• 지능정보연구
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• 제23권2호
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• pp.123-138
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• 2017

주식 시장은 거래자들의 기업과 시황에 대한 기대가 반영되어 움직이기에, 다양한 원천의 텍스트 데이터 분석을 통해 주가 움직임을 예측하려는 연구들이 진행되어 왔다. 주가의 움직임을 예측하는 것이기에 단순히 주가의 등락 뿐만이 아니라, 뉴스 기사나 소셜 미디어의 반응에 따라 거래를 하고 이에 따른 수익률을 분석하는 연구들이 진행되어 왔다. 주가의 움직임을 예측하는 연구들도 다른 분야의 텍스트 마이닝 접근 방안과 동일하게 단어-문서 매트릭스를 구성하여 분류 알고리즘에 적용하여 왔다. 문서에 많은 단어들이 포함되어 있기 때문에 모든 단어를 가지고 단어-문서 매트릭스를 만드는 것보다는 단어가 문서를 범주로 분류할 때 기여도가 높은 단어들을 선정하여야 한다. 단어의 빈도를 고려하여 너무 적은 등장 빈도나 중요도를 보이는 단어는 제거하게 된다. 단어가 문서를 정확하게 분류하는 데 기여하는 정도를 측정하여 기여도에 따라 사용할 단어를 선정하기도 한다. 단어-문서 매트릭스를 구성하는 기본적인 방안인 분석의 대상이 되는 모든 문서를 수집하여 분류에 영향력을 미치는 단어를 선정하여 사용하는 것이었다. 본 연구에서는 개별 종목에 대한 문서를 분석하여 종목별 등락에 모두 포함되는 단어를 중립 단어로 선정한다. 선정된 중립 단어 주변에 등장하는 단어들을 추출하여 단어-문서 매트릭스 생성에 활용한다. 중립 단어 자체는 주가 움직임과 연관관계가 적고, 중립 단어의 주변 단어가 주가 상승에 더 영향을 미칠 것이라는 생각에서 출발한다. 생성된 단어-문서 매트릭스를 가지고 주가의 등락 여부를 분류하는 알고리즘에 적용하게 된다. 본 연구에서는 종목 별로 중립 단어를 1차 선정하고, 선정된 단어 중에서 다른 종목에도 많이 포함되는 단어는 추가적으로 제외하는 방안을 활용하였다. 온라인 뉴스 포털을 통해 시가 총액 상위 10개 종목에 대한 4개월 간의 뉴스 기사를 수집하였다. 3개월간의 뉴스 기사를 학습 데이터로 분류 모형을 수립하였으며, 남은 1개월간의 뉴스 기사를 모형에 적용하여 다음 날의 주가 움직임을 예측하였다. 본 연구에서 제안하는 중립 단어 활용 알고리즘이 희소성에 기반한 단어 선정 방안에 비해 우수한 분류 성과를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.741-746
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• 1992

The effects of 5%, 10%, 15% and 20% dietary cellulose levels on the nutrient utilization in chickens were investigated. Four experimental diets were alternatively given to 8 colostomized White Leghorn cockerels to make a $4{\times}4$ Latin-square design. The diets of 70 g.day were force-fed once a day, and water was given freely. The digestibilities of DM and energy increased linearly with the increase in dietary cellulose level. The digestibilities of ether extract and nitrogen-free extract were not so much influenced by the dietary cellulose level. The digestibility of acid detergent fiber was very low and not influenced by the dietary cellulose level. The digestibility of neutral detergent fiber was not different among the diets containing 5%-15% cellulose, but that of the 20% cellulose diet was diminished. This might be due to the reduction of hemicellulose digestibility. True digestibility and biological value of protein were also not influenced by the dietary cellulose level from 5% to 20%. In conclusion, no ill-effect was found even when the chicken was fed a diet containing 20% of cellulose.

• KSBB Journal
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• 제25권4호
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• pp.363-370
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• 2010

Lipid from Scenedesmus sp. was extracted, fractionated and purified by silicic acid column chromatography. Total lipid content of extract was $21.38{\pm}1.03$ wt%, and triacylglycerol, an index lipid for biodiesel production was detected. Ten species of $C_{16}{\sim}C_{22}$ with saturated and unsaturated fatty acid were identified showing the very adequate fatty acid profiles for biodiesel production with a good flow property at low temperature. The fractions of glycolipid, neutral and phospholipid were 52.64, 28.10 and 19.26% of total lipid, respectively. The triacylglycerol of 12.63% and chlorophyll a of 49.47% was fractioned using stepwise elution of n-hexane-diethyl ether (95:5, v/v) solvent. The high content of chlorophyll was considered as a potential source of value-added co-product.

• 한국의류산업학회지
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• 제10권1호
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• pp.106-112
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• 2008

The purpose of this study is to define optimal conditions for wool blend fabric dyeing using Rhus verniciflua extract. K/S value, surface color change, the fastness to light, fastness to dry-cleaning, metal mordanting effects and antimicrobial activities were investigated. The results were summarized as follows; As the storage time of Rhus verniciflua stokes dyeing solution was longer, K/S was improved. K/S value showed the highest one when dyeing temperature and time were at 100oC and 60 minutes respectively. As for the changes of pH values of the dyeing solution, fabric was dyed well with the pH value of acid or neutral. K/S value recorded the highest at pH6 and the lowest at pH10. Fastness to light showed the unmordanted fabric is 2.84, and Fe is 1.69 on color difference. Antibacterial activities of Rhus verniciflua dyeing solution recorded high figures in both dyed fabric with unmordanted and dyed fabric with mordanting.

