Search results for "Alphabet"
showing 10 items of 68 documents
Balanced Words Having Simple Burrows-Wheeler Transform
2009
The investigation of the "clustering effect" of the Burrows-Wheeler transform (BWT) leads to study the words having simple BWT , i.e. words w over an ordered alphabet $A=\{a_1,a_2,\ldots,a_k\}$, with $a_1 < a_2 < \ldots <a_k$, such that $bwt(w)$ is of the form $a_k^{n_k} a_{k-1}^{n_{k-1}} \cdots a_1^{n_1}$, for some non-negative integers $n_1, n_2, \ldots, n_k$. We remark that, in the case of binary alphabets, there is an equivalence between words having simple BWT, the family of (circular) balanced words and the conjugates of standard words. In the case of alphabets of size greater than two, there is no more equivalence between these notions. As a main result of this paper we prove that, u…
Ranking and unrankingk-ary trees with a 4k –4 letter alphabet
1997
Abstract The problem of the direct generation in A-order of binary trees was stated by Zaks in 1980. In 1988 Roelants van Baronaigien and Ruskey gave a solution for k-ary trees with n internal nodes using an encoding sequence of kn+1 integers between 1 and n. Vajnovszki and Pallo improved this result for binary trees in 1994 using words of length n–1 on a four letter alphabet. Recently Korsh generalized the Vajnovszki and Pallo’s generating algorithm to k-ary trees using an alphabet whose cardinality depends on k but not on n. We give in this paper ranking and unranking algorithms for k-ary trees using the Korsh’s encoding scheme.
Symbolic Dynamics of Geodesic Flows on Trees
2019
In this chapter, we give a coding of the discrete-time geodesic ow on the nonwandering sets of quotients of locally finite simplicial trees X without terminal vertices by nonelementary discrete subgroups of Aut(X) by a subshift of finite type on a countable alphabet.
A Note on a Conjecture of Duval and Sturmian Words
2002
We prove a long standing conjecture of Duval in the special case of Sturmian words. Mathematics Subject Classication. ??????????????. Let U be a nonempty word on a nite alphabet A: A nonempty word B dierent from U is called a border of U if B is both a prex and sux of U: We say U is bordered if U admits a border, otherwise U is said to be unbordered. For example, U = 011001011 is bordered by the factor 011; while 00010001001 is unbordered. An integer 1 k n is a period of a word U = U1 :::U n if and only if for all 1 i n k we have Ui = Ui+k. It is easy to see that k is a period of U if and only if the prex B of U of length n k is a border of U or is empty. Let (U) denote the smallest period …
Tally languages accepted by alternating multitape finite automata
1997
We consider k-tape 1-way alternating finite automata (k-tape lafa). We say that an alternating automaton accepts a language L\(\subseteq\)(Σ*)k with f(n)-bounded maximal (respectively, minimal) leaf-size if arbitrary (respectively, at least one) accepting tree for any (w1, w2,..., wk) ∈ L has no more than $$f\mathop {(\max }\limits_{1 \leqslant i \leqslant k} \left| {w_i } \right|)$$ leaves. The main results of the paper are the following. If k-tape lafa accepts language L over one-letter alphabet with o(log n)-bounded maximal leaf-size or o(log log n)-bounded minimal leaf-size then the language L is semilinear. Moreover, if a language L is accepted with o(log log(n))-bounded minimal (respe…
Amphiphilic poly(hydroxyethylaspartamide) derivative-based micelles as drug delivery systems for ferulic acid
2008
Self-assembling micelles, potentially useful as drug delivery systems for ferulic acid (FA), were obtained in aqueous media from amphiphilic alpha,beta-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers bearing at the polyamino acidic backbone both poly(ethyleneglycol) (2000 or 5000 Da) and hexadecylamine (C(16)) moieties, at a concentration of 7 x 10(- 3) and 4 x 10(- 3) g/l, respectively, with nanometre size and negative zeta potential. These micelles were able to entrap FA and to release it in a prolonged way in phosphate buffer solution at pH 7.4 and human plasma. These systems were also stable in storage conditions and have no cytotoxic effects on Caco-2, 16 HBE, HuDe and K562 cel…
La circulación manuscrita de los poemas alfabéticos de Francisco de Osuna: El caso del manuscrito «MSS/74» de la Biblioteca Nacional de España
2013
International audience; A raíz del redescubrimiento en la BNE del manuscrito MSS/74 —una copiosa antología de cartas y opúsculos místicos del siglo xvi—, se pudieron identificar dos de los tres «alfabetos» anónimos al amor de Dios que cierran dicho compendio: se trata en realidad de dos poemas alfabéticos de Francisco de Osuna. Constituyendo un ejemplo inédito de versiones manuscritas de los poemas del franciscano andaluz, estos alfabetos presentan variantes significativas respecto de las versiones impresas procedentes del Segundo y del Cuarto Abecedario espiritual. El cotejo de ambas versiones, y el análisis atento de dichas variantes, evidencian la realidad de una circulación oral y manus…
I Like Cities; Do You Like Letters? Introducing Urban Typography in Art Education
2010
This article proposes a study of the letters and graphics found in the city, while at the same time opening up unusual spaces linked to the cultural arena and visual geographies for the creation of learning spaces in art education, introducing urban typography for training teachers. The letters in urban spaces can help us reinterpret the patrimonial fabric of cities. With the help of typography, visual arts educators have a powerful graphic resource with which to articulate the complex communicative network of streets. We suggest walking as an aesthetic practice; strolling around the city as a very cultural means to motivate our students. We have at our disposal in our cities a genuine muse…
The Polish Case: From Natio to Nation
2009
The reader may ask why I chose to deal first with the Poles and their language politics. In Chapter 2, I focused first on Czech out from the four Central European languages to which this book is devoted. I took as a guideline the fact that the initial documents written in Czech predate those jotted down in Hungarian (Magyar), Polish, or Slovak. Here, however, I decided that continuity of literary tradition and the use of an idiom as an official language allows me to concentrate on Polish first. With this approach I do not wish to rank these four languages along some imaginary scale of importance or quality; not at all. Simply, I stress the use of a language in public and political sphere as…
On the Existence of 1-Bounded Bi-ideals with the WELLDOC Property
2015
A combinatorial condition called well distributedoccurrences, or WELLDOC for short, has been introducedrecently. The proofs that WELLDOC property holds for thefamily of Sturmian words, and more generally, for Arnoux-Rauzy words are given in two papers by Balkova et al. The WELLDOC property for bounded bi-ideals is analysed inthis paper. The existence of a 1-bounded bi-ideal over thefinite alphabet that satisfies the WELLDOC property has beenproved by the authors.