Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

PageRank Topic Model : Estimation of Multinomial Distributions using Network Structure Analysis Methods

Ikegami K., Ohsawa Y.

Fundamenta Informaticae

2018

Vol. 159, nr 3

257--277

It is useful to extract review sentences based on an assigned viewpoint for purposes such as summarization tasks. Previous studies have considered review extraction using semi-supervised learning or association mining. However, we approach this task using a clustering method. In particular, we focus on a topic model as a clustering method. In the conventional topic model, after randomly initializing the word distribution and the topic distribution, these distributions are estimated in order to minimize the perplexity using Gibbs sampling or variational Bayes. We introduce a new method called the PageRank topic model (PRTM) for estimating multinomial distributions over topics and words using network structure analysis methods. PRTM extracts topics by focusing on the co-occurrence relationships of words and it does not need randomly initialized values. Therefore, it can calculate unique word and topic distributions. In experiments using synthetic data, we showed that PRTM can infer an appropriate number of topics by clustering short sentences, and it was particularly effective when the sentences were covered by a small number of topics. Furthermore, in a real-world review data experiment, we showed that PRTM performed better with a shorter runtime compared with other models that infer the number of topics.

Experimental investigation of viscoelastic properties of epoxy resin during curing process

Ikegami K.

International Journal of Applied Mechanics and Engineering

2003

Vol. 8, no spec.

245-249

Viscoelastic properties of epoxy resin are experimentally investigated by using a rheometer of double cylinders at various temperature conditions. The creep behavior of the resin is measured by the method at various constant temperatures. The results are formulated by a viscoelastic model of three elements and the coefficients of the model are determined at various temperature conditions. Shrinkages of the resin are experimentally measured by using a dilatometer at various temperature conditions. The relations between shrinkage amount and curing time at various temperature conditions are formulated. Internal stresses of the resin during curing conditions are numerically calculated by using the finite element method. The analysis is applied to two-layered model composed of epoxy resin and aluminum alloy. The magnitude of the deformation of the model is compared with the analyzed results and good correlation are obtained between the experimental and analyzed results.