Computing and Visualizing Solution Sets of Interval Linear Systems

The paper has been presented at the 12th International Conference on Applications of Computer Algebra, Varna, Bulgaria, June, 2006

Discriminant Sets of Families of Hyperbolic Polynomials of Degree 4 and 5

∗ Research partially supported by INTAS grant 97-1644

Description Reduction for Restricted Sets of (0,1) Matrices

* The research is supported partly by INTAS: 04-77-7173 project, http://www.intas.be

Distributed Genetic Algorithm Implementation by Means of Remote Methods Invocation Technique – Java RMI

The aim of this work is distributed genetic algorithm implementation (so called island algorithm) to accelerate the optimum searching process in space of solutions. Distributed genetic algorithm has also smaller chances to fall in local optimum. This conception depends on mutual cooperation of the clients which realize separate working of genetic algorithms on local machines. As a tool for implementation of distributed genetic algorithm, created to produce net's applications Java technology was chosen. In Java technology, there is a technique of remote methods invocation - Java RMI. By means of invoking remote methods it can send objects between clients and server RMI.

Measurement of intervertebral cervical motion by means of dynamic X-ray image processing and data interpolation

Accurate measurement of intervertebral kinematics of the cervical spine can support the diagnosis of widespread diseases related to neck pain, such as chronic whiplash dysfunction, arthritis, and segmental degeneration. The natural inaccessibility of the spine, its complex anatomy, and the small range of motion only permit concise measurement in vivo. Low dose X-ray fluoroscopy allows time-continuous screening of cervical spine during patient's spontaneous motion. To obtain accurate motion measurements, each vertebra was tracked by means of image processing along a sequence of radiographic images. To obtain a time-continuous representation of motion and to reduce noise in the experimental data, smoothing spline interpolation was used. Estimation of intervertebral motion for cervical segments was obtained by processing patient's fluoroscopic sequence; intervertebral angle and displacement and the instantaneous centre of rotation were computed. The RMS value of fitting errors resulted in about 0.2 degree for rotation and 0.2 mm for displacements. © 2013 Paolo Bifulco et al.

An Overview of Modelling Bulgarian Wildland Fire Behaviour by Application of a Mathematical Game Method and WRF-Fire Models

This paper presents the main achievements of the author’s PhD dissertation. The work is dedicated to mathematical and semi-empirical approaches applied to the case of Bulgarian wildland fires. After the introductory explanations, short information from every chapter is extracted to cover the main parts of the obtained results. The methods used are described in brief and main outcomes are listed. ACM Computing Classification System (1998): D.1.3, D.2.0, K.5.1.

A racionális kisvállalati gazdálkodás tényezői, 2006-2010 (Factors in rational operation of small business, 2006-2010)

A tanulmány a hazai kis- és középvállalati szektorban 2006-ban elvégzett, majd 2010-ben megismételt kérdőíves felmérések eredményei alapján igyekszik bemutatni a racionális vállalati gazdálkodás sajátosságait. Vizsgálatunk fő kérdése, hogy e szektor vállalkozásainak gazdálkodását milyen tényezők teszik ésszerűvé, s hogy a 2006-2010 között eltelt időszakban milyen változások figyelhetők meg a gazdálkodói magatartásuk alakulásában. Eredményeink alapján megállapíthatjuk, hogy a mai napig megtalálhatók a kisvállalkozói - háztartási szemléletű, megélhetésorientált - gazdálkodás nyomai, de a racionális gazdálkodás általunk használt mutatói szerint e vállalkozások körében szakszerűbbé vált a gazdálkodás. Ebben a folyamatban szerepet játszott a gazdasági válság, amely által előidézett helyzethez kénytelenek voltak alkalmazkodni a kis- és közepes vállalkozások: felismerték, hogy célravezetőbb a hatékonyság és a költségek szempontjából a racionális pénzpiaci magatartás követése, s ezzel összhangban a válság miatti zavarok elhárítására kiadáscsökkentő eszközök alkalmazása. A kis- és közepes vállalkozások gazdálkodásával kapcsolatos racionális döntések előmozdításában elsősorban a korszerű pénzügyi ismereteknek és a szakmai tudásnak van szerepe. / === / The study seeks to identify the attributes of rational business operation, using a questionnaire survey of small and medium-sized firms made in 2006 and a repeat of it in 2010. The main questions addressed are what factors contribute to rational operation in the firms in the sector and what changes over the 2006-10 period can be discerned in business behaviour. The findings show that traces of small business-style operation (a household or livelihood orientation) could still be found, but the indicators of rationality employed in the survey show that the operation of the firms became more rational. A role in the process was played by the economic crisis, which forced small and medium-sized businesses to adapt: they recognized that it was better from the point of view of efficiency and costs to follow rational money-market behaviour, and in line with that, use spending-reduction tools to evade the disturbances of the crisis. The main factors behind the shift towards rational decision-making in the running of small and medium-sized firms are up-to-date financial information and professional expertise.

