• Korean Journal of Plant Taxonomy
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• v.52 no.2
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• pp.85-96
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• 2022

The plant "Hong-do-go-deul-ppae-gi" has been considered as Crepidiastrum × muratagenii, a hybrid between C. denticulatum and C. lanceolatum, based on its morphological traits and geographical distribution. To reveal the hybrid origin of Hong-do-go-deul-ppae-gi, we examined additional morphological traits of this plant and its putative parents (C. denticulatum, C. lanceolatum, C. platyphyllum) and analyzed one nuclear ribosomal internal transcribed spacer (ITS) region and four chloroplast regions (trnT-L, trnL-F, rpl16 intron, and rps16 intron). As a result of examining the morphological traits, putative hybrid individuals were classified into three types based on the habit, cauline leaf, outer phyllary, and achene beak traits. A molecular analysis found that the ITS sequences of Type 1 and Type 2 individuals showed additive species-specific sites of C. denticulatum and C. lanceolatum. Plastid sequences of Type 1 and Type 2 individuals showed C. denticulatum and C. lanceolatum sequences, respectively. However, Type 3 individuals had ITS and plastid sequences corresponding to C. denticulatum. Accordingly, Type 1 and Type 2 individuals not only share morphological traits with C. denticulatum and C. lanceolatum but also show additive species-specific sites for C. denticulatum and C. lanceolatum, and not C. platyphyllum, supporting its origin as a hybrid between C. denticulatum and C. lanceolatum. Type 3 had morphological traits similar to other hybrid types but was distinguished with respect to outer phyllaries and demonstrated some resemblance to C. denticulatum. In a molecular analysis, Type 3 was found to be identical with regard to the sequence of C. denticulatum and was judged to be an ecological variation of C. denticulatum.

• Journal of Life Science
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• v.12 no.6
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• pp.821-834
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• 2002

In order to measure the inter- and intraspecific genetic divergences within the genus Alexandrium, the variations within the internal transcribed spacer (ITS1 and ITS2) regions and 5.85 ribosomal RNA gene of eight Alexandrium species were examined for 33 strains from diverse geographical locations by direct sequencing. Five isolates of A. tamarense (AT-2, AT-6, AT-10, AT-A and AT-B) from Jinhae Bay, Korea were found to be completely identical to a Japanese strain OFX151-A. The length of the amplified ITSI-5.85-ITS2 region varied from 481 nucleotides (in A. margalefi) to 528 nucleotides (in A. affine CU1-1). ITS1 and ITS2 nucleotide lengths were negatively correlated, whereas a positive correlation was found between their G＋C content. The degree of sequence divergence ranged from 0.3% (1 bp) to a maximum of 53% (305 Up). Pairwise sequence comparisons revealed a small degree of divergence between A. tamarense and A. Pundyense isolates (1.2 - 2.3% ＝ 6-12 bp), but a high degree of divergence between A. tamarense and A. catenella (19.8% ＝ 102 bp), and between A. catenella and A. Pundyense (19.7%). Although most nodes were weakly supported by bootstrap values, some types tend to form independent molecular groups. A. catenella isolates also formed an independent molecular sub-group, with relaticula strong bootstrap values (94% or 85% and 79% or 98%, respectively in PAUP and NJ trees). Interestingly, A. cohorticula and A. frateculus always clustered within the same sub-group, this result being supported by strong bootstrap values. Our results indicate that the ITS regions provide useful informations on hierarchical population genetic structure and a high phylogenetic resolution in intraspecific and interspecific Alexandrium population.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6B
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• pp.597-603
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• 2006

The purpose of this study is to improve the short term rainfall forecast skill using neural network model that can deal with the non-linear behavior between satellite data and ground observation, and minimize the flood damage. To overcome the geographical limitation of Korean peninsula and get the long forecast lead time of 3 to 6 hour, the developed rainfall forecast model took satellite imageries and wide range AWS data. The architecture of neural network model is a multi-layer neural network which consists of one input layer, one hidden layer, and one output layer. Neural network is trained using a momentum back propagation algorithm. Flood was estimated using rainfall forecasts. We developed a dynamic flood inundation model which is associated with 1-dimensional flood routing model. Therefore the model can forecast flood aspect in a protected lowland by levee failure of river. In the case of multiple levee breaks at main stream and tributaries, the developed flood inundation model can estimate flood level in a river and inundation level and area in a protected lowland simultaneously.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.575-579
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• 2006

The land use in suburban area has been changed rapidly due to the urban expansion in Korea during the last few decades. And such land use changes result in various environmental problems such as biodiversity decrease, habitat fragmentation, air pollution and urban heat island. Remote Sensing (RS) and Geographical Information Systems (GIS) can be used for land cover change detection to understand the impact and trend of the land use change. Change detection is the process of identifying differences in the state of an object or phenomenon by observing it at different times and it can provide quantitative and comparative information for the land use/cover change. RS is less expansive than field survey for producing land use maps, and can be accessed quickly and repetitively for large area. Also it can be used for change detection using multi-temporal land use/cover by accumulated data. Therefore, the purpose of this study is to detect and quantitatively evaluate urban land cover change in urban stream watershed area for the last few decades and ultimately to provide the basic data for urban land use planning and management.

