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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Entity Matching for Intelligent Information Integration

Wang, Gang Alan January 2006 (has links)
Due to the rapid development of information technologies, especially the network technologies, business activities have never been as integrated as they are now. Business decision making often requires gathering information from different sources. This dissertation focuses on the problem of entity matching, associating corresponding information elements within or across information systems. It is devoted to providing complete and accurate information for business decision making. Three challenges have been identified that may affect entity matching performance: feature selection for entity representative, matching techniques, and searching strategy. This dissertation first provides a theoretical foundation for entity matching by connecting entity matching to the similarity and categorization theories developed in the field of cognitive science. The theories provide guidance for tackling the three challenges identified. First, based on the feature contrast similarity model, we propose a case-study-based methodology that identifies key features that uniquely identify an entity. Second, we propose a record comparison technique and a multi-layer naïve Bayes model that correspond respectively to the deterministic and the probability response selection models defined in the categorization theory. Experiments show that both techniques are effective in linking deceptive criminal identities. However, the probabilistic matching technique is preferable because it uses a semi-supervised learning method, which requires less human intervention during training. Third, based on the prototype access assumption proposed in the categorization theory, we apply an adaptive detection algorithm to entity matching so that efficiency can be greatly improved by the reduced search space. Experiments show that this technique significantly improves matching efficiency without significant accuracy loss. Based on the above findings we developed the Arizona IDMatcher, an identity matching system based on the multi-layer naïve Bayes model and the adaptive detection method. We compare the proposed system against the IBM Identity Resolution tool, a leading commercial product developed using heuristic decision rules. Experiments do not suggest a clear winner, but provide the pros and cons of each system. The Arizona IDMatcher is able to capture more true matches than IBM Identity Resolution (i.e., high recall). On the other hand, the matches identified by IBM Identity Resolution are mostly true matches (i.e., high precision).
2

Kolektivní propojování entit pro aplikaci ClueMaker / Collective Entity Matching Solution for ClueMaker Application

Jaroschy, Petr January 2021 (has links)
ClueMaker (CM) is a Java desktop application used for data visualisation (via graph) by subjects like insurance companies (to unravel fraud activity), Czech organisation Hlí- dač Státu (to identify connections between subjects) or many others. This application currently uses a naive way to merge entities from different data sources (matching one field by exact string match). Goal of this thesis is to analyse, create and integrate a solution to CM, which would allow for merging entities based on entity similarity, and integrate such solution into the GUI of CM. Such solution should allow the user to merge two graph entities, show user the potentially same or very similar entities and allow for a global scan of the graph for potential merges. Furthermore, this solution should make use of data relationships within CM in addition to the attributes of entities. 1
3

Temporal Graph Record Linkage and k-Safe Approximate Match

Jupin, Joseph January 2016 (has links)
Since the advent of electronic data processing, organizations have accrued vast amounts of data contained in multiple databases with no reliable global unique identifier. These databases were developed by different departments for different purposes at different times. Organizing and analyzing these data for human services requires linking records from all sources. RL (Record Linkage) is a process that connects records that are related to the identical or a sufficiently similar entity from multiple heterogeneous databases. RL is a data and compute intensive, mission critical process. The process must be efficient enough to process big data and effective enough to provide accurate matches. We have evaluated an RL system that is currently in use by a local health and human services department. We found that they were using the typical approach that was offered by Fellegi and Sunter with tuple-by-tuple processing, using the Soundex as the primary approximate string matching method. The Soundex has been found to be unreliable both as a phonetic and as an approximate string matching method. We found that their data, in many cases, has more than one value per field, suggesting that the data were queried from a 5NF data base. Consider that if a woman has been married 3 times, she may have up to 4 last names on record. This query process produced more than one tuple per database/entity apparently generating a Cartesian product of this data. In many cases, more than a dozen tuples were observed for a single database/entity. This approach is both ineffective and inefficient. An effective RL method should handle this multi-data without redundancy and use edit-distance for approximate string matching. However, due to high computational complexity, edit-distance will not scale well with big data problems. We developed two methodologies for resolving the aforementioned issues: PSH and ALIM. PSH – The Probabilistic Signature Hash is a composite method that increases the speed of Damerau-Levenshtein edit-distance. It combines signature filtering, probabilistic hashing, length filtering and prefix pruning to increase the speed of edit-distance. It is also lossless because it does not lose any true positive matches. ALIM – Aggregate Link and Iterative Match is a graph-based record linkage methodology that uses a multi-graph to store demographic data about people. ALIM performs string matching as records are inserted into the graph. ALIM eliminates data redundancy and stores the relationships between data. We tested PSH for string comparison and found it to be approximately 6,000 times faster than DL. We tested it against the trie-join methods and found that they are up to 6.26 times faster but lose between 10 and 20 percent of true positives. We tested ALIM against a method currently in use by a local health and human services department and found ALIM to produce significantly more matches (even with more restrictive match criteria) and that ALIM ran more than twice as fast. ALIM handles the multi-data problem and PSH allows the use of edit-distance comparison in this RL model. ALIM is more efficient and effective than a currently implemented RL system. This model can also be expanded to perform social network analysis and temporal data modeling. For human services, temporal modeling can reveal how policy changes and treatments affect clients over time and social network analysis can determine the effects of these on whole families by facilitating family linkage. / Computer and Information Science
4

