Minería de datos con Oracle Data Miner

La intención del proyecto es mostrar las diferentes características que ofrece Oracle en el campo de la minería de datos, con la finalidad de saber si puede ser una plataforma apta para la investigación y la educación en la universidad. En la primera parte del proyecto se estudia la aplicación “Oracle Data Miner” y como, mediante un flujo de trabajo visual e intuitivo, pueden aplicarse las distintas técnicas de minería (clasificación, regresión, clustering y asociación). Para mostrar la ejecución de estas técnicas se han usado dataset procedentes de la universidad de Irvine. Con ello se ha conseguido observar el comportamiento de los distintos algoritmos en situaciones reales. Para cada técnica se expone como evaluar su fiabilidad y como interpretar los resultados que se obtienen a partir de su aplicación. También se muestra la aplicación de las técnicas mediante el uso del lenguaje PL/SQL. Gracias a ello podemos integrar la minería de datos en nuestras aplicaciones de manera sencilla. En la segunda parte del proyecto, se ha elaborado un prototipo de una aplicación que utiliza la minería de datos, en concreto la clasificación para obtener el diagnóstico y la probabilidad de que un tumor de mama sea maligno o benigno, a partir de los resultados de una citología.

BM: Empresa Oracle

La posibilidad de realizar un trabajo acerca de la Compañía en la que cual se labora, implica varias actividades y retos, pues no sólo se trata de la búsqueda y análisis de cierta información que aunque se sabe dónde esta no siempre se sabe por que medios o a través de quien conseguirla con suficiente objetividad. También implica el cuestionamiento personal de cuanto se ha aprendido y de si el tiempo de permanencia en la empresa ha sido o no de provecho. Se tratan además algunos aspectos que podrían estar en desacuerdo con el propio punto de vista o con situaciones que de ser uno el encargado, se manejarían de forma diferente. Se pone a prueba también en todo momento la capacidad personal para la recolección, valoración, desecho y complementación de información que en la mayoría de las ocasiones proviene de innumerables fuentes y personas. Lograr hacer esto, y por último poder presentar un conjunto de descripciones y análisis que concuerden entre si y que mantengan una estructura lógica e intrínsecamente se encadenen unos con otros, es una tarea pocas veces valorada. Nosotros como Administradores de Empresas o Ejecutivos , la mayoría de las veces recibimos la información ya estructurada, redactada y filtrada. Tomamos decisiones con base en esta, pero son otros los que hacen esta labor. Es importante conocer siempre los dos lados de la moneda y esta es una ocasión para ello, es correcto utilizar la información en beneficio nuestro y el de las empresas para las cuales trabajamos, pero estamos la mayoría de las veces capacitados para presentarla y exponerla de tal forma que pueda ser utilizada en la toma de decisiones ?.... este es el interrogante. Considero que un trabajo de estas características permite dar respuesta al mismo. Este trabajo se refiere a una Empresa que se desempeña en la industria de la Tecnología de Información. Para ubicar al lector, esta industria es aquella que fabrica, distribuye y ofrece los servicios relacionados de todos los productos que tienen que ver con el manejo de información. Este manejo de información abarca otras industrias tales como la industria de computadoras, la transmisión de datos, las telecomunicaciones y la propia en la cual se ubica ORACLE, el almacenamiento de datos; transformación y manejo eficiente de información y soluciones automatizadas para procesos comerciales e industriales. La tecnología de la información es una industria relativamente nueva pues data tan solo de tres a lo máximo cuatro décadas y esto en los países más desarrollados. En el tercer mundo puede decirse que comenzó realmente hace 15 años con la implementación a escala de grandes supercomputadoras.

Password Based Server Aided Key Exchange

We propose a new password-based 3-party protocol with a formal security proof in the standard model. Under reasonable assumptions we show that our new protocol is more efficient than the recent protocol of Abdalla and Pointcheval (FC 2005), proven in the random oracle model. We also observe some limitations in the model due to Abdalla, Fouque and Pointcheval (PKC 2005) for proving security of such protocols.

