• Proceedings of the Acoustical Society of Korea Conference
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• 1991.06a
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• pp.113-116
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• 1991

본 논문에서는 고속 도로 주변에서 교통 소음 대책으로 사용되는 방음벽 효과에 대해 교통 소음 모델에 의한 예측값과 실측값을 비교하였다. 도로 교통 소음로서는 일본 음향 학회 모델, 국립 환경원 모델, 조한인 모델을 대상으로 하였다. 세가지 모델의 예측값과 실측값의 비교 결과, 갓길(노견)에서는 일본 음향 학회 모델과 국립 환경원 모델에 의한 예측값이 실측값과 $\pm$3.5dB(A) 차이로 비슷한 결과를 보였으며, 소음 측정 지점이 음원과 먼 경우는 속도가 빠를수록 일본 음향 학회 모델은 예측값과 실측값의 차이가 커졌다. 조한인 모델은 시가지 도로에서는 잘 맞지만 고속 도로에 적용하기에는 적합하지 않았다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.108-114
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• 2008

Near infrared spectroscopy (NIRS) is a rapid and accurate analytical method for determining the composition of agricultural products and feeds. The applicability of near infrared reflectance spectroscopic method was tested to determine the color value (L, a, b) of green tea. A total of 162 green tea calibration samples and 82 validation samples were used for NIRS equation development and validation, respectively. In the developed NIRS equation for analysis of the color value (L, a, b), the most accurate equation for L value was obtained at 2, 8, 6, 1 (2nd derivative, 8 nm gap, 6 points smoothing, and 1pointsecond smoothing), and for a, and b value were obtained at 1, 4, 4, 1 (1st derivative, 4 nm gap, 4points smoothing, and 1 point second smoothing) math treatment condition with SNVD (Standard Normal Variate and Detrend) scatter correction method and entire spectrum ($400{\sim}2,500\;nm$) by using MPLS (Modified Partial Least Squares) regression. Validation results of these NIRS equations showed very low bias (L: 0.005%, a: 0.003%, b: -0.013%) and standard error of prediction (SEP, L: 0.361%, a: 0.141%, b: 0.306%) as well as high coefficient of determination ($R^2$, L: 0.905, a: 0.986, b: 0.931). Therefore, these NIRS equations can be applicable and reliable for determination of color value (L, a, b) of green tea, and NIRS method could be used as a mass screening technique for breeding programs and quality control in the green tea industry.

• The KIPS Transactions:PartB
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• v.17B no.4
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• pp.275-286
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• 2010

Reversible watermarking which can preserve the original quality of the digital contents and protect the copyright has been studied actively. Especially, in medical, military, and art fields, the need for reversible watermarking is increasing. This paper proposes a high-capacity reversible watermarking through predicted error expansion and error estimation compensation. Watermark is embedded by expanding the difference histogram between the original value and the predicted value. Differently from previous methods calculating the difference between adjacent pixels, the presented method calculates the difference between the original value and the predicted value, and that increases the number of the histogram value, where the watermark is embedded. As a result, the high capacity is achieved. The inserted watermark is extracted by restoring the histogram between the original value and the predicted value. To prove the performance, the presented algorithm is compared with other previous methods on various test images. The result supports that the presented algorithm has a perfect reversibility, a high image quality, and a high capacity.

• The KIPS Transactions:PartB
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• v.10B no.7
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• pp.829-836
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• 2003

In this paper, we propose a stochastic model for sentence speech understanding using dictionary and thesaurus. The proposed model extracts words from an input speech or text into a sentence. A computer is sellected category of dictionary database compared the word extracting from the input sentence calculating a probability value to the compare results from stochastic model. At this time, computer read out upper dictionary information from the upper dictionary searching and extracting word compared input sentence caluclating value to the compare results from stochastic model. We compare adding the first and second probability value from the dictionary searching and the upper dictionary searching with threshold probability that we measure the sentence understanding rate. We evaluated the performance of the sentence speech understanding system by applying twenty questions game. As the experiment results, we got sentence speech understanding accuracy of 79.8%. In this case, probability ($\alpha$) of high level word is 0.9 and threshold probability ($\beta$) is 0.38.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1451-1456
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• 2013

This paper propose a method for fast convergence technique in frequency domain independent component analysis (FDICA) using eigenanalysis. It important, such as SONAR system, to eliminate the interference sources through fast algorithm. Through eigenanalysing a two-by-two delayed mixture case, information of delay can be used for initial weighting parameters. Simulations show the improved performances in convergence speed and noise rejection rate. The proposed method can present close weights for optimal convergence, noise can be diminished drastically about 3 times epoch, and get the better resultss with 1~3dB than the conventional method.

• Journal of the Korean earth science society
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• v.36 no.4
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• pp.351-359
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• 2015

This study is to analyze the sensitivity for the parameters (a and b values, $M_{max}$, attenuation formula, and seismo-tectonic model) which are essential for the seismic hazard map. The values of each parameter were suggested by 10 members of the expert group. The results show that PGA increases as a value and $M_{max}$ become larger and as b value smaller. Big impact on the seismic hazard is observed for attenuation formula, a and b values although there is little impact on $M_{max}$ and seismo-tectonic model. These parameters with big impact require careful consideration for obtaining adequate values that well reflects the seismic characteristics of the Korean peninsula.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.736-742
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• 2003

This paper presents the propagation path loss in a tunnel which is a kinds of underground environments. To predict propagation path loss more accurately, we choose a straight tunnel with rectangular cross-section. The simulated receiver powers that are using a hybrid waveguide model and a Ray-Tracing method, are compared with the measured ones as a function of distance between TX and RX antennas in tunnel. The attenuation value of regression analysis for measured power in the tunnel is 0.0238dB/m which is similar to the one of the EH1.2 mode, 0.0246dB/m in hybrid waveguide model. By comparing simulation with measurement in tunnels, it has been shown that the measured values are approximate to the simulated results of ray-tracing model. In the analysis of wide-band channel characteristics of the tunnel, the more the distance between TX and RX antennas in tunnel increases, RMS delay spread increases and coherence bandwidth decreases.

