scholarly journals Shifts with decidable language and non-computable entropy

2008 ◽  
Vol Vol. 10 no. 3 (Automata, Logic and Semantics) ◽  
Author(s):  
Peter Hertling ◽  
Christoph Spandl

Automata, Logic and Semantics International audience We consider subshifts of the full shift of all binary bi-infinite sequences. On the one hand, the topological entropy of any subshift with computably co-enumerable language is a right-computable real number between 0 and 1. We show that, on the other hand, any right-computable real number between 0 and 1, whether computable or not, is the entropy of some subshift with even polynomial time decidable language. In addition, we show that computability of the entropy of a subshift does not imply any kind of computability of the language of the subshift

2016 ◽  
Vol 56 ◽  
pp. 269-327 ◽  
Author(s):  
Maximilian Fickert ◽  
Joerg Hoffmann ◽  
Marcel Steinmetz

Recent work has shown how to improve delete relaxation heuristics by computing relaxed plans, i.e., the hFF heuristic, in a compiled planning task PiC which represents a given set C of fact conjunctions explicitly. While this compilation view of such partial delete relaxation is simple and elegant, its meaning with respect to the original planning task is opaque, and the size of PiC grows exponentially in |C|. We herein provide a direct characterization, without compilation, making explicit how the approach arises from a combination of the delete-relaxation with critical-path heuristics. Designing equations characterizing a novel view on h+ on the one hand, and a generalized version hC of hm on the other hand, we show that h+(PiC) can be characterized in terms of a combined hcplus equation. This naturally generalizes the standard delete-relaxation framework: understanding that framework as a relaxation over singleton facts as atomic subgoals, one can refine the relaxation by using the conjunctions C as atomic subgoals instead. Thanks to this explicit view, we identify the precise source of complexity in hFF(PiC), namely maximization of sets of supported atomic subgoals during relaxed plan extraction, which is easy for singleton-fact subgoals but is NP-complete in the general case. Approximating that problem greedily, we obtain a polynomial-time hCFF version of hFF(PiC), superseding the PiC compilation, and superseding the modified PiCce compilation which achieves the same complexity reduction but at an information loss. Experiments on IPC benchmarks show that these theoretical advantages can translate into empirical ones.


2021 ◽  
Vol 180 (1-2) ◽  
pp. 53-76
Author(s):  
Andreas Malcher

Insertion systems or insertion grammars are a generative formalism in which words can only be generated by starting with some axioms and by iteratively inserting strings subject to certain contexts of a fixed maximal length. It is known that languages generated by such systems are always context sensitive and that the corresponding language classes are incomparable with the regular languages. On the other hand, it is possible to generate non-semilinear languages with systems having contexts of length two. Here, we study decidability questions for insertion systems. On the one hand, it can be seen that emptiness and universality are decidable. Moreover, the fixed membership problem is solvable in deterministic polynomial time. On the other hand, the usually studied decidability questions such as, for example, finiteness, inclusion, equivalence, regularity, inclusion in a regular language, and inclusion of a regular language turn out to be undecidable. Interestingly, the latter undecidability results can be carried over to other models which are basically able to handle the mechanism of inserting strings depending on contexts. In particular, new undecidability results are obtained for pure grammars, restarting automata, clearing restarting automata, and forgetting automata.


2015 ◽  
Vol DMTCS Proceedings, 27th... (Proceedings) ◽  
Author(s):  
C. Ceballos ◽  
T. Manneville ◽  
V. Pilaud ◽  
L. Pournin

International audience The $n$-dimensional associahedron is a polytope whose vertices correspond to triangulations of a convex $(n + 3)$-gon and whose edges are flips between them. It was recently shown that the diameter of this polytope is $2n - 4$ as soon as $n > 9$. We study the diameters of the graphs of relevant generalizations of the associahedron: on the one hand the generalized associahedra arising from cluster algebras, and on the other hand the graph associahedra and nestohedra. Related to the diameter, we investigate the non-leaving-face property for these polytopes, which asserts that every geodesic connecting two vertices in the graph of the polytope stays in the minimal face containing both. L’associaèdre de dimension $n$ est un polytope dont les sommets correspondent aux triangulations d’un $(n + 3)$-gone convexe et dont les arêtes sont les échanges entre ces triangulations. Il a été récemment démontré que le diamètre de ce polytope est $2n - 4$ dès que $n > 9$. Nous étudions les diamètres des graphes de certaines généralisations de l’associaèdre : d’une part les associaèdres généralisés provenant des algèbres amassées, et d’autre part les associaèdres de graphes et les nestoèdres. En lien avec le diamètre, nous étudions si toutes les géodésiques entre deux sommets de ces polytopes restent dans la plus petite face les contenant.


2014 ◽  
Vol DMTCS Proceedings vol. AT,... (Proceedings) ◽  
Author(s):  
Vincent Pilaud

International audience An associahedron is a polytope whose vertices correspond to the triangulations of a convex polygon and whose edges correspond to flips between them. J.-L. Loday gave a particularly elegant realization of the associahedron, which was then generalized in two directions: on the one hand to obtain realizations of graph associahedra, and on the other hand to obtain multiple realizations of the associahedron parametrized by a sequence of signs. The goal of this paper is to unify and extend these two constructions to signed tree associahedra. Un associaèdre est un polytope dont les sommets correspondent aux triangulations d’un polygone convexe et dont les arêtes correspondent aux flips entre ces triangulations. J.-L. Loday a donné une construction particulièrement élégante de l’associaèdre qui a été généralisée dans deux directions : d’une part pour obtenir des réalisations des associaèdres de graphes, et d’autre part pour obtenir de multiples réalisations de l’associaèdre paramétrées par une suite de signes. L’objectif de ce travail est d’unifier et d’étendre ces constructions aux associaèdres d’arbres signés.


