Improving document representation by accumulating relevance feedback : the relevance feedback accumulation (RFA) algorithm

Document representation (indexing) techniques are dominated by variants of the term-frequency analysis approach, based on the assumption that the more occurrences a term has throughout a document the more important the term is in that document. Inherent drawbacks associated with this approach include: poor index quality, high document representation size and the word mismatch problem. To tackle these drawbacks, a document representation improvement method called the Relevance Feedback Accumulation (RFA) algorithm is presented. The algorithm provides a mechanism to continuously accumulate relevance assessments over time and across users. It also provides a document representation modification function, or document representation learning function that gradually improves the quality of the document representations. To improve document representations, the learning function uses a data mining measure called support for analyzing the accumulated relevance feedback. Evaluation is done by comparing the RFA algorithm to other four algorithms. The four measures used for evaluation are (a) average number of index terms per document; (b) the quality of the document representations assessed by human judges; (c) retrieval effectiveness; and (d) the quality of the document representation learning function. The evaluation results show that (1) the algorithm is able to substantially reduce the document representations size while maintaining retrieval effectiveness parameters; (2) the algorithm provides a smooth and steady document representation learning function; and (3) the algorithm improves the quality of the document representations. The RFA algorithm\u27s approach is consistent with efficiency considerations that hold in real information retrieval systems. The major contribution made by this research is the design and implementation of a novel, simple, efficient, and scalable technique for document representation improvement

The psychological influence of the diagnosis of breast cancer on therapeutic options selection

The therapeutic management decision-making process for breast cancer is complex, and is influenced by multiple factors including patient age, comorbidities, ethnicity, education, and availability of immediate or delayed reconstruction options. Our study analysed 276 patients diagnosed with breast cancer in the “Colțea” Clinical Hospital between 2014 and 2015. Mean patients age was 61.24, median 62, with a range of 31 to 89 years. Younger age was associated with a less advanced local disease and younger patients were more likely to choose and benefit from conservative surgery. Most patients (61.76%) came from rural areas. Place of origin had a significant influence on the tumor size at the time of diagnosis (3.9 cm vs. 1.8cm) as well as on the choice of surgical procedure. Personalized treatment management plans that include aesthetic satisfaction coupled with oncological safety should be the objectives of contemporary breast surgery. Patient age is so important to the decision making process that it has been proposed as a determinant of educational and counselling strategies. From our experience, young patients from urban areas were more proactive patients. They were diagnosed earlier and more involved in treatment decisions compared with patients from rural areas, who generally did not question the surgeon’s opinion. Factors that influence the decision-making process likely include age, socioeconomic status, availability of radiotherapy, the necessity of periodic follow-up and the concern about recurrence

The structural characterization of the Borrelia afzelii species by means FT-IR spectroscopy

A FT-IR study of the Borrelia afzelii species is reported for the first time. The FT-IR spectrum was obtained in the wavelength interval between 450-4000 cm-1, and the assignation of the absorption bands and the structural interpretation was performed. These spectral domains contain information about DNA, RNA, polysaccharides, proteins, phospholipids

Détection directe de la matière sombre avec le détecteur à gouttelettes surchauffées dans le cadre du projet PICASSO

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal

Numerical analyses of an experimental excavation supported by panels of lime-cement columns

The influence of ground improvement with panels of overlapping lime-cement columns on the behavior of a braced excavation loaded to failure has been investigated using 3D numerical analyses and the results are compared with an experimental full-scale failure test. The analyses reveal that stress-induced strength anisotropy of lime-cement improved clay needs to be considered when the stress path for the actual field conditions differs from that in conventional laboratory testing. In addition to strength parameters, the modulus of deformation that is consistent with the actual encountered stress path is also needed for reasonable predictions

The Influence of Storage Conditions on the Biochemical Composition and Morphology of Dahlia Tubers

The aim of this study was to assess by means of biometric measurements and FT-IR and FT-Raman spectroscopic techniques the influence of storage conditions on the morphology and biochemical composition of Dahlia tubers. Investigated samples belong to ‘Kennemerland’ and ‘Red Pygmy’ cultivars of the Dahlia hybrida species, which were preserved over winter at 5-8 °C, 30-40% air humidity in different substrates: sand, sand and sawdust, peat and sawdust. The biometric parameters revealed that the peat and sawdust substrate is the most appropriate one for tubers storage, whereas the sand substrate is the least suitable one. The inulin signature was evidenced in all tuber samples as well as the changes of biochemical composition induced by different storage conditions. The analysis of the FT-IR and FT-Raman spectra demonstrated that the inulin accumulation inside the tubers is favourably influenced by the sand storage, and depends on the cultivar type. Moreover, it was established that the peat and sawdust substrate favours the polyacetylene formation inside the tubers probably because it facilitates the occurrence and development of pathogens inside the tuber. It was also found that the polyacetylene concentration increased, which is associated with the plant response to the pathogen invasion, depends on the cultivar type

Generating Better Concept Hierarchies Using Automatic Document Classification

ABSTRACT This paper presents a hybrid concept hierarchy development technique for web returned documents retrieved by a meta-search engine. The aim of the technique is to separate the initial retrieved documents into topical oriented categories, prior to the actual concept hierarchy generation. The topical categories correspond to different semantic aspects of the query. This is done using a 1-of-n automatic document classification, on the initial set of returned documents. Then, an individual topical concept hierarchy is automatically generated inside each of the resulted categories. Both steps are executed on the fly at retrieval time. Due to the efficiency constraints imposed by the web retrieval context, the algorithm only uses document snippets (rather than full web pages) for both document classification and concept hierarchy generation. Experimental results show that the algorithm is able to improve the quality of the concept hierarchy presented to the searcher; at the same time, the efficiency parameters are kept within reasonable intervals