On deep annotation The success of the Semantic Web crucially depends on the easy creation , integration and use of semantic data . For this purpose , we consider an integration scenario that defies core assumptions of current metadata construction methods . We describe a framework of metadata creation when web pages are generated from a database and the database owner is cooperatively participating in the Semantic Web . This leads us to the definition of ontology mapping rules by manual semantic annotation and the usage of the mapping rules and of web services for semantic queries . In order to create metadata , the framework combines the presentation layer with the data description layer -- in contrast to `` conventional '' annotation , which remains at the presentation layer . Therefore , we refer to the framework as deep annotation 1 . We consider deep annotation as particularly valid because , ( i ) , web pages generated from databases outnumber static web pages , ( ii ) , annotation of web pages may be a very intuitive way to create semantic data from a database and , ( iii ) , data from databases should not be materialized as RDF files , it should remain where it can be handled most efficiently -- in its databases .

O O B O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

document and text editing
information integration
mapping and merging
wrapping


Temporal rules for mobile web personalization Many systems use past behavior , preferences and environmental factors to attempt to predict user navigation on the Internet . However we believe that many of these models have shortcomings , in that they do not take into account that users may have many different sets of preferences . Here we investigate an environmental factor , namely time , in making predictions about user navigation . We present methods for creating temporal rules that describe user navigation patterns . We also show the benefit of using these rules to predict user navigation and also show the benefits of these models over traditional methods . An analysis is carried out on a sample of usage logs for Wireless Application Protocol ( WAP ) browsing , and the results of this analysis verify our hypothesis .

O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O

hypertext/hypermedia
miscellaneous
temporal models
user modeling
user/machine systems
www


A community-aware search engine Current search technologies work in a `` one size fits all '' fashion . Therefore , the answer to a query is independent of specific user information need . In this paper we describe a novel ranking technique for personalized search servicesthat combines content-based and community-based evidences . The community-based information is used in order to provide context for queries andis influenced by the current interaction of the user with the service . Ouralgorithm is evaluated using data derived from an actual service available on the Web an online bookstore . We show that the quality of content-based ranking strategies can be improved by the use of communityinformation as another evidential source of relevance . In our experiments the improvements reach up to 48 % in terms of average precision .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A game based approach to assign geographical relevance to web images Geographical context is very important for images . Millions of images on the Web have been already assigned latitude and longitude information . Due to the rapid proliferation of such images with geographical context , it is still difficult to effectively search and browse them , since we do not have ways to decide their relevance . In this paper , we focus on the geographical relevance of images , which is defined as to what extent the main objects in an image match landmarks at the location where the image was taken . Recently , researchers have proposed to use game based approaches to label large scale data such as Web images . However , previous works have not shown the quality of collected game logs in detail and how the logs can improve existing applications . To answer these questions , we design and implement a Web-based and multi-player game to collect human knowledge while people are enjoying the game . Then we thoroughly analyze the game logs obtained during a three week study with 147 participants and propose methods to determine the image geographical relevance . In addition , we conduct an experiment to compare our methods with a commercial search engine . Experimental results show that our methods dramatically improve image search relevance . Furthermore , we show that we can derive geographically relevant objects and their salient portion in images , which is valuable for a number of applications such as image location recognition .

O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Evaluation with informational and navigational intents Given an ambiguous or underspecified query , search result diversification aims at accomodating different user intents within a single `` entry-point '' result page . However , some intents are informational , for which many relevant pages may help , while others are navigational , for which only one web page is required . We propose new evaluation metrics for search result diversification that considers this distinction , as well as a simple method for comparing the intuitiveness of a given pair of metrics quantitatively . Our main experimental findings are : ( a ) In terms of discriminative power which reflects statistical reliability , the proposed metrics , DIN # - nDCG and P+Q # , are comparable to intent recall and D # - nDCG , and possibly superior to α-nDCG ; ( b ) In terms of preference agreement with intent recall , P+Q # is superior to other diversity metrics and therefore may be the most intuitive as a metric that emphasises diversity ; and ( c ) In terms of preference agreement with effective precision , DIN # - nDCG is superior to other diversity metrics and therefore may be the most intuitive as a metric that emphasises relevance . Moreover , DIN # - nDCG may be the most intuitive as a metric that considers both diversity and relevance . In addition , we demonstrate that the randomised Tukey 's Honestly Significant Differences test that takes the entire set of available runs into account is substantially more conservative than the paired bootstrap test that only considers one run pair at a time , and therefore recommend the former approach for significance testing when a set of runs is available for evaluation .

B O O O O B O O O O O O O O O B O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B B O O O B O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O

diversification evaluation intents metrics

information search and retrieval
novelty
redundancy


Post-processing inkml for random-access navigation of voluminous handwritten ink documents The goal of this research is the improvement of browsing voluminous InkML data in two areas : ease of rendering continuous ink-flow for replay-browsing , and ease of random access navigation in eLearning domains . The notion of real-time random access navigation in ink documents has not yet been fully exploited . Users of existing eLearning browsers are restricted to viewing static annotated slides that are inferior in quality when compared to actively replaying the same slides with sequenced ink-flow of the annotated freehand writings . We are developing a tool to investigate ways of managing massive InkML data for efficient `` active visible scrolling '' of recorded freehand writings in ink documents . This work will also develop and evaluate new post-processing techniques that take advantage of the relationship between ink volumes and active-rendering times for real-time random access navigation .

O B O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O


RDF triples in XML RDF\/XML does not layer RDF on top of XML ina useful way . We use a simple direct representation of the RDF abstract syntax in XML . We add the ability to name graphs , noting that in practice this is already widely used . We use XSLT as a general syntactic extensibility mechanism to provide human friendly macros for our syntax . This provides a simple serialization solving a persistent problem in the Semantic Web .

B O O B O O O O B O O O B O O O O O O O O O O O O B O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O


Track globally , deliver locally : improving content delivery networks by tracking geographic social cascades Providers such as YouTube offer easy access to multimedia content to millions , generating high bandwidth and storage demand on the Content Delivery Networks they rely upon . More and more , the diffusion of this content happens on online social networks such as Facebook and Twitter , where social cascades can be observed when users increasingly repost links they have received from others . In this paper we describe how geographic information extracted from social cascades can be exploited to improve caching of multimedia files in a Content Delivery Network . We take advantage of the fact that social cascades can propagate in a geographically limited area to discern whether an item is spreading locally or globally . This informs cache replacement policies , which utilize this information to ensure that content relevant to a cascade is kept close to the users who may be interested in it . We validate our approach by using a novel dataset which combines social interaction data with geographic information : we track social cascades of YouTube links over Twitter and build a proof-of-concept geographic model of a realistic distributed Content Delivery Network . Our performance evaluation shows that we are able to improve cache hits with respect to cache policies without geographic and social information .

