• 제목/요약/키워드: relative frequencies

검색결과 376건 처리시간 0.023초

Computational Study of Proline - Water Cluster

  • Lee, Kyung-Min;Park, Sung-Woo;Jeon, In-Sun;Lee, Bo-Ra;Ahn, Doo-Sik;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • 제26권6호
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    • pp.909-912
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    • 2005
  • Calculations are presented for the structures of various conformers of the bare proline and proline –($H_2O$) cluster. The effects of hydrogen bonding with a water molecule on the relative stability of the low energy conformers of proline are examined. Microsolvation by a water molecule is predicted to affect the relative stability, structures and the infrared frequencies of the conformers to a large degree.

차콜 화강암에서의 AE/MA파의 감쇄특성 (Attenuation Characteristics of AE/MA Waves in Charcoal Granite)

  • 김교원
    • 지질공학
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    • 제6권3호
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    • pp.131-136
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    • 1996
  • 세립화강암 시료에 개별 보정된 6개의 탐촉자를 부착하고 연필심 파괴로 급재하하여 AE/MA파를 발신 시키면서 고주파인 AE/MA파의 감쇄특성을 연구하였다. AE/MA파의 강도는 거리뿐만 아니라 발신원과 수신점의 상대적인 방위에 의하여 결정되며 Charcoal 세립화강암의 감쇄상수는 1.058이다. 이 상수는 AE/MA파으 주어진 경로에 대하여서 발신원과 수신점의 상대적인 방위에 무관하게 적용 가능한 것으로 평가된다.

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Free Surface Tracking for the Accurate Time Response Analysis of Nonlinear Liquid Sloshing

  • Cho Jin-Rae;Lee Hong-Woo
    • Journal of Mechanical Science and Technology
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    • 제19권7호
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    • pp.1517-1525
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    • 2005
  • Liquid sloshing displays the highly nonlinear free surface fluctuation when either the external excitation is of large amplitude or its frequency approaches natural sloshing frequencies. Naturally, the accurate tracking of time-varying free surface configuration becomes a key task for the reliable prediction of the sloshing time-history response. However, the numerical instability and dissipation may occur in the nonlinear sloshing analysis, particularly in the long-time beating simulation, when two simulation parameters, the relative time-increment parameter a and the fluid mesh pattern, are not elaborately chosen. This paper intends to examine the effects of these two parameters on the potential-based nonlinear finite element method introduced for the large amplitude sloshing flow.

Vibration analysis of graphene platelet reinforced stadium architectural roof shells subjected to large deflection

  • Abeer Qasim Jbur;Wael Najm Abdullah;Nadhim M. Faleh;Zahraa N. Faleh
    • Structural Engineering and Mechanics
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    • 제86권2호
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    • pp.157-165
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    • 2023
  • In the present work, the vibration characteristics of sandwich nanocomposite shells, fortified with graphene platelets (GPLs) have been researched. The shell has been considered as the stadium roof shape with double curvatures under vibration due to earthquake. The nanocomposite has the matrix of concrete which is fortified with uniform or linear dispersions of GPLs. Also, the core possesses cellular type square architecture for which the effective elastic modulus has been defined in the context of relative density based relations. Based upon the classic shell strains containing two identical curvatures, the governing equations have been established and solved through differential quadrature approach. It will be seen that the vibrational frequencies rely on the core relative density, height of layers, the amount and dispersions of GPLs and even shell geometric parameters.

TORSIONAL MHD OSCILLATIONS OF THE SUN

  • HIREMATH K. M.;GOKHALE M. H.
    • 천문학회지
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    • 제29권spc1호
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    • pp.313-314
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    • 1996
  • Assuming that the solar activity and the solar cycle phenomena may be manifestations of global torsional MHD oscillations, we compute the Alfven wave travel times along the field lines in the five models of magnetic field described in the following text. For all these models, we compute standard deviation and it's ratio to mean Alfvenic wave travel times. The last two models yield the smallest relative bandwidth for the frequencies of the MHD oscillations. However, the last model is the only admissible one which can sustain global Alfvenic oscillations with well defined frequency for the fundamental mode

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Computational Study of Catechol-(H2O)n(n=1-3) Clusters

  • Jang, Sang-Hee;Park, Sung-Woo;Kang, Joo-Hye;Lee, Sung-Yul
    • Bulletin of the Korean Chemical Society
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    • 제23권9호
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    • pp.1297-1303
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    • 2002
  • Computations are presented for the catechol-$(H_2O)_n$ (n = 1-3) clusters. A variety of conformers are predicted,and their relative energies are compared. Binding energies of the clusters are computed, and detailed analysis is presented on the harmonic frequencies of stretching modes involving the hydrogen bonding in the clusters, comparing with the experimental observations.

