• Computers and Concrete
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• v.30 no.5
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• pp.369-375
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• 2022

Current exertion reports the numerical analysis of boundary layer slip flow of Casson Nano fluid along a permeable cylinder that is stretching in exponential manner. The modeled PDEs are changed into nonlinear ODEs through appropriate nonlinear transformations. Numerical results are attained using a renowned numerical scheme shooting method with Runge-Kutta procedure of 6^th-order. Influential role of relevant parameters like Reynolds, suction, Casson fluid and slip parameters on velocity profile is investigated. The effect of influence of slip parameter γ on temperature profile is seen through graph. To ensure the authenticity of numerical procedure, outcomes of some special cases of present work are compared with published work and strong agreement is noticed.

• (The)Study of the Eastern Classic
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• no.50
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• pp.261-294
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• 2013

The purpose of this paper lies how the original text of Chinese classical literary works have been implemented in the paintings of China and Korea, and inspect the ways how of these original text interpreted in paintings. It is an experiment of trying to analyze through literature with painting and read again painting through literature. Qu Yuan(屈原) Prose Poem of Fisherman("漁父辭"), Tao Yuanming(陶淵明) Prose Poem of Returning Home("歸去來辭") and the prose with a poem on the peach blossom spring("桃花源記幷詩"), Du Fu(杜甫), Song of Eight Drunken Celestials("飮中八仙歌"), Su Shi(蘇軾), Odes on the Red Cliff("赤壁賦"), Ou Yangxiu(歐陽脩), Odes of the Sounds of Autumn("秋聲賦") and the paintings which based on these texts were the target of examination. These literary texts shared by Chinese and Korea have been compared in the aspects of acceptance and enjoyment. And on the basis of this process the characteristics of korean paintings expressing the ideas of classical literary works was induced. As a result, the following facts are derived. First, By the emergence of the typical style which was formed historically in China at the korean painting shows that korean painters not only actively embraced the art style of China also did not lose the international sense. Second, through the profound study for chinese painting, they transformed it in accordance with korean aesthetic view and finally revealed typical korean characteristics. Third, the results as described above showed the difference of perception and interpretation of literary works between China and Korea.

• Journal of the Korean Institute of Gas
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• v.7 no.4 s.21
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• pp.44-52
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• 2003

In this work dynamic heat transfer in a CPFS (cable penetration fire stop) system built in the firewall of nuclear power plants is three-dimensionally investigated to develop a test-simulator that can be used to verify effectiveness of the sealant. Dynamic heat transfer in the fire stop system is formulated in a parabolic PDE (partial differential equation) subjected to a set of initial and boundary conditions. First, the PDE model is divided into two parts; one corresponding to heat transfer in the axial direction and the other corresponding to heat transfer on the vertical planes. The first PDE is converted to a series of ODEs (ordinary differential equations) at finite discrete axial points for applying the numerical method of SOR (successive over-relaxation) to the problem. The ODEs are solved by using an ODE solver In such manner, the axial heat flux can be calculated at least at the finite discrete points. After that, all the planes are separated into finite elements, where the time and spatial functions are assumed to be of orthogonal collocation state at each element. The initial condition of each finite element can be obtained from the above solution. The heat fluxes on the vertical planes are calculated by the Galerkin FEM (finite element method). The CPFS system was modeled, simulated, and analyzed here. The simulation results were illustrated in three-dimensional graphics. Through simulation, it was shown clearly that the temperature distribution was influenced very much by the number, position, and temperature of the cable stream, and that dynamic heat transfer through the cable stream was one of the most dominant factors, and that the feature of heat conduction could be understood as an unsteady-state process.

• Journal of Korean Philosophical Society
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• v.137
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• pp.439-462
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• 2016

This Article's aim is to articulate Confucius's theory of poetics in analects. Confucius tried to establish Humanism and educate the idea of 'learning to become a sage' based upon six classics. He empathized with the education of The Book of Poetry. Sze-ma Tseen said that the old poems amounted to more than 3,000. Confucius removed those which were only repetitions of others and sang to them with his lute, bringing them into accordance with the appropriate musical style. This is the first notice which we have of any compilation of the ancient poems by Confucius. Confucius said, "If you do not learn the Odes, you are not fit to converse with. The Odes 1) serve to stimulate the mind, 2) may be used for purposes of self-contemplation, 3) teach the art of sociability, 4) show how to regulate feelings of resentment, 5-6.) 'From them you learn the more immediate duty of serving one's father, and the remoter one of serving one's prince. and from them we become largely acquainted with the names of birds, beasts, and plants.' Confucius' said, 'In the Book of Poetry are three hundred pieces, but the design of them all may be embraced in one sentence-- "Having no depraved thoughts."' This sentence is the final definition of Poetics.

• Advances in Computational Design
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• v.4 no.3
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• pp.307-326
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• 2019

A low computational cost semi-analytical method is developed, based on eigenfunction expansion, to study the vibration of rectangular plates subjected to a series of moving sprung masses, representing a bridge deck under multiple vehicle or train moving loads. The dynamic effects of the suspension system are taken into account by using flexible connections between the moving masses and the base structure. The accuracy of the proposed method in predicting the dynamic response of a rectangular plate subjected to a series of moving sprung masses is demonstrated compared to the conventional rigid moving mass models. It is shown that the proposed method can considerably improve the computational efficiency of the conventional methods by eliminating a large number of time-varying components in the coupled Ordinary Differential Equations (ODEs) matrices. The dynamic behaviour of the system is then investigated by performing a comprehensive parametric study on the Dynamic Amplification Factor (DAF) of the moving loads using different design parameters. The results indicate that ignoring the flexibility of the suspension system in both moving force and moving mass models may lead to substantially underestimated DAF predictions and therefore unsafe design solutions. This highlights the significance of taking into account the stiffness of the suspension system for accurate estimation of the plate maximum dynamic response in practical applications.

