Role based behavior analysis

Tese de mestrado, Segurança Informática, Universidade de Lisboa, Faculdade de Ciências, 2009Nos nossos dias, o sucesso de uma empresa depende da sua agilidade e capacidade de se adaptar a condições que se alteram rapidamente. Dois requisitos para esse sucesso são trabalhadores proactivos e uma infra-estrutura ágil de Tecnologias de Informacão/Sistemas de Informação (TI/SI) que os consiga suportar. No entanto, isto nem sempre sucede. Os requisitos dos utilizadores ao nível da rede podem nao ser completamente conhecidos, o que causa atrasos nas mudanças de local e reorganizações. Além disso, se não houver um conhecimento preciso dos requisitos, a infraestrutura de TI/SI poderá ser utilizada de forma ineficiente, com excessos em algumas áreas e deficiências noutras. Finalmente, incentivar a proactividade não implica acesso completo e sem restrições, uma vez que pode deixar os sistemas vulneráveis a ameaças externas e internas. O objectivo do trabalho descrito nesta tese é desenvolver um sistema que consiga caracterizar o comportamento dos utilizadores do ponto de vista da rede. Propomos uma arquitectura de sistema modular para extrair informação de fluxos de rede etiquetados. O processo é iniciado com a criação de perfis de utilizador a partir da sua informação de fluxos de rede. Depois, perfis com características semelhantes são agrupados automaticamente, originando perfis de grupo. Finalmente, os perfis individuais são comprados com os perfis de grupo, e os que diferem significativamente são marcados como anomalias para análise detalhada posterior. Considerando esta arquitectura, propomos um modelo para descrever o comportamento de rede dos utilizadores e dos grupos. Propomos ainda métodos de visualização que permitem inspeccionar rapidamente toda a informação contida no modelo. O sistema e modelo foram avaliados utilizando um conjunto de dados reais obtidos de um operador de telecomunicações. Os resultados confirmam que os grupos projectam com precisão comportamento semelhante. Além disso, as anomalias foram as esperadas, considerando a população subjacente. Com a informação que este sistema consegue extrair dos dados em bruto, as necessidades de rede dos utilizadores podem sem supridas mais eficazmente, os utilizadores suspeitos são assinalados para posterior análise, conferindo uma vantagem competitiva a qualquer empresa que use este sistema.In our days, the success of a corporation hinges on its agility and ability to adapt to fast changing conditions. Proactive workers and an agile IT/IS infrastructure that can support them is a requirement for this success. Unfortunately, this is not always the case. The user’s network requirements may not be fully understood, which slows down relocation and reorganization. Also, if there is no grasp on the real requirements, the IT/IS infrastructure may not be efficiently used, with waste in some areas and deficiencies in others. Finally, enabling proactivity does not mean full unrestricted access, since this may leave the systems vulnerable to outsider and insider threats. The purpose of the work described on this thesis is to develop a system that can characterize user network behavior. We propose a modular system architecture to extract information from tagged network flows. The system process begins by creating user profiles from their network flows’ information. Then, similar profiles are automatically grouped into clusters, creating role profiles. Finally, the individual profiles are compared against the roles, and the ones that differ significantly are flagged as anomalies for further inspection. Considering this architecture, we propose a model to describe user and role network behavior. We also propose visualization methods to quickly inspect all the information contained in the model. The system and model were evaluated using a real dataset from a large telecommunications operator. The results confirm that the roles accurately map similar behavior. The anomaly results were also expected, considering the underlying population. With the knowledge that the system can extract from the raw data, the users network needs can be better fulfilled, the anomalous users flagged for inspection, giving an edge in agility for any company that uses it

Layout Inference and Table Detection in Spreadsheet Documents

