Full AFL Research Articles

Addressing Physical, Functional, and Physiological Outcomes in Older Adults using an Integrated mHealth Intervention "Active for Life": A Pilot Randomized Controlled Trial.

We evaluated components of an integrated, mobile health-based intervention "Activate for Life" (AFL) on health outcomes in lower-income older adults (≥ 60 years). AFL incorporates balance (Otago; OG), physical strength (Gentle Yoga and yogic Breathing; GYYB), and mental engagement (Behavioral Activation; BA) components. Thirty participants were randomly allocated to one of three study arms (n=10): OG (Arm 1), OG+GYYB (Arm 2), or OG+GYYB+BA (Arm 3; a.k.a. "full AFL"). Participants were evaluated for physical, functional, and physiological endpoints at baseline and post-intervention (12-weeks and/or 3-month follow up). Improvements in pain interference and 1,5- anhydroglucitol biomarker levels over time were noted for all arms. No significant changes were observed for other physical, functional, or physiological measures. This study illustrates potential benefits of the AFL intervention on the health of lower-income older adults. Lessons learned from this pilot trial will inform design improvements for a large-scale randomized controlled trial.

Addressing physical, functional, and physiological outcomes in older adults via integrated mHealth intervention

Objective: We evaluated components of an integrated mobile (m)Health-based intervention "Activate for Life" (AFL) on health outcomes in lower-income older adults (65 years and older). Method: AFL incorporates balance (Otago; OG), physical strength (Gentle Yoga and Yogic Breathing; GYYB), and mental engagement (Behavioral Activation; BA) components. Thirty participants were randomly allocated to one of three Arms (n=10 per each arm): OG (Arm 1), (OG+GYYB (Arm2), or OG+GYYB+BA (Arm 3, or full AFL). Groups were evaluated for physical, functional and physiological endpoints at baseline, and posttreatment (12-weeks and/or 3-month follow up). Results: Improvements over time in pain interference and 1,5 Ag biomarker were noted for all groups. No significant changes were observed in other physical, functional and physiological measures. DiscussionThis study illustrated potential benefits of the AFL intervention on the health of lower-income older adults and lessons learned from this pilot will be used to make improvements for a large-scale randomized controlled trial.

Semilinearity of Families of Languages

Techniques are developed for creating new and general language families of only semilinear languages, and for showing families only contain semilinear languages. It is shown that for language families [Formula: see text] that are semilinear full trios, the smallest full AFL containing [Formula: see text] that is also closed under intersection with languages in [Formula: see text] (where [Formula: see text] is the family of languages accepted by [Formula: see text]s augmented with reversal-bounded counters), is also semilinear. If these closure properties are effective, this also immediately implies decidability of membership, emptiness, and infiniteness for these general families. From the general techniques, new grammar systems are given that are extensions of well-known families of semilinear full trios, whereby it is implied that these extensions must only describe semilinear languages. This also implies positive decidability properties for the new systems. Some characterizations of the new families are also given.

Ogden's lemma, multiple context-free grammars, and the control language hierarchy

I present a simple example of a multiple context-free language for which a very weak variant of generalized Ogden's lemma fails. This language is generated by a non-branching (and hence well-nested) 3-MCFG as well as by a (non-well-nested) binary-branching 2-MCFG; it follows that neither the class of well-nested 3-MCFLs nor the class of 2-MCFLs is included in Weir's control language hierarchy, for which Palis and Shende proved an Ogden-like iteration theorem. I then give a simple sufficient condition for an MCFG to satisfy a natural analogue of Ogden's lemma, and show that the corresponding class of languages is a substitution-closed full AFL which includes Weir's control language hierarchy. My variant of generalized Ogden's lemma is incomparable in strength to Palis and Shende's variant. I also prove a strengthening of my pumping lemma for well-nested MCFLs which places a bound on the combined length of the substrings that can be iterated.

