567,595 research outputs found
On Generalized Pseudostandard Words Over Binary Alphabets
International audienceIn this paper, we study generalized pseudostandard words over a two-letter alpha- bet, which extend the classes of standard Sturmian, standard episturmian and pseu- dostandard words, allowing different involutory antimorphisms instead of the usual palindromic closure or a fixed involutory antimorphism. We first discuss about pseu- doperiods, a useful tool for describing words obtained by iterated pseudopalindromic closure. Then, we introduce the concept of normalized directive bi-sequence (Θ,w) of a generalized pseudostandard word, that is the one that exactly describes all the pseudopalindromic prefixes of it. We show that a directive bi-sequence is normalized if and only if its set of factors does not intersect a finite set of forbidden ones. Moreover, we provide a construction to normalize any directive bi-sequence. Next, we present an explicit formula, generalizing the one for the standard episturmian words introduced by Justin, that computes recursively the next prefix of a generalized pseudostandard word in term of the previous one. Finally, we focus on generalized pseudostandard words having complexity 2n, also called Rote words. More precisely, we prove that the normalized bi-sequences describing Rote words are completely characterized by their factors of length 2
Generalized resolution for orthogonal arrays
The generalized word length pattern of an orthogonal array allows a ranking
of orthogonal arrays in terms of the generalized minimum aberration criterion
(Xu and Wu [Ann. Statist. 29 (2001) 1066-1077]). We provide a statistical
interpretation for the number of shortest words of an orthogonal array in terms
of sums of values (based on orthogonal coding) or sums of squared
canonical correlations (based on arbitrary coding). Directly related to these
results, we derive two versions of generalized resolution for qualitative
factors, both of which are generalizations of the generalized resolution by
Deng and Tang [Statist. Sinica 9 (1999) 1071-1082] and Tang and Deng [Ann.
Statist. 27 (1999) 1914-1926]. We provide a sufficient condition for one of
these to attain its upper bound, and we provide explicit upper bounds for two
classes of symmetric designs. Factor-wise generalized resolution values provide
useful additional detail.Comment: Published in at http://dx.doi.org/10.1214/14-AOS1205 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Generalized trapezoidal words
The factor complexity function of a finite or infinite word
counts the number of distinct factors of of length for each .
A finite word of length is said to be trapezoidal if the graph of its
factor complexity as a function of (for ) is
that of a regular trapezoid (or possibly an isosceles triangle); that is,
increases by 1 with each on some interval of length , then
is constant on some interval of length , and finally
decreases by 1 with each on an interval of the same length . Necessarily
(since there is one factor of length , namely the empty word), so
any trapezoidal word is on a binary alphabet. Trapezoidal words were first
introduced by de Luca (1999) when studying the behaviour of the factor
complexity of finite Sturmian words, i.e., factors of infinite "cutting
sequences", obtained by coding the sequence of cuts in an integer lattice over
the positive quadrant of made by a line of irrational slope.
Every finite Sturmian word is trapezoidal, but not conversely. However, both
families of words (trapezoidal and Sturmian) are special classes of so-called
"rich words" (also known as "full words") - a wider family of finite and
infinite words characterized by containing the maximal number of palindromes -
studied in depth by the first author and others in 2009.
In this paper, we introduce a natural generalization of trapezoidal words
over an arbitrary finite alphabet , called generalized trapezoidal
words (or GT-words for short). In particular, we study combinatorial and
structural properties of this new class of words, and we show that, unlike the
binary case, not all GT-words are rich in palindromes when , but we can describe all those that are rich.Comment: Major revisio
Palindromic richness for languages invariant under more symmetries
For a given finite group consisting of morphisms and antimorphisms of a
free monoid , we study infinite words with language closed under
the group . We focus on the notion of -richness which describes words
rich in generalized palindromic factors, i.e., in factors satisfying
for some antimorphism . We give several
equivalent descriptions which are generalizations of know characterizations of
rich words (in the terms of classical palindromes) and show two examples of
-rich words
Factor frequencies in generalized Thue-Morse words
We describe factor frequencies of the generalized Thue-Morse word t_{b,m}
defined for integers b greater than 1, m greater than 0 as the fixed point
starting in 0 of the morphism \phi_{b,m} given by
\phi_{b,m}(k)=k(k+1)...(k+b-1), where k = 0,1,..., m-1 and where the letters
are expressed modulo m. We use the result of A. Frid, On the frequency of
factors in a D0L word, Journal of Automata, Languages and Combinatorics 3
(1998), 29-41 and the study of generalized Thue-Morse words by S. Starosta,
Generalized Thue-Morse words and palindromic richness, arXiv:1104.2476v2
[math.CO].Comment: 11 page
Review: Burden on Family Caregivers Caring for Patients with Schizophrenia and Its Related Factors
