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Search Results: 1 - 10 of 43 matches for " Zsofia Bognar "
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Investigation of Rotational Splitting in the Pulsating White Dwarf GD 154
Zsofia Bognar,Margit Paparo
Physics , 2013,
Abstract: We observed the ZZ Ceti star GD 154 over a whole season at the mountain station of Konkoly Observatory. Our long time base allowed to detect the sign of rotational triplets around the independent modes. To check whether these can be real detections we made a test on our data set. We searched for characteristic spacing values performing Fourier analysis of numerous peaks determined around five frequencies in the main pulsation region. The analysis revealed regular peak spacings with separations around 3.7 and 2.6 microHz. These values are in accordance with the ones determined by consecutive prewhitening of Whole Earth Telescope observations.
Historical development and politico-geographical characteristics of the border and borderland between the Republic of Croatia and Republic of Slovenia on umberak and in the Rivers Kupa and abranka Valley
Helena Ilona Bognar,Andrija Bognar
Geoadria , 2010,
Abstract: Although natural basis cannot be a decisive criterion in defining borders, historical and politico-geographic development of the researched area reveals that natural bounds have been considerably used in the boundary demarcation between the Republic of Croatia and Republic of Slovenia. This can be also concluded for the analyzed sectors which are tied with the umberak Mountain and the Kupa and abranka River valleys. Besides natural favours (the boundary line runs over the top ridges of the mountain massif of umberak/Gorjanci, as well as along the river flows), one must point out the fact that it is adapted to spatial organization of the borderland. Therefore, the boundary line is subsequent and co-operative here. Evolutionally, the border and borderland developed from terra nullius, frontier, and, finally, since the 16th century, have become a boundary line on the rivers Kupa and abranka, and since 1816, on umberak. Consequently, in spite of disputes in particular historical periods about the researched area's state and property appurtenance, the border has a centuries-old continuity. This can explain that nowadays the quoted sectors are least disputable in the boundary demarcation of the two sovereignties.
Monitoring a high--amplitude Delta Sct star for 152 days: discovery of 12 additional modes and modulation effects in the light curve of CoRoT 101155310
Ennio Poretti,Monica Rainer,Werner W. Weiss,Zsofia Bognar,Andy Moya,Ewa Niemczura,Juan Carlos Suarez,Michel Auvergne,Annie Baglin,Frederic Baudin,Jozsef M. Benko,Jonas Debosscher,Rafa Garrido,Luciano Mantegazza,Margit Paparo
Physics , 2011, DOI: 10.1051/0004-6361/201016045
Abstract: The detection of small-amplitude nonradial modes in high-amplitude Delta Sct (HADS) variables has been very elusive until at least five of them were detected in the light curve of V974 Oph obtained from ground-based observations. The combination of radial and nonradial modes has a high asteroseismic potential, thanks to the strong constraints we can put in the modelling. The continuous monitoring of ASAS 192647-0030.0=CoRoT 101155310 (P=0.1258 d, V=13.4) ensured from space by the CoRoT (Convection, Rotation and planetary Transits) mission constitutes a unique opportunity to exploit such potential. The 22270 CoRoT measurements were performed in the chromatic mode. They span 152 d and cover 1208 consecutive cycles. After the correction for one jump and the long-term drift, the level of the noise turned out to be 29 micromag. The phase shifts and amplitude ratios of the coloured CoRoT data, the HARPS spectra, and the period-luminosity relation were used to determine a self-consistent physical model. In turn, it allowed us to model the oscillation spectrum, also giving feedback on the internal structure of the star. In addition to the fundamental radial mode f1=7.949 c/d with harmonics up to 10f1, we detected 12 independent terms. Linear combinations were also found and the light curve was solved by means of 61 frequencies (smallest amplitude 0.10 mmag). The newest result is the detection of a periodic modulation of the f1 mode (triplets at +/-0.193 c/d centred on f1 and 2f1), discussed as a rotational effect or as an extension of the Blazhko effect to HADS stars. The physical model suggests that CoRoT 101155310 is an evolved star, with a slight subsolar metallic abundance, close to the terminal age main sequence. All the 12 additional terms are identified with mixed modes in the predicted overstable region.
