• Title/Summary/Keyword: Divergence time

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Comparative study: nonsynonymous and synonymous substitution of SARS-CoV-2, SARS-CoV, and MERS-CoV genome

  • Sohpal, Vipan Kumar
    • Genomics & Informatics
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    • v.19 no.2
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    • pp.15.1-15.7
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    • 2021
  • The direction of evolution can estimate based on the variation among nonsynonymous to synonymous substitution. The simulative study investigated the nucleotide sequence of closely related strains of respiratory syndrome viruses, codon-by-codon with maximum likelihood analysis, z selection, and the divergence time. The simulated results, dN/dS > 1 signify that an entire substitution model tends towards the hypothesis's positive evolution. The effect of transition/transversion proportion, Z-test of selection, and the evolution associated with these respiratory syndromes, are also analyzed. Z-test of selection for neutral and positive evolution indicates lower to positive values of dN-dS (0.012, 0.019) due to multiple substitutions in a short span. Modified Nei-Gojobori (P) statistical technique results also favor multiple substitutions with the transition/transversion rate from 1 to 7. The divergence time analysis also supports the result of dN/dS and imparts substantiating proof of evolution. Results conclude that a positive evolution model, higher dN-dS, and transition/transversion ratio significantly analyzes the evolution trend of severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, and Middle East respiratory syndrome coronavirus.

NUMERICAL IMPLEMENTATION OF THE TWO-DIMENSIONAL INCOMPRESSIBLE NAVIER-STOKES EQUATION

  • CHOI, YONGHO;JEONG, DARAE;LEE, SEUNGGYU;KIM, JUNSEOK
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.19 no.2
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    • pp.103-121
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    • 2015
  • In this paper, we briefly review and describe a projection algorithm for numerically computing the two-dimensional time-dependent incompressible Navier-Stokes equation. The projection method, which was originally introduced by Alexandre Chorin [A.J. Chorin, Numerical solution of the Navier-Stokes equations, Math. Comput., 22 (1968), pp. 745-762], is an effective numerical method for solving time-dependent incompressible fluid flow problems. The key advantage of the projection method is that we do not compute the momentum and the continuity equations at the same time, which is computationally difficult and costly. In the projection method, we compute an intermediate velocity vector field that is then projected onto divergence-free fields to recover the divergence-free velocity. Numerical solutions for flows inside a driven cavity are presented. We also provide the source code for the programs so that interested readers can modify the programs and adapt them for their own purposes.

A Study of Convergence and Divergence Characteristics -Case Study of Fashion Market- (컨버전스와 디버전스 특성에 관한 연구 -패션마켓 사례를 중심으로-)

  • Park, Yonjin;Lee, Young Jae
    • Journal of Fashion Business
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    • v.22 no.5
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    • pp.64-82
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    • 2018
  • As sustainability of fashion brands is becoming more important in the prolonged depression, the fashion market is also seeking ways to create new value through convergence with various fields. In the fashion market, convergence marketing is engaged with diverse technologies combined with advanced technologies and strategies. This study established the conceptual characteristics of convergence and divergence from a market perspective. Convergence can be summarized as Borderless, Compounding, Diversification, Recombination and Affiliation. The conceptual characteristics of the divergence can be summarized as de-fusion, individualization, differentiation, specialization, and segmentation. The characteristics of convergence revealed through the case of fashion market include the expandability of the new category, the expandability of the consumer, the brand experience, and the expandability of time and space. Divergence is the differentiation of brand value, target customer, and product nature. Through this study, we could understand the differentiation of the fashion market and the direction of the marketing strategy by looking at the characteristic of the convergence marketing - oriented research that has the contrary conceptual characteristics from the extended viewpoint. Based on this, it is possible to see the changes and patterns of brand marketing strategies and techniques in recent fashion market. In the future, it is expected that the systematic study of the marketing strategy of the domestic fashion brand based on the convergence and change characteristics of the fashion market proposed in this study will continue.

