Tree transducers, L systems, and two-way machines

A relationship between parallel rewriting systems and two-way machines is investigated. Restrictions on the “copying power” of these devices endow them with rich structuring and give insight into the issues of determinism, parallelism, and copying. Among the parallel rewriting systems considered are the top-down tree transducer; the generalized syntax-directed translation scheme and the ETOL system, and among the two-way machines are the tree-walking automaton, the two-way finite-state transducer, and (generalizations of) the one-way checking stack automaton. The. relationship of these devices to macro grammars is also considered. An effort is made .to provide a systematic survey of a number of existing results

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)C 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

A study in parallel rewriting systems

In this paper we study systematically three basic classes of grammars incorporating parallel rewriting: Indian parallel grammars, Russian parallel grammars and L systems. In particular by extracting basic characteristics of these systems and combining them we introduce new classes of rewriting systems (ETOL[k] systems, ETOLIP systems and ETOLRP systems) Among others, some results on the combinatorial structure of Indian parallel languages and on the combinatorial structures of the new classes of languages are proved. As far as ETOL systems are concerned we prove that every ETOL language can be generated with a fixed (equal to 8) bounded degree of parallelism

How students can combine earning with learning through flexible business process sourcing: a proposition

Research by the Centre for Global Sourcing and Services at Loughborough University has highlighted an emerging skills gap between the entry-level of those professional careers that form the bedrock of business support services within organisations and the ‘talent pipeline’ to senior roles such as business partner. The reconfiguration, re-engineering and relocation of many back and middle-office roles through business process outsourcing (BPO) and shared service centres (SSC) is causing a serious career entry problem, because the training 'nurseries', where the skills, knowledge and behaviours of a life-long professional career, are forged. At present this trend is largely under the media radar because the SSC operates within company boundaries and migration to offshore locations is generally both piecemeal and phased. Economic effects are also masked by a 'honeymoon' effect of lower costs for organisations but little resistance from displaced workers as they retire, receive redundancy compensation or leave through natural wastage when migration is phased. However, portents of the future are already manifesting: Indeed, typical student debt has now risen to around £50,000, graduate entry jobs are now falling (Association of Graduate Recruiters, 2016) and at the same time there is evidence emerging that the 'talent pipeline' into mid-level career roles such as business partners and data analysis experts is drying up. More positively, our report suggests that it should be attractive for organisations to employ undergraduates in ‘middle-office’ work on an Earn-to-Learn basis throughout the course of their degree programmes. The idea is to enable students to access quality work-based learning which will allow them to improve their work-readiness and graduate with lower debt, and perhaps near to debt-free especially where schemes are able to access graduate apprenticeship funding. There are significant advantages for a range of stakeholders. Universities have an opportunity to widen access by encouraging those potential students who may be put off by high graduation debt and thus, improve employability rates. Organisations will have access to a new, intelligent, flexible workforce, at an attractive cost relative to many offshore destinations, especially with the lower Sterling exchange rate. Moreover, there is the opportunity to rebuild the talent pipeline and contribute to Corporate Social Responsibility by helping young people to get a career start. For government and regional economies there is a chance to stem the outflow of good quality service work and build capability in new knowledge work by designing programmes for data analytics and robotic process automation solutions. Moving forward will require a partnership between organisations, universities, professional bodies and regional policy makers and each group must be flexible in its demands; there are rewards for all parties but nothing will be achieved without co-operation