• Title/Summary/Keyword: Taylor Number

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Solute Transport in Rock Fractures

  • Yeo, In-Wook
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.89-92
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    • 2001
  • This study aims at investigating the relationship between dispersion coefficient ratio to molecular diffusion coefficient (D$_{l}$ /D$_{m}$) and Peclet number (Pe) for multi-solute system in non-Darcian flow regime. Existing understanding on solute dispersion is primarily derived from one-solute system in Darcian flow regime. We found that solute dispersion in rock fractures can be characterized by the mechanism of both macrodispersion and Taylor dispersion, even for non-Darcian f]ow domain. For the Darcian flow regime even different solutes lead to the same D$_{l}$ /D$_{m}$ at same Pe. However, as the flow becomes non-Darcian, solute with a higher molecular diffusion coefficient result in higher D$_{l}$ /D$_{m}$ at tile same Pe than that with a lower diffusion coefficient.cient.

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Variations and Series Expansions of the Symbolic Multiple-Valued Logic functions (기호 다치 논리함수와 그 변화 및 전개)

  • 이성우;정환묵
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.20 no.5
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    • pp.1-7
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    • 1983
  • Generally, multiple-valued logic algebra is based on the number system of modulo-M. In this paper, characters a, b, c‥… each of them represents the independent state, are regarded as the elements of the symbolic multiple-valued logic. By using the set theory, the symbolic multiple - valued logic and their functions are defined. And Varation for the symbolic logic function due to the variation of a variable and their properties are suggested and analized. With these variations, the MacLaurin's and Taylor's Series expansions of the symbolic logic functions are proposed and proved.

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The benthic marine algae of the tropical and subtropical Western Atlantic: changes in our understanding in the last half century

  • Wynne, Michael J.
    • ALGAE
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    • v.26 no.2
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    • pp.109-140
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    • 2011
  • Taylor's (1960) floristic treatment of the benthic marine algae of the tropical and subtropical western Atlantic and Wynne's (2011) "checklist: third revision" serve as benchmarks in a review of changes made in the past half-century period. There has been a great increase in the number of recognized taxa of red, brown and green algae at all taxonomic ranks: from 758 to 1,393 species, an increase of 84%; from 231 to 406 genera, an increase of 75%; and from 63 to 106 families, an increase of 68%. In regard to recognized infraspecific taxa, the increase was less dramatic, from 140 to 185, thus a 32% change in the 50-year period. This review addresses the question: What factors were responsible for this proliferation of taxa that are now recognized in this domain of the tropical and subtropical western Atlantic? The answer is that many reasons contributed to these changes. Foremost among these causes have been the advances in gene-sequencing technologies. Revised phylogenetic relationships have led to many genera being divided into more than one genus, as well as new families and orders being delineated. Numerous examples of cryptic species have been discovered by gene-sequence and DNA-bar coding studies. This trend is depicted by case studies. Examples of genera being divided are Galaxaura, Liagora and Laurencia. Tricleocarpa and Dichotomaria have been segregated from Galaxaura. Trichogloeopsis, Ganonema, Izziella, Yamadaella, and Titanophycus have been segregated from Liagora. Chondrophycus, Osmundea, Palisada, and Yuzurura have been segregated from Laurencia. Examples are given of other genera present in this region of the western Atlantic that have been split up. Many genera have increased in terms of the number of species now assigned to them. Taylor's (1960) treatment recognized only two species in Hypoglossum, whereas Wynne's (2011) checklist contained a total of 9 species of Hypoglossum. Taylor's account included only two species of Botryocladia, but this number had grown to 15 in Wynne's checklist. Examples of new genera and species occurring in the region of the western Atlantic are given, and examples of taxa being newly reported for this domain are provided. An increase in the number of phycologists in Latin and South America, exploration of previously unexplored regions, and the increasing use of SCUBA for collecting and at greater depths have all contributed to the increase in the number of algal taxa that are now recognized as occurring in the tropical and subtropical western Atlantic.

