Praktické datové struktury

V této práci implementujeme datové struktury pro uspořádané a neuspořádané slovníky a měříme jejich výkon v hlavní paměti pomocí syntetických i praktických experimentů. Náš průzkum zahrnuje jak obvyklé datové struktury (B-stromy, červeno-černé stromy, splay stromy a hashování), tak exotičtější přístupy (k-splay stromy a k-lesy). Powered by TCPDF (www.tcpdf.org)In this thesis, we implement several data structures for ordered and unordered dictionaries and we benchmark their performance in main memory on synthetic and practical workloads. Our survey includes both well-known data structures (B-trees, red-black trees, splay trees and hashing) and more exotic approaches (k-splay trees and k-forests). Powered by TCPDF (www.tcpdf.org)Department of Applied MathematicsKatedra aplikované matematikyMatematicko-fyzikální fakultaFaculty of Mathematics and Physic

Exogenous delivery of water to Mercury

Radar and spacecraft observations show the permanently shadowed regions around Mercury's North Pole to contain water ice and complex organic material. One possible source of this material are impacts by interplanetary dust particles (IDPs), asteroids, and comets. We have performed numerical simulations of the dynamical evolution of asteroids and comets over the few Myr and checked for their impacts with Mercury. We use the N-body integrator RMVS/Swifter to propagate the Sun and the eight planets from their current positions. We add comets and asteroids to the simulations as massless test particles, based on their current orbital distributions. Asteroid impactors are assigned a probability of being water-rich (C-class) based on the measured distribution of taxonomic types. For comets, we assume a constant water fraction. For IDPs, we use a dynamical meteoroid model to compute the dust flux on Mercury. Relative to previous work on asteroid and comet impacts (Moses et al. 1999), we leverage 20 years of progress in minor body surveys. Immediate post-impact ejection of impactor material into outer space is taken into account as is the migration efficiency of water across Mercury's surface to the polar cold traps. We find that asteroids deliver $\sim 1 \times 10^{3}$ kg/yr of water to Mercury, comets deliver $\sim 1 \times 10^{3}$ kg/yr and IDPs deliver $\sim 16 \times 10^{3}$ kg/yr within a factor of several. Over a timescale of $\sim 1$ Gyr, this is enough to deliver the minimum amount of water required by the radar and MESSENGER observations. While other sources of water on Mercury are not ruled out by our analysis, we show that they are not required to explain the currently available observational lower limits.Comment: 38 pages, 10 figures, published in Icaru

Disentangling the pollen signal from fen systems : modern and Holocene studies from southern and eastern England

Thick deposits of peat derived from fen environments accumulated in the coastal lowland areas adjacent to the North Sea during the middle and late Holocene. These sediments are frequently used in pollen-based reconstructions of in situ and more distant vegetation. However, discriminating between wetland and dry land originating pollen signals, and between the potential fen communities present in the wetland, is complex. In this study, a suite of analytical approaches are used to explore the pollen signal of modern fen communities and compare them against Holocene pollen assemblages. At two sites in eastern England, Woodwalton Fen and Upton Broad, vegetation composition was recorded around a series of moss polster sampling points. The communities investigated included herbaceous fen communities under different cutting regimes, a grazed area, glades, and woodland with canopies dominated by Alnus glutinosa and Betula. Cluster analysis is used to provide an overview of, and compare the structure within, the datasets consisting of the vegetation, the vegetation converted to palynological equivalents, and the pollen data. It is demonstrated that any loss of taxonomic precision in pollen identifications does not pose particular problems when attempting to identify fen communities, including tall-herbaceous vegetation, in the pollen record. Indices of Association imply pollen presence can be interpreted as indicating the local presence for some taxa, though few of these are confined to a particular community. Herbaceous fen vegetation subject to different management regimes are, however, shown to produce distinctive pollen signatures. Middle and late Holocene pollen assemblages from eastern (Fenland) and southern (Romney Marsh) England, interpreted as derived from fen vegetation, are compared against the modern pollen dataset using ordination. Most of the fossil samples plot out within or adjacent to the groupings produced by the modern samples in the ordinations. While these investigations demonstrate that modern pollen work can help improve the interpretation of Holocene assemblages they also call attention to a number of limitations including the restricted range of communities from which modern samples are currently available and the potential for non-analogous modern vegetation. The paper concludes with ideas to aid the interpretation of pollen data collected from fen peats and suggestions for future work

Biomarkers of Nutrition for Development (BOND)—Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health. The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation

What affects the attendance demand of handball matches?