O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

content delivery networks
online social networks

information propagation
on-line information services


Leveraging interlingual classification to improve web search In this paper we address the problem of improving accuracy of web search in a smaller , data-limited search market ( search language ) using behavioral data from a larger , data-rich market ( assist language ) . Specifically , we use interlingual classification to infer the search language query 's intent using the assist language click-through data . We use these improved estimates of query intent , along with the query intent based on the search language data , to compute features that encode the similarity between a search result ( URL ) and the query . These features are subsequently fed into the ranking model to improve the relevance ranking of the documents . Our experimental results on German and French languages show the effectiveness of using assist language behavioral data especially , when the search language queries have small click-through data .

O O O O O B I O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

cross-lingual information retrieval
information search and retrieval
machine translation
text classification


Improving recommendation for long-tail queries via templates The ability to aggregate huge volumes of queries over a large population of users allows search engines to build precise models for a variety of query-assistance features such as query recommendation , correction , etc. . Yet , no matter how much data is aggregated , the long-tail distribution implies that a large fraction of queries are rare . As a result , most query assistance services perform poorly or are not even triggered on long-tail queries . We propose a method to extend the reach of query assistance techniques ( and in particular query recommendation ) to long-tail queries by reasoning about rules between query templates rather than individual query transitions , as currently done in query-flow graph models . As a simple example , if we recognize that ` Montezuma ' is a city in the rare query `` Montezuma surf '' and if the rule ` city surf → beach has been observed , we are able to offer `` Montezuma beach '' as a recommendation , even if the two queries were never observed in a same session . We conducted experiments to validate our hypothesis , first via traditional small-scale editorial assessments but more interestingly via a novel automated large scale evaluation methodology . Our experiments show that general coverage can be relatively increased by 24 % using templates without penalizing quality . Furthermore , for 36 % of the 95M queries in our query flow graph , which have no out edges and thus could not be served recommendations , we can now offer at least one recommendation in 98 % of the cases .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A user profile-based approach for personal information access : shaping your information portfolio In the spread of internet , internet-based information service business has started to become profitable . One of the key technologies is personalization . Successful internet information services must realize personalized information delivery , by which the users can automatically receive highly tuned information according to their personal needs and preferences . In order to realize such personalized information services , we have developed an automatic user preference capture and an automatic information clipping function based on a Personalized Information Access technique . In this paper , those techniques will be demonstrated by showing a deployed personalized webpage service application .

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

information retrieval
internet behavior
language constructs and features
system
user profile


Upgrading relational legacy data to the semantic web In this poster , we describe a framework composed of the R2O mapping language and the ODEMapster processor to upgrade relational legacy data to the Semantic Web . The framework is based on the declarative description of mappings between relational and ontology elements and the exploitation of such mapping descriptions by a generic processor capable of performing both massive and query driven data upgrade .

O O O O O O B I O O O O O O O O O O O O O O O O O O O B O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O

database applications
database-to-ontology mappings
relational databases


Parsing owl dl : trees or triples ? The Web Ontology Language ( OWL ) defines three classes of documents : Lite , DL , and Full . All RDF\/XML documents are OWL Full documents , some OWL Full documents are also OWL DL documents , and some OWL DL documents are also OWL Lite documents . This paper discusses parsing and species recognition -- that is the process of determining whether a given document falls into the OWL Lite , DL or Full class . Wedescribe two alternative approaches to this task , one based on abstract syntax trees , the other on RDF triples , and compare their key characteristics .

O B O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O B O O O O B O O O O B O O O O O B O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O


LINDEN : linking named entities with knowledge base via semantic knowledge Integrating the extracted facts with an existing knowledge base has raised an urgent need to address the problem of entity linking . Specifically , entity linking is the task to link the entity mention in text with the corresponding real world entity in the existing knowledge base . However , this task is challenging due to name ambiguity , textual inconsistency , and lack of world knowledge in the knowledge base . Several methods have been proposed to tackle this problem , but they are largely based on the co-occurrence statistics of terms between the text around the entity mention and the document associated with the entity . In this paper , we propose LINDEN , a novel framework to link named entities in text with a knowledge base unifying Wikipedia and WordNet , by leveraging the rich semantic knowledge embedded in the Wikipedia and the taxonomy of the knowledge base . We extensively evaluate the performance of our proposed LINDEN over two public data sets and empirical results show that LINDEN significantly outperforms the state-of-the-art methods in terms of accuracy .

O O O O O O B I O B I O O O O O O O B I O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B O O O O O O O B I O O O B O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

entity linking
knowledge base
semantic knowledge
wikipedia

fact integration
information search and retrieval


Declarative platform for data sourcing games Harnessing a crowd of users for the collection of mass data ( data sourcing ) has recently become a wide-spread practice . One effective technique is based on games as a tool that attracts the crowd to contribute useful facts . We focus here on the data management layer of such games , and observe that the development of this layer involves challenges such as dealing with probabilistic data , combined with recursive manipulation of this data . These challenges are difficult to address using current declarative data management framework works , and we thus propose here a novel such framework , and demonstrate its usefulness in expressing different aspects in the data management of Trivia-like games . We have implemented a system prototype with our novel data management framework at its core , and we highlight key issues in the system design , as well as our experimentations that indicate the usefulness and scalability of the approach .

O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

crowdsourcing
data description languages
databases


Sentence-level contextual opinion retrieval Existing opinion retrieval techniques do not provide context-dependent relevant results . Most of the approaches used by state-of-the-art techniques are based on frequency of query terms , such that all documents containing query terms are retrieved , regardless of contextual relevance to the intent of the human seeking the opinion . However , in a particular opinionated document , words could occur in different contexts , yet meet the frequency attached to a certain opinion threshold , thus explicitly creating a bias in overall opinion retrieved . In this paper we propose a sentence-level contextual model for opinion retrieval using grammatical tree derivations and approval voting mechanism . Model evaluation performed between our contextual model , BM25 , and language model shows that the model can be effective for contextual opinion retrieval such as faceted opinion retrieval .

O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O

grammatical tree derivation
information search and retrieval
sentence level


A framework for XML data streams history checking and monitoring The need of formal verification is a problem that involves all the fields in which sensible data are managed . In this context the verification of data streams became a fundamental task . The purpose of this paper is to present a framework , based on the model checker SPIN , for the verification of data streams . The proposed method uses a linear temporal logic , called TRIO , to describe data constraints and properties . Constraints are automatically translated into Promela , the input language of the model checker SPIN in order to verify them .

O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Not so creepy crawler : easy crawler generation with standard xml queries Web crawlers are increasingly used for focused tasks such as the extraction of data from Wikipedia or the analysis of social networks like last . fm . In these cases , pages are far more uniformly structured than in the general Web and thus crawlers can use the structure of Web pages for more precise data extraction and more expressive analysis . In this demonstration , we present a focused , structure-based crawler generator , the `` Not so Creepy Crawler '' ( nc2 ) . What sets nc2 apart , is that all analysis and decision tasks of the crawling process are delegated to an ( arbitrary ) XML query engine such as XQuery or Xcerpt . Customizing crawlers just means writing ( declarative ) XML queries that can access the currently crawled document as well as the metadata of the crawl process . We identify four types of queries that together sufice to realize a wide variety of focused crawlers . We demonstrate nc2 with two applications : The first extracts data about cities from Wikipedia with a customizable set of attributes for selecting and reporting these cities . It illustrates the power of nc2 where data extraction from Wiki-style , fairly homogeneous knowledge sites is required . In contrast , the second use case demonstrates how easy nc2 makes even complex analysis tasks on social networking sites , here exemplified by last . fm .

