Eotvos University of Budapest

Budapest, Hungary

Eotvos University of Budapest

Budapest, Hungary
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Molnar B.,Eotvos University of Budapest | Benczur A.,Eotvos University of Budapest
International Journal of Web Portals | Year: 2013

The modeling of Information Systems in general, and Web Information Systems (WIS) especially, is a permanent issue so that there have been already several attempts and proposals for representing various facets of WIS. In our proposed approach, we focus on the organizational and business activity modeling and we concentrate on documents that represent the information of enterprises in the form of unstructured and semi-structured documents. The compilation of documents mirrors implicitly or explicitly the structure of enterprises, the interrelationship of business processes, and activities and tasks within processes. The documents represent, at the same time, the system roles along with tasks and activities. Our modeling approach concentrates on the co-existence and co-operation of documents and activities of business. The Story Algebra, or more generally the process algebra approach provides a formal framework that promises a formal describing method for modeling precisely the event triggered processes coupled with data in document format within an Enterprise Architecture Framework. Copyright © 2013, IGI Global.


Gabris Gy.,Eotvos University of Budapest | Horvath E.,Eotvos University of Budapest | Novothny A.,Eotvos University of Budapest | Ruszkiczay-Rudiger Zs.,Eotvos University of Budapest
Geologie en Mijnbouw/Netherlands Journal of Geosciences | Year: 2012

Present study provides a review of the latest results on fluvial and aeolian landscape evolution in Hungary achieved by our team during the last 20 years. The Hungarian river terrace system and its chronology was described with special emphasise on the novel threshold concept. A revised terrace system was created by the compilation of novel terrace chronology and MIS data. Evolution of river terraces was not only governed by climatic factors but tectonic ones too. Incision rate of the Danube, and uplift rate of the Transdanubian Range (TR) was around 0.1-0.3 mm/a in the marginal zones of the TR (mostly based on the published U-series data) and was above 1 mm/a in its axial zone (based on 3He exposure age dating of strath terraces). According to a detailed geomorphological investigation of the different channel-planform morphologies in the Middle Tisza region and SajóHernád alluvial fan, six phases of river pattern change and four incision periods were detected during the last 20,000 years. Wind polished rock surfaces dated by in situ produced cosmogenic 10Be suggest that deflation was active in Hungary as early as 1.5 Ma ago. According to these exposure age data, Pleistocene denudation rate of the study area (Balaton Highland) was 40-80 m/Ma. In sand covered areas the alternations of wind-blown layers and buried fossil soils provide information about climate and environment changes. In this study, periods of sand movement were mostly determined by optically stimulated luminescence (OSL) dating methods and five aeolian sand accumulation periods were recognised during the last 25 000 years. A new loess stratigraphical view was elaborated using the most recent dating methods (luminescence, AAR). The lower part of Mende Upper (MF 1-2) pedokomplex is suggested to represent the last interglacial period (MIS 5e). During the last interglacial/glacial period (MIS 5 - MIS 2) several soil-forming periods existed but the preservation of these paleosoils is variable depending on their paleogeomorphological position.


Molnar B.,Eotvos University of Budapest | Vinceller Z.,Eotvos University of Budapest
4th IEEE International Conference on Cognitive Infocommunications, CogInfoCom 2013 - Proceedings | Year: 2013

A survey of software and technology architecture about systems dedicated for analysis of Online Social Networks (OSN) will be presented. Based on the comparison and own experiments a novel approach proposed. The steps of experiments are described. The proposed solution is applied for Twitter and Facebook. © 2013 IEEE.


Molnar B.,Eotvos University of Budapest | Szabo G.,Dennis Gabor College | Benczur A.,Eotvos University of Budapest
Infocommunications Journal | Year: 2014

The application and introduction of ERP systems have become a central issue for management and operation of enterprises. The competition on market enforces the improvement and optimization of business processes at enterprises to increase their efficiency, effectiveness, and to manage better the resources outside of the company. The primary task of ERP systems is to achieve the before-mentioned objectives. For this reason the selection of a particular ERP system has a decisive effect on the future operation and profitability of the enterprise, i.e. the selection phase is highly relevant step within the introduction and implementation stage of an ERP system. The issues that are worth investigating are the criteria applied at the decision. The qualitative correlation between the size of enterprises, market position, etc. and the applied selection criteria for ERP systems could be analyzed as to whether which criteria are made use of at multinational enterprises or at SMEs. Our research is grounded in a literature review and case studies of everyday practice related to introduction, implementation and roll-out of ERP systems and it tries to provide answers for the above raised questions.