부분근입된 말뚝의 자유진동 특성 (Free Vibration Characteristics of Partially Embedded Piles)

  • 신성철;진태기;오상진;박광규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.435-440
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    • 2002
  • The free vibration of partially embedded piles is investigated. The pile model is based on the Bernoulli-Euler beam theory and the soil is idealized as a Winkler model for mathematical simplicity. The governing differential equation for the free vibrations of such members is solved numerically The piles with one typical end constraint (clamped/hinged/free) and the other hinged end with rotational spring are applied in numerical examples. The lowest three natural frequencies are calculated over a range of non-dimensional system parameters: the rotational spring parameter, the relative stiffness and the embedded ratio.

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EVOLUTION OF THE GALACTIC DISK: FOCUS ON THE SOLAR NEIGHBOURHOOD

  • ANDERSEN J.;NORDSTROM B.;OLSEN E. H.;MAYOR M.;PONT F.
    • 천문학회지
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    • 제29권spc1호
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    • pp.127-128
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    • 1996
  • The solar neighbourhood is the starting point for studies of the structure and evolution of the Galactic disk. Yet, our knowledge of the relative frequencies, distances, ages, chemical abundances, velocities, and birthplaces of the nearby stars is severely incomplete. We have determined complete, homogeneous, and precise such data for a kinematically unbiased sample of $\~$12,000 local F and G dwarf stars and describe a first, significant result from it.

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진도견(珍島犬) 정세관상피(精細管上皮)의 정자발생(精子發生)과 미세구조(微細構造) (Spermatogenesis and its fine structure of the seminiferous epithelium in the Jindo dog)

  • 김용환;박영석
    • 대한수의학회지
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    • 제33권1호
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    • pp.23-36
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    • 1993
  • To investigate the cycle and relative frequences and the fine structure of seminiferous epithelia in mature Jindo dogs, histologic study was performed. The results obtained were summarized as follows; 1. Type A spermatogonia appeared approximately 1.6 times as many at stage II as compared to stage I while type In spermatogonia appeared small amount in stage III, IV and V. type B spermatogonia were found during the stage VI to VIII, though not detectable during stage I to V. The type B spermatogonia divided at stage VII to produce the preleptotene primary spermatocytes at stage VIII. The number of primary spermatocytes of the leptotene phase markedly increased during stage I to II, and the primary spermatocytes of the pachytene phase were shown the least in number at stage IV. The secondary spermatocytes could be seen only at stage IV. 2. The relative frequencies of each stage from stages I to VIII of the cycle of seminiferous epithelia were 31.6, 11.9, 10.0, 3.2, 8.2, 10.1, 11.7 and 13.2% respectively. 3. On electron microscopic observations, acrosomal vesicle of spermatids appeared larger though the bulk of germ cells were the morphologically same as those of the other animal species. Thread line structures light microscopically observed in the cytoplasm of Sertoli cell were the longitudinal orientation of mitochondria.

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한국재래산양 태자의 위장관에 있어서 gastrin, secretin 및 pancreatic polypeptide 면역반응세포의 분포 및 출현빈도에 관한 연구 (Regional distribution and relative frequency of the gastrin, secretin and pancreatic polypeptide-immunoreactive cells in the gastrointestinal tract of the fetus of Korean native goat)

  • 이형식;구세광;이재현
    • 대한수의학회지
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    • 제39권1호
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    • pp.12-19
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    • 1999
  • The regional distributions and relative frequencies of the gastrin, secretin and pancreatic polypeptide(PP)-immunoreactive cells in the gastrointestinal tract of the fetus(180 days of gestation) of Korean native goat were studied with immunohistochemical(ABC) methods. Gastrin-immunoreactive cells were detected in fundus, pylorus and duodenum and these cells were most predominant in pylorus. Secretin-immunoreactive cells were observed in pylorus, duodenum and ileum. PP-immunoreactive cells were restricted to fundus. These immunoreactive cells were situated in surface epithelium and mucosal gland regions. The regional distribution and relative frequency of PP-immunoreactive cells was somewhat different to the adult Korean native goat. Immunoreactive cells in the surface epithelial regions were open typed cells which were spindle shaped cells but closed typed cells which were round or/to spherical shaped cells were observed in the mucosal gland regions.

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