627 resultados para Szemeredi`s regularity lemma
Resumo:
2000 Mathematics Subject Classification: 60H15, 60H40
Resumo:
In the proof of Lemma 3.1 in [1] we need to show that we may take the two points p and q with p ≠ q such that p+q+(b-2)g21(C′)∼2(q1+… +qb-1) where q1,…,qb-1 are points of C′, but in the paper [1] we did not show that p ≠ q. Moreover, we hadn't been able to prove this using the method of our paper [1]. So we must add some more assumption to Lemma 3.1 and rewrite the statements of our paper after Lemma 3.1. The following is the correct version of Lemma 3.1 in [1] with its proof.
Resumo:
2000 Mathematics Subject Classification: 49J15, 49J30, 53B50.
Resumo:
MSC 2010: 26A33, 34A08, 34K37
Resumo:
We study the statistical and dynamical behavior of turbulent Kelvin waves propagating on quantized vortices in superfluids and address the controversy concerning the energy spectrum that is associated with these excitations. Finding the correct energy spectrum is important because Kelvin waves play a major role in the dissipation of energy in superfluid turbulence at near-zero temperatures. In this paper, we show analytically that the solution proposed by [L’vov and Nazarenko, JETP Lett. 91, 428 (2010)] enjoys existence, uniqueness, and regularity of the prefactor. Furthermore, we present numerical results of the dynamical equation that describes to leading order the nonlocal regime of the Kelvin-wave dynamics. We compare our findings with the analytical results from the proposed local and nonlocal theories for Kelvin-wave dynamics and show an agreement with the nonlocal predictions. Accordingly, the spectrum proposed by L’vov and Nazarenko should be used in future theories of quantum turbulence. Finally, for weaker wave forcing we observe an intermittent behavior of the wave spectrum with a fluctuating dissipative scale, which we interpreted as a finite-size effect characteristic of mesoscopic wave turbulence.
Resumo:
A kohéziós politika hatékonyságát, eredményességét és szabályszerűségét a nemzetállami szint mellett közösségi szinten is értelmezhetjük. Azonban a közösségi szint nem a tagállami részek összege, hanem annál sokkal jelentősebb. Ha a közösségi szinten nem támasztható alá a kohéziós politika szükségszerűsége, akkor annak költségvetése és ezáltal jelentősége az EU következő pénzügyi perspektívájában csökkenhet, amelynek súlyos kihatásai lennének a tagállamok és régióik közötti kohéziós folyamatokra. Éppen ezért fontos a kohéziós politika objektív és részletes elemzése tagállami szinten, valamint a közösségi szintű kohéziós politika kritikáinak és a különböző reformelképzeléseknek vizsgálata. / === / The efficiency, effectiveness and regularity of cohesion policy can be defined both on the community level and on the national level. But the community level more than the sum of the member states. If the necessity of the cohesion policy cannot be backed sufficiently, then its budget of the policy can be decreased in the next financial framework of the EU. This could deeply undermine the process of convergence of the less developed regions of the member states. This is why the objective and detailed analysis of the cohesion policy is important, together with knowing the criticisms and reform proposals of the community level cohesion policy.
Resumo:
A dolgozat célja, hogy rövid bevezetést adjon a folytonos idejű sztochasztikus analízisbe. A hazai pénzügyi oktatási gyakorlat nagyrészt a diszkrét idejű és gyakran diszkrét állapotterű modellekre épül. Ennek oka a folytonos időparaméterű sztochasztikus folyamatok elméletétől való érthető idegenkedés. A folytonos időparaméterű sztochasztikus analízis a modern matematika egyik csúcsteljesítménye, amely teljeskörű matematikai megértése egyrészt feltételezi, hogy az olvasó tisztában van a modern analízis szinte minden részletével; másrészt a matematikai részletek pontos megértése nem sok segítséget jelent a pénzügyi gondolatok elsajátításakor. / === / In the article we present a short, intuitive introduction to stochastic analysis. Our presentation is aimed for economist and we try to discuss only the most elementary properties of the stochastic analysis. Instead of precise proofs we present some simplified intuitive arguments. The central concept of the discussion is the quadratic variation and the Itō's lemma.
