• 천문학회지
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• 제45권4호
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• pp.93-99
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• 2012

We present a 1.1mm emission map of the OMC1 region observed with AzTEC, a new large-format array composed of 144 silicon-nitride micromesh bolometers, that was in use at the James Clerk Maxwell Telescope (JCMT). These AzTEC observations reveal dozens of cloud cores and a tail of filaments in a manner that is almost identical to the submillimeter continuum emission of the entire OMC1 region at 450 and $850{\mu}m$. We perform Fourier analysis of the image with a modified periodogram and the density power spectrum, which provides the distribution of the length scale of the structures, is determined. The expected value of the periodogram converges to the resulting power spectrum in the mean squared sense. The present analysis reveals that the power spectrum steepens at relatively smaller scales. At larger scales, the spectrum flattens and the power law becomes shallower. The power spectra of the 1.1mm emission show clear deviations from a single power law. We find that at least three components of power law might be fitted to the calculated power spectrum of the 1.1mm emission. The slope of the best fit power law, ${\gamma}{\approx}-2.7$ is similar to those values found in numerical simulations. The effect of beam size and the noise spectrum on the shape and slope of the power spectrum are also included in the present analysis. The slope of the power law changes significantly at higher spatial frequency as the beam size increases.

• 한국수산과학회지
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• 제38권4호
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• pp.257-264
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• 2005

We studied age and growth of the sea urchin, Pseudocentrotus depressus, to obtain some informations regarding its sustainable production and appropriate resources reinforcement. The samples were collected at two locations (Ongpo and Bubhwan) in Jeju, Korea. Annual rings were formed from October to January, and this period was well matched with the time just prior to or during their reproduction. Two population regression lines generated by using Walford's plotting with mean radius of each age group showed significant differences in their growth rate between the two sampling locations (p<0.0l). When the regression equations were calculated using either madreporite's radius (R) and test diameter (L) or body weight (W) and test diameter (L), the results were L=23.830+ 11.735R and $W=0.0004L^3$, and no statistically significant differences were detected between the two populations (p>0.2). Based on the data of madreporite's radius and test diameters, two estimated growth equations were $L_t(mm)=72.988(1-e^{-0.412(t-0.596)}\;and\;L_t(mm)=70.195(1-e{-0.365(t-0.51l)}$ in Ongpo and Bubhwan population, respectively. Three distinct annulus groups were recognizable within the distribution of the radii of the annual rings measured from age I to age 5. The mean radii calculated from the same annulus group were all identical even though they were from different age groups.

• Wind and Structures
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• 제19권5호
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• pp.481-503
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• 2014

A new theoretical model on rain-wind induced vibration (RWIV) of a continuous stay cable is developed in this paper. Different from the existing theoretical analyses in which the cable was modeled as a segmental rigid element, the proposed scheme focuses on the in-plane and out-of-plane responses of a continuous stay cable, which is identical with the prototype cable on cable-stayed bridge. In order to simplify the complexities, the motion law of the rivulet on the cable surface is assumed as a sinusoidal way according to some results obtained from wind tunnel tests. Quasi-steady theory is utilized to determine the aerodynamic forces on the cable. Equations of motion of the cable are derived in a Cartesian Coordinate System and solved by using finite difference method to obtain the in-plane and out-of-plane responses of the cable. The results show that limited cable amplitudes are achieved within a limited range of wind velocity, which is a unique characteristic of RWIV of stay cable. It appears that the in-plane cable amplitude is much larger than the out-of-plane cable amplitude. Rivulet frequency, rivulet distribution along cable axis, and mean wind velocity profile, all have significant effects on the RWIV responses of the prototype stay cable. The effects of damping ratio on RWIVs of stay cables are carefully investigated, which suggests that damping ratio of 1% is needed to well mitigate RWIVs of prototype stay cables.

• 한국지진공학회논문집
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• 제21권6호
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• pp.277-286
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• 2017

On September 12, 2016, Gyeongju earthquake occurred. Its local magnitude was announced to be $M_L=5.8$ by Korea Meteorological Administration (KMA). Ground motion data recorded at KMA, EMC and KERC stations was obtained from their data bases. From the data, horizontal and vertical response spectra, and V/H ratio were calculated. The horizontal spectrum was defined as geometric mean spectrum, GMRotI50. From the statistical analysis of the geometric mean spectra, a mean plus one standard deviation spectrum in lognormal distribution is obtained. Regression analysis is performed on this curve to determine the shape of spectrum including transition periods. Applying the same procedure, the shape and transition periods of vertical spectrum was obtained. These results were compared with the Korean standard design spectra, which were developed from domestic and overseas intraplate earthquake records. The response spectra of Gyeongju earthquake were found to be almost identical with the newly proposed design spectra. Even the V/H ratios showed good agreement. These results confirmed that the method adopted when developing the standard design spectra were valid and the developed design spectra were reliable.

• Journal of Ginseng Research
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• 제40권2호
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• pp.176-184
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• 2016

Background: Wild ginseng, Panax ginseng Meyer, is an endangered species of medicinal plants. In the present study, we analyzed variations within the ribosomal DNA (rDNA) cluster to gain insight into the genetic diversity of the Oriental ginseng, P. ginseng, at artificial plant cultivation. Methods: The roots of wild P. ginseng plants were sampled from a nonprotected natural population of the Russian Far East. The slides were prepared from leaf tissues using the squash technique for cytogenetic analysis. The 18S rDNA sequences were cloned and sequenced. The distribution of nucleotide diversity, recombination events, and interspecific phylogenies for the total 18S rDNA sequence data set was also examined. Results: In mesophyll cells, mononucleolar nuclei were estimated to be dominant (75.7%), while the remaining nuclei contained two to four nucleoli. Among the analyzed 18S rDNA clones, 20% were identical to the 18S rDNA sequence of P. ginseng from Japan, and other clones differed in one to six substitutions. The nucleotide polymorphism was more expressed at the positions 440-640 bp, and distributed in variable regions, expansion segments, and conservative elements of core structure. The phylogenetic analysis confirmed conspecificity of ginseng plants cultivated in different regions, with two fixed mutations between P. ginseng and other species. Conclusion: This study identified the evidences of the intragenomic nucleotide polymorphism in the 18S rDNA sequences of P. ginseng. These data suggest that, in cultivated plants, the observed genome instability may influence the synthesis of biologically active compounds, which are widely used in traditional medicine.

• Asian-Australasian Journal of Animal Sciences
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• 제23권2호
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• pp.272-278
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• 2010

In this study, we cloned, sequenced and characterized porcine y+L Amino Acid Transporter-1 (y+LAT1). By screening a translated EST database with the protein sequence of the human $y^{+}$LAT1 and by using rapid amplification of cDNA ends (RACE), the full-length cDNA encoding porcine $y^{+}$LAT1 was isolated from porcine intestine RNA. It was 2,111 bp long, encoding a 511 amino acid trans-membrane glycoprotein composed of 12 transmembrane domains. The predicted amino acid sequence was found to be 91%, 90%, 87% and 87% identical to those of cattle, human, mouse and rat $y^{+}$LAT1 respectively. Real-time RT-PCR results indicated that the small intestine had the highest $y^{+}$LAT1 mRNA abundance and the lung had the lowest $y^{+}$LAT1 mRNA abundance. Baby hamster kidney (BHK) cells transfected with green fluorescent protein (GFP) tagged porcine $y^{+}$LAT1 cDNA indicated that the cellular localization of the gene product in BHK was on the plasma membrane.

• Ocean and Polar Research
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• 제27권2호
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• pp.205-214
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• 2005

From ancient Antarctic glacier ice, we extracted total genomic DNA that was suitable for prokaryotic 16S rDNA gene cloning and sequencing, and bacterial artificial chromosome (BAC) library and end-sequencing. The ice samples were from the Dry Valley region. Age dating by $^{40}Ar/^{39}Ar$ analysis on the volcanic ashes deposited in situ indicated the ice samples are minimum 100,000-300,000 yr (sample DLE) and 8 million years (sample EME) old. Further assay proved the ice survived freeze-thaw cycles or other re-working processes. EME, which was from a small lobe of the basal Taylor glacier, is the oldest known ice on Earth. Microorganisms, preserved frozen in glacier ice and isolated from the rest of the world over a geological time scale, can provide valuable data or insight for the diversity, distribution, survival strategy, and evolutionary relationships to the extant relatives. From the 16S gene cloning study, we detected no PCR amplicons with Archaea-specific primers, however we found many phylotypes belonging to Bacteria divisions, such as Actinobacteria, Acidobacteria, Proteobacteria $({\alpha},\;{\beta},\;and\;{\gamma})$, Firmicutes, and Cytophaga-Flavobacterium-Bacteroid$. BAC cloning and sequencing revealed protein codings highly identical to phenylacetic acid degradation protein paaA, chromosome segregation ATPases, or cold shock protein B of present day bacteria. Throughput sequencing of the BAC clones is underway. Viable and culturable cells were recovered from the DLE sample, and characterized by their 16S rDNA sequences. Further investigation on the survivorship and functional genes from the past should help unveil the evolution of life on Earth, or elsewhere, if any.

• 보존과학회지
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• 제12권1호
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• pp.31-47
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• 2003

천안 운전리의 청동기 유적지에서 출토된 석기 및 유적지 주변에 분포는 석기와 동일한 암석의 대자율 값은 보통 $0.5(\times10^{-3}\;SI\;unit)$ 이하이나, 섬장암질 석부(2.37), 편암질 석부(0.19) 및 점판암질 석도(0.11)는 노두의 암석과 차이가 있다. 이들을 석기와 근원암석으로 짝을 이루어 원소의 거동과 부화 및 호정성과 불호정성을 이용하여 표준화 하였을때 석기와 암석의 지구화학적 진화경향이 동일한 것으로 보아, 대부분의 석기는 유적지 주변에 분포하는 암석을 원료로 제작하였을 가능성이 상당히 높다. 그러나 일부 석부(편암), 석도(점판암) 및 석촉(셰일)의 구성암석은 운전리 유적지 및 반경 10 km 이내에서 전형적인 산출상태와 분포지역을 확인할 수 없었다. 따라서 운전리 일대의 석기는 현지에서 재료를 구하고 현장에서 제작한 자급형 석기(갈판, 갈돌, 석부)와 다른 지역에서 도입된 외래형 석기(석도, 석촉 및 석부)가 공존하고 있는 것으로 해석된다.

• 대한본초학회지
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• 제26권3호
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• pp.57-63
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• 2011

Objectives : Peucedani Radix ('Jeonho' in Korean) is the root of Peucedanum praeruptorum or Angelica decursiva. However, the root of Anthriscus sylvestris has usually been distributed as Jeonho. This study was performed to determine the discriminative criteria of Jeonho, focused on distribution in Korean markets. Methods : We have determined identification keys to discriminate each Jeonho samples, through observation of external morphology of original plants, and the research of external and internal morphological features of dried Jeonho herbs. Results : Because of identical to the Korean plant name 'Jeonho', Anthrisci Radix had been came into use as a substitute of Jeonho in Korea during the time of Japanese colonial rule. The original plants of Jeonho and its substitute are discriminated with shape of leaf, leaf margin and color of stem. External morphological features of the medicinal herbs of Jeonho are different in the color of cross-sections, pellucid dot, white powder. Internal morphological points, such as fiber bundle of xylem, seconadary mudullary ray and ray of xylem were also used as discriminative criteria for Jeonho. Further details(e.g. identificaion keys) are in the article. Conclusions : We think that these discriminative criteria will be meaningful in identifying the substitutes and adulterants of Jeonho.

• 한국재료학회지
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• 제21권10호
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• pp.568-572
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• 2011

The preparation of $Y_2O_3$-doped $ZrO_2$ nanoparticles in Igepal CO-520/cyclohexane reverse micelle solutions is studied here. In this work, we synthesized nanosized $Y_2O_3$-doped $ZrO_2$ powders in a reverse micelle process using aqueous ammonia as the precipitant. In this way, a hydroxide precursor was obtained from nitrate solutions dispersed in the nanosized aqueous domains of a microemulsion consisting of cyclohexane as the oil phase, with poly (oxyethylene) nonylphenylether (Igepal CO-520) as the non-ionic surfactant. The synthesized and calcined powders were characterized by thermogravimetrydifferential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The crystallite size was found to nearly identical with an increase in the water-to-surfactant (R) molar ratio. A FTIR analysis was carried to monitor the elimination of residual oil and surfactant phases from the microemulsion-derived precursor and the calcined powder. The average particle size and distribution of the synthesized $Y_2O_3$-doped $ZrO_2$ were below 5 nm and narrow, respectively. The TG-DTA analysis showed that the phase of the $Y_2O_3$-doped $ZrO_2$ nanoparticles changes from the monoclinic phase to the tetragonal phase at temperatures close to $530^{\circ}C$. The phase of the synthesized $Y_2O_3$-doped $ZrO_2$ when heated to $600^{\circ}C$ was tetragonal $ZrO_2$.