• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.1
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• pp.63-68
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• 2010

Ecological characteristics of Undariopsis peterseniana, an endangered brown alga, were investigated from January to December 2007 at Jeju Island, Korea. The U. peterseniana population formed dense patches at depths of 12~17 m depth. Growth in length of the alga reached a maximum of $168{\pm}36cm$ at June. Sorus were observed from May to August, and a maturation peak was detected in June, when bottom seawater temperatures were around $18^{\circ}C$. After zoospore release, the alga bleached and disappeared after August. Developmental initiation of sporophytes occurred at temperature above $15^{\circ}C$, and sorus formation required approximately 236 degree-days. This is the first study to examine a U. peterseniana population throughout the entire year in a natural habitat.

• ALGAE
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• v.37 no.4
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• pp.265-279
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• 2022

The primary production (PP) by phytoplankton in marine ecosystems is essential for carbon cycling and fueling food webs. Hence, estimating the PP in the territorial sea of each country is a necessary step to achieving carbon neutrality. To estimate the PP in the territorial sea of the Republic of Korea from 2005 to 2021, we analyzed various physiochemical parameters, such as sea surface temperature (SST), Secchi depth, and concentrations of chlorophyll-a and nutrients in the seas of five regions, including the East Sea, West Sea, western South Sea, eastern South Sea, and the waters off Jeju Island. During the 17-year study period, the SST tended to increase, while the nutrient concentrations declined, except in the Jeju area. Overall, the PP did not show a specific temporal trend, but daily PP in the western South Sea was the highest among the five regions. Moreover, the maximum PP in the Korean territorial waters (76,450 km²) was estimated at 11,227 Gg C y^-1, which accounts for 0.03% of the global PP. The results may give insights into a better understanding of the PP, further resource utilization, and environmental sustainability in the studied region.

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.476-493
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• 2013

Geoturism has been discussed from multiple perspectives in geomorphology and geology as well as tourism domain since 2000. As of May 2013, 172 academic papers and reports on Geoturism have been published in domestic journals. Themes of these researches can be categorized into 6 topics: resource development (i.e. natural resource development, cultural resource development, development of geopark), conservation and management, geoturist, local resident participation and public relations marketing, political approaches. Resource development among those topics has been treated the most: development and utilization of important geomorphological and geological landscape resources, storytelling development about cultual resources, contents development for geopark. On the whole, it is significant that geotourism is actively discussed in geography domain such as geomorphology rather than in geology domain. Up to date, those topics have also been treated only in certain academic areas. In the future researches, efforts for the balance among those topics and creating new themes from various research areas is necessary. Moreover, community networking among locals-municipalities-academia is also necessary to increase local participants.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.2
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• pp.20-29
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• 2019

The purpose of this study is to verify and reconstruct the record information for big old trees of Jeju on the basis of the precise map of Jeju island in 1918 which was produced 100 years ago. For the analysis of high altitude, coordinate system and georeferencing were performed by selecting representative points using ArcGIS. We extracted digitized information by using point extraction method and extracted attribute information based on legend type and relative size in map. Based on the map of the past 100 years ago, the present situation of the big old tree in Jeju was analyzed and their characteristics were analyzed. In addition, based on the information of the protected big old trees in present, we discussed the characteristics of past tree (1918), present tree (2019), and contribution of big old tree in Jeju landscape and vegetation. As a result, 1,013 individuals were distributed in Jeju Island 100 years ago. Even when it was intensive in the use of timber, the big old trees were protected, and contributed as a representative component of Jeju's unique landscape. The remaining distribution of Jeju's big old tree is 159 trees. As in the past, distribution has been confirmed around the lowlands, but declines in numbers are found throughout the island. The major factors for the decline of individuals are large-scale development projects such as reaching the limit of life, natural disturbance (typhoon, disease, pest, drought, etc.). However, it is presumed that a large number of individuals have played a leading role in shaping the current forests as contributing to important species sources in the restoration process of Jeju vegetation. However, it is presumed that a large number of individuals (405) have played a leading role in forming the present forest by contributing to the species pool in the restoration process of Jeju vegetation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.294-302
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• 2019

