• Title/Summary/Keyword: Quantum Mechanics

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A Study on Distributed Particle Swarm Optimization Algorithm with Quantum-infusion Mechanism (Quantum-infusion 메커니즘을 이용한 분산형 입자군집최적화 알고리즘에 관한 연구)

  • Song, Dong-Ho;Lee, Young-Il;Kim, Tae-Hyoung
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.4
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    • pp.527-531
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    • 2012
  • In this paper, a novel DPSO-QI (Distributed PSO with quantum-infusion mechanism) algorithm improving one of the fatal defect, the so-called premature convergence, that degrades the performance of the conventional PSO algorithms is proposed. The proposed scheme has the following two distinguished features. First, a concept of neighborhood of each particle is introduced, which divides the whole swarm into several small groups with an appropriate size. Such a strategy restricts the information exchange between particles to be done only in each small group. It thus results in the improvement of particles' diversity and further minimization of a probability of occurring the premature convergence phenomena. Second, a quantum-infusion (QI) mechanism based on the quantum mechanics is introduced to generate a meaningful offspring in each small group. This offspring in our PSO mechanism improves the ability to explore a wider area precisely compared to the conventional one, so that the degree of precision of the algorithm is improved. Finally, some numerical results are compared with those of the conventional researches, which clearly demonstrates the effectiveness and reliability of the proposed DPSO-QI algorithm.

A Homomorphism on Orthoimplication Algebras for Quantum Logic (양자논리를 위한 직교함의 대수에서의 준동형사상)

  • Yon, Yong-Ho
    • Journal of Convergence for Information Technology
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    • v.7 no.3
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    • pp.65-71
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    • 2017
  • The quantum logic was introduced by G. Birkhoff and 1. von Neumann in order to study projections of a Hilbert space for a formulation of quantum mechanics, and Husimi proposed orthomodular law and orthomodular lattices to complement the quantum logic. Abott introduced orthoimplication algebras and its properties to investigate an implication of orthomodular lattice. The commuting relation is an important property on orthomodular lattice which is related with the distributive law and the modular law, etc. In this paper, we define a binary operation on orthoimplication algebra and the greatest lower bound by using this operation and research some properties of this operation. Also we define a homomorphism and characterize the commuting relation of orthoimplication algebra by the homomorphism.

COSMIC DUST AND COSMOLOGY

  • PREVENSLIK, THOMAS V.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.327-330
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    • 2015
  • Cosmology considers the Hubble redshift of galaxy light by the Doppler effect as proof the Universe has been expanding since the Big Bang. However, cosmic dust that permeates the Universe also redshifts galaxy light that if not corrected over-predicts the velocities of all astronomical measurements inferred by the Doppler effect. Hubble redshifts corrected for cosmic dust suggest the Universe may not be expanding, the consequence of which may allow the outstanding problems in cosmology to possibly be resolved by Newtonian mechanics.

Molecular dynamics simulation of bulk silicon under strain

  • Zhao, H.;Aluru, N.R.
    • Interaction and multiscale mechanics
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    • v.1 no.2
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    • pp.303-315
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    • 2008
  • In this paper, thermodynamical properties of crystalline silicon under strain are calculated using classical molecular dynamics (MD) simulations based on the Tersoff interatomic potential. The Helmholtz free energy of the silicon crystal under strain is calculated by using the ensemble method developed by Frenkel and Ladd (1984). To account for quantum corrections under strain in the classical MD simulations, we propose an approach where the quantum corrections to the internal energy and the Helmholtz free energy are obtained by using the corresponding energy deviation between the classical and quantum harmonic oscillators. We calculate the variation of thermodynamic properties with temperature and strain and compare them with results obtained by using the quasi-harmonic model in the reciprocal space.

Hierarchical Circuit Visualization for Large-Scale Quantum Computing (대규모 양자컴퓨팅 회로에 대한 계층적 시각화 기법)

  • Kim, JuHwan;Choi, Byung-Soo;Jo, Dongsik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.05a
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    • pp.611-613
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    • 2021
  • Recently, research and development of quantum computers, which exceed the limits of classical computers, have been actively carried out in various fields. Quantum computers, which use quantum mechanics principles in a way different from the electrical signal processing of classical computers, have various quantum mechanical phenomena such as quantum superposition and quantum entanglement. It goes through a very complicated calculation process compared to the calculation of a classical computer for performing an operation using its characteristics. In order to utilize each element efficiently and accurately, it is necessary to visualize the data before driving the actual quantum computer and perform error verification, optimization, reliability, and verification. However, when visualizing all the data of various elements configured inside the quantum computer, it is difficult to intuitively grasp the necessary data, so it is necessary to visualize the data selectively. In this paper, we visualize the data of various elements that make up a quantum computer, and hierarchically visualize the internal circuit components of a quantum computer that are complicatedly configured so that the data can be observed and utilized intuitively.

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디랙과 수학적 아름다움

  • 이상하
    • Journal for History of Mathematics
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    • v.14 no.2
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    • pp.77-92
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    • 2001
  • P. Dirac's contribution to the advent of the modern quantum mechanics is undeniable. His main research guideline is the principle of mathematical beauty. What is this principle on the earth\ulcorner Are there distinctive features between pure mathematician's mind and theoretical physicist' mind about the mathematical beauty\ulcorner These problems will be analyzed with respect to Dirac's case which can reflect a historical interrelationship between science and philosophy.

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Molecular Modeling and its Experimental Verification for the Catalytic Mechanism of Candida antarctica Lipase B

  • Kwon, Cheong-Hoon;Shin, Dae-Young;Lee, Jong-Ho;Kim, Seung-Wook;Kang, Jeong-Won
    • Journal of Microbiology and Biotechnology
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    • v.17 no.7
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    • pp.1098-1105
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    • 2007
  • Quantum mechanical and molecular dynamics simulation analysis has been performed on the model system for CALB (Candida antarctica lipase B) with esters to study the reaction mechanism and conformational preference of catalytic hydrolysis and the esterification reaction. Using quantum mechanical analysis, the ping-pong bi-bi mechanism was applied and energies and 3-dimensional binding configurations of the whole reaction pathways were calculated. Further molecular dynamics simulation analysis was performed on the basis of the transition state obtained from quantum mechanical study to observe the effect of structures of the substrates. Calculation results using substrates of different chain length and chiral configurations were compared for conformational preference. The calculated results showed very small influence on chain length, whereas chiral conformation showed big differences. Calculated results from molecular modeling studies have been compared qualitatively with the experimental data using racemic mixtures of (${\pm}$)-cis-4-acetamido-cyclopent-2-ene-1-ethyl acetate as substrates.

Elastic Network Model for Nano and Bio System Analysis (나노 및 바이오 시스템 해석을 위한 탄성네트워크모델)

  • Kim, Moon-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.668-669
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    • 2008
  • In this paper, we introduce various coarse-grained elastic network modeling (ENM) techniques as a novel computational method for simulating atomic scale dynamics in macromolecules including DNA, RNA, protein, and polymer. In ENM, a system is modeled as a spring network among representative atoms in which each linear elastic spring is well designed to replace both bonded and nonbonded interactions among atoms in the sense of quantum mechanics. Based on this simplified system, a harmonic Hookean potential is defined and used for not only calculating intrinsic vibration modes of a given system, but also predicting its anharmonic conformational change, both of which are strongly related with its functional features. Various nano and bio applications of ENM such as fracture mechanics of nanocomposite and protein dynamics show that ENM is one of promising tools for simulating atomic scale dynamics in a more effective and efficient way comparing to the traditional molecular dynamics simulation.

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