• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.4
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• pp.390-403
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• 2017

Smoothed Particle Hydrodynamics (SPH) method has a good adaptability for the simulation of free surface flow problems. There are two forms of SPH. One is weak compressible SPH and the other one is incompressible SPH (ISPH). Compared with the former one, ISPH method performs better in many cases. ISPH based on Rankine source solution can perform better than traditional ISPH, as it can use larger stepping length by avoiding the second order derivative in pressure Poisson equation. However, ISPH_R method needs to solve the sparse linear matrix for pressure Poisson equation, which is one of the most expensive parts during one time stepping calculation. Iterative methods are normally used for solving Poisson equation with large particle numbers. However, there are many iterative methods available and the question for using which one is still open. In this paper, three iterative methods, CGS, Bi-CGstab and GMRES are compared, which are suitable and typical for large unsymmetrical sparse matrix solutions. According to the numerical tests on different cases, still water test, dam breaking, violent tank sloshing, solitary wave slamming, the GMRES method is more efficient than CGS and Bi-CGstab for ISPH method.

• The Korean Journal of Pharmacology
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• v.9 no.1
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• pp.47-51
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• 1973

A benzomorphan derivative, pentazocine has both opioid agonistic actions and weak narcotic antagonistic activity. In this paper, authors attempted to study the dose response of pentazocine on the blood sugar level, serum transaminase and alkaline phosphatase activity in rabbits. Eighteen rabbits were devided into 3 groups, and each group were injected with pentazocine 5mg, 15mg, and 30mg/kg respectively. And metabolic effects were investigated measuring the change of blood sugar contents, serum transaminase (S-GOT, S-GPT) activities and alkaline phosphatase activities in rabbits. The results were obtained as follows; 1. Pentazocine significantly increased the blood sugar content in rabbits. 2. Pentazocine significantly increased the serum GOT activity but in the serum GPT activity, it significantly increased in large dose. 3. Pentazocine significantly increased serum alkaline phosphatase activity.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1482-1485
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• 2012

A natural furan derivative was isolated from the methanolic extract of the fruit bodies of Fomitiporia ellipsoidea. Its chemical structure was elucidated as methyl 3,5-dioxo-1,3,5,7-tetrahydrobenzo[1,2-c:4,5-c']difuran-4-carboxylate by means of extensive NMR and MS data analysis, and named as fomitiporiaester A (1). Compound 1 showed significant antitumor activity to hepatoma $H_{22}$ in vivo, and the inhibition rates were 42.94%, 49.17%, and 58.15% at concentrations of 5, 10, and 20 mg/kg, respectively. Compound 1 showed weak cytotoxic activities against the human hepatoblastoma (HepG-2) and human oophoroma (Skov 3) cell lines with$IC_{50}$ values of more than $100{\mu}M$.

• Animal cells and systems
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• v.6 no.4
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• pp.305-309
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• 2002

Actinorhodin antibiotics produced by Streptomyces lividans TK24 are blue pigments with a weak antibiotic activity, derived from one acetyl-CoA and 15 malonyl-CoA units via a typical ployketide pathway. In an attempt to clone polyketide biosynthetic genes of S. lividans TK24, hybridizing fragments in the genomic DNA of S. lividans TK24 were detected by use of acn and act III polyketide synthase gene probes. Since typical aromatic polyketide bio-synthetic gene clusters are roughly 22-34 Kb long, we constructed in E. coli XL-Blue MR using the Streptomyces-E. coli bifunctional shuttle cosmid vector (pojn46). Then, about 5,000 individual E. coii colonies were thor-oughly screened with acrl-ORFI and actIII probes. From these cosmid libra-ries, 12 positive clones were identified. Restriction analysis and southern hybridization showed two polyketide biosynthetic gene clusters in this organism. These cosmid clones can be transformed into Streptomyces parvulus 12434 for expression test that identify product of actinorhodin biosynthetic genes by heterologous expression. Thus, heterologous expres-sion of a derivative compound of a actinorhodin biosynthetic intermediate was obtained in pKE2430. Expression of these compounds by the trans-formants was detected by photodiode array HPLC analysis of crude extracts.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.711-714
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• 1997

In an effort to enhance the lipophilicities, thereby, the penetration into the cell membrane and to increase the antitumor activities of modified derivatives of 2',3'-didehydro-3'-deoxythymidine (d4T, 1), derivatives of 1 were designed and synthesized. Starting from thymidine, 1, 2',3'-didehydro-3'-deoxythymidine-5'-phosphate, disodium salt (d4T-p, 7), and two nicotinate esters of 1; 2',3'-didehydro-3'-deoxy-5'-O-(3-pyridinylcarbonyl)thymidine (d4T-NA, 5) and 2',3'-didehydro-3'-deoxy-5'-phosphoryl-O-(3-pyridinylcarbonyl)thymidine (d4T-p-NA, 8) were synthesized. The lipophilicities of the synthesized compounds were measured by P-values and antitumor activities of those were estimated against mouse leukemia P388, murine mammary carcinoma FM3A, and human histiocytic lymphoma U937 tumor cells in vitro. Although the lipophilicities of the nicotinate esters, 5 and 8 were increased 2.75- and 9.71-fold relative to that of 1 and 7, respectively, the synthesized compounds, 1, 5, 7, and 8 were found to be inactive against P388 and FM3A cells except weak antitumor activity against U937 cell.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.26-30
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• 1998

Tetradecapeptide, Mastoparan B(MP B) and its [$Ala^2$]-, [$Ala^4$]-, [$Ala^6$]-, [$Ala^9$]-MP B derivatives were synthesized, and then their antibacterial and hemolytic activities were assayed to examine the effect of hydrophobicity and amphiphilicity on the MP B-induced those activities. MP B and more hydrophobic [$Ala^2$]-, [$Ala^4$]-MP B showed stronger antibacterial activity and less hydrophobic [$Ala^6$]-MP B than MP B did similar or weaker activity, so more hydrophobic [Ala]-MP B derivative had stronger activity. But more hydrophobic [$Ala^9$]-MP B than MP B showed weaker activity because of its Trp substitution by Ala. On the other hand, [$Ala^2$]- and [$Ala^4$]-MP B showed 100.0% and 69.4% hemolytic activity, but [$Ala^6$]-MP B did the weakest activity(6.1%) and [$Ala^9$]-MP B, weaker activity(26.0%) than MP-B. Therefore, more hydrophobic [Ala]-MP B derivative had stronger activity and the effect of amphiphilicity on the activity was weak.

