74 research outputs found

    The existence of an inverse limit of inverse system of measure spaces - a purely measurable case

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    The existence of an inverse limit of an inverse system of (probability) measure spaces has been investigated since the very beginning of the birth of the modern probability theory. Results from Kolmogorov [10], Bochner [2], Choksi [5], Metivier [14], Bourbaki [3] among others have paved the way of the deep understanding of the problem under consideration. All the above results, however, call for some topological concepts, or at least ones which are closely related topological ones. In this paper we investigate purely measurable inverse systems of (probability) measure spaces, and give a sucient condition for the existence of a unique inverse limit. An example for the considered purely measurable inverse systems of (probability) measure spaces is also given

    Statistical mechanics of spatial evolutionary games

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    We discuss the long-run behavior of stochastic dynamics of many interacting players in spatial evolutionary games. In particular, we investigate the effect of the number of players and the noise level on the stochastic stability of Nash equilibria. We discuss similarities and differences between systems of interacting players maximizing their individual payoffs and particles minimizing their interaction energy. We use concepts and techniques of statistical mechanics to study game-theoretic models. In order to obtain results in the case of the so-called potential games, we analyze the thermodynamic limit of the appropriate models of interacting particles.Comment: 19 pages, to appear in J. Phys.

    Production Technology and Competitiveness In the Hungarian Manufacturing Industry

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    Following the big transformations of the 1990s, enterprise structure and technological level seem to have become stabilised in Hungary. Under these circumstances it is especially interesting to identify the elements responsible for competitiveness in general, and the role technology plays in development in particular, according to managers experienced in production and marketing. This empirical study – based on in-depth interviews and field research – summarises characteristics of the technological level in the sectors examined, role of technology and labour in production, effects of foreign direct investment, relations between competition and firm-level factors determining competitiveness, and concludes by summing up those most frequently mentioned proposals that should be incorporated into economic policy according to managers. Main findings indicate that more qualified, more intensive and cheaper labour can be substituted for high technology. The competitiveness of an enterprise is not determined by technology alone, but rather by a combination of technology, the parameters of available labour and the costs of investment increasing productivity. The insufficiency of inter-company relations, together with a shortage of available assets necessary for investment constitute the major threat undermining the competitiveness of enterprises in present-day Hungary

    Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

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    A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index) and sensor response are discussed

    Application of spatio-temporal data in site-specific maize yield prediction with machine learning methods

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    In order to meet the requirements of sustainability and to determine yield drivers and limiting factors, it is now more likely that traditional yield modelling will be carried out using artificial intelligence (AI). The aim of this study was to predict maize yields using AI that uses spatio-temporal training data. The paper has advanced a new method of maize yield prediction, which is based on spatio-temporal data mining. To find the best solution, various models were used: counter-propagation artificial neural networks (CP-ANNs), XY-fused Querynetworks (XY-Fs), supervised Kohonen networks (SKNs), neural networks with Rectangular Linear Activations (ReLU), extreme gradient boosting (XGBoost), support-vector machine (SVM), and different subsets of the independent variables in five vegetation periods. Input variables for modelling included: soil parameters (pH, P2O5, K2O, Zn, clay content, ECa, draught force, Cone index), micro-relief averages, and meteorological parameters for the 63 treatment units in a 15.3 ha research field. The best performing method (XGBoost) reached 92.1% and 95.3% accuracy on the training and the test sets. Additionally, a novel method was introduced to treat individual units in a lattice system. The lattice-based smoothing performed an additional increase in Area under the curve (AUC) to 97.5% over the individual predictions of the XGBoost model. The models were developed using 48 different subsets of variables to determine which variables consistently contributed to prediction accuracy. By comparing the resulting models, it was shown that the best regression model was Extreme Gradient Boosting Trees, with 92.1% accuracy (on the training set). In addition, the method calculates the influence of the spatial distribution of site-specific soil fertility on maize grain yields. This paper provides a new method of spatio-temporal data analyses, taking the most important influencing factors on maize yields into account

    The Gifted and Gifted Education in Hungary

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    The real challenge is to see value that is not yet in its true form. Becoming gifted is a process, during which characteristics of giftedness are present throughout, but not necessarily in a form perceptible or acceptable to the environment. Giftedness does not hide itself, only to the extent that the environment believes it hidden. Perception defines the pattern that manifests itself. The beginning of the 20th century is a success story of Hungarian gifted education. Outstanding teachers and their students have reached outstanding achievements through gifted education linked to everyday education. Their methods and ideas are durable, and are therefore worth recalling

    Radiative-capture cross sections for the La139(n,γ) reaction using thermal neutrons and structural properties of La140

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    A set of prompt partial γ-ray production cross sections from thermal neutron capture were measured for the 139La (n,γ) reaction using a guided beam of subthermal (thermal and cold) neutrons incident on a nat La2O3 target at the Prompt Gamma Activation Analysis facility of the Budapest Research Reactor. Absolute 140La cross sections were determined relative to the well-known comparator 35Cl(n,γ) cross sections from the irradiation of a stoichiometric nat LaCl3 sample. The total cross section for radiative thermal neutron capture on 139La from the sum of experimentally measured cross sections observed to directly feed the 140 La ground state was determined to be σ0 = 8.58(50) b. To assess completeness of the decay scheme and as a consistency check, the measured cross sections for transitions feeding the ground state from levels below a critical energy of Ec = 285 keV were combined with a modeled contribution accounting for ground-state feeding from the quasi continuum to arrive at a total cross section of σ0 = 9.36(74) b. In addition, a neutron-separation energy of Sn = 5161.001(21) keV was determined from a least-squares fit of the measured primary γ-ray energies to the low-lying levels of the 140La decay scheme. Furthermore, several nuclear structure improvements are proposed for the decay scheme. The measured cross-section and separation-energy results are comparable to earlier measurements of these quantities

    Muscle Fiber Viability, a Novel Method for the Fast Detection of Ischemic Muscle Injury in Rats

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    Acute lower extremity ischemia is a limb- and life-threatening clinical problem. Rapid detection of the degree of injury is crucial, however at present there are no exact diagnostic tests available to achieve this purpose. Our goal was to examine a novel technique - which has the potential to accurately assess the degree of ischemic muscle injury within a short period of time - in a clinically relevant rodent model. Male Wistar rats were exposed to 4, 6, 8 and 9 hours of bilateral lower limb ischemia induced by the occlusion of the infrarenal aorta. Additional animals underwent 8 and 9 hours of ischemia followed by 2 hours of reperfusion to examine the effects of revascularization. Muscle samples were collected from the left anterior tibial muscle for viability assessment. The degree of muscle damage (muscle fiber viability) was assessed by morphometric evaluation of NADH-tetrazolium reductase reaction on frozen sections. Right hind limbs were perfusion-fixed with paraformaldehyde and glutaraldehyde for light and electron microscopic examinations. Muscle fiber viability decreased progressively over the time of ischemia, with significant differences found between the consecutive times. High correlation was detected between the length of ischemia and the values of muscle fiber viability. After reperfusion, viability showed significant reduction in the 8-hour-ischemia and 2-hour-reperfusion group compared to the 8-hour-ischemia-only group, and decreased further after 9 hours of ischemia and 2 hours of reperfusion. Light- and electron microscopic findings correlated strongly with the values of muscle fiber viability: lesser viability values represented higher degree of ultrastructural injury while similar viability results corresponded to similar morphological injury. Muscle fiber viability was capable of accurately determining the degree of muscle injury in our rat model. Our method might therefore be useful in clinical settings in the diagnostics of acute ischemic muscle injury
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