• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.71.1-71.1
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• 2013

Among quadruples or higher multiplicity stars, only a few binary systems have been discovered. They are important targets to understand the formation and evolution of multiple stellar systems because we can obtain accurate stellar parameters from photometric and spectroscopic studies. We present the observational results of this kind of rare object 1SWASP J093010.78+533859.5, for which the doubly eclipsing feature had been detected previously from the SuperWASP photometric archive. Individual PSF photometry for two objects with a separation of about 1.9 arcsec was performed for the first time in this study. Our time-series photometric data show that the brighter object A is an Algol-type detached eclipsing binary with an orbital period of 1.3 days and the fainter B is a W UMa-type contact eclipsing binary with a period of 0.23 days. Using the high-resolution optical spectra, we obtained well-defined radial velocity variations of the system A. Furthermore, stationary spectral lines were detected and should have originated from the other stellar component, which was confirmed by the third object contribution from the light curve analysis. No spectral feature of the system B was detected, probably due to its faintness. We obtained the binary parameters and the absolute dimensions from each light curve synthesis. The primary and secondary components of the system A have a spectral type of K1 and K5 main sequences, respectively. Two components of system B have nearly the same type of K3 main sequence. Light variations at out of eclipses were appeared in both systems, interpreting as the effect of stellar spots on these late spectral type stars. We estimated the distances to the systems A and B individually. They may have similar distances of about 70 pc and seem to be gravitationally bound with a separation of about 130 AU. In conclusion, we suggest that 1SWASP J093010.78+533859.5 is a quintuple stellar system with a hierarchical structure of a triple system A(ab)c and a binary system B(ab).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.8-13
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• 2016

The purpose of this study was to discover who designed the common type and the individual type Goon office buildings in the Japanese colonial period, and to determine how the individual type's space-compositions were compared with the common types. The study used the literature research method. The method used an analysis of the digital images of the Goon office buildings kept in the national archive of Korea, the annotation of the images, the official documents between the Japanese government-general of Korea and To, the employee's registers of the Japanese government-general of Korea, and newspapers or journals from the Japanese colonial period. The designers of the common types were the engineers of the building-construction part in the Japanese government-general of Korea and also those in To. The space-composition of the individual types was similar to and also different from the common types at the same time, and the difference was attributed to the designers' ability and their preferences.

• Korean Journal of Weed Science
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• v.30 no.1
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• pp.17-24
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• 2010

Field study to find appropriate species for phytoremediation and phytomonitoring with higher plants was carried out at four abandoned metalliferous mines. In order to know the tolerant degree of plant resources collected at heavy metal polluted sites, soil and plants were sampled at same sites and metal concentrations were determined. Most serious heavy metal polluted in the sites was As that showed range from 29.1 to 1372.2 mg $kg^{-1}$ in investigated area. The dominant species were Oenothera biennis, Commelina communis, Persicaria senticosa, Conyza annuus, Artemisia princeps, and Erigeron canadensis. These species were predominant species that were proliferated in any survey area. Compared with other sites, vegetational characteristics of Dal-Seong, a mine site abandoned early in 1973, showed higher diversity index and lower dominance index. Distributions of weed species according to life cycle indicated that the proportions of perennial plants were lowered in every investigated site. Although the polluted areas were distant from each other, similarity indices among these vegetation were relatively similar. These results means the vegetations of abandoned mine areas were beginning stage of vegetational succession, and the vegetations were adversely affected by disturbance with heavy-metals and lack of water in soil.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.5-9
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• 2016

This survey was conducted to identify weed occurrence and to investigate weed management methods in the apple orchard fields in Chungnam province including Daejeon and Sejong from April to June and from September to October, 2015. In this survey, 64 weed species in 27 families including 39 annuals and 25 perennials were identified. Based on the importance values, the most dominant weed species in the first survey was Poa annua (6.51), followed by Veronica didyma (5.36), Plantago asiatica (5.36). In the second survey, Stellaria media (5.73), Digitaria ciliaris (5.36), and Rumex crispus (5.18) were dominant. When the 64 weed species were classified by family, the most abundant weed species belong to Compositae (12 species), followed by Poaceae (7 species), Polygonaceae (6 species), and Cruciferae (6 species). These 31 weed species in the most occurred four families accounted for 48% of total weed occurrence. Based on the questionnaire survey in which weed management methods in the apple orchard were asked, applied mowing + herbicide, mowing + tillage, and mowing + sod-culture was methods commonly conducted in apple orchard fields.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.184-190
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• 2013

It is important for genetic resources to collect and identify in native medium-leaf type zoysiagrasses species distributed in Korea. This study was conducted to investigate morphological variation and characteristics of native medium-leaf type zoysiagrasses from coastal, island and inland regions in Korea. Among them, 75 collected lines was confirmed to have various morphological variations, accessions were classified into 2 main based group coastal and inland regions by morphological characteristics and site environment. Group I included Z. sinica type, this group showed 3.7 mm in leaf width, 29 in number of seed per spikelet and 5.0 mm in seed length. Group II included Z. japonica type, this group showed 4.4 mm in leaf width, 42 in number of seed per spikelet and 3.5 mm in seed length. There is a need for additional research on growth characteristics and the molecular level for the introgressive hybridization between species which confirmed that cross-pollination is possible due to protogyny. The individuals showing variations should be preserved as valuable genetic resources for the expansion of variations in zoysiagrasses, and the results of this investigation on the genetic resources collected will be highly valuable in breeding high quality turfgrass.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.256-259
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• 2016

