• Journal of Ecology and Environment
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• v.44 no.1
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• pp.41-44
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• 2020

The Chinese many-toothed snake (Sibynophis chinensis) is an endangered species in South Korea. To determine its reproductive activity, here we captured a gravid S. chinensis from Mulyeongari Oreum Wetland Conservation Area, Jeju Island, on May 27, 2018, and reared it at Animal Taxonomy and Morphology Laboratory, Jeju National University, South Korea. The snake oviposited a clutch of six eggs between June 12 and 20, 2018, with an average size of 24.86 ± 1.36 mm in length and 9.86 ± 0.49 mm in width, which were artificially incubated at a constant temperature of 27 ℃. After incubating for 34-41 days, five of these six eggs successfully hatched. Average snoutvent length (SVL), tail length (TL), and body weight (BW) of hatchlings were 136.5 ± 5.17 mm, 47.76 ± 2.80 mm, and 1.66 ± 0.12 g, respectively. This study observed the reproductive activity of S. chinensis and characterized its eggs and hatchlings for the first time, providing valuable information for the long-term conservation plan of S. chinensis in South Korea.

• Animal Systematics, Evolution and Diversity
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• v.32 no.1
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• pp.1-8
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• 2016

Vermamoeba vermiformis is a very important free-living amoeba for human health in association with Legionnaires' disease and keratitis. This interesting amoeba was firstly isolated from a freshwater of Dokdo (island), which was historically used for drinking water. Trophozoites and cyst forms of V. vermiformis strain MG1 are very similar to previous reported species. Trophozoites of V. vermiformis strain MG1 showed cylindrical shape with prominent anterior hyaline region. The average ratio of length and width was about 6.5. Typically, cysts of the strain MG1 showed a spherical or slightly ovoidal shape with smooth wall, and lacked cyst pores. Some cysts had crenulate-walled ectocyst, which was separated from endocyst wall. Further, 18S rRNA gene sequence of V. vermiformis strain MG1 showed very high similarity to other V. vermiformis species (99.4%-99.9% identity). Molecular phylogenetic analysis based on 18S rRNA gene sequences clearly confirmed that the isolate was one strain of V. vermiformis with maximum bootstrap value (maximum likelihood: 100%) and Bayesian posterior probability of 1. Thus, the freshwater of Dokdo in Korea could harbor potentially pathogenic amoeba that may cause diseases in humans.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.129-134
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• 2017

This study aims to develop the traffic accident models by circular intersection type using count data model. The number of accident, the number of fatal and injured persons(FSI), and EPDO are calculated from the traffic accident data of TAAS. The circular intersection accident models are developed through Poisson and negative binomial regression analysis. The main results of this study are as follows. First, the null hypotheses that there are differences in the number of traffic accidents, FSI and EPDO by type of circular intersections are rejected. Second, the scale of intersection(median, large), number of approach road, mean width and length of exit road, area of the circulating roadway and central island are selected as factors influencing the number of traffic accidents, FSI and EPDO in rotary. Third, the scale of intersection(median), guide signs(limited speed, direction, roundabout), number of approach road, entry angle, area of the intersection and central island are adopted as factors influencing the number of traffic accidents, FSI and EPDO in roundabout. Finally, transferring from rotary to roundabout could be expected to make the accident decrease.

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.491-496
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• 2014

A total of six specimens (57.03-100.72 mm in standard length) belonging to the family Diodontidae were collected around Jeju Island, Korea between July and August 2013. On the Basis of morphological and molecular analyses, we identified the specimens as Cyclichthys orbicularis (Bloch, 1785), a new record to the Korean fish fauna. Morphologically, the species is characterized by nine caudal fin rays, immovable spines on the head and body except the caudal peduncle, and small black spots dorsally. Some morphometric characters changed disproportionately with growth, which was a new finding. Caudal peduncle length, body width and preanus length to standard length tend to grow at a rate different from that of overall growth. When the 601 base pairs of mitochondrial DNA cytochrome c oxidase subunit I sequences of our specimens were compared with those of other diodontid fishes, our specimens clustered tightly around C. orbicularis (d = 0.000-0.002) in an NJ tree, with a high bootstrap value (99%). We herein describe the morphological and molecular traits of the specimens, and propose a new Korean name, "gud-ga-si-bok-sok" for the genus Cyclichthys, and "dung-geun-gud-ga-si-bok" for C. orbicularis.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.4
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• pp.630-636
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• 2008

