• Structural Engineering and Mechanics
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• v.35 no.4
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• pp.479-491
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• 2010

Advances in geological studies, have identified increased seismic activity in the world's ocean once believed to be far from seismic hazards. The increase in demand of oil and other hydrocarbons leaves no option but to install a suitable offshore platform on these seismically sensitive offshore basins. Therefore, earthquake based design criteria for offshore structures are essential. The focus of the present review is on various computational techniques involved for seismic response study. The structural and load modeling approaches, the disturbed fluid-structure and soil-structure interaction as well as hydrodynamic damping due to earthquake excitation are also discussed. A brief description on the reliability-based seismic design approach is also presented.

• Journal of applied mathematics & informatics
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• v.37 no.5_6
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• pp.469-480
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• 2019

A generalized tiling is defined as a generalization of the properties of tiling a region of ${\mathbb{Z}}^2$ with dominoes, and comprises tiling with rhombus and any other tilings that admits height functions which can be ordered into a distributive lattice. By using properties of the distributive lattice, we prove that the Markov chain consisting of moving from one height function to the next by a flip is fast mixing and the mixing time ${\tau}({\epsilon})$ is given by ${\tau}({\epsilon}){\leq}(kmn)^3(mn\;{\ln}\;k+{\ln}\;{\epsilon}^{-1})$, where mn is the area of the grid ${\Gamma}$ that is a k-regular polycell. This result generalizes the result of the authors (T-tetromino tiling Markov chain is fast mixing, Theor. Comp. Sci. (2018)) and improves on the mixing time obtained by using coupling arguments by N. Destainville and by M. Luby, D. Randall, A. Sinclair.

• Bulletin of the Korean Chemical Society
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• v.11 no.4
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• pp.290-296
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• 1990

Ion-surface collision studies at low kinetic energies (1-100 eV) provide a unique opportunity for investigating reactions and collision dynamics at surfaces. A special ion optics system for generating an energy- and mass-selected ion beam of this energy is designed and constructed. An ultrahigh vacuum (UHV) reaction chamber, in which the ions generated from the beamline collide with a solid surface, is equipped with Auger electron spectroscopy (AES) and thermal desorption spectrometry (TDS) as in-situ surface analytical tools. The resulting beam from the system has the following characteristics : ion current of 5-50 nA, energy spread < 2eV, current stability within ${\pm}5%,$ and unit mass resolution below 20 amu. The performance of the instrument is illustrated with data representing the implantation behavior of $Ar^+$ into a graphite (0001) surface.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.10-10
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• 2021

Natural products have been used as drugs and cosmetics due to their bioactivity and their biochemical diversity. Natural products usually refer to secondary metabolites produced by various living organisms including marine animals, insects, microbes, amphibians, and plants. These secondary metabolites, which usually have molecular weights less than 2,000 amu, are unnecessary for survival, development, growth, and reproduction but play major roles in plant defense systems against other species. These secondary metabolites such as lignans, flavonoids, monoterpenes, and phenylethanoid glycosides showed various biological activities like anti-oxidant behavior, anti-cancer properties, neuroprotective properties, and so forth. Thus, isolation and elucidation of secondary metabolites from living organisms is of great significance to human life.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.263-270
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• 2019

