12,444 research outputs found

    Augmented Session Similarity Based Framework for Measuring Web User Concern from Web Server Logs

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    In this paper, an augmented sessions similarity based framework is proposed to measure web user concern from web server logs. This proposed framework will consider the best usage similarity between two web sessions based on accessed page relevance and URL based syntactic structure of website within the session. The proposed framework is implemented using K-medoids clustering algorithms with independent and combined similarity measures. The clusters qualities are evaluated by measuring average intra-cluster and inter-cluster distances. The experimental results show that combined augmented session dissimilarity metric outperformed the independent augmented session dissimilarity measures in terms of cluster validity measures

    Walking across Wikipedia: a scale-free network model of semantic memory retrieval.

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    Semantic knowledge has been investigated using both online and offline methods. One common online method is category recall, in which members of a semantic category like "animals" are retrieved in a given period of time. The order, timing, and number of retrievals are used as assays of semantic memory processes. One common offline method is corpus analysis, in which the structure of semantic knowledge is extracted from texts using co-occurrence or encyclopedic methods. Online measures of semantic processing, as well as offline measures of semantic structure, have yielded data resembling inverse power law distributions. The aim of the present study is to investigate whether these patterns in data might be related. A semantic network model of animal knowledge is formulated on the basis of Wikipedia pages and their overlap in word probability distributions. The network is scale-free, in that node degree is related to node frequency as an inverse power law. A random walk over this network is shown to simulate a number of results from a category recall experiment, including power law-like distributions of inter-response intervals. Results are discussed in terms of theories of semantic structure and processing

    From Frequency to Meaning: Vector Space Models of Semantics

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    Computers understand very little of the meaning of human language. This profoundly limits our ability to give instructions to computers, the ability of computers to explain their actions to us, and the ability of computers to analyse and process text. Vector space models (VSMs) of semantics are beginning to address these limits. This paper surveys the use of VSMs for semantic processing of text. We organize the literature on VSMs according to the structure of the matrix in a VSM. There are currently three broad classes of VSMs, based on term-document, word-context, and pair-pattern matrices, yielding three classes of applications. We survey a broad range of applications in these three categories and we take a detailed look at a specific open source project in each category. Our goal in this survey is to show the breadth of applications of VSMs for semantics, to provide a new perspective on VSMs for those who are already familiar with the area, and to provide pointers into the literature for those who are less familiar with the field

    Efficient Diversification of Web Search Results

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    In this paper we analyze the efficiency of various search results diversification methods. While efficacy of diversification approaches has been deeply investigated in the past, response time and scalability issues have been rarely addressed. A unified framework for studying performance and feasibility of result diversification solutions is thus proposed. First we define a new methodology for detecting when, and how, query results need to be diversified. To this purpose, we rely on the concept of "query refinement" to estimate the probability of a query to be ambiguous. Then, relying on this novel ambiguity detection method, we deploy and compare on a standard test set, three different diversification methods: IASelect, xQuAD, and OptSelect. While the first two are recent state-of-the-art proposals, the latter is an original algorithm introduced in this paper. We evaluate both the efficiency and the effectiveness of our approach against its competitors by using the standard TREC Web diversification track testbed. Results shown that OptSelect is able to run two orders of magnitude faster than the two other state-of-the-art approaches and to obtain comparable figures in diversification effectiveness.Comment: VLDB201

    QueRIE: Collaborative Database Exploration

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    Interactive database exploration is a key task in information mining. However, users who lack SQL expertise or familiarity with the database schema face great difficulties in performing this task. To aid these users, we developed the QueRIE system for personalized query recommendations. QueRIE continuously monitors the user’s querying behavior and finds matching patterns in the system’s query log, in an attempt to identify previous users with similar information needs. Subsequently, QueRIE uses these “similar” users and their queries to recommend queries that the current user may find interesting. In this work we describe an instantiation of the QueRIE framework, where the active user’s session is represented by a set of query fragments. The recorded fragments are used to identify similar query fragments in the previously recorded sessions, which are in turn assembled in potentially interesting queries for the active user. We show through experimentation that the proposed method generates meaningful recommendations on real-life traces from the SkyServer database and propose a scalable design that enables the incremental update of similarities, making real-time computations on large amounts of data feasible. Finally, we compare this fragment-based instantiation with our previously proposed tuple-based instantiation discussing the advantages and disadvantages of each approach