In this bachelor thesis is analyzed the attendance demand of handball matches in the Czech Republic and in Germany. The research is based on data about 516 matches of highest handball competition in the Czech Republic (Extraliga) and 918 matches of highest handball competition in Germany (Bundesliga). One of the main differences is that Czech spectators care only about short-term performance of home team and long-term performance of away team, but in Germany care about short-term and long-term performance of both, home and away team. Next one is the influence of temperature. In Extraliga there is an optimal point of temperature 8,75°C. In Bundesliga the attendance is decreasing while the temperature is rising. In both countries is the attendance decreasing while the distance is increasing (the Czech Republic 3,2% per 100km, Germany 0,8% per 100km). If the match was broadcasted on television the attendance demand was higher (in the Czech Republic by 12,3%, in Germany by 14%). The reason is that the variable means more the attractiveness and importance of match than the substation. The same is also that playing in afternoon hours is the best option; in Czech is the attendance bigger at weekends than in weekdays. Next result was that there is no competition with more popular sports (in Czech Republic with football and ice-hockey, in Germany with football). Home team fixed effects results show the same thing that the average attendances show. In Germany the attendance is about 10 times higher. Season fixed effects results show the decrease of attendance in season 2011/12

Analysis of the Determinants of the Formation of Flat Prices

Cílem této práce bylo analyzovat tvorbu prodejních cen bytů v České republice. Na základě dosavadních poznatků a ekonomické teorie byl vytvořen ekonomický model a zkonstruovány proměnné, které by mohly cenu bytů ovlivňovat. Ke zkoumání těchto vlivů bylo shromážděno 1100 pozorování bytů v 8 městech České republiky. Pomocní regresní analýzy a odhadem modelu metodou nejmenších čtverců byl vliv těchto faktorů změřen. Jako nejvýraznější faktory ovlivňující cenu bych uvedl: s každým metrem čtverečním plochy roste cena bytu přibližně o 1,28%. Dále bylo vyzkoumáno, že byty v přízemí jsou výrazně levnější než všechny ostatní byty, rozdíl roste až do pátého patra, pokud je byt v patře posledním, cena naopak klesá. Z ostatních proměnných pak má nejvyšší vliv na cenu, pokud je součástí bytu balkon, a sice balkon zvýší cenu o téměř 33%. Z koeficientů fixních efektů lokality je zřejmé, že nejdražší byty jsou v Praze, nejlevnější v Ústí nad Labem.In this diploma thesis are analyzed selling prices of flats in Czech Republic. Based on literature and economic theory about similar topic was made economic model and constructed variables, which could have effect on the price. For the analysis were used information about 1100 flats in 8 Czech cities. The effect of the variables was measured using ordinary least square method. Increase of size of the flat by one squared meter cause 1,28% increase of price. Price of flats in ground floor is lower than other flats. This effect raises until fifth floor. Flats in last floor are cheaper than others. The effect of balcony is almost 33% higher price. Fixed effects of cities give the results that Prague is the most attractive, at the end is Ústí nad Labem

Analysis of the Determinants of the Formation of Flat Prices

In this diploma thesis are analyzed selling prices of flats in Czech Republic. Based on literature and economic theory about similar topic was made economic model and constructed variables, which could have effect on the price. For the analysis were used information about 1100 flats in 8 Czech cities. The effect of the variables was measured using ordinary least square method. Increase of size of the flat by one squared meter cause 1,28% increase of price. Price of flats in ground floor is lower than other flats. This effect raises until fifth floor. Flats in last floor are cheaper than others. The effect of balcony is almost 33% higher price. Fixed effects of cities give the results that Prague is the most attractive, at the end is Ústí nad Labem

Praktické datové struktury

In this thesis, we implement several data structures for ordered and unordered dictionaries and we benchmark their performance in main memory on synthetic and practical workloads. Our survey includes both well-known data structures (B-trees, red-black trees, splay trees and hashing) and more exotic approaches (k-splay trees and k-forests). Powered by TCPDF (www.tcpdf.org