Background: The gelada baboon, Theropithecus gelada Ruppell, 1835, is an endemic primate of the central and western highlands of Ethiopia occurring between altitudes of 1800-4400 m. Variability in activity time budget between the two gelada social units, i.e., one-male units (OMUs) and all-male units (AMUs), has not been studied previously. Thus, the present study was an effort to understand intra- and inter-variations in group size and daily activity time budget in gelada baboon OMUs and AMUs at Guassa Community Conservation Area, Central Ethiopia. The instantaneous sampling method was used in the data collection. Results: Both OMU and AMU groups allocated more time for feeding (OMUs = 36.96%; AMUs = 35%) followed by moving (OMU = 25.8%; AMUs = 27%). Grooming was the most frequent social activity in both family groups (OMUs = 8.56%; AMUs = 11.81%). OMUs and AMUs did not show significant variation between themselves in the time budget and temporal distribution of their daily activities. However, the overall variation in the time budget allocated for daily activities within OMUs and AMUs was statistically significant (p < 0.05%). The different age and sex groups in OMUs (i.e., immature, sub-adult females, subordinate males, adult females, and alpha males) showed statistically significant variation in their time budget allocation for the daily activities (p < 0.05) except for feeding and moving. Alpha males had the highest proportion of resting (32.14%) and aggression (31.92%). Immature individuals were responsible for > 90% of the time budget recorded for playing while adult females showed the highest frequency of grooming. Group size of OMUs ranged between 5 and 15 individuals (mean ± SD = 11.25 ± 1.95). Adult females comprised the highest number within OMUs (mean = 4.5) followed by immature individuals (mean = 3). The group size of AMUs ranged from 4 to 8 (mean ± SD = 6.6 ± 1.5). Conclusion: Our results showed that the gelada baboon spent less time on foraging compared to previous studies at the Simien Mountains and Debre-Libanos area. We suggested this variation could be explained based on higher forage quality at Guassa Community Conservation Area resulting from better conservation of the habitat.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.470-479
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• 2012

This study was designed to investigate and analyze children's preference on animation characters according to age and gender of the subjects, by surveying 255 children aged from 3 to 5. The animation characters were represented in pictures, and the reasons of preference were collected through individual interview with the children. The $x^2$ verification of SPSS 18.0 Window statistic program was used to verify the difference in preference. As a result, children aged from 3 to 5 showed higher preference on animations produced in foreign countries than the ones produced in Korea, as Korean animations and foreign-country animations had preference rate of 35.7% and 64.3%, and Korean characters and foreign-country characters had preference rate of 22.4% and 77.6% respectively. Depending on the age of children, there was significant difference among animation characters that the children prefer ($x^2=302.474^{***}$, P<.001), and it was shown that children at the age of 3 showed preference on 'Pororo' of Pororo the Little Penguin, children at the age of 4 on 'Tayo' of Tayo the Little Bus and 'Amu' of Shugo Chara, and children at the age of 5 on 'Shin Chan' of Crayon Shin Chan. It was also revealed that there was significant difference among animation characters according to the gender of children ($x^2=120.864^{***}$, P<.001); boys preferred 'Pororo' of Pororo the Little Penguin the most, followed by 'Doraemon' of Doraemon, 'Thomas' of Thomas and Friends and 'Tayo' of Tayo the Little Bus, and girls preferred 'Pororo' of Pororo the Little Penguin the most, followed by 'Apple' of Little Princess, 'Amu' of Shugo Chara and 'Loopy' of Pororo the Little Penguin. Through this study, it is hoped that the development of children animation would advance further, and that this study could be used as the preliminary resource.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.58-65
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• 2003

Various physicochemical parameters for the active ingredients of 245 herbicides were calculated to develope a diagnosis and estimation system for utility as herbicide. The range of physico-chemical parameters for each inhibitors of photo system II (H1), acetolactate synthase (ALS) (H2) and herbicides were confirmed. The distribution ranges of 85% dependence for each physicochemical parameters were Obs.logP :$-0.90\sim4.50$, dipol moment: $1.80\sim12.22$ (debye), molecular refractivity: $53.0\sim104.0(cm^3/mol)$, polarizability: $19.0\sim37.0(\AA^3)$, HOMO energy: $-9.98\sim-7.34$ (eV), LUMO energy:$-2.76\sim0.40$ (eV), Van der Waals molecular volumes: $558.0\sim995.0(cm^3)$, molecular weight: $202.0\sim430.0$ (amu) and surface areas (Grids): $194.0\sim356.0(\AA^2)$, hydration energy: $-10.16\sim114.7$ Kcal/mol, respectively. It is suggested that MR and polarizability constants will be able to distinguish between herbicides and medicinal drugs. Results revealed that various compounds based on the range of physicochemical parameters of herbicides could be diagnosed and estimated.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.29-33
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• 2020