Background: Family caregiver is the most important person who cares for patient with schizophrenia. However when care is provided for long time, he/she may experiences the burden.Purpose: The purpose was to review concept and factors related to burden on family caregivers caring for patients with schizophrenia.Method: A literatures were searched from databases: Pubmed, CINAHL, and Science Direct. Key words used to retrieve literature include caregiver burden and schizophrenia. Searching was limited in English language, full text, and the year of publication from 2000 to 2009 was used.Results: Twenty two studies were reviewed in this paper. The result showed that the caregivers caring for patients with schizophrenia experience burden. Burden was defined as a negative impact of caring for the impaired person experienced by caregiver on their activity (objective burden) or feeling (subjective burden) that involves emotional, physical health, social life, and financial status. Factors related to burden on family caregiver were grouped into: 1) caregiver‟s factors included age, gender, educational level, income, health status, and spent time per day, knowledge of schizophrenia, culture, and coping; 2) patient‟s factors included age, clinical symptoms, and disability in daily life; 3) environmental factors included mental health service and social support.Conclusion: Definition of burden have quite same meaning and mostly factors focus on the patient‟s symptoms, demographic factors of caregiver, and time spent per day. Most of studies cannot be generalized due to small sample used in the study and that too conducted in western countries. For further research, the correlation between burden and resources of family caregiver should be investigated particularly in eastern country
Generating functions for Wilf equivalence under generalized factor order
Kitaev, Liese, Remmel, and Sagan recently defined generalized factor order on
words comprised of letters from a partially ordered set by
setting if there is a subword of of the same length as
such that the -th character of is greater than or equal to the -th
character of for all . This subword is called an embedding of
into . For the case where is the positive integers with the usual
ordering, they defined the weight of a word to be
, and the corresponding weight
generating function . They then
defined two words and to be Wilf equivalent, denoted , if
and only if . They also defined the related generating
function where
is the set of all words such that the only embedding of
into is a suffix of , and showed that if and only if
. We continue this study by giving an explicit formula for
if factors into a weakly increasing word followed by a weakly
decreasing word. We use this formula as an aid to classify Wilf equivalence for
all words of length 3. We also show that coefficients of related generating
functions are well-known sequences in several special cases. Finally, we
discuss a conjecture that if then and must be
rearrangements, and the stronger conjecture that there also must be a
weight-preserving bijection such
that is a rearrangement of for all .Comment: 23 page
Дослідження впливу середовища на реакцію оксосинтезу
Узагальнено дані по константах швидкості реакції оксосинтезу з метилакрилатом
у різних розчинниках за допомогою лінійного багатопараметрового рівняння, причому сольватаційні параметри сприяють реакції, а енергія когезії та мольний об’єм
розчинників її сповільнюють. Подібно можна узагальнити дані по каталізуючому
впливу додатку третинних амінів, але тут вплив сольватаційних характеристик
протилежний.
Ключові слова: оксосинтез, метилакрилат, багатопараметрові рівнянняValues of the rate constants of oxosynthese reaction with the methylmetacrylate in various solvents have
been generalized by means of a linear multiparameter equation in which the solvation factors favour the
reaction. On the contrary the cohesion energy density and molar volume of solvents decelerate it. The data of
catalysing influence of tertiary amines addition can be similarly generalized too, however in such case the
influence of solvation characteristics is opposite.
Key words: oxosynthesis, methylacrylate, multiparametric equations
Quantitative Social Dialectology: Explaining Linguistic Variation Geographically and Socially
In this study we examine linguistic variation and its dependence on both social and geographic factors. We follow dialectometry in applying a quantitative methodology and focusing on dialect distances, and social dialectology in the choice of factors we examine in building a model to predict word pronunciation distances from the standard Dutch language to 424 Dutch dialects. We combine linear mixed-effects regression modeling with generalized additive modeling to predict the pronunciation distance of 559 words. Although geographical position is the dominant predictor, several other factors emerged as significant. The model predicts a greater distance from the standard for smaller communities, for communities with a higher average age, for nouns (as contrasted with verbs and adjectives), for more frequent words, and for words with relatively many vowels. The impact of the demographic variables, however, varied from word to word. For a majority of words, larger, richer and younger communities are moving towards the standard. For a smaller minority of words, larger, richer and younger communities emerge as driving a change away from the standard. Similarly, the strength of the effects of word frequency and word category varied geographically. The peripheral areas of the Netherlands showed a greater distance from the standard for nouns (as opposed to verbs and adjectives) as well as for high-frequency words, compared to the more central areas. Our findings indicate that changes in pronunciation have been spreading (in particular for low-frequency words) from the Hollandic center of economic power to the peripheral areas of the country, meeting resistance that is stronger wherever, for well-documented historical reasons, the political influence of Holland was reduced. Our results are also consistent with the theory of lexical diffusion, in that distances from the Hollandic norm vary systematically and predictably on a word by word basis
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