O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

information search and retrieval
web crawler
web query


TJFast : effective processing of XML twig pattern matching Finding all the occurrences of a twig pattern in an XML database is a core operation for efficient evaluation of XML queries . A number of algorithms have been proposed to process a twig query based on region encoding . In this paper , based on a novel labeling scheme : extended Dewey , we propose a novel and efficient holistic twig join algorithm , namely TJFast . Compared to previous work , our algorithm only needs to access the labels of leaf query nodes . We report our experimental results to show that our algorithms are superior to previous approaches in terms of the number of elements scanned and query performance .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Planetary-scale views on a large instant-messaging network We present a study of anonymized data capturing a month of high-level communication activities within the whole of the Microsoft Messenger instant-messaging system . We examine characteristics and patterns that emerge from the collective dynamics of large numbers of people , rather than the actions and characteristics of individuals . The dataset contains summary properties of 30 billion conversations among 240 million people . From the data , we construct a communication graph with 180 million nodes and 1.3 billion undirected edges , creating the largest social network constructed and analyzed to date . We report on multiple aspects of the dataset and synthesized graph . We find that the graph is well-connected and robust to node removal . We investigate on a planetary-scale the oft-cited report that people are separated by `` six degrees of separation '' and find that the average path length among Messenger users is 6.6 . We find that people tend to communicate more with each other when they have similar age , language , and location , and that cross-gender conversations are both more frequent and of longer duration than conversations with the same gender .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

communication networks
large data
online communication
social networks
user demographics


Flickr tag recommendation based on collective knowledge Online photo services such as Flickr and Zooomr allow users to share their photos with family , friends , and the online community at large . An important facet of these services is that users manually annotate their photos using so called tags , which describe the contents of the photo or provide additional contextual and semantical information . In this paper we investigate how we can assist users in the tagging phase . The contribution of our research is twofold . We analyze a representative snapshot of Flickr and present the results by means of a tag characterisation focussing on how users tags photos and what information is contained in the tagging . Based on this analysis , we present and evaluate tag recommendation strategies to support the user in the photo annotation task by recommending a set of tags that can be added to the photo . The results of the empirical evaluation show that we can effectively recommend relevant tags for a variety of photos with different levels of exhaustiveness of original tagging .

B B I O O B I O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

collective knowledge
flickr
tag characterisation
tag recommendation

aggregated tag suggestion
content analysis and indexing
on-line information services
photo annotations
tag co-occurence


Mashroom : end-user mashup programming using nested tables This paper presents an end-user-oriented programming environment called Mashroom . Major contributions herein include an end-user programming model with an expressive data structure as well as a set of formally-defined mashup operators . The data structure takes advantage of nested table , and maintains the intuitiveness while allowing users to express complex data objects . The mashup operators are visualized with contextual menu and formula bar and can be directly applied on the data . Experiments and case studies reveal that end users have little difficulty in effectively and efficiently using Mashroom to build mashup applications .

O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O

end-user programming
reusable software
spreadsheet


Hubble : an advanced dynamic folder system for XML Organizing large document collections for finding information easily and quickly has always been an important user requirement . This paper describes a flexible and powerful dynamic folder technology , called Hubble , which exploits XML semantics to precisely categorize XML documents into categories or folders .

O O O O B I O O B O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B O O O O B O O O O O O


A case study in web search using TREC algorithms

keyword-based ranking
link-based ranking
search engines
trec ad-hoc


Privacy in dynamic social networks Anonymization of social networks before they are published or shared has become an important research question . Recent work on anonymizing social networks has looked at privacy preserving techniques for publishing a single instance of the network . However , social networks evolve and a single instance is inadequate for analyzing the evolution of the social network or for performing any longitudinal data analysis . We study the problem of repeatedly publishing social network data as the network evolves , while preserving privacy of users . Publishing multiple instances of the same network independently has privacy risks , since stitching the information together may allow an adversary to identify users in the networks . We propose methods to anonymize a dynamic network such that the privacy of users is preserved when new nodes and edges are added to the published network . These methods make use of link prediction algorithms to model the evolution of the social network . Using this predicted graph to perform group-based anonymization , the loss in privacy caused by new edges can be reduced . We evaluate the privacy loss on publishing multiple social network instances using our methods .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Extraction and classification of dense communities in the web The World Wide Web ( WWW ) is rapidly becoming important for society as a medium for sharing data , information and services , and there is a growing interest in tools for understanding collective behaviors and emerging phenomena in the WWW . In this paper we focus on the problem of searching and classifying communities in the web . Loosely speaking a community is a group of pages related to a common interest . More formally communities have been associated in the computer science literature with the existence of a locally dense sub-graph of the web-graph ( where web pages are nodes and hyper-links are arcs of the web-graph ) . The core of our contribution is a new scalable algorithm for finding relatively dense subgraphs in massive graphs . We apply our algorithm on web-graphs built on three publicly available large crawls of the web ( with raw sizes up to 120M nodes and 1G arcs ) . The effectiveness of our algorithm in finding dense subgraphs is demonstrated experimentally by embedding artificial communities in the web-graph and counting how many of these are blindly found . Effectiveness increases with the size and density of the communities : it is close to 100 % for communities of a thirty nodes or more ( even at low density ) . It is still about 80 % even for communities of twenty nodes with density over 50 % of the arcs present . At the lower extremes the algorithm catches 35 % of dense communities made of ten nodes . We complete our Community Watch system by clustering the communities found in the web-graph into homogeneous groups by topic and labeling each group by representative keywords .

O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O


Partitioning of Web graphs by community topology We introduce a stricter Web community definition to overcome boundary ambiguity of a Web community defined by Flake , Lawrence and Giles ( 2 ) , and consider the problem of finding communities that satisfy our definition . We discuss how to find such communities and hardness of this problem . We also propose Web page partitioning by equivalence relation defined using the class of communities of our definition . Though the problem of efficiently finding all communities of our definition is NP-complete , we propose an efficient method of finding a subclass of communities among the sets partitioned by each of n-1 cuts represented by a Gomory-Hu tree ( 10 ) , and partitioning a Web graph by equivalence relation defined using the subclass . According to our preliminary experiments , partitioning by our method divided the pages retrieved by keyword search into several different categories to some extent .