• 생약학회지
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• 제27권3호
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• pp.254-261
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• 1996

A potent immuno-stimulating activity was detected from the watersoluble and ethanol-precipitated crude extract (AG-1) of the root of Angelica gigas Nakai. The crude extract was fractionated into two fractions, an acidic AG-2 and a neutral AG-3 fraction by DEAE-cellulose adsorption. The two fractions contained polysaccharides of which M.W. were 10 Kdal and >2,000 Kdal respectively, proteins, and various inorganic components. The immunostimulating activities of two fractions were not reduced by proteinase K, acid or alkali treatment. The polysaccharides obtained from the root of A. gigas were mainly composed of arabinose, galactose, and galacturonic acid. These results indicated that immuno- stimulating components of the root of A. gigas was a kind of pectic polysaccharides or arabinogalactans.

• 한국식품과학회지
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• 제27권2호
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• pp.216-220
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• 1995

김치의 천연보존제로서의 이용가능성을 검토하기 위하여 15종의 식물성 김치재료를 MeOH로 추출, 용매분획하여 얻어진 산성구, 중성구 그리고 수용액구에 대해 김치 주발효미생물인 Leuconostoc mesenteroides, Pediococcus cerevisiae, Lactobacillus plantarum과 Saccharomyces cerevisiae를 대상으로 항미생물활성을 검색한 결과, 마늘과 부추추출물의 중성구에서 뚜렷한 항미생물활성을 나타냈다. 특히 부추추출물은 김치의 숙성 및 산패원인균으로 알려진 Ped. cerevisiae와 L. plantarum에 대해서 현저한 항미생물활성을 나타내, 김치의 천연보존제 및 산패억제제로서 부추추출물의 이용가능성이 시사되었다.

• 한국식품영양학회지
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• 제9권1호
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• pp.76-84
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• 1996

This study was carried out to evaluate the effect of Ganoderma lueuidum (GL) water extract on fat accumulation in the fatted rats Induced by the oral high fat administration for six weeks. Total cholesterol, neutral fat and epididymal fat pad of GL groups were lower than the control group. On the other hand, high density lipoprotein(HDL) -cholesterol was somewhat higher in GL than In the control group. In addition, the same result as the above case was obtained when examining adipose for liver and epididymal fat components. During the feeding experiment, level of low density lipoprotein(LDL) and very low density lipoprotein (VLDL) increased while HDL was decreased in the control group as compared with normal group. The decree of LDL and VLDL was decreased, but HDL was increased in GL group as compared with the control group. Experiment group showed the Increased excretion as compared with the control group, in the excretion. Based on the above results, It was shown that it is possible to improve fat accumulation induced by high fat dietary through using the oral administration of Ganoderma lueidum boiling extract solutions.

• KSBB Journal
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• 제18권6호
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• pp.511-516
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• 2003

개오동나무 (Catalpa ovata G. Don) 잎의 MeOH 추출물은 DPPH 라디칼 소거활성을 나타냈으며, 이에 개오동나무 잎에 함유된 항산화물질을 구명하고자 하였다. MeOH 추출물을 용매분획하여 EtOAc 가용 중성획분을 얻고, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography로 정제한 다음 HPLC에 의해 3종의 활성물질을 단리하였다. 단리된 물질들은 HR-MS, 1H-NMR, 13C-NMR, 2D-NMR 등의 기기분석에 의해 piperitol, pinoresinol, lariciresinol로 동정하였다. 이들 물질들을 대상으로 DPPH 라디칼 소거활성을 조사한 결과, lariciresinol ($SC_{50}$/, 19$\mu\textrm{g}$/mL) ＞ pinoresinol ($SC_{50}$/, 31$\mu\textrm{g}$/mL) ＞ piperitol ($SC_{50}$/, 59$\mu\textrm{g}$/mL)의 순으로 항산화활성이 나타났다.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.745-750
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• 2007

An isotope dilution-liquid chromatography/tandem mass spectrometric method was developed as a candidate reference method for the accurate determination of folic acid in infant milk formula. Sample was spiked with 13C5-folic acid and then extracted with phosphate buffer (pH 6) solution. The extract was further cleaned up by deproteinization followed by a C18 solid-phase extraction cartridge. The extract was analyzed by using LC/ ESI/MS/MS with selectively monitoring the collisionally induced dissociation channels of m/z 442 → m/z 295 and m/z 447 → m/z 295, which are the neutral glutamyl loss from the [M+H]+ ions of folic acid and 13C5-folic acid, respectively. LC/MS/MS chromatograms showed substantially reduced background from chemical noises compared to LC/MS chromatograms. Repeatability and reproducibility studies showed that the LC/MS/ MS method is a reliable and reproducible method which can provide less than 1.5 relative percentage of method precision.

• Natural Product Sciences
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• 제22권1호
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• pp.20-24
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• 2016

Pentacyclic triterpenes, mainly, asiatic acid, madecassic acid, asiaticoside, and madecassoside are the active constituents of Centella asiatica. A pentacyclic triterpene enriched C. asiatica extract (PRE) was prepared and standardized to contain a total pentacyclic triterpenes not less than 65% w/w. This work was focused on determination of antiinflammatory, antioxidant, and tyrosinase inhibitory activities of PRE and its stability. The PRE exhibited a satisfactory nitric oxide inhibitory effect, with an $IC_{50}$ value of $64.6{\mu}g/mL$. In addition, the PRE inhibited tyrosinase enzyme activity with an $IC_{50}$ value of $104.8{\mu}g/mL$. In contrast, the PRE possessed only weak antioxidant activity. The PRE was stable over a period of four months when stored as a dried powder but only in a well-closed container protected from light at $4^{\circ}C$. An aqueous alcoholic solution of the PRE was stable at pH values of 5.8 and 7.0, but was not stable at a pH of 8.2. Preparations of the PRE in an aqueous solution should be performed in acidic or neutral conditions.