51 resultados para Bounded languages
em CentAUR: Central Archive University of Reading - UK
Resumo:
The EP2025 EDS project develops a highly parallel information server that supports established high-value interfaces. We describe the motivation for the project, the architecture of the system, and the design and application of its database and language subsystems. The Elipsys logic programming language, its advanced applications, EDS Lisp, and the Metal machine translation system are examined.
Computing the continuous-spectrum linearised bounded standing wave on a plane bed of arbitrary slope
Resumo:
Long distance dispersal (LDD) plays an important role in many population processes like colonization, range expansion, and epidemics. LDD of small particles like fungal spores is often a result of turbulent wind dispersal and is best described by functions with power-law behavior in the tails ("fat tailed"). The influence of fat-tailed LDD on population genetic structure is reported in this article. In computer simulations, the population structure generated by power-law dispersal with exponents in the range of -2 to -1, in distinct contrast to that generated by exponential dispersal, has a fractal structure. As the power-law exponent becomes smaller, the distribution of individual genotypes becomes more self-similar at different scales. Common statistics like G(ST) are not well suited to summarizing differences between the population genetic structures. Instead, fractal and self-similarity statistics demonstrated differences in structure arising from fat-tailed and exponential dispersal. When dispersal is fat tailed, a log-log plot of the Simpson index against distance between subpopulations has an approximately constant gradient over a large range of spatial scales. The fractal dimension D-2 is linearly inversely related to the power-law exponent, with a slope of similar to -2. In a large simulation arena, fat-tailed LDD allows colonization of the entire space by all genotypes whereas exponentially bounded dispersal eventually confines all descendants of a single clonal lineage to a relatively small area.
Resumo:
This article reports on the findings of an investigation into the attitudes of English students aged 16 to 19 years towards French and how they view the reasons behind their level of achievement. Those students who attributed success to effort, high ability, and effective learning strategies had higher levels of achievement, and students intending to continue French after age 16 were more likely than noncontinuers to attribute success to these factors. Low ability and task difficulty were the main reasons cited for lack of achievement in French, whereas the possible role of learning strategies tended to be overlooked by students. It is argued that learners' self-concept and motivation might be enhanced through approaches that encourage learners to explore the causal links between the strategies they employ and their academic performance, thereby changing the attributions they make for success or failure.
Resumo:
Information systems for business are frequently heavily reliant on software. Two important feedback-related effects of embedding software in a business process are identified. First, the system dynamics of the software maintenance process can become complex, particularly in the number and scope of the feedback loops. Secondly, responsiveness to feedback can have a big effect on the evolvability of the information system. Ways have been explored to provide an effective mechanism for improving the quality of feedback between stakeholders during software maintenance. Understanding can be improved by using representations of information systems that are both service-based and architectural in scope. The conflicting forces that encourage change or stability can be resolved using patterns and pattern languages. A morphology of information systems pattern languages has been described to facilitate the identification and reuse of patterns and pattern languages. The kind of planning process needed to achieve consensus on a system's evolution is also considered.