O O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

graph partitioning
maximum flow algorithm


Applying NavOptim to minimize navigational effort A major factor in the effectiveness of the interaction which users have with Web applications is the ease with which they can locate information and functionality which they are seeking . Effective design is however complicated by the multiple design purposes and diverse users which Web applications typically support . In this paper we describe a navigational design method aimed at optimising designs through minimizing navigational entropy . The approach uses a theoretical navigational depth for the various information and service components to moderate a nested hierarchical clustering of the content .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


MedSearch : a specialized search engine for medical information People are thirsty for medical information . Existing Web search engines can not handle medical search well because they do not consider its special requirements . Often a medical information searcher is uncertain about his exact questions and unfamiliar with medical terminology . Therefore , he prefers to pose long queries , describing his symptoms and situation in plain English , and receive comprehensive , relevant information from search results . This paper presents MedSearch , a specialized medical Web search engine , to address these challenges . MedSearch can assist ordinary Internet users to search for medical information , by accepting queries of extended length , providing diversified search results , and suggesting related medical phrases .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


k-Centralities : local approximations of global measures based on shortest paths A lot of centrality measures have been developed to analyze different aspects of importance . Some of the most popular centrality measures ( e.g. betweenness centrality , closeness centrality ) are based on the calculation of shortest paths . This characteristic limits the applicability of these measures for larger networks . In this article we elaborate on the idea of bounded-distance shortest paths calculations . We claim criteria for k-centrality measures and we introduce one algorithm for calculating both betweenness and closeness based centralities . We also present normalizations for these measures . We show that k-centrality measures are good approximations for the corresponding centrality measures by achieving a tremendous gain of calculation time and also having linear calculation complexity O ( n ) for networks with constant average degree . This allows researchers to approximate centrality measures based on shortest paths for networks with millions of nodes or with high frequency in dynamically changing networks .

O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O

betweenness centrality
closeness centrality
shortest paths

centrality approximation
graph theory
large networks


Invasive browser sniffing and countermeasures We describe the detrimental effects of browser cache\/history sniffing in the context of phishing attacks , and detail an approach that neutralizes the threat by means of URL personalization ; we report on an implementation performing such personalization on the fly , and analyze the costs of and security properties of our proposed solution .

O O B O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O B O O O O O O O O B O O O O O O O O O O O O O O O O O


Leveraging auxiliary text terms for automatic image annotation This paper proposes a novel algorithm to annotate web images by automatically aligning the images with their most relevant auxiliary text terms . First , the DOM-based web page segmentation is performed to extract images and their most relevant auxiliary text blocks . Second , automatic image clustering is used to partition the web images into a set of groups according to their visual similarity contexts , which significantly reduces the uncertainty on the relatedness between the images and their auxiliary terms . The semantics of the visually-similar images in the same cluster are then described by the same ranked list of terms which frequently co-occur in their text blocks . Finally , a relevance re-ranking process is performed over a term correlation network to further refine the ranked term list . Our experiments on a large-scale database of web pages have provided very positive results .

O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

image-text alignment
relevance re-ranking


IRLbot : scaling to 6 billion pages and beyond This paper shares our experience in designing a web crawler that can download billions of pages using a single-server implementation and models its performance . We show that with the quadratically increasing complexity of verifying URL uniqueness , BFS crawl order , and fixed per-host rate-limiting , current crawling algorithms can not effectively cope with the sheer volume of URLs generated in large crawls , highly-branching spam , legitimate multi-million-page blog sites , and infinite loops created by server-side scripts . We offer a set of techniques for dealing with these issues and test their performance in an implementation we call IRLbot . In our recent experiment that lasted 41 days , IRLbot running on a single server successfully crawled 6.3 billion valid HTML pages ( $ 7.6 $ billion connection requests ) and sustained an average download rate of 319 mb\/s ( 1,789 pages\/s ) . Unlike our prior experiments with algorithms proposed in related work , this version of IRLbot did not experience any bottlenecks and successfully handled content from over 117 million hosts , parsed out 394 billion links , and discovered a subset of the web graph with 41 billion unique nodes .

B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Dynamic placement for clustered web applications We introduce and evaluate a middleware clustering technology capable of allocating resources to web applications through dynamic application instance placement . We define application instance placement as the problem of placing application instances on a given set of server machines to adjust the amount of resources available to applications in response to varying resource demands of application clusters . The objective is to maximize the amount of demand that may be satisfied using a configured placement . To limit the disturbance to the system caused by starting and stopping application instances , the placement algorithm attempts to minimize the number of placement changes . It also strives to keep resource utilization balanced across all server machines . Two types of resources are managed , one load-dependent and one load-independent . When putting the chosen placement in effect our controller schedules placement changes in a manner that limits the disruption to the system .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

dynamic application placement
performance management
system management


On integrating catalogs

catalog integration
categorization
classification
web marketplaces
web portals


Answering search queries with CrowdSearcher Web users are increasingly relying on social interaction to complete and validate the results of their search activities . While search systems are superior machines to get world-wide information , the opinions collected within friends and expert\/local communities can ultimately determine our decisions : human curiosity and creativity is often capable of going much beyond the capabilities of search systems in scouting `` interesting '' results , or suggesting new , unexpected search directions . Such personalized interaction occurs in most times aside of the search systems and processes , possibly instrumented and mediated by a social network ; when such interaction is completed and users resort to the use of search systems , they do it through new queries , loosely related to the previous search or to the social interaction . In this paper we propose CrowdSearcher , a novel search paradigm that embodies crowds as first-class sources for the information seeking process . CrowdSearcher aims at filling the gap between generalized search systems , which operate upon world-wide information - including facts and recommendations as crawled and indexed by computerized systems - with social systems , capable of interacting with real people , in real time , to capture their opinions , suggestions , emotions . The technical contribution of this paper is the discussion of a model and architecture for integrating computerized search with human interaction , by showing how search systems can drive and encapsulate social systems . In particular we show how social platforms , such as Facebook , LinkedIn and Twitter , can be used for crowdsourcing search-related tasks ; we demonstrate our approach with several prototypes and we report on our experiment upon real user communities .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

crowd sourcing
exploratory search
multi-domain search
search engine
search service


Autonomous resource provisioning for multi-service web applications Dynamic resource provisioning aims at maintaining the end-to-end response time of a web application within a pre-defined SLA . Although the topic has been well studied for monolithic applications , provisioning resources for applications composed of multiple services remains a challenge . When the SLA is violated , one must decide which service ( s ) should be reprovisioned for optimal effect . We propose to assign an SLA only to the front-end service . Other services are not given any particular response time objectives . Services are autonomously responsible for their own provisioning operations and collaboratively negotiate performance objectives with each other to decide the provisioning service ( s ) . We demonstrate through extensive experiments that our system can add\/remove\/shift both servers and caches within an entire multi-service application under varying workloads to meet the SLA target and improve resource utilization .

