Albertetti, Fabrizio

2015-12-17, Albertetti, Fabrizio, Grossrieder, Lionel, Ribaux, Olivier, Stoffel, Kilian

The extension of traditional data mining methods to time series has been effectively applied to a wide range of domains such as finance, econometrics, biology, security, and medicine. Many existing mining methods deal with the task of change points detection, but very few provide a flexible approach. Querying specific change points with linguistic variables is particularly useful in crime analysis, where intuitive, understandable, and appropriate detection of changes can significantly improve the allocation of resources for timely and concise operations. In this paper, we propose an on-line method for detecting and querying change points in crime-related time series with the use of a meaningful representation and a fuzzy inference system. Change points detection is based on a shape space representation, and linguistic terms describing geometric properties of the change points are used to express queries, offering the advantage of intuitiveness and flexibility. An empirical evaluation is first conducted on a crime data set to confirm the validity of the proposed method and then on a financial data set to test its general applicability. A comparison to a similar change-point detection algorithm and a sensitivity analysis are also conducted. Results show that the method is able to accurately detect change points at very low computational costs. More broadly, the detection of specific change points within time series of virtually any domain is made more intuitive and more understandable, even for experts not related to data mining.

2013-6-4, Albertetti, Fabrizio, Cotofrei, Paul, Grossrieder, Lionel, Ribaux, Olivier, Stoffel, Kilian

Grouping crimes having similarities has always been interesting for analysts. Actually, when a set of crimes share common properties, the capability to conduct reasoning and the automation with this set drastically increase. Conjunction, interpretation and explanation based on similarities can be key success factors to apprehend criminals. In this paper, we present a computerized method for high-volume crime linkage, based on a fuzzy MCDM approach in order to combine situational, behavioral, and forensic information. Experiments are conducted with series in burglaries from real data and compared to expert results.

2012-11-11, Albertetti, Fabrizio, Stoffel, Kilian

Nowadays, crime analyses are often conducted with computational methods. These methods, using several different systems (such as decision support systems), need to handle forensic data in a specific way. In this paper we present a methodology to structure police report data for crime analysis. The proposed artifact is mainly about applying data warehousing concepts to forensic data in a crime analysis perspective. Moreover, a proof of concept is carried out with real forensic data to illustrate and evaluate our methodology. These experiments highlight the need of such framework for crime analysis.

2013-6-31, Albertetti, Fabrizio, Cotofrei, Paul, Grossrieder, Lionel, Ribaux, Olivier, Stoffel, Kilian

2015, Albertetti, Fabrizio, Stoffel, Kilian

Cette thèse de doctorat investigue le rôle des méthodes d'extraction de connaissances dans l'analyse criminelle en tant que projet interdisciplinaire, avec une orientation sur les méthodes non supervisées traitant les aspects d'incertitude qui sont intrinsèques à l'environnement du crime.
Dans un contexte où les données générées par les activités criminelles sont de plus en plus disponibles grâce à l'évolution des technologies, l'utilisation de méthodes automatisées pour créer de la valeur à partir de ces données devient une nécessité. Ces méthodes d'analyse requièrent une conception spécifique selon la nature des données qu'elles traitent, principalement collectées à partir de scènes de crimes. Les analystes criminels ont désespérément besoin de telles méthodes pour être mieux informés et efficients dans la lutte perpétuelle contre le crime. Cependant, leurs choix en termes d’étendue et de disponibilité sont très limités.
Un framework qui délimite et explique le rôle des méthodes d’extraction de connaissance pour l’analyse criminelle est proposé. Ce framework adresse un défi particulier : développer des méthodes de data mining non supervisées qui permettent de traiter l’incertitude des données criminelles.
Trois approches sont développées pour confronter ce défi. (1) Comment structurer et représenter des données criminelles pour exploiter pleinement leur potentiel à révéler des connaissances par la conduite d’autres analyses ? (2) Quelle est la méthode appropriée d’analyse de liens entre les crimes qui prenne en compte des données à la fois quantitatives et qualitatives ? Et (3) quelle est la méthode appropriée pour aider les analystes criminels à détecter des changements dans des tendances criminelles d’une manière flexible et compréhensible ?
L’importance de cette recherche interdisciplinaire peut être résumée en deux points : elle clarifie et délimite le rôle du data mining dans l’analyse criminelle, en fournissant une perspective sur son applicabilité dans cet environnement particulier ; et elle facilite l’extraction de connaissances par l’utilisation des méthodes proposée guidées par le métier., This doctoral thesis investigates the role of knowledge extraction methods in the analysis of crime as an interdisciplinary project, with a focus on unsupervised methods dealing with the uncertain aspects that are intrinsic to the crime environment.
In a context where data generated from criminal activities are increasingly available due to the evolution of technology, the use of automated methods to create value from these data becomes a necessity. These analytic methods require a specific design with regard to the nature of the data they deal with, mostly gathered from crime scenes. Crime analysts desperately need such methods to be better informed and efficient in the perpetual struggle against crime. However, their choices in terms of range and availability are very limited.
A framework delineating and explaining the role of knowledge extraction methods for crime analysis is provided. This framework addresses a particular challenge: developing unsupervised data mining methods dealing with the uncertainty of crime data.
Three approaches are developed to confront this challenge. (1) How to structure and represent crime data to fully exploit the potential of revealing knowledge with further analyses? (2) What is the appropriate method to analyze links between crimes that can deal with both qualitative and quantitative crime data? And (3) what is the appropriate method to help crime analysts to flexibly and understandably detect changes in crime trends?
The significance of this interdisciplinary research can be summarized in two points: it clarifies and delineates the role of data mining in crime analysis, by giving some insights into its applicability in this particular environment; and it makes easier the extraction of knowledge by the use of the proposed domain-driven methods.

