The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform

M.a. Wickert - One of the best experts on this subject based on the ideXlab platform.

  • Direct-sequence spread-spectrum using directionally constrained adaptive beam forming to null interference
    IEEE Journal on Selected Areas in Communications, 1995
    Co-Authors: M.a. Jones, M.a. Wickert
    Abstract:

    A direct-sequence spread-spectrum communication System using an adaptive antenna array to null interference is examined. The System model is a modification of Compton's (1978) System, using a digital implementation and a directional constraint. Computer simulations are used to compare the behavior of the directionally constrained model with Compton's model with emphasis on spread-spectrum code synchronization. In the Directed System, nulling of a tone jammer occurs without respect to direct-sequence code acquisition, and nulling of an off-beam desired signal occurs very slowly. Theoretical results are obtained by using the System covariance matrix, and incorporating the effects of spread-spectrum filtering to compute the System response as a function of time. The simulated results indicate that incomplete directional knowledge may be exploited to enhance signal quality and speed up code acquisition.

  • Directionally constrained adaptive beam forming to enhance interference nulling in direct-sequence spread-spectrum communication Systems
    Proceedings of MILCOM '93 - IEEE Military Communications Conference, 1993
    Co-Authors: M.a. Jones, M.a. Wickert
    Abstract:

    The authors examine a direct-sequence spread-spectrum communication System using an adaptive antenna array to null interference. The System model is a modification of Compton's (1990) System, using a digital implementation and a directional constraint. One of the primary roles of spread-spectrum modulation in the System is to remove the desired signal from the adaptive beam forming process. The simulated results of this Directed System indicate that nulling of a tone jammer occurs without respect to direct-sequence code acquisition and that nulling of the desired signal occurs very slowly. Theoretical results are also obtained by using the System covariance matrix, and incorporating the effects of spread-spectrum filtering, to compute the System response as a function of time. These results show that the System may be made to null the jammer quickly and consistently, by using the auxiliary beam output power as a parameter in the least mean-squares (LMS) adaptive beam-forming algorithm.

M.a. Jones - One of the best experts on this subject based on the ideXlab platform.

  • Direct-sequence spread-spectrum using directionally constrained adaptive beam forming to null interference
    IEEE Journal on Selected Areas in Communications, 1995
    Co-Authors: M.a. Jones, M.a. Wickert
    Abstract:

    A direct-sequence spread-spectrum communication System using an adaptive antenna array to null interference is examined. The System model is a modification of Compton's (1978) System, using a digital implementation and a directional constraint. Computer simulations are used to compare the behavior of the directionally constrained model with Compton's model with emphasis on spread-spectrum code synchronization. In the Directed System, nulling of a tone jammer occurs without respect to direct-sequence code acquisition, and nulling of an off-beam desired signal occurs very slowly. Theoretical results are obtained by using the System covariance matrix, and incorporating the effects of spread-spectrum filtering to compute the System response as a function of time. The simulated results indicate that incomplete directional knowledge may be exploited to enhance signal quality and speed up code acquisition.

  • Directionally constrained adaptive beam forming to enhance interference nulling in direct-sequence spread-spectrum communication Systems
    Proceedings of MILCOM '93 - IEEE Military Communications Conference, 1993
    Co-Authors: M.a. Jones, M.a. Wickert
    Abstract:

    The authors examine a direct-sequence spread-spectrum communication System using an adaptive antenna array to null interference. The System model is a modification of Compton's (1990) System, using a digital implementation and a directional constraint. One of the primary roles of spread-spectrum modulation in the System is to remove the desired signal from the adaptive beam forming process. The simulated results of this Directed System indicate that nulling of a tone jammer occurs without respect to direct-sequence code acquisition and that nulling of the desired signal occurs very slowly. Theoretical results are also obtained by using the System covariance matrix, and incorporating the effects of spread-spectrum filtering, to compute the System response as a function of time. These results show that the System may be made to null the jammer quickly and consistently, by using the auxiliary beam output power as a parameter in the least mean-squares (LMS) adaptive beam-forming algorithm.

Abdel Belaïd - One of the best experts on this subject based on the ideXlab platform.

  • ICDAR - A syntax Directed System for the recognition of printed Arabic mathematical formulas
    2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015
    Co-Authors: Kaouther Khazri Ayeb, Afef Kacem Echi, Abdel Belaïd
    Abstract:

    In this paper we addressed the problem of Arabic mathematical formula recognition, extracted from scanned images of clearly printed documents. Two main stages are followed by the proposed System: symbol recognition and structural analysis of the mathematical formula. For the first stage, our System uses a combination of different statistical features like Run length, Hu and Zernike moments, Bi-level co-occurrence and white pixel's portion and an instance-based classifier K*. High accuracy for the recognition of isolated mathematical symbols is achieved. In the second stage, the System proceeds by top-down and bottom-up parsing scheme based on operator dominance. A set of replacement rules is defined by a coordinate grammar based on symbol recognition and symbol arrangement analysis results. In the proposed System, the recognition and parsing modules interact more closely. Thus, we can use the context information collected during structural analysis to help us guess about the symbols, overcoming our incorrect assumption of perfect symbol recognition. The System provides output in MathML which is easily transmitted for subsequent processing by computer algebra Systems. The syntax-Directed recognition System, described here, has been successfully demonstrated in many types of formulas and achieved satisfactory results. 91% of formulas are correctly recognized.

  • A syntax Directed System for the recognition of printed Arabic mathematical formulas
    2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015
    Co-Authors: Kaouther Khazri Ayeb, Afef Kacem Echi, Abdel Belaïd
    Abstract:

    In this paper we addressed the problem of Arabic mathematical formula recognition, extracted from scanned images of clearly printed documents. Two main stages are followed by the proposed System: symbol recognition and structural analysis of the mathematical formula. For the first stage, our System uses a combination of different statistical features like Run length, Hu and Zernike moments, Bi-level co-occurrence and white pixel's portion and an instance-based classifier K*. High accuracy for the recognition of isolated mathematical symbols is achieved. In the second stage, the System proceeds by top-down and bottom-up parsing scheme based on operator dominance. A set of replacement rules is defined by a coordinate grammar based on symbol recognition and symbol arrangement analysis results. In the proposed System, the recognition and parsing modules interact more closely. Thus, we can use the context information collected during structural analysis to help us guess about the symbols, overcoming our incorrect assumption of perfect symbol recognition. The System provides output in MathML which is easily transmitted for subsequent processing by computer algebra Systems. The syntax-Directed recognition System, described here, has been successfully demonstrated in many types of formulas and achieved satisfactory results. 91% of formulas are correctly recognized.

Kaouther Khazri Ayeb - One of the best experts on this subject based on the ideXlab platform.

  • ICDAR - A syntax Directed System for the recognition of printed Arabic mathematical formulas
    2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015
    Co-Authors: Kaouther Khazri Ayeb, Afef Kacem Echi, Abdel Belaïd
    Abstract:

    In this paper we addressed the problem of Arabic mathematical formula recognition, extracted from scanned images of clearly printed documents. Two main stages are followed by the proposed System: symbol recognition and structural analysis of the mathematical formula. For the first stage, our System uses a combination of different statistical features like Run length, Hu and Zernike moments, Bi-level co-occurrence and white pixel's portion and an instance-based classifier K*. High accuracy for the recognition of isolated mathematical symbols is achieved. In the second stage, the System proceeds by top-down and bottom-up parsing scheme based on operator dominance. A set of replacement rules is defined by a coordinate grammar based on symbol recognition and symbol arrangement analysis results. In the proposed System, the recognition and parsing modules interact more closely. Thus, we can use the context information collected during structural analysis to help us guess about the symbols, overcoming our incorrect assumption of perfect symbol recognition. The System provides output in MathML which is easily transmitted for subsequent processing by computer algebra Systems. The syntax-Directed recognition System, described here, has been successfully demonstrated in many types of formulas and achieved satisfactory results. 91% of formulas are correctly recognized.

  • A syntax Directed System for the recognition of printed Arabic mathematical formulas
    2015 13th International Conference on Document Analysis and Recognition (ICDAR), 2015
    Co-Authors: Kaouther Khazri Ayeb, Afef Kacem Echi, Abdel Belaïd
    Abstract:

    In this paper we addressed the problem of Arabic mathematical formula recognition, extracted from scanned images of clearly printed documents. Two main stages are followed by the proposed System: symbol recognition and structural analysis of the mathematical formula. For the first stage, our System uses a combination of different statistical features like Run length, Hu and Zernike moments, Bi-level co-occurrence and white pixel's portion and an instance-based classifier K*. High accuracy for the recognition of isolated mathematical symbols is achieved. In the second stage, the System proceeds by top-down and bottom-up parsing scheme based on operator dominance. A set of replacement rules is defined by a coordinate grammar based on symbol recognition and symbol arrangement analysis results. In the proposed System, the recognition and parsing modules interact more closely. Thus, we can use the context information collected during structural analysis to help us guess about the symbols, overcoming our incorrect assumption of perfect symbol recognition. The System provides output in MathML which is easily transmitted for subsequent processing by computer algebra Systems. The syntax-Directed recognition System, described here, has been successfully demonstrated in many types of formulas and achieved satisfactory results. 91% of formulas are correctly recognized.

Michael Luck - One of the best experts on this subject based on the ideXlab platform.

  • The Contract Net as a Goal Directed System
    Springer Series on Agent Technology, 2020
    Co-Authors: Mark D'inverno, Michael Luck
    Abstract:

    The models defined in smart provide a structure that can be applied directly to describe and analyse multi-agent Systems and theories, and to derive models that highlight relevant aspects. In this chapter, the path from the initial smart framework to the modelling of such specific Systems is completed by describing a mechanism for implementing the contract net protocol.

  • MAAMAW - Formalising the contract net as a goal-Directed System
    Lecture Notes in Computer Science, 1996
    Co-Authors: Mark D'inverno, Michael Luck
    Abstract:

    In response to the problems that have arisen regarding the terminology and concepts of agent-oriented Systems, previous work has described a formal framework for understanding agency and autonomy. In this paper we outline the framework and refine it by adding further levels of detail to develop a formal model of the Contract Net Protocol. The model serves to make precise both the operations of nodes in the contract net, and the state of the net at various points during the protocol. In particular, the nature of the dependencies between the nodes in the net is explicated. Finally, we generalise the relationships that can be found in the contract net which are brought out by the formalisation, and introduce more general concepts such as cooperation and engagement.