• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.439-446
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• 2006

In the present study, we applied wavelet transform to decompose the hydro-meteorological data such as precipitation and temperature into the components with different return periods with a primary objective for extraction of nonlinear dynamical component. For the transform, we used the Daubechies wavelet of order 9 ('db9') as a basis function. Also, we applied the correlation dimension analysis to determine whether or not the detail and approximation components at the respective decomposition stage with the increasing of scale in the wavelet transform reveal the nonlinear dynamical characteristics. In other words, we proposed the combined use of the wavelet transform and the correlation dimension analysis as methodology to extract the nonlinear dynamical component from the hydro-meteorological data. The derived result has shown the method proposed in the present study is suitable for the segregation and extraction of the nonlinear dynamical component which is, in general, difficult to reveal by using the raw data.

• Food Industry And Nutrition
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• v.7 no.2
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• pp.40-44
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• 2002

매실의 향기성분은 50여종 중 알콜류가 benzyl alcohol, linalool, 1,6-octadien-3-ol, n-haxanol 등 10종, aldehyde류가 2-hexenal, benzaldehyde, n-hexanal 등 3종, acid류가 butandeionic acid, acetic acid, 2종, 2-iodo-hexane 등 hydrocarbon류가 5종, butanedioic acid-diethyl estet를 포함한 ester류가 3종, B-ionone을 포함한 ketone류가 3종 그리고 기타 성분이 2종이었다. 매실이 성숙함에 따라 향기성분의 수가 증가하고 그 함량도 증가하는 경향이었다. 매실의 비휘발성 유기산의 조성은 succinic, fumaric, oxalic, malic, tartaric 및 citric acid이었다. 매실이 비휘발성 유기산은 성숙 초기에는 malic acid와 oxalic acid의 함량이 높았다. Citric acid의 함량이 증가한 반면에 대부분의 유기산은 감소하는 경향이었다. 휘발성 유기산은 성숙중에 formic acid함량은 감소하고 butyric acid의 함량은 증가하는 경향이었다. 총 유기산의 함량은 매실 성숙에 현저히 감소하는 경향이었다.

• Journal of Sensor Science and Technology
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• v.10 no.1
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• pp.80-85
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• 2001

$Hg_{1-x}Cd_xTe$(MCT) thin films were grown onto ITO glass and titanium plate by stationary cathodic electrodeposition in aqueous solution contained $CdSO_4$, $TeO_2$, and $HgCl_2$. During deposition two main fabrication parameters were taken into account deposition potential and growth temperature. MCT films deposited by varying two parameters were studied by X-ray diffraction, electron probe micro analyser(EPMA) and scanning electron microscope measurements. It was shown by XRD and EPMA measurements that the structure of MCT films was zinc blonde and the composition of MCT films can be controlled with the deposition potential.

• Journal of Food Hygiene and Safety
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• v.6 no.2
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• pp.73-78
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• 1991

As reported previously, it was found that glucomannan, contains a potent cholesterol-lowering material. This study was designed to characterize this material further. Both the water sluble and the alcohol soluble extracts of glucomannan were prepared, and each of these extracts were capable of reducing serum and liver cholestrol levels of rats: This finding indicates that a potent cholesterol-lowering material contained in glucomannan is an organic compound with hydrophilic groups.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.893-905
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• 2016

Puff processing is one of the preparation and processing methods of herbal medicines. This study analyzed the quality characteristics in schisandra chinensis extracts by puff processing ($1kgf/cm^2$, $3kgf/cm^2$, $5kgf/cm^2$) through changes of the lignan contents and antioxidant activity. The lignan contents and antioxidant activity of puff processing schisandra chinensis extracts (PPSCE) increased higher than compared to a control. Also, as lignan contents and antioxidant activity of PPSCE was increased with the increasing pressure but it was reduced from $5kgf/cm^2$. The results suggest that puff processing was attributed to the quality increase schisandra chinensis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.556-562
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• 2013

