• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1146-1151
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• 2011

Acoustic load from rocket propulsion system is main source of random vibration working on the payload. To protect payload from this acoustic load, additional APS(acoustic protection system) is generally applied. Noise reduction capacity of APS can be verified through acoustic test and vibro-acoustic coupled analysis. This paper compared the results of acoustic test and vibro-acoustic coupled analysis about KSLV-I payload fairing with APS.

• Journal of applied mathematics & informatics
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• v.33 no.5_6
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• pp.635-648
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• 2015

We consider a weakly coupled system of singularly perturbed convection-diffusion equations with discontinuous source term. The diffusion term of each equation is associated with a small positive parameter of different magnitude. Presence of discontinuity and different parameters creates boundary and weak interior layers that overlap and interact. A numerical method is constructed for this problem which involves an appropriate piecewise uniform Shishkin mesh. The numerical approximations are proved to converge to the continuous solutions uniformly with respect to the singular perturbation parameters. Numerical results are presented which illustrates the theoretical results.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.348-351
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• 2006

This paper presents preliminary laboratory investigations on the electrokinetic (EK) remediation coupled with permeable reactive barrier (PRB) system. Atomizing slag was adopted as a PRB reactive material for remediation of groundwater contaminated with inorganic and/or organic substances. A series of laboratory experiments were performed with variable conditions such as (i) type of contaminant, (ii) applied electric field strength, (iii) processing time, and (iv) the application of PRB system. From the preliminary investigations, the coupled technology of EK with PRB system would be effective to remediate contaminated grounds without the extraction of pollutants from subsurface due to the reactions between the reactive materials and contaminants.

• Journal of KSNVE
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• v.8 no.3
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• pp.477-484
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• 1998

An analytical procedure on the base of the substructure synthesis and assumed modes method is developed to investigate the flexibility effect of bladed disk assembly on vibrational modes of flexible rotor system. In modeling the system, Coriolis forces, gyroscopic moments, and centrifugal stiffening effects are taken into account. The coupled vibrations between the shaft and bladed disk are then extensively investigated through the numerical simulation of simplified models, with varying the shaft rotational speed and the prewist and stagger angles of the blade. It is found that the Coriolis and inertia forces and the inertia torque, which are induced by the one nodal diameter modes of the bladed disk and vary depending upon the stagger and prewist angles, lead to the coupled motions of the shaft and the bladed disk.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1040-1045
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• 2000

This paper presents results of coupled axial and torsional vibration analysis of shafting system in large diesel engines and generators for stationary power plants. Axial vibration of the shafting system takes place due to mainly torsional deformation or vibration and breathing effect of crank throws, caused by cylinder gas forces and reciprocating inertia of the engine. Cross-coupled stiffness matrix of the crank throws is calculated employing a finite element model of the crank throw and a static condensation method. Forced response analysis of the shafting system is performed using the calculated stiffness matrix and derived governing equations.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.10
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• pp.842-846
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• 2002

Design of gas concentration process using a fully thermally coupled distillation is conducted with the commercial design software HYSYS. Detailed procedure of the design is explained, and the performance of the process is compared with that of a conventional system A structural design is exercised for the design convenience. The design outcome indicates that the procedure is simple and efficient. The structural information yielded from equilibrium distillation gives an easy formulation of distillation system which is the initial input required from the setup of the distillation system The performance of the new process indicates that an energy saving of 17.6 % is obtained compared with the conventional process while total number of trays maintains at the same.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1002-1006
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• 2015

In this paper, design and analysis of permanent magnet synchronous generator for ocean thermal energy conversion (OTEC) considering magnetically coupled turbine-rotor system is discussed. In particular, the rotor dynamics considering bearing span and journal shaft diameter is highlighted. The two topologies of permanent magnet synchronous generator with magnetic coupling are employed for comparison of computed rotor dynamics and generating characteristics. The analysis results show that the critical speed of the turbine-rotor system is higher when the rotor is coupled by magnetically coupling. Finally, the experimental results confirmed the validity of the proposed design and analysis scheme and successful development.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.196-201
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• 2011

Acoustic load from rocket propulsion system is main source of random vibration working on the payload. To protect payload from this acoustic load, additional APS(acoustic protection system) is generally applied. Noise reduction capacity of APS can be verified through acoustic test and vibro-acoustic coupled analysis. This paper compared the results of acoustic test and vibro-acoustic coupled analysis about KSLV-I payload fairing with APS.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.768-771
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• 2007

Carbon nanotubes (CNTs) were synthesized by inductively coupled plasma CVD at $450^{\circ}C$. CNTs were grown on the 1-nm-thick Fe-Ni-Co with $C_2H_2$ and $H_2$ at different pressures and plasma powers. CNTs were grown longer in height as the $H_{\alpha}/CH$ ratios became lower by decreasing plasma powers and increasing growth pressures.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.93-96
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• 2004

Since a ductile coupled shear wall system is the primary seismic load resisting systems of many structures, a coupling beams of these system must exhibit excellent ductility and energy absorption capacity. In this paper, the seismic response of coupled shear wall system is discussed. The cyclic response of steel coupling beams embedded into reinforced concrete boundary elements was studied. Three half-scale subassemblies representing a portion of a prototype structure were designed. constructed, and tested. The main test variables were the connection details of hybrid coupled shear wall. These efforts have resulted in details for increasing the seismic capacity of steel coupling beam in the seismic behavior of buildings.