Search results for "Clusterin"
showing 10 items of 478 documents
Growing Hierarchical Self-organizing Maps and Statistical Distribution Models for Online Detection of Web Attacks
2013
In modern networks, HTTP clients communicate with web servers using request messages. By manipulating these messages attackers can collect confidential information from servers or even corrupt them. In this study, the approach based on anomaly detection is considered to find such attacks. For HTTP queries, feature matrices are obtained by applying an n-gram model, and, by learning on the basis of these matrices, growing hierarchical self-organizing maps are constructed. For HTTP headers, we employ statistical distribution models based on the lengths of header values and relative frequency of symbols. New requests received by the web-server are classified by using the maps and models obtaine…
Verbal fluency in school-aged Spanish children: analysis of clustering and switching organizational strategies, employing different semantic categori…
2021
La tarea de fluidez verbal (FV) es una medida de la flexibilidad cognitiva y la estrategia de búsqueda dentro del léxico y el tema semántico. En este trabajo, se probó el uso de estrategias organizativas, es decir, agrupación y cambio en la fluidez semántica y fonológica en niños españoles sanos divididos en dos grupos: el grupo 1 de niños más pequeños (de 8 a 9 años) y el grupo 2 de niños mayores (de 10 años de edad) –11) introducción de diferentes letras (F, A, S y P, M, R) y categorías semánticas (animales y comidas o bebidas). La fluidez semántica fue mayor que la fluidez fonológica en ambos grupos de edad. Además, los niños mayores mostraron un mejor desempeño de ambas fluencias que lo…
Overexpression of apolipoprotein J in human fibroblasts protects against cytotoxicity and premature senescence induced by ethanol and tert-butylhydro…
2008
Human diploid fibroblasts (HDFs) exposed to subcytotoxic stresses under H2O2, tert-butylhydroperoxide (t-BHP), and ethanol (EtOH) undergo stress-induced premature senescence (SIPS) characterized by many biomarkers of HDFs replicative senescence. Among these biomarkers are a growth arrest, an increase in the senescence-associated β-galactosidase activity, a senescent morphology, an overexpression of p21waf-1 and the subsequent inability to phosphorylate pRb, the presence of the common 4977-bp mitochondrial deletion, and an increase in the steady-state level of several senescence-associated genes such as apolipoprotein J (apo J). Apo J has been described as a survival gene against cytotoxic s…
A hybrid approach to semantic web services matchmaking
2008
AbstractDeploying the semantics embedded in web services is a mandatory step in the automation of discovery, invocation and composition activities. The semantic annotation is the “add-on” to cope with the actual interoperability limitations and to assure a valid support to the interpretation of services capabilities. Nevertheless many issues have to be reached to support semantics in the web services and to guarantee accurate functionality descriptions. Early efforts address automatic matchmaking tasks, in order to find eligible advertised services which appropriately meet the consumer’s demand. In the most of approaches, this activity is often entrusted to software agents, able to drive re…
An interest-aware video streaming platform: Shaping its architecture to better suit users' demands
2014
This paper investigates how a p2p television platform can take advantage of the presence of frequent channel viewers to grant them a more satisfying service than to less regular spectators. The idea we explore is to learn beforehand about the users’ interests, in order to cluster them in groups that display different behaviors; then, the video chunk scheduling algorithm of the p2p overlay is altered, with the aim of serving frequent spectators in a privileged manner, providing them with a faster access to the selected channel. An analytical model is developed, to capture the difference in startup delay that the proposed changes introduce; several additional performance metrics are numerical…
Solution Using Clustering Methods
1987
The main aim of this analysis is to find out typical morphologies from the multivariate and longitudinal data set on growing children and to describe the morphological evolution of the found groups of girls. The finding out of typical morphologies is, in our opinion, strictly linked to the search of structures in the individuals and in the variables.
Robust refinement of initial prototypes for partitioning-based clustering algorithms
2007
Non-uniqueness of solutions and sensitivity to erroneous data are common problems to large-scale data clustering tasks. In order to avoid poor quality of solutions with partitioning-based clustering methods, robust estimates (that are highly insensitive to erroneous data values) are needed and initial cluster prototypes should be determined properly. In this paper, a robust density estimation initialization method that exploits the spatial median estimate to the prototype update is presented. Besides being insensitive to noise and outliers, the new method is also computationally comparable with other traditional methods. The methods are compared by numerical experiments on a set of syntheti…
A hierarchical clustering strategy and its application to proteomic interaction data
2003
We describe a novel strategy of hierarchical clustering analysis, particularly useful to analyze proteomic interaction data. The logic behind this method is to use the information for all interactions among the elements of a set to evaluate the strength of the interaction of each pair of elements. Our procedure allows the characterization of protein complexes starting with partial data and the detection of "promiscuous" proteins that bias the results, generating false positive data. We demonstrate the usefulness of our strategy by analyzing a real case that involves 137 Saccharomyces cerevisiae proteins. Because most functional studies require the evaluation of similar data sets, our method…
Correlation based hierarchical clustering in financial time series
2005
We review a correlation based clustering procedure applied to a portfolio of assets synchronously traded in a financial market. The portfolio considered consists of the set of 500 highly capitalized stocks traded at the New York Stock Exchange during the time period 1987-1998. We show that meaningful economic information can be extracted from correlation matrices.
“Local Production”: What Do Consumers Think?
2022
Since the mid-1990s, there has been a growing interest among consumers and producers in downscaling to a local level the length of the agri-food chains as a solution for fairer and more sustainable food production systems. From the point of view of consumption, the attribute “local” is assuming an important role in defining food purchasing preferences, both in terms of expectations of product quality and in terms of its perceived relevance in determining the supply chain sustainability. This research aims to define how individuals’ perception of local production influences the definition of “local” among consumers based on a survey submitted to a sample of 500 consumers in North-Western Ita…