• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.1
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• pp.43-50
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• 2016

This paper is on an acoustic echo canceller solving the double-talk problem by using the blind signal separation technology. The acoustic echo canceller may be deteriorated or diverged during the double-talk period. So we use the blind signal separation to detect the double talking by separating the near-end speech signal from the mixed microphone signal. The blind signal separation extracts the near-end signal from dual microphones by the iterative computations using the 2nd order statistical character in the closed reverberation environment. By this method, the acoustic echo canceller operates irrespective of the double-talking. We verified performances of the proposed acoustic echo canceller in the computer simulations. The results show that the acoustic echo canceller with this algorithm detects the double-talk periods well, and then operates stably without diverging of the coefficients after ending the double-talking. The merits are in the simplicity and stability.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.172-172
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• 1993

Acetaminophen(이하 AAP)은 간의 mixed function oxidase system에 의해 toxic metabolite로 대사되어 간괴사를 일으킨다. 최근에는 지금까지 임상적으로 사용되어온 한약이나 생약의 cytochrome P450의 활성과 간의 glutathion 합성에 미치는 영향에 대한 연구가 활발하게 진행되고 있다. 본 연구에서는 AAP의 간독성을 억제하는 물질을 규명하고자 민간이나 한방에서 보간 또는 해독제로 많이 사용되고 있는 생약을 screening하였다. 그 결과 간의 약물대사 효소계에 엉힝을 미치는 것으로 보고된 강활(Angelica koreana)과 민간이나 한방에서 간질환치료의 목적이나 해독제로 쓰여온 시호(Buplerum falcatum), 토복령(Smilax china) 및 금은화(Lonicera japonica)가 AAP로 유발된 간독성에 미치는 효과를 살펴보았다. 방법: 예비실험을 통해 강활, 시호, 토복령 및 금은화의 MeOH ext.가 AAP로 유도된 간독성에 방어효과가 있음을 확인하고 이를 hexane, ether, ethyl acetate 및 butanol로 계통분획하여 랫트에 전처치한 후 고농도의 AAP를 투여하여 간 손상을 일으키고 혈청중의 효소활성과 지질ㆍcholesterolㆍbilirubin함량 등을 측정하였다.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.131-138
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• 2014

This paper is on a stereo acoustic echo canceller with the blind signal separation for post processing. The convergence speed of the stereo acoustic echo canceller is deteriorated due to mixing two residual signals which are update signals of each echo canceller. To solve this problem, we are to use the blind signal separation(BSS) method separating the mixed signals after the echo cancellers. The blind signal separation method can extracts the source signals by means of the iterative computations with two input signals. We had verified performances of the proposed acoustic echo canceller for stereo through simulations. The results of simulations show that the acoustic echo canceller for stereo using this algorithm operates stably without divergence in the normal state. And, when the speech signals were inputted, this echo canceller achieved about 2dB higher ERLE with the BSS post processing method than without this method. This stereo echo canceller showed the best performance in the case of inputting the real voice signal.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.125-131
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• 2012

This paper is on a stereo acoustic echo canceller with the blind signal separation. The convergence speed of the stereo acoustic echo canceller is deteriorated due to mixing two residual signals in the update signal of each echo canceller. To solve this problem, we are to use the blind signal separation(BSS) method separating the mixed signals. The blind signal separation method can extracts the source signals by means of the iterative computations with two input signals. We had verified performances of the proposed acoustic echo canceller for stereo through simulations. The results of simulations show that the acoustic echo canceller for stereo using this algorithm operates stably without divergence in the normal state. And, when the speech signals were inputted, this echo canceller achieved about 3dB higher ERLE in the case of using the BSS algorithm than the case of not using the BSS algorithm. But this echo canceller didn't get good performances in the case of inputting the white noises as stereo signals.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.330-342
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• 2008