ACTA MATHEMATICA UNIVERSITATIS COMENIANAE
G. Bognar and O. Dosly
ACTA MATHEMATICA UNIVERSITATIS COMENIANAE , 2003,
Abstract: . We established a Picone-type identity for the second order partial differential equation $$ \sum_{i=1}^N\frac{\partial}{\partial x_i} \left(r_i(x)\varphi\left(\frac{\partial u}{\partial x_i}\right)\right)+ c(x)\varphi(u)=0,\quad \varphi(u)=|u|^{p-1}u,\ p>0. \leqno{(*)} $$ Using this identity we prove the Leighton-type comparison theorem for a pair of equations of the form (*). Properties of the principal eigenvale of a certain eigenvalue problem associated with (*) are investigated as well.
Study of adolescents’ multifactorial self-image components based on their own self-characterizations
Horvath, Zsofia Iren
Romanian Journal of Applied Psychology , 2012,
Abstract: The most important questions of human existence and development – Who am I? What am I like? – concerned every thinking human in all cultural-historical ages. These questions remain timely even in our rapidly changing postmodern society.The goal of our research is the examination of adolescents’ self-characterization, the outlining of the self-image components age characteristics, the establishment of differences resulting from their environment. Our examination is part of the 2005/2006 school year evaluation (Pletl, 2011) regarding Transylvanian students’ composition skills. In the present research we have analyzed a total of 1602 self-characterization of Transylvanian Hungarian students. Results show that fifth grade students have dichotomous thinking that becomes more sophisticated by the time they get into the eighth grade. Eighth grade students referred significantly more often to the categories Emotions, Satisfaction, Social attitudes, School achievement, Special interests and mentioned more personality traits. In the comparison by location, more similarities and fewer differences were outlined. However, urban students referred significantly more often to emotions and satisfaction, while rural students mentioned more frequently characteristics like good-hearted and diligent. The study also outlined two major deficiencies. No significant difference was found between the two grades in naming abilities, and referring to Science and Language. We strongly believe that school should be more than simply a place for traditional teaching; effective education and personal development should spread to new areas like the development of self-reflective thinking, the shaping of personal competence and the operation of Career and Vocational Counseling.
Self-similar analytic solution of the two dimensional Navier-Stokes equation with a non-Newtonian type of viscosity
Imre Ferenc Barna,Gabriella Bognar
Physics , 2014,
Abstract: We investigate the two dimensional incompressible Navier-Stokes(NS) and the continuity equations in Cartesian coordinates and Eulerian description for non-Newtonian fluids. As a non-Newtonian viscosity we consider the Ladyzenskaya model with a non-linear velocity dependent stress tensor. The key idea is the multi-dimensional generalization of the well-known self-similar Ansatz, which was already used for non-compressible and compressible viscous flow studies. The geometrical interpretations of the trial function is also discussed. We compare our recent results to the former Newtonian ones.
EXOTIME: searching for planets around pulsating subdwarf B stars
Sonja Schuh,Roberto Silvotti,Ronny Lutz,Bjoern Loeptien,Elizabeth M. Green,Roy H. Ostensen,Silvio Leccia,Seung-Lee Kim,Gilles Fontaine,Stephane Charpinet,Myriam Francoeur,Suzanna Randall,Cristina Rodriguez-Lopez,Valerie van Grootel,Andrew P. Odell,Margit Paparo,Zsofia Bognar,Peter Papics,Thorsten Nagel,Benjamin Beeck,Markus Hundertmark,Thorsten Stahn,Stefan Dreizler,Frederic V. Hessman,Massimo Dall'Ora,Dario Mancini,Fausto Cortecchia,Serena Benatti,Riccardo Claudi,Rimvydas Janulis
Physics , 2010, DOI: 10.1007/s10509-010-0356-4
Abstract: In 2007, a companion with planetary mass was found around the pulsating subdwarf B star V391 Pegasi with the timing method, indicating that a previously undiscovered population of substellar companions to apparently single subdwarf B stars might exist. Following this serendipitous discovery, the EXOTIME (http://www.na.astro.it/~silvotti/exotime/) monitoring program has been set up to follow the pulsations of a number of selected rapidly pulsating subdwarf B stars on time-scales of several years with two immediate observational goals: 1) determine Pdot of the pulsational periods P 2) search for signatures of substellar companions in O-C residuals due to periodic light travel time variations, which would be tracking the central star's companion-induced wobble around the center of mass. These sets of data should therefore at the same time: on the one hand be useful to provide extra constraints for classical asteroseismological exercises from the Pdot (comparison with "local" evolutionary models), and on the other hand allow to investigate the preceding evolution of a target in terms of possible "binary" evolution by extending the otherwise unsuccessful search for companions to potentially very low masses. While timing pulsations may be an observationally expensive method to search for companions, it samples a different range of orbital parameters, inaccessible through orbital photometric effects or the radial velocity method: the latter favours massive close-in companions, whereas the timing method becomes increasingly more sensitive towards wider separations. In this paper we report on the status of the on-going observations and coherence analysis for two of the currently five targets, revealing very well-behaved pulsational characteristics in HS 0444+0458, while showing HS 0702+6043 to be more complex than previously thought.
