• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.102-110
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• 2017

In this paper, we have implemented an real-time adaptive feedback cancellation(AFC) algorithm that can be applied to multi-channel digital hearing aid. Multichannel digital hearing aid typically use the FFT filterbank based Wide Dynamic Range Compression(WDRC) algorithm to compensate for hearing loss. The implemented real-time acoustic feedback cancellation algorithm has one integrated structure using the same FFT filter bank with WDRC, which can be beneficial in terms of computation affecting the hearing aid battery life. In addition, when the AFC fails to operate due to nonlinear input and output, the reduction gain is applied to improve robustness in practical environment. The implemented algorithm can be further improved by adding various signal processing algorithm such as speech enhancement.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.82-88
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• 2016

In this paper, we propose an intelligibility enhancement algorithm for multimedia contents using spectral shaping. The dialogue signals is essential to understand the plot of audio-visual media contents such as movie and TV. However, the non-dialogue components as like sound effects and background music often degrade the dialogue clarity. To overcome this problem, this paper tries to improves the dialogue clarity of audio soundtracks which contain important cues for the visual scenes. In the proposed method, the dialogue components are first detected by soft masker based on speech presence probability (SPP) which is widely used in speech enhancement field. Then, extracted dialogue signals are applied to the spectral shaping method. It reallocate the spectral-temporal energy of speech to enhanced the intelligibility. The total energy is maintained as unchanged via a loudness normalization process to prevent saturation. The algorithm was evaluated using the modeled and real movie soundtracks and it was shown that the proposed algorithm enhances the dialogue clarity while preserving the total audio power.

• Water for future
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• v.9 no.2
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• pp.101-114
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• 1976

This paper presents a hydrologic method of probabilistic design flood calculation for ungauged small river basins. It is based on the study and analysis of the physiographic characteristics of the river basin for which stream flow records may not be available. Rainfall data is used at nearby station which has the rainfall intensity-duration-frequency relations. Musim cheon, second tributary of the Guem river, is selected for the sample study. Design floods for the stream reaches are computed by the Rational formula, the runoff coefficients being determined with the physiographic data such as soil type, land use and vepetal covers. Derived unit hydrograph at conneted main river basin is used to compute the peak flood discharge. Kajiyama formula and modified Kajiyama formula are used to calculated the most probable maximum flood discharge. The result of this study shows that synthesized unit hydrograph method is more accurate and applicable way to com pute design flood for ungauged small river basins.

• Journal of fish pathology
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• v.14 no.1
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• pp.3-10
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• 2001

The present study was to obtain a basic research data about medicinal herbs by screening in vitro antimicrobial activity and the production of superoxide anion($O_2^-$) from the head kidney phagocytes of olive flounder, Paralichthys olivaceus. The following fourteen kinds of medicinal herbs extracted by boiling water were used : Gosam, Gwijeonu, Gujeolcho, Bagha, Bangpung, Yeongyo, Yagssug, Jiyu, Sambaegcho, Samjiguyeobcho, Sangbaegpi, Sohwehyang, Pyeonchug, Palgag. Antimicrobial activity against fish pathogenic bacteria, Listonella anguillarum, Vibrio sp., Vibrio alginolyticus, Edwardsiella tarda, Streptococcus sp. and Lactococcus garvieae, and the production of superoxide in kidney macrophage of olive flounder were examined by disk method and nitroblue tetrazolium(NBT) reaction, respectively. Among the tested herbs, Yagssug showed the highest antimicrobial activity against those fish pathogenic bacteria and stimulation of $O_2^-$ production.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.173-181
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• 2005

This study deals with a method to identify damages of free vibrating thin plate structures using the combined finite element method (FEM) and the advanced uniform micro-genetic algorithm.To solve the inverse problem using the combined method, this study uses several natural frequencies instead of mode shapes in a structure as the measured data. The technique described in this paper allows us not only to detect the damaged elements but also to find their numbers, locations, and the extent of damage.To demonstrate the feasibility of the proposed method, the algorithm is applied to a free vibrating steel thin plate structures with arbitrary damages. From the standpoint of computation efficiency, the proposed method in this study has advantages when compared with the existing simple genetic algorithms. The numerical examples demonstrate that the method using micro-genetic algorithms can possibly detect correctly the damages of thin plates from only several natural frequencies instead of their natural modes.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.29-35
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• 2015