We examined the anti-obesity effects of water-soluble polysaccharides (WSP-A) extracted from the seaweed Hijikia fusiforme (Tott in Korean). The extracted alginate-like polysaccharide (verified by FT-IR and HPAEC-PAD analysis) was examined in a lipase inhibition assay and animal experiments. WSP-A inhibited lipase up to 30%, with over 80% of the initial activity retained until the 1 hour reaction in vitro. There was a 30% loss in the rate of weight gain in rats fed a high-fat diet. WSP-A therefore seems to serve as a healthy weight loss agent by inhibiting lipases, thus preventing the absorption of fat in the body.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.874-880
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• 2007

Volatile flavor compounds of 4 grape species (Campbell, Sheridan, Red globe, and Meoru) were identified during 3-day storage at either $4^{\circ}C$ or room temperature. Each sample was analyzed by solid-phase micro-extraction (SPME) method combined with gas chromatography-mass spectrometry. Also electronic nose composed of 12 different metal oxide sensors was used to differentiate flavors of grapes. Sensitivities (delta $R_{gas}/R_{air}$) of sensors from electronic nose were obtained by principal component analysis (PCA). Proportion of the first principal component was 99.30% at $4^{\circ}C$ and 99.36% at room temperature, respectively. In our result, flavor patterns of grape can be differentiated according to the storage period. The major volatile flavor compounds were 1-hexanol, hexanoic acid and its ethyl ester, and phenylethyl alcohol with the presence of butanoic acid and its ethyl ester, acetic acid, benzeneacetic acid and its ethyl ester.

• Analytical Science and Technology
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• v.26 no.3
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• pp.190-198
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• 2013

Ambers have been used mostly as beads, jewelry and ornaments from ancient times and excavated as a buried artifact. When excavated, they are severely weathered to be cracked, exfoliated and disintegrated. Monitoring of changes in composition of amber according to weathering is very important for diagnosing the condition of amber and applying conservation materials and techniques. In this study, we tried to find the components of amber by analyzing amber with pyrolysis/GC/MS. The changes in the composition of pyrolzates after artificial ageing for 60 days under heat and oxygen were also observed. Abietic acid was detected as a main component of fresh amber and monoterpene, alkene, aromatic hydrocarbon were detected as major pyrolyzates. Changes with artificial ageing was estimated by comparing the peak area ratio of 23 components, and it was found that abietic acid abruptly decreased in the presence of heat and oxygen together, revealing that oxygen is a key factor to the deterioration of amber. It was also tried to understand the weathered surface of original amber gemstone based on the result of this ageing experiment.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.19 no.2
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• pp.151-161
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• 2007

Statistical characteristic analysis was carried out using the non-tidal components computed by the harmonic analysis of the tidal elevation data in East coast. The tide gauging stations included in this study are the Sokcho, Mukho, Hupo, Pohang, Ulsan and Ulreungdo stations. In this study, the variance and skewness coefficient (SC) information changes, i.e., the max. value, min. value, mean and standard deviation of the variance and SC, are compared and analysed in detail by the various analysis periods increased from one year to the maximum available period. Based on the result of the statistical information (SI) range analysis, the minimum analysis period required in order to satisfy the confidence interval of the ${\pm}5%$ range of the variance and the ${\pm}0.1$ range of the SC is suggested as the 12 years, except the Ulreungdo stations. The auto-correlation and spectral density change patterns show the very similar shapes in every stations even though the absolute values are a little bit different each other.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.251-254
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• 1998

초음파 수신 신호의 공진주파수 변화를 이용한 온도 측정법에서 협대역 변환기를 사용한 초음파 온도측정이 가능함을 보여준다. 그리고 이를 위하여 공진주파수 변화와 온도변화간의 비례상수를 변화시켰다. 기존의 측정법은 온도변화와 기본주파수 변화와의 관계를 비례상수로 정의하였기 때문에, 최소한 3개 이상의 하모닉을 포함하는 광대역 변환기가 필요하였다. 하지만 협대역 변환기를 이용한 온도측정법에서는 비례상수를 주파수 변화비와 온도변화간의 관계로 나타내기 때문에 한 성분의 하모닉만을 측정하여도 온도측정이 가능하게 된다.