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Data mining techniques using decision tree model in materialised projection and selection view.

Y. W. Teh (2004)

Mathware and Soft Computing

With the availability of very large data storage today, redundant data structures are no longer a big issue. However, an intelligent way of managing materialised projection and selection views that can lead to fast access of data is the central issue dealt with in this paper. A set of implementation steps for the data warehouse administrators or decision makers to improve the response time of queries is also defined. The study concludes that both attributes and tuples, are important factors to be...

Data probes, vertical trajectories and classification: a tentative study

David Pearson (2007)

International Journal of Applied Mathematics and Computer Science

In this paper we introduce a method of classification based on data probes. Data points are considered as point masses in space and a probe is simply a particle that is launched into the space. As the probe passes by data clusters, its trajectory will be influenced by the point masses. We use this information to help us to find vertical trajectories. These are trajectories in the input space that are mapped onto the same value in the output space and correspond to the data classes.

Data types as algorithms

M. A. Nait Abdallah (1984)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Data-driven models for fault detection using kernel PCA: A water distribution system case study

Adam Nowicki, Michał Grochowski, Kazimierz Duzinkiewicz (2012)

International Journal of Applied Mathematics and Computer Science

Kernel Principal Component Analysis (KPCA), an example of machine learning, can be considered a non-linear extension of the PCA method. While various applications of KPCA are known, this paper explores the possibility to use it for building a data-driven model of a non-linear system-the water distribution system of the Chojnice town (Poland). This model is utilised for fault detection with the emphasis on water leakage detection. A systematic description of the system's framework is followed by...

Decidability of code properties

Henning Fernau, Klaus Reinhardt, Ludwig Staiger (2007)

RAIRO - Theoretical Informatics and Applications

We explore the borderline between decidability and undecidability of the following question: “Let C be a class of codes. Given a machine 𝔐 of type X, is it decidable whether the language L ( 𝔐 ) lies in C or not?” for codes in general, ω-codes, codes of finite and bounded deciphering delay, prefix, suffix and bi(pre)fix codes, and for finite automata equipped with different versions of push-down stores and counters.

Deciding inclusion of set constants over infinite non-strict data structures

Manfred Schmidt-Schauss, David Sabel, Marko Schütz (2007)

RAIRO - Theoretical Informatics and Applications

Various static analyses of functional programming languages that permit infinite data structures make use of set constants like Top, Inf, and Bot, denoting all terms, all lists not eventually ending in Nil, and all non-terminating programs, respectively. We use a set language that permits union, constructors and recursive definition of set constants with a greatest fixpoint semantics in the set of all, also infinite, computable trees, where all term constructors are non-strict. This...

Deciding knowledge in security protocols under some e-voting theories

Mouhebeddine Berrima, Narjes Ben Rajeb, Véronique Cortier (2011)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

In the last decade, formal methods have proved their interest when analyzing security protocols. Security protocols require in particular to reason about the attacker knowledge. Two standard notions are often considered in formal approaches: deducibility and indistinguishability relations. The first notion states whether an attacker can learn the value of a secret, while the latter states whether an attacker can notice some difference between protocol runs with different values of the secret. Several...

Deciding knowledge in security protocols under some e-voting theories

Mouhebeddine Berrima, Narjes Ben Rajeb, Véronique Cortier (2011)

RAIRO - Theoretical Informatics and Applications

In the last decade, formal methods have proved their interest when analyzing security protocols. Security protocols require in particular to reason about the attacker knowledge. Two standard notions are often considered in formal approaches: deducibility and indistinguishability relations. The first notion states whether an attacker can learn the value of a secret, while the latter states whether an attacker can notice some difference between protocol runs with different values of the secret. Several...

Deciding whether a relation defined in Presburger logic can be defined in weaker logics

Christian Choffrut (2008)

RAIRO - Theoretical Informatics and Applications

We consider logics on ℤ and ℕ which are weaker than Presburger arithmetic and we settle the following decision problem: given a k-ary relation on ℤ and ℕ which are first order definable in Presburger arithmetic, are they definable in these weaker logics? These logics, intuitively, are obtained by considering modulo and threshold counting predicates for differences of two variables.

Decimations and sturmian words

Jacques Justin, Giuseppe Pirillo (1997)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Decision problems among the main subfamilies of rational relations

Olivier Carton, Christian Choffrut, Serge Grigorieff (2006)

RAIRO - Theoretical Informatics and Applications

We consider the four families of recognizable, synchronous, deterministic rational and rational subsets of a direct product of free monoids. They form a strict hierarchy and we investigate the following decision problem: given a relation in one of the families, does it belong to a smaller family? We settle the problem entirely when all monoids have a unique generator and fill some gaps in the general case. In particular, adapting a proof of Stearns, we show that it is recursively decidable whether...

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