2020 ◽  
Vol DMTCS Proceedings, 28th... ◽  
Author(s):  
Sabine Beil

International audience In this work triangular puzzles that are composed of unit triangles with labelled edges are considered. To be more precise, the labelled unit triangles that we allow are on the one hand the puzzle pieces that compute Schubert calculus and on the other hand the flipped K-theory puzzle piece. The motivation for studying such puzzles comes from the fact that they correspond to a class of oriented triangular fully packed loop configurations. The main result that is presented is an expression for the number of these puzzles with a fixed boundary in terms of Littlewood- Richardson coefficients.


Author(s):  
Stefan Krause ◽  
Markus Appel

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.


2005 ◽  
Vol 44 (03) ◽  
pp. 107-117
Author(s):  
R. G. Meyer ◽  
W. Herr ◽  
A. Helisch ◽  
P. Bartenstein ◽  
I. Buchmann

SummaryThe prognosis of patients with acute myeloid leukaemia (AML) has improved considerably by introduction of aggressive consolidation chemotherapy and haematopoietic stem cell transplantation (SCT). Nevertheless, only 20-30% of patients with AML achieve long-term diseasefree survival after SCT. The most common cause of treatment failure is relapse. Additionally, mortality rates are significantly increased by therapy-related causes such as toxicity of chemotherapy and complications of SCT. Including radioimmunotherapies in the treatment of AML and myelodyplastic syndrome (MDS) allows for the achievement of a pronounced antileukaemic effect for the reduction of relapse rates on the one hand. On the other hand, no increase of acute toxicity and later complications should be induced. These effects are important for the primary reduction of tumour cells as well as for the myeloablative conditioning before SCT.This paper provides a systematic and critical review of the currently used radionuclides and immunoconjugates for the treatment of AML and MDS and summarizes the literature on primary tumour cell reductive radioimmunotherapies on the one hand and conditioning radioimmunotherapies before SCT on the other hand.


2003 ◽  
pp. 15-26
Author(s):  
P. Wynarczyk
Keyword(s):  
The Core ◽  

Two aspects of Schumpeter' legacy are analyzed in the article. On the one hand, he can be viewed as the custodian of the neoclassical harvest supplementing to its stock of inherited knowledge. On the other hand, the innovative character of his works is emphasized that allows to consider him a proponent of hetherodoxy. It is stressed that Schumpeter's revolutionary challenge can lead to radical changes in modern economics.


2018 ◽  
Vol 4 (1) ◽  
pp. 67-84
Author(s):  
Wahyudin Noor

Abstract Pesantren are often associated with backwardness and traditionalism in everything: facilities, technology, learning methods, and even the curriculum. For now, it seems like the traditional term for pesantren is no longer relevant enough. The pace of movement in the era of renewal marked by the rapid development of technology has demanded pesantren to make adjustments. However, on the one hand, when viewed from the direction of change, the reform efforts pursued by pesantren are not to erase the old tradition, but merely to add something new so that the old tradition and conditions can be maintained while accepting the presence of a new one. On the other hand, the reform efforts undertaken by pesantren have implications for the fact that the typical values of the pesantren are fading away. Abstrak  Pesantren seringkali diasosiasikan dengan keterbelakangan dan tradisional dalam segala hal: fasilitas, teknologi, metode pembelajaran, dan bahkan kurikulumnya. Untuk saat ini, sepertinya istilah tradisional untuk pesantren, sudah tidak lagi cukup relevan. Laju gerak pembaharuan zaman yang ditandai dengan pesatnya perkembangan teknologi telah menuntut pesantren untuk melakukan penyesuaian diri. Kendatipun demikian, di satu sisi, jika dilihat dari arah perubahan, upaya pembaharuan yang ditempuh pesantren tidaklah untuk menghapus tradisi yang lama, tetapi sekadar menambah dengan sesuatu yang baru sehingga tradisi maupun kondisi yang lama bisa dipertahankan sambil menerima kehadiran yang baru. Di sisi yang lain, upaya pembaharuan yang dilakukan pesantren ternyata berimplikasi pada kenyataan akan semakin pudarnya nilai-nilai khas yang dimiliki oleh pesantren.


2018 ◽  
Vol 1 (1) ◽  
pp. 37-52
Author(s):  
Karimatul Khasanah
Keyword(s):  

BASYARNAS’s verdict in resolving dispute can be negotiated or cancelled by submitting nullification to the Religious Court if the parties or one of them felt dissatisfied with the BASYARNAS verdicts. This case is important to be reviewed academically because of its paradox and ambiguity. On the one hand the decision is final and binding, but on the other hand it could be cancelled through the Religious Court. If the BASYARNAS verdicts really want to be final and binding, the nullification of the verdicts should be abolished. It can be replaced by an amendment of the verdict submitted to BASYARNAS and handed back to the arbitrator (arbitrator panel) who handles the dispute. Apart being fast and confidential, the arbitrator (judge) is more aware of the case, the reasons, evidences and witnesses of the dispute.


Sign in / Sign up

Export Citation Format

Share Document