    Behaviour modelling with data obtained from the Internet and contributions to cluster validation

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    [EN]This PhD thesis makes contributions in modelling behaviours found in different types of data acquired from the Internet and in the field of clustering evaluation. Two different types of Internet data were processed, on the one hand, internet traffic with the objective of attack detection and on the other hand, web surfing activity with the objective of web personalization, both data being of sequential nature. To this aim, machine learning techniques were applied, mostly unsupervised techniques. Moreover, contributions were made in cluster evaluation, in order to make easier the selection of the best partition in clustering problems. With regard to network attack detection, first, gureKDDCup database was generated which adds payload data to KDDCup99 connection attributes because it is essential to detect non-flood attacks. Then, by modelling this data a network Intrusion Detection System (nIDS) was proposed where context-independent payload processing was done obtaining satisfying detection rates. In the web mining context web surfing activity was modelled for web personalization. In this context, generic and non-invasive systems to extract knowledge were proposed just using the information stored in webserver log files. Contributions were done in two senses: in problem detection and in link suggestion. In the first application a meaningful list of navigation attributes was proposed for each user session to group and detect different navigation profiles. In the latter, a general and non-invasive link suggestion system was proposed which was evaluated with satisfactory results in a link prediction context. With regard to the analysis of Cluster Validity Indices (CVI), the most extensive CVI comparison found up to a moment was carried out using a partition similarity measure based evaluation methodology. Moreover, we analysed the behaviour of CVIs in a real web mining application with elevated number of clusters in which they tend to be unstable. We proposed a procedure which automatically selects the best partition analysing the slope of different CVI values.[EU]Doktorego-tesi honek internetetik eskuratutako datu mota ezberdinetan aurkitutako portaeren modelugintzan eta multzokatzeen ebaluazioan egiten ditu bere ekarpenak. Zehazki, bi mota ezberdinetako interneteko datuak prozesatu dira: batetik, interneteko trafikoa, erasoak hautemateko helburuarekin; eta bestetik, web nabigazioen jarduera, weba pertsonalizatzeko helburuarekin; bi datu motak izaera sekuentzialekoak direlarik. Helburu hauek lortzeko, ikasketa automatikoko teknikak aplikatu dira, nagusiki gainbegiratu-gabeko teknikak. Testuinguru honetan, multzokatzeen partizio onenaren aukeraketak dakartzan arazoak gutxitzeko multzokatzeen ebaluazioan ere ekarpenak egin dira. Sareko erasoen hautemateari dagokionez, lehenik gureKDDCup datubasea eratu da KDDCup99-ko konexio atributuei payload-ak (sareko paketeen datu eremuak) gehituz, izan ere, ez-flood erasoak (pakete gutxi erabiltzen dituzten erasoak) hautemateko ezinbestekoak baitira. Ondoren, datu hauek modelatuz testuinguruarekiko independenteak diren payload prozesaketak oinarri dituen sareko erasoak hautemateko sistema (network Intrusion Detection System (nIDS)) bat proposatu da maila oneko eraso hautemate-tasak lortuz. Web meatzaritzaren testuinguruan, weba pertsonalizatzeko helburuarekin web nabigazioen jarduera modelatu da. Honetarako, web zerbizarietako lorratz fitxategietan metatutako informazioa soilik erabiliz ezagutza erabilgarria erauziko duen sistema orokor eta ez-inbasiboak proposatu dira. Ekarpenak bi zentzutan eginaz: arazoen hautematean eta esteken iradokitzean. Lehen aplikazioan sesioen nabigazioa adierazteko atributu esanguratsuen zerrenda bat proposatu da, gero nabigazioak multzokatu eta nabigazio profil ezberdinak hautemateko. Bigarren aplikazioan, estekak iradokitzeko sistema orokor eta ez-inbasibo bat proposatu da, eta berau, estekak aurresateko testuinguruan ebaluatu da emaitza onak lortuz. Multzokatzeak balioztatzeko indizeen (Cluster Validity Indices (CVI)) azterketari dagokionez, gaurdaino aurkitu den CVI-en konparaketa zabalena burutu da partizioen antzekotasun neurrian oinarritutako ebaluazio metodologia erabiliz. Gainera, CVI-en portaera aztertu da egiazko web meatzaritza aplikazio batean normalean baino multzo kopuru handiagoak dituena, non CVI-ek ezegonkorrak izateko joera baitute. Arazo honi aurre eginaz, CVI ezberdinek partizio ezberdinetarako lortzen dituzten balioen maldak aztertuz automatikoki partiziorik onena hautatzen duen prozedura proposatu da.