Spell checkers and correctors : a unified treatment

The aim of this dissertation is to provide a unified treatment of various spell checkers and correctors. Firstly, the spell checking and correcting problems are formally described in mathematics in order to provide a better understanding of these tasks. An approach that is similar to the way in which denotational semantics used to describe programming languages is adopted. Secondly, the various attributes of existing spell checking and correcting techniques are discussed. Extensive studies on selected spell checking/correcting algorithms and packages are then performed. Lastly, an empirical investigation of various spell checking/correcting packages is presented. It provides a comparison and suggests a classification of these packages in terms of their functionalities, implementation strategies, and performance. The investigation was conducted on packages for spell checking and correcting in English as well as in Northern Sotho and Chinese. The classification provides a unified presentation of the strengths and weaknesses of the techniques studied in the research. The findings provide a better understanding of these techniques in order to assist in improving some existing spell checking/correcting applications and future spell checking/correcting package designs and implementations.Dissertation (MSc)--University of Pretoria, 2009.Computer Scienceunrestricte

Mustererkennungsbasierte Verteidgung gegen gezielte Angriffe

The speed at which everything and everyone is being connected considerably outstrips the rate at which effective security mechanisms are introduced to protect them. This has created an opportunity for resourceful threat actors which have specialized in conducting low-volume persistent attacks through sophisticated techniques that are tailored to specific valuable targets. Consequently, traditional approaches are rendered ineffective against targeted attacks, creating an acute need for innovative defense mechanisms. This thesis aims at supporting the security practitioner in bridging this gap by introducing a holistic strategy against targeted attacks that addresses key challenges encountered during the phases of detection, analysis and response. The structure of this thesis is therefore aligned to these three phases, with each one of its central chapters taking on a particular problem and proposing a solution built on a strong foundation on pattern recognition and machine learning. In particular, we propose a detection approach that, in the absence of additional authentication mechanisms, allows to identify spear-phishing emails without relying on their content. Next, we introduce an analysis approach for malware triage based on the structural characterization of malicious code. Finally, we introduce MANTIS, an open-source platform for authoring, sharing and collecting threat intelligence, whose data model is based on an innovative unified representation for threat intelligence standards based on attributed graphs. As a whole, these ideas open new avenues for research on defense mechanisms and represent an attempt to counteract the imbalance between resourceful actors and society at large.In unserer heutigen Welt sind alle und alles miteinander vernetzt. Dies bietet mächtigen Angreifern die Möglichkeit, komplexe Verfahren zu entwickeln, die auf spezifische Ziele angepasst sind. Traditionelle Ansätze zur Bekämpfung solcher Angriffe werden damit ineffektiv, was die Entwicklung innovativer Methoden unabdingbar macht. Die vorliegende Dissertation verfolgt das Ziel, den Sicherheitsanalysten durch eine umfassende Strategie gegen gezielte Angriffe zu unterstützen. Diese Strategie beschäftigt sich mit den hauptsächlichen Herausforderungen in den drei Phasen der Erkennung und Analyse von sowie der Reaktion auf gezielte Angriffe. Der Aufbau dieser Arbeit orientiert sich daher an den genannten drei Phasen. In jedem Kapitel wird ein Problem aufgegriffen und eine entsprechende Lösung vorgeschlagen, die stark auf maschinellem Lernen und Mustererkennung basiert. Insbesondere schlagen wir einen Ansatz vor, der eine Identifizierung von Spear-Phishing-Emails ermöglicht, ohne ihren Inhalt zu betrachten. Anschliessend stellen wir einen Analyseansatz für Malware Triage vor, der auf der strukturierten Darstellung von Code basiert. Zum Schluss stellen wir MANTIS vor, eine Open-Source-Plattform für Authoring, Verteilung und Sammlung von Threat Intelligence, deren Datenmodell auf einer innovativen konsolidierten Graphen-Darstellung für Threat Intelligence Stardards basiert. Wir evaluieren unsere Ansätze in verschiedenen Experimenten, die ihren potentiellen Nutzen in echten Szenarien beweisen. Insgesamt bereiten diese Ideen neue Wege für die Forschung zu Abwehrmechanismen und erstreben, das Ungleichgewicht zwischen mächtigen Angreifern und der Gesellschaft zu minimieren

Third International Conference on Technologies for Music Notation and Representation TENOR 2017

The third International Conference on Technologies for Music Notation and Representation seeks to focus on a set of specific research issues associated with Music Notation that were elaborated at the first two editions of TENOR in Paris and Cambridge. The theme of the conference is vocal music, whereas the pre-conference workshops focus on innovative technological approaches to music notation