• Journal of the Korea Society for Simulation
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• v.25 no.3
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• pp.97-105
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• 2016

This paper discusses the effect of numerical reinforcement modeling methods on the penetration performance of a penetrator into a concrete target. AUTODYN-3D has been used to conduct the numerical penetration analyses. In order to validate the computational approach, experimental data of Hanchak have been compared to a computation result and a reasonably good agreement could be obtained. The strength and the diameter of a reinforcement have been changed to find out the effect of reinforcement modeling methods on the penetration performance. The impact locations and velocities of a penetrator are also changed to investigate the effect of reinforcement modeling methods. Residual velocities of a penetrator are quantitatively compared in detail for the evaluation of reinforcement modeling effects on the penetration performance.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.79-88
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• 2010

This paper dealt with the performance modeling of a low bypass turbofan engine for supersonic aircraft. The Pratt and Whitney F100-PW-229 engine has been employed for low bypass turbofan engine performance modeling. Generally, the complete commercially-classified informations concerning the engine are unknown. The components' generic characteristics and assumptions made in order to build the F100-PW-229 engine performance model using by the published data from the open literature as basic data are described. Through the comparison of engine performance model's analysis data using Gasturb11 with engine deck data showed that the engine performance model was evaluated to be properly constructed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.239-248
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• 2010

This paper dealt with the Performance Modeling of a low-bypass turbofan engine for supersonic aircraft. The Pratt and Whitney F100-PW-229 engine has been employed for low-bypass turbofan engine performance modeling. Generally, The complete commercially-classified information concerning the engine are unknown. So, Components' generic characteristics are described and assumptions made in order to model the F100-PW-229 engine performance model. All the analysis has been undertaken using published data taken from the open literature. The results of the Engine Performance using Gasturb11 showed that the Engine performance model was evaluated to be properly constructed.

• The Journal of the Acoustical Society of Korea
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• v.22 no.1E
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• pp.33-42
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• 2003

Kuo et al proposed an on-line method for an adaptive prediction error filter for improving secondary path modeling performance in the modeling method of the secondary path. This method have some disadvantages, namely having to use additive noise with the result that noise control performance is not good since it is focused on the estimated performance of the secondary path. In this paper, we proposes a modified Kuo model using gain control parameter and delay. It uses a reference signal for additive noise to improve the problems in the existing Kuo model.

• 한국연소학회:학술대회논문집
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• 2013.06a
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• pp.59-60
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• 2013

Rotary kiln furnace is one of the most widely used gas-solid reactors in the industrial field. Although the rotary kiln is a versatile system and has different size, approach to the reactor modeling can be generalized in terms of flow motion of the solid and gas phase, heat transfer and chemical reactions on purpose. In this paper, a performance analysis example case of axial direction direct flame rotary kiln is introduced.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.8 s.239
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• pp.1153-1160
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• 2005

Many methods of spot weld modeling have been developed to increase efficiency and guarantee the robustness fer the CAE analysis. In this research they are introduced and the performance is compared in a viewpoint of stiffness and durability. For evaluating the performance a multi-spot welded specimen as well as two single welded specimen is used. The results show that the CWELD element considering 'patch to patch' is stiffer than other modeling methods in stiffness and more conservative in durability. It also offers simple modeling and since it is much easier to maintain the orrhogonality of the BAR element expressing a nugget, we can obtain more exact reaction forces and moments in a nugget. Therefore the CWELD element is the most excellent in the assessment of durability.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.6
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• pp.616-628
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• 2000

In this paper, we present the modeling of the ozone prediction system using Neuro-Fuzzy approaches. The mechanism of ozone concentration is highly complex, nonlinear, and nonstationary, the modeling of ozone prediction system has many problems and the results of prediction is not a good performance so far. The Dynamic Polynomial Neural Network(DPNN) which employs a typical algorithm of GMDH(Group Method of Data Handling) is a useful method for data analysis, identification of nonlinear complex system, and prediction of a dynamical system. The structure of the final model is compact and the computation speed to produce an output is faster than other modeling methods. In addition to DPNN, this paper also includes a Fuzzy Logic Method for modeling of ozone prediction system. The results of each modeling method and the performance of ozone prediction are presented. The proposed method shows that the prediction to the ozone concentration based upon Neuro-Fuzzy approaches gives us a good performance for ozone prediction in high and low ozone concentration with the ability of superior data approximation and self organization.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.383-388
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• 2004

A piezoelectric actuator yields hysteresis effect due to its composed ferroelectric. Hysteresis nonlinearty is neglected when a piezoelectric actuator moves with short stroke. However when it moves with long stroke and high frequency, the hysteresis nonlinearty can not be neglected. The hysteresis nonlinearty of piezoelectric actuator degrades the control performance in precision position control. In this paper, in order to improve the control performance of piezoelectric actuator, an inverse modeling scheme is proposed to compensate the hysteresis nonlinearty problem. And feedforward - feedback controller is proposed to give a good tracking performance. The Feedforward controller is inverse hysteresis model, Nueral network and PID control is used as a feedback controller. To show the feasibility of the proposed controller and hysteresis modeling, some experiments have been carried out. It is concluded that the proposed control scheme gives good tracking performance

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.592-596
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• 2012

The details of engine data are essentially needed for engine modeling and simulation. But, the engine data are kept secret because the information is company's experiential property. In this paper performed the performance modeling of the mixed flow turbofan engine cycles from the general available engine data, and verify the validity.

• Journal of the Korean Solar Energy Society
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• v.28 no.4
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• pp.56-61
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• 2008

The modeling of PV (Photovoltaic) module is useful to perform detailed analysis of PV system performance for changing meteorological conditions, verify actual rated power of PV system sizing and determine the optimal design of PV system and components. This paper indicates a modeling approach of PV module performance in terms of meteorological conditions and identifies validity of this modeling method by comparing measured with simulated value of various PV modules using simulation model.