The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Sergei Nirenburg - One of the best experts on this subject based on the ideXlab platform.

  • Ontological Semantics
    MIT Press, 2004
    Co-Authors: Sergei Nirenburg, Victor Raskin
    Abstract:

    This book introduces ontological semantics, a comprehensive approach to the treatment of text meaning by computer. Ontological semantics is an integrated complex of theories, methodologies, descriptions and implementations. In ontological semantics, a theory is viewed as a set of statements determining the format of descriptions of the phenomena with which the theory deals. A theory is associated with a methodology used to obtain the descriptions. Implementations are computer systems that use the descriptions to solve specific problems in text processing. Implementations of ontological semantics are combined with other processing systems to produce applications, such as information extraction or machine translation. The theory of ontological semantics is built as a society of Microtheories covering such diverse ground as specific language phenomena, world knowledge organization, processing heuristics and issues relating to knowledge representation and implementation system architecture. The theory briefly sketched above is a top-level microtheory, the ontological semantics theory per se. Descriptions in ontological semantics include text meaning representations, lexical entries, ontological concepts and instances as well as procedures for manipulating texts and their meanings. Methodologies in ontological semantics are sets of techniques and instructions for acquiring an

  • Adjectival Modification in Text Meaning Representation Victor Raskin and Sergei Nirenburg
    1996
    Co-Authors: Computing Research Laboratory, Victor Raskin, Sergei Nirenburg
    Abstract:

    Tiffs work belongs to a family of research cfforts, called microtleories and aimed at describing the static mereting of all lexical categories in several lang. uages in the fr,-unework of the MikroKosnos project on computational semantics. The latter also involves other static Microtheories describ- ing word knowledge and syntax-semantics mapping as well as dynamic microtleorics comected with the actual process of text analysis. Tiffs paper describes our approach to detecting ,'red recording adjectival meaning, colnpares it with the body of lmowledgc on adjectives in literattire and presents a detailed, practically tested methodology for the acquisition of lexical entries for adjcc- fives, The work was based on the set of over 6,000 English and about 1,500 Spinfish adjectives obtained from task-oriented corpora

  • Lexical Rules for Deverbal Adjectives
    1996
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    This work belongs to a family of research efforts, called Microtheories and aimed at describing the static meaning of all lexical categories in several languages in the framework of the MikroKosmos project on computational semantics. The latter also involves other static Microtheories describing world knowledge and syntax-semantics mapping as well as dynamic Microtheories connected with the actual process of text analysis. This pape

  • Adjectival Modification in Text Meaning Represention
    1996
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    Tiffs work belongs to a family of research efforts, called nficrotheories and aimed at describing the static inemfing of all lexical categories in several languages in the fr,'unework of tile MikroKosmos project on computational semantics. The latter also involves other static Microtheories describ-ing world kalowledge and syntax-semantics map-ping as well as dynamic Microtheories comlected with the actual process of text analysis. Tiffs pa-per describes our approach to detecting,'rod re-cording adjectival meaning, compares it with the body of kalowledge on adjectives in literature and presents a detailed, practically tested methodolo-gy for the acquisition of lexical entries for adjec-fives. The work was based on the set of over 6,000 English and about 1,500 Spanish adjectives obtained from task-oriented corpora

  • Lexical Semantics of Adjectives: A Microtheory Of Adjectival Meaning
    1995
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    . This work belongs to a family of research efforts, called Microtheories and aimed at describing the static meaning of all lexical categories in several languages in the framework of the MikroKosmos project on computational semantics. The latter also involves other static Microtheories describing world knowledge and syntax-semantics mapping as well as dynamic Microtheories connected with the actual process of text analysis. This paper describes our approach to determining and representing adjectival meaning, compares it with the body of knowledge on adjectives in literature and presents a detailed, practically tested methodology and heuristics for the acquisition of lexical entries for adjectives. The work was based on the set of over 6,000 English and about 1,500 Spanish adjectives obtained from task-oriented corpora. Introduction The topic of this paper is the information about adjectival meaning which should be included in a computational lexicon. Thus, we concentrate on..

Edward C Prescott - One of the best experts on this subject based on the ideXlab platform.

  • a reassessment of real business cycle theory
    The American Economic Review, 2014
    Co-Authors: Ellen R Mcgrattan, Edward C Prescott
    Abstract:

    During the downturn of 2008–2009, output and hours fell significantly while labor productivity rose. These facts have led many to conclude that there is a significant deviation between observations and current macrotheories that assume business cycles are driven, at least in part, by fluctuations in total factor productivities of firms. We show that once investment in intangible capital is included in the analysis, there is no inconsistency. Measured labor productivity rises if the fall in output is underestimated; this occurs when there are large unmeasured intangible investments. Microevidence suggests that these investments are large and cyclically important.

  • a reassessment of real business cycle theory
    Research Papers in Economics, 2014
    Co-Authors: Ellen R Mcgrattan, Edward C Prescott
    Abstract:

    During the downturn of 2008–2009, output and hours fell significantly, but labor productivity rose. These facts have led many to conclude that there is a significant deviation between observations and current macrotheories that assume business cycles are driven, at least in part, by fluctuations in total factor productivities of firms. We show that once investment in intangible capital is included in the analysis, there is no inconsistency. Measured labor productivity rises if the fall in output is underestimated; this occurs when there are large unmeasured intangible investments. Microevidence suggests that these investments are large and cyclically important.

Victor Raskin - One of the best experts on this subject based on the ideXlab platform.

  • Ontological Semantics
    MIT Press, 2004
    Co-Authors: Sergei Nirenburg, Victor Raskin
    Abstract:

    This book introduces ontological semantics, a comprehensive approach to the treatment of text meaning by computer. Ontological semantics is an integrated complex of theories, methodologies, descriptions and implementations. In ontological semantics, a theory is viewed as a set of statements determining the format of descriptions of the phenomena with which the theory deals. A theory is associated with a methodology used to obtain the descriptions. Implementations are computer systems that use the descriptions to solve specific problems in text processing. Implementations of ontological semantics are combined with other processing systems to produce applications, such as information extraction or machine translation. The theory of ontological semantics is built as a society of Microtheories covering such diverse ground as specific language phenomena, world knowledge organization, processing heuristics and issues relating to knowledge representation and implementation system architecture. The theory briefly sketched above is a top-level microtheory, the ontological semantics theory per se. Descriptions in ontological semantics include text meaning representations, lexical entries, ontological concepts and instances as well as procedures for manipulating texts and their meanings. Methodologies in ontological semantics are sets of techniques and instructions for acquiring an

  • Adjectival Modification in Text Meaning Representation Victor Raskin and Sergei Nirenburg
    1996
    Co-Authors: Computing Research Laboratory, Victor Raskin, Sergei Nirenburg
    Abstract:

    Tiffs work belongs to a family of research cfforts, called microtleories and aimed at describing the static mereting of all lexical categories in several lang. uages in the fr,-unework of the MikroKosnos project on computational semantics. The latter also involves other static Microtheories describ- ing word knowledge and syntax-semantics mapping as well as dynamic microtleorics comected with the actual process of text analysis. Tiffs paper describes our approach to detecting ,'red recording adjectival meaning, colnpares it with the body of lmowledgc on adjectives in literattire and presents a detailed, practically tested methodology for the acquisition of lexical entries for adjcc- fives, The work was based on the set of over 6,000 English and about 1,500 Spinfish adjectives obtained from task-oriented corpora

  • Lexical Rules for Deverbal Adjectives
    1996
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    This work belongs to a family of research efforts, called Microtheories and aimed at describing the static meaning of all lexical categories in several languages in the framework of the MikroKosmos project on computational semantics. The latter also involves other static Microtheories describing world knowledge and syntax-semantics mapping as well as dynamic Microtheories connected with the actual process of text analysis. This pape

  • Adjectival Modification in Text Meaning Represention
    1996
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    Tiffs work belongs to a family of research efforts, called nficrotheories and aimed at describing the static inemfing of all lexical categories in several languages in the fr,'unework of tile MikroKosmos project on computational semantics. The latter also involves other static Microtheories describ-ing world kalowledge and syntax-semantics map-ping as well as dynamic Microtheories comlected with the actual process of text analysis. Tiffs pa-per describes our approach to detecting,'rod re-cording adjectival meaning, compares it with the body of kalowledge on adjectives in literature and presents a detailed, practically tested methodolo-gy for the acquisition of lexical entries for adjec-fives. The work was based on the set of over 6,000 English and about 1,500 Spanish adjectives obtained from task-oriented corpora

  • Lexical Semantics of Adjectives: A Microtheory Of Adjectival Meaning
    1995
    Co-Authors: Victor Raskin, Sergei Nirenburg
    Abstract:

    . This work belongs to a family of research efforts, called Microtheories and aimed at describing the static meaning of all lexical categories in several languages in the framework of the MikroKosmos project on computational semantics. The latter also involves other static Microtheories describing world knowledge and syntax-semantics mapping as well as dynamic Microtheories connected with the actual process of text analysis. This paper describes our approach to determining and representing adjectival meaning, compares it with the body of knowledge on adjectives in literature and presents a detailed, practically tested methodology and heuristics for the acquisition of lexical entries for adjectives. The work was based on the set of over 6,000 English and about 1,500 Spanish adjectives obtained from task-oriented corpora. Introduction The topic of this paper is the information about adjectival meaning which should be included in a computational lexicon. Thus, we concentrate on..

Ellen R Mcgrattan - One of the best experts on this subject based on the ideXlab platform.

  • a reassessment of real business cycle theory
    The American Economic Review, 2014
    Co-Authors: Ellen R Mcgrattan, Edward C Prescott
    Abstract:

    During the downturn of 2008–2009, output and hours fell significantly while labor productivity rose. These facts have led many to conclude that there is a significant deviation between observations and current macrotheories that assume business cycles are driven, at least in part, by fluctuations in total factor productivities of firms. We show that once investment in intangible capital is included in the analysis, there is no inconsistency. Measured labor productivity rises if the fall in output is underestimated; this occurs when there are large unmeasured intangible investments. Microevidence suggests that these investments are large and cyclically important.

  • a reassessment of real business cycle theory
    Research Papers in Economics, 2014
    Co-Authors: Ellen R Mcgrattan, Edward C Prescott
    Abstract:

    During the downturn of 2008–2009, output and hours fell significantly, but labor productivity rose. These facts have led many to conclude that there is a significant deviation between observations and current macrotheories that assume business cycles are driven, at least in part, by fluctuations in total factor productivities of firms. We show that once investment in intangible capital is included in the analysis, there is no inconsistency. Measured labor productivity rises if the fall in output is underestimated; this occurs when there are large unmeasured intangible investments. Microevidence suggests that these investments are large and cyclically important.

Helbing Dirk - One of the best experts on this subject based on the ideXlab platform.

  • Random Deviations Improve Micro-Macro Predictions: An Empirical Test
    'SAGE Publications', 2020
    Co-Authors: Maes Michael, Helbing Dirk
    Abstract:

    Many sociological theories make critically different macropredictions when their microassumptions are implemented stochastically rather than deterministically. Deviations from individuals’ behavioral patterns described by Microtheories can spark cascades that change macrooutcomes, even when deviations are rare and random. With two experiments, we empirically tested whether macrophenomena can be critically shaped by random deviations. Ninety-six percent of participants’ decisions were in line with a deterministic theory of bounded rationality. Despite this impressive microlevel accuracy, the deterministic model failed to predict the observed macrooutcomes. However, a stochastic version of the same microtheory largely improved macropredictions. The stochastic model also correctly predicted the conditions under which deviations mattered. Results also supported the hypothesis that nonrandom deviations can result in fundamentally different macrooutcomes than random deviations. In conclusion, we echo the warning that deterministic Microtheories can be misleading. Our findings show that taking into account deviations in sociological theories can improve explanations and predictions