Systems of symplectic forms on four-manifolds

We study almost Hermitian 4-manifolds with holonomy algebra, for the canonical Hermitian connection, of dimension at most one. We show how Riemannian 4-manifolds admitting five orthonormal symplectic forms fit therein and classify them. In this set-up we also fully describe almost Kaehler 4-manifolds.Comment: Final version, to appear in Annali di SNS.added thm. 5.

Complex homothetic foliations on K\"ahler manifolds

We obtain a local classification of complex homothetic foliations on Kaehler manifolds by complex curves. This is used to construct almost Kaehler, Ricci-flat metrics subject to additional curvature properties.Comment: Final version, up to typos. To appear in BLM

Nyilvános diplomácia = Public diplomacy

A kutatás újszerűsége magának a témának is köszönhető, hiszen a modern nyilvános diplomácia tematikájával magyar szakirodalomban elvétve találkozhatunk. Tehát egyrészt a komplex elméleti-gyakorlati eredményeknek az összességét tekinthetjük tudományos eredménynek, másrészt pedig a kutatás újszerű produktumát, nevezetesen egy hatékony magyar nyilvános diplomácia kialakításához szükséges módszertan kidolgozását. A kutatás elméleti jelentősége azon kommunikációs szegmens meghatározása, mely a magyar nyilvános diplomácia sarokköve lehet, illetve annak bemutatása, hogy a nyilvános diplomáciában fontos a belföldre és külföldre szóló üzenetek összehangolása, hiszen ezek nem választhatók szét, együttesen alakítják az országról kialakult képet. Gyakorlati jelentősége a nyilvános diplomácia tematikájának megjelenése a magyar szakirodalomban és felsőoktatásban, mely a szerző reményei szerint a magyar szakembereket, illetve a nemzetközi kapcsolatok képzésben résztvevő hallgatókat további kutatásokra ösztönözheti

Assessment Methods for Comparing Shared Mobility and Conventional Transportation Modes in Urban Areas

Shared mobility is an innovative and sustainable approach to passenger transportation, which has only recently emerged. In urban areas car-sharing, bike-sharing and other special vehicles (e.g., scooters) are popular. For greater distances, ridesharing is considered as a great option beside own private car usage or public transportation. We elaborated an assessment to analyse mobility modes. The research consists of two main parts. First, a wide spectrum of key variables is identified. We classified the variables among the following indicators: flexibility, comfort, and dynamic characteristics. These indicators support mode choice decisions. The second part is the model of service level. In the model, we included parameters to represent the importance of certain attributes. The model can be used to support mode choice decisions. We applied the method to analyse a simple urban mobility palette and place shared mobility within it. We found that shared mobility modes can be placed between private car usage and public transportation according to the aggregated indicators

Monte Carlo simulation and analytic approximation of epidemic processes on large networks

Low dimensional ODE approximations that capture the main characteristics of SIS-type epidemic propagation along a cycle graph are derived. Three different methods are shown that can accurately predict the expected number of infected nodes in the graph. The first method is based on the derivation of a master equation for the number of infected nodes. This uses the average number of SI edges for a given number of the infected nodes. The second approach is based on the observation that the epidemic spreads along the cycle graph as a front. We introduce a continuous time Markov chain describing the evolution of the front. The third method we apply is the subsystem approximation using the edges as subsystems. Finally, we compare the steady state value of the number of infected nodes obtained in different ways. © 2012 Versita Warsaw and Springer-Verlag Wien

Survey of Cubic Fibonacci Identities When Cuboids Carry Weight

The aim of this paper is to present a comprehensive survey of cubic Fibonacci identities, trying to uncover as many as possible. From the outset, our rationale for a very careful search on an apparently obscure problem was not only a matter of mathematical curiosity, but also motivated by a quest for 3D Fibonacci spirals. As we were not able to find any survey on the particular topic of cubic Fibonacci identities we decided to try to fill this void. We started by surveying many Fibonacci identities and recording cubic ones. Obviously, tracing all Fibonacci identities (for identifying a handful) is a daunting task. Checking several hundred we have realized that it is not always clear who the author is. The reason is that in many cases an identity was stated in one article (sometimes without a proof, e.g., as an open problem, or a conjecture) while later being proven in another article, or effectively rediscovered independently by other authors. However, we have done our best to present the identities chronologically. We have supplied our own proof for one identity, having tried, but failed, to find a published proof. For all the other identities, we either proved them on a computer, or else verified by hand their original published proofs. Somehow unexpectedly, our investigations have revealed only a rather small number of cubic Fibonacci identities, representing a tiny fraction of all published Fibonacci identities (most of which are linear or quadratic). Finally, out of these, only a handful of cubic Fibonacci identities are homogeneous

Consumer satisfaction and word-of-mouth in Electronic Commerce: a possible segmentation method

Over the last 10 years the B2C online market and its characteristics – for example the perceived electronic service quality (e-SQ) – has become a relevant research area, not only in the Western countries but also in smaller, less-developed countries. Therefore the first aim of this paper is to provide a description of an analysis into how the dimensions of perceived eSQ relate to satisfaction and WOM intention in Hungary. Secondly, using the results of a PLS-SEM model we show how consumers may be segmented based on their perceptions of quality. According to our research only the dimension of efficiency and responsiveness have a significant positive effect on satisfaction, and the perception of the quality of fulfilment’s also significantly influences word-of-mouth intention. Using the relevant latent variable scores a segmentation method was developed in which four significantly different segments were identified