• Journal of Ocean Engineering and Technology
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• v.33 no.5
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• pp.387-393
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• 2019

In this study, the free motion of a riser due to vortex shedding was numerically simulated with Large Eddy Simulation (LES) and Detached Eddy Simulation (DES) turbulence models. A numerical simulation program was developed by applying the Rhie-Chow interpolation method to the pressure correction of the OpenFOAM standard solver pimpleDyMFoam. To verify the developed program, the vortex shedding around the fixed riser at Re = 3900 was calculated, and the results were compared with the existing experimental and numerical data. Moreover, the vortex-induced vibration of a riser supported by a linear spring was numerically simulated while varying the spring constant. The results are compared with published direct numerical simulation (DNS) results. The present calculation results show that the numerical method is appropriate for simulating the vortex-induced motion of a riser, including lock-in phenomena.

• Journal of the Korea Society for Simulation
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• v.24 no.4
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• pp.51-58
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• 2015

Since SBA is regarded as mandatory for DM&S, many M&S frameworks and solutions were developed and applied to military simulation systems. Simulation systems developed based on such framework or solution are consist of simulation control part, scenario generation part and modeling part in common. Although the functions of these parts are similar between another simulation systems, these are developed separately by different implementation, so it causes increase of development cost. In order to solve these problems, we developed a simulation scenario framework which can be reusable regardless of simulation purpose. In this paper, we propose an architecture of simulation scenario framework and its functions.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.546-547
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• 2014

본 논문에서는 LabVIEW와 Multisim을 이용한 Co-simultion 기능으로 얻은 시뮬레이션 결과와 그 과정을 기술한다. 3-Level NPC Inverter를 제어하였으며 동일한 조건에서 PSIM으로 시뮬레이션한 결과와 비교하여 보았다.

• Journal of Information Processing Systems
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• v.9 no.3
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• pp.499-510
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• 2013

Hardware-Software co-simulation of a multiple image encryption technique shall be described in this paper. Our proposed multiple image encryption technique is based on the Latin Square Image Cipher (LSIC). First, a carrier image that is based on the Latin Square is generated by using 256-bits of length key. The XOR operation is applied between an input image and the Latin Square Image to generate an encrypted image. Then, the XOR operation is applied between the encrypted image and the second input image to encrypt the second image. This process is continues until the nth input image is encrypted. We achieved hardware co-simulation of the proposed multiple image encryption technique by using the Xilinx System Generator (XSG). This encryption technique is modeled using Simulink and XSG Block set and synthesized onto Virtex 2 pro FPGA device. We validated our proposed technique by using the hardware software co-simulation method.

• Corrosion Science and Technology
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• v.15 no.2
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• pp.78-83
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• 2016

The e-coating to inhibit induced corrosion can deposit a coating not only on the exterior surface but also on the inside of whole metallic components of body-in-white (BIW). But it is difficult to deposit paint films on the inside area because metallic components are multi layered. It may cause shortness of e-coating thickness. The only way to properly verify e-coating thickness is by performing the use of tear-down prototypes. When paint films' thickness is inadequate, a structural modification on each metallic component is needed. Verification of the thickness improvement for a structural modification requires much manual effort and leads to increasing development time. Recently, the simulation technology has been developed to predict the e-coating thickness in e-coating field. By applying the simulation to BIW, improvement in paint thickness quality and shortening of development period are expected. The paper explains a validated solution that allows simulating the effect of design changes to the e-coating thickness and current density, thereby delivering results within a time frame of a few days.

• Proceedings of the Korean Magnestics Society Conference
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• 1993.03a
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• pp.94-95
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• 1993

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.396-399
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• 1999

In this paper, the efficient HW/SW co-simulation method which selects the ISA model dynamically is proposed. Because the ISA models with only fixed accuracy have been used in previous co-simulation environment, it may result in bad performance in speed or accuracy. In the proposed method, the cycle accurate ISA model is used in the case that the states of the detailed system are to be inspected. In other case, instruction-based model is executed in order to accelerate the simulation speed. The proposed dynamic model selection can be done by setting the conversion point in the application code before the simulation starts. The experiment on the embedded RISC processor have been performed, and its result shows that the proposed method is more efficient than the case of using fixed ISA model.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.573-574
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• 2011

본 논문에서는 DC-DC 컨버터의 설계 및 해석 방법을 PSpice와 Simulink를 이용한 Co-Simulation방법으로 제안하였다. 일반적인 회로 및 제어기 설계방식은 회로와 제어기를 각각 설계하여 시제품으로 측정하는 방법과 이상적인 모델을 이용하여 시뮬레이션 하는 방법을 사용한다. 본 논문에서는 상용 소자모델로 구성된 컨버터를 PSpice로 설계하였고, Simulink에서 PSpice Solver를 이용하여 시뮬레이션 함으로써 일반적인 설계 방식보다 높은 신뢰성을 가진 시뮬레이션 방법을 제안한다.

• Journal of Information Display
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• v.6 no.3
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• pp.26-29
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• 2005

Nanosize cobalt aluminate($CoAl_2O_4$) power was coated as filter layer for us to improve the color purity and contrast performances on the inner face of CRT panel. We simulated color properties by measuring the transmittance and thickness of the coated filter layer. Contrast performance could be improved and color gamut was also changed by the selective light absorption of filter layer at 580${\sim}$605 nm.

• Membrane and Water Treatment
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• v.7 no.5
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• pp.463-476
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• 2016

In this study, application of polypropylene hollow fiber membrane contactors for $CO_2$ removal from water in liquid-liquid extraction (LLE) mode was simulated. For this purpose, a steady state 2D mathematical model was developed. In this model axial and radial diffusion was considered to $CO_2$ permeation through the hollow fibers. $CO_2$ laden water is fed at a constant flow rate into the lumen side, permeated through the pores of membrane and at the end of this process, $CO_2$ solution in the lumen side was extracted by means of aqueous diethanolamine (DEA) and chemical reaction. The simulation results were validated with the experimental data and it was found a good agreement between them, which confirmed the reliability of the proposed model. Both simulation and experimental results confirmed the reduction in the percentage of $CO_2$ removal by increment of feed flow rate.