Objectives : The objective of this research was to investigate the antibacterial and antioxidant activities of bio-fermented Sanguisorbae Radix extract.Methods : The Sanguisorbae Radix extract was fermented byStreptococcus thermophilus,and their products was tested for antibacterial activity against pathogenic microorganisms namely,Bacillus cereus,Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Vibrio parahaemolyticusandSalmonella typhimuriumby paper disc diffusion method and the antioxidant activities of extract was evaluated by five different assays as electron donating ability(EDA), superoxide dismutase(SOD)-like activity, polyphenol, flavonoid contents and nitrite scavenging ability.Results : The bio-fermented Sanguisorbae Radix extract was safe from heat. Antibacterial activity of fermented Sanguisorbae Radix extract appeared relatively highly againstBacillus cereusandStaphylococcus aureusand didn't show any difference. EDA in comparison to Vitamin C showed over 90% activity at about the same time of Sanguisorbae Radix extract expressed highly. SOD activity showed 15% in fermentation before and after. The nitrite scavenging ability of Sanguisorbae Radix extract before and after fermentation showed higher numerical value over 70% in pH 2.5 than that of butylated hydroxytoluene(BHT). But SOD activity, EDA and nitrite scavenging ability were not different between the Sanguisorbae Radix extract before and after fermentation. Total polyphenol content expressed over about 20 mg/g, and that of the Sanguisorbae Radix extracts was increased than that of the fermented Sanguisorbae Radix extracts.Conclusions : The results suggest the usefulness of developing functional materials using antioxidant active Sanguisorbae Radix extract was fermented bySalmonella typhimuriumwith high polyphenol contents and nitrite scavenging ability.

• The Korea Journal of Herbology
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• v.27 no.3
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• pp.23-29
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• 2012

Objective : Sanguisorbae Radix(SO). that belong to Rosaceae is widely distributed in Asia including Korea, Japan and China. It has been used as traditional medicine from old times as a treatment for anti-inflammatory drugs. This study was designed to investigate the effects of n-BuOH fractions of SO on anti-oxidant effect and anti-microbial effect on $Streptococcus$ $mutans$ ($S.$ $mutans$). Methods : The anti-microbial effect of $n$-BuOH fractions of SO. was assessed by the paper disk diffusion method and anti-oxidant effect was assessed by the DPPH radical scavenging effect, Superoxide anion radical scavenging effect and SOD like ability. Results : DPPH radical scavenging of the $n$-BuOH fraction from SO in 50 ug/mL was shown to be Fr-2 (89.9%), Fr-3 (88.7%), Fr-4 (76.3%), Fr-1 (59.4%), Fr-5 (56.2%). Superoxside anion radical scavenging activity of the n-BuOH fraction from SO. in 50 ug/mL for Fr-3 was shown to be 78%. SOD-like activity of n-BuOH fraction from the SO in 1000 ug/mL for Fr-3 were shown to be 76.1% respectively. The $n$-BuOH fraction from the SO had high anti-microbial effect on $S.$ $mutans$. Conclusion : As a result, the $n$-BuOH fraction from SO. has good anti-microbial and anti-oxidant effects in a concentration-dependent manner.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.1
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• pp.32-38
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• 2009

In this study, we investigated the anti-obesity activity of the herbal extract mixture (HEM). The inhibitory effect of HEM on triglyceride accumulation of 3T3-L1 preadipocyte was examined by Oil-Red O staining. HEM inhibited the triglyceride accumulation of 3T3-L1 preadipocyte cell and reduced glycerol-3-phosphate dehydrogenase (GPDH) activity. We further investigated the effect of HEM in prevention of obesity in male ICR mouse for 5 weeks. Experimental groups were divided into high fat diet group (HFD), HFD supplemented with 100 mg/kg HEM group (HEM1) and HFD supplemented with 200 mg/kg HEM group (HEM2). Body weight and food efficiency ration of HEM1 and HEM2 was decreased by 52% and 50% and by 45% and 50%, respectively. The amount of adipocyte in body weight was decreased. Blood triglyceride and total cholesterol of HEM1 was significantly decreased. These results indicate that HEM may be useful in preventing obesity.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.620-624
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• 2016

