基于域加权词频法的XML文档级检索实现与评价

利用BM25F模型,通过实验,在INEX 04数据集的基础上,实现了对多个域(元素)词频进行加权的XML文档级检索。XML文档结构的确蕴含了一定的语义信息。利用这些语义信息,可以提高检索性能。表2。图1。参考文献16。     

Elite wheelchair rugby: a quantitative analysis of chair configuration in Australia

Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.     

Issues relating to curriculum,policy and gender raised by national and international surveys of achievement in mathematics

Scottish schools have provided performance data for five international surveys of attainment in mathematics since 1990. Performance measured against national targets and progression over time and between age‐stages have been monitored nationally, on a regular basis, for 20 years, within the Assessment of Achievement Programme (AAP) (Scotland). The 1994 AAP mathematics survey findings facilitated interpretation of the age 9 and 13 TIMSS results for Scotland. Both studies were influential in formulation of national policies to improve learning and teaching of mathematics, at ages 5–14. Research available to support policies recommended in 1997 is examined. Concerns about validity and reliability of findings from international studies are discussed in the context of a collaboration undertaken between Scotland and France in 1994. It is concluded that simplistic comparisons ignore important cultural and curricular differences. Outcomes of more recent national and international surveys are reported and performance findings from 1988–2000 that relate to gender are reviewed.     

A rule induction framework for the determination of representative learning design in skilled performance

Representative learning design provides a framework for the extent to which practice simulates key elements of a performance setting. Improving both the measurement and analysis of representative learning design would allow for the refinement of sports training environments that seek to replicate competition conditions and provide additional context to the evaluation of athlete performance. Using rule induction, this study aimed to develop working models for the determination of high frequency, representative events in Australian Rules football kicking. A sample of 9005 kicks from the 2015 Australian Football League season were categorised and analysed according to the following constraints: type of pressure, kick distance, possession source, time in possession, velocity and kick target. The Apriori algorithm was used to develop two models. The first consisted of 10 rules containing the most commonly occurring constraint sets occurring during the kick in AF, with support values ranging from 0.15 to 0.22. None of the rules contained more than three constraints and confidence values ranged from 0.63 to 0.84. The second model considered ineffective and effective kick outcomes and displayed 70% classification accuracy. This research provides a measurement approach to determine the degree of representativeness of sports practice and is directly applicable to various team sports.     

Laplace Transforms Without Integration

Calculating Laplace transforms from the definition often requires tedious integrations. This paper provides an integration-free technique for calculating Laplace transforms of many familiar functions. It also shows how the technique can be applied to probability theory.     

A case study of integration and destreaming: Teachers and students in an Ontario secondary school respond

The direction that secondary school reform should take has become a contested question in the province of Ontario, Canada, during the 1990s. This case study of one secondary school examines some of the issues surrounding the transition years. Two policies, destreaming and integration, mandatedbythe OntarioMinistryof Education in 1993, and fully implemented by 1995, are examined by means of interview and survey. Administrators, teachers and students commented on the transition from elementary to secondary school. We discuss questions related to destreaming (especially how teachers contend with mixed-ability classes) and integration (with a particular focus on mathematics, science and technology).     

Prolog programming techniques

In this paper we introduce the concept of a Prolog programming technique. This concept is then distinguished both from that of an algorithm and that of a programming cliché. We give examples and show how a knowledge of them can be useful in both programming environments and in teaching programming skills. The extraction of the various techniques is outlined. Finally, we discuss the problem of representing techniques where we conclude that the most promising approach is the development of a suitable meta-language.     

A probabilistic model of information retrieval: development and comparative experiments: Part 2

The paper combines a comprehensive account of the probabilistic model of retrieval with new systematic experiments on TREC Programme material. It presents the model from its foundations through its logical development to cover more aspects of retrieval data and a wider range of system functions. Each step in the argument is matched by comparative retrieval tests, to provide a single coherent account of a major line of research. The experiments demonstrate, for a large test collection, that the probabilistic model is effective and robust, and that it responds appropriately, with major improvements in performance, to key features of retrieval situations.Part 1 covers the foundations and the model development for document collection and relevance data, along with the test apparatus. Part 2 covers the further development and elaboration of the model, with extensive testing, and briefly considers other environment conditions and tasks, model training, concluding with comparisons with other approaches and an overall assessment.Data and results tables for both parts are given in Part 1. Key results are summarised in Part 2.