• Korean Journal of Ichthyology
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• v.34 no.4
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• pp.262-269
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• 2022

A distribution survey was conducted from 2018 to 2020 to evaluate the distribution status, habitat characteristics, and extinction threat of the short ninespine stickleback Pungitius kaibarae (Gasterosteidae). Literature reports of P. kaibarae distribution have been sorted by each period, 1980~1996, 1997~2005, and 2007~2017, and the samples were collected in 32, 43, and 64 stations for each period. Among the 75 streams and 193 sampling sites investigated during the study period, 1,400 P. kaibarae individuals were collected from 26 streams at 39 sites. The main habitat of P. kaibarae was downstream or brackish water zones with a low altitude, slow water velocity, and many aquatic plants. The main reasons for the decline in population size were assumed to be drought and flood, river work for flood restoration and river maintenance, bridges construction, and predation by the exotic fish species Micropterus salmoides. Previous evidence reported a 42.6% reduction in occupancy within 10 years, a decline in habitat quality, and the spread and impact of the exotic fish species Micropterus salmoides. Therefore, P. kaibarae is now considered a Vulnerable (VU A2ace) species based on the IUCN Red List categories and criteria. Therefore, P. kaibarae should be redesignated as an endangered species by the Ministry of Environment and systematically managed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.71-94
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• 2020

Korea's innovation cluster policy has been implemented since 2005 with the goal of balanced regional development. The purpose of this study is to investigate the factors affecting the sustainability of innovative cluster tenants by using Pangyo Techno Valley as an example. Pangyo Techno Valley was established under the leadership of the local government (Gyeonggi-do) rather than the central government and it is called "Silicon Valley of Korea" and "Asia Silicon Valley" and is becoming more representative. The growing number of companies in Pangyo Techno Valley decreased in 2017 compared to 2016. This is because Pangyo Techno Valley's business ecosystem will change from 2019. In this paper, quantitative and qualitative studies were conducted to investigate the influencing factors. Quantitative research was conducted based on the survey and qualitative research was applied through interviews. The quantitative research examined the factors affecting the sustainability of Pangyo Techno Valley, and the qualitative research examined the specific reasons and additional factors for the quantitative research results. The quantitative results showed that factors affecting sustainability in terms of changes in corporate internal conditions, human and physical infrastructure, cooperation and synergy, and occupancy patterns. The specific reason for the impact appeared in the qualitative research process. The support category of local governments did not show any significant factors in quantitative research. In addition, qualitative research suggested 'Good image of Pangyo Techno Valley' as the category that has the greatest impact on sustainability. It is shown that companies are passive and expect the role of local governments in activating cooperation network in Pangyo Techno Valley. In this paper, based on the results of the study, Pangyo Techno Valley is presented with a realistic plan based on real estate issues and an ideal plan with a long-term perspective.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.62-67
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• 1999

Infection rates of oyster ovarian parasite, Marteiliodes chungmuensis and productivity of the oyster shellstock infected with the parasite were investigated at the main seed collection areas in the southern coast of Korea where the extreme bad seed collection of oyster occurred in 1992 and 1993 to evaluate the cause of the bad seed collection. Additionally, the bacterial flora of the sea water and oyster lana were examined to identify the shellfish larva pathogenic bacteria like Vibrio sp. and Pseueomonas sp. In August 1992 to September 1993, infection rate of oyster ovarian parasite, M. chungmuensis at Tongyong, Kyongsangnam province, and Yosu, Chollanam province where the bad seed collection occurred, were $11.8\~100\%$ and $14.3\~100\%$, respectively. But the parasite was not detected in the shellstock collected at Daechon, Chungchongnam province. While a virus-like particle was identified in the cytoplasm of the egg infected by the parasite. The parasite infected egg was not able to fertilize completely. Uninfected egg in the gonad contaminated by the parasite could be able to fertilize but showed an abnormal development till D-shaped larva and then, died of necrosis after D-shaped lana. And some lana developed from low lipid content egg could not develop to the spat and died after the early umbo stage. The predominant bacteria in the oyster lana collected at bad seed collection areas were Pseudomonas sp. and Pseudomonas like bacteria and the occupancy rates were $53.3\~87.1\%$.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.92-105
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• 2019

Spatial and temporal characteristics of phytoplankton communities around the coastal waters of Jeju Island were investigated with environmental factors such as water temperature, salinity, and dissolved oxygen. Monthly samples were collected at 0 and 30 m depths of 10 stations from March 2015 to February 2016. During the survey period, water temperature ranged in 13.7~25.9 and $13.6{\sim}20.8^{\circ}C$ at 0 and 30 m, salinity in 31.51~34.47 and 33.03~34.47 psu at 0 and 30 m, and dissolved oxygen in 6.12~8.10 and $5.73{\sim}7.88mg\;L^{-1}$ at 0 and 30 m, respectively. Chlorophyll-a ranged in 0.28~2.48 and $0.44{\sim}1.01{\mu}g\;L^{-1}$ at 0 and 30 m, respectively. Phytoplankton abundance fluctuated in the range of $5,300{\sim}639,900cells\;L^{-1}$ during the year, showing the lowest in February at all stations, and the highest in July at the northern and western sea as well as in August at the southern and eastern sea of Jeju Island. A total of 362 species were occurred including 181 spp. of Bacillariophyta, 147 spp. of Dinophyta and 34 spp. of other phytoflagellates. Dominant species with occupancy rate over 20 percent of phytoplankton abundance showed apparent seasonal succession such as Paralia sulcata and Skeletonema costatum in spring and autumn, 6 spp. of genus Chaetoceros in summer, and 2 spp. of genus Chaetoceros and Thalassionema frauenfeldii in winter. Monthly abundance in the northern and western sea fluctuated with similar tendency, and the southern and eastern sea also showed similar pattern of monthly abundance variation. Species composition and dominant species succession mentioned above were quite different from previous studies, so some physical changes such as water temperature, salinity and current pattern might cause the changes of phytoplankton assemblages around Jeju Island.