Leveraging the entity matching performance through adaptive indexing and efficient parallelization

MESTRE, Demetrio Gomes. 11 September 2018 (has links)
Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-09-11T19:44:07Z No. of bitstreams: 1 DEMETRIO GOMES MESTRE – TESE (PPGCC) 2018.pdf: 15362740 bytes, checksum: eb531a72836b3c7f2f4e0171c7f563dc (MD5) / Made available in DSpace on 2018-09-11T19:44:07Z (GMT). No. of bitstreams: 1 DEMETRIO GOMES MESTRE – TESE (PPGCC) 2018.pdf: 15362740 bytes, checksum: eb531a72836b3c7f2f4e0171c7f563dc (MD5) Previous issue date: 2018-03-27 / Entity Matching (EM), ou seja, a tarefa de identificar entidades que se referem a um mesmo objeto do mundo real, é uma tarefa importante e difícil para a integração e limpeza de fontes de dados. Uma das maiores dificuldades para a realização desta tarefa, na era de Big Data, é o tempo de execução elevado gerado pela natureza quadrática da execução da tarefa. Para minimizar a carga de trabalho preservando a qualidade na detecção de entidades similares, tanto para uma ou mais fontes de dados, foram propostos os chamados métodos de indexação ou blocagem. Estes métodos particionam o conjunto de dados em subconjuntos (blocos) de entidades potencialmente similares, rotulando-as com chaves de bloco, e restringem a execução da tarefa de EM entre entidades pertencentes ao mesmo bloco. Apesar de promover uma diminuição considerável no número de comparações realizadas, os métodos de indexação ainda podem gerar grandes quantidades de comparações, dependendo do tamanho dos conjuntos de dados envolvidos e/ou do número de entidades por índice (ou bloco). Assim, para reduzir ainda mais o tempo de execução, a tarefa de EM pode ser realizada em paralelo com o uso de modelos de programação tais como MapReduce e Spark. Contudo, a eficácia e a escalabilidade de abordagens baseadas nestes modelos depende fortemente da designação de dados feita da fase de map para a fase de reduce, para o caso de MapReduce, e da designação de dados entre as operações de transformação, para o caso de Spark. A robustez da estratégia de designação de dados é crucial para se alcançar alta eficiência, ou seja, otimização na manipulação de dados enviesados (conjuntos de dados grandes que podem causar gargalos de memória) e no balanceamento da distribuição da carga de trabalho entre os nós da infraestrutura distribuída. Assim, considerando que a investigação de abordagens que promovam a execução eficiente, em modo batch ou tempo real, de métodos de indexação adaptativa de EM no contexto da computação distribuída ainda não foi contemplada na literatura, este trabalho consiste em propor um conjunto de abordagens capaz de executar a indexação adaptativas de EM de forma eficiente, em modo batch ou tempo real, utilizando os modelos programáticos MapReduce e Spark. O desempenho das abordagens propostas é analisado em relação ao estado da arte utilizando infraestruturas de cluster e fontes de dados reais. Os resultados mostram que as abordagens propostas neste trabalho apresentam padrões que evidenciam o aumento significativo de desempenho da tarefa de EM distribuída promovendo, assim, uma redução no tempo de execução total e a preservação da qualidade da detecção de pares de entidades similares. / Entity Matching (EM), i.e., the task of identifying all entities referring to the same realworld object, is an important and difficult task for data sources integration and cleansing. A major difficulty for this task performance, in the Big Data era, is the quadratic nature of the task execution. To minimize the workload and still maintain high levels of matching quality, for both single or multiple data sources, the indexing (blocking) methods were proposed. Such methods work by partitioning the input data into blocks of similar entities, according to an entity attribute, or a combination of them, commonly called “blocking key”, and restricting the EM process to entities that share the same blocking key (i.e., belong to the same block). In spite to promote a considerable decrease in the number of comparisons executed, indexing methods can still generate large amounts of comparisons, depending on the size of the data sources involved and/or the number of entities per index (or block). Thus, to further minimize the execution time, the EM task can be performed in parallel using programming models such as MapReduce and Spark. However, the effectiveness and scalability of MapReduce and Spark-based implementations for data-intensive tasks depend on the data assignment made from map to reduce tasks, in the case of MapReduce, and the data assignment between the transformation operations, in the case of Spark. The robustness of this assignment strategy is crucial to achieve skewed data handling (large sets of data can cause memory bottlenecks) and balanced workload distribution among all nodes of the distributed infrastructure. Thus, considering that studies about approaches that perform the efficient execution of adaptive indexing EM methods, in batch or real-time modes, in the context of parallel computing are an open gap according to the literature, this work proposes a set of parallel approaches capable of performing efficient adaptive indexing EM approaches using MapReduce and Spark in batch or real-time modes. The proposed approaches are compared to state-of-the-art ones in terms of performance using real cluster infrastructures and data sources. The results carried so far show evidences that the performance of the proposed approaches is significantly increased, enabling a decrease in the overall runtime while preserving the quality of similar entities detection.
5

