• MALSORI
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• no.60
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• pp.67-84
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• 2006

The purpose of this study is to find some acoustic parameters on frequency domain to distinguish the Korean nasals, $/m,\;n,\;{\eta}/$ from each other. The new parameters are devised on the basis of LTAS (Long Term Average Spectrum). The maximum peak amplitude and the relevant formant frequency are measured in low and high frequency range, respectively. The frequency of spectral valley and its energy level are also obtained in the specific frequency range of the spectrum. Spectral slope, total energy value in specific frequency range, statistical distribution of spectral energy like centroid, skewness, and kurtosis are suggested as new parameters as well. The parameters that show statistically significant differences across nasals are summerized as follows. 1) in syllable initial positions: the total energy value from 1,500 to 2,200 Hz(zeroENG); 2) in syllable final positions: the peak amplitude of the first formant(peak1_a), the formant frequency with maximum peak amplitude from 4,000 to 8,000 Hz(peak2_f), the maximum peak amplitude of the formant frequency from 4,000 to 8,000 Hz(peak2_a), and the total energy value from 1,500 to 2,200 Hz(zeroENG).

• Wind and Structures
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• v.34 no.6
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• pp.469-482
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• 2022

The generalized extreme value distribution (GEVD) is frequently used to fit the block maximum of environmental parameters such as the annual maximum wind speed. There are several methods for estimating the parameters of the GEV distribution, including the least-squares method (LSM). However, the application of the LSM with the expected order statistics has not been reported. This study fills this gap by proposing a fitting method based on the expected order statistics. The study also proposes a plotting position to approximate the expected order statistics; the proposed plotting position depends on the distribution shape parameter. The use of this approximation for distribution fitting is carried out. Simulation analysis results indicate that the developed fitting procedure based on the expected order statistics or its approximation for GEVD is effective for estimating the distribution parameters and quantiles. The values of the probability plotting correlation coefficient that may be used to test the distributional hypothesis are calculated and presented. The developed fitting method is applied to extreme thunderstorm and non-thunderstorm winds for several major cities in Canada. Also, the implication of using the GEVD and Gumbel distribution to model the extreme wind speed on the structural reliability is presented and elaborated.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2576-2583
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• 2024

In this paper, the similarity criterion and dimensionless conversion method combined with the elasticity condition and Hooke's law are used to derive the functional relationship of the maximum effective value of the vibration velocity between the prototype pump and the model pump. The seawater circulation pump of a nuclear power plant is used as the prototype pump, and the model pump is obtained by performance conversion and choosing the appropriate scale, and the vibration state of the model pump under different flow rates is measured and analyzed. The vibration data of the model pump through the function relationship to find out the vibration parameters of the prototype model pump, and compare with the vibration data of the seawater circulation pump in reality. It can be seen that with the increase of flow rate, the maximum effective value of the vibration velocity of both model and prototype decreases and then increases, and the relative error is small, the maximum value is 7.7757%. Therefore, it can be considered that the functional relationship of model pump converted to prototype pump derived in this paper can be used to analyze the vibration of the actual seawater circulation pump of coastal nuclear power plant.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.5
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• pp.231-241
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• 2013

In this paper, we propose an average approximation filter which can effectively remove the noises of the images. The noises include impulse noises, gaussian noises and mixed noises. The algorithm is as follows. First, as a step of noise detection, we find whether the difference between the pixel value and the average value is greater than the threshold value or not after getting the average value that removed the minimum and maximum values in the applied mask. If the pixel value is greater than the threshold value, the pixel value is processed as noise. If it is less than or equal to the threshold value, it is processed as non-noise. Next, as the noise reduction step, we output the approximate value in mask as the pixel value and the average value except the minimum and maximum values of the pixel including the noise. As the result of applying this average approximation filter to the mixed noise images, the approximation filter can reduce the noises effectively more than 0.4[dB] as compared with applying the median filter and the average filter, respectively.

• Journal of Ocean Engineering and Technology
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• v.16 no.3
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• pp.54-58
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• 2002

This study investigates a relationship between fracture mechanics parameters (Stress Intensity Factor Range: ΔK, Maximum Stress Intensity Factor; Kmax) and X-ray parameters (residual stress:$\sigma$r half-value breadth: B) for SG365 steel at elevated temperature up to 30$0^{\circ}C$. The fatigue crack propagation test were carried out and X-ray diffraction technique according to the direction of crack length was applied to fatigue fractured surface. The residual stress on the fracture surface was found to increase at low ΔK region, to reach a maximum value at a certain value of Kmax or ΔK and then to decrease. Residual stress was independent of stress ratio by arrangement of ΔK and half value breadth were independent of the arrangement of Kmax. The equation of $\sigma$r-ΔK was established by the experimental data. therefore, fracture mechanics parameters could be estimated by the measurement of X-ray parameters.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.187-193
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• 1998

Seasonal changes of nitrogen fixation and growth characteristics of Melilotus suaveolens population under different light conditions were quantitatively analyzed during growting period. Height growth of M. suaveolens population was promoted after April and the shade (site 2) showed 10-20% increase of height growth in compared with that of sunny (site 1). Seasonal changes of biomass were in creased after March, the biomass at site 1 attained 78.5% that of site 2 in May. Chlorophyll content was maintained high value from March to April but, Chlorophyll content of leaf at site 1 was decreased 11.7% compared to that of site 2 in May. The nitrogen content of each organ of M. suaveolens showed higher value in March and then decreased, the high nitrogen contents of reproductive organ were achieved at the flowering stage at site 1. The root nodule of M. suaveolens population appeared in March and showed maximum value in early June and decreased remarkably after July, the amount of nodule formation of M. suaveolens at site 2 showed higher than that of site 1. The nitrogen fixation activity of root nodule of M. suaveolens initiated with shoot growth and showed maximum value in mid April, and attained second peak in early June and then decreased after July. The total nitrogen fixation of the plant showed higher value at site 2 than that of site 1. From the overall results, M. suaveolens showed increased growth under half-shady, well ventilated barren soil than fertile sunny site.