Universally composable contributory group key exchange

We treat the security of group key exchange (GKE) in the universal composability (UC) framework. Analyzing GKE protocols in the UC framework naturally addresses attacks by malicious insiders. We define an ideal functionality for GKE that captures contributiveness in addition to other desired security goals. We show that an efficient two-round protocol securely realizes the proposed functionality in the random oracle model. As a result, we obtain the most efficient UC-secure contributory GKE protocol known.

Strongly Secure Certificateless Key Agreement

We introduce a formal model for certificateless authenticated key exchange (CL-AKE) protocols. Contrary to what might be expected, we show that the natural combination of an ID-based AKE protocol with a public key based AKE protocol cannot provide strong security. We provide the first one-round CL-AKE scheme proven secure in the random oracle model. We introduce two variants of the Diffie-Hellman trapdoor the introduced by \cite{DBLP:conf/eurocrypt/CashKS08}. The proposed key agreement scheme is secure as long as each party has at least one uncompromised secret. Thus, our scheme is secure even if the key generation centre learns the ephemeral secrets of both parties.

Efficient one-round key exchange in the standard model

We consider one-round key exchange protocols secure in the standard model. The security analysis uses the powerful security model of Canetti and Krawczyk and a natural extension of it to the ID-based setting. It is shown how KEMs can be used in a generic way to obtain two different protocol designs with progressively stronger security guarantees. A detailed analysis of the performance of the protocols is included; surprisingly, when instantiated with specific KEM constructions, the resulting protocols are competitive with the best previous schemes that have proofs only in the random oracle model.

Efficient one-round key exchange in the efficient one-round key exchange in the standard model

We consider one-round key exchange protocols secure in the standard model. The security analysis uses the powerful security model of Canetti and Krawczyk and a natural extension of it to the ID-based setting. It is shown how KEMs can be used in a generic way to obtain two different protocol designs with progressively stronger security guarantees. A detailed analysis of the performance of the protocols is included; surprisingly, when instantiated with specific KEM constructions, the resulting protocols are competitive with the best previous schemes that have proofs only in the random oracle model.

Efficient one-round key exchange in the standard model

We consider one-round key exchange protocols secure in the standard model. The security analysis uses the powerful security model of Canetti and Krawczyk and a natural extension of it to the ID-based setting. It is shown how KEMs can be used in a generic way to obtain two different protocol designs with progressively stronger security guarantees. A detailed analysis of the performance of the protocols is included; surprisingly, when instantiated with specific KEM constructions, the resulting protocols are competitive with the best previous schemes that have proofs only in the random oracle model.

Attribute-based authenticated key exchange

We introduce the concept of attribute-based authenticated key exchange (AB-AKE) within the framework of ciphertext policy attribute-based systems. A notion of AKE-security for AB-AKE is presented based on the security models for group key exchange protocols and also taking into account the security requirements generally considered in the ciphertext policy attribute-based setting. We also extend the paradigm of hybrid encryption to the ciphertext policy attribute-based encryption schemes. A new primitive called encapsulation policy attribute-based key encapsulation mechanism (EP-AB-KEM) is introduced and a notion of chosen ciphertext security is de�ned for EP-AB-KEMs. We propose an EP-AB-KEM from an existing attribute-based encryption scheme and show that it achieves chosen ciphertext security in the generic group and random oracle models. We present a generic one-round AB-AKE protocol that satis�es our AKE-security notion. The protocol is generically constructed from any EP-AB-KEM that satis�es chosen ciphertext security. Instantiating the generic AB-AKE protocol with our EP-AB-KEM will result in a concrete one-round AB-AKE protocol also secure in the generic group and random oracle models.