• Korean journal of applied entomology
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• v.48 no.3
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• pp.295-299
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• 2009

Adoxophyes spp. (Lepidoptera: Tortricidae) are economically important pests of fruit trees in Asia and Europe. The geographical distribution of three Adoxophyes species, A. orana, A. honmai and A. paraorana, in Korea was surveyed using species-specific sex pheromone traps for males in 2006 and 2007. The distribution of A. orana was restricted in the midwestern area, while A. honmai was found mainly in the southern area. In contrast to these two species, A. paraorana was widely distributed. Moreover, A. paraorana coexisted with A. orana in the midwestern area, and with A. honmai in the southern area. The seasonal fluctuation of male catches was monitored with pheromone traps in 2008. In the central regions, males of A. orana and A. paraorana were captured from May to September, with peak numbers in late May, middle July, and late August. A. honmai males were trapped from late April to late September, with peak catches in middle May, late June, early August, and early September in Naju.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.171-176
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• 2011

Sclerotinia homoeocarpa, the causal agent of dollar spot, is one of the most common pathogens of cool season turfgrasses in South Korea. The vegetative compatibility group (VCG) assay was carried out using nitrate-nonutilizing (nit) mutants recovered from 13 South Korean isolates with various geographical origins. The mutants were divided into four phenotypic classes based on mutation loci associated with nitrogen assimilation: nit1, nit2, nit3, and NitM. The recovered number of nit mutants greatly varied among the isolates, ranging from 0 to 15 mutants. Of the mutants isolated, nit1 and nit2 mutants were most common (80%) while NitM and nit3 were relatively rare. One dominant and four minor VCGs were determined from 18 mutant isolates tested. To study population structures of Korean S. homoeocarpa isolates and increase our understanding of its ecological and epidemiological aspects for dollar spot management on turfgrass, more generated mutants should be tested with more diverse isolate collections.

• Korean Journal of Remote Sensing
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• v.38 no.6_3
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• pp.1837-1846
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• 2022

The annual increase in chemical accidents is causing damage to life and the environment due to the spread and residual of substances. Environmental damage investigation is more difficult to determine the geographical scope and timing than human damage investigation. Considering the reality that there is a lack of professional investigation personnel, it is urgent to develop an efficient quantitative evaluation method. In order to improve this situation, this paper conducted a chemical accidents investigation using unmanned aerial vehicles(UAV) equipped with various sensors. The damaged area was calculated by Ortho-image and strength of agreement was calculated using the normalized difference vegetation index image. As a result, the Cohen's Kappa coefficient was 0.649 (threshold 0.7). However, there is a limitation in that analysis has been performed based on the pixel of the normalized difference vegetation index. Therefore, there is a need for a chemical accident investigation plan that overcomes the limitations.

• Korean journal of health promotion
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• v.18 no.4
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• pp.184-193
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• 2018

Background: Despite increasing the number of newly licensed nurses across Korea, shortages caused by geographical imbalances remains a significant concern. Therefore, understanding nursing students' attitudes to working and living, factors influencing where they first choose to work after graduation is useful in formulating appropriate interventions to retain nurses in regional areas. Methods: A total of 329 senior nursing students from areas outside Metropolitan Seoul completed self-report questionnaires. Data were analyzed using t-test, chi-square test and multiple logistic regression analysis. Results: Of the respondents, 57.8% reported that they planned to work in the region in which their school was located. The three factors ranked as having the greatest influence on their decision to work in non-metropolitan regions were: the cost of living, housing costs, and the proximity to family. Enjoyable aspects of rural life contributed positively to students' intentions to work in non-metropolitan regions, whereas isolation and socialization problems negatively affected their intentions to work in such areas. Conclusions: Greater consideration should be given to improving working conditions and housing environments in non-metropolitan regions.

• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.147-153
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• 2018

There are few available studies for insect diversity in relation to coastal dune despite the unique landscape features and high conservation value. Therefore, this study compared ground beetle assemblages inhabiting between windbreak forests and sand dunes in the Taeanhaean National Park. It investigated five windbreak forests and three coastal dunes using pitfall traps from middle of June to middle of October in 2014. A total of 2,335 ground beetles belonging to 30 species of 15 genera were collected. Synuchus arcuarticollis (158 individuals) and Dolichus halensis halensis (153 individuals) were dominant of 25 specifies collected from sand dunes while Synuchus arcuarticollis (1,630 individuals), Synuchus nitidus (130 individuals), and Synuchus cycloderus (42 individuals) were dominant of 14 species collected from windbreak forests. The similarity of ground beetles compositions in sand dunes and windbreak forests was significantly low at 27.4%. The results of this study showed that sand dune geographical features found in the Taeanhaean National Park had different insect assemblages from windbreak forests. It will be the useful information for conservation of insects in the future.

• Korean Journal of Remote Sensing
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• v.22 no.6
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• pp.621-626
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• 2006

Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Extraction of 3D building information from high resolution satellite imagery is one of the most active research topics. There have been many previous works to extract 3D information based on stereo analysis, including sensor modelling. Practically, it is not easy to obtain stereo high resolution satellite images. On single image performance, most studies applied the roof-bottom points or shadow length extracted manually to sensor models with DEM. It is not suitable to apply these algorithms for dense buildings. We aim to extract 3D building information from a single satellite image in a simple and practical way. To measure as many buildings as possible, in this paper, we suggested a new way to extract building height by triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and decrease the digitizing error and the computation efficiency.