O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A smart hill-climbing algorithm for application server configuration The overwhelming success of the Web as a mechanism for facilitating information retrieval and for conducting business transactions has ledto an increase in the deployment of complex enterprise applications . These applications typically run on Web Application Servers , which assume the burden of managing many tasks , such as concurrency , memory management , database access , etc. , required by these applications . The performance of an Application Server depends heavily on appropriate configuration . Configuration is a difficult and error-prone task dueto the large number of configuration parameters and complex interactions between them . We formulate the problem of finding an optimal configuration for a given application as a black-box optimization problem . We propose a smart hill-climbing algorithm using ideas of importance sampling and Latin Hypercube Sampling ( LHS ) . The algorithm is efficient in both searching and random sampling . It consists of estimating a local function , and then , hill-climbing in the steepest descent direction . The algorithm also learns from past searches and restarts in a smart and selective fashion using the idea of importance sampling . We have carried out extensive experiments with an on-line brokerage application running in a WebSphere environment . Empirical results demonstrate that our algorithm is more efficient than and superior to traditional heuristic methods .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

automatic tuning
gradient method
simulated annealing
system configuration


Efficient query subscription processing for prospective search engines Current web search engines are retrospective in that they limit users to searches against already existing pages . Prospective search engines , on the other hand , allow users to upload queries that will be applied to newly discovered pages in the future . We study and compare algorithms for efficiently matching large numbers of simple keyword queries against a stream of newly discovered pages .

O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Hierarchical , perceptron-like learning for ontology-based information extraction Recent work on ontology-based Information Extraction ( IE ) has tried to make use of knowledge from the target ontology in order to improve semantic annotation results . However , very few approaches exploit the ontology structure itself , and those that do so , have some limitations . This paper introduces a hierarchical learning approach for IE , which uses the target ontology as an essential part of the extraction process , by taking into account the relations between concepts . The approach is evaluated on the largest available semantically annotated corpus . The results demonstrate clearly the benefits of using knowledge from the ontology as input to the information extraction process . We also demonstrate the advantages of our approach over other state-of-the-art learning systems on a commonly used benchmark dataset .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

hierarchical learning
semantic annotation


Extracting data records from the web using tag path clustering Fully automatic methods that extract lists of objects from the Web have been studied extensively . Record extraction , the first step of this object extraction process , identifies a set of Web page segments , each of which represents an individual object ( e.g. , a product ) . State-of-the-art methods suffice for simple search , but they often fail to handle more complicated or noisy Web page structures due to a key limitation -- their greedy manner of identifying a list of records through pairwise comparison ( i.e. , similarity match ) of consecutive segments . This paper introduces a new method for record extraction that captures a list of objects in a more robust way based on a holistic analysis of a Web page . The method focuses on how a distinct tag path appears repeatedly in the DOM tree of the Web document . Instead of comparing a pair of individual segments , it compares a pair of tag path occurrence patterns ( called visual signals ) to estimate how likely these two tag paths represent the same list of objects . The paper introduces a similarity measure that captures how closely the visual signals appear and interleave . Clustering of tag paths is then performed based on this similarity measure , and sets of tag paths that form the structure of data records are extracted . Experiments show that this method achieves higher accuracy than previous methods .

O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

data record extraction
information extraction


Dissemination of heterogeneous xml data A lot of recent research has focused on the content-based dissemination of XML data . However , due to the heterogeneous data schemas used by different data publishers even for data in the same domain , an important challenge is how to efficiently and effectively disseminate relevant data to subscribers whose subscriptions might be specified based on schemas that are different from those used by the data publishers . This paper examines the options to resolve this schema heterogeneity problem in XML data dissemination , and proposes a novel paradigm that is based on data rewriting . Our experimental results demonstrate the effectiveness of the data rewriting paradigm and identifies the tradeoffs of the various approaches

B O B B O O O O O O O O O O O B O B O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O

data rewriting
dissemination
heterogeneous
xml


Reappraising cognitive styles in adaptive web applications The mechanisms for personalisation used in web applications are currently the subject of much debate amongst researchers from many diverse subject areas . One of the most contemporary ideas for user modelling in web applications is that of cognitive styles , where a user 's psychological preferences are assessed stored in a database and then used to provide personalised content and\/or links . We describe user trials of a case study that utilises visual-verbal preferences in an adaptive web-based educational system ( AWBES ) . Students in this trial were assessed by the Felder-Solomon Inventory of Learning Styles ( ILS ) instrument , and their preferences were used as a means of content personalisation . Contrary to previous findings by other researchers , we found no significant differences in performance between matched and mismatched students . Conclusions are drawn about the value and validity of using cognitive styles as a way of modelling user preferences in educational web applications .

O B I O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O

cognitive styles
user modelling
user trials
web applications


A content and structure website mining model We present a novel model for validating and improving the content and structure organization of a website . This model studies the website as a graph and evaluates its interconnectivity in relation to the similarity of its documents . The aim of this model is to provide a simple way for improving the overall structure , contents and interconnectivity of a website . This model has been implemented as a prototype and applied to several websites , showing very interesting results . Our model is complementary to other methods of website personalization and improvement .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Estimating the cardinality of RDF graph patterns Most RDF query languages allow for graph structure search through a conjunction of triples which is typically processed using join operations . A key factor in optimizing joins is determining the join order which depends on the expected cardinality of intermediate results . This work proposes a pattern-based summarization framework for estimating the cardinality of RDF graph patterns . We present experiments on real world and synthetic datasets which confirm the feasibility of our approach .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

pattern cardinality estimation
statistical summaries


Adaptive bidding for display advertising Motivated by the emergence of auction-based marketplaces for display ads such as the Right Media Exchange , we study the design of a bidding agent that implements a display advertising campaign by bidding in such a marketplace . The bidding agent must acquire a given number of impressions with a given target spend , when the highest external bid in the marketplace is drawn from an unknown distribution P. The quantity and spend constraints arise from the fact that display ads are usually sold on a CPM basis . We consider both the full information setting , where the winning price in each auction is announced publicly , and the partially observable setting where only the winner obtains information about the distribution ; these differ in the penalty incurred by the agent while attempting to learn the distribution . We provide algorithms for both settings , and prove performance guarantees using bounds on uniform closeness from statistics , and techniques from online learning . We experimentally evaluate these algorithms : both algorithms perform very well with respect to both target quantity and spend ; further , our algorithm for the partially observable case performs nearly as well as that for the fully observable setting despite the higher penalty incurred during learning .

B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

concentration bounds
general
guaranteed delivery
guess-then-double algorithms


An infrastructure for searching , reusing and evolving distributed ontologies The vision of the Semantic Web can only be realized through proliferation of well-known ontologies describing different domains . To enable interoperability in the Semantic Web , it will be necessary to break these ontologies down into smaller , well-focused units that may be reused . Currently , three problems arise in that scenario . Firstly , it is difficult to locate ontologies to be reused , thus leading to many ontologies modeling the same thing . Secondly , current tools do not provide means for reusing existing ontologies while building new ontologies . Finally , ontologies are rarely static , but are being adapted to changing requirements . Hence , an infrastructure for management of ontology changes , taking into account dependencies between ontologies is needed . In this paper we present such an infrastructure addressing the aforementioned problems .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

ontology evolution
ontology registry
ontology reuse


Web services security configuration in a service-oriented architecture Security is one of the major concerns when developing mission-critical business applications , and this concern motivated the Web Services Security specifications . However , the existing tools to configure the security properties of Web Services give a technology-oriented view ; only assisting in choosing data to encrypt and the encryption algorithms to use . A user must manually bridge the gap between the security requirements and the configuration , which could cause extra configuration costs and lead to potential misconfiguration hazards . To ease this situation , we came up with refining security requirements from business to technology , leveraging the concepts of Service-Oriented Architecture ( SOA ) and Model-Driven Architecture ( MDA ) . Security requirements are gradually transformed to more detailed ones or countermeasures by bridging the gap between them by using best practice patterns .