A comprehensive quality survey for PCDDs/PCDFs and coplanar PCBs as well as heavy metals (Cu, Zn, Cd and Pb) in sediments has been investigated in August 2006, Korea. Monitoring was undertaken at five streams representing different surrounding environments throughout Juwang and Gapyeong streams (reference sites), Jungrang stream (dense population site), Ansan stream (mixed small population and industrial site), and Siheung stream (heavy industrial site). The levels of heavy metal in samples were found to be significantly higher in sediment from Siheung stream compared to those of other stream sites. The heavy metal concentrations (dry weight basis) in sediment from Siheung stream were as follows; Cd (3.7 ${\mu}g$/g), Pb (1,295 ${\mu}g$/g), Cu (713.4 ${\mu}g$/g) and Zn (358.1 ${\mu}g$/g). Among 12 coplanar PCBs and 17 PCDDs/PCDFs selected as target compounds in this study, PCB (IUPAC no. 118) and OCDD were the most abundant congeners found in all sediment samples, followed by 1,2,3,4,6,7,8-HpCDD, OCDF and 1,2,3,4,6,7,8HpCDF as well as PCB (IUPAC no. 105). These results were shown to be in the same trend as the sediment samples of other countries. The levels of PCDDs/PCDFs/coplanar PCBs in sediment samples were expressed as concentrations and WHO- TEQ values. The PCDDs/PCDFs/coplanar PCBs concentrations and their WHO-TEQ values in sediment from Siheung stream were remarkably high. The levels detected were 788.16 pg/g and 36.080 pg WHO-TEQ/g dry weight for PCDDs/ PCDFs and 314 pg/g and 0.4189 pg WHO-TEQ/g dry weight for coplanar PCBs, respectively, beyond the safety level of sediment value 20 pg WHO-TEQ/g. Sediment samples of the five streams were also monitored by sensitive biomarkers using insect immune responses: hemocyte-spreading behavior and immune-associated enzyme activities of phospholipase A$_2$ (PLA$_2$) and phenoloxidase. Organic extracts of Siheung and Jungrang sediments significantly interfered with the hemocytespreading behavior, whereas those of Ansan, Gapyeong, and Juwang did not. These organic extracts did not inhibit the PLA$_2$ and phenoloxidase activities. However, phenoloxidase was highly susceptible to exposure to aqueous extracts in all site sediments. In comparison, PLA$_2$ activities of the hemocytes were significantly inhibited only by aqueous extracts of Siheung, Jungrang, and Gapyeong sediments, but not by those of Ansan and Juwang. Despite some disparity between bioand chemical monitoring results, the biomarkers can be recommended as a device warning the contamination of biohazard environmental chemicals because of a fast and inexpensive detection method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.420-426
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• 2004

In this study, among 10 medicinal plants extracted with 50%-ethanol, antimicrobial activities measured by paper disc method were showed in Scutellaria baicalensis (Sb) on Leu mesenteroides and in Phellodendron amurene (Pa) on Lac. plantarum and Leu. mesenteroides. While 0.05∼0.2% of Pa extracts showed also relatively strong growth inhibition of both strains of lactic acid bacteria cultured in MRS broth for 24 hours at 3$0^{\circ}C$, Sb extract at concentration of 0.1% showed similar inhibitory effect on Leu mesenteroides to that of 0.05% of Pa extract. Addition of 0.02∼0.04% of Pa extracts to kimchi lowered effectively extents of pH decrease and acidity increase, and numbers of lactic acid bacteria and total bacteria compared to those of control during fermentation at 4$^{\circ}C$. This extending effect on fermentation period was obtained by adding 0.04% in case of Sb. Mixed extracts of Pa and Sb (Pa-Sb) by ratio 1 : 1 delayed also fermentation of kimchi at 0.03∼0.04%. In sensory evaluation kimchi containing 0.04% of Pa extract were less sour than kimchi containing 0.02% of Sb extract and/or control at late stage of fermentation.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• Nutrition Research and Practice
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• v.15 no.6
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• pp.715-731
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• 2021