The objective of this study was to develop a fast and accurate method of variety discrimination and geographical discrimination origin of Korean angelica (Korean variety, Angelica gigas Nakai) by using TDU-GC/MS. Two peaks of decursin and decursinol, which are coumarin derivatives were identified in the range of Total Ion Chromatogram (TIC) RT 26.9-27.2 of the Korean angelica by GC/MS analysis at the time of condensation in a refrigerated condensation system after thermal desorption of sample extracts. In case of Chinese angelica (Chinese variety), ligustilide peak was detected at the RT 17.2. In order to investigate the difference of volatile components according to the geographical origin of Korean variety, the mass spectra were measured by TDU-GC/MS at the range of m/z 40-400 amu. The TIC of domestic cultivation and Chinese cultivation of the Korean variety, Angelica gigas Nakai showed the same tendency as a whole. However, in partial scans of TIC, two peaks detected at 15.54 and 16.05 of RT showed different peak patterns between Korean angelica (Korean variety) cultivated in Korea and in China. The ratio of Peak A (RT 15.54) and B (RT 16.05) was 0.0-0.2 for domestic cultivation and 0.5-2.8 for Chinese cultivation, confirming the possibility of discriminating origin by comparing the TIC peak pattern of TDU-GC/MS.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.273-279
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• 2011

Various honeys from different sources were analyzed using an electronic nose based on a mass spectrometer. Various honeys were separated with different mixing ratios. Wild honey and artificial honey were blended at ratios of 100:0, 95:5, 90:10, 85:15, 80:20, 75:25, and 70:30, respectively. Data obtained from the electronic nose were used for discriminant function analysis (DFA). The DFA plot indicated a significant separation of honey from different sources. As the concentration of artificial honey increased, the first discriminant function score (DF1) moved from positive to negative (DF1: $r^2$=0.9962, F=490.6; DF2: $r^2$=0.9128, F=19.44). Furthermore, when acacia honey was mixed with artificial honey and separated with the mixing ratios, the DF scores were: DF1: $r^2$=0.9957, F=396.64; DF2: $r^2$=0.9447, F=29.3. When artificial honey was added to wild honey, it was possible to predict the following equation; DF1= -0.106${\times}$(concentration of artificial honey)+0.426 ($r^2$= 0.96). For acacia honey, the DF1= -0.112${\times}$(concentration of artificial honey)+0.434 ($r^2$=0.968).

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.613-617
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• 2011

This study was conducted to compare the quality of the brown rice (BR) and milled rice (MR) during storage. To assess quality, BR and MR were analysed by their fat acidity and flavor pattern using a SMart Nose$^{(R)}$. BR was stored for 30 days at $30^{\circ}C$, and analysed after 5, 15, 20, and 30 days of storage. MR produced in 2005, 2009, and 2010 were also tested. The fat acidity of both rice groups was increased with extended storage and the fat acidity of BR was more rapidly increased than that of MR in general. The flavor patterns from the SMart Nose$^{(R)}$ results were analyzed by the principal component analysis (PCA). The major groups of atomic mass unit (amu) for good discrimination contribution were from 41 to 85 amus. The PCA1 and PCA2 of BR were 95.64% and 2.78%, respectively when the samples were categorized by storage period. The PCA1 and PCA2 of MR were 81.18% and 13.85%, respectively when the samples were compared by production year. Both rice groups could be practically differentiated into flavor patterns by volatile properties for storage period. With regard to the correlation between fat acidity and flavor pattern, we could find that increasing storage period increased fat acidity value and changed flavor pattern from SMart Nose$^{(R)}$. Accordingly, SMart Nose$^{(R)}$ could be successfully used for easy screening and quality evaluation of stored rice.