Spreadsheets have found wide use in many different domains and settings. They provide a broad range of both basic and advanced functionalities. In this way, they can support data collection, transformation, analysis, and reporting. Nevertheless, at the same time spreadsheets maintain a friendly and intuitive interface. Additionally, they entail no to very low cost. Well-known spreadsheet applications, such as OpenOffice, LibreOffice, Google Sheets, and Gnumeric, are free to use. Moreover, Microsoft Excel is widely available, with millions of users worldwide. Thus, spreadsheets are not only powerful tools, but also have a very low entrance barrier. Therefore, they have become very popular with novices and professionals alike. As a result, a large volume of valuable data resides in these documents. From spreadsheets, of particular interest are data coming in tabular form, since they provide concise, factual, and to a large extend structured information. One natural progression is to transfer tabular data from spreadsheets to databases. This would allow spreadsheets to become a direct source of data for existing or new business processes. It would be easier to digest them into data warehouses and to integrate them with other sources. Nevertheless, besides databases, there are other means to work with spreadsheet data. New paradigms, like NoDB, advocate querying directly from raw documents. Going one step further, spreadsheets together with other raw documents can be stored in a sophisticated centralized repository, i.e., a data lake. From then on they can serve (on-demand) various tasks and applications. All in all, by making spreadsheet data easily accessible, we can prevent information silos, i.e., valuable knowledge being isolated and scattered in multiple spreadsheet documents. Yet, there are considerable challenges to the automatic processing and understanding of these documents. After all, spreadsheets are designed primarily for human consumption, and as such, they favor customization and visual comprehension. Data are often intermingled with formatting, formulas, layout artifacts, and textual metadata, which carry domain-specific or even user-specific information (i.e., personal preferences). Multiple tables, with different layout and structure, can be found on the same sheet. Most importantly, the structure of the tables is not known, i.e., not explicitly given by the spreadsheet documents. Altogether, spreadsheets are better described as partially structured, with a significant degree of implicit information. In literature, the automatic understanding of spreadsheet data has only been scarcely investigated, often assuming just the same uniform table layout. However, due to the manifold possibilities to structure tabular data in spreadsheets, the assumption of a uniform layout either excludes a substantial number of tables from the extraction process or leads to inaccurate results. In this thesis, we primarily address two fundamental tasks that can lead to more accurate information extraction from spreadsheet documents. Namely, we propose intuitive and effective approaches for layout analysis and table detection in spreadsheets. Nevertheless, our overall solution is designed as a processing pipeline, where specialized steps build on top of each other to discover the tabular data. One of our main objectives is to eliminate most of the assumptions from related work. Instead, we target highly diverse sheet layouts, with one or multiple tables. On the same time, we foresee the presence of textual metadata and other non-tabular data in the sheet. Furthermore, we make use of sophisticated machine learning and optimization techniques. This brings flexibility to our approach, allowing it to work even with complex or malformed tables. Moreover, this intended flexibility makes our approaches transferable to new spreadsheet datasets. Thus, we are not bounded to specific domains or settings.:1 INTRODUCTION 1.1 Motivation 1.2 Contributions 1.3 Outline 2 FOUNDATIONS AND RELATED WORK 2.1 The Evolution of Spreadsheet Documents 2.1.1 Spreadsheet User Interface and Functionalities 2.1.2 Spreadsheet File Formats 2.1.3 Spreadsheets Are Partially-Structured 2.2 Analysis and Recognition in Electronic Documents 2.2.1 A General Overview of DAR 2.2.2 DAR in Spreadsheets 2.3 Spreadsheet Research Areas 2.3.1 Layout Inference and Table Recognition 2.3.2 Unifying Databases and Spreadsheets 2.3.3 Spreadsheet Software