LIMES M/R: Parallelization of the LInk discovery framework for MEtric Spaces using the Map/Reduce paradigm

Hillner, Stanley 26 February 2018 (has links)
The World Wide Web is the most important information space in the world. With the change of the web during the last decade, today’sWeb 2.0 offers everybody the possibility to easily publish information on the web. For instance, everyone can have his own blog, write Wikipedia articles, publish photos on Flickr or post status messages via Twitter. All these services on the web offer users all around the world the opportunity to interchange information and interconnect themselves with other users. However, the information, as it is usually published today, does not offer enough semantics to be machine-processable. As an example, Wikipedia articles are created using the lightweight Wiki markup language and then published as HyperText Markup Language (HTML) files whose semantics can easily be captured by humans, but not machines.
6

Multiple Entity Reconciliation

Samoila, Lavinia Andreea January 2015 (has links)
Living in the age of "Big Data" is both a blessing and a curse. On he one hand, the raw data can be analysed and then used for weather redictions, user recommendations, targeted advertising and more. On he other hand, when data is aggregated from multiple sources, there is no guarantee that each source has stored the data in a standardized or even compatible format to what is required by the application. So there is a need to parse the available data and convert it to the desired form. Here is where the problems start to arise: often the correspondences are not quite so straightforward between data instances that belong to the same domain, but come from different sources. For example, in the film industry, information about movies (cast, characters, ratings etc.) can be found on numerous websites such as IMDb or Rotten Tomatoes. Finding and matching all the data referring to the same movie is a challenge. The aim of this project is to select the most efficient algorithm to correlate movie related information gathered from various websites automatically. We have implemented a flexible application that allows us to make the performance comparison of multiple algorithms based on machine learning techniques. According to our experimental results, a well chosen set of rules is on par with the results from a neural network, these two proving to be the most effective classifiers for records with movie information as content.
7

Data Preparation from Visually Rich Documents

Sarkhel, Ritesh January 2022 (has links)
No description available.
8

Implementierung eines File Managers für das Hadoop Distributed Filesystem und Realisierung einer MapReduce Workflow Submission-Komponente

Fischer, Axel 02 February 2018 (has links)
Die vorliegende Bachelorarbeit erläutert die Entwicklung eines File Managers für das Hadoop Distributed Filesystem (HDFS) im Zusammenhang mit der Entwicklung des Dedoop Prototyps. Der File Manager deckt die Anwendungsfälle refresh, rename, move und delete ab. Darüber hinaus erlaubt er Uploads vom und Downloads zum lokalen Dateisystem des Anwenders. Besonders beachtet werden mussten hierbei die speziellen Anforderungen des Mehrbenutzerbetriebs. Darüber hinaus beschreibt die Bachelorarbeit die Entwicklung einer MapReduce Workflow Submission-Komponente für Dedoop, welche für die Übertragung und Ausführung der vom Anwender erzeugten Worflows verantworklich ist. Auch hierbei mussten die Anforderungen des Mehrbenutzer- und Multi-Cluster-Betriebs beachtet werden.
9

Rapprochement de données pour la reconnaissance d'entités dans les documents océrisés / Data matching for entity recognition in ocred documents

