• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.813-826
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• 2015

This research deals with an estimation method for kinetic reaction model. The kinetic reaction model is a model to explain spread or changing process based on interaction between species on the Biochemical area. This model can be applied to a model for disease spreading as well as a model for system Biology. In the search, we assumed that the spread of species is stochastic and we construct the reaction model based on stochastic movement. We utilized Gillespie algorithm in order to construct likelihood function. We introduced a Bayesian estimation method using Markov chain Monte Carlo methods that produces more stable results. We applied the Bayesian estimation method to the Lotka-Volterra model and gene transcription model and had more stable estimation results.

• Journal of Ecology and Environment
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• v.40 no.2
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• pp.125-135
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• 2016

Background: The objectives of this study were to establish a swimming capability model for largemouth bass using the FishXing (version 3) program, and to determine the swimming speed and feasibility of fish passage through a waterway tunnel. This modeling aimed to replicate the waterway tunnel connecting the Andong and Imha Reservoirs in South Korea, where there is a concern that largemouth bass may be able to pass through this structure. As largemouth bass are considered an invasive species, this spread could have repercussions for the local environment. Results: Flow regime of water through the waterway tunnel was calculated via the simulation of waterway tunnel operation, and the capability of largemouth bass to pass through the waterway tunnel was then estimated. The swimming speed and distance of the largemouth bass had a positive linear function with total length and negative linear function with the flow rate of the waterway tunnel. The passing rate of small-size largemouth bass (10-30 cm) was 0%at a flow of $10m^3/s$ due to rapid exhaustion from prolonged upstream swimming through the long (1.952 km) waterway tunnel. Conclusions: The results of FishXing showed that the potential passing rate of large size largemouth bass (>40 cm) through the waterway tunnel was greater than 10%; however, the passage of largemouth bass was not possible because of the mesh size ($3.4{\times}6.0cm$) of the pre-screening structures at the entrance of the waterway tunnel. Overall, this study suggests that the spread of largemouth bass population in the Imha Reservoir through the waterway tunnel is most likely impossible.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.413-422
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• 1997

Fire characteristics of a typical apartment building in Korea was studied through full scale experiment and zone model simulation. The fire was ignited at the living room and allowed to spread to other parts of a single unit in a five storied apartment building. Various data including temperatures, species concentrations, and images were collected in the experiment. A zone model(CFAST) was used to analyze the same apartment building that represents the average households in Korea. The results were compared with a full scale experiments. While CFAST allows one compartment involved with fire, the experiment allowed the fire to spread to other compartments. Therefore, the comparison between experimental data and Zone-Model data is valid until the living-room fire spread to other parts of the apartment. Flashover occurred at approximately 380 seconds in a fire experiment, and at approximately 420 seconds in Zone-Model. Based on all of data between experimental data and Zone-Model data, it is concluded that the safe escape time is about 250 seconds.

• The Plant Pathology Journal
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• v.40 no.4
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• pp.377-389
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• 2024

The possibility of new viruses emerging in various regions worldwide has increased due to a combination of factors, including climate change and the expansion of international trading. Plant viruses spread through various transmission routes, encompassing well-known avenues such as pollen, seeds, and insects. However, research on potential transmission routes beyond these known mechanisms has remained limited. To address this gap, this study employed metatranscriptomic analysis to ascertain the presence of plant viruses in imported frozen fruits, specifically cherries and blueberries. This analysis aimed to identify pathways through which plant viruses may be introduced into countries. Virome analysis revealed the presence of six species of plant viruses in frozen cherries and blueberries: cherry virus A (CVA), prunus necrotic ringspot virus (PNRSV), prune dwarf virus (PDV), prunus virus F (PrVF), blueberry shock virus (BlShV), and blueberry latent virus (BlLV). Identifying these potential transmission routes is crucial for effectively managing and preventing the spread of plant viruses and crop protection. This study highlights the importance of robust quality control measures and monitoring systems for frozen fruits, emphasizing the need for proactive measures to mitigate the risk associated with the potential spread of plant viruses.

• Journal of Ecology and Environment
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• v.47 no.3
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• pp.63-74
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• 2023

Background: Comparing with the several types of infrastructures, linear infrastructures are known to facilitate the spread of undesirable species in ecosystems. Recently, some new man-made habitats (e.g., gravel pads of the high-voltage towers, solid wastes and sewage habitats) were established along the Deltaic Mediterranean coast of Egypt as a result of the construction of the E-W coastal international highway. The current study evaluates the floristic composition associated with the pads of high-voltage towers that had been constructed for stabilizing the power line towers in the North Nile Delta. Plant cover was measured for 22 randomly stand. Results: Eighty-four species were recorded, of which 35 are perennials (41.6%), 2 biennials (2.3%) and 47 annuals (56.0%) belonging to 23 families. The largest families were Asteraceae (16 species), Poaceae (15 species), Chenopodiaceae (12 species), and Fabaceae (7 species). Ten aliens (10.7%) out of the 84 species were recorded. Therophytes have the highest percentage (58%), followed by hemicryptophytes (14%), chamaephytes (11%). Six vegetation groups were recognized in the study area after the application of two way indicator species analysis (TWINSPAN), Arthrocnemum macrostachyum, Phragmites australis, and Mesembryanthemum nodiflorum have the highest presence percentage. Both of Salsola cyclophylla and Solanum villosum were recorded for the first time in North Nile Delta. Natural habitat had the highest α-diversity, but the lowest β-diversity (4.9, 15.4), while gravel pads had the reverse (2.7, 30.8). Some species which are native to the desert habitats (e.g., Rumex pictus, Salsola kali, and Carthamus tenuis) were able to invade the North Nile Delta. Conclusions: Habitat of gravel pads is an expressing form about the intense of disturbance in Deltaic Mediterranean coast of Egypt. More of efforts should be carried out to avoid more human disturbances that creating as ruderal habitats which open the gate to invasive species in the flora of North Nile Delta.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.321-324
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• 2008