Spatial Distribution and Sampling Plan for Pink Citrus Rust Mite, Aculops pelekassi (Acari: Eriophyidae) in Citrus Orchard (감귤원에서 귤녹응애 공간분포 분석과 표본조사법 개발)

  • Song, Jeong-Heub;Hong, Soon-Yeong;Lee, Shin-Chan
    • Korean journal of applied entomology
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    • v.51 no.2
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    • pp.91-97
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    • 2012
  • The dispersion indices, spatial pattern and sampling plan for pink citrus rust mite (PCRM), Aculops pelekassi, monitoring was investigated. Dispersion indices of PCRM indicated the aggregated spatial pattern. Taylor's power law provided better description of variance-mean relationship than Iwao's patchiness regression. Fixed-precision levels (D) of a sequential sampling plan were developed using by Taylor's power law parameters generated from PCRM on fruit sample (cumulated number of PCRM in $cm^2$ of fruit). Based on Kono-Sugino's empirical binomial the mean density per $cm^2$ could be estimated from fruit ratio with more than 12 rust mites per $cm^2$: $ln(m)=4.61+1.23ln[-ln(1-p_{12})]$. To determine the optimal tally threshold, the variance (var(lnm)) for mean (lnm) in Kono-Sugino equation was estimated. The lower and narrow ranged change of variance for esimated mean showed at a tally threshold of 12. To estimate PCRM mean density per $cm^2$ at fixed precision level 0.25, the required sample number was 13 trees, 5 fruits per tree and 2 points per fruit (total 130 samples).

Sample Size Determination for the Estimation of Population Density of Marine Benthos on a Tidal Flat and a Subtidal Area, Korea

  • Koh, Chul-Hwan;Kang, Seong-Gil
    • Journal of the korean society of oceanography
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    • v.33 no.3
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    • pp.113-122
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    • 1998
  • The requisite numbers of sample replicates for the population study of soft-bottom benthos were estimated from survey data on the Songdo tidal flat and subtidal zone in Youngil Bay, Korea. Large numbers of samples were taken; two-hundred-fifty 0.02 m$^2$ box corers and fifty 0.1m$^2$ van Veen grabs were taken on the Songdo tidal flat and in Youngil Bay, respectively. The effect of sampler size on sampling efforts was investigated by pooling the unit samples in pairs, fours, eights, etc. The requisite number of sample replicates (n$_r$) was determined by sample variance (s$^2$) and mean (m) function (n$_r$:s$^2$/P$^2$m$^2$), at P=0.2 level, in which s$^2$ and m were calculated from the counts of individuals collected. For example, seven samples of 0.02 m$^2$ corer for the intertidal and two samples of 0.1 m$^2$ van Veen grab for subtidal fauna were required to estimate the total density of community. The smaller sampler size was more efficient than larger ones when sampling costs were compared on the basis of the total sampling area. The requisite number of sample replicates was also predicted ($\^{n}$n$_r$) by substituting $\^{s}$$^2$ obtained from the regression of s$^2$ against m using the Taylor's power law ($\^{s}$$^2$:am$^b$). The regression line of survey data on s$^2$ and m plotted on log scale was well fitted to the Taylor's power law (r$^2$${\geq}$0.95, p<;0.001) over the whole range of m. The exponent b was, however, varied when it was estimated from m which was categorized into classes by its scale. The fitted exponent b was large when both density class and the sampler size were large. The number of sample replicates, therefore, could be more significantly estimated, if regression coefficients (a and b) would be calculated from sample variance and mean categorized into density classes.

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Kth order Newton-Raphson's Floating Point Number Nth Root (K차 뉴톤-랍손 부동소수점수 N차 제곱근)

  • Cho, Gyeong-Yeon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.13 no.1
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    • pp.45-51
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    • 2018
  • In this paper, a tentative Kth order Newton-Raphson's floating point number Nth root algorithm for K order convergence rate in one iteration is proposed by applying Taylor series to the Newton-Raphson root algorithm. Using the proposed algorithm, $F^{-1/N}$ and $F^{-(N-1)/N}$ can be computed from iterative multiplications without division. It also predicts the error of the algorithm iteration and iterates only until the predicted error becomes smaller than the specified value. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a floating point number Nth root unit.