The Wnt/β-catenin signaling pathway is mandatory in adipogenesis. In this study, we investigated the applicability of functional materials for the treatment of obesity by examining Wnt/β-catenin pathway reporter activity related to adipocyte differentiation inhibiting with korean native plant extracts. The luciferase activity of HEK 293-TOP cells increased the reporter activity approximately 152% and 130% by treatment with Sanguisorba officinalis and Thuja orientalis, respectively. Ricinus communis were represented about 90% higher activity, two samples(Rosa rugosa and Sophorae Flos) showed 80% higher activity than the control. Three samples of plant extracts (Zanthoxylum piperitum, Pueraria thunbergiana, Solanum nigrum) were about 70% higher activity compared with the non-treated control. Cytotoxicity of plant extracts was not detected in the rat neural stem cells. These results suggest that the selected eight plant extracts are safe compounds. Our findings indicate that Wnt/β-catenin pathway reporter activity could be used for high throughput screening system. In addition, the plant extracts selected as candidates for adipocyte differentiation inhibiting may be potential therapeutic agents for obesity, it will be exploring the possibility of developing an anti-obesity materials through further experiments with selected plant extracts.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.200.1-200
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• 2003

본 연구에서는 식품의 부패에 관여하는 미생물인 Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureu, Salmonella typhimurium Lactobacillus plantarum에 항균 활성을 나타내는 생약제의 효능을 살펴보았다. 금산 약초시장에서 구입한 생약재로부터 물 추출물과 70%에탄을 추출물을 제조하여 6종의 세균에 대해 항균활성을 탐색한 결과, 생약재 물 추출물의 경우에 가자 추출물은 E. coli, P. aeruginosa B. subtilis, S. aureus, S. typhimurium, L. plantarum의 6가지 균종에 대해서 모두 높은 항균활성을 나타내었으며, 복분자와 지유의 물추출물에서는 L. plantarum의 균종을 제외한 5가지 균종에 대해 높은 항균 활성을 나타내었다. 또한 소목 과 황련의 추출물에서는 E. coli를 제외한 5가지 균종에서 항균활성을 나타내었으며, 정향 추출물에서는 E. coli균주에 대해서는 약한 항균활성을 나타내었으나, B. subtilis, P. aeruginosa, S. aureus, S. typhimurium의 4종의 균주에 대해서는 우수한 항균활성을 나타내었다. 이 외에 감초 추출물은 P. aeruginosa, 석곡 추출물은 S. aureus, S. typhimurium, 계피 추출물은 S. typhimurium, 산수유 추출물은 B. subtilis, S. aureus, 파고지는 S. aureus균종에 대해서 항균활성을 나타내었다. 70% ethanol 추출물은 대부분의 생약재에서 높은 항균 활성을 나타내었다. 특히 가자, 감초, 강황, 복분자, 석곡, 소목, 오미자, 작약 ,정향, 지유, 파고지, 호장근, 황련 의 13가지 생약재 추출물에서 높은 항균활성을 나타내었다. 가자의 70% ethanol추출물의 경우는 물 추출물의 결과에서 같이 6가지 균종에 대해 모두 높은 항균활성을 나타냈으며, 복분자, 작약, 정향, 지유의 70% ethanol 추출물은 L. plantarum균을 제외한 5가지 균종에 대해 높은 항균 활성을 나타내었다. 소목의 70% ethanol 추출물의 경우에는 E. coli 균을 제외한 5가지 균종에서 높은 항균 활성을 보였으며, 이외에 생약재는 강황, 석곡, 황련, 호장근의 70% ethanol 추출물은 4가지의 균주에 대해서 항균 활성을 나타내었다. 또한 파고지, 오미자의 70% ethanol 추출물은 3가지 균주에 대해서 항균활성을 나타냈으며, 천궁, 육두구, 오수유, 갈근, 계피, 가시오가피의 70% ethanol 추출물은 2가지 균주에 대해 항균 활성을 나타내었다. 항균활성이 우수한 생약재를 농도별로 활성을 조사한 결과, 물 추출물과 10% Ethanol 추출물 모두 낮은 농도에서도 우수한 항균활성을 나타내었다.