A method for solving LSM problems of small size in the AHP

The Analytic Hierarchy Process (AHP) is one of the most popular methods used in Multi-Attribute Decision Making. It provides with ratio-scale measurements of the prioirities of elements on the various leveles of a hierarchy. These priorities are obtained through the pairwise comparisons of elements on one level with reference to each element on the immediate higher level. The Eigenvector Method (EM) and some distance minimizing methods such as the Least Squares Method (LSM), Logarithmic Least Squares Method (LLSM), Weighted Least Squares Method (WLSM) and Chi Squares Method (X2M) are of the tools for computing the priorities of the alternatives. This paper studies a method for generating all the solutions of the LSM problems for 3 × 3 matrices. We observe non-uniqueness and rank reversals by presenting numerical results.

Maguk urai – a magyar vállalkozó lelkialkata (A magyarországi kisvállalkozók értékvilágának néhány jellemzője) Their own bosses – The character of the Hungarian entrepreneur (Some aspects of the value system of small entrepreneurs in Hungary)

The study uses the value test developed by Shalom Schwartz to examine the value system of Hungarian entrepreneurs. First, the dataset of the last wave of the European Social Survey is used to define those value orientations which generally distinguish entrepreneurs from the rest of society in Europe. Second, the prevalence of these ‘entrepreneurial values’ in the general populations of various countries, and Hungary in particular, is explored. Third, using compatible data from a survey of 300 Hungarian small entrepreneurs, the value orientations that distinguish them from other European entrepreneurs and Hungarian non-entrepreneurs are examined. Multivariate regression analyses allow us to draw a nuanced value-portrait of the typical Hungarian entrepreneur. The main conclusion is that although Hungarian small entrepreneurs share the ’core values’ of entrepreneurs in Europe, they are less adventurous and less materialist, but held personal freedom and human relations especially dear.

Az e-business kooperatív turisztikai adaptációja : "A kicsi, a szép esélyei hazánkban" (The cooperative touristy adoption of e-business: "The chances of small beautiful in Hungary")

A cikk legfontosabb megválaszolandó kérdése: Milyen esélyekkel és milyen szükséges lépésekkel indulhatnak a nemzetközileg kevéssé ismert hazai célállomások és vállalkozásaik a turisztikai piac globális versenyében, melynek egyre jelentősebb színterét az internet adja? A turisztikai piacon az internet piacalakító hatása és az individualista, élmény, és értékközpontú kereslet megjelenése olyan változásokat indított el az elmúlt közel húsz évben, melyek befolyásolva a szereplők erőviszonyait a fejlődés lehetőségét hordozzák a regionális célállomások, a kevéssé ismert desztinációk számára. Mindezen trendek egyúttal kihívást jelentenek, mivel élesítik a versenyt, és megújulásra ösztönzik a globálisan ismert desztinációkat is, valamint számos nehézség megoldására késztetik a több szempontból hátrányban szenvedő vidéki régiókat. A cikkben ismertetendő kutatás célja az, hogy egy best practice-ként ismert osztrák és három hazai eset alapján felderítse azon tényezőket, melyek a desztinációfejlesztés kezdeti lépésétől az e-business sikeres adaptációjához, a desztinációmenedzsment-rendszerek bevezetéséhez és működtetéséhez vezetnek. __________ The main question of the paper: What kind of steps should the Hungarian less-known destinations take to meet the challenges of the global competition increasingly taking place on the internet? The trends of “new tourism” – driven by post-materialistic values –, and the growing role of internet in touristy activity have formed new conditions and changed the balance of forces in the touristy market. These two trends hand in hand have intensified the competition: on the one hand force global destinations to renew, on the other hand give great but challenging possibilities for regional destinations in comparative disadvantage. The aim of the paper is to identify the success-factors of adopting e-business solution called destination management system in the regional, undeveloped areas starting destination management from zero position. For this purpose case studies were examined by analyzing Hungarian regional destinations’ development and making a benchmark analysis through an Austrian best practice.