• Journal of Korea Port Economic Association
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• v.39 no.1
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• pp.131-147
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• 2023

Gwangyang Port Marine Industry Cluster is the only marine industry cluster in Korea that is currently in operation, but despite the implementation of various revitalization policies since its opening, the occupancy rate has been low so far. Accordingly, this study aims to identify the constraints of the current system that hinder the inducement of tenant companies and to suggest revitalization measures. For this purpose, this study analyzed the current status of research and development(R&D) projects in the port, shipping and logistics sector, which is a core industry of the Gwangyang Port Marine Industry Cluster. And a survey was conducted on companies with potential to move in. As a result, the proportion of R&D in the core industry sectors is lower than in other sectors, and most of R&D projects are being carried out mainly by small and medium-sized enterprises. In addition, the low need for port facilities and low accessibility to Gwangyang Port were derived as constraints. Considering the results, this study suggests four revitalization measures to induce tenant companies as follows. First, it is necessary to expand the scope of core industries from the current shipping, ports, and logistics to the entire maritime and fisheries, so that companies performing R&D in the industry can move in. Second, the industry code currently specified as a qualification need to be revised to include both the industry of the enterprise carrying out R&D projects and the core industry. Therefore, this study suggests an expanded industry code list that can replace current list. Third, a transition of tenant recruitment system from the regular system(once or twice a year) to the occasional system is proposed so that companies can move in flexibly when demand arises. Finally, in order to overcome geographically low accessibility, technology development support projects specialized in R&D that prospective tenant companies actually need are needed rather than financial support.

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.48-57
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• 2024

Distribution status and extinction threat evaluation of an endangered species, Cobitis choii, were investigated from 2015 to 2019. In 2015 and 2018, we investigated past appearance sites of C. choii. In 2015, 163 individuals from nine sites were collected by surveying 19 stations. In 2018, 19 individuals from five sites were collected by surveying 22 sites. In 2019, 156 individuals from 12 sites were collected as a result of a survey of 79 sites of past appearance and potential appearance of C. choii. Appearance regions were Mihocheon (Baekgokcheon (2 sites), Chopyeongcheon (1 sites)), Gapcheon (3 sites), Yugucheon (2 sites), Jicheon (4 sites), and Geumgang mainstream (2 sites). Among these appearing regions, Baekgokcheon, Yugucheon, and Mihocheon mainstreams showed a sharp decline in population. Baekgokcheon was estimated to have a habitat change due to a project to raise the bank of Baekgok Reservoir. Yugucheon was estimated to have a habitat disturbance due to flood-induced collapse and reconstruction of weir. Mihocheon mainstream was estimated to have water pollution and habitat disturbance. On the other hand, Chopyeongcheon and Geumgang mainstream were newly habitat identified and Gapcheon was noted to show an increase in the number of individuals. After performing extinction threat evaluation, C. choii was evaluated as Endangered (EN A2ac) due to its rapid population decline (more than 50%) in its habitats of Baekgokcheon, Yugucheon, and Mihocheon based on criteria A, while it was evaluated as Vulnerable (VU B1ab (iii,v) +B2ab +B2ab (iii,v)) due to its narrow extent of occurrence (EOO, 1,735 km²) and area of occupancy (AOO, 36 km²) in 6 locations with a continuous population decline based on criteria B. Therefore, the final threat of extinction grade was evaluated as Endangered (EN A2ac). In Baekgokcheon, Yugucheon, and Mihocheon mainstream where the population has declined rapidly recently, conservation measures are urgently required to increase its population.

• Land and Housing Review
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• v.15 no.1
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• pp.1-22
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• 2024

This research explores the household and housing characteristics of young renters aged between 19 and 34 living independently in rental housing of non-Seoul Metropolitan Area (non-SMA) and to determine the factors of their housing affordability and residential environment qualities in two districts of non-SMA - metropolises and non-metropolises. Using the 2020 Korean Housing Survey (KHS), this study identified 1,191 unmarried young renters, and most were single adults in mid-twenties who were salaried workers with a bachelor's degree or higher. Also, many lived in single-room occupancy of non-APT housing for less than 2 years and rarely relied on social services. The findings showed that the distinction of local housing market between metropolises and non-metropolises forced the former to spend more housing expense (tenancy deposit and rental fees) than the latter. With regard to housing affordability indices (Schwabe index, housing expense ratio and rent to income ratio), most were housing cost-burdened and nearly one quarter were severely rent-burdened. The regression analysis indicated that housing affordability in both districts was positively affected by income increase and social services, and housing satisfaction in non-metropolises was added to its determinants. Further, residential environment qualities were largely divided into two groups of livelihood and urban infrastructure, and the two factors influenced residential assessment in both districts. Since young renters interdependently living had suffered with housing affordability, both income growth and housing assistance are critically required to enable them not just to reduce the burden but to ensure livability.