Kooli, Nihel 13 September 2016 (has links)
Cette thèse traite de la reconnaissance d'entités dans les documents océrisés guidée par une base de données. Une entité peut être, par exemple, une entreprise décrite par son nom, son adresse, son numéro de téléphone, son numéro TVA, etc. ou des méta-données d'un article scientifique tels que son titre, ses auteurs et leurs affiliations, le nom de son journal, etc. Disposant d'un ensemble d'entités structurées sous forme d'enregistrements dans une base de données et d'un document contenant une ou plusieurs de ces entités, nous cherchons à identifier les entités contenues dans le document en utilisant la base de données. Ce travail est motivé par une application industrielle qui vise l'automatisation du traitement des images de documents administratifs arrivant en flux continu. Nous avons abordé ce problème comme un problème de rapprochement entre le contenu du document et celui de la base de données. Les difficultés de cette tâche sont dues à la variabilité de la représentation d'attributs d'entités dans la base et le document et à la présence d'attributs similaires dans des entités différentes. À cela s'ajoutent les redondances d'enregistrements et les erreurs de saisie dans la base de données et l'altération de la structure et du contenu du document, causée par l'OCR. Devant ces problèmes, nous avons opté pour une démarche en deux étapes : la résolution d'entités et la reconnaissance d'entités. La première étape consiste à coupler les enregistrements se référant à une même entité et à les synthétiser dans un modèle entité. Pour ce faire, nous avons proposé une approche supervisée basée sur la combinaison de plusieurs mesures de similarité entre attributs. Ces mesures permettent de tolérer quelques erreurs sur les caractères et de tenir compte des permutations entre termes. La deuxième étape vise à rapprocher les entités mentionnées dans un document avec le modèle entité obtenu. Nous avons procédé par deux manières différentes, l'une utilise le rapprochement par le contenu et l'autre intègre le rapprochement par la structure. Pour le rapprochement par le contenu, nous avons proposé deux méthodes : M-EROCS et ERBL. M-EROCS, une amélioration/adaptation d'une méthode de l'état de l'art, consiste à faire correspondre les blocs de l'OCR avec le modèle entité en se basant sur un score qui tolère les erreurs d'OCR et les variabilités d'attributs. ERBL consiste à étiqueter le document par les attributs d'entités et à regrouper ces labels en entités. Pour le rapprochement par les structures, il s'agit d'exploiter les relations structurelles entre les labels d'une entité pour corriger les erreurs d'étiquetage. La méthode proposée, nommée G-ELSE, consiste à utiliser le rapprochement inexact de graphes attribués modélisant des structures locales, avec un modèle structurel appris pour cet objectif. Cette thèse étant effectuée en collaboration avec la société ITESOFT-Yooz, nous avons expérimenté toutes les étapes proposées sur deux corpus administratifs et un troisième corpus extrait du Web / This thesis focuses on entity recognition in documents recognized by OCR, driven by a database. An entity is a homogeneous group of attributes such as an enterprise in a business form described by the name, the address, the contact numbers, etc. or meta-data of a scientific paper representing the title, the authors and their affiliation, etc. Given a database which describes entities by its records and a document which contains one or more entities from this database, we are looking to identify entities in the document using the database. This work is motivated by an industrial application which aims to automate the image document processing, arriving in a continuous stream. We addressed this problem as a matching issue between the document and the database contents. The difficulties of this task are due to the variability of the entity attributes representation in the database and in the document and to the presence of similar attributes in different entities. Added to this are the record redundancy and typing errors in the database, and the alteration of the structure and the content of the document, caused by OCR. To deal with these problems, we opted for a two-step approach: entity resolution and entity recognition. The first step is to link the records referring to the same entity and to synthesize them in an entity model. For this purpose, we proposed a supervised approach based on a combination of several similarity measures between attributes. These measures tolerate character mistakes and take into account the word permutation. The second step aims to match the entities mentioned in documents with the resulting entity model. We proceeded by two different ways, one uses the content matching and the other integrates the structure matching. For the content matching, we proposed two methods: M-EROCS and ERBL. M-EROCS, an improvement / adaptation of a state of the art method, is to match OCR blocks with the entity model based on a score that tolerates the OCR errors and the attribute variability. ERBL is to label the document with the entity attributes and to group these labels into entities. The structure matching is to exploit the structural relationships between the entity labels to correct the mislabeling. The proposed method, called G-ELSE, is based on local structure graph matching with a structural model which is learned for this purpose. This thesis being carried out in collaboration with the ITESOFT-Yooz society, we have experimented all the proposed steps on two administrative corpuses and a third one extracted from the web
10