Estimation of Allowable Path-deviation Time in Free-space Optical Communication Links Using Various Aircraft Trajectories

  • Kim, Chul Han
    • Current Optics and Photonics
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    • v.3 no.3
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    • pp.210-214
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    • 2019
  • The allowable path-deviation time of aircraft in a free-space optical communication system has been estimated from various trajectories, using different values of aircraft speeds and turn rates. We assumed the existence of a link between the aircraft and a ground base station. First, the transmitter beam's divergence angle was calculated through two different approaches, one based on a simple optical-link equation, and the other based on an attenuation coefficient. From the calculations, the discrepancy between the two approaches was negligible when the link distance was approximately 110 km, and was under 5% when the link distance ranged from 80 to 140 km. Subsequently, the allowable path-deviation time of the aircraft within the tracking-error tolerance of the system was estimated, using different aircraft speeds, turn rates, and link distances. The results indicated that the allowable path-deviation time was primarily determined by the aircraft's speed and turn rate. For example, the allowable path-deviation time was estimated to be ~3.5 s for an aircraft speed of 166.68 km/h, a turn rate of $90^{\circ}/min$, and a link distance of 100 km. Furthermore, for a constant aircraft speed and turn rate, the path-deviation time was observed to be almost unchanged when the link distance ranged from 80 to 140 km.

Fundamental restrictions for the closed-loop control of wind-loaded, slender bridges

  • Kirch, Arno;Peil, Udo
    • Wind and Structures
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    • v.12 no.5
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    • pp.457-474
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    • 2009
  • Techniques for stabilising slender bridges under wind loads are presented in this article. A mathematically consistent description of the acting aerodynamic forces is essential when investigating these ideas. Against this background, motion-induced aerodynamic forces are characterised using a linear time-invariant transfer element in terms of rational functions. With the help of these functions, the aeroelastic system can be described in the form of a linear, time-invariant state-space model. It is shown that the divergence wind speed constitutes an upper bound for the application of the selected mechanical actuators. Even active control with full state feedback cannot overcome this limitation. The results are derived and explained with methods of control theory.

Functional Conservation and Divergence of FVE Genes that Control Flowering Time and Cold Response in Rice and Arabidopsis

  • Baek, Il-Sun;Park, Hyo-Young;You, Min Kyoung;Lee, Jeong Hwan;Kim, Jeong-Kook
    • Molecules and Cells
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    • v.26 no.4
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    • pp.368-372
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    • 2008
  • Recent molecular and genetic studies in rice, a short-day plant, have elucidated both conservation and divergence of photoperiod pathway genes and their regulators. However, the biological roles of rice genes that act within the autonomous pathway are still largely unknown. In order to better understand the function of the autonomous pathway genes in rice, we conducted molecular genetic analyses of OsFVE, a rice gene homologous to Arabidopsis FVE. OsFVE was found to be ubiquitously expressed in vegetative and reproductive organs. Overexpression of OsFVE could rescue the flowering time phenotype of the Arabidopsis fve mutants by up-regulating expression of the SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1) and down-regulating FLOWERING LOCUS C (FLC) expression. These results suggest that there may be a conserved function between OsFVE and FVE in the control of flowering time. However, OsFVE overexpression in the fve mutants did not rescue the flowering time phenotype in in relation to the response to intermittent cold treatment.

A Study of Threshold Determination of The GPS measurement failure using GPS Code-Carrier Divergence Test (GPS 의사거리-반송파 위상 측정치의 고장검출을 위한 임계값 결정 연구)

  • Son, Eunseong;Kim, Koon-Tack;Im, Sung-Hyuck;Lee, Eun-Sung;Heo, Moon Beom;Nam, Gi-Wook
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.24 no.1
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    • pp.10-15
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    • 2016
  • In this study, The code-carrier divergence test was applied to GPS measurements, and the results were compared and analyzed. The GPS data used for the threshold determination were obtained from Global Navigation Satellite System permanent stations built by the Korea Aerospace Research Institute. At each permanent station, identical dual-frequency receiver and choke ring antenna with radome are installed. The analysis method, root mean square values were compared and analyzed for each permanent station and satellite. As a result, the root mean square value generally decreased as the satellite elevation angle increased although the trend was gentle. Threshold were finally selected based on the average and standard deviation of root mean square for each permanent station. For improving of availability and continuity in real-time operation when the threshold is over the limits, Code-Carrier divergence test values are initialized.

