Problems of Harmonic Analysis Related to Finite-Type Hypersurfaces in R3, and Newton Polyhedra Detlef Müller

This chapter presents three sets of problems and explains how these questions can be answered in an (almost) complete way in terms of Newton polyhedra associated to the given surface S (here, a smooth, finite type hypersurface in R³ with Riemannian surface measure dσ‎). The first problem is a classical question about estimates for oscillatory integrals, and there exists a huge body of results on it, in particular for convex hypersurfaces. The other two problems had first been formulated by Stein: the study of maximal averages along hypersurfaces has been initiated in Stein's work on the spherical maximal function, and also the idea of Fourier restriction goes back to him.

Author(s):  
Isroil A. Ikromov ◽  
Detlef Müller

This is the first book to present a complete characterization of Stein–Tomas-type Fourier restriction estimates for large classes of smooth hypersurfaces in three dimensions, including all real-analytic hypersurfaces. The range of Lebesgue spaces for which these estimates are valid is described in terms of Newton polyhedra associated to the given surface. The book begins with Elias M. Stein's concept of Fourier restriction and some relations between the decay of the Fourier transform of the surface measure and Stein–Tomas-type restriction estimates. Varchenko's ideas relating Fourier decay to associated Newton polyhedra are briefly explained, particularly the concept of adapted coordinates and the notion of height. It turns out that these classical tools essentially suffice already to treat the case where there exist linear adapted coordinates, and thus the book concentrates on the remaining case. Here the notion of r-height is introduced, which proves to be the right new concept. The book then describes decomposition techniques and related stopping time algorithms that allow to partition the given surface into various pieces, which can eventually be handled by means of oscillatory integral estimates. Different interpolation techniques are presented and used, from complex to more recent real methods by Bak and Seeger. Fourier restriction plays an important role in several fields, in particular in real and harmonic analysis, number theory, and PDEs. This book will interest graduate students and researchers working in such fields.


2018 ◽  
Vol 4 (1) ◽  
pp. 105-123
Author(s):  
Ágnes Langó-Tóth

Abstract In this study an experiment is presented on how Hungarian children interpret two word orders of recursive PPs (subject-PP-verb and PP-subject-verb order). According to the research of Roeper (2011) and Hollebrandse and Roeper (2014), children tend to give conjunctive interpretation to multiple embedded sentences at the beginning of language acquisition. This interpretation later turns into an adult-like, recursive interpretation. Our aim is to discover (i) whether Hungarian children start with conjunction as well, and whether (ii) the apparently more salient functional head lévő appearing in Hungarian recursive PPs can help them to acquire the correct, recursive interpretation early. We also want to find out whether (iii) the word orders in recursive PPs have an influence on the acquisition of children. In this paper two experiments are presented conducted with 6 and 8-year-olds and adults, in which the participants were asked to choose between two pictures. One of the pictures depicted recursive and the other one depicted conjunctive interpretation of the given sentence. In the first experiment subject-PP-verb order was tested, but in the second one sentences were tested with PP-subject-verb order. We will claim that lévő, which is (arguably) a more salient Hungarian functional element than -i, does not help children to acquire the embedded reading of recursive sentences, because both of them are overt functional heads. However, the two types of word orders affect the acquisition of recursive PPs. PP-subject-verb order is easier to compute because the order of the elements in the sentences and the order of the elements in the pictures matches.


1994 ◽  
Vol 29 (7) ◽  
pp. 327-333
Author(s):  
Y. Matsui ◽  
F. Yamaguchi ◽  
Y. Suwa ◽  
Y. Urushigawa

Activated sludges were acclimated to p-nitrophenol (PNP) in two operational modes, a batch and a continuous. The operational mode of the PNP acclimation of activated sludges strongly affected the physiological characteristics of predominant microorganisms responsible for PNP degradation. Predominant PNP degraders in the sludge in batch mode (Sludge B) had lower PNP affinity and were relatively insensitive to PNP concentration. Those of the sludge in continuous mode (Sludge C), on the other hand, had very high PNP affinity and were sensitive to PNP. MPN enumeration of PNP degraders in sludge B and C using media with different PNP concentrations (0.05, 0.2,0.5 and 2.0 mM) supported the above results. Medium with 0.2 mM of PNP did not recover PNP degraders in sludge C well, while it recovered PNP degraders in sludge B as well as the medium with 0.05 mM did. When switching from one operational mode to the other, the predominant population in sludge B shifted to the sensitive group, but that of sludge C did not shift at the given loading of PNP, showing relative resistance to inhibitive concentration.


Author(s):  
Jean-Yves Lacoste ◽  
Oliver O’Donovan

Giving and promise must be thought together. Being-in-the world entails being-with the other, who is both “given” and bearer of a gift promised. But any disclosure may be understood as a gift; it is not anthropomorphic to speak of “self-giving” with a wider reference than person-to-person disclosure. Which implies that no act of giving can exhaust itself in its gift. Present experience never brings closure to self-revealing. Yet giving is crystallized into “the given,” the closure of gift. “The given” is what it is, needing no gift-event to reveal it. But the given, too, is precarious, and can be destabilized when giving brings us face to face with something unfamiliar. Nothing appears without a promise of further appearances, and God himself can never be “given.”