As a series of fundamental researches on the development of an automatic identification monitoring system for fishing gear. Firstly, the study on the installation method of automated identification buoy for the coastal improvement net fishing net with many loss problems on the west coast was carried out. Secondly, the study was conducted find out how to install an automatic identification buoy for coastal gill net which has the highest loss rate among the fisheries. GPS for fishing was used six times in the coastal waters around Seogwipo city in Jeju Island to determine the developmental status and underwater behavior to conduct a field survey. Next, a questionnaire was administered in parallel on the type of loss and the quantity and location of fishing gear to be developed and the water transmitter. In the field experiment, the data collection was possible from a minimum of 13 hours, ten minutes to a maximum of 20 hours and ten minutes using GPS, identifying the development status and underwater behavior of the coastal gillnet fishing gear. The result of the survey showed that the loss of coastal net fishing gear was in the following order: net (27.3%), full fishing gear (24.2%), buoys, and anchors (18.2%). The causes were active algae (50.0%), fish catches (33.3%) and natural disasters (12.5%). To solve this problem, the installation method is to attach one and two electronic buoys to top of each end of the fishing gear, and one underwater transmitter at both ends of the float line connected to the anchor. By identifying and managing abnormal conditions such as damage or loss of fishing gear due to external factors such as potent algae and cutting of fishing gear, loss of fishing gear can be reduced. If the lost fishing gear is found, it will be efficiently collected.

• Journal of the Mineralogical Society of Korea
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• v.23 no.1
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• pp.15-23
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• 2010

The absolute clay mineral compositions and regional distribution of the 131 bulk marine surface sediments around the Jeju Island was compared to their relative compositions and distribution using quantitative X-ray diffraction analysis. Average absolute clay mineral composition is illite 15.3% (0.5~40.5%), chlorite 2.6% (0~7.9%), and kaolinite 1% (0~5.6%). Total contents of the clay minerals are very high in the South Sea of Korea, northwestern part and southern offshore of Jeju Island. The average relative composition is illite 70.9% (16.7~89%), chlorite 21.5% (8.4~68.5%), and kaolinite 7.6% (0~29.3%). Relative illite contents are high in the northwestern and southeastern part of study area, and southern part of Jeju Island. Chlorite contents are high in the eastern part of study area and western part of Jeju Island. Kaolinite contents are high in the western and southern part of Jeju Island, and southern offshore of Jeju Isand. Absolute Distribution patterns are very similar to those of fine-grained (from clay to silt) sediment, whereas relative distribution patterns do not show any relationship with those of fine-grained sediment.

• Journal of the Speleological Society of Korea
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• no.67
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• pp.53-63
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• 2005

This study is basic research to present the activation of cave tourism. So first of all for establishing of this study, we examined the distribution characteristics of natural caves and monument caves. The results of this study are as follows; First, monument caves concentrate upon Gangwon-do and Jeju-do. Second, open caves concentrate upon Gangwon-do and Chungcheongbuk-do. Third, typical linkage characteristics of tourism resources surrounding open caves are very high in natural tourism resources. Fourth, It is necessary to develop tourism route though the linkage with other tourism resources. But this study have been partial and fragmentary. in order to increase the number of tourists, we should make them curious about the specific region by presenting the unique characteristics of the region, for example its cultural, social, recreational etc. in other words, in order to attract the tourists open caves should differentiate from other open caves.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.303-311
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• 2018