• International Journal of Aeronautical and Space Sciences
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• v.3 no.2
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• pp.46-58
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• 2002

An inverse method is introduced to construct benchmark problems for the numerical solution of initial value problems. Benchmark problems constructed through this method have a known exact solution, even though analytical solutions are generally not obtainable. The solution is constructed such that it lies near a given approximate numerical solution, and therefore the special case solution can be generated in a versatile and physically meaningful fashion and can serve as a benchmark problem to validate approximate solution methods. A smooth interpolation of the approximate solution is forced to exactly satisfy the differential equation by analytically deriving a small forcing function to absorb all of the errors in the interpolated approximate solution. A multi-variable orthogonal function expansion method and computer symbol manipulation are successfully used for this process. Using this special case exact solution, it is possible to directly investigate the relationship between global errors of a candidate numerical solution process and the associated tuning parameters for a given code and a given problem. Under the assumption that the original differential equation is well-posed with respect to the small perturbations, we thereby obtain valuable information about the optimal choice of the tuning parameters and the achievable accuracy of the numerical solution. Illustrative examples show the utility of this method not only for the ordinary differential equations (ODEs) but for the partial differential equations (PDEs).

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.761-772
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• 2009

The introduction of KTX (Korea Train eXpress) provided passengers with a much faster mode of transport, and KTX has become a model railway system. Express railway stations are emphasized as public transit transfer centers, but their service evaluations were not performed appropriately so far. It is possible to know the level of service by developing valuation criteria for their evaluations. The evaluation of transfer centers mainly consists of two parts; connective service with other travel m odes, and transfer service inside transfer stations. Connection is defined as the inter-connection of multi-transportation vehicles, and transfer means that a passenger changes his travel mode to another. Such connective service and transfer service are evaluated by the level of service in terms of transfer facilities, the appropriateness of station layout and the quality of information throughout the facilities. We developed the service evaluation indicators of connective facilities and referred to the indicators of transfer facilities. We examined the 7 stations in Korea that are currently in operation and standardized the methodology of the evaluation process by applying the indicators suggested in this study.

• Journal of the Korean Mathematical Society
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• v.49 no.4
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• pp.779-794
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• 2012

In this paper, we study the global stability of two mathematical models for human immunodeficiency virus (HIV) infection with intra-cellular delays. The first model is a 5-dimensional nonlinear delay ODEs that describes the interaction of the HIV with two classes of target cells, $CD4^+$ T cells and macrophages taking into account the saturation infection rate. The second model generalizes the first one by assuming that the infection rate is given by Beddington-DeAngelis functional response. Two time delays are used to describe the time periods between viral entry the two classes of target cells and the production of new virus particles. Lyapunov functionals are constructed and LaSalle-type theorem for delay differential equation is used to establish the global asymptotic stability of the uninfected and infected steady states of the HIV infection models. We have proven that if the basic reproduction number $R_0$ is less than unity, then the uninfected steady state is globally asymptotically stable, and if the infected steady state exists, then it is globally asymptotically stable for all time delays.

• Ocean Systems Engineering
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• v.6 no.4
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• pp.363-375
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• 2016

Large numbers of submarine pipelines are laid as the world now is attaching great importance to offshore oil exploitation. Free spanning of submarine pipelines may be caused by seabed unevenness, change of topology, artificial supports, etc. By combining Iwan's wake oscillator model with the differential equation which describes the vibration behavior of free-span submarine pipelines, the pipe-fluid coupling equation is developed and solved in order to study the effect of both internal and external fluid on the vibration behavior of free-span submarine pipelines. Through generalized integral transform technique (GITT), the governing equation describing the transverse displacement is transformed into a system of second-order ordinary differential equations (ODEs) in temporal variable, eliminating the spatial variable. The MATHEMATICA built-in function NDSolve is then used to numerically solve the transformed ODE system. The good convergence of the eigenfunction expansions proved that this method is applicable for predicting the dynamic response of free-span pipelines subjected to both internal flow and external current.

• Steel and Composite Structures
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• v.47 no.5
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• pp.569-585
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• 2023

This paper proposes an efficient approach for the structural topology optimization of bi-directional functionally graded structures by incorporating popular radial basis functions (RBFs) into an implicit level set (ILS) method. Compared to traditional element density-based methods, a level set (LS) description of material boundaries produces a smoother boundary description of the design. The paper develops RBF implicit modeling with multiquadric (MQ) splines, thin-plate spline (TPS), exponential spline (ES), and Gaussians (GS) to define the ILS function with high accuracy and smoothness. The optimization problem is formulated by considering RBF-based nodal densities as design variables and minimizing the compliance objective function. A LS-RBF optimization method is proposed to transform a Hamilton-Jacobi partial differential equation (PDE) into a system of coupled non-linear ordinary differential equations (ODEs) over the entire design domain using a collocation formulation of the method of lines design variables. The paper presents detailed mathematical expressions for BiDFG beams topology optimization with two different material models: continuum functionally graded (CFG) and mechanical functionally graded (MFG). Several numerical examples are presented to verify the method's efficiency, reliability, and success in accuracy, convergence speed, and insensitivity to initial designs in the topology optimization of two-dimensional (2D) structures. Overall, the paper presents a novel and efficient approach to topology optimization that can handle bi-directional functionally graded structures with complex geometries.