On the Effect of the IO-Substitution on the Parikh Image of Semilinear Full AFLs

Back in the 1980's, the class of mildly context-sensitive formalisms was introduced so as to capture the syntax of natural languages. While the languages generated by such formalisms are constrained by the constant-growth property, the most well-known and used ones--like tree-adjoining grammars or multiple context-free grammars--generate languages which verify the stronger property of being semilinear. In (Bourreau et al. 2012), the operation of IO-substitution was created so as to exhibit mildly-context sensitive classes of languages which are not semilinear. In the present article, we extend the notion of semilinearity, and characterize the Parikh image of the languages in IO(L), the closure of a class L of semilinear languages under IO-substitution, as universally-semilinear. Based on this result and on the work of Fischer on macro-grammars, we then show that IO(L) is not closed under inverse homomorphism when L is closed under inverse homomorphism, and encompasses the class of regular languages. This result proves that IO(MCFL) is not a full AFL, where $$\mathbf {MCFL}$$MCFL denotes the class of multiple context-free languages, closing an open question in Bourreau et al. (2012). More importantly, our proof gives an insight into the relation between the non-closure under inverse homomorphism of $$\mathbf {IO(MCFL)}$$IO(MCFL) and how IO-substitution breaks semilinearity.

On simple generators of recursively enumerable languages

For each language L, let Fˆ∩(L) (Cˆ∩(L), resp.) be the intersection-closed full AFL (full trio, resp.) generated by L. Furthermore, for each natural number k≥2 let Pk={ank|n∈N}. By applying certain classical and recent results on Diophantine equations we show that LRE=Fˆ∩(Pk), where LRE is the family of all recursively enumerable languages. This allows us to answer to an open problem of S. Ginsburg and J. Goldstine in [3]. A general method to reduce certain restricted membership problems in language families to number theory (in particular to systems of Diophantine equations) is then considered. In the third part of the paper, we show that the Cˆ∩(REP)=Cˆ∩(BREP)=LRE where REP={(amb)n|m,n∈N} and BREP={(anb)n|n∈N}. The results give an answer to two problems left open by P. Turakainen in [11].

Innovative Strategies to Inform Coaching Practices in Australian Football

Innovative strategies were used to inform coaching practices regarding the skill of set-shot goal kicking in Australian Football (AF). An action learning approach was adopted including planning, data gathering, analyses and dissemination phases. Three distinct approaches were used to inform AF coaches of evidence and strategies to guide implementation, a) applying statistical trend data, b) applying expert knowledge, and c) applying biomechanical principles. Trend data from a full AFL season consisting of over 4,000 set-shots was used to inform coaches on numerous performance related parameters (e.g., distance, angle). Expert insider perspectives were generated through in-depth interviews with eight retired AF goal kicking champions. The past players had all kicked over 500 goals at the elite level and four had obtained AFL Hall of Fame or AFL Legend status. The related analyses produced six primary themes (a) correct technique (b) incorrect technique, (c) pre-kick routine, (d) mental skills (e) challenges/choices and (h) training. Third, biomechanical principles were applied to set-shot kicking with accompanying images and drills provided to coaches. A two year follow-up indicated the results were highly transferable to training and competitions. Coaches in sports that include closed skills may benefit from transferring where applicable these strategies to their sports.

Finite turns and the regular closure of linear context-free languages

Turn bounded pushdown automata with different conditions for beginning a new turn are investigated. Their relationships with closures of the linear context-free languages under regular operations are studied. For example, automata with an unbounded number of turns that have to empty their pushdown store up to the initial symbol in order to start a new turn are characterized by the regular closure of the linear languages. Automata that additionally have to re-enter the initial state are (almost) characterized by the Kleene star closure of the linear languages. For both a bounded and an unbounded number of turns, requiring to empty the pushdown store is a strictly stronger condition than requiring to re-enter the initial state. Several new language families are obtained which form a double-stranded hierarchy. Closure properties of these families under AFL operations are derived. The regular closure of the linear languages share the strong closure properties of the context-free languages, i.e., the family is a full AFL. Interestingly, three natural new language families are not closed under intersection with regular languages and inverse homomorphism. Finally, an algorithm is presented parsing languages from the new families in quadratic time.

Abstract Families of Abstract Categorial Languages

We show that the class of string languages generated by abstract categorial grammars is a substitution-closed full AFL. The result also holds of each class G(m,n) in de Groote's hierarchy. We also show that the class of string languages generated by lexicalized ACGs is a substitution-closed AFL, and that most of the results about string languages carry over to tree languages.