O O B I O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

security configuration
web services security

best practice pattern
methodologies
model-driven architecture
service-oriented architecture


Web ontology segmentation : analysis , classification and use Ontologies are at the heart of the semantic web . They define the concepts and relationships that make global interoperability possible . However , as these ontologies grow in size they become more and more difficult to create , use , understand , maintain , transform and classify . We present and evaluate several algorithms for extracting relevant segments out of large description logic ontologies for the purposes of increasing tractability for both humans and computers . The segments are not mere fragments , but stand alone as ontologies in their own right . This technique takes advantage of the detailed semantics captured within an OWL ontology to produce highly relevant segments . The research was evaluated using the GALEN ontology of medical terms and procedures .

O B B O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B B O O O O O O O O O O O O O B O O O O O O


Investigating web services on the world wide web Searching for Web service access points is no longer attached to service registries as Web search engines have become a new major source for discovering Web services . In this work , we conduct a thorough analytical investigation on the plurality of Web service interfaces that exist on the Web today . Using our Web Service Crawler Engine ( WSCE ) , we collect metadata service information on retrieved interfaces through accessible UBRs , service portals and search engines . We use this data to determine Web service statistics and distribution based on object sizes , types of technologies employed , and the number of functioning services . This statistical data can be used to help determine the current status of Web services . We determine an intriguing result that 63 % of the available Web services on the Web are considered to be active . We further use our findings to provide insights on improving the service retrieval process .

O B I O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O

crawler
searching
service portals
web services
wsce

crawling
interface
uddi
uddi business registries
wsdl


A web middleware architecture for dynamic customization of content for wireless clients We present a new Web middleware architecture that allows users to customize their view of the Web for optimal interaction and system operation when using non-traditional resource-limited client machines such as wireless PDAs ( personal digital assistants ) . Web Stream Customizers ( WSC ) are dynamically deployable software modules and can be strategically located between client and server to achieve improvements in performance , reliability , or security . An important design feature is that Customizers provide two points of control in the communication path between client and server , supporting adaptive system-based and content-based customization . Our architecture exploits HTTP 's proxy capabilities , allowing Customizers to be seamlessly integrated with the basic Web transaction model . We describe the WSC architecture and implementation , and illustrate its use with three non-trivial , adaptive Customizer applications that we have built . We show that the overhead in our implementation is small and tolerable , and is outweighed by the benefits that Customizers provide .

O O B O O O O O O O B O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


CloudGenius : decision support for web server cloud migration Cloud computing is the latest computing paradigm that delivers hardware and software resources as virtualized services in which users are free from the burden of worrying about the low-level system administration details . Migrating Web applications to Cloud services and integrating Cloud services into existing computing infrastructures is non-trivial . It leads to new challenges that often require innovation of paradigms and practices at all levels : technical , cultural , legal , regulatory , and social . The key problem in mapping Web applications to virtualized Cloud services is selecting the best and compatible mix of software images ( e.g. , Web server image ) and infrastructure services to ensure that Quality of Service ( QoS ) targets of an application are achieved . The fact that , when selecting Cloud services , engineers must consider heterogeneous sets of criteria and complex dependencies between infrastructure services and software images , which are impossible to resolve manually , is a critical issue . To overcome these challenges , we present a framework ( called CloudGenius ) which automates the decision-making process based on a model and factors specifically for Web server migration to the Cloud . CloudGenius leverages a well known multi-criteria decision making technique , called Analytic Hierarchy Process , to automate the selection process based on a model , factors , and QoS parameters related to an application . An example application demonstrates the applicability of the theoretical CloudGenius approach . Moreover , we present an implementation of CloudGenius that has been validated through experiments .

O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

cloud computing
criteria
decision support
factors

automation
computer-aided software engineering
migration process
selection algorithm
service selection


SCTP : an innovative transport layer protocol for the web We propose using the Stream Control Transmission Protocol ( SCTP ) , a recent IETF transport layer protocol , for reliable web transport . Although TCP has traditionally been used , we argue that SCTP better matches the needs of HTTP-based network applications . This position paper discusses SCTP features that address : ( i ) head-of-line blocking within a single TCP connection , ( ii ) vulnerability to network failures , and ( iii ) vulnerability to denial-of-service SYN attacks . We discuss our experience in modifying the Apache server and the Firefox browser to benefit from SCTP , and demonstrate our HTTP over SCTP design via simple experiments . We also discuss the benefits of using SCTP in other web domains through two example scenarios ? multiplexing user requests , and multiplexing resource access . Finally , we highlight several SCTP features that will be valuable to the design and implementation of current HTTP-based client-server applications .

B O O O O O O O O O O O O O B I I I O B O O O O O O O O O O O B I O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O

sctp
stream control transmission protocol
web transport

fault-tolerance
head-of-line blocking
internet
standards
transport layer service
web applications


A comparison of implicit and explicit links for web page classification It is well known that Web-page classification can be enhanced by using hyperlinks that provide linkages between Web pages . However , in the Web space , hyperlinks are usually sparse , noisy and thus in many situations can only provide limited help in classification . In this paper , we extend the concept of linkages from explicit hyperlinks to implicit links built between Web pages . By observing that people who search the Web with the same queries often click on different , but related documents together , we draw implicit links between Web pages that are clicked after the same queries . Those pages are implicitly linked . We provide an approach for automatically building the implicit links between Web pages using Web query logs , together with a thorough comparison between the uses of implicit and explicit links in Web page classification . Our experimental results on a large dataset confirm that the use of the implicit links is better than using explicit links in classification performance , with an increase of more than 10.5 % in terms of the Macro-F1 measurement .

O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

explicit link
implicit link
miscellaneous
query log
virtual document


Mining contiguous sequential patterns from web logs Finding Contiguous Sequential Patterns ( CSP ) is an important problem in Web usage mining . In this paper we propose a new data structure , UpDown Tree , for CSP mining . An UpDown Tree combines suffix tree and prefix tree for efficient storage of all the sequences that contain a given item . The special structure of UpDown Tree ensures efficient detection of CSPs . Experiments show that UpDown Tree improves CSP mining in terms of both time and memory usage comparing to previous approaches .