Molnar B.,Eotvos University of Budapest | Szabo G.,Dennis Gabor College
Proceedings of the International Conference on Information Technology Interfaces, ITI | Year: 2011

The competition on the market enforces companies to adapt to the changing environment. Most recently, economic and financial crisis accelerates the alteration of both business and IT models of enterprises. The forces of globalization and internationalization motivate the restructuring the business processes then consequently IT processes. To depict the changes in a unified framework, we need the concept of enterprise architecture as a theoretical approach that deals with the various tiers, aspects and views of business processes and different layers of application, software and hardware systems. The research carried out up to now unraveled the typical structural changes, the models for internal business networking and their modification reflects the centralization, decentralization and hybrid approaches. Based on the results achieved recently by investigation future research program are drawn up to deepen our understanding the trends within the world of ERP systems.


Mezey P.G.,Memorial University of Newfoundland | Mezey P.G.,Eotvos University of Budapest
Journal of Mathematical Chemistry | Year: 2012

For a specific functional group, considered as a molecular fragment, the rest of the molecule produces a range of interactions which influence various properties of the functional group. Considering a family of molecules with the "same" functional group, the range of variations in properties determines the range of chemical reactivity of the functional group, and a similar conclusion is valid for more general molecular fragments. By the application of conventional as well as more advanced indices of fragment properties, including local electron density shape characterization, various shape variation indices can be introduced for fragments, and their relations to the holographic properties of electron densities can be examined. © 2011 Springer Science+Business Media, LLC.


Antal Z.,Memorial University of Newfoundland | Mezey P.G.,Memorial University of Newfoundland | Mezey P.G.,Eotvos University of Budapest
Journal of Mathematical Chemistry | Year: 2012

The fragment shape variation index approach is applied to intramolecular interactions involving C6 aromatic molecular fragments in the special case where the shape-modifying interactions are also caused primarily by other C6 aromatic fragments of the same molecule. This report is a part of a series of studies aimed at the detailed modeling of various components of intramolecular interactions among molecular fragments, including aromatic ring interactions, aromatic ring and non-aromatic conjugated and non-conjugated system interactions, and more general through-space and through-bond interactions. The ultimate purpose of these studies is a better understanding of the electron density shape modifying effects of intramolecular interactions. © 2011 Springer Science+Business Media, LLC.


Mezey P.G.,Memorial University of Newfoundland | Mezey P.G.,Eotvos University of Budapest
Journal of Mathematical Chemistry | Year: 2012

Latent molecular properties are not exhibited by the given molecular structure but are reproducibly exhibited by the same molecule in a different electronic state or if some molecular interactions have taken place. A consequence of the Holographic Electron Density Theorem, as applied to latent properties, provides a framework that allows an extension of the expectation value formalism, leading to "unexpected" expectation value expressions for latent properties. Connections of special cases of this approach to earlier density matrix extrapolation methods are pointed out. © 2011 Springer Science+Business Media, LLC.


Simon E.,Memorial University of Newfoundland | Mezey P.G.,Memorial University of Newfoundland | Mezey P.G.,Eotvos University of Budapest
Journal of Mathematical Chemistry | Year: 2012

A special adaptation of the fragment shape variation index approach is applied to a series of rod-like structures obtained by replacing all C-C atom pairs by B-N atom pairs in linear polymers constructed by stacking adamantane units on top of each other. A special feature of these structures is a systematic, monotonic increase of the length of B-N bonds roughly parallel with the axis of the rods when moving from the B-terminus towards the N-terminus of the rods. All other changes in the unit cells of these short polymers are less important and less systematic, consequently, focusing on these B-N bonds of the given structures is especially suitable for the application of the fragment shape variation index approach used for a single type of internal coordinate shape descriptor. The results reveal additional trends which are easy to miss if one is restricted to a simple inspection of the data. The study also confirms that in special cases one may replace the detailed electron density shape descriptors with the far simpler bond length data as formal, but limited shape descriptors, whenever the overall structures and shapes show only minor changes, affecting primarily only one type of the internal coordinates. © 2011 Springer Science+Business Media, LLC.

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