Contactless Thermal Characterization Method of PCB-s Using an IR Sensor Array
Gy. Bognar,V. Szekely,M. Rencz
Computer Science , 2007,
Abstract: In this paper the feasibility study of an IR sensor card is presented. The methodology and the results of a quasi real-time thermal characterization tool and method for the temperature mapping of circuits and boards based on sensing the infrared radiation is introduced. With the proposed method the IR radiation-distribution of boards from the close proximity of the sensor card is monitored in quasi real-time. The proposed method is enabling in situ IR measurement among operating cards of a system e.g. in a rack.
A New Tool for Resistance Management: Baseline Toxicity, Ovicidal Activity, and Field Efficacy of the Novel Insecticide Tolfenpyrad on Colorado Potato Beetle, Leptinotarsa decemlineata  [PDF]
Adam F. Wimer, Christopher R. Philips, Thomas P. Kuhar, James C. Adams, Zsofia Szendrei
Advances in Entomology (AE) , 2015, DOI: 10.4236/ae.2015.34017
Abstract: Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) is one of the most important insect pests of potato (Solanum tuberosum L.). Because of the high value of potato crops, most growers approach management in a similar manner. Chemical control of arthropod pests in potato is the standard pest management practice, and will likely continue to be in the foreseeable future. This heavy reliance on chemical control has led to high levels of insecticide resistance. Strategies that rotate chemistries are critical in order to maintain insecticide efficacy, highlighting the immediate need to evaluate novel chemistries to continue to manage this pest successfully. Working with different populations of L. decemlineata, field and lab experiments were conducted to evaluate the baseline toxicity, ovicidal activity, and field efficacy of the novel insecticide tolfenpyrad to L. decemlineata. Lab assays revealed that tolfenpyrad was toxic to both larvae and adults, and that L. decemlineata treated egg masses had a 0% hatch rate. Potato field plots treated with tolfenpyrad had significantly fewer larvae, less defoliation, and higher tuber yields. These data will provide accurate field rates for proper labeling, a baseline reference for tracking changes in L. decemlineata susceptibility, as well as provide a novel chemistry to aid in resistance management programs.
Remote Engineering and Virtual Instrumentation Using Jini Technology
Zoltan Juhasz,Gabor Bognar,Krisztian Kuntner,Akos Pasztory
International Journal of Online Engineering (iJOE) , 2006,
Abstract: The rise of Internet and web technology have transformed our society by providing access to unprecedented amount of information, supporting communication and collaboration, empowering e-business and e-commerce. Its role in advancing science is equally important. It has become possible to disseminate scientific information more effectively, access large databases, share computational resources, measurement devices, control experiments and collaborate at a global scale. The human user centered traditional world wide web technology, however, cannot provide the suitable technological platform necessary for the further development and improvement of online and remote engineering applications. New, service-oriented technologies are required, which support higher level of automation, enable seamless programmatic and interactive access to remote devices and systems, and have an adequate programming model suitable for creating large and complex distributed scientific applications. In this paper, we describe such a technology, Jini technology, and illustrate with case studies its various benefits for the remote engineering, virtual instrumentation community.
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