Forest fire danger rate of thinning area was lower than that of non thinning area, because height rate of leewardside in burned stem of tree, damage rate of crown and mortality of tree in thinning area were 30.8%, 37% and 48.4% lower than that in non-thinning area, respectively. Intensity of forest fire varied depending upon topographical condition up slope, down slope, aspect, location as well as species, breast height diameter and forest tree density. Especially, a mountaintop area was burned down when forest fire was spread to up slope ridge of mountain.

• Journal of Species Research
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• v.8 no.1
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• pp.136-159
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• 2019

This study was carried out to investigate the flora of six islands belonging to the Gogunsan Archipelago (i.e., Sinsi-do, Seonyu-do, Munyeo-do, Yami-do, Bian-do, and Duri-do) in the Korean Peninsula. As results of five field surveys from March to October of 2016, we have identified 575 total taxa, representing 527 species, five subspecies, 42 varieties, and one hybrid, placed in 358 genera and 118 families. Of these 575 taxa, four are endemic to Korea, six taxa are listed on the Korean Red List of threatened species, 67 are floristic regional indicator plants, and 74 are invasive alien species. In this study, we compared species richness among the islands, and find that the larger the islands, the higher the species richness. In the case of habitat affinity types, forest species were most common, followed by farmland, seacoast, bare ground and wetland species. From similarity analyses based on the composition of vascular plants, each island did not exhibit either local specificity or unique diversity. On the contrary, the proportion of invasive alien and ruderal species may increase by human activities. Investigations and analyses of island flora such as this are important to assess the current status of the flora, predict future vegetation patterns and the spread of the alien species, and establish managment plans of plant diversity.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.138-151
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• 2013

This study was carried out to investigate the distribution and habitat types of prickly lettuce, Lactuca scariola of Europe origin for supplying the basic data of management plan. It showed fairly nation-wide distribution although excessive growth was rather limited in the wild. Its habitat types were divided into four types like open fields, roadsides, seashores and riversides. Species diversity examined by species rank-dominance curve tended to increase over riverside > seashores > open fields > roadsides. As a result of analyzing life form, therophytes were more than 50%, means that the habitats of L. scariola were disturbed by human activities etc. Urbanization Index was analyzed 9.1% in roadsides, 7.4% in seashores, 5.8% in open fields and riversides. It has high spread potential with a large number of wind-flying seed per plant. It was evaluated that prickly lettuce was mainly spread along the newly constructed road, expressway and invaded the original ecosystem in the cultivated land as weeds. But it has played a role as a pioneer species in open fields. It is recommended to remove where it has considerable impact on the native plant species of conservation value.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.323-328
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• 2018

Despite rising global concerns over the potential impacts of invasive alien species on indigenous species, the consequences of such introductions are lacking. The cabbage seedpod weevil (CSPW, Ceutorhynchus obstrictus) was found invaded into Korea in the early of 1990s. A large-scale survey in Korea reveals that, in about 20 years post-arrival, the invasive CSPW has become the most abundant on rape flowers and spread almost parts of South Korea including Is. Jeju and Is. Ulleung. Its spread is concurrent with the habitat retraction to cruciferous weeds of the native rapseed weevil (RSW, C. albosuturalis). However, Is. Yeoseo located between the mainland and Is. Jeju, showed their ratio with about 1:1. It suggests that the population of CSPW recently entered this island. Although underlying mechanisms of the decline of native species and increase of invaded species remain unknown, the potential roles of exploitative competition cannot be ruled out. Given that invasive weevil can rapidly replace native congeners, increased level of surveillances is demanding to discourage further invasion of othe alien pests.

• Korean System Dynamics Review
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• v.16 no.2
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• pp.53-74
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• 2015

Nutria(Myocastor coypus) is one of the most notorious invasive species in many countries. The Nutria's original range was South America like Brazil, Chile and Argentina. But it has been introduced to North America, Europe, Africa, and Asia including Korea, by fur ranchers. Like most invasive and disturbing species, nutria not only destroys habitats but also impacts many native species throughout most of its range with destructive feeding behavior. The purpose of this study is to investigate the dynamics of survival mechanism, population increase and spatial distribution, and eradication effect of Nutria on Nakdong River Area with the systems thinking. The result of this study revealed that Nutria can survive during winter with the behavior that the colder the winter was, the more deeply it burrowed. Further, the study uncovered the dynamics that nutria has survived more and more strongly during the extreme cold winter in almost every region and their population has increased dramatically as a result of the uncontrolled reproduction. Finally, the result showed that the action delay in eradicating Nutria, which was originated from the information delay of perception of nutria's survival and reproduction structure, reinforced the spread of Nutria across the nation.