The Experts below are selected from a list of 10101 Experts worldwide ranked by ideXlab platform

Donald L Simon - One of the best experts on this subject based on the ideXlab platform.

  • kalman Filter Constraint switching for turbofan engine health estimation
    European Journal of Control, 2006
    Co-Authors: Dan Simon, Donald L Simon
    Abstract:

    Kalman Filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman Filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable Constraints are often neglected because they do not fit easily into the structure of the Kalman Filter. Recently published work has shown a new method for incorporating state variable inequality Constraints in the Kalman Filter, which has been shown to generally improve the Filter s estimation accuracy. However, the incorporation of inequality Constraints poses some risk to the estimation accuracy as the Kalman Filter is theoretically optimal. This paper proposes a way to tune the Filter Constraints so that the state estimates follow the unconstrained (theoretically optimal) Filter when the confidence in the unconstrained Filter is high. When confidence in the unconstrained Filter is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.

Dan Simon - One of the best experts on this subject based on the ideXlab platform.

  • kalman Filter Constraint switching for turbofan engine health estimation
    European Journal of Control, 2006
    Co-Authors: Dan Simon, Donald L Simon
    Abstract:

    Kalman Filters are often used to estimate the state variables of a dynamic system. However, in the application of Kalman Filters some known signal information is often either ignored or dealt with heuristically. For instance, state variable Constraints are often neglected because they do not fit easily into the structure of the Kalman Filter. Recently published work has shown a new method for incorporating state variable inequality Constraints in the Kalman Filter, which has been shown to generally improve the Filter s estimation accuracy. However, the incorporation of inequality Constraints poses some risk to the estimation accuracy as the Kalman Filter is theoretically optimal. This paper proposes a way to tune the Filter Constraints so that the state estimates follow the unconstrained (theoretically optimal) Filter when the confidence in the unconstrained Filter is high. When confidence in the unconstrained Filter is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.

Bahaj Mohamed - One of the best experts on this subject based on the ideXlab platform.

  • Query Migration from Object Oriented World to Semantic World
    'Universidad Internacional de La Rioja', 2021
    Co-Authors: Soussi Nassima, Bahaj Mohamed
    Abstract:

    — In the last decades, object-oriented approach was able to take a large share of databases market aiming to design and implement structured and reusable software through the composition of independent elements in order to have programs with a high performance. On the other hand, the mass of information stored in the web is increasing day after day with a vertiginous speed, exposing the currently web faced with the problem of creating a bridge so as to facilitate access to data between different applications and systems as well as to look for relevant and exact information wished by users. In addition, all existing approach of rewriting object oriented languages to SPARQL language rely on models transformation process to guarantee this mapping. All the previous raisons has prompted us to write this paper in order to bridge an important gap between these two heterogeneous worlds (object oriented and semantic web world) by proposing the first provably semantics preserving OQLto-SPARQL translation algorithm for each element of OQL Query (SELECT clause, FROM clause, Filter Constraint, implicit/ explicit join and union/intersection SELECT queries)

Soussi Nassima - One of the best experts on this subject based on the ideXlab platform.

  • Query Migration from Object Oriented World to Semantic World
    'Universidad Internacional de La Rioja', 2021
    Co-Authors: Soussi Nassima, Bahaj Mohamed
    Abstract:

    — In the last decades, object-oriented approach was able to take a large share of databases market aiming to design and implement structured and reusable software through the composition of independent elements in order to have programs with a high performance. On the other hand, the mass of information stored in the web is increasing day after day with a vertiginous speed, exposing the currently web faced with the problem of creating a bridge so as to facilitate access to data between different applications and systems as well as to look for relevant and exact information wished by users. In addition, all existing approach of rewriting object oriented languages to SPARQL language rely on models transformation process to guarantee this mapping. All the previous raisons has prompted us to write this paper in order to bridge an important gap between these two heterogeneous worlds (object oriented and semantic web world) by proposing the first provably semantics preserving OQLto-SPARQL translation algorithm for each element of OQL Query (SELECT clause, FROM clause, Filter Constraint, implicit/ explicit join and union/intersection SELECT queries)

Peter Van Roy - One of the best experts on this subject based on the ideXlab platform.

  • practical uses of Constraint programming in music using relation domains
    Emille journal, 2013
    Co-Authors: Sascha Van Cauwelaert, Gustavo Adolfo Gutierrez Sabogal, Peter Van Roy
    Abstract:

    The use of Constraint Programming in Music is not new and is still very active today. This paper presents some advances and examples in the use of a completely new approach, Constraint programming in music using relation domains. It defines a new high‐level Constraint, the Filter Constraint. This Constraint is used in the modeling of a musical problem, the harmonized round problem. The paper presents the modeling of this problem and of some variants. In addition, another section describes a new concept, the constrained rewriting system. Its use is promising for some future practices in computer‐aided composition. Rewriting systems have indeed been used in music for a long time and this new approach allows constraining those structures: production results and production rules can be constrained in order to ensure some desired properties. Some preliminary results are given regarding this new concept.