Resumo:
This study compares the effects of cooperative delivery (CD) and individual delivery (ID) of integrated learning system (ILS) instruction in mathematics on achievement, attitudes and behaviors in adult (16-21 yrs.) high school students (grades 9-13). The study was conducted in an urban adult high school in Miami-Dade County Public Schools using a pre-test/post-test design. Achievement was measured using the Test of Adult Basic Education (TABE) by CTB MC-Graw-Hill and Compass Learning. An attitudinal survey measured attitudes towards mathematics, the computer-related lessons, and attitudes toward group activities. Behavior was assessed using computer lab observations. ^ Two-way analyses of variance (ANOVA) were conducted on achievement (TABE and Compass) by group and time (pre and post). A one-way ANOVA was conducted on the overall attitude by group on the five components (i.e., content mathematics, delivery/computers, cooperative, partners, and self efficacy) and a one-way ANOVA was conducted on the on-task behavior by group. ^ The results of the study revealed that CD and ID students working on mathematics activities delivered by the ILS performed similarly on achievement tests of the TABE. The CD-ILS students had significantly better overall mathematics attitudes than the ID-ILS students and the ID-ILS group was on-task significantly more than the CD-ILS group. This study concludes that regularity and period of time over which the ILS is used may prove to be important variables although there were insufficient data to fully investigate the impact of models of use. Additionally, a minimum amount of time-on-system is necessary before gains can become apparent in innumeracy and increasing exposure to the system may have beneficial effects on learning. ^
Resumo:
ABSTRACT This study aimed to evaluate the quality of prenatal Primary Care in Rio G rande do Norte, Brazil in 2012 under the program Improving Access and Quality of Primary Care. The study was cross - sectional, quantitative. Included 156 mothers of children under 2 years who received prenatal care at the health evaluated. We applied a ques tionnaire on profile, minimum queries, regularity of attendance, laboratory tests, vaccination, participation in educational activities, guidance received, clinical and obstetric procedures and prescription Ferrous sulphate and folic acid. The descriptive analysis of the criteria used Humanization Program Prenatal and Birth. The results showed that 92% of mothers had six or more visits; 85% with the same care was professional; 94% subsequent appointments scheduled. As for tests and procedures the percentage s were: Urine 98%; HIV - 96%; VDRL and 88%; 91% glucose; tetanus vaccination 93%; educational groups 56% with 36% participation, knowledge of the delivery location and 59% achievement breast exam 65%, 33% and preventive gynecological 43%; 98% supplemented wi th 96% Ferrous Sulfate and Folic Acid. It was concluded that there were advances in Rio Grande do Norte concerning assistance and there are weaknesses in the educational practices and conducting some minimal clinical examinations.
Resumo:
A new generalized schematic map of distribution of recent sediments within Eurasian Arctic shelves is considered. The sediments have accumulated as a result of interaction of various factors and processes specific to high latitudes. They include input of terrigenous material by modern glaciers, ice transport, thermal abrasion, sedimentation controlled by many years of ice cover, and others. Characteristic regularity is marked over Arctic shelves: in seas with heavier ice cover, the most fine-grained deposits are distributed, they contain minimum amount of coarse-grained ice rafted debris; in seas with lighter ice cover mosaic distribution of various types of sediments is observed. Composition of surface sediments from the Arctic shelves corresponds to a relatively cool stage of the modern interglacial period. In the 21-st century a new warming is expected.
Resumo:
The paper considers various extended asymmetric multivariate conditional volatility models, and derives appropriate regularity conditions and associated asymptotic theory. This enables checking of internal consistency and allows valid statistical inferences to be drawn based on empirical estimation. For this purpose, we use an underlying vector random coefficient autoregressive process, for which we show the equivalent representation for the asymmetric multivariate conditional volatility model, to derive asymptotic theory for the quasi-maximum likelihood estimator. As an extension, we develop a new multivariate asymmetric long memory volatility model, and discuss the associated asymptotic properties.