• Journal of Powder Materials
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• v.11 no.2
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• pp.137-142
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• 2004

In this study, chemical solution mixing and hydrogen reduction method was used to fabricate nanostructured $Fe_xCo_{1-x}$ alloy powders. Fe-Co chloride mixture, FeCl$_2$ and COCI$_2$ with 99.9％ purity, were reduced in hydrogen atmosphere. Nanostructured Fe-Co alloy powders with a grain size of 50 nm were successfully fabricated. Magnetic properties of fabricated $Fe_xCo_{1-x}$(x=0, 10, 30, 50, 70, 100) alloy powders with the same grain size were measured because size factor can affect magnetic properties. Coercivity of Fe-Co alloy powders were increased with increasing Co contents. Maximum value of coercivity in various Co contented Fe-Co alloy powders with similar grain size was 125 Oe at Fe$_{100}$. Saturation magnetization value at Fe$_{70}$Co$_{30}$ composition showed maximum value of 219 emu/g and saturation magnetization value decreased with increasing Co contents and minimum value of 155 emu/g was observed at Co$_{100}$.

• Transactions on Electrical and Electronic Materials
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• v.13 no.1
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• pp.10-15
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• 2012

In conventional, skin detection methods using for skin color definitions is based on prior knowledge. By experimentation, the threshold value for dividing the background from the skin region is determined subjectively. A drawback of such techniques is that their performance is dependent on a threshold value which is estimated from repeated experiments. To overcome this, the present paper introduces a skin region detection method. This method uses a histogram approximation based on the mean shift algorithm. This proposed method applies the mean shift procedure to a histogram of a skin map of the input image. It is generated by comparing with the standard skin colors in the $C_bC_r$ color space. It divides the background from the skin region by selecting the maximum value according to the brightness level. As the histogram has the form of a discontinuous function. It is accumulated according to the brightness values of the pixels. It is then, approximated by a Gaussian mixture model (GMM) using the Bezier curve technique. Thus, the proposed method detects the skin region using the mean shift procedure to determine a maximum value. Rather than using a manually selected threshold value, as in existing techniques this becomes the dividing point. Experiments confirm that the new procedure effectively detects the skin region.

• Journal of Korean Physical Therapy Science
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• v.25 no.2
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• pp.47-54
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• 2018

Purpose: The purpose of this study was to investigate the most effective exercise position of Latissimus dorsi's activities during Pull up, Push up and Lat pull down among few positions of hand grips(pronation, Supination and neutral grip) and grip widths(30cm, 60cm) based on EMG activities. Method: 10 healthy adults were participated in this study and the surface EMG activities of the Latissimus dorsi were measured during Pull up, Push up and Lat pull down exercise according to specific hand grip and grip width positions. The maximum and mean value of Latissimus dorsi's EMG activities at all positions were recorded and analysed by ONE-WAY REAPTED ANOVA. Results: The showed that the most Latissimus dorsi's activities is during Pull up exercise. Main results are as follows 1)maximum value: For Pull up, among all studied positions, Rt Latissumus dorsi, position of Supinated grip and 60cm grip width showed strongest muscle activation based on maximum EMG value. Statistical significance was assumed at p<.05. 2)mean value: For Pull up, among all studied positions, Both Latissimus dorsi, position of pronated grip and 60cm grip width showed strongest muscle activation based on mean EMG value. Statistical significance was assumed at p<.05. Conclusion: Therefore, taking the results of this study, Pull up exercise would be the best exercise of Latissimus dorsi's activation. It is recommended to do in pronated grip position and 60cm grip width during Pull up to make body fit.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1663-1668
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• 2004

This study was carried out to evaluate the potential nutritive value of commonly found grasses collected at native pasture in West Sumatra, Indonesia during dry and rainy seasons. Variables measured included chemical composition, in vitro digestibility, concentration of Ca, P and Mg, gas production and metabolizable energy (ME) content of the grasses. The results showed that species and season had significant effect on chemical composition and mineral concentration. Crude protein content in the dry season ranged from 6.5% (B. decumbens) to 14.4% (P. maximum) and increased slightly from 7.8% (B. decumbens) to 14. 8% (A. compressus) in the rainy season. Data on fiber fraction showed that grass contained more NDF, ADF and ADL in dry season than in rainy season. Data on mineral concentration showed that C. plectostachyus and P. maximum in dry season had higher Ca than those of other species, while in rainy season P. maximum had highest Ca concentration. In dry season, the DMD varied from 50. 4% (P.purpuphoides) to 59.1% (P. purpureum), while in rainy season ranged from 50.3% (A. gayanus) to 61.8% (P. purpureum). The potential and rate of gas production were significantly (p<0.05) affected by species and season. During dry season, potential of gas production ranged from 21.8 ml/200 mg (A. compressus) to 45.1 ml/200 mg (C. plectostachyus), while in rainy season it varied from 35.6 ml/200 mg (A. gayanus) to 47.5 ml/200 mg (P. purpureum). ME content of grasses varied from 6.0 to 8.3 MJ/kg in dry season and increased slightly from 6.4 to 8.6 MJ/kg in rainy season. Both in dry and rainy seasons, the highest ME content was occurred in P. purpureum and C. plectostachyus. In conclusion, nutritive value of the observed grasses in West Sumatra, Indonesia was relatively higher during rainy season compared with dry season. Pennisetum purpureum and Cynodon plectostachyus had the best nutritive value in both dry and rainy seasons.