Floating Point Number N'th Root K'th Order Goldschmidt Algorithm (부동소수점수 N차 제곱근 K차 골드스미스 알고리즘)

  • Cho, Gyeong Yeon
    • Journal of Korea Multimedia Society
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    • v.22 no.9
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    • pp.1029-1035
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    • 2019
  • In this paper, a tentative Kth order Goldschmidt floating point number Nth root algorithm for K order convergence rate in one iteration is proposed by applying Taylor series to the Goldschmidt square root algorithm. Using the proposed algorithm, Nth root and Nth inverse root can be computed from iterative multiplications without division. It also predicts the error of the algorithm iteration. It iterates until the predicted error becomes smaller than the specified value. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a floating point number Nth root unit.

On Numerical Method for Radiation Problem of a 2-D Floating Body (2차원 부유체 강제동요문제의 수치해석에 관하여)

  • Y.S. Shin;K.P. Rhee
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.2
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    • pp.43-53
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    • 1993
  • There exist two difficulties in the nonlinear wave-body problems. First is the abrupt behavior near the intersection point between the body and the free surface, and second is the far field treatment. In this paper, the far field treatment is considered. The main idea is the Taylor series expansion of free-surface geometry and the application of F.F.T. algorithm. The numerical step is as follows. The velocity potential is expressed by the Green's theorem. and the solution is obtained by iteration method. In the iteration stage, the expressions by the Green's theorem are transformed to the convolution forts with the expansion of free surface by the wave slope. Here F.F.T. is applied, so the computing time can be of O(Nlog N) where N is the number of unknowns. The numerical analysis is carried out and the results are compared with other results in linear floating body problem and nonlinear moving pressure patch problem, and good agreements are obtained. Finally nonlinear floating body radiation problem is carried out with computing time of O(Nlog N).

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A LINEARIZED FINITE-DIFFERENCE SCHEME FOR THE NUMERICAL SOLUTION OF THE NONLINEAR CUBIC SCHRODINGER EQUATION

  • Bratsos, A.G.
    • Journal of applied mathematics & informatics
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    • v.8 no.3
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    • pp.683-691
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    • 2001
  • A linearized finite-difference scheme is used to transform the initial/boundary-value problem associated with the nonlinear Schrodinger equation into a linear algebraic system. This method is developed by replacing the time and the nonlinear term by an appropriate parametric linearized scheme based on Taylor’s expansion. The resulting finite-difference method is analysed for stability and convergence. The results of a number of numerical experiments for the single-soliton wave are given.

Modeling and assessment of VWNN for signal processing of structural systems

  • Lin, Jeng-Wen;Wu, Tzung-Han
    • Structural Engineering and Mechanics
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    • v.45 no.1
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    • pp.53-67
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    • 2013
  • This study aimed to develop a model to accurately predict the acceleration of structural systems during an earthquake. The acceleration and applied force of a structure were measured at current time step and the velocity and displacement were estimated through linear integration. These data were used as input to predict the structural acceleration at next time step. The computation tool used was the Volterra/Wiener neural network (VWNN) which contained the mathematical model to predict the acceleration. For alleviating problems of relatively large-dimensional and nonlinear systems, the VWNN model was utilized as the signal processing tool, including the Taylor series components in the input nodes of the neural network. The number of the intermediate layer nodes in the neural network model, containing the training and simulation stage, was evaluated and optimized. Discussions on the influences of the gradient descent with adaptive learning rate algorithm and the Levenberg-Marquardt algorithm, both for determining the network weights, on prediction errors were provided. During the simulation stage, different earthquake excitations were tested with the optimized settings acquired from the training stage to find out which of the algorithms would result in the smallest error, to determine a proper simulation model.