• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.3
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• pp.23-32
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• 2002

We predict the erosion rate of unknown cannon tubes by substituting measured values of the standard cannon, 155㎜ Howitzer M185 and ballistic data for the erosion equation. We know ten measured erosion values of the standard cannon at every 400 rounds. An approximate formula is derived to interpolate six values up to 2,000 rounds. Numerical example is presented and its results are analyzed. The new erosion equation is also suggested. This equation produces more accurate cannon tube erosion rate than the Rauf Imam's empirical approaches. Computer simulations are presented.

• BMB Reports
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• v.30 no.1
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• pp.7-12
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• 1997

The kinetics of the interesterification of triolein and stearic acid catalyzed by immobilized Rhizopus delemar lipase were studied in a batch operation. In order to clarify the mechanisms of this reaction, three models are discussed under various conditions in terms of the ratio of triolein and stearic acid. The rate constants involved in the proposed model were determined by combining the numerical Gauss-elemination method, and the trial-and-error method so as to fit the calculated results with the experimental data. The accuracy of the obtained rate constants was confirmed after they were substituted for simultaneous differential equations and the equations simulated using an adaptive step-size Runge-Kutta method. Finally, the model which agrees with the calculated results and the experimental data was selected.

• Journal of ILASS-Korea
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• v.7 no.4
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• pp.9-15
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• 2002

Convolution Fourier transformation tomographically reconstructs the spatially resolved spray injection rate from direct measuring cells. Asymmetric sprays generated from a twin-hole air shroud injector are tested with 12 equiangular projections of measurements. For each projection angle, line of sight integrated injection rate was measured at 35 positions with equal spacing measuring cells of 3 mm in width, 100 mm in length, 55 mm in depth and 0.5 mm thickness of separating wall. Interpolated data between the projection angles effectively increase the number of projections, which significantly enhances the signal-to-noise level in the reconstructed data. This modified convolution Fourier transformation scheme predicts well the structure of asymmetric sprays. Comparative study has been made between sprays with and without air shrouding. Tomograhpic reconstruction of injection rate from direct measuring cells obtained can be used to estimate the accuracy of volume fraction of spray from the LDPA tomographic reconstruction.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1316-1319
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• 2002

In this paper, an online SNR estimator is derived for turbo coded multicode DS/SS systems in Nakagami fading channels. The multicode DS/SS approach is one of promising solutions to obtain higher-rate data transmission in DS/SS technologies. Turbo coding has paid much attention because of the significant improvements on error rate performances in various communication systems including multicode DS/SS systems. However, in the turbo decoding, channel state information, especially signal-to-noise ratio (SNR) at the correlator outputs, is desired in order to obtain such improvements. We evaluate the accuracy of the derived SNR estimation. It is shown that the bit error rate performance using our SNR estimation is close to the performance with perfect knowledge of channel state information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.217-221
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• 2005

The E-field intensity by mobile handsets in a phantom is measured by a 3 axes miniature probe. The detected DC voltage by a Schottky diode in a probe has nonlinear characteristics by itself. If a pertinent diode compression point (DCP) is applied for the compensation specific absorption rate(SAR) as much as 200 W/kg can be measured with a good measurement accuracy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2072-2078
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• 2003

In this paper, the boundary element analysis of viscoelastic strain energy release rate G(t) for the cracked linear viscoelastic solids has been attempted. This study proposes the G(t) equation and the calculating method of G(t) by time-domain boundary element analysis for the viscoelastic solids. The G(t) is defined as the derivative of the viscoelastic potential energy II(t) with respect to crack length a. Two example problems are presented to show the applicability of the proposed method to the analysis of the cracked linear viscoelastic solids. Numerical results of example problems show the accuracy and effectiveness of the proposed method.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.4
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• pp.56-63
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• 2008

Image calibration at preprocessing step is very important for face recognition rate improvement, and background noise deletion affects accuracy of face recognition specially. In this paper, a method is proposed to remove background area utilizing elliptical model at preprocessing step for face recognition rate improvement. As human face has the shape of ellipse, a face contour can be easily detected by using the elliptical model in face images.

• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.305-310
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• 2002

The measured rate of the tracking sensor becomes biased under some operational situation. For a highly maneuverable aircraft in 3D space, the target dynamics changes from time to time, and the Kalman filter using position measurement only can not be used effectively to reject the rate measurement bias error. To cope with this problem, we present a new algorithm which incorporate FIR-type filter and FIR-type fixed-lag smoother, and demonstrate that it has the optimal performance in terms of both estimation accuracy and response time through an application example to the anti-aircraft gun fire control system(AAGFCS).

• Journal of Korea Multimedia Society
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• v.20 no.2
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• pp.234-243
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• 2017

With the development of smartphone technologies enable photoplethysmogram (PPG) acquisition by camera and heart rate (HR) measurement. This papers presents improved algorithm to extract HR from PPG signal recorded by smartphone camera and to develop real-time PPG signal processing Android application. 400 video samples recorded by Samsung smartphone camera are imported as input data for further processing and evaluating algorithm on MATLAB. An optimized algorithm is developed and tested on Android platform with different kind of Samsung smartphones. To assess algorithm's performance, medical device Beurer BC08 is used as reference. According to related works, accuracy parameters includes 90% number of samples that has relative errors less than 5%, Person correlation (r) more than 0.9, and standard estimated error (SEE) less than 5 beats-per-minutes (bpm).

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1505-1510
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• 2001

A method for mapping quantitative trait loci (QTL) was introduced incorporating the information of mixed progeny from complex pedigrees. The method consisted of two steps based on single marker analysis. The first step was to examine the marker-trait association with a mixed model considering common environmental effect and reversed QTL-marker linkage phase. The second step was to estimate QTL effects by a weighted least square analysis. A simulation study indicated that the method incorporating mixed progeny from multiple generations improved the accuracy of QTL detection. The influence of within-genotype variance and recombination rate on QTL analysis was further examined. Detecting a QTL with a large within-genotype variance was more difficult than with a small within-genotype variance. Most of the significant marker-QTL association was detectable when the recombination rate was less than 15%.