Author(s):  
Meng-Shiun Tsai ◽  
Ying-Che Huang

In this paper, an integrated acceleration/deceleration with dynamics interpolation scheme is proposed to confine the maximum contour error at the junction of linear junction. The dynamic contour error equation is derived analytically and then it is utilized for the interpolation design. Based on the derived formulations which could predict the command and dynamic errors, the advanced interpolation design could adjust the connecting velocity of the two blocks to confine the overall contour errors under the given tolerance. Simulation results validate the proposed algorithm can achieve higher accurate trajectory as compared to the other interpolation algorithm proposed in the past.


Lipar ◽  
2020 ◽  
Vol XXI (73) ◽  
pp. 203-216
Author(s):  
Jovana Milovanović ◽  

This article discusses reception and production of academic vocabulary among native speakers of Serbian language. Academic vocabulary is one of the key elements of academic language competence, and a modest lexicon and underdeveloped academic language competence can cause problems in both comprehension and production. In this research, we used a vocabulary test consisting of 12 items taken from general culture entrance exams used at the Faculty of Philosophy, University of Belgrade. The participants are BA students of French language at the Faculty of Philology, University of Belgrade, years 1-4. The participants were instructed to provide a synonym or a definition for each item, as well as a sentence containing the given word. The aim of this research is to highlight issues in comprehension of academic vocabulary and establish the influence of factors such as word etymology or university level on the success of the participants. We analysed the results and classified them in three categories: correct, incorrect and unanswered. The majority of participants successfully identified just half of the given words (in order of success: poliglota 95,76%, bestseler 92,37%, pacifista 66,10%, suveren 58,47%, prototip 57,63%, elokventan 56,78%). The success level for the other half of the items from the test was below 50% (in order of success: erudita 49,15%, hipokrizija 39,83%, nepotizam 22,03%, skrupulozan 18,64%, šprahfeler 10,17%, eksproprijacija 8,47%). The influence of etymology was analysed through a comparison of the results for six items of French/Latin origin with the results for the other six items which did not originate from Romance languages. This analysis shows that the participants had similar results in both groups of items, with three words from each group having above 50% of correct answers (suveren, elokventan, pacifista; poliglota, bestseler, prototip). Lastly, we examined success levels from year 1, year 2, year 3 and year 4 students and determined that the median of correct answers for each year does vary, but that there is no strong linear progression (median year 1=5, year 2=6, year 3=7, year 4=6). The results indicate a lack of knowledge of academic vocabulary and difficulties in identifying and manipulating this type of lexis. We believe it is necessary to integrate academic language skills, including academic vocabulary, in high school curriculum and introduce Serbian language as a subject at university level.


2021 ◽  
Vol 12 (3) ◽  
pp. 150-156
Author(s):  
A. V. Galatenko ◽  
◽  
V. A. Kuzovikhina ◽  

We propose an automata model of computer system security. A system is represented by a finite automaton with states partitioned into two subsets: "secure" and "insecure". System functioning is secure if the number of consecutive insecure states is not greater than some nonnegative integer k. This definition allows one to formally reflect responsiveness to security breaches. The number of all input sequences that preserve security for the given value of k is referred to as a k-secure language. We prove that if a language is k-secure for some natural and automaton V, then it is also k-secure for any 0 < k < k and some automaton V = V (k). Reduction of the value of k is performed at the cost of amplification of the number of states. On the other hand, for any non-negative integer k there exists a k-secure language that is not k"-secure for any natural k" > k. The problem of reconstruction of a k-secure language using a conditional experiment is split into two subcases. If the cardinality of an input alphabet is bound by some constant, then the order of Shannon function of experiment complexity is the same for al k; otherwise there emerges a lower bound of the order nk.


2001 ◽  
Vol 56 (1-2) ◽  
pp. 89-94 ◽  
Author(s):  
Reinhold Deml

Abstract Scolus secretions and hemolymph of caterpillars of Satumia pyri fed with two different foodplants (Crataegus monogyna, Prunus spinosa) were chemically analyzed and their chemical similarities determined. The secondary-compound patterns obtained for the two body fluids showed no significant differences when compared between the two groups of alterna­ tively fed last-instar larvae. Thus, the composition of these fluids of full-grown caterpillars is not influenced by the larval diet. However, younger larvae on P. spinosa revealed a diversity of compounds differing significantly from that of larger caterpillars fed with either C. mono­gyna (both body fluids) or P. spinosa (hemolymph only). This indicates that, on the one hand, the hemolymph composition is adapted to the changing physiological requirements of the given instars whereas, on the other hand, the defensive mixtures remain unaltered in the late larval instars due to a constant spectrum of potential enemies.


2019 ◽  
Vol 150 (4) ◽  
pp. 1853-1870 ◽  
Author(s):  
R. I. Dmytryshyn

AbstractIn the paper the correspondence between a formal multiple power series and a special type of branched continued fractions, the so-called ‘multidimensional regular C-fractions with independent variables’ is analysed providing with an algorithm based upon the classical algorithm and that enables us to compute from the coefficients of the given formal multiple power series, the coefficients of the corresponding multidimensional regular C-fraction with independent variables. A few numerical experiments show, on the one hand, the efficiency of the proposed algorithm and, on the other, the power and feasibility of the method in order to numerically approximate certain multivariable functions from their formal multiple power series.


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