Resumo:
This research analyzes the average previous stressed vowels [ε] and [e] and later [ɔ] and [o] in nominal and verbal forms in the 1st person singular and 3rd person singular and plural in the present tense, specifically the umlaut process of mid vowels /e/ and /o/, which assimilate in /ε/ and /ᴐ/ in stressed position. The general objective of this research is to describe and quantify the occurrence of umlaut and subsequently analyze in which words there is regularity or not. As specific objectives we have: i) to compile and to label an oral, spontaneous, synchronic and regional corpus, from radio programs produced in the city of Ituiutaba, Minas Gerais; ii) to describe the characteristics of the corpus to be compiled; iii) to investigate the alternating timbre of mid vowels in stressed position; iv) to identify instances of nominal and verbal umlaut of the middle vowels in stressed position; v) to describe the identified cases of nominal and verbal umlaut; vi) to analyze the probable causes for the variation of the middle vowels. To perform the proposed analysis, we have adopted as a theoretical-methodological basis multi-representational models: Phonology of Use (BYBEE, 2001) and Exemplar Theory (PIERREHUMBERT, 2001) combined with the precepts of Corpus Linguistics (BEBER SARDINHA, 2004). The corpus consisted of 16 radio programs – eight political and eight religious – from the city of Ituiutaba-MG, with recordings of about 20 to 40 minutes. We note, by means of the results generated by WordSmith Tools® software, version 6.0 (SCOTT, 2012), that the analyzed forms show little variation, which shows that the umlaut is a process already lexicalized in participants of the radio programs analyzed. We conclude that the results converge with the proposal of the Phonology of Use (BYBEE, 2001; PHILLIPS, 1984) that less frequent words that have no phonetic environment conducive to change, are changed first.
Resumo:
After the 2012 London Summit on Family Planning, there have been major strides in advancing the family planning agenda for low and middle-income countries worldwide. Much of the existing infrastructure and funding for family planning access is in the form of supplying free contraceptives to countries. While the average yearly value of donations since 2000 was over 170 million dollars for contraceptives procured for developing countries, an ongoing debate in the empirical literature is whether increases in contraceptive access and supply drive declines in fertility (UNFPA 2014).
This dissertation explores the fertility and behavioral effects of an increase in contraceptive supply donated to Zambia. Zambia, a high-fertility developing country, receives over 80 percent of its contraceptives from multilateral donors and aid agencies. Most contraceptives are donated and provided to women for free at government clinics (DELIVER 2015). I chose Zambia as a case study to measure the relationship between contraceptive supply and fertility because of two donor-driven events that led to an increase in both the quantity and frequency of contraceptives starting in 2008 (UNFPA 2014). Donations increased because donors and the Zambian government started a systematic method of forecasting contraceptive need on December 2007, and the Mexico City Policy was lifted in January 2009.
In Chapter 1, I investigate whether a large change in quantity and frequency of donated contraceptives affected fertility, using available data on contraceptive donations to Zambia, and birth records from the 2007 and 2013 Demographic and Health Surveys. I use a difference-in-difference framework to estimate the fertility effects of a supply chain improvement program that started in 2011, and was designed to ensure more regularity of contraceptive supply. The increase in total contraceptive supply after the Mexico City Policy was rescinded is associated with a 12 percent reduction in fertility relative to the before period, after controlling for demographic characteristics and time controls. There is evidence that a supply chain improvement program led to significant fertility declines for regions that received the program after the Mexico City Policy was rescinded.
In Chapter 2, I explore the effects of the large increase in donated contraceptives on modern contraceptive uptake. According to the 2007 and 2013 Demographic and Health Surveys, there was a dramatic increase in current use of injectables, implants, and IUDs. Simultaneously, declines occurred in usage of condoms, lactational amenorrhea method (LAM), and traditional methods. In this chapter, I estimate the effect of the increase in donations on uptake, composition of contraceptive usage, and usage of methods based on distance to contraceptive access points. The results show the post-2007 period is associated with an increase in usage of injectables and the pill among women living further away from access points.
In Chapter 3, I explore attitudes towards the contraceptive supply system, and identify areas for improvement, based on qualitative interviews with 14 experts and 61 Zambian users and non-users of contraceptives. The interviews uncover systemic barriers that prevent women from consistently accessing methods, and individual barriers that exacerbate the deficiencies in supply chain procedures. I find that 39 out of 61 women interviewed, both users and non-users, had personal experiences with stock out. The qualitative results suggest that the increase in contraceptives brought to the country after 2007 may have not contributed to as large of a decline in fertility because of bottlenecks in the supply chain, and problems in maintaining stock levels at clinics. I end the chapter with a series of four recommendations for improvements in the supply chain going forward, in light of recent commitments by the Zambian government during the 2012 London Summit on Family Planning.
