• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.359-364
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• 2004

This paper deals with the comparison of signal processing techniques of ultrasonic data. The goal of signal processing is the ultrasonic speckle suppression and the visibility enhancement of flaw-reflected ultrasonic echo. The performance of conventional SSP(split spectrum processing) method and the wavelet denoising method are compared and discussed for tested ultrasonic data. Tested ultrasonic data obtained from the weld area of centrifugal-casted stainless steel material and safe-ending material with holes and notch of variable depths are presented. In experimental results, the outputs of wavelet-based denoising method show the clear and sharp peaks at the positions of flaw-reflected echos comparing with those of SSP method.

• Journal of the Korean Data and Information Science Society
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• v.18 no.1
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• pp.17-29
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• 2007

The major purpose of this article is the comparison of estimation method with Newton-Raphson, Kalman-filter, and prediction method with Kalman prediction. Conditional expectation in space time bilinear(STBL) model, which is a very powerful and parsimonious nonlinear time-series model for the space time series data can be viewed as a set of time series collected simultaneously at a number of spatial locations and time points, and which have appeared in a important applications areas: geography, geology, natural resources, ecology, epidemiology, etc.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.210-215
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• 2003

Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The KHST figured 7 cars was modeled for dynamic simulation with Vampire program. and the data acquisition system was used to test successfully the on-line test for proving the dynamic performance of KHST. The comparison between test and simulation results for dynamic behavior of KHST was tried in this paper and it was very difficult because the environmental conditions and running conditions have an effect on the test results and these conditions are unable to be modeled for dynamic analysis. Also the parameters for data acquisition system for test are usually not same to simulation conditions. Therefor, in this paper the acceleration data after filtering with low pass filter below 1Hz were used to compare between test and simulation results because the low frequency range is useful to evaluate the dynamic performance for railway vehicle system, so as steady state curving acceleration. The results show that both are similar in low frequency range.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.177-183
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• 2015

A high speed VLSI digital Winner-Take-All (WTA) circuit called simultaneous digital WTA (SDWTA) circuit is presented in this paper. A minimized comparison-cell (w-cell) is developed to reduce the size and to achieve high-speed. The w-cell which is suitable for VLSI implementation consists of only four transistors. With a minimized comparison-cell structure SDWTA can compare thousands of data simultaneously. SDWTA is scalable with O(mlog n) time-complexity for n of m-bit data. According to simulations, it takes 16.5 ns with $1.2V-0.13{\mu}m$ process technology in finding a winner among 1024 of 16-bit data.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.556-561
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• 2011

It is generally known that particle filters can produce consistent target tracking performance in comparison to the Kalman filter for non-linear and non-Gaussian systems. In this paper, I propose a Rao-Blackwellized multiple model particle filter(RBMMPF) to enhance computational efficiency of the particle filters as well as to reduce sensitivity of modeling. Despite that the Rao-Blackwellized particle filter needs less particles than general particle filter, it has a similar tracking performance with a less computational load. Comparison results for performance is listed for the using single sensor information RBMMPF and using multisensor data fusion RBMMPF.

• Journal of Korea Multimedia Society
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• v.21 no.3
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• pp.391-399
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• 2018

In this paper, we construct and compare various guitar chord classification systems using perceptron neural network and convolutional neural network without pre-processing other than Fourier transform to identify the optimal chord classification system. Conventional guitar chord classification schemes use, for better feature extraction, computationally demanding pre-processing techniques such as stochastic analysis employing a hidden markov model or an acoustic data filtering and hence are burdensome for real-time chord classifications. For this reason, we construct various perceptron neural networks and convolutional neural networks that use only Fourier tranform for data pre-processing and compare them with dataset obtained by playing an electric guitar. According to our comparison, convolutional neural networks provide optimal performance considering both chord classification acurracy and fast processing time. In particular, convolutional neural networks exhibit robust performance even when only small fraction of low frequency components of the data are used.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.184-187
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• 2005

Forging process is one of the forming process and is used widely in automobile parts and manufacture industry. Especially the gears like spur gear, helical gear, bevel gear were produced by machine tool, but recently they have been manufactured by forging process. The goal of this study is to study forming process with data obtained by comparison between forward extrusion and upsetting simulation results and formability improvement by various heat treatment conditions. By analysis data of 3D FEM by upsetting and forward extrusion forming, the forming process of clutch gear develops using data based on 3D FEM analysis. Through tensile test using specimens by various heat treatment conditions, the optimal heat treatment condition is obtained by comparison the results of tensile test.

• The Korean Journal of Health Service Management
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• v.6 no.4
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• pp.267-277
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• 2012

The purpose of this descriptive research is to identify the recognition and attitude of college students towards Complementary & Alternative Medicine (CAM). The subjects of the study were 620 students of a junior college in the D metropolitan city. The data was collected from July 2 to July 31, 2012 and SPSS/WIN 18.0 program was used to analyze the data. From the comparison of CAM recognition between the two groups. There were significant differences for each item of CAM recognition. For the attitude on CAM, there were significant differences between the two groups. There needs to be more follow-up studies based on the current study in order to establish the basic data that can help find specific educational methods for the areas of CAM that lack recognition from the students.

• The Korean Journal of Applied Statistics
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• v.21 no.5
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• pp.855-866
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• 2008

Recently many small area estimation methods using the lattice data analysis have been studied and known that they have good performances. In the case of using the lattice data which is mainly used for small area estimation, the choice of better neighborhood information system is very important for the efficiency of the data analysis. Recently Lee and Shin (2008) compared and analyzed some neighborhood information systems based on GIS methods. In this paper, we evaluate the effect of various neighborhood information systems which were suggested by Lee and Shin (2008). For comparison of the estimators, MSE, Coverage, Calibration, Regression methods are used. The number of unemployment in Economic Active Population Survey(2001) is used for the comparison.

• Nuclear Engineering and Technology
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• v.27 no.1
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• pp.74-83
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• 1995

The accurate determination of the fast neutron flux/fluence onto the pressure vessel is an essential part of the reactor pressure vessel surveillance program. It has been reported recently that the iron cross section data in ENDF/B versions III through V might underestimate the flux/fluence of fast neutrons in steel structures such as reactor pressure vessel. In this study, for the comparison of iron data of ENDF/B-IV and VI we produced two 47-group cross section sets, CXFe-IV and CXFe-Ⅵ, which are based on Yonggwang nuclear unit-3/4 model and the iron data of ENDF/B-IV and VI, respectively. A comparison was made of the results obtained from DOT4.3 calculation using CXFe-IV and CXFe-VI. From the results, it was found that the fast flux(E 〉 1.0 MeV), which is important for the pressure vessel embrittlement analysis, increases by about 7.6％ at the inner wall and 20％ at the outer wall of the vessel, if the iron data are used from ENDF/B-VI instead of ENDF/B-IV.