Engineering 2.3.4 Data Wrangling Approaches 3 AN EMPIRICAL STUDY OF SPREADSHEET DOCUMENTS 3.1 Available Corpora 3.2 Creating a Gold Standard Dataset 3.2.1 Initial Selection 3.2.2 Annotation Methodology 3.3 Dataset Analysis 3.3.1 Takeaways from Business Spreadsheets 3.3.2 Comparison Between Domains 3.4 Summary and Discussion 3.4.1 Datasets for Experimental Evaluation 3.4.2 A Processing Pipeline 4 LAYOUT ANALYSIS 4.1 A Method for Layout Analysis in Spreadsheets 4.2 Feature Extraction 4.2.1 Content Features 4.2.2 Style Features 4.2.3 Font Features 4.2.4 Formula and Reference Features 4.2.5 Spatial Features 4.2.6 Geometrical Features 4.3 Cell Classification 4.3.1 Classification Datasets 4.3.2 Classifiers and Assessment Methods 4.3.3 Optimum Under-Sampling 4.3.4 Feature Selection 4.3.5 Parameter Tuning 4.3.6 Classification Evaluation 4.4 Layout Regions 4.5 Summary and Discussions 5 CLASSIFICATION POST-PROCESSING 5.1 Dataset for Post-Processing 5.2 Pattern-Based Revisions 5.2.1 Misclassification Patterns 5.2.2 Relabeling Cells 5.2.3 Evaluating the Patterns 5.3 Region-Based Revisions 5.3.1 Standardization Procedure 5.3.2 Extracting Features from Regions 5.3.3 Identifying Misclassified Regions 5.3.4 Relabeling Misclassified Regions 5.4 Summary and Discussion 6 TABLE DETECTION 6.1 A Method for Table Detection in Spreadsheets 6.2 Preliminaries 6.2.1 Introducing a Graph Model 6.2.2 Graph Partitioning for Table Detection 6.2.3 Pre-Processing for Table Detection 6.3 Rule-Based Detection 6.3.1 Remove and Conquer 6.4 Genetic-Based Detection 6.4.1 Undirected Graph 6.4.2 Header Cluster 6.4.3 Quality Metrics 6.4.4 Objective Function 6.4.5 Weight Tuning 6.4.6 Genetic Search 6.5 Experimental Evaluation 6.5.1 Testing Datasets 6.5.2 Training Datasets 6.5.3 Tuning Rounds 6.5.4 Search and Assessment 6.5.5 Evaluation Results 6.6 Summary and Discussions 7 XLINDY: A RESEARCH PROTOTYPE 7.1 Interface and Functionalities 7.1.1 Front-end Walkthrough 7.2 Implementation Details 7.2.1 Interoperability 7.2.2 Efficient Reads 7.3 Information Extraction 7.4 Summary and Discussions 8 CONCLUSION 8.1 Summary of Contributions 8.2 Directions of Future Work BIBLIOGRAPHY LIST OF FIGURES LIST OF TABLES A ANALYSIS OF REDUCED SAMPLES B TABLE DETECTION WITH TIRS B.1 Tables in TIRS B.2 Pairing Fences with Data Regions B.3 Heuristics Framewor

Layout inference and table detection in spreadsheet document

Spreadsheet applications have evolved to be a tool of great importance for businesses, open data, and scientific communities. Using these applications, users can perform various transformations, generate new content, analyze and format data such that they are visually comprehensive. The same data can be presented in different ways, depending on the preferences and the intentions of the user. These functionalities make spreadsheets user-friendly, but not as much machine-friendly. When it comes to integrating with other sources, the free-for-all nature of spreadsheets is disadvantageous. It is rather difficult to algorithmically infer the structure of the data when they are intermingled with formatting, formulas, layout artifacts, and textual metadata. Therefore, user involvement is often required, which results in cumbersome and time-consuming tasks. Overall, the lack of automatic processing methods limits our ability to explore and reuse a great amount of rich data stored into partially-structured documents such as spreadsheets. In this thesis, we tackle this open challenge, which so far has been scarcely investigated in literature. Specifically, we are interested in extracting tabular data from spreadsheets, since they hold concise, factual, and to a large extend structured information. It is easier to process such information, in order to make it available to other applications. For instance, spreadsheet (tabular) data can be loaded into databases. Thus, these data would become instantly available to existing or new business processes. Furthermore, we can eliminate the risk of losing valuable company knowledge, by moving data or integrating spreadsheets with other more sophisticated information management systems. To achieve the aforementioned objectives and advancements, in this thesis, we develop a spreadsheet processing pipeline. The requirements for this pipeline were derived from a large scale empirical analysis of real-world spreadsheets, from business and Web settings. Specifically, we