• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.206-215
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• 2007

The objective of this study was to establish the optimal system operating strategies for nitrogen and phosphorus removal through model simulation system built for advanced wastewater treatment targeting on simultaneous temporal/special phase isolation BNR process. The simulation system was built with unit process modules using object modules in GPS-X code. The system was well verified by field experiment data. Simulation study was carried out to investigate performance response to design and operation parameters, i.e. hydraulic retention time (HRT), solids retention time (SRT), and cycle time. The process operated at HRTs of 10~15 hours, longer SRTs, and cycle time of 2 hours showed optimal removal of nitrogen. The HRTs of 10~15 hours, SRTs of 20~25 days, and longer cycle time was optimal for phosphorus removal. Both simulation and field studies showed that optimal operating strategies satisfying both the best nitrogen and phosphorus removals include HRTs ranged 10~15 hours, SRTs ranged 20~25 days, and cycle times of 4~8 hours. The simulation system with modularization of generalized components in BNR processes was, therefore, believed to be a powerful tool for establishing optimal strategies of advanced wastewater treatment.

• Journal of the Korea Computer Graphics Society
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• v.25 no.3
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• pp.55-63
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• 2019

Recently, the GPU computing method has been utilized to improve the performance of the physics simulation field. In particular, in the case of a deformed object simulation requiring a large amount of computation, a GPU-based parallel processing algorithm is required to guarantee real-time performance. We have studied the parallel structure design method to improve the performance of the mass spring simulation method which is one of the methods of implementing the deformation object simulation. We used OpenGL's GLSL, a graphics library that allows direct access to the GPU, and implemented the GPGPU environment using an independent pipeline, the compute shader. In order to verify the effectiveness of the parallel structure design method, the mass - spring system was implemented based on CPU and GPU. Experimental results show that the proposed method improves computation speed by about 6,000% compared to the CPU Environment. It is expected that the lightweight simulation technology can be effectively applied to the augmented reality and the virtual reality field by using the design method proposed later in this research.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.2
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• pp.135-145
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• 2023

Developing high-fidelity Computational Fluid Dynamics (CFD) simulation methods used to evaluate the airwake characteristics along a flight deck of a large ship, the various kind of data such as actual ship measurement and wind tunnel results are required to verify the accuracy of CFD simulation. Inflow velocity profile at the bow, local unsteady flow field data around the flight deck, and highly reliable wind tunnel data which were measured after reviewing Atmospheric Boundary Layer (ABL) simulation and Reynolds Number effects were also used to determine the key parameters such as turbulence model, time resolution and accuracy, grid resolution and type, inflow condition, domain size, simulation length, and so on in STAR CCM⁺. Velocity ratio and turbulent intensity difference between Full-scale CFD and actual ship measurement at the measurement points show less than 2% and 1.7% respectively. And differences in velocity ratio and turbulence intensity between wind tunnel test and small-scale CFD are both less than 2.2%. Based upon this fact, the selected parameters in CFD simulation are highly reliable for a specific wind condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.4
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• pp.102-107
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• 2015

In this paper, the generator control system by using PSCAD/EMTDC was modeled and several faults simulation were performed. The generator control system is composed of generator, turbine, exciter and governor. The parameters of generator control system model were obtained from field power plant. And then, the various transient phenomena through obtained several signal of developed modeling were analyzed.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.110-116
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• 2009

In the present study, we proposed a simulation model of vacuum booster with AMESIM software to predict the output characteristic. And we performed the sensitivity analysis of output characteristic with main design parameters, such as diaphragm diameter. All of these parameters are main design parameters in the procedure of vacuum booster design. The simulation results of this paper offer qualitative information of vacuum booster output. Therefore, the simulation results of this paper will be used effectively for the design procedure of vacuum booster in the industrial field.

• Journal of Korean Society of Transportation
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• v.11 no.1
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• pp.23-36
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• 1993

The two-lane, two-way highway simulation program(TWOPAS) is evaluated for Korean Highway Capacity Manual Study. TWOPAS program input variables, especially related vehicle performance, traffic flow relationship, car-following model and passing logic are examined and modified through the analysis results of our two-lane, two-way highway traffic characteristics. Simulation outputs with and without modification are compared with the field data. The results show that improved TWOPAS program(TWOPAS KI) is well suitable for simulating our two-lane, two-way highway condition.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.261-267
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• 2005

The unsteady flow analysis of staging system is conducted. This study focuses on comparing the results of two different governing equations between Euler equations and Navier-Stokes equations. The Chimera grid scheme is applied to moving simulations for unsteady flow analysis with dynamic simulation. As a result, it is certified that inviscid simulation have capabilities enough to analyze the present staging problem.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.826_827
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• 2009

This paper introduces major potential faults of Poly-Phase Permanent Magnet Synchronous Motor and their simulation realization methods. The faults of Poly-Phase PM Synchronous Motor, generally, stator turn faults, demagnetizing field. Based on the derived expressions, Poly-Phase PM synchronous Motor simulation model, which is capable of representing stator turn faults, is implemented in Maxwell.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.34-34
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• 2006

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.5-9
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• 2003

Stress and deflection of Active Fiber Composite(AFC) embedded and/or attached composite structures are numerically investigated at the constituent level by the Direct Numerical Simulation(DNS). The DNS approach which models and simulates the fiber and matrix directly using 3D finite elements need to be solved by efficient way. To handle this large scale problem, parallel program for solving piezoelectric behavior was developed and run on the parallel computing environment. Also, the stress result from DNS approach is compared with that from uniform field model.