• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.231-232
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• 2002

Various methods that utilize erosion rate measurement of standard cannon, 155mm Howitzer M185, as reference, are being used to calculate erosion rate of an interested unknown cannon tubes. We know ten measured erosion values of the standard cannon from 391 rounds to 4.000. An approximate function fitting these value s is derived. The new erosion equation is also suggested and computer simulations arc presented.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1867-1873
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• 2000

Function approximation from a set of input-output pairs has numerous applications in scientific and engineering areas. Support vector machine (SVM) is a new and very promising classification, regression and function approximation technique developed by Vapnik and his group at AT&TG Bell Laboratories. However, it has failed to establish itself as common machine learning tool. This is partly due to the fact that this is not easy to implement, and its standard implementation requires the use of optimization package for quadratic programming (QP). In this appear we present simple iterative Kernel Adatron (KA) algorithm for function approximation and compare it with standard SVM algorithm using QP.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.3
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• pp.274-280
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• 1992

In this paper, an Improved Error Back Propagation Algorithm is introduced, which avoids Network Paralysis, one of the problems of the Error Backpropagation learning rule. For this purpose, we analyzed the reason for Network Paralysis and modified the Activation Function Derivative of the standard Error Backpropagation Algorithm which is regarded as the cause of the phenomenon. The characteristics of the modified Activation Function Derivative is analyzed. The performance of the modified Error Backpropagation Algorithm is shown to be better than that of the standard Error Back Propagation algorithm by various experiments.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.335-342
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• 2001

In this paper, an improved Element-Free Galerkin (EFG) method is proposed by adding enrichment function to the standard EFG approximation and a discontinuity function is implemented in constructing the shape function across the crack surface. In this method, the singularity and the discontinuity of the crack are efficiently modeled by using initial node distribution to evaluate reliable stress intensity factor, though the standard EFG method requires placing additional nodes near the crack tip. The proposed method enables the initial node distribution to be kept without any additional nodal d.o.f. and expresses the asymptotic stress field near the crack tip successfully. Numerical example verifies the improvement and the effectiveness of the method.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.1
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• pp.10-18
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• 2009

Numerical simulation has been performed in this study to investigate the capabilities of turbulence modeling schemes on estimating the film cooling at a referenced parallel wall jet-nozzle configuration. Also a additional simulation has been performed for film cooling under 2-dimensional axis symmetry conditions at a parallel wall jet-nozzle configuration. It was concluded that the best turbulence model is the standard $k-{\epsilon}$ model with enhanced wall functions. Also a additional simulation showed the film cooling characteristics that are resonable physically.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.381-390
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• 2001

In this paper, a new improved crack analysis technique by Element-Free Galerkin(EFG) method is proposed, in which the singularity and the discontinuity of the crack successfully described by adding enrichment terms containing a singular basis function to the standard EFG approximation and a discontinuity function implemented in constructing the shape function across the crack surface. The standard EFG method requires considerable addition of nodes or modification of the model. In addition, the proposed method significantly decreases the size of system of equation compared to the previous enriched EFG method by using localized enrichment region near the crack tip. Numerical example show the improvement and th effectiveness of the previous method.

• Journal of the Korean Ceramic Society
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• v.47 no.5
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• pp.373-380
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• 2010

In this study, we studied on the durability of restorative cement mortar for deteriorated concrete at complex deteriorated conditions as variation of temperature and of humidities. We made a comparison between restorative materials with insulation function and restorative materials without insulation function in items of compressive and bending strength and permeability of water, durability for carbonation, salt damage, diffusion coefficient of salt at complex deterioration conditions like change of temperature, change of humidity, For insulation, we used close-pore type Alumino-Silicate lightweight aggregate and substituted 12 wt% and 15 wt% out of original restorative cement mortar without insulation function. As a result, it was found that original restorative cement mortar without insulation function fail to meet Korean Standard on polymer modified cement mortar for maintenance in concrete structure, but restorative cement mortar with insulation function is in contentment Korean Standard to meet excellent than restorative materials without insulation function for durability at complex deteriorated conditions.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.586-592
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• 1999

We investigate the characteristic of 소데 responses of the Manabe standard form which is used recently for design of the controller. We obtain some theorems and these theorems have the properties of the relationship between the roots of the polynomial and the stability indices which are used for the Manabe standard form. The Manabe standard form has the following properties: The sum of the squal to zero, the sum of the reciprocal of the squared roots is greater than zero and the parameter $\tau$ is the negative value of the sum of the reciprocal of the roots. We compare the step responses of the Manabe standard form with those of the ITAE form, the dead beat response and Bessel forms. We choose the 6th order closed loop polynomial and keep the same settling time for the four forms. Under these conditions we find that the Manabe standard form have faster 90% rising time than the Bessel and dead beat response. We see that the ITAE, bessel and dead beat responses have some overshoot, whereas the Manabe standard form has none. We also compare the Manabe form with the other three forms for the controller design using the pole assignment technique. If the open loop transfer function is a type-1 system (transfer functions having one integrator), then, for the closed loop system associated with the open loop transfer function, the steady state error of the unit ramp input is obtained in terms of the parameter $\tau$ of the Manabe standard form.

• Journal of Auto-vehicle Safety Association
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• v.12 no.3
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• pp.27-33
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• 2020

In this paper, the process of predicting efficient durability performance for vibration durability test of automobile parts using vibration test load on automobile fuel tank is presented. First of all, the common standard load that can be applied to the initial development process of the automobile was used for the fuel tank and the vulnerability of the fuel tank to the vibration fatigue load was identified through frequency response analysis. In addition, the vulnerability of the fuel tank was re-enacted through vibration durability test results, and the scale factor was applied to the standard load. In order to predict the vibration durability performance required for detailed design, vibration fatigue analysis was performed on the developed vehicle with the frequency of vibration severity equivalent to the durability test, and the vulnerability and life span of the fuel tank were identified through the process of applying weights to these selected standard loads, thereby reducing the test time of the development vehicle.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.141-146
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• 2020

Cine-Hangeul is a program that can predict the running time of a movie based on the screenplay before production. This paper seeks to verify the prediction reporting function of Cine-Hangeul, which is the standard Korean screenplay format. Moreover, this paper presents a method to increase the accuracy of the Cine-Hangeul reporting function. The objective of this paper is to offer a correction method based on scientific evidence because the current Cine-Hangeul reporting function has many errors. The verification process for five scenarios and movies confirmed that the default setting value of Cine- Hangeul's screening time prediction reporting was many errors. Cine-Hangeul analyzes the amount of textual information to predict the time of the scene and the time of the dialogue and helps predict the total time of the movie. Therefore, if a certain amount of text information is not available, the accuracy is unreliable. The current Cine-Hangeul prediction report confirms that the efficiency is high when the scenario volume is about 90 to 100 pages. As a result, prediction of screening time by Cine-Hangeul, a Korean scenario standard format program, confirmed the verification that it could secure the same level of reliability as the actual screening time by correcting the reporting settings. This verification also affirms that when applying about 50 percent of the basic set of screening time reporting, it is almost identical to the screening time.