Useful Templates and Iterated Template-Guided DNA Recombination in Ciliates

The family of stichotrichous ciliates contains several single-celled organisms possessing a unique genetic mechanism: the ability to descramble genes which exist in a scrambled state in their genomes. We continue the theoretical investigation of the iterated template-guided recombination operation. This operation is suggested by the recombination of DNA strands based on template guides proposed by Prescott, Ehrenfeucht and Rozenberg. A variety of results is demonstrated including a study of computational power, characterizations and other abstract properties, such as a "pumping lemma". The notion of a useful template is defined and forms a critical basis for much of the results demonstrated in the paper. The main result shows that every full AFL is closed under iterated template-guided recombination with regular templates.

Branching synchronization grammars with nested tables

A generalization of ET0L systems is introduced: grammars with branching synchronization and nested tables. The main result is that branching synchronization grammars with tables of nesting depth n have the same string- and tree-generating power as n-fold compositions of top-down tree transducers. Based on this it is shown, e.g., that the family of generated string languages is a full principal AFL for each n.

Decidability of the Finiteness of Ranges of Tree Transductions

The finiteness of ranges of tree transductions is shown to be decidable for TBY + , the composition closure of macro tree transductions. Furthermore, TBY + definable sets and TBY + computable relations are considered, which are obtained by viewing a tree as an expression that denotes an element of a given algebra. A sufficient condition on the considered algebra is formulated under which the finiteness problem is decidable for TBY + definable sets and for the ranges of TBY + computable relations. The obtained result applies in particular to the class of string languages that can be defined by TBY + transductions via the yield mapping. This is a large class which is proved to form a substitution-closed full AFL.

Context free closed families of languages

We study context free closed families of languages, that is families L verifying the equation CF o L = L where CF denotes the family of context free languages and o is the substitution operation. Call a family L a context free AFL if it is both context free closed and a rational cone. The families CF and RE (of recursively enumerable languages) have this property. We show that the class of context free AFL's is properly contained into that of full AFL's. Moreover the context free AFL generated by a family L, is given by the formula L Δ = CF o LΓ where LΓ denotes the rational cone generated by L. Using this result we establish the remarkable inclusion (L o M)Δ ⊃ LΔ o MΔ holding for all families L and M as well as the equality LΔ = CF o LΓ LΓ being the full AFL generated by L.

On multiple context-free grammars

Multiple context-free grammars ( mcfg's) is a subclass of generalized context-free grammars introduced by Pollard (1984) in order to describe the syntax of natural languages. The class of languages generated by mcfg's (called multiple context-free languages or, shortly, mcfl's) properly includes the class of context-free languages and is properly included in the class of context-sensitive languages. First, the paper presents results on the generative capacity of mcfg's and also on the properties of mcfl's such as formal language-theoretic closure properties. Next, it is shown that the time complexity of the membership problem for multiple context-free languages is O( n e ), where n is the length of an input string and e is a constant called the degree of a given mcfg. Head grammars ( hg's) introduced by Pollard and tree adjoining grammars ( tag's) introduced by Joshi et al. (1975) are also grammatical formalisms to describe the syntax of natural languages. The paper also presents the following results on the generative capacities of hg's, tag's and 2-mcfg's, which are a subclass of mcfg's: (1) The class HL of languages generated by hg's is the same as the one generated by tag's; (2) HL is the same as the one generated by left-wrapping hg's (or right-wrapping hg's) which is a proper subclass of hg's; (3) HL is properly included in the one generated by 2-mcfg's. As a corollary of (1), it is also shown that HL is a substitution-closed full AFL.

The generative power of multiple context‐free grammars and head grammars

AbstractMultiple context‐free grammars (mcfg's) and head grammars (hg's) are subclasses of generalized context‐free grammars introduced by Pollard to describe the syntax of natural languages. In this paper, the following properties of mcfg's and hg's are shown: (1) the class HL of languages generated by hg's is the same as that generated by the tree adjoining grammars introduced by Joshi et al.; (2) HL is the same as that generated by left‐wrapping hg's (or right‐wrapping hg's) which is a proper subclass of hg's; (3) HL is properly included in the one generated by 2‐mcfg's, which is a proper subclass of mcfg's. As a corollary of (1), it is also shown that HL is a substitution closed full AFL.