Monitoring the location of the shoreline and foreshore changes through the time and core tasks are carried out by coastal engineers for a wide range of research. With the advent of digital imaging technology, the shore-based video monitoring system provides many advantages than field surveys. This study presents the development and construction(installation) of video monitoring system to assist the study of coastal and shoreline dynamics and evolution, especially sandbar variation at the Nakdong river estuary. For the purpose of this study, at high building near the Dadea-po beach (St. 2) and Jinudo(island) (St. 1) foreshore region, where coastline variation is highly active, 5 video cameras installed; the coastline movement has monitored since Aug. 2007 using the systems. From the image results of video camera, the 'Spit' type sandbar appears at the foreshore region of Doyodeung and Dadea-po beach and measured the deposition process of Jinudo(island) foreshore region. As a result, the monitoring system using video-based technique built in this study would be able to identify changes in the area and width of shoreline and beach of Nakdong river estuary.

• Korean Journal of Environmental Biology
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• v.25 no.2
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• pp.139-148
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• 2007

In 2005, an unrecorded bryozoan, Bantariella sp., invading on black corals was observed at Munseom in Jejudo Island. An intensive study was performed in the portion of 180 m width and $10{\sim}30m$ deep of Hangae-chang at Munseom during the period from Jan. to Nov. 2006. The following two black corals, Antipathes japonica and A. lata are occurring in this area. To investigate the quantitative change of invasion rates, 26 colonies with initial invasion rate of 0%, 30%, 70% and 100% respectively were individually tagged at the beginning of this study. After that, the change of reinvasion rates was monitored in a timely manner with the pictures taken by underwater camera and ensile observation. These data were analyzed as to host species, depth and initial invasion rates. According to host species, the removal effect was higher in A. lata than A. japonica. The reinvasion rate of black corals showed a maximal effect at $20{\sim}30m$ deep, and the most successful removal effect appeared in the colonies of initial invasion rates of $30{\sim}70%$. Especially, the invasion of Bantariella sp. on black corals is related to seawater temperature in seasonal manner and this appearance was limitedly observed at Munseom. This study is to document the impact by bryozoan proposing removal methods and its proper time of removal. It could contribute to the conservation of black corals and furthermore help to predict the change of marine environments.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.69-78
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• 2007

Constructed wetlands and other aquatic systems have been successfully used for waste and wastewater treatment in either temperate or tropical regions. To treat waste or wastewater in a sustainable manner, the integrated eco-engineering designs are explained in this paper with 2 case studies: (i) a combination of vertical-flow constructed wetland (CW) with plant irrigation systemfor fecal sludge management and (ii) integrated CW units with landscaping at full-scale application for domestic wastewater treatment. The pilot-scale study of fecal sludge management employed 3 vertical-flow CW units, each with a dimension of $5{\times}5{\times}0.65m$ (width ${\times}$ length ${\times}$ media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/$m^2.yr$ and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80 - 96%. The accumulated sludge layers of about 80 - 90 cm was found at the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation Sunflower plant (Helianthus annuus) plots, each with a dimension of $4.5{\times}4.5m$ ($width{\times}length$). In the study, the CW percolate were fed to the treatment plots at the application rate of 7.5 mm/day but the percolate was mixed with tap water at different ratio of 20%, 80% and 100%. Based on a 1-year data of 3-crop plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increasing in CW percolate ratios. The highest plant biomass yield and oil content of 1,000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower is found. In addition to the pilot-scale and field experiments, a case study of the integrated CW systems for wastewater treatment at Phi Phi Island (a Tsunami-hit area), Krabi province, Thailand is illustrated. The $5,200-m^2$ CW systems on Phi Phi Island are not only for treatment of $400m^3/day$ wastewater from hotels, households or other domestic activities, but also incorporating public consultation in the design processes, resulting in introducing the aesthetic landscaping as well as reusing of the treated effluent for irrigating green areas on the Island.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.81-98
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• 2005

