• Publications of The Korean Astronomical Society
• /
• v.7 no.1
• /
• pp.149-153
• /
• 1992

We determined the efficiencies of the aperture. beam and forward spillover and scattering of 13.7 m radio telescope at Daeduk Radio Astronomy Observatory through the observations of the planets and Moon. The main panels adjustments were carried out on September 1991 and the improvements in the efficiencies were checked by comparing the observations made before and after the panel adjustments. The efficiencies were turned out to be 0.35, 0,47 and 0.83 at 115.27 GHz for the aperture, beam and forward scattering and spillover. respectively. These marked nearly a factor of two upgrade of the efficiencies previously measured.

• The Korean Journal of Ecology
• /
• v.21 no.2
• /
• pp.163-167
• /
• 1998

One new species of cellular slime molds, Dictyostelium caudabasis sp. nov. Shim et chang, is isolated from soils in the Quercus mongolica forest of Seorak monutain, South Korea. D. caudabasis is charaterized by small sorophores, scarecely phototrophic, irregularly or sparsely branches, capitate-simple or capitate-compound and sometimes obtuse-simple tips, and conical and sometimes clavate bases. Spore are elliptical, $6.52~4.82{\times}3.40~2.83{\mu}m(avg.\;5.72{times}3.17{\mu}m$), L/W index 1.70-1.92(avg. 1.80) without polar grnules.

• Journal for History of Mathematics
• /
• v.17 no.4
• /
• pp.65-76
• /
• 2004

Even though mathematics and music play very different roles in our society, they are closely related to each other. In this paper, we studies relations between mathematics and Korean traditional music, and give some ideas to use such relations in mathematics education.

• Journal of Korean Society of Water and Wastewater
• /
• v.12 no.4
• /
• pp.70-77
• /
• 1998

On this study, removal ability of nitrate was researched in the anaerobic zone arounding collection pipes in landfill. Stability state time of column was after 20 days and 20~90ml/day in flux. In this time, removal rate of phosphate was about 80%. Removal ability and average removal rate of CODCr is $36g/m^3{\cdot}d$, 25.3%, respectively. It was that reactor is able to remove more nitrate. Maximum nitrate removal ability was $4.83g/m^3{\cdot}d$.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.8 no.11
• /
• pp.79-83
• /
• 1985

This paper is to develop four heuristic algorithms for $n/m/D/F/F_{max}$. A study present numerical example for (H1) algorithm. Among the sequence generated, the best sequence is J2, J1, J6, J7, J4, J3, J5 and makespan is 528. The optimal makespan of this numerical example can be found as 528 as also, and the worst value of heuristic solution is only 7.2 % away from it.

• International Journal of Oral Biology
• /
• v.41 no.2
• /
• pp.83-88
• /
• 2016

Periodontitis is an inflammatory disease, which destroys the connective tissue and the alveolar bone. Recently, it has been suggested that the effect of natural substances could be induced into an anti-inflammatory environment. However, the effect of Safflower seed extract (SAF-M) associated with periodontitis has not been investigated yet. Therefore, the purpose of this study was to assess the anti-inflammatory effects of SAF-M. Cytotoxicity was assessed through MTS analysis using hGF and hPDL cells. Periodontitis was induced by injecting LPS into gingival tissue on the maxillary molars of rats ($45{\mu}g$ LPS/one time, 3 times a week for 3 weeks). SAF-M was administered daily at 30 mg/kg and 100 mg/kg. Alveolar bone resorption was evaluated through the micro-CT. hGF and hPDL cells showed differential cytotoxicity in response to SAF-M at 5 mg/ml and 1 mg/ml concentrations. Micro-CT showed reduction of the alveolar bone resorption in the SAF-M treatment group. These results suggested that SAF-M is a potential therapeutic agent for periodontitis.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 1999.11b
• /
• pp.79-83
• /
• 1999

A cationic demand(CD) is a very useful indication for determining the optimum dosage rate of retention aids to the papermaking stock at the wet end. Polyelectrolyte titration has been most often used to determine a CD. Highly accurate results can be obtained by this method when the ionic strength of sample is low. But this is accompanied by the serious errors when the ionic strength is higher than that corresponding to 20 milli molar(mM) monovalent, 2 mM divalent or 0.2 mM trivalent ions because of no occurrence of the end point of titration. Therefore, it is very difficult or almost impossible for the conventional method to be applied to the industrial suspensions such as papermaking stock and industrial waste water. Then a novel method using chromophoric labeled cationic polymer which can be applicable to the sample with high ionic strength has been developed.

• Journal of Ocean Engineering and Technology
• /
• v.1 no.2
• /
• pp.83-92
• /
• 1987

Inorder ot estimate the running life of turbine rotors, fatigue crack propagation low, da/dN = C(${\DELTA}K)^m$, proposed by paris et al. has been widely applied. In this study, fatigue crack propagation rates for 16 samples of 1% Cr-Mo-V rotor steel were measured and statistical characteristics of m and C values in above equation were reviewed. The results are summarized as follows. 1. C and m follow a log-normal distribution and normal distribution, respectively. And the relation of C and shows a strong negative correlation. 2. Fatigue crack propagation equation can be expressed as da/dN=$4.11{\times}10^{-4}({\Delta}K/153.8)^m$, introducing the ralationship C=$C_oK_o^{-m}$. In this case, contribution of $C_o$ distribution to the distribution of log C shows very small compared to degrees of contribution by m.

• Journal of Information Technology Services
• /
• v.5 no.1
• /
• pp.83-95
• /
• 2006

The main objectives of this study are (1) to identify the conflict types in IS integration process with respect to M&A, (2) to propose the ways to manage the origin of conflict to be expected, and (3) to develop the conflict management model which establishes the relationship among the M&A strategy, the IS integration strategy and change management process that influence the source of conflict. In order to achieve these research objectives, this study focuses on banking industry under M&A with the viewpoint of change management instead of existing technology-oriented IS integration strategy. The findings of this study are thought not only to be useful as a practical guideline in carrying out IS integration project under M&A but also to provide significant basis for constructing the theoretical framework of effective IS integration strategy.

• Natural Product Sciences
• /
• v.28 no.3
• /
• pp.115-120
• /
• 2022

Ten compounds, consisting of neoflavonoids (1-5), isoflavonoids (6 and 7), flavanone (8), and chalcones (9 and 10) were isolated from the ethyl acetate and n-butanol-soluble fractions of the heartwood of Dalbergia melanoxylon. The chemical structures were identified on the basis of spectroscopic evidence and compared to previously reported spectra. Compounds 1-10 were evaluated for cytotoxicity against HCT116 human colorectal cancer, MDA-MB-231 human metastatic breast cancer, and A2058 human melanoma cell lines. Among them, compounds 3 and 10 showed the strongest cytotoxic activity with IC₅₀ values of 11.92±1.07 μM, 10.83±1.02 μM, and 14.37±1.02 μM, 13.62±1.09 μM against HCT116 and MDA-MB-231 cell lines, respectively. Compounds 9 and 10 also had cytotoxic activity with IC₅₀ values of 13.49±1.18 μM and 9.82±0.91 μM against A2058 cell lines, respectively. To the best our knowledge, compounds 2 and 5-10 were isolated from this source for the first time.