[ES]Esta tesis doctoral hace contribuciones en el modelado de comportamientos encontrados en diferentes tipos de datos adquiridos desde internet y en el campo de la evaluación del clustering. Dos tipos de datos de internet han sido procesados: en primer lugar el tráfico de internet con el objetivo de detectar ataques; y en segundo lugar la actividad generada por los usuarios web con el objetivo de personalizar la web; siendo los dos tipos de datos de naturaleza secuencial. Para este fin, se han aplicado técnicas de aprendizaje automático, principalmente técnicas no-supervisadas. Además, se han hecho aportaciones en la evaluación de particiones de clusters para facilitar la selección de la mejor partición de clusters. Respecto a la detección de ataques en la red, primero, se generó la base de datos gureKDDCup que añade el payload (la parte de contenido de los paquetes de la red) a los atributos de la conexión de KDDCup99 porque el payload es esencial para la detección de ataques no-flood (ataques que utilizan pocos paquetes). Después, se propuso un sistema de detección de intrusos (network Intrusion Detection System (IDS)) modelando los datos de gureKDDCup donde se propusieron varios preprocesos del payload independientes del contexto obteniendo resultados satisfactorios. En el contexto de la minerı́a web, se ha modelado la actividad de la navegación web para la personalización web. En este contexto se propondrán sistemas genéricos y no-invasivos para la extracción del conocimiento, utilizando únicamente la información almacenada en los ficheros log de los servidores web. Se han hecho aportaciones en dos sentidos: en la detección de problemas y en la sugerencia de links. En la primera aplicación, se propuso una lista de atributos significativos para representar las sesiones de navegación web para después agruparlos y detectar diferentes perfiles de navegación. En la segunda aplicación, se propuso un sistema general y no-invasivo para sugerir links y se evaluó en el contexto de predicción de links con resultados satisfactorios. Respecto al análisis de ı́ndices de validación de clusters (Cluster Validity Indices (CVI)), se ha realizado la más amplia comparación encontrada hasta el momento que utiliza la metodologı́a de evaluación basada en medidas de similitud de particiones. Además, se ha analizado el comportamiento de los CVIs en una aplicación real de minerı́a web con un número elevado de clusters, contexto en el que los CVIs tienden a ser inestables, ası́ que se propuso un procedimiento para la selección automática de la mejor partición en base a la pendiente de los valores de diferentes CVIs.Grant of the Basque Government (ref.: BFI08.226); Grant of Ministry of Economy and Competitiveness of the Spanish Government (ref.: BES-2011-045989); Research stay grant of Spanish Ministry of Economy and Competitiveness (ref.: EEBB-I-14-08862); University of the Basque Country UPV/EHU (BAILab, grant UFI11/45); Department of Education, Universities and Research of the Basque Government (grant IT-395-10); Ministry of Economy and Competitiveness of the Spanish Government and by the European Regional Development Fund - ERDF (eGovernAbility, grant TIN2014-52665-C2-1-R)

    User-Based Web Recommendation System: A Case Study of the National Museum of History

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    With the explosion and the rapidly growing market of the Internet, it is imperative that managers re-think to using technology, especially internet, to deliver services faster, cheaper, and with better quality than their competitors do. The web site provides a communication way that reveals real-time assess data and fruitful information of customers. Therefore, the call for customer with personalized web pages has become loud. To achieve personalized web pages, this study proposes recommendation algorithm of user behavior oriented by using the web log files from National Museum of History
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