propose a series of specialized steps that build on top of each other with the goal of discovering the structure of data in spreadsheet documents. Our approach is bottom-up, as it starts from the smallest unit (i.e., the cell) to ultimately arrive at the individual tables of the sheet. Additionally, this thesis makes use of sophisticated machine learning and optimization techniques. In particular, we apply these techniques for layout analysis and table detection in spreadsheets. We target highly diverse sheet layouts, with one or multiple tables and arbitrary arrangement of contents. Moreover, we foresee the presence of textual metadata and other non-tabular data in the sheet. Furthermore, we work even with problematic tables (e.g., containing empty rows/columns and missing values). Finally, we bring flexibility to our approach. This not only allows us to tackle the above-mentioned challenges but also to reuse our solution for different (spreadsheet) datasets.Els fulls de càlcul s’empren massivament en molts dominis i contexts diferents, ja que proporcionen una àmplia gamma de funcionalitats, bàsiques i avançades, de gestió de dades. D’aquesta manera, donen suport a la recollida, transformació, anàlisi i visualització de dades. A la mateixa vegada, els fulls de càlcul tenen una interfície amigable i intuïtiva i tenen un cost molt baix d’implantació. Aplicacions de full de càlcul molt conegudes, com OpenOffice, LibreOffice, Google Sheets i Gnumeric, poden utilitzar-se de forma gratuïta i d’altres, com Microsoft Excel, són a l’abast d’una gran majoria d’usuaris. Per tant, han esdevingut molt populars tant per a novells com per professionals. Com a resultat, un gran volum de dades valuoses resideixen en aquests documents. Són de particular interès les dades que es presenten en format tabular dins dels fulls de càlcul, ja que proporcionen informació concreta, factual i parcialment estructurada. Com a conseqüència, hi ha interès en transferir dades tabulars des de fulls de càlcul a bases de dades. Això permetria que els fulls de càlcul es converteixin en una font directa de dades per a processos empresarials, i introduir aquestes dades als magatzems de dades i integrar-les amb altres fonts. Un pas més enllà, els fulls de càlcul juntament amb altres documents en brut es poden emmagatzemar en repositoris de dades centralitzats avançats, com per exemple, els data lake. Un cop al data lake, es podran fer servir (sota demanda) per a diverses tasques i aplicacions. Tot plegat, l’objectiu és fer accessibles les dades emmagatzemades als fulls de càlcul. Malgrat tot, hi ha reptes considerables en el processament i comprensió automàtica d’aquests documents. Els fulls de càlcul estan dissenyats principalment per al consum humà i, per tant, afavoreixen la personalització i la comprensió visual. Les dades sovint s’entrellacen amb formatació, fórmules, artefactes de disseny i metadades textuals, que porten informació específica del domini o fins i tot informació específica de l’usuari. Al mateix full es poden trobar diverses taules, amb una estructura i disseny diferents. A més, el format de cada taula no es declara a priori, és a dir, no hi ha cap mecanisme per definir l’estructura d’una taula, com passa a les bases de dades. Per aquest motiu, els fulls de càlcul es coneixen com a fonts de dades parcialment estructurades, amb un grau rellevant d'informació implícita. A la literatura, la comprensió automàtica de les dades emmagatzemades en fulls de càlcul s'ha investigat superficialment, sovint assumint el mateix format uniforme de taula a tots els fulls de càlcul. Tanmateix, a causa de les múltiples possibilitats d'estructurar les dades tabulars en fulls de càlcul, la suposició d'un disseny uniforme o bé exclou un nombre substancial de taules del procés d'extracció o condueix a resultats inexactes. En aquesta tesi, abordem tasques fonamentals que contribueixen a l’extracció d’informació dels fulls de càlcul d’una manera més precisa. Proposem mètodes intuïtius i eficaços per a l’anàlisi de la distribució i detecció de taules en fulls de càlcul. Un dels nostres objectius principals és eliminar la majoria dels supòsits de l’estat de l’art actual. Per fer-ho, considerem estructures tabulars altament heterogènies, contingudes en fulls de càlcul amb una o més taules. Addicionalment, preveiem la presencia de metadades i altres tipus de dades no tabulars al mateix full. Per últim, utilitzem tècniques d’optimització i d’aprenentatge automàtic per identificar l’estructura de les taules. Això aporta flexibilitat al nostre enfocament, permetent-lo treballar, fins i tot, amb taules complexes o malformades. Aquesta flexibilitat fa que els nostres mètodes siguin transferibles a nous conjunts de fulls de càlcul amb dades d’altres dominis. Per tant, no estem limitats a dominis o configuracion

