La vente en ligne de faux documents d’identité - Une recherche exploratoire

Travail dirigé présenté à la Faculté des études supérieures et postdoctorales en vue de l’obtention du grade de Maître ès sciences (M.Sc.) en criminologie, option Criminalistique et information

La vente en ligne de faux documents d’identité - Une recherche exploratoire

Travail dirigé présenté à la Faculté des études supérieures et postdoctorales en vue de l’obtention du grade de Maître ès sciences (M.Sc.) en criminologie, option Criminalistique et information

La légende urbaine des snuff movies : histoire, théorie, esthétiques, technologies

La présente étude propose une analyse historique de la légende urbaine des snuff movies. En premier lieu, elle se penche sur l’émergence de cette rumeur dans le paysage médiatique américain des années 70 tout en focalisant sur certains objets filmiques l’ayant crédibilisée, principalement les stag et les mondo movies. Ce mémoire analyse par la suite l’influence majeure de deux événements sur l’implantation de la légende urbaine dans l’imaginaire collectif, soit l’assassinat de Sharon Tate et la circulation du film de Zapruder. Après avoir étudié la persistance de la rumeur, cet essai focalise sur la promotion et l’exploitation de Snuff (1976) en plus de proposer une analyse de ce long métrage. Ensuite, il se penche sur deux types de représentations du snuff dans le cinéma de fiction ainsi que leurs impacts sur l’authentification de la légende urbaine. Il est d’abord question des mises en scène du snuff dans le cinéma populaire qui s’inspirent de la rumeur pour ensuite l’actualiser. Sont ensuite étudiées les représentations du snuff à titre de faux documents, soit ces œuvres qui tentent par divers procédés de se faire passer pour de véritables films clandestins et, de ce fait, authentifient l’objet auquel ils se réfèrent. Puisque cette étude analyse l’évolution médiatique de la légende urbaine, elle se conclut sur son déplacement du cinéma vers Internet et de sa nouvelle crédibilisation grâce aux vidéos macabres, à la pornographie juvénile et au récent cas Magnotta.

K-tree : large scale document clustering

We introduce K-tree in an information retrieval context. It is an efficient approximation of the k-means clustering algorithm. Unlike k-means it forms a hierarchy of clusters. It has been extended to address issues with sparse representations. We compare performance and quality to CLUTO using document collections. The K-tree has a low time complexity that is suitable for large document collections. This tree structure allows for efficient disk based implementations where space requirements exceed that of main memory.

Document clustering with K-tree

This paper describes the approach taken to the XML Mining track at INEX 2008 by a group at the Queensland University of Technology. We introduce the K-tree clustering algorithm in an Information Retrieval context by adapting it for document clustering. Many large scale problems exist in document clustering. K-tree scales well with large inputs due to its low complexity. It offers promising results both in terms of efficiency and quality. Document classification was completed using Support Vector Machines.

Application of K-tree to document clustering

Digital collections are growing exponentially in size as the information age takes a firm grip on all aspects of society. As a result Information Retrieval (IR) has become an increasingly important area of research. It promises to provide new and more effective ways for users to find information relevant to their search intentions. Document clustering is one of the many tools in the IR toolbox and is far from being perfected. It groups documents that share common features. This grouping allows a user to quickly identify relevant information. If these groups are misleading then valuable information can accidentally be ignored. There- fore, the study and analysis of the quality of document clustering is important. With more and more digital information available, the performance of these algorithms is also of interest. An algorithm with a time complexity of O(n2) can quickly become impractical when clustering a corpus containing millions of documents. Therefore, the investigation of algorithms and data structures to perform clustering in an efficient manner is vital to its success as an IR tool. Document classification is another tool frequently used in the IR field. It predicts categories of new documents based on an existing database of (doc- ument, category) pairs. Support Vector Machines (SVM) have been found to be effective when classifying text documents. As the algorithms for classifica- tion are both efficient and of high quality, the largest gains can be made from improvements to representation. Document representations are vital for both clustering and classification. Representations exploit the content and structure of documents. Dimensionality reduction can improve the effectiveness of existing representations in terms of quality and run-time performance. Research into these areas is another way to improve the efficiency and quality of clustering and classification results. Evaluating document clustering is a difficult task. Intrinsic measures of quality such as distortion only indicate how well an algorithm minimised a sim- ilarity function in a particular vector space. Intrinsic comparisons are inherently limited by the given representation and are not comparable between different representations. Extrinsic measures of quality compare a clustering solution to a “ground truth” solution. This allows comparison between different approaches. As the “ground truth” is created by humans it can suffer from the fact that not every human interprets a topic in the same manner. Whether a document belongs to a particular topic or not can be subjective.

Joinder to a later unsigned document?

It is well known that a statutory requirement of formality is associated with contracts concerning land. In this regard, s 59 of the Property Law Act 1974 (Qld) provides: No action may be brought upon any contract for the sale or other disposition of land or any interest in land unless the contract upon which such action is brought, or some memorandum or note of the contract, is in writing, and signed by the party to be charged, or by some person by the party lawfully authorised. In addition to the possibility of a formal contract, the statutory wording clearly contemplates reliance on an informal note or memorandum. To constitute a sufficient note or memorandum for the purposes of the statute, the signed note or memorandum must contain details of the parties to the contract, an adequate description of the property, the price and any other essential terms. It is also accepted that the doctrine of joinder may be invoked in circumstances where the document signed by the party to be charged contains an express or implied reference to any other document. In this way, a sufficient note or memorandum may be constituted by the joinder of a number of documents.

TOPSIG : Topology Preserving Document Signatures

Performance comparisons between File Signatures and Inverted Files for text retrieval have previously shown several significant shortcomings of file signatures relative to inverted files. The inverted file approach underpins most state-of-the-art search engine algorithms, such as Language and Probabilistic models. It has been widely accepted that traditional file signatures are inferior alternatives to inverted files. This paper describes TopSig, a new approach to the construction of file signatures. Many advances in semantic hashing and dimensionality reduction have been made in recent times, but these were not so far linked to general purpose, signature file based, search engines. This paper introduces a different signature file approach that builds upon and extends these recent advances. We are able to demonstrate significant improvements in the performance of signature file based indexing and retrieval, performance that is comparable to that of state of the art inverted file based systems, including Language models and BM25. These findings suggest that file signatures offer a viable alternative to inverted files in suitable settings and positions the file signatures model in the class of Vector Space retrieval models.