• The Journal of the Acoustical Society of Korea
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• v.35 no.4
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• pp.295-302
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• 2016

Underwater acoustic communication channel is often defined as a multipath fading channel since the multipath arrivals from various paths interfere with each other and cause frequency dependent constructive or destructive interference in received signals. Therefore signal-to-noise ratio (SNR) of received signal fluctuates as a function of frequency. In addition, sea surface fluctuation induces frequency dependent time variant signal fading due to coherent component variation of surface bounce path. The frequency shift keying (FSK) system is known to be less sensitive and more robust under these interference and fading, and M-ary frequency shift keying (MFSK) system is adopted to increase a data rate. In this study, a bit error rate (BER) of 4 channels 4FSK system are examined in shallow sea multipath channel. Experimental results show that RS code reduces efficiently the BER of 4FSK system since frequency dependent time-varying fading is characterized to give burst errors. The BER of a different data rate or different source-to-receiver range depends on not only the channel coherent bandwidth but also frequency dependent multipath fading.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.96-109
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• 2014

The purpose of this study is to sort out the plants in "The Book of Songs", and to analyze the cultural significance of plants from the viewpoint of the symbolic elements and the landscape elements in the 3~11 century BC. The conclusions are as follows. First, there were 147 plant names and 136 plant species in "The Book of Songs", and these results can confirm that the plants were existed in the 3~11 century BC. Second, through analyzing the cultural significance of the plants, cattail, lotus, etc. are the symbol of lovers; peony and willow are the symbol of farewell; bamboo is the symbol of gentleman; and Japanese pepper is the symbol of fecundity. Third, at the viewpoint of the landscape elements, the poplar, dwarf elm, etc. can be used as a place of affection; reed and nepenthe can make a place of melancholy, hazel and chestnut tree, etc. can make a place of power and position, celery and water shield etc. can be used as a place of knowledge. Based on the research of "The Book of Songs", it can help to understand the plants culture in 3~11 century BC, and it will be a useful information for the plant design.

• The Journal of Korean Society of Virology
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• v.28 no.3
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• pp.275-285
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• 1998

Based on the geographic range and distribution of its rodent reservoir host, the European common vole (Microtus arvalis), Tula virus is likely to be widespread throughout Eurasia. Tula virus-infected voles have been captured in Central Russia, Austria, Czech and Slovak Republics, and the former Yugoslavia. Although serologic evidence for Hantaan (HTN) or Seoul (SEO) virus infection can be found in the vast majority of the more than 300 cases of hemorrhagic fever with renal syndrome (HFRS) occurring annually in Korea, approximately 4% of Korean patients with HFRS show a more than 4-fold higher antibody titer to Puumala (PUU) virus than to HTN or SEO virus by double-sandwich IgM ELISA, suggesting the existence of pathogenic Puumala-related hantaviruses in Korea. To further define the geographic distribution and genetic diversity of Tula virus in Eurasia and to investigate the existence of previously unrecognized Microtus-borne hantavirus in Korea, arvicolid rodents were captured in Lodz, Poland in 1995 and in Yunchon-kun, Kyungki-do during April to May, 1998. In addition, sera from 18 Korean HFRS patients who showed higher (or the same) antibody titer to Tula virus than HTN and SEO viruses were examined for hantavirus RNA by RT-PCR. Hantaviral sequences were not detected in any of the 18 patients or in 35 reed voles (Microtus fortis) in Korea. Alignment and comparison of a 208-nucleotide region of the S segment, amplified from lung tissues of two hantavirus-seropositive Marvalis captured in Poland, revealed $80.8{\sim}83.2%$ sequence similarity, respectively, with Tula virus strains from Central Russia and the Czech and Slovak Republics. Phylogenetic analysis indicated that the newfound Tula virus strains from Poland were closely related to other Tula hantaviruses from Eurasia.

• Toxicological Research
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• v.34 no.3
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• pp.191-197
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• 2018

In 2015, a candidate for the second national reference standard (NRS) of Gloydius snake venom was produced to replace the first NRS of Gloydius snake venom. In the present study, the potencies of the candidate were determined by a collaborative study, and the qualification of the candidate was estimated. The potencies of the candidate were determined by measuring the murine lethal titers and lapine hemorrhagic titers of venom against the regional working reference standard (RWRS) for antivenom using the methods described in the previous report for the first NRS of Gloydius snake venom. Three Korean facilities contributed data from a total of 30 independent assays. Subsequently, two foreign national control research laboratories contributed to this collaborative study. The results were calculated using the Reed-Muench method for lethality and determined using a mixed-effects model for hemorrhage. The general common potencies of the lethal and hemorrhagic titers were obtained from the results of the 30 tests performed at three Korean facilities. The results are expressed in micrograms for 1 test dose (TD) with a 95% confidence interval as follows: a lethal titer of $90.13{\mu}g/TD$ (95% confidence interval = $87.39{\sim}92.86{\mu}g$) and a hemorrhagic titer of $10.80{\mu}g/TD$ (95% confidence interval = $10.46{\sim}11.14{\mu}g$). In addition, the candidate preparation showed good quality evaluation according to the results of the quality estimation of the candidate and is judged to be suitable to serve as the Korean NRS for snake venom. In conclusion, the second NRS of Gloydius snake venom was established in this study and will be used for national quality control, including a national lot release test of Korean antivenom products.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.422-431
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• 2017

The biogeochemical information of riverine organic matter gives a detailed and integrated recording of natural and anthropogenic activity within a watershed. To investigate the changes in quality and quantity of organic carbon transporting from mountain to ocean via river channels, we estimated the concentrations of dissolved (DOC) and particulate organic carbon (POC), and then traced the source origin of POC using stable carbon isotopes ratio before and after summer rainfalls in the Tamjin River and Ganjin Bay, Korea. Along the small watershed, a total of 13 sites including headwaters, dam reservoir, river and estuary were established for the study. We found some interesting findings in the aspect of distribution of DOC/POC concentration changing their origin sources dynamically flowing downstream. In particular, the river channel transport downstream mainly DOC to river mouth, although upper dam reservoir increased POC concentration by phytoplankton production in summer. Whereas, in the river mouth and estuary, POC was dominated not only by local supply from nearby reed saltmarsh, but also by marine phytoplankton production, respectively. The findings can contribute to increasing the understanding of riverine organic carbon transport in upper large dam and lower open estuary system.

• Journal of Korean Society on Water Environment
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• v.25 no.4
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• pp.589-596
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• 2009

The spectroscopic characteristics and chemical oxygen demand (COD) oxidation efficiencies were investigated for dissolved organic matters (DOM) from diverse sources, which may indirectly affect the concentrations and the quality of DOM found in watersheds. The DOM investigated for this study showed a wide range of the percent distributions of refractory organic matter (R-OM) from 8 to 100%. Relatively high R-OM distributions were observed for the DOM with the source of head water, sediments, paddy soils, field soils, and treated sewage whereas the DOM from livestock waste, reed, weeds, algae, and attached algae exhibited lower R-OM percent distributions. The percent distribution of R-OM had positive correlations with specific UV absorbance (SUVA) and humidification indices (HIX) of DOM. The investigated DOM was classified into four different source groups (i.e., biota, vegetables, soils, sediments) by comparing the synchronous fluorescence spectra. The DOM group from biota source was characterized by a prominent presence of protein-like fluorescence (PLF) whereas fulvic-like fluorescence (FLF) was additionally observed for vegetable-source DOM. FLF became significant for the DOM from both soils and sediments although no PLF was found for soil-derived DOM. A range of COD oxidation efficiency was observed for the various DOM, ranging from 36 to 94% and from 65 to 125% for $COD_{Mn}$ and $COD_{Cr}$, respectively. The results indicate that $COD_{Cr}$ reflects the higher OM concentration than $COD_{Mn}$. However, 95% confidence intervals of the COD oxidation efficiencies were similar for the two types of COD, suggesting that $COD_{Cr}$ may not be the superior OM index to $COD_{Mn}$ in terms of the variability of the oxidation efficiency. No significant correlations were obtained between COD oxidation efficiencies and the spectroscopic characteristics of DOM for this study.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.82-88
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• 1999

In this study, to evaluate newly developed Japanese encephalitis (JE) vaccine candidate CJ50003, we assessed its immunogenicity along with a previously commercialized inactivated JE Biken vaccine. The CR0003 viral antigens produced in Vero cells were administered suhcutaneouly to mice either with alum-adjuvanled or free form. The ELISA titers and neutralizing (NEUV antibody titers accounting for major protective immunity in JE were determined. Mice given alum-adjuvanted vaccine had a 10 times higher antigen-specific NEUT antibody response than did those which {lad received free antigens. This NEUT antibody response was maintained until day 168 with NEUT titer more than 1:160. Even with the 0.5 ng of alum-adjuvanted antigen dose, NEUT titer was induced more than 1:10 which is considered as an evidence for seroconversion and protection. Thc mice immune sera had a similar rate of cross-reactivity against three different viral antigens, Nakayama-NlH, P3 and SA14; as determined by ELISA assay. In a mice challenge model, vaccination with the GI50003 conferred more protection than with commercialized Biken vaccine against Nakayama virus. These data demonstrated that CJ50003 vaccine candidate has an excellent prophylactic efficacy and implicated it has a strong potential for further development and commercialization.

• Ecology and Resilient Infrastructure
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• v.6 no.4
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• pp.243-249
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• 2019

The purpose of this study is to analyze the reflectance of bed materials according to changes in the water level using a drone-based hyperspectral sensor. For this purpose, we took hyperspectral images of bed materials such as soil, gravel, cobble, reed, and vegetation to compare and analyze the spectral data of each material. To adjust the water level, we constructed an experimental channel to control the discharge and installed the bed materials within the channel. In this study, we configured 3 cases according to the water level (0.0 m, 0.3 m, 0.6 m). After the imaging process, we used the mean value of 10 points for each bed material as analytical data. According to the analysis, each material showed a similar reflectance by wavelength and the intrinsic reflectance characteristics of each material were shown in the visible and near-infrared region. Also, the deeper the water level, the lower the peak reflectance in the visible and near-infrared region, and the rate of decrease differed depending on the bed material. We expect the intrinsic properties of these bed materials to be used as basic research data to evaluate river environments in the future.

• Korean journal of applied entomology
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• v.27 no.1
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• pp.28-34
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• 1988

Henosepilachna vigintioctomaculata (Motschulsky) (Coleoptera: Coccinellidae), important pests of agricultural crops in Korea, including eggplant and potato, were collected in the Kyonggido area each summer from 1983 to 1986. Data were recorded for rates of parasitism against each host stage and seasonal activity. The parasitoids NothoserPhus afissae (Watanabe), (Hymenoptera: Proctotrupidae), Uga menoni (Kerrich), (Hymenoptera: Cha1cididae), and Pediobius foveolatus (Crawford), (Hymenoptera: Eulophidae) were reared from the host insects. A solitary larval parasitoid, N. afissae, was reared from 2nd to 4th instar brval hosts, with parasitism being highest in the 3rd instar collection. U. menoni, a solitary larval-pupal parasitoid, was reared from 3rd instar larvae to pupae, and parasitism was highest in the pupal collection. N. afissae and U. menoni occurred during June to September. N. afissae showed relatively high parasitism during the entire study period as compared with other species, while parasitization by U. menoni was highest in July. P. foveolatus, a gregarious larval parasitoid, did not generally appear until September, although it appeared in early August in the southern part of Korea. The number of P. foveolatus emerging from a mummy varied, ranging from 7 to 26 (mean = 13. 8).

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.665-669
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• 2015

The Kepler mission has shown that small planets are extremely common. It is likely that nearly every star in the sky hosts at least one rocky planet. We just need to look hard enough-but this requires vast amounts of telescope time. MINERVA (MINiature Exoplanet Radial Velocity Array) is a dedicated exoplanet observatory with the primary goal of discovering rocky, Earth-like planets orbiting in the habitable zone of bright, nearby stars. The MINERVA team is a collaboration among UNSW Australia, Harvard-Smithsonian Center for Astrophysics, Penn State University, University of Montana, and the California Institute of Technology. The four-telescope MINERVA array will be sited at the F.L. Whipple Observatory on Mt Hopkins in Arizona, USA. Full science operations will begin in mid-2015 with all four telescopes and a stabilised spectrograph capable of high-precision Doppler velocity measurements. We will observe ~100 of the nearest, brightest, Sun-like stars every night for at least five years. Detailed simulations of the target list and survey strategy lead us to expect $15{\pm}4$ new low-mass planets.