Resolving LR Type Conflicts at Translation or Compile Time

The paper considers circumstances in which it is advantageous to resolve reduce-reduce conflicts at compile time, rather than at compiler-construction time. The application considered is that of translating English to one of the Romance languages, such as Italian, where adjectives and nouns have distinctive forms depending on their gender

Evaluating Terminal Heads Of Length K

This paper presents an alternative algorithm for finding the terminal heads of length k of a given string in a given context-free grammar for given k

The Lane Table Method Of Constructing LR(1) Parsers

The first practical application of the LR algorithm was by [1] for the LALR(1) subset of LR(1) grammars. In [2] an efficient method of producing an LR(1) parser for all LR(1) grammars was described which involves resolving conflicts at states of the LR(0) parsing machine, employing two phases. In Phase 1 the contexts of the productions involved in conflicts are evaluated by a process described there called “lane tracing”. If conflicts cannot be resolved by these means, then in Phase 2 the parts of the machine involved in lane tracing are regenerated, avoiding the combination of states that potentially lead to conflicts. Other works along the same lines include [4, 5]. The criterion employed in [2] for determining whether or not states may be combined was that of weak compatibility, as defined in [3]. In this paper we describe an alternative method for determining whether states can be combined. According to testing by [6] this method requires less computation. It is also more efficient. when extending the method from LR(1) to LR(k) parsing as described in [7] where very large grammars may be used for the purposes of natural language translation. Taken together with Phase 1, this new method of Phase 2 will, as before, produce a conflict-free LR(1) parser for all LR(1) grammars

The cognitive development of mathematics - Spatial and timing measures associated with algorithms

The thesis considers in turn measures of algorithms, measures of programs, and measures of computations. We define an algorithm's measure as the average of the space time requirements of its associated computations, and here, as with measures for programs, a question of optimisation arises: that of finding the algorithm fora function which has the least such measure. The problem of optimisation for algorithmic measure in its general form, proves to be unsolvable, but we show that an effective optimisation procedure does exist with regard to algorithms for finite functions, and give in detail the solution of the special case for functions with a domain of two elements. Further, we reduce the determination of the optimum algorithm for infinite functions to that of calculating the value of a primitive recursive function for any sufficiently large t. Taking a different viewpoint, we investigate the existence of lower bounds to the measures of algorithms for certain functions. A similar analysis is applied to the spatial measure defined for programs, program length, and we discuss some of the philosophical ramifications of program brevity. In addition, a pseudo-spatial measure, the number of instructions a program contains is considered. By using reduction theorems which map onto one another corresponding instructions in equivalent programs, we are able to adapt to this pseudo-spatial measure our results on program length. We then examine a problem of secondary optimisation, which involves a minimisation of both algorithmic and program measure. Measures of computations have been analysed by Myhill, Trakhtenbrot, Smullyan, Ritchie, Cleave, Rabin, Arbib and Blum. An essential element in Blum's definition of computational measure are the 'measuring predicates' and we investigate certain relations between their spatial and timing. Requirements (as where an upper bound on one such quantity places a lower bound on another). The relevant literature is discussed in brief, and we take up a number of points which arise. Most of the arguments and results in the thesis are formulated in terms of Turing machines, but they are applicable to other means of representing algorithms. In the final chapter we investigate how the definition of Turing machines may be extended so as to provide a more authentic model of actual computers both in regard to space-time measure, and to the domain of functions they encompass. <p

Short-term memory for emotional faces in dysphoria

The study aimed to determine if the memory bias for negative faces previously demonstrated in depression and dysphoria generalises from long- to short-term memory. A total of 29 dysphoric (DP) and22 non-dysphoric (ND) participants were presented with a series of faces and asked to identify the emotion portrayed (happiness, sadness, anger, or neutral affect). Following a delay, four faces were presented (the original plus three distractors) and participants were asked to identify the target face. Half of the trials assessed memory for facial emotion, and the remaining trials examined memory for facial identity. At encoding, no group differences were apparent. At memory testing, relative to ND participants, DP participants exhibited impaired memory for all types of facial emotion and for facial identity when the faces featured happiness, anger, or neutral affect, but not sadness. DP participants exhibited impaired identity memory for happy faces relative to angry, sad, and neutral, whereas ND participants exhibited enhanced facial identity memory when faces were angry. In general, memory for faces was not related to performance at encoding. However, in DP participants only, memory for sad faces was related to sadness recognition at encoding. The results suggest that the negative memory bias for faces in dysphoria does not generalise from long- to short-term memory

Factors influencing research engagement: research interest, confidence and experience in an Australian speech-language pathology workforce

Background: Recent initiatives within an Australia public healthcare service have seen a focus on increasing the research capacity of their workforce. One of the key initiatives involves encouraging clinicians to be research generators rather than solely research consumers. As a result, baseline data of current research capacity are essential to determine whether initiatives encouraging clinicians to undertake research have been effective. Speech pathologists have previously been shown to be interested in conducting research within their clinical role; therefore they are well positioned to benefit from such initiatives. The present study examined the current research interest, confidence and experience of speech language pathologists (SLPs) in a public healthcare workforce, as well as factors that predicted clinician research engagement

Entry and Fusion of Emerging Paramyxoviruses

Paramyxoviruses are a family of non-segmented RNA viruses that includes major human pathogens such as measles virus and respiratory syncytial virus (RSV) and significant animal viruses like rinderpest. In recent years, several new paramyxoviruses have been identified, further increasing the breadth and importance of this viral family. While many elements of the fusion and entry mechanisms of these recently identified pathogens are conserved, there are interesting differences, including variations in receptor binding, cell tropism, fusion (F) protein proteolytic activation, and triggering of membrane fusion. Thus, study of their entry mechanisms has highlighted the diversity of these critical events in the family

Communication between family carers and health professionals about end-of-life care for older people in the acute hospital setting: a qualitative study

This paper focuses on communication between hospital staff and family carers of patients dying on acute hospital wards, with an emphasis on the family carers’ perspective. The age at which people in the UK die is increasing and many continue to die in the acute hospital setting. Concerns have been expressed about poor quality end of life care in hospitals, in particular regarding communication between staff and relatives. This research aimed to understand the factors and processes which affect the quality of care provided to frail older people who are dying in hospital and their family carers