 4 feletti értékelést kaptak a tesztelés során (1-5 skála) nyelvhelyesség, stílus és koherencia dimenziókban
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