BACKGROUND/OBJECTIVES: Premenstrual syndrome (PMS) is a disorder characterized by repeated emotional, behavioral, and physical symptoms before menstruation, and the exact cause and mechanism are uncertain. Hyperprolactinemia interferes with the normal production of estrogen and progesterone, leading to PMS symptoms. Thus, we judged that the inhibition of prolactin hypersecretion could mitigate PMS symptoms. MATERIALS/METHODS: Hordeum vulgare L. extract (HVE), Chrysanthemum zawadskii var. latilobum extract (CZE), and Lomens-P0 the mixture of these extracts were tested in subsequent experiments. The effect of extracts on prolactin secretion at the in vitro level was measured in GH3 cells. Nitric oxide and pro-inflammatory mediator expression were measured in RAW 264.7 cells to confirm the anti-inflammatory effect. Also, the hyperprolactinemic Institute for Cancer Research (ICR) mice model was used to measure extract effects on prolactin and hormone secretion and uterine inflammation. RESULTS: Anti-inflammatory effects of and prolactin secretion suppress by HVE and CZE were confirmed through in vitro experiments (P < 0.05). Treatment with Lomens-P0 inhibited prolactin secretion (P < 0.05) and restored normal sex hormone secretion in the hyperprolactinemia mice model. In addition, extracts significantly inhibited the expression of pro-inflammatory biomarkers, including interleukin-1𝛽, and -6, tumor necrosis factor-𝛼, inducible nitric oxide synthase, and cyclooxygenase-2 (P < 0.01). We used high-performance liquid chromatography analyses to identify tricin and chlorogenic acid as the respective components of HVE and CZE that inhibit prolactin secretion. The Lomens-P0, which includes tricin and chlorogenic acid, is expected to be effective in improving PMS symptoms in the human body. CONCLUSIONS: The Lomens-P0 suppressed the prolactin secretion in hyperprolactinemia mice, normalized the sex hormone imbalance, and significantly suppressed the expression of inflammatory markers in uterine tissue. This study suggests that Lomens-P0 may have the potential to prevent or remedy materials to PMS symptoms.

• The Korea Journal of Herbology
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• v.28 no.4
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• pp.25-32
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• 2013

Objectives : The purpose of this study was to evaluate the hepatoprotective effect of Hovenia dulcis extract on acute and chronic liver injuries induced by alcohol and $CCl_4$ in mice and rats. Methods : In acute alcohol-induced liver injury, mice were administered Hovenia dulcis extracts (60 and 200 mg/kg) orally before and after alcohol administration. In chronic alcohol-induced liver injury, mice were administered alcohol containing liquid diet for 4 weeks. The mice were administered H. dulcis extracts (60 and 200 mg/kg) mixed with the liquid diet. In acute $CCl_4$-induced liver injury, rats received a single dose of $CCl_4$ (2 mL/kg in olive oil, intraperitoneally). Rats were administered H. dulcis extracts (30, 100 and 300 mg/kg) before and after $CCl_4$ administrations. After the ends of the administrations, the serum levels of AST and ALT were measured using chemical analyzer, and ${\gamma}$-GTP levels were measured using spectrophotometer. Results : In acute alcohol-induced liver injury, H. dulcis extracts treated group showed significant reduction in ALT levels compared to those of control group. In chronic alcohol-induced liver injury, it inhibited weight-loss compared to normal group and showed significant reduction in AST, ALT and ${\gamma}$-GTP levels compared to control group. In acute $CCl_4$-induced liver injury, it also showed significant reduction in AST, ALT levels compared to control group. Conclusions : The results show that H. dulcis extract has hepatoprotective effect in acute and chronic alcohol-induced liver injury and acute $CCl_4$-induced liver injury. These findings suggest that H. dulcis could be a potent hepatoprotective agent.

• Journal of Life Science
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• v.28 no.1
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• pp.26-36
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• 2018

This study was performed to identify the antioxidant and ${\alpha}$-glucosidase inhibitory activities of water and 70% ethanol extracts of the three following herbs: G. procumbens, M. charantia, and C. longa. In addition, the antioxidant and antidiabetic activities of five types of Jerusalem artichoke composites (JA1 - 5), which were prepared by adding ethanol extracts of several herbs to Jerusalem artichoke concentrate, were studied and compared. The results showed that the total phenol and flavonoid contents of the ethanol extracts were higher than those of the water extracts. The DPPH and ABTS radical scavenging activities and reducing power depended on the total phenol and flavonoid contents. The antioxidant activities of ethanol extracts from G. procumbens and C. longa were comparable. Moreover, the ${\alpha}$-glucosidase inhibitory activity of the ethanol extracts ($2,000{\mu}g/ml$) from each herb was found to be over 50%. In contrast, the five types of JA composites showed higher total phenol and flavonoid contents than those of JA concentrate. In addition, increased antioxidant and ${\alpha}$-glucosidase inhibitory activities were observed, with that of JA1 being the highest. However, all concentrations ($1{\sim}100{\mu}g/ml$) of JA tested did not affect the cell viability of Chang cells. In addition, JA induced the activation of AMP-activated protein kinase (AMPK) in Chang cells and significantly increased the glucose uptake in C2C12 cells. Therefore, it could be concluded that the JA composites (JA1 - 5) mixed with G. procumbens, M. charantia, and C. longa extracts were effective in increasing the extracts' antioxidant and antidiabetic activities.