Michael J. Nelson

Evaluation of a simple and effective music information retrieval method

We developed, and then evaluated, a music information retrieval (MIR) system based upon the intervals found within the melodies of a collection of 9354 folksongs. The songs were converted to an interval-only representation of monophonic melodies and then fragmented t into length-n subsections called n-grams. The length of these n-grams and the degree to which we precisely represent the intervals are variables analyzed in this paper. We constructed a collection of “musical word” databases using the text-based, SMART information retrieval system. A group of simulated queries, some of which contained simulated errors, was run against these databases. The results were evaluated using the normalized precision and normalized recall measures. Our concept of “musical words” shows great merit thus implying that useful MIR systems can be constructed simply and efficiently using pre-existing text-based information retrieval software. Second, this study is a formal and comprehensive evaluation of a MIR system using rigorous statistical analyses to determine retrieval effectiveness.

Split size-rank models for the distribution of index terms

Since the introduction of the Zipf distribution, many functions have been suggested for the frequency of words in text. Some of these models have also been applied to the distribution of index terms in a set of documents. The models are of two forms: rank‐frequency and frequency‐size. The former serve well to describe the distribution of high‐frequency terms; the latter the distribution of low‐frequency terms. In this article, a split model is proposed, which uses both a rank function for the high frequency terms and a size function for the low frequency terms, with the point of transition being determined either empirically or by rule. This model is fitted to the marginal empirical term distributions for four document datasets. Distributions to describe index term exhaustivity and term co‐occurrence are also considered briefly.

Simulation of user judgments in bibliographic retrieval systems

The general model and simulation algorithms for bibliographic retrieval systems presented in an earlier paper are expanded. The new model integrates the physical as well as the logical and semantic elements of these systems. A modified algorithm is developed for the simulation of user relevance judgments, and is validated, by means of recall-precision curves and a Kolmogorov-Smirnov test of recall, for two test collections. Other approaches to goodness-of-fit testing are suggested.

Informetric analysis of a music database

We analyse the statistical properties a database of musical notes for the purpose of designing an information retrieval system as part of the Musifind project. In order to reduce the amount of musical information we convert the database to the intervals between notes, which will make the database easier to search. We also investigate a further simplification by creating equivalence classes of musical intervals which also increases the resilience of searches to errors in the query. The Zipf, Zipf-Mandelbrot, Generalized Waring (GW) and Generalized Inverse Gaussian-Poisson (GIGP) distributions are tested against these various representations with the GIGP distribution providing the best overall fit for the data. There are many similarities with text databases, especially those with short bibliographic records. There are also some differences, particularly in the highest frequency intervals which occur with a much lower frequency than the highest frequency “stopwords” in a text database. This provides evidence to support the hypothesis that traditional text retrieval methods will work for a music database.

Visualization of citation patterns of some Canadian journals

SummaryIn order to easily see the citation patterns of a journal or subject area it is very useful to use a graphical diagram to visualize all the connections between journals. Using data derived from the Journal Citation Reports, this study investigates the visualization of citation patterns for three Canadian journals in three different subject areas: library and information science, psychology and mathematics.

Fluidized-Bed Bioreactor Applications for Biological Wastewater Treatment: A Review of Research and Developments

Abstract Wastewater treatment is a process that is vital to protecting both the environment and human health. At present, the most cost-effective way of treating wastewater is with biological treatment processes such as the activated sludge process, despite their long operating times. However, population increases have created a demand for more efficient means of wastewater treatment. Fluidization has been demonstrated to increase the efficiency of many processes in chemical and biochemical engineering, but it has not been widely used in large-scale wastewater treatment. At the University of Western Ontario, the circulating fluidized-bed bioreactor (CFBBR) was developed for treating wastewater. In this process, carrier particles develop a biofilm composed of bacteria and other microbes. The excellent mixing and mass transfer characteristics inherent to fluidization make this process very effective at treating both municipal and industrial wastewater. Studies of lab- and pilot-scale systems showed that the CFBBR can remove over 90% of the influent organic matter and 80% of the nitrogen, and produces less than one-third as much biological sludge as the activated sludge process. Due to its high efficiency, the CFBBR can also be used to treat wastewaters with high organic solid concentrations, which are more difficult to treat with conventional methods because they require longer residence times; the CFBBR can also be used to reduce the system size and footprint. In addition, it is much better at handling and recovering from dynamic loadings (i.e., varying influent volume and concentrations) than current systems. Overall, the CFBBR has been shown to be a very effective means of treating wastewater, and to be capable of treating larger volumes of wastewater using a smaller reactor volume and a shorter residence time. In addition, its compact design holds potential for more geographically localized and isolated wastewater treatment systems.

A prefix trie index for inverted files

A prefix trie index (originally called trie hashing) is applied to the problem of providing fast search times, fast load times and fast update properties in a bibliographic or full text retrieval system. For all but the largest dictionaries a single key search in the dictionary under trie hashing takes exactly one disk read. Front compression of search keys is used to enhance performance. Partial combining of the postings into the dictionary is analyzed as a method to give both faster retrieval and improved update properties for the trie hashing inverted file. Statistics are given for a test database consisting of an online catalog at the Graduate School of Library and Information Science Library of the University of Western Ontario. The effect of changing various parameters of prefix tries are tested in this application.

Informetric applications for information retrieval research. Sponsored by SIG CRS, SIG MET

Informetric aspects of information retrieval system content and use are introduced and discussed. Examples of research that employ informetric methodologies for information retrieval research are presented along with applications for system design, evaluation, and usage.