Extending information retrieval system model to improve interactive web searching.

The research set out with the broad objective of developing new tools to support Web information searching. A survey showed that a substantial number of interactive search tools were being developed but little work on how these new developments fitted into the general aim of helping people find information. Due to this it proved difficult to compare and analyse how tools help and affect users and where they belong in a general scheme of information search tools. A key reason for a lack of better information searching tools was identified in the ill-suited nature of existing information retrieval system models. The traditional information retrieval model is extended by synthesising work in information retrieval and information seeking research. The purpose of this new holistic search model is to assist information system practitioners in identifying, hypothesising, designing and evaluating Web information searching tools. Using the model, a term relevance feedback tool called ‘Tag and Keyword’ (TKy) was developed in a Web browser and it was hypothesised that it could improve query reformulation and reduce unnecessary browsing. The tool was laboratory experimented and quantitative analysis showed statistical significances in increased query reformulations and in reduced Web browsing (per query). Subjects were interviewed after the experiment and qualitative analysis revealed that they found the tool useful and saved time. Interestingly, exploratory analysis on collected data identified three different methods in which subjects had utilised the TKy tool. The research developed a holistic search model for Web searching and demonstrated that it can be used to hypothesise, design and evaluate information searching tools. Information system practitioners using it can better understand the context in which their search tools are developed and how these relate to users’ search processes and other search tools

Representations of wreath products of algebras

Filtrations of modules over wreath products of algebras are studied and corresponding multiplicity formulas are given in terms of Littlewood–Richardson coefficients. An example relevant to Jantzen filtrations in Schur algebras is presented

Long Memory in Import and Export Price Inflation and Persistence of Shocks to the Terms of Trade

Long memory models have been successfully used to investigate the dynamic time-series behavior of inflation rates based on the CPI and WPI. However, almost no attention has been paid to import and export price inflation, nor to the terms of trade which they make up. This article investigates the dynamics of the terms of trade by focusing first on the time-series characteristics of these price series. It tests for long memory in export and import price inflation series and estimates the fractional differencing parameter using a number of approaches. To give a better idea of the degree of persistence of each series, estimates of the impulse responses are computed which take into account possible fractional integration. The dynamic behavior in changes in the terms of trade is then related to the long memory behavior of the import and export price inflation series. In a sample of eleven economies for which data is available, evidence of long memory in import and export price inflation occurs in about half the cases. Granger (1980) points out that the natural occurrence of long memory may be attributed to aggregation in macroeconomic series. Our analysis provides evidence of an alternative explanation, namely that long-memory may result from the differencing of a linear relationship between non-cointegrating variables. Specifically, the results from our analysis of eleven economies reveal that shocks to the terms of trade will persist if the constituent price inflation series are not cointegratedlong memory, terms of trade, imported inflation