The solution-seeking behavior of small Hungarian enterprises between 2006 and 2010

This paper describes the results of an investigation into the finance-related innovative ability of Hungarian micro, small and medium sized enterprises (SMEs) by using two datasets (from 2006 and 2010). The author explored SMEs’ levels of openness to new financial solutions and identified features which influence their innovative solution-seeking behavior. Additionally, changes in innovation between 2006 and 2010 were analyzed according to the SME sector and whether there is a correlation between having an active solution seeking attitude and business performance was examined. The findings show that shared/multiple ownership in businesses (having interests in different enterprises simultaneously) has a significant positive effect on flexibility and innovative ability. However, the size of the business, industrial sector, type of ownership and market of the SME also have some effect. Furthermore, the hypothesis that an active solution-seeking attitude increases after-tax performance per employee was confirmed.

"Lájk első látásra?" – Mi inspirálja a márkák kedvelését az online térben, kis vendéglátóhelyek esetében? ("Like at first sight?" – What inspires liking brands in online social media in the case of small catering establishments?)

A márkatulajdonosok számára elsődleges fontosságú, hogy feltérképezzék saját márkaközösségüket, ezáltal is elősegítve a közösségi fókuszú kommunikációs tevékenységüket. Különösen igaz ez a jellemzően kis- és középvállalati formában működő vendéglátóhelyek számára, ahol a közösségi média sokszor az egyetlen rendelkezésre álló marketingkommunikációs eszköz. Empirikus kutatásunkban fogyasztói narratívákat (n=151) elemzünk a tartalomelemzés módszertanával. A válaszadókat arra kértük, hogy írjanak kedvenc vendéglátóhelyükkel való kapcsolatukról az online térben. Elemzésünkben arra keressük a választ, hogy a márkaközösségek tagjai milyen belső indíttatásból kerültek kapcsolatba kedvenc vendéglátóhelyeikkel a közösségi platformokon. Az elsősorban fogyasztási élményekhez kötött kapcsolat online közösségi térbe való kiterjesztésére olyan belső motivációkat tártunk fel, mint a pragmatikusabb információközpontú indíttatások (pl. kizárólagos információk, naprakészség, vállalati ajánlatok, közösségimédia-specifikus tartalmakhoz való hozzáférés igénye), az érzelmi kötődés kifejezése (pl. nosztalgia, ismerősöknek való ajánlás, személyes érintettség), a társas befolyás (oldalak kedvelése mint kommunikációs tartalom, konformitás, önkifejezés), valamint a vállalati alapképességeken túlmutató egyéb tematikus kapcsolódások. ____ It is of primary importance for brand owners to map their own brand community, in order to stimulate their social-focused communication activity. This is especially true for typically small and medium-sized catering enterprises, where in most cases, social media is the only available marketing communications tool. In our empirical research, we analyze consumer narratives (n=151) with the methodology of content analysis. We asked the respondents to write about their relationship with their most preferred catering establishments in the online social sphere. In our research, we search for the inner intention by which members of brand communities got connected with their most preferred catering establishments on social platforms. We revealed such inner motivations for users extending a primarily experience (an consumption) based relationship to the online social sphere like rather pragmatic, information-focused intentions (e.g. exclusive information, timeliness, company offers, access claim for social media -specific contents), the expression of emotional binding (e.g. nostalgia, reference for acquaintances, personal involvement), social influence (the like as communication content, conformity, self-expression), and other thematic linkages beyond core company competences.

"Lájkolom őket, de ennék is náluk?" – Aktivitásra buzdító kis- és középvállalati közösségimédia-tevékenységek fogyasztói fogadtatása magyarországi vendéglátóhelyek példáján keresztül ("I like them, but would I eat at their place?" – Encouraging social media activities of small and medium-sized enterprises and their consumerreactions – the case of Hungarian catering establishments)