A meta-study of SAP financials in the Queensland Government

This thesis consists of three related studies: an ERP Major Issues Study; an Historical Study of the Queensland Government Financial Management System; and a Meta-Study that integrates these and other related studies conducted under the umbrella of the Cooperative ERP Lifecycle Knowledge Management research program. This research provides a comprehensive view of ERP lifecycle issues encountered in SAP R/3 projects across the Queensland Government. This study follows a preliminary ERP issues study (Chang, 2002) conducted in five Queensland Government agencies. The Major Issues Study aims to achieve the following: (1) identify / explicate major issues in relation to the ES life-cycle in the public sector; (2) rank the importance of these issues; and, (3) highlight areas of consensus and dissent among stakeholder groups. To provide a rich context for this study, this thesis includes an historical recount of the Queensland Government Financial Management System (QGFMS). This recount tells of its inception as a centralised system; the selection of SAP and subsequent decentralisation; and, its eventual recentralisation under the Shared Services Initiative and CorpTech. This historical recount gives an insight into the conditions that affected the selection and ongoing management and support of QGFMS. This research forms part of a program entitled Cooperative ERP Lifecycle Knowledge Management. This thesis provides a concluding report for this research program by summarising related studies conducted in the Queensland Government SAP context: Chan (2003); Vayo et al (2002); Ng (2003); Timbrell et al (2001); Timbrell et al (2002); Chang (2002); Putra (1998); and, Niehus et al (1998). A study of Oracle in the United Arab Emirates by Dhaheri (2002) is also included. The thesis then integrates the findings from these studies in an overarching Meta-Study. The Meta-Study discusses key themes across all of these studies, creating an holistic report for the research program. Themes discussed in the meta-study include common issues found across the related studies; knowledge dynamics of the ERP lifecycle; ERP maintenance and support; and, the relationship between the key players in the ERP lifecycle.

An evaluation of IS-impact utility and intuitiveness

This study is conducted within the IS-Impact Research Track at Queensland University of Technology (QUT). The goal of the IS-Impact Track is, "to develop the most widely employed model for benchmarking information systems in organizations for the joint benefit of both research and practice" (Gable et al, 2006). IS-Impact is defined as "a measure at a point in time, of the stream of net benefits from the IS [Information System], to date and anticipated, as perceived by all key-user-groups" (Gable Sedera and Chan, 2008). Track efforts have yielded the bicameral IS-Impact measurement model; the "impact" half includes Organizational-Impact and Individual-Impact dimensions; the "quality" half includes System-Quality and Information-Quality dimensions. The IS-Impact model, by design, is intended to be robust, simple and generalisable, to yield results that are comparable across time, stakeholders, different systems and system contexts. The model and measurement approach employs perceptual measures and an instrument that is relevant to key stakeholder groups, thereby enabling the combination or comparison of stakeholder perspectives. Such a validated and widely accepted IS-Impact measurement model has both academic and practical value. It facilitates systematic operationalisation of a main dependent variable in research (IS-Impact), which can also serve as an important independent variable. For IS management practice it provides a means to benchmark and track the performance of information systems in use. From examination of the literature, the study proposes that IS-Impact is an Analytic Theory. Gregor (2006) defines Analytic Theory simply as theory that ‘says what is’, base theory that is foundational to all other types of theory. The overarching research question thus is "Does IS-Impact positively manifest the attributes of Analytic Theory?" In order to address this question, we must first answer the question "What are the attributes of Analytic Theory?" The study identifies the main attributes of analytic theory as: (1) Completeness, (2) Mutual Exclusivity, (3) Parsimony, (4) Appropriate Hierarchy, (5) Utility, and (6) Intuitiveness. The value of empirical research in Information Systems is often assessed along the two main dimensions - rigor and relevance. Those Analytic Theory attributes associated with the ‘rigor’ of the IS-Impact model; namely, completeness, mutual exclusivity, parsimony and appropriate hierarchy, have been addressed in prior research (e.g. Gable et al, 2008). Though common tests of rigor are widely accepted and relatively uniformly applied (particularly in relation to positivist, quantitative research), attention to relevance has seldom been given the same systematic attention. This study assumes a mainly practice perspective, and emphasises the methodical evaluation of the Analytic Theory ‘relevance’ attributes represented by the Utility and Intuitiveness of the IS-Impact model. Thus, related research questions are: "Is the IS-Impact model intuitive to practitioners?" and "Is the IS-Impact model useful to practitioners?" March and Smith (1995), identify four outputs of Design Science: constructs, models, methods and instantiations (Design Science research may involve one or more of these). IS-Impact can be viewed as a design science model, composed of Design Science constructs (the four IS-Impact dimensions and the two model halves), and instantiations in the form of management information (IS-Impact data organised and presented for management decision making). In addition to methodically evaluating the Utility and Intuitiveness of the IS-Impact model and its constituent constructs, the study aims to also evaluate the derived management information. Thus, further research questions are: "Is the IS-Impact derived management information intuitive to practitioners?" and "Is the IS-Impact derived management information useful to practitioners? The study employs a longitudinal design entailing three surveys over 4 years (the 1st involving secondary data) of the Oracle-Financials application at QUT, interspersed with focus groups involving senior financial managers. The study too entails a survey of Financials at four other Australian Universities. The three focus groups respectively emphasise: (1) the IS-Impact model, (2) the 2nd survey at QUT (descriptive), and (3) comparison across surveys within QUT, and between QUT and the group of Universities. Aligned with the track goal of producing IS-Impact scores that are highly comparable, the study also addresses the more specific utility-related questions, "Is IS-Impact derived management information a useful comparator across time?" and "Is IS-Impact derived management information a useful comparator across universities?" The main contribution of the study is evidence of the utility and intuitiveness of IS-Impact to practice, thereby further substantiating the practical value of the IS-Impact approach; and also thereby motivating continuing and further research on the validity of IS-Impact, and research employing the ISImpact constructs in descriptive, predictive and explanatory studies. The study also has value methodologically as an example of relatively rigorous attention to relevance. A further key contribution is the clarification and instantiation of the full set of analytic theory attributes.