Leaf morphology was examined for Prunus species from Jeju Island. Analyzed were the leaf blade length, petiole length, width of blade, number of veins and angle of the base to the mid-vein as quantitative characters and the distribution of trichome, position of glandsand leaf features qualitative characters. A total of 25 OTU were phenetically analyzed by UPGMA. The resuling phenograms slightly differ from the currently recognized taxonomic system in two points. Prunus mume was clustered with P. padus and P. buergeriana. Prunu spendula and P. yedoensis were separated from the cluster of P. jaamasakura, P. speciosa, P. sargentii and P. jamasakura var. quelpaertensis. Except for the members of subgenus Cerasus, subgenera Padus (P. buergeriana and P. padus), Microcerasus (P. japonica) and Amygdalus were well defined. Some morphological characters of leaves such as the ratio of blade length to width, the length of blade to petiole, number of veins, the distance between the gland and base, the angle of base to mid-vein, and the distribution of trichome were useful as diagnostic features for Prunus from Jeju Island.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.618-630
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• 2020

Muna teakwood, especially from old stands, has been popular as raw material for timber industries in Indonesia for the past ten decades. Due to the scarcity of this wood, superior-grown seedlings of Muna teakwood have been developed and widely planted. Since there is no information on its characteristics, therefore, the aim of this research was to investigate wood characteristics of the 8-year-old superior-grown teak from Muna Island to ensure their proper utilization as raw material for wooden furniture. Wood discs and boards from basal area of three different trees were used as the samples. Macroscopic and microscopic anatomical characteristics were observed following the IAWA's list, while their physical-mechanical properties were measured following British Standard 373-57. Results showed that anatomical characteristics of this wood sample are similar to regular teakwood, but its heartwood portion is higher. Differences among trees are found in regards to wood texture, growth ring width, as well as early and latewood portion. The green moisture content was lower than that of fast-growing teak of a similar age. The wood is more stable than the old teakwood, but its specific gravity is lower. In general, mechanical properties of this wood were higher than those of the regular fast-growing teakwood, but lower than the old one. Based on its specific gravity, this superior Muna teakwood was categorized as a Strength Class of III. The wood is suitable enough for wooden furniture manufacturing.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.49-57
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• 2019

The street trees increase the liveability of cities by reducing stormwater runoff, improving air quality, storing carbon, providing shade, and ameliorating the urban heat-island effect. In this study, the health status of street trees in Suwon was evaluated, and the factors affecting the growth of the trees were also derived. In order to evaluate the growth and health of street trees, field survey was carried out on a total of 125 trees in 25 sections of the Deogyeong-daero where is through the city. During the field survey, the following items were examined: Street trees health status (i.e. species, height, DBH (diameter at breast height), planting types, vigor, etc.), soil factors (i.e. soil temperature, humidity, pH, hardness, etc.), and environmental factors (i.e. landuse, road width, etc.). As the results of field survey, the main species of the street trees was Zelkova serrata, which was healthy in most of the sections. The factors such as planting types, soil temperatures, tree root cover, road extension, distance from the road were derived to affect the growth and health of street trees, and the differences were significant. The results of this study were derived the following conclusions for vigorous street trees: First, it is important to install and maintain the protection facilities like tree root cover for the growth of trees. Second, it is necessary to discuss how to plant multiple trees in narrow spaces like a street green space. Third, it is important to provide appropriate soil conditions continuously for growth of threes. Finally, it should be utilized as a mitigation measure of urban heat island effects.