A vendéglátóipari egységek kommunikációjában fontos szerepe van a közösségi médiában való jelenlétnek. Hazánkban a leggyakrabban használt felület a Facebook, amely sok ilyen vállalkozás esetében kiemelt fontosságú, vagy akár az egyetlen reálisan elérhető marketingkommunikációs felület. Kutatásunkban azt vizsgáljuk, hogy a felhasználók hogyan érzékelik a feléjük továbbított üzleti célú információkat a közösségi felületen, illetve hogy a fogyasztókra milyen mértékű aktivitás jellemző kedvenc vendéglátóipari egységük oldalán. Ennek céljából szubjektív fogyasztói narratívákat (n=151) elemzünk a kvalitatív tartalomelemzés módszertanával. A válaszadókat arra kértük, hogy írjanak kedvenc vendéglátóhelyükkel való kapcsolatukról az online térben. A "belájkolt" vendéglátóipari egységek felületeinek fogyasztók által észlelt aktivitása segítheti a vállalkozásokat abban, hogy alaptevékenységük elemeinek kommunikálásával, vagy akár ettől teljesen eltérő közösségi stratégiát használva pozicionálják márkájukat. A márkák tudatos tartalommenedzselése hozzájárulhat továbbá a felhasználók virtuális térben való hatékonyabb eléréséhez és bevonásához. ____ Presence in social media is an important element in the communication of catering establishments. The most frequently used platform in Hungary – that is extraordinarily important, or even the only reasonably accessible marketing communications platform for many catering companies – is Facebook. In our research, we analyse how users perceive the business-purposed information forwarded to them on the social media platform, and how intensive are the consumers’ activities on their most preferred catering establishment's site. For this purpose we analyse subjective consumer narratives (N=151) with the methodology of qualitative content analysis. We asked the respondents to write about the relationship with their most preferred catering establishment in the online sphere. Perceived activity of the "liked" catering establishment's platform could help enterprises to position themselves by communicating their core activities, or by using a totally different social strategy. Moreover, conscious content management of brands could contribute to reach and to engage users in the virtual sphere more efficiently.

Binding of small molecules to DNA junctions

Previous results in our laboratory suggest that the (CG) 4 segments whether present in a right-handed or a left-handed conformation form distinctive junctions with adjacent random sequences. These junctions and their associated sequences have unique structural and thermodynamic properties that may be recognized by DNA-binding molecules. This study probes these sequences by using the following small ligands: actinomycin D, 1,4-bis(((di(aminoethyl)amino)ethyl)amino)anthracene-9,10-dione, ametantrone, and tris(phenanthroline)ruthenium (II). These ligands may recognize the distinctive features associated to the (CG)4 segment and its junctions and thus interact preferentially near these sequences. Restriction enzyme inhibition assays were used to determine whether or not binding interactions took place, and to approximate locations of these interactions. These binding studies are first carried out using two small synthetic oligomers BZ-III and BZ-IV. The (5meCG)4 segment present in BZ-III adopts the Z-conformation in the presence of 50 m M Co(NH3)63+. In BZ-IV, the unmethylated (CG)4 segment changes to a non-B conformation in the presence of 50 m M Co(NH3)63+. BZ-IV, containing the (CG)4 segment, was inserted into a clone plasmid then digested with the restriction enzyme Hinf I to produce a larger fragment that contains the (CG)4 segment. The results obtained on the small oligomers and on the larger fragment for restriction enzyme Mbo I indicate that 1,4-bis(((di(aminoethyl)amino)ethyl)amino)anthracene-9,10-dione binds more efficiently at or near the (CG)4 segment. Restriction enzymes EcoRV, Sac I and Not I with cleavage sites upstream and downstream of the (CG)4 insert were used to further localize binding interactions in the vicinity of the (CG)4 insert. RNA polymerase activity was studied in a plasmid which contained the (CG)4 insert downstream from the promoter sites of SP6 and T7 RNA polymerases. Activities of these two polymerases were studied in the presence of each one of the ligands used throughout the study. Only actinomycin D and spider, which bind at or near the (CG)4 segment, alter the activities of SP6 and T7 RNA polymerases. Surprisingly, enhancement of polymerase activity was observed in the presence of very low concentrations of actinomycin D. These results suggest that the conformational features of (CG) segments may serve in regulatory functions of DNA. ^

Life history trade-offs and community dynamics of small fishes in a seasonally pulsed wetland

We used a one-dimensional, spatially explicit model to simulate the community of small fishes in the freshwater wetlands of southern Florida, USA. The seasonality of rainfall in these wetlands causes annual fluctuations in the amount of flooded area. We modeled fish populations that differed from each other only in efficiency of resource utilization and dispersal ability. The simulations showed that these trade-offs, along with the spatial and temporal variability of the environment, allow coexistence of several species competing exploitatively for a common resource type. This mechanism, while sharing some characteristics with other mechanisms proposed for coexistence of competing species, is novel in detail. Simulated fish densities resembled patterns observed in Everglades empirical data. Cells with hydroperiods less than 6 months accumulated negligible fish biomass. One unique model result was that, when multiple species coexisted, it was possible for one of the coexisting species to have both lower local resource utilization efficiency and lower dispersal ability than one of the other species. This counterintuitive result is a consequence of stronger effects of other competitors on the superior species.