In this study, a preliminary evaluation of the antioxidant and anti-inflammatory activity of the Ficus erecta var. sieboldii (Miq.) King (FES) leaf extract has been performed to assess its potential as a natural resource for food and medicinal materials. FES was extracted using 70% EtOH and then fractionated sequentially using n-hexane, $CH_2Cl_2$, EtOAc, and n-BuOH. To screen for antioxidant and anti-inflammatory agents effectively, the inhibitory effect of the FES extracts on the production of oxidant stresses (DPPH, xanthine oxidase, and superoxide) and pro-inflammatory factors (NO, iNOS, COX-2, $PGE_2$, IL-6, and $IL-1{\beta}$) in the murine macrophage cell line RAW 264.7 activated with lipopolysaccharide (LPS) was examined. Among the sequential solvent fractions of FES, the $CH_2Cl_2$ and EtOAc fractions showed decreased production of oxidant stresses (DPPH, xanthine oxidase and superoxide), and the hexane and $CH_2Cl_2$ fractions of FES inhibited the production of pro-inflammatory factors (NO, iNOS, COX-2, and $PGE_2$). The $CH_2Cl_2$ fraction also inhibited the production of pro-inflammatory cytokines ($TNF-{\alpha}$, IL-6, and $IL-1{\beta}$). These results suggest that FES has a significant effects on the production of oxidant stresses and pro-inflammatory factors and may be used a natural resource for antioxidant and anti-inflammatory agents.

• Journal of Korean Society of Rural Planning
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• v.30 no.2
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• pp.13-24
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• 2024

This study conducts an analysis of social media big data pertaining to island tourism resources, aiming to discern the diverse forms and categories of island tourism favored by consumers, ascertain predominant resources, and facilitate objective decision-making grounded in scientific methodologies. To achieve this objective, an examination of blog posts published on Naver from 2022 to 2023 was undertaken, utilizing keywords such as 'Island tourism', 'Island travel', and 'Island backpacking' as focal points for analysis. Text mining techniques were applied to sift through the data. Among the resources identified, the port emerged as a significant asset, serving as a pivotal conduit linking the island and mainland and holding substantial importance as a focal point and resource for tourist access to the island. Furthermore, an analysis of the disparity between existing island tourism resources and those acknowledged by tourists who actively engage with and appreciate island destinations led to the identification of 186 newly emerging resources. These nascent resources predominantly clustered within five regions: Incheon Metropolitan City, Tongyeong/Geoje City, Jeju Island, Ulleung-gun, and Shinan-gun. A scrutiny of these resources, categorized according to the tourism resource classification system, revealed a notable presence of new resources, chiefly in the domains of 'rural landscape', 'tourist resort/training facility', 'transportation facility', and 'natural resource'. Notably, many of these emerging resources were previously overlooked in official management targets or resource inventories pertaining to existing island tourism resources. Noteworthy examples include ports, beaches, and mountains, which, despite constituting a substantial proportion of the newly identified tourist resources, were not accorded prominence in spatial information datasets. This study holds significance in its ability to unearth novel tourism resources recognized by island tourism consumers through a gap analysis approach that juxtaposes the existing status of island tourism resource data with techniques utilizing social media big data. Furthermore, the methodology delineated in this research offers a valuable framework for domestic local governments to gauge local tourism demand and embark on initiatives for tourism development or regional revitalization.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.17-29
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• 2012

In order to improve a trip pattern in Mt. Halla climbing only to a summit, two trip programs with nature interpretation have been developed using the geomorphic characteristics of Mt. Halla which are distinct from those of mountains in the Korean peninsula. It also aims to help conservation of natural environment of Mt. Halla and to enhance the visitor satisfaction in Mt. Halla. The subalpine trip program is carried out on a 1.5 km-long trail between Wissaeoreum Hut and Janggumokoreum. Program participants are able to learn expertise about, and understand vulnerability of, a subalpine ecosystem, Consequently, the program can obtain an educational attainment getting them to recognize the necessity of preserving the subalpine zone of Mt. Halla as an important natural resource. The mountain river trip program is performed on a 1.5 km-long reach of Byeongmun River between Gwaneumsa trailhead and a gorge upstream of Gurin Cave. The program is capable of exhibiting effectively the river characteristics of Jeju Island using the geomorphic and hydrologic properties of Byeongmun River which differ from those of rivers in the Korean peninsula. Since the subalpine grassland and ephemeral stream of Mt. Halla are the visiting places which are rarely experienced in the Korean peninsula, the program participants can understand the regionality of Jeju Island as well as Mt. Halla through trip activities.