Resumo:
Laminated sediments spanning the last 20,000 years (though not continuously) in the Shaban Deep, a brine-filled basin in the northern Red Sea, were analyzed microscopically and with backscattered electron imagery in order to determine laminae composition with emphasis on the diatomaceous component. Based on this detailed study, we present schematic models to propose paleoflux scenarios for laminae formation at different time-slices. The investigated core (GeoB 5836-2; 26°12.61'N, 35°21.56'E; water depth 1475 m) shows light and dark alternating laminae that are easily distinguishable in the mid-Holocene and at the end of the deglaciation (13-15 ka) period. Light layers are mainly composed of coccoliths, terrigenous material and diatom fragments, while dark layers consist almost exclusively of diatom frustules (monospecific or mixed assemblages). The regularity in the occurrence of coccolith/diatom couplets points to an annual deposition cycle where contrasting seasons and associated plankton blooms are represented (diatoms-fall/winter deposition, coccoliths-summer signal). We propose that, for the past ~15,000 years, the laminations represent two-season annual varves. Strong dissolution of carbonate, with the concomitant loss of the coccolith-rich layer in sediments older than 15 ka, prevents us from presenting a schematic model of annual deposition. However, the diatomaceous component reveals a marked switch in species composition between Last Glacial Maximum (LGM) sediments (dominated by Chaetoceros resting spores) and sediments somewhat younger (18-19 ka; dominated by Rhizosolenia). We propose that different diatom assemblages reflect changing conditions in stratification in the northern Red Sea: Strong stratification conditions, such as during two meltwater pulses at 14.5 and 11.4 ka, are reflected in the sediment by Rhizosolenia layers, while Chaetoceros-dominated assemblages represent deep convection conditions.
Resumo:
The lamination and burrowing patterns in 17 box cores were analyzed with the aid of X-ray photographs and thin sections. A standardized method of log plotting made statistical analysis of the data possible. Several 'structure types' were established, although it was realized that the boundaries are purely arbitrary divisions in what can sometimes be a continuous sequence. In the transition zone between marginal sand facies and fine-grained basin facies, muddy sediment is found which contains particularly well differentiated, alternating laminae. This zone is also characterized by layers rich in plant remains. The alternation of laminae shows a high degree of statistical scattering. Even though a small degree of cyclic periodicity could be defined, it was impossible to correlate individual layers from core to core across the bay. However, through a statistical handling of the plots, zones could be separated on the basis of the number of sand layers they contained. These more or minder sandy zones clarified the bottom reflections seen in the records of the echograph from the area. The manner of facies change across the bay, suggests that no strong bottom currents are effective in the Eckernförde Bay. The marked asymmetry between the north and south flanks of the profile can be attributed to the stronger action of waves on the more exposed areas. Grain size analyses were made from the more homogeneous units found in a core from the transition-facies zone. The results indicate that the most pronounced differences between layers appear in the silt range, and although the differences are slight, they are statistically significant. Layers rich in plant remains were wet-sieved in order to separate the plant detritus. This was than analyzed in a sediment settling balance and found to be hydrodynamically equivalent to a well-sorted, finegrained sand. A special, rhythmic cross-bedding type with dimensions in the millimeter range, has been named 'Crypto-cross-lamination' and is thought to represent rapid sedimentation in an area where only very weak bottom currents are present. It is found only in the deepest part of the basin. Relatively large sand grains, scattered within layers of clayey-silty matrix, seem to be transported by flotation. Thin section examination showed that the inner part of Eckernförder Bay carbonate grains (e. g. Foraminifera shells) were preserved throughout the cores, while in the outer part of the bay they were not present. Well defined tracks and burrows are relatively rare in all of the facies in comparision to the generally strongly developed deformation burrowing. The application of special measures for the deformation burrowing allowed to plot their intensity in profile for each core. A degree of regularity could be found in these burrowing intensity plots, with higher values appearing in the sandy facies, but with no clear differences between sand and silt layers in the transition facies. Small sections in the profiles of the deepest part of the bay show no bioturbation at all.