Some applications of logic to feasibility in higher types

While it is commonly accepted that computability on a Turing machine in polynomial time represents a correct formalization of the notion of a feasibly computable function, there is no similar agreement on how to extend this notion on functionals, that is, what functionals should be considered feasible. One possible paradigm was introduced by Mehlhorn, who extended Cobham's definition of feasible functions to type 2 functionals. Subsequently, this class of functionals (with inessential changes of the definition) was studied by Townsend who calls this class POLY, and by Kapron and Cook who call the same class basic feasible functionals. Kapron and Cook gave an oracle Turing machine model characterisation of this class. In this article, we demonstrate that the class of basic feasible functionals has recursion theoretic properties which naturally generalise the corresponding properties of the class of feasible functions, thus giving further evidence that the notion of feasibility of functionals mentioned above is correctly chosen. We also improve the Kapron and Cook result on machine representation.Our proofs are based on essential applications of logic. We introduce a weak fragment of second order arithmetic with second order variables ranging over functions from NN which suitably characterises basic feasible functionals, and show that it is a useful tool for investigating the properties of basic feasible functionals. In particular, we provide an example how one can extract feasible programs from mathematical proofs that use nonfeasible functions.

Design and analysis of group key exchange protocols

A group key exchange (GKE) protocol allows a set of parties to agree upon a common secret session key over a public network. In this thesis, we focus on designing efficient GKE protocols using public key techniques and appropriately revising security models for GKE protocols. For the purpose of modelling and analysing the security of GKE protocols we apply the widely accepted computational complexity approach. The contributions of the thesis to the area of GKE protocols are manifold. We propose the first GKE protocol that requires only one round of communication and is proven secure in the standard model. Our protocol is generically constructed from a key encapsulation mechanism (KEM). We also suggest an efficient KEM from the literature, which satisfies the underlying security notion, to instantiate the generic protocol. We then concentrate on enhancing the security of one-round GKE protocols. A new model of security for forward secure GKE protocols is introduced and a generic one-round GKE protocol with forward security is then presented. The security of this protocol is also proven in the standard model. We also propose an efficient forward secure encryption scheme that can be used to instantiate the generic GKE protocol. Our next contributions are to the security models of GKE protocols. We observe that the analysis of GKE protocols has not been as extensive as that of two-party key exchange protocols. Particularly, the security attribute of key compromise impersonation (KCI) resilience has so far been ignored for GKE protocols. We model the security of GKE protocols addressing KCI attacks by both outsider and insider adversaries. We then show that a few existing protocols are not secure against KCI attacks. A new proof of security for an existing GKE protocol is given under the revised model assuming random oracles. Subsequently, we treat the security of GKE protocols in the universal composability (UC) framework. We present a new UC ideal functionality for GKE protocols capturing the security attribute of contributiveness. An existing protocol with minor revisions is then shown to realize our functionality in the random oracle model. Finally, we explore the possibility of constructing GKE protocols in the attribute-based setting. We introduce the concept of attribute-based group key exchange (AB-GKE). A security model for AB-GKE and a one-round AB-GKE protocol satisfying our security notion are presented. The protocol is generically constructed from a new cryptographic primitive called encapsulation policy attribute-based KEM (EP-AB-KEM), which we introduce in this thesis. We also present a new EP-AB-KEM with a proof of security assuming generic groups and random oracles. The EP-AB-KEM can be used to instantiate our generic AB-GKE protocol.

