• Journal of the Korean Society for information Management
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• v.10 no.2
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• pp.3-22
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• 1993

In recent years various document ranking methods such as Relevance. R-Distance and K-Distance have been developed wh~ch can be used in thesaurus-based boolean retrieval systems. They give high quality document rankings in many cases by using term dependence lnformatlon from a thesaurus. However, they suffer from several problems resulting from inefficient and Ineffective evaluation of boolean operators AND. OR and NOT. In this paper we propose new thesaurus-based document ranking methods called KB-FSM and KB-EBM by exploitmg the enhanced fuzzy set model and the extended boolean model. The proposed methods overcome the problems of the previous methods and use term dependencies from a thesaurs effectively. We also show through performance comparison that KB-FSM and KBEBM provide higher retrieval effectiveness than Relevance. R-D~stance and K-Distance.

• Korean Journal of Microbiology
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• v.30 no.3
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• pp.218-224
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• 1992

Recombinant plasmid shuttle vectors were constructed for genetic studies on the oxidation of carbon monoxide by carboxydobacteria. Two vectors. pYK322 (7.2 kb, Ap'. Tc') and pYK 324 (7.2 kb, Ap', Tc'), were constructed using pBR322 and pYK100. a small plasmid in Pseudomonas carbo,xydovorans. Four plasmids. pYK2IO (5.2 kb. Cm'), pYK220 (5.2 kb, Cmr), pYK230 (5.2 kb, Cm'), and pYK232 (5.2 kb. Cm'), were constructed using pACYC184 and pYK100. Transformation of several carboxydobacteria with pYK322 and pYK220 was round to be efficient when the cells were transformed by the methoti of Bagdasarian and Timmis (Curr. Top. Microbiol. Immunol. 96:47-67. 1982) with several modifications; cells growing on 0.2% succinate were harvested at the mid-exponential phase. 10 mM RbCl in transformation solution was substituted with 100 mM KCI. cclls in transformation solution were incubated for 12 h at 4'C before addition of DNA and heat shock was carried out for 3 min at 45$^{\circ}$C. Plasmid vectors used for transformation, however. were not detected from antibiotics-resistant transformants, suggesting that the vectors may be integrated into the chromosomal DNA.

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.129-138
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• 1995

DNA fragment being able to restore in vitro activity of ${\beta}-1,3-glucan$ synthase was cloned by transformation of the Saccharomyces cerevisiae LP353 mutant strain with genomic library constructed in the YCp50. For the selection of transformants which showed no detectable phenotype linked to recovery of the defect in ${\beta}-1,3-glucan$ synthase activity, the colony autoradiography was succesfully applied. The restriction map of the cloned DNA fragment, which is 8.5-kb in length, was constructed. Both the YEplac195 and the YCp50 carrying the 8.5-kb fragment increased ${\beta}-1,3-glucan$ synthase activity of LP353 by two fold. Neither the YEplac195 nor the YCp50 carrying the 8.5-kb DNA fragment, however, complemented the temperature-dependent osmotic sensitivity which is another distinctive phenotype of LP353. Subcloning experiments indicated that a functional region was located in 4.8-kb BglII-KpnI fragment. The 4.8-kb fragment was also able to increase the level of ${\beta}-1,3-glucan$ content in cell wall as well as the resistance of cells to cell wall lytic enzyme, ${\beta}-1,3-glucanase$. The growth rate of the LP353 with 4.8-kb fragment was almost same as that of wild type strain in liquid medium with 1.2 M sorbitol at nonpermissive temperature. Taken these results together, the 4.8-kb fragment seemed to contain the BGS2 gene for ${\beta}-1,3-glucan$ synthase activity in yeast S. cerevisiae.

• The Journal of the Petrological Society of Korea
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• v.10 no.1
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• pp.36-55
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• 2001

Hornblende geobarometry has been applied to estimate the emplacement depth of the Jurassic Yeongiu, Andong, and Gimcheon granites in the Yeongnam Massif. Geobarometry was determined from the twenty two samples of the Yeongiu granite, ten samples of the Andong granite and twelve samples of the Gimcheon granite, using the composition of hornblende rims coexisting with the mineral assemblage required for pressure determination. Amphibole compositions in the three granites vary from edenite to ferropargasite with the increase of pressure. According to the equation of Schmidt(1992), the pressures of emplacement of the Yeongiu, Andong, and Gimcheon granites are 5.6 to 7.9 kb, 5.5 to 7.5 kb, and 4.1 kb to 5.3 kb, respectively. The emplacement depth in the Yeongiu granites increase systematically from about 6 kb in the northwest to about 7.5 kb in the southeast. Andong granite shows no systematic change of the pressure estimates. The Gimcheon granite shows almost consistent pressure distribution. The pressure difference of about 1.5 kb across the Yeongiu granite may be explained by a model combining late postemplacement upsurge of a deeper part of the pluton in the south with tilting of the batholith by Yecheon shear zone.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.11a
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• pp.336-341
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• 2002

현재 연구개발 중인 웹 정보 에이전트는 Agent Manager와 KB Manager. Web Manager로 구성되어 있다. 이 시스템은 동물영역에 관련된 정보를 영어로 서비스하고 있어 국내 접근보다는 외국에서의 접근이 더 많았다. 그러므로 국내 사용을 높이기 위해 애완용 동물을 위주로 한 정보추출(IE)을 수행하여 지식베이스(KB)의 확장을 시도하고 있다. 이를 위하여 태그(tag) 및 심볼(symbol)의 패턴(pattern) 유사성 정보를 찾아내고, 기존 KB와 연계하여 KB의 확장 및 수정에 이용하기 위한 유효 정보 패턴 결정에 활용함으로써 정보 추출의 새로운 방법을 고찰하고 그 가능성을 제시하고자 한다.

• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.473-477
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• 1993

Both glycerol-phosphate acyltransferase (GPAT) and 7.2 kb mRNAs were present at the highest level in liver. Glycerol-phosphate acyltransferase and 7.2 kb mRNA levels increased dramatically when fasted mice were refed a high carbohydrate diet. In mature 3T3-L1 adipocytes, insulin increased both glycerol-phosphate acyltransferase and 7.2kb mRNA levels 2.6 to 3-fold while dibutyryl cAMP decreased mRNA levels by 50% and 80%, respectively. These results indicate positive regulation by insulin and negative regulation by dibutyryl cAMP of both glycerol-phosphate acyltransferase and 7.2 kb mRNA.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.242-246
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• 1996

Hatomarubigins inhibited the growth of various cancer cell lines including multidrug-resistance cells. Hatomarubigins were found to potentiate the colchicine- and vinblastine-induced cytotoxicity against KB-C2 cell, but not the adriamycin-induced cytotoxicity against KB-C2 cells. Hatomarubigins didn't affect the sensitive KB cells. These results suggest that hatomarubigins are specific potentiators of colchicine. Among four hatomarubigins, hatomarubigin A sho- wed the highest synergestic effect on colchine-induced cytotoxicity. Similar effect of hatomarubigin A was found against V79/ADM cells.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.197-204
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• 1999

A total of 22 Leptospiua inlermgans field isolates from the ~ a t s captured in 5 provinces of Korea in 1996, and 6 antigenically closely related relerence serovars of lai, yeonchon, birkini. gem, mwogolo. and canicola were analysed. When the antigenic characteristics were analysed by reactivity with 7 monoclonal antibodies prepared with sh.ains belongng to serogroup Icterohaemorrhagiae. all 22 isolates showed the same reaction pattern with that of serovar lai. Large restriction fragment patterns obtained after cleavage of geno~nic DNAs with infrequently cuttimg restriction enzymes were analyzed by pulsed-field pel electrophoresis(PFGE). Identification of leptospira strains by PFGE with Nor I, Asc I or Iise I digests correlated with their antigenically typed serovars, silh a few exceptions. PFGE of isolates, except for JR89, digested wjth Nor I showed identical pattern w~th serovar lai, showing 13 Cragments between 940 kb and 63 kb. When PFGE pallerns of JR89 were compared with those of serovar lai, Not I digest showed additional two hands of 1000 kb and 460 kb, while Asc I digest showed 650 kb fragment and Fse I digest did not show the fragment of 280 kb. Whereas serovar yeonchon. which was isolated in Korea and identified as a new serovar previously. could be differentiated from serovar lai in antigenic reactivities with monoclonal antibodres. it showed the similar PFGE pattern with serovar lai includin~ reference and field isolates. It was suggested that Korean leptospiral field isolates are closely related in DNA level.

• KSBB Journal
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• v.14 no.1
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• pp.76-81
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• 1999

Characteristics and oxidizing ability of both $NH_4-N$ and$NO^2$-N were examined for the strains isolated from wastewater treatment facilities and from natural systems by using Winogradsky columns. In case of $NH_4$-N, the most efficient strain was Nitrosomonas KB1 isolated from wastewater treatment facility of K corporation and in case of $NO_2$-N, it was Nitrobacter KB2 from the same site as Nitrosomonas KB1. For Nitrosomonas KB1, 91% of $NH_4$-N was oxidized after 4 days of cultivation. Optimal growth temperature and initial pH of Nitrosomonas KB1 were $28^{\circ}C$ and 7, respectively. In comparison to oxidizing rates with changing initial concentration of $NH_4$-N, the ammonia oxidizing rate was increased up to 6.7 mg/day for the initial $NO_2$-N concentrations for the region lower than 100 mg $NH_4-N/L$, but it was gradually reduced for the region higher than 100 mg $NH_4-N/L$. For Nitrobacter KB2 90% of $NO_2$-N was removed after culturing for 4 days. Optimal growth temperature and initial pH of Nitrobacter KB2 was $28^{\circ}C$ and 7, respectively. And the nitrite oxidizing rate was increased in proportion to the initial concentrations of $NO_2$-N up to 200 mg/$\ell$, and it was maintained almost 4.2 mg/day irrespective of initial $NO_2$-N higher than 200 mg/L.

• Journal of dental hygiene science
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• v.10 no.5
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• pp.365-372
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• 2010

Caesalpinia sappan L. has long been commonly used in oriental folk medicines and as dyes materials. To investigate the antioxidative activities and antiproliferation effects of brazilin from C. sappan heart wood, the MeOH soluble extract was successively fractionated by using hexane, $CHCl_{3}$, EtOAc, BuOH, MeOH, and $H_{2}O$. In these fractions, we were purified brazilin from EtOAc fraction which partitioned to 3.94% of the highest yields. The effects of brazilin and the extracts on human oral carcinoma cells (KB) by MTT assay and their antioxidant activities by DPPH, TCA assay and Fenton reaction were tested. The results showed that the brazilin could inhibits the proliferation of KB cells and obviously decreased the production of nitric oxide of the cells. When the concentration of the brazilin reached to $100\;{\mu}g/ml$, the inhibition percentage of the cell growth was about 60%. In assay on antioxidant activities, The results showed that brazilin exhibit the highest capacity of DPPH free radical scavenging effects among tested extracts. When the concentration of brazilin reached to 1 mg/ml, the lipid peroxide inhibition and radical inhibition activities were determined to be 65.0% and 85.8%, respectively. These results are suggest that brazilin have stronger antiproliferation effect on KB cell and antioxidant properties.