Finding duplicate offers in the online marketplace catalogue using transformer based methods : An exploration of transformer based methods for the task of entity resolution / Hitta dubbletter av erbjudanden i online marknadsplatskatalog med hjälp av transformer-baserade metoder : En utforskning av transformer-baserad metoder för uppgiften att deduplicera

Damian, Robert-Andrei January 2022 (has links)
The amount of data available on the web is constantly growing, and e-commerce websites are no exception. Considering the abundance of available information, finding offers for the same product in the catalogue of different retailers represents a challenge. This problem is an interesting one and addresses the needs of multiple actors. A customer is interested in finding the best deal for the product they want to buy. A retailer wants to keep up to date with the competition and adapt its pricing strategy accordingly. Various services already offer the possibility of finding duplicate products in catalogues of e-commerce retailers, but their solutions are based on matching a Global Trade Identification Number (GTIN). This strategy is limited because a GTIN may not be made publicly available by a competitor, may be different for the same product exported by the manufacturer to different markets or may not even exist for low-value products. The field of Entity Resolution (ER), a sub-branch of Natural Language Processing (NLP), focuses on solving the issue of matching duplicate database entries when a deterministic identifier is not available. We investigate various solutions from the the field and present a new model called Spring R-SupCon that focuses on low volume datasets. Our work builds upon the recently introduced model, R-SupCon, introducing a new learning scheme that improves R-SupCon’s performance by up to 74.47% F1 score, and surpasses Ditto by up 12% F1 score for low volume datasets. Moreover, our experiments show that smaller language models can be used for ER with minimal loss in performance. This has the potential to extend the adoption of Transformer-based solutions to companies and markets where datasets are difficult to create, like it is the case for the Swedish marketplace Fyndiq. / Mängden data på internet växer konstant och e-handeln är inget undantag. Konsumenter har idag många valmöjligheter varifrån de väljer att göra sina inköp från. Detta gör att det blir svårare och svårare att hitta det bästa erbjudandet. Även för återförsäljare ökar svårigheten att veta vilken konkurrent som har lägst pris. Det finns tillgängliga lösningar på detta problem men de använder produktunika identifierare såsom Global Trade Identification Number (förkortat “GTIN”). Då det finns en rad utmaningar att bara förlita sig på lösningar som baseras på GTIN behövs ett alternativt tillvägagångssätt. GTIN är exempelvis inte en offentlig information och identifieraren kan dessutom vara en annan när samma produkt erbjuds på en annan marknad. Det här projektet undersöker alternativa lösningar som inte är baserade på en deterministisk identifierare. Detta projekt förlitar sig istället på text såsom produktens namn för att fastställa matchningar mellan olika erbjudanden. En rad olika implementeringar baserade på maskininlärning och djupinlärning studeras i detta projekt. Projektet har dock ett särskilt fokus på “Transformer”-baserade språkmodeller såsom BERT. Detta projekt visar hur man generera proprietär data. Projektet föreslår även ett nytt inlärningsschema och bevisar dess fördelar. / Le volume des données qui se trouve sur l’internet est en une augmentation constante et les commerces électroniques ne font pas note discordante. Le consommateur a aujourd’hui beaucoup des options quand il decide d’où faire son achat. Trouver le meilleur prix devient de plus en plus difficile. Les entreprises qui gerent cettes plates-formes ont aussi la difficulté de savoir en tous moments lesquels de ses concurrents ont le meilleur prix. Il y-a déjà des solutions en ligne qui ont l’objectif de résoudre ce problème, mais ils utilisent un identifiant de produit unique qui s’appelle Global Trade identification number (ou GTIN). Plusieurs difficultés posent des barriers sur cette solution. Par exemple, GTIN n’est pas public peut-être, ou des GTINs différents peut-être assigne par la fabricante au même produit pour distinguer des marchés différents. Ce projet étudie des solutions alternatives qui ne sont pas basées sur avoir un identifiant unique. On discute des methods qui font la décision en fonction du nom des produits, en utilisant des algorithmes d’apprentissage automatique ou d’apprentissage en profondeur. Le projet se concentre sur des solutions avec ”Transformer” modèles de langages, comme BERT. On voit aussi comme peut-on créer un ensemble de données propriétaire pour enseigner le modèle. Finalement, une nouvelle method d’apprentissage est proposée et analysée.

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