Layout inference and table detection in spreadsheet document

Tesi en modalitat de cotutela: Universitat Politècnica de Catalunya i Technische Universität DresdenSpreadsheet applications have evolved to be a tool of great importance for businesses, open data, and scientific communities. Using these applications, users can perform various transformations, generate new content, analyze and format data such that they are visually comprehensive. The same data can be presented in different ways, depending on the preferences and the intentions of the user. These functionalities make spreadsheets user-friendly, but not as much machine-friendly. When it comes to integrating with other sources, the free-for-all nature of spreadsheets is disadvantageous. It is rather difficult to algorithmically infer the structure of the data when they are intermingled with formatting, formulas, layout artifacts, and textual metadata. Therefore, user involvement is often required, which results in cumbersome and time-consuming tasks. Overall, the lack of automatic processing methods limits our ability to explore and reuse a great amount of rich data stored into partially-structured documents such as spreadsheets. In this thesis, we tackle this open challenge, which so far has been scarcely investigated in literature. Specifically, we are interested in extracting tabular data from spreadsheets, since they hold concise, factual, and to a large extend structured information. It is easier to process such information, in order to make it available to other applications. For instance, spreadsheet (tabular) data can be loaded into databases. Thus, these data would become instantly available to existing or new business processes. Furthermore, we can eliminate the risk of losing valuable company knowledge, by moving data or integrating spreadsheets with other more sophisticated information management systems. To achieve the aforementioned objectives and advancements, in this thesis, we develop a spreadsheet processing pipeline. The requirements for this pipeline were derived from a large scale empirical analysis of real-world spreadsheets, from business and Web settings. Specifically, we propose a series of specialized steps that build on top of each other with the goal of discovering the structure of data in spreadsheet documents. Our approach is bottom-up, as it starts from the smallest unit (i.e., the cell) to ultimately arrive at the individual tables of the sheet. Additionally, this thesis makes use of sophisticated machine learning and optimization techniques. In particular, we apply these techniques for layout analysis and table detection in spreadsheets. We target highly diverse sheet layouts, with one or multiple tables and arbitrary arrangement of contents. Moreover, we foresee the presence of textual metadata and other non-tabular data in the sheet. Furthermore, we work even with problematic tables (e.g., containing empty rows/columns and missing values). Finally, we bring flexibility to our approach. This not only allows us to tackle the above-mentioned challenges but also to reuse our solution for different (spreadsheet) datasets.Els fulls de càlcul s’empren massivament en molts dominis i contexts diferents, ja que proporcionen una àmplia gamma de funcionalitats, bàsiques i avançades, de gestió de dades. D’aquesta manera, donen suport a la recollida, transformació, anàlisi i visualització de dades. A la mateixa vegada, els fulls de càlcul tenen una interfície amigable i intuïtiva i tenen un cost molt baix d’implantació. Aplicacions de full de càlcul molt conegudes, com OpenOffice, LibreOffice, Google Sheets i Gnumeric, poden utilitzar-se de forma gratuïta i d’altres, com Microsoft Excel, són a l’abast d’una gran majoria d’usuaris. Per tant, han esdevingut molt populars tant per a novells com per professionals. Com a resultat, un gran volum de dades valuoses resideixen en aquests documents. Són de particular interès les dades que es