O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

contiguous sequential pattern
sequential pattern


Evaluating a new approach to strong web cache consistency with snapshots of collected content The problem of Web cache consistency continues to be an important one . Current Web caches use heuristic-based policies for determining the freshness of cached objects , often forcing content providers to unnecessarily mark their content as uncacheable simply to retain control over it . Server-driven invalidation has been proposed as a mechanism for providing strong cache consistency for Web objects , but it requires servers to maintain per-client state even for infrequently changing objects . We propose an alternative approach to strong cache consistency , called MONARCH , which does not require servers to maintain per-client state . In this work we focus on a new approach for evaluation of MONARCH in comparison with current practice and other cache consistency policies . This approach uses snapshots of content collected from real Web sites as input to a simulator . Results of the evaluation show MONARCH generates little more request traffic than an optimal cache coherency policy .

O O O O O O O B I O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

applications
change characteristics
object composition
object relationships
server invalidation
web caching


Distributing private data in challenged network environments Developing countries face significant challenges in network access , making even simple network tasks unpleasant . Many standard techniques - caching and predictive prefetching - help somewhat , but provide little or no assistance for personal data that is needed only by a single user . Sulula addresses this problem by leveraging the near-ubiquity of cellular phones able to send and receive simple SMS messages . Rather than visit a kiosk and fetch data on demand - a tiresome process at best - users request a future visit . If capacity exists , the kiosk can schedule secure retrieval of that user 's data , saving time and more efficiently utilizing the kiosk 's limited connectivity . When the user arrives at a provisioned kiosk , she need only obtain the session key on-demand , and thereafter has instant access . In addition , Sulula allows users to schedule data uploads . Experimental results show significant gains for the end user , saving tens of minutes of time for a typical email\/news reading session . We also describe a small , ongoing deployment in-country for proof-of-concept , lessons learned from that experience , and provide a discussion on pricing and marketplace issues that remain to be addressed to make the system viable for developing-world access .

O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

caching
limited connectivity
personal data
prefetching
sms

band-width
developing regions
ethiopia
latency
www access


A contextual-bandit approach to personalized news article recommendation Personalized web services strive to adapt their services ( advertisements , news articles , etc. ) to individual users by making use of both content and user information . Despite a few recent advances , this problem remains challenging for at least two reasons . First , web service is featured with dynamically changing pools of content , rendering traditional collaborative filtering methods inapplicable . Second , the scale of most web services of practical interest calls for solutions that are both fast in learning and computation . In this work , we model personalized recommendation of news articles as a contextual bandit problem , a principled approach in which a learning algorithm sequentially selects articles to serve users based on contextual information about the users and articles , while simultaneously adapting its article-selection strategy based on user-click feedback to maximize total user clicks . The contributions of this work are three-fold . First , we propose a new , general contextual bandit algorithm that is computationally efficient and well motivated from learning theory . Second , we argue that any bandit algorithm can be reliably evaluated offline using previously recorded random traffic . Finally , using this offline evaluation method , we successfully applied our new algorithm to a Yahoo ! Front Page Today Module dataset containing over 33 million events . Results showed a 12.5 % click lift compared to a standard context-free bandit algorithm , and the advantage becomes even greater when data gets more scarce .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O B I O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

exploration/exploitation dilemma
on-line information services
personalization
recommender systems


OpenRuleBench : an analysis of the performance of rule engines The Semantic Web initiative has led to an upsurge of the interest in rules as a general and powerful way of processing , combining , and analyzing semantic information . Since several of the technologies underlying rule-based systems are already quite mature , it is important to understand how such systems might perform on the Web scale . OpenRuleBench is a suite of benchmarks for analyzing the performance and scalability of different rule engines . Currently the study spans five different technologies and eleven systems , but OpenRuleBench is an open community resource , and contributions from the community are welcome . In this paper , we describe the tested systems and technologies , the methodology used in testing , and analyze the results .

B O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

benchmark
performance evaluation
rule systems


Disambiguating Web appearances of people in a social network Say you are looking for information about a particular person . A search engine returns many pages for that person 's name but which pages are about the person you care about , and which are about other people who happen to have the same name ? Furthermore , if we are looking for multiple people who are related in some way , how can we best leverage this social network ? This paper presents two unsupervised frameworks for solving this problem : one based on link structure of the Web pages , another using Agglomerative\/Conglomerative Double Clustering ( A\/CDC ) -- an application of a recently introduced multi-way distributional clustering method . To evaluate our methods , we collected and hand-labeled a dataset of over 1000 Web pages retrieved from Google queries on 12 personal names appearing together in someones in an email folder . On this dataset our methods outperform traditional agglomerative clustering by more than 20 % , achieving over 80 % F-measure .

O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

document clustering
information bottleneck
information search and retrieval
name disambiguation
web appearance


DEW : DNS-enhanced web for faster content delivery With a key component of latency on the Web being connection set up between clients and Web servers , several ways to avoid connections have been explored . While the work in recent years on Content Distribution Networks ( CDNs ) have moved some content ` closer ' to users at the cost of increasing DNS traffic , they have not fully exploited the available unused potential of existing protocols . We explore ways by which a variety of Web responses can be piggybacked on DNS messages . While we evaluated our idea in the Web context , the approach is generic and not restricted to Web responses . We propose an architecture for HTTP piggybacking in DNS messages and carry out a detailed performance analysis based on a trace-driven simulation study . Our architecture requires minimal extensions to existing protocols , utilizing only the allowed optional fields for these extensions . It is fully compatible and can coexist with the current Web .

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Ad-hoc object retrieval in the web of data Semantic Search refers to a loose set of concepts , challenges and techniques having to do with harnessing the information of the growing Web of Data ( WoD ) for Web search . Here we propose a formal model of one specific semantic search task : ad-hoc object retrieval . We show that this task provides a solid framework to study some of the semantic search problems currently tackled by commercial Web search engines . We connect this task to the traditional ad-hoc document retrieval and discuss appropriate evaluation metrics . Finally , we carry out a realistic evaluation of this task in the context of a Web search application .

O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B O O O O O O O O O O O O

evaluation
object retrieval
semantic search


Geotracker : geospatial and temporal RSS navigation The Web is rapidly moving towards a platform for mass collaboration in content production and consumption . Fresh content on a variety of topics , people , and places is being created and made available on the Web at breathtaking speed . Navigating the content effectively not only requires techniques such as aggregating various RSS-enabled feeds , but it also demands a new browsing paradigm . In this paper , we present novel geospatial and temporal browsing techniques that provide users with the capability of aggregating and navigating RSS-enabled content in a timely , personalized and automatic manner . In particular , we describe a system called GeoTracker that utilizes both a geospatial representation and a temporal ( chronological ) presentation to help users spot the most relevant updates quickly . Within the context of this work , we provide a middleware engine that supports intelligent aggregation and dissemination of RSS feeds with personalization to desktops and mobile devices . We study the navigation capabilities of this system on two kinds of data sets , namely , 2006 World Cup soccer data collected over two months and breaking news items that occur every day . We also demonstrate that the application of such technologies to the video search results returned by YouTube and Google greatly enhances a user . s ability in locating and browsing videos based on his or her geographical interests . Finally , we demonstrate that the location inference performance of GeoTracker compares well against machine learning techniques used in the natural language processing\/information retrieval community . Despite its algorithm simplicity , it preserves high recall percentages .

O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O


A possible simplification of the semantic web architecture In the semantic Web architecture , Web ontology languages arebuilt on top of RDF ( S ) . However , serious difficulties have arisen when trying to layer expressive ontology languages , like OWL , on top of RDF-Schema . Although these problems can be avoided , OWL ( andthe whole semantic Web architecture ) becomes much more complex than it should be . In this paper , a possible simplification of thesemantic Web architecture is suggested , which has several import antadvantages with respect to the layering currently accepted by the W3C Ontology Working Group .

O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

description logics
ontology web language
resource description framework
resource description framework schema


Probabilistic query expansion using query logs Query expansion has long been suggested as an effective way to resolve the short query and word mismatching problems . A number of query expansion methods have been proposed in traditional information retrieval . However , these previous methods do not take into account the specific characteristics of web searching ; in particular , of the availability of large amount of user interaction information recorded in the web query logs . In this study , we propose a new method for query expansion based on query logs . The central idea is to extract probabilistic correlations between query terms and document terms by analyzing query logs . These correlations are then used to select high-quality expansion terms for new queries . The experimental results show that our log-based probabilistic query expansion method can greatly improve the search performance and has several advantages over other existing methods .

O B I O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O

information search and retrieval
log mining
probabilistic model
search engine


A hybrid approach for searching in the semantic web This paper presents a search architecture that combines classical search techniques with spread activation techniques applied to a semantic model of a given domain . Given an ontology , weights are assigned to links based on certain properties of the ontology , so that they measure the strength of the relation . Spread activation techniques are used to find related concepts in the ontology given an initial set of concepts and corresponding initial activation values . These initial values are obtained from the results of classical search applied to the data associated with the concepts in the ontology . Two test cases were implemented , with very positive results . It was also observed that the proposed hybrid spread activation , combining the symbolic and the sub-symbolic approaches , achieved better results when compared to each of the approaches alone .

O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

information search and retrieval
network analysis
ontologies
semantic associations
semantic search
spread activation algorithms


SmartInt : using mined attribute dependencies to integrate fragmented web databases Many web databases can be seen as providing partial and overlapping information about entities in the world . To answer queries effectively , we need to integrate the information about the individual entities that are fragmented over multiple sources . At first blush this is just the inverse of traditional database normalization problem - rather than go from a universal relation to normalized tables , we want to reconstruct the universal relation given the tables ( sources ) . The standard way of reconstructing the entities will involve joining the tables . Unfortunately , because of the autonomous and decentralized way in which the sources are populated , they often do not have Primary Key - Foreign Key relations . While tables do share attributes , direct joins over these shared attributes can result in reconstruction of many spurious entities thus seriously compromising precision . We present a unified approach that supports intelligent retrieval over fragmented web databases by mining and using inter-table dependencies . Experiments with the prototype implementation , SmartInt , show that its retrieval strikes a good balance between precision and recall .

O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O


Inverted index compression via online document routing Modern search engines are expected to make documents searchable shortly after they appear on the ever changing Web . To satisfy this requirement , the Web is frequently crawled . Due to the sheer size of their indexes , search engines distribute the crawled documents among thousands of servers in a scheme called local index-partitioning , such that each server indexes only several million pages . To ensure documents from the same host ( e.g. , www.nytimes.com ) are distributed uniformly over the servers , for load balancing purposes , random routing of documents to servers is common . To expedite the time documents become searchable after being crawled , documents may be simply appended to the existing index partitions . However , indexing by merely appending documents , results in larger index sizes since document reordering for index compactness is no longer performed . This , in turn , degrades search query processing performance which depends heavily on index sizes . A possible way to balance quick document indexing with efficient query processing , is to deploy online document routing strategies that are designed to reduce index sizes . This work considers the effects of several online document routing strategies on the aggregated partitioned index size . We show that there exists a tradeoff between the compression of a partitioned index and the distribution of documents from the same host across the index partitions ( i.e. , host distribution ) . We suggest and evaluate several online routing strategies with regard to their compression , host distribution , and complexity . In particular , we present a term based routing algorithm which is shown analytically to provide better compression results than the industry standard random routing scheme . In addition , our algorithm demonstrates comparable compression performance and host distribution while having much better running time complexity than other document routing heuristics . Our findings are validated by experimental evaluation performed on a large benchmark collection of Web pages .

O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O

index partitioning
inverted index
miscellaneous
online algorithm


The language observatory project ( LOP ) The first part of the paper provides a brief description of the Language Observatory Project ( LOP ) and highlights the major technical difficulties to be challenged . The latter part gives how we responded to these difficulties by adopting UbiCrawler as a data collecting engine for the project . An interactive collaboration between the two groups is producing quite satisfactory results .

O B O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

character sets
content analysis and indexing
language digital divide
language identification
scripts
web crawler


Detectives : detecting coalition hit inflation attacks in advertising networks streams Click fraud is jeopardizing the industry of Internet advertising . Internet advertising is crucial for the thriving of the entire Internet , since it allows producers to advertise their products , and hence contributes to the well being of e-commerce . Moreover , advertising supports the intellectual value of the Internet by covering the running expenses of publishing content . Some content publishers are dishonest , and use automation to generate traffic to defraud the advertisers . Similarly , some advertisers automate clicks on the advertisements of their competitors to deplete their competitors ' advertising budgets . This paper describes the advertising network model , and focuses on the most sophisticated type of fraud , which involves coalitions among fraudsters . We build on several published theoretical results to devise the Similarity-Seeker algorithm that discovers coalitions made by pairs of fraudsters . We then generalize the solution to coalitions of arbitrary sizes . Before deploying our system on a real network , we conducted comprehensive experiments on data samples for proof of concept . The results were very accurate . We detected several coalitions , formed using various techniques , and spanning numerous sites . This reveals the generality of our model and approach .

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approximate set similarity
click spam detection
cliques enumeration
coalition fraud attacks
real data experiments
similarity-sensitive sampling


Dynamic cost-per-action mechanisms and applications to online advertising We study the Cost-Per-Action or Cost-Per-Acquisition ( CPA ) charging scheme in online advertising . In this scheme , instead of paying per click , the advertisers pay only when a user takes a specific action ( e.g. fills out a form ) or completes a transaction on their websites . We focus on designing efficient and incentive compatible mechanisms that use this charging scheme . We describe a mechanism based on a sampling-based learning algorithm that under suitable assumptions is asymptotically individually rational , asymptotically Bayesian incentive compatible and asymptotically ex-ante efficient . In particular , we demonstrate our mechanism for the case where the utility functions of the advertisers are independent and identically-distributed random variables as well as the case where they evolve like independent reflected Brownian motions .

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cost-per-action
general
internet advertising
mechanism design