In this paper, we propose using Spherical K-means algorithm as a preprocessing step to using Latent Semantic Indexing (LSI). LSI is a well known approach in Information Retrieval (IR). Spherical K-means is a fast clustering algorithm that puts similar documents together, thus forming K clusters. We propose using Spherical Kmeans to form the matrix of normalized concept vectors yields high reduc...

A classification of LSI polynomials into optimal and suboptimal LSI polynomials is presented in this note. By an example it is shown that a suboptimal LSI polynomial can be unstable even if the original polynomial does not have any zeros on the unit circle. This has invalidated the proof for modified Shanks’ conjecture in the 2-D case as presented in the paper’ leaving the conjecture to remain ...

The three-membered silacyclic ring compounds LSi[N(2)(Ph)(2)]tBu (1), LSi[HCN(Ph)(2)]tBu (2) and LSi[C(2)(Ph)(2)]tBu (3) were obtained by the treatment of base stabilized monoalkylsilylenes LSitBu (L = PhC(NtBu)(2)) with PhN=NPh, PhN=CHPh and PhC≡CPh. The reaction of PhN=NPh and PhC≡CPh with LSitBu shows a different reactivity pattern with base stabilized monochlorosilylene LSiCl. The arrangeme...

This paper describes the participation of the EMSE team at the clinical decision support track of TREC 2015 (Task A). Our team submitted three automatic runs based only on the summary field. The baseline run uses the summary field as a query and the query likelihood retrieval model to match articles. Other runs explore different approaches to expand the summary field: RM3, LSI with pseudo relev...

This paper presents an application of nonlinear neural networks to topic spotting. Neural networks allow us to model higher-order interaction between document terms and to simultaneously predict multiple topics using shared hidden features. In the context of this model, we compare two approaches to dimensionality reduction in representation: one based on term selection and another based on Late...

DNA has been irradiated in aqueous solutions with 16 MeV electron pulses (duration: 50— 100 ns). In the presence of p-nitroacetophenone (PNAP) the light scattering intensity (LSI) increased after the pulse in Arand 02-saturated solutions indicating intermolecular crosslinking. The LSI increase was greatest in Ar-sat. solutions containing t-butanol (1 mol/1). In the absence of PNAP and t-butanol...