The use of phase in complex spectrum subtraction for robust speech recognition

In this paper we propose a new method for utilising phase information by complementing it with traditional magnitude-only spectral subtraction speech enhancement through Complex Spectrum Subtraction (CSS). The proposed approach has the following advantages over traditional magnitude-only spectral subtraction: (a) it introduces complementary information to the enhancement algorithm; (b) it reduces the total number of algorithmic parameters, and; (c) is designed for improving clean speech magnitude spectra and is therefore suitable for both automatic speech recognition (ASR) and speech perception applications. Oracle-based ASR experiments verify this approach, showing an average of 20% relative word accuracy improvements when accurate estimates of the phase spectrum are available. Based on sinusoidal analysis and assuming stationarity between observations (which is shown to be better approximated as the frame rate is increased), this paper also proposes a novel method for acquiring the phase information called Phase Estimation via Delay Projection (PEDEP). Further oracle ASR experiments validate the potential for the proposed PEDEP technique in ideal conditions. Realistic implementation of CSS with PEDEP shows performance comparable to state of the art spectral subtraction techniques in a range of 15-20 dB signal-to-noise ratio environments. These results clearly demonstrate the potential for using phase spectra in spectral subtractive enhancement applications, and at the same time highlight the need for deriving more accurate phase estimates in a wider range of noise conditions.

Encryption schemes and key exchange protocols in the certificateless setting

The contributions of this thesis fall into three areas of certificateless cryptography. The first area is encryption, where we propose new constructions for both identity-based and certificateless cryptography. We construct an n-out-of- n group encryption scheme for identity-based cryptography that does not require any special means to generate the keys of the trusted authorities that are participating. We also introduce a new security definition for chosen ciphertext secure multi-key encryption. We prove that our construction is secure as long as at least one authority is uncompromised, and show that the existing constructions for chosen ciphertext security from identity-based encryption also hold in the group encryption case. We then consider certificateless encryption as the special case of 2-out-of-2 group encryption and give constructions for highly efficient certificateless schemes in the standard model. Among these is the first construction of a lattice-based certificateless encryption scheme. Our next contribution is a highly efficient certificateless key encapsulation mechanism (KEM), that we prove secure in the standard model. We introduce a new way of proving the security of certificateless schemes based that are based on identity-based schemes. We leave the identity-based part of the proof intact, and just extend it to cover the part that is introduced by the certificateless scheme. We show that our construction is more efficient than any instanciation of generic constructions for certificateless key encapsulation in the standard model. The third area where the thesis contributes to the advancement of certificateless cryptography is key agreement. Swanson showed that many certificateless key agreement schemes are insecure if considered in a reasonable security model. We propose the first provably secure certificateless key agreement schemes in the strongest model for certificateless key agreement. We extend Swanson's definition for certificateless key agreement and give more power to the adversary. Our new schemes are secure as long as each party has at least one uncompromised secret. Our first construction is in the random oracle model and gives the adversary slightly more capabilities than our second construction in the standard model. Interestingly, our standard model construction is as efficient as the random oracle model construction.