• Wind and Structures
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• v.29 no.2
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• pp.129-137
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• 2019

The maximum along-wind displacement of a considerable amount of building under simulated wind loads is computed with the aim to produce a simple prediction model using multiple regression analysis with variables transformation. The Shinozuka and Newmark methods are used to simulate the turbulent wind and to calculate the dynamic response, respectively. In order to evaluate the prediction performance of the regression model with longer degree of determination, two complex structural models were analyzed dynamically. In addition, the prediction model proposed is used to estimate and compare the maximum response of two test buildings studied with wind loads by other authors. Finally, it was proved that the prediction model is reliable to estimate the maximum displacements of structures subjected to the wind loads.

• Journal of Aerospace System Engineering
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• v.13 no.4
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• pp.10-17
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• 2019

This study is concerned with a numerical analysis based on the finite element method to describe the effect of midplane delamination in smart laminated composite plate structures. A new finite element model for centrally located delamination and healthy section was developed and coded in Matlab. The transient analysis of delaminated composite plate with integrated Active Fiber Composite (AFC) was investigated in the present article. The formulation of the governing equation was based on the minimum total potential energy approach. The Newmark time integration technique was employed to solve the differential equations. A parametric study on the effects of boundary conditions and AFC patch location, in presence of delamination on the laminated plate were studied.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.51.1-51.1
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• 2019

The Korea Astronomy and Space Science Institute (KASI) has been developing a coronagraph in collaboration with the National Aeronautics and Space Administration (NASA), to install it on the International Space Station (ISS). The coronagraph will utilize spectral information to simultaneously measure electron density, temperature, and velocity. For this, we develop the coronagraph as a two-step process. First, we will perform a stratospheric balloon-borne experiment, so called BITSE, in 2019 with a new type of coronagraph. Second, the coronagraph will be installed and operate on the ISS (CODEX) in 2021 to address a number of questions (e.g., source and acceleration of solar wind, and coronal heating) that are both fundamental and practically important in the physics of the solar corona and of the heliosphere. In this presentation, we will introduce recent progresses.

• Earthquakes and Structures
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• v.22 no.4
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• pp.431-437
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• 2022

One of the best choice for transportation of oil and gas at the end of rivers or seas is concrete pipelines. In this article, a concrete pipe at the end of river is assumed under the earthquake load. The Classic shell theory is applied for the modelling and the corresponding motion equations are derived by energy method. An external force induced by fluid around the pipe is asssumed in the final motion equations. For the solution of motion equations, the differential quadrature method (DQM) and Newmark method are applied for deriving the dynamic deflection of the pipe. The effects of various parameters including boundary conditions, fluid and length to thickness ratio are presented on the seismic response of the concrete pipe. The outcomes show that the clamped pipe has lower dynamic deflection with respect to simply pipe. In addition, with the effect of fluid, the dynamic defelction is increased significantly.

• Coupled systems mechanics
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• v.12 no.1
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• pp.83-102
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• 2023

First introduced in 2016, the dynamic foundation model is an interesting topic in which the foundation is described close to reality by taking into account the influence of the foundation mass in the calculation of oscillation and is an important parameter that should be considered. In this paper, a follow-up investigation is conducted with the object of the Mindlin plate on a nonlinear dynamic foundation under moving loads. The base model includes nonlinear elastic springs, linear Pasternak parameters, viscous damping, and foundation mass. The problem is formulated by the finite element analysis and solved by the Newmark-β method. The displacement results at the center of the plate are analyzed and discussed with the change of various parameters including the nonlinear stiffness, the foundation mass, and the load velocity. The dynamic response of the plate sufficiently depends on the foundation mass.

• Advances in nano research
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• v.14 no.2
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• pp.179-193
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• 2023

Physical activities enhance blood flow in the vessels, which may increase the quality of medicine delivery. The emergence of revolutionary technologies such as nanoscience, made it possible to treat the incurable illnesses such as cancer. This paper investigates the impact of sport and physical exercises on the quality and quantity of the drug-delivery based on the mathematical modeling of a nanomotor made by nanotubes carrying the nano-drug capsules. Accordingly, the mathematical equations of rotating nanomotor are generated by considering the both of higher-order beam model and nonlocal strain gradient model, as a comprehensive continuum theory. Next, through the generalized differential quadrature together with Newmark-beta methods, the differential relations are discretized and solved. Finally, the impact of varied parameters on the dynamical behavior of the nanomotor is examined in detail. The outcomes of this investigation can be useful to achieve an excellent design of nanomotors carrying nano-drugs.

• Steel and Composite Structures
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• v.42 no.5
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• pp.649-655
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• 2022

In presented paper, moving load problem of simply supported axially functionally graded (AFG) beam is investigated under temperature rising based on the first shear beam theory. The material properties of beam vary along the axial direction. Material properties of the beam are considered as temperature-dependent. The governing equations of problem are derived by using the Lagrange procedure. In the solution of the problem the Ritz method is used and algebraic polynomials are used with the trivial functions for the Ritz method. In the solution of the moving load problem, the Newmark average acceleration method is used in the time history. In the numerical examples, the effects of material graduation, temperature rising and velocity of moving load on the dynamic responses ofAFG beam are presented and discussed.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.56.4-56.4
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• 2019

The Korea Astronomy and Space Science Institute (KASI) has been collaborating with the NASA's Goddard Space Flight Center, to install a coronagraph on the International Space Station (ISS). The coronagraph will utilize spectral information to simultaneously measure electron density, temperature, and velocity. As a first step, we developed a new coronagraph and launched it on a stratospheric balloon in 2019 (BITSE) from Fort Sumner, New Mexico in USA. As the next step, the coronagraph will be be further developed, installed and operate on the ISS (CODEX) in 2022 to address a number of important questions (e.g., source and acceleration of solar wind, and coronal heating) in the physics of the solar corona and the heliosphere. Recently, BITSE has been launched at Fort Sumner, New Mexico. In this presentation, we will introduce the BITSE mission and discuss recent progress.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.57.1-57.1
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• 2019

NASA and Korea Astronomy and Space Science Institute (KASI) have been collaborated to develop the Space solar coronagraph instrument to detect the solar wind speed and corona temperature. As an intermediate stage, BITSE is the Balloon-Borne instrument to prove our proposed technical method which uses a polarized light in 4 different bandwidth wavelengths. In the presentation, the optical design based on the requirements, tests and alignment process for integrating the system are discussed.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.58.2-58.2
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• 2019

BITSE is a technology demonstration mission to remotely measure the speed, temperature, and density of the solar wind as it forms as close as 3 Rs. BITSE obtained coronal images during its one day flight above more than 99% of the atmosphere, and calibration data are taken in the laboratory as well as during the flight. As the linearly polarized K-corona is much fainter than other bright sources like diffraction, sky, and F-corona, a careful data reduction is required to obtain reliable scientific results. We will report status of the obtained data, the reduction progress, and future plan.