4,520 research outputs found
Comparative performances of stochastic competitive evolutionary neural tree (SCENT) with neural classifiers
A stochastic competitive evolutionary neural tree (SCENT) is described and evaluated against the best neural classifiers with equivalent functionality, using a collection of data sets chosen to provide a variety of clustering scenarios. SCENT is firstly shown to produce flat classifications at least as well as the other two neural classifiers used. Moreover its variability in performance over the data sets is shown to be small. In addition SCENT also produces a tree that can show any hierarchical structure contained in the data. For two real world data sets the tree captures hierarchical features of the data.Peer reviewe
Hierarchical topological clustering learns stock market sectors
The breakdown of financial markets into sectors provides an intuitive classification for groups of companies. The allocation of a company to a sector is an expert task, in which the company is classified by the activity that most closely describes the nature of the company's business. Individual share price movement is dependent upon many factors, but there is an expectation for shares within a market sector to move broadly together. We are interested in discovering if share closing prices do move together, and whether groups of shares that do move together are identifiable in terms of industrial activity. Using TreeGNG, a hierarchical clustering algorithm, on a time series of share closing prices, we have identified groups of companies that cluster into clearly identifiable groups. These clusters compare favourably to a globally accepted sector classification scheme, and in our opinion, our method identifies sector structure clearer than a statistical agglomerative hierarchical clustering metho
High capacity associative memory with bipolar and binary, biased patterns
The high capacity associative memory model is interesting due to its significantly higher capacity when compared with the standard Hopfield model. These networks can use either bipolar or binary patterns, which may also be biased. This paper investigates the performance of a high capacity associative memory model trained with biased patterns, using either bipolar or binary representations. Our results indicate that the binary network performs less well under low bias, but better in other situations, compared with the bipolar network.Peer reviewe
Gender classification of face images: the role of global and feature-based information
Peer reviewe
Connection Strategies in Associative Memory Models
“The original publication is available at www.springerlink.com”. Copyright Springer.The problem we address in this paper is that of finding effective and parsimonious patterns of connectivity in sparse associative memories. This problem must be addressed in real neuronal systems, so results in artificial systems could throw light on real systems. We show that there are efficient patterns of connectivity and that these patterns are effective in models with either spiking or non-spiking neurons. This suggests that there may be some underlying general principles governing good connectivity in such networks.Peer reviewe
Phase conjugate fluorozirconate fibre laser operating at 800nm
We report phase-conjugate feedback into a fluorozirconate optical fiber amplifier at infrared wavelengths. By using a semiconductor laser diode at 807 nm, a grating is established in photorefractive BaTiO3 that, in the ring configuration, provides feedback into the amplifier necessary for laser action. Once written, the grating is self-sustaining, and lasing is observed even after the laser diode is removed
Irradiation of the secondary star in X-ray Nova Scorpii 1994 (=GRO J1655--40)
We have obtained intermediate resolution optical spectra of the black-hole
candidate Nova Sco 1994 in June 1996, when the source was in an X-ray/optical
active state (R~15.05). We measure the radial velocity curve of the secondary
star and obtain a semi-amplitude of 279+/-10 km/s; a value which is 30 per cent
larger than the value obtained when the source is in quiescence. Our large
value for K_2 is consistent with 60 +9,-7 per cent of the secondary star's
surface being heated; compared to 35 per cent, which is what one would expect
if only the inner face of the secondary star were irradiated. Effects such as
irradiation-induced flows on the secondary star may be important in explaining
the observed large value for K_2.Comment: 5 pages, 2 figures, accepted by MNRA
Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study
ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area
Pengaruh Latihan Kegel Terhadap Frekuensi Inkontinensia Urine Pada Lansia Di Unit Rehabilitasi Sosial Margo Mukti Rembang
The purpose of this study was to determine the influence of the Kegel exercise on frequency of urinary incontinence in the elderly. This study used a quasi -experimental with one group pre and post test study design, conducted on 27 respondents selected by purposive sampling technique. Respondents were divided into three groups which were the first group with frequency of exercise 2 times, the second group with 3 times and the third group 4 times a day for six weeks. Data on the frequency of urinary incontinence were collected in pre and post intervention Kegel exercise. Data were analyzed using t-test (paired t-test).The results of the study revealed that group I , II & III in sequence value of t-count 21.92, t=11,418 and t=15.307 with P values p=0, 00. Further comparisons between the three groups showed group III showed the mean frequency of urinary incontinence at least. It can be concluded that Kegel exercises affect the decrease in the frequency of urinary incontinence in the elderly, and it is suggested that Kegel exercises should be done regularly
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