• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.4
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• pp.51-60
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• 2007

In this study, we consider the minimum ADM problem which is the fundamental problem for the cost-effective design of SONET ADM embedded in WDM ring networks. To minimize the number of SONET ADMs, efficient algorithms for the routing and wavelength assignment are needed. We propose a mathematical model based on the graph theory for the problem and propose a branch-and-price approach to solve the suggested model effectively within reasonable time. By exploiting the mathematical structure of ring networks, we developed polynomial time algorithms for column generation subroutine at branch-and-bound tree. In a computer simulation study, the suggested approach can find the optimal solution for sufficient size networks and shows better performance than the greedy heuristic method.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1214-1217
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• 2012

One Helicosporium strain, isolated from a wilted chestnut tree, evidenced in vitro antimicrobial activity against various types of bacteria and fungi, and generated a diffusible pigment. The antimicrobial compounds and the diffusible pigment of the Helicosporium sp. isolate were purified via solvent fractionation, column chromatography, and recycling preparative chromatography. Both the major antimicrobial compound and the diffusible pigment were identified as 2-methylresorcinol via nuclear magnetic resonance spectroscopy. Therefore, 2-methylresorcinol, a diffusible pigment generated by Helicosporium sp., appears to be an active antimicrobial principle. This pigment also exhibited considerable cytotoxicity against mammalian cells.

• Korean Journal of Medicinal Crop Science
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• v.10 no.4
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• pp.284-287
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• 2002

Four olefinic catechols, commonly referred to as urushiol were isolated from the sap of Korean Rhus verniciflua Stokes and had the stronger inhibitory effects on the reverse transcriptase of AIDS. The hexane extract with a inhibitory effects on reverse transcriptase was purified by silica and ODS gel column chromatography. The active compounds were identified by MS and $^1H-NMR$ as 3-[8' (Z), 11' (Z), 14' -pentadecatrienyl]catechol, 3-[8' (Z), 11' (Z)-pentadecadienyl]catechol, 3-[8' (Z)-penta- decenyl]catechol, and 3-pentadecylcatechol. All of these compounds showed strong inhibitory effects on reverse transcriptase of AIDS, in which 3-pentadecylcatechol exhibited the highest activity $(IC_{50}\;:\;10.87\;{\mu}g/ml)$.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.529-536
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• 1999

The objective of the research stated herein is to observe th elastic and inelastic behaviors and ultimate capacity of 1 : 5 scale 3-story reinforced concrete frame. Pushover tests were performed to 1:5 scale 3-story reinforced concrete frames without and with infilled masonry. To simulate the earthquake effect, the lateral force distribution was maintained to be an inverted triangle by using the whiffle tree. From the results of tests, the relations between the total lateral load and the roof drift, the distribution of column shears, the relation between story shear and story drift, and the angular rotations at the critical portions of structures were obtained. The effects of infilled masonry are investigated with regards to the stiffness, strength, and ductility of structures. Final collapse modes of structures with and without infilled masonry are compared.

• Journal of the Korean Wood Science and Technology
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• v.37 no.2
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• pp.171-176
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• 2009

The chemical constituents of Acer komarovii Pojark. which belongs to Aceraceae has never been reported. The bark of A. komarovii was extracted with 70% aqueous acetone, and the concentrated extract was successively partitioned with n-hexane, dichloromethane, ethyl acetate and $H_2O$. From the ethyl acetate soluble fraction, four compounds were isolated by the repeated Sephadex LH-20 and RP C-18 column chromatography. From the results of spectroscopic methods including FAB-MS, 1D and 2D NMR, the structures of the compounds were determined as quercetin (1), guaijaverin (2), hirsutrin (3) and hyperin (4). These compounds (1-4) have not been reported in this tree yet.