Almost Context-Free Languages

We define a superclass of the class of context-free languages, denoted ACFL (almost context-free languages) and construct an infinite sequence of non-context-free languages of decreasing complexity, belonging to ACFL. The languages in ACFL share many important properties of context-free languages. For example, a slight generalization of pumping lemma for context-free languages holds also for languages in ACFL. Similarly, some of the questions decidable for context-free languages are decidable in ACFL and start to be undecidable immediately outside the class. ACFL is a full AFL and contains an infinite strictly decreasing chain of full AFLs.

Hierarchies of hyper-AFLs

For a full semi-AFL K, B( K) is defined as the family of languages generated by all K-extended basic macro grammars, while H( K) ⊆ B( K) is the smallest full hyper-AFL containing K; a full basic-AFL is a full AFL K such that B( K) = K (hence every full basic-AFL is a full hyper-AFL). For any full semi-AFL K, K is a full basic-AFL if and only if B( K) is substitution closed if and only if H( K) is a full basic-AFL. If K is not a full basic-AFL, then the smallest full basic-AFL containing K is the union of an infinite hierarchy of full hyper-AFLs. If K is a full principal basic-AFL (such as INDEX, the family of indexed languages), then the largest full AFL properly contained in K is a full basic-AFL. There is a full basic-AFL lying properly in between the smallest full basic-AFL and the largest full basic-AFL in INDEX.

Extended macro grammars and stack controlled machines

K-extended basic macro grammars are introduced, where K is any class of languages. The class B(K) of languages generated by such grammars is investigated, together with the class LB(K) of languages generated by the corresponding linear basic grammars. For any full semi-AFL K, B(K) is a full AFL closed under iterated LB(K)-substitution, but not necessarily under substitution. For any machine type D, the stack controlled machine type corresponding to D is introduced, denoted S(D), and the checking-stack controlled machine type CS(D). The data structure of this machine is a stack which controls a pushdown of data structures from D. If D accepts K, then S(D) accepts B(K) and CS(D) accepts LB(K). Thus the classes B(K) are characterized by stack controlled machines and the classes LB(K), i.e., the full hyper-AFLs, by checking-stack controlled machines. A full basic-AFL is a full AFL K such that B( K) ⊆ K. Every full basic-AFL is a full hyper-AFL, but not vice versa. The class of OI macro languages (i.e., indexed languages, i.e., nested stack automaton languages) is a full basic-AFL, properly containing the smallest full basic-AFL. The latter is generated by the ultrabasic macro grammars and accepted by the nested stack automata with bounded depth of nesting (and properly contains the stack languages, the ETOL languages, i.e., the smallest full hyper-AFL, and the basic macro languages). The full basic-AFLs are characterized by bounded nested stack controlled machines.

An Inverse Homomorphic Characterization of Full Principal AFL

The main result of this paper is: Let L be a full principal AFL closed under context-free substitution. Then there is a fixed language l 0 in L such that for each L in L there exist a weak coding h and a homomorphism g such that L = hg −1( L 0). As a corollary, it immediately follows that there is a fixed ETOL language L 0 such that for each ETOL language L there exist a weak coding h and a homomorphism g such that L = hg −1( L 0).

Langages á un Compteur

We study restricted one-counter languages, that is, languages belonging to Rocl, the full trio generated by D' 1 ∗, the restricted Dyck language over one pair of parentheses. We show that every generator of Rocl is a bifaithful one and that there exists a one-counter language which dominates the other ones by length-preserving rational transduction. Then, we establish that the pumping lemma for linear languages is almost true for restricted one-counter languages. Finally, we prove that Rocl contains no nonrational AFL and, if Rocl is included in the smallest full AFL containing a full semi-AFL L, then Rocl is included in L. If Rocl is included in the smallest full AFL closed under substitution containing a context-free full trio L, then Rocl is included in L.