• The Korean Journal of Food And Nutrition
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• v.23 no.2
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• pp.218-225
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• 2010

To make sponge cake using Lentinus edodes powder, which is useful and valuable as a functional food material, we tested samples with 3, 6, 9, and 12% L. edodes powder to ascert200ain the quality characteristic and make optimize preparation. Samples and L. edodes powder-free control sponge cakes were compared in terms of quality characteristics including batter viscosity and specific gravity, moisture content, volume index, weight, color, textural characteristics, and sensory qualities, to determine the optimal ratio of L. edodes powder in the formulation. Viscosity and specific gravity of sample and control batter were not significantly different. Moisture content of the sample and control sponge cake also did not differ significantly, and weight of sample and control sponge cakes did not differ appreciably. The volume index of the samples displayed contrasting values, increasing with 3~6% L. edodes powder and decreasing with 9~12% powder. L, a, and b crust color values of samples sponge cakes were lower than those of control cakes. The L and a values of the control cakes was maximal, with values progressively decreasing with incorporation of more L. edodes powder. The b value decreased by 3% with the addition of up 6% L. edodes powder with no further decrease thereafter. L. edodes powder was the lower value. So was the color a, and L. edodes powder increased, a-values decreased. 3% difference was shown in b, the color and none between the samples with 6~12%. L. edodes powder showed lower values making a comparison with the control. Hardness and fracturablility were not appreciably affected by 3% L. edodes powder, but was affected by concentrations 6%. Fracturability og sample sponge cakes was consistently lower than control cakes. Fracturability made little difference in 3% samples, but it was not the same with more than 6% L. edodes powder samples; the samples showed lower value than the control. Adhesiveness was not significantly affected. Chewiness was lower in all sample cakes except those prepared with 3% L. edodes powder. Use of L. edodes powder conferreds higher resilience values as compared to thecontrols. Sensory attributes of color, flavor, softness and overall acceptability were the highest in control sponge cakes, as the amount of L. edodes powder increased, the acceptability decreased. L. edodes-flavor, pleasant taste and off-flavor were the lowest in control cakes, and values increased as the amount of L. edodes powder increased. The control sponge cakes showed the highest values in egg-flavor and moistness, which progressively increased as added L. edodes powder increased. The results indicate that control sponge cakes displayed were. the highest overall acceptability, with acceptability decreasing and it decreased as L. edodes powder content increased. However, 3~6% L. edodes powder can produce an acceptable product, and may be used as anoptimized mixture ratio.

• Journal of Life Science
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• v.12 no.6
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• pp.654-660
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• 2002

This study was carried out to investigate the effect of addition of perilla leaf(PL) powder and carcass grade on the surface color, residual nitrite and shelf-life of pork sausage. Pork sausage was prepared by four type such as grade B pork sausage(A sausage), grade B pork sausage containing perilla leaf(B sausage), grade I pork sausage(C sausage) and grade I pork sausage containing perilla leaf(D sausage) and the surface color, residual nitrite, pH, volatile basic nitrogen(VBN), thiobarbituric acid reactive substances(TBARS) and total bacterial counts of the samples were determined during storage at 4$^{\circ}C$. $L^*$ value of pork sausage showed the highest early stage of storage, pork sausage containing PL was lower than pork sausage without PL. The $a^*$ value of A sausage had the lowest on the storage of 8th week, B sausage had the highest on the storage of 4th week, and the $a^*$ value of C and D sausage were not significantly different during storage. The$a^*$ value of pork sausage containing PL was lower than pork sausage without PL, the $b^*$ value was higher than pork sausage without PL. The residual nitrite of pork sausage containing PL highly decreased until storage for 2 weeks, pork sausage without PL highly decreased until storage for 4 weeks, therefore addition of PL was affected in the reduction of residual nitrite of pork sausage. The pH of A and B sausage decreased until storage at 4 weeks, but increased from 6 weeks. The VBN contents were 6.7~8.4 mg% in the early stage of storage, was 16.1~19.5 mg% on the storage of 8th weeks. The TBARS of pork sausage were increased gradually during storage. Pork sausage containing PL showed lower value than pork sausage non added PL during storage. The total bacterial counts of pork sausage were increased gradually during storage, pork sausage containing PL was lower than that of free PL during storage.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.4
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• pp.363-370
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• 2017

In this paper, we proposed a low-complexity speech enhancement algorithm based on a improved minima controlled recursive averaging (IMCRA) and log minimum mean square error (logMMSE). The IMCRA algorithm track the minima value of input power within buffers in local window and identify the speech presence using ratio between input power and its minima value. In this process, many number of operations are required. To reduce the number of operations of IMCRA algorithm, minima value is tracked using time-varying frequency-dependent smoothing based on speech presence probability. The proposed algorithm enhanced speech quality by 2.778%, 3.481%, 2.980% and 2.162% in 0, 5, 10 and 15dB SNR respectively and reduced computational complexity by average 9.570%.