• KCI Concrete Journal
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• v.11 no.3
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• pp.165-174
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• 1999

The objective of the research stated herein is to observe the elastic and inelastic behaviors and ultimate capacity of 1:5 scale 3-story reinforced concrete frame. Pushover tests were performed to 1:5 scale 3-story reinforced concrete frames with and without infilled masonry. To simulate the earthquake effect, the lateral force distribution was maintained by an inverted triang1e by using the whiffle tree. From the test results, the relation ships between the total lateral load and the roof drift, the distribution of column shears, the relation between story shear and story drift, and the angular rotations at the critical portions of structures were obtained. The effects of infilled masonry were investigated with regards to the stiffness, strength, and ductility of structures. Final collapse modes of structures with and without infilled masonry were compared.

• Journal of the Korean Wood Science and Technology
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• v.26 no.4
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• pp.56-60
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• 1998

The bark of Fraxinus rhynchophylla, one of ash trees grown in domestic, was collected, extracted with acetone-$H_2O$(7:3, v/v) and freeze dried to give 50g of ethylacetate soluble powder. A portion of the freeze dried powder was chromatographed on a Sephadex LH-20 and a TSK 40F column using a series of aqueous methanol and ethanol-hexane mixture as eluents. The extractives contained a large amount of coumarin derivatives in addition to a small amount of ester compounds such as ligstroside and oleuropein which have not been isolated from this tree species yet. Some spectrometric analyses such as NMR and FAB-MS including TLC were performed to identify the structures of the isolated ester compounds.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.194.1-194.1
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• 2003

Ternstroemia japonica (Theaceae) is widely distributed in Korea, Japan, Taiwan and China. The tree is a useful source of lumber, dye and horticulture. Its fruits have been used as folk medicine in Japan for the treatment of chest pain or numbness. Previously, we have isolated saponins and jacaranone derivatives from the fruits. In our continuous study on the same plant, the leaves of Ternstroemia japonica were extracted with MeOH and the MeOH extract was fractionated with solvents. The n-BuOH soluble fraction was separated by repeated column chromatographies on silica gel and Sephadex LH-20, and further purified by reversed phase HPLC. (omitted)

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.67-71
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• 2004

Pata de Vaca (Bauhinia forficata) Is a tree which grows naturally in the rainforests and tropical parts of Peru and Brazil, as well as tropical zones of Asia, eastern Paraguay and northeastern Argentina. The active fraction (Pata-50) of the 70% ethanol extract from Pata de Vaca was sequentially fractionated by HP-20 Diaion column chromatography and C-18 column chromatography, and its characteristics were investigated. The growth of all cancer cells tested except for MCF-7 was Inhibited in a concentration-dependent manner by Pata-50. Its $IC_{50}$ values were estimated to be 40.4 $\mu\textrm{g}$/$m\ell$ on AGS, 51.3 $\mu\textrm{g}$/$m\ell$ on HT-29, 52.1$\mu\textrm{g}$/$m\ell$ on HepG2, 65.2$\mu\textrm{g}$/$m\ell$ on A549, and 77.5$\mu\textrm{g}$/$m\ell$ on HeLa cells. A flow cytometric analysis of HepG2 cells revealed induction of apoptosis, but cell cycle regulation was not affected. The HepG2 cell population of apoptosis region increased In a concentration-dependent manner by Pata-50.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.6
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• pp.980-989
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• 2009

Amur cork tree was extracted in methanol with the purpose of investigating the most effective extraction procedure for detecting the chromophore using the GC-MS analysis. Different procedures of waterbath and hotplate extractions were carried out and five different GC-MS instrument parameters including the operating temperatures in the GC capillary column and the MSD scan range were tested for their efficiencies. Berberine was determined by the detection of dihydroberberine at 15.0 min r.t. Hotplate was a better device for extracting amur cork tree than waterbath shaker either with or without presoaking in the room temperature. Water was not an adequate extraction medium for the berberine detection. The most effective GC-MS parameter was Method 4; the initial temperature at $50^{\circ}C$ followed by the temperature increase of $23^{\circ}C$/min until $210^{\circ}C$, then increase of $30^{\circ}C$/min until the final temperature reach at $305^{\circ}C$, then hold for 14 minutes to maintain the total run time 24.12 minutes. The MSD scan range for Method 4 was $35\sim400$m/z.