Divergence-free algorithms for moment-thrust-curvature analysis of arbitrary sections

  • Chen, Liang;Liu, Si-Wei;Chan, Siu-Lai
    • Steel and Composite Structures
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    • v.25 no.5
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    • pp.557-569
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    • 2017
  • Moment-thrust-curvatures ($M-P-{\Phi}$ curves) are fundamental quantities for detailed descriptions of basic properties such as stiffness and strength of a section under axial loads required for accurate computation of the deformations of reinforced concrete or composite columns. Currently, the finite-element-based methods adopting small fibers for analyzing a section are commonly used for generating the $M-P-{\Phi}$ curves and they require large amounts of computational time and effort. Further, the conventional numerical procedure using the force-control method might encounter divergence problems under high compression or tension. Therefore, this paper proposes a divergence-free approach, combining the use of the displacement-control and the Quasi-Newton scheme in the incremental-iterative procedure, for generating the $M-P-{\Phi}$ curves of arbitrary sections. An efficient method for computing the strength from concrete components is employed, where the stress integration is executed by layer-based algorithms. For easy modeling of residual stress, cross sections of structural steel components are meshed into fibers for strength resultants. The numerical procedure is elaborated in detail with flowcharts. Finally, extensive validating examples from previously published research are given for verifying the accuracy of the proposed method.

A Study on the Design of an Elevator Driving Control Circuit Using SFC Language (SFC언어를 이용한 Elevator 운전 제어회로 설계에 관한 연구)

  • Lee Sang-mun;Kim Min-Chan;Kwak Gun-Pyong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.6
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    • pp.1260-1268
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    • 2005
  • Ladder Diagram(LD) is the most extensively used among PLC standard language for the design of control system. But LD has the disadvantages for data processing and maintenance. On the other hand, the Sequential Function Chart(SFC) graphic language is very powerful for describing the sequential logic control algorithm. SFC is based on flow chart, so control flow understanding is very easy and divergence can possible improving its ability. In this paper, we propose the efficient management elevator system using the action qualifiers and choice divergence. From the result, we confirm the SFC language reduced program memory capacity and processing time is faster than LD language.

Geographic Variation of Granulilittorina exigua (Littorinidae, Gastropoda) in Korea Based on the Mitochondrial Cytochrome b Gene Sequence

  • Song, Jun-Im;Suh, Jae-Hwa;Kim, Sook-Jung
    • Animal cells and systems
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    • v.4 no.3
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    • pp.267-272
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    • 2000
  • Partial sequence of the mitochondrial cytochrome b gene was analyzed to investigate genetic variation from 10 geographic populations of Granulilittorina exigua in Korea. The sequence of 282 base pairs was determined by PCR-directed silver sequencing method. The sequences of two species within the genus Littorina reserved in NIH blast search were utilized to determine geographic variations of species referred. The levels of mtDNA sequence differences were 0.00-2.54% within populations and 0.71-4.43% between populations. There were four amino acid differences between representative species of the genera Granulilittorina and Littorina, but no differences within populations of the genus Granulilittorina. The UPGMA and the N-J trees based on Tamura-Nei genetic distance matrix were constructed, which showed that the genus Granulilittorina was divided into three groups such as eastern (even exception for Tokdo population), southern, and western regional populations. The degrees of genetic divergence within populations of each group were p=0.021, p=0.019, and p=0.018, respectively. The divergence between the eastern and southern populations was p=0.032, showing closer relationship than with the western populations (p=0.052). Based on the diverged time estimation, the eastern and southern populations of Granulilittorina exigua in Korea diverged from the western populations about 2.1 MYBP, and the eastern and southern populations diverged from each other about 1.3 MYBP.

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