presenten en format tabular dins dels fulls de càlcul, ja que proporcionen informació concreta, factual i parcialment estructurada. Com a conseqüència, hi ha interès en transferir dades tabulars des de fulls de càlcul a bases de dades. Això permetria que els fulls de càlcul es converteixin en una font directa de dades per a processos empresarials, i introduir aquestes dades als magatzems de dades i integrar-les amb altres fonts. Un pas més enllà, els fulls de càlcul juntament amb altres documents en brut es poden emmagatzemar en repositoris de dades centralitzats avançats, com per exemple, els data lake. Un cop al data lake, es podran fer servir (sota demanda) per a diverses tasques i aplicacions. Tot plegat, l’objectiu és fer accessibles les dades emmagatzemades als fulls de càlcul. Malgrat tot, hi ha reptes considerables en el processament i comprensió automàtica d’aquests documents. Els fulls de càlcul estan dissenyats principalment per al consum humà i, per tant, afavoreixen la personalització i la comprensió visual. Les dades sovint s’entrellacen amb formatació, fórmules, artefactes de disseny i metadades textuals, que porten informació específica del domini o fins i tot informació específica de l’usuari. Al mateix full es poden trobar diverses taules, amb una estructura i disseny diferents. A més, el format de cada taula no es declara a priori, és a dir, no hi ha cap mecanisme per definir l’estructura d’una taula, com passa a les bases de dades. Per aquest motiu, els fulls de càlcul es coneixen com a fonts de dades parcialment estructurades, amb un grau rellevant d'informació implícita. A la literatura, la comprensió automàtica de les dades emmagatzemades en fulls de càlcul s'ha investigat superficialment, sovint assumint el mateix format uniforme de taula a tots els fulls de càlcul. Tanmateix, a causa de les múltiples possibilitats d'estructurar les dades tabulars en fulls de càlcul, la suposició d'un disseny uniforme o bé exclou un nombre substancial de taules del procés d'extracció o condueix a resultats inexactes. En aquesta tesi, abordem tasques fonamentals que contribueixen a l’extracció d’informació dels fulls de càlcul d’una manera més precisa. Proposem mètodes intuïtius i eficaços per a l’anàlisi de la distribució i detecció de taules en fulls de càlcul. Un dels nostres objectius principals és eliminar la majoria dels supòsits de l’estat de l’art actual. Per fer-ho, considerem estructures tabulars altament heterogènies, contingudes en fulls de càlcul amb una o més taules. Addicionalment, preveiem la presencia de metadades i altres tipus de dades no tabulars al mateix full. Per últim, utilitzem tècniques d’optimització i d’aprenentatge automàtic per identificar l’estructura de les taules. Això aporta flexibilitat al nostre enfocament, permetent-lo treballar, fins i tot, amb taules complexes o malformades. Aquesta flexibilitat fa que els nostres mètodes siguin transferibles a nous conjunts de fulls de càlcul amb dades d’altres dominis. Per tant, no estem limitats a dominis o configuracionsPostprint (published version

Text categorization methods for automatic estimation of verbal intelligence

In this paper we investigate whether conventional text categorization methods may suffice to infer different verbal intelligence levels. This research goal relies on the hypothesis that the vocabulary that speakers make use of reflects their verbal intelligence levels. Automatic verbal intelligence estimation of users in a spoken language dialog system may be useful when defining an optimal dialog strategy by improving its adaptation capabilities. The work is based on a corpus containing descriptions (i.e. monologs) of a short film by test persons yielding different educational backgrounds and the verbal intelligence scores of the speakers. First, a one-way analysis of variance was performed to compare the monologs with the film transcription and to demonstrate that there are differences in the vocabulary used by the test persons yielding different verbal intelligence levels. Then, for the classification task, the monologs were represented as feature vectors using the classical TF–IDF weighting scheme. The Naive Bayes, k-nearest neighbors and Rocchio classifiers were tested. In this paper we describe and compare these classification approaches, define the optimal classification parameters and discuss the classification results obtained