Named Entity Recognition and Disambiguation using Linked Data and Graph-based Centrality Scoring

Hakimov S, Oto SA, Dogdu E. Named Entity Recognition and Disambiguation using Linked Data and Graph-based Centrality Scoring. In: SIGMOD, SWIM 2012. 2012: 4.Named Entity Recognition (NER) is a subtask of informationextraction and aims to identify atomic entities in text that fall intopredefined categories such as person, location, organization, etc.Recent efforts in NER try to extract entities and link them tolinked data entities. Linked data is a term used for data resourcesthat are created using semantic web standards such as DBpedia.There are a number of online tools that try to identify namedentities in text and link them to linked data resources. Althoughone can use these tools via their APIs and web interfaces, they usedifferent data resources and different techniques to identify namedentities and not all of them reveal this information. One of themajor tasks in NER is disambiguation that is identifying the rightentity among a number of entities with the same names; forexample “apple” standing for both “Apple, Inc.” the company andthe fruit. We developed a similar tool called NERSO, short forNamed Entity Recognition Using Semantic Open Data, toautomatically extract named entities, disambiguating and linkingthem to DBpedia entities. Our disambiguation method is based onconstructing a graph of linked data entities and scoring them usinga graph-based centrality algorithm. We evaluate our system bycomparing its performance with two publicly available NER tools.The results show that NERSO performs better

Semantic Question Answering System over Linked Data using Relational Patterns

Hakimov S, Tunc H, Akimaliev M, Dogdu E. Semantic Question Answering System over Linked Data using Relational Patterns. In: EDBT/ICDT LWDM 2013. 2013.Question answering is the task of answering questions in naturallanguage. Linked Data project and Semantic Web communitymade it possible for us to query structured knowledge bases likeDBpedia and YAGO. Only expert users, however, with theknowledge of RDF and ontology definitions can build correctSPARQL queries for querying knowledge bases formally. In thispaper, we present a method for mapping natural languagequestions to ontology-based structured queries to retrieve directanswers from open knowledge bases (linked data). Our tool isbased on translating natural language questions into RDF triplepatterns using the dependency tree of the question text. Inaddition, our method uses relational patterns extracted from theWeb. We tested our tool using questions from QALD-2, QuestionAnswering over Linked Data challenge track and found promisingpreliminary results

A Data-Model Driven Web Application Development Framework

Dogdu E, Hakimov S, Yumusak S. A Data-Model Driven Web Application Development Framework. In: Proc. of the 52nd ACM Southeast Conference. 2014

SyD: A Middleware Testbed for Collaborative Applications over Small Heterogeneous Devices and Data Stores

Abstract. Currently, it is possible to develop a collaborative application running on a collection of heterogeneous, possibly mobile, devices, each potentially hosting data stores, using existing middleware technologies such as JXTA, BREW, compact.NET and J2ME. However, they require too many ad-hoc techniques as well as cumbersome and time-consuming programming. Our System on Mobile Devices (SyD) middleware, on the other hand, has a modular architecture that makes such application de-velopment very systematic and streamlined. The architecture supports transactions over mobile data stores, with a range of remote group invo-cation options and embedded interdependencies among such data store objects. The architecture further provides a persistent uniform object view, group transaction with Quality of Service (QoS) speci¯cations, and XML vocabulary for inter-device communication. This paper presents the basic SyD concepts, introduces the architecture and the design of the SyD middleware and its components. We also provide guidelines fo

Scheduling Adaptive Transactions in Real-Time Databases

. A new transaction model, called the Adaptive Transaction Model, is proposed for Real-Time Database Management Systems (RTDBMSs) applications. The Adaptive Transaction Model is an extended transaction model with a nested structure containing optional and required subtransactions. Adaptive Transactions (ATs) have time constraints to support real-time database applications. Optional substransactions can be omitted during the execution if time does not permit. Scheduling issues for a special case of adaptive transactions, called chain-structured adaptive transactions, are discussed. Several priority-based scheduling policies are proposed and experimental results are reported under lock-based and timestamp-ordering concurrency control protocols. A priority assignment policy (MSF-MES) is found to provide superior (low) miss ratios compared to other policies. 1 Introduction Timeliness is the key issue in scheduling transactions in a Real-Time Database System (RTDBMS). In an RTDBMS, transa..

Adaptive Real-Time Transactions and Risk-based Load Control

An extended transaction model, called the Adaptive Transaction Model, is proposed for Real-Time Database Management System (RTDBMS) applications where partial and/or approximate results are utilized. The Adaptive Transaction Model is a nested transaction model with optional and required subtransactions. Adaptive Transactions (ATs) have time constraints to support real-time database applications. Optional subtransactions can be eliminated during execution if time (or the scheduling policy) does not permit for completion, thereby reporting partial results. A risk-based transaction load control mechanism determines each transaction's probability of completion within its deadline as well as the overall system load. 1 Introduction Recent research in real-time systems and databases has focused on the idea of utilizing partial results so that jobs (i.e., transactions) meet their deadlines. In other words, transactions report estimate or approximate results when they cannot complete within th..

A Generic Database Web Service

Abstract — Web applications built using Java technologies usually access relational databases via JDBC API. This requires a database system specific JDBC driver to be installed on the application side. On the other hand, a paradigm shift is taking place in web application architectures. Future web applications will be built around Service-Oriented Architectures (SOA) where applications will be assembled using remote “web services ” components. These newly assembled applications will provide functionalities using remote web services components over Internet via XML messages. Same paradigm shift will eventually apply to the data communication between applications and databases. Future applications will utilize standard “database web services ” for data storage and querying requirements. Here we propose a new architectural model and present a prototype “database web service ” for relational database systems. In our model, web applications do not need to deal with database drivers but leave the driver-oriented communication to a database web service. Our database web service eliminates the need for installation, maintenance, and other issues involved in maintaining JDBC drivers in distributed web application development