The linear landscape of external contextual languages

The class of external contextual languages isstrictly included in the class of linear languages. A reason for the strict inclusion in linear languages is that external contextual grammars generate languages in the exhaustive way: each sentential form belongs to the language of a grammar. In this paper we study the effect of adding various squeezing mechanisms to the basic classes of exhaustive contextual grammars. We obtain in this way a characterization of linear languages and a whole landscape of sublinear families. By restricting the contexts to be one-sided (only left-sided or only right-sided) we obtain a characterization of regular languages — here the subregular landscape reduces to two families.     

Combinatorial Properties of Dependence Graphs

Combinatorial properties of dependence graphs are considered. In particular, a characterization is given of sets of unlabelled transitive graphs that can be labelled according to a dependence alphabet.     

Effects of uncontrollability on subsequent decision making: Testing the cognitive exhaustion hypothesis.

The cognitive exhaustion model of helplessness (predicting withdrawal from constructive effortful processing after uncontrollability) was applied to decision making. After unsolvable problems (or no preexposure), Ss requested information from a matrix with 5 alternatives (films)?×?10 attributes and then chose the best film. Films in a set were either similar (difficult decision) or dissimilar (easy decision) in attractiveness. As predicted, Ss with an uncontrollable preexposure spent less time on predecisional information search, disregarded their own importance criteria when asking for information, and had attention highly focused on a selected option for the easy decision condition but diffused across options for the difficult decision condition. The implications of these findings for understanding cognitive mechanisms of learned helplessness and depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pharmacoeconomics of menopause treatments: epidemiological data and hormonal and non-hormonal prescription attitude of Belgian gynecologists

In an economic analysis one has not only to consider costs induced by hormonal substitution therapy (HRT) but also its impact health. Different therapy costs will be considered and related to potential benefits on health. HRT decreases the incidence of symptoms of the menopause, the risk of osteoporosis and perhaps the incidence of coronary hearth disease and the risk of Alzheimer disease but probably increases the incidence of breast cancer. For a majority of women, the favorable impact seems to dominate, increasing their life expectancy.     

On ET0L Systems with rank

The notion of an ET0L system with rank is defined. It naturally extends already studied notions of a D0L system with rank and of an ET0L system of finite index. It turns out that in this way one gets an infinite hierarchy of classes of languages (each one being a full AFL) within the class of ET0L languages. This hierarchy starts with the class of ET0L languages of finite index and it fills in the class of nonexpansive ET0L languages. Some other properties of the class of ET0L systems with rank are also studied.     

Equations for the heat fluxes in the cathode and anode sections of a two-jet plasma source

General relationships are derived for the heat fluxes at the cathode, anode, and nozzles of a two-jet plasma source working with air at atmospheric pressure.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 6, pp. 1054–1058, June 1978.     

A relationship between ET0L and EDT0L languages

This paper provides a method of “decomposing” a subclass of ET0L languages into deterministic ET0L languages. This allows one to use every known example of a language which is not a deterministic ET0L language to produce languages which are not ET0L languages.     

On proving that certain languages are not ETOL

Summary In this paper a partial characterization for a subclass of ETOL languages is obtained. The main result binds together the number of occurrences (in words of a given ETOL language) of letters, from a given set, with their distribution. It provides a very helpful tool to prove that certain languages are not ETOL.     

Apex graph grammars and attribute grammars

Summary Apex graph grammars are a particular type of directed node-label controlled (DNLC) graph grammars: the embedding edges are established between terminal nodes only. Apex graph grammars, slightly generalized, can generate the sets of dependency graphs of attribute grammars. The other way around, every apex graph language can be obtained from such a dependency graph language by a graph replacement (which is an operation analogous to a string homomorphism).