An obligate plant pathogenic fungus Puccinia zoysiae Dietel, the causal agent of rust disease, which is implicated in the damage of zoysiagrass (Zoysia spp.) in Korea. The fungus is one of the important pathogens, which attacks and colonizes susceptible zoysiagrass. Zoysia rust disease was observed in Jangseong, Hoengseong and Hapcheon in 2014 and 2015, Korea. The typical symptoms of the disease appeared first as small white spots on the leaf and stem of zoysiagrass plants, and turn brownish, dark brown spores revealed on the lesions. Uredospores were light brown in color, ellipsoid or spherical in shape and $22.0{\sim}25.0{\times}15.0{\sim}17.5{\mu}m$ in size. On the basis of the morphological characteristics, the fungus was identified as P. zoysiae. Pathogenicity of the fungus was proved by artificial inoculation on Z. japonica. The rust disease firstly appeared approx. early or middle June and then increased middle of October in Korea. In field, Z. matrella ecotypes were more resistant than Z. japonica ecotypes against the pathogen. Disease response against the pathogen was different among ecotypes of each species, respectively.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.179-188
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• 2017

In order to provide basic data for efficient control of weedy rice, we analyzed emergence rate of 100 weedy rice genetic resources collected in South Korea according to growth temperature and soil burial depth. Analyzing of emergence rate using low dormancy weedy rice genetic resources, emergence was increased at 12 and $14^{\circ}C$ of mean temperature condition. When calculating the effective accumulated temperature above $10^{\circ}C$, emergence rate increased 0.6% and 0.5% in 1 cm and 3 cm of soil depth, respectively according to increase of $1^{\circ}C$. However it reduced as 0.28% in 5 cm of soil depth condition. Analyzing of emergence rate using high dormancy weedy rice, red rice showed 55%, 46%, 41% of emergence rate in 1 cm, 3 cm and 5 cm of soil depth condition, respectively. However those of white rice decreased as 10%, 8% and 5.7% in 1 cm, 3 cm and 5 cm of soil depth condition, respectively. Relative emergence, assuming the final emergence rate as 100%, reached 80%, 90% and 100% when effective accumulated temperature was $83-112^{\circ}C$, $100-123^{\circ}C$, $148-160^{\circ}C$ respectively.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.185-190
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• 2022

The purpose of this study is to suggest library marketing strategies for Korean academic libraries to provide sustainable services at COVID-19 pandemic situation. For this purpose, development plans of academic libraries in Korea were collected and homepages of academic libraries in and out of Korea were analyzed. This study found that academic libraries in and out of Korea had taken various measures to meet disastrous situation and had kept up services for users to make use of collection, facilities, services and programs of libraries without being disconnected. As a conclusion, this study suggests reinforcement of basics and value marketing, space marketing, blue ocean marketing as library marketing strategies for providing sustainable services. This study can be used as a reference for academic libraries and librarians to sustain or extend library services. The marketing strategies suggested in this paper can be helpful for academic libraries to overcome pandemic crisis in Korea. As follow-up studies, an in-depth case study about academic libraries which develop and activate new services and programs in and out of Korea to face COVID-19, a study on developing in-depth strategies of various library marketing to stabilize library services are needed.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.71-77
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• 2014

Surveys of weed species in paddy fields were conducted in Korea to identify weed occurrence from June to September 2013. Total 3,434 sites of paddy fields in 155 City/Gun, eight Provinces were investigated. From the nation-wide survey, 90 weed species in 28 families were identified and classified to 52 annuals, 3 biennials and 35 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (18 species). 17, 8 and 6 weed species belonged to Cyperaceae, Scrophulariaceae and Polygonaceae, respectively, and these 49 weed species in the most four families accounted for 54% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (17.4%), followed by Monochoria vaginalis (12.4%), Eleocharis kuroguwai (7.8%), Bidens tripartite (9.27%), Scirpus juncoides (6.2%) and Sagittaria sagittifolia (6.1%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields of Korea.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.356-363
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• 1998

In general weed vegetation analysis has been applied to the study of weed population shift. However, it is a limited tool for understanding a problem region and a specific weed species in a certain area. Recently GIS may be used as an important tool to solve this target or to conduct specific field analysis which enables to introduce a reasonable management strategy. Thus, the GIS study was carried out to understand an integrated weed population changes between 1981 and 1992 in Korea. The nationwide weed survey was performed through the whole rice paddy fields in 1981 and 1992. Weed occurrence was totally different over whole country based on these data. In 1981 a region with high weed occurrence was at western and central areas of Korea in terms of weed population density but this was changed into western and southern area in 1992. In both years there were high weed population density at Taean, Seosan county of Chungnam province in Korea. Thus, this particular area may be needed to introduce a special strategy to reduce weed population density and/or to control problem weed species.