• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.302-307
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• 2005

Love wave and Rayleigh wave are the major elastic waves belonging to the category of the surface wave. The fact that Love wave is not contaminated by P-wave which makes Love wave superior to Rayleigh wave and other body waves. Therefore, the information that Love wave carries is more distinct and clearer than the information of Rayleigh wave. Based on theoretical research, the joint inversion analysis which is used both Love wave dispersion information and Rayleigh wave dispersion information was proposed. Purpose of the joint inversion analysis is to improve accuracy and convergency of inversion results utilizing that frequency contribution of each wave is different. This analysis technique is consisted of the forward modeling using transfer matrix, the sensitivity matrix determined to the ground system and DLSS(Damped Least Square Solution) as a inversion technique. The application of this analysis was examined through the field test.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.367-371
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• 1989

As a menas of designing a robust servo system for electrical motor drive system, an iterative learning control method is proposed by employing the structure of the model algorithmic control. A sufficient condition for the convergency is shown, and via simulation for permanent magnet synchronous motor drive system, it is demonstrated 1hat the method yields a 'good performance even in the presence of the external load distrurbances.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.474-478
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• 1999

Genetic algorithm is an efficient search method using principles of natural selection and population genetics. In conventional genetic algorithms, however, the size of gene pool should be increased to insure a convergency. Therefore, many memory spaces and much computation time were needed. Also, since child chromosomes were generated by chromosome crossover and gene mutation, the algorithms have a complex structure. Thus, in this paper, a compact stereo matching algorithm using a population-based incremental teaming based on probability vector is proposed to reduce these problems. The PBIL method is modified for matching environment. Since the Proposed algorithm uses a probability vector and eliminates gene pool, chromosome crossover, and gene mutation, the matching algorithm is simple and the computation load is considerably reduced. Even if the characteristics of images are changed, stable outputs are obtained without the modification of the matching algorithm.

• Tunnel and Underground Space
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• v.5 no.3
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• pp.205-213
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• 1995

In order to construct underground structural systems safely and economically, exact identification of the system parameters and accurate analysis of the system behaviors are required. Therefore, necessity of back analysis which is able to identify material properties of underground structural systems is increased. In this study a back analysis program which can identify the system parameters is developed using the direct method to be combined with the forward analysis program. Results of the back analysis program show good agreement with that of Gens et al. Sensitivity of the accuracy and convergency of the back analysis program on the number of measuring points is investigated. Comparison between the results of the back analysis with measurement data and the obtained material properties from the field tests shows good agreement for the real construction site.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.355-360
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• 2012

It is difficult to converge power flow for the power system planning data. The main cause of power flow diverse is reactive power imbalance. A active power could be adjust by ELD or merit order but a reactive power couldn't dispatch before power flow analysis. The lack of reactive power of power system is cause a inadequate voltage drop This paper suggest new reactive power dispatch algorithm using switched shunt admittance. This algorithm uses reactive power sensitivity called switch shunt jacobian. When proposed algorithm applies to real system data that couldn't be conversed in PSS/E the power flow analysis is converged.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.8 s.239
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• pp.1061-1069
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• 2005

In part I of this papter Nonlinear Response Optimization using Equivalent Static Loads (NROESL) method/algorithm is developed to conduct optimization for nonlinear behavior structures. The method/algorithm is also verified to show its convergency and optimality. In this present paper, the NROESL algorithm is applied to several structural problems with geometric and/or material nonlinearity. Conventional optimization with sensitivity analysis using the finite difference method is also applied to the same examples. The results of the optimizations are compared. The proposed method is very efficient and derives good solutions.

• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.181-189
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• 1998

A numerical study based on the three-dimensional Reynolds averaged Navier-Stokes equations is presented to analyze the transonic flowfield through two-stage axial compressor. Explicit four-step Runge-Kutta scheme is used for solution algorithm, and local time step and implicit residual averaging are introduced for enhancing the convergency. Artificial dissipation model is adopted to assure the stability of solution. The solver is coupled with Baldwin-Lomax model to describe turbulence. To avoid calculating the unsteady flow, a mixing process is modeled at a station between rotating and stationary blade rows. Results show a variety of important physical phenomena. Comparison of the flowfields with and without tip clearance shows that the effect is considerable in this flowfield. Comparisons with experimental data carried out to validate the calculational results show reasonable agreements. Some remedies are also suggested to improve the revealed problems.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1430-1435
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• 2003

Satellite upper platform is optimized by response surface method which has non-gradient, semi-glogal, discrete and fast convergency characteristics. Sampling points are extracted by design of experiments using Central Composite Method and Factorial Design. Also response surface is generated by the various regression functions. Structure analysis is execuated with regard for static and dynamic environment in launching stage. As a result response surface method is superior to other optimization method with respect to optimum value and cost of computation time. Also a confidence is varified in the various regression models.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.39-40
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• 2012

Construction IT convergency proposes advanced management abilities of a construction project. Sensing data provided by various sensor technologies can be utilized for diverse management areas. This study analyzes required functions of sensors for implementing time, cost, safety and quality management, focusing on the ground works including excavation, pipe installation, retaining wall etc. Therefore, this study first generates essential management areas, analyzes cutting-edge sensor technologies appropriated for the areas, and finally proposes a matrix system that represents relationships between the management areas and sensor technologies, The proposed system is expected to reinforce construction management abilities by integrating sensor technologies.

• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.95-110
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• 1995

n this research neural -based model was developed to forecast link travel times , And it is also compared wiht other time series forecasting models such as Box-Jenkins model, Kalman filter model. These models are validated to evaluate the accuracy of models with real time series data gathered by the license plate method. Neural network's convergency and generalization were investigated by modifying learning rate, momentum term and the number of hidden layer units. Through this experiment, the optimum configuration of the nerual network architecture was determined. Optimumlearining rate, momentum term and the number of hidden layer units hsow 0.3, 0.5, 13 respectively. It may be applied to DRGS(dynamic route guidance system) with a minor modification. The methods are suggested at the condlusion of this paper, And there is no doubt that this neural -based model can be applied to many other itme series forecating problem such as populationforecasting vehicel volume forecasting et .