2013-5-20, Albertetti, Fabrizio, Stoffel, Kilian

2012-9-12, Grossrieder, Lionel, Albertetti, Fabrizio, Stoffel, Kilian, Ribaux, Olivier, Ioset, Sylvain

In this research, we attempt to study the contribution of data mining techniques in crime analysis and intelligence. It is an interdisciplinary project, combining forensic, criminological and computational methods. We search to develop a frame in which data mining techniques, driven by crime analysis and forensic processes, take an active part to data interpretation and information analysis (in order to extract knowledge). Realized in collaboration with the cantonal police forces of Vaud in Switzerland, the first phase of this project consists to focus on residential burglary data. The sample is provided by the Concept Intercantonal de Coordination Opérationnelle et Préventive (CICOP) database, which is the regional center for crime analysis in French-speaking part of Switzerland. The CICOP analysts use phenomenon codes to define a particular crime situation. These CICOP codes are directly related to the situational approaches in criminology. Concretely, we have three main purposes: residential burglary classification, new phenomena discovery, and series or trends detection. That brings, in first hand, to formalize processes identified in crime analysis with the help of a standard notation called Business Process Modeling Notation (BPMN). Then, different data mining techniques are tested on data, and assessed by confronting them with phenomena identified by police forces analysts. Finally, we make a criminological analysis on the results to check the consistency with main situational theories in criminology. Accuracy and results relevance exam is an important step, because the different data mining algorithms can generate trivial and unexplainable rules. We note then the need of a human interpretation, and in this case, of a criminological interpretation. The first results are hopeful and classification algorithms are effective to classify residential burglaries like CICOP analysts did it.

2013-8-12, Albertetti, Fabrizio, Cotofrei, Paul, Grossrieder, Lionel, Ribaux, Olivier, Stoffel, Kilian

Grouping events having similarities has always been interesting for analysts. Actually, when a label is put on top of a set of events to denote they share common properties, the automation and the capability to conduct reasoning with this set drastically increase. This is particularly true when considering criminal events for crime analysts; conjunction, interpretation and explanation can be key success factors to apprehend criminals. In this paper, we present the CriLiM methodology for investigating both serious and high-volume crime. Our artifact consists in implementing a tailored computerized crime linkage system, based on a fuzzy MCDM approach in order to combine spatio-temporal, behavioral, and forensic information. As a proof of concept, series in burglaries are examined from real data and compared to expert results.

2013-4-1, Grossrieder, Lionel, Albertetti, Fabrizio, Stoffel, Kilian, Ribaux, Olivier

Le "data mining", ou "fouille de données", est un ensemble de méthodes et de techniques attractif qui a connu une popularité fulgurante ces dernières années, spécialement dans le domaine du marketing. Le développement récent de l’analyse ou du renseignement criminel soulève des problématiques auxquelles il est tentant d’appliquer ces méthodes et techniques. Le potentiel et la place du data mining dans le contexte de l’analyse criminelle doivent être mieux définis afin de piloter son application. Cette réflexion est menée dans le cadre du renseignement produit par des systèmes de détection et de suivi systématique de la criminalité répétitive, appelés processus de veille opérationnelle. Leur fonctionnement nécessite l’existence de patterns inscrits dans les données, et justifiés par les approches situationnelles en criminologie. Muni de ce bagage théorique, l’enjeu principal revient à explorer les possibilités de détecter ces patterns au travers des méthodes et techniques de data mining. Afin de répondre à cet objectif, une recherche est actuellement menée en Suisse à travers une approche interdisciplinaire combinant des connaissances forensiques, criminologiques, et computationnelles

2012-5-13, Grossrieder, Lionel, Albertetti, Fabrizio, Stoffel, Kilian, Ribaux, Olivier, Ioset, Sylvain