349 research outputs found
A termondinamika II. főtétele a környezettudományokban - Entrópia, extrópia, exergia
A termodinamika a fizikának, e leghosszabb múlttal rendelkező természet-tudománynak egy „viszonylag újkeletű” – durván százhatvan éves múltra visszatekintő – tudományterülete, amely az energia különböző formákban való megjelenései közti átalakulásokkal foglalkozik. Az ezen folyamatokra vonatkozó alapvető szabályszerűségeket négy főtétel1 foglalja össze. Ezek közül is a megértés szempontjából a legnagyobb kihívást a második tartogatja számunkra
Inducible super-enhancers are organized based on canonical signal-specific transcription factor binding elements
Áramlástérkép R-ben
A természeti környezet és az emberi társadalom egyaránt dinamikus rendszer, számos
eleme állandó mozgásban van: vírusok, áruk, javak, ötletek, információk, emberek, üzenetek,
az állatvilág egyedei változtatják helyüket a tér egyik pontjáról a tér másik pontjára
(Tobler 2003). Az ilyen mozgásokat általánosan térbeli interakcióknak nevezzük (Batty 2008). Az interakciók jelentős szerepet játszanak társadalmi folyamatok alakításában, sok
esetben a folyamatok meghatározó hajtóerőinek tekinthetők. Az interakciók megjelenítésének legkönnyebben értelmezhető és emiatt leggyakrabban használt eszköze az áramlástérkép
(flow map).
Tanulmányunkban az áramlástérkép R programnyelvben megvalósított változatát mutatjuk
be. Az általunk javasolt megoldás nem tartalmaz a sokak által ismert kereskedelmi
(Mapinfo, ArgGIS, Mapviewer) vagy nyílt forráskódú szoftverekhez képest új vizualizációs eljárást. Elsődleges célunk az volt, hogy felhívjuk a figyelmet az R-ben rejlő ábrázolási,
valamint adatelőkészítési lehetőségekre.
Tanulmányunkban először röviden áttekintjük térbeli áramlások ábrázolásának történeti előzményeit, utalunk a migrációs mozgások ábrázolására használt, szabadon elérhető
szoftverekre. Elemzésünkben az elmúlt negyedszázad megyei szintű állandó vándorlásainak
(belföldi vándorlások) mátrixaira támaszkodtunk. A vándorlásokat életciklushoz
viszonylag egyértelműen köthető korcsoportok szerint vizsgáltuk. Az ábrázolást a könnyebb
megértés érdekében lépésenként mutatjuk be. Tanulmányunkat a fontosabb tapasztalatok
összefoglalásával zárju
Alternatively Constructed Estrogen Receptor Alpha-Driven Super-Enhancers Result in Similar Gene Expression in Breast and Endometrial Cell Lines
L
A választói viselkedés térbeli modellje – empirikus kísérlet budapesti adatok alapján = A spatial model of voting behaviour - an empirical study based on Budapest data
One condition of the stable and balanced functioning of democratic systems is the active participation of citizens. Considering the political subsystem, civilian activity is primarily, although not exclusively, manifested in participation at elections. The relationship between participation in the 2010 parliamentary election and the number of votes cast in favour of the winning party was in the focus of our investigations in this study. According to Klimek et al. (2012), who greatly inspired the current research, conclusions can be drawn about the fairness of the election based on the concentration of votes cast for the winning party. This is possible because salient differences observable in the joint distributions of concentration and participation may suggest problems concerning the fairness of the election. Since the chance of salient differences occurring is negligible, these might suggest manipulation. In our study, we argue that a method which ignores spatial effects may be inefficient in the case of auto-correlated error components because the independence assumption is not met, so this method may lead to biased estimations. In order to answer the research question, we relied on data derived from voting districts in Budapest which were used to create a geo-referenced spatial point database. Data were entered by voting district, then areal data was created with the help of Voronoi tesselation. In order to shed light on the relationship between participation and the votes cast for the winning party, we relied on spatial filtering as suggested by Getis and Ord, which enables the explicit expression of spatial effects. The non-parametric Getis spatial filtering has been investigated with the help of optimal distances and first-order topological neighbourhood as well, although the method is primarily based on determining distance-based auto-correlations. The approach which took topological relations into consideration did not result in significant differences in parameter estimates, although it had a somewhat better fit (higher R2 and lower AIC value). This calls attention to the problems of applying distance approaches in the case of very unevenly sized irregular configurations. By the decomposition of variables to spatial and non-spatial components and by the explicit expression of spatial effects, the independence assumption of error components can be fulfilled. As a consequence, it is possible to return to using the traditional Ordinary Least Squares (OLS) method. The most important finding of our research was that the relationship between voting turnout and votes cast for the winning party in Budapest in 2010 was unjustifiable. Relying on the OLS method and disregarding spatial effects led to serious consequences; it resulted in biased estimations. For this reason, we emphasize the importance of handling auto-correlations properly in the case of spatial data
Butterfly and skipper records from Lebanon (Lepidoptera: Papilionoidea)
Eighty-five specimens of 30 papilionoid species have been collected in Lebanon during entomological expeditions launched in 2015 and 2016 by the joint project of the Hungarian Natural History Museum and the Holy Spirit University of Kaslik. Th e collecting sites and events are listed, and the species annotated. With 23 figures
Application and assessment of a GPU-based LES method for predicting dynamic wind loads on buildings
This study presents the assessment of a fast Large Eddy Simulation method for estimating dynamic wind loads on buildings using a GPU-based CFD software, which produces statistically converged results on a nine-million-cell mesh in approximately 6 hours. The surface pressure distribution of a cuboid building model was validated with experimental data obtained in an atmospheric boundary layer wind tunnel and compared with field measurements. Although due to the applied equidistant Cartesian grid the large gradients near the edges are not fully resolved, good overall agreement was found for the mean and fluctuating pressure distributions (correlation coefficient: 0.90/0.73, FAC2: 0.92/0.98, FB: −/0.06, MG: −/0.95, NMSE: −/0.10, VG: −/1.08). It was shown that the numerical model is able to produce matching turbulent spectra in an intermediate frequency range within the inertial subrange, limited by the domain size and the spatial resolution. Mesh refinement for capturing large gradients as well as for expanding the frequency limits can be achieved by using a GPU with higher VRAM capacity for the simulation. The continuing advancement of the presented model is a promising development for estimating dynamic wind loads on buildings and identifying design problems fast enough for the engineering practice, without high-performance computing
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