• Journal of Convergence for Information Technology
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• v.12 no.3
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• pp.178-185
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• 2022

This study compared and analyzed the characteristics of new words by classifying 197 newly coined Korean and Chinese characters in 2017 and 2018 into single, compound, derivative, abbreviated, and hybrid words according to the coined method. In the case of a single language, Korean is all words borrowed from Chinese and English. However, no monolingual language appeared in Chinese. In the case of compound words, the format of the Chinese synthesis method was much more diverse and the generative power was stronger than that of Korea. In the case of derivatives, there are not many prefixes in both countries, and Korean suffixes have the strongest productivity of Chinese suffixes and weak productivity of foreign and native suffixes. Korean foreign language suffixes were characterized by relatively more appearance than Chinese. In the case of abbreviations, it can be seen that the productivity of dark syllables is stronger for Korean abbreviations, and the productivity of empty syllables is stronger for Chinese abbreviations. In the case of mixed languages, the hybrid form of Korean was much more diverse than that of Chinese. Through this study, it will be possible to help Chinese Korean learners understand the process of forming a new language, and to develop their ability to guess the meaning of Korean words while learning a new language.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.422-429
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• 2009

Invasion and metastasis is the main cause of cancer mortality. Angiogenesis is a prerequisite for the tumor growth and metastasis. Matrix metalloproteinases (MMPs) are the key enzymes playing in the invasive growth and metastasis of cancer as well as angiogenesis. Xanthohumol, a prenylated chalcone of the Hop plant (Humulus lupulus L), has been reported to suppress cancer invasion and angiogenesis. In the present study, we investigated the antiinvasive effects of xanthohumol (1) and its synthetic derivatives, 4'-O-methylxanthohumol SEM ether (2), xanthohumol C (3), and xanthohumol C MOM ether (4) in relation to MMP expression in HT-1080 human fibrosarcoma cells. The compound 1 and its derivative, 3 and 4, significantly inhibited serum-induced HT-1080 cell invasion, and 12-O-tetradecanoylphorbol-13-acetate (TPA)-enhanced activity and expression level of MMP-2 and MMP-9 in a concentration-dependant manner. In addition, they inhibited TPA-enhanced expression of MT1-MMP with relatively weak inhibition in tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 level. The compound 1 significantly decreased the cell viability, whereas the derivatives, 2 and 3 showed no cytotoxicity, and compound 4 showed slight cytotoxicity in the cells. Furthermore, in a chick chorioallantoic membrane (CAM) assay, the derivatives 3 and 4 dose-dependently suppressed vascular endothelial growth factor (VEGF)-induced angiogenesis, which is similar to that of compound 1. Taken together, the results indicate that compounds 3 and 4 may be valuable anti-angiogenic agents in the treatment of chronic diseases such as cancer and inflammation working through suppression of MMP-2 and MMP-9.

• Atmosphere
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• v.25 no.3
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• pp.543-557
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• 2015

The present study examines an interaction between the eddy and mean meridional circulation (MMC) comparing the results in three reanalysis data sets including ERA-Interim, NCEP2, and JRA-55 during the boreal winter in the Northern Hemisphere. It is noteworthy that the JRA-55 tends to produce stronger MMC compared to those of others, which is mainly due to the weak eddy flux. ERA-Interim represents the ensemble averages of MMC. The MMC-eddy interaction equation was adopted to investigate the scale interaction of the eddy momentum flux (EMF), eddy heat flux (EHF), and diabatic heating (DHT) with MMC. The EMF (EHF) shows a significant correlation coefficient with streamfunction under (above) 200 hPa-level. The perturbation (time mean) part of each eddy is dominant compared to another part in the EMF (EHF). The DHT is strongly interacted with streamfunction in the region between the equator and extra-tropical latitude over whole vertical column. Thus, the dominant term in each significant region modulates interannual variability of MMC. The inverse (proportional) relationship between MMC and pressure (meridional) derivative of the momentum (heat) divergence contributions is well represented in the three reanalysis data sets. The region modulated interannual variability of MMC by both EMF and DHT (EHF) is similar in ERA-Interim and JRA-55 (ERA-Interim and NCEP2). JRA-55 shows a lack of significant region of EHF due to the high resolution, compared to other data sets.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.107-119
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• 1999

There is no authentic solution in a face detection problem though it is an important part of pattern recognition and has many diverse application fields. The reason is that there are many unpredictable deformations due to facial expressions, view point, rotation, scale, gender, age, etc. To overcome these problems, we propose an algorithm based on feature-based method, which is well known to be robust to these deformations. We detect a face by calculating a similarity between the formation of real face feature and candidate feature formation which consists of eyebrow, eye, nose, and mouth. In this paper, we use a steerable filter instead of general derivative edge detector in order to get more accurate feature components. We applied deformable template to verify the detected face, which overcome the weak point of feature-based method. Considering the low detection rate because of face detection method using whole input images, we design an adaptive skin-color filter which can be applicable to a diverse skin color, minimizing target area and processing time.