This paper addresses the problem of clustering in large sets discussed in the context of financial time series. The goal is to divide stock market trading rules into several classes so that all the trading rules within the same class lead to similar trading decisions in the same stock market conditions. It is achieved using Kohonen self-organizing maps and the K-means algorithm. Several validity indices are used to validate and assess the clustering. Experiments were carried out on 350 stock market trading rules observed over a period of 1300 time instants.
The Self-Organizing Map (SOM) is a popular unsupervised neural network able to provide effective clustering and data visualization for data represented in multidimensional input spaces. In this paper, we describe Fast Learning SOM (FLSOM) which adopts a learning algorithm that improves the performance of the standard SOM with respect to the convergence time in the training phase. We show that FLSOM also improves the quality of the map by providing better clustering quality and topology preservation of multidimensional input data. Several tests have been carried out on different multidimensional datasets, which demonstrate better performances of the algorithm in comparison with the original SOM.
In this article we present a novel method for mobile phone positioning using a vector space model, suffix trees and an information retrieval approach. The algorithm is based on a database of previous measurements which are used as an index which looks for the nearest neighbor toward the query measurement. The accuracy of the algorithm is, in most cases, good enough to accomplish the E9-1-1 standards requirements on tested data. In addition, we are trying to look at the clusters of patterns that we have created from measured data and we have reflected them to the map. We use Self-Organizing Maps for these purposes.
Riziko CNS progrese u vysoce agresivních lymfomů (lymfoblastový a Burkittův lymfom) dosahovalo v historických souborech až 30%, podařilo se jej však výrazně snížit pomocí intratekální profylaktické terapie a inkorporací systémových cytostatik prostupujících hematoencefalickou bariéru do léčebných protokolů. U ostatních agresivních lymfomů je riziko CNS progrese nižší (pod 10 % v recentních studiích), avšak u vybrané skupiny nemocných se může i zde pohybovat kolem 25–30 %. Bohužel, na rozdíl od lymfoblastového a Burkittova lymfomu se u jiných agresivních histologií nepodařilo profylaktické úspěchy zopakovat. Tento článek se zabývá incidencí, rizikovými faktory a možnostmi profylaxe CNS relapsu u imunokompetentních pacientů s difuzním velkobuněčným B-lymfomem, lymfomem z buněk pláště, periferními T-lymfomy a primárním mediastinálním B-lymfomem. Zmíněny jsou rovněž možnosti terapie CNS progrese, pokud nastane., The risk of CNS progression in highly aggressive lymphomas (lymphoblastic, Burkitt‘s) reached up to 30% in historical cohorts, but it was significantly diminished by intrathecal prophylactic treatment and by incorporation of systemic cytostatics penetrating blood-brain barrier into treatment protocols. In other aggressive lymphomas, the risk of CNS progression is lower (under 10% in recent studies), but in selected patients can even here reach 25–30 %. Unfortunately, unlike in lymphoblastic and Burkitt‘s lymphomas, prophylaxis does not seem to be particularly effective in other histologies. This article discusses incidence, risk factors and prophylactic strategies in immunocompetent patients with diffuse large B-cell lymphoma, mantle-cell lymphoma, peripheral T-cell lymphomas and primary mediastinal B lymphoma. Also, treatment possibilities for CNS relapse, if it occurs, are reviewed., Robert Pytlík, and Literatura
Srdeční selhání se zachovalou ejekční frakcí levé komory (heart failure with preserved ejection fraction – HFPEF, heart failure with normal ejection fraction – HFNEF) je epidemiologicky závažným onemocněním, jehož výskyt v populaci postupně narůstá. Etiologie jeho vzniku není ještě zcela objasněna. Nově bylo zjištěno, že prozánětlivý stav spojený s řadou komorbidit, jako např. obezita či diabetes, potencuje rozvoj HFPEF. Také sérové koncentrace některých působků, jako např. adiponektin, mají souvislost s tímto onemocněním. Hlavním znakem HFPEF je diastolická dysfunkce, která je ale doprovázena řadou dalších kardiálních i nekardiálních poruch organizmu. Prognóza se i přes dlouhodobě užívané, ale i nově zavedené terapeutické postupy nemění. Zlatým standardem v diagnostice HFPEF zůstává katetrizace srdce. K ozřejmění základní choroby vedoucí k srdečnímu selhání jsou využívána další vyšetření, jako elektrokardiografie (EKG), RTG srdce a plic, laboratorní odběry včetně markerů srdečního selhání a hlavně echokardiografie včetně pulzního dopplerovského měření., Heart failure with preserved ejection fraction of left ventricle (heart failure with normal ejection fraction, HFPEF, HFNEF) is frequent disease with serious consequences. Incidence of HFPEF in population is still growing. The exact pathophysiological mechanism of HFPEF remain unclear .Recent evidence suggests a relationship between inflammation associated with obesity or Diabetes mellitus and progression of HFPEF. Consistently, it has been reported that serum concentration of some pro-inflammatory markers such as adiponectin is positively related to HFPEF. By HFPEF is attended diastolic dysfunction. Diastolic dysfunction is linked to many other cardiac and non-cardiac diseases. Despite the great effort and new therapeutic approaches the prognosis of HFPEF does not improve. The gold standard in HFPEF diagnosis remains heart catheterization. Electrocardiography, chest X-ray, blood examination including diagnostic markers of heart failure and mainly echocardiography with Doppler imaging are used diagnose the underlying disease leading to heart failure., and Zdeňka Gregorová, Jaroslav Meluzín, Lenka Špinarová
More than half of all of the children in the world, which die before the age of five, die in Africa. Wider availability of several highly effecti - ve interventions such as oral rehyd - ration therapy in cases of diarrhoea could prevent large proportion of these child deaths. Unfortunately these interventions are usually not available in African countries. Ho - wever both availability of different life-saving health interventions and child mortality varies a lot across African countries. The purpose of this article is to explore what are determinants of child mortality and availability of these interventions in Africa. Both a review of existing research and a statistical analysis of data from 41 African countries point to the quality of governance and control of corruption as the most significant determinant of health system performance and availability of these life-saving interventions in Africa., Jan Klusáček, and Literatura