The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform

Sujit Samaddar - One of the best experts on this subject based on the ideXlab platform.

  • Case Study: Effect of Soil-Structure Interaction and Ground Motion Incoherency on Nuclear Power Plant Structures
    Volume 8: Seismic Engineering, 2009
    Co-Authors: Sujit Samaddar
    Abstract:

    The soil-Structure interaction (SSI) has a significant impact on nuclear power plant (NPP) Structures, especially for massive and rigid Structures Founded on soils, such as containments. The U.S. Nuclear Regulatory Commission’s (NRC) Standard Review Plan (SRP) provides the requirement and acceptance criteria for incorporating the SSI effect in the seismic design and analyses of NPP Structures. The NRC staff uses the SRP for safety review of license applications. Recent studies have indicated that ground motions in recorded real earthquake events have exhibited spatial incoherency in high-frequency contents. Several techniques have been developed to incorporate the incoherency effect in the seismic response analyses. Section 3.7.2 of Revision 3 of the SRP also provided guidance for use in the safety evaluation of seismic analyses considering ground motion spatial incoherency effect. This paper describes a case study of the SSI and incoherency effects on seismic response analyses of NPP Structures. The study selected a typical containment Structure. The SSI model is generated based on the typical industry practice for SSI computation of containment Structures. Specifically, a commercial version of SASSI was used for the study, which considered a surface-Founded Structure. The SSI model includes the foundation, represented with brick elements, and the superStructure, represented using lumped mass and beams. The study considered various soil conditions and ground motion coherency functions to investigate the effect of the range of soil stiffness and the ground motion incoherency effect on SSI in determining the seismic response of the Structures. This paper describes the SSI model development and presents the analysis results as well as insights into the manner in which the SSI and incoherency effects are related to different soil conditions.

  • Case Study: Effect of SSI and Ground Motion Incoherency on NPP Structures
    2009
    Co-Authors: Sujit Samaddar
    Abstract:

    It has been recognized that the soil-Structure interaction (SSI) has significant impact on nuclear power plant (NPP) Structures, especially for massive and rigid Structures Founded on soils such as containments. Requirement and acceptance criteria for incorporating the SSI effect in the seismic design and analyses of NPP Structures are provided in the Nuclear Regulatory Commission (NRC) standard review plan (SRP), which the NRC staff uses for safety review of license applications. Recent studies have indicated that ground motions in recorded real earthquake events have exhibited spatial incoherency in high frequency contents. Several techniques have been developed to incorporate the incoherency effect in the seismic response analyses. Section 3.7.2 of SRP, rev.3 also provided guidance foe use in safety evaluation of seismic analyses considering ground motion spatial incoherency effect. This paper describes a case study of the SSI and incoherency effects on seismic response analyses of NPP Structures. A typical containment Structure is selected for the study. The SSI model is generated based on the typical industry practice for SSI computation of containment Structures. Specifically, a commercial version of SASSI was used for the study and surface Founded Structure considered. The SSI model includes the foundation represented with brick elements and the superStructure represented using lumped mass and beams. Various soil conditions and ground motion coherency functions are considered to investigate the effect of the range of soil stiffness and ground motion incoherency effect on SSI in determining the seismic response of the Structures. This paper provides a description SSI model development and presents the analysis results, as well as insights into the manner in which the SSI and incoherency effects are related to different soil conditions.

E. V. Krishnamurthy - One of the best experts on this subject based on the ideXlab platform.

  • International Conference on Computational Science - Problems and prospects for quantum computational speed-up
    Lecture Notes in Computer Science, 2003
    Co-Authors: E. V. Krishnamurthy
    Abstract:

    This paper studies the problems involved in the speed-up of the classical computational algorithms using the quantum computational paradigm. In particular, we relate the primitive recursive function approach used in computability theory with the harmonic oscillator basis used in quantum physics. Also, we raise some basic issues concerning quantum computational paradigm: these include failures in programmability and scalability, limitation on the size of the decoherence - free space available and lack of methods for proving quantum programs correct. In computer science, time is discrete and has a well-Founded Structure. But in physics, time is a real number, continuous and is infinitely divisible; also time can have a fractal dimension. As a result, the time complexity measures for conventional and quantum computation are incomparable. Proving properties of programs and termination rest heavily on the well-Founded properties, and the transfinite induction principle. Hence transfinite induction is not applicable to reason about quantum programs.

Donal Smith - One of the best experts on this subject based on the ideXlab platform.

  • COSMO: A new COre Structural MOdel for Ireland
    2017
    Co-Authors: Adele Bergin, Niall Conroy, Abian Garcia Rodriguez, Dawn Holland, Niall Mcinerney, Edgar Morgenroth, Donal Smith
    Abstract:

    COSMO is a new structural econometric model of the Irish economy, with a theoretically Founded Structure and specification. It is designed to be used for medium-term economic projections and policy analysis. This paper outlines the key mechanisms in the model and explores the behaviour of the model by examining a range of shocks. One of the key contributions of COSMO is the incorporation of financial frictions in a small open economy model. The behavioural equations in COSMO are estimated econometrically, and the second contribution of the model relates to how all available information at both annual and quarterly frequency is exploited in estimation, applying a novel technique to convert dynamics estimated at one frequency into the other.

Adele Bergin - One of the best experts on this subject based on the ideXlab platform.

  • COSMO: A new COre Structural MOdel for Ireland
    2017
    Co-Authors: Adele Bergin, Niall Conroy, Abian Garcia Rodriguez, Dawn Holland, Niall Mcinerney, Edgar Morgenroth, Donal Smith
    Abstract:

    COSMO is a new structural econometric model of the Irish economy, with a theoretically Founded Structure and specification. It is designed to be used for medium-term economic projections and policy analysis. This paper outlines the key mechanisms in the model and explores the behaviour of the model by examining a range of shocks. One of the key contributions of COSMO is the incorporation of financial frictions in a small open economy model. The behavioural equations in COSMO are estimated econometrically, and the second contribution of the model relates to how all available information at both annual and quarterly frequency is exploited in estimation, applying a novel technique to convert dynamics estimated at one frequency into the other.

Gerard ’t hooft - One of the best experts on this subject based on the ideXlab platform.

  • On the Foundations of Superstring Theory
    Foundations of Physics, 2013
    Co-Authors: Gerard ’t hooft
    Abstract:

    Superstring theory is an extension of conventional quantum field theory that allows for stringlike and branelike material objects besides pointlike particles. The basic foundations on which the theory is built are amazingly shaky, and, equally amazingly, it seems to be this lack of solid foundations to which the theory owes its strength. We emphasize that such a situation is legitimate only in the development phases of a new doctrine. Eventually, a more solidly Founded Structure must be sought. Although it is advertised as a “candidate theory of quantum gravity”, we claim that string theory may not be exactly that. Rather, just like quantum field theory itself, it is a general mathematical framework for a class of theories. Its major flaw could be that it still embraces a Copenhagen view on the relation between quantum